JPS635263B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a laminated film that transmits visible light and reflects infrared rays and has selective light transmittance. A preferred embodiment of the present invention is a laminated film that blocks infrared rays and has sufficient transparency for visible rays when attached to a window or facepiece. Such laminated films are not only useful for protecting the human body, especially the face, during high-temperature work such as welding, melting, and firefighting, but also for protecting buildings,
Of the sunlight that enters through the glass windows of containers, vehicles, etc., it blocks infrared rays without interfering with visible rays, and is effective in improving cooling and heating effects. In addition, we also provide thermal insulation, freezing, and
It can also be widely used for cold storage in refrigerated cases and for preventing heat radiation from the windows of solar collectors. [Prior art] Conventionally, aluminum, aluminum,
Laminated films are known in which thin layers of metals such as silver, copper, and gold are vacuum-deposited. These laminated films are
In order to prevent scratches, contamination, and oxidation of the thin metal layer, the metal surface is usually coated with an organic polymer protective layer having a thickness of 1 to 100 microns. The infrared reflectance of such a laminated film depends on the thickness of the metal layer, and in order to obtain a high infrared reflectance, it is necessary to make the metal layer sufficiently thick. As a result, if an attempt is made to increase the infrared ray blocking effect, the visible ray transmittance will be significantly reduced, resulting in insufficient lighting and unclear recognition of objects. Also, if you try to increase the infrared reflectance,
At the same time, the reflectance of visible light increases, resulting in unpleasant reflected light being emitted outdoors. In order to improve this problem, the surface of the thin metal layer is coated with an inorganic derivative with a high refractive index, such as titanium oxide, bismuth oxide, or zinc sulfide, to a thickness of several hundred angstroms. A method of improving transparency by preventing reflection is known. As a method for depositing these inorganic dielectrics on the surface of a metal thin layer, physical film forming methods such as vacuum evaporation and sputtering, or chemical film forming methods such as solution coating and chemical vapor deposition are used. However, when the single metal compound mentioned above is used as an antireflection coating in the form of a large-area film, the coating has poor abrasion resistance, lacks flexibility, and easily peels off from the substrate due to friction or bending. It had some drawbacks, such as being easy to use. Additionally, in order to improve these mechanical properties, attempts have been made to incorporate organic substances into the coating film using organic titanates or organic silicates as raw materials, but these efforts lack light resistance to ultraviolet light, weather resistance, and heat resistance. I had a problem with it getting worse. Particularly in order to obtain a large-area film at low cost, it is necessary to form the film at high speed, but the faster the film formation speed, the more the above-mentioned drawbacks become more pronounced. [Problems to be Solved by the Invention] The present inventors have created an antireflection film that does not have these drawbacks. High transmittance of visible light,
As a result of intensive studies to obtain a laminated film with a high reflectance of infrared rays, the present invention was arrived at. That is, an object of the present invention is to provide a laminated film having a high visible light transmittance and a high infrared reflectance, which has an antireflection film having excellent abrasion resistance, light resistance, and heat resistance. [Means for Solving the Problems] This purpose is to provide a transparent thin layer (B) containing a metal compound with a thickness of 0.02μ to 0.3μ on at least one side of the organic polymer film (A); The metal thin layer (C) with a thickness of 30 Å to 500 Å is A/C/B or A/B/
In the film laminated in the order of C/B, 60% by weight or more of the transparent thin layer (B) is zirconium (Zr),
Consisting of silicon (Si) and oxygen, 60 mol% or more of the metal elements in B are composed of Zr and Si, and
This is achieved by a laminated film characterized in that the molar ratio of Zr/Si is in the range of 80/20 to 20/80. The organic polymer film (A) used in the present invention has a thickness of 6μ to 1000μ, preferably 9μ to 1000μ.
125μ, flexible, wavelength 400n
Light transmittance from m to 2000nm is 40% or more,
Preferably, it has a characteristic of 70% or more.
For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polyamides such as nylon 6, nylon 66, and nylon 12, polycarbonate, polymethyl acrylate, polyvinyl chloride, polyvinylidene chloride, and polysulfon. , polyphenylene sulfide, polyphenylene oxide, polyether sulfone, polyacrylonitrile, polytetrafluoroethylene, polyamideimide, polyimide, polyvinyl alcohol,
Examples include cellulose acetate. These may be used as a homopolymer, or may be a copolymer or a mixture of two or more of them. Further, the organic polymer film (A) may be biaxially stretched or uniaxially stretched. moreover,
Depending on the purpose, these organic polymer films (A) may contain ultraviolet absorbers, antioxidants, anti-aging agents,
Additives such as colorants, plasticizers, stabilizers, antistatic agents and the like may be added as appropriate. Among them, organic polymer films (A) suitable for exhibiting the effects of the present invention include biaxially oriented polyethylene terephthalate, biaxially oriented polypropylene, biaxially oriented polyamide, polycarbonate, and polymethyl acrylate. , polyimide film. The metal useful for the metal thin layer (C) in the present invention preferably has a bulk resistivity of 10 ^-4 ohm cm or less, such as aluminum, copper, silver, gold,
Metals such as tin, zinc, iron, nickel, cobalt, palladium, titanium, zirconium, chromium, etc., or metals mainly composed of the above metals such as duralumin, sterling silver, brass, bronze, white gold, stainless steel, nichrome, etc. Alloys or mixtures of more than one species are used. Among them, the bulk resistivity is 5×10 ^-6 ohm・cm
The following are preferred, and those with high malleability are preferred in order to prevent occurrence of cracks, detachment, etc. during molding, bending during adhesion, and stretching. From these points, the thin metal layer (C) used in the present invention is preferably silver, copper, gold, aluminum, or alloys mainly composed of these metals, and particularly preferably silver and alloys mainly composed of silver. Give results. The thickness of the thin metal plate (C) is an important factor in exhibiting light transmittance and infrared blocking performance, and in the present invention, the thickness of the thin metal plate (C) is determined by Defined by thickness. That is, it is expressed as a value obtained by dividing the weight of a film attached to a certain area by the specific gravity of the bulk. Metal thin layer in the present invention
The thickness of (C) needs to be in the range of 30 Å to 500 Å. If the thickness is less than 30 Å, the reflectance of infrared rays will be extremely small, and if it is more than 500 Å, the transmittance of visible light will be significantly reduced, which is not preferable. The optimal thickness of metal required varies slightly depending on the material used, but is preferably from 50 Å.
300 Å, particularly preferably from 80 Å
It is in the range of 200 Å. In the case of the silver and silver-based alloys mentioned above, a range of 80 Å to 200 Å is most preferred. Examples of methods for forming the thin metal plate (C) include vacuum deposition, sputtering, ion plating, plating, chemical vapor deposition, and thermal decomposition. Among them, vacuum evaporation and sputtering methods are suitable for uniformly and rapidly forming a thin metal layer (C) over a wide area of an organic polymer film (A) or a transparent thin layer (B). In addition, sputtering is the most suitable method in terms of film adhesion and composition control of the alloy material. In the present invention, the transparent thin layer (B) containing a metal compound with a thickness of 0.02μ to 0.3μ is composed of Zr and Si, in which 60 mol% or more of the total metal elements in the metal compound constituting B, Moreover, it is necessary that the molar ratio of Zr/Si is in the range of 80/20 to 20/80. In the above structural requirements, if the sum of Zr and Si in all metal elements does not reach 60 mol% or more, the antireflection effect or mechanical properties may be insufficient, especially light resistance. This is not preferable since weather resistance and heat resistance will be impaired. Furthermore, in the above configuration,
When the Zr/Si molar ratio is 80/20 or more, the resulting film becomes brittle and has poor adhesion, resulting in a film with poor wear resistance. On the other hand, if the Zr/Si molar ratio is less than 20/80, it may cause discoloration when irradiated with ultraviolet rays or a decrease in infrared reflectance, and the film may have poor weather resistance and heat resistance, making it difficult to withstand long-term use. This is not preferable because it results in a film that is opaque. In the present invention, the sum of zirconium, silicon, and oxygen accounts for 60% by weight or more of B, both from the viewpoint of the characteristics of B and from the viewpoint of the characteristics of the laminated film of the present invention. preferable. B
Metal elements other than silicon and zirconium, such as titanium, zinc, cadmium, etc., non-metallic elements, or organic substances may be included as long as the amount is less than 40% by weight. In the present invention, the above B preferably has a visible light transmittance of 60% or more,
Particularly preferably, it is 80% or more, which is more effective in achieving the object of the present invention. In the present invention, the thickness of the above-mentioned B is preferably 0.02 to 0.3μ from the viewpoint of high transmission characteristics of visible light and high reflection characteristics of infrared rays, and particularly preferably.
Thicknesses of 0.03 to 0.09 microns are useful for purposes of this invention. In order to laminate the above-mentioned light-transmitting thin layer (B), materials having the composition of B may be laminated by a vacuum thin film forming method such as sputtering, or finally the above-mentioned B
The composition B may be obtained by applying the raw material or intermediate forming the composition by vacuum deposition sputtering or coating, and then subjecting it to polymerization, condensation, oxidation, or other reactions.For example,
General formula ZrX _l (OR) _4-l [R is an alkyl group having 1 to 6 carbon atoms, and X is a β-diketone compound or a β-ketoester compound. l is an integer from 0 to 4. ) and one or more zirconium compounds represented by the general formula SiY _l (OR) _4-l [R is 1 to 1 carbon number]
6, Y is an alkyl group having 1 to 6 carbon atoms, or a halogenated alkyl group, a phenyl group, a vinyl group, or a glycidoxy group. (l is an integer of 0 to 2) or a hydrolyzed mixture thereof is coated on the above A or A/B laminate, and this is heated and reacted. It can be obtained by drying and performing a type of polycondensation reaction. In the mixed composition in this case, other materials, intermediates, or additives may be added as necessary, as long as the finally obtained composition satisfies the condition B above. Representative examples of the zirconium compound and silicon compound represented by the above general formula include the following, but those effective in the present invention are not limited to these. That is, examples of silicon compounds include tetrabutoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and phenyltrimethoxysilane. silane,
γ-glycidoxypropyltrimethoxysilane,
Examples of zirconium compounds include γ-mercaptotrimethoxysilane, N-βaminoethylpropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. ,
zirconium-trialkoxy-monoalkylacetoacetate (such as zirconium-tributoxy-monoethyl acetoacetate), zirconium-dialkoxy-dialkyl acetoacetate, zirconium-monoalkoxy-trialkyl acetoacetate (zirconium-monobutoxy- zirconium alkyl acetylacetonate compounds (such as triethylacetoacetate). The desired film can also be obtained by so-called reactive vapor deposition or reactive sputtering, in which a mixture or alloy of zirconium and silicon is deposited in atomic or molecular form under reduced pressure containing oxygen. The laminated film according to the present invention has the characteristics of high transmittance of visible light and high reflectance of infrared rays, and has excellent light resistance, weather resistance, and heat resistance.
It has excellent flexibility and adhesive properties. In general, titanium oxide and zinc oxide, which have a refractive index of 2.0 or higher, are considered to be effective as anti-reflection layers for thin metal films.On the other hand, materials with low refractive indexes such as silicon oxide can be used as anti-reflection layers for thin metal films. It is considered inappropriate. This is also supported theoretically. However, the present inventors have found that when silicon compounds such as silicon oxide are not used alone but are used in combination with zirconium compounds, the molar ratio of Zr/Si is 20/80, and silicon compounds are the main component. However, the basis of the present invention is that visible light transmittance can be significantly improved by significantly preventing reflection of visible light without significantly reducing infrared reflectance. Furthermore, by containing a certain amount or more of a ziconium compound, light resistance to ultraviolet rays and weather resistance can be improved, and by using a mixed system of a zirconium compound and a silicon compound, heat resistance can also be improved. It is another foundation. The laminated film of the present invention is an organic polymer film.
(A), the transparent thin layer (B) and the metal thin layer (C) are A/
It is constructed by laminating in the order of C/B/, but further A/
By adopting the B/C/B configuration, durability can be further improved. Furthermore, on the front or back surface of the laminate of the present invention,
Other layers such as a protective layer, an ultraviolet absorbing layer, a surface hardening layer, a dew condensation prevention layer, etc. may be laminated as appropriate within a range that does not impair the intended effects of the present invention. Moreover, the organic polymer film (A) of the present invention
Prior to depositing a thin metal layer on the transparent thin layer (B), known surface treatments such as EC treatment, plasma treatment, surface roughening treatment, reverse sputtering treatment, etching treatment, etc. are also employed. It's good. The main applications of the laminated film according to the present invention are as an eye adjustment film that is often exposed to ultraviolet rays and high temperatures, a heat insulating film, a cold insulating film, a work facepiece, etc. The film can be used alone, or it can be laminated on glass or plastic plates. In addition to being used, the electrical conductivity of thin metal layers can be used to shield static electricity and electromagnetic waves.
It can also be used for transparent heating elements, display electrodes, etc. Hereinafter, specific embodiments of the present invention will be shown in Examples. The measurement methods shown in the Examples are as follows. Light transmittance: Measured with a spectrophotometer model 323 manufactured by Hitachi, Ltd. It is shown as a measured value at a wavelength of 550 nm. Infrared reflectance: Measured with a spectrophotometer model 323 manufactured by Hitachi, Ltd., and shown as a measured value at a wavelength of 1700 nm. Abrasion resistance: Manufactured by Daiei Kagaku Seiki Seisakusho, JIS, L0823
Measured with an abrasion fastness tester based on , load 500g
It is expressed as the number of frictions until the film detaches. Metal film thickness: Weight-equivalent film thickness determined by atomic absorption method. Thickness of translucent thin layer: Geometric thickness of an ultra-thin section observed with a transmission electron microscope. Composition of the transparent thin layer: Measured using an X-ray spectrometer (ESCA) manufactured by Kokusai Electric Co., Ltd., ES-200.
The total weight percentage of zirconium, silicon, and oxygen and the composition ratio of zirconium and silicon are calculated by correcting the measured value of the detected element using the detection sensitivity of ESCA. Surface electrical resistance: 35 mm wide film, electrode spacing 35
Value measured with a load of 500g using a mm copper electrode. The unit of measurement is ohm/square. Light resistance: UV fade meter (Tokyo Shibaura Electric)
Uses a mercury lamp H-400F (manufactured by Co., Ltd.). Retention rate of infrared reflectance after 800 hours of irradiation. Weather resistance: Uses Sunshine Carbon Weather Meter (manufactured by Suga Test Instruments Co., Ltd.). Retention rate of infrared reflectance after 500 hours of irradiation. Heat resistance: Circulating hot air oven (Tabai Seisakusho Co., Ltd.)
manufactured by) used. Infrared reflectance retention rate after holding at 80℃ for 720 hours. Examples 1 to 7, Comparative Examples 1 to 5 A thin silver layer with a thickness of 120 Å was provided by a sputtering method on a biaxially stretched polyethylene terephthalate film with a light transmittance of 87% and a thickness of 25 μm. Sputtering is done 5 times using magnetron method.
This was done by applying a DC voltage of 550 V to a 99.9% pure silver target under an argon pressure of 10 ^-3 Torr. The surface electrical resistance value of the obtained silver film was 9 ohms/mouth. Next, a light-transmitting thin layer made of a zirconium compound and a silicon compound was formed on the silver thin layer to obtain a laminated film having selective light-transmitting properties. The transparent thin layer was prepared by mixing the following solutions A and B at the respective mixing ratios, then applying the mixture using a gravure roll coater, drying and heat treating at 140°C for 2 minutes, and forming a layer with a thickness of 0.05 μm. A membrane was obtained. The metal elements in the light-transmitting thin layer consisted of zirconium and silicon, and the total weight percentages of zirconium, silicon, and oxygen in the thin layer were the values shown in Table 1. Solution A Tributoxyzirconium monoethyl acetoacetate 44g Isopropyl alcohol 593g Butanol 297g Toluene 297g Solution B Tetrabutyl silicate hydrolysis solution 52g Isopropyl alcohol 300g Butanol 150g Toluene 150g The tetrabutyl silicate hydrolysis solution used in Solution B contains butyl It was obtained by mixing and stirring 32 g of silicate, 16 g of ethyl alcohol, and 8.6 g of 0.1N aqueous hydrochloric acid solution, and performing a dehydration treatment. The solid content concentration of the liquid was 12.5%. When the zirconium compound alone and the molar ratio of Zr/Si exceeded 80/20, the film became powdery and cloudy, the abrasion resistance was extremely poor, and the infrared reflectance after the heat resistance test was reduced. Also Zr/Si
When the molar ratio was less than 20/80, the film had poor light resistance and weather resistance, resulting in decreased light transmittance and infrared reflectance. The optical properties, abrasion resistance,
Table 1 shows the results of measuring durability. Examples 8 to 10 In the same manner as in Example 1, except that tributoxyzirconium monoethyl acetoacetate in solution A of Example 1 was replaced with tetrabutylzirconium, the molar ratio of Zr/Si was 70/1, respectively.
Laminated films having transparent thin layers with composition ratios of 30, 50/50, and 30/70 and total weight percentages of zirconium, silicon, and oxygen of 95, 96, and 96%, respectively, were obtained. The light transmittance of each film was 75, 75, and 74%, and the infrared reflectance was 78, 78, and 79%. The retention rates of infrared reflectance after the light resistance test using an ultraviolet fade meter were 80, 80, and 85%, respectively. In addition, the abrasion resistance was good at 100 times or more in all cases. Comparative Example 6 On the silver-coated polyethylene terephthalate film used in Example 1, 3 parts of tetrabutyl titanate and 97 parts of a coating solution (solution B of Example 1) mainly consisting of a hydrolyzed solution of tetrabutyl silicate were applied. A solution consisting of was applied with a wire bar and dried at 140°C for 2 minutes to provide a thin translucent layer. The resulting film had a light transmittance of 70% and an infrared reflectance of 75%. This film has an infrared reflectance retention rate of 20% after a light resistance test using ultraviolet irradiation.
However, discoloration occurred and the transparent thin layer turned white. Example 11 On a biaxially stretched polyethylene terephthalate film having a light transmittance of 87% and a thickness of 25 μm, a film having a weight ratio of silver and gold of 2:1 was deposited by a sputtering method. The thickness of the metal film is 100 Å, and the surface electrical resistance is
14 ohms/mouth, light transmittance was 63%, and infrared reflectance was 77%. On top of this, a 0.045 μm thick translucent thin layer containing a mixture of zirconium oxide and silicon oxide was formed by sputtering. Sputtering was performed by distributing zirconium and silicon targets on the cathode and introducing a mixed gas of argon, oxygen, and nitrogen (mixing ratio: 40:12:48% by volume). The Zr/Si molar ratio of the obtained film was determined by atomic absorption method.
I confirmed that it was 55/45. As measured by FSCA, the transparent thin layer was composed of zirconium, silicon, and oxygen. This laminated film had a light transmittance of 83% and an infrared reflectance of 76%. The abrasion resistance did not change even after being abraded 100 times, and the initial optical properties were maintained even after the light resistance test and the heat resistance test. The infrared reflectance retention rate after a weather resistance test using a sunshine inweather meter was also good at 80%. Examples 12 to 16 Gold, palladium, aluminum,
Metal thin films of silver-aluminum alloy (weight ratio 10/1) were each produced. Solution A and solution B used in Example 1 were applied onto these metal thin films at a Zr/Si molar ratio of 50/50.
A mixed solution prepared as follows was applied with a wire bar and dried at 140°C for 2 minutes to form a uniform transparent light-transmitting thin layer with a thickness of 0.06 μm. The metal elements in the transparent thin layer were zirconium and silicon, and the total weight percentage of zirconium, silicon, and oxygen was 97%. The film thickness, optical properties, abrasion resistance, and durability of the obtained laminated film were measured, and the results shown in Table 2 were obtained. Example 17 A biaxially stretched polypropylene film having a thickness of 15 μm was adhesively laminated on the transparent thin film layer side of the laminated film obtained in Example 4. The light transmittance of this film was 68%, and the infrared reflectance was 72%.
The infrared reflectance retention rates after light resistance, weather resistance, and heat resistance tests were 85%, 80%, and 90%.

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Claims (1)

[Claims] 1. On at least one side of the organic polymer film (A), a transparent thin layer (B) containing a metal compound with a thickness of 0.02 μ to 0.3 μ and a thin metal layer (C) with a thickness of 30 Å to 500 Å. However, in a film laminated in the order of A/C/B or A/B/C/B, 60% by weight or more of the transparent thin layer (B) consists of zirconium (Zr), silicon (Si) and oxygen. , a laminated film characterized in that 60 mol% or more of the metal elements in B are composed of Zr and Si, and the molar ratio of Zr/Si is in the range of 80/20 to 20/80.