JP2006282402A - Method for producing thin film, transparent electromagnetic wave-shielding film, optical filter, and plasma display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a thin film capable of suppressing generation of cracks more than before even when using a sol-gel method and an ultraviolet radiation method in combination for obtaining a thin film containing a metal oxide, and to provide a transparent electromagnetic wave-shielding film having a thin film containing a metal oxide produced by the method for producing a thin film. <P>SOLUTION: The method for producing a thin film containing a metal oxide comprises applying a solution containing a metal oxide to at least one surface of a transparent polymer film, drying the coating to form a thin-film precursor, and irradiating the thin-film precursor with an ultraviolet light, wherein the irradiation of the ultraviolet light is performed in two or more steps, thereby obtaining the quantity of the ultraviolet light required as a whole. The transparent electromagnetic wave-shielding film has a thin film containing a metal oxide produced by the method for producing a thin film on a transparent polymer film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thin film manufacturing method, a transparent electromagnetic wave shielding film, an optical filter, and a plasma display, and more specifically, a thin film manufacturing method for manufacturing a thin film containing a metal oxide using a sol-gel method and an ultraviolet irradiation method, The present invention relates to a transparent electromagnetic wave shielding film having a thin film containing a metal oxide produced by the thin film production method, an optical filter having the transparent electromagnetic wave shielding film, and a plasma display having the transparent electromagnetic wave shielding film or the optical filter.

  In recent years, various functional thin films have been used in various industrial fields in order to realize higher-order functions such as optical functions and electrical functions.

  For example, in the field of display devices such as a plasma display panel (hereinafter referred to as “PDP”), a metal oxide is formed on a transparent polymer film for the purpose of providing an electromagnetic shielding function, a near infrared shielding function, and the like. Transparent electromagnetic wave shielding films in which physical thin films and metal thin films are alternately laminated are widely used.

  In this type of transparent electromagnetic wave shielding film, a metal oxide thin film is conventionally formed by physical vapor deposition (PVD) such as vacuum deposition or sputtering, or chemical vapor deposition such as thermal CVD or plasma CVD ( The mainstream method is manufacturing by a vapor phase method such as CVD.

  However, these gas phase methods have disadvantages such as high cost because large equipment such as vacuum equipment is required, and high productivity. Therefore, recently, there are advantages such as film formation in the atmosphere, low cost, and superior productivity compared with the vapor phase method. Therefore, the metal oxidization is performed using the sol-gel method which is a liquid phase method. A method for producing a thin film is attracting attention.

  For example, in Patent Document 1, an organic compound solution of titanium is applied to the surface of a transparent polymer film and dried to form a thin film precursor. Then, a specific illuminance and a specific light amount are applied to the thin film precursor. A thin film production method for forming a titanium oxide thin film by irradiating the ultraviolet ray once, and a transparent electromagnetic wave shielding film having a titanium oxide thin film produced by this thin film production method are disclosed.

JP 2004-197189 A

  However, as disclosed in Patent Document 1, when manufacturing a thin film containing a metal oxide by combining the sol-gel method and the ultraviolet irradiation method, there is still room for improvement in the following points.

  That is, when a thin film containing a metal oxide is produced by combining a sol-gel method and an ultraviolet irradiation method, in general, hydrolysis / condensation reaction does not proceed sufficiently to the inside of the thin film precursor, and the resulting thin film In addition, starting materials such as metal organic compounds are likely to remain.

  Therefore, in order to reduce the remaining amount of unreacted components and obtain a thin film containing a metal oxide having a refractive index as high as possible, the amount of ultraviolet light irradiated to the thin film precursor is increased as much as possible, and hydrolysis / It is desirable to promote the condensation reaction to reduce unreacted components.

  However, when this is done, the surface temperature of the transparent polymer film supporting the thin film rises rapidly due to ultraviolet irradiation, and the thin film is likely to crack due to thermal expansion of the transparent polymer film. It turns out that a problem occurs.

  Therefore, the problem to be solved by the present invention is to suppress the generation of cracks compared to conventional cases even when a sol-gel method and an ultraviolet irradiation method are used in combination in obtaining a thin film containing a metal oxide. An object of the present invention is to provide a possible thin film manufacturing method.

  Another object is to provide a transparent electromagnetic wave shielding film having a thin film containing a metal oxide produced by the thin film production method, an optical filter having the transparent electromagnetic wave shielding film, and a plasma display having the transparent electromagnetic wave shielding film or the optical filter. Is to provide.

  In order to solve the above-described problems, a thin film manufacturing method according to the present invention is a method in which a solution containing a metal compound is applied to at least one surface of a transparent polymer film and dried to form a thin film precursor. In producing a thin film containing a metal oxide by irradiating with ultraviolet rays, the gist is to irradiate the ultraviolet rays a plurality of times, thereby obtaining a necessary amount of ultraviolet rays as a whole.

  In this case, the metal compound is preferably a titanium compound, and the metal oxide is preferably a titanium oxide.

  On the other hand, the gist of the transparent electromagnetic wave shielding film according to the present invention is to have at least one thin film containing a metal oxide produced by the above thin film production method on at least one surface of the transparent polymer film.

  Moreover, the optical filter which concerns on this invention makes it a summary to have the said transparent electromagnetic wave shielding film.

  The gist of the plasma display according to the present invention is that it has the transparent electromagnetic wave shielding film or the optical filter.

  In the method for producing a thin film according to the present invention, in producing a thin film containing a metal oxide by irradiating a thin film precursor with ultraviolet rays, ultraviolet rays are irradiated in a plurality of times, thereby obtaining a necessary amount of ultraviolet rays as a whole. I am going to do that.

  Therefore, since the heat energy at the time of ultraviolet irradiation is more dispersed than when the necessary amount of ultraviolet light is given once, an increase in the surface temperature of the transparent polymer film can be suppressed. Therefore, the thin film obtained by reducing the amount of thermal expansion of the transparent polymer film is difficult to crack.

  In addition, since the necessary amount of ultraviolet light is ensured as a whole, a thin film containing a metal oxide having a refractive index equivalent to that of the prior art can be obtained.

  At this time, if the metal compound is a titanium compound and the metal oxide is an oxide of titanium, a thin film having a particularly high refractive index can be obtained.

  On the other hand, since the transparent electromagnetic wave shielding film according to the present invention includes a thin film containing a metal oxide with fewer cracks than in the past, it is excellent in reliability.

  Moreover, since the optical filter according to the present invention has the transparent electromagnetic wave shielding film, it is excellent in reliability.

  In addition, since the plasma display according to the present invention has the transparent electromagnetic wave shielding film or the optical filter, it is difficult to impair image quality and the like and is excellent in reliability.

  The thin film manufacturing method, the transparent electromagnetic wave shielding film, the optical filter, and the plasma display according to the present embodiment will be described in detail (hereinafter, the thin film manufacturing method according to the present embodiment is referred to as “the thin film manufacturing method” and the transparent according to the present embodiment). The electromagnetic shielding film may be referred to as “this film”, the optical filter according to this embodiment may be referred to as “this filter”, and the plasma display according to this embodiment may be referred to as “this display”).

1. This thin-film manufacturing method is a method of applying a solution containing a metal compound to at least one surface of a transparent polymer film, drying it to form a thin-film precursor, and irradiating the thin-film precursor with ultraviolet rays. This is a method for producing a thin film containing a metal oxide by performing ultraviolet irradiation in a plurality of times and thereby obtaining a necessary amount of ultraviolet light as a whole.

1.1 Solution containing a metal compound In this thin film manufacturing method, a solution containing a metal compound is used as a starting solution. This solution can be prepared by dissolving the metal compound of the metal constituting the metal oxide in the thin film in an appropriate solvent.

  Examples of the metal compound include titanium, zinc, indium, tin, magnesium, aluminum, zirconium, niobium, cerium, silicon, hafnium, lead and other metal organic compounds, inorganic compounds, and the like. Two or more kinds may be contained.

  Examples of the metal organic compound include metal alkoxides of the above metals, metal chelates such as metal acylates, metal acetylacetonates, and metal carboxylates. On the other hand, examples of the metal inorganic compound include carbonates, hydroxides, nitrates, and chlorides of the above metals.

  In the present thin film manufacturing method, the metal compound contained in the solution is not particularly limited, but a metal metal compound that can be a metal oxide having a high refractive index can be suitably used. An example of such a metal compound is a titanium compound. In addition, in this application, a high refractive index means the case where the refractive index with respect to 633 nm light is 1.75 or more.

  Examples of the titanium compound contained in the solution include M-O-R bonds (R represents an alkyl group, such as tetra-n-butoxy titanium, tetraethoxy titanium, tetra-i-propoxy titanium, tetramethoxy titanium, Titanium alkoxide having M) and titanium acylate having M—O—CO—R bond (R represents an alkyl group and M represents a titanium atom) such as isopropoxy titanium stearate, Titanium chelates such as diisopropoxytitanium bisacetylacetonate, dihydroxybislactotitanium, diisopropoxybistriethanolaminatotitanium, diisopropoxybisethylacetoacetitanium, etc. can be exemplified, Two or more kinds may be mixed.

  Examples of the solvent for dissolving the metal compound include alcohols such as methanol, ethanol, propanol, butanol, heptanol and isopropyl alcohol, organic acid esters such as ethyl acetate, ketones such as acetonitrile, acetone and methyl ethyl ketone, and tetrahydrofuran. And cycloethers such as dioxane, acid amides such as formamide and N, N-dimethylformamide, hydrocarbons such as hexane, aromatics such as toluene, and the like. The above may be mixed.

  In addition, various additives may be added to the solution as necessary. As said additive, what has an ultraviolet absorptive functional group etc. can be illustrated as a suitable thing, for example. In this thin film manufacturing method, hydrolysis / condensation reaction is carried out using ultraviolet rays. Therefore, if an ultraviolet absorbing functional group is introduced into the starting solution, ultraviolet irradiation is performed at the place where the ultraviolet absorbing chelate is formed in advance. This is because it is easy to obtain a thin film containing a metal oxide having less unreacted components, a high refractive index, and high stability.

  Examples of this type of additive include additives such as β diketones, alkoxy alcohols, and alkanolamines. More specifically, examples of the β diketones include acetylacetone, benzoylacetone, ethyl acetoacetate, methyl acetoacetate, diethyl malonate, and the like. Examples of alkoxy alcohols include 2-methoxyethanol, 2-ethoxyethanol, 2-methoxy-2-propanol, and the like. Examples of alkanolamines include monoethanolamine, diethanolamine, and triethanolamine. These may be used alone or in combination.

  Moreover, as a mixture ratio of the said additive, the range of 0.1-20 times mole etc. can be illustrated with respect to 1 mol of said metal compounds.

1.2 Transparent polymer film In this thin film manufacturing method, the transparent polymer film is a base for forming a thin film. As the material for the transparent polymer film, any material can be used as long as it has transparency in the visible light region and can form a thin film on its surface without hindrance.

  Specific examples of the material for the transparent polymer film include polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polystyrene, polyimide, polyamide, polybutylene terephthalate, polyethylene naphthalate. Examples thereof include polymer materials such as phthalate, polysulfone, polyethersulfone, polyetheretherketone, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, triacetyl cellulose, polyurethane, and cycloolefin polymer. Preferably, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, cycloolefin polymer, and the like can be suitably used.

  The thickness of the transparent polymer film can be variously adjusted in consideration of the material used.

1.3 Coating Method In this thin film manufacturing method, the method of coating the solution containing the metal compound on the transparent polymer film in the form of a film includes spin coating, gravure coating, dip coating, bar coating, and the like. Various known coating methods such as a coating method, a doctor blade method, and a reverse roll coating method can be exemplified, and can be appropriately selected and used.

  In this thin film manufacturing method, the solution containing the metal compound may be applied only to one side of the transparent polymer film, or may be applied to both sides. In addition, in the present thin film production method, coating the solution containing the metal compound on the transparent polymer film means a metal thin film formed on the transparent polymer film, other than when directly coating on the transparent polymer film. The case where it coats on other thin films is also included.

1.4 Drying method In this thin film manufacturing method, the solution coated on the transparent polymer film is dried to form a thin film precursor. As a drying method in this case, for example, a transparent polymer film coated with the above solution may be placed in a known drying apparatus. In this case, examples of the drying conditions include a temperature range of 40 ° C. to 120 ° C., a drying time of 0.5 minutes to 60 minutes, and the like.

1.5 Irradiation of Ultraviolet Light In this thin film manufacturing method, the thin film precursor formed on the transparent polymer film is irradiated with ultraviolet light. Examples of the ultraviolet irradiator include a mercury lamp, a xenon lamp, a deuterium lamp, an excimer lamp, and a metal halide lamp.

  Here, in this thin film manufacturing method, the above-mentioned ultraviolet irradiation is performed in a plurality of times, thereby obtaining a necessary amount of ultraviolet light as a whole. In other words, the amount of ultraviolet light necessary to hydrolyze and condense the thin film precursor to form a thin film containing a metal oxide having a desired refractive index is substantially the same as the amount of ultraviolet light when ultraviolet light is irradiated once. It is the same.

  In this case, the amount of ultraviolet rays when the ultraviolet rays are irradiated in a plurality of times (hereinafter sometimes referred to as “divided irradiation”) may be the same for each time or may be different for each time. That is, as long as the integral value of the ultraviolet light amount by the divided irradiation is substantially the same as the ultraviolet light amount by the single irradiation, the divided irradiation may be performed with any ultraviolet light amount and is not particularly limited.

  In addition, the number of times of irradiation with ultraviolet rays is such that the thin film containing the formed metal oxide is observed on the surface with, for example, a microscope to reduce the occurrence of cracks or to substantially eliminate the cracks. May be set as appropriate.

  The number of times of irradiation with ultraviolet rays depends on the required amount of ultraviolet rays as a whole, but generally, the effect of suppressing the occurrence of cracks tends to be reduced as the number of times of irradiation with ultraviolet rays decreases. On the other hand, the upper limit of the number of times of irradiation with ultraviolet rays may be appropriately adjusted in consideration of equipment costs and productivity.

  The lower limit of the number of times of irradiation with ultraviolet rays can be exemplified twice.

  Further, the necessary amount of ultraviolet light as a whole can be variously adjusted in consideration of the type of metal compound mainly forming the thin film precursor, the required refractive index, and the like. In general, if the necessary amount of ultraviolet light is too small as a whole, it tends to be difficult to increase the refractive index of the thin film. On the other hand, if the necessary amount of ultraviolet light is excessively large as a whole, it tends to be difficult to suppress the occurrence of cracks unless the number of times of ultraviolet irradiation is increased. Therefore, these should be noted.

Examples of the necessary amount of ultraviolet light as a whole include, for example, 300 mJ / cm ² , 500 mJ / cm ^{2, and the} like as lower limits, and 8000 mJ / cm ² as an upper limit that can be combined with these lower limits. Examples include 5000 mJ / cm ² .

  Although depending on the material of the transparent polymer film, the transparent polymer film is, for example, 25 ° C. to 180 ° C. from the viewpoint of suppressing the deformation of the transparent polymer film due to heat generated during ultraviolet irradiation. The temperature may be adjusted to be in the temperature range of ° C.

2. Present Film 2.1 Schematic Form of Present Film In this film, thin films containing metal oxides manufactured by the above-described thin film manufacturing method and metal thin films are alternately laminated on a transparent polymer film.

  In the present film, the thin film containing metal oxide and the metal thin film may be formed only on one surface of the transparent polymer film or may be formed on both surfaces of the transparent polymer film.

  Moreover, as a basic unit of the laminated structure which this film has, the thin film containing a metal oxide | metal thin film | metal thin film | metal thin film containing a metal oxide etc. can be illustrated from the transparent polymer film side, for example. These basic units may be laminated one or more times.

  In the case of using the former basic unit, a thin film containing a metal oxide is separately laminated on the surface farthest from the transparent polymer film from the viewpoint of preventing deterioration of the metal thin film and ensuring transparency. preferable.

  Further, in the laminated structure of the present film, the number of laminated layers can be varied in consideration of materials and film thicknesses such as thin films containing metal oxides, metal thin films, required optical characteristics, electromagnetic wave shielding functions, and the like. . In general, examples of the number of stacked layers include 3 to 9 layers.

  In the stacked structure, the thin film containing a metal oxide and the composition or material of the metal thin film may be formed from the same composition or material, or may be formed from different compositions or materials.

  In the above laminated structure, the thickness of the thin film containing metal oxide and the thickness of the metal thin film may be substantially the same or different for each film.

2.2 Each composition of this film 2.2.1 Transparent polymer film In this film, a transparent polymer film becomes a base for forming a thin film. Examples of the material for the transparent polymer film include the polymer materials described above.

  The thickness of the transparent polymer film can be variously adjusted in consideration of the material used. Generally, 10 μm, 25 μm, and the like can be exemplified as the lower limit value, and 500 μm, 250 μm, etc. can be exemplified as the upper limit value that can be combined with these lower limit values.

2.2.2 Thin film containing metal oxide In this film, the thin film containing metal oxide has transparency in the visible light region and functions as a high refractive index layer.

  Specific examples of the metal oxide include titanium oxide, zinc oxide, indium oxide, tin oxide, indium and tin oxide, magnesium oxide, and aluminum oxide. Products, zirconium oxide, niobium oxide, cerium oxide, and the like, and these may be used alone or in combination. The metal oxide may be a double oxide in which two or more metal oxides are combined.

As the metal oxide, in particular, titanium oxide (IV) (TiO ₂ ), ITO, zinc oxide (ZnO), tin oxide (SnO ₂ ) or the like having a relatively large refractive index with respect to visible light is preferably used. These may be included alone or in combination of two or more.

  In addition, the thin film containing the metal oxide can ensure a necessary refractive index and has a negative effect on the optical characteristics and the like, and the precursor of the metal oxide used during the synthesis of the metal oxide, for example, , Metal alkoxides, metal chelates such as metal acylates, metal carbonates, metal organic or inorganic compounds such as hydroxides, various additives, inevitable impurities, and other substances other than metal oxides good. When a small amount of a metal organic compound such as a metal alkoxide is contained, there are advantages such as excellent flexibility of the transparent electromagnetic wave shielding film.

  Here, in the present film, as the thin film containing the metal oxide in the laminated structure, basically, a thin film formed by the above-described thin film manufacturing method may be used.

  In this case, all of the thin films containing metal oxides may be formed by being irradiated with the same number of ultraviolet rays, or may be formed by being irradiated with different numbers of ultraviolet rays for each thin film.

  Further, the laminated structure may include a thin film containing a metal oxide formed by a single ultraviolet irradiation with an ultraviolet light amount that does not cause cracks.

  In addition, the thickness of the thin film containing the metal oxide can be variously adjusted in consideration of transparency and color tone. Generally, 10 nm, 20 nm, etc. can be illustrated as the lower limit, and 150 nm, 100 nm, etc. can be illustrated as the upper limit that can be combined with these lower limits.

2.2.3 Metal thin film In this film, the metal thin film mainly functions as an electromagnetic wave shielding layer and a near infrared shielding layer.

  Specific examples of the metal constituting the metal thin film include silver, gold, platinum, copper, aluminum, chromium, titanium, zinc, tin, nickel, cobalt, niobium, tantalum, tungsten, zirconium, lead, palladium, and the like. Examples thereof include metals such as indium and alloys composed of two or more of these metals. These may be contained alone or in combination of two or more.

  As a metal constituting the metal thin film, silver can be suitably used from the viewpoint of excellent conductivity, infrared reflectivity, visible light transmittance during lamination, and the like. Further, from the viewpoint of improving the stability to the environment such as heat, light, and water vapor, a silver alloy in which one or more metals such as gold, platinum, palladium, and copper are added to silver may be used as necessary. In this case, as the metal other than silver in the silver alloy, gold, palladium, or the like can be suitably used because the metal thin film is excellent in durability.

  Moreover, when using a silver alloy, as a ratio of metals other than silver, 0.1 weight%, 0.5 weight% etc. can be illustrated as the lower limit, As an upper limit which can be combined with these lower limits Examples thereof include 10% by weight and 20% by weight.

  Moreover, as a method for forming a metal thin film in this film, for example, physical vapor deposition (PVD) such as vacuum deposition, sputtering, ion plating, MBE, laser ablation, thermal CVD, plasma, etc. Examples include chemical vapor deposition (CVD) such as CVD. In the above laminated structure, each metal thin film may be formed by any one of these methods, or may be formed by using two or more methods.

  More specifically, for example, when a vacuum deposition method is used, a desired metal is used as an evaporation source, and a metal thin film is formed by heat vapor deposition by resistance heating, laser heating, electron beam heating, or the like. good.

  For example, when using a sputtering method, a desired metal is used as a target, an inert gas such as argon or neon is used as a sputtering gas, and a direct current (DC) voltage is applied between the target and the transparent polymer film. A metal thin film may be formed by applying a (DC sputtering method) or a radio frequency (RF) voltage (RF sputtering method). From the viewpoint of increasing the deposition rate, a direct current magnetron sputtering method or a high frequency magnetron sputtering method may be used.

  For example, when using the ion plating method, a desired metal is used as an evaporation source, a low-pressure gas is introduced into the vacuum deposition apparatus to generate a plasma by applying an electric field, and the evaporated particles from the evaporation source are ionized. The metal thin film may be formed by vapor deposition.

  The thickness of the metal thin film can be variously adjusted in consideration of the balance between surface resistance (electromagnetic wave shielding ability) and visible light transmittance. In general, when the thickness of the metal thin film is excessively large, the visible light transmittance tends to decrease. On the other hand, when the thickness is excessively thin, the surface resistance tends to increase. Generally as thickness of a metal thin film, 5 nm, 10 nm etc. can be illustrated as a lower limit, and 30 nm etc. can be illustrated as an upper limit which can be combined with these lower limits.

  The structure of this film has been described above. In the laminated structure of the present film, the thin film containing metal oxide and the material of the metal thin film can be appropriately selected from those described above as necessary. Examples of the most suitable combination of film materials include a titanium oxide as a thin film containing a metal oxide, and silver or a silver alloy as a metal in the metal thin film. This is because it is particularly excellent in transparency, electromagnetic wave shielding function and infrared shielding function.

2.3 Manufacturing method of this film The following methods can be illustrated as a manufacturing method of this film.

  That is, a thin film containing a metal oxide is formed on the surface of the transparent polymer film by the above-described thin film manufacturing method, and this is wound around a roll. Next, the roll is mounted in the film forming chamber of the thin film forming apparatus using the vapor phase method described above, and a metal thin film is formed on the surface of the thin film containing the metal oxide while the roll is fed out. . If such an operation is repeated a desired number of times, the film can be produced.

3. This filter uses this film. That is, the present filter has a configuration in which the present film is laminated on at least one surface of the transparent support base via the pressure-sensitive adhesive layer.

  Here, as a material for the transparent support substrate, any material can be used without particular limitation as long as it is excellent in transparency and has sufficient mechanical strength. Specific examples include glass such as semi-tempered glass and tempered glass, and polymer materials such as acrylic resin and polycarbonate resin.

  Further, the thickness of the transparent support substrate can be variously adjusted in consideration of mechanical strength, rigidity, and the like. Generally, the range of 1.0-5.0 mm etc. can be illustrated.

  Moreover, as an adhesive which forms an adhesive layer, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a polyvinyl butyral adhesive, an ethylene-vinyl acetate adhesive etc. can be illustrated, for example. .

  Moreover, the thickness of an adhesive is not specifically limited, Generally, the range of 5-100 micrometers etc. can be illustrated.

  In addition, with this filter, a functional film having various functions such as an antireflection function, an antiglare function, an impact absorption function, an environmental resistance function, and a toning function within the limit that does not significantly impair the optical characteristics. One or two or more of them may be further bonded through the above-mentioned pressure-sensitive adhesive layer.

4). This display The above-mentioned pressure-sensitive adhesive layer is formed on the surface of this film, or if necessary, a functional film having an antireflection function or the like is attached via the pressure-sensitive adhesive layer, and this is attached to the front surface of the plasma display. This display using the present film can be obtained by pasting directly on the display section and electrically connecting the ground and the metal thin film.

  On the other hand, the present display using the present filter can be obtained by arranging the present filter on the front side of the plasma display body through the air layer and electrically connecting the ground and the metal thin film.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in addition to display device applications, this film is used for, for example, snow melting glass, vehicle glass, cooling showcase glass, heating panel heaters, cooking panel heaters, and other electrothermal applications, measuring instrument glass windows, It can be used for various applications that require a conductive function and / or near-infrared shielding function and visible light transmission, such as electromagnetic wave shielding applications such as intelligent building glass and vehicle glass.

Hereinafter, the present invention will be described in detail using examples.
1. Thin film manufacturing method according to this example (Example 1)
First, a solution containing a titanium compound was prepared by the following procedure. That is, tetra-n-butoxy titanium tetramer (manufactured by Nippon Soda Co., Ltd., “B4”) and acetylacetone were mixed in a mixed solvent of n-butanol and isopropyl alcohol, and this was mixed using a stirrer. A solution containing a titanium compound was prepared by mixing for a minute. At this time, the blending ratio of tetra-n-butoxytitanium tetramer / acetylacetone / n-butanol / isopropyl alcohol was 7.50 wt% / 3.75 wt% / 58.75 wt% / 30.0 wt%. .

  Next, a quartz substrate (manufactured by Senyo Optical Co., Ltd.) having a diameter of 50 mm and a thickness of 1 mm was prepared for refractive index measurement, and the above solution was applied to the upper surface by spin coating. At the same time, for observation of cracks, a polyethylene terephthalate film having a thickness of 100 μm having an easy-adhesion layer formed on one side (“Cosmo Shine (registered trademark) A4100” manufactured by Toyobo Co., Ltd.) (hereinafter “PET film with an easy-adhesion layer” The quartz substrate is affixed to the surface of the easy-adhesion layer side of the adhesive layer (manufactured by Nitto Denko Corporation, “CS9621”), and the above solution is applied to the surface opposite to the easy-adhesion layer by spin coating. Worked. The spin coating conditions were a solution dripping amount of 0.3 cc, a preliminary rotation of 500 rpm × 3 seconds, and a main rotation of 2100 rpm × 30 seconds.

  Subsequently, the said coating solution was dried at 100 degreeC for 80 second using the drying apparatus, and the thin film precursor was formed on the quartz substrate and PET film with an easily bonding layer.

  Next, humidified air blown from a humidifier having a humidifying capacity of 700 ml / h (manufactured by Mitsubishi Heavy Industries Air Conditioning System Co., Ltd., “SHE706D-G”) was directly blown onto the thin film precursor. At this time, the time during which the thin film precursor was in contact with the humidified air was 10 seconds. The distance between the humidified air outlet and the thin film precursor was 20 cm.

  Subsequently, this sample was immediately put in an ultraviolet irradiation machine (manufactured by Fusion UV Systems Japan Co., Ltd.), and ultraviolet (UV) irradiation was performed with a UV lamp.

At this time, the necessary amount of ultraviolet light was 3.9, 2.6, 2.0, 1.6, 1.3 J / cm ² as a whole, and each was irradiated with ultraviolet rays in two portions.

  Here, the said ultraviolet irradiation machine has a structure as shown in FIG. That is, a slide table 12 is provided inside the ultraviolet irradiator 10, and a temperature control base 16 on which the sample 14 is placed is provided above the slide table 12. A connecting pipe 18 and a return pipe 20 are connected to the temperature control pedestal 16, and the temperature of the quartz substrate and the PET film with an easy adhesion layer in the sample 14 can be adjusted by supplying cold / hot water. ing. In this embodiment, the temperature of the temperature control base 16 is 60 ° C.

  Then, when the slide table 12 reciprocates at a constant linear velocity in the direction of the arrow in the figure, the sample 14 is irradiated with ultraviolet rays from the UV lamp 22. At this time, in the ultraviolet irradiator, if the slide table is moved one way in the left direction from the position shown in the figure, the ultraviolet ray can be irradiated once, and if the slide table is moved by one reciprocation, the ultraviolet ray can be irradiated twice. When moved, ultraviolet rays can be irradiated three times (four or more ultraviolet rays may be reciprocated in accordance with these). In Example 1, the slide table was reciprocated once to irradiate ultraviolet rays in two portions.

  Thus, a thin film containing a titanium oxide (hereinafter referred to as “thin film according to Example 1”) was manufactured.

(Example 2)
A thin film according to Example 2 was produced in the same manner as in Example 1 except that ultraviolet rays were irradiated in three portions.

(Comparative example)
A thin film according to a comparative example was produced in the same manner as in Example 1 except that the ultraviolet light was not divided and irradiated only once to obtain the necessary amount of ultraviolet light as a whole.

(Evaluation method for cracks, refractive index and substrate temperature)
The presence or absence of cracks was confirmed by observing the thin film in the crack observation samples in the above Examples and Comparative Examples with a microscope (magnification × 450).

  Moreover, the refractive index of the thin film in the sample for refractive index measurement in the said Example and a comparative example was measured with the ellipsometer. The refractive index is a value at a wavelength of 633 nm.

  Further, the surface temperature of the substrate when irradiated with ultraviolet rays was measured by attaching a K-type thermocouple to the quartz substrate.

  The evaluation results are shown in Table 1 and FIG.

  According to Table 1 and FIG. 2, the thin film according to Example 1 and Example 2 manufactured so as to obtain the necessary amount of ultraviolet light as a whole by performing the irradiation of ultraviolet rays a plurality of times causes cracks. You can see that it is difficult. On the other hand, it can be seen that the thin film according to the comparative example manufactured by performing the ultraviolet irradiation only once and obtaining the necessary ultraviolet light amount easily causes cracks.

  This is because, in the thin films according to Example 1 and Example 2, the thermal energy during UV irradiation is more dispersed than when the necessary amount of UV light is given as a whole, so that the surface temperature of the PET film is increased. This is considered to be because the amount of thermal expansion of the PET film was reduced.

  Moreover, according to Example 1 and Example 2, it has confirmed that the thin film which has a refractive index equivalent to the past was obtained, suppressing generation | occurrence | production of a crack than before.

  In Examples 1 and 2, there was a tendency for cracks to occur in the thin film when the necessary amount of ultraviolet light increased as a whole. However, it is possible to substantially prevent the thin film from cracking by increasing the number of times of irradiation with ultraviolet rays in consideration of the productivity of the thin film.

2. Production of Transparent Electromagnetic Wave Shielding Film According to This Example Next, a transparent electromagnetic wave shielding film having a thin film containing an oxide of titanium produced by the thin film producing method according to this example was produced.

  That is, the surface of the PET film with the easy adhesion layer opposite to the easy adhesion layer was subjected to microgravure coating using a coating machine (EB-700, manufactured by Yasui Seiki Co., Ltd.). Next, this was dried at 100 ° C. for 2 minutes and 40 seconds to form a thin film precursor.

Next, with an ultraviolet irradiation device [high pressure mercury lamp (160 W / cm)] provided in the coating machine, the irradiation speed is 200 mm (illuminance: 400 mW / cm ² , measurement wavelength range: 300 to 390 nm), Ultraviolet rays were irradiated twice at the same speed (1.5 m / min) (the irradiation time of ultraviolet rays at each time was about 3 seconds) to form a thin film containing titanium oxide.

Next, after exposing the surface of the thin film containing the oxide of titanium by oxygen glow discharge, pure silver (purity: 4N, 126 mm × 506 mm size) as a target and argon gas as a sputtering gas, a direct current magnetron sputtering method [power : 1.1 kW (1.73 W / cm ² ), degree of vacuum: 2.5 Torr, film forming temperature: 40 ° C., target / thin film distance: 6 to 8 cm], an Ag thin film at a line speed of 2 m / min. Formed.

  Subsequently, in the same manner as described above, formation of a thin film containing an oxide of titanium was repeated twice.

Next, an Ag thin film was formed on the surface of the thin film containing the titanium oxide in the same manner as described above. However, the electric power in the DC magnetron sputtering method was 1.4 kW (2.20 W / cm ² ).

  Subsequently, in the same manner as described above, formation of a thin film containing an oxide of titanium was repeated twice.

Next, an Ag thin film was formed on the surface of the thin film containing the titanium oxide in the same manner as described above. However, the electric power in the DC magnetron sputtering method was 1.1 kW (1.73 W / cm ² ).

  Next, in the same manner as described above, a thin film containing an oxide of titanium was formed once.

  As a result, a thin film containing titanium oxide (thickness 30 nm, refractive index 1.9) | Ag thin film (thickness 9.5 nm) | Thin film (thickness 60 nm, refractive index 1.9) | Ag thin film (thickness 11.5 nm) | Thin film containing titanium oxide (thickness 60 nm, refractive index 1.9) | Ag thin film (thickness 9.5 nm) | A transparent electromagnetic wave shielding film having a 7-layer structure obtained by laminating an oxide-containing thin film (thickness 30 nm, refractive index 1.9) was obtained.

3. Front filter and plasma display according to the present example Next, the obtained transparent electromagnetic wave shielding film was attached on a glass substrate through an adhesive layer to prepare a front filter for plasma display. In addition, this front filter was attached to the front surface of the display body through an air layer to produce a plasma display.

It is the schematic of the ultraviolet irradiation machine used with the thin film manufacturing method concerning a present Example. It is the figure which showed the relationship between the refractive index of the thin film containing the oxide of titanium, and generation | occurrence | production of a crack in the case where it divides and irradiates with ultraviolet rays.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ultraviolet irradiation machine 12 Slide table 14 Sample 16 Temperature control base 18 Outgoing pipe 20 Return pipe 22 UV lamp

Claims (5)

A thin film manufacturing method in which a solution containing a metal compound is applied to at least one surface of a transparent polymer film and dried to form a thin film precursor, and the thin film precursor is irradiated with ultraviolet rays to produce a thin film containing a metal oxide. A method,
A method for producing a thin film, characterized in that the ultraviolet irradiation is performed in a plurality of times so that a necessary amount of ultraviolet light is obtained as a whole.   2. The thin film manufacturing method according to claim 1, wherein the metal compound is a titanium compound, and the metal oxide is a titanium oxide.   A transparent electromagnetic wave shielding film comprising at least one thin film containing a metal oxide produced by the thin film production method according to claim 1 or 2 on at least one surface of the transparent polymer film.   An optical filter comprising the transparent electromagnetic wave shielding film according to claim 3.   A plasma display comprising the transparent electromagnetic wave shielding film according to claim 3 or the optical filter according to claim 4.

Images