JP2018058329A - Laminated body and method for producing laminated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated body having excellent oxygen and water vapor barrier properties.SOLUTION: A laminated body has an inorganic compound and an organic and inorganic mixed layer in this order from the base material film side on at least one surface of the base material film, where the organic and inorganic mixed layer contains a vinyl alcohol-based resin and metal alkoxide represented by Si(OR), and a ratio V/S of a free volume V of a hole determined by a positron annihilation method represented by formula (1) to a silicon amount S determined by fluorescent X-ray analysis is 0.01 or more and 0.1 or less.SELECTED DRAWING: None

Description

  The present invention relates to a laminate having excellent oxygen and water vapor barrier properties.

  Various packaging materials have been used to wrap various items such as food, drinks, pharmaceuticals, and daily necessities. These packaging materials have oxygen barrier properties and water vapor barrier properties to prevent deterioration of the contents. Needed. Examples of the packaging material having excellent gas barrier properties include aluminum foil, but aluminum foil tends to generate pinholes and has limited applications. Moreover, since there is no visibility, there is a drawback that the contents cannot be seen or the microwave oven cannot be used.

  In order to solve these problems, a laminate comprising a layer having a barrier property such as polyvinylidene chloride (PVDC) or ethylene-vinyl alcohol copolymer (EVOH) on a resin film such as polyester has been used. However, since PVDC contains chlorine atoms in its structure, chlorine gas is generated during incineration after use, and there is a problem in environmental health. On the other hand, EVOH has an excellent oxygen barrier property in a dry state, but has a problem that it has no water vapor barrier property and easily dissolves in hot water.

  As another method, a vapor deposition film is also proposed in which a vapor deposition film of an inorganic oxide such as aluminum oxide or silicon oxide is provided on a film of polyester or the like by a vacuum vapor deposition method or the like. Since these inorganic oxides are transparent, they have visibility and can be used for cooking using a microwave oven. However, since the inorganic oxide layer is hard, there is a problem that cracks and pinholes are generated by bending and the gas barrier property is remarkably lowered.

  Therefore, by providing an inorganic compound layer such as silicon oxide or aluminum oxide on a resin film such as polyester and further polymer coating on it, a gas barrier layer is laminated to achieve both oxygen barrier properties and water vapor barrier properties. A barrier film is disclosed (Patent Documents 1 and 2).

Japanese Patent No. 2790054 Japanese Patent No. 5228284

  In Patent Document 1, a metal oxide layer is provided as a first layer on a resin substrate, and a gas barrier film including a water-soluble polymer and at least one of alkoxide or tin chloride is provided as a second layer. It is a gas barrier laminate film. Further, in Patent Document 2, a vapor deposition film is provided on a transparent plastic substrate film, and a coating agent containing a metal alkoxide and a polyvinyl alcohol resin and / or an ethylene / vinyl alcohol copolymer is applied to form a transparent barrier. A method for producing a conductive laminated film is disclosed. However, although all patent documents improve the barrier property by heat-treating the gas barrier film or including a coupling agent, the factors for improving the barrier property are not clearly understood and are stable and good. There was a problem in obtaining a good barrier property.

  In view of this problem, an object of the present invention is to provide a laminate having excellent barrier properties by clarifying a preferable state of the laminate.

The laminate of the present invention is a laminate having an inorganic compound layer and an organic-inorganic mixed layer in this order from the base film side on at least one surface of the base film, and the organic-inorganic mixed layer is vinyl alcohol. Of the vacancy free volume V obtained by the positron annihilation method represented by the formula (1) and the silicon amount S obtained by the fluorescent X-ray analysis, which contains a metal-based resin and a metal alkoxide represented by Si (OR) ₄ The ratio V / S is 0.01 or more and 0.1 or less.

  Further, the laminate of the present invention is a laminate having an inorganic compound layer and an organic-inorganic mixed layer in this order from the base film side on at least one surface of the base film, and the organic-inorganic mixed layer is a laser. The ratio A1 / A2 between the Raman band area A1 indicating a random network structure derived from a metal alkoxide and the Raman band area A2 indicating a linear polysiloxane obtained by Raman spectroscopy is 3.0 or more. It is 9.0 or less.

  According to the present invention, a laminate having excellent oxygen and water vapor barrier properties can be provided.

  Hereinafter, the laminate of the present invention will be described in more detail.

The laminate of the present invention is a laminate having an inorganic compound layer and an organic-inorganic mixed layer in this order from the base film side on at least one surface of the base film, and the organic-inorganic mixed layer is vinyl alcohol. Free volume V obtained by the positron annihilation method represented by the formula (1), and the silicon content S obtained by fluorescent X-ray analysis, including a resin based on metal and a metal alkoxide represented by Si (OR) ₄ The ratio V / S is 0.01 or more and 0.1 or less.

  Further, the laminate of the present invention is a laminate having an inorganic compound layer and an organic-inorganic mixed layer in this order from the base film side on at least one surface of the base film, and the organic-inorganic mixed layer is a laser. The ratio A1 / A2 between the Raman band area A1 indicating a random network structure derived from a metal alkoxide and the Raman band area A2 indicating a linear polysiloxane obtained by Raman spectroscopy is 3.0 or more. It is 9.0 or less.

[Base film]
The base film according to the present invention is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate, polyethylene-2, 6-naphthalate, polypropylene terephthalate, and polybutylene terephthalate, polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene, poly Polyolefin resins such as methylpentene, cyclic polyolefin resins, polyamide resins, polyimide resins, polyether resins, polyester amide resins, polyether ester resins, acrylic resins, polyurethane resins, polycarbonate resins, or Examples thereof include polyvinyl chloride resin. Among these, a polyester film is preferable from the viewpoint of adhesion with the inorganic oxide layer and handling. Although the base film may be unstretched or stretched (uniaxial or biaxial), it is preferably a biaxially stretched film from the viewpoint of thermal dimensional stability.

  Although there is no restriction | limiting in particular in the thickness of a base film, 1 micrometer or more and 100 micrometers or less are preferable, 5 micrometers or more and 50 micrometers or less are more preferable, and 10 micrometers or more and 30 micrometers or less are more preferable.

  The surface of the base film may be subjected to corona treatment, ozone treatment, plasma treatment, glow discharge treatment or the like as necessary in order to improve the adhesion with the inorganic oxide layer.

[Inorganic compound layer]
The inorganic compound layer according to the present invention includes an inorganic compound. Examples of the inorganic compound include aluminum, magnesium, titanium, tin, indium, silicon, and oxides thereof. These may be used alone or as a mixture of two or more. The inorganic compound layer may contain a metal such as aluminum, but more preferably contains a metal oxide or metal nitride. In the case where the inorganic compound layer contains a metal oxide or a metal nitride, the visibility of the contents is improved, and it can be incinerated after use, which is preferable. Examples of the metal oxide include aluminum oxide, magnesium oxide, titanium oxide, tin oxide, indium oxide alloy, silicon oxide, and silicon oxynitride. Examples of the metal nitride include aluminum nitride, titanium nitride, and silicon nitride. These inorganic compounds may be used alone or as a mixture of two or more. Among these, aluminum oxide is preferable from the viewpoint of processing cost and gas barrier performance.

  The method for forming the inorganic compound layer is not particularly limited, and can be formed by a known method such as a vapor deposition method, a sputtering method, an ion plating method, a plasma vapor phase growth method, etc., but a vacuum vapor deposition method is preferable from the viewpoint of productivity.

  The thickness of the inorganic compound layer is preferably 5 nm or more and 100 nm or less. When the thickness is 5 nm or less, the barrier property may be insufficient, while when the thickness is 100 nm or more, the deposited film may break.

[Organic / inorganic mixed layer]
The organic / inorganic mixed layer contains a vinyl alcohol-based resin and a metal alkoxide represented by Si (OR) ₄ . Examples of the vinyl alcohol resin include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and modified polyvinyl alcohol. These resins may be used alone or in a mixture of two or more. The vinyl alcohol resin is generally obtained by saponifying polyvinyl acetate, and may be partially saponified or partially saponified by saponifying a part of the acetate group. Higher is preferable. The degree of saponification is preferably 90% or more, more preferably 95% or more. If the saponification degree is low and a large amount of acetic acid groups having a large steric hindrance are contained, the free volume of the layer may be increased. The degree of polymerization of the vinyl alcohol resin is preferably 1,000 or more and 3,000 or less, and more preferably 1,000 or more and 2,000 or less. When the degree of polymerization is low, the polymer is difficult to be fixed and the barrier property may be lowered.

The metal alkoxide represented by Si (OR) ₄ can be fixed to the vinyl alcohol resin by mixing with the above-described vinyl alcohol resin and forming a network in the organic-inorganic mixed layer. R in the metal alkoxide is preferably a lower alkyl group, and examples thereof include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. Specific examples of the metal alkoxide include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane, which may be used alone or as a mixture of two or more.

Metal alkoxides can be hydrolyzed to form a network. The metal alkoxide is hydrolyzed in the presence of Si (OR) ₄ , water, a catalyst, and an organic solvent. The water used for hydrolysis is preferably 0.8 equivalents or more and 5 equivalents or less with respect to the alkoxy group of Si (OR) ₄ . If the amount of water is less than 0.8 equivalent, hydrolysis may not proceed sufficiently, and a network may not be formed or may not be mixed with an aqueous vinyl alcohol resin solution. When the amount of water is more than 5 equivalents, the reaction of metal alkoxide described later proceeds at random, the network structure ratio becomes too high, the free volume of the film becomes large, and the barrier property may be lowered.

  The catalyst used for hydrolysis is preferably an acid catalyst. Examples of the acid catalyst include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, tartaric acid and the like, and are not particularly limited. Usually, the hydrolysis and polycondensation reaction of the metal alkoxide can proceed regardless of whether it is an acid catalyst or a base catalyst. However, the use of an acid catalyst is preferable because the free volume of the reaction product can be reduced. When an acid catalyst is used, the monomers in the system are easily hydrolyzed on average, and are likely to have a linear or network structure. On the other hand, when a base catalyst is used, it is a reaction mechanism in which hydrolysis / polycondensation reaction of an alkoxide bonded to the same molecule easily proceeds, so that the reaction product tends to be granular with many voids.

  The laminated body concerning this invention can be used as a barrier film, and it is desirable to make a free volume small in order to obtain high barrier property. When the reaction product of the metal alkoxide has a structure with many pores, oxygen and water vapor molecules pass through many pores as pathways, so the barrier property is low. On the other hand, in the case of a polycondensate bonded in a linear or network form, the molecular chain has few pores and the molecular chains can exist at a high density. Therefore, when the reaction product of the metal alkoxide is linear or network-like, the path through which oxygen and water vapor can pass can be blocked, so that the barrier property is considered to be high. The amount of the catalyst used is preferably 0.1 mol% or more and 0.05 mol% or less with respect to the total molar amount of the metal alkoxide.

  As the organic solvent used for hydrolysis, alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol that can be mixed with water and metal alkoxide can be used.

The organic-inorganic mixed layer according to the present invention is preferable because the barrier property is high when the linear polysiloxane and the random network structure are present in an appropriate ratio. Although the analysis and ratio of the structure will be described later, the movement of the polymer chain of the resin that forms the organic-inorganic mixed layer is suppressed by a random network structure, and the expansion of oxygen and water vapor permeation paths due to environmental changes such as temperature is suppressed. It is thought that you can. One linear polysiloxane is considered to contribute to the formation of a dense structure by facilitating mixing of the random network structure and the vinyl alcohol resin. In order to mix the linear polysiloxane and the random network structure, the hydrolysis temperature is preferably 20 ° C. or higher and 45 ° C. or lower. When the reaction is carried out at less than 20 ° C., the reactivity is low, and the hydrolysis of Si (OR) ₄ does not proceed and it may be difficult to form a random network structure. On the other hand, when the reaction is carried out at a temperature exceeding 45 ° C., hydrolysis and polycondensation reactions may proceed rapidly, resulting in gelation or an increase in free volume. Moreover, as a method of mixing the linear polysiloxane and the random network structure, an oligomer in which a plurality of Si (OR) ₄ is bonded in advance can be mixed with Si (OR) ₄ and used.

  The organic / inorganic mixed 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 and the like as long as the barrier property is not impaired. Examples of the crosslinking agent include metal alkoxides such as aluminum, titanium, and zirconium, and complexes thereof.

  The organic / inorganic mixed layer can be obtained by coating and drying a coating liquid containing a vinyl alcohol resin and a metal alkoxide on the inorganic compound layer. The coating liquid containing a vinyl alcohol resin and a metal alkoxide can be obtained by mixing a solution obtained by dissolving a vinyl alcohol resin in water or a water / alcohol mixed solvent and a solution containing a metal alkoxide. Examples of the alcohol used in the solvent for the vinyl alcohol resin include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol.

The mixing ratio of the metal alkoxide to the vinyl alcohol resin is a mass ratio obtained by converting the metal alkoxide to SiO ₂ , and a range of vinyl alcohol resin / metal alkoxide = 15/85 to 85/15 is preferable, and 20/80 to 65/35. Is more preferable, and the range of 20/80 to 50/50 is more preferable. The mass ratio in terms of SiO _{2 is a value} converted to SiO ₂ mass from the number of moles of silicon atoms contained in the metal alkoxide, and is represented by vinyl alcohol resin / metal alkoxide (mass ratio). If this value exceeds 85/15, the vinyl alcohol-based resin cannot be immobilized, and the water vapor barrier property may be lowered. On the other hand, when the ratio is less than 15/85, the ratio of the metal alkoxide becomes high and the layer becomes hard, so that a crack may be generated and the barrier property may be lowered.

  The coating liquid containing vinyl alcohol resin and metal alkoxide can be applied on the inorganic compound layer by direct gravure method, reverse gravure method, micro gravure method, rod coating method, bar coating method, die coating method, spray coating. There is no particular limitation on the method and the like, and a known method can be used.

  The drying temperature of the coating film is preferably 100 ° C. or higher and 200 ° C. or lower, more preferably 120 ° C. or higher and 180 ° C. or lower, and further preferably 150 ° C. or higher and 180 ° C. or lower. When the temperature is lower than 100 ° C., water contained as a solvent does not sufficiently evaporate and the layer may not be cured.

  The metal alkoxide contained in the organic / inorganic mixed layer undergoes a polycondensation reaction by heat. When the polycondensation reaction proceeds, the alkoxy group and / or hydroxyl group contained in the metal alkoxide is reduced and the hydrophilicity is lowered, so that the interaction with water molecules can be reduced. Moreover, since the molecular weight of the metal alkoxide is increased by the polycondensation reaction, the ability to fix the vinyl alcohol resin is enhanced. Therefore, since the organic-inorganic mixed layer can improve the barrier property by advancing the reaction by heat, it is preferable that the drying temperature is higher. However, when the drying temperature exceeds 200 ° C., the base film may be shrunk by heat, or the inorganic compound layer may be distorted or cracked to deteriorate the barrier property.

  The thickness of the organic / inorganic mixed layer is preferably 200 nm or more and 600 nm or less, and more preferably 350 nm or more and 500 nm or less. When the thickness is less than 200 nm, pinholes and cracks in the inorganic compound layer cannot be sufficiently filled, and a sufficient barrier function may not be exhibited. On the other hand, if the thickness exceeds 600 nm, cracks due to the thickness may occur, or the barrier property may decrease due to insufficient curing. The thickness of the organic-inorganic mixed layer can be measured by observing the cross section with an operation electron microscope (hereinafter abbreviated as SEM).

  As described above, the organic-inorganic mixed layer undergoes a condensation reaction due to heat, and has high barrier properties. Therefore, it is also preferable to further heat-treat the laminate after forming the organic-inorganic mixed layer in order to improve the barrier property. The heat treatment temperature is preferably 30 ° C. or higher and 100 ° C. or lower, and more preferably 40 ° C. or higher and 80 ° C. or lower. The heat treatment time is preferably 1 day or more and 14 days or less, and more preferably 3 days or more and 7 days or less. When the heat treatment temperature is less than 30 ° C, the heat energy necessary for promoting the reaction may be insufficient and the effect may be small. When the heat treatment temperature exceeds 100 ° C, the base material may curl, and the cost for equipment and production may be low. May be higher.

[Analysis of laminates]
In order to improve the barrier property of the laminate, it is better not to allow a substance to be blocked, such as water vapor or oxygen, to pass through. Therefore, a smaller free volume is preferable. The free volume V of the laminate according to the present invention is measured by the positron annihilation method. The positron annihilation method is a kind of positron annihilation lifetime measurement method, which measures the time from when a positron enters a sample until it annihilates, and calculates the free volume of holes from the annihilation lifetime. The free volume V determined by the positron annihilation method is preferably 0.04 nm ³ or more and 0.13 nm ³ or less. When the free volume exceeds 0.13 nm ³ , the density of the laminate may be lowered, and the barrier property may be lowered.

  A method for reducing the free volume includes controlling the bonding state of the metal alkoxide described above. Since the metal alkoxide immobilizes the vinyl alcohol resin, it becomes a hydrolysis and polycondensation product. At that time, when an acid is used as a hydrolysis condition, that is, as a hydrolysis catalyst, a linear or network structure is formed, and the free volume is reduced. As another method, it is also effective in reducing the free volume to sufficiently advance the polycondensation reaction of the metal alkoxide to form a network structure and fix the resin. When a large amount of unreacted metal alkoxide remains, the unreacted portion has a high degree of freedom of movement and the free volume increases. In order to sufficiently advance the reaction of the metal alkoxide, it is important to give sufficient thermal energy in drying after coating or heat treatment of the laminate. Furthermore, not using a compound having a structure with a large steric hindrance is effective in reducing the free volume. For example, when the saponification degree of the vinyl alcohol resin is low, the vinyl alcohol resin contains many acetic acid groups having a large steric hindrance instead of hydroxyl groups. If an acetate group is present, the free volume may increase due to steric hindrance. Similarly, when an additive such as a silane coupling agent having an organic functional group is used, if the steric hindrance is large, the free volume is increased or the hindrance to the generation of the network structure is inhibited. May work against sex.

The organic-inorganic mixed layer according to the present invention includes a vinyl alcohol resin and a metal alkoxide represented by Si (OR) ₄ . Since vinyl alcohol resin often has low water resistance, it is designed to be fixed with a metal alkoxide represented by Si (OR) ₄ . Therefore, in order to securely fix the vinyl alcohol resin, it is necessary to contain a sufficient amount of metal alkoxide with respect to the vinyl alcohol resin. Since the metal alkoxide used for fixation in the present invention is Si (OR) ₄ , the amount of metal alkoxide can be replaced with the amount of silicon. That is, in order to fix the vinyl alcohol resin, it is necessary to contain sufficient silicon. The amount of silicon can be obtained by fluorescent X-ray analysis. In the X-ray fluorescence analysis, fluorescent X-rays specific to an element are generated by X-ray irradiation and detected. Since the generated X-ray dose is proportional to the amount of elements contained in the measurement object, the X-ray intensity S (unit: cps / μA) obtained by measurement is defined as the silicon amount S.

  The laminated body according to the present invention has a ratio V / S (hereinafter referred to as V / S) of the free volume V of vacancies determined by the positron annihilation method represented by Formula 1 and the silicon amount S determined by fluorescent X-ray analysis. May be from 0.01 to 0.1, more preferably from 0.03 to 0.08, and even more preferably from 0.04 to 0.06.

  When V / S is less than 0.01, the silicon amount S is too large, and the organic-inorganic mixed layer becomes a glass-like state in which metal alkoxide is condensed and becomes brittle, and cracks are likely to occur. . When V / S is greater than 0.1, the free volume may be large due to the structure having a large steric hindrance or the presence of unreacted metal alkoxide, which may lower the barrier property.

In order to improve the barrier property of the laminate according to the present invention, the resin polymer chain constituting the organic-inorganic mixed layer becomes difficult to move due to a change in temperature or the like, that is, the metal alkoxide forms a network structure. It is preferable to fix the organic / inorganic mixed layer. Since the metal alkoxide represented by Si (OR) ₄ can extend bonds in four directions via oxygen atoms, it can form various structures such as a straight chain, a network structure, and a ring structure. Among these structures, linear polysiloxane can be expected to increase the density when entering the voids, but its ability to fix is low, so it may move due to environmental changes such as temperature and reduce barrier properties. There is also. On the other hand, when a network structure is formed by reacting randomly, it can be expected to suppress movement due to environmental changes due to entanglement with the three-dimensional structure of the molecule and vinyl alcohol resin, but the network structure ratio is high. If it becomes too much, it may be easily separated from the vinyl alcohol-based resin, or the free volume may be reduced. As a result of intensive studies, the inventors have obtained a ratio A1 / A2 between the Raman band area A1 indicating the random network structure and the Raman band area A2 indicating the linear polysiloxane obtained by measurement by laser Raman spectroscopy. It was found that when the value is 3.0 or more and 9.0 or less, good barrier properties are exhibited.

The bonding state of the metal alkoxide represented by Si (OR) ₄ can be analyzed by laser Raman spectroscopy. A typical structure of a product derived from a metal alkoxide, a linear polysiloxane, a random network structure including a ring structure including a 5-membered ring or more and a branch, and a Raman band of a 4-membered ring structure are Observed at 400 to 500 cm ⁻¹ . Because these Raman bands superimposed, 4-membered ring structure 495Cm ^-1, linear polysiloxane 488Cm ^-1, as a band random network structure with spread 450 cm ^-1 or less because it is not a single ordered structure Observed, these can be fitted with Gaussian function approximation to separate peaks. In the laminate according to the present invention, the ratio A1 / A2 of the Raman band area A1 indicating the random network structure and the Raman band area A2 indicating the linear polysiloxane obtained by measurement by laser Raman spectroscopy is 3 It is preferably 0.0 or more and 9.0 or less, and more preferably 4.5 or more and 9.0 or less. When A1 / A2 is less than 3.0, since the random network structure ratio is low, the movement of the polymer chain of the resin constituting the organic-inorganic mixed layer cannot be suppressed, and the barrier property may be deteriorated. If it exceeds 0.0, it may be difficult to mix with the vinyl alcohol resin and separate, and sufficient barrier properties may not be obtained.

[Usage]
The laminate of the present invention can be suitably used as a gas barrier film taking advantage of high barrier properties.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples.

(1) Calculation of free volume by positron annihilation method The positron annihilation lifetime was measured under the following conditions by using a sample which was laminated on a 15 mm x 15 mm silicon wafer and vacuum degassed at 25 ° C.

Measuring device: Fuji Inback's compact positron annihilation generator PALS-200A
Positron beam source: ²² Na-based positron annihilation γ-ray detector: BaF ₂ scintillator and photomultiplier tube Beam intensity: 3 keV
Measurement temperature: 25 ° C
Measurement atmosphere: room temperature Total count: about 5,000,000 counts.

The obtained positron annihilation lifetime curve was subjected to a three-component analysis using the nonlinear least square program POSITRONFIT, and the annihilation lifetime was determined to be τ ₁ , τ ₂ , τ ₃ . From the longest average annihilation lifetime τ ₃ , a free volume radius R ₃ was calculated using the following formula, and a free volume V (unit: nm ³ ) was calculated from the radius.

τ ₃ = (1/2) [1- {R ₃ / (R ₃ +0.166)} + (1 / 2π) sin {2πR ₃ / (R ₃ +0.166)}] ⁻¹
V = (4/3) π (R ₃ ) ³ (nm ³ ).

(2) Measurement of silicon amount S by fluorescent X-ray analysis The silicon amount was determined by measuring the intensity of specific X-ray Kα of silicon using a fluorescent X-ray analyzer EDX-700 manufactured by Shimadzu Corporation. The X-ray intensity S (unit: cps / μA) obtained by the measurement was defined as the silicon amount S.

(3) Analysis of bonded state of silicon The organic-inorganic mixed layer of the laminate was separated by cutting and analyzed by Raman spectroscopy using the following conditions.
Measuring device: T-6400 manufactured by Jobin Yvon / Ehime Bussan
Measurement mode: Microscopic Raman objective lens: 100 times beam diameter: 1 μm
Light source: Ar + laser / 514.5nm
Laser power: 200mW
Diffraction grating: Single 600gr / mm
Slit: 100 μm
Detector: 1024 × 256 made by CCD / Jobin Yvon
The analysis conditions of the Raman spectrum for calculating the area A1 of the network structure and the area A2 of the linear polysiloxane are as follows. The obtained Raman spectrum was analyzed using spectrum analysis software GRAMS / Thermo Scientific. The Raman spectrum was baseline corrected by linear approximation, and then fitted in the range of 600 to 250 cm ⁻¹ . Fitting, four-membered ring structure (peak wavenumber 495cm ^-1, the half width 35 cm ^-1), the linear polysiloxane (peak wavenumber 488cm ^-1, the half width 35 cm ^-1), and separated into three components of the network structure. Since the network structure is a broad peak reflecting the continuous structure, automatic fitting was performed assuming that the three components combined with the four-membered ring structure and linear polysiloxane were separated by Gaussian function approximation. The area of the region surrounded by the obtained band and the baseline was calculated, the area of the network structure was A1, the area of the linear polysiloxane was A2, and A1 / A2 was calculated.

(4) Thickness of organic-inorganic mixed layer The thickness of the organic-inorganic mixed layer was obtained by cutting the laminated body in the thickness direction with a microtome, and observing the cross section of the laminated body with SEM. SEM used Hitachi scanning electron microscope S-3400N manufactured by Hitachi High-Technologies Corporation, and three points were imaged at a magnification of 50,000 times. With the three images obtained, the thickness of the base film of the organic-inorganic mixed layer was measured, and the average value of these was taken as the thickness of the organic-inorganic mixed layer.

(5) Oxygen permeability Oxygen permeability (hereinafter sometimes abbreviated as OTR) is an oxygen permeability measuring device (model name) manufactured by MOCON, USA under the conditions of a temperature of 23 ° C. and a humidity of 90% RH. , Oxytran (registered trademark) (OXTRAN 2/20)). The measurement was performed twice for two test pieces, and the average value of a total of four measurement values was used as the oxygen permeability value.

(6) Water vapor transmission rate The water vapor transmission rate (hereinafter sometimes abbreviated as WVTR) is a water vapor transmission rate measuring device (MOCON), USA, under the conditions of a temperature of 40 ° C. and a humidity of 90% RH ( Model name, Permatran (registered trademark) W3 / 31). The measurement was performed twice for each of the two test pieces, and the average value of a total of four measurement values was used as the value of water vapor transmission rate.

[Example 1]
<Inorganic compound layer>
A biaxially stretched polyethylene terephthalate film (P60 manufactured by Toray Industries, Inc.) having a thickness of 12 μm was used as a base film, and an aluminum oxide layer having a thickness of 15 nm was provided by a vacuum deposition method to form an inorganic compound layer.

<Vinyl alcohol resin solution>
As a vinyl alcohol-based resin, polyvinyl alcohol (hereinafter sometimes abbreviated as PVA. Polymerization degree 1,700, saponification degree 98.5%) was charged into a solvent having a mass ratio of water / isopropyl alcohol = 97/3, The mixture was heated and stirred at 90 ° C. to obtain a polyvinyl alcohol solution having a solid content of 10% by mass.

<Metal alkoxide solution>
A TEOS hydrolyzed solution is obtained by dropping 18.6 g of a 0.02N hydrochloric acid aqueous solution into a mixed solution of 11.7 g of tetraalkoxysilane (hereinafter sometimes abbreviated as TEOS) and 4.7 g of methanol while stirring. Got.

<Organic / inorganic mixed layer>
And solids content of the PVA, the mass ratio of SiO ₂ in terms solids polyvinyl alcohol solution as (SiO ₂ converted solid weight of the solid content / TEOS of PVA, the same applies hereinafter) is 35/65, the metal alkoxide solution The mixture was stirred and diluted with water to obtain a coating solution having a solid content of 12% by mass. This coating solution was applied onto the inorganic compound layer and dried at 150 ° C. to form an organic / inorganic mixed layer, thereby obtaining a laminate.

[Example 2]
A laminate was obtained in the same manner as in Example 1 except that the mass ratio of the solid content of PVA and the solid content of TEOS in terms of SiO ₂ was 50/50.

[Example 3]
A laminate was obtained in the same manner as in Example 1 except that the mass ratio of the solid content of PVA and the solid content of TEOS in terms of SiO ₂ was 65/35.

[Example 4]
A laminate was obtained in the same manner as in Example 1 except that the thickness of the organic-inorganic mixed layer was 195 nm.

[Example 5]
A laminate was obtained in the same manner as in Example 2 except that the thickness of the organic / inorganic mixed layer was changed to 610 nm.

[Example 6]
The laminated body of Example 1 was further heat-treated at 40 ° C. for 1 week to obtain a laminated body.

[Example 7]
The laminated body of Example 1 was further heat-treated at 80 ° C. for 3 days to obtain a laminated body.

[Example 8]
The laminated body of Example 1 was further heat-treated at 80 ° C. for 1 week to obtain a laminated body.

[Example 9]
A laminate was obtained in the same manner as in Example 2 except that the drying temperature at the time of coating the organic / inorganic mixed layer was 120 ° C.

[Example 10]
The laminate of Example 9 was heat treated at 80 ° C. for 1 week to obtain a laminate.

[Example 11]
A laminate was obtained in the same manner as in Example 2 except that the drying temperature at the time of coating the organic / inorganic mixed layer was 180 ° C.

[Example 12]
A laminate was obtained in the same manner as in Example 1 except that aluminum tris (ethyl acetoacetate) was added to the coating solution for the organic / inorganic mixed layer so as to be 0.02% by mass.

[Example 13]
A vinyl alcohol-based resin solution is obtained by combining PVA (polymerization degree 1,700, saponification degree 98.5%) and ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH, ethylene copolymerization ratio 29 mol%). A laminate was obtained in the same manner as in Example 1 except that the mixture was mixed at a mass ratio of 10/1.

[Example 14]
A laminate was obtained in the same manner as in Example 1 except that the metal alkoxide solution was tetramethoxysilane (hereinafter sometimes abbreviated as TMOS).

[Example 15]
An organic-inorganic mixed layer was formed in the same manner as in Example 13 except that the mass ratio of the solid content of PVA and the solid content of TEOS in terms of SiO ₂ was 20/80. Furthermore, it heat-processed at 80 degreeC for 1 week, and was set as the laminated body.

  [Example 16] An organic-inorganic mixed layer was formed in the same manner as in Example 1 except that the metal alkoxide was prepared while keeping the liquid temperature at 35 ° C. Furthermore, it heat-processed at 80 degreeC for 1 week, and was set as the laminated body.

  [Example 17] A metal alkoxide solution was prepared according to the procedure shown below, and a laminate was obtained in the same manner as in Example 1 except that the drying temperature during application of the organic-inorganic mixed layer was 180 ° C.

<Metal alkoxide solution>
A TEOS hydrolyzed solution was obtained by dropping 18.6 g of a 0.02N hydrochloric acid aqueous solution into a mixed solution of 11.7 g of TEOS and 4.7 g of methanol while stirring. On the other hand, 7.0 g of a 0.06N hydrochloric acid aqueous solution was dropped into a solution obtained by mixing 11.2 g of ethyl silicate 48 (average 10-mer) manufactured by Colcoat Co., Ltd. and 16.9 g of methanol to obtain a silicate hydrolyzed solution. It was. The TEOS hydrolyzed liquid and the silicate hydrolyzed liquid were mixed so that the mass ratio of the solid content in terms of SiO ₂ was 40/60 to obtain a metal alkoxide solution.

  [Example 18] The laminate of Example 17 was further heat-treated at 80 ° C for 1 week to obtain a laminate.

And Example 19 solid PVA content, the weight ratio of SiO ₂ in terms the solid content of the TEOS, except that was set to 20/80 to form an organic-inorganic mixed layer in the same manner as in Example 1. Furthermore, it was heat-treated at 80 ° C. for 1 week to obtain a laminate.

  [Example 20] A laminate was obtained in the same manner as in Example 19 except that the metal alkoxide solution used in Example 17 was mixed with PVA and the drying temperature was 150 ° C.

[Comparative Example 1]
Example 1 except that a metal alkoxide solution was made into a TEOS hydrolyzed solution by dropping 18.6 g of 0.02N sodium acetate aqueous solution into a mixed solution of 11.7 g of TEOS and 4.7 g of methanol while stirring. Thus, a laminate was obtained.

[Comparative Example 2]
A laminate was obtained in the same manner as in Example 2 except that the vinyl alcohol resin solution was changed to PVA (polymerization degree 1,700, saponification degree 88%).

[Comparative Example 3]
Polyacrylic acid (weight average molecular weight of about 10,000) as a crosslinking agent in the coating solution for the organic / inorganic mixed layer is 3.0 parts by mass with respect to 100 parts by mass of the total solid content of PVA and metal alkoxide. A laminate was obtained in the same manner as in Example 1 except for the addition.

[Comparative Example 4]
A laminate was obtained in the same manner as in Example 1 except that the coating liquid was prepared so that the solid content of PVA and the solid content of TEOS in terms of SiO ₂ were 10/90. Cracks occurred in the mixed layer, and barrier properties could not be obtained. In Comparative Example 4, V / S and A1 / A2 could not be measured because of cracks in the organic / inorganic mixed layer.

[Comparative Example 5]
A laminate was obtained in the same manner as in Example 1 except that the coating liquid was prepared such that the mass ratio of the solid content of PVA and the solid content of TEOS in terms of SiO ₂ was 90/10.

  [Comparative Example 6] A laminate was obtained in the same manner as in Example 1 except that 10 mol% of TEOS was replaced with the silane coupling agent 3-glycidoxypropyltrimethoxysilane.

  [Comparative Example 7] A laminate was obtained in the same manner as in Example 1 except that the metal alkoxide was prepared while keeping the liquid temperature at 10 ° C.

Claims (5)

A laminate having an inorganic compound layer and an organic-inorganic mixed layer in this order from the base film side on at least one surface of the base film, wherein the organic-inorganic mixed layer comprises a vinyl alcohol resin and Si (OR) and a metal alkoxide represented by _4, and the free volume V of the pores determined by positron annihilation method represented by the formula (1), the ratio V / S of the silicon amount S obtained in X-ray fluorescence analysis 0 A laminate having a thickness of .01 or more and 0.1 or less.

A laminate having an inorganic compound layer and an organic-inorganic mixed layer in this order from the base film side on at least one surface of the base film, and obtained by measuring the organic-inorganic mixed layer by laser Raman spectroscopy The ratio A1 / A2 between the area A1 of the Raman band showing a random network structure derived from a metal alkoxide and the area A2 of the Raman band showing a linear polysiloxane is 3.0 or more and 9.0 or less. Laminated body. The laminate according to claim 1, wherein the inorganic compound layer contains aluminum oxide. The laminate according to any one of claims 1 to 3, wherein the organic-inorganic mixed layer has a thickness of 200 nm to 600 nm. A method for producing a laminate in which an inorganic compound layer and an organic-inorganic mixed layer are laminated in this order from the base film side on at least one surface of a base film, wherein the organic-inorganic mixed layer is a vinyl alcohol resin. And a metal alkoxide represented by Si (OR) ₄ , and a heat treatment is performed at 30 ° C. or higher and 100 ° C. or lower.