Laminate, composite laminate, and packaging body including same

Abstract

The present invention provides: a laminate that has excellent gas barrier properties and that is suitable for recycling; and a packaging body that uses the laminate. Provided is a laminate in which an inorganic layer and a protective layer are laminated in this order on one side of an olefin-based substrate film, wherein the protective layer contains a water soluble resin and a silicon alkoxide, and the average composition ratio (Si / C) of elemental silicon (Si) to elemental carbon (C) is 1.30-2.30 as measured via X-ray photoelectron spectroscopy (XPS) in the thickness direction to 1 / 3 of the thickness of the protective layer from the protective layer surface side on the opposite side from the inorganic layer side.

Description

Laminates, composite laminates, and packages containing them

[0001] The present invention relates to a laminate, a composite laminate, and packaging materials using the same, which have excellent gas barrier properties and are suitable for recycling.

[0002] Various packaging materials have been used to package a variety of items, including food and beverages, medicines, and daily necessities. These packaging materials require oxygen and water vapor barrier properties to prevent deterioration of the contents. Aluminum foil, which has excellent gas barrier properties, is used as a packaging material for retort foods. However, packaging materials using aluminum foil are difficult to recycle, limiting their uses.

[0003] Furthermore, packaging materials have been proposed that use a film in which aluminum or aluminum oxide is vapor-deposited as a gas barrier layer on a thermoplastic film such as a polyester film using a physical vapor deposition method such as a vacuum deposition method. For boiled and retort food applications, which are used in harsh environments, it has been proposed to laminate a protective layer on the gas barrier layer to prevent deterioration of gas barrier performance, and to apply a specific element composition to the protective layer or a specific water-soluble polymer to the protective layer. However, using such a material by laminating it with a polyester film or other resin film is still considered disadvantageous from the perspective of recycling (Patent Documents 1, 2, and 3).

[0004] Packaging materials using olefin-based films such as polyethylene and polypropylene have been proposed to improve recyclability. For example, a packaging material has been proposed in which a specific resin layer is provided on an olefin-based film, a gas barrier layer made of a metal or inorganic compound is vapor-deposited, and a protective layer having a specific element composition containing a metal alkoxide is further laminated thereon (Patent Document 4). Another packaging material has been proposed in which a base layer is provided on a multi-layered olefin-based substrate, a gas barrier layer made of an inorganic compound is vapor-deposited, and a protective layer containing a metal alkoxide is further laminated thereon (Patent Document 5).

[0005] Furthermore, a so-called mono-material packaging body has been proposed, which combines the same types of materials suitable for recycling (Patent Document 4).Furthermore, packaging bodies have been proposed in which the thermal shrinkage rates of the materials used in the mono-material packaging and the order in which the materials are combined have been devised (Patent Documents 6 and 7).

[0006] Japanese Patent No. 7097011 International Publication No. 2024 / 111477 Japanese Patent No. 7089709 Japanese Patent No. 7331537 Japanese Patent No. 7377425 Japanese Patent No. 7088138 Japanese Patent No. 7231095

[0007] All of the patent documents use olefin-based films and substrates to improve recyclability, but olefin-based materials have issues with heat resistance and mechanical properties. Therefore, with the combinations of conventional technologies disclosed in the patent documents, deformation of the olefin-based film and substrate can cause cracks in the layers laminated on the substrate, and the gas barrier properties and adhesion can deteriorate after moist heat resistance tests. This leaves room for applications in boiled and retort food products, which are used in harsh environments.

[0008] In view of this problem, the present invention aims to stably provide a laminate having excellent gas barrier properties and adhesion, and a package using the same, by clarifying the preferred state of the laminate.

[0009] The laminate of the present invention is a laminate in which an inorganic layer and a protective layer are laminated in this order on one side of an olefin-based substrate film, the protective layer containing a water-soluble resin and a silicon alkoxide, and the average composition ratio (Si / C) of elemental silicon (Si) to elemental carbon (C) measured by X-ray photoelectron spectroscopy (XPS) in a portion in the thickness direction from the surface side of the protective layer opposite the inorganic layer side to one-third of the thickness of the protective layer is 1.30 to 2.30.

[0010] In the laminate described above, the protective layer further contains a linear polysiloxane.

[0011] In addition, in the laminate described above, the silicon alkoxide includes a silicon alkoxide having a ureido group.

[0012] The laminate may further include an anchor layer between the olefin-based substrate film and the inorganic layer.

[0013] In the laminate described above, the inorganic layer contains aluminum (Al) and / or silicon (Si).

[0014] In the laminate described above, the solid content ratio of the silicon alkoxide having a ureido group to the solid content of the protective layer is 2.5 mass % or more.

[0015] In addition, the SiO of each of the linear polysiloxane and silicon alkoxide contained in the protective layer ２ The laminate described above has a converted mass ratio of linear polysiloxane / silicon alkoxide in the range of 15 / 85 to 90 / 10.

[0016] In the laminate described above, the protective layer has a thickness of 100 to 1000 nm.

[0017] In the laminate described above, the inorganic layer contains aluminum oxide.

[0018] The present invention also provides a composite laminate in which a second olefin layer containing an olefin-based resin is laminated on at least one side of the above-described laminate via a resin layer.

[0019] In addition, in the composite laminate described above, the second olefin layer has a smaller heat shrinkage rate than the laminate after heating at 120°C for 15 minutes.

[0020] The present invention also provides the composite laminate described above, wherein a third olefin layer containing an olefin-based resin is further laminated on at least one of the laminate side and / or the second olefin layer side of the composite laminate via a resin layer.

[0021] In the composite laminate described above, at least one or both of the second olefin layer and the third olefin layer have a smaller heat shrinkage rate after heating at 120° C. for 15 minutes than the laminate.

[0022] Also provided is a package comprising any of the laminates described above and / or any of the composite laminates described above.

[0023] According to the present invention, it is possible to provide a laminate that has excellent gas barrier properties and is suitable for recycling, and a package using the same.

[0024] The laminate of the present invention will be described in more detail below.

[0025] The laminate of the present invention is a laminate in which at least an inorganic layer and a protective layer are laminated on one side of an olefin-based substrate film, and is characterized in that the protective layer contains a water-soluble resin and / or silicon alkoxide, and the average composition ratio (Si / C) of silicon element (Si) to carbon element (C) is 1.30 to 2.30 as measured by X-ray photoelectron spectroscopy (XPS) in the thickness direction from the surface side of the protective layer opposite the inorganic layer side to one-third of the thickness of the protective layer.

[0026] [Substrate Film] The substrate film according to the present invention is preferably a substrate film containing an olefin-based resin. There are no particular limitations on the olefin-based resin, and examples include polyolefin-based resins such as polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene, and polymethylpentene; cyclic polyolefin-based resins; copolymer or modified polyolefin resins such as ethylene-vinyl acetate copolymer resins and polyvinyl alcohol resins; and mixed resins thereof. Among these, polypropylene is preferred from the viewpoints of physical properties such as mechanical properties and heat resistance and ease of recycling, and it is preferable that the resin contains 3 to 55% by mass of recycled raw materials. The recycled raw materials may be those recycled by mechanical recycling or chemical recycling, and are not particularly limited. Furthermore, the resin constituting the substrate film may contain biomass-derived (plant-derived) raw materials and be a mixed resin with chemical fuel-derived raw materials.

[0027] The substrate film may be unstretched or stretched (monoaxially or biaxially), but is preferably a biaxially stretched film from the viewpoint of thermal dimensional stability, and is particularly preferably a biaxially stretched polypropylene film.

[0028] The thickness of the substrate film is not particularly limited, but is preferably from 1 μm to 100 μm, more preferably from 5 μm to 50 μm, and even more preferably from 10 μm to 30 μm.

[0029] The surface of the substrate film may be subjected to corona treatment, ozone treatment, plasma treatment, glow discharge treatment or the like, as needed, in order to improve adhesion to the inorganic layer.

[0030] [Inorganic Layer] The inorganic layer according to the present invention is a layer containing an inorganic substance or an inorganic compound, and may be a mixture of an inorganic substance and an inorganic compound. Examples of inorganic layers include aluminum, magnesium, titanium, tin, indium, silicon, zinc, and oxides thereof, which may be used alone or in a mixture of two or more. The inorganic layer is preferably an inorganic compound containing a metal oxide or a metal nitride. When the inorganic layer contains a metal oxide or a metal nitride, it is preferable because it improves durability against heat during boiling and retort treatment and, when the laminate of the present invention is used as a package containing acidic contents, its acidic contents are improved. Examples of metal oxides include aluminum oxide, magnesium oxide, titanium oxide, tin oxide, indium oxide alloy, silicon oxide, and silicon oxynitride. Examples of metal nitrides include aluminum nitride, titanium nitride, and silicon nitride. These inorganic compounds may be used alone or in a mixture of two or more. Of these, it is more preferable for the inorganic layer in the present invention to contain aluminum (Al) and / or silicon (Si), since this will improve the durability against heat applied during the boiling / retort treatment and the acid resistance against acidic contents. Furthermore, the elemental composition within the inorganic layer may vary in the thickness direction. The difference in the elemental composition of the inorganic layer in the thickness direction improves the adhesion between the inorganic layer and the protective layer, and when a laminate is formed, peeling between the inorganic layer and the protective layer is less likely to occur. Among these, oxygen, aluminum, and silicon are preferred as elements for the inorganic layer, from the viewpoints of production costs, gas barrier properties, heat resistance against heat applied during the boiling / retort treatment, and acid resistance against acidic contents. Aluminum oxide consisting of oxygen and aluminum is more preferred. The aluminum oxide of the inorganic layer in the present invention is fully oxidized aluminum oxide (Al ２ O ３ ), but as described above, it may also be suboxidized aluminum oxide in which the elemental composition of the inorganic layer varies in the thickness direction, or a mixed aluminum oxide containing suboxidized aluminum oxide.

[0031] There are no particular limitations on the method for forming the inorganic layer, and it can be formed by known methods such as vapor deposition, sputtering, ion plating, and plasma vapor deposition, but vacuum vapor deposition is preferred from the viewpoint of productivity.

[0032] As an example of a method for forming an inorganic layer in which the elemental composition varies in the thickness direction, a method for forming an inorganic layer in which the composition changes continuously from an aluminum metal layer to an aluminum oxide layer will be described. In this case, a method for forming the inorganic layer in which the composition changes continuously from an aluminum metal layer to an aluminum oxide layer in a vacuum chamber is preferred. The inorganic layer can be formed by known methods such as vapor deposition, sputtering, ion plating, and plasma vapor deposition, but vapor deposition is preferred from the viewpoint of productivity.

[0033] A more detailed explanation follows. A roll of substrate film is placed in a vacuum chamber, the substrate film is unwound, and aluminum is heated and evaporated. Methods for thermally evaporating aluminum include resistance heating, high-frequency heating, and electron beam heating. The heated and evaporated aluminum adheres to the substrate film, forming an aluminum metal layer. After the aluminum metal layer is formed, oxygen gas is introduced into the latter half of the vapor deposition process. The introduced oxygen gas diffuses from the winding side of the substrate film to the unwinding side, so that the oxygen reaction from the aluminum metal layer to the aluminum oxide layer proceeds continuously, forming an inorganic layer with a gradient structure in which the composition changes continuously in the film thickness direction.

[0034] Furthermore, the gradient structure of the inorganic layer can be controlled by adjusting or changing the amount of oxygen and the introduction speed when introducing the oxygen gas, the position, shape, and number of introduction ports of the oxygen nozzle or the like, the conveying speed of the base film, etc., but is not particularly limited to these.

[0035] The method for measuring the film thickness of a gradient structure is to use X-ray photoelectron spectroscopy (XPS) to perform composition analysis and evaluation in the depth direction, and to confirm the film composition of the inorganic compound using a depth profile. For metal elements, oxide components and metal components are separated and profiled. Data is collected from the surface layer on the protective layer side while performing ion etching until the substrate is reached, and the presence or absence of a continuous increase or decrease in composition is confirmed from the depth profile of each element obtained. Regarding the presence or absence of a continuous increase or decrease, a continuous increase or decrease is determined to exist if the length of the increase or decrease is 2 nm or more.

[0036] Next, the total thickness of the inorganic layer is determined by the method described below. The film thickness in the gradient structure is calculated from the total thickness of the inorganic layer and the region of the depth profile corresponding to the inorganic layer.

[0037] The thickness of the inorganic layer in the present invention is preferably 5 nm to 150 nm, and more preferably 7 nm to 100 nm, since this facilitates gas barrier properties and the avoidance of cohesive failure within the inorganic layer, as described below, and thus facilitates adhesion. If the thickness is 5 nm or less, the gas barrier properties may be insufficient, while if the thickness is 150 nm or more, the cohesive force of the inorganic layer may decrease, causing cohesive failure within the inorganic layer, which may result in cracking or peeling of the inorganic layer.

[0038] [Protective Layer] The protective layer according to the present invention contains a water-soluble resin and / or silicon alkoxide, and has an average composition ratio (Si / C) of silicon (Si) to carbon (C) of 1.30 to 2.30 as measured by X-ray photoelectron spectroscopy (XPS) in the thickness direction from the surface of the protective layer opposite the inorganic layer to one-third of the protective layer thickness. It is presumed that when the protective layer is formed as described above, the protective layer becomes dense even when laminated on an olefin-based substrate film that has issues with heat resistance and mechanical properties, and can exhibit excellent gas barrier properties and adhesion even after boiling or retorting, which are used in harsh environments.

[0039] The protective layer in the present invention has an average composition ratio (Si / C) of silicon (Si) to carbon (C) of 1.30 to 2.30 as measured by X-ray photoelectron spectroscopy (XPS) in the thickness direction from the surface of the protective layer opposite the inorganic layer to one-third of the protective layer thickness. Incidentally, "the protective layer contains silicon (Si) and carbon (C)" means that the content of each element is 5.0 atm% or more of the total atoms constituting the protective layer (100.0 atm%), as detected by evaluation using XPS (X-ray Photoelectron Spectroscopy, also known as ESCA (Electron Spectroscopy for Chemical Analysis)) under the conditions described in the Examples. Therefore, if the content of either silicon element (Si) or carbon element (C) is less than 5.0 atm % of all atoms constituting the protective layer (100.0 atm %), the protective layer is considered to be different from the protective layer defined in the present invention. The detailed evaluation conditions for the XPS method in the present invention are as described in the Examples.

[0040] This method can obtain the composition ratio in the depth direction from the surface side of the protective layer opposite the inorganic layer side, but because the region up to 0.4 nm deep in the surface of the protective layer contains information about surface contamination, the composition of the protective layer is calculated from a position deeper than 0.4 nm deep, and the average composition ratio (Si / C) in the depth direction up to the inorganic layer is obtained. In this case, the protective layer thickness is first obtained by the method described later, and the depth from the protective layer surface to the interface of the inorganic layer in the composition ratio in the depth direction measured by X-ray photoelectron spectroscopy (XPS) is taken as the protective layer thickness, and the composition ratio measurements at each measurement point in the thickness direction up to 1 / 3 of the protective layer thickness are averaged to obtain the average composition ratio (Si / C) in the present invention. The average composition ratio (Si / C) in the protective layer in the present invention is 1.30 to 2.30, preferably 1.50 to 2.00, and more preferably 1.70 to 1.90. This is believed to facilitate the formation of a denser protective layer, even when laminated on an olefin-based substrate film that has issues with heat resistance and mechanical properties, and therefore, by blocking gas permeation paths such as water vapor and oxygen, facilitates the development of gas barrier properties and adhesion even after boiling and retort treatment, which are harsh environments for use. If the average composition ratio (Si / C) is less than 1.30, the protective layer is believed to be insufficiently dense, resulting in inferior gas barrier properties. When the protective layer is formed into a composite laminate or package, as described below, the gas barrier properties will be insufficient after boiling and retort treatment, which are harsh environments for use. Furthermore, it is estimated that if the average composition ratio (Si / C) is greater than 2.30, the protective layer becomes excessively dense and hard, increasing the risk of cracks or breakage in the protective layer or inorganic layer, and as a result, the gas barrier properties will be insufficient, just as in the case where the average composition ratio (Si / C) is less than 1.30.

[0041] The protective layer of the present invention preferably contains a water-soluble resin. Examples of water-soluble resins include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and modified polyvinyl alcohol. These polymers may be used alone or in mixtures of two or more. However, vinyl alcohol-based polymers (including modified polyvinyl alcohol) are preferred. Vinyl alcohol-based polymers (including modified polyvinyl alcohol) are generally obtained by saponifying polyvinyl acetate. They may be partially saponified by saponifying a portion of the acetate groups, or completely saponified, but a higher degree of saponification is preferred. The degree of saponification is preferably 90% or more, more preferably 95% or more. A low degree of saponification and a large number of acetate groups with high steric hindrance may increase the free volume of the protective layer. The degree of polymerization of the vinyl alcohol-based resin is preferably 1,000 to 3,000, more preferably 1,000 to 2,000. A low degree of polymerization may make it difficult for the polymer to be fixed, resulting in poor adhesion and gas barrier properties.

[0042] Furthermore, a particularly preferred water-soluble resin is a vinyl polymer having a carbonyl group in a cyclic structure. By including a vinyl polymer having a carbonyl group in a cyclic structure as the water-soluble resin in the protective layer, the hydrophobicity of the cyclic structure and the interaction of the carbonyl group with the polymer periphery form a dense film, improving water resistance. This provides a protective layer with a dense structure with low hydrophilicity, reducing interactions with gas molecules such as oxygen and water vapor, and blocking the permeation pathways of gas molecules, thereby exhibiting excellent adhesion and gas barrier properties. In the present invention, the vinyl polymer having a carbonyl group in a cyclic structure preferably accounts for 20 to 100% by mass of 100% by mass of the water-soluble resin in the protective layer. If it is less than 20% by mass, the effect of improving gas barrier properties may be poor. Therefore, it is most preferred that all of the water-soluble resins in the protective layer be vinyl polymers having a carbonyl group in a cyclic structure (100% by mass).

[0043] The cyclic structure is not particularly limited as long as it is a three- or greater-membered ring (e.g., a three- to six-membered ring). It may also be a heterocyclic ring containing a heteroatom other than carbon, such as nitrogen, oxygen, sulfur, or phosphorus, within the cyclic structure. The carbonyl group-containing moiety within the cyclic structure may be located in either the main chain, side chain, or crosslinked chain of the vinyl polymer. Specific examples of vinyl polymers containing a carbonyl group within a cyclic structure include lactone structures, which are cyclic esters, and lactam structures, which are cyclic amides. These may be used alone or in combination with two or more of these. While not particularly limited, lactone structures are preferred. Using a vinyl polymer having a lactone structure as the water-soluble polymer provides stability against the acid catalyst used in the hydrolysis of silicon alkoxides, as described below, and facilitates maintaining gas barrier properties. Examples of vinyl polymers having a lactone structure include α-acetolactone, β-propiolactone, γ-butyrolactone, and δ-valerolactone.

[0044] The protective layer in the present invention preferably contains silicon alkoxide. Examples of silicon alkoxide include Si(OR) ４Examples include those represented by the formula: R in the silicon alkoxide is preferably a lower alkyl group, such as a methyl group, an ethyl group, an n-propyl group, or an n-butyl group. Specific examples of silicon alkoxides include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane, which may be used alone or in combination. In particular, in the present invention, it is more preferable that the protective layer further contains a linear polysiloxane. It is believed that by including a linear polysiloxane in the protective layer, the molecular chains become densely entangled, forming and fixing a molecular chain network within the protective layer, thereby suppressing the movement of the molecular chains of the components that make up the protective layer and limiting the pathways through which gas molecules such as oxygen and water vapor permeate. In particular, linear polysiloxane has few pores in its molecular chains, allowing the molecular chains to exist at high density. Therefore, it is believed that by forming and fixing a molecular chain network within the protective layer, the movement of the molecular chains of the components that make up the protective layer can be suppressed, resulting in a protective layer with a dense structure. As a result, the gas barrier properties are improved, resulting in a protective layer with a dense structure that can suppress the expansion of permeation paths for oxygen and water vapor gas molecules due to environmental changes such as temperature. It is believed that even when laminated onto an olefin-based substrate film that has issues with heat resistance and mechanical properties, excellent gas barrier properties are exhibited even after high-temperature hot water treatment such as boiling or retort treatment. The linear polysiloxane is represented by the following chemical formula (1), where n in chemical formula (1) is an integer of 2 or greater. R in chemical formula (1) represents a lower alkyl group such as a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, or a branched alkyl group such as an isopropyl group or a t-butyl group. In the present invention, a long linear structure of the linear polysiloxane facilitates the formation and fixation of a network in the protective layer, so n is preferably 5 or greater, more preferably 10 or greater. There is no particular upper limit for n, but if it is 30 or greater, some components will form a cyclic network structure, which may conversely result in a sparse protective layer, so it is preferable to adjust it appropriately.

[0045]

[0046] Linear polysiloxanes can be obtained from silicon alkoxides, which can be hydrolyzed to obtain linear polysiloxanes, for example. Silicon alkoxides include Si(OR) ４ The water used for the hydrolysis is Si(OR) ４ The amount of water is preferably 0.8 to 5 equivalents, more preferably 1.0 to 4 equivalents, relative to the alkoxy groups. If the amount of water is less than 0.8 equivalents, hydrolysis may not proceed sufficiently, making it impossible to obtain a linear polysiloxane. If the amount of water is more than 5 equivalents, the reaction of silicon alkoxide, which will be described later, may proceed randomly, forming a large amount of non-linear polysiloxane and making it impossible to obtain a linear polysiloxane.

[0047] The catalyst used for hydrolysis is preferably an acid catalyst. Examples of acid catalysts include, but are not limited to, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, tartaric acid, etc. Usually, the hydrolysis and polycondensation reaction of silicon alkoxides can be carried out using either an acid catalyst or a base catalyst. However, when an acid catalyst is used, the monomers in the system tend to be hydrolyzed on average and tend to become linear. On the other hand, when a base catalyst is used, the reaction mechanism favors the hydrolysis and polycondensation reaction of alkoxides bonded to the same molecule, so the reaction proceeds randomly and the reaction product tends to have many voids. The amount of catalyst used is preferably 0.1 mol% or more and 0.5 mol% or less based on the total molar amount of silicon alkoxides.

[0048] The organic solvent used for hydrolysis may be water or an alcohol miscible with silicon alkoxide, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, or n-butyl alcohol.

[0049] The hydrolysis temperature is preferably 20° C. or higher and 45° C. or lower. If the reaction is carried out at a temperature lower than 20° C., the reactivity is low and Si(OR) ４On the other hand, if the reaction is carried out at a temperature above 45°C, the hydrolysis and polycondensation reaction may proceed too rapidly, resulting in gelation or the formation of a random, sparse polysiloxane that is not linear.

[0050] The protective layer in the present invention preferably further contains a silicon alkoxide having a ureido group. By containing a silicon alkoxide having a ureido group, when a composite laminate described later is formed, the protective layer interacts with the functional groups contained in other adjacent layers (printing ink layer, adhesive layer, resin layer, etc.), and is also bonded and incorporated into the molecular chain network of the water-soluble resin and linear polysiloxane described above, so that the components remain without being detached when a peeling force is applied, which is presumably improving adhesion. As a result, even when laminated on an olefin-based base film that has problems with heat resistance and mechanical properties, even after high-temperature hot water treatment such as boiling or retort treatment, even better gas barrier properties are likely to be exhibited. The silicon alkoxide having a ureido group in the present invention may be a silicon alkoxide having mono- to trifunctional ureido groups, or may be one in which the ureido group is bonded to the silicon atom in the silicon alkoxide via a linear or branched alkyl chain such as methyl, ethyl, or propyl. One or more types may be mixed depending on the required properties, productivity, etc. Examples of silicon alkoxides having a ureido group include KBM-585 and KBM-585A manufactured by Shin-Etsu Chemical Co., Ltd., A-1160 manufactured by Momentive Performance Materials Japan, LLC, and "DOWSIL" (registered trademark) Z-6119 Silan, "DOWSIL" Z-6120 Silan, and "DOWSIL" Z-6675 Silan manufactured by Dow-Toray Industries, Inc. Commercially available products from various manufacturers can be used.

[0051] The protective layer in the present invention may contain, in addition to the water-soluble resin, linear polysiloxane, and silicon alkoxide having a ureido group, another silicon alkoxy having a functional group such as a silane coupling agent, and is not particularly limited as long as it does not impair the effects of the present invention.

[0052] [Component Composition of Protective Layer] In the present invention, the solid content ratio of the silicon alkoxide having a ureido group to the total solid content in the protective layer is preferably 2.5% by mass or more. When the solid content ratio of the silicon alkoxide having a ureido group is 2.5% by mass or more, bonding and entanglement are likely to occur within the molecular chain network of the water-soluble resin and linear polysiloxane, and the components are more likely to remain without being detached during peeling, making it easier to exhibit better adhesion. The solid content ratio of the silicon alkoxide having a ureido group is preferably 5.0% by mass or more, more preferably 8.0% by mass or more. Furthermore, the upper limit of the solid content ratio of the silicon alkoxide having a ureido group is not particularly limited, but if it is higher than 50% by mass, the amount of water-soluble resin or linear polysiloxane in the protective layer may decrease, resulting in a sparser molecular chain network and reduced gas barrier properties. Therefore, it is preferable that it be 50% by mass or less. The solid content ratio of the silicon alkoxide having a ureido group can be measured by the method described below.

[0053] In the present invention, the total content of all water-soluble resins in the protective layer is preferably 20 to 80% by mass, based on 100% by mass of the protective layer. When the water-soluble resin content is 20 to 80% by mass, the protective layer is likely to have a dense structure, and is likely to exhibit excellent adhesion and gas barrier properties. When the water-soluble resin content is less than 20% by mass, the protective layer is likely to harden, causing cracks and resulting in reduced gas barrier properties. When the water-soluble resin content is more than 80% by mass, the water-soluble resin may not be able to be fixed, resulting in reduced gas barrier properties. The water-soluble resin content is more preferably 25 to 60% by mass, and even more preferably 30 to 50% by mass.

[0054] In the present invention, the total content of all linear polysiloxanes in the protective layer may be 20 to 80% by mass relative to 100% by mass of the protective layer. However, as described above, silicon alkoxides (including hydrolysates of silicon alkoxides) having or not having a ureido group may be separately contained. Therefore, the content is determined by dividing the linear polysiloxanes and silicon alkoxides by SiO ２The total content of inorganic components in the protective layer (hereinafter, the inorganic components in the protective layer may be referred to as "protective layer inorganic components") is preferably 20 to 80% by mass, and more preferably 30 to 65% by mass, based on 100% by mass of the protective layer. The contents of the water-soluble resin and the protective layer inorganic components in the protective layer can be measured by the method described below.

[0055] In the present invention, the mixing ratio of the linear polysiloxane and the silicon alkoxide in the protective layer can be adjusted. The mixing ratio can be adjusted by adjusting the SiO ２ In terms of the converted mass ratio, the linear polysiloxane / silicon alkoxide ratio is preferably in the range of 15 / 85 to 90 / 10, more preferably 40 / 60 to 85 / 15, and even more preferably 40 / 60 to 65 / 35. If this value exceeds 90 / 10, the interaction between the linear polysiloxanes becomes strong, which may prevent the water-soluble resin and the silicon alkoxide having a ureido group from being immobilized, resulting in reduced adhesion and gas barrier properties. On the other hand, if the ratio is less than 15 / 85, the number of Si—OH bonds derived from the silicon alkoxide increases, which may increase hydrophilicity and reduce gas barrier properties. The mixing ratio of the linear polysiloxane to the silicon alkoxide in the protective layer can be measured by the method described below.

[0056] As the linear polysiloxane, Si(OR) ４ By using an oligomer raw material in which multiple Si(OR) are bonded, the mixing ratio of the linear polysiloxane and the silicon alkoxide can be easily adjusted. ４ Examples of oligomer raw materials in which a plurality of groups are bonded include linear oligomers in which alkyl silicates such as methyl silicate in which R in chemical formula (1) is a methyl group and ethyl silicate in which R is an ethyl group are oligomers.

[0057] In the present invention, the protective layer can be formed by thermally promoting a polycondensation reaction of the linear polysiloxane and silicon alkoxide contained in the protective layer. As the polycondensation reaction progresses, the alkoxy groups and / or hydroxyl groups contained in the linear polysiloxane and silicon alkoxide decrease, resulting in a protective layer with a dense and tough structure. Furthermore, the molecular weight of the linear polysiloxane and silicon alkoxide increases due to the polycondensation reaction, thereby enhancing their ability to fix the water-soluble resin and the silicon alkoxide having a ureido group. Therefore, since the gas barrier properties and adhesion of the protective layer can be improved by promoting the reaction with heat, a high temperature is preferred when forming the protective layer by thermally promoting the polycondensation reaction. However, if the temperature exceeds 180°C, an olefin-based substrate film, which has issues with heat resistance and mechanical properties, may shrink due to heat, or the inorganic layer may become distorted or cracked, resulting in a decrease in gas barrier properties.

[0058] The protective layer can be obtained by coating a coating liquid containing the components of the protective layer (hereinafter sometimes abbreviated as protective layer coating liquid) on an inorganic layer and drying it. Therefore, the drying temperature of the coating film, which is the temperature for promoting the polycondensation reaction, is preferably 100°C or higher and 200°C or lower, more preferably 120°C or higher and 180°C or lower, and even more preferably 150°C or higher and 180°C or lower. If the temperature is lower than 100°C, water contained as a solvent (described later) may not evaporate sufficiently, and the layer may not be cured.

[0059] The protective layer coating liquid can be obtained by mixing a solution of a water-soluble resin in water or a water / alcohol mixed solvent with a solution containing a linear polysiloxane and a silicon alkoxide with or without a ureido group. Examples of alcohols used as solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

[0060] The method for applying the protective layer coating liquid onto the inorganic layer is not particularly limited, and any known method can be used, such as a direct gravure method, a reverse gravure method, a microgravure method, a rod coating method, a bar coating method, a die coating method, or a spray coating method.

[0061] The protective layer according to the present invention may contain a leveling agent, a crosslinking agent, a curing agent, an adhesion agent, a stabilizer, an ultraviolet absorber, an antistatic agent, etc., as long as the gas barrier property and adhesion are not impaired. Examples of the crosslinking agent include metal alkoxides of aluminum, titanium, zirconium, etc., and complexes thereof.

[0062] The thickness of the protective layer in the present invention is preferably 10 nm to 1,000 nm, more preferably 100 nm to 600 nm, and even more preferably 250 nm to 500 nm. If the thickness is less than 10 nm, pinholes and cracks in the inorganic layer may not be sufficiently filled, and sufficient gas barrier properties may not be achieved. On the other hand, if the thickness exceeds 1,000 nm, cracks may occur due to the thickness.

[0063] As described above, the protective layer undergoes a condensation reaction due to heat, improving the gas barrier properties and adhesion. Therefore, in order to improve the gas barrier properties and adhesion, it is also preferable to further heat-treat the laminate after forming the protective layer. The heat treatment temperature is preferably 30°C or higher and 100°C or lower, more preferably 40°C or higher and 80°C or lower. The heat treatment time is preferably 1 day or higher and 14 days or lower, more preferably 3 days or higher and 7 days or lower. If the heat treatment temperature is lower than 30°C, the thermal energy required to promote the reaction may be insufficient, resulting in a small effect. If the heat treatment temperature is higher than 100°C, curling of the olefin-based substrate film may occur, oligomers and additives may bleed out, and the costs for equipment and production may increase.

[0064] [Analysis of Laminate. This will be described later, but will also be explained here.] The presence of linear polysiloxane in the protective layer according to the present invention can be confirmed by laser Raman spectroscopy. Laser Raman spectroscopy has revealed that the bonding state of linear polysiloxane and metal alkoxide (including hydrolyzates of metal alkoxide) is classified into linear polysiloxane, random network structure which is a structure containing a ring structure of five or more members and also having branches, and four-membered ring structure, the Raman band of which is 400 to 500 cm －１ These Raman bands overlap, so the four-membered ring structure is observed at 495 cm －１ , linear polysiloxane is 488 cm －１ , because the random network structure is not a single ordered structure, －１ These are observed as broad bands, and peak separation is possible by fitting these with a Gaussian function approximation.

[0065] The method for determining the content of water-soluble resin and inorganic components (linear polysiloxane and silicon alkoxide (including silicon alkoxide hydrolysates)) in the protective layer will be described below. As mentioned above, the amount of inorganic components, linear polysiloxane and silicon alkoxide (including silicon alkoxide hydrolysates), can be replaced with the amount of silicon, which can be obtained by X-ray fluorescence analysis. First, five standard samples with known silicon contents but different silicon contents are prepared, and X-ray fluorescence analysis is performed on each sample. X-ray fluorescence analysis involves irradiating X-rays to generate fluorescent X-rays specific to an element and detecting them. The amount of X-rays generated is proportional to the amount of element contained in the measurement target, so the X-ray intensity S (unit: cps / μA) of silicon obtained by measurement is proportional to the amount of silicon. Here, the thickness of the standard sample is calculated in the same manner as the average thickness T described below, and the X-ray intensity S determined by X-ray fluorescence analysis is divided by the thickness of the standard sample to calculate the X-ray intensity S per unit thickness. The known amount of silicon and the X-ray intensity S per unit thickness are plotted to create a calibration curve. Thereafter, for the laminate of the present invention, the X-ray intensity S per unit thickness is determined in the same manner from the X-ray fluorescence analysis and the average thickness T, and the amount of silicon is calculated from the calibration curve and its value. From this amount of silicon, the total number of moles of silicon atoms contained in the linear polysiloxane and silicon alkoxide is determined, and SiO ２ By converting it into mass, the total mass ratio S of the inorganic components of the protective layer can be determined, and the contents of the water-soluble resin and various inorganic components can be calculated.

[0066] The mixing ratio of the linear polysiloxane and silicon alkoxide in the inorganic components of the protective layer is determined by measuring the area A1 of the Raman band showing the random network structure by the laser Raman spectroscopy and the area A2 of the Raman band showing the linear polysiloxane, and the ratio A2 / A1 is determined by the linear polysiloxane / silicon alkoxide mixing ratio (SiO ２ (equivalent mass ratio).

[0067] Furthermore, the mixing ratio of the water-soluble resin and the linear polysiloxane / silicon alkoxide (SiO ２After determining the mass ratio (converted to the mass ratio of silicon alkoxide having a ureido group) of the solid content corresponding to the silicon alkoxide in the composition, five types of standard samples with known but different solid content ratios of silicon alkoxide having a ureido group among the solid content corresponding to the silicon alkoxide in the composition are prepared, and X-ray fluorescence analysis is performed on each sample as described above to detect the amount of X-rays generated. Here, the X-ray intensity S (unit: cps / μA) of silicon varies depending on the solid content ratio of silicon alkoxide having a ureido group. As described above, the thickness of the standard sample is calculated in the same manner as the average thickness T described below, and the known solid content ratio of silicon alkoxide having a ureido group and the X-ray intensity S per unit thickness are plotted to create a calibration curve. Thereafter, for the laminate of the present invention, the X-ray intensity S per unit thickness is similarly determined from the X-ray fluorescence analysis and the average thickness T, and the calibration curve and its value are converted and calculated into the solid content ratio of silicon alkoxide having a ureido group.

[0068] [Anchor layer] The laminate of the present invention preferably has an anchor layer between the olefin-based substrate film and the inorganic layer. By having the anchor layer as an underlayer on the olefin-based substrate film, the adhesion between the olefin-based substrate film and the inorganic layer can be improved, and even after boiling or retorting, which are used in harsh environments, the adhesion is more likely to be exhibited when the laminate is made into a composite laminate or a package, as described below.

[0069] The anchor layer is not particularly limited as long as it can improve the adhesion between the olefin-based substrate film and the inorganic layer, and preferred examples include organic or inorganic polymers.

[0070] Examples of inorganic polymers include inorganic oxides, such as silicon oxides, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, and tetra-n-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, and n-propyltriethoxysilane. Butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-pentyltriethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3 , 3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl Polymers obtainable by hydrolysis and polymerization reaction from trialkoxysilanes such as trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, and vinyltriacetoxysilane, and organoalkoxysilanes such as methyltriacetyloxysilane and methyltriphenoxysilane can be used.

[0071] Examples of organic polymers include thermoplastic resins, thermosetting resins, and photocurable resins, such as polyester resins, polycarbonate resins, (meth)acrylic resins, polyurethane resins, polyether resins, polyepoxy resins, polyamide resins, ABS resins, polyimide resins, olefin resins such as polyethylene and polypropylene, polystyrene resins, polyvinyl acetate resins, melamine resins, phenolic resins, resins containing chlorine (Cl) such as polyvinyl chloride and polyvinylidene chloride, and organic polymer compounds, and at least one of these may be selected based on the required properties, productivity, etc., or two or more of these may be mixed. In addition, a curing agent may be further added to the organic polymer. Examples of the curing agent include aliphatic, aromatic, and alicyclic isocyanate-based curing agents. Preferred examples of the curing agent include aromatic monomers such as tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), and aliphatic monomers such as xylene diisocyanate (XDI), hexane diisocyanate (HMDI), and isophorone diisocyanate (IPDI), as well as polymers and derivatives thereof, which may be used alone or in combination.

[0072] [Composite Laminate] The composite laminate of the present invention is a composite laminate in which a second olefin layer containing an olefin resin is laminated on at least one side of the laminate via a resin layer, and further a third olefin layer containing an olefin resin is laminated on at least one side of the laminate side or the second olefin layer side via a resin layer. Therefore, the surface on which the second olefin layer is laminated may be the protective layer side of the laminate or the side opposite the protective layer of the laminate.

[0073] When laminating the laminate of the present invention with the second olefin layer and further with the third olefin layer, the method for laminating the resin layer includes, but is not particularly limited to, a method in which a molten resin is extruded onto either the laminate side or the second olefin layer or the third olefin layer side to provide a resin layer, and then the laminate and the second olefin layer and further with the third olefin layer, or a method in which an adhesive is used as the resin layer and the laminate and the second olefin layer and further with the third olefin layer via the adhesive.

[0074] In the former case where a resin layer is provided by extrusion, the resin layer preferably has a low melting point to reduce thermal damage caused by the extruded molten resin, and is preferably an olefin-based resin such as polyethylene or polypropylene, or a mixed resin thereof, taking recyclability into consideration.

[0075] Furthermore, as for adhesives used in laminating using an adhesive as a resin layer as in the latter case, preferred examples of adhesives used include one-component or two-component curing type vinyl-based, (meth)acrylic-based, polyamide-based polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, solvent-based, aqueous-based, emulsion-based adhesives, etc. Commercially available examples include two-component curing polyester-based adhesives such as TM-570 / CAT-RT37 manufactured by Toyo Ink Co., Ltd., LX500 / KO55 manufactured by DIC Corporation, RU-77T / H-7 manufactured by Rock Paint Co., Ltd., A-620 / A-6 manufactured by Mitsui Chemicals, Inc., A4210R / CA75 manufactured by Dainichiseika Color & Chemicals Co., Ltd., and LA2760 / LA5891 manufactured by Henkel. Furthermore, for the purpose of improving gas barrier properties, PASLIM VM001 / VM108CP manufactured by DIC Corporation can also be used.

[0076] The adhesive can be applied by any method, including, but not limited to, direct gravure coating, reverse roll coating, kiss coating, and fountain coating. The amount of adhesive applied after drying is 0.1 g / m. ２ 10g / m or more ２ Preferably, it is less than 1 g / m ２ 5g / m or more ２The following is the result.

[0077] The second and third olefin layers contain an olefin-based resin, and examples of the olefin-based resin include copolymer or modified polyolefin resins such as polyethylene-based resins, polypropylene-based resins, polyisobutylene-based resins, polybutene-based resins, polymethylpentene-based resins, cyclic polypropylene-based resins, cyclic polyolefin-based resins, cyclic olefin copolymer resins, ethylene-vinyl acetate copolymer resins, and polyvinyl alcohol resins, as well as copolymer resins containing these resins as the main component, or mixed resins containing an olefin-based resin. In particular, in the present invention, from the viewpoints of ease of forming a package, physical properties such as mechanical properties and heat resistance, and ease of recycling, which will be described later, a resin film containing a polyethylene resin or a polypropylene resin is preferred as a heat-sealable olefin resin. Examples of such a resin include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), unstretched or oriented polypropylene (PP), ethylene-α-olefin copolymers polymerized using a metallocene catalyst, random or block copolymers of ethylene and polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), and ethylene-maleic acid copolymer.

[0078] In the composite laminate of the present invention, it is preferable that the heat shrinkage rate of the second olefin layer and / or the third olefin layer is smaller than that of the laminate after heating at 120°C for 15 minutes. If the heat shrinkage rate of the second olefin layer and / or the third olefin layer is smaller than that of the laminate, it is easier to form a package (described later), and when formed into a package, it is easier to obtain physical properties such as gas barrier properties with less curling and wrinkling. The method for measuring the heat shrinkage rate in the present invention is as described in the Examples.

[0079] Furthermore, a printing ink may be laminated as a printing ink layer on the composite laminate of the present invention. The printing ink layer may be laminated on either or both of the protective layer side and the side opposite the protective layer side of the laminate, or on either or both of the second and third olefin layers. Generally, the printing ink layer is laminated for purposes such as displaying content information, light blocking, decorativeness, and design, and therefore comprises a colorant and a resin. If necessary, any additive may be added, such as a curing agent, a lubricant, an antiblocking agent, a leveling agent, an antifoaming agent, a pigment dispersant, a silane coupling agent, an ultraviolet absorber, a rust inhibitor, a plasticizer, a flame retardant, a reinforcing agent, an antistatic agent, and a viscosity modifier. The colorant is not particularly limited, and inorganic pigments, organic pigments, dyes, and the like may be appropriately selected and used. Resins for the printing ink layer include, but are not limited to, castor oil, polyester resin, polyurethane resin, epoxy resin, (meth)acrylic resin, melamine resin, polystyrene resin, phenolic resin, polyvinyl chloride resin, polyvinyl acetate resin, polyamide resin, nitrocellulose, acrylate compound polymer, and mixtures thereof. Methods for forming the printing ink layer include letterpress printing, gravure printing, offset printing, flexographic printing, and screen printing, and can be selected as desired. Commercially available printing inks can be used, including reverse printing gravure inks such as the LP Bio series and Rio Alpha S series manufactured by Toyo Ink Co., Ltd., the Finart S series and Finart BM series manufactured by DIC Corporation, the Bell Color series and Bell Flora series manufactured by Sakata Inx Corporation, the Lamic SR series, Lamic BP series, and NB300BP series manufactured by Dainichiseika Color & Chemicals Co., Ltd., and the LG-NT series manufactured by Tokyo Ink Co., Ltd.

[0080] [Packaging] The packaging of the present invention is a bag-shaped product made from either the laminate or composite laminate of the present invention. The use of the laminate or composite laminate of the present invention not only makes it suitable for recycling, but also provides excellent gas barrier properties and adhesion, and allows the contents to be safely stored without deterioration of the gas barrier properties or peeling after filling with the contents. Therefore, it is possible to provide a packaging that has high gas barrier properties and adhesion even in harsh environments, such as heat after boiling or retort treatment, or the acid of the acidic contents if the contents are acidic.

[0081] The laminate of the present invention is a laminate that has excellent gas barrier properties and is suitable for recycling, and composite laminates and packages containing it are suitably used in applications where these properties are required.

[0082] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0083] (1) Component analysis and structural identification of the protective layer (water-soluble resin, linear polysiloxane, silicon alkoxide having a ureido group) The protective layer was peeled off from the sample and dissolved in a solvent in which it could be dissolved. Next, the solution was filtered to separate the particles from the filtrate. If necessary, general chromatography such as silica gel column chromatography, gel permeation chromatography, and high performance liquid chromatography was applied to separate and purify the components contained in the protective layer and resin layer into single substances. Then, each single substance was purified by DMSO-d ６ The solution was dissolved by heating to 60°C, and the resultant solution was analyzed by nuclear magnetic resonance spectroscopy. １ H-NMR, １３C-NMR measurements were performed. Next, qualitative analysis was performed on each single substance using an appropriate combination of IR (infrared spectroscopy), various mass spectrometry methods (gas chromatography-mass spectrometry (GC-MS), pyrolysis gas chromatography-mass spectrometry (pyrolysis GC-MS), matrix-assisted laser desorption / ionization mass spectrometry (MALDI-MS), time-of-flight mass spectrometry (TOF-MS), time-of-flight matrix-assisted laser desorption / ionization mass spectrometry (MALDI-TOF-MS), dynamic secondary ion mass spectrometry (Dynamic-SIMS), and time-of-flight secondary ion mass spectrometry (TOF-SIMS)) to identify the components contained in the sample and identify their structures. When these qualitative analyses were combined, priority was given to those that could be measured with fewer combinations.

[0084] (2) Protective Layer Thickness, Inorganic Layer Thickness The protective layer thickness and the inorganic layer thickness were measured by observing the cross section using a TEM. First, a sample for cross-sectional observation was prepared by FIB using a microsampling system (Hitachi, Ltd., FB-2000A) (specifically, based on the method described in "Polymer Surface Processing Science" (by Akira Iwamori) pp. 118-119). Next, a transmission electron microscope (Hitachi, Ltd., H-9000UHRII) was used to observe the cross section at an accelerating voltage of 300 kV, and the observation magnification was adjusted so that the layer thickness accounted for 30-70% of the observed image. Similarly, a total of five samples were measured, and the average value of the five points was calculated. The value converted to nm was used as the protective layer thickness and the inorganic layer thickness.

[0085] (3) Measurement of the content ratio of water-soluble resin and inorganic component (linear polysiloxane, silicon alkoxide) in the protective layer. The water-soluble resin is polyvinyl alcohol (hereinafter sometimes abbreviated as PVA, polymerization degree 1,700, saponification degree 98.5%), and the inorganic component is a hydrolyzate of tetraalkoxysilane (hereinafter sometimes abbreviated as TEOS). The content ratio of water-soluble resin / inorganic component (inorganic component is SiO ２ Films obtained by mixing the components in ratios (by mass) of 80 / 20, 65 / 35, 50 / 50, 35 / 65, and 20 / 80 were prepared as standard samples with different content ratios.

[0086] Next, the intensity of the specific X-ray Kα of silicon was measured for each standard sample using an EDX-700 X-ray fluorescence analyzer manufactured by Shimadzu Corporation, and the resulting X-ray intensity S (unit: cps / μA) was determined. The thickness of each standard sample was measured using the method described in (2) above, and the X-ray intensity S per unit thickness was calculated, and the content of the water-soluble resin and inorganic component (the inorganic component was SiO ２ A calibration curve was created using the mass equivalent.

[0087] Next, for the laminate of the present invention, the X-ray intensity S per unit thickness was determined from the fluorescent X-ray analysis and the average thickness T, and the contents of the water-soluble resin and inorganic component were determined from the calibration curve.

[0088] (4) Analysis of silicon bonding state (presence or absence of linear polysiloxane), (mixing ratio of linear polysiloxane / silicon alkoxide (SiO ２ The protective layer of the laminate was separated by cutting and analyzed by Raman spectroscopy under the following conditions: Measuring device: Jobin Yvon / Atago Bussan T-6400 Measuring mode: Microscopic Raman Objective lens: 100x Beam diameter: 1 μm Light source: Ar ＋ Laser / 514.5 nm Laser power: 200 mW Diffraction grating: Single 600 gr / mm Slit: 100 μm Detector: CCD / Jobin Yvon 1,024 × 256

[0089] The Raman spectrum analysis conditions for calculating the area A1 representing the random network structure made of silicon alkoxide and the area A2 representing the linear polysiloxane are as follows. The obtained Raman spectrum was analyzed using the spectrum analysis software GRAMS / Thermo Scientific. After baseline correction of the Raman spectrum by linear approximation, the 600-250 cm －１ The fitting was performed in the range of 4-membered ring structure (peak wave number 495 cm －１ , half width 35 cm －１ ), linear polysiloxane (peak wave number 488 cm －１ , half width 35 cm －１The random network structure composed of silicon alkoxide resulted in a broad peak reflecting a continuous structure, so automatic fitting was performed to separate the spectrum into three components, including the four-membered ring structure and linear polysiloxane, using a Gaussian function approximation.

[0090] The area of ​​the region surrounded by the obtained band and the baseline is calculated to determine whether or not linear polysiloxane is present. The area representing the random network structure consisting of silicon alkoxide is defined as A1, the area representing linear polysiloxane is defined as A2, and A2 / A1 (mixing ratio of linear polysiloxane / silicon alkoxide (SiO ２ The converted mass ratio was calculated.

[0091] (5) Ratio of solid content of silicon alkoxide having ureido group to solid content in the protective layer. The mixing ratio of the water-soluble resin and the linear polysiloxane / silicon alkoxide (SiO ２ The mass ratio (based on the converted mass ratio) was determined. Five types of standard samples were then prepared, each having a known, different solid content ratio of silicon alkoxide having a ureido group among the solid content corresponding to silicon alkoxide in the composition, and fluorescent X-ray analysis was performed on each sample in the same manner as in (3) above, to detect the amount of X-rays generated. Next, in the same manner as in (2) and (3) above, the solid content ratio of silicon alkoxide having a ureido group versus the X-ray intensity S per unit thickness was plotted to create a calibration curve.

[0092] Next, for the laminate of the present invention, the X-ray intensity S per unit thickness was similarly determined from the X-ray fluorescence analysis and the average thickness T, and this value was converted into the solids ratio of silicon alkoxide having a ureido group from the calibration curve and the resulting value, thereby determining the solids ratio of silicon alkoxide having a ureido group.

[0093] (6) Gas barrier properties (oxygen barrier properties: oxygen permeability, water vapor barrier properties: water vapor permeability) A sample to be evaluated was prepared. Next, the oxygen permeability (hereinafter sometimes abbreviated as OTR) was measured under conditions of a temperature of 23 ° C. and a humidity of 90% RH using an oxygen permeability measuring device manufactured by MOCON ("OX-TRAN" (registered trademark) 2 / 21) in accordance with JIS K7126-2 (2006). The measurement was performed twice for two test pieces, and the average value of the four measured values ​​was taken as the oxygen permeability value. In addition, the water vapor permeability (hereinafter sometimes abbreviated as WVTR) was measured under conditions of a temperature of 40 ° C. and a humidity of 90% RH using a water vapor permeability measuring device manufactured by MOCON ("PERMATRAN" (registered trademark) -W 3 / 31) in accordance with JIS K7129-2 (2019). The measurement was carried out twice for each of two test pieces, and the average value of the four measured values ​​was taken as the water vapor transmission rate.

[0094] Next, a 60 μm thick unstretched polypropylene film (ZK100 manufactured by Toray Advanced Film Co., Ltd.) was laminated as a second olefin layer on the protective layer side of the laminate of the present invention via an adhesive consisting of a polyester urethane-based base agent (LX500 manufactured by DIC Corporation) and an aromatic isocyanate curing agent (KW75 manufactured by DIC Corporation), and the film was then aged for 3 days in an oven heated to 40° C. to cure the adhesive, thereby obtaining composite laminate A.

[0095] Next, a 60 μm-thick unstretched polypropylene film (ZK100, manufactured by Toray Advanced Film Co., Ltd.) was prepared as the second olefin layer, and a 20 μm-thick biaxially oriented polypropylene film (FOR, manufactured by Futamura Chemical Co., Ltd.) was prepared as the third olefin layer. The corona-treated side of the biaxially oriented polypropylene film for the third olefin layer was laminated to the protective layer side of the laminate of the present invention via an adhesive consisting of a polyester urethane-based base material (LX500, manufactured by DIC Corporation) and an aromatic isocyanate curing agent (KW75, manufactured by DIC). Then, a 60 μm-thick unstretched polypropylene film (ZK100, manufactured by Toray Advanced Film Co., Ltd.) was laminated to the substrate side opposite the protective layer of the laminate via an adhesive consisting of a polyester urethane-based base material (LX500, manufactured by DIC Corporation) and an aromatic isocyanate curing agent (KW75, manufactured by DIC). The laminate was then aged for 3 days in an oven heated to 40° C. to cure the adhesive, yielding a composite laminate B.

[0096] Next, the composite laminates A and B were subjected to retort sterilization (high-temperature hot water treatment) at 130°C for 30 minutes to produce composite laminates A and B for barrier evaluation after retort treatment. Two test pieces were measured twice using the same method as described above, and the average values ​​of a total of four measured values ​​were used as the oxygen permeability and water vapor permeability values ​​after retort treatment.

[0097] (7) Evaluation of Adhesion (Lamination Strength) The evaluation of adhesion was carried out by the following method.

[0098] First, the composite laminates A and B obtained in (6) were cut to a width of 15 mm and a length of 150 mm to prepare composite laminates A and B for adhesion evaluation. Then, for composite laminate A for adhesion evaluation, the peel angle between the laminate of the present invention and the unstretched polypropylene film serving as the second olefin layer was 180°, and for composite laminate B for adhesion evaluation, the peel angle between the laminate of the present invention and the biaxially oriented polypropylene film serving as the third olefin layer was 180°. The peel strength was measured using a tensile tester (Tensilon) at a peel rate of 50 mm / min. Three samples were measured using the above measurement method, and the average of the measurements for composite laminates A and B was used as the initial laminate strength. Furthermore, composite laminates A and B were subjected to retort sterilization at 130°C for 30 minutes, and similarly cut to a width of 15 mm and a length of 150 mm. The peel strength of the three samples was measured using the same method, and the average of the measurements for composite laminates A and B was used as the laminate strength after retort treatment.

[0099] (8) Heat Shrinkage The laminate of the present invention and the second and third olefin layers were each cut into 200 mm square pieces, and 100 mm long lines were drawn in the MD (running direction) and TD (direction forming a 90-degree angle with the MD). The lengths of the lines in the MD and TD directions were measured using a projector (Mitutoyo PJ-H3000) and recorded as the lengths before heating. Furthermore, after heating the laminate and the second and third olefin layers at 120°C for 15 minutes, the lengths of the lines in the MD and TD directions were similarly measured using a projector (Mitutoyo PJ-H3000) and recorded as the lengths after heating. The heat shrinkage in the MD and TD directions was calculated using (Equation 1).

[0100] Heat shrinkage rate (%)=100×(length before heating−length after heating) / length before heating (Equation 1) Next, the heat shrinkage rates of the laminate and the second and third olefin layers of the composite laminate were compared with each other for smaller values ​​and larger values, and since a smaller heat shrinkage rate of either or both of the second olefin layer and the third olefin layer than that of the laminate results in less curling and wrinkling when made into a package and physical properties such as gas barrier properties are more easily obtained, a composite laminate in which the heat shrinkage rate of either or both of the second olefin layer and the third olefin layer was smaller than that of the laminate was judged to pass, and a composite laminate in which any heat shrinkage rate of the laminate was greater than that of the second olefin layer or the third olefin layer was judged to fail.

[0101] (9) Average composition ratio (Si / C) of silicon element (Si) and carbon element (C) in the protective layer: The composition was analyzed and evaluated in the depth direction from the surface side of the protective layer of the laminate using X-ray photoelectron spectroscopy (XPS) under the following conditions, and the film structure was confirmed by the depth profile. Data was collected while performing ion etching from the protective layer side until the inorganic layer was reached, and the presence or absence of a continuous increase or decrease in composition was confirmed from the obtained depth profile of each element. Note that, regarding the presence or absence of a continuous increase or decrease, it was determined that a continuous increase or decrease was present when the length of the increase or decrease was 2 nm or more.

[0102] First, the thickness of the protective layer was determined by the method (2) described above, and the depth from the surface of the protective layer to the interface of the inorganic layer in the depth profile of the composition ratio in the depth direction measured by X-ray photoelectron spectroscopy (XPS) was defined as the protective layer thickness. The average composition ratio (Si / C) was calculated by averaging the composition ratio measurements at each measurement point in the thickness direction up to 1 / 3 of the protective layer thickness.

[0103] The measurement conditions were as follows: Apparatus: X-ray photoelectron spectrometer (Quantera SXM manufactured by PHI) Excitation X-ray: monochromatic AlKα １，２ ray (1486.6 eV) X-ray diameter: 100 μm Photoelectron escape angle: 45° (inclination of the detector relative to the sample surface) Ion etching conditions: Ar ＋Ion 3 kV, raster size 2 × 2 mm (etching area), etching rate 12.0 nm / min.

[0104] Example 1 Inorganic Layer A 25 μm-thick uniaxially oriented polyethylene film (PE3K-BT, manufactured by Futamura Chemical Co., Ltd.) was used as a substrate film. The corona-treated surface of the film was provided with a 15 nm-thick aluminum oxide layer by vacuum deposition to form an inorganic layer.

[0105] <Protective Layer> (Organic Component Solution) Polyvinyl alcohol (degree of polymerization 1,700, degree of saponification 98.5%) as a water-soluble resin was added to a solvent of water / isopropyl alcohol = 97 / 3 in mass ratio, and the mixture was heated and stirred at 90°C to obtain an organic component solution with a solid content of 12 mass%.

[0106] (Inorganic Component Solution) A silicon alkoxide having a ureido group (KBM-585A manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with 11.7 g of the silicon alkoxide having a ureido group and 4.7 g of methanol, and 18.6 g of a 0.02 N aqueous hydrochloric acid solution was added dropwise to the solution while stirring, to obtain a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A).

[0107] Next, 7.0 g of a 0.06 N hydrochloric acid solution was added dropwise to a solution prepared by mixing 11.2 g of Ethyl Silicate 40 (a linear oligomer having an average pentamer content) manufactured by Colcoat Co., Ltd. as a linear polysiloxane and 16.9 g of methanol, to obtain a pentamer silicate hydrolyzed solution (hydrolyzed solution B).

[0108] (Formation of Protective Layer) A protective layer was prepared by mixing a PVA film containing 20% ​​by mass, a silicon alkoxide having a ureido group having a solid content of 2.0% by mass, and a linear polysiloxane and a silicon alkoxide having a SiO content of 2.0% by mass. ２ The organic component solution, hydrolyzed liquid A, and hydrolyzed liquid B were mixed and stirred so that the converted mass ratio was 97 / 3, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 100 nm after drying, thereby producing a laminate.

[0109] Example 2 Inorganic Layer A 15 nm thick aluminum oxide layer was formed by vacuum deposition on the corona treated surface of a 20 μm thick biaxially oriented polypropylene film (OP ME-1 manufactured by Mitsui Chemicals Tocello Inc.) used as a substrate film to form an inorganic layer.

[0110] <Protective Layer> (Organic Component Solution) In the same manner as in Example 1, an organic component solution of PVA was obtained.

[0111] (Inorganic Component Solutions) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) and a pentameric silicate hydrolyzed solution (hydrolyzed solution B) were obtained.

[0112] (Formation of Protective Layer) In the same manner as in Example 1, a protective layer having a thickness of 100 nm after drying was formed to obtain a laminate.

[0113] Example 3 Inorganic Layer A 20 μm-thick biaxially oriented polypropylene film (OP ME-1, manufactured by Mitsui Chemicals Tohcello Inc.) was used as a substrate film. A 15 nm-thick silicon oxide layer was formed by vacuum deposition on the corona-treated surface to form an inorganic layer.

[0114] <Protective Layer> (Organic Component Solution) In the same manner as in Example 1, an organic component solution of PVA was obtained.

[0115] (Inorganic Component Solutions) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) and a pentameric silicate hydrolyzed solution (hydrolyzed solution B) were obtained.

[0116] (Formation of Protective Layer) In the same manner as in Example 1, a protective layer having a thickness of 100 nm after drying was formed to obtain a laminate.

[0117] [Example 4] <Inorganic Layer> A 20 μm-thick biaxially oriented polypropylene film (OP ME-1, manufactured by Mitsui Chemicals Tohcello, Inc.) was prepared as a substrate film. Next, a resin composition obtained by mixing a polyester resin (Takelac A-3210, manufactured by Mitsui Chemicals, Inc.) and an aliphatic isocyanate curing agent (Takelac A-3070, manufactured by Mitsui Chemicals, Inc.) at a weight ratio of 3:1 was applied to the substrate film as an anchor layer. The resin composition was dried at 80° C. and then aged at 40° C. for 72 hours to form a 400 nm-thick anchor layer. Next, a 15 nm-thick aluminum oxide layer was provided on the anchor layer by vacuum deposition to form an inorganic layer.

[0118] <Protective Layer> (Organic Component Solution) In the same manner as in Example 1, an organic component solution of PVA was obtained.

[0119] (Inorganic Component Solutions) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) and a pentameric silicate hydrolyzed solution (hydrolyzed solution B) were obtained.

[0120] (Formation of Protective Layer) In the same manner as in Example 1, a protective layer having a thickness of 100 nm after drying was formed to obtain a laminate.

[0121] Example 5 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0122] <Protective Layer> (Organic Component Solution) A modified polyvinyl alcohol (hereinafter sometimes abbreviated as modified PVA; degree of polymerization 1,700, degree of saponification 93.0%) having γ-butyrolactone, which is a lactone structure, as a cyclic structure having a carbonyl group, as a water-soluble resin was added to a solvent having a mass ratio of water / isopropyl alcohol = 97 / 3, and the mixture was heated and stirred at 90°C to obtain an organic component solution with a solid content of 12 mass%.

[0123] (Inorganic Component Solutions) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) and a pentameric silicate hydrolyzed solution (hydrolyzed solution B) were obtained.

[0124] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 20% by mass, a solid content of silicon alkoxide having a ureido group at 2.0% by mass, and SiO of each of linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, and hydrolyzed liquid B were mixed and stirred so that the converted mass ratio was 97 / 3, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 100 nm after drying, thereby producing a laminate.

[0125] Example 6 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0126] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0127] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0128] Next, 7.0 g of a 0.06 N hydrochloric acid solution was added dropwise to a solution prepared by mixing 11.2 g of Ethyl Silicate 48 (a linear oligomer having an average decamer) manufactured by Colcoat Co., Ltd. as a linear polysiloxane and 16.9 g of methanol, to obtain a decamer silicate hydrolyzed liquid (hydrolyzed liquid B).

[0129] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 3.2% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, and hydrolyzed liquid B were mixed and stirred so that the converted mass ratio was 95 / 5, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 350 nm after drying, thereby producing a laminate.

[0130] Example 7 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0131] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0132] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0133] Next, 7.0 g of a 0.06 N hydrochloric acid solution was added dropwise to a solution prepared by mixing 11.2 g of Methyl Silicate 51 (a linear oligomer with an average tetramer) manufactured by Colcoat Co., Ltd. as a linear polysiloxane and 16.9 g of methanol, to obtain a tetramer silicate hydrolyzed solution (hydrolyzed solution B).

[0134] Next, 11.7 g of KBE-04 (tetraethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., which was used as a silicon alkoxide having no ureido groups, and 4.7 g of methanol were mixed, and 18.6 g of a 0.02 N aqueous hydrochloric acid solution was added dropwise to the solution while stirring, to obtain a silicon alkoxide hydrolyzed solution having no ureido groups (hydrolyzed solution C).

[0135] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 3.2% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 15 / 85, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 500 nm after drying, thereby producing a laminate.

[0136] Example 8 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0137] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0138] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0139] Next, 7.0 g of a 0.06 N hydrochloric acid solution was added dropwise to a solution prepared by mixing 11.2 g of Methyl Silicate 53A (a linear oligomer having an average heptamer content) manufactured by Colcoat Co., Ltd. as a linear polysiloxane and 16.9 g of methanol, to obtain a heptamer silicate hydrolyzed solution (hydrolyzed solution B).

[0140] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0141] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 3.2% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 15 / 85, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 500 nm after drying, thereby producing a laminate.

[0142] Example 9 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0143] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0144] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0145] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0146] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0147] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 50% by mass, a solid content of silicon alkoxide having a ureido group at 5.5% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 50 / 50, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 250 nm after drying, thereby producing a laminate.

[0148] Example 10 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0149] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0150] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0151] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0152] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0153] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 8.4% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 60 / 40, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 250 nm after drying, thereby producing a laminate.

[0154] Example 11 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0155] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0156] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0157] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0158] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0159] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 8.4% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 40 / 60, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 250 nm after drying, thereby producing a laminate.

[0160] Example 12 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0161] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0162] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0163] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0164] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0165] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 7.8% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 40 / 60, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 250 nm after drying, thereby producing a laminate.

[0166] Example 13 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0167] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0168] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0169] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0170] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0171] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 3.2% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 40 / 60, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 250 nm after drying, thereby producing a laminate.

[0172] [Example 14] <Inorganic Layer> An anchor layer was formed on a substrate film in the same manner as in Example 4. Next, aluminum was evaporated on the unwound substrate film in a roll-to-roll vacuum deposition machine using a high-frequency induction heating crucible-type aluminum evaporation source, and aluminum was deposited on the anchor layer of the substrate film. Oxygen gas was supplied to the position closest to the winding side where the evaporated aluminum was deposited on the anchor layer of the substrate film, thereby continuously forming an inorganic layer so that the aluminum metal layer thickness was 40 nm and the aluminum oxide layer thickness was 4 nm. The thicknesses of the aluminum metal layer and the aluminum oxide layer were measured using the following methods.

[0173] First, X-ray photoelectron spectroscopy (XPS) was used to perform a composition analysis evaluation in the depth direction, and the inorganic film structure was confirmed by the depth profile. Regarding metal elements, oxide components and metal components were separated and profiled. Data was collected from the surface layer on the resin layer and protective layer side while performing ion etching until the substrate was reached, and the presence or absence of a continuous increase or decrease in composition was confirmed from the depth profile of each element obtained. Regarding the presence or absence of a continuous increase or decrease, a continuous increase or decrease was determined to exist if the length of the increase or decrease was 2 nm or more.

[0174] The measurement conditions were as follows: Apparatus: X-ray photoelectron spectrometer (Quantera SXM manufactured by PHI) Excitation X-ray: monochromatic AlKα １，２ ray (1486.6 eV) X-ray diameter: 100 μm Photoelectron escape angle: 45° (inclination of the detector relative to the sample surface) Ion etching conditions: Ar ＋ Ion 3 kV, raster size 2 × 2 mm (etching area), etching rate 12.0 nm / min. Next, the total thickness of the inorganic layer was determined by the method described above. From the total thickness of the inorganic layer and the area of ​​the depth profile corresponding to the inorganic layer, the thickness of the aluminum metal layer and the thickness of the aluminum oxide layer were calculated.

[0175] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0176] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0177] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0178] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0179] (Formation of Protective Layer) A protective layer was prepared by coating a film containing a modified PVA at a content of 30% by mass, a solid content of silicon alkoxide having a ureido group at 3.2% by mass, and SiO of each of the linear polysiloxane and silicon alkoxide. ２ The organic component solution, hydrolyzed liquid A, hydrolyzed liquid B, and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 40 / 60, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied onto the inorganic layer and dried at 80°C to form a protective layer with a thickness of 250 nm after drying, thereby producing a laminate.

[0180] Example 15 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0181] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0182] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0183] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0184] (Protective Layer Formation) A coating liquid with a solid content of 12% by mass was obtained by mixing and stirring an organic component solution, hydrolyzed liquid A, and hydrolyzed liquid C, which contained 30% by mass of modified PVA, 3.2% by mass of silicon alkoxide having a ureido group, and no linear polysiloxane. This coating liquid was then applied onto the inorganic layer and dried at 80°C to form a 350 nm thick protective layer containing no linear polysiloxane (SiO of each of the linear polysiloxane and silicon alkoxide). ２ The mass ratio calculated as a function of the thickness of the laminate was 0 / 100. Since the laminate of the present invention does not contain a linear polysiloxane, the gas barrier property and adhesion after retort treatment were poor.

[0185] Example 16 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0186] <Protective Layer> (Organic Component Solution) In the same manner as in Example 5, an organic component solution of modified PVA was obtained.

[0187] (Inorganic Component Solution) In the same manner as in Example 6, a decameric silicate hydrolyzed solution (hydrolyzed solution B) was obtained.

[0188] Then, in the same manner as in Example 7, a silicon alkoxide hydrolyzed solution containing no ureido groups (hydrolyzed solution C) was obtained.

[0189] (Formation of Protective Layer) The content of modified PVA was 30% by mass, and SiO of linear polysiloxane and silicon alkoxide (only tetraethoxysilane) was used without using silicon alkoxide having a ureido group. ２ Only hydrolyzed liquid B and hydrolyzed liquid C were mixed and stirred so that the converted mass ratio was 40 / 60, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied to the inorganic layer and dried at 80°C to form a protective layer that did not contain a silicon alkoxide having a ureido group and had a thickness of 350 nm after drying, resulting in a laminate, but the adhesiveness was poor.

[0190] Example 17: A 60 μm thick unstretched polypropylene film (ZK100, manufactured by Toray Advanced Film Co., Ltd.) was annealed at 100° C. for 1 minute to form the second olefin layer. Next, the laminate of Example 14 was prepared, and the annealed unstretched polypropylene film was laminated on the protective layer side as the second olefin layer via an adhesive consisting of a polyester urethane-based base resin (LX500, manufactured by DIC Corporation) and an aromatic isocyanate curing agent (KW75, manufactured by DIC Corporation). The adhesive was then cured by aging in an oven heated to 40° C. for 3 days to obtain a composite laminate A'. The composite laminate A' failed the thermal shrinkage evaluation.

[0191] Example 18 As the third olefin layer, a biaxially oriented polypropylene film (FOR manufactured by Futamura Chemical Co., Ltd.) having a thickness of 20 μm was annealed at 100° C. for 1 minute. Next, the laminate of Example 14, a 60 μm thick unstretched polypropylene film (ZK100 manufactured by Toray Advanced Film Co., Ltd.) as the second olefin layer, and the annealed biaxially oriented polypropylene film as the third olefin layer were prepared. The corona-treated side of the annealed biaxially oriented polypropylene film of the third olefin layer was laminated to the protective layer side of the laminate of the present invention via an adhesive consisting of a polyester urethane-based base material (LX500 manufactured by DIC Corporation) and an aromatic isocyanate curing agent (KW75 manufactured by DIC Corporation). Then, a 60 μm thick unstretched polypropylene film was laminated to the substrate side opposite the protective layer of the laminate via an adhesive consisting of a polyester urethane-based base material (LX500 manufactured by DIC Corporation) and an aromatic isocyanate curing agent (KW75 manufactured by DIC Corporation). The composite laminate B' was then aged for 3 days in an oven heated to 40° C. to cure the adhesive, yielding a composite laminate B'. The composite laminate B' failed the heat shrinkage evaluation.

[0192] Comparative Example 1 Evaluation was performed on a laminate having only an inorganic layer similar to that of Example 1 without providing a protective layer, but the laminate had poor gas barrier properties, gas barrier properties after retort treatment, and adhesion.

[0193] Comparative Example 2 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0194] <Protective layer> (organic component solution) None.

[0195] (Inorganic Component Solution) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) was obtained.

[0196] Next, in the same manner as in Example 6, a decameric silicate hydrolyzed liquid (hydrolyzed liquid B) was obtained.

[0197] (Formation of Protective Layer) A protective layer was formed without using a water-soluble resin, in which the solid content of silicon alkoxide having a ureido group was 2.0 mass %, and the SiO of each of the linear polysiloxane and silicon alkoxide was 2.0 mass %. ２Only hydrolyzed liquid A and hydrolyzed liquid B were mixed and stirred so that the converted mass ratio was 98 / 2, and the mixture was diluted with water to obtain a coating liquid with a solid content of 12 mass %. This coating liquid was applied to the inorganic layer and dried at 80°C to form a protective layer containing no water-soluble resin and having a thickness of 350 nm after drying, to obtain a laminate. However, cracks occurred in the protective layer, making it impossible to evaluate.

[0198] Comparative Example 3 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0199] <Protective Layer> (Organic Component Solution) In the same manner as in Example 1, an organic component solution of PVA was obtained.

[0200] (Inorganic component solution) None.

[0201] (Protective Layer Formation) A solution of only the organic component of PVA was applied onto an inorganic layer without using any silicon component such as silicon alkoxide, linear polysiloxane, or silicon alkoxide having a ureido group, and the layer was dried at 80°C to form a protective layer consisting of only a water-soluble resin with a thickness of 350 nm after drying, to give a laminate. However, the gas barrier properties of the laminate, the gas barrier properties after retort treatment, and the adhesion were all poor.

[0202] Comparative Example 4 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0203] <Protective Layer> (Organic Component Solution) In the same manner as in Example 1, an organic component solution of PVA was obtained.

[0204] (Inorganic Component Solutions) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) and a pentameric silicate hydrolyzed solution (hydrolyzed solution B) were obtained.

[0205] (Formation of Protective Layer) A protective layer was prepared by mixing a PVA film containing 15% by mass, a silicon alkoxide having a ureido group having a solid content of 2.0% by mass, and a linear polysiloxane and a silicon alkoxide having a SiO content of 2.0% by mass. ２The organic component solution, hydrolyzed liquid A, and hydrolyzed liquid B were mixed and stirred so that the converted mass ratio was 97 / 3, and the mixture was diluted with water to obtain a coating solution with a solids content of 12 mass%. This coating solution was applied to the inorganic layer and dried at 80°C to form a protective layer with a thickness of 100 nm after drying, thereby producing a laminate. The average composition ratio (Si / C) in the protective layer of this laminate was as high as 2.44, resulting in poor gas barrier properties.

[0206] Comparative Example 5 Inorganic Layer An inorganic layer was formed in the same manner as in Example 4.

[0207] <Protective Layer> (Organic Component Solution) In the same manner as in Example 1, an organic component solution of PVA was obtained.

[0208] (Inorganic Component Solutions) In the same manner as in Example 1, a silicon alkoxide hydrolyzed solution having a ureido group (hydrolyzed solution A) and a pentameric silicate hydrolyzed solution (hydrolyzed solution B) were obtained.

[0209] (Formation of Protective Layer) A protective layer containing a PVA content of 82% by mass, a solid content of silicon alkoxide having a ureido group of 2.0% by mass, and SiO of each of linear polysiloxane and silicon alkoxide was formed. ２ The organic component solution, hydrolyzed liquid A, and hydrolyzed liquid B were mixed and stirred so that the converted mass ratio was 97 / 3, and the mixture was diluted with water to obtain a coating solution with a solids content of 12 mass%. This coating solution was applied to the inorganic layer and dried at 80°C to form a protective layer with a thickness of 100 nm after drying, thereby producing a laminate. The average composition ratio (Si / C) in the protective layer of this laminate was as low as 1.21, and the gas barrier property was poor.

[0210] For each of the above Examples and Comparative Examples, Table 1 shows the composition of the laminate, Table 2 shows the properties of the laminate, and Tables 3 and 4 show the properties of the composite laminate.

[0211]

[0212]

[0213]

[0214]

[0215] As is clear from the results of each of the above examples, the laminate of the present invention has excellent gas barrier properties, and the composite laminate using this laminate has excellent gas barrier properties and adhesion after retort treatment.

[0216] By laminating an inorganic layer and a protective layer on a polyethylene film, which is an olefin-based substrate film, and the protective layer containing a water-soluble resin and a silicon alkoxide and having an average composition ratio (Si / C) in the range of 1.30 to 2.30 (Example 1), the gas barrier properties and gas barrier properties after retort treatment and adhesion of the laminate were improved compared to when no protective layer was provided (Comparative Example 1), when a protective layer was provided but did not contain any of the components (Comparative Examples 2 and 3), or when the average composition ratio (Si / C) of the protective layer was not satisfied (Comparative Examples 4 and 5). Furthermore, even when the type of olefin-based substrate film was changed (Example 3) or when the type of inorganic layer was changed (Examples 4 and 14), the gas barrier properties and gas barrier properties after retort treatment of the laminate were similarly exhibited, and adhesion was further improved particularly when an anchor layer was provided (Example 4).

[0217] Furthermore, compared to Example 1, the gas barrier properties were improved by using a water-soluble resin in the protective layer that was a vinyl polymer having a carbonyl group in its cyclic structure (Example 5). Furthermore, not only the gas barrier properties but also the adhesion properties were improved by using a silicon alkoxide having a ureido group in a solid content ratio of 2.5% or more relative to the solid content of the protective layer (Example 6).

[0218] By including a silicon alkoxide having no ureido group in the protective layer, and by changing the type of linear polysiloxane used therein (tetramer or heptamer) and the thickness of the protective layer, the adhesion and the gas barrier properties after retort treatment were improved (Examples 7 and 8). Furthermore, by changing the solid content ratio of the silicon alkoxide having a ureido group in the protective layer and the SiO of each of the linear polysiloxane and the silicon alkoxide, ２ By changing the converted mass ratio (Examples 9 to 13), various physical properties could be adjusted while improving adhesion, gas barrier properties, and resistance after retort treatment (adhesion, gas barrier properties).

[0219] On the other hand, when no protective layer was provided (Comparative Example 1), the adhesion and gas barrier properties were poor, and when a protective layer was provided but did not contain a water-soluble resin and did not satisfy the average composition ratio (Si / C) (Comparative Example 2), cracks occurred on the side where each layer was laminated, making it impossible to evaluate. Furthermore, when the protective layer did not contain a silicon alkoxide and did not satisfy the average composition ratio (Si / C) (Comparative Example 3), various gas barrier properties and adhesion after retort treatment were poor. Furthermore, even if a water-soluble resin and a silicon alkoxide were included, when the average composition ratio (Si / C) was not satisfied (Comparative Examples 4 and 5), either the gas barrier properties or the adhesion were insufficient, making it difficult to achieve both physical properties as a composite.

[0220] Furthermore, in the composite laminate, when the thermal shrinkage rate of either or both of the second olefin layer and the third olefin layer was smaller than that of the laminate (Example 14), various gas barrier properties and adhesion properties were superior compared to when the thermal shrinkage rate was larger (Examples 17 and 18).

Claims

1. A laminate in which an inorganic layer and a protective layer are laminated in this order on one side of an olefin-based substrate film, the protective layer containing a water-soluble resin and silicon alkoxide, and the average composition ratio (Si / C) of silicon element (Si) to carbon element (C) measured by X-ray photoelectron spectroscopy (XPS) in a thickness direction from the surface side of the protective layer opposite the inorganic layer to one-third of the thickness of the protective layer is 1.30 to 2.

30.

2. The laminate according to claim 1, wherein the protective layer further comprises a linear polysiloxane.

3. The laminate according to claim 1, wherein the silicon alkoxide comprises a silicon alkoxide having a ureido group.

4. The laminate according to claim 1, which has an anchor layer between the olefin-based substrate film and the inorganic layer.

5. The laminate according to claim 1, wherein the inorganic layer contains aluminum (Al) and / or silicon (Si).

6. The laminate according to claim 3, wherein the solid content ratio of the silicon alkoxide having a ureido group to the solid content of the protective layer is 2.5 mass % or more.

7. The SiO of each of the linear polysiloxane and silicon alkoxide contained in the protective layer ２ 3. The laminate according to claim 2, wherein the converted mass ratio of linear polysiloxane to silicon alkoxide is in the range of 15 / 85 to 90 / 10.

8. The laminate according to claim 1, wherein the protective layer has a thickness of 100 to 1,000 nm.

9. The laminate of claim 1, wherein the inorganic layer comprises aluminum oxide.

10. A composite laminate comprising a second olefin layer containing an olefin resin laminated on at least one side of the laminate according to claim 1 via a resin layer.

11. The composite laminate of claim 10, wherein the second olefin layer has a lower heat shrinkage than the laminate after heating at 120°C for 15 minutes.

12. The composite laminate according to claim 10, further comprising a third olefin layer containing an olefin-based resin laminated on at least one of the laminate side and / or the second olefin layer side of the composite laminate via a resin layer.

13. The composite laminate according to claim 12, wherein at least one or both of the second olefin layer and the third olefin layer have a smaller heat shrinkage rate after heating at 120°C for 15 minutes than the laminate.

14. A package comprising a laminate according to any one of claims 1 to 9 and / or a composite laminate according to any one of claims 10 to 13.

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