JP2011256249A - Method of forming barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a barrier film which is reduced in the generation of a burr crack at the cut of the barrier film which uses polysilazane as a raw material, or is formed of a gas barrier layer obtained by modifying a coating film of the polysilazane.SOLUTION: In the method of forming the barrier film which cures a polysilazane film by emitting a vacuum ultrasonic ray to the film from the coating face side of a base material after forming the polysilazane film by applying a coating liquid containing the polysilazane on the surface of the base material, and drying it, a cut part of the barrier film is cut after the barrier film is cured so that the cut part and a non-cut part of the barrier film may differ from each other in hardness.

Description

  The present invention relates to a method for producing a barrier film, and more particularly to a method for producing a barrier film with less occurrence of burrs and cracks during cutting.

  Conventionally, a barrier film in which a metal oxide thin film such as aluminum oxide, magnesium oxide, silicon oxide or the like is formed on the surface of a plastic substrate or film is used for packaging of articles and foods that require blocking of various gases such as water vapor and oxygen. It is widely used in packaging applications to prevent the alteration of industrial products and pharmaceuticals. In addition to packaging applications, it is used in liquid crystal display elements, solar cells, organic EL substrates, and the like.

  In recent years, transparent substrates, which are being applied to liquid crystal display elements and solar cells, can be produced in roll-to-roll, in addition to the demands for lighter weight and larger size, and have long-term reliability and shape. High demands such as high degree of freedom and curved surface display are added, and film base materials such as transparent plastics are beginning to be used instead of glass substrates that are heavy and easily broken. For example, an example using a polymer film as a substrate of an organic electroluminescence element is disclosed. As the transparent substrate, for example, a material having a relatively high oxygen permeability such as polyethylene terephthalate (hereinafter abbreviated as “PET”) is used.

  However, a film substrate such as a transparent plastic has a problem that the gas barrier property is inferior to glass. For example, when used as a substrate of an organic photoelectric conversion element, there is a problem that if a base material with poor gas barrier properties is used, water vapor or air penetrates and the performance is likely to deteriorate with time.

  In order to solve such problems, it is known to form a metal oxide thin film on a film substrate to form a barrier film substrate. Known barrier films used for packaging materials and liquid crystal display elements include those obtained by depositing silicon oxide or aluminum oxide on a substrate.

  A barrier film (for example, see Patent Documents 1 and 2) made of a gas barrier layer containing polysilazane as a main component using a film substrate such as a transparent plastic is known.

  In general, the cured barrier film is cut (for example, see Patent Document 3). However, the gas barrier layer mainly composed of polysilazane has poor brittleness, and a contact-type cutting method such as a slitter has cracks at the time of cutting. Or chipping occurs, cutting at the time of manufacture is a problem.

  In order to solve such problems, a hard coat film having an ionizing radiation curable resin hard coat layer on the base film is provided with an elastomer layer between the hard coat layer to solve the cutting problem. Is also disclosed (see, for example, Patent Document 3), but the gas barrier film including the gas barrier layer is extremely harder than the hard coat layer, and it is sufficient to provide the elastomer layer as described above. Since the stress relaxation effect cannot be exhibited, the problem at the time of cutting cannot be solved.

JP 2007-237588 A JP 2009-255040 A JP 2002-254561 A

  An object of the present invention is to provide a method for producing a barrier film with less occurrence of burrs and cracks by reducing the hardness of a cut portion when cutting a barrier film composed of a gas barrier layer mainly composed of polysilazane. .

  The above object of the present invention can be achieved by the following configuration.

  1. A method for producing a barrier film in which a coating liquid containing polysilazane is applied on the surface of a base material, dried to form a polysilazane film, and then irradiated with vacuum ultraviolet light from the coating surface side of the base material to cure the polysilazane film The method for producing a barrier film comprising: cutting the cut portion after curing so that the hardness of the cut portion and the non-cut portion of the barrier film are different.

  2. 2. The method for producing a barrier film according to 1 above, wherein the cutting portion has a hardness of less than 5 GPa.

  3. The method of curing the barrier film so that the hardness of the cut portion and the non-cut portion is different, the cutting portion is a method of weakening the activation energy of vacuum ultraviolet light as compared to the non-cut portion. A method for producing the barrier film according to 1 or 2.

  4). The method of curing the barrier film so that the cut portion and the non-cut portion have different hardnesses is a method of hardening the polysilazane film while injecting a gas that absorbs vacuum ultraviolet light to the cut portion. The manufacturing method of the barrier film of any one of 1-3.

  5. 5. The method for producing a barrier film as described in 4 above, wherein the gas that absorbs the vacuum ultraviolet light is oxygen.

  6). 5. The method for producing a barrier film as described in 4 above, wherein the method of curing so that the cut portions of the barrier film and the non-cut portions have different hardnesses is a method of spraying a cooled gas.

  7). 5. The method for producing a barrier film as described in 4 above, wherein the gas sprayed to the cutting part is at least one selected from oxygen, nitrogen, and oxygen and nitrogen.

  8). 2. The method for producing a barrier film as described in 1 above, wherein the method of curing the cut portions of the barrier film and the non-cut portions is a method of shielding vacuum ultraviolet light.

  9. 2. The method for producing a barrier film as described in 1 above, wherein the method of curing the barrier film so that the cut portions and the non-cut portions have different hardnesses is a method in which a coating film is not formed on the cut portion.

  10. 10. The method for producing a barrier film according to any one of 1 to 9, wherein the vacuum ultraviolet light is an excimer lamp.

  11. 11. The method for producing a barrier film according to any one of 1 to 10, wherein the cutting method of the cutting portion of the barrier film is a method using a slitter or a laser.

  12 12. The method for producing a barrier film according to any one of 1 to 11, wherein the dry thickness of the polysilazane film in the cut portion of the barrier film is 10 to 1000 nm.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a barrier film with few generation | occurrence | production of a burr | flash crack can be provided by reducing the hardness of a cutting part at the time of the cutting of the barrier film which consists of a gas barrier layer which has polysilazane as a main component. .

It is a schematic diagram of the coating line used for the manufacturing method of the barrier film of this invention. It is the schematic diagram seen from the bottom of the excimer apparatus of the state light-shielded in the case of manufacture of the barrier film of this invention. It is sectional drawing of the slitter which can be used by this invention.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

(Apparatus that can be used in the present invention)
Hereinafter, an apparatus that can be used in the present invention will be described with reference to the drawings.

  In FIG. 1A, the base material fed from the unwinding roll 1 is coated with a coating liquid containing polysilazane on the surface by an extrusion head 2 and dried by a dryer 3 to form a barrier film 9 having a polysilazane film formed thereon. , Continuously conveyed in the direction of the arrow. FIG. 1B is a schematic view from below of the vacuum ultraviolet light generator 4. Gas is jetted onto the polysilazane film from the gas discharge heads 7 installed before and after the excimer lamp 8 of the vacuum ultraviolet light generator 4. At the time of excimer irradiation, nitrogen gas was allowed to flow into the irradiation chamber from the nitrogen outlet so that the oxygen concentration other than the cut portion was 0.1% or less. The oxygen concentration was measured using an oxygen concentration meter (new Cosmo Electric XP-3180) installed in the irradiation chamber.

  The direction in which the gas is ejected is set at a position where vacuum ultraviolet light is irradiated onto the polysilazane film. The vacuum ultraviolet light generated by the vacuum ultraviolet light generator 4 is reduced in activation energy by this gas, and the polysilazane film in the gas existing portion (cutting portion) does not harden, and the hardness is lower than that in the non-cutting portion. . In the whole, nitrogen gas is blown out from the nitrogen discharge port 6.

  This type of apparatus is used in carrying out the inventions of claims 4 to 7 of the present invention. The gas of claim 5 is oxygen, claim 6 is a cooled gas, and claim 7 is an invention using oxygen or nitrogen.

  FIG. 2 is a perspective view from below of the vacuum ultraviolet light generator 4 used in carrying out the invention of claim 8. As a curing inhibiting device, a shutter unit 11 is provided below the vacuum ultraviolet light generating device 4 to block vacuum ultraviolet light from the excimer lamp 8 to the cutting unit, thereby preventing the polysilazane film from curing.

  The produced gas barrier film is cut with a slitter or a laser. However, since the periphery of the cut portion is uncured, problems such as deterioration of the barrier performance and sticking to the back surface of the substrate during winding may occur. Therefore, it is preferable that excimer treatment is performed around the cut portion after cutting, so that curing can be promoted and problems such as deterioration in barrier properties and sticking to the back surface can be avoided.

(Slitter)
A typical slitter that can be used in the present invention will be described with reference to FIG.

  The slitter refers to a machine that cuts a film sheet into a required size width as desired and winds it into a roll. As a slitter cutting method, a gobel method, a gang method, and a spring gang method are known. In FIG. 3A, the govel method is arranged so that the upper blades 111 are pressed against each other from the one side in the axial direction of the plurality of lower blades 112 (so that the clearance becomes 0). 112 is a method of cutting the workpiece W into multiple lines. As shown in FIG. 3 (b), the gang method is a method in which a plurality of upper and lower blades 211 and 212 are arranged alternately and so that both axial sides thereof are close to each other (with a clearance). In this method, the workpiece W is cut into multiple lines by the upper and lower blades 211 and 212. Further, as shown in FIG. 3 (c), the spring gang method means that a plurality of upper and lower blades 311 and 312 are alternately arranged and are arranged so as to press both sides in the axial direction. In this method, the work W is cut into multiple lines by 312.

(Cutting by laser)
Laser cutting is a method of cutting a substrate by melting or evaporating the substrate by irradiating the cutting part with laser light. The kind of laser light to be used is not particularly limited, and any laser such as a gas laser, a solid laser, a semiconductor laser, and a dye laser can be used. Moreover, if the conveyance speed of a base material is about 10-30 m / min, it is preferable that a laser output is 10 W or more and 50 W or less.

(Base material)
A base material will not be specifically limited if it is formed with the organic material which can hold | maintain the polysilazane layer which has the barrier property mentioned later.

  For example, acrylic ester, methacrylate ester, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP) Each base material such as polystyrene (PS), nylon (Ny), aromatic polyamide, polyether ether ketone, polysulfone, polyether sulfone, polyimide, polyetherimide, and silsesquioxane having an organic-inorganic hybrid structure And a heat-resistant transparent film (product name: Sila-DEC, manufactured by Chisso Corporation), and a substrate formed by laminating two or more layers of the plastic. In terms of cost and availability, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), and the like are preferably used. Also, optical transparency, heat resistance, inorganic layer and In terms of adhesion, a heat-resistant transparent film having a basic skeleton of silsesquioxane having an organic-inorganic hybrid structure can be preferably used. As for the thickness of a base material, about 5-500 micrometers is preferable, More preferably, it is 25-250 micrometers.

  Moreover, it is preferable that the base material which concerns on this invention is transparent. Since the base material is transparent and the layer formed on the base material is also transparent, it becomes possible to make a transparent barrier film, so that it can be made a transparent substrate such as a solar cell or an organic EL element. Because it becomes.

  Moreover, the base material using the above-described plastics may be an unstretched film or a stretched film.

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

  Moreover, in the base material which concerns on this invention, you may give a corona treatment before forming an organic layer or an inorganic layer.

Furthermore, you may form an anchor coating agent layer in the base-material surface concerning this invention for the purpose of the adhesive improvement with a coating film. Examples of the anchor coating agent used in this anchor coating agent layer include polyester resins, isocyanate resins, urethane resins, acrylic resins, ethylene vinyl alcohol resins, vinyl modified resins, epoxy resins, modified styrene resins, modified silicon resins, and alkyl titanates. Can be used alone or in combination. Conventionally known additives can be added to these anchor coating agents. The above-mentioned anchor coating agent is coated on a substrate by a known method such as roll coating, gravure coating, knife coating, dip coating, spray coating, etc., and anchor coating is performed by drying and removing the solvent, diluent, etc. be able to. The application amount of the anchor coating agent is preferably about 0.1 to 5 g / m ² (dry state).

(Modification treatment of polysilazane film)
(Vacuum ultraviolet light (VUV light) treatment)
The gas barrier layer of the present invention is preferably formed by applying a polysilazane-containing solution on a substrate and drying it, and then forming a modified film by a method of irradiating the coating film containing polysilazane with vacuum ultraviolet light. This vacuum ultraviolet light (VUV light) irradiation breaks the molecular bond of polysilazane, and even a small amount of oxygen in the film or atmosphere can be efficiently converted into ozone or active oxygen. The ceramicization (silica modification) is promoted, and the resulting polysilazane film becomes denser. VUV light irradiation is effective at any time point after the coating film is formed.

Specifically, vacuum ultraviolet light (VUV light) of 100 to 200 nm is used as the vacuum ultraviolet light in the present invention. 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. The distance between the coating film and the lamp is set so that the strength of the coating film surface is 10 to 300 mW / cm ² , and irradiation can be performed for 0.1 second to 10 minutes, preferably 0.5 second to 3 minutes. . As the vacuum ultraviolet light irradiation apparatus, a commercially available lamp (for example, manufactured by USHIO INC.) Can be used.

  VUV 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, Ushio Electric 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 the processing zone equipped with the vacuum ultraviolet light 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.

1. What is excimer luminescence? Since rare gas atoms such as Xe, Kr, Ar, and Ne do not form molecules by chemically bonding, they are called inert gases. However, noble gas atoms (excited atoms) that have gained energy by discharge or the like can be combined with other atoms to form molecules. When the rare gas is xenon, e + Xe → e + Xe ^*
Xe ^* + Xe + Xe → Xe ^{2 *} + Xe
Then, 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. Moreover, since extra light is not radiated | emitted, the temperature of a target 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 emission, 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 emission, electrodeless 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 lamp outer surface. 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 emission is sealed inside.

  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. If the curved surface is mirrored with aluminum, it 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 layer 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.

(Vacuum ultraviolet light irradiation intensity)
(High irradiation intensity treatment and maximum irradiation intensity)
If the irradiation intensity is high, the probability that the photons and chemical bonds in the polysilazane collide increases, and the modification reaction can be shortened. Further, since the number of photons penetrating to the inside increases, the modified film thickness can be increased and / or the film quality can be improved (densification). However, if the irradiation time is too long, the planarity may be deteriorated and other materials of the barrier film may be damaged. Generally, the reaction progress is considered by the integrated light quantity expressed by the product of irradiation intensity and irradiation time. However, in the case of materials having the same composition but different structures, such as silicon oxide, the irradiation intensity The absolute value of may be important.

Therefore, in the present invention, in the VUV irradiation step, it is preferable to perform a modification treatment that gives a maximum irradiation intensity of 100 to 200 mW / cm ² at least once. If it is below this strength, the reforming efficiency will deteriorate rapidly, and it will take time to process, and if the irradiation intensity is higher than this, the increase in gas barrier performance will slow down, but not only damage to the substrate, The damage to the lamp and other members of the lamp unit also increases, and the lamp itself deteriorates faster.

(Oxygen concentration during VUV light irradiation)
In the present invention, the oxygen concentration at the time of VUV light irradiation is preferably 500 ppm to 10000 ppm (1%). More preferably, it is 1000 ppm to 5000 ppm. If the oxygen concentration is higher than the above concentration range, as will be described later, an oxygen-excess gas barrier film is formed, and the gas barrier properties deteriorate. When the oxygen concentration is lower than the above range, the replacement time with the atmosphere becomes longer. At the same time, when continuous production such as roll-to-roll is performed, the amount of air (oxygen) The oxygen concentration cannot be adjusted without flowing a large flow of gas.

  According to the inventor's study, in the polysilazane-containing coating film, oxygen and a small amount of water are mixed at the time of application, and there are also adsorbed oxygen and adsorbed water on the substrate other than the coating film. It has been found that there are enough oxygen sources to supply oxygen required for the reforming reaction without introducing oxygen. Rather, when the VUV light is irradiated in an atmosphere containing a large amount of oxygen gas (a few percent level), the gas barrier film after the modification has an excessive oxygen structure and the gas barrier properties deteriorate. Further, as described above, the 172 nm VUV light is absorbed by oxygen and the amount of light at 172 nm reaching the film surface is reduced, so that the efficiency of the light treatment is lowered. That is, at the time of irradiation with VUV light, it is preferable to perform the modification treatment in a state where the VUV light efficiently reaches the coating film with the oxygen concentration as low as possible.

  As the gas other than oxygen at the time of VUV light irradiation, a dry inert gas is preferable, and dry nitrogen gas is particularly preferable from the viewpoint of cost. The oxygen concentration can be adjusted by measuring the flow rate of oxygen gas and inert gas introduced into the irradiation chamber and changing the flow rate ratio.

(VUV light irradiation time)
Although the irradiation time can be arbitrarily set, the irradiation time in the high illuminance process is preferably 0.1 second to 10 minutes from the viewpoint of substrate damage and film defect generation and from the viewpoint of reducing variation in gas barrier performance. More preferably, it is 0.5 second to 3 minutes.

<Polysilazane film>
The polysilazane film according to the present invention is formed by applying a coating solution containing at least one polysilazane compound on a 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.

“Polysilazane” used in the present invention is a polymer having a silicon-nitrogen bond, and is composed of Si—N, Si—H, N—H, etc., such as SiO ₂ , Si ₃ N _4, and both intermediate solid solutions SiOxNy, etc. It is a precursor inorganic polymer.

  In order not to damage the film substrate, the following compounds that are converted to silica by being converted to ceramic at a relatively low temperature as described in JP-A-8-112879 are preferred.

However, each of R ¹ , R ² , and R ^{3 in} the formula 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. .

In the present invention, perhydropolysilazane in which all of R ¹ , R ² , and R ³ are hydrogen atoms is particularly preferable from the viewpoint of the denseness as the resulting barrier 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 alkyl group such as a methyl group, so that the adhesion to the base substrate is improved and the polysilazane is hard and brittle. The ceramic film can be toughened, and there is an advantage that generation 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, silicon alkoxide-added polysilazane obtained by reacting silicon alkoxide with polysilazane of the above chemical formula 1 (Japanese Patent Laid-Open No. 5-238827), glycidol addition obtained by reacting glycidol Polysilazane (JP-A-6-122852), alcohol-added polysilazane obtained by reacting an alcohol (JP-A-6-240208), metal carboxylate-added polysilazane obtained by reacting a metal carboxylate 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 (specialty) Kaihei 7-19 986 JP), and the like.

  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.

  The organic polysilazane may be a derivative in which the hydrogen part bonded to Si is partially substituted with an alkyl group or the like. By having an alkyl group, especially a methyl group having the smallest molecular weight, the adhesion to the base material can be improved, and the hard and brittle silica film can be toughened, and even if the film thickness is increased, cracks are not generated. Occurrence is suppressed.

  In order to promote the modification 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.

Catalyst concentration In order to promote hydrolysis and dehydration condensation by converting the catalyst, the production rate of Si—OH groups varies greatly depending on the amount added. That is, if it is added too much, a film with a great change over time is formed by an excessive Si—OH group. Further, as described above, when sufficient energy is applied to break molecular bonds such as irradiation with vacuum ultraviolet light, amine-based catalysts may be decomposed and evaporated. When decomposition and evaporation of the catalyst occur, impurities and voids are included in the reformed film, and the barrier property is deteriorated.

  In the present invention, in order to avoid excessive silanol formation by the catalyst, reduction in film density, and increase in film defects, it is preferable to adjust the amount of catalyst added to polysilazane to 2% by mass or less. Furthermore, it is more preferable not to add a catalyst from the viewpoint of suppressing Si—OH production.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1
A process for forming a polysilazane film will be described below with reference to FIG.

(Base material)
A 125 μm thick polyester film (manufactured by Teijin DuPont Films Ltd., extremely low heat yield PET Q83) with easy adhesion processing on both sides was used as the substrate.

(Formation of polysilazane film)
Sample 1 was prepared by applying and drying a polysilazane film on a substrate.

  As the perhydropolysilazane solution, a 20% by mass dibutyl ether solution (Aquamica NN120-20 manufactured by AZ Electronic Materials Co., Ltd.) was used, and this solution was diluted with dibutyl ether to adjust the PHPS concentration. The support fed from the unwinding roll 1 is coated with a polysilazane coating solution on the support by an extrusion method in the coating step 2, and then dried at 80 ° C. for 3 minutes by a hot air method in the drying step 3. A 170 nm perhydropolysilazane film was formed. At this time, the polysilazane film was not completely solidified.

[Preparation of gas barrier film 1]
1 was used, oxygen was used as a gas injected from the gas injection unit 7 to the polysilazane film, and the polysilazane film was cured under the following conditions to produce a gas barrier film 1.

  At the time of excimer irradiation, nitrogen gas was allowed to flow from the N2 gas supply port into the irradiation chamber so that the oxygen concentration other than the cut portion was 0.1% or less. The oxygen concentration was measured using an oxygen concentration meter (new Cosmo Electric XP-3180) installed in the irradiation chamber.

(Vacuum ultraviolet light irradiation)
As a vacuum ultraviolet light generator, a xenon excimer irradiation device MODEL: MECL-M-1-200 (wavelength 172 nm) manufactured by MD Excimer is used, the irradiation distance between the lamp and the sample is set to 1 mm, and the sample 1 is conveyed. The speed was conveyed at a speed of 20 m / min.

  In the step of irradiating the vacuum ultraviolet light, the gas barrier layer was formed by irradiating the vacuum ultraviolet light while spraying the gas (oxygen) that absorbs the vacuum ultraviolet light onto the portion to be cut. The oxygen injection speed was 10 m / s.

[Preparation of gas barrier film 2]
In the production of the gas barrier film 1, a gas barrier film 2 was produced in the same manner as the gas barrier film 1 except that the gas to be injected was a mixed gas of oxygen and nitrogen. The oxygen concentration was adjusted by the following method.

(Adjustment of oxygen concentration)
The oxygen concentration during irradiation with vacuum ultraviolet light is determined by measuring the flow rate of nitrogen gas and oxygen gas introduced into the vacuum ultraviolet light irradiation unit with a flow meter, and the oxygen concentration based on the nitrogen gas / oxygen gas flow rate ratio of the gas introduced into the irradiation unit. Was adjusted to fall within the range of 0.9% to 1.1%.

[Preparation of gas barrier film 3]
In the production of the gas barrier film 2, a gas barrier film 3 was produced in the same manner as the gas barrier film 2 except that the mixed gas of oxygen and nitrogen to be injected was cooled to 1 to 5 ° C.

[Preparation of gas barrier film 4]
In the process of irradiating the sample 1 to be continuously conveyed with vacuum ultraviolet light using the apparatus of FIG. 2, the obtained sample 1 is shielded from being irradiated with vacuum ultraviolet light so as to cure the polysilazane film. Thus, a gas barrier film 4 was produced.

[Preparation of gas barrier film 5]
In the production of the gas barrier film 1, when applying the perhydropolysilazane solution, a shim is placed in the slit portion of the extrusion die, and the polysilazane film is cured after being applied so that no coating film is formed on the cut portion. Film 5 was produced.

[Preparation of gas barrier film 6]
On the obtained barrier film 1, a polysilazane film is further formed in the same manner as in the sample 1, and the polysilazane film is formed into two layers, the second layer is dried, and after drying, a perhydropolysilazane film having a film thickness of 170 nm is formed. After that, excimer irradiation and oxygen injection were performed in the same manner as the gas barrier film 1 to produce a gas barrier film 6.

[Preparation of gas barrier film 7]
In the production of the gas barrier film 1, a gas barrier film 7 was produced in the same manner as the gas barrier film 1 except that oxygen injection was not performed.

[Preparation of gas barrier film 8]
In the production of the gas barrier film 1, a xenon excimer device manufactured by MD Excimer was not used, and a low pressure mercury lamp: ULO-6AB-5A manufactured by Ushio Electric was used instead. Otherwise, the gas barrier film 8 was produced in the same manner as the gas barrier film 1.

[Preparation of gas barrier film 9]
In the production of the gas barrier film 9, the gas barrier film 9 was produced in the same manner as the gas barrier film 1 except that the dried perhydropolysilazane film was 8 nm.

[Production of Gas Barrier Film 10]
In the production of the gas barrier film 9, a gas barrier film 10 was produced in the same manner as the gas barrier film 1 except that the dried perhydropolysilazane film was 1200 nm.

[Preparation of gas barrier film 11]
A UV curable organic / inorganic hybrid hard coating material OPSTAR Z7535 manufactured by JSR Corporation was applied to one side of the substrate, applied by a reduced pressure extrusion method so that the film thickness after drying was 4 μm, and then in a drying step 3 by a hot air method Drying condition: Drying at 80 ° C. for 3 minutes, and then curing condition in UV ultraviolet light irradiation step 5: Film 12 having a hard coat film formed by curing with a high-pressure mercury lamp under 1.0 J / cm ² air. Produced.

(Evaluation methods)
The obtained gas barrier films 1 to 11 were cut into a width of 400 mm by a contact method using a slitter TS-18XCA manufactured by Toray Engineering. Further, the gas barrier film was cut into a width of 400 mm by a non-contact method using an air-cooled CO ₂ laser. At this time, the laser illuminance was 15 W and the beam diameter was 0.1 mm while the film was being conveyed at 20 m / min. As described above, the following evaluations were performed on the films cut by the two types of methods, and the obtained results are shown in Table 1. Moreover, the surface hardness by the nano indentation of the location (cutting part) which performed the countermeasure against hardening of the gas barrier films 1-11 (cutting part) and the place which did not perform (non-cutting part) is measured, and a result is shown in Table 1.

(Evaluation of Bali)
The cut surface was observed with a microscope, and the burrs were observed as follows. Table 1 shows the results.

○: Less than 10 μm Δ: 10 μm or more, less than 50 μm ×: 50 μm or more (Crack evaluation)
The cut surface was observed using a Keyence Corporation laser microscope (VK-8700) and evaluated as follows.

  The results are shown in Table 1 for the products in which no cracks occurred and the lengths for the products in which cracks occurred.

(Measurement of surface hardness)
The hardness (H) was measured by attaching a Triscope from Hystron to a Nanoscope III from Digital Instruments. For the measurement, a triangular pyramid type diamond indenter called a Belkovic indenter (tip ridge angle 142.3 °) was used as an indenter. A triangular pyramid-shaped diamond indenter was applied to the sample surface at a right angle, a load was gradually applied, and the load was gradually returned to 0 after reaching the maximum load. A value P / A obtained by dividing the maximum load P (g) at this time by the projected area A (μm ² ) of the indenter contact portion was calculated as nanoindentation hardness (H) (GPa). The maximum load condition at this time was 100 μN. The results are shown in Table 1.

  As is apparent from Table 1, it can be seen that the barrier film produced by the production method of the present invention has few burrs and few cracks. No. At the level of 8, since the low pressure mercury lamp was used when the polysilazane film was cured, the curing did not proceed and the hardness decreased as compared with the case where the excimer lamp was used. No. At the level of 9, the film thickness was thin, so that the cured coating film cracked, leading to deterioration of the barrier performance. No. At a level of 10, it was confirmed that an uncured portion was generated inside the coating film, and dirt was deposited on the contact-type cutting blade. In addition, gas considered to be unreacted was generated during laser cutting.

DESCRIPTION OF SYMBOLS 1 Unwinding roll 2 Extruding head 3 Dryer 4 Excimer apparatus 5 Low pressure mercury lamp 6 Nitrogen discharge port 7 Gas discharge head 8 Excimer lamp 9 Barrier film in which a polysilazane film is formed 11 Light shielding plates 111, 211, 311 Upper blades 112, 212, 312 Lower blade W Workpiece

Claims (12)

  A method for producing a barrier film in which a coating liquid containing polysilazane is applied on the surface of a base material, dried to form a polysilazane film, and then irradiated with vacuum ultraviolet light from the coating surface side of the base material to cure the polysilazane film The method for producing a barrier film comprising: cutting the cut portion after curing so that the hardness of the cut portion and the non-cut portion of the barrier film are different.   The method for producing a barrier film according to claim 1, wherein the cutting portion has a hardness of less than 5 GPa.   The method of curing the barrier film cut portion and the non-cut portion with different hardnesses, wherein the cut portion is a method of weakening the activation energy of vacuum ultraviolet light as compared with the non-cut portion. Item 3. A method for producing a barrier film according to Item 1 or 2.   The method of curing so that the hardness of the cut portion and the non-cut portion of the barrier film are different from each other, wherein the polysilazane film is cured while injecting a gas that absorbs vacuum ultraviolet light into the cut portion. Item 4. The method for producing a barrier film according to any one of Items 1 to 3.   The method for producing a barrier film according to claim 4, wherein the gas that absorbs the vacuum ultraviolet light is oxygen.   The method for producing a barrier film according to claim 4, wherein the method of curing so that the cut portions and the non-cut portions of the barrier film have different hardnesses is a method of spraying a cooled gas.   The method for producing a barrier film according to claim 4, wherein the gas sprayed to the cutting part is at least one selected from oxygen, nitrogen, and oxygen and nitrogen.   The method for producing a barrier film according to claim 1, wherein the method of curing so that the cut portions and the non-cut portions of the barrier film have different hardnesses is a method of shielding vacuum ultraviolet light.   The method for producing a barrier film according to claim 1, wherein the method of curing so that the hardness of the cut portion and the non-cut portion of the barrier film is a method in which a coating film is not formed on the cut portion.   The said vacuum ultraviolet light is an excimer lamp, The manufacturing method of the barrier film of any one of Claims 1-9 characterized by the above-mentioned.   The method for producing a barrier film according to any one of claims 1 to 10, wherein the cutting method of the cutting portion of the barrier film is a method using a slitter or a laser.   The method for producing a barrier film according to any one of claims 1 to 11, wherein the dry film thickness of the polysilazane film in the cut portion of the barrier film is 10 to 1000 nm.

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