JP5217571B2 - Gas barrier film - Google Patents

Description

  The present invention relates to a gas barrier film excellent in heat resistance and gas barrier properties.

  Attempts to produce a display or a device on a flexible base film made of a polymer material are widely performed. In recent years, a higher level of gas barrier property is required, and a gas barrier film having a good gas barrier property in which a gas barrier layer made of silicon oxynitride or silicon oxide is formed on a base film has been proposed (for example, Patent Document 1). reference).

However, there is a problem in that protrusions and the like exist on the surface of the base film made of a polymer material, and the defects and pinholes are generated in the gas barrier layer due to the protrusions and the gas barrier property is lowered. For such a problem, a gas barrier film having a good gas barrier property in which a flattening layer is formed on a base film to reduce defects and the like has been proposed (see, for example, Patent Documents 2 and 3).
JP 2004-276564 A JP-A-2005-324406 JP 2006-7624 A

  Recently, high gas barrier properties and high heat resistance are required for film members applied to display applications such as liquid crystal display elements and organic EL elements. However, although the gas barrier film proposed in Patent Documents 2 and 3 can achieve a certain level of gas barrier performance in a low-temperature use environment, the gas barrier film is subject to dimensional changes due to thermal expansion of the base film in a high-temperature use environment. There is a problem that the dimensional change of the layer cannot be followed, and the gas barrier layer is cracked or peeled off to deteriorate the gas barrier property.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a gas barrier film having both high gas barrier properties and heat resistance.

  The gas barrier film of the present invention for solving the above-mentioned problems is characterized in that a solvent-resistant layer, a cardo polymer layer, and a silicon oxynitride layer are formed in this order on both sides of a polyimide film. Here, the solvent resistant layer is specifically a layer for the solvent contained in the cardo polymer layer forming coating solution.

  According to the present invention, since a polyimide film having a low linear expansion coefficient is used as the base film, the dimensional change in a high temperature use environment is small, and the generation of cracks, peeling, etc. is prevented in the silicon oxynitride layer serving as a gas barrier layer. Can do. Moreover, since the cardo polymer layer is provided as a planarization layer, the gas barrier property of the silicon oxynitride layer having excellent gas barrier properties can be further improved. Moreover, since the solvent resistant layer was provided between the polyimide film and the cardo polymer layer, the polyimide film can be prevented from being deteriorated by being attacked by the solvent contained in the cardo polymer layer forming coating solution. In addition, since the solvent-resistant layer, cardo polymer layer, and silicon oxynitride layer are provided on both sides of the polyimide film, the polyimide film absorbs water and swells, and the upper layer film is prevented from cracking or peeling due to swelling. be able to.

  The preferable aspect of the gas barrier film of this invention is comprised so that the said solvent-resistant layer may be a layer with respect to diglycol diether. Since this solvent is a solvent that may be contained in the coating liquid for forming the cardo polymer layer, the solvent-resistant layer can prevent solvent damage to the polyimide film.

  In a preferred embodiment of the gas barrier film of the present invention, the cardo polymer layer is composed of an epoxy-based cured resin, and the solvent-resistant layer is composed of an acrylic-based cured resin. According to the present invention, these combinations are particularly preferred, and a gas barrier film excellent in gas barrier properties and heat resistance can be constituted.

A preferred embodiment of the gas barrier film, between the solvent layer and the cardo polymer layer, further, silicon oxide, silicon oxynitride, silicon nitride, as a gas barrier layer consisting of either aluminum oxide is formed Configure. A gas barrier layer may also be formed on silicon oxynitride. According to these inventions, the gas barrier property can be further improved by providing the gas barrier layer between the solvent-resistant layer and the cardo polymer layer or on the silicon oxynitride layer.

  According to the gas barrier film of the present invention, the dimensional change in a high-temperature use environment is small, the silicon oxynitride layer serving as the gas barrier layer can be prevented from being cracked or peeled off, and the silicon oxynitride layer having excellent gas barrier properties The gas barrier property can be further improved. In addition, the polyimide film can be prevented from being deteriorated by being attacked by the solvent contained in the cardo polymer layer forming coating solution, and the polyimide film can be absorbed by water to swell, or the upper layer film can be cracked by swelling, It can prevent peeling.

  Since such a gas barrier film can maintain high gas barrier properties even in a high temperature use environment, it can be preferably used as a gas barrier packaging material for food and electronic parts, and can also be preferably used for display applications such as liquid crystal display elements and organic EL elements. .

  Next, the gas barrier film of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and may be arbitrarily modified within the scope of the present invention. can do.

  FIG. 1 is a cross-sectional view showing an example of the gas barrier film of the present invention. As shown in FIG. 1, the gas barrier film 1A of the present invention has a basic structure in which a solvent-resistant layer 3, a cardo polymer layer 4, and a silicon oxynitride layer 5 are formed in this order on both sides of a polyimide film 2. Have. Hereinafter, each constituent layer will be described.

(Polyimide film)
The polyimide film 2 is a base film of the gas barrier film of the present invention. Polyimide is a general term for polymers containing a cyclic imide group in the molecular main chain skeleton, and the material for forming the polyimide film 2 is classified according to the structure of the bonding group that binds to the cyclic imide group in the molecular main chain skeleton. Aliphatic polyimide, alicyclic polyimide, aromatic polyimide may be used, or linear polyimide (plastic type polyimide) or three-dimensional network polyimide (cured type polyimide) classified by the shape of the skeleton chain may be used. Alternatively, a condensation type polyimide or an addition type polyimide classified by reaction type may be used.

  In the present invention, any polyimide can be used, but generally used condensed aromatic polyimides are preferably used. Since normal aromatic polyimide does not melt and does not have an appropriate organic solvent, it is formed into a film by a method such as casting a solution of a soluble polyamic acid that is a precursor of polyimide. As such a film, a polyimide film generally used for electronic circuits and electronic devices can be used. For example, a polyimide film commercially available from Ube Industries, Toray DuPont, Mitsubishi Gas Chemical Co., Ltd. Etc. can be used.

  Such a polyimide film 2 has stable mechanical, electrical, physical, and chemical properties in a very wide range of temperatures from a very low temperature of liquid helium to a high temperature range of about 400 ° C. It is preferable as a base film of a gas barrier film used in a range (for example, 200 ° C. to 300 ° C.). In particular, the polyimide film 2 has a small coefficient of linear expansion, and dimensional stability over a wide operating temperature range is overwhelming compared to polyester films such as PET (polyethylene terephthalate) film and PEN (polyethylene naphthalate) film, and other substrate films. Therefore, there is a problem that the gas barrier property is deteriorated based on the occurrence of cracks and peeling of the silicon oxynitride layer due to the difference in thermal expansion between the base film at a high temperature and the silicon oxynitride layer as a gas barrier layer as in the past. There is an advantage that it does not occur.

  For example, when used as a gas barrier film such as an automobile device used in a high temperature environment, as a gas barrier film such as a lighting device that generates heat during use, or as a transistor exposed to a high temperature environment during processing. When used as a material, it is particularly preferable to use a polyimide film as a base film.

  The thickness of the polyimide film 2 is not particularly limited, but is preferably 3 μm or more and 500 μm or less, and preferably 12 μm or more and 300 μm or less. The polyimide film 2 having a thickness within this range is preferable because it is flexible and can be wound into a roll.

  The polyimide film 2 may be a long material or a sheet material, but a long film can be preferably used. Although the length of the longitudinal direction of the long polyimide film 2 is not specifically limited, For example, a long film of 10 m or more is used preferably. In addition, the upper limit of length is not limited, For example, the thing of about 10 km may be sufficient.

(Solvent resistant layer)
The solvent-resistant layer 3 is a layer formed to prevent the solvent contained in the cardo polymer layer-forming coating liquid described later from attacking the polyimide film 2, and is formed on both surfaces of the polyimide film 2 as shown in FIG. Has been. Diglycol diether is used as a solvent contained in the cardo polymer layer forming coating liquid described later, but this solvent dissolves the polyimide film 2. Therefore, the solvent-resistant layer 3 is not particularly limited as long as such a solvent does not allow the solvent to penetrate the polyimide film 2, but a thermosetting resin layer, an ultraviolet curable resin layer, an electron beam curable resin layer, a sol-gel material layer. And inorganic compound layers.

  Examples of the thermosetting resin layer include polymethyl methacrylate, polyacrylate, polycarbonate, methyl phthalate homopolymer or copolymer, polyethylene terephthalate, polystyrene, diethylene glycol bisallyl carbonate, acrylonitrile / styrene copolymer, poly (-4 -The layer which consists of 1 type (s) or 2 or more types, such as a methyl pentene-1), a phenol resin, an epoxy resin, cyanate resin, maleimide resin, a polyimide resin, is mentioned. Also, those resins modified with polyvinyl butyral, acrylonitrile-butadiene rubber, polyfunctional acrylate compounds, etc., crosslinked polyethylene resin, crosslinked polyethylene / epoxy resin, crosslinked polyethylene / cyanate resin, polyphenylene ether / epoxy resin, polyphenylene ether The layer which consists of thermosetting resin etc. which modified | denatured with thermoplastic resins, such as / cyanate resin, can be mentioned.

  Examples of the ultraviolet curable resin layer and the electron beam curable resin layer include, for example, a resin composition made of an acrylate compound having a radical reactive unsaturated compound, an oligomer such as epoxy acrylate, urethane acrylate, polyester acrylate, and polyether acrylate. And a resin composition in which is dissolved in a polyfunctional acrylate monomer. Moreover, you may use the mixture of these resin compositions.

  The method for forming each of the curable resin layers is not particularly limited, and may be any of a spin coating method, a spray coating method, a blade coating method, a dip method, a roll coating method, and the like. The thermosetting resin layer, the ultraviolet curable resin layer, and the electron beam curable resin layer as described above may contain additives such as an antioxidant, an ultraviolet absorber, and a plasticizer as necessary. In any of the resin layers, a resin or an additive for the purpose of improving film formability or preventing pinholes may be blended. Furthermore, when each resin layer is formed, the resin material is dissolved or dispersed in an appropriate dilution solvent such as ethanol. However, since any solvent used does not attack the underlying polyimide film 2, it can be preferably used. .

  Examples of the sol-gel material layer include siloxane materials and materials mainly composed of alkoxide solutions such as Si, Al, and Ti. This sol-gel material layer can be applied and formed by spin coating, die coating, or the like.

As the inorganic compound layer, SiO _x , SiON, SiN, AlO _x , ZnO, MgO, ITO (indium tin oxide), SnO ₂ , DLC (diamond-like carbon), or one or two of these A mixed film of seeds or more can be mentioned. These inorganic compound layers can be formed by sputtering, ion plating, CVD, or the like.

  Each of the above-described layers is a layer formed in order to prevent the solvent contained in the below-described cardo polymer layer-forming coating solution from attacking the polyimide film 2, and any of them can be preferably used. A layer made of an acrylic curable resin such as polyacrylate (including heat curing, ultraviolet curing, and electron beam curing) is preferable.

  For example, when using a coating solution for a solvent resistant layer containing pentaerythritol triacrylate which is an acrylic curing resin, for example, toluene is used as a solvent, and Irgacure 184 is used as an additive for UV curing, Examples include 100 parts by weight of pentaerythritol triacrylate, 100 parts by weight to 350 parts by weight of toluene as a solvent, and 1 part by weight to 10 parts by weight of Irgacure 184 as an additive. Such a solvent-resistant layer coating solution is formed by applying, drying, and curing simultaneously on both sides or one side by a conventionally known coating method such as a roll coating method, a Miya bar coating method, and a gravure coating method. be able to. Moreover, after immersing the polyimide film 2 in the water tank containing the coating solution for the solvent resistant layer, it may be dried and cured to form both surfaces simultaneously.

  By providing the solvent-resistant layer 3 on both surfaces of the polyimide film 2, damage to the polyimide film 2 due to the solvent can be prevented. Moreover, since the polyimide film 2 has a large polarity of imide groups, one of the few drawbacks is that it has a large water absorption (hygroscopicity) and swells. However, providing the solvent-resistant layer 3 on both surfaces of the polyimide film 2 also has an effect of preventing such a problem.

  The thickness of the solvent-resistant layer 3 when formed by a wet method using a coating solution or the like is usually 500 nm or more, preferably 1 μm or more, and usually 50 μm or less, preferably 10 μm or less. Further, the thickness of the solvent-resistant layer 3 when formed by a dry method such as a sputtering method is usually 10 nm or more, preferably 50 nm or more, and usually 1 μm or less, preferably 500 nm or less. By providing the solvent resistant layer 3 having the above thickness range on both surfaces of the polyimide film 2, it is possible to prevent the polyimide film 2 from being dissolved by the solvent contained in the cardo polymer layer forming coating liquid. (Moisture absorption) can be prevented. In addition, by providing this solvent-resistant layer 3 in the above thickness range, it can also be used as a layer that complements flattening by the cardo polymer layer 4 described later. For example, when a defect, a protrusion, or the like exists on the surface of the polyimide film 2, the defect, the protrusion, or the like is covered in advance, and planarization by the cardo polymer layer 4 described later can be assisted.

  When the thickness of the solvent resistant layer 3 is less than the above range, for example, a portion where the solvent resistant layer 3 is not formed may occur, and the function as the solvent resistant layer may not be exhibited. Further, when the thickness of the solvent resistant layer 3 exceeds the above range, the stress of the solvent resistant layer 3 may increase or cracks may occur, and the manufacturing cost may increase. .

(Cardopolymer layer)
The cardo polymer layer 4 is a layer that acts as an excellent flattening layer, and is formed of a resin composition mainly containing a cardo polymer. The coating liquid for forming this cardo polymer layer 4 usually contains diglycol diether, but since this solvent dissolves the polyimide film 2, this cardo polymer layer 4 is composed of the above-mentioned solvent-resistant layer 3 as a polyimide film. 2 is formed after being provided on both sides. By setting it as such a structure, it can prevent that a polyimide film is invaded by the solvent contained in the coating liquid for cardo polymer layer formation, and deteriorates.

  The cardo polymer layer 4 is formed by applying a cardo polymer layer forming coating solution containing a cardo polymer, a solvent, and other resin materials and additive materials blended as necessary. The cardo polymer is a polymer having a cardo structure of the following formula. The cardo polymer is preferably a cardo epoxy polymer, but in addition, a cardo polyester polymer, a cardo acrylic polymer, and the like can be applied.

  The cardo structure constituting the cardo polymer has a large number of aromatic rings, and due to its steric hindrance, the fluorene skeleton part and the main chain direction are twisted. For this reason, since the central carbon atom portion can change the bond angle relatively freely, it is strong and tough, but it is not brittle even at low temperatures, and has high hardness and scratch resistance. The cardo polymer layer 4 containing such a cardo polymer is stable in a wide temperature range, has good leveling properties, fills and covers defects, and makes the dried surface smoother. Furthermore, since this cardo polymer layer 4 has good affinity and wettability with an inorganic compound, if a silicon oxynitride layer 5 described later is provided on the cardo polymer layer 4, it will be formed on the flat cardo polymer layer 4 without defects. Since the silicon oxynitride layer 5 can be uniformly formed without defects and with good affinity, the gas barrier property of the silicon oxynitride layer 5 can be remarkably enhanced.

  Since the cardo polymer layer 4 only needs to contain a cardo polymer as a main component, other additive materials may be blended as required. For example, additives such as a plasticizer, a filler, an antistatic agent, a lubricant, an antiblocking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, and a modifying resin may be added.

  Thus, by forming the cardo polymer layer 4 on both sides of the polyimide film 2 via the solvent-resistant layer 3, the surface smoothness of the lower ground of the silicon oxynitride layer 5 can be remarkably improved. The gas barrier property of the silicon oxynitride layer 5 formed on the cardo polymer layer 4 can be remarkably enhanced.

  The method for forming the cardo polymer layer 4 is not particularly limited, and is a wet coating method such as a spin coating method, a spray coating method, a blade coating method, a dip coating method, a roller coating method, or a land coating method, or vapor deposition. Any dry coating method can be used. In the composition for coating used for coating, in the case of a thermosetting resin or a photocurable resin, an additive such as an antioxidant, an ultraviolet absorber, or a plasticizer, if necessary, in addition to the above-described components. In addition, an appropriate resin or additive may be added to improve film formability and prevent pinholes from being formed in the film. As the solvent, a suitable solvent such as diethylene glycol dimethyl ether, cyclohexanone, ethanol, chloroform, tetrahydrofuran, or dioxane can be used.

  It is particularly preferable that the cardo polymer layer 4 is composed of an epoxy-based cured resin and the solvent-resistant layer 3 is composed of an acrylic-based cured resin, and a gas barrier film excellent in gas barrier properties and heat resistance can be configured.

  Hereinafter, the cardo polymer will be described in more detail.

The cardo polymer preferably contains a resin having a fluorene skeleton derived from a bisphenol compound represented by the following formula. In the formula, R ₁ and R ₂ are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom, and may be the same or different from each other.

  Specific examples of the bisphenol compound represented by the above formula include 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, and 9,9. -Bis (4-hydroxy-3-chlorophenyl) fluorene, 9,9-bis (4-hydroxy-3-bromophenyl) fluorene, 9,9-bis (4-hydroxy-3-fluorophenyl) fluorene, 9,9 -Bis (4-hydroxy-3-methoxyphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dimethylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dichlorophenyl) fluorene Or 9,9-bis (4-hydroxy-3,5-dibromophenyl) fluorene. Besides it is possible to use only one of either alone, it can be used in combination of two or more.

  The cardo polymer is derived from an epoxy (meth) acrylate resin obtained by reacting an epoxy group having two or more epoxy groups in one molecule with an unsaturated monocarboxylic acid and a polybasic acid anhydride. An epoxy (meth) acrylate acid adduct is preferable. In addition, the description of (meth) acrylate means an acrylate or a methacrylate.

  Specific examples of the epoxy resin used to form such an epoxy (meth) acrylate acid adduct include bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) sulfone, and 2,2-bis (4 -Hydroxyphenyl) propane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) hexafluoropropane, 9,9-bis (4-hydroxyphenyl) fluorene, bis (4-hydroxyphenyl) dimethylsilane, 4 , 4′-biphenol, bisphenols such as tetramethyl-4,4′-biphenol, phenol novolac, cresol novolac, naphthol or naphthalenediol and polyfunctional phenols such as a condensation compound of 1,4-bisxylenol, Some or all of these aromatic ring hydrogens There halogen atom include those having two or more epoxy groups in one molecule obtained by polyfunctional phenols substituted on an alkyl group having 1 to 4 carbon atoms is reacted with epichlorohydrin.

  This epoxy group can be made into an epoxy (meth) acrylate resin by reacting an epoxy resin with an equal amount of acrylic acid such as acrylic acid or methacrylic acid by a known method. Furthermore, this epoxy (meth) acrylate resin Can be made an addition product of an epoxy (meth) acrylate resin and a polybasic acid anhydride by reacting with a polybasic acid anhydride.

  Specific examples of polybasic acid anhydrides used in the formation of such addition products include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride. Acid, alicyclic acid anhydrides such as methylcyclohexene dicarboxylic acid anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, ethylene glycol bistrimellitic anhydride. Examples thereof include aromatic acid anhydrides such as glycerol tristrimellitic anhydride and biphenyltetracarboxylic dianhydride, and halogen acid anhydrides such as het anhydride and tetrabromophthalic anhydride. Further, the epoxy resin, acrylate, and acid anhydride may be one kind or a mixture of two or more kinds.

  Among the epoxy (meth) acrylate acid adducts thus obtained, in the present invention, as seen in JP-A-60-152091, JP-A-6-1938, JP-A-8-146111. In addition, it is preferable that the organic resin layer 31 contains a resin having a carboxysyl group and a photopolymerizable unsaturated group in the same molecule and having a weight average molecular weight of 1000 or more. Specifically, the acid of adduct of epoxy acrylate having a fluorene skeleton, V259M or V301M manufactured by Nippon Steel Chemical Co., Ltd. or an improved product thereof, or the acid of cresol novolac type epoxy acrylate manufactured by Nippon Kayaku Co., Ltd. Examples include adducts.

  The epoxy acrylate resin having a fluorene skeleton is preferably one obtained by reacting an epoxy resin obtained from 9,9-bis (4-hydroxyphenyl) fluorene with acrylic acid.

  Further, as the above-mentioned polyfunctional acrylate monomer used in the present invention, specifically, addition polymerization having a boiling point of 100 ° C. or higher at normal pressure and having at least two ethylenically unsaturated groups in one molecule. What is a compound is mentioned. Such materials include those obtained by combining a polyhydric alcohol and an α, β-unsaturated carboxylic acid, such as diethylene glycol (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol diester. (Meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,3-propanediol (meth) acrylate, 1,3-butanediol (meth) acrylate, pentaerythritol tetra (meta ) Acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate and other polyfunctional acrylates and corresponding polyfunctional methacrylates, 2,2-bis (4-acryloxydiethoxyphenyl) ) A mixture of propane, 2,2-bis (4-methacryloxydipentaethoxysiphenyl) propane, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane (made by Shin-Nakamura Chemical Co., Ltd., trade name; BEP-500) and the like, and those obtained by adding an α, β-unsaturated carboxylic acid such as acrylic acid or methacrylic acid to a glycidyl group-containing compound, such as trimethylolpropane triglycidyl ether (meth) acrylate, bisphenol A diester Glycidyl ether di (meth) acrylate, acrylic acid adduct of diglycidyl ether having a fluorene ring (manufactured by Nippon Steel Chemical Co., Ltd., trade name: ASF400), and unsaturated amides such as methylenebisacryloamide 1,6-hexamethylenebisacrylamide and the like, vinyl esters, such as Examples include divinyl succinate, divinyl adipate, divinyl phthalate, divinyl terephthalate, divinylbenzene-1,3-disulfonate.

  As a polymerization initiator, if a radical is generated upon heating and a cured film can be formed by polymerizing an unsaturated group of a polyfunctional acrylate monomer and a thermosetting resin having a cardo polymer, a known thermal polymerization is possible. Although an initiator can be used, the 10-hour half-life temperature is preferably 80 ° C. or more and the curing temperature or less, and more preferably 100 ° C. or more and the curing temperature. Examples of the thermal polymerization initiator include t-butylcumyl peroxide, t-butylperoxy-2-ethylhexanoate, and di-t-butyldiperoxyphthalate.

  When the above polymerization is carried out by ultraviolet irradiation, instead of the thermal polymerization initiator. A photopolymerization initiator can also be used. As the photopolymerization initiator, known ones can be used alone or in combination, for example, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one (Ciba Specialty Chemicals Co., Ltd., trade name: “Irgacure 907”), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (Ciba Specialty Chemicals Co., Ltd.) Product name: “Irgacure 369”), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (manufactured by Ciba Specialty Chemicals Co., Ltd., product name: “CGI819”), 2,4,6-trimethylbenzoyl Diphenylphosphine oxide (manufactured by BASF, trade name: “Lucirin TPO”) or 2,4-trick Romechiru - (Pipuroroniru) -6-triazine (Japan Siber Hegner Co., Ltd., trade name; "triazine PP") and the like can be used.

  Furthermore, as the epoxy resin having two or more epoxy groups in one molecule, an epoxy compound having a hydrolyzable chlorine content of less than 1000 ppm is preferable. For example, tetramethyldiphenyl type epoxy resin manufactured by Yuka Shell Co., Ltd. YX4000, EOCN series (EOCN1020, 4400, 102S, 103S, 104S, etc.) manufactured by Nippon Kayaku Co., Ltd., cresol novolac epoxy resin, phenol novolac epoxy resin, liquid trifunctional epoxy manufactured by Toto Kasei Co., Ltd. Examples thereof include ZX-1542 as a resin and a polyfunctional epoxy compound in which a glycidyl group is introduced into a secondary hydroxyl group in an epoxy compound. In such an epoxy resin, an epoxy group reacts with a carboxyl group in a resin component containing a cardo polymer by heating or the like, and has a crosslinked structure in addition to the unsaturated group of the resin containing the cardo polymer and the polyfunctional acrylate. To form.

(Silicon oxynitride layer)
The silicon oxynitride layer 5 is a layer containing silicon, oxygen, and nitrogen, and is provided on the cardo polymer layer 4. The silicon oxynitride layer 5 is represented by SiN _x O _y (where x = 0.5 to 1.5, y = 0.15 to 1). Since such a silicon oxynitride layer 5 is provided on the cardo polymer layer 4 which has a large amount of Si—N bonds per unit thickness and a high density and is excellent as a flattening layer, it can exhibit excellent gas barrier properties. it can.

_X in SiN _x O _y of the silicon oxynitride layer 5 is 0.5 or more, preferably 0.7 or more, and 1.5 or less, preferably 1.3 or less. If it is set as such a range, the quantity of the Si-N bond in the silicon oxynitride layer 5 can be ensured, and high gas barrier property can be shown. On the other hand, y is 0.15 or more, preferably 0.25 or more, more preferably 0.3 or more, and 1 or less, preferably 0.7 or less. If it is set as such a range, content of oxygen in the silicon oxynitride layer 5 can be ensured, and the silicon oxynitride layer 5 can have flexibility.

  The silicon oxynitride layer 5 may contain, for example, impurities such as carbon and additives within a range not impairing the above-described effects, but the content is desirably 30% by weight or less. In some cases, carbon is contained in the silicon oxynitride layer 5. This carbon is a component of the cardo polymer layer 4 that enters the silicon oxynitride layer 5, or an organic material such as a planarizing film described later. When a film is provided, carbon which is a constituent component of the film enters the silicon oxynitride layer 5.

  Whether or not the silicon oxynitride layer 5 is in the above composition range can be confirmed, for example, by determining the atomic ratio of Si, N, and O. As a method for obtaining such an atomic ratio, a conventionally known method can be used, and for example, evaluation can be made based on results obtained by an analyzer such as XPS (X-ray photoelectron analyzer). In the present invention, XPS is measured by XPS (manufactured by VG Scientific, ESCA LAB220i-XL). As the X-ray source, MgKα ray which is an X-ray source having an Ag-3d-5 / 2 peak intensity of 300 Kcps to 1 Mcps is used, and a slit having a diameter of about 1 mm is used. The measurement is performed with the detector set on the normal line of the sample surface subjected to the measurement, and appropriate charge correction is performed. The analysis after the measurement uses the software Eclipse version 2.1 attached to the above-mentioned XPS apparatus, and uses peaks corresponding to the binding energies of Si: 2p, C: 1s, N: 1s, and O: 1s. Is going. At this time, among the peaks of C: 1s, each peak shift is corrected with the peak corresponding to the hydrocarbon as a reference, and the binding state of the peaks is attributed. Then, background of Shirley is removed for each peak, and sensitivity coefficient correction of each element is performed on the peak area (Si = 0.87, N = 1.77, O = 2 with respect to C = 1.0). .85) to obtain the atomic ratio. About the obtained atomic ratio, the number of Si atoms is set to 1, and the number of atoms of N and O which are other components is calculated and set as the component ratio.

  The thickness of the silicon oxynitride layer 5 is usually 5 nm or more, preferably 10 nm or more, particularly preferably 30 nm or more, usually 10 μm or less, preferably 1000 nm or less, particularly preferably 500 nm or less. When the thickness of the silicon oxynitride layer 5 is within the above range, the silicon oxynitride layer 5 having excellent gas barrier properties can be obtained. If the thickness of the silicon oxynitride layer 5 is less than 5 nm, the entire surface of the substrate cannot be covered with the silicon oxynitride layer 5 and high gas barrier properties may not be obtained. If the thickness exceeds 10 μm, Cracks are likely to occur, and gas barrier properties may be reduced.

  When such a silicon oxynitride layer 5 is used as a gas barrier layer of a light-emitting element such as an organic EL display that requires transparency, the silicon oxynitride layer 5 is preferably transparent. More specifically, for example, it is preferable that the silicon oxynitride layer 5 has a transparency with an average light transmittance of 75% or more in a visible range of 400 nm to 700 nm.

  The method for producing the silicon oxynitride layer 5 is not particularly limited. For example, a vacuum deposition method, a sputtering method, an ion plating method, a Cat-CVD method, a plasma CVD method, an atmospheric pressure plasma CVD method, or the like can be used. Such a manufacturing method may be selected in consideration of the kind of film forming material, easiness of film forming, process efficiency, and the like. Hereinafter, typical production methods such as a vacuum deposition method, a sputtering method, an ion plating method, and a plasma CVD method will be described.

  In the vacuum deposition method, the material contained in the crucible is heated and evaporated by resistance heating, high-frequency induction heating, beam heating such as an electron beam or an ion beam, etc., and deposited on the cardo polymer layer 4 to form silicon oxynitride. In this method, the layer 5 is formed. The heating temperature and heating method can be changed depending on the composition of the silicon oxynitride layer 5 and a reactive vapor deposition method that causes an oxidation reaction or the like during film formation can also be used.

  In the sputtering method, a target is placed in a vacuum chamber, a rare gas element (usually argon) ionized by applying a high voltage is made to collide with the target, atoms on the target surface are ejected, and the above cardo polymer layer 4 is formed. In this method, the silicon oxynitride layer 5 is deposited. At this time, a reactive sputtering method is used in which a predetermined amount of nitrogen gas or oxygen gas is allowed to flow into the chamber to react the element ejected from the target with nitrogen or oxygen to form the silicon oxynitride layer 5. May be. Examples of the sputtering method include DC dipolar sputtering, RF dipolar sputtering, tripolar and quadrupolar sputtering, ECR sputtering, ion beam sputtering, and magnetron sputtering. Industrially, magnetron sputtering is used. preferable.

  The ion plating method is a combined technique of vacuum deposition and plasma, and is a method of forming a thin film by activating a part of evaporated particles as ions or excited particles using gas plasma in principle. In the ion plating method, reactive ion plating in which a reactive gas plasma is combined with evaporated particles to synthesize a compound film is effective. Since the operation is in plasma, the first condition is to obtain a stable plasma. In many cases, low-temperature plasma using weakly ionized plasma in a low gas pressure region is used. For this reason, it is preferably used when a mixture or a complex oxide is formed. The means for generating a discharge is roughly classified into a direct current excitation type and a high frequency excitation type. In addition, a hollow cathode or an ion beam may be used for the evaporation mechanism.

  The plasma CVD method is a kind of chemical vapor deposition method. In the plasma CVD method, raw materials are vaporized and supplied during plasma discharge, and the gases in the system are mutually activated and radicalized by collision. Therefore, reactions at low temperatures that are impossible only by thermal excitation are possible. It becomes possible. A silicon oxynitride layer 5 is formed by a reaction during discharge between the electrodes. It is classified into HF (several tens to hundreds of kHz), RF (13.56 MHz), and microwave (2.45 GHz) depending on the frequency used for generating plasma. When microwaves are used, the method is roughly classified into a method of exciting a reaction gas and forming a film in an after glow, and an ECR plasma CVD in which microwaves are introduced into a magnetic field (875 Gauss) that satisfies the ECR condition. Further, when classified by the plasma generation method, it is classified into a capacitive coupling method (parallel plate type) and an inductive coupling method (coil method).

  The silicon oxynitride layer 5 is formed on the cardo polymer layer 4 using such a film forming unit, and such a film forming unit conveys a film forming member (polyimide film 2 / solvent resistant layer 3 / cardo polymer layer 4). It is preferable to install it facing the conveyance path. Such a film-forming member is attached to a glass substrate with an adhesive tape or the like, and when the film-forming member is conveyed, for example, when a film is formed by a sputtering method, high frequency power or pulsed DC power is applied to the target. By generating a plasma and introducing a rare gas and a reactive gas at that time, silicon oxynitride can be formed on the deposition target member. At that time, the temperature of the film forming member may be adjustable.

(Other layers)
Various layers can be further provided in the gas barrier film of the present invention as required. For example, any one selected from a gas barrier layer, a transparent conductive layer, a hard coat layer, a protective layer, an antistatic layer, an antifouling layer, an antiglare layer, a color filter, and the like can be provided.

Figure 2 is a sectional view showing another example of a gas barrier film. Gas barrier film 1B, in the gas barrier film of the embodiment shown in FIG. 1, in which further the formation of the gas barrier layer 6 between the solvent layer 3 and the cardo polymer layer 4. By providing such a gas barrier layer 6, the gas barrier layers become a total of two layers, and the gas barrier properties that the silicon oxynitride layer 5 plays can be supplemented to further improve the gas barrier properties.

  When the gas barrier layer 6 is formed, the flat surface of the solvent-resistant layer 3 has a larger effect of improving the gas barrier property. Therefore, the solvent-resistant layer 3 is preferably formed so as to have a smooth surface. The solvent-resistant layer 3 to be a smooth surface is easily formed by using a solvent-resistant layer coating solution containing pentaesitol triacrylate, which is an acrylic cured resin, among the solvent-resistant layers 3. be able to.

  As the gas barrier layer 6, similarly to the silicon oxynitride layer 5 described above, a layer made of silicon oxynitride having excellent gas barrier properties can be preferably applied, and a layer made of any of silicon oxide, silicon nitride, and aluminum oxide can also be applied. The gas barrier layer 6 is formed with the same thickness by the same film forming means as the silicon oxynitride layer 5 described above. Since the cardo polymer layer 4 that also functions as a planarizing layer is formed on the gas barrier layer 6, even if a defect or pinhole occurs in the gas barrier layer 6, the defect or pinhole or the like Is repaired by the cardopolymer layer 4.

Figure 3 is a sectional view showing still another example of a gas barrier film. Gas barrier film 1C, in the gas barrier film of the embodiment shown in FIG. 1, in which further the formation of the gas barrier layer 7 on top of the silicon oxynitride layer 5. By providing such a gas barrier layer 7, the gas barrier layer becomes a total of two layers (three layers when the above gas barrier layer 6 is formed), complementing the gas barrier property of the silicon oxynitride layer 5 and providing the gas barrier property. Further improvement can be achieved.

  As the gas barrier layer 7, similarly to the silicon oxynitride layer 5, a layer made of silicon oxynitride having excellent gas barrier properties can be preferably applied, and a layer made of any of silicon oxide, silicon nitride, and aluminum oxide can also be applied. The gas barrier layer 7 is formed with the same thickness by the same film forming means as the silicon oxynitride layer 5 described above. Since the gas barrier layer 7 is provided on the silicon oxynitride layer 5 having a refractive index of about 1.6 to 2.0, silicon oxide or aluminum oxide having a refractive index smaller than that of the silicon oxynitride layer 5 is used. When the gas barrier layer 7 is provided on the silicon oxynitride layer 5, the gas barrier layer 7 can function as a low reflection layer, and can be used as a gas barrier film used for the display surface of the display element.

A transparent conductive layer (not shown) may be provided on the silicon oxynitride layer 5. In particular, when the gas barrier film of the present invention is used for organic EL display applications, the transparent conductive layer provided on the silicon oxynitride layer 5 can be used as the anode of the organic EL element. The transparent conductive layer is not particularly limited, but the formation material thereof is indium-tin oxide (ITO), indium-tin-zinc oxide (ITZO), ZnO ₂ system, CdO system, SnO ₂ system, and the like. In particular, an ITO film is preferable. These can be formed by a vacuum film forming method such as a resistance heating evaporation method, an induction heating evaporation method, an EB evaporation method, a sputtering method, an ion plating method, a thermal CVD method, and a plasma CVD method. The transparent conductive layer may be a coating film mainly composed of a hydrolyzate such as metal alkoxide or an inorganic oxide formed by applying a hydrolyzate such as transparent conductive particles and metal alkoxide. The thickness of the transparent conductive layer is usually 10 nm or more, preferably 60 nm or more, more preferably 100 nm or more, and usually 1000 nm or less, preferably 450 nm or less, more preferably 200 nm or less.

  The description of the hard coat layer, the protective layer, the antistatic layer, the antifouling layer, the antiglare layer, the color filter, etc., which are functional films other than the gas barrier layer and the transparent conductive layer, is omitted. Conventionally known techniques can be applied.

(Gas barrier properties)
The gas barrier film of the present invention is excellent in gas barrier properties, the water vapor transmission rate is 0.01 g / m ² / day or less, preferably 5 × 10 ⁻³ g / m ² / day or less, and the oxygen transmission rate is 0.00. 01 cc / m ² / day · atm or less, preferably 5 × 10 ⁻³ cc / m ² / day · atm or less. The gas barrier film of the present invention having such a gas barrier property can be applied to various uses, for example, for liquid crystal display panels, organic EL display panels, solar cells, packaging materials such as electronic devices, foods and pharmaceuticals, etc. It can be used for packaging materials.

  In addition, the gas barrier film of this invention may be made into a sheet | seat form or a roll form, and can be arbitrarily produced according to a use or an application process. For example, when the gas barrier film of the present invention is applied to an organic EL display or the like, any form of gas barrier film can be applied depending on the application process.

As described above, according to the gas barrier fill arm of the present invention, since using a smaller polyimide film 2 coefficient of linear expansion as the substrate film, small dimensional change at elevated temperatures using environment, silicon oxynitride as a barrier layer Generation | occurrence | production of a crack, peeling, etc. to the layer 5 can be prevented. Further, since the cardo polymer layer 4 is provided as a planarizing layer, the gas barrier property of the silicon oxynitride layer 5 having excellent gas barrier property can be further improved. Moreover, since the solvent-resistant layer 3 is provided between the polyimide film 2 and the cardo polymer layer 4, it is possible to prevent the polyimide film 2 from being deteriorated by being attacked by the solvent contained in the cardo polymer layer-forming coating solution. it can. Further, since the solvent-resistant layer 3, the cardo polymer layer 4, and the silicon oxynitride layer 5 are provided on both surfaces of the polyimide film 2, the polyimide film 2 absorbs water and swells, or the upper layer film breaks or peels off due to swelling. Can be prevented.

  In particular, since the gas barrier film of the present invention is excellent in heat resistance (dimensional stability against heat and gas barrier properties), it is particularly preferably applied when a gas barrier film is produced by a method in which high temperature is applied during processing or when it is used in a high use temperature. it can.

  Next, the present invention will be described in more detail with reference to examples and comparative examples.

( Reference example )
As a base film, transparent polyimide film 2 (manufactured by Mitsubishi Gas Chemical Company, L3430) having a thickness of 100 μm × length of 300 mm × width of 200 mm was used. In order to form the solvent-resistant layer 3 on the polyimide film 2, an acrylic solution (pentaerythritol triacrylate (manufactured by Nippon Kayaku): 22%, Irgacure 184: 2%, toluene: 76%) is 700 rpm. After coating for 30 seconds, the solvent was dried on a hot plate at about 120 ° C. for 1 minute, and then cured by irradiation with energy of 100 mJ / cm ^{2 with} a UV irradiator. The formed solvent-resistant layer 3 had a thickness of about 1 μm. Thereafter, the other surface of the polyimide film 2 was also formed, and the solvent-resistant layer 3 was formed on both sides.

A SiON layer was formed as a gas barrier layer 6 on the solvent resistant layer 3 by a sputtering apparatus. The film forming conditions were Ar gas flow rate: 60 sccm, N ₂ gas flow rate: 40 sccm, pressure in the chamber: 0.15 Pa, sputtering target: Si ₃ N ₄ , applied power: 2 kW, and SiO _x N with a film thickness of about 100 nm. _{A y} layer (x = 0.2, y = 1.0) was formed. A SiON layer was continuously formed on the other surface.

  Next, a cardo polymer layer 4 was formed on the SiON layer. The cardo polymer layer 4 is coated with a spin coater under conditions of 500 rpm and 30 seconds using a cardo polymer layer-forming coating solution, and then hotplate under conditions of about 120 ° C. and 1 minute. Then, the solvent was dried, and then heated in an oven at 290 ° C. for 1 hour to form a cardo polymer layer 4 having a thickness of about 1 μm. The cardo polymer layer-forming coating solution used at this time was Nippon Steel Chemical: V-259EH (including diethylene glycol dimethyl ether as diglycol diether). The same cardo polymer layer 4 was continuously formed on the other surface.

Next, a silicon oxynitride layer 5 was formed on the cardo polymer layer 4. This silicon oxynitride layer 5 was formed by the same method and conditions as the above-mentioned SiON layer. That is, the film was formed by a sputtering apparatus, and the film formation conditions were Ar gas flow rate: 60 sccm, N ₂ gas flow rate: 40 sccm, pressure in the chamber: 0.15 Pa, sputtering target: Si ₃ N ₄ , applied power: 2 kW, Then, a SiO _x N _y layer (x = 0.2, y = 1.0) having a film thickness of about 100 nm was formed, and the same silicon oxynitride layer 5 was continuously formed on the other surface.

Thus, in the order of lamination, silicon oxynitride layer 5 / cardo polymer layer 4 / SiON layer (gas barrier layer 6) / solvent resistant layer 3 / polyimide film 2 / solvent resistant layer 3 / SiON layer (gas barrier layer 6) / cardo polymer layer 4 / Gas barrier film of Reference Example configured to be a silicon oxynitride layer 5 was obtained. The gas barrier film had a water vapor transmission rate of 0.8 × 10 ⁻³ g / m ² / day and an oxygen transmission rate of 5 × 10 ⁻³ cc / m ² / day · atm. Here, the water vapor transmission rate (WVTR) was measured according to JIS-K7129, using a water vapor transmission rate measuring device (manufactured by MOCON, PERMATRAN-W 3/31) under the conditions of 40 ° C. and 100% Rh. The measurement limit of the water vapor transmission rate is 0.5 × 10 ⁻³ g / m ² · day. On the other hand, the oxygen permeability was measured using an oxygen gas permeability measuring device (manufactured by MOCON, OX-TRAN 2/20) under the conditions of a temperature of 23 ° C. and dry (0% RH). The measurement was performed by the measurement method “with independent zero” to remove the background. The measurement limit of oxygen permeability is 5 × 10 ⁻³ cc / m ² / day · atm.

(Example 1 )
In the reference example , the silicon oxynitride layer 5 / the cardo polymer layer 4 / the resistance to resistance in the same order as in the reference example except that the SiON layer (gas barrier layer 6) immediately above the solvent-resistant layer 3 was not formed. A gas barrier film of Example 1 was produced which was configured to be solvent layer 3 / polyimide film 2 / solvent resistant layer 3 / cardo polymer layer 4 / silicon oxynitride layer 5. The gas barrier film had a water vapor transmission rate of 5.0 × 10 ⁻³ g / m ² / day and an oxygen transmission rate of 5 × 10 ⁻³ cc / m ² / day · atm.

(Comparative Example 1)
In the reference example , the silicon oxynitride layers were sequentially formed in the stacking direction in the same manner as in the reference example except that the solvent resistant layer 3 and the SiON layer (gas barrier layer 6) immediately above the solvent resistant layer 3 were not formed. A gas barrier film of Comparative Example 1 was prepared so as to be 5 / cardo polymer layer 4 / polyimide film 2 / cardo polymer layer 4 / silicon oxynitride layer 5. In this gas barrier film, the solvent (diethylene glycol dimethyl ether) in the cardo polymer layer forming coating solution attacked the polyimide film 2, and bubbles were generated on the surface.

(Comparative Example 2)
In the reference example , the silicon oxynitride layer 5 / acrylic layer (same as the solvent resistant layer 3) in the stacking direction in the same manner as in the reference example except that the same layer as the solvent resistant layer 3 was formed instead of the cardo polymer layer 4. Layer) / SiON layer (gas barrier layer 6) / solvent resistant layer 3 / polyimide film 2 / solvent resistant layer 3 / SiON layer (gas barrier layer 6) / acrylic layer (same layer as solvent resistant layer 3) / silicon oxynitride layer 5 The gas barrier film of the comparative example 2 comprised so that it might become was produced. The gas barrier film had a water vapor transmission rate of 3.0 × 10 ⁻³ g / m ² / day and an oxygen transmission rate of 5 × 10 ⁻³ cc / m ² / day · atm.

(Comparative Example 3)
In the reference example , the SiON layer (gas barrier layer 6) immediately above the solvent-resistant layer 3 and the cardo polymer layer 4 above the SiON layer were not formed, and in the same manner as in the reference example , in the stacking direction. A gas barrier film of Comparative Example 3 was prepared, which was configured to have silicon oxynitride layer 5 / solvent resistant layer 3 / polyimide film 2 / solvent resistant layer 3 / silicon oxynitride layer 5. The gas barrier film had a water vapor transmission rate of 2.5 × 10 ⁻² g / m ² / day and an oxygen transmission rate of 5 × 10 ⁻² cc / m ² / day · atm.

(Evaluation)
In the gas barrier film of Example 1 and the reference example , the polyimide film is not affected by the solvent (diglycol diether) contained in the cardo polymer layer forming coating solution, and the polyimide film absorbs water and swells. The upper layer film was not cracked or peeled off due to swelling.

The gas barrier film of the reference example showed very high gas barrier properties. Moreover, the gas barrier film of Example 1 showed extremely high gas barrier properties as a gas barrier film having a total of two gas barrier layers. In addition, the gas barrier film of Comparative Example 2 has a lower value than the reference example as a gas barrier film having a total of four gas barrier layers on the front and back sides, and the gas barrier film of Comparative Example 3 also has a total of two layers on the front and back sides. The gas barrier film having a low value compared to Example 1 .

  The gas barrier films of Examples 1 and 2 and Comparative Examples 2 and 3 were evaluated for heat resistance. The presence or absence of cracks generated in the silicon oxynitride layer 5 after each gas barrier film was exposed to an atmosphere of 250 ° C. for 180 minutes was confirmed. As a result, in Examples 1 and 2, the occurrence of cracks that lowered the gas barrier properties was not observed, but in Comparative Examples 2 and 3, the occurrence of cracks that lowered the gas barrier properties was confirmed.

It is sectional drawing which shows an example of the gas barrier film of this invention. It is a sectional view showing another example of a gas barrier film. It is a sectional view showing still another example of a gas barrier film.

Explanation of symbols

1A, 1B, 1C Gas barrier film 2 Polyimide film 3 Solvent resistant layer 4 Cardo polymer layer 5 Silicon oxynitride layer 6, 7 Gas barrier layer

Claims (5)

A gas barrier film comprising: a silicon oxynitride layer / a cardo polymer layer / a solvent resistant layer / a polyimide film / a solvent resistant layer / a cardo polymer layer / a silicon oxynitride layer in the order of lamination.   The gas barrier film according to claim 1, wherein the solvent-resistant layer is a layer against a solvent contained in the cardo polymer layer-forming coating solution.   The gas barrier film according to claim 1 or 2, wherein the solvent-resistant layer is a layer for diglycol diether.    The gas barrier film according to claim 1, wherein the cardo polymer layer is made of an epoxy-based cured resin, and the solvent-resistant layer is made of an acrylic-based cured resin. The gas barrier film according to any one of claims 1 to 4 , wherein a gas barrier layer made of any of silicon oxide, silicon nitride, and aluminum oxide is further formed on the silicon oxynitride layer.

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