JP7192781B2 - LAMINATED FILM, BARRIER LAMINATED FILM, GAS BARRIER PACKAGING MATERIAL AND GAS BARRIER PACKAGE USING THE BARRIER LAMINATED FILM - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention can be suitably used as a packaging material for retorting foods, pharmaceuticals, pet foods, etc., has excellent barrier properties against oxygen and water vapor, and improves adhesion between a plastic substrate and an aluminum oxide deposited film after retorting. The present invention relates to a laminated film having a superior barrier property, a barrier laminated film using the laminated film having retort resistance, and a packaging material.

In fields that require retort processing, such as food and pharmaceuticals, high barrier properties that are not affected by temperature, humidity, etc. There is a demand for a barrier laminated film that can exert its function as a barrier film, and a barrier laminated film having a multi-layer structure in which a barrier layer consisting of a thin film of a deposited film of silicon oxide, aluminum oxide, etc. and a barrier coating layer are laminated has also been developed.

However, the plastic base material of the laminated film, which has a vapor-deposited film with excellent barrier properties, is easily affected by temperature, humidity, etc., and is susceptible to dimensional changes. , it is difficult to follow the deposited film such as silicon oxide deposited film or aluminum oxide deposited film provided thereon.
As a result, delamination often occurs between the plastic base material and the deposited film such as silicon oxide deposited film or aluminum oxide deposited film under a severe environment of high temperature and high humidity, and cracks, pinholes, etc. also occur. Occur.
As a result, there is a problem that the original barrier performance is significantly impaired and it is extremely difficult to maintain the barrier performance.

In the case of forming a vapor-deposited film of an inorganic oxide such as aluminum oxide on a plastic substrate by the above vapor-deposited film method, in order to obtain high adhesion between the plastic substrate and the formed vapor-deposited film, Methods for modifying the surface of plastic substrates, such as in-line plasma pretreatment using a parallel plate apparatus and formation of an undercoat treatment layer, have been implemented (see, for example, Patent Documents 1 and 2).

However, the in-line plasma treatment method of Patent Document 1, which uses a generally used parallel plate type apparatus, introduces functional groups such as hydroxyl groups and carbonyl groups into the plastic surface, and the functional groups intervene between the deposited films. It expresses adhesion. However, in the high temperature and high humidity environment required for electronic devices such as electronic paper and retort packaging materials, adhesiveness is significantly reduced because hydrogen bonds are destroyed. There is a problem of declining.
In addition, since the film is simply passed through a plasma atmosphere generated in the air in the above-mentioned plasma treatment, sufficient adhesion cannot be obtained between the base material and the deposited film under a severe environment of high temperature and high humidity. is the actual situation.

In addition, the undercoat treatment method described in Patent Document 2 provides an undercoat layer as an adhesive layer on the surface of a plastic film, and is generally practiced.

Therefore, a technology has been implemented to improve adhesion by pre-treating the surface of a plastic substrate using a reactive ion etching (RIE) method in which plasma is generated with the electrode for plasma generation on the substrate side. (Patent Document 3).
The plasma RIE method simultaneously obtains two effects: a chemical effect such as imparting functional groups to the surface of the base material, and a physical effect such as ion-etching the surface to remove impurities and smooth the surface. It expresses adhesiveness.

In the RIE method, unlike the above-mentioned in-line plasma treatment, adhesion is not developed by hydrogen bonding, so no decrease in adhesion is observed under a high-temperature and high-humidity environment.
However, since the RIE method provides functional groups on the plastic base material, the water resistance and hot water resistance that cause hydrolysis at the interface are still insufficient. Also, in order to obtain sufficient adhesion by the RIE method, an Ed value (=plasma density×processing time) of a certain value or more is required.
In order to obtain an Ed value above a certain value in this method, a method of increasing the plasma density and a method of increasing the processing time are conceivable. There is a problem that the damage to the base material becomes large, and when the treatment time is lengthened, there is a problem of a decrease in productivity (see Patent Documents 4 and 5).

Therefore, the above-mentioned problem in forming an inorganic oxide vapor deposition film on the surface of the transported plastic substrate is solved, and the adhesiveness between the plastic substrate and the vapor deposition film is good even after retort treatment. , a laminated film with excellent barrier properties is desired.

In particular, in fields that require high-temperature and high-pressure retort processing and sterilization of foods and pharmaceuticals, etc., it is necessary to prevent deterioration of the content and maintain its functions and properties without being affected by temperature, humidity, etc. , There is a demand for a barrier laminated film that can stably exhibit higher barrier properties, and has a multi-layer structure in which a barrier layer made of a thin film of aluminum oxide such as silicon oxide or aluminum oxide and a barrier coating layer are laminated. A barrier laminate film with excellent retort resistance is desired.

JP-A-7-233463 JP-A-2000-43182 JP 2005-335109 A Japanese Patent No. 4461737 Japanese Patent No. 4135496

A problem of the prior art is that the retort treatment by hot water treatment gives a large mechanical and chemical stress to the interface between the plastic substrate and the evaporated aluminum oxide film. This stress degrades the barrier properties. This area is stressed because it is the most vulnerable part of the stack. Therefore, in order to obtain retort resistance, it is important to firmly cover the interface with the base material with a deposited film.
On the other hand, due to its chemical structure, aluminum hydroxide has good adhesion to plastic substrates, and since it itself forms a dense network, it has high water vapor barrier properties. However, the bonding structure based on hydrogen bonding between aluminum hydroxide and the substrate tends to collapse microscopically in a strong environment such as retort treatment. Also, the aluminum hydroxide network easily permeates into the film due to the affinity between the water molecules and the grain boundaries of the aluminum hydroxide.

The present invention has been made in view of the above-mentioned problems and findings, and its object is to improve the adhesion between a plastic substrate and an aluminum oxide deposited film even after hot water treatment, In addition, a laminated film having a vapor-deposited film with excellent barrier properties, a barrier laminated film including the laminated film and provided with a vapor-deposited aluminum oxide film having excellent so-called retort resistance, and the barrier laminated film are used to improve adhesion and An object of the present invention is to provide a gas-barrier packaging material and a gas-barrier package having excellent barrier properties and retort resistance.

In order to achieve these objects, the laminated film of the present invention is a laminated film having a barrier property in which an aluminum oxide deposited film containing aluminum oxide as a main component is formed on the surface of a plastic substrate, and is formed on the surface of the substrate film. A transition region is formed in the vapor deposition film that defines the adhesion strength with the vapor deposition film mainly composed of aluminum oxide vapor deposition film, and the transition region is measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Using TOF-SIMS for an aluminum oxide deposited film defined by etching using TOF-SIMS, containing elemental bonds Al ₂ O ₄ H metamorphosed to aluminum hydroxide detected by etching with The transformation ratio of the transition region defined by the ratio of the transition region to be transformed defined by the above shall be 45% or less.

Secondary Ion Mass Spectrometry (SIMS) is a method of analyzing elemental concentration distribution in which the surface of a sample to be analyzed is irradiated with a primary ion beam and the secondary ions sputtered and emitted from the surface of the sample are analyzed by mass analysis. is. In this secondary ion mass spectrometry, secondary ion intensity is detected while sputtering is progressing. Therefore, by converting the transition time into the depth for the data of the time transition of the ion intensity of the secondary ions, that is, the ions of the element to be detected or the molecular ions bound to the element to be detected, the depth direction of the sample surface can be obtained. It is possible to know the concentration distribution of the element to be detected.

In the present invention, conversion of transition time to depth is performed by measuring the depth of depressions formed on the sample surface by irradiation with primary ions using a surface roughness meter, and averaging the depth of the depressions and the transition time. The sputtering speed is calculated, and under the assumption that the sputtering speed is constant, the irradiation time (that is, transition time) is converted into the depth (sputter amount).

In the present invention, while repeating soft etching at a constant rate as described above with a Cs (cesium) ion gun, the aluminum oxide deposited film of the laminated film is subjected to time-of-flight secondary ion mass spectrometry (TOF-SIMS). A transition that defines the adhesion strength between the substrate film surface and the deposited film mainly composed of the formed aluminum oxide deposited film by measuring the ions derived from the deposited aluminum oxide film and the ions derived from the plastic substrate. A region is formed. The transition region contains elementally bound Al ₂ O ₄ H that transforms into aluminum hydroxide detected by etching using time-of-flight secondary ion mass spectrometry (TOF-SIMS), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The ratio of the transformed transition region defined using time-of-flight secondary ion mass spectrometry to the deposited aluminum oxide film defined by etching using time-of-flight mass spectrometry (TOF-SIMS) It is based on the knowledge that a laminate film having barrier properties with improved adhesion strength can be specified by defining the transformation rate of the transition region that transforms into aluminum hydroxide defined by the following.

Specifically, the present invention uses a time-of-flight secondary ion mass spectrometer to etch from the outermost surface of an aluminum oxide vapor-deposited film with Cs. and measured the element bonding of the deposited film, and obtained actual measurement graphs for the measured elements and element bonding (Fig. 3 graph analysis chart), and the plastic substrate and deposited film formed by aluminum hydroxide in the aluminum oxide deposited film. _In order to narrow the transition region of the interface of , 1) the position where the intensity of the graph of element C6 becomes _half is set as the interface between the plastic substrate and aluminum oxide, and from the surface 2) A peak in a graph representing elemental bonding Al ₂ O ₄ H is obtained, and a transition region from the peak to the interface is obtained, 3) (elemental bonding Al ₂ O ₄ H The transformation rate of the transition region to aluminum hydroxide is obtained by (transition region from the peak to the interface/aluminum oxide deposition film)×100 (%).

According to the present invention, a barrier coating layer is further formed on the laminated film by setting the transition rate of the transition region of the vapor deposited aluminum oxide film to 45% or less, and the plastic substrate and the vapor deposited aluminum oxide film of the barrier laminated film are combined. The adhesion strength at the interface should be 2.1 N/15 mm or more even after hot water treatment at 135°C for 40 minutes (high retort treatment) or after hot water treatment at 121°C for 40 minutes (semi-retort treatment). Thus, it is possible to produce a barrier laminate film that does not cause delamination during molding or retort processing of retort pouches, has improved adhesion, and has retort resistance.

In the present invention, by setting the transformation ratio of the transition region of the vapor-deposited aluminum oxide film to 45% or less, the oxygen permeability and water vapor permeability after high retort treatment and semi-retort treatment are respectively 0.2 cc/m ² ·24 hr. Below, at 0.9 g/m ² ·24 hr or less, to produce a barrier laminated film exhibiting sufficient barrier properties to the extent that quality deterioration of contents after retort processing and deterioration of storage life do not occur. can be done.
Therefore, the deposited aluminum oxide film of the present invention not only can improve the adhesion at the interface with the plastic substrate, but also has excellent barrier properties such as resistance to moist heat and hot water after retort treatment, and can improve retort resistance. is.

The present invention is characterized by the following points.
1. In a laminate film having barrier properties, in which an aluminum oxide vapor deposition film containing aluminum oxide as a main component is formed on the surface of a plastic base material, the adhesive strength between the substrate film surface and the formed vapor deposition film mainly composed of aluminum oxide vapor deposition film is improved. A defined transition region of the deposited film is formed, the transition region transforming into aluminum hydroxide detected by etching using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Defined by the ratio of the transformed transition region defined using TOF-SIMS to the evaporated aluminum oxide film containing elementally bound Al ₂ O ₄ H and defined by etching using TOF-SIMS The above laminated film, wherein the transition region has a metamorphic rate of 45% or less.
2. 2. The laminated film as described in 1 above, wherein the plastic substrate is a polyethylene terephthalate film.
3. 2. The laminated film of claim 1, wherein the plastic substrate comprises recycled polyethylene terephthalate film.
4. 2. The laminated film as described in 1 above, wherein the plastic substrate is a polybutylene terephthalate film.
5. 2. The laminated film according to 1 above, wherein the plastic substrate is a biomass-derived polyester film.
6. 2. The laminated film as described in 1 above, wherein the plastic substrate is a high-stiffness polyester film.
7. 7. The laminated film as described in any one of 1 to 6 above, wherein the surface of the plastic substrate is an oxygen plasma-treated surface.
8. 8. The laminated film as described in 7 above, wherein an aluminum oxide vapor-deposited film is laminated in-line on the oxygen plasma-treated surface.
9. A barrier laminate film comprising a barrier coating layer laminated on the surface of the aluminum oxide deposited film of the laminate film according to any one of 1 to 8 above.
10. 10. The barrier laminate film as described in 9 above, wherein the barrier coating layer is a layer obtained by applying a mixed solution of a metal alkoxide and a water-soluble polymer, followed by heating and drying.
11. 10. The barrier laminate film as described in 9 above, wherein the barrier coating layer is a layer formed by applying a mixed solution of a metal alkoxide, a silane coupling agent and a water-soluble polymer, followed by heating and drying.
12. 12. A gas-barrier packaging material obtained by laminating a heat-sealable thermoplastic resin on the barrier laminated film according to any one of 9 to 11 above.
13. 13. The gas barrier packaging material according to 12 above, which is used for packaging for retort sterilization.
14. 14. A gas barrier package produced from the gas barrier packaging material according to 12 or 13 above.

In the present invention, in order to narrow the transition region of the interface with the plastic substrate where aluminum hydroxide is formed in the aluminum oxide deposition film as much as possible, and to optimize the rate of modification to aluminum hydroxide, elemental bonding Al ₂ O ₄ is used. Focusing on H, by setting the transformation rate of the transition region of the vapor-deposited aluminum oxide film in the laminated film to 45% or less and increasing the ratio of the aluminum oxide film, which has relatively little aluminum hydroxide, the minute particles caused by water molecules during retort treatment It greatly suppresses the visual destruction of the deposited film and the destruction of the interface with the plastic substrate. As a result, it is possible to provide a laminated film having improved adhesion and unprecedented retort resistance, and a barrier laminated film containing such a layer film.
In the barrier laminated film of the present invention, the adhesion strength at the interface between the plastic substrate and the vapor deposited aluminum oxide film is 2.1 N/15 mm or more even after high retort treatment and semi-retort treatment, and high retort treatment, It has barrier properties of oxygen permeability and water vapor permeability after semi-retorting of 0.2 cc/m ² ·24 hr or less and 0.9 g/m ² ·24 hr or less, respectively, and is excellent in retort resistance.

Cross-sectional view showing an example of laminated film A (FIG. 1a) of the present invention, barrier laminated film B (FIG. 1b) laminated with a barrier coating layer, and another laminated film A (FIG. 1c). A diagram showing an example of an apparatus for forming an aluminum oxide vapor deposition film of the present invention. An example of a graph analysis diagram of the analysis result of the aluminum oxide deposited film laminated film of the present invention by time-of-flight secondary ion mass spectrometry.

BEST MODE FOR CARRYING OUT THE INVENTION A laminate film having an aluminum oxide deposited film with barrier properties and improved adhesion and a barrier laminate film including the laminate film according to embodiments of the present invention will be described below with reference to the drawings. It should be noted that this example is merely an example, and does not limit the present invention in any way.
FIG. 1a is a cross-sectional view showing an example of a laminated film of the present invention, and FIG. 1b is a cross-sectional view showing an example of a barrier laminated film containing the laminated film and having a barrier coating layer laminated on the surface, FIG. 1c is a cross-sectional view showing an example of a laminate film in which the substrate layer is composed of multiple layers, and FIG. It is a figure which shows typically the structure of a type|mold continuous vapor deposition film-forming apparatus. In order to form a barrier laminate film in which a barrier coating layer is laminated, a barrier coating agent coating device is arranged continuously with a vapor deposition film forming device, but a known roller coating device is installed continuously. Yes, and are omitted here.

As shown in FIG. 1a, a laminated film A having a barrier property with improved adhesion is provided on one surface of a plastic substrate 1 with a barrier property with improved adhesion. In the present invention, as shown in FIG. 1b, a barrier coating layer 3 is further provided on the vapor deposition film 2 of the laminated film A as shown in FIG. A barrier laminate film B having a laminated structure in which the films are laminated and having excellent adhesion and barrier properties and excellent retort resistance is obtained.

The plastic substrate is not particularly limited, and known plastic films or sheets can be used. For example, polyethylene terephthalate, biomass-derived polyester, polybutylene terephthalate, polyethylene naphthalate, recycled polyethylene terephthalate, polyester resins such as polyethylene furanoate, polyamide resin 6, polyamide resin 66, polyamide resin 610, polyamide resin 612, polyamide resin 11 , polyamide resins such as polyamide resin 12, polyolefin resins such as α-olefin polymers such as polyethylene and polypropylene, and the like. A polyester resin known as a polyethylene terephthalate film is particularly preferably used.

(Polybutylene terephthalate film (PBT))
Polybutylene terephthalate film has a high heat distortion temperature, excellent mechanical strength and electrical properties, and good molding processability. It is possible to suppress the deformation of the packaging bag and the reduction in its strength.

Polybutylene terephthalate film has high strength. Therefore, by using a polybutylene terephthalate film, the packaging bag can be made puncture-resistant, as in the case where the packaging material constituting the packaging bag includes a nylon film.
Polybutylene terephthalate film hydrolyzes in a high-temperature, high-humidity environment, and thus exhibits a decrease in adhesion strength and barrier properties after retort treatment, but it has the property of absorbing less moisture than nylon. Therefore, even when the polybutylene terephthalate film is arranged on the outer surface of the packaging material, it is possible to prevent the laminate strength between the packaging materials of the packaging bag from deteriorating. Due to such properties, when polybutylene terephthalate film is used for retort packaging bags, it is preferably used because it can replace the conventional laminated packaging material of polyethylene terephthalate film and nylon film.

A polybutylene terephthalate film is a film containing polybutylene terephthalate (hereinafter also referred to as PBT) as a main component, preferably a resin film containing 60% by mass or more of PBT. The polybutylene terephthalate film is divided into two types according to its structure.

The content of PBT in the polybutylene terephthalate film according to the first aspect is preferably 60% by mass or more, more preferably 70% by mass or more, particularly preferably 75% by mass or more, and most preferably 80% by mass or more. .
PBT used as a main component preferably contains 90 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, and most preferably 100% terephthalic acid as a dicarboxylic acid component. in mol %. As a glycol component, 1,4-butanediol is preferably 90 mol % or more, more preferably 95 mol % or more, still more preferably 97 mol % or more.

The polybutylene terephthalate film may contain polyester resins other than PBT. Polyester resins other than PBT include polyester resins such as PET, polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and polypropylene terephthalate (PPT), as well as isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and biphenyldicarboxylic acid. , PBT resins copolymerized with dicarboxylic acids such as cyclohexanedicarboxylic acid, adipic acid, azelaic acid, and sebacic acid, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, neopentyl glycol, 1,5 Examples include PBT resins obtained by copolymerizing diol components such as -pentanediol, 1,6-hexanediol, diethylene glycol, cyclohexanediol, polyethylene glycol, polytetramethylene glycol, and polycarbonate diol.

The addition amount of these polyester resins other than PBT is preferably 40% by mass or less. If the amount of the polyester resin other than PBT added exceeds 40% by mass, the mechanical properties of PBT may be impaired, and impact strength, pinhole resistance, and drawability may become insufficient.

The layer structure of the polybutylene terephthalate film according to the first aspect is produced by casting a multi-layered resin by a casting method, and consists of a multi-layered structure section including a plurality of unit layers. Each of the plurality of unit layers contains PBT as a main component. For example, each of the unit layers contains 60% by mass or more of PBT. In addition, in the plurality of unit layers, the (n+1)th unit layer is directly laminated on the nth unit layer. That is, no adhesive layer or adhesion layer is interposed between the plurality of unit layers. Such a polybutylene terephthalate film is composed of a multilayer structure containing at least 10 or more, preferably 60 or more, more preferably 250 or more, and still more preferably 1000 or more unit layers.

The polybutylene terephthalate film according to the second aspect is composed of a single layer containing polyester having PBT as a main repeating unit. A polyester having PBT as a main repeating unit includes, for example, 1,4-butanediol as a glycol component or an ester-forming derivative thereof, and terephthalic acid as a dibasic acid component or an ester-forming derivative thereof as a main component. , including homo- or copolymer-type polyesters obtained by condensing them. The PBT content of the second configuration is preferably 70% by mass or more, more preferably 80% by mass or more, and most preferably 90% by mass or more.

The polybutylene terephthalate film according to the second aspect may contain a polyester resin other than PBT in an amount of 30% by mass or less. By containing the polyester resin, PBT crystallization can be suppressed, and the stretchability of the polybutylene terephthalate film can be improved. Polyester having ethylene terephthalate as a main repeating unit can be used as the polyester resin to be blended with PBT. For example, a homotype containing ethylene glycol as a glycol component and terephthalic acid as a dibasic acid component as main components can be preferably used.

A polybutylene terephthalate film according to the second configuration can be produced by a tubular method or a tenter method. An unstretched raw sheet may be stretched simultaneously in the machine direction and the transverse direction, or may be stretched successively in the machine direction and the transverse direction by a tubular method or a tenter method. Among these methods, the tubular method is particularly preferably employed because it is possible to obtain a stretched film having a good balance of physical properties in the circumferential direction.

(polyester film derived from biomass)
The biomass-derived polyester film is composed of a resin composition containing a polyester composed of a diol unit and a dicarboxylic acid unit as a main component, and the resin composition is such that the diol unit is biomass-derived ethylene glycol and the dicarboxylic acid unit. is a fossil fuel-derived dicarboxylic acid in an amount of 50 to 95% by mass, preferably 50 to 90% by mass, based on the total resin composition.

Biomass-derived ethylene glycol has the same chemical structure as conventional fossil fuel-derived ethylene glycol. There is no inferiority in terms of physical properties such as Therefore, since the laminated film of the present invention and the barrier laminated film using the same have a layer made of a carbon-neutral material, the laminated film produced from the raw material obtained from conventional fossil fuels and the barrier laminated film using the same have barrier properties. Compared to laminated films, the amount of fossil fuels used can be greatly reduced, and the environmental load can be reduced.

Biomass-derived ethylene glycol is produced from biomass such as sugar cane and corn (biomass ethanol) as a raw material. For example, biomass-derived ethylene glycol can be obtained by a method in which biomass ethanol is converted into ethylene glycol via ethylene oxide by a conventionally known method. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be preferably used.

The dicarboxylic acid units of the polyester use dicarboxylic acids derived from fossil fuels. As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. Examples of derivatives of aromatic dicarboxylic acids include lower alkyl esters of aromatic dicarboxylic acids, specifically methyl esters, ethyl esters, propyl esters and butyl esters. Ester etc. are mentioned. Among these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as the aromatic dicarboxylic acid derivative.

The polyester that may be contained at a rate of 5 to 45% by mass in the resin composition that forms the biomass-derived polyester film is a fossil fuel-derived polyester, a recycled polyester of a fossil fuel-derived polyester product, or a biomass-derived polyester product. of recycled polyester.

The resin composition containing the polyester obtained as described above preferably contains 10 to 19% of biomass-derived carbon based on radiocarbon ( ¹⁴ C) measurement with respect to the total carbon in the polyester. Since carbon dioxide in the atmosphere contains ¹⁴ C at a certain rate (105.5 pMC), the ¹⁴ C content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. is known to be It is also known that fossil fuels contain almost no ¹⁴ C. Therefore, the ratio of biomass-derived carbon can be calculated by measuring the ratio of ¹⁴ C contained in the total carbon atoms in the polyester.

In the present invention, the biomass-derived carbon content Pbio is defined as follows, where P ¹⁴ C is the content of ¹⁴ C in the polyester.
Pbio (%) = ^P14C /105.5 x 100
Taking polyethylene terephthalate as an example, polyethylene terephthalate is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms at a molar ratio of 1:1, so only ethylene glycol derived from biomass is used. is used, the biomass-derived carbon content Pbio in the polyester is 20%. In the present invention, the content of biomass-derived carbon measured by radioactive carbon ( ¹⁴ C) is preferably 10 to 19% of the total carbon in the resin composition. If the biomass-derived carbon content in the resin composition is less than 10%, the effect as a carbon offset material is poor. On the other hand, as described above, the biomass-derived carbon content in the resin composition is preferably as close to 20% as possible. Since it is preferable to include additives, the practical upper limit is 18%.

(recycled polyethylene terephthalate)
As the resin base material of the present invention, one containing polyethylene terephthalate recycled by mechanical recycling (hereinafter, polyethylene terephthalate is also referred to as PET) can be used.
Specifically, the resin base material contains PET obtained by mechanically recycling PET bottles, and this PET contains ethylene glycol as a diol component and terephthalic acid and isophthalic acid as a dicarboxylic acid component.

Here, mechanical recycling generally refers to the process of pulverizing collected PET bottles and other polyethylene terephthalate resin products, washing with alkali to remove dirt and foreign matter from the surface of the PET resin products, and then drying for a certain period of time under high temperature and reduced pressure. In this method, the contaminants remaining inside the PET resin are diffused and decontaminated, the dirt on the resin product made of the PET resin is removed, and the resin product is returned to the PET resin.

Hereinafter, in this specification, polyethylene terephthalate obtained by recycling PET bottles is referred to as "recycled polyethylene terephthalate (hereinafter also referred to as recycled PET)", and polyethylene terephthalate that is not recycled is referred to as "virgin polyethylene terephthalate (hereinafter also referred to as virgin PET). )”.

Among the PET contained in the resin base material, the content of the isophthalic acid component is preferably 0.5 mol % or more and 5 mol % or less, and 1.0 mol %, of the total dicarboxylic acid components constituting the PET. It is more preferable that the content is at least 2.5 mol % or less.
If the content of the isophthalic acid component is less than 0.5 mol %, the flexibility may not be improved.

PET may be biomass PET in addition to PET derived from ordinary fossil fuels. “Biomass PET” contains biomass-derived ethylene glycol as a diol component and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid component. This biomass PET may be formed only of PET having biomass-derived ethylene glycol as a diol component and fossil fuel-derived dicarboxylic acid as a dicarboxylic acid component, or may be formed from biomass-derived ethylene glycol and fossil fuel-derived diol. It may be formed of PET having a diol component and a fossil fuel-derived dicarboxylic acid as a dicarboxylic acid component.

PET used for PET bottles can be obtained by a conventionally known method of polycondensing the above diol component and dicarboxylic acid component.

Specifically, a general method of melt polymerization such as performing an esterification reaction and/or a transesterification reaction between the diol component and the dicarboxylic acid component and then performing a polycondensation reaction under reduced pressure, or an organic solvent can be produced by a known solution heating dehydration condensation method using

The amount of the diol component used in the production of the above PET is substantially equimolar to 100 mol of the dicarboxylic acid or its derivative, but in general, esterification and/or transesterification and/or polycondensation Since there is distillation during the reaction, it is used in excess of 0.1 mol % or more and 20 mol % or less.
Moreover, the polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added at the time of charging the raw materials or at the start of depressurization.

After the PET from recycled PET bottles is polymerized and solidified as described above, solid state polymerization is performed as necessary to further increase the degree of polymerization and remove oligomers such as cyclic trimers. you can go
Specifically, in the solid state polymerization, PET is chipped and dried, and then heated at a temperature of 100° C. or higher and 180° C. or lower for about 1 to 8 hours to pre-crystallize the PET, followed by 190° C. It is carried out by heating at a temperature of 230° C. or less in an inert gas atmosphere or under reduced pressure for 1 hour to several tens of hours.

The intrinsic viscosity of PET contained in recycled PET is preferably 0.58 dl/g or more and 0.80 dl/g or less. If the intrinsic viscosity is less than 0.58 dl/g, the mechanical properties required for the PET film as the resin base material may be insufficient. On the other hand, when the intrinsic viscosity exceeds 0.80 dl/g, the productivity in the film forming process may be impaired. In addition, the intrinsic viscosity is measured at 35° C. with an orthochlorophenol solution.

Recycled PET preferably contains recycled PET at a ratio of 50% by weight or more and 95% by weight or less, and may contain virgin PET in addition to recycled PET.
The virgin PET may be PET containing ethylene glycol as the diol component and terephthalic acid and isophthalic acid as the dicarboxylic acid component, or PET containing no isophthalic acid as the dicarboxylic acid component. good too. Moreover, the resin base material layer may contain polyester other than PET. For example, the dicarboxylic acid component may include aliphatic dicarboxylic acid and the like in addition to aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid.

Specific examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid, which usually have 2 to 40 carbon atoms. cyclic or alicyclic dicarboxylic acids. Derivatives of aliphatic dicarboxylic acids include lower alkyl esters such as methyl esters, ethyl esters, propyl esters and butyl esters of the above aliphatic dicarboxylic acids, and cyclic acid anhydrides of the above aliphatic dicarboxylic acids such as succinic anhydride. . Among these, as the aliphatic dicarboxylic acid, adipic acid, succinic acid, dimer acid, or a mixture thereof is preferable, and those containing succinic acid as a main component are particularly preferable. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

A resin base material composed of such PET may be a single layer or a multilayer.
As shown in FIG. 1c, when recycled PET as described above is used for the resin base material, the resin base material may have three layers of a first layer 1a, a second layer 1b, and a third layer 1c.
In this case, the second layer 1b is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 1a and the third layer 1c are composed only of virgin PET. is preferred.

Thus, by using only virgin PET for the first layer 1a and the third layer 1c, it is possible to prevent the recycled PET from coming out from the front surface or the back surface of the resin base material layer. Therefore, the sanitation of the laminate can be ensured.
Alternatively, the resin base layer may be a resin base layer having two layers, the second layer 1b and the third layer 1c, without providing the first layer 1a shown in FIG. 1c. Furthermore, the resin base layer may be a resin base layer having two layers, the first layer 1a and the second layer 1b, without providing the third layer 1c shown in FIG. 1c. Also in these cases, the second layer 1b is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the first layer 1a and the third layer 1c are layers composed only of virgin PET. It is preferable to

When recycled PET and virgin PET are mixed and molded into one layer, there are a method of feeding them separately to a molding machine, a method of feeding them after mixing by dry blending, and the like. Among them, the method of mixing by dry blending is preferable from the viewpoint of simple operation.

PET constituting the resin base material can contain various additives in the production process or after the production, as long as the properties are not impaired. Additives such as plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, release agents, antioxidants, ions exchange agents, color pigments, and the like. The additive is contained in the total resin composition containing PET in an amount of 5% by mass or more and 50% by mass or less, preferably 5% by mass or more and 20% by mass or less.

The resin substrate can be formed by forming a film from the PET described above, for example, by a T-die method. Specifically, after drying the above PET, it is supplied to a melt extruder heated to a temperature (Tm) above the melting point of PET to Tm + 70 ° C. to melt the resin composition, for example, a T die A film can be formed by extruding a sheet from a die such as the above, and rapidly cooling and solidifying the extruded sheet with a rotating cooling drum or the like. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

The film obtained as described above is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to obtain a longitudinally stretched film. This stretching is preferably carried out using a difference in circumferential speed between two or more rolls. Longitudinal stretching is usually performed in a temperature range of 50°C or higher and 100°C or lower. Further, the longitudinal stretching ratio is preferably 2.5 times or more and 4.2 times or less, although it depends on the properties required for the film application. If the draw ratio is less than 2.5 times, the thickness unevenness of the PET film becomes large, making it difficult to obtain a good film.

The longitudinally stretched film is then successively subjected to transverse stretching, heat setting, and heat relaxation steps to obtain a biaxially stretched film. Lateral stretching is usually performed in a temperature range of 50°C or higher and 100°C or lower. The lateral stretching ratio is preferably 2.5 times or more and 5.0 times or less, although it depends on the properties required for the application. If it is less than 2.5 times, the thickness of the film becomes uneven, making it difficult to obtain a good film.

After the transverse stretching, heat setting treatment is carried out, and the preferable temperature range for heat setting is Tg+70 to Tm−10° C. of PET. Moreover, the heat setting time is preferably 1 second or more and 60 seconds or less. Furthermore, for applications that require a reduction in heat shrinkage, heat relaxation treatment may be performed as necessary.

The thickness of the PET film obtained as described above is arbitrary according to its use, but is usually about 5 μm to 100 μm, preferably 5 μm to 25 μm. The breaking strength of the PET film is 5 kg/mm ² or more and 40 kg/mm ^{2 or less in the MD direction, and 5 kg/mm 2 or more and 35 kg/mm 2 or less} in the TD direction. % or more and 350% or less, and 50% or more and 300% or less in the TD direction. Moreover, the shrinkage rate when left in a temperature environment of 150° C. for 30 minutes is 0.1% or more and 5% or less.

Virgin PET may be fossil fuel polyethylene terephthalate (hereinafter also referred to as fossil fuel PET) or biomass PET. Here, the term "fossil fuel PET" means that a fossil fuel-derived diol is used as a diol component, and a fossil fuel-derived dicarboxylic acid is used as a dicarboxylic acid component. Recycled PET may be obtained by recycling PET resin products formed using fossil fuel PET, or obtained by recycling PET resin products formed using biomass PET. There may be.

(high stiffness polyester film)
A high-stiffness polyester film is an oriented plastic film having a loop stiffness of 0.0017 N/15 mm or more in the machine direction (MD) and the vertical direction (TD) and containing 51% by weight or more of polyester.
Loop stiffness is a parameter representing the stiffness of a film. A method for measuring the loop stiffness of a film will be described below.

First, the film is cut into strips having long sides and short sides to prepare test pieces. Subsequently, the strip test piece is bent so that the long strip draws a loop to form a circular loop with a predetermined diameter, and the short sides at both ends of the strip in the long side direction are fixed. The circular loop is then pushed in from the outside for a given distance. Then, the load required for pushing is recorded as the loop stiffness.

In this embodiment, the length of the short side of the strip is set to 15 mm, and the length of the long side is set to 150 mm. Also, the diameter of the circular loop was set to 60 mm, and the pushing distance of the circular loop was set to 40 mm. The loop stiffness of "0.0017 N/15 mm" means that a load of 0.0017 N is required to push a circular loop of a strip test piece with a short side length of 15 mm into 40 mm.

When measuring the loop stiffness in the machine direction, a test piece is prepared so that the machine direction of the film coincides with the long side direction of the strip. When measuring the loop stiffness in the vertical direction, the test piece is prepared so that the vertical direction of the film coincides with the long side direction of the strip. As a loop stiffness measuring device, for example, LOOP STIFFNESS TESTER manufactured by Toyo Seiki Co., Ltd. can be used.

Preferred mechanical properties of the high stiffness polyester film are further described.
The puncture strength of the high-stiffness polyester film is preferably 9.5N or more, more preferably 10.0N or more.

The tensile strength of the high stiffness polyester film in the machine direction is preferably 250 MPa or higher, more preferably 280 MPa or higher. The tensile strength of the high stiffness polyester film in the vertical direction is preferably 250 MPa or more, more preferably 280 MPa or more.

The tensile elongation of the high stiffness polyester film in the machine direction is preferably 130% or less, more preferably 120% or less. The tensile elongation of the high stiffness polyester film in the vertical direction is preferably 120% or less, more preferably 110% or less.

Furthermore, in at least one direction, the value obtained by dividing the tensile strength of the high-stiffness polyester film by the tensile elongation is preferably 2.0 MPa/% or more.
For example, the value obtained by dividing the tensile strength of the high stiffness film in the vertical direction (TD) by the tensile elongation is preferably 2.0 MPa/% or more, more preferably 2.2 MPa/% or more. The value obtained by dividing the tensile strength of the high stiffness film in the machine direction (MD) by the tensile elongation is preferably 1.8 MPa/% or more, more preferably 2.0 MPa/% or more.

Tensile strength and tensile elongation can be measured according to JIS K7127. As a measuring instrument, a tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used. A rectangular film having a width of 15 mm and a length of 150 mm cut out from the film can be used as the test piece. The distance between the pair of chucks holding the specimen at the start of the measurement is 100 mm, and the pulling speed is 300 mm/min. The environmental temperature during the test is 25°C.

The heat shrinkage of the high-stiffness polyester film in the machine direction is preferably 0.7% or less, more preferably 0.5% or less. The heat shrinkage of the high-stiffness polyester film in the vertical direction is preferably 0.7% or less, more preferably 0.5% or less. The heating temperature for measuring the thermal shrinkage is 100° C., and the heating time is 40 minutes.

The Young's modulus of the high stiffness polyester film in the machine direction is preferably 4.0 GPa or more, more preferably 4.5 MPa or more. The Young's modulus of the high stiffness polyester film in the vertical direction is preferably 4.0 GPa or more, more preferably 4.5 GPa or more.

In the process of producing a high-stiffness polyester film, for example, first, the polyester film obtained by melting and molding the polyester is stretched 3 to 4.5 times at 90 ° C. to 145 ° C. in the machine direction and the vertical direction, respectively. A first stretching step of stretching to is carried out.

Subsequently, the polyester film is stretched 1.1 times to 3.0 times at 100° C. to 145° C. in the machine direction and the vertical direction, respectively.

Thereafter, heat setting is performed at a temperature of 190°C to 220°C. Subsequently, a relaxation treatment is performed at a temperature of 100° C. to 190° C. in the machine direction and the vertical direction to reduce the width of the polyester film by about 0.2% to 2.5%.

In these steps, by adjusting the draw ratio, draw temperature, heat setting temperature, and relaxation treatment rate, a high-stiffness polyester film having the above mechanical properties can be obtained. Types of polyester used for high-stiffness polyester films is preferably polyethylene terephthalate.

The thickness of the plastic film as the plastic substrate of the present invention as described above is not subject to any particular limitation. Any material can be used as long as it can be treated as a film, and from the viewpoint of flexibility and shape retention, the range of 6 to 400 μm, preferably 9 to 200 μm is desirable. However, in the case of a high-stiffness polyester film, the thickness is preferably 5 μm or more, more preferably 7 μm or more, further preferably 25 μm or less, more preferably 20 μm or less. When the thickness of the plastic film is within the above range, it is easy to bend, does not break during transportation, and has a barrier property with improved adhesion. Easy to handle with vapor deposition film deposition equipment.
In particular, when a high-stiffness polyester film is used as the plastic substrate, it is possible to reduce the thickness and weight of the laminated film and obtain a laminated film having rigidity, tensile strength, and puncture strength equal to or higher than those of the laminated film.

Next, an aluminum oxide deposited film will be described. In the present invention, the aluminum oxide vapor deposition film is formed on the surface of the film of the plastic substrate in order to improve the adhesion between the plastic substrate and the aluminum oxide vapor deposition film. It is preferable to carry out a special oxygen plasma pretreatment using The special oxygen plasma pretreatment in the present invention is a pretreatment for strengthening and improving the adhesion, etc. between various resin films or sheets and aluminum oxide vapor deposition films compared to conventional methods. It is implemented in an apparatus.

A roller-type continuous vapor deposition film forming apparatus 10, which is preferably used for producing a laminated film having an aluminum oxide vapor deposition film having a barrier property with improved adhesion of the present invention, is provided in a decompression chamber 12, as shown in FIG. Partition walls 35a to 35c are formed in the . The partition walls 35a to 35c form the substrate transfer chamber 12A, the plasma pretreatment chamber 12B, and the film formation chamber 12C. 12C are formed, and each chamber is further formed with an exhaust chamber inside as required.
(special oxygen plasma pretreatment)

In the plasma pretreatment chamber 12B, a part of a plasma pretreatment roller 20 that conveys the plastic substrate S to be pretreated and enables plasma treatment is provided so as to be exposed to the substrate transfer chamber 12A. The plastic base material S is moved to the plasma pretreatment chamber 12B while being wound up.

The plasma pretreatment chamber 12B and the film formation chamber 12C are provided in contact with the substrate transfer chamber 12A, and can be moved without exposing the plastic substrate S to the atmosphere. The pretreatment chamber 12B and the substrate transfer chamber 12A are connected by a rectangular hole, and a part of the plasma pretreatment roller 20 protrudes toward the substrate transfer chamber 12A through the rectangular hole. A gap is formed between the wall of the transfer chamber and the pretreatment roller 20, and the substrate S can be moved from the substrate transfer chamber 12A to the film formation chamber 12C through the gap. A similar structure is provided between the substrate transfer chamber 12A and the film forming chamber 12C, and the plastic substrate S can be moved without being exposed to the atmosphere.

The base material transfer chamber 12A is used as a winding means to roll up the plastic base material S having a deposited film formed on one side thereof, which is moved to the base material transfer chamber 12A again by the film forming roller 23. A take-up roller is provided so that the plastic base material S on which the vapor deposition film is formed can be taken up.

When manufacturing a laminated film having an aluminum oxide deposited film having a barrier property with improved adhesion according to the present invention, the plasma pretreatment chamber 12B separates the space in which plasma is generated from other regions, and separates the opposing space from the other regions. Efficient evacuation facilitates control of the plasma gas concentration and improves productivity. The pretreatment pressure formed by reducing the pressure can be set and maintained at about 0.1 Pa to 100 Pa. In particular, the special oxygen plasma pretreatment is used to achieve a preferred transformation rate in the transition region of the aluminum oxide vapor deposition film of the present invention. The processing pressure of 1 to 20 Pa is preferable.

The transport speed of the plastic substrate S is not particularly limited, but from the viewpoint of production efficiency, it can be at least 200 to 1000 m/min. The conveying speed for the special oxygen plasma pretreatment is preferably 300 to 800 m/min.

The plasma pretreatment roller 20, which constitutes the plasma pretreatment device, prevents the plastic substrate S from shrinking or breaking due to heat during plasma treatment by the plasma pretreatment means, and applies the oxygen plasma P to the plastic substrate S. It is intended to be applied uniformly and over a wide area.
It is preferable that the pretreatment roller 20 can be adjusted to a constant temperature between -20° C. and 100° C. by adjusting the temperature of the temperature adjusting medium circulating in the pretreatment roller.

The plasma pretreatment means includes plasma supply means and magnetism formation means. The plasma pretreatment means cooperates with the plasma pretreatment roller 20 to confine an oxygen plasma P near the plastic substrate S surface.

The plasma pretreatment means is provided so as to partially cover the pretreatment roller 20 . Specifically, the plasma supply means and the magnetism forming means constituting the plasma pretreatment means are arranged along the surface of the pretreatment roller 20 in the vicinity of the outer periphery, and the pretreatment roller 20 and the plasma raw material gas are supplied and the plasma P Plasma supply nozzles 22a to 22c, which also serve as electrodes for generating plasma P, and magnetism forming means having a magnet 21 and the like for promoting the generation of plasma P are installed so as to form a gap sandwiched between them.
As a result, the plasma supply nozzles 22a to 22c are opened in the spaces of the gaps to inject plasma toward the surface of the base material, and the spaces in the gaps are used as plasma formation regions. By forming a region of high plasma density in the vicinity of the surface, the special oxygen plasma pretreatment of the present invention for forming a plasma-treated surface on one side of the plastic substrate S can be performed.

The plasma supply means of the plasma pretreatment means includes a raw material volatilization supply device 18 connected to a plasma supply nozzle provided outside the decompression chamber 12, and a raw material gas supply line for supplying the raw material gas from the device. The plasma raw material gas to be supplied is oxygen alone or a mixed gas of oxygen gas and argon, helium, nitrogen, or one or more of these gases. supplied in batches.

These gases to be supplied are mixed at a predetermined ratio as required to form a plasma raw material gas alone or a mixed gas for plasma formation, which is supplied to the plasma supply means. The single or mixed gas is supplied to the plasma supply nozzles 22a to 22c of the plasma supply means, and is supplied to the vicinity of the outer circumference of the pretreatment roller 20 where the supply ports of the plasma supply nozzles 22a to 22c are open.
The nozzle openings are directed toward the plastic substrate S on the pretreatment roller 20, and are arranged and configured so as to allow the oxygen plasma P to be uniformly diffused and supplied over the entire surface of the plastic substrate S. A uniform plasma pretreatment can be performed on a large-area portion of the material S.

The mixing ratio of oxygen gas and argon or helium is 5:1, preferably 2:1, in the special oxygen plasma pretreatment to obtain the transformation ratio of the transition region of the deposited aluminum oxide film of the present invention. By setting the mixing ratio to 5:1, the film-forming energy of vapor-deposited aluminum on the plastic film substrate is increased, and by setting the mixing ratio to 2:1, aluminum hydroxide is formed near the interface of the substrate. ie the metamorphic rate of the transition region is reduced.

The plasma supply nozzles 22a to 22c function as counter electrodes for the pretreatment roller 20, and are designed to have an electrode function. The supplied plasma raw material gas is excited by the potential difference due to the frequency voltage or the like, and the plasma P is generated and supplied.

Specifically, the plasma supply means of the plasma pretreatment means installs a plasma pretreatment roller as a plasma power supply, applies an AC voltage with a frequency of 10 Hz to 2.5 GHz between the counter electrode, and controls the input power or , impedance control, etc., and any voltage can be applied between it and the plasma pretreatment roller 20, and processing for physically or chemically modifying the surface properties of the base material can be performed. A power supply 32 is provided which can apply a bias voltage that makes the oxygen plasma P positive.
The plasma intensity per unit area employed in the present invention is 50 to 8000 W·sec/m ² . At 50 W·sec/m ² or less, the effect of plasma pretreatment is not observed, and 8000 W·sec/m ² or less. Under the above conditions, deterioration of the base material due to plasma, such as consumption of the base material, breakage and coloring, and baking, tends to occur. In particular, the plasma intensity of the special oxygen plasma pretreatment is preferably 100 to 1000 W·sec/m ² in order to achieve a transformation rate in the transition region of the aluminum oxide deposited film of the present invention.

The plasma pretreatment means comprises magnetic forming means. As magnetism forming means, an insulating spacer and a base plate are provided in the magnet case, and a magnet 21 is provided on the base plate. An insulating shield plate is provided in the magnet case, and electrodes are attached to this insulating shield plate.
Therefore, the magnet case and the electrodes are electrically insulated, and even if the magnet case is installed and fixed in the decompression chamber 12, the electrodes can be electrically floating level.

A power supply wiring 31 is connected to the electrodes, and the power supply wiring 31 is connected to a power supply 32 . Further, a temperature control medium pipe for cooling the electrode and the magnet 21 is provided inside the electrode.
The magnet 21 is provided to concentrate and apply the oxygen plasma P from the plasma supply nozzles 22a to 22c, which are electrodes and plasma supply means, to the substrate S. As shown in FIG. By providing the magnet 21, the reactivity in the vicinity of the base material surface is increased, and it becomes possible to form a favorable plasma pretreated surface at high speed.

The magnet 21 has a magnetic flux density of 10 gauss to 10000 gauss at the surface position of the plastic substrate S. If the magnetic flux density on the surface of the plastic substrate S is 10 gauss or more, the reactivity in the vicinity of the substrate surface can be sufficiently increased, and a good pretreated surface can be formed at high speed.

Because the ions and electrons formed during the plasma pretreatment move according to the arrangement structure of the magnets 21 of the electrodes, for example, when plasma pretreatment is performed on a plastic substrate S having a large area of 1 m ² or more. Electrons, ions, and decomposition products of the base material are uniformly diffused over the entire electrode surface, and even when the plastic base material S has a large area, a uniform and stable target pretreatment can be achieved with a desired plasma intensity. It is.

(aluminum oxide deposition film)
The plastic substrate S that has undergone the special oxidizing plasma treatment is moved from the substrate transfer chamber 12A to the film forming chamber 12C by guide rolls 14a to 14d for guiding to the next film forming chamber 12C, where an aluminum oxide deposited film is formed in the film forming section. is formed.

The aluminum oxide deposition film is a thin film of an inorganic oxide containing aluminum oxide as a main component, and can contain aluminum compounds such as aluminum oxide or nitrides, carbides, and hydroxides of aluminum alone or in mixtures thereof. It is a layer containing aluminum as a main component.
Further, the deposited aluminum oxide film contains the aluminum compound as a main component, and includes silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, magnesium oxide, titanium oxide, tin oxide, indium oxide, zinc oxide, and zirconium oxide. metal oxides, such as metal oxides, or metal nitrides, carbides, and mixtures thereof.

The vapor-deposited aluminum oxide film of the present invention has a transformation rate of 45% or less in the transition region of the vapor-deposited aluminum oxide film.
The transformation rate of the transition region of the vapor-deposited aluminum oxide film was determined by repeatedly soft-etching the vapor-deposited aluminum oxide film 2 of the laminate film A having barrier properties with a Cs (cesium) ion gun at a constant rate, while performing time-of-flight secondary By measuring the ions derived from the deposited aluminum film and the ions derived from the plastic base material using ion mass spectrometry (TOF-SIMS), a graphical analysis chart such as that shown in FIG. 3 is obtained.
Specifically, using a time-of-flight secondary ion mass spectrometer, etching is performed from the outermost surface of the vapor deposited aluminum oxide film with Cs under certain conditions, and elemental bonding at the interface between the vapor deposited aluminum oxide film and the plastic substrate is detected. and the element bonding of the vapor-deposited aluminum oxide film, and obtained respective graphs for the measured elements and element bonding (Fig. 3 graph analysis chart). As the interface between the material and aluminum oxide, the area from the surface to the interface is obtained as an aluminum oxide deposition film, 2) the peak in the graph representing the elemental bond Al ₂ O ₄ H is obtained, and the transition region from the peak to the interface is obtained. ) (transition region from the peak of elemental bond Al ₂ O ₄ H to the interface/aluminum oxide deposition film)×100 (%) and the metamorphic rate of the transition region.

The transformation rate of the transition region of the vapor-deposited aluminum oxide film layer of the present invention is desirably 45% or less. If it exceeds 45%, the adhesiveness between the plastic substrate and the vapor-deposited film decreases after hot water treatment at 135°C for 40 minutes (high retort) or after hot water treatment at 121°C for 40 minutes (semi-retort), Also, the barrier performance against water vapor is lowered.

Hot water treatment (retort treatment) imparts great mechanical and chemical stress to the interface between the plastic substrate and the deposited aluminum oxide film. This stress degrades the barrier properties. This area is stressed because it is the most vulnerable part of the stack.
Therefore, in order to obtain retort resistance, it is important to firmly cover the interface with the base material with the deposited film.
Due to its chemical structure, aluminum hydroxide has good adhesion to plastic substrates, and since it itself forms a dense network, it has high water vapor barrier properties. However, the bonding structure based on hydrogen bonding between aluminum hydroxide and the substrate tends to collapse microscopically in a strong environment such as retort treatment. Also, the aluminum hydroxide network easily permeates into the film due to the affinity between the water molecules and the grain boundaries of the aluminum hydroxide.

In the present invention, in order to minimize the transition region at the interface with the plastic substrate formed by aluminum hydroxide in the vapor deposited aluminum oxide film, attention is focused on the elemental bond Al ₂ O ₄ H, and the amount thereof is controlled. , By suppressing aluminum hydroxide generated from elemental bonding Al ₂ O ₄ H by hydrothermal treatment and increasing the ratio of aluminum oxide film with relatively less aluminum hydroxide, microscopic vapor deposition film by water molecules by retort treatment Breakage and interfacial breakage with the plastic substrate were greatly suppressed. As a result, it is possible to provide a laminated film having unprecedented adhesion and barrier properties and retort resistance.

The vapor-deposited aluminum oxide film of the present invention can be formed by forming a vapor-deposited film on the surface of a plastic substrate pretreated with special oxygen plasma. As a vapor deposition method for forming a vapor deposition film, various vapor deposition methods selected from physical vapor deposition and chemical vapor deposition can be applied.
The physical vapor deposition method can be selected from the group consisting of vapor deposition method, sputtering method, ion plating method, ion beam assist method, and cluster ion beam method, and the chemical vapor deposition method includes plasma CVD method, plasma polymerization method, thermal It can be selected from the group consisting of CVD method and catalytic CVD method. In the present invention, a vapor deposition method of physical vapor deposition is suitable.

Formation of an aluminum oxide vapor deposition film using a roller type continuous vapor deposition film forming apparatus 10 shown in FIG.

The vapor deposition film forming apparatus is arranged in the decompressed film forming chamber 12C, and transports the plastic substrate S pretreated by the plasma pretreatment apparatus with the treated surface facing outward, A deposition film is formed on the surface of the plastic base material by evaporating a film forming roller 23 for film forming and a target of a film forming source 24 disposed facing the film forming roller.
The vapor deposition film forming means 24 is of a resistance heating type, uses aluminum as an evaporation source, uses a metal wire of aluminum, and supplies oxygen to oxidize the aluminum vapor to form an aluminum oxide vapor deposition film on the surface of the plastic substrate S. form a film.

In the present invention, a plurality of aluminum metal wires are arranged in the axial direction of the roller 23 in a boat-shaped (referred to as "boat type") vapor deposition vessel and heated by resistance heating. By doing so, it is possible to evaporate the aluminum metal material while suppressing the amount of heat and the amount of heat supplied, and to form an aluminum oxide deposition film while suppressing the thermal deformation of the plastic substrate S as much as possible. can.

The thickness of the evaporated aluminum oxide film formed as described above is 3 to 50 nm, preferably 8 to 30 nm. Within this range, barrier properties can be maintained.

(Barrier coating layer)
The barrier coating layer laminated on the surface of the deposited aluminum oxide film of the laminated film of the present invention mechanically and chemically protects the deposited aluminum oxide film and improves the barrier performance of the laminated film having barrier properties. It is. The barrier coating layer to be coated to form a barrier laminated film having excellent barrier properties and retort resistance will be described below.

The barrier coating layer is formed by applying a barrier coating agent onto the deposited aluminum oxide film and solidifying the coating. The barrier coating agent is composed of a metal alkoxide, a water-soluble polymer, a silane coupling agent added as necessary, a sol-gel catalyst, an acid, and the like.

The metal alkoxide has the general formula R ¹ _n M(OR ² ) _m (wherein R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n is , represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) at least one metal alkoxide represented by M, the metal represented by M of the metal alkoxide Examples of atoms include silicon, zirconium, titanium, aluminum, and the like. For example, it is preferable to use an alkoxysilane in which M is Si.

Examples of the above alkoxysilane include those represented by the general formula Si(ORa) ₄ (wherein Ra represents a lower alkyl group). In the above, as Ra, a methyl group, an ethyl group, an n-propyl group, an n-butyl group and the like are used. Specific examples of the above alkoxysilanes include tetramethoxysilane Si(OCH ₃ ) ₄ , tetraethoxysilane Si(OC ₂ H ₅ ) 4 , tetrapropoxysilane Si(OC ₃ H ₇ ) ₄ and tetrabutoxysilane Si. (OC ₄ H ₉ ) ₄ , etc. can be used.
The alkoxide may be used in combination of two or more

As the silane coupling agent, one having a reactive group such as a vinyl group, an epoxy group, a methacrylic group, an amino group, or the like can be used. Particularly preferred are organoalkoxysilanes having an epoxy group, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxysilane. Propyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyldimethylethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or the like can be used. The above silane coupling agents may be used singly or in combination of two or more.

As the water-soluble polymer, a polyvinyl alcohol resin or an ethylene/vinyl alcohol copolymer can be used alone, or a polyvinyl alcohol resin and an ethylene/vinyl alcohol copolymer can be used in combination. can do. In the present invention, a polyvinyl alcohol resin is suitable.

As polyvinyl alcohol-based resins, those obtained by saponifying polyvinyl acetate can generally be used. The polyvinyl alcohol resin may be a partially saponified polyvinyl alcohol resin in which several tens of percent of acetic acid groups remain, a fully saponified polyvinyl alcohol in which no acetic acid groups remain, or a modified polyvinyl alcohol resin in which OH groups have been modified. good. Regarding the degree of saponification of the polyvinyl alcohol resin, it is necessary to use at least one that crystallizes to improve the film hardness of the gas barrier coating film, and preferably has a degree of saponification of 70% or more. Also, the degree of polymerization may be within the range used in the conventional sol-gel method (about 100 to 5000). Examples of such polyvinyl alcohol-based resins include RS resin "RS-110 (degree of saponification = 99%, degree of polymerization = 1,000)" manufactured by Kuraray Co., Ltd., and "Gosenol" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. NM-14 (degree of saponification = 99%, degree of polymerization = 1,400)” and the like.

As the ethylene/vinyl alcohol copolymer, a saponified copolymer of ethylene and vinyl acetate, that is, a product obtained by saponifying an ethylene-vinyl acetate random copolymer can be used.
Examples include partially saponified products in which several tens of mol % of acetic acid groups remain, to complete saponified products in which only several mol % of acetic acid groups or no acetic acid groups remain, and are not particularly limited. However, from the viewpoint of barrier properties, it is preferable to use those having a degree of saponification of 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more.

In the present invention, the barrier coating layer can be produced by the following method.
First, the above metal alkoxide, optionally added silane coupling agent, water-soluble polymer, sol-gel catalyst, acid, and organic solvent such as water, methyl alcohol, ethyl alcohol, isopropanol, etc. are mixed. and prepare a barrier coating agent.
Next, the above barrier coating agent is applied on the deposited aluminum oxide film by a conventional method and dried. This drying step further promotes polycondensation of the metal alkoxide, silane coupling agent and water-soluble polymer to form a coating film. A plurality of coating films consisting of two or more layers may be formed on the first coating film by repeating the coating operation described above.
Further, heat treatment is performed at a temperature of 20 to 200° C. and a temperature lower than the melting point of the plastic substrate, preferably a temperature in the range of 50 to 180° C. for 3 seconds to 10 minutes. As a result, a barrier coating layer of the barrier coating agent can be formed on the deposited aluminum oxide film.

The barrier coating agent is composed of 100 parts by weight of alkoxysilane, 100 to 500 parts by weight of water-soluble polymer such as polyvinyl alcohol resin, and 1 to 20 parts by weight of silane coupling agent. can do. In the above, if the silane coupling agent is used in excess of 20 parts by weight, the resulting barrier coating film will have increased rigidity and brittleness, which is undesirable.

The barrier coating layer formed as described above has a layer thickness of 100 to 500 nm. This range is preferable because the coating film does not crack and the vapor deposition film surface is sufficiently covered.

(Gas barrier packaging material)
The barrier laminated film of the present invention has good adhesion between the plastic substrate and the aluminum oxide vapor-deposited film and has excellent gas barrier properties even after hot water treatment, particularly after retort treatment of high-temperature hot water treatment. , food retort packaging materials, medical high-temperature hot water treatment packaging materials, as well as packaging materials for contents to be retorted such as pet food.
The gas-barrier packaging material of the present invention is obtained by laminating at least one heat-sealable layer on a barrier laminated film. It is laminated as the innermost layer and imparted with heat-sealing properties. As the gas barrier packaging material, further functions to be imparted as a packaging material, such as a light-shielding layer for imparting light-shielding properties, decorative properties, a printing layer for imparting printing, a pattern layer, laser printing, etc. Various functional layers such as a layer and an absorbent/adsorptive layer that absorbs or adsorbs odors can be added as a layer structure to form a gas barrier packaging material.

Moreover, it can be produced by laminating a functional film according to the application. For example, in the case of retort gas barrier packaging materials, a multi-layer film gas barrier packaging material laminated with a nylon film as a pinhole resistant structure and a heat resistant sealant CPP etc. as a heat resistant structure, or a gas barrier for liquid paper containers. Examples of flexible packaging materials include laminate packaging materials in which paper is laminated.
Especially in the case of a packaging material made from a laminated film using a high-stiffness polyester film as a plastic base material, the thickness and weight of the packaging material can be reduced, and the laminated film has the same or higher rigidity, tensile strength, and puncture strength. can be obtained.

The heat-sealable thermoplastic resin may be any resin layer, film or sheet that can be melted and bonded to each other by heat. condition) Any film or sheet of low-density resin may be used.
And, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, polypropylene, polymethylpentene, polystyrene, ethylene-vinyl acetate copolymer, α-olefin copolymer, Ionomer resins, ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl methacrylate copolymers, ethylene-propylene copolymers, elastomers, and other resins or resins consisting of one or more resins, or these It is preferable to use a sheet that is made into a film. Among them, as a layer that comes in contact with the contents of food, etc., it is a type of olefin resin such as polyethylene and polypropylene that has hygienic, heat-resistant, chemical-resistant, and aroma-retaining properties. It is more preferable to use a resin made of 1 or more or a sheet obtained by forming a film of these.
The thickness is preferably about 3 to 100 μm, more preferably about 15 to 70 μm.

[Gas barrier package]
The gas-barrier package of the present invention is a package made from the gas-barrier packaging material of the present invention.
For example, by heat-sealing a sealant layer of a gas-barrier packaging material composed of a multi-layer film, a pillow packaging bag, a three-side seal, a four-side seal, a gusset type gas-barrier package, or the like can be produced. Further, if the gas barrier packaging material is made of a laminated film in which paper is laminated, a gobel-top liquid paper container packaging for liquor, juice, or the like can be produced.

(Measurement method for evaluation items)
Measure a laminated film having an aluminum oxide deposited film with barrier properties and improved adhesion, or a barrier laminated film having a barrier coating layer on the laminated film, manufactured under the conditions shown in the above Examples or Comparative Examples. Transformation rate, oxygen permeability, water vapor permeability, and adhesion strength of the transition region of the deposited film were measured using the following methods.

(Metamorphic rate of transition region)
In the present invention, the transformation rate of the transition region of the vapor deposited film is measured by time-of-flight secondary ion mass spectrometry (time-of-flight secondary ion mass spectrometry) while repeating soft etching at a constant rate with a Cs (cesium) ion gun on the surface of the vapor deposited aluminum oxide film of the laminated film. Using TOF-SIMS), the ions derived from the deposited aluminum oxide film and the ions derived from the plastic base material are measured to obtain the graphical analysis diagram of FIG. Here, the unit (intensity) of the vertical axis of the graph is the intensity of the measured ions, and the unit (cycle) of the horizontal axis is the number of times of etching.
As a time-of-flight secondary ion mass spectrometer used in the TOF-SIMS, TOF. Using SIMS5, measurement was performed under the following measurement conditions.

(TOFSIMS measurement conditions)
・Primary ion type: Bi ₃ ⁺⁺ (0.2 pA, 100 μs)
・Measurement area: 150 × 150 μm ²
・Et (etching) gun type: Cs (1 keV, 60 nA)
・ Et (etching) area: 600 × 600 μm ²
・Et (etching) rate: 3 sec/cycle
・Evacuation time: 15 hours or more at 1×10 ⁻⁶ mbar or less ・Measured within 30 hours after starting vacuuming

In order to measure ions derived from aluminum oxide to be measured, it is usually necessary to separate ions derived from a plurality of aluminum oxide from ions derived from other components, and sufficient Cs ions are selected in the present invention because it is necessary to select ions with high intensity and particularly for the purpose of obtaining a depth distribution that can be approximately converted to the concentration distribution of elementally bonded Al ₂ O ₄ H.

Using Cs, etching was performed from the outermost surface of the vapor deposited aluminum oxide film, and elemental bonding at the interface between the vapor deposited aluminum oxide film and a film substrate such as a polyester film was analyzed and the elemental bonding of the vapor deposited film was measured. Each graph of Graph 1 of elements and element bonds was obtained. It should be noted that the graph shows elements and elemental bonds at measured mass numbers such as 118.93 for Al ₂ O ₄ H, 101.94 for Al ₂ O ₃ , 72.00 for C6, etc. was created by specifying In the graph, the position where the intensity of the element C6 is half that of the plastic substrate layer portion was defined as the interface between the film substrate and the aluminum oxide, and the area from the surface to the interface was the evaporated aluminum oxide film.
Next, the peak in the graph representing the measured elemental bond Al ₂ O ₄ H is determined, and the transition region from the peak to the interface can be determined.
By performing the above operations, the transformation rate of the transition region of the vapor-deposited aluminum oxide film was (the transition region from the peak of the elemental bond Al ₂ O ₄ H to the interface/the vapor-deposited aluminum oxide film) × 100 (%).
I asked as

(oxygen permeability)
Barrier laminated film/adhesive/nylon film 15 μm/ Adhesive/CPP 70 μm composite laminate film, set the above test sample so that the oxygen supply side is the film surface of the barrier laminate film, and measure under the conditions of 23 ° C. and 100% RH atmosphere, JIS K 7126 B method. Measured according to
As a measurement sample,
1) Composite laminated film before retort treatment 2) High retort treatment conditions: Composite laminated film on one side of bag of composite laminated film treated at 135°C for 40 minutes 3) Semi-retort treatment conditions: 121°C, The composite laminated film on one side of the bag of the composite laminated film that had been treated for 40 minutes and was in the form of a bag was used.

(water vapor permeability)
Using a water vapor transmission rate measuring device (measuring machine manufactured by MOCON [model name, PERMATRAN 3/33]), the above test sample was measured so that the sensor side was the film surface of the barrier laminate film. was set and measured in accordance with JIS K 7126 B method under the measurement conditions of 37.8° C. and 100% RH atmosphere.
As a measurement sample,
1) Composite laminated film before retort treatment 2) High retort treatment conditions: Composite laminated film on one side of bag of composite laminated film treated at 135°C for 40 minutes 3) Semi-retort treatment conditions: 121°C, The composite laminated film on one side of the bag of the composite laminated film that had been treated for 40 minutes and was in the form of a bag was used.

(Adhesion strength between substrate and aluminum oxide deposited film)
<Measurement of adhesion strength (1); adhesion strength before high-retort/semi-retort treatment>
A two-component curable polyurethane adhesive was applied to the barrier coating layer side of the barrier laminated film and then dried. A laminated composite film was prepared by dry laminating a 15 μm stretched nylon film and a laminated film.
After aging the laminated composite film for 48 hours, a sample cut into a strip with a width of 15 mm was subjected to JIS K6854- using a tensile tester (manufactured by Orientec Co., Ltd. [model name: Tensilon Universal Material Testing Machine]). 2, the strength of the barrier laminated film substrate and the aluminum oxide deposition film was measured.

For the measurement, the polypropylene film side and the barrier laminate film side, which had been peeled off in advance for measurement, were each held by the grips of the measuring instrument, and the polypropylene film and the barrier laminate film were still laminated in the plane direction. In the directions orthogonal to each other, the films were pulled in opposite directions (180° peeling: T-shaped peeling method) at a rate of 50 mm/min, and the average value of the tensile stress in the stable region was measured.
Peeling occurs between the plastic substrate of the barrier laminate film and the vapor-deposited aluminum oxide film, which has the weakest adhesion strength in the laminated composite film. It was taken as the adhesion strength of the deposited film.

<Measurement of adhesion strength (2); adhesion strength after high retort treatment>
A two-component curable polyurethane adhesive was applied to the barrier coating layer side of the barrier laminated film and then dried. A 15 μm stretched nylon film and the laminated film were dry-laminated to prepare a laminated composite film.
100 mL of water was poured into a four-side pouch made to B5 size using the laminated composite film, and hot water retort treatment was performed at 135° C. for 40 minutes. After the retort treatment, water was removed from the four-sided pouch, and samples were cut into strips of 15 mm in width. Using this sample, adhesion strength was measured in the same manner as measurement of adhesion strength (1).

<Measurement of adhesion strength (3): adhesion strength after semi-retort treatment>
Measurement of Adhesion Strength In the configuration of (2), a laminated composite film was produced by using a polypropylene film with a thickness of 70 μm without using a nylon film.
100 mL of water was poured into a four-side pouch prepared in B5 size using the laminated composite film, and hot water retort treatment was performed at 121° C. for 40 minutes. After the retort treatment, water was removed from the four-sided pouch, and samples were cut into strips of 15 mm in width. Using this sample, adhesion strength was measured in the same manner as measurement of adhesion strength (1).

Example 1
<Aluminum oxide deposition film>
First, a roll was prepared by winding a 12 μm-thick polyester film (hereinafter referred to as a PET film) as a base material.
Next, on the surface of the PET film on which the vapor-deposited film is to be formed, using a continuous vapor deposition film forming apparatus in which the pretreatment section in which the plasma pretreatment apparatus is arranged and the film formation section are separated, in the pretreatment section, under the following plasma conditions: Plasma was introduced from the plasma supply nozzle, subjected to special oxygen plasma pretreatment at a conveying speed of 400 m/min, and continuously conveyed. A 12 nm-thick aluminum oxide deposition film was formed on a PET film by a heating method.

(Plasma pretreatment conditions)
・Plasma intensity: 150 W・sec/m ²
- Plasma forming gas: argon 1200 (sccm), oxygen 3000 (sccm)
・Magnetism forming means: 1000 gauss permanent magnet ・Applied voltage between pretreatment drum and plasma supply nozzle: 340V
・Vacuum degree of pretreatment section: 3.8 Pa
(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa
・Conveyance speed: 400m/min
・Light transmittance at wavelength 366 nm: 92%

<Barrier coating layer>
385 g of water, 67 g of isopropyl alcohol and 9.1 g of 0.5N hydrochloric acid were mixed and adjusted to pH 2.2. To the solution was added 175 g of tetraethoxysilane and 9.2 g of glycidoxypropyltrimethoxysilane while cooling to 10°C. Solution A was prepared by mixing.
A solution B was prepared by mixing 14.7 g of polyvinyl alcohol having a degree of polymerization of 2400 and a degree of saponification of 99% or more, 324 g of water and 17 g of isopropyl alcohol.
A solution obtained by mixing the A solution and the B solution in a weight ratio of 6.5:3.5 was used as a barrier coating agent.

<Barrier laminated film>
The barrier coating agent prepared above was coated on the vapor-deposited aluminum oxide film of the PET film by spin coating. After that, heat treatment was performed in an oven at 180° C. for 60 seconds to form a barrier coating layer having a thickness of about 400 nm on the vapor-deposited aluminum oxide film, thereby obtaining a barrier laminated film.

Example 2
A barrier laminated film was obtained in the same manner as in Example 1, except that the thickness of the deposited aluminum oxide film was changed to 14 nm.
(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa
・Conveyance speed: 340m/min
・Light transmittance at wavelength 366 nm: 92%

Example 3
A barrier laminate film was obtained in the same manner as in Example 1, except that a biomass-derived polyester film having a thickness of 12 μm was used as the substrate.
(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa
・Conveyance speed: 400m/min
・Light transmittance at wavelength 366 nm: 92%

Example 4
A barrier laminated film was obtained in the same manner as in Example 1, except that a polybutylene terephthalate film having a thickness of 12 μm was used as the substrate and the thickness of the aluminum oxide deposited film was changed to 10 nm.
(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa
・Conveyance speed: 400m/min
・Light transmittance at wavelength 366 nm: 92%

Example 5
A barrier laminate film was obtained in the same manner as in Example 1, except that a high-stiffness polyester film XP-55 (thickness: 16 μm) manufactured by Toray Industries, Inc. was used as the base material.

Comparative example 1
A barrier laminate film was obtained in the same manner as in Example 1, except that the plasma pretreatment was not performed.

Comparative example 2
First, a roll was prepared by winding a PET film having a thickness of 12 μm as a base material. Next, the surface of the PET film on which the deposited layer was to be formed was plasma-treated by a direct plasma method under the following conditions to obtain a take-up roll of the plasma-treated PET film. Next, on the plasma-treated surface of this PET film, a vapor deposition film of aluminum oxide having a thickness of 12 nm was formed under the following conditions by a reactive resistance heating method.

(Plasma pretreatment conditions)
・Direct current plasma intensity: 150 W・sec/m ²
- Plasma forming gas: argon 1200 (sccm), oxygen 3000 (sccm)
・Magnetic forming means: None ・Applied voltage between pretreatment drum and plasma supply nozzle: None

(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa
・Conveyance speed: 400m/min
・Light transmittance at wavelength 366 nm: 92%

Next, a barrier coating layer was formed on the deposited aluminum oxide film in the same manner as in Example 1 to obtain a barrier laminate film.

Table 1 shows the measurement results. As shown in Examples 1 to 5, the denaturation rate of the transition region of the deposited aluminum oxide film of the laminated film of the present invention is 45% or less, and the denaturation rate of the transition region is high in Comparative Examples 1 and 2, After the high retort treatment, the semi-retort treatment, and in Comparative Examples 1 and 2, even if the peel strength before the retort treatment was almost the same as in the examples, the peel strength after the retort treatment was as low as 1 N/15 mm or less, and the peel strength suddenly decreased. Deterioration is seen. In contrast, according to the present invention, the adhesion strength is sufficiently maintained with a peel strength of 2.1 N/15 mm or more, and no significant decrease in adhesion strength due to retort treatment is observed, and deterioration is suppressed.

In terms of barrier performance, in Examples 1 to 5, after high retort treatment and semi-retort treatment, the water vapor transmission rate was 0.9 g/m ² /24 hr or less, and deterioration of barrier performance due to retort treatment was suppressed. A certain level of permeability can be maintained after any retort treatment. On the other hand, in Comparative Examples 1 and 2, even though the water vapor transmission rate before retort treatment was almost the same as in Examples, after high retort treatment, the value was as high as 1.2 g/m ² /24 hr, indicating deterioration. The oxygen permeability also shows a high value of 0.5 cc/m ² /24 hr or more, which is more than twice as high, indicating deterioration of the barrier performance due to the retort treatment.
As can be seen from these results, the laminated film of the present invention in which the transformation rate of the aluminum oxide transition region is controlled exhibits excellent retort resistance.

The present invention provides an aluminum oxide vapor deposition film having improved adhesion and barrier properties by properly setting the transformation ratio of the transition region of the aluminum oxide vapor deposition film between the vapor deposition film and the plastic substrate. A laminate film and a barrier laminate film can be obtained.
By improving the deterioration of the adhesion strength between the vapor-deposited film and the plastic substrate before and after the retort treatment, it is possible to obtain a barrier laminated film having a barrier property and adhesion property that prevents permeation of oxygen gas, water vapor, etc. Uses requiring durability and barrier properties such as packaging materials for foods and pharmaceuticals that require laminated materials that can withstand processing associated with processing such as retort processing and sterilization, as well as electrical and electronic component packaging and protective sheets. It can be applied to industrial materials, etc. in fields where the environment is severe.

1, S ...... Plastic base material 2 ...... Aluminum oxide vapor deposited film 3 Barrier coating layer A Laminated film or vapor deposited film B Barrier laminated film P Plasma 10 ……Roller-type continuous deposition film-forming apparatus 12 ……Decompression chamber 12A ……Base material transfer chamber 12B ……Plasma pretreatment chamber 12C ……Film-forming chambers 14a to d ……Guide roll 18 …… Raw material gas volatilization supply device 20 Pretreatment roller 21 Magnet 22 Plasma supply nozzle 23 Film forming roller 24 Evaporated film forming means 31 Electric power supply wiring 32 ……Power sources 35a to 35c ……Partition wall

Claims (14)

A laminate film having barrier properties, in which an aluminum oxide vapor-deposited film containing aluminum oxide as a main component is formed on the surface of a plastic substrate,
The laminated film having barrier properties comprises a plastic substrate and a vapor deposited film mainly composed of a vapor deposited aluminum oxide film formed on the surface of the substrate film,
A transition region of the deposited film is formed, which defines the adhesion strength between the base film surface and the deposited film mainly composed of the formed aluminum oxide deposited film,
The transition region contains elementally bound Al ₂ O ₄ H that transforms into aluminum hydroxide detected by etching using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The transformation ratio of the transition region defined by the ratio of the transformed transition region defined by TOF-SIMS to the deposited aluminum oxide film defined by etching using TOF-SIMS is 45% or less,
Solution A composed of the above laminated film/tetraethoxysilane and glycidoxypropyltrimethoxysilane, and solution B composed of polyvinyl alcohol, water, and isopropyl alcohol, which were prepared for the measurement, were mixed together at a weight ratio of 6. A composite laminated film consisting of a 400 nm barrier coating layer obtained by a sol-gel method from a solution mixed at 5:3.5/adhesive/15 μm nylon film/adhesive/70 μm CPP was used as a test sample,
The test sample was set so that the oxygen supply side was the film surface of the barrier laminated film, and the measurement conditions were 23°C, 100% RH, and measured according to JISK7126B method. The oxygen permeability after high-retort hot water treatment is 0.2 cc/m ² ·24 hr or less,
The above test sample was set so that the sensor side was the film surface of the barrier laminate film, and the measurement conditions were 37.8°C and 100% RH in accordance with JISK 7126B method. Water vapor permeability after high retort hot water treatment for 1 minute is 0.9 g/m ² · 24 hr or less,
The laminated film described above. 2. The laminated film of Claim 1, wherein the plastic substrate is a polyethylene terephthalate film. 2. The laminated film of claim 1, wherein the plastic substrate comprises recycled polyethylene terephthalate film. 2. The laminated film according to claim 1, wherein the plastic substrate is a polybutylene terephthalate film. The laminated film according to claim 1, wherein the plastic substrate is a biomass-derived polyester film. The plastic base material is a high-stiffness polyester film,
The high-stiffness polyester film is an oriented plastic film having a loop stiffness of 0.0017 N/15 mm or more in the machine direction (MD) and the vertical direction (TD) and containing 51% by weight or more of polyester.
The laminated film according to claim 1. 7. The laminated film according to any one of claims 1 to 6, wherein the surface of the plastic substrate is an oxygen plasma treated surface. 8. The laminate film according to claim 7, wherein an aluminum oxide deposition film is laminated inline on the oxygen plasma-treated surface. A barrier laminate film comprising a barrier coating layer laminated on the surface of the aluminum oxide deposited film of the laminate film according to any one of claims 1 to 8. 10. The barrier laminate film according to claim 9, wherein the barrier coating layer is a layer obtained by applying a mixed solution of a metal alkoxide and a water-soluble polymer, followed by heating and drying. 10. The barrier laminate film according to claim 9, wherein the barrier coating layer is a layer formed by applying a mixed solution of a metal alkoxide, a silane coupling agent and a water-soluble polymer, followed by heating and drying. A gas-barrier packaging material obtained by laminating a heat-sealable thermoplastic resin on the barrier laminated film according to any one of claims 9 to 11. 13. The gas barrier packaging material according to claim 12, which is used for packaging for retort sterilization. A gas barrier package made from the gas barrier packaging material according to claim 12 or 13.

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