JP2012086393A - Method of manufacturing functional multilayer film, gas barrier film, and organic element device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a functional multilayer film which has excellent bending resistance in addition to extremely high weather resistance, contamination resistance, gas barrier performance, and scratch resistance, and to provide a gas barrier film and an organic element device using the functional multilayer film manufactured by the method.SOLUTION: The method of manufacturing the functional multilayer film includes laminating, on a base material, a UV cutting layer containing an inorganic UV absorbent and a UV hardening resin and a silica layer formed by performing reforming treatment on a polysilazane-containing coating film in this order. The UV cutting layer is formed by UV hardening treatment, and the silica layer is formed by reforming treatment by irradiation with vacuum ultraviolet rays having a wavelength of 200 nm or less.

Description

  The present invention relates to a method for producing a functional multilayer film, a gas barrier film using the functional multilayer film produced by the production method, and an organic element device. More specifically, a method for producing a functional multilayer film excellent in bending resistance as well as weather resistance, antifouling property, gas barrier property, and scratch resistance that can be sufficiently used in outdoor applications, and a functional multilayer produced by the production method. The present invention relates to a gas barrier film using a film and an organic element device.

  Substrates used in various devices such as liquid crystal display elements, photoelectric conversion elements, and organic electroluminescence (hereinafter also referred to as organic EL) substrates are required to have good physical properties such as gas barrier properties. Until now, hard substrates of inorganic materials such as glass substrates have been used for substrates of various devices. In recent years, in addition to demands for weight reduction and size increase, roll-to-roll production is possible. With the addition of high demands such as long-term reliability and high degree of freedom in shape and the ability to display curved surfaces, film substrates such as transparent plastics have begun to be adopted.

  However, a film substrate such as a transparent plastic has a problem of light deterioration due to ultraviolet rays of sunlight, and a problem that the water vapor and oxygen are easily permeated and diffused in the device, thereby deteriorating the device.

  In particular, when used outdoors, such as materials for solar cells, an ultraviolet cut function, gas barrier property, scratch resistance and the like for preventing light deterioration due to ultraviolet rays of sunlight are also required.

  There has been proposed a method of coating a UV-cutting layer on a substrate with a layer made of a polysilazane-based solution to impart weather resistance, scratch resistance, etc. (for example, Patent Documents 1, 2, and 3). However, in these methods, the method of forming a layer made of a polysilazane solution uses heat drying or UV curing, and the scratch resistance and gas barrier properties are not sufficient. Further, Patent Document 2 uses an organic UV absorber for the UV-cutting layer, which is not sufficient as a UV-cutting function, and bleeds out to the surface with time, resulting in insufficient weather resistance.

  On the other hand, as a technique for imparting gas barrier properties, Patent Document 4 discloses a technique in which a layer made of polysilazane is irradiated with a vacuum ultraviolet excimer lamp to form a silica layer, and the silica layer is laminated. However, since there is no UV cut function, it is impossible to prevent photodegradation of the substrate due to ultraviolet rays, and the weather resistance is not sufficient. In addition, although this technology can form a high-density silica film, a uniformly high-density silica film is very brittle with respect to flexibility, and cracks frequently occur.

JP-A-8-143331 Japanese Patent Laid-Open No. 11-309805 JP 2002-52640 A JP 2009-255040 A

  The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a method for producing a functional multilayer film that has extremely high weather resistance, antifouling properties, gas barrier properties, scratch resistance, and excellent bending resistance. It is another object of the present invention to provide a gas barrier film using a functional multilayer film manufactured by the manufacturing method and an organic element device.

  The above object of the present invention is achieved by the following configurations.

  1. A UV-cutting layer containing an inorganic UV absorber and a UV curable resin is formed on the substrate, and a silica layer formed by applying a modification treatment to the polysilazane-containing coating film is laminated in this order. The method for producing a functional multilayer film is characterized in that the UV-cutting layer is formed by a UV curing treatment, and the silica layer is formed by a modification treatment that irradiates vacuum ultraviolet light having a wavelength of 200 nm or less.

  2. 2. The method for producing a functional multilayer film according to 1 above, wherein the particle surface of the inorganic UV absorber in the UV-cutting layer is surface-treated with an inorganic substance.

  3. 3. The method for producing a functional multilayer film as described in 1 or 2 above, wherein the inorganic UV absorber in the UV-cutting layer is titanium oxide or zinc oxide.

  4). Any one of the above 1-3, wherein the thickness of the layer modified by the modification treatment in the silica layer is 30 to 80% of the coating film containing polysilazane before the modification treatment. The manufacturing method of the functional multilayer film as described in a term.

  5. 5. The method for producing a functional multilayer film according to any one of 1 to 4, wherein a UV curing treatment is further performed after forming the UV-cutting layer and the silica layer.

  6). The functional multilayer film produced by the production method according to any one of 1 to 5 above has a gas barrier layer on the substrate opposite to the UV-cutting layer and the silica layer. A gas barrier film characterized by that.

  7). 7. An organic element device using the gas barrier film as described in 6 above.

  According to the present invention, there is provided a method for producing a functional multilayer film having excellent weather resistance, antifouling properties, gas barrier properties, scratch resistance, and excellent bending resistance, and a functional multilayer produced by the production method. A gas barrier film using the film and an organic element device could be provided.

It is sectional drawing which shows an example of the solar cell which consists of a bulk heterojunction type organic photoelectric conversion element. It is sectional drawing which shows an example of the solar cell which consists of an organic photoelectric conversion element by which the electric power generation layer became 3 layer structure. It is sectional drawing which shows an example of the solar cell which consists of an organic photoelectric conversion element provided with a tandem-type bulk heterojunction layer.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the present inventor performed a modification treatment on a UV-cutting layer containing an inorganic UV absorber and a UV curable resin on a substrate, and a polysilazane-containing coating film. The formed silica layers are laminated in this order, and the UV-cutting layer is formed by a UV curing treatment, and the silica layer is formed by a modification treatment that irradiates vacuum ultraviolet light having a wavelength of 200 nm or less. It has been found that the production method of a functional multilayer film can realize a production method of a functional multilayer film that is excellent in bending resistance as well as extremely high weather resistance, antifouling properties, gas barrier properties, and scratch resistance, It is up to the present invention.

〔Base material〕
The substrate (also referred to as “support”) of the functional multilayer film of the present invention is preferably formed of an organic material capable of holding a UV-cutting layer and a silica layer described later.

  Examples of the organic material include methacrylic acid ester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polystyrene (PS), aromatic polyamide, polyether ether ketone, polysulfone, and polyether. Examples include resin films such as sulfone, polyimide, and polyetherimide, and resin films formed by laminating two or more layers of the above resins. In view of cost and availability, polyethylene terephthalate (PET) is preferably used.

  The thickness of the support is preferably about 5 to 500 μm, more preferably 25 to 250 μm.

  The support according to the present invention is preferably transparent. Since the support is transparent and the layer formed on the support is also transparent, a transparent functional multilayer film can be obtained, and thus a transparent substrate such as an organic EL element can be obtained. Because.

  In addition, the support using the above-described resins or the like may be an unstretched film or a stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression.

  The support used in the present invention can be produced by a conventionally known general method. For example, an unstretched support that is substantially amorphous and not oriented can be produced by melting a resin as a material with an extruder, extruding it with an annular die or a T-die, and quenching. Further, the unstretched support is uniaxially stretched, tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, tubular-type simultaneous biaxial stretching, and other known methods, such as the flow (vertical axis) direction of the support, or A stretched support can be produced by stretching in the direction perpendicular to the flow direction of the support (horizontal axis). The draw ratio in this case can be appropriately selected according to the resin as the raw material of the support, but is preferably 2 to 10 times in the vertical axis direction and the horizontal axis direction.

  In addition, the support used in the present invention may be subjected to relaxation treatment or off-line heat treatment in terms of dimensional stability. It is preferable that the relaxation treatment is performed in a process from the heat setting in the stretching process of the polyester film to the winding in the transversely stretched tenter or after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature of 80 to 200 ° C, more preferably a treatment temperature of 100 to 180 ° C. Moreover, it is preferable that the relaxation rate is in the range of 0.1 to 10% in both the longitudinal direction and the width direction, and more preferably, the relaxation rate is 2 to 6%. The relaxed support is subjected to the following off-line heat treatment to improve heat resistance and further improve dimensional stability. Although it does not specifically limit as a method of off-line heat processing, For example, the method of conveying by the roll conveyance method by a some roll group, the air conveyance etc. which blow an air on a film and levitate | float (one side of a film surface from heating air) Or, a method of spraying on both surfaces), a method of using radiant heat from an infrared heater, a method of hanging the film by its own weight, and a method of conveying such as winding below. The conveyance tension of the heat treatment is made as low as possible to promote thermal shrinkage, thereby providing a support with good dimensional stability. The treatment temperature is preferably a glass transition temperature of the support + 50 ° C. to + 150 ° C.

The support of the present invention is preferably coated with an undercoat layer coating solution inline on one side or both sides in the film forming process. In the present invention, undercoating during the film forming process is referred to as in-line undercoating. Examples of resins used in the undercoat layer coating solution useful in the present invention include polyester resins, acrylic-modified polyester resins, polyurethane resins, acrylic resins, vinyl resins, vinylidene chloride resins, polyethyleneimine vinylidene resins, polyethyleneimine resins, and polyvinyl alcohol resins. , Modified polyvinyl alcohol resin, gelatin and the like, and any of them can be preferably used. A conventionally well-known additive can also be added to these undercoat layers. The undercoat layer can be coated by a known method such as roll coating, gravure coating, knife coating, dip coating or spray coating. The coating amount of the undercoat layer is preferably about 0.01 to ² g / m ² (dry state).

  Further, since the support of the present invention is used outdoors, a film having hydrolysis resistance can be used. For example, using the technology for increasing the intrinsic viscosity of a film disclosed in Japanese Patent Application Laid-Open No. 2007-70430 or the technology for suppressing the terminal carboxylic acid of polyester in the film disclosed in Japanese Patent Application Laid-Open No. 2007-204538, the hydrolysis resistance is improved. can do.

[UV-cutting layer]
The functional multilayer film according to the present invention has a UV-cutting layer on at least one side. In the present invention, the UV-cutting layer is located between the silica layer and the substrate. Since the UV-cutting layer is located between the silica layer and the base material, the UV-cutting function, gas barrier properties, and antifouling properties can be efficiently functioned. It is effective as a functional multilayer film because it is possible to efficiently suppress a decrease in strength due to the above.

  The UV-cutting layer in the present invention is basically composed of a combination of a UV curable resin and an inorganic UV absorber.

(UV curable resin)
The UV curable resin in the present invention can be used without particular limitation as long as it forms a transparent resin composition by curing, such as silicone resin, epoxy resin, vinyl ester resin, acrylic resin, allyl ester resin, etc. Is mentioned. Particularly preferably, an acrylic resin can be used from the viewpoints of hardness, smoothness, and transparency.

  Examples of the acrylic resin composition include acrylate compounds having a radical reactive unsaturated compound, mercapto compounds having an acrylate compound and a thiol group, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polyethylene glycol acrylate, glycerol methacrylate and the like. What dissolved the polyfunctional acrylate monomer etc. are mentioned. It is also possible to use an arbitrary mixture of the above resin compositions, and any photosensitive resin containing a reactive monomer having one or more photopolymerizable unsaturated bonds in the molecule can be used. There are no particular restrictions.

  As a photoinitiator, a well-known thing can be used and it can be used by 1 type, or 2 or more types of combination.

  From the viewpoint of hardness, smoothness and transparency, the acrylic resin is a reactive silica particle in which a photosensitive group having photopolymerization reactivity is introduced on the surface as described in International Publication No. 2008/035669 ( In the following, it is preferable to simply include “reactive silica particles”. Here, examples of the photopolymerizable photosensitive group include a polymerizable unsaturated group represented by a (meth) acryloyloxy group. The photosensitive resin contains a photopolymerizable photosensitive group introduced on the surface of the reactive silica particles and a compound capable of photopolymerization, for example, an unsaturated organic compound having a polymerizable unsaturated group. It may be. In addition, a polymerizable unsaturated group-modified hydrolyzable silane reacts with a silica particle that forms a silyloxy group and is chemically bonded to the silica particle by a hydrolysis reaction of the hydrolyzable silyl group. Can be used as conductive silica particles. Here, the average particle diameter of the reactive silica particles is preferably 0.001 to 0.1 μm. By setting the average particle diameter in such a range, transparency, smoothness, and hardness can be satisfied in a well-balanced manner.

  Moreover, a fluorine-containing vinyl monomer can also be used for acrylic resin at the point which can adjust a refractive index. Examples of the fluorine-containing vinyl monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid moieties or fully fluorinated alkyl ester derivatives (for example, biscoat 6FM (trade name) And R-2020 (trade name, manufactured by Daikin) and the like, and fully or partially fluorinated vinyl ethers.

(Inorganic UV absorber)
The inorganic UV absorber in the present invention is preferably used in the form of particles. As the inorganic UV absorber particles, known inorganic UV absorbers can be added. Examples include titanium dioxide, zinc oxide, cerium oxide, hybrid inorganic powder obtained by compounding titanium dioxide fine particles with iron oxide, and hybrid inorganic powder obtained by coating the surface of cerium oxide fine particles with amorphous silica. However, titanium dioxide and zinc oxide are preferable from the viewpoint of the UV cut function.

  The particle size of the UV absorber particles is preferably 0.1 μm or less from the viewpoint of transparency and smoothness.

  The inorganic UV absorber particles are preferably surface-treated with an inorganic substance from the viewpoint of suppressing photocatalyst and improving dispersion stability. As general inorganic substances, oxides and hydroxides containing silicon, aluminum, zirconium, titanium, zinc and the like are known, and surface treatment with aluminum oxide and silicon dioxide is particularly desirable from the viewpoint of weather resistance. .

  The surface treatment method of the inorganic UV absorber particles is not particularly limited, and examples thereof include a method of coating with a hydrous oxide such as the above compound. The particle size of the inorganic UV absorber after the surface treatment is preferably 5 to 200 nm. The amount of the surface treatment agent is subjected to the surface treatment within a range of 40% or less in terms of mass ratio, but is preferably 20% or less. When the amount of the surface treatment agent exceeds 40%, the blending amount of the inorganic UV absorber is reduced, and the UV absorption effect is reduced.

  The said UV absorber may be used independently and may be used in combination of 2 or more type. Although there is no restriction | limiting in particular as content in a UV-cutting layer, From the point of transparency and smoothness, 0.1-80 mass%, Preferably the range of 30-70 mass% is preferable.

  When the inorganic UV absorber is used in combination with the organic UV absorber described later, the amount of the inorganic UV absorber used is 3 to 20% by mass, preferably 5 to 10% by mass with respect to the total mass of the UV absorbing layer. The amount of the organic UV absorber used is 0.1 to 10% by mass, preferably 0.5 to 5% by mass. When an inorganic UV absorber and an organic UV absorber are used in combination within the above-mentioned range of use, the transparency of the UV absorbing layer is high and the weather resistance is also good.

  The thickness of the UV-cutting layer in the present invention is 1 to 10 μm, preferably 2 to 7 μm. If it is larger than 1 μm, the hardness is sufficient and preferable. On the other hand, when it is smaller than 10 μm, the smooth layer and transparency are improved, which is preferable.

  The film forming method of the UV-cutting layer is not particularly limited, but is preferably formed by a wet coating method such as a spin coating method, a spray method, a blade coating method, a dip method, or a dry coating method such as an evaporation method.

  As a method of curing with ultraviolet rays, it can be carried out by irradiating ultraviolet rays in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm, emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp or the like. .

  In the formation of the UV-cutting layer, additives such as an antioxidant, a plasticizer, a matting agent, and a thermoplastic resin can be added to the above-described resin as necessary. Moreover, as a solvent used when forming a smooth layer using the coating liquid which melt | dissolved or disperse | distributed resin in the solvent, a well-known thing can be used.

[Silica layer]
The functional multilayer film according to the present invention has a silica layer on the UV-cutting layer. The silica layer according to the present invention is formed by applying a polysilazane-containing film on a UV-cutting layer formed on a substrate and then subjecting it to a modification treatment by vacuum ultraviolet light irradiation. The silica layer is a layer that is not easily soiled or scratched and has a high gas barrier property.

  The silica layer of the present invention may be a single layer or a plurality of similar films, and the plurality of layers can further improve the scratch resistance and gas barrier properties.

In the present invention, the gas barrier property means that the water vapor permeability (60 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a method according to JIS K 7129-1992 is 1 × 10 ^−3. g ^/ (m 2 · 24h) or less, the oxygen permeability measured in compliance with the method provided in JIS K 7126-1987 is, the ^{1 × 10 -3 ml / m 2} · 24h · atm or less (1 atm, 1 .01325 × 10 ⁵ Pa).

(Polysilazane-containing coating film)
The polysilazane-containing film is preferably formed by coating a coating liquid containing a polysilazane compound on the UV-cutting layer formed on the substrate.

  Any appropriate method can be adopted as a coating method. Specific examples include a spin coating method, a roll coating method, a flow coating method, an ink jet method, a spray coating method, a printing method, a dip coating method, a casting film forming method, a bar coating method, and a gravure printing method. The coating thickness can be appropriately set according to the purpose. For example, the coating thickness can be set so that the thickness after drying is preferably about 1 nm to 100 μm, more preferably about 10 nm to 10 μm, and most preferably about 10 nm to 1 μm.

The “polysilazane” used in the present invention is a polymer having a silicon-nitrogen bond, and includes SiO ₂ , Si ₃ N ₄ and both intermediate solid solutions SiO _x N _{y made of} Si—N, Si—H, N—H, or the like. Such as a ceramic precursor polymer.

  In order not to damage the film substrate, it has a partial structure represented by the following general formula 1 which is converted to silica by being ceramicized at a relatively low temperature as described in JP-A-8-112879. Those are preferred.

In the formula, each of R ¹ , R ² , and R ³ independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group, an alkoxy group, or the like.

Perhydropolysilazane, in which all of R ¹ , R ² , and R ³ are hydrogen atoms, is particularly preferred from the viewpoint of the denseness of the resulting silica film.

  On the other hand, the organopolysilazane in which the hydrogen part bonded to Si is partially substituted with an alkyl group or the like has an improved adhesion to the lower layer by having an alkyl group such as a methyl group, and is a ceramic film made of polysilazane which is hard and brittle Toughness can be imparted, and there is an advantage that the occurrence of cracks can be suppressed even when the film thickness is increased. These perhydropolysilazane and organopolysilazane may be appropriately selected according to the application, and may be used in combination.

  Perhydropolysilazane is presumed to have a linear structure and a ring structure centered on 6- and 8-membered rings. The molecular weight is about 600 to 2000 (polystyrene conversion) in terms of number average molecular weight (Mn), is a liquid or solid substance, and varies depending on the molecular weight. These are marketed in a solution state dissolved in an organic solvent, and the commercially available product can be used as it is as a polysilazane-containing coating solution.

  As another example of polysilazane which is ceramicized at a low temperature, a silicon alkoxide-added polysilazane obtained by reacting a polysilazane of the above general formula 1 with a silicon alkoxide (Japanese Patent Laid-Open No. 5-238827), a glycidol obtained by reacting glycidol Addition polysilazane (JP-A-6-122852), alcohol-added polysilazane obtained by reacting alcohol (JP-A-6-240208), metal carboxylate-added polysilazane obtained by reacting metal carboxylate (special Kaihei 6-299118), acetylacetonate complex-added polysilazane obtained by reacting a metal-containing acetylacetonate complex (JP-A-6-306329), metal fine particle-added polysilazane obtained by adding metal fine particles ( JP-A-7- JP), etc. 96986 can be mentioned.

  As an organic solvent for preparing a liquid containing polysilazane, it is not preferable to use an alcohol or water-containing one that easily reacts with polysilazane. Specifically, hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, ethers such as halogenated hydrocarbon solvents, aliphatic ethers and alicyclic ethers can be used. Specific examples include hydrocarbons such as pentane, hexane, cyclohexane, toluene, xylene, solvesso and turben, halogen hydrocarbons such as methylene chloride and trichloroethane, and ethers such as dibutyl ether, dioxane and tetrahydrofuran. These solvents may be selected according to purposes such as the solubility of polysilazane and the evaporation rate of the solvent, and a plurality of solvents may be mixed.

  The polysilazane concentration in the polysilazane-containing coating solution is about 0.2 to 35% by mass, although it varies depending on the target silica film thickness and the pot life of the coating solution.

  In order to promote the conversion to a silicon oxide compound, an amine or metal catalyst may be added. Specific examples include Aquamica NAX120-20, NN110, NN310, NN320, NL110A, NL120A, NL150A, NP110, NP140, and SP140 manufactured by AZ Electronic Materials Co., Ltd.

(Polysilazane film forming process)
The polysilazane-containing coating film preferably has moisture removed before or during the modification treatment. Therefore, it is preferable to divide into the 1st process for the purpose of removing the solvent in a polysilazane film | membrane, and the 2nd process for the purpose of removing the water | moisture content in the polysilazane film | membrane following it.

  In the first step, the drying conditions for mainly removing the solvent can be appropriately determined by a method such as heat treatment, but the conditions may be such that moisture is removed at this time. The heat treatment temperature is preferably high from the viewpoint of rapid treatment, but the temperature and treatment time can be determined in consideration of thermal damage to the resin substrate. For example, when a PET substrate having a glass transition temperature (Tg) of 70 ° C. is used as the resin substrate, the heat treatment temperature can be set to 200 ° C. or less. The treatment time is preferably set to a short time so that the solvent is removed and the thermal damage to the substrate is reduced. If the heat treatment temperature is 200 ° C. or less, the treatment time can be set within 30 minutes.

  The second step is a step for removing moisture in the polysilazane film, and the method for removing moisture is preferably in a form maintained in a low humidity environment. Since the humidity in the low humidity environment varies depending on the temperature, a preferable form of the relationship between the temperature and the humidity is indicated by the definition of the dew point temperature. A preferable dew point temperature is 4 ° C. or less (temperature 25 ° C./humidity 25%), a more preferable dew point temperature is −8 ° C. (temperature 25 ° C./humidity 10%) or less, and a more preferable dew point temperature is (temperature 25 ° C./humidity 1%). ) −31 ° C. or lower, and the maintained time varies depending on the thickness of the polysilazane film. Under the condition of a polysilazane film thickness of 1 μm or less, the preferable dew point temperature is −8 ° C. or less, and the maintained time is 5 minutes or more. Moreover, you may dry under reduced pressure in order to make it easy to remove a water | moisture content. The pressure in the vacuum drying can be selected from normal pressure to 0.1 MPa.

  As a preferable condition of the second step with respect to the condition of the first step, for example, when the solvent is removed at a temperature of 60 to 150 ° C. and a treatment time of 1 to 30 minutes in the first step, the dew point of the second step is 4 ° C. or less. The treatment time can be selected from 5 minutes to 120 minutes under conditions for removing moisture. The first process and the second process can be distinguished by changing the dew point, and can be classified by changing the dew point of the process environment by 10 degrees or more.

  The polysilazane film is preferably subjected to a modification treatment while maintaining its state even after moisture is removed in the second step.

(Water content of polysilazane film)
The water content of the polysilazane film can be detected by the following analysis method.

Headspace-gas chromatograph / mass spectrometry apparatus: HP6890GC / HP5973MSD
Oven: 40 ° C. (2 min), then heated to 150 ° C. at a rate of 10 ° C./min Column: DB-624 (0.25 mm × 30 m)
Inlet: 230 ° C
Detector: SIM m / z = 18
HS condition: 190 ° C, 30min
The water content in the polysilazane film in the present invention is a value obtained by dividing the water content obtained by the above analysis method by the volume of the polysilazane film, and is preferably 0.1% in a state where moisture is removed by the second step. It is as follows. A more preferable moisture content is 0.01% or less (below the detection limit).

  This is a preferred mode for promoting the dehydration reaction of the polysilazane film converted to silanol by removing water before or during the modification treatment as in the present invention.

(Modification process)
In the present invention, the modification treatment refers to a treatment in which a polysilazane-containing coating film is irradiated with vacuum ultraviolet light to be converted into a silicon oxide such as silicon dioxide or a silicon oxynitride compound. This vacuum ultraviolet light irradiation breaks the molecular bond of polysilazane, and even a small amount of oxygen in the film or atmosphere can be efficiently converted to ozone or active oxygen, facilitating the conversion of polysilazane into ceramics. In addition, the resulting ceramic film becomes denser. The vacuum ultraviolet light irradiation is effective at any time point after the coating film is formed.

  In the present invention, vacuum ultraviolet light refers to electromagnetic waves having a wavelength of 10 to 200 nm, but vacuum ultraviolet light of 100 to 200 nm is preferably used from a practical aspect.

In the irradiation with vacuum ultraviolet light, the irradiation intensity and / or the irradiation time are set within a range in which the substrate carrying the irradiated coating film is not damaged. Taking the case of using a plastic film as a substrate in an example, intensity 10mW ^/ cm ² ~300mW ^/ cm 2 of substrate surface, preferably the substrate so as to 50~200mW / cm ² - a lamp distance It is preferable to perform irradiation for 0.1 seconds to 10 minutes, preferably 0.5 seconds to 3 minutes.

  A commercially available lamp (for example, manufactured by USHIO INC.) Can be used for the vacuum ultraviolet light irradiation apparatus.

  Vacuum ultraviolet light irradiation can be adapted to both batch processing and continuous processing, and can be appropriately selected depending on the shape of the substrate to be coated. For example, in the case of batch processing, a substrate (eg, silicon wafer) having a polysilazane coating film on the surface can be processed in a vacuum ultraviolet light baking furnace equipped with a vacuum ultraviolet light generation source. The vacuum ultraviolet light baking furnace itself is generally known, and for example, a product manufactured by I-Graphics Co., Ltd. can be used. In addition, when the base material having a polysilazane coating film is a long film, it is continuously irradiated with vacuum ultraviolet light in a drying zone equipped with a vacuum ultraviolet light generation source as described above while being transported. By doing so, it can be converted into ceramics.

  Since the vacuum ultraviolet light is larger than the interatomic bonding force of most substances, it can be preferably used because the bonding of atoms can be cut directly by the action of only photons called photon processes. By using this action, the reforming process can be efficiently performed at a low temperature without requiring hydrolysis.

  As a vacuum ultraviolet light source required for this, a rare gas excimer lamp is preferably used.

Excimer light is laser light using a rare gas excimer or a hetero excimer as an operating medium. Since noble gas atoms such as Xe, Kr, Ar, Ne and the like are chemically bonded to form no molecule, they are called inert gases. However, a rare gas atom (excited atom) that has gained energy by discharge or the like can combine with other atoms to form a molecule. When the rare gas is xenon, e + Xe → e + Xe ^*
Xe ^* + Xe + Xe → Xe ₂ ^* + Xe
Xe ₂ ^* → Xe + Xe + hν (172 nm)
Thus, when the excited excimer molecule Xe ₂ ^* transitions to the ground state, excimer light of 172 nm is emitted. A feature of the excimer lamp is that the radiation is concentrated on one wavelength, and since only the necessary light is not emitted, the efficiency is high.

  Further, since no extra light is emitted, the temperature of the object can be kept low. Furthermore, since no time is required for starting and restarting, instantaneous lighting and blinking are possible.

  In order to obtain excimer light, a method using dielectric barrier discharge is known. Dielectric barrier discharge refers to lightning generated in a gas space by arranging a gas space between both electrodes via a dielectric (transparent quartz in the case of an excimer lamp) and applying a high frequency high voltage of several tens of kHz to the electrode. When the micro discharge streamer reaches the tube wall (dielectric) in a similar very thin discharge called micro discharge, the electric charge accumulates on the dielectric surface, and the micro discharge disappears. This micro discharge spreads over the entire tube wall, and is a discharge that is repeatedly generated and extinguished. For this reason, flickering of light that can be seen with the naked eye occurs. Moreover, since a very high temperature streamer reaches a pipe wall directly locally, there is a possibility that deterioration of the pipe wall may be accelerated.

  As a method for efficiently obtaining excimer light, electrodeless electric field discharge can be used in addition to dielectric barrier discharge.

  Electrodeless electric field discharge by capacitive coupling, also called RF discharge. The lamp and electrodes and their arrangement may be basically the same as for dielectric barrier discharge, but the high frequency applied between the two electrodes is lit at several MHz. Since the electrodeless field discharge can provide a spatially and temporally uniform discharge in this way, a long-life lamp without flickering can be obtained.

  In the case of dielectric barrier discharge, micro discharge occurs only between the electrodes, so the outer electrode covers the entire outer surface and allows light to pass through in order to extract light to the outside in order to discharge in the entire discharge space. Must. For this reason, an electrode in which a fine metal wire is formed in a net shape is used. Since this electrode uses as thin a line as possible so as not to block light, it is easily damaged by ozone generated by vacuum ultraviolet light in an oxygen atmosphere.

  In order to prevent this, it is necessary to provide an atmosphere of an inert gas such as nitrogen around the lamp, that is, the inside of the irradiation apparatus, and provide a synthetic quartz window to extract the irradiation light. Synthetic quartz windows are not only expensive consumables, but also cause light loss.

  Since the double cylindrical lamp has an outer diameter of about 25 mm, the difference in distance to the irradiation surface cannot be ignored between the position directly below the lamp axis and the side surface of the lamp, resulting in a large difference in illuminance. Therefore, even if the lamps are arranged in close contact, a uniform illuminance distribution cannot be obtained. If the irradiation device is provided with a synthetic quartz window, the distance in the oxygen atmosphere can be made uniform, and a uniform illuminance distribution can be obtained.

  When electrodeless field discharge is used, it is not necessary to make the external electrodes mesh. The glow discharge spreads over the entire discharge space simply by providing an external electrode on a part of the outer surface of the lamp. As the external electrode, an electrode that also serves as a light reflector made of an aluminum block is usually used on the back of the lamp. However, since the outer diameter of the lamp is as large as in the case of the dielectric barrier discharge, synthetic quartz is required to obtain a uniform illuminance distribution.

  The biggest feature of the capillary excimer lamp is its simple structure. The quartz tube is closed at both ends, and only gas for excimer light is sealed inside. Therefore, a very inexpensive light source can be provided.

  Since the double cylindrical lamp is processed by connecting both ends of the inner and outer tubes, it is more likely to be damaged during handling and transportation than a thin tube lamp.

  The outer diameter of the tube of the thin tube lamp is about 6 to 12 mm, and if it is too thick, a high voltage is required for starting.

  As for the form of discharge, either dielectric barrier discharge or electrodeless field discharge can be used. The electrode may have a flat surface in contact with the lamp, but if the shape is matched to the curved surface of the lamp, the lamp can be firmly fixed and the discharge is more stable when the electrode is in close contact with the lamp. Also, if the curved surface is made into a mirror surface with aluminum, it also becomes a light reflector.

  The Xe excimer lamp is excellent in luminous efficiency because it emits ultraviolet light having a short wavelength of 172 nm at a single wavelength. Since this light has a large oxygen absorption coefficient, radical oxygen atomic species and ozone can be generated at a high concentration with a small amount of oxygen. In addition, it is known that the energy of light having a short wavelength of 172 nm for dissociating the bonds of organic substances has high ability. Due to the high energy of the active oxygen, ozone and ultraviolet radiation, the polysilazane film can be modified in a short time. Therefore, compared with low-pressure mercury lamps with wavelengths of 185 nm and 254 nm and plasma cleaning, it is possible to shorten the process time associated with high throughput, reduce the equipment area, and irradiate organic materials and plastic substrates that are easily damaged by heat. .

  Since the excimer lamp has high light generation efficiency, it can be lit with low power. In addition, light having a long wavelength that causes a temperature rise due to light is not emitted, and energy is irradiated at a single wavelength in the ultraviolet region, so that the rise in the surface temperature of the object to be fired is suppressed. For this reason, it is suitable for flexible film materials such as PET that are easily affected by heat.

(Oxygen concentration during vacuum ultraviolet light irradiation)
The oxygen concentration during irradiation with vacuum ultraviolet light according to the present invention is preferably 500 ppm to 10000 ppm (1%), and more preferably 1000 ppm to 5000 ppm.

  By adjusting the oxygen concentration within the above range, it is possible to prevent the formation of an oxygen-excess gas barrier film and to prevent deterioration of gas barrier properties, as will be described later.

(Modified thickness)
The silica layer according to the present invention may be formed only from a layer modified by a modification treatment, that is, a layer converted into a silicon oxide such as silicon dioxide or a silicon oxynitride compound. It may be formed from a layer (modified layer) and an unmodified layer (unmodified layer). In the case where the silica layer is composed of a modified layer and an unmodified layer, the film thickness of the modified layer is that of the polysilazane-containing material before the modification treatment from the viewpoint of achieving both scratch resistance, gas barrier properties and flexibility. It is preferably 30 to 80% of the coating film. By adjusting the modified film thickness (%) within this range, the modified layer and the UV-cutting layer are placed between the dense modified layer and the UV-cutting layer that exhibit high scratch resistance and gas barrier properties. By arranging an unmodified layer having intermediate physical properties, it is possible to prevent stress concentration at the interface and improve the adhesion of the silica layer, and in addition to gas barrier properties, bending resistance is also improved, which is preferable. .

  The modified film thickness of the silica layer can be measured by observing the dislocation line of the cross section with an ultra high resolution transmission electron microscope (TEM). Although a clear interface is not observed, it is possible to distinguish between the modified layer and the unmodified layer by observing a gradation between the modified film and the unmodified film. In the present invention, the film thickness can be estimated with the middle of the gradation portion as the interface between the modified layer and the unmodified layer, and the modified film thickness (%) can be calculated.

  On the other hand, when regions having different properties are stacked by vapor deposition, an interface always exists due to the properties. Dislocation lines such as screw dislocations and edge dislocations are generated at the time of deposition of gas phase molecules in the stacking direction due to minute nonuniformity occurring at the interface, and are observed by an ultrahigh resolution TEM. Since the silica layer according to the present invention modifies the coating film, it is presumed that regions having different properties can be formed without an interface without generating clear dislocation lines that are likely to occur during deposition of gas phase molecules.

[UV curing treatment after formation of UV-cutting layer and silica layer]
The functional multilayer film of the present invention may be further subjected to UV curing treatment after forming a UV-cutting layer and a silica layer on the surface of the substrate. By this UV curing treatment, the surface of the silica layer can be further densified, and high scratch resistance and gas barrier properties can be obtained. As a method of curing with ultraviolet rays, it can be carried out by irradiating ultraviolet rays in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm emitted from an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp or the like. .

[Gas barrier film and gas barrier layer]
The functional multilayer film of the present invention can be used as a gas barrier film having a lower permeability by forming a gas barrier layer on the opposite side of the UV-cutting layer and the silica layer laminated on the substrate.

  The gas barrier layer is for preventing deterioration of the base material and various functional elements protected by the base material due to high humidity. As the gas barrier layer, a single layer or a plurality of similar films may be laminated, and the gas barrier property can be further improved by a plurality of layers.

  The gas barrier layer is not particularly limited in its formation method, but a method of forming an inorganic oxide film by applying a ceramic precursor of an inorganic oxide film and then heating and / or irradiating ultraviolet rays is preferably used. The sol-like organometallic compound or polysilazane is preferable as the ceramic precursor. The organometallic compound is not particularly limited as long as it can be hydrolyzed, and preferred organometallic compounds include metal alkoxides.

  The silicon oxide or silicon oxynitride compound for forming the gas barrier layer of silicon oxide or silicon oxynitride compound is supplied as a gas as in a CVD method (Chemical Vapor Deposition). However, it is possible to form a more uniform and smooth gas barrier layer when applied to the surface of the barrier film substrate. It is well known that in the case of a CVD method or the like, a foreign material called unnecessary particles is generated in the gas phase simultaneously with the step of depositing the source material having increased reactivity in the gas phase on the substrate surface. By preventing the raw material from being present in the gas phase reaction space, the generation of these particles can be suppressed.

<Polysilazane-containing coating film>
The polysilazane-containing coating film is preferably formed by coating a coating solution containing at least a polysilazane compound on a substrate opposite to the silica layer.

  Any appropriate method can be adopted as a coating method. Specific examples include a spin coating method, a roll coating method, a flow coating method, an ink jet method, a spray coating method, a printing method, a dip coating method, a casting film forming method, a bar coating method, and a gravure printing method. The coating thickness can be appropriately set according to the purpose. For example, the coating thickness can be set so that the thickness after drying is preferably about 1 nm to 100 μm, more preferably about 10 nm to 10 μm, and most preferably about 10 nm to 1 μm.

The “polysilazane” used in the present invention is a polymer having a silicon-nitrogen bond as described above, and is composed of SiO ₂ , Si ₃ N _4, and intermediate solid solution SiO of Si—N, Si—H, N—H or the like. a ceramic precursor polymer, such as _x N _y.

  The gas barrier layer having polysilazane on the surface opposite to the silica layer is also preferably modified. For the modification treatment, the method described in the silica layer can be used.

  By having the modified polysilazane on both surfaces, the gas barrier property and the like can be further improved.

  In order not to damage the film base material, it has a partial structure represented by the above general formula 1 that is converted to silica by being ceramicized at a relatively low temperature as described in JP-A-8-112879. Those are preferred.

[Functional multilayer film]
The film according to the present invention has, on a substrate, a UV-cutting layer containing an inorganic UV absorber and an actinic ray curable resin, and a silica layer formed by modifying a polysilazane-containing coating film. In addition, it is a functional multilayer film that has sufficient weather resistance, antifouling properties, gas barrier properties, scratch resistance and bending resistance that can be used even outdoors. The surface of the film on the opposite side of the UV-cutting layer and the silica layer is surface treated with a laminating agent, an adhesive bonding method, etc. to provide high transparency and weather resistance and antifouling. Functions, gas barrier properties, scratch resistance, and the like can be imparted to the surface of the adherend and used in a wide range of applications such as organic element devices.

[Other layers]
As a layer constituting the functional multilayer film in the present invention, a smooth layer, a bleed-out prevention layer, or the like can be provided in addition to the UV-cutting layer and the silica layer substrate on the substrate described above.

  The smooth layer flattens the rough surface of the transparent resin film substrate where protrusions and the like exist, or fills the unevenness and pinholes generated in the transparent inorganic compound layer by the protrusions present on the transparent resin film substrate and flattens the surface. Provided for. Such a smooth layer is basically formed by curing a photosensitive resin.

  As the photosensitive resin of the smooth layer, for example, a resin composition containing an acrylate compound having a radical reactive unsaturated compound, a resin composition containing an acrylate compound and a mercapto compound having a thiol group, epoxy acrylate, urethane acrylate, Examples thereof include a resin composition in which a polyfunctional acrylate monomer such as polyester acrylate, polyether acrylate, polyethylene glycol acrylate, or glycerol methacrylate is dissolved. It is also possible to use an arbitrary mixture of the above resin compositions, and any photosensitive resin containing a reactive monomer having one or more photopolymerizable unsaturated bonds in the molecule can be used. There are no particular restrictions.

  The bleed-out prevention layer is used for the purpose of suppressing the phenomenon that, when a film having a smooth layer is heated, unreacted oligomers migrate from the film substrate to the surface and contaminate the contact surface. Provided on the opposite side of the substrate having the layer. The bleed-out prevention layer may basically have the same configuration as the smooth layer as long as it has this function.

[Organic device]
The gas barrier film of the present invention can be used as a film for organic element devices. Examples of the organic element device include an organic EL element and an organic photoelectric conversion element. The configuration and details of using the gas barrier film of the present invention for an organic EL device and an organic photoelectric conversion device are described below.

(Organic EL device)
Next, embodiments of the organic EL element which is an example of the organic EL of the present invention will be described in detail. However, the contents described below are representative examples of the embodiments of the present invention, and the present invention does not exceed the gist thereof. As long as it is not limited to these contents.

(Organic EL device)
Preferred specific examples of the layer structure of the organic EL element are shown below.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode Here, in order for the light generated in the light emitting layer to be emitted to the outside, it is necessary that at least one of the anode and the cathode is transparent. In the method, it is preferable to use the transparent conductive layer mainly as an anode.

  The light emitting layer preferably contains at least two kinds of light emitting materials having different emission colors, and a single layer or a light emitting layer unit composed of a plurality of light emitting layers may be formed. The hole transport layer also includes a hole injection layer and an electron blocking layer.

(Transparent conductive layer)
As the transparent conductive layer in the organic EL device of the present invention, a material having a work function (4 eV or more) of a metal, an alloy, an electrically conductive compound and a mixture thereof as an electrode material for forming the transparent conductive layer is preferably used. . Specific examples of such electrode substances include metals such as Au, and conductive light-transmitting materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, a material such as IDIXO (In ₂ O ₃ —ZnO) that can form an amorphous light-transmitting conductive film may be used. In the present invention, the transparent conductive layer is preferably used as an anode. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method. ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film forming methods, such as a printing system and a coating system, can also be used. The sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 50 to 200 nm.

  Moreover, a metal nanowire can also be used for this transparent conductive layer. In the case of using metal nanowires, in order to form a long conductive path with one metal nanowire and to express appropriate light scattering properties, the average length is preferably 3 μm or more, and more preferably 3 to 500 μm. It is preferable that it is 3-300 micrometers especially. In addition, the relative standard deviation of the length is preferably 40% or less. Moreover, it is preferable that an average diameter is small from a transparency viewpoint, On the other hand, the larger one is preferable from an electroconductive viewpoint. In this invention, 10-300 nm is preferable as an average diameter of metal nanowire, and it is more preferable that it is 30-200 nm. In addition, the relative standard deviation of the diameter is preferably 20% or less.

  The metal composition of the metal nanowire is not particularly limited, and can be composed of one or more metals such as a noble metal element and a base metal element. Osmium etc.) and at least one metal belonging to the group consisting of iron, cobalt, copper and tin is preferable, and at least silver is more preferable from the viewpoint of conductivity.

  In order to achieve both conductivity and stability (sulfurization and oxidation resistance of metal nanowires and migration resistance), it is also preferable to include silver and at least one metal belonging to a noble metal other than silver. When the metal nanowire contains two or more kinds of metal elements, for example, the metal composition may be different between the inside and the surface of the metal nanowire, or the entire metal nanowire may have the same metal composition.

  As a manufacturing method of Ag nanowire, Adv. Mater. , 2002, 14, 833-837; Chem. Mater. , 2002, 14, 4736-4745, etc. As a method for producing Co nanowires, a method for producing Au nanowires is disclosed in JP 2006-233252A, and a method for producing Cu nanowires is disclosed in JP 2002-266007 A, etc. Reference can be made to Japanese Unexamined Patent Publication No. 2004-149871. In particular, Adv. Mater. And Chem. Mater. The method for producing Ag nanowires reported in 1 can easily produce Ag nanowires in water, and since silver has the highest conductivity in metals, it can be preferably applied as a method for producing metal nanowires. it can.

(Light emitting layer)
The light-emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light-emitting portion is the light-emitting layer even in the light-emitting layer. It may be an interface with an adjacent layer.

  As a light emitting layer, if the light emitting material contained satisfies the said requirements, there will be no restriction | limiting in particular in the structure. Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength. Moreover, it is preferable to have a non-light emitting intermediate | middle layer between each light emitting layer.

  The total thickness of the light emitting layers is preferably in the range of 1 to 100 nm, and more preferably 30 nm or less because a lower driving voltage can be obtained. Note that the total film thickness of the light emitting layer is a film thickness including the intermediate layer when a non-light emitting intermediate layer exists between the light emitting layers.

  The thickness of each light emitting layer is preferably adjusted to a range of 1 to 50 nm, more preferably adjusted to a range of 1 to 20 nm. There is no particular limitation on the relationship between the film thicknesses of the blue, green and red light emitting layers.

  For the production of the light emitting layer, a light emitting material or a host compound, which will be described later, is formed by forming a film by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, or the like. it can.

  A plurality of light emitting materials may be mixed in each light emitting layer, and a phosphorescent light emitting material and a fluorescent light emitting material may be mixed and used in the same light emitting layer.

  As a structure of the light emitting layer, it is preferable to contain a host compound and a light emitting material (also referred to as a light emitting dopant compound) and emit light from the light emitting material.

  As the host compound contained in the light emitting layer of the organic EL device, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.

  As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of luminescent material mentioned later, and can thereby obtain arbitrary luminescent colors.

  The host compound used may be a conventionally known low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). .

  As the known host compound, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable. Here, the glass transition point (Tg) is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

  Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. 2002-302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Next, the light emitting material will be described.

  As the light-emitting material, a fluorescent compound or a phosphorescent material (also referred to as a phosphorescent compound or a phosphorescent compound) can be used.

  A phosphorescent material is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0.01 or more at 25 ° C. However, the preferable phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of the Fourth Edition Experimental Chemistry Course 7. The phosphorescence quantum yield in a solution can be measured using various solvents. However, when a phosphorescent material is used in the present invention, the phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

  There are two types of light emission principles of phosphorescent materials. One is the recombination of carriers on the host compound to which carriers are transported, generating an excited state of the host compound, and this energy is transferred to the phosphorescent material. The energy transfer type is to obtain light emission from the phosphorescent light emitting material, and the other is that the phosphorescent light emitting material becomes a carrier trap, and carrier recombination occurs on the phosphorescent light emitting material, and light emission from the phosphorescent light emitting material is obtained. In any case, the excited state energy of the phosphorescent light emitting material is required to be lower than the excited state energy of the host compound.

  The phosphorescent light-emitting material can be appropriately selected from known materials used for the light-emitting layer of the organic EL element, and is preferably a complex compound containing a group 8-10 metal in the periodic table of elements. More preferably, an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

  A fluorescent substance can also be used for the organic EL element. Representative examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Conventionally known dopants can also be used in the present invention. For example, WO 00/70655, JP-A 2002-280178, 2001-181616, 2002-280179, 2001-181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178, 2002-302671, 2001-345183, 2002 No. 324679, International Publication No. 02/15645, JP 2002-332291 A, 2002-50484, 2002-332292, 2002-83684, JP 2002-540572 A JP, 2002-11 No. 978, No. 2002-338588, No. 2002-170684, No. 2002-352960, WO 01/93642, JP-A No. 2002-50483, No. 2002-1000047. JP 2002-173674, 2002-359082, 2002-17584, 2002-363552, 2002-184582, 2003-7469, JP 2002-525808, JP 2003-7471 A, JP 2002-525833 A, JP 2003-31366 A, 2002-226495 A, 2002-234894 A, 2002-23076 A, 2002-241751 Gazette, 200 -319779, 2001-319780, 2002-62824, 2002-1000047, 2002-203679, 2002-343572, 2002-203678, and the like. .

  In the present invention, at least one light emitting layer may contain two or more kinds of light emitting materials, and the concentration ratio of the light emitting materials in the light emitting layer may vary in the thickness direction of the light emitting layer.

(Middle layer)
A case where a non-light emitting intermediate layer (also referred to as an undoped region or the like) is provided between the light emitting layers will be described.

  The non-light emitting intermediate layer is a layer provided between the light emitting layers in the case of having a plurality of light emitting layers. The film thickness of the non-light emitting intermediate layer is preferably in the range of 1 to 20 nm, and further in the range of 3 to 10 nm suppresses interaction such as energy transfer between adjacent light emitting layers, and the current of the device This is preferable because a large load is not applied to the voltage characteristics.

  The material used for the non-light emitting intermediate layer may be the same as or different from the host compound of the light emitting layer, but may be the same as the host material of at least one of the adjacent light emitting layers. preferable.

  The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) In the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, or the molecular structure of the host compound is the same, etc.) The barrier is reduced, and the effect of easily maintaining the injection balance of holes and electrons even when the voltage (current) is changed can be obtained. Furthermore, by using a host material having the same physical characteristics or the same molecular structure as the host compound contained in each light-emitting layer in the undoped light-emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

  Since the host material is responsible for carrier transportation, a material having carrier transportation ability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance between injection and transport of holes and electrons, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

  On the other hand, in order to optimally adjust the injection balance of holes and electrons, it is also preferable that the non-light emitting intermediate layer functions as a blocking layer described later, that is, a hole blocking layer and an electron blocking layer. Can be mentioned.

(Injection layer: electron injection layer, hole injection layer)
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

(Blocking layer: hole blocking layer, electron blocking layer)
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  In a broad sense, the hole blocking layer has a function of an electron transport layer and is composed of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes, while transporting electrons. By blocking holes, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

  On the other hand, the electron blocking layer, in a broad sense, has a function of a hole transport layer, and is made of a material having a function of transporting holes while having a remarkably small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

(Hole transport layer)
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer is formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Can do. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  It is preferable to use such a hole transport layer having a high p property because an element with lower power consumption can be manufactured.

(Electron transport layer)
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as well as the hole injection layer and the hole transport layer. It can be used as an electron transport material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

(Counter electrode)
The counter electrode is an electrode facing the transparent conductive layer. In the present invention, since the transparent conductive layer is mainly used as an anode, the following cathode can be used as the counter electrode. As the cathode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

  Moreover, after producing the said metal with a film thickness of 1 nm-20 nm on a cathode, a transparent or semi-transparent cathode can be produced by producing an electroconductive transparent material on it, By applying this, An element in which both the anode and the cathode are transmissive can be manufactured.

[Production method of organic EL]
The organic EL of the present invention can be produced by sequentially forming a light extraction layer, a transparent conductive layer, an organic electroluminescence layer, and a counter electrode on a transparent substrate.

(Formation of transparent conductive layer)
A transparent conductive layer can be formed on a transparent substrate using a desired electrode material. For example, when ITO (indium oxide added with tin) is used as the electrode material, the transparent conductive layer can be formed by a method such as vapor deposition or sputtering. In addition, a transparent conductive layer can be formed from a material containing metal nanowires, a conductive polymer, or a transparent conductive metal oxide by a liquid phase film forming method such as a coating method or a printing method.

  From the viewpoint of improving productivity, improving electrode quality such as smoothness and uniformity, and reducing environmental impact, it is possible to form a transparent conductive layer containing metal nanowires by a liquid phase film-forming method such as a coating method or a printing method. preferable. As coating methods, roll coating method, bar coating method, dip coating method, spin coating method, casting method, die coating method, blade coating method, bar coating method, gravure coating method, curtain coating method, spray coating method, doctor coating method Etc. can be used. As the printing method, a letterpress (letter) printing method, a stencil (screen) printing method, a lithographic (offset) printing method, an intaglio (gravure) printing method, a spray printing method, an ink jet printing method, and the like can be used. In addition, as necessary, physical surface treatment such as corona discharge treatment or plasma discharge treatment can be applied to the surface of the releasable substrate as a preliminary treatment for improving the adhesion and coating properties.

(Formation of organic electroluminescence layer)
A layer formed between the transparent conductive layer and the cathode, consisting of all or part of the anode buffer layer, hole transport layer, light emitting layer, hole blocking layer, electron transport layer, and cathode buffer layer is called an organic electroluminescence layer. . As an example of a method for producing this organic electroluminescence layer, a method for producing an organic electroluminescence layer comprising a hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer will be described.

  An organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are constituent materials of the organic EL layer, is formed on the transparent base material on which the transparent conductive layer is formed.

As a method for thinning the organic compound thin film, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a uniform film and a pinhole. From the point of being difficult to form, a vacuum deposition method, a spin coating method, an ink jet method, and a printing method are particularly preferable. Further, different film forming methods may be applied for each layer. When employing a vapor deposition method for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a degree of vacuum of 10 ⁻⁶ to 10 ⁻² Pa, and a vapor deposition rate of 0.01 to It is desirable to select appropriately within the range of 50 nm / second, substrate temperature −50 to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 to 200 nm.

(Formation of cathode)
After forming the organic electroluminescence layer, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm. Is provided.

  Through the above steps, an organic electroluminescence layer is obtained. The organic electroluminescence layer is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor liquid crystal display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

(Organic light conversion element)
Although the preferable aspect of the organic photoelectric conversion element which concerns on this invention is demonstrated, it is not limited to this. There is no restriction | limiting in particular as an organic photoelectric conversion element, The electric power generation layer (The layer which mixed the p-type semiconductor and the n-type semiconductor, the bulk heterojunction layer, and i layer) sandwiched between the anode and the cathode at least 1 is provided. Any element that has more than one layer and generates current when irradiated with light may be used.

The preferable specific example of the layer structure of an organic photoelectric conversion element is shown below.
(I) anode / power generation layer / cathode (ii) anode / hole transport layer / power generation layer / cathode (iii) anode / hole transport layer / power generation layer / electron transport layer / cathode (iv) anode / hole transport layer / P-type semiconductor layer / power generation layer / n-type semiconductor layer / electron transport layer / cathode (v) anode / hole transport layer / first light emitting layer / electron transport layer / intermediate electrode / hole transport layer / second light emitting layer Here, the power generation layer needs to contain a p-type semiconductor material capable of transporting holes and an n-type semiconductor material capable of transporting electrons, which are substantially two layers and heterojunction. Alternatively, a bulk heterojunction that is in a mixed state in one layer may be formed, but a bulk heterojunction configuration is preferable because of higher photoelectric conversion efficiency. A p-type semiconductor material and an n-type semiconductor material used for the power generation layer will be described later.

  Like the organic EL element, the efficiency of taking out holes and electrons to the anode / cathode can be increased by sandwiching the power generation layer between the hole transport layer and the electron transport layer. Therefore, the structure having them ((ii), ( iii)) is preferred. Further, in order to improve the rectification of holes and electrons (selection of carrier extraction), the power generation layer itself is sandwiched between layers of a p-type semiconductor material and a single n-type semiconductor material as shown in (iv). It may be a configuration (also referred to as a pin configuration). Moreover, in order to improve the utilization efficiency of sunlight, the tandem configuration (configuration (v)) in which sunlight of different wavelengths is absorbed by each power generation layer may be employed.

  Instead of the sandwich structure in the organic photoelectric conversion element 10 shown in FIG. 1 for the purpose of improving the sunlight utilization rate (photoelectric conversion efficiency), a hole transport layer 14 and an electron transport layer 16 are respectively formed on a pair of comb-like electrodes. The back contact type organic photoelectric conversion element can be configured such that the photoelectric conversion unit 15 is disposed thereon.

  Furthermore, the preferable aspect of the organic photoelectric conversion element which concerns on detailed this invention is demonstrated below.

  FIG. 1 is a cross-sectional view showing an example of a solar cell composed of a bulk heterojunction organic photoelectric conversion element. In FIG. 1, a bulk heterojunction organic photoelectric conversion element 10 has an anode 12, a hole transport layer 17, a power generation layer 14 of a bulk heterojunction layer, an electron transport layer 18, and a cathode 13 sequentially stacked on one surface of a substrate 11. Has been.

  The substrate 11 is a member that holds the anode 12, the power generation layer 14, and the cathode 13 that are sequentially stacked. In the present embodiment, since light that is photoelectrically converted enters from the substrate 11 side, the substrate 11 can transmit the light that is photoelectrically converted, that is, with respect to the wavelength of the light to be photoelectrically converted. It is a transparent member. As the substrate 11, for example, a glass substrate or a resin substrate is used. The substrate 11 is not essential. For example, the bulk heterojunction organic photoelectric conversion element 10 may be configured by forming the anode 12 and the cathode 13 on both surfaces of the power generation layer 14.

  The power generation layer 14 is a layer that converts light energy into electrical energy, and includes a bulk heterojunction layer in which a p-type semiconductor material and an n-type semiconductor material are uniformly mixed. The p-type semiconductor material functions relatively as an electron donor (donor), and the n-type semiconductor material functions relatively as an electron acceptor (acceptor).

  In FIG. 1, light incident from the anode 12 through the substrate 11 is absorbed by the electron acceptor or electron donor in the bulk heterojunction layer of the power generation layer 14, and electrons move from the electron donor to the electron acceptor. A pair of holes and electrons (charge separation state) is formed. The generated electric charge is caused by an internal electric field, for example, when the work function of the anode 12 and the cathode 13 is different, the electrons pass between the electron acceptors and the holes are electron donors due to the potential difference between the anode 12 and the cathode 13. The photocurrent is detected by passing through different electrodes to different electrodes. For example, when the work function of the anode 12 is larger than that of the cathode 13, electrons are transported to the anode 12 and holes are transported to the cathode 13. If the magnitude of the work function is reversed, electrons and holes are transported in the opposite direction. In addition, the transport direction of electrons and holes can be controlled by applying a potential between the anode 12 and the cathode 13.

  Although not shown in FIG. 1, other layers such as a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, or a smoothing layer may be included.

  As a more preferable configuration, the power generation layer 14 has a so-called p-i-n three-layer configuration (FIG. 2). A normal bulk heterojunction layer is a single i layer 14i in which a p-type semiconductor material and an n-type semiconductor layer are mixed, but a p-layer 14p made of a single p-type semiconductor material and an n-layer 14n made of a single n-type semiconductor material. As a result, the rectifying property of holes and electrons becomes higher, loss due to recombination of charge-separated holes and electrons is reduced, and higher photoelectric conversion efficiency can be obtained.

  Furthermore, it is good also as a tandem-type structure which laminated | stacked such a photoelectric conversion element for the purpose of the improvement of sunlight utilization factor (photoelectric conversion efficiency).

  FIG. 3 is a cross-sectional view illustrating an example of a solar cell including an organic photoelectric conversion element including a tandem bulk heterojunction layer. In the case of the tandem configuration, the anode (transparent electrode) 12 and the first power generation layer 14 'are sequentially stacked on the substrate 11, the charge recombination layer 15 is stacked, the second power generation layer 16, and then the cathode. By stacking the (counter electrode) 13, a tandem configuration can be obtained. The second power generation layer 16 may be a layer that absorbs the same spectrum as the absorption spectrum of the first power generation layer 14 ′ or may be a layer that absorbs a different spectrum, but is preferably a layer that absorbs a different spectrum. Further, both the first power generation layer 14 ′ and the second power generation layer 16 may have the above-described three-layer structure of pin.

  Below, the material which comprises these layers is described.

(Organic photoelectric conversion element material)
<P-type semiconductor material>
Examples of the p-type semiconductor material used for the power generation layer (bulk heterojunction layer) include various condensed polycyclic aromatic low-molecular compounds and conjugated polymers / oligomers.

  Examples of the condensed polycyclic aromatic low-molecular compound include anthracene, tetracene, pentacene, hexacene, heptacene, chrysene, picene, fluorene, pyrene, peropyrene, perylene, terylene, quaterylene, coronene, ovalene, circumanthracene, bisanthene, zesulene, Compounds such as heptazethrene, pyranthrene, violanthene, isoviolanthene, cacobiphenyl, anthradithiophene, porphyrin, copper phthalocyanine, tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bis (ethylenedithio) tetrathiafur Examples include valene (BEDT-TTF) -perchloric acid complex, and derivatives and precursors thereof.

  Examples of the derivative having the above condensed polycycle include International Publication No. 03/16599, International Publication No. 03/28125, US Pat. No. 6,690,029, Japanese Patent Application Laid-Open No. 2004-107216. A pentacene derivative having a substituent described in JP-A No. 2003-136964, a pentacene precursor described in US Patent Application Publication No. 2003/136964, and the like; Amer. Chem. Soc. , Vol127. No. 14.4986, J. MoI. Amer. Chem. Soc. , Vol. 123, p9482; Amer. Chem. Soc. , Vol. 130 (2008), no. 9, acene-based compounds substituted with a trialkylsilylethynyl group described in 2706 and the like.

  Examples of the conjugated polymer include a polythiophene such as poly-3-hexylthiophene (P3HT) and an oligomer thereof, or a technical group described in Technical Digest of the International PVSEC-17, Fukuoka, Japan, 2007, P1225. Polythiophene, Nature Material, (2006) vol. 5, p328, polythiophene-thienothiophene copolymer, WO2008 / 000664, polythiophene-diketopyrrolopyrrole copolymer, Adv Mater, 2007p4160, polythiophene-thiazolothiazole copolymer, Nature Mat. vol. 6 (2007), p497 described in PCPDTBT, polypyrrole and its oligomer, polyaniline, polyphenylene and its oligomer, polyphenylene vinylene and its oligomer, polythienylene vinylene and its oligomer, polyacetylene, polydiacetylene, Examples thereof include polymer materials such as σ-conjugated polymers such as polysilane and polygermane.

  In addition, oligomeric materials instead of polymer materials include thiophene hexamer α-sexual thiophene α, ω-dihexyl-α-sexual thiophene, α, ω-dihexyl-α-kinkethiophene, α, ω-bis (3 Oligomers such as -butoxypropyl) -α-sexithiophene can be preferably used.

  Among these compounds, compounds that have high solubility in organic solvents to the extent that solution processing is possible, can form a crystalline thin film after drying, and can achieve high mobility are preferable.

  Further, when the electron transport layer is formed on the power generation layer by coating, there is a problem that the electron transport layer solution dissolves the power generation layer. Therefore, a material that can be insolubilized after coating by a solution process may be used. .

  Examples of such materials include materials that can be insolubilized by polymerizing the coating film after coating, such as polythiophene having a polymerizable group described in Technical Digest of the International PVSEC-17, Fukuoka, Japan, 2007, P1225. Or by applying energy such as heat as described in U.S. Patent Application Publication No. 2003/136964 and Japanese Patent Application Laid-Open No. 2008-16834, etc., the soluble substituent reacts to insolubilize (to form a pigment). ) Materials can be mentioned.

<N-type semiconductor material>
The n-type semiconductor material used in the bulk heterojunction layer is not particularly limited. For example, perfluoro compounds in which a hydrogen atom of a p-type semiconductor is substituted with a fluorine atom, such as fullerene and octaazaporphyrin (perfluoropentacene or perfluorophthalocyanine). ), Naphthalenetetracarboxylic acid anhydride, naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, perylenetetracarboxylic acid diimide, and other aromatic carboxylic acid anhydrides and polymer compounds containing the imidized compounds thereof be able to.

  However, fullerene derivatives that can perform charge separation with various p-type semiconductor materials at high speed (˜50 fs) and efficiently are preferable. Fullerene derivatives include fullerene C60, fullerene C70, fullerene C76, fullerene C78, fullerene C84, fullerene C240, fullerene C540, mixed fullerene, fullerene nanotubes, multi-walled nanotubes, single-walled nanotubes, nanohorns (conical), and the like. Some are hydrogen atoms, halogen atoms, substituted or unsubstituted alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, cycloalkyl groups, silyl groups, ether groups, thioether groups, amino groups, silyl groups, etc. Examples thereof include substituted fullerene derivatives.

  Among them, [6,6] -phenyl C61-butyric acid methyl ester (abbreviation PCBM), [6,6] -phenyl C61-butyric acid-nbutyl ester (PCBnB), [6,6] -phenyl C61-buty Rick acid-isobutyl ester (PCBiB), [6,6] -phenyl C61-butyric acid-n hexyl ester (PCBH), Adv. Mater. , Vol. 20 (2008), p2116, etc., aminated fullerenes such as JP-A 2006-199674, metallocene fullerenes such as JP-A 2008-130889, and cyclics such as US Pat. No. 7,329,709. It is preferable to use a fullerene derivative having a substituent and having improved solubility, such as fullerene having an ether group.

<Hole transport layer and electron block layer>
Since the organic photoelectric conversion element 10 according to the present invention can extract the hole transport layer 17 between the bulk heterojunction layer and the anode, and more efficiently take out the charges generated in the bulk heterojunction layer. It is preferable to have a layer.

  As a material constituting these layers, for example, as the hole transport layer 17, PEDOT such as Stark Vitec Co., Ltd., trade name BaytronP, polyaniline and its doped material, cyan compounds described in WO2006019270, etc. Can be used. Note that the hole transport layer having a LUMO level shallower than the LUMO level of the n-type semiconductor material used for the bulk heterojunction layer has a rectifying effect that prevents electrons generated in the bulk heterojunction layer from flowing to the anode side. It has an electronic block function. Such a hole transport layer is also called an electron block layer, and it is preferable to use a hole transport layer having such a function. As such a material, a triarylamine compound described in JP-A-5-271166 or a metal oxide such as molybdenum oxide, nickel oxide, or tungsten oxide can be used. A layer made of a single p-type semiconductor material used for the bulk heterojunction layer can also be used. The means for forming these layers may be either a vacuum deposition method or a solution coating method, but is preferably a solution coating method. Forming the coating film in the lower layer before forming the bulk heterojunction layer is preferable because it has the effect of leveling the coating surface and reduces the influence of leakage and the like.

<Electron transport layer / hole blocking layer>
In the organic photoelectric conversion element 10 according to the present invention, the electron transport layer 18 is formed between the bulk heterojunction layer and the cathode, so that charges generated in the bulk heterojunction layer can be taken out more efficiently. It is preferable to have these layers.

  As the electron transport layer 18, octaazaporphyrin, a p-type semiconductor perfluoro product (perfluoropentacene, perfluorophthalocyanine, etc.) can be used. Similarly, a p-type semiconductor material used for a bulk heterojunction layer is used. The electron transport layer having a HOMO level deeper than the HOMO level is given a hole blocking function having a rectifying effect so that holes generated in the bulk heterojunction layer do not flow to the cathode side. Such an electron transport layer is also called a hole blocking layer, and it is preferable to use an electron transport layer having such a function. Examples of such materials include phenanthrene compounds such as bathocuproine, n-type semiconductor materials such as naphthalenetetracarboxylic acid anhydride, naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, perylenetetracarboxylic acid diimide, and titanium oxide. N-type inorganic oxides such as zinc oxide and gallium oxide, and alkali metal compounds such as lithium fluoride, sodium fluoride, and cesium fluoride can be used. A layer made of a single n-type semiconductor material used for the bulk heterojunction layer can also be used. The means for forming these layers may be either a vacuum deposition method or a solution coating method, but is preferably a solution coating method.

<Other layers>
For the purpose of improving energy conversion efficiency and improving the lifetime of the element, a structure having various intermediate layers in the element may be employed. Examples of the intermediate layer include a hole block layer, an electron block layer, a hole injection layer, an electron injection layer, an exciton block layer, a UV absorption layer, a light reflection layer, and a wavelength conversion layer.

<Transparent electrode (first electrode)>
The transparent electrode is not particularly limited to a cathode and an anode, and can be selected depending on the element configuration. Preferably, the transparent electrode is used as an anode. For example, when used as an anode, it is preferably an electrode that transmits light of 380 to 800 nm. As the material, for example, transparent conductive metal oxides such as indium tin oxide (ITO), SnO ₂ and ZnO, metal thin films such as gold, silver and platinum, metal nanowires and carbon nanotubes can be used.

  Also, a conductive material selected from the group consisting of polypyrrole, polyaniline, polythiophene, polythienylene vinylene, polyazulene, polyisothianaphthene, polycarbazole, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, polyphenylacetylene, polydiacetylene and polynaphthalene. A functional polymer can also be used. A plurality of these conductive compounds can be combined to form a transparent electrode.

<Counter electrode (second electrode)>
The counter electrode may be a single layer of a conductive material, but in addition to a conductive material, a resin that holds these may be used in combination. As the conductive material of the counter electrode, a material having a small work function (4 eV or less) metal, alloy, electrically conductive compound and a mixture thereof is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the viewpoint of electron extraction performance and durability against oxidation, etc., a mixture of these metals and a second metal which is a stable metal having a larger work function value than this, for example, a magnesium / silver mixture, magnesium / Aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The counter electrode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The (average) film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm.

  If a metal material is used as the conductive material of the counter electrode, the light coming to the counter electrode side is reflected and reflected to the first electrode side, and this light can be reused and is absorbed again by the photoelectric conversion layer, and more photoelectric conversion efficiency Is preferable.

  The counter electrode 13 may be a metal (for example, gold, silver, copper, platinum, rhodium, ruthenium, aluminum, magnesium, indium, etc.), a nanoparticle made of carbon, a nanowire, or a nanostructure. If the dispersion is, a transparent and highly conductive counter electrode can be formed by a coating method.

  In addition, when the counter electrode side is made light-transmitting, for example, a conductive material suitable for the counter electrode such as aluminum and aluminum alloy, silver and silver compound is made thin with an average film thickness of about 1 to 20 nm. Thereafter, a light-transmitting counter electrode can be obtained by providing a film of the conductive light-transmitting material mentioned in the description of the transparent electrode.

<Intermediate electrode>
In addition, the material of the intermediate electrode required in the case of the tandem configuration as in the above (v) (or FIG. 3) is preferably a layer using a compound having both transparency and conductivity. (Such as ITO, AZO, FTO, transparent metal oxides such as titanium oxide, very thin metal layers such as Ag, Al, Au, etc., or layers containing nanoparticles / nanowires, PEDOT: PSS, polyaniline) Or the like can be used.

  In addition, among the hole transport layer and the electron transport layer described above, there is also a combination that works as an intermediate electrode (charge recombination layer) by stacking in an appropriate combination. With such a configuration, a step of forming one layer is omitted. Can be preferable.

<Metal nanowires>
As the conductive fibers, organic fibers or inorganic fibers coated with metal, conductive metal oxide fibers, metal nanowires, carbon fibers, carbon nanotubes, and the like can be used. Metal nanowires are preferable.

  In general, the metal nanowire refers to a linear structure having a metal element as a main component. In particular, the metal nanowire in the present invention means a linear structure having a diameter of nm size.

  As a metal nanowire, in order to form a long conductive path with one metal nanowire and to express appropriate light scattering properties, the average length is preferably 3 μm or more, and more preferably 3 to 500 μm. Particularly preferred is 3 to 300 μm. In addition, the relative standard deviation of the length is preferably 40% or less. Moreover, it is preferable that an average diameter is small from a transparency viewpoint, On the other hand, the larger one is preferable from an electroconductive viewpoint. In this invention, 10-300 nm is preferable as an average diameter of metal nanowire, and it is more preferable that it is 30-200 nm. In addition, the relative standard deviation of the diameter is preferably 20% or less.

  The metal composition of the metal nanowire is not particularly limited, and can be composed of one or more metals such as a noble metal element and a base metal element, but noble metals (for example, gold, platinum, silver, palladium, rhodium, iridium, ruthenium, Osmium etc.) and at least one metal belonging to the group consisting of iron, cobalt, copper and tin is preferable, and at least silver is more preferable from the viewpoint of conductivity. In order to achieve both conductivity and stability (sulfurization and oxidation resistance of metal nanowires and migration resistance), it is also preferable to include silver and at least one metal belonging to a noble metal other than silver. When the metal nanowire includes two or more kinds of metal elements, for example, the metal composition may be different between the surface and the inside of the metal nanowire, or the entire metal nanowire may have the same metal composition.

  In the present invention, the means for producing the metal nanowire is not particularly limited, and for example, known means such as a liquid phase method and a gas phase method can be used. Moreover, there is no restriction | limiting in particular in a specific manufacturing method, A well-known manufacturing method can be used. For example, as a method for producing Ag nanowires, Adv. Mater. , 2002, 14, 833-837; Chem. Mater. , 2002, 14, 4736-4745, etc. As a method for producing Co nanowires, a method for producing Au nanowires is disclosed in JP 2006-233252A, and a method for producing Cu nanowires is disclosed in JP 2002-266007 A, etc. Reference can be made to Japanese Unexamined Patent Publication No. 2004-149871. In particular, Adv. Mater. And Chem. Mater. The method for producing Ag nanowires reported in 1 can easily produce Ag nanowires in water, and since silver has the highest conductivity in metals, it can be preferably applied as a method for producing metal nanowires. it can.

  In the present invention, the metal nanowires come into contact with each other to form a three-dimensional conductive network, exhibiting high conductivity, and allowing light to pass through the window of the conductive network where no metal nanowire exists. In addition, the power generation from the organic power generation layer can be efficiently performed by the scattering effect of the metal nanowires. If a metal nanowire is installed in the 1st electrode at the side close | similar to an organic electric power generation layer part, since this scattering effect can be utilized more effectively, it is more preferable embodiment.

<Optical function layer>
The organic photoelectric conversion element according to the present invention may have various optical functional layers for the purpose of more efficient reception of sunlight. As the optical functional layer, for example, a light condensing layer such as an antireflection film or a microlens array, or a light diffusion layer that can scatter light reflected by the cathode and enter the power generation layer again may be provided. .

  Various known antireflection layers can be provided as the antireflection layer. For example, when the transparent resin film is a biaxially stretched polyethylene terephthalate film, the refractive index of the easy adhesion layer adjacent to the film is 1.57. It is more preferable to set it to ˜1.63 because the interface reflection between the film substrate and the easy adhesion layer can be reduced and the transmittance can be improved. The method for adjusting the refractive index can be carried out by appropriately adjusting the ratio of the oxide sol having a relatively high refractive index such as tin oxide sol or cerium oxide sol and the binder resin. The easy adhesion layer may be a single layer, but may be composed of two or more layers in order to improve adhesion.

  As the condensing layer, for example, it is processed so as to provide a structure on the microlens array on the sunlight receiving side of the support substrate, or the amount of light received from a specific direction is increased by combining with a so-called condensing sheet. Conversely, the incident angle dependency of sunlight can be reduced.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it is smaller than this, the effect of diffraction is generated and colored, and if it is too large, the thickness becomes thick, which is not preferable.

  Examples of the light scattering layer include various antiglare layers, layers in which nanoparticles or nanowires such as metals or various inorganic oxides are dispersed in a colorless and transparent polymer, and the like.

<Film forming method / Surface treatment method>
<Method for forming various layers>
Examples of a method for forming a bulk heterojunction layer in which an electron acceptor and an electron donor are mixed, and a transport layer / electrode include a vapor deposition method and a coating method (including a cast method and a spin coat method). Among these, examples of the method for forming the bulk heterojunction layer include a vapor deposition method and a coating method (including a casting method and a spin coating method). Among these, the coating method is preferable in order to increase the area of the interface where charges and electrons are separated from each other as described above and to produce a device having high photoelectric conversion efficiency. The coating method is also excellent in production speed.

  Although there is no restriction | limiting in the coating method used in this case, For example, a spin coat method, the casting method from a solution, a dip coat method, a blade coat method, a wire bar coat method, a gravure coat method, a spray coat method etc. are mentioned. Furthermore, patterning can also be performed by a printing method such as an ink jet method, a screen printing method, a relief printing method, an intaglio printing method, an offset printing method, or a flexographic printing method.

  After coating, it is preferable to perform heating in order to cause removal of residual solvent, moisture and gas, and improvement of mobility and absorption longwave due to crystallization of the semiconductor material. When annealing is performed at a predetermined temperature during the manufacturing process, a part of the material is microscopically aggregated or crystallized, and the bulk heterojunction layer can have an appropriate phase separation structure. As a result, the carrier mobility of the bulk heterojunction layer is improved and high efficiency can be obtained.

  The power generation layer (bulk heterojunction layer) 14 may be composed of a single layer in which an electron acceptor and an electron donor are uniformly mixed, but a plurality of layers in which the mixing ratio of the electron acceptor and the electron donor is changed. You may comprise. In this case, it can be formed by using a material that can be insolubilized after coating as described above.

<Patterning>
There is no particular limitation on the method and process for patterning the electrode, the power generation layer, the hole transport layer, the electron transport layer, and the like, and known methods can be applied as appropriate.

  If it is a soluble material such as a bulk heterojunction layer and a transport layer, only unnecessary portions may be wiped after the entire surface of die coating, dip coating, etc., or direct patterning at the time of coating using a method such as an ink jet method or screen printing. May be.

  In the case of an insoluble material such as an electrode material, the electrode can be patterned by a known method such as mask vapor deposition during vacuum deposition or etching or lift-off. Alternatively, the pattern may be formed by transferring a pattern formed on another substrate.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
(Support)
A 50 μm-thick polyester film with easy adhesion on both sides, Teijin DuPont Films, KDL86W-50 μm (PET1) was used as a support.

(Production of functional multilayer film)
The functional multilayer film formed the functional multilayer films 1 to 12 so as to have the layer configuration shown in Table 1 while conveying the support at a speed of 30 m / min. As the formation order, after the formation of the bleed-out preventing layer, the first layer and the second layer on the UV-cutting layer side were formed in this order. The configuration and forming method of each layer are shown below.

(Formation of bleed-out prevention layer 1 (BA prevention))
BA prevention layer: After applying UV curable organic / inorganic hybrid hard coat material OPSTAR Z7535 manufactured by JSR Corporation on one side of the above support and applying it with a wire bar so that the (average) film thickness after drying is 4 μm. Curing conditions: 1.0 J / cm ² under air, using a high-pressure mercury lamp, drying conditions: Curing was performed at 80 ° C. for 3 minutes to form a bleed-out prevention layer 1.

(Formation of UV-cutting layer)
UV-cutting layer 1: UV curable hard coat agent TYN65 (containing UV curable organic / zinc oxide particles, refractive index adjusted to 1.65) manufactured by Toyo Ink Co., Ltd., containing inorganic UV absorber according to the present invention The UV-cutting layer coating solution 1 was obtained. After applying this, it was applied to the above support with a wire bar so that the (average) film thickness after drying was 4 μm, then dried in an air atmosphere at 80 ° C. for 1 minute, and then a high-pressure mercury lamp was used. Then, UV curing treatment was performed under an air atmosphere under curing conditions: 400 mJ / cm ² , and a UV-cutting layer 1 (UV1) was formed on one side of the support as shown in Table 1.

  UV-cutting layer 2: 50% silica coated fine particle zinc oxide Maxlite ZS64 made by Showa Denko KK containing inorganic UV absorber according to the present invention is dispersed in UV curable resin Aulex 349 made by China Paint Co., Ltd. In the same manner as the UV-cutting layer 1, coating, drying, and UV-curing treatment were performed, and a UV-cutting layer 2 (UV2) was formed at the position shown in Table 1.

  UV cut layer 3: Organic UV absorber, 10% of Tinufin 477 manufactured by BASF Japan KK, dispersed in UV curable resin Aulex 349 manufactured by China Paint Co., Ltd. In the same manner as the UV-cutting layer 1, coating, drying and UV-curing treatment were performed, and a UV-cutting layer 3 (UV3) was formed at the position shown in Table 1.

(Formation of silica layer)
A silica layer was formed under the following conditions so as to have a configuration as shown in Table 1. In Comparative Example 4, a silica layer was formed on the first layer under the following conditions, and then a silica layer was formed on the second layer in the same manner.

Silica layer A:
(Silica layer coating solution)
Perhydropolysilazane (PHPS) 20% by weight dibutyl ether solution AZ Electronic Materials Co., Ltd. Aquamica NN320
With a wireless bar, coating was performed so that the (average) film thickness after drying was 0.30 μm to obtain a coated sample.

(First step; drying treatment)
The obtained coated sample was treated for 1 minute in an atmosphere having a temperature of 85 ° C. and a humidity of 55% RH to obtain a dried sample.

(Second step; dehumidification treatment)
The dried sample was further held for 10 minutes in an atmosphere of a temperature of 25 ° C. and a humidity of 10% RH (dew point temperature −8 ° C.) to perform dehumidification.

(Modification process)
The sample subjected to the dehumidification treatment was subjected to a modification treatment under the following modification treatment conditions A and B to form silica layer A (silica A) and silica layer B (silica B), respectively. The dew point temperature during the reforming treatment was -8 ° C.

(Modification equipment)
Ex. Irradiator MODEL: MECL-M-1-200, wavelength 172 nm, lamp filled gas Xe manufactured by M.D.Com
The sample fixed on the operation stage was modified under the following conditions.

(Reforming treatment condition A)
Excimer light intensity 130mW / cm ² (172nm)
1mm distance between sample and light source
Stage heating temperature 70 ℃
Oxygen concentration in irradiation device 0.5%
Excimer irradiation time 3 seconds (reforming treatment condition B)
Excimer light intensity 80mW / cm ² (172nm)
1mm distance between sample and light source
Stage heating temperature 70 ℃
Oxygen concentration in irradiation device 0.5%
Excimer irradiation time 20 seconds ・ Silica layer C:
A sample that had been subjected to dehumidification treatment in the same manner as in the silica layer A was dried in a dryer at 300 ° C. for 1 hour to be sufficiently cured to form a silica layer C (silica C).

Silica layer D:
A sample that has been subjected to dehumidification treatment in the same manner as silica layer A is sufficiently cured by performing UV curing treatment at 300 mJ / cm ² using a high-pressure mercury lamp in an air atmosphere to form silica layer D (silica D). did.

(UV curing treatment)
The functional multilayer films 4, 6, 7, and 8 were further UV-cured after formation of the first and second layers, using a high-pressure mercury lamp, under an air atmosphere, and under curing conditions of 400 mJ / cm ² . (Indicated in the table as additional UV curing.)
[Evaluation of functional multilayer film]
The weather resistance, antifouling property, gas barrier property, and scratch resistance were evaluated by the following measurement methods.

<Weather resistance>
Using a metal halide lamp type weather resistance tester (Daipura Wintes Co., Ltd.), sample surface radiation intensity: 2.16 MJ / m ² or less, black panel temperature: 63 ° C., relative humidity: 50%, irradiation time: 500 hours The weather resistance was evaluated by measuring the elongation at break of the irradiated sample using the following tensile tester. A larger elongation until breakage indicates better weather resistance.

  Using a variable temperature tensile tester (“Shimadzu Autograph AGS-100D”; manufactured by Shimadzu Corporation), a gas barrier film specimen cut to a width of 10 mm was subjected to conditions of 23 ° C., a distance between chucks of 50 mm, and a tensile speed of 50 mm / min. The elongation rate until breaking was obtained by the following formula.

Elongation rate (%) = [(length at break-original length) / original length] × 100
<Anti-fouling>
The functional multilayer films 1 to 12 are exposed southward at 30 ° and 90 ° (vertical) for 1 year outdoors, and the presence or absence of soiling on the vertical surface and the degree of soiling on the 30 ° surface are ΔE from the initial (blank). The value (JIS standard Z-8729) was evaluated. For color difference measurement, an optical color difference meter (JP7200F) manufactured by JUKI Corporation was used. If the ΔE value exceeds 3.0, it is determined that the antifouling property is poor.

<Gas barrier properties (evaluation of water vapor permeability)>
The following measurement methods were used for evaluation.

(apparatus)
Vapor deposition apparatus: JEOL Ltd. vacuum vapor deposition apparatus JEE-400
Constant temperature and humidity oven: Yamato Humidic Chamber IG47M
(raw materials)
Metal that reacts with water and corrodes: Calcium (granular)
Water vapor-impermeable metal: Aluminum (φ3-5mm, granular)
(Preparation of water vapor barrier property evaluation cell)
Vapor deposition of functional multilayer film samples before applying a transparent conductive film on a silica layer side of functional multilayer film samples 1 to 12 shown in Table 1 using a vacuum deposition apparatus (vacuum deposition apparatus JEE-400 manufactured by JEOL Ltd.) Masking was performed except for the portions (9 mm of 12 mm × 12 mm) that were desired to be deposited, and metallic calcium was deposited. Thereafter, the mask was removed in a vacuum state, and aluminum was deposited from another metal deposition source on the entire surface of one side of the sheet. After aluminum sealing, the vacuum state is released, and immediately facing the aluminum sealing side through a UV-curable resin for sealing (made by Nagase ChemteX) on quartz glass with a thickness of 0.2 mm in a dry nitrogen gas atmosphere The cell for evaluation was produced by irradiating with ultraviolet rays.

  The obtained sample with both sides sealed was stored at 60 ° C. and 90% RH under high temperature and high humidity, and permeated into the cell from the corrosion amount of metallic calcium based on the method described in JP-A-2005-283561. The amount of water was calculated.

  In addition, in order to confirm that there is no permeation of water vapor from other than the functional multilayer film surface, instead of the functional multilayer film sample as a comparative sample, metallic calcium was deposited using a quartz glass plate having a thickness of 0.2 mm. The obtained sample was stored under the same high temperature and high humidity conditions of 60 ° C. and 90% RH, and it was confirmed that no corrosion of metallic calcium occurred even after 1000 hours.

  The obtained water content was classified into the following five stages.

A: Less than 1 × 10 ⁻⁵ g / m ² / day B: 1 × 10 ⁻⁵ g / m ² / day or more, less than 1 × 10 ⁻⁴ g / m ² / day C: 1 × 10 ⁻⁴ g / day m ² / day or more, less than 1 × 10 ⁻³ g / m ² / day D: 1 × 10 ⁻³ g / m ² / day or more, less than 1 × 10 ⁻² g / m ² / day E: 1 × 10 ^-2 g / m ² / day or more <Modified layer thickness of silica layer>
The modified layer film thickness of the silica layer according to the present invention was measured by observing dislocation lines with an ultrahigh resolution transmission electron microscope (TEM) in the cross section. Although a clear interface is not observed, it is possible to distinguish between the modified layer and the unmodified layer by observing a gradation between the modified film and the unmodified film. The film thickness was estimated assuming that the middle of the gradation part was the interface between the modified layer and the unmodified layer. In Table 1, it was described as the modified film thickness%. Modified film thickness% is a percentage display of a value obtained by dividing the modified layer film thickness by the total film thickness (modified layer film thickness + unmodified layer film thickness).

<Abrasion resistance>
The surface of the film was rubbed 10 times under a load of 200 g using steel wool # 0000, and then the level of scratching was confirmed. The determination was in accordance with the following criteria. A level of 3 or more is a practically acceptable level.

      5: Not at all.

      4: Slightly scratches are seen from 1 to 2 pieces.

      3: 1 or 2 with slight scratches.

      2: Three or more scratches are seen.

      1: 10 or more scratches are observed.

(Bending resistance)
The bending resistance was evaluated by measuring the adhesion after bending as described below.

  Each functional multilayer film obtained was placed on the outside with a gas barrier layer surface and held in a φ50 mm metal roll, and 100 reciprocations were carried out at a temperature of 25 ° C. and 50% RH under a tension of 10 g / cm (98 mN / cm). It was conveyed.

  The adhesion was evaluated according to the following criteria by the cross-cut (cross-cut) method in JIS K5400.

5: Number of peeled mass 0-5 / 100
4: Peeling mass number 6 to 10/100
3: Peeling mass number 11-30 / 100
2: Number of peeled masses 31-50 / 100
1: Peeling mass number 51 or more / 100
Note that rank 3 or higher can withstand practical use.

  Table 1 shows the contents of the samples and the evaluation results.

In Table 1, the abbreviations are as follows.
PET1: Teijin DuPont Films, Polyester film, KDL86W-50μm
BA1: Bleed-out prevention layer 1
UV1: UV-cutting layer 1
UV2: UV-cutting layer 2
UV3: UV-cutting layer 3
Silica A: Silica layer A
Silica B: Silica layer B
Silica C: Silica layer C
Silica D: Silica layer D

  As is apparent from the results shown in Table 1, the samples of the present invention are functional multilayer film 10 using an organic UV absorber, functional multilayer films 9 and 11 obtained by heat drying or UV curing polysilazane, and Compared with the functional multilayer film 12 that does not use a UV-cutting layer, it clearly has excellent bending resistance in addition to antifouling properties, water vapor barrier properties, weather resistance, and scratch resistance. Further, it can be seen that a sample using the silica layer B having a modified film thickness% in the range of 50 to 80% and the UV-cutting layer 2 in which the zinc oxide of the inorganic UV absorber is surface-treated with silica is found to be highly effective. .

Example 2
[Formation of gas barrier film]
With respect to the functional multilayer films 1-12 produced in Example 1, a gas barrier layer was further formed on the BA prevention layer under the following conditions, and the corresponding gas barrier films 1-12 were produced.

(Gas barrier layer coating solution)
Perhydropolysilazane (PHPS) 20% by mass dibutyl ether solution AZ Electronic Materials Co., Ltd. Aquamica NN120-20
A roll coater was applied so that the (average) film thickness after drying was 0.17 μm to obtain a coated sample.

  The obtained coated sample was dried at 80 ° C. for 3 minutes with dry air having a dew point of −5 ° C.

(Perhydropolysilazane layer modification (oxidation) treatment conditions)
Using a stage movable xenon excimer irradiation device MODEL: MECL-M-1-200 (wavelength 172 nm) manufactured by MD Excimer, the sample was fixed so that the irradiation distance between the lamp and the sample was 1 mm, and the sample temperature was 85 The sample was reciprocated at a stage moving speed of 10 mm / sec while keeping the temperature at 0 ° C., and the sample was taken out after a total of 7 reciprocating irradiations.

(Adjustment of oxygen concentration)
The oxygen concentration during irradiation with vacuum ultraviolet light (VUV) is determined by measuring the flow rate of nitrogen gas introduced into the vacuum ultraviolet light (VUV) irradiation chamber and oxygen gas with a flow meter, and nitrogen gas introduced into the irradiation chamber. The oxygen concentration was adjusted so as to be in the range of 0.2 vol% to 0.4 vol% by the / oxygen gas flow ratio.

[Production of organic photoelectric conversion element]
Each of the gas barrier films 1 to 12 prepared above deposited on the gas barrier layer side with an indium tin oxide (ITO) transparent conductive film having a thickness of 150 nm (sheet resistance 10 Ω / □) is obtained by using a normal photolithography technique and a wet process. The first electrode was formed by patterning to a width of 2 mm using etching. The patterned first electrode was washed in the order of ultrasonic cleaning with a surfactant and ultrapure water, followed by ultrasonic cleaning with ultrapure water, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

  On this transparent substrate, Baytron P4083 (manufactured by Starck Vitec), which is a conductive polymer, is applied and dried so that the (average) film thickness is 30 nm, and then heat treated at 150 ° C. for 30 minutes to form a hole transport layer. A film was formed.

  Thereafter, the substrate was brought into a nitrogen chamber and manufactured in a nitrogen atmosphere.

  First, the substrate was heat-treated at 150 ° C. for 10 minutes in a nitrogen atmosphere. Next, P3HT (manufactured by Prectronics: regioregular poly-3-hexylthiophene) and PCBM (manufactured by Frontier Carbon Co., Ltd .: 6,6-phenyl-C61-butyric acid methyl ester) are added to 3.0% by mass of chlorobenzene. A liquid mixed at 1: 0.8 was prepared so that the film was filtered (filtered) with a filter so that the (average) film thickness was 100 nm, and allowed to dry at room temperature. Subsequently, a heat treatment was performed at 150 ° C. for 15 minutes to form a photoelectric conversion layer.

Next, the substrate on which the series of functional layers is formed is moved into a vacuum deposition apparatus chamber, the inside of the vacuum deposition apparatus is depressurized to 1 × 10 ⁻⁴ Pa or less, and then fluorinated at a deposition rate of 0.01 nm / second. Laminate 0.6 nm of lithium, and then continue to deposit 100 nm of Al metal at a deposition rate of 0.2 nm / sec through a shadow mask with a width of 2 mm (vaporization is performed so that the light receiving part is 2 × 2 mm). A second electrode was formed. The obtained organic photoelectric conversion element was moved to a nitrogen chamber, and sealed using a sealing cap and a UV curable resin, to produce an organic photoelectric conversion element having a light receiving portion of 2 × 2 mm size. The sealing process using a gas barrier film is described below.

(Sealing of organic photoelectric conversion elements)
In an environment purged with nitrogen gas (inert gas), two gas barrier film samples 1 to 12 were used, and an epoxy photocurable adhesive was applied as a sealing material to the surface provided with the gas barrier layer. After the organic photoelectric conversion elements corresponding to the samples 1 to 12 obtained by the method described above are sandwiched between the adhesive-coated surfaces of the two gas barrier film samples 1 to 21 coated with the adhesive, The organic photoelectric conversion elements 1 to 12 were prepared by irradiating and curing UV light from one side of the substrate.

<Evaluation of weather resistance of organic photoelectric conversion element>
(<< Evaluation of energy conversion efficiency >>)
About each of the produced organic photoelectric conversion elements 1-12 corresponding to the gas barrier films 1-12 which provided the gas barrier layer further to the functional multilayer films 1-12 produced in Example 1, solar simulator (AM1. 5G filter) is irradiated with light of 100 mW / cm ² intensity, a mask with an effective area of 4.0 mm ² is overlaid on the light receiving portion, and IV characteristics are evaluated, whereby short circuit current density Jsc (mA / cm ² ) , Open-circuit voltage Voc (V) and fill factor FF (%) were measured for each of four light receiving portions formed on the same element, and the four-point average value of energy conversion efficiency PCE (%) obtained according to the following equation 1 Estimated.
(Formula 1) PCE (%) = [Jsc (mA / cm ² ) × Voc (V) × FF (%)] / 100 mW / cm ²
The conversion efficiency as the initial battery characteristics was measured, and the degree of deterioration in performance over time was measured using a metal halide lamp type weather resistance tester (manufactured by Daipura Wintes Co., Ltd.). Sample surface radiation intensity: 2.16 MJ / m ² In the following, a weather resistance test was conducted under the conditions of a black panel temperature of 63 ° C., a relative humidity of 50%, and an irradiation time of 500 hours, and the conversion efficiency remaining rate after the acceleration test was ranked as follows to obtain light, heat, and humidity. The weather resistance to was evaluated. The higher this value, the better the weather resistance. Ratio of conversion efficiency / initial conversion efficiency after acceleration test 5: 90% or more 4: 70% or more, less than 90% 3: 40% or more, less than 70% 2: 20% or more, less than 40% 1: less than 20%, respectively The evaluation results are shown in Table 2.

  As is clear from the results shown in Table 2, it can be seen that the organic photoelectric conversion element produced using the gas barrier film of the present invention hardly undergoes performance deterioration even under a severe environment.

DESCRIPTION OF SYMBOLS 10 Bulk heterojunction type organic photoelectric conversion element 11 Substrate 12 Anode 13 Cathode 14 Power generation layer 14p p layer 14i i layer 14n n layer 14 '1st power generation layer 15 Charge recombination layer 16 2nd power generation layer 17 Hole transport layer 18 Electron transport layer

Claims (7)

  A UV-cutting layer containing an inorganic UV absorber and a UV curable resin is formed on the substrate, and a silica layer formed by applying a modification treatment to the polysilazane-containing coating film is laminated in this order. The method for producing a functional multilayer film is characterized in that the UV-cutting layer is formed by a UV curing treatment, and the silica layer is formed by a modification treatment that irradiates vacuum ultraviolet light having a wavelength of 200 nm or less.   The method for producing a functional multilayer film according to claim 1, wherein the surface of the inorganic UV absorber particles in the UV-cutting layer is surface-treated with an inorganic substance.   The method for producing a functional multilayer film according to claim 1 or 2, wherein the inorganic UV absorber in the UV-cutting layer is titanium oxide or zinc oxide.   The film thickness of the layer modified by the modification treatment in the silica layer is 30 to 80% of the polysilazane-containing coating film before the modification treatment. 2. A method for producing a functional multilayer film according to item 1.   The method for producing a functional multilayer film according to any one of claims 1 to 4, wherein after the UV-cutting layer and the silica layer are formed, a UV curing treatment is further performed.   A functional multilayer film produced by the production method according to any one of claims 1 to 5, having a gas barrier layer on the substrate opposite to the UV-cutting layer and the silica layer. A gas barrier film characterized by comprising:   An organic element device using the gas barrier film according to claim 6.

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