JP2010100916A - Gas barrier material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas barrier material which has a vapor-deposition film containing hydroxy-apatite as a film-forming component, formed on the surface of a plastic base material and has an extremely improved gas-barrier property of the plastic base material by making the best use of a characteristic of the hydroxy-apatite. <P>SOLUTION: The gas barrier material is composed of a plastic base material 1, and a vapor-deposition film 3 including a region 3a in which calcium phosphate compounds are distributed in stratum on the surface of the plastic base material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas barrier material in which a vapor deposition film is formed on the surface of a plastic substrate, and more particularly to a gas barrier material in which a vapor deposition film containing a calcium phosphate compound component is formed on the surface of a plastic substrate.

Conventionally, a calcium phosphate compound called hydroxyapatite is known. This compound has the following formula:
Ca ₁₀ (PO ₄ ) ₆ (OH) ₂
The biocompatibility is high because it is close to the components of human bones and teeth, and it is applied to various applications using this characteristic. For example, it is used for medical purposes such as artificial bones, artificial tooth roots (implants), and dental abrasives, and is also used as an antibacterial material in combination with titanium oxide. Furthermore, it is also used in applications such as chromatography for the purpose of separation and purification of proteins and cosmetics and food additives, and is also known as a catalyst for adding ethanol to gasoline.

  As described above, hydroxyapatite is used for various purposes by taking advantage of its high biocompatibility. In recent years, it has also been proposed to apply it to packaging materials. Has been proposed to impart antibacterial properties by forming a deposited film of hydroxyapatite on the surface of a thin film film such as polycarbonate. Patent Document 2 discloses that hydroxyapatite and hydroxyapatite are formed on the surface of a transparent food packaging sheet. It has been shown that by forming a coating layer with titanium dioxide, Escherichia coli and the like can be adsorbed and retained to prevent the propagation of various bacteria in the packaged food, and the freshness of the food can be maintained.

JP-A-6-92366 JP 2001-191458 A

  However, application of hydroxyapatite to packaging materials has hardly been established, and sufficient studies have not been made. For example, the vapor deposition film of hydroxyapatite proposed in Patent Document 1 is completely wrong, and such a vapor deposition film does not have antibacterial properties. In fact, in the examples of Patent Document 1, antibacterial properties are not evaluated. From this, it can be said that Patent Document 1 does not recognize the characteristics of the hydroxyapatite deposited film at all. Furthermore, Patent Document 2 shows that the coating film containing apatite and titanium dioxide is excellent in the ability to adsorb bacteria, but other characteristics such as gas barrier properties and the most required characteristics as a packaging material are examined. Has not been made.

As a result of repeated research on the hydroxyapatite deposited film as described above from the viewpoint of packaging materials, the present inventors have not only excellent transparency but also excellent gas barrier properties. I found.
Accordingly, an object of the present invention is to provide a gas barrier in which a vapor-deposited film containing hydroxyapatite as a film-forming component is formed on the surface of a plastic substrate, and the gas barrier property of the plastic substrate is remarkably enhanced by utilizing the characteristics of hydroxyapatite. To provide materials.

  As a result of further research on the gas barrier properties of the hydroxyapatite vapor-deposited film described above, the inventors have formed such a hydroxyapatite vapor-deposited film on the surface of a plastic substrate in combination with other vapor-deposited films. As a result, it was found that the gas barrier property is synergistically improved, and the present invention has been completed.

  According to the present invention, a plastic substrate and a vapor deposition film including a region in which the calcium phosphate compound is distributed in a layer form on the surface or inside are formed on at least one surface of the plastic substrate. A gas barrier material is provided.

In the present invention,
(1) The calcium phosphate compound is hydroxyapatite,
(2) The region in which the calcium phosphate compound is distributed in a layered manner has a thickness of at least 2 nm,
(3) The deposited film includes a region in which the calcium phosphate is distributed in layers together with a region in which the calcium compound is distributed in layers,
(4) The silicon compound is at least one selected from silicon oxide, silicon nitride, or silicon nitride oxide,
Is preferred.

  The gas barrier material of the present invention has a structure in which a vapor deposition film is formed on the surface of a plastic substrate. In this vapor deposition film, a region in which calcium phosphate compounds are distributed in layers (hereinafter referred to as a calcium phosphate compound layer). Gas barrier properties are remarkably improved.

For example, as shown in the experimental results of Examples described later, the moisture permeation amount when a 100 nm thick polyethylene terephthalate (PET) film is formed on the surface of a 100 μm thick polyethylene terephthalate (PET) film is 4.0. ^3. The water permeation amount when a hydroxyapatite vapor deposition film having a thickness of 100 nm is formed on the surface of the same PET film is the same as that when a silicon oxide vapor deposition film is formed, which is × 10 ⁻² g / m ² / day. 0 × 10 ⁻² g / m ² / day (Experimental Example 1, Experimental Example 2). Therefore, when a 50 nm silicon oxide vapor-deposited film and a 50 nm hydroxyapatite vapor-deposited film are formed on this PET film (the order of forming these films may be any), the water permeation amount is 4.0 × 10 ^−2. It is expected to be g / m ² / day. However, as shown in Experimental Example 3, when the silicon oxide vapor-deposited film and the hydroxyapatite vapor-deposited film having the above thickness are actually formed on the PET film, the water permeation amount is 10 ⁻³ g / m ² / It can be seen that the barrier property is much better than expected. Such a barrier property is similar to oxygen.

  As described above, in the present invention, a layer in which the calcium phosphate compound is distributed in layers is formed in the vapor deposition film, so that it is expected from the case where the vapor deposition film of the calcium phosphate compound and the vapor deposition film of other compounds are formed independently. The gas barrier property which is remarkably superior to that obtained is obtained.

In the present invention, the reason why the excellent gas barrier property can be obtained as described above is not clearly elucidated, but the present inventors presume as follows.
That is, when a deposited film is formed by sputtering or the like, it is known that defects such as pinholes exist in the film to a small extent. This is due to the deposition of a phosphate compound typified by hydroxyapatite. The same applies not only to the film but also to the case where a deposited film of another compound is formed. However, the vapor deposition film of a phosphoric acid compound such as hydroxyapatite itself has excellent gas barrier properties, and the vapor deposition film of the present invention has a region in which the compound having excellent gas barrier properties is distributed in a layered manner. Since it has a multilayer structure on the surface or inside, the defects existing in each layer are closed by the adjacent layers, and as a result, the gas barrier property can be effectively prevented from being deteriorated due to the defects present in the deposited film. As a result, the gas barrier property in the region where the calcium phosphate compound is distributed and the gas barrier property in the region where the other compound is distributed are fully exhibited without being reduced, and the excellent gas barrier property as described above is exhibited. It seems to be done.

  Since the gas barrier material of the present invention has excellent barrier properties against moisture (water vapor) and oxygen, it is extremely useful in the field of packaging materials, but the region where the calcium phosphate compound is distributed also has good transparency. Therefore, by forming such a region in a vapor-deposited film having good transparency, it can be effectively applied to applications in fields other than packaging materials that require transparency as well as gas barrier properties.

Hereinafter, the present invention will be described in detail based on specific examples shown in the accompanying drawings.
FIG. 1 is a diagram showing a schematic cross-sectional structure of a gas barrier material of the present invention.

  In FIG. 1, the gas barrier material of the present invention comprises a plastic substrate 1 and a vapor deposition film 3 formed on the surface of the plastic substrate 1, and the vapor deposition film 3 has a region in which calcium phosphate compounds are distributed in layers. The (calcium phosphate compound layer) 3a is formed, and has the area | region (other inorganic compound layer) 3b in which the other inorganic compound was distributed with such a calcium phosphate compound layer 3a.

  As understood from FIG. 1, the position of the calcium phosphate compound layer 3 a in the vapor deposition film 3 is not particularly limited, and the calcium phosphate compound layer 3 a is the surface of the plastic substrate 1 as shown in FIG. It may be located on the side, or as shown in FIG. 1B, it may be formed exposed on the surface of the vapor deposition film 3, and further shown in FIG. As described above, the calcium phosphate compound layer 3a may be sandwiched between other inorganic compound layers 3b. Although not shown, it is possible to have a structure in which a plurality of calcium phosphate compound layers 3b are formed, and it is of course possible to form the vapor deposition film 3 on both surfaces of the plastic substrate 1. That is, the layer structure of the vapor deposition film 3 can be an appropriate layer structure according to the use of the gas barrier material and the required characteristics.

<Plastic substrate 1>
In the present invention, the plastic substrate 1 on which the vapor deposition film 3 is to be formed is a thermoplastic resin known per se, such as low-density polyethylene, high-density polyethylene, polypropylene, poly-1-butene, poly-4-methyl- Olefin resins such as 1-pentene or α-olefins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, random or block copolymers, cyclic olefin copolymers; ethylene / vinyl acetate copolymer Copolymers, ethylene / vinyl alcohol copolymers, ethylene / vinyl copolymers such as ethylene / vinyl chloride copolymers; polystyrene, acrylonitrile / styrene copolymers, ABS, styrene such as α-methylstyrene / styrene copolymers Resin: polyvinyl chloride, polyvinylidene chloride, vinyl chloride / chloride Vinylidene copolymers, vinyl resins such as polymethyl acrylate and polymethyl methacrylate; polyamide resins such as nylon 6, nylon 6-6, nylon 6-10, nylon 11 and nylon 12; polyethylene terephthalate, polybutylene terephthalate, Polyester resins such as polyethylene naphthalate and their copolyesters; polycarbonate resins; polyphenylene oxide resins; biodegradable resins such as polylactic acid; or blends of these resins;

  These plastic base materials 1 may have any form depending on the application, and may be in the form of, for example, a film or sheet, a bottle, a cup, a tube, or other shaped molded article, However, when the vapor deposition film 3 is formed by sputtering, the film base 1 in the form of a film or a sheet is generally used, and plasma CVD or the like is used. When film formation is performed, the film substrate 1 may have an arbitrary form. For example, the vapor deposition film 3 can be formed on either the inner surface or the outer surface of the film substrate 1 as a form of a bottle or the like. When this gas barrier material is used in the field of packaging materials, polyethylene terephthalate (PET) or polyolefin resin is the most common material for the plastic substrate 1.

  Further, the plastic substrate 1 may have a multilayer structure. For example, the above-described thermoplastic resin (preferably an olefin resin) is used as an inner and outer layer, and an oxygen-absorbing layer is provided between these inner and outer layers. It may be a gas barrier multilayer structure provided.

  The thickness of the plastic substrate 1 described above is not particularly limited, and may have an appropriate thickness depending on the application.

<Calcium phosphate compound layer 3a>
The calcium phosphate compound layer 3a in the vapor deposition film 3 is a region formed by the calcium phosphate compound, and the calcium phosphate compound is distributed in a layered manner and exhibits high barrier properties against moisture, oxygen, and the like.

  In the present invention, the thickness of the calcium phosphate compound layer 3a is not particularly limited, but is preferably 2 nm or more in order to sufficiently exhibit the gas barrier property improving effect. In addition, if it is formed thicker than necessary, even if the gas barrier property is improved by that amount, the plastic substrate 1 may be impaired in properties such as flexibility and transparency. For example, the thickness of the calcium phosphate compound layer 3a should be in the range of 1 μm or less.

As the calcium phosphate compound, hydroxyapatite is representative. As mentioned earlier, hydroxyapatite ideally has the following formula:
Ca ₁₀ (PO ₄ ) ₆ (OH) ₂
However, when such a compound is formed by vapor deposition, the composition is likely to fluctuate due to P deficiency or the like, so the composition of the calcium phosphate compound in the film is, for example, in atomic ratio,
Ca: P: O = 1: 0.1 to 0.7: 0.3 to 2.7
The gas barrier property is excellent as long as it is adjusted to such a range.

  The vapor deposition for forming the calcium phosphate compound layer 3a can be performed by sputtering, a CVD method using microwave plasma, high frequency plasma, or the like, but sputtering is preferable. That is, when a film is formed by the CVD method, a reactive gas containing an organic acid Ca salt or the like as a Ca source and phosphoric acid or the like as a P source is used, but it is difficult to adjust the composition of the film. Film formation by sputtering is preferred.

When vapor deposition is performed by sputtering, hydroxyapatite is preferably used as a target, but considering the deficiency of P, a calcium phosphate compound having a P / Ca (atomic ratio) of about 0.8 to 1.2 ( For example, CaHPO ₄ ) or the like can be used. Also, as the ion source for sputtering, ions of an inert gas such as He, Ne, Ar, Kr, Xe are used, and the plastic substrate 1 on which a film is to be formed usually in an atmosphere of a vacuum degree of 10 Pa or less. Sputtering is performed under heating to a temperature that does not cause thermal deformation, and film formation is performed for a period of time until the calcium phosphate compound layer 3a having a target thickness is formed.

  Further, in sputtering, it is preferable to use ion irradiation together for composition adjustment, and as the ions to be irradiated, ions of inert gas and oxygen ions exemplified above are preferable, and ion acceleration at this time The voltage may usually be in the range of 100V to 2kV.

<Other inorganic compound layer 3b>
In the present invention, the other inorganic compound layer 3b that forms the vapor deposition film 3 together with the calcium phosphate compound 3a described above can be formed by vapor deposition, and various metal compounds that can form a transparent vapor deposition film, such as Si and Al. Formed from a compound such as Ti, Zr, etc., but particularly from a viewpoint of high gas barrier properties against oxygen and the like and easy film formation, formed from a silicon compound, particularly silicon oxide, silicon nitride or silicon nitride oxide. It is preferred that In addition, the inorganic compound layer 3b may have a multilayer structure, for example, a structure in which a layer made of silicon nitride or the like is formed on a layer made of silicon oxide. Of course, an organic silicon polymer film or an organic inorganic silicon polymer film may be provided on the surface or inside of silicon oxide, silicon nitride, or silicon oxide.
Furthermore, it is also possible to form a hydrocarbon-based film such as a DLC film as the vapor deposition film 3b.

  The thickness of the other inorganic compound layer 3b is not particularly limited, and may have an appropriate thickness depending on the use of the gas barrier material. From the viewpoint of sufficiently exhibiting the characteristics of the layer 3b. It preferably has a thickness of 2 nm or more. In addition, if the thickness of the inorganic compound layer 3b is excessively large, there is a possibility that the flexibility, transparency, etc. peculiar to the plastic substrate 1 may be impaired. Therefore, generally, the thickness of the calcium phosphate compound layer 3a described above is reduced. Accordingly, the thickness of the inorganic compound layer 3b may be set so that the total thickness of the vapor deposition layer 3 is 2 μm or less.

The inorganic compound layer 3b in the vapor deposition film 3 can be formed by sputtering, plasma CVD, or the like according to a conventional method.
Sputtering may be performed under known conditions. For example, an inorganic compound for forming the layer 3b such as silicon oxide (silica), silicon nitride, or silicon nitride oxide is used as a target, and inert gas ions are used for sputtering. It can be used as an ion source while heating the plastic substrate 1 to a temperature at which deformation does not occur in an atmosphere of an appropriate degree of vacuum. In this case, ion irradiation with inert gas ions is used in combination as necessary. You can also

<Application>
The gas barrier material of the present invention in which the vapor deposition film 3 is formed on the surface of the plastic substrate 1 as described above has extremely high gas barrier properties, particularly moisture barrier properties, and the calcium phosphate compound layer 3a has reduced transparency. Because it is not an area to be used, it has excellent transparency as a whole, and it is a substance that does not cause any problems when calcium phosphate compounds, especially hydroxyapatite, are taken into the body together with food. Because it is used even if it is affixed to, it can be used as a packaging material, particularly as a bag-like container in the form of a film or a sheet, and as a container for food or medical products. Preferably used.

  In addition, it is expected to be used as a barrier material for liquid crystal display panel protection panels, glass substitute plastic sheets for solar cells, and organic EL elements that require prevention of moisture and oxygen penetration and transparency. . In particular, it is most preferable to provide the barrier material of the present invention having the above-described characteristics on the transparent electrode side of the organic EL element in which the organic light emitting layer is provided between the transparent electrode substrate and the counter electrode substrate.

  The invention is illustrated by the following experimental example.

1. Composition analysis method in film The composition of the film was measured by an X-ray photoelectron spectrometer (Quantum 2000) manufactured by PHI. In the case of a silicon oxide film, the respective compositions of silicon and oxygen are measured. In the case of a silicon nitride film, the respective compositions of silicon and nitrogen are measured. In the case of a silicon nitride oxide film, the respective compositions of silicon, nitrogen and oxygen are measured. In the case of a hydroxyapatite film, the respective compositions of calcium, phosphorus and oxygen were measured.

2. Moisture permeability measurement method The moisture permeability (40 ° C.-90%) of the film base material on which the deposited film was formed was measured with a moisture permeability measuring device (manufactured by Modern Control, PERMATRAN).

3. Oxygen transmission rate measuring method The oxygen transmission rate (25 degreeC-60%) of the film base material in which the vapor deposition film was formed was measured with the oxygen transmission rate measuring apparatus (Modern Control company make, OX-TRAN).

<Experimental example 1>
For the deposition of silicon oxide film, a high frequency output power source with a frequency of 27.12 MHz and a maximum output of 2 kW, a matching box, a metal cylindrical plasma processing chamber with a diameter of 300 mm and a height of 450 mm, and an oil rotary vacuum pump that evacuates the processing chamber. The CVD apparatus which has is used.
As the plastic substrate, a polyethylene terephthalate (PET) film having a 120 mm square and a thickness of 100 μm was used.
A plastic substrate is placed on parallel plates in the processing chamber, hexamethyldisiloxane is introduced at 3 sccm and oxygen is introduced at 45 sccm. A high frequency oscillator is used to oscillate a high frequency with an output of 600 W, and plasma treatment is performed on one surface of the plastic substrate. A silicon oxide film was coated.
The composition of the silicon oxide film compound in the film was atomic ratio, Si: O = 1: 2.1, and the coating time was controlled so that the film thickness was 100 nm.
Table 1 shows the moisture permeation and oxygen permeation of the plastic substrate coated with the silicon oxide film.

<Experimental example 2>
For deposition of hydroxyapatite film, a high frequency output power source with a frequency of 13.56 MHz and a maximum output of 200 W, a matching box, a metal-type cylindrical sputter processing chamber with a diameter of 400 mm and a height of 500 mm, and an oil rotary vacuum pump that evacuates the processing chamber. A sputtering apparatus (manufactured by ULVAC: production number MB04-1047) was used.
The same base material as in Experimental Example 1 was used as the plastic base material.
A plastic substrate is installed in the processing chamber, and after introducing 4 sccm of argon, a high frequency oscillator is used to oscillate a high frequency with an output of 150 W, and a hydroxyapatite target is sputtered to cover one surface of the plastic substrate with a hydroxyapatite film. did.
The composition of the hydroxyapatite film compound in the film is atomic ratio,
The coating time was controlled so that Ca: P: O = 1: 0.3: 0.6 and the film thickness was 100 nm.
Table 1 shows the moisture permeation amount and oxygen permeation amount of the plastic substrate coated with this hydroxyapatite film.

<Experimental example 3>
Using the same apparatus and the same plastic substrate as in Experimental Example 1, the coating time was controlled so that the film thickness was 50 nm by the same coating method, and the silicon oxide film was coated.
Thereafter, the surface of the plastic substrate was coated with a hydroxyapatite film by the same apparatus and the same coating method as in Experimental Example 2 while controlling the coating time so that the film thickness became 50 nm.
As a result, the combined film thickness of the silicon oxide film and the hydroxyapatite film was set to 100 nm, which is the same as Experimental Example 1 and Experimental Example 2.
Table 1 shows the moisture permeation amount and oxygen permeation amount of the plastic substrate having the hydroxyapatite film coated on the surface of the silicon oxide film.

<Experimental example 4>
Using the same apparatus and the same plastic substrate as in Experimental Example 2, the coating time was controlled so that the film thickness was 50 nm by the same coating method, and the hydroxyapatite film was coated.
Thereafter, the surface of the plastic substrate was coated with a silicon oxide film by the same apparatus and the same coating method as in Experimental Example 1 while controlling the coating time so that the film thickness was 50 nm.
As a result, the combined thickness of the hydroxyapatite film and the silicon oxide film was set to 100 nm as in Experimental Examples 1 to 3.
Table 1 shows the moisture permeation amount and oxygen permeation amount of the plastic base material in which the surface of this hydroxyapatite film is coated with a silicon oxide film.

<Experimental example 5>
Using the same equipment and the same plastic base material as in Experimental Example 2, installing a plastic base material in the processing chamber, introducing 15 sccm of nitrogen, oscillating a high frequency with an output of 150 W by a high frequency oscillator, and performing a sputtering process on a silicon target A silicon nitride film was coated on one side of the plastic substrate.
The composition of the silicon nitride film compound in the film was an atomic ratio of Si: N = 1: 1.3, and the coating time was controlled so that the film thickness was 50 nm.
After that, using the same equipment and the same plastic base material as those of Experimental Example 2 on the surface of the plastic base material, the same coating method is used to perform sputtering treatment on the hydroxyapatite target and control the coating time so that the film thickness becomes 50 nm. And coated with a hydroxyapatite film.
As a result, the combined film thickness of the silicon nitride film and the hydroxyapatite film was set to 100 nm, which is the same as in Experimental Examples 1 to 4.
Table 1 shows the water permeation amount and oxygen permeation amount of the plastic base material in which the surface of this silicon nitride film is coated with a hydroxyapatite film.

<Experimental example 6>
Using the same equipment and the same plastic base material as in Experimental Example 2, placing the plastic base material in the processing chamber, introducing 6 sccm of argon, oscillating high frequency with a high frequency oscillator at 150 W output, and sputtering the silicon nitride target A silicon nitride oxide film was coated on one surface of the plastic substrate.
The composition of the silicon nitride oxide film compound in the film was atomic ratio Si: N: O = 1: 0.8: 0.2, and the coating time was controlled so that the film thickness was 50 nm.
After that, using the same equipment and the same plastic base material as those of Experimental Example 2 on the surface of the plastic base material, the same coating method is used to perform sputtering treatment on the hydroxyapatite target and control the coating time so that the film thickness becomes 50 nm. And coated with a hydroxyapatite film.
As a result, the combined thickness of the silicon nitride oxide film and the hydroxyapatite film was set to 100 nm, which is the same as in Experimental Examples 1 to 5.
Table 1 shows the moisture permeation amount and oxygen permeation amount of the plastic substrate in which the hydroxyapatite film was coated on the surface of the silicon nitride oxide film.

  From the above results, it can be seen that the silicon oxide film or the hydroxyapatite deposited film of Experimental Example 1 and Experimental Example 2 has a reduced water permeation amount and oxygen permeation amount as compared with the untreated PET film. It can be seen that the water permeation amount and the oxygen permeation amount are greatly reduced by the combination with other deposited films as shown in FIGS.

The figure which shows schematic sectional structure of the gas barrier material of this invention.

Explanation of symbols

1: Plastic base material 3: Deposition film 3a: Calcium phosphate compound layer 3b: Other inorganic compound layer

Claims (5)

  A gas barrier material, comprising: a plastic substrate; and a vapor deposition film including a region in which the calcium phosphate compound is distributed in a layered state on or in the surface of at least one surface of the plastic substrate.   The gas barrier material according to claim 1, wherein the calcium phosphate compound is hydroxyapatite.   The gas barrier material according to claim 1 or 2, wherein a region in which the calcium phosphate compound is distributed in layers has a thickness of at least 2 nm.   The gas barrier material according to any one of claims 1 to 3, wherein the deposited film includes a region where the calcium phosphate is distributed in a layered manner and a region where the silicon compound is distributed in a layered manner.   The gas barrier material according to claim 4, wherein the silicon compound is at least one selected from silicon oxide, silicon nitride, or silicon nitride oxide.

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