WO2016133040A1

WO2016133040A1 - Method for producing transparent barrier film

Info

Publication number: WO2016133040A1
Application number: PCT/JP2016/054248
Authority: WO
Inventors: 清司伊関; 沼田　幸裕; 晃侍伊藤; 崇江畑; 稲垣　京子
Original assignee: 東洋紡株式会社
Priority date: 2015-02-20
Filing date: 2016-02-15
Publication date: 2016-08-25
Also published as: JP6614134B2; JPWO2016133040A1

Abstract

The present invention provides a transparent barrier film that has excellent printing resistance, and that includes an inorganic layer and an organic layer having excellent adhesion and made by employing a vacuum. The present invention is a method for producing a transparent evaporation-deposition barrier film, wherein: the barrier film includes an inorganic layer and an organic layer on at least one surface of a plastic film; the organic layer is made by crosslinking at least two types of compounds each including an acryloyl group or a methacryloyl group; at least one type of said compound is a silane coupling agent; and the method comprises forming the organic layer on the inorganic layer by flash evaporation deposition wherein the compound mixture is evaporated by metallic copper heated to a temperature from 200°C to 300°C inclusive, and curing the organic layer with electronic beams.

Description

Production method of transparent barrier film

The present invention relates to a method for producing a transparent barrier film used as a packaging material that requires airtightness such as foods, pharmaceuticals, and electronic parts having excellent gas barrier properties, or a gas barrier material.

As a film having excellent gas barrier properties, a film obtained by laminating an aluminum foil on a plastic film and a film coated with vinylidene chloride or an ethylene vinyl alcohol copolymer are known. In addition, as a material using an inorganic thin film, a material in which a silicon oxide, an aluminum oxide thin film, or the like is laminated is known (for example, see Patent Document 1).
However, since the inorganic layer formed on the plastic film is very thin, it may deteriorate when post-processing such as printing on the inorganic thin film layer. For example, in the printing process, due to rubbing with the gravure roll and pigment particles contained in the ink, the inorganic layer may be damaged and the barrier property may be lowered. For this improvement, there is a method of coating an organic layer on an inorganic layer. A solution obtained by dissolving a coating agent in a solvent is applied and dried to form an organic layer. There is also a method using a vacuum process (see, for example, Patent Document 2).

In the coating method, organic layers can be formed by mixing various materials to improve the adhesion between the inorganic layer and the organic layer, but in a general method using a vacuum process, two or more substances with different evaporation temperatures are mixed. When evaporated, the mixing ratio of the vapor deposition materials and the composition of the deposited film are shifted. Therefore, a flash vapor deposition method in which the material is brought into contact with a heating plate whose temperature has been sufficiently raised from the evaporation temperature of the substance and evaporated instantly is used.
However, when a reactive organic substance is flash-deposited, it may be fixed by a heating plate and there may be a problem in stability. Then, the method of laminating | stacking without mixing is proposed (for example, refer permission document 3).
However, in this method, it is difficult to always make it constant, such as mixing of two layers laminated in a liquid phase. Further, a mechanism for evaporating two kinds of monomers is required, and the apparatus becomes complicated.

Japanese Patent No. 2700019 Japanese Patent No. 4,604,674 JP 2006-95932 A

The present invention solves the above-mentioned problems, and has an excellent barrier property in which an inorganic layer is provided on one surface of a plastic film and an organic layer having excellent adhesion containing a silane coupling agent is laminated thereon. A method for producing a barrier film is provided.

That is, the present invention is a method for producing a transparent barrier film having an inorganic layer and an organic layer in this order on at least one side of a plastic film, wherein the organic layer has at least two kinds of compounds having an acryloyl group and / or a methacryloyl group. And at least one compound of at least two or more compounds having an acryloyl group and / or a methacryloyl group is a silane coupling agent, and the compound is 200 ° C. or more, 300 A method for producing a transparent barrier film, comprising: forming a liquid organic layer by flash vapor deposition using metallic copper heated to a temperature of not higher than ° C .;

In this case, the acceleration voltage of the electron beam is preferably 500 V or more and 10 kV or less.

According to the present invention, an excellent adhesion strength between the organic layer and the inorganic layer is obtained, and a high-performance barrier film is obtained, and the barrier property is deteriorated even after processing such as printing or lamination with another film. Thus, it is possible to produce a transparent barrier film that can be used as a packaging material that requires high airtightness or a gas barrier material.

Schematic of transparent barrier film produced by the production method of the present invention Schematic of an example of an apparatus used in the production method of the present invention Schematic of an example of an organic vapor deposition source used in the production method of the present invention

The production method of the present invention will be described with an example. FIG. 1 shows a laminate of transparent gas barrier films produced by the production method of the present invention, and FIGS. 2 and 3 show production apparatuses used in the production method as an example.

(Plastic film)
The plastic film (1) referred to in the present invention is a film obtained by melt-extrusion of an organic polymer and stretching, cooling, and heat setting in the longitudinal direction and / or the width direction as necessary. As polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, wholly aromatic polyamide, polyamideimide, Examples thereof include polyimide, polyetherimide, polysulfone, polyphenylene sulfide, and polyphenylene oxide. These (organic polymers) organic polymers may be copolymerized or blended with a small amount of other organic polymers.

Furthermore, known additives such as ultraviolet absorbers, antistatic agents, plasticizers, lubricants, colorants and the like may be added to the organic polymer, and the transparency thereof is not particularly limited. When used as a transparent gas barrier film, those having a transmittance of 50% or more are preferred.
As long as the object of the present invention is not impaired, the plastic film (1) of the present invention is subjected to corona discharge treatment, glow discharge treatment and other surface roughening treatment prior to laminating the thin film layer. Alternatively, a known anchor coat treatment, printing, or decoration may be applied.

The thickness of the plastic film (1) in the present invention is preferably in the range of 1 μm to 300 μm, more preferably in the range of 9 μm to 25 μm.

(Inorganic layer)
The inorganic layer (2) referred to in the present invention includes, as materials, metals such as Al, Si, Ti, Zn, Zr, Mg, Sn, Cu, and Fe, and oxides, nitrides, fluorides, sulfides of these metals. Specific examples include SiOx (x = 1.0 to 2.0), alumina, magnesia, zinc sulfide, titania, zirconia, cerium oxide, or a mixture thereof. The inorganic layer (1) may be a single layer or a laminate of two or more layers.

In the present invention, a particularly preferable inorganic layer (2) is preferably a composite oxide layer prepared by vapor deposition of aluminum oxide and silicon oxide or a composite oxide layer prepared by vapor deposition of aluminum oxide and magnesium oxide.
In the case of a composite oxide prepared by vapor deposition of aluminum oxide and silicon oxide, the weight ratio of aluminum oxide contained in the inorganic compound thin film is not particularly limited, but aluminum oxide and silicon oxide (oxidized) contained in the inorganic compound thin film are not limited. The ratio of aluminum oxide is preferably 10% by weight or more, more preferably 20% by weight or more, and further preferably 30% by weight or more with respect to 100% by weight of the total (magnesium). The aluminum oxide ratio is preferably 90% by weight or less, more preferably 75% by weight or less, and further preferably 65% by weight or less.
If the ratio of aluminum oxide exceeds 75% by weight, the flexibility tends to be poor, so that cracking due to handling is likely to occur, and stable barrier properties may be difficult to obtain. On the other hand, when the ratio of aluminum oxide is less than 30% by weight, the barrier property tends to be lowered.

The film thickness of the inorganic layer (2) of the present invention is not particularly limited, but is preferably 5 to 500 nm, more preferably 8 nm or more and 100 nm or less, and the inorganic layer (2) having a film thickness of less than 5 nm is satisfactory. However, even if the thickness exceeds 500 nm, the corresponding effect of improving the gas barrier property cannot be obtained, which is disadvantageous in terms of bending resistance and manufacturing cost. It becomes.

As a method for forming the inorganic layer (2) of the present invention, a known method such as a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method or an ion plating method, a chemical vapor deposition method such as PECVD, or the like is employed.

In the vacuum deposition method, the deposition material is a metal such as aluminum, silicon, titanium, magnesium, zirconium, cerium, zinc, SiOx (x = 1.0 to 2.0), alumina, magnesia, zinc sulfide, titania, Compounds such as zirconia and mixtures thereof are used. As the heating method, resistance heating, induction heating, electron beam heating or the like is employed. Moreover, you may employ | adopt the reactive vapor deposition method which introduce | transduced oxygen etc. as a reactive gas, or used means, such as ozone addition and ion assist.

(Organic layer)
The organic layer (3) referred to in the present invention is obtained by crosslinking at least two kinds of compounds having an acryloyl group and / or a methacryloyl group. Furthermore, at least one of the compounds needs to be a silane coupling agent. At this time, the weight of the compound of the silane coupling agent is preferably 5% by weight or more based on the total weight of the compound having an acryloyl group or a methacryloyl group.
Examples of the compound having an acryloyl group and / or a methacryloyl group include a compound having an acryloyl group and / or a methacryloyl group and not a silane coupling agent, and a compound having an acryloyl group and / or a methacryloyl group and a silane coupling agent.

The compound having an acryloyl group and / or a methacryloyl group and not a silane coupling agent is not particularly limited. For example, phenoxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, methacrylic acid, glycidyl methacrylate, 2-methacryloyloxyethyl acid phosphate, diethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1.4-butanediol dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, Triethylene glycol dimethacrylate, PEG # 200 dimethacrylate, PEG # 400 dimethacrylate Methoxypolyethylene glycol methacrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxydipropylene glycol acrylate, 2-hydroxybutyl acrylate, 2-hydroxy-3phenoxypropyl acrylate, 2-acryloyloxyethyl succinic acid, 2 -Acryloyloxyethyl hexahydrophthalic acid, 2-acryloyloxyethyl-phthalic acid, 2-acryloyloxyethyl acid phosphate, triethylene glycol diacrylate, PEG200 # diacrylate, PEG400 # diacrylate, PEG600 # diacrylate, Polytetramethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxy Phosphoric acid neopentyl glycol acrylic acid adduct, trimethylolpropane triacrylate, EO modified trimethylolpropane triacrylate, and the like pentaerythritol triacrylate.

The compound which is a silane coupling agent having an acryloyl group and / or a methacryloyl group refers to an organosilicon compound having at least an acryloyl group or a methacryloyl group and a hydrolyzable group. For example, raising 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, etc. Can do.

These compounds preferably have a viscosity at 20 ° C. of 500 mPa · s or less from the viewpoint of material supply during vapor deposition. More preferably, it is 200 mPa * s or less.
From the viewpoint of safety, the skin primary irritation index (PII) is 2 or less, preferably 1 or less.

Silane coupling agent having acryloyl group and / or methacryloyl group with respect to the total weight of the compound having acryloyl group and / or methacryloyl group and not silane coupling agent and compound having acryloyl group and / or methacryloyl group and silane coupling agent The weight ratio of the compound can be calculated by measuring the amount of silicon atoms contained in the organic layer.

The compound having an acryloyl group and / or a methacryloyl group and being a silane coupling agent contributes to improving the adhesion between the inorganic layer and the organic layer, but the content is preferably 5% by weight or more. More preferably, it is 10 weight% or more. As the content of the compound having an acryloyl group and / or methacryloyl group and being a silane coupling agent increases, the adhesion is improved, but the compound having an acryloyl group and / or methacryloyl group and being a silane coupling agent is expensive and Moreover, since the excess which cannot react at the interface with the inorganic layer also increases, 50% by weight or less is preferable. It is more preferably 40% by weight or less, and most preferably 30% by weight or less.

The organic layer has a protective function for the inorganic layer and a function for improving the adhesion when pasted with a sealant and an adhesive. In order to satisfy the protective function, the organic layer is preferably 50 nm or more. If the thickness is 50 nm or less, the inorganic layer cannot be protected from pigment particles contained in the pigment ink. Further, when the film thickness is 150 nm or more, the protective function is increased, but the distortion is increased and the adhesion is reduced.

The flash vapor deposition referred to in the present invention is a method in which a vapor deposition material is brought into contact with a heated plate or the like little by little and instantly evaporated. In general, a material such as a plate to be heated may have only heat resistance, but a metal is preferable from the viewpoint of workability. In the present invention, the heating plate material metal is preferably copper having a purity of at least 90%. In other metals, a compound having an acryloyl group or a methacryloyl group used in the present invention may be cross-linked by a heating plate, resulting in an increase in molecular weight and difficulty in evaporation. The material that has not evaporated adheres to the surface of the heating plate. The adhering material is polymerized and becomes a solid substance, which cuts off the heat from the heating plate to reduce the evaporation amount and lower the evaporation efficiency.

A known technique can be used as a method of heating the heating plate. Examples include a method of installing a heating wire so that thermal contact is good on the opposite surface where the vapor deposition material contacts the heating plate, a method of circulating a heating medium, and a method of heating with an IR heater.

The temperature of the heating plate is preferably 200 ° C. or higher for a compound of 500 mPa · s or less that has fluidity as a liquid supply. High temperature is preferable for flash vapor deposition, but if it is too high, the compound decomposes and is not preferable. Moreover, 300 degrees C or less is preferable from mechanical factors, such as a dimensional change of the heating plate with temperature.

As a method of crosslinking and curing a liquid organic layer of a compound having an acryloyl group and / or a methacryloyl group formed on an inorganic layer of a plastic film by flash vapor deposition, curing by electron beam irradiation is suitable. Although there is a curing method by ultraviolet irradiation, a photopolymerization initiator must be mixed with the compound, and in this case, storage in a cool and dark place is necessary, which is a problem.

A known source can be used as the electron source. The acceleration voltage of electrons is preferably 500 V or higher. If it is 500 V or less, electrons do not sufficiently enter the compound, and radicals necessary for initiation of crosslinking are not sufficiently generated. At an acceleration voltage of 10 kV or more, the number of electrons that pass through the organic layer increases and efficiency decreases. In addition, the generation of X-rays also occurs, causing a problem in safety and health.

The transparent vapor deposition barrier film manufacturing method of the present invention will be described with reference to FIGS. The plastic film roll of the substrate is set on the unwinding roll (4). The unrolled plastic film (1) passes through the plasma processor (5) to treat the surface. The ceramic contained in the crucible (7) is heated and evaporated by the electron gun (6) to form an inorganic layer on the plastic film running on the inorganic coating roll (8).

A mixed compound (13) comprising at least two or more kinds of compounds having an acryloyl group and / or a methacryloyl group, and at least one of which is a silane coupling agent, is placed in a liquid container (14). The mixed compound (13) is transferred into the organic vapor deposition source (16) by the liquid pump (15). The transferred mixed compound (13) comes into contact with the heating plate (18) heated by the heating wire (17) and becomes steam. The vapor moves in the organic vapor deposition source (16) heated so as not to condense and reaches the organic nozzle (9).

It vapor-deposits on the plastic film which laminated | stacked the inorganic layer which drive | works on an organic coating roll (10) from the heated organic nozzle (9). A liquid layer of the compound mixture is formed on the inorganic layer. The formed liquid layer is irradiated with an electron beam using an electron beam irradiation device (11) and cured by crosslinking. In this way, an organic layer is formed on the inorganic layer and wound around the winding roll (12).

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples. The film properties obtained in each example were measured and evaluated by the following methods.

(1) Adhesive strength of laminate A 40 μm thick polyethylene film (Toyobo Co., Ltd. L4102) was adhered to a transparent vapor-deposited barrier film using an adhesive for dry lamination (TM590, CAT56 manufactured by Toyo Morton Co., Ltd.) to produce a laminate film did.
The adhesive strength of the laminate is measured by cutting the laminate film to a width of 15 mm, peeling a part of the laminate film, using a universal material testing machine (Tensilon), pulling the peel piece at a speed of 300 mm / min, and peeling it 180 °. did.

(2) Oxygen permeation amount Oxygen permeation amount is measured according to JIS K7126-2 A method by preparing an oxygen permeation amount measuring device (manufactured by OXTRAN 2/21 MOCOM) in an atmosphere of temperature 23 degrees and humidity 65% RH. did.

(3) Measurement of film thickness and composition of inorganic layer A method for measuring the composition of each content of aluminum oxide and silicon oxide in the inorganic film will be described below.
First, a film having an inorganic compound thin film composed of aluminum oxide and silicon oxide was prepared, and the adhesion amounts of aluminum oxide and silicon oxide were determined by an inductively coupled plasma emission method (ICP method). The composition of the prepared inorganic oxide thin film was calculated from the obtained adhesion amount of aluminum oxide and silicon oxide.
The film thickness was calculated on the assumption that the density of the inorganic oxide thin film was 80% of the bulk density, and that the volume was maintained even when aluminum oxide and silicon oxide were mixed.
The content ratio wa (%) in the aluminum oxide film and the content ws (%) in the silicon oxide film are Ma (g / cm ² ) as the adhesion amount per unit area of aluminum oxide, and the unit area of silicon oxide. When the amount of adhesion per unit is Mm (g / cm ² ), the following formulas (1) and (2) are obtained.
wa = 100 × [Ma / (Ma + Mm)] (1)
ws = 100-wa (2)
The deposition amount per unit area of aluminum oxide is Ma (g / cm ² ), the density of the bulk is ρa (3.97 g / cm ³ ), and the deposition amount per unit area of silicon oxide is Ms (g / cm ^2). ), Where the bulk density is ρs (2.65 g / cm ³ ), the film thickness t (nm) is obtained by the following formula (3).
t = ((Ma / (ρa × 0.8) + Ms / (ρs × 0.8)) × 10 ⁻⁷ ... Formula (3) Several types of inorganic oxide thin films that define the film thickness and composition are prepared and fluorescence is obtained. A calibration curve was prepared by measuring with an X-ray apparatus.
Using a fluorescent X-ray analyzer (“ZSX100e” manufactured by Rigaku Corporation), the film thickness composition was measured with a calibration curve prepared in advance. The conditions for the excitation X-ray tube were 50 kV and 70 mA.

(4) Measurement of film thickness and composition of organic layer Acryloyl relative to the total weight of a compound having an acryloyl group and / or methacryloyl group and not a silane coupling agent and a compound having an acryloyl group and / or methacryloyl group and a silane coupling agent The weight ratio of the compound having a group and / or a methacryloyl group and being a silane coupling agent was calculated by measuring the amount of silicon atoms contained in the organic layer.
A cured organic layer is formed in advance with various thicknesses by irradiation with an electron beam comprising a compound having an acryloyl group and / or a methacryloyl group and being a silane coupling agent alone. This organic layer was measured with a fluorescent X-ray analyzer, and a calibration curve was prepared from the fluorescent X-ray intensity of silicon atoms and the thickness of the organic layer consisting of the compound alone as the silane coupling agent.
The film thickness of an organic layer obtained by crosslinking and copolymerizing a compound having an acryloyl group and / or a methacryloyl group and not a silane coupling agent and a compound having an acryloyl group and / or a methacryloyl group and a silane coupling agent was measured. Further, measurement was performed with fluorescent X-rays, and the equivalent film thickness of the compound having an acryloyl group and / or a methacryloyl group and being a silane coupling agent was calculated from the calibration curve using the value.
As a method for measuring the film thickness of the organic layer, there is a method in which a cross section is directly measured by a transmission electron microscope (TEM). In addition, a method of measuring using interference by an ellipsometer can be used. In this case, a correlation is obtained with the value obtained by TEM, and the value is converted into the value.
The content ratio was calculated by dividing the equivalent film thickness of the compound having an acryloyl group and / or methacryloyl group calculated from the result of fluorescent X-ray and being a silane coupling agent by the total film thickness of the organic layer.
At this time, an organic layer composed of a compound alone having an acryloyl group and / or a methacryloyl group and a silane coupling agent, a compound having an acryloyl group and / or a methacryloyl group and not a silane coupling agent, and an acryloyl group and / or a methacryloyl group The density of the organic layer crosslinked and copolymerized with the compound that is a silane coupling agent was calculated as the same.

(Example 1)
While a polyethylene terephthalate film (E5100 thickness 12 μm, manufactured by Toyobo Co., Ltd.) was run as a plastic film at 150 m / min, aluminum oxide and silicon oxide were separately put into a crucible and heated individually with an electron gun for vapor deposition. . The formed inorganic layer had a thickness of 13 nm and an aluminum oxide content of 41% by weight.
Subsequently, 9 parts of PEG200 # diacrylate (Light Ester 4EG manufactured by Kyoeisha Chemical Co., Ltd.) and 1 part of silane coupling agent 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are formed on the inorganic layer. Was added dropwise on a copper heating plate at a rate of 7 ml / min. The heating plate is heated by a heating wire, and the temperature is controlled at 250 ° C. by a thermocouple installed behind the heating plate. Mixed compound vapor was applied onto the inorganic layer from an organic nozzle heated to 200 ° C. The formed liquid layer was irradiated with electrons from an electron gun at an acceleration voltage of -8 kV and a current of 400 mA to be crosslinked and cured.
The organic film thickness was 77 nm. Table 1 shows the oxygen transmission amount and the laminate strength of the transparent barrier film. Table 2 shows the situation of the heating plate.

(Comparative Example 1)
In Example 1, it carried out similarly to Example 1 except heating the copper heating plate to 110 degreeC with the heat medium, and dripping the mixed compound at the speed | rate of 1 ml / min. The state of the heating plate is shown in Table 2.

(Comparative Example 2)
Comparative Example 1 was the same as Comparative Example 1 except that an aluminum heating plate was used. Observe the condition of the heating plate and record it in Table 2.

According to the present invention, a transparent barrier film having excellent printing resistance and excellent adhesion can be provided.

1: Plastic film 2: Inorganic layer 3: Organic layer 4: Unwinding roll 5: Plasma treatment device 6: Electron gun 7: Crucible 8: Inorganic coating roll 9: Organic nozzle 10: Organic coating roll 11: Electron beam irradiation device 12 : Winding roll 13: mixed compound 14: liquid container 15: liquid pump 16: organic vapor deposition source 17: heating wire 18: heating plate

Claims

A method for producing a transparent barrier film having an inorganic layer and an organic layer in this order on at least one side of a plastic film, wherein the organic layer is formed by crosslinking at least two kinds of compounds having an acryloyl group and / or a methacryloyl group. In addition, at least one of at least two kinds of compounds having an acryloyl group and / or a methacryloyl group is a silane coupling agent, and the compound is heated to 200 ° C. or higher and 300 ° C. or lower. A method for producing a transparent barrier film, comprising forming a liquid organic layer by flash vapor deposition using copper, and then curing the film by electron beam irradiation.
The method for producing a transparent vapor-deposited barrier film according to claim 1, wherein the acceleration voltage of the electron beam is 500 V or more and 10 kV or less.