JP2012201938A - Material for vapor deposition and gas barrier vapor deposition film, and method of manufacturing vapor deposition film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier vapor deposition film that prevents an occurrence of splash phenomenon and has high gas barrier property.SOLUTION: An inorganic oxide film 2 is formed on a polymer film base material 1 by depositing a vapor deposition material using a heating method, wherein the vapor deposition material includes metallic silicon, silicon dioxide, and metallic bismuth or bismuth oxide powder, the ratio {O/(Si+Bi)} of atomic number of oxygen to atomic number in total of silicon and bismuth is 1.0 to 1.8, and the ratio (Bi/Si) of atomic number of bismuth to that of silicon is 0.02 to 0.10. In the deposited film, the ratio {O/(Si+Bi)} of atomic number of oxygen to atomic number in total of silicon and bismuth is 1.6 to 1.9 and the ratio (Bi/Si) of atomic number of bismuth to that of silicon is 0.02 to 0.10.

Description

  The present invention relates to a vapor deposition material, a gas barrier vapor deposition film, and a method for producing the vapor deposition film.

  Gas barrier vapor-deposited films are widely used in the field of components that need to block oxygen and water vapor in the backsheet of solar cells, the packaging field of foods and pharmaceuticals, or the non-packaging field.

  It is necessary to protect the contents of precision electronic parts such as hard disks and semiconductor modules, or packaging materials used for packaging foods and pharmaceuticals. Particularly in food packaging, it is necessary to suppress the oxidation and alteration of proteins, fats and oils, and to maintain the taste and freshness.

  In order to prevent the active ingredient from being altered and maintain its efficacy in pharmaceuticals that require handling under aseptic conditions, and to prevent corrosion of metal parts and poor insulation in precision electronic parts. There is a need for a package having a gas barrier property that blocks oxygen, water vapor, and other gases that alter the contents of the packaging material.

  Therefore, metal foils such as aluminum and aluminum vapor deposited films that are not affected by temperature, humidity, etc., or polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN). ) And plastic films laminated or coated with these resins have been used favorably.

  However, packaging materials using metal foils such as aluminum and aluminum vapor-deposited films are excellent in gas barrier properties, but are opaque, so it is difficult not only to identify the contents through the packaging material, but also after use. However, it has the disadvantages that it must be treated as an incombustible material at the time of disposal, and that foreign matter inspection by a metal detector and heat treatment in a microwave oven cannot be performed.

  In addition, a gas barrier resin film or a film coated with a gas barrier resin is highly temperature dependent and cannot maintain high gas barrier properties. Furthermore, after use, PVDC, PAN, and the like have problems such as the possibility of causing harmful substances during disposal and incineration.

Therefore, as a packaging material that overcomes these drawbacks, a gas barrier film in which an inorganic oxide such as magnesium oxide, calcium oxide, aluminum oxide, or silicon oxide is vapor-deposited on a transparent base film has recently been put on the market. (See Patent Documents 1 and 2)
These gas barrier vapor-deposited films are known to have transparency and gas barrier properties such as oxygen and water vapor, and are suitable as packaging materials having both transparency and gas barrier properties that cannot be obtained with metal foil or the like. In the film deposited with silicon oxide SiOx, it is used as a food packaging film. In addition, vapor deposition by a heating method using silicon oxide SiOx as a vapor deposition material has a very high film formation rate and high productivity.

  However, the silicon oxide SiOx (0 <x <2), which is a deposition material used here, is manufactured by vacuum deposition using metal silicon and silicon dioxide as raw materials, and thus has the following drawbacks. ing.

  Since silicon oxide SiOx (0 <x <2), which is a material for vapor deposition produced by vacuum vapor deposition, is not a production method suitable for mass production, there is a problem that the material cost is high and the production cost is high. Further, the silicon oxide SiOx (0 <x <2) of this vapor deposition material has a density close to the true density and has a very dense structure.

  Therefore, when a barrier film is produced by evaporating this deposition material, unvaporized deposition material is scattered as high-temperature particles due to thermal shock caused by heating during vapor deposition or the pressure of gas generated from the inside. There is a problem that a phenomenon called splash occurs.

  When high-temperature particles reach the polymer film, pinholes and foreign matters are generated, resulting in a decrease in barrier properties and poor appearance. Further, in the heating method described above, particularly heating by an electron gun, the above-described splash and foreign matter are more noticeably generated when the deposition material receives a larger thermal shock.

  On the other hand, the mixed vapor deposition material of metal silicon and silicon dioxide is relatively inexpensive, but it is difficult to evaporate because it has a higher vapor pressure than silicon monoxide during heating, and it is a melt type vapor deposition material. Therefore, a larger thermal shock is required, and the vapor deposition material is scattered and splash is likely to occur. In addition, the generation of oxygen gas due to the decomposition of silicon dioxide increases the pressure in the film formation chamber, resulting in a decrease in deposition rate, that is, a decrease in productivity, and a decrease in barrier properties of the deposited film due to a decrease in deposited film density. There is also a problem.

JP-A-8-296036 JP-A-6-016848

  The present invention is intended to solve the above-described problems of the prior art, a vapor deposition material capable of suppressing the occurrence of a splash phenomenon and imparting a high gas barrier property, a gas barrier vapor deposition film deposited using the material, and the film It aims at providing the manufacturing method of a vapor deposition film.

  The present invention has been made in view of the above problems, and the invention of claim 1 is a heating type vapor deposition material containing metallic silicon, silicon dioxide, and metallic bismuth or bismuth oxide powder, The ratio of the total number of atoms of bismuth and the number of atoms of oxygen {O / (Si + Bi)} is 1.0 to 1.8, and the ratio of the number of atoms of bismuth and silicon (Bi / Si) is 0.02 to 0.02. It is a material for vapor deposition characterized by being 0.10.

Invention of Claim 2 is a vapor deposition material of Claim 1 whose bulk density is the range of 0.9-1.5 g / cm < ³ >.

  The invention according to claim 3 is the evaporation material according to claim 1, wherein the silicon dioxide powder contains at least 20% of a crystal structure.

  According to a fourth aspect of the present invention, there is provided a ratio {O / (Si + Bi) of the total number of atoms of silicon and bismuth and the number of atomic atoms of oxygen in a vapor deposition film deposited by evaporating the vapor deposition material according to the first aspect by a heating method. )} Is 1.6 to 1.9, and the ratio of the number of atoms of bismuth and silicon (Bi / Si) is 0.02 to 0.10.

  The invention of claim 5 contains metal silicon, silicon dioxide, metal bismuth or bismuth oxide powder, and the ratio of the total number of atoms of silicon and bismuth to the number of oxygen atoms {O / (Si + Bi)} A vapor deposition material having a ratio of the number of atoms of Bismuth to silicon (Bi / Si) of 0.02 to 0.10 is evaporated by an electron beam heating method to obtain a polymer film base. A method for producing a gas barrier vapor-deposited film, comprising forming a film on a material.

  According to the present invention, a splash phenomenon can be suppressed even when an electron beam heating vapor deposition method with a high output is used to improve productivity, and a vapor deposition film having a high gas barrier property can be obtained.

Sectional drawing of the gas barrier vapor deposition film by one Embodiment of this invention.

  Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view of a gas barrier vapor deposition film of the present invention. This gas barrier vapor-deposited film is obtained by depositing an inorganic oxide film 2 formed by vapor-depositing metal silicon, silicon dioxide, metal bismuth or bismuth oxide on a polymer film substrate 1 by a vacuum deposition method. It is. This is preferable from the viewpoint of gas barrier performance and uniformity.

  As a means for forming the inorganic oxide film 2, a heat evaporation method using an electron beam, a laser beam, or the like is preferably used among the vacuum evaporation methods, and in particular, the electron beam heat evaporation method is used for film formation speed or inorganic oxide evaporation. This is effective in that the temperature can be raised and lowered to the material in a short time.

  The silicon dioxide contains at least 20% of a crystal structure. For this purpose, oxygen gas can be generated from silicon dioxide by an electron beam, and this oxygen gas can be reacted with metallic silicon and metallic bismuth or bismuth oxide. Further, the inorganic oxide film 2 may be formed on both surfaces of the polymer film substrate 1, may be multilayered, or may be the inorganic oxide film 2 having different compositions on the front and back sides.

  The polymer film substrate 1 is not particularly limited, and a known one can be used. For example, polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene naphthalate, polyethylene terephthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polystyrene, ethylene vinyl alcohol, polyvinyl chloride, polyimide, polyvinyl alcohol , Polymer film bases such as polycarbonate, polyethersulfone, acrylic, and cellulose (triacetylcellulose, diacetylcellulose, etc.), but not particularly limited.

  It is preferable to use a transparent film as the polymer film substrate 1 because it is suitable for mass production. In addition, the thickness is not particularly limited, and is practically preferably in the range of 12 to 188 μm in consideration of workability such as vapor deposition processing for forming a gas barrier vapor deposition film.

  In general, the thickness of the inorganic oxide film 2 formed on the surface of the polymer film substrate 1 by the mixed vapor deposition material composed of evaporated metal silicon and silicon dioxide is desirably in the range of 5 to 300 nm. The value is appropriately selected.

  However, if the thickness of the inorganic oxide film 2 is less than 5 nm, uniform film quality may not be obtained, or the film thickness may not be sufficient, and sufficient barrier performance may not be exhibited. In addition, when the film thickness exceeds 300 nm, the film cannot retain flexibility, and there is a possibility that the film may crack due to external factors such as bending and tension after the film formation.

  In the present invention, the heating type vapor deposition material containing metal silicon, silicon dioxide, and metal bismuth or bismuth oxide powder used as the vapor deposition material is composed of the total number of atoms of silicon and bismuth and oxygen atoms. The ratio of the number {O / (Si + Bi)}, the ratio of the number of atoms of bismuth and silicon (Bi / Si), and preferably the inorganic oxidation that is less susceptible to thermal shock by electron beams by controlling the bulk density The physical film 2 can be formed. Therefore, the thermal shock resistance of the inorganic oxide film 2 is improved, and the splash phenomenon is suppressed.

  In other words, during vapor deposition by electron beam heating, preferably by controlling the bulk density, the thermal conductivity is lowered so as not to become a dense structure, and silicon dioxide having a low thermal conductivity is mixed. As a result, it is possible to suppress the occurrence of bumping due to a rapid temperature rise due to electron beam heating, and to reduce the splash phenomenon.

  Also, when silicon dioxide is heated, oxygen gas is desorbed, and the heated metal silicon reacts without bumping because it is in the vicinity of oxygen gas generated from silicon dioxide, and becomes SiOx vapor. Bismuth metal reacts with oxygen gas desorbed from silicon dioxide to form BiOy vapor, and bismuth oxide also evaporates into BiOy vapor, thereby forming a SiOx / BiOy film on the polymer substrate film. And since melted silicon dioxide remains in the surface layer of vapor deposition material, it is thought that a vapor deposition film with a high barrier property can be formed because splash is suppressed.

  Regarding the heating type vapor deposition material containing metal silicon, silicon dioxide, and metal bismuth or bismuth oxide powder of the present invention, the ratio of the total number of atoms of silicon and bismuth and the number of oxygen atoms {O / ( Si + Bi)} is preferably 1.0 to 1.8. That is, when O / (Si + Bi) is less than 1.0, the amount of silicon dioxide contained in the material is small, so that the melted portion of the material surface layer is small and splash is likely to occur. On the other hand, when O / (Si + Bi) exceeds 1.8, the generation of oxygen gas increases, so the pressure in the film forming chamber increases, the deposition rate decreases, that is, the productivity decreases, and the deposited film density also decreases. The barrier property of the deposited film is lowered due to the decrease in.

  In addition, for a heating vapor deposition material containing metal silicon, silicon dioxide, and metal bismuth or bismuth oxide powder, the ratio of the number of atoms of bismuth and silicon (Bi / Si) is 0.02 to 0.10. Is desirable. That is, when Bi / Si is less than 0.02, the effect of improving the barrier property by adding the bismuth component cannot be obtained. On the other hand, when Bi / Si exceeds 0.10, the amount of bismuth contained in the deposited film increases, so that the water resistance of the film decreases.

The bulk density of the vapor deposition material is preferably 0.9 to 1.5 g / cm ³ . When the bulk density of the vapor deposition material is less than 0.9 g / cm ³ , the vapor deposition material is likely to be cracked or scattered, and when the bulk density exceeds 1.5 g / cm ³ , more energy is required for evaporation of the material. Since this is necessary, the evaporation rate is lowered, and the deposition rate is lowered, that is, the productivity is lowered.

  Further, the vapor deposition materials are easily mixed when using the same particle size, and the temperature raising process of the vapor deposition material is simplified by using a powder of 1 μm to 100 μm. This is presumably because the metal silicon is uniformly mixed with the vapor deposition material, so that the material is easily heated and the electron beam is not easily defocused.

  As the silicon oxide used here, it is desirable to use silicon dioxide having at least 20% X-ray crystal structure. This is because the use of silicon dioxide having a crystallinity of less than 20%, that is, a crystal structure of less than 20% lowers the evaporation rate of the evaporation material and the barrier property of the evaporated film. For the measurement of the crystalline portion and the non-crystalline portion of silicon dioxide, each peak was separated using an X-ray diffractometer (XRD), and the degree of crystallinity was determined from the ratio of integrated intensity.

  Further, regarding a deposited film obtained by evaporating a deposition material of a heating method containing metal silicon, silicon dioxide, and metal bismuth or bismuth oxide powder of the present invention by evaporation by a heating method, the total of the silicon and bismuth The ratio of the number of atoms to the number of oxygen atoms {O / (Si + Bi)} is preferably 1.6 to 1.9. That is, when O / (Si + Bi) is less than 1.6, the transparency of the film is lowered because the silicon dioxide contained in the deposited film is small. On the other hand, when O / (Si + Bi) exceeds 1.9, silicon dioxide contained in the deposited film increases, and thus the barrier property of the deposited film is lowered due to the lowered deposited film density.

  In addition, regarding a deposited film obtained by evaporating a deposition material of a heating method containing metal silicon, silicon dioxide, and metal bismuth or bismuth oxide powder by a heating method, the ratio of the number of atoms of bismuth and silicon ( Bi / Si) is preferably 0.02 to 0.10. When Bi / Si is less than 0.02, the effect of improving the barrier property due to the inclusion of the bismuth component cannot be obtained. When Bi / Si exceeds 0.10, the amount of bismuth contained in the deposited film increases. The water resistance of is reduced.

  As described above, the vapor deposition material of the present invention has the ratio of the total number of atoms of silicon and bismuth to the number of atoms of oxygen {O / (Si + Bi)}, the ratio of the number of atoms of bismuth and silicon (Bi / Si), In addition, it is preferable to control the bulk density, and further to control the crystallinity of silicon dioxide, so that a gas barrier vapor-deposited film having a high barrier property is produced without causing a splash phenomenon as compared with conventional vapor deposition materials. Can be obtained.

  Examples of the present invention will be specifically described below.

<Example 1>
Metallic silicon uses a powder having a diameter of 50 μm or less of 95% or more, and silicon dioxide contains a crystal structure of 95% and a powder having a diameter of 50 μm or less is 95% or more. As the bismuth, 95% or more of powder having a diameter of 50 μm or less was used. The ratio of the total number of atoms of silicon and bismuth and the number of atoms of oxygen {O / (Si + Bi)} is 1.4, and the ratio of the number of atoms of bismuth and silicon (Bi / Si) is 0.05. A vapor deposition material composed of metallic silicon, silicon dioxide, and metallic bismuth mixed as described above was produced and press-molded so that the bulk density was 1.0 g / cm ³ .

  Next, an electron beam emitted from an electron gun was irradiated onto the mixed vapor deposition material by an electron beam heating type vacuum vapor deposition apparatus to evaporate it, and a film was formed on the polymer film substrate.

<Example 2>
For metal silicon, a powder having a diameter of 50 μm or less is 95% or more, and for silicon dioxide, a crystal structure containing 95% is used, and a powder having a diameter of 50 μm or less is 95% or more. As the bismuth, 95% or more of powder having a diameter of 50 μm or less was used. The ratio of the total number of atoms of silicon and bismuth to the number of atoms of oxygen {O / (Si + Bi)} is 1.5, and the ratio of the number of atoms of bismuth and silicon (Bi / Si) is 0.03. A vapor deposition material composed of metallic silicon, silicon dioxide, and bismuth oxide mixed in this manner was prepared, and press-molded so that the bulk density was 1.0 g / cm ³ .

  Hereinafter, comparative examples of the present invention will be described.

<Comparative Example 1>
The metal silicon used was a powder having a diameter of 50 μm or less of 95% or more, and the silicon dioxide containing a crystal structure containing 95% and a powder having a diameter of 50 μm or less was 95% or more. A material for mixed vapor deposition composed of silicon metal and silicon dioxide mixed so that the ratio of the number of silicon atoms to the number of oxygen atoms (O / Si) is 1.5 is prepared, and the bulk density is 1.0 g / cm ^3. It was press-molded so that

<Comparative example 2>
Similarly to the vapor deposition material produced in Comparative Example 1, press molding was performed so that the bulk density was 1.5 g / cm ³ .

<Comparative Example 3>
Similar to the vapor deposition material prepared in Example 1, the ratio of the total number of atoms of silicon and bismuth to the number of atoms of oxygen {O / (Si + Bi)} is 1.3, and the number of atoms of bismuth and silicon. A vapor deposition material made of metal silicon, silicon dioxide, and metal bismuth mixed so that the ratio (Bi / Si) of the metal was 0.12, was press-molded so that the bulk density was 1.0 g / cm ³ . .

  About the gas-barrier vapor deposition film of the said Examples 1-2 and Comparative Examples 1-3, generation | occurrence | production of the splash was checked with the following method, and the water-vapor-permeation rate was measured. Further, O / (Si + Bi) and Bi / Si of the deposited film evaporated and evaporated were measured.

<About splash>
The gas barrier vapor deposition films of Examples 1 and 2 and Comparative Examples 1 to 3 were cut into an area of width 500 mm × length 100 m, and about these gas barrier vapor deposition films, whether or not there are pinholes and foreign matters due to splash by visual inspection. Examined. In addition, in the evaluation of the presence or absence of splash, the case where there is no pinhole or foreign matter due to splash is rated as ◯, the number of pinholes or foreign matter due to splash is 1 to 10, and there are 11 or more pinholes or foreign matters due to splash Was marked with x.

<About water vapor barrier properties>
The water vapor barrier properties of the gas barrier vapor deposited films of Examples 1 and 2 and Comparative Examples 1 to 3 were measured at 40 ° C. and 90% RH using a water vapor permeability measuring device (trade name; MOCON PERMATRAN 3/21) manufactured by Modern Control. Measured in the atmosphere.

<O / (Si + Bi) and Bi / Si of the deposited film>
The O / (Si + Bi) and Bi / Si of the vapor deposition films in the gas barrier vapor deposition films of Examples 1-2 and Comparative Examples 1-3 were measured by the following methods.

(Measuring method)
The polymer film substrate 1 on which the inorganic oxide film 2 was formed was cut into a 10 mm × 10 mm square, and the composition of the film was analyzed using an X-ray photoelectron spectrometer (ESCA). The composition analysis was repeated three times or more in the depth direction of the deposited film with Ar ions, the average was obtained, and O / (Si + Bi) and Bi / Si were calculated.

The following Table 1 shows the measurement results.

<Evaluation>
As shown in Table 1, the gas barrier vapor-deposited film of Comparative Example 2 was confirmed to generate splash, whereas the gas barrier vapor-deposited films of Example 1 and Example 2 did not generate splash. This means that splash occurs due to the high bulk density of the vapor deposition material.

Furthermore, since the gas barrier vapor deposition films of Example 1 and Example 2 are obtained by adding metal bismuth or bismuth oxide to the vapor deposition material, a remarkable improvement in water vapor barrier properties is observed. That is, in the gas barrier vapor deposition films of Comparative Examples 1 to 3, the vapor barrier properties of the vapor deposition films made of the vapor deposition materials of metal silicon and silicon dioxide were worse than 1 g / m ² · day, whereas Examples 1 and Examples The gas barrier vapor deposition film 2 has a vapor barrier property better than 1 g / m ² · day by forming a vapor deposition film made of a vapor deposition material to which metal bismuth or bismuth oxide is added into a composite film of SiOx and BiOy. It is considered that the water vapor barrier property was improved.

  Since the present invention can provide a transparent gas barrier film having high productivity and low gas barrier performance at a low cost, it is necessary to cut off oxygen and water vapor in the packaging field of food, daily necessities, and medical products, or in the relative packaging field. Can be widely applied to.

DESCRIPTION OF SYMBOLS 1 ... Polymer film base material 2 ... Inorganic oxide film

Claims (5)

  A heating-type deposition material containing metallic silicon, silicon dioxide, and metallic bismuth or bismuth oxide powder, wherein the ratio of the total number of atoms of silicon and bismuth to the number of oxygen atoms {O / (Si + Bi) } Is 1.0 to 1.8, and the ratio of the number of atoms of bismuth and silicon (Bi / Si) is 0.02 to 0.10. The material for vapor deposition according to claim 1, wherein the bulk density is in the range of 0.9 to 1.5 g / cm ³ .   The deposition material according to claim 1, wherein the silicon dioxide powder contains at least 20% of a crystal structure.   The ratio {O / (Si + Bi)} of the total number of atoms of silicon and bismuth and the number of atoms of oxygen in the vapor deposition film deposited by evaporating the vapor deposition material according to claim 1 by a heating method is 1.6 to A gas barrier vapor-deposited film having a ratio of 1.9 bismuth to silicon (Bi / Si) of 0.02 to 0.10.   It contains metallic silicon, silicon dioxide, and metallic bismuth or bismuth oxide powder, and the ratio of the total number of atoms of silicon and bismuth to the number of oxygen atoms {O / (Si + Bi)} is 1.0 to 1.8. A deposition material having a bismuth / silicon atom ratio (Bi / Si) of 0.02 to 0.10 is evaporated by an electron beam heating method to form a film on a polymer film substrate. A process for producing a gas barrier vapor-deposited film characterized by the above.

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