Laminate, and packaging material

Abstract

To provide a film-shaped laminate that does not require electron beam irradiation, is excellent in high heat seal strength and packaging machine suitability and is excellent in recyclability, and a packaging material using the same.SOLUTION: A laminate comprises, in this order, a resin layer (A1) primarily composed of cyclic olefin resin (a1), an adhesive layer (C) consisting of adhesive (c1), and a resin layer (B2) primarily composed of non-cyclic olefin resin (b1), wherein the mass of the cyclic olefin resin (a1) is 15 mass% or less relative to the total mass of olefin resin in the laminate, and the mass of olefin resin is 95 mass% or more relative to the total mass of the laminate. There is also provided a packaging material.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a film-like laminate applicable to packaging materials, and more particularly to a film-like laminate that is suitable for use in packaging machines and is recyclable, and to a packaging material made of said laminate. [Background technology]

[0002] In recent years, there has been a demand for highly functional and recyclable packaging materials that do not degrade the quality of recycled plastics. As a way to improve the quality of recycled plastics without compromising the functionality of packaging materials as much as possible, there is a movement to "use packaging materials from as single a type of raw material as possible" (sometimes called "mono-materialization"), and proposals have begun to be made to use laminated films (sometimes called mono-material films) made from polyolefin resins such as polyethylene film as the main raw material for plastic as packaging materials.

[0003] Known examples of laminate films made of polyolefin resins that have heat sealability suitable for packaging and excellent recyclability include the polyethylene laminate described in Patent Document 1. This laminate requires irradiation with an electron beam, and it is disclosed that polyethylene laminates that are not irradiated with an electron beam fuse to a heat seal bar in a heat seal test.

[0004] Known olefin-based laminates that do not require electron beam irradiation and have high heat seal strength and excellent suitability for packaging machines include the laminates described in Patent Documents 2 and 3. However, these laminates were not developed from the perspective of improving the quality of recycled plastics. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-55176 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-201032 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-89619 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a film-like laminate that does not require electron beam irradiation and has high heat seal strength, excellent suitability for packaging machines, and excellent recyclability, and to provide a packaging material using the same.

[0007] Although the laminates described in Patent Documents 2 and 3 are made of polyolefin resin, they do not necessarily satisfy the recyclability required of current recycled plastics (for example, EU recycled plastic regulations, etc.). As a result of extensive research, the inventors of the present application have discovered a film-like laminate that can be used as a packaging material, which satisfies the recyclability requirements currently placed on recycled plastics, does not require electron beam irradiation, has high heat seal strength, and is excellent in suitability for packaging machines.

[0008] That is, the present invention provides a laminate having, in this order, a resin layer (A1) mainly composed of a cyclic polyolefin resin (a1), an adhesive layer (C) made of an adhesive (c1), and a resin layer (B2) mainly composed of an olefin resin (b1) not containing a cyclic structure, wherein the mass of the cyclic polyolefin resin (a1) relative to the total mass of the olefin resins in the laminate is 15 mass% or less, and the mass of the olefin resin relative to the total mass of the laminate is 95 mass% or more.

[0009] The present invention also provides a packaging material comprising the laminate described above. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a film-like laminate that does not require electron beam irradiation and has high heat seal strength, excellent suitability for packaging machines, and excellent recyclability, and a packaging material using the same. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention provides a laminate obtained by laminating a resin layer (A1) (hereinafter sometimes referred to as cyclic polyolefin resin layer (A1)) mainly composed of a cyclic polyolefin resin (a1) and a resin layer (B2) (hereinafter sometimes referred to as olefin resin layer (B2)) mainly composed of an olefin resin (b1) that does not contain a cyclic structure with an adhesive layer (C) made of an adhesive (c1).

[0012] The packaging material of the present invention is formed by heat-sealing the laminate of the present invention with a heat seal bar or the like, and in this process, the layer that comes into contact with the contents (the inner layer when the packaging material is made) is a layer other than the cyclic polyolefin resin layer (A1). The heat-resistant cyclic polyolefin resin layer (A1) is the outermost layer that comes into contact with the heat seal bar when the packaging material is made, and this layer makes it less likely to cause appearance problems such as distortion or shrinkage due to the heat of the heat seal bar.

[0013] (Resin layer (A1) mainly composed of cyclic polyolefin resin (a1) The cyclic polyolefin resin layer (A1) used in the present invention is mainly composed of a cyclic polyolefin resin (a1). Examples of the cyclic polyolefin resin (a1) include norbornene polymers, vinyl alicyclic hydrocarbon polymers, and cyclic conjugated diene polymers. Among these, norbornene polymers are preferred. Examples of norbornene polymers include ring-opening polymers of norbornene monomers (hereinafter sometimes referred to as "COP") and norbornene copolymers (hereinafter sometimes referred to as "COC") obtained by copolymerizing a norbornene monomer with an olefin such as ethylene. Furthermore, hydrogenated products of COP and COC are particularly preferred. The weight-average molecular weight of the cyclic polyolefin resin is preferably 5,000 to 500,000, more preferably 7,000 to 300,000.

[0014] The norbornene monomer used as a raw material for the norbornene polymer is an alicyclic monomer having a norbornene ring. Examples of such norbornene monomers include norbornene, tetracyclododecene, ethylidenenorbornene, vinylnorbornene, ethylidetetracyclododecene, dicyclopentadiene, dimethanotetrahydrofluorene, phenylnorbornene, methoxycarbonylnorbornene, and methoxycarbonyltetracyclododecene. These norbornene monomers may be used alone or in combination of two or more.

[0015] The norbornene copolymer is a copolymer of the norbornene monomer and a copolymerizable olefin, and examples of such olefins include olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene; cycloolefins such as cyclobutene, cyclopentene, and cyclohexene; and non-conjugated dienes such as 1,4-hexadiene. These olefins can be used alone or in combination of two or more.

[0016] As commercially available products of the cyclic polyolefin resin, examples of ring-opening polymers (COP) of norbornene-based monomers include "ZEONOR" manufactured by Zeon Corporation, and examples of norbornene-based copolymers (COC) include "APEL" manufactured by Mitsui Chemicals, Inc. and "TOPAS" manufactured by Polyplastics Co., Ltd.

[0017] The cyclic polyolefin resin layer (A1) preferably contains a cyclic polyolefin resin as its main component, since this effectively suppresses unnecessary evaporation even when the contents are prone to evaporation, and also facilitates favorable tearing opening of the packaging material. It is preferable that the cyclic polyolefin resin account for 60% by mass or more of the resin components constituting the cyclic polyolefin resin layer (A) be cyclic polyolefin resin, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0018] In particular, in order to suppress the volatilization of unnecessary contents and to facilitate easy opening, it is preferable that 40% by mass or more of the resin components contained in the cyclic polyolefin resin layer (A) be a cyclic polyolefin resin having a low glass transition temperature (hereinafter sometimes referred to as Tg) of 100°C or less, more preferably 50% by mass or more, and particularly preferably 50 to 80% by mass. Note that the glass transition temperature, melting point, etc. referred to in the present invention are values measured by differential scanning calorimetry (DSC). The glass transition temperature of the low Tg cyclic polyolefin resin is more preferably 90°C or less, particularly preferably 60 to 80°C.

[0019] It is also preferable to use a high-Tg cyclic polyolefin resin having a glass transition temperature exceeding 100°C in combination with the low-Tg cyclic polyolefin resin having a glass transition temperature of 100°C or less. The combined use of a low-Tg cyclic polyolefin resin and a high-Tg cyclic polyolefin resin facilitates improving the tensile strength and tear resistance of the resulting packaging material. The content of the high-Tg cyclic polyolefin resin in the cyclic polyolefin resin layer (B) is preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 20 to 50% by mass, of the resin components contained in the cyclic polyolefin resin layer (B), because this facilitates achieving suitable rigidity and impurity sealability and suppressing pinholes when improving the tensile strength and tear resistance of the resulting packaging material. The glass transition temperature of the high-Tg cyclic polyolefin resin is preferably 120°C or higher, more preferably 130°C or higher, and particularly preferably 135 to 150°C.

[0020] In order to improve tear resistance and bag rupture resistance, it is also effective to use a polyolefin resin, such as a polypropylene resin or a polyethylene resin, that does not contain a cyclic structure in the cyclic polyolefin resin layer (A1). When using such a polyolefin resin that does not contain a cyclic structure, its content is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less of the resin components contained in the cyclic polyolefin resin layer (A1). The lower limit of the content of the polyolefin resin that does not contain a cyclic structure is preferably 1% by mass or more, more preferably 2% by mass or more.

[0021] The thickness of the cyclic polyolefin resin layer (A1) may be adjusted as appropriate depending on the mode of use, but is preferably 3 to 12 μm, more preferably 4 to 10 μm, and particularly preferably 5 to 8 μm, from the viewpoints of favorably suppressing evaporation of the contents, easily ensuring favorable sealing properties against foreign matter, and easily suppressing pinholes during packaging.

[0022] (Resin layer (B1) mainly composed of olefin-based resin (b1) not containing a cyclic structure) In the present invention, it is preferable to have a resin layer (B1) (hereinafter sometimes referred to as the olefin resin layer (B1)) in contact with the cyclic polyolefin resin layer (A1) and containing an olefin resin (b1) as a main component, which does not contain a cyclic structure. By having the olefin resin layer (B1), it is possible to easily achieve the constituent element of the present invention, "the mass of the cyclic polyolefin resin (a1) relative to the total mass of the olefin resins in the laminate is 15 mass% or less." Furthermore, even if the contents are prone to volatilization, for example, the volatilization can be suppressed and good tearability of the packaging material can be achieved.

[0023] As the olefin resin used in the olefin resin layer (B1), polyethylene resin, polypropylene resin, or copolymers thereof can be used. Examples of polyethylene resins include polyethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE); ethylene copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and further ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers, which may be used alone or in combination of two or more. Among these, LLDPE can be preferably used because it can suppress the volatilization of transdermal absorption components and the deterioration of the patch's adhesive performance (hereinafter sometimes referred to as "volatilization of contents"), and it can easily achieve heat sealability such as a wide temperature range suitable for heat sealing and good adhesion.

[0024] The LDPE may be a branched low-density polyethylene obtained by high-pressure radical polymerization, and is preferably a branched low-density polyethylene obtained by homopolymerizing ethylene by high-pressure radical polymerization.

[0025] LLDPE and LMDPE are produced by copolymerizing ethylene monomer as the main component with an α-olefin such as butene-1, hexene-1, octene-1, or 4-methylpentene as a comonomer by low-pressure radical polymerization using a single-site catalyst. The comonomer content is preferably in the range of 0.5 to 20 mol%, and more preferably in the range of 1 to 18 mol%.

[0026] Examples of the single-site catalyst include various single-site catalysts, such as metallocene catalyst systems that combine a metallocene compound of a transition metal of Group IV or V of the periodic table with an organoaluminum compound and / or an ionic compound. Single-site catalysts have uniform active sites, and therefore, compared with multi-site catalysts with non-uniform active sites, the molecular weight distribution of the resulting resin is sharper. Therefore, when the single-site catalyst is formed into a film, there is less precipitation of low-molecular-weight components, and a resin with excellent physical properties, such as stable adhesive strength between resin layers, is obtained, which is preferable.

[0027] The MFR (190°C, 21.18N) of the polyethylene resin is preferably 2 to 20 g / 10 min, more preferably 3 to 10 g / 10 min. If the MFR is within this range, the extrusion moldability of the film is improved. The density of LLDPE is 0.905 g / cm3 from the viewpoints of packaging suitability, sealability against foreign matter, and pinhole resistance. 3 ~0.925g / cm 3 is preferable, and 0.915 g / cm is particularly preferable because it is easy to suppress evaporation of the contents. 3 ~0.925g / cm 3 It is particularly preferred that:

[0028] Examples of the polypropylene-based resin include propylene homopolymers, propylene-α-olefin random copolymers, such as propylene-ethylene copolymers, propylene-butene-1 copolymers, propylene-ethylene-butene-1 copolymers, and metallocene-catalyzed polypropylenes. These may be used alone or in combination. Propylene-α-olefin random copolymers are preferred, and propylene-α-olefin random polymers polymerized using metallocene catalysts are particularly preferred. When these polypropylene-based resins are used as the intermediate layer (B), the film's heat resistance and softening temperature can be increased, making them suitable for use as laminating films for packaging materials with excellent steam and high-pressure heat sterilization properties, such as boiling or hot filling at temperatures below 100°C, or retort sterilization at temperatures above 100°C.

[0029] Furthermore, these polypropylene resins preferably have an MFR (230°C) of 0.5 to 30.0 g / 10 min and a melting point of 110 to 165°C, and more preferably have an MFR (230°C) of 2.0 to 15.0 g / 10 min and a melting point of 115 to 162°C. If the MFR and melting point are within these ranges, the film formability is improved.

[0030] The olefin resin layer (B1) preferably contains an olefin resin as a main component, since this makes it easy to achieve suitable adhesion, and preferably 80% by mass or more of the resin components constituting the olefin resin layer (B1) is an olefin resin other than the cyclic polyolefin resins exemplified above, more preferably 90% by mass or more, and particularly preferably 100% by mass. In addition, 80% by mass of the olefin resin contained in the olefin resin layer (B1) is an olefin resin having a density of 0.9 g / cm 3 The above olefin-based resins are preferred because they are particularly easy to obtain adhesion, and more preferably 90% by mass or more. In particular, 80% by mass of the olefin-based resin contained in the olefin resin layer (B1) is preferably a linear low-density polyethylene resin, and more preferably 90% by mass or more.

[0031] In order to suppress evaporation of the contents, it is also preferable that the olefin resin layer (B1) contains a cyclic polyolefin resin. However, in order to easily ensure suitable adhesion, the content of the cyclic polyolefin resin in the olefin resin layer (B1) is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably substantially none.

[0032] The thickness of the olefin resin layer (B1) may be adjusted as appropriate depending on the mode of use, but is preferably 2 to 8 μm, more preferably 3 to 6 μm, in order to ensure favorable heat sealability while favorably suppressing the evaporation of the contents, etc.

[0033] (Layer structure of cyclic polyolefin resin layer (A1) and olefin resin layer (B1)) In the present invention, when the olefin resin layer (B1) is present, the cyclic polyolefin resin layer (A1) and the olefin resin layer (B1) are directly laminated together. With this configuration, even if the contents are prone to volatilization, the volatilization can be suppressed and the packaging material can have good tearability. Furthermore, in the layer structure (A1) / (B1) in which the cyclic polyolefin resin layer (A1) and the olefin resin layer (B1) are directly laminated together, the laminate may have another layer in contact with the olefin resin layer (B1), such as a cyclic polyolefin resin layer (AX) containing a cyclic polyolefin resin or a resin layer (BX) containing an olefin resin.

[0034] Preferable examples of the structure in which these other layers are laminated include, for example, (1) Cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX) (2) Cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / resin layer containing olefin-based resin (AX) Three-layer structure such as (3) A four-layer structure such as cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX) / resin layer containing an olefin-based resin (BX) can be mentioned. Among these, the four-layer structure (3) is preferred because it is particularly easy to adjust the properties such as suppression of evaporation of the contents, ease of opening, heat sealability, etc. Each layer may have the same composition or different compositions.

[0035] (Cyclic polyolefin resin layer (AX)) The presence of the cyclic polyolefin resin layer (AX) can suitably suppress the migration of the contents, components contained in the adhesive layer (C) described below, printing ink when a printed layer is provided, etc. It is also preferable because it makes it easy to adjust curl resistance, etc.

[0036] As the cyclic polyolefin resin used in the cyclic polyolefin resin layer (AX), the same cyclic polyolefin resin as that used in the cyclic polyolefin resin layer (A1) can be preferably used.

[0037] The cyclic polyolefin resin layer (AX) preferably contains a cyclic polyolefin resin as its main component, and it is preferable that 80% by mass or more, and more preferably 90% by mass or more, of the resin components constituting the cyclic polyolefin resin layer (AX) is a cyclic polyolefin resin.

[0038] The glass transition temperature of the cyclic polyolefin resin used in the cyclic polyolefin resin layer (AX) is preferably 200°C or lower, from the viewpoints of ease of production by co-extrusion lamination with other resin layers and ease of industrially obtaining raw materials. A cyclic polyolefin resin having such a Tg preferably contains a norbornene monomer in a range of 40 to 90% by mass, more preferably 50 to 90% by mass, and even more preferably 60 to 85% by mass. A content in this range facilitates improvements in rigidity, tearability, and lamination properties.

[0039] Furthermore, in order to easily prevent migration of low-molecular-weight compounds, volatile components, and the like from the contents to the laminate layer, the high-Tg cyclic polyolefin resin, which has a glass transition point of more than 100°C, is preferably 20 to 60% by mass, and more preferably 20 to 50% by mass, of the resin components contained in the cyclic polyolefin resin layer (AX). This range is preferable because it is easy to improve the tearability and rigidity of the resulting packaging material. The glass transition temperature of the high-Tg cyclic polyolefin resin is preferably 120°C or higher, more preferably 130°C or higher, and particularly preferably 135 to 150°C.

[0040] On the other hand, norbornene copolymers with high Tg have low tensile strength and can be extremely prone to tearing and ripping. Therefore, taking into consideration the balance between lamination strength and the suitability for take-up and winding during film formation and slitting, it is also preferable to blend a low-Tg cyclic polyolefin resin having a glass transition point of 100°C or less with a high-Tg cyclic polyolefin resin. In particular, blending a COC with a Tg of less than 100°C is preferable to achieve high seal strength and improve bag rupture resistance. The content of the low-Tg cyclic polyolefin resin is more preferably 50% by mass or more, and particularly preferably 50 to 80% by mass, of the resin components contained in the resin layer (D). The glass transition temperature of the low-Tg cyclic polyolefin resin is more preferably 90°C or less, and particularly preferably 60 to 80°C.

[0041] It is also effective to blend a polyolefin resin, such as a polypropylene resin or polyethylene resin, which does not contain a cyclic structure and has good compatibility with COC, into the cyclic polyolefin resin layer (AX). When using such a polyolefin resin, it is preferable that it accounts for 20% by mass or less of the resin components contained in the cyclic polyolefin resin layer (AX), more preferably 10% by mass or less, and even more preferably 5% by mass or less. The lower limit of the content of the polyolefin resin that does not contain a cyclic structure is preferably 1% by mass or more, more preferably 2% by mass or more.

[0042] The thickness of the cyclic polyolefin resin layer (AX) may be adjusted appropriately depending on the mode of use, but is preferably 1 to 10 μm, more preferably 2 to 8 μm, and particularly preferably 2 to 5 μm, since this facilitates production by co-extrusion lamination.

[0043] (Resin layer (BX) containing olefin-based resin) As the resin layer (BX) containing an olefin-based resin, the same olefin-based resin as that used in the olefin resin layer (B1) can be preferably used. However, from the viewpoint of easy interlayer adhesion with other layers and industrial availability, it is preferable to use a polyethylene-based resin or a polypropylene-based resin, and a polyethylene-based resin is particularly preferable.

[0044] The polyethylene resin has a density of 0.915 to 0.950 g / cm because it is easy to obtain cold resistance, pinhole resistance, interlayer adhesion with other layers, etc. 3 Preferably, the density is 0.920 to 0.945 g / cm. 3 The following can be preferably used. The melting point is generally preferably in the range of 70 to 130°C, more preferably 80 to 125°C. If the melting point is in this range, processing stability and co-extrusion processability with the cyclic polyolefin resin (a) are improved. Furthermore, the MFR (190°C, 21.18N) of the polyethylene resin is preferably 2 to 20 g / 10 min, more preferably 3 to 10 g / 10 min. If the MFR is in this range, the extrusion moldability of the film is improved.

[0045] Among polyethylene resins, LLDPE and LMDPE are particularly preferred because they provide favorable tear-opening properties and pinhole resistance to the packaging material.

[0046] Furthermore, the polypropylene resin preferably has an MFR (230°C) of 0.5 to 30.0 g / 10 min and a melting point of 110 to 165°C, and more preferably an MFR (230°C) of 2.0 to 15.0 g / 10 min and a melting point of 115 to 162°C. If the MFR and melting point are within these ranges, the film formability is improved.

[0047] The content of the olefin-based resin in the resin layer (BX) containing the olefin-based resin is preferably 80 mass% or more of the resin components constituting the resin layer (BX) containing the olefin-based resin, and more preferably 90 mass% or more.

[0048] Resins other than the olefin-based resin may be mixed within a range that does not impair the effects of the present invention. The other resins that can be mixed and used in this case are preferably those to which the co-extrusion lamination method can be applied, such as the above-mentioned cyclic polyolefin-based resins.

[0049] The thickness of the resin layer (BX) containing the olefin-based resin may be adjusted as appropriate depending on the mode of use, but is preferably 10 to 30 μm, more preferably 13 to 20 μm, as this facilitates obtaining suitable packaging suitability and sealing properties against foreign matter.

[0050] (Coextrusion laminate) In the present invention, (1) Cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX), (2) A three-layer structure such as a cyclic polyolefin resin layer (A1) / an olefin resin layer (B1) / a resin layer containing an olefin-based resin (AX), or (3) Four-layer structure including cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX) / resin layer containing olefin resin (BX) The layer structure (A1) / (B1) in which the cyclic polyolefin resin layer (A1) and the olefin resin layer (B1) are directly laminated together, as typified by the above, or the structure in which another layer, such as a cyclic polyolefin resin layer (AX) containing a cyclic polyolefin resin or a resin layer (BX) containing an olefin resin, is further laminated in contact with the olefin resin layer (B1), is preferably a co-extruded laminate. The coextruded laminate is preferable because it allows the thickness ratio of each layer to be adjusted relatively freely, is excellent in hygiene, and is cost-effective.

[0051] A preferred method of coextrusion lamination is, for example, a coextrusion method in which each resin or resin mixture used for each layer is heated and melted in a separate extruder, and each layer is laminated in a molten state using a method such as a coextrusion multilayer die method or a feed block method, and then formed into a film using an inflation method or a T-die / chill roll method. In particular, when a low-density polyethylene resin is used as the olefin resin layer (B1), the difference between the melting point and Tg of the cyclic polyolefin resin layer (A1) is large, which may cause deterioration in the appearance of the laminate during co-extrusion processing or difficulty in forming a uniform layer structure. In order to prevent such deterioration, it is preferable to form the laminate using a T-die / chill roll method, which allows melt extrusion at a relatively high temperature.

[0052] When the layer structure is a four-layer structure of cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX) / olefin-based resin-containing resin layer (BX) as described above in (3), the thickness ratio of the cyclic polyolefin resin layer (A1) to the total thickness is preferably 10 to 25%, more preferably 10 to 20%, because this facilitates obtaining favorable heat-sealing properties and favorably suppressing volatilization of the contents. Furthermore, the thickness ratio of the olefin resin layer (B1) to the total thickness is preferably 15 to 30%, because this facilitates suppressing volatilization of the contents and favorable openability. Furthermore, the ratio of the combined thickness of the olefin-based resin (B1) and olefin resin layer (BX) to the total thickness is preferably 40% to 60%, because this facilitates obtaining favorable openability. The total thickness of the cyclic polyolefin resin layer (A1) and the cyclic polyolefin resin layer (AX) may be adjusted as appropriate depending on the mode of use. However, it is preferably 6 to 15 μm, and more preferably 8 to 13 μm, because this facilitates ensuring favorable openability while favorably suppressing evaporation of the contents.

[0053] Each resin layer, such as the cyclic polyolefin resin layer (A1), olefin resin layer (B1), cyclic polyolefin resin layer (AX), or resin layer (BX) containing an olefin resin, may optionally contain components such as antifogging agents, antistatic agents, heat stabilizers, nucleating agents, antioxidants, lubricants, antiblocking agents, mold release agents, UV absorbers, and colorants, provided that the object of the present invention is not impaired. In particular, in order to impart processability during film formation and packaging suitability for filling machines, the friction coefficient of the film surface of the cyclic polyolefin resin layer (A1) is preferably 1.5 or less, and more preferably 1.0 or less. Therefore, it is preferable to appropriately add a lubricant or an antiblocking agent to the cyclic polyolefin resin layer (A1).

[0054] (Barrier layer (D)) The laminate of the present invention preferably has a barrier layer (D) between a resin layer (B1) (when the resin layer (AX) or the resin layer (BX) is present, the resin layer (AX) or the resin layer (BX)) containing an olefin resin (b1) containing no cyclic structure as a main component and an adhesive layer (C) described below. The presence of the barrier layer (D) can reduce the permeation of gases such as oxygen, carbon dioxide, and water vapor, and is excellent in maintaining the freshness and quality of the product for a long period of time.

[0055] As described below, the barrier layer (D) is preferably and simply provided by coating the surface of the resin layer (B1) or the like with a barrier composition (d1), and it is preferable to use a liquid barrier coating agent suitable for such a method.

[0056] (Barrier coating agent (d1-1)) A specific example of such a liquid barrier coating agent is a barrier coating agent (d1-1) containing a vinyl alcohol polymer, a polyalkyleneimine, and an aqueous solvent, which has excellent adhesion to various substrates including olefin-based substrates and is therefore preferred.

[0057] (Vinyl alcohol polymer) The vinyl alcohol polymer may be a hydrolyzate of a vinyl ester homopolymer or copolymer obtained by a known, commonly used method, or a reaction product of a vinyl ester homopolymer or copolymer hydrolyzate with an aldehyde obtained by a known, commonly used method.

[0058] Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and vinyl benzoate, and these can be used alone or in combination of two or more. Vinyl acetate is preferred.

[0059] Examples of polymerizable compounds copolymerizable with vinyl esters include ethylene, propene, 1-butene, isobutylene, 1,3-butadiene, isopropenyl acetate, 2-propenyl acetate, styrene, α-methylstyrene, vinyl chloride, acrylonitrile, maleic anhydride, methyl acrylate, methyl methacrylate, N-vinyl-N-methylformamide, vinylacetamide, N-vinylformamide, N-(hydroxymethyl)-N-vinylformamide, hydroxyethyl acrylate, methyl vinyl ketone, and diacetone acrylamide, and these can be used alone or in combination of two or more. Among these, ethylene, isopropenyl acetate, and 2-propenyl acetate are preferably used.

[0060] When a vinyl ester and a polymerizable compound are used in combination, the amounts used can be adjusted as appropriate. However, from the viewpoint of gas barrier properties, the amount of the polymerizable compound blended is preferably kept to 60 mol % or less, and more preferably 25 mol % or less, of the total amount of the vinyl ester and the polymerizable compound.

[0061] The degree of polymerization of the vinyl alcohol polymer or the vinyl ester polymer, which is its precursor, is not particularly limited, but is, for example, 500 to 10,000, more preferably 800 to 6,000, and even more preferably 1,000 to 3,000. This makes it possible to provide a coating agent with an excellent balance between gas barrier properties and coatability.

[0062] Aldehydes used for acetalization include aliphatic aldehydes such as formaldehyde, acetaldehyde, propyl aldehyde, butyl aldehyde, octyl aldehyde, and dodecyl aldehyde; alicyclic aldehydes such as cyclohexane carbaldehyde; aromatic aldehydes such as benzaldehyde, naphthaldehyde, anthraldehyde, phenyl acetaldehyde, tolualdehyde, dimethylbenzaldehyde, cumin aldehyde, and benzyl aldehyde; cyclohexene aldehyde, dimethylcyclohexene aldehyde, acrylonitrile, and the like; Examples of such aldehydes include unsaturated aldehydes such as chlorine; aldehydes having a heterocycle such as furfural and 5-methylfurfural; hemiacetals such as glucose and glucosamine; and aldehydes having an amino group such as 4-aminobutyraldehyde. In addition, aliphatic ketones such as 2-propanone, methyl ethyl ketone, 3-pentanone, and 2-hexanone; alicyclic ketones such as cyclopentanone and cyclohexanone; and aromatic ketones such as acetophenone and benzophenone can be used singly or in combination of two or more.

[0063] As the acid catalyst used in the acetalization, conventionally known organic or inorganic acids such as acetic acid, paratoluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid can be used.

[0064] Specific examples of suitable vinyl alcohol polymers include polyvinyl alcohol, ethylene vinyl alcohol, and polyvinyl butyral. One of these may be used alone, or two or more may be used in combination. From the viewpoint of the balance between gas barrier properties and adhesion, it is more preferable to use either polyvinyl alcohol or ethylene vinyl alcohol, or both.

[0065] The vinyl alcohol polymer preferably has a saponification degree of 90% or more, more preferably 95% or more, because it has excellent gas barrier properties. It may also be 100%. The saponification degree can be measured by FTIR using, for example, a Nicolet 5700 FTIR spectrometer controlled by OMNIC software. The vinyl alcohol polymer is preferably one obtained by acetalizing a precursor having a saponification degree of 95% or more.

[0066] (Polyalkyleneimine) Polyalkyleneimine is a resin having a polyalkyleneimine skeleton, and is obtained by polymerizing one or more alkyleneimines (e.g., ethyleneimine, propyleneimine) by a conventional method. By using a vinyl alcohol polymer in combination with a polyalkyleneimine, the gas barrier properties of the coating agent can be maintained while improving adhesion to olefinic substrates.

[0067] The polyalkyleneimine may be a linear polyalkyleneimine having a linear polyalkyleneimine chain, or a branched polyalkyleneimine having a branched polyalkyleneimine chain. Examples of polyalkyleneimines include polyethyleneimine and polypropyleneimine. The polyalkyleneimine may have a substituent (e.g., a hydroxypropyl group or a hydroxyethyl group) introduced into at least some of the nitrogen atoms of the polyalkyleneimine chain. Polyalkyleneimines modified with organometallic compounds such as tetraisopropyl titanate, tetra-normal-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetramethyl titanate, polyhydroxytitanium stearate, titanium bisacetylacetonate, titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium ethylacetoacetate, titanium lactate, titanium triethanolamine, and titanium stearate may also be used, and two or more polyalkyleneimines may be used in combination.

[0068] The polyalkyleneimine is believed to contribute to improving the adhesion between the vinyl alcohol polymer and the olefin film through its amino groups (NHR groups, NH2 groups) and ethylene groups. Because of its effectiveness in improving adhesion, the polyalkyleneimine preferably contains a branched polyalkyleneimine. The degree of branching of the polyalkyleneimine can be expressed by the proportion of primary, secondary, and tertiary amino groups contained in the polyalkyleneimine. This can be appropriately adjusted depending on the vinyl alcohol polymer used and its blending amount. For example, it is preferable to use a polyalkyleneimine having a primary amino group proportion of 20 to 40%, a secondary amino group proportion of 30 to 60%, and a tertiary amino group proportion of 20 to 35%. The proportions of primary, secondary, and tertiary amine groups contained in the polyalkyleneimine can be measured by C-NMR spectroscopy. The branched polyalkyleneimine is preferably a branched polyethyleneimine.

[0069] The number-average molecular weight of the polyalkyleneimine is preferably 5,000 or more, more preferably 9,000 or more, and even more preferably 50,000 or more, because it has excellent adhesive properties. There is no particular upper limit, but an example is 100,000 or less. The number-average molecular weight of the polyalkyleneimine is measured by GPC (gel permeation chromatography) using pullulan as a standard substance.

[0070] In the barrier coating agent (d1-1), the blending amount of polyalkyleneimine is preferably 1% by mass or more and 90% by mass or less of the total amount of vinyl alcohol polymer and polyalkyleneimine. This allows the gas barrier properties of the coating agent of the present invention to be maintained while more reliably improving adhesion to olefin-based substrates. More preferably, it is 10% by mass or more and 50% by mass or less. If the coating agent of the present invention does not contain polyalkyleneimine, adhesion to olefin-based substrates is insufficient. If the coating agent does not contain a vinyl alcohol-based polymer (if the resin consists only of polyalkyleneimine), the coating film will be sticky and unsuitable for post-processing.

[0071] The barrier coating agent (d1-1) may contain a resin (P) other than a vinyl alcohol polymer or polyalkylimine. Examples of such resins (P) include cellulose resins, polyesters, polyurethanes, vinyl resins such as homopolymers or copolymers of olefins or styrene, acrylic resins, epoxy resins, amide resins, natural rubber, and composites thereof (e.g., core-shell resins). One or more of these resins (P) may be used in combination. Since gas barrier properties may be reduced if the amount of resin (P) is too high, the amount of resin (P) is preferably kept to 10% by mass or less of the total amount of resin (vinyl alcohol polymer, polyalkylimine, and resin (P)). It is more preferably 5% by mass or less, and even more preferably 1% by mass or less. It may even be 0% by mass.

[0072] (water-based solvent) The aqueous solvent may be water, a water-soluble organic solvent that dissolves in water, or the like. As the water, pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water may be used. From the viewpoint of long-term storage, it is preferable to use water that has been sterilized by ultraviolet irradiation or the addition of hydrogen peroxide, for example, in order to prevent the growth of mold or bacteria.

[0073] Examples of water-soluble organic solvents include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; diols such as butanediol, pentanediol, and hexanediol; glycol esters such as propylene glycol laurate; diethylene glycol ethers such as diethylene glycol monoethyl, diethylene glycol monobutyl, diethylene glycol monohexyl, and carbitol; glycol ethers such as cellosolves containing propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; alcohols such as methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, butyl alcohol, and pentyl alcohol; lactones such as sulfolane, esters, ketones, and γ-butyrolactone; lactams such as N-(2-hydroxyethyl)pyrrolidone; and various other solvents known as aqueous organic solvents, such as glycerin and its polyalkylene oxide adducts. These aqueous organic solvents can be used alone or in combination.

[0074] (additives) The barrier coating agent (d1-1) used in the present invention may further contain additives in addition to the vinyl alcohol polymer and aqueous solvent. Examples of additives include layered inorganic compounds, crosslinking agents capable of reacting with functional groups possessed by the vinyl alcohol polymer or polyalkylimine, inorganic fillers, antifoaming agents, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, leveling agents, etc.

[0075] Examples of layered inorganic compounds include natural smectites such as montmorillonite, synthetic smectites, natural mica, synthetic mica, hydrotalcite, and talc, as well as lipophilic-treated smectites and lipophilic synthetic mica, which are obtained by organically treating these compounds. The use of layered inorganic compounds improves the gas barrier properties of the coating agent, but tends to reduce adhesion to olefin-based substrates. The amount of layered inorganic compound blended is preferably 10 to 100 parts by mass per 100 parts by mass of resin (A), as this provides an excellent balance between gas barrier properties and adhesion.

[0076] Examples of crosslinking agents include aldehydes such as formalin and glutaraldehyde; acetals such as diacetalized products of glutaraldehyde; aliphatic polyisocyanates such as hexamethylene diisocyanate and its derivatives (adduct, nurate, biuret, etc.), aromatic aliphatic polyisocyanates such as xylylene diisocyanate and its derivatives, aromatic polyisocyanates such as toluene diisocyanate and its derivatives, and isocyanates such as urethane prepolymers which are reaction products of these isocyanates with polyols; epoxies; titanium, silicon, aluminum, zirconium, Examples of suitable isocyanates include organometallic compounds of boron or the like with alkoxides or the like; methylol ureas such as methylol urea and methylol melamine; carboxyl group-containing polymers such as polyacrylic acid polymers and maleic anhydride polymers; carbodiimides such as p-phenylene-bis(2,6-xylylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), and cyclohexane-1,4-bis(methylene-t-butylcarbodiimide); boric acid; and titanium lactate. As the isocyanates, blocked isocyanates prepared using known blocking agents or emulsion-type isocyanates may be used.

[0077] The use of a crosslinking agent improves adhesion to olefin-based substrates, but tends to reduce gas barrier properties. The amount of crosslinking agent blended is preferably 5 to 50 parts by mass per 100 parts by mass of resin (A), as this provides an excellent balance between gas barrier properties and adhesion.

[0078] (Barrier coating agent (d1-2)) Also preferred as a liquid barrier coating agent is a two-component curing coating agent (d1-2) of polyol and isocyanate, which comprises a polyol composition containing a polyester polyol (dA), an isocyanate composition containing an isocyanate compound (dB), an organic solvent (dC), and a drying aid (dD). The two-component curing coating agent (d1-2) has superior drying properties at low temperatures compared to aqueous coating agents, and is less likely to leave residual organic solvents in the coating film. The drying aid (D) may be present in the polyol composition, or may be prepared separately from the polyol composition and the isocyanate composition and mixed with them immediately before coating. The organic solvent (C) may be contained in either the polyol composition or the isocyanate composition, or may be present in both.

[0079] (Polyester polyol (dA)) The polyester polyol (dA) is a reaction product of a monomer composition (A') containing a polycarboxylic acid and a polyhydric alcohol, and includes at least one of a polyester polyol (dA1) obtained by polycondensation of a polycarboxylic acid, including an ortho-oriented aromatic polycarboxylic acid, with a polyhydric alcohol, a polyester polyol (dA2) having an isocyanuric ring, and a polyester polyol (dA3) having a polymerizable carbon-carbon double bond.

[0080] Examples of ortho-oriented polycarboxylic acids used in the synthesis of polyester polyol (dA1) include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracene carboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group.

[0081] The polycarboxylic acid used in the synthesis of the polyester polyol (dA1) may contain a polycarboxylic acid other than the ortho-orientated polycarboxylic acid. Examples of polycarboxylic acids other than ortho-oriented polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; and aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, and acid anhydrides or ester-forming derivatives of these dicarboxylic acids, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids. These may be used alone or in combination of two or more. Of these, succinic acid, 1,3-cyclopentanedicarboxylic acid, isophthalic acid and acid anhydrides thereof are preferred.

[0082] When the polycarboxylic acid contains a polycarboxylic acid other than an ortho-oriented polycarboxylic acid, the proportion of the ortho-oriented polycarboxylic acid in the total amount of polycarboxylic acids is preferably 70 to 100 mass %.

[0083] The polyhydric alcohol used in the synthesis of the polyester polyol (dA1) preferably contains at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, and cyclohexanedimethanol, and more preferably contains at least one selected from ethylene glycol and glycerin.

[0084] The polyhydric alcohol may be used in combination with polyhydric alcohols other than those mentioned above. Examples of the polyhydric alcohol include aliphatic diols such as 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol; trihydric or higher polyhydric alcohols such as tris(2-hydroxyethyl)isocyanurate, 1,2,4-butanetriol, pentaerythritol, and dipentaerythritol; hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, bisphenol F, and tetramethylbiphenol; ethylene oxide-extended products of these; and aromatic polyhydric phenols such as hydrogenated alicyclic alcohols.

[0085] When the polyester polyol (dA1) has three or more hydroxyl groups (referred to as polyester polyol (dA1) for convenience), some of the hydroxyl groups may be modified with acid groups. Such polyester polyols are hereinafter also referred to as polyester polyol (A1'). The polyester polyol (A1') is obtained by reacting the polyester polyol (dA1) with a polycarboxylic acid or its acid anhydride. The proportion of hydroxyl groups modified with the polycarboxylic acid is preferably 1 / 3 or less of the hydroxyl groups in the polyester polyol (dA1). Examples of polycarboxylic acids used for modification include, but are not limited to, succinic anhydride, maleic acid, fumaric acid, 1,2-cyclohexanedicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, phthalic anhydride, 2,3-naphthalenedicarboxylic anhydride, trimellitic anhydride, oleic acid, and sorbic acid.

[0086] The polyester polyol (dA2) can be obtained, for example, by reacting a triol having an isocyanuric ring with a polycarboxylic acid including an ortho-oriented aromatic polycarboxylic acid and a polyhydric alcohol. Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid. The ortho-oriented aromatic polycarboxylic acid, polycarboxylic acid, and polyhydric alcohol can be the same as those used for the polyester polyol (dA1).

[0087] As the triol compound having an isocyanuric ring, 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid is preferably used. As the ortho-oriented aromatic polycarboxylic acid, orthophthalic anhydride is preferably used. As the polyhydric alcohol, ethylene glycol is preferably used.

[0088] The polyester polyol (dA3) can be obtained by using a component having a polymerizable carbon-carbon double bond as a polycarboxylic acid or a polyhydric alcohol.

[0089] Examples of polycarboxylic acids having a polymerizable carbon-carbon double bond include maleic anhydride, maleic acid, fumaric acid, 4-cyclohexene-1,2-dicarboxylic acid and its anhydride, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid and its anhydride, etc. Maleic anhydride, maleic acid, and fumaric acid are preferred because it is believed that the fewer the number of carbon atoms, the less flexible the molecular chain becomes and the less oxygen permeates. Examples of polyhydric alcohols having a polymerizable carbon-carbon double bond include 2-butene-1,4-diol.

[0090] In addition to the above, polycarboxylic acids and polyhydric alcohols not having a polymerizable carbon-carbon double bond may be used in combination. The same polycarboxylic acids and polyhydric alcohols as those used in the polyester polyols (dA1) and (A2) can be used. The polycarboxylic acid is preferably at least one selected from the group consisting of succinic acid, 1,3-cyclopentanedicarboxylic acid, orthophthalic acid, orthophthalic acid anhydride, and isophthalic acid, and more preferably at least one of orthophthalic acid and its acid anhydride. The polyhydric alcohol is preferably at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol, and more preferably ethylene glycol.

[0091] The hydroxyl value of the polyester polyol (dA) is preferably 1 mgKOH / g or more and 350 mgKOH / g or less. When the polyester polyol (dA) has acid groups, the acid value is preferably 200 mgKOH / g or less. There is no particular lower limit, but an example is 0.5 mgKOH / g or more. It may be 0 mgKOH / g. The hydroxyl value of the polyester polyol (dA) can be measured by the hydroxyl value measurement method described in JIS-K0070, and the acid value can be measured by the acid value measurement method described in JIS-K0070.

[0092] The number average molecular weight of the polyester polyol (dA) is particularly preferably 400 to 5000, since a crosslinking density sufficient to achieve an excellent balance between adhesion to the substrate and gas barrier properties can be obtained. The number average molecular weight is more preferably 500 to 2500. The number average molecular weight is calculated from the obtained hydroxyl value and the designed number of functional hydroxyl groups.

[0093] The glass transition temperature of the polyester polyol (dA) is preferably 10°C or higher and 80°C or lower, more preferably 20°C or higher and 60°C or lower, and even more preferably 35°C or higher and 60°C or lower, in view of the balance between adhesion to the substrate and gas barrier properties.

[0094] The polyester polyol (dA) may be a polyester polyurethane polyol obtained by urethane elongating the polyester polyols (dA1) to (A3) through a reaction with a diisocyanate compound to give a number average molecular weight of 1,000 to 15,000. The urethane-elongated polyester polyol contains components with molecular weights above a certain level and urethane bonds, and therefore can be used as a coating agent with excellent gas barrier properties.

[0095] (Isocyanate compounds (dB)) The isocyanate compound (dB) can be any known compound having multiple isocyanate groups, without any particular limitation. Examples of such isocyanate compounds (dB) include polyisocyanates having an aromatic structure in their molecular structure, such as tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and xylylene diisocyanate, and compounds in which some of the NCO groups of these polyisocyanates have been modified with carbodiimide;

[0096] Polyisocyanates with an alicyclic structure in the molecular structure, such as isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane;

[0097] Linear aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, lysine diisocyanate, and trimethylhexamethylene diisocyanate, and compounds in which some of the NCO groups of these polyisocyanates have been modified with carbodiimide;

[0098] Examples include isocyanurates of these polyisocyanates; allophanates of these polyisocyanates; biuret forms of these polyisocyanates; adducts of these polyisocyanates modified with trimethylolpropane; and polyurethane polyisocyanates which are reaction products of these polyisocyanates and polyols.

[0099] When a polyurethane polyisocyanate is used as the isocyanate compound (dB), in terms of the balance between the cohesive strength and flexibility of the coating agent film, it is preferable to use one obtained by reacting the above-mentioned polyisocyanate with a polyol in a ratio such that the equivalent ratio of the isocyanate group to the hydroxyl group, [NCO] / [OH], is 1.5 to 5.0.

[0100] As the polyol used in the synthesis of polyurethane polyisocyanate, the polyhydric alcohols exemplified as the raw material for the polyester polyol (dA), polyester polyols, polyether polyols, etc. can be used.

[0101] It is preferable to use an isocyanate having an aromatic ring or a derivative thereof (isocyanurate, allophanate, biuret, adduct, polyurethane polyisocyanate) (B1) as the isocyanate compound (dB) because good gas barrier properties can be obtained. Specific examples of the isocyanate compound (B1) include isocyanate compounds having a skeleton derived from xylylene diisocyanate, hydrogenated xylylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate.

[0102] In view of the good gas barrier properties obtained, the isocyanate compound (dB) is also preferably a polyurethane polyisocyanate (B2) obtained by reacting at least one selected from polyester polyols (dA1), (dA2), and (dA3) with an isocyanate having an aromatic ring or a derivative thereof (B1) in such a ratio that the equivalent ratio of the isocyanate group to the hydroxyl group, [NCO] / [OH], is 1.5 to 5.0.

[0103] (organic solvent (dC)) The barrier coating agent (d1-2) contains an organic solvent (dC) capable of diluting (dissolving) the polyester polyol. Examples of the organic solvent (dC) include esters such as ethyl acetate, butyl acetate, and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; dimethyl sulfoxide; and dimethyl sulfamide. The organic solvent used as a reaction medium during the production of the components of the polyol composition or polyisocyanate composition may also be used as a diluent during coating. It is preferable to use at least one of esters and ketones.

[0104] (Drying aid (dD)) The drying aid (dD) has the function of promoting the evaporation of the organic solvent. Examples of drying aids (dD) include isosorbide, isomannide, isoidide, triacetin, etc. Isosorbide is preferably used. Generally, organic solvents tend to be less likely to volatilize from compositions containing a polyester polyol and an organic solvent. However, coating agents using the above-mentioned polyester polyols (dA1) to (A3) in particular can form coating films with excellent gas barrier properties, but due to their excellent gas barrier properties, they tend to easily hinder the evaporation of the organic solvent. By including a drying aid, the organic solvent is more likely to volatilize during the drying process, resulting in a gas barrier coating agent with excellent drying properties and less likely to retain the organic solvent in the cured coating film.

[0105] Furthermore, it is preferable that the drying aid (dD) has a hydroxyl group. This allows it to react with the isocyanate compound and be incorporated into the cured coating film. Therefore, unlike additives without functional groups, there is no risk of it migrating from the gas barrier coating layer to other layers over time, and it has little effect on the physical properties of the gas barrier coating layer over time. Note that the drying process here refers to the process of mixing the polyol composition and the polyisocyanate composition, applying it to a substrate, and then passing it through an oven to volatilize the organic solvent contained in the coating film of the gas barrier coating agent.

[0106] The hydroxyl group of the drying aid (dD) is preferably a secondary hydroxyl group, which has lower reactivity with isocyanate compounds than a primary hydroxyl group, and therefore can effectively prevent reaction with isocyanate compounds before the drying step.

[0107] From the viewpoint of effectively suppressing the residual organic solvent, the amount of the drying aid (dD) is preferably 0.5% by mass or more, more preferably 1% by mass or more, of the total solid content of the barrier coating agent (d1-2).From the viewpoint of the blocking resistance of the barrier coating agent (d1-2), the amount is preferably 30% by mass or less, more preferably 10% by mass or less.

[0108] (Other ingredients of barrier coating agent (d1-2)) The barrier coating agent (d1-2) may contain components other than those mentioned above. These components may be contained in either or both of the polyol composition and the isocyanate composition, or may be prepared separately and mixed immediately before application of the coating agent. Each component will be described below.

[0109] (Polyol (dE)) The polyol composition may contain a polyol (dE) other than the polyester polyol (dA). Examples of the polyol (dE) include polyester polyols, polyester polyether polyols, polyester polyurethane polyols, polyether polyols, polyether polyurethane polyols, polyurethane polyols, polycarbonate polyols, and the polyhydric alcohols exemplified as raw materials for polyester polyols.

[0110] The polycarboxylic acids and polyhydric alcohols used in the synthesis of the polyester skeleton polyol can be the same as those exemplified as raw materials for the polyester polyol.The isocyanate compounds used in the synthesis of the polyurethane skeleton polyol can be the same as those exemplified as the isocyanate compounds.The polyether polyols include those obtained by ring-opening polymerization of polyoxyethylene glycol, polyoxypropylene glycol, aliphatic polyols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether.

[0111] When the polyol composition contains polyol (dE), the amount thereof is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and more preferably 10 parts by mass or more, per 100 parts by mass of the total amount of polyester polyol (dA) and polyol (dE).

[0112] The barrier coating agent (d1-2) may contain an inorganic filler (dF). Examples of inorganic fillers include silica, alumina, aluminum flakes, and glass flakes. In particular, using a plate-like inorganic compound as the inorganic filler (F) is preferred because it improves gas barrier properties, light-shielding properties, and the like. Examples of plate-like inorganic compounds include hydrous silicates (such as phyllosilicate minerals), kaolinite-serpentine clay minerals (such as halloysite, kaolinite, endelite, dickite, nacrite, antigorite, and chrysotile), pyrophyllite-talc clay minerals (such as pyrophyllite, talc, and keroli), smectite clay minerals (such as montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, and stevensite), vermiculite clay minerals (such as vermiculite), mica or mica clay minerals (such as muscovite and phlogopite, margarite, tetrasilylic mica, and taeniolite), chlorite (such as cookeite, sudoite, clinochlore, chamosite, and nimite), hydrotalcite, plate-like barium sulfate, boehmite, and aluminum polyphosphate. These minerals may be natural or synthetic clay minerals. The plate-like inorganic compounds can be used alone or in combination of two or more.

[0113] The plate-like inorganic compound may be ionic, having an interlayer charge, or nonionic, having no charge. The presence or absence of an interlayer charge does not have a significant direct effect on the gas barrier properties of the coating layer. However, ionic plate-like inorganic compounds and inorganic compounds that swell in water have poor dispersibility in solvent-based coating agents, and increasing the amount added may cause the coating agent to thicken or become thixotropic, resulting in reduced applicability. For this reason, it is preferable that the plate-like inorganic compound be nonionic, having no interlayer charge.

[0114] The average particle size of the plate-like inorganic compound is not particularly limited, but is preferably 0.1 μm or more, and more preferably 1 μm or more. If it is smaller than 0.1 μm, the bypass path for oxygen molecules will not be long, and sufficient improvement in gas barrier properties cannot be expected. There is no particular upper limit to the average particle size, but if the particle size is too large, defects such as streaks may occur on the coated surface depending on the coating method. Therefore, as an example, the average particle size is preferably 100 μm or less, and more preferably 20 μm or less. In this specification, the average particle size of the plate-like inorganic compound refers to the particle size that appears most frequently when the particle size distribution of the plate-like inorganic compound is measured using a light scattering measurement device.

[0115] The aspect ratio of the plate-like inorganic compound is preferably high in order to improve gas barrier properties due to the oxygen labyrinth effect. Specifically, it is preferably 3 or more, more preferably 10 or more, and most preferably 40 or more. The upper limit of the aspect ratio is, for example, 500.

[0116] From the viewpoint of the balance between gas barrier properties and drying properties of the organic solvent, the proportion of the inorganic filler (dF) in the total amount of solids of the polyol composition and the polyisocyanate composition is preferably 0.001 to 50 mass%, more preferably 0.01 to 40 mass%.

[0117] (Anti-skinning agent (dG)) The barrier coating agent (d1-2) also preferably contains an anti-skinning agent (dG). The anti-skinning agent (dG) is an organic solvent that has a higher boiling point than the organic solvent and has high solubility for polyester polyol. The inclusion of the anti-skinning agent (dG) prevents the surface of the gas barrier coat layer from drying out before the organic solvent volatilizes from inside the coating film of the coating agent, thereby preventing the organic solvent from volatilizing.

[0118] Specific examples of the anti-skinning agent (dG) include propylene glycol monomethyl ether, ethyl cellosolve, propyl acetate, butyl acetate, and the like.

[0119] From the viewpoint of the balance between the gas barrier property and the drying property of the organic solvent, the amount of the anti-skinning agent (dG) to be blended is preferably 0.1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the total amount of the polyol composition and the polyisocyanate composition excluding the anti-skinning agent (dG) (including volatile components such as the organic solvent).

[0120] (Catalyst (dH)) The curing reaction of the barrier coating agent (d1-2) can be accelerated by using a catalyst (dH) as needed. The catalyst (dH) is not particularly limited as long as it accelerates the urethane reaction of the polyol composition and the polyisocyanate composition, and examples thereof include metal catalysts, amine catalysts, aliphatic cyclic amide compounds, and titanium chelate complexes.

[0121] Examples of metal catalysts include metal complex catalysts, inorganic metal catalysts, and organic metal catalysts. Examples of metal complex catalysts include acetylacetonate salts of metals selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate. From the viewpoints of toxicity and catalytic activity, iron acetylacetonate (Fe(acac)3) or manganese acetylacetonate (Mn(acac)2) is preferred.

[0122] Examples of inorganic metal catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, and the like.

[0123] Examples of the organometallic catalyst include organic zinc compounds such as zinc octylate, zinc neodecanoate, and zinc naphthenate; organic tin compounds such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organic nickel compounds such as nickel octylate and nickel naphthenate; organic cobalt compounds such as cobalt octylate and cobalt naphthenate; organic bismuth compounds such as bismuth octylate, bismuth neodecanoate, and bismuth naphthenate; and titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride.

[0124] Examples of amine catalysts include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethylaminopropyl)isopropanolamine, Propanolamine, 3-quinuclidinol, N,N,N',N'-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methylimidazole, 1 ,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethylhexanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, 1-(2-hydroxypropyl)-2-methylimidazole, etc.

[0125] Examples of the aliphatic cyclic amide compound include δ-valerolactam, ε-caprolactam, ω-enantholactam, η-capryllactam, β-propiolactam, etc. Among these, ε-caprolactam is more effective in accelerating curing.

[0126] Titanium chelate complexes are compounds whose catalytic activity is enhanced by ultraviolet irradiation, and titanium chelate complexes having an aliphatic or aromatic diketone as a ligand are preferred because of their excellent curing-accelerating effect. In the present invention, titanium chelate complexes having an alcohol having 2 to 10 carbon atoms as a ligand in addition to an aromatic or aliphatic diketone are preferred because the effects of the present invention are more pronounced.

[0127] The catalyst (dH) can be used alone or in combination of two or more. The amount of the catalyst (dH) to be added is preferably 0.001 to 3 parts by mass, and more preferably 0.01 to 2 parts by mass, per 100 parts by mass of the total solid content of the polyol composition and the polyisocyanate composition.

[0128] (Coupling Agent (dI)) The barrier coating agent (d1-2) may contain a coupling agent (dI). Examples of the coupling agent (dH) include silane coupling agents, titanate-based coupling agents, and aluminum-based coupling agents.

[0129] Examples of silane coupling agents include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane; hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane, and the like.

[0130] Examples of titanate coupling agents include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.

[0131] Examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate.

[0132] The barrier coating agent (d1-2) may contain a phosphoric acid (dJ). Examples of the phosphoric acid (dJ) include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate. When the coating agent of the present invention contains a phosphoric acid (dJ), the amount of the phosphoric acid (dJ) is preferably 1 ppm or more and 200 ppm or less of the total solids content of the barrier coating agent (d1-2).

[0133] (Other additives) In addition to the above-mentioned components, the barrier coating agent (d1-2) may contain leveling agents, polymethyl methacrylate-based organic fine particles, antifoaming agents, anti-sagging agents, wetting and dispersing agents, viscosity modifiers, ultraviolet absorbers, metal deactivators, peroxide decomposers, flame retardants, reinforcing agents, plasticizers, lubricants, surface conditioners, rust inhibitors, fluorescent brighteners, inorganic heat absorbers, flame retardants, antistatic agents, dehydrating agents, known and commonly used thermoplastic elastomers, tackifiers, melamine resins, reactive elastomers, etc. The amounts of these additives added are adjusted as appropriate within a range that does not impair the desired properties of the barrier coating agent (d1-2).

[0134] (Blend amount) In the barrier coating agent (d1-2), the polyol composition and the polyisocyanate composition are preferably used such that the molar ratio ([NCO] / [OH]) of the isocyanate groups contained in the polyisocyanate composition to the hydroxyl groups contained in the polyol composition is adjusted to 0.3 to 6.

[0135] The barrier layer (D) is preferably provided by coating on the layer opposite to the cyclic polyolefin resin layer (A1), in any of the following cases: a resin layer (A1) mainly composed of a cyclic polyolefin resin (a1); a layer structure (A1) / (B1) in which the cyclic polyolefin resin layer (A1) and an olefin resin layer (B1) are directly laminated together; or a structure in which another layer, such as a cyclic polyolefin resin layer (AX) containing a cyclic polyolefin resin or a resin layer (BX) containing an olefin resin, is laminated in contact with the olefin resin layer (B1). Specifically, if the resin layer (A1) is composed mainly of a cyclic polyolefin resin (a1), the resin layer (A1) is directly laminated thereon; if the layer structure is (A1) / (B1) in which the cyclic polyolefin resin layer (A1) and the olefin resin layer (B1) are directly laminated thereon, the olefin resin layer (B1) is directly laminated thereon; Alternatively, in the case of (A1) / (B1) / (AX) / (BX) where a cyclic polyolefin resin layer (AX) containing a cyclic polyolefin resin or a resin layer (BX) containing an olefin resin is further provided in contact with the olefin resin layer (B1), it is preferable to provide the layer on the resin layer (BX) side.

[0136] The coating method for the barrier layer (D) is not particularly limited, and examples thereof include spraying, spin coating, dipping, roll coating, blade coating, doctor roll coating, doctor blade coating, curtain coating, slit coating, screen printing, inkjet printing, dispensing, die coating, direct gravure coating, reverse gravure coating, flexography, knife coating, and dot coating.

[0137] The thickness of the barrier layer (D) can be adjusted appropriately depending on the type of substrate and the desired level of gas barrier property, but is, for example, 0.2 μm to 2.0 μm. If the thickness is too thin, the gas barrier property cannot be expected to be significantly improved, and if it is too thick, adhesion may decrease.

[0138] (Adhesive layer (C)) In the present invention, the adhesive (c1) used in the adhesive layer (C) may be any adhesive that can be used in a general-purpose lamination method, such as dry lamination, wet lamination, non-solvent lamination, and extrusion lamination. The adhesive used in the dry lamination may be, for example, a one-component or two-component curable or non-curable vinyl, (meth)acrylic, polyamide, polyester, polyether, polyurethane, epoxy, rubber, or other solvent-based, aqueous, or emulsion adhesive. A two-component curable adhesive may be a two-component curable adhesive made of a polyol and an isocyanate compound. The laminating adhesive may be applied by, for example, direct gravure roll coating, gravure roll coating, kiss coating, reverse roll coating, Fountain coating, transfer roll coating, or other methods. For example, the DIC Dry series manufactured by DIC Corporation may be preferably used.

[0139] Various types of adhesives can also be used, with pressure-sensitive adhesives being preferred. Examples of pressure-sensitive adhesives include rubber-based adhesives prepared by dissolving polyisobutylene rubber, butyl rubber, or mixtures thereof in organic solvents such as benzene, toluene, xylene, or hexane, or those prepared by blending these rubber-based adhesives with tackifiers such as abiethoxylated rosin esters, terpene-phenol copolymers, or terpene-indene copolymers, or acrylic-based adhesives prepared by dissolving acrylic copolymers with a glass transition temperature of −20° C. or lower, such as 2-ethylhexyl acrylate-n-butyl acrylate copolymers or 2-ethylhexyl acrylate-ethyl acrylate-methyl methacrylate copolymers, in organic solvents.

[0140] The adhesive (c1) may be a functional adhesive. For example, as an adhesive having barrier properties, the oxygen barrier adhesive PASLIM series manufactured by DIC Corporation, which is a two-component reactive adhesive of polyester polyol and an isocyanate compound, may be used.

[0141] (Resin layer (B2) mainly composed of olefin-based resin (b1) not containing a cyclic structure) The olefin resin layer (B2) used in the present invention may be a resin layer similar to the olefin resin layer (B1), and the olefin resin (b2) not containing a cyclic structure as the main component may be a resin similar to the olefin resin (b1) not containing a cyclic structure used in the olefin resin layer (B1). Among these, the polyethylene resin or the polypropylene resin is preferred.

[0142] (Mass of the cyclic polyolefin resin (a1) in the laminate) The laminate of the present invention is characterized in that the mass of the cyclic polyolefin resin (a1) relative to the total mass of the olefin resins in the laminate is 15 mass% or less, and the mass of the olefin resin relative to the total mass of the laminate is 95 mass% or more. This structure ensures the uniformity of the laminate due to the high content of olefin resin. In addition, the mass of the cyclic polyolefin resin is 15 mass% or less, so there is little effect on the physical properties of the polyolefin resin and on the physical properties of the recycled plastic, ensuring the consistency of the quality of the recycled plastic.

[0143] (total thickness of laminate) The laminate of the present invention preferably suppresses evaporation of the contents, etc., easily achieves favorable heat-sealing properties and openability, and is also easily laminated with other substrates, so that its total thickness is preferably in the range of 10 to 200 μm, more preferably in the range of 10 to 100 μm, and even more preferably in the range of 20 to 60 μm.

[0144] (Method of manufacturing laminate) The laminate of the present invention can be obtained, for example, by laminating a resin layer (A1) mainly composed of a cyclic polyolefin resin (a1) and a resin layer (B2) mainly composed of an olefin resin (b1) not containing a cyclic structure with an adhesive (c1).

[0145] Examples of methods for laminating the resin layer (A1) mainly composed of the cyclic polyolefin resin (a1) and the resin layer (B2) mainly composed of an olefin resin (b1) not containing a cyclic structure with the adhesive (c) include dry lamination, wet lamination, non-solvent lamination, and extrusion lamination.

[0146] In the case of a laminate having a resin layer (A1) mainly composed of a cyclic polyolefin resin (a1) and a resin layer (B1) mainly composed of an olefin resin (b1) not containing a cyclic structure, for example, the method includes co-extrusion laminating a resin composition mainly composed of a cyclic polyolefin resin (a1) and a resin composition mainly composed of an olefin resin (b1) not containing a cyclic structure to obtain a co-extruded laminate film (A1B1) composed of the resin layer (A1) mainly composed of the cyclic polyolefin resin (a1) and the resin layer (B1) mainly composed of the olefin resin (b1) not containing a cyclic structure; The coextruded laminate film (A1B1) can be obtained by laminating a resin layer (B2) containing an olefin resin (b1) not containing a cyclic structure as a main component with an adhesive (c).

[0147] In the process of obtaining the coextruded laminate film (A1B1), for example, a resin composition primarily composed of a cyclic polyolefin resin (a1) and a resin composition primarily composed of an olefin resin (b1) not containing a cyclic structure are heated and melted in separate extruders, and the resulting molten films are laminated in the desired layer order by a method such as a multilayer coextrusion die method or a feed block method, and then formed into a film by an inflation method, a T-die chill roll method, or the like. This coextrusion method is preferred because it allows relatively free adjustment of the thickness ratio of each layer and produces a multilayer film that is hygienic and has excellent cost performance.

[0148] When a resin composition mainly composed of the cyclic polyolefin resin (a1) and a resin composition mainly composed of an olefin resin (b1) not containing a cyclic structure are coextruded and laminated, a coextruded laminate film (A1B1) can be obtained, which has a resin layer (A1) mainly composed of the cyclic polyolefin resin (a1) and a resin layer (B1) mainly composed of the olefin resin (b1) not containing a cyclic structure.

[0149] In the present invention, (1) Cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX), (2) Three-layer structure such as cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / resin layer containing olefin-based resin (AX), (3) Coextruded laminate films (A1B1) having a layer structure (A1) / (B1) in which the cyclic polyolefin resin layer (A1) and the olefin resin layer (B1) are directly laminated together, such as a four-layer structure of cyclic polyolefin resin layer (A1) / olefin resin layer (B1) / cyclic polyolefin resin layer (AX) / resin layer (BX) containing an olefin resin, or structures in which other layers, such as a cyclic polyolefin resin layer (AX) containing a cyclic polyolefin resin or a resin layer (BX) containing an olefin resin, are laminated in contact with the olefin resin layer (B1), are preferably obtained by a coextrusion method.

[0150] After step 1 to obtain the coextruded laminate film (A1B1) or the like, a step (hereinafter referred to as step 3) is carried out in which a barrier layer (D) made of a barrier composition (d1) is provided by coating on the surface of the resin layer (B1) of the coextruded laminate film (A1B1), and then step 2 is carried out, thereby obtaining a laminate having a barrier layer (D) between the resin layer (B1) mainly composed of an olefin resin (b1) not containing a cyclic structure and the adhesive layer (C).

[0151] A laminate having a barrier layer (D) made of a barrier composition (d1) can be obtained, for example, by the steps of coextrusion laminating a resin composition mainly composed of a cyclic polyolefin resin (a1) and a resin composition mainly composed of an olefin resin (b1) not containing a cyclic structure to obtain a coextruded laminate film (A1B1) composed of a resin layer (A1) mainly composed of a cyclic polyolefin resin (a1) and a resin layer (B1) mainly composed of an olefin resin (b1) not containing a cyclic structure; providing a barrier layer (D) made of the barrier composition (d1) on the resin layer (B1) side of the coextruded laminate film (A1B1) by coating; and laminating the barrier layer (D) side of the coextruded laminate film (A1B1) and a resin layer (B2) mainly composed of an olefin resin (b1) not containing a cyclic structure with an adhesive (c).

[0152] (packaging material) The packaging material of the present invention can be obtained by overlapping and heat-sealing the olefin-based resin layer (B1) or (BX) of the laminate of the present invention as a heat-sealable layer. Alternatively, the olefin-based resin layer (B1) or (BX) of the laminate of the present invention may be overlapped with another heat-sealable resin layer and the olefin-based resin layer (B1) and heat-sealed. Examples of other heat-sealable resin layers include LDPE and EVA, which have relatively low mechanical strength. Furthermore, a packaging material may be produced by heat-sealing a laminate film obtained by laminating a film such as LDPE or EVA with a stretched film with relatively good tearability, such as a biaxially oriented polyethylene terephthalate film (OPET) or a biaxially oriented polypropylene film (OPP).

[0153] For example, two sheets of the laminate can be cut to the desired size of the packaging material, stacked, and heat-sealed on three sides to form a bag, after which the contents can be filled in through the one side that is not heat-sealed and heat-sealed to seal.Furthermore, packaging can also be formed by sealing the ends of a rolled film into a cylindrical shape using an automatic packaging machine, and then sealing the top and bottom.

[0154] In packaging materials using the laminate of the present invention, it is preferable to form any tear initiation portion such as a V notch, I notch, perforation, or micropore in the sealed portion in order to weaken the initial tear strength and improve openability.

[0155] Since the laminate of the present invention has directional tearability, it is suitable for use in a variety of packaging forms, including drawstring packaging in which the top of the package is bound with tape, metal fittings, or a resin closure, and resealable packaging in which a zipper, zip fastener, or other linear fastener with resealing function is attached in the direction perpendicular to the flow direction of the film (TD).

[0156] (recycled plastic) The laminate or packaging material of the present invention can also be processed as is using various known recycling plastic processing methods to produce recycled plastics. As an example of a specific embodiment, recycled plastics can be obtained by a production method including the steps of immersing the laminate of the present invention in a general-purpose desorption treatment liquid such as an alkaline solution to separate the recovered material into each component, or crushing the laminate or packaging material of the present invention as is, melting and kneading the crushed film pieces, and pelletizing the melt-kneaded mixture.

[0157] The crusher used for crushing (pulverizing) is not particularly limited and any known crusher may be used. The crushed film pieces are physically blended using methods such as melt mixing, solvent cast blending, latex blending, and polymer complexing. Melt mixing is particularly common. Examples of mixing devices include tumblers, Henschel mixers, rotary mixers, super mixers, ribbon tumblers, and V-blenders. The film pieces are melt-mixed using these mixers and then pelletized. Single- or multi-screw extruders are typically used for melt mixing and pelletization. The film pieces may be fed directly into the extruder or may be compressed with or without heating before being added. In addition to these extruders, Banbury mixers, roller mixers, Ko-kneaders, blast mills, and Prabender Bloutographs can also be used, operated batchwise or continuously. Alternatively, the film pieces may be used as molding resins without melt mixing and then melt-kneaded in the heating barrel of a molding machine. [Example]

[0158] Next, the present invention will be described in more detail with reference to examples and comparative examples.

[0159] Example 1 The resins and resin mixtures forming each layer were prepared using the following resins as resin components forming the innermost olefin resin layer (B1) and the outermost cyclic polyolefin resin layer (A1).

[0160] <Olefin resin layer (B1)> Linear low-density polyethylene (density: 0.905 g / cm 3 100 parts by mass of LLDPE (1), melting point 110°C, MFR: 5g / 10min (190°C, 21.18N); hereinafter referred to as "LLDPE (1)"

[0161] <Cyclic polyolefin resin layer (A1)> 50 parts by mass of a ring-opening polymer of a norbornene-based monomer ("APEL APL8008T" manufactured by Mitsui Chemicals, Inc., MFR: 15 g / 10 min (260°C, 21.18 N), glass transition point: 70°C; hereinafter referred to as "cyclic olefin resin (1)"), 50 parts by mass of a ring-opening polymer of a norbornene-based monomer ("APEL APL6015T" manufactured by Mitsui Chemicals, Inc., MFR: 10 g / 10 min (260°C, 21.18 N), glass transition point: 145°C; hereinafter referred to as "cyclic olefin resin (2)")

[0162] These resins were fed into an extruder (50 mm diameter) for the olefin resin layer (B1) and an extruder (50 mm diameter) for the cyclic polyolefin resin layer (A1), respectively, and melted at 200–250°C. The molten resins were then fed into a T-die / chill roll coextrusion multilayer film manufacturing apparatus equipped with a feedblock (feedblock and T-die temperature: 250°C), where they were co-extruded to obtain a two-layer (B1) / (A1) coextruded multilayer film with a thickness of 24 μm / 6 μm (total 30 μm). The surface of the innermost layer (B) was then corona-treated. The surface tension of the corona-treated surface measured with a wetting agent was 42 mN / m.

[0163] Adhesive 1 (DIC LX470 / SP60) was applied to the corona-treated surface of the multilayer film using a bar coater to a coating weight of 3.0 g / m2 (solids), and the film was dried by volatilizing the dilution solvent in a dryer set at 70°C. This was then laminated with DIC "DIFAREN L3501T (50 μm)" to produce a composite film with a layer structure of multilayer film / adhesive / L3501T. This composite film was then aged at 40°C for 3 days to cure the adhesive, yielding a multilayer film.

[0164] Example 2 The resin component used for the cyclic polyolefin resin layer (A1) was the same as in Example 1. A coextruded multilayer film with a layer thickness of 25.5 μm / 4.5 μm (total 30 μm) was produced, and the surface of the surface layer (B) was subjected to a corona treatment. The surface tension of the corona-treated surface measured with a wetting agent was 42 mN / m. An adhesive was applied to the treated surface in the same manner as in Example 1, and dry-laminated with L3501T to obtain a composite film.

[0165] Example 3 The resin component used for the cyclic polyolefin resin layer (A1) was the same as in Example 1. A coextruded multilayer film was produced with a layer thickness of 27 μm / 3 μm (total 30 μm), and the surface of the surface layer (B) was subjected to a corona treatment. The surface tension of the corona-treated surface measured with a wetting agent was 42 mN / m. An adhesive was applied to the treated surface in the same manner as in Example 1, and dry-laminated with L3501T to obtain a composite film.

[0166] Example 4 A coextruded multilayer film was produced in the same manner as in Example 1, except that the resin components used in the cyclic polyolefin resin layer (A1) were as follows, and the surface of the surface layer (B) was subjected to a corona treatment. The surface tension of the corona-treated surface measured with a wetting reagent was 42 mN / m. An adhesive was applied to the treated surface in the same manner as in Example 1, and dry-laminated with L3501T to obtain a composite film. <Cyclic polyolefin resin layer (A1)> Cyclic olefin resin (1) 30 parts by mass, cyclic olefin resin (2) 70 parts by mass

[0167] Example 5 The resin components used for the cyclic polyolefin resin layer (A1) were the same as in Example 4. A coextruded multilayer film with a layer thickness of 25.5 μm / 4.5 μm (total 30 μm) was produced, and the surface of the surface layer (B) was subjected to a corona treatment. The surface tension of the corona-treated surface measured with a wetting agent was 42 mN / m. An adhesive was applied to the treated surface in the same manner as in Example 1, and dry-laminated with L3501T to obtain a composite film.

[0168] Example 6 A coextruded multilayer film was produced using the same resin components as in Example 4 for the cyclic polyolefin resin layer (A1), with each layer having a thickness of 27 μm / 3 μm (total 30 μm), and the surface of the surface layer (B) was subjected to a corona treatment. The surface tension of the corona-treated surface measured with a wetting agent was 42 mN / m. An adhesive was applied to the treated surface in the same manner as in Example 1, and the film was dry-laminated with L3501T to obtain a composite film.

[0169] (Comparative Example 1) One side of a uniaxially stretched polyethylene film (HIBLON-P, thickness 25 μm: manufactured by Futamura Chemical Co., Ltd.) was subjected to a corona treatment, and an adhesive was applied to the corona-treated side in the same manner as in Example 1, followed by dry lamination with L3501T to obtain a composite film.

[0170] (Comparative Example 2) One side of a 30 μm thick L3501T was subjected to a corona treatment, and an adhesive was applied to the corona-treated surface in the same manner as in Example 1, followed by dry lamination with L3501T to obtain a composite film.

[0171] The films obtained in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in the table below.

[0172] [Heat seal test] Using the films obtained in the examples and comparative examples, heat sealing was performed at 0.2 MPa for 1 second with a seal width of 10 mm while changing the sealing temperature, and the degree of melting and shrinkage of the film on the sealed surface was observed, and the degree was evaluated using a grade of ◯, △, or ×. ○: No melting or shrinkage on the surface of the seal. △: There is some melting or shrinkage on the surface of the seal. ×: Melting or shrinkage occurred on the surface of the sealed portion.

[0173] The results are shown in Tables 1 and 2.

[0174] [Table 1]

[0175]

Table 2

Claims

1. a resin layer (A1) containing a cyclic polyolefin resin (a1) as a main component; an adhesive layer (C) made of an adhesive (c1); a resin layer (B2) containing an olefin-based resin (b1) containing no cyclic structure as a main component; A laminate having, in this order, the mass of the cyclic polyolefin resin (a1) relative to the total mass of the olefin resins in the laminate is 15 mass% or less, The mass of the olefin resin relative to the total mass of the laminate is 95 mass% or more. A laminate characterized by:

2. The laminate according to claim 1, wherein the content of the cyclic polyolefin resin in the resin component contained in the resin layer (A1) is 80 mass % or more.

3. The laminate according to claim 1, wherein the cyclic polyolefin resin (a1) has a glass transition temperature of 100°C or lower.

4. a resin layer (A1) containing a cyclic polyolefin resin (a1) as a main component; a resin layer (B1) containing an olefin-based resin (b1) containing no cyclic structure as a main component; an adhesive layer (C) made of an adhesive (c1); 2. The laminate according to claim 1, further comprising, in this order, a resin layer (B2) containing an olefin resin (b1) not containing a cyclic structure as a main component.

5. 2. The laminate according to claim 1, further comprising a barrier layer (D) between the resin layer (B1) containing as a main component an olefin resin (b1) not containing a cyclic structure and the adhesive layer (C).

6. 2. The laminate according to claim 1, wherein the total thickness of the laminate is 10 to 200 μm.

7. A packaging material comprising the laminate according to any one of claims 1 to 6.

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