JPS60132754A - Optical transmitting sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a light-transmissive sheet that transmits visible light and rays and transmits infrared rays. More specifically, it is a selective light-transmissive sheet that transmits visible light and reflects near-infrared light to infrared light.

[Prior art] In general, conductive metal thin films such as gold, silver, copper, and various alloys containing these as main components are stacked between transparent high-refractive-index dielectric layers, and the thickness of each constituent thin film is controlled. It is well known that it is possible to obtain a device that selectively reflects light in a specific wavelength range. In particular, a laminate that is transparent in the visible region and selectively reflects infrared wavelengths is a heat ray reflective film! Bill as Rem.

It is effective from the point of view of energy saving in houses, use of solar energy, etc. However, energy saving in buildings, houses, etc.
In order to further improve the utilization efficiency in the field of solar energy utilization, it is necessary to improve the energy distribution of sunlight in the visible light region (450 nm to 7000 m), the near-infrared region, etc.
It is more effective to provide selectivity to the transmission characteristics (<10.1 nm to 2tO0 nm). In other words, the amount of solar energy is not felt in the cloth, but it is about 5% of the heat rays.
Further reduces the transmission characteristics of the near-infrared region where 0% exists,
Improving the transmission characteristics of the visible light part is more effective for heat insulation, and since it does not impair transparency in any way, it can be applied to various fields without affecting the surrounding environment or safety. . Examples of application fields include improving the heat insulation of monitoring windows during high-temperature work, further improving the cooling effect by improving the ability to block solar energy that enters through the windows of buildings, cars, trains, and other vehicles, and improving the heat insulation of transparent food containers. improvement, and further improvement of the cold retention effect in frozen and refrigerated showcases. As such an optical interference filter having selective permeability, the Fabry-Perot filter is generally well known. This is known as an interference filter in which a transparent dielectric material having a specific optical film thickness is sandwiched between opposing semi-transparent mirrors, and only a specific wavelength □longer light is transmitted. This Fabbri.

- U.S. Patent No. 3,682,528 shows that by applying a Perot filter, a selective light transmitting sheet with high transmission characteristics in the visible region and high reflection characteristics in the near-infrared region can be obtained. . According to this, for example, the structure of the substrate/metal layer/dielectric/metal layer/dielectric layer is "C glass/Ni
/AQ /AI 20a /Ni /A(1/Al2O
Structure r 3 has a transmittance of 70% or more from 400nl to 700r+m and a reflectance of about 10%, 700nl
A selective light transmitting laminate having a transmittance of 10% or less at a wavelength of 2,500 nm and a reflectance of about 90% or more has been obtained.

E-problem For Fabry-Perot filters, half.

It is known that by reducing the thickness of the metal film that is a transmissive reflector, the transmission wavelength width will be expanded and the transmittance will be improved, and if the dielectric and body refractive indexes are lowered, the transmission wavelength width will be narrowed. ing. By setting the refractive index and thickness of the dielectric material to 550 nm, for example.
1. Select so that a transmission peak can be obtained. If the metal film thickness is made sufficiently thin, it is possible to construct a filter that has high transmission characteristics in the visible region and good blocking characteristics in the near-infrared region. Conventionally, filters have been mainly used for precision optics, and for this reason, metal compounds such as oxides with stable optical constants and low absorption have been used as transparent dielectrics. However, when used in building windows for energy-saving purposes such as blocking solar energy, it must be applied over a large area, and production on an industrial scale is impossible using conventional metal compounds as transparent dielectrics.

□This'' means that the technology to uniformly cover a large area of the surface of a metal thin film layer is still unfinished by Metal Oxide Film Company. In the following cases, it is possible to simply form a metal oxide film by thermal oxidation, etc.
It can be said that it is impractical to uniformly produce an oxide film with a thickness comparable to that of a human being over a large area on an industrial scale.

[Structure and operation of the invention] - We have made extensive studies to apply this structure to a wide range of energy-saving applications such as the use of solar energy.

As a result, by uniformly coating an organic compound with a refractive index of 1.35 to 1.65, a transparent dielectric layer that is optically transparent and has uniform optical properties is formed. I discovered that what I can do is possible. □Until now, organic 41-containing compounds have not been used in optical materials, with some exceptions, due to their non-uniform optical properties, high optical loss, and lack of long-term stability. There was a problem with sexuality. As a result of further research to overcome the drawbacks of such organic compounds, the present inventors discovered that such drawbacks could be overcome by using a specific organic compound, that is, an organic crosslinked polymer in the transparent dielectric layer, and arrived at the present invention. This is what I did.

□ That is, the present invention has a metal thin film layer (B) with a thickness of 40 to 300 people on at least one side of the organic polymer (A>),
Transparent dielectric layer (C) from 200 Å to 3,000 Å thick
and the transparent protective layer (D) is (A)/(E3')/(C)/
(B) or (A)/(B)/(C)/(B)
This light-transmitting sheet is characterized in that the transparent dielectric layer (C) is made of an organic crosslinked polymer in the light-transmitting sheet laminated in the order of /(D).

The organic polymer film (A) referred to in the present invention does not need to be particularly limited, but the transmittance at 550 nnl is low for the purpose of applying the light transmitting sheet of the present invention to a transparent window etc. It is necessary to have a transparency of 50% or more, preferably 75% or more, and any conventionally known organic polymer film <A> that satisfies this condition may be used. , polyethylene terephthalate film, polycarbonate 1~ film, polypropylene film, polyethylene film, polyethylene naphthalate film, polysulfone film,
Bolier, -tilsulfone film, nylon film, etc. are preferred, and polyethylene terephthalate film is particularly preferably used.

Furthermore, even if these organic polymer films contain colorants, ultraviolet absorbers, two dyes, etc. to the extent that they do not impair the mechanical properties and optical properties of the organic polymer film base, the organic polymers used in the present invention will not be affected. There is no problem with the combined film.

1 The material of the metal vawA layer (B) used in the present invention can be any alloy as long as gold Wrh3 has low absorption loss in the visible region and has high electrical conductivity, but especially It is preferable that silver is the main component.Other metals that may be included include gold and copper.

Aluminum, aluminum, etc. are preferable, but any other metal may be included as long as it does not reduce the characteristic 1 of silver. The content of silver is an important factor governing the optical properties of the resulting light-transmitting sheet, and it is preferably contained at least 40% by weight, preferably 50% by weight or more.

In addition, in order to obtain a laminate with particularly high infrared reflectivity, gold, silver,
Preferably, the metal thin film layer (B) is an alloy of two or three metals selected from the three elements copper, or a single metal thin film layer (B) of these metals.

The thickness of the metal thin film layer (B) is not particularly limited as long as it satisfies the required optical properties of the obtained light-transmissive sheet, but since it has infrared light reflective ability or electrical conductivity. It is necessary to have continuity in discipline in at least some areas. The thickness of the metal thin film that changes from an island-like structure to a continuous structure is approximately 300 mm or more, and in order to improve the visible light transmission characteristics, which is the object of the present invention, the film thickness is approximately 300 mm or more.
It is preferable that it is 8 or less.

In order for the light-transmitting sheet to have sufficient visible light transmittance and sufficient infrared light reflectance, it is particularly preferable that the thickness of the metal 111 layer (B) is about 40 Å or more and about 120 Å or less.

□ Metal! 111Glli (B) can be formed by any conventionally known method such as vacuum evaporation, Kasitos sputtering, ion blating, etc., but it is stable at a film thickness of 1iÅ or less. In order to form a ``□'' film, high-energy particles such as cathode sputtering and ion-plating methods are used.
A film formation method is preferred. In particular, when obtaining an alloy thin film, the Cassitos sputtering method is preferred from the viewpoint of uniformity of the composition of the formed thin film and uniformity of the formed thin film and film thickness.

□Also, when forming the metal thin film layer (B), a known method ``r-'' is used to stabilize the thin metal layer.
It is possible to pre-treat the material that will serve as the substrate. These methods include, for example, cleaning treatments such as ion bombardment, undercoating treatments such as coating with organic silicates, organic titanates, organic zirconate compounds, and/or coatings with metals such as Ni, Ti, 3i, B1Zr.
There is a nucleation stabilization treatment in which 'tv;T'a, etc. and oxides of these metals are formed in advance by sputtering, etc., and these should be appropriately selected within a range that does not adversely affect the optical properties of the light-transmitting sheet. Just use it. If these pre-treatments involve an increase in thickness, the droplets will be more noticeable. A treatment similar to the pre-treatment of ε- may be performed on the metal! as a post-treatment.

As the organic compound used in the transparent dielectric layer (C) of the present invention, an organic crosslinked polymer is preferably used. □ Organic crosslinkers [i. Crosslinkable with phenolic resin compounds, alkyd resin compounds, unsaturated polyester resin compounds, epoxy resin compounds, polyurethane resin compounds, etc.]
9. Air the polymer having functional groups. All organic crosslinked polymers crosslinked by the action of heat, light, or a crosslinking agent are preferably used. You can use only one type of these cross-polymers, but you can use two or more types together! I can also do things.

Such an organic crosslinked polymer is used to form a transparent dielectric layer (C) in the present invention. In the present invention, such a transparent dielectric layer (C) is formed by a coating method, etc.
A polymer having a crosslinkable functional group as described above is diluted and dissolved in an appropriate solvent together with a crosslinking agent if necessary to an appropriate concentration, and then applied, dried or further heat treated if necessary.
A method of forming an organic crosslinked polymer by irradiation with light or the like is preferably used.

When forming a transparent dielectric layer (C) using such a coating method, spin coating is used if the area is small.

It can be obtained by coating with a bar coater or doctor knife and drying.

In the case of a large area, a transparent dielectric layer (C) of any thickness can be formed by drying after coating with a machine such as a gravure roll coater or a reverse roll coater.
- In order for the light-transmitting sheet of the present invention to optically achieve its purpose, the thickness of the transparent dielectric layer (C) must be between 200 and 3,000 mm.

In particular, to increase the transmittance of visible light, from 500^
1., Ka in the question to 500 is preferred.

In particular, the light-transmitting sheet in the present invention is exposed to visible light of 550
In order to have a maximum transmittance near 01, the thickness of the transparent dielectric layer (C) should be from 600 to 1,300.
It is particularly preferable that it be between.

Furthermore, the degree of crosslinking of the organic crosslinked polymer used in the transparent dielectric layer (C) of the present invention does not necessarily have to be high, but rather depends on the conditions under which the light-transmitting sheet of the present invention is used (environmental conditions, post-treatment conditions, etc.) It is preferable to select it appropriately depending on the situation.

When using an organic compound for optical purposes like the light-transmitting sheet of the present invention, the physical properties of the resulting coating film control the optical properties of the laminate, so it is necessary to select a resin with excellent purity and uniformity. In addition, it is necessary to appropriately select a coating method that can achieve a uniform film thickness. Preferably, it is necessary to keep the film thickness within ±5% of the set film thickness. □
The light-transmitting sheet of the present invention includes a protective layer (D) on the outermost layer (B) for the purpose of protecting the laminated structure (A)/(B)/(C)/(B) having an optical function. You will be able to maintain your dignity as you get older. Such a protective layer (D) protects the laminate of the present invention from mechanical damage. It has the role of protecting against contaminants such as chemicals, moisture, etc., and humans.1 In order to achieve this purpose and avoid adverse effects on the optical properties of the laminate, a protective layer (D
) is preferably a material that is optically transparent and has excellent protective ability. Protective layer (D) that can be used in the present invention
7) U at,, -c LL, 3i, AI,
T! , Zr, ``l-a'' or other inorganic compounds such as oxides or mixed oxides of two or three of the above metals, or acrylonitrile, polymethacrylic 0
Nitrile.

, Polymethino 1me? Acrylic resins such as acrylates, acrylate resins and their copolymers, polystyrene resins, vinyl acetate resin II1. Phenoxy resin.

Organic compounds formed from resins such as polyester resins and polyt-vitane resins, mixtures thereof, copolymers, crosslinked polymers, etc. are frequently used.

If the usage environment is particularly severe, polyethylene films, polypropylene films, nylon films, triacetate films, polyester films, polyvinyl butyral sheets, polycarbonate sheets, etc. of various thicknesses may be laminated using a known method to preserve the material.
It can also be used as D).

When using a film made of an inorganic compound as the protective layer (D), physical forming methods such as sputtering, vacuum evaporation, and ion blasting are preferably used. The protective layer (D) made of a metal oxide can also be obtained by a known metal oxide thin film formation method of diluted coating.

When a film made of an organic compound is used as the protective layer (D), the protective layer (D) made of an organic compound is prepared by dissolving it in a suitable solvent that dissolves the resin mentioned above, applying and drying it.
D) can be obtained. The protective layer (D) in the present invention is not limited to a single layer, and may have a laminated structure of 2 layers or 13 layers. This may be a mutually laminated structure of inorganic compounds and organic compounds, or a mutually laminated structure of organic compounds,
It may also have a laminated structure of inorganic compounds. The protection of these laminated structures! By forming the iI layer (D), the protective layer (D) of the present invention having a better protective function can be obtained.

The thickness of the protective layer (D) of the present invention is not limited as long as it has the ability to protect the laminate;
．． The thickness is preferably 0.5 parts or more, and 50 μm or less, particularly preferably 35 μm or less, in order not to deteriorate the optical properties of the laminate.

The light-transmitting sheet of the present invention can be used depending on its purpose, but for example, when used for building windows, etc., it can be applied directly to the glass of the window with an adhesive, or When used in the windows of automobiles, etc., it can be placed inside laminated glass, known as safety glass, using polyvinyl butyral using a known method. I can do things. When the light-transmitting sheet of the present invention is used for such safety glass, it exhibits its properties in particular, and can avoid the occurrence of discoloration and racking.

In this manner, the form of the light-transmitting sheet of the present invention can be selected depending on the purpose of use, and it can be effectively used not only for controlling the incidence of solar energy but also for all fields of heat radiation prevention.

IXI'', examples, and 9 pieces of manual explanations and explanations.

Note that all parts are parts by weight.

[Example 1] A biaxially stretched polyester film with a thickness of 125 μm was used as the substrate (A), and a metal film consisting of a thin film layer of silver and copper (containing 10% by weight of copper) with a thickness of 80 mm was formed as a first layer on the substrate (A). The thin film layer (B) was used as a second layer, and a transparent dielectric layer (C) made of a copolymer crosslinked product of polymethacrylonitrile (80 parts) and 2-hydroxyethyl methacrylate (20 parts) with a thickness of 750A was used as the second layer. , the third layer has the same thickness as the first layer, 80A.
(A) / (B) / (C) / in which metal thin film layers (B) consisting of silver and copper film layers (containing 10% by weight of copper) were laminated in sequence.
A light-transmitting sheet having the structure (B) was formed as follows.

The silver-copper 1111 layer of the metal thin film layer (B) contains 10% by weight of copper.
Targeting the silver-copper alloy containing Ar gas pressure 5 x
It was formed by DC magnetron anti-buttering under 10-3 T 0rr. The input power was 2 W/+I per unit area of the target.

The transparent dielectric layer (C) is made of polymethacrylonitrile and 2
- 1 part of a copolymer of human oxyethyl methacrylate and an isocyanate compound (trade name: Takenate A-10":
0.5 parts (manufactured by Takeda Pharmaceutical Co., Ltd.), 2 weights of a copolymer of polymethacrylonitrile and 2-human 0-xyethyl methacrylate in a mixed solvent consisting of 5 parts of cyclohexanone, 2 parts of acetone, and 1 part of methyl ethyl ketone. After dissolving it so as to form a thick trace of 100%, it was coated using a ζ bar coater and dried at 130° C. for 3 minutes.

The obtained light transmitting sheet had a transmittance of 78% at a wavelength of 500 rv, and an infrared reflectance of 82% at a wavelength of 10 μm.

A polyvinyl butyral sheet with a thickness of 300 μm was placed on both sides of the obtained light-transmitting sheet, and a polyvinyl butyral sheet with a thickness of 300 μm was placed on both sides.
After combining mg of 70-I-glass, 1Ky/cr
A selectively transmitting laminated glass was prepared by holding the glass at 150° C. for 1 hour while applying a pressure of 1 liter. The integrated visible transmittance of the obtained light-selective transmittance laminated glass was 11%, and the integrated near-infrared light transmittance was 29%.

Actual flow side 2] Except for replacing the second transparent dielectric layer (C) of Example 1 with a crosslinked copolymer of polymethacrylonitrile and 2]hydroxyethyl methacrylate and using a crosslinked polymer made of polyvinyl alcohol. A light-transmitting sheet having the same structure as in Example 1 was formed.

The transparent dielectric layer (C') made of a crosslinked polymer made of polyvinyl alcohol (saponification degree 75%)
A mixture consisting of 1 part of polyvinyl alcohol and 0.5 parts of formaldehyde was dissolved in water to give a mold openness of 1.4%, coated with a bar coater, and then dried in a vacuum at 135°C.

%, and the integrated near-infrared light transmittance was 31%.

A biaxially stretched polyester film with a thickness of 75 μm was used as the substrate (A), and on top of it, as a first layer, a titanium oxide layer with a thickness of 10 A, a thin silver film layer with a thickness of 55 μm, and a titanium oxide layer with a thickness of 20 μm. A thin metal film layer (B) having a pre-treatment layer and a post-treatment layer consisting of 75% acetic acid with i-limethylpropane and 2.4-tolylene diisocyanate to a thickness of 800 mm is used as the second layer. Ethyl solution (made by Japan Polyurethane ■:
A transparent dielectric layer (C) of a frame 4i polymer consisting of a polyester resin (manufactured by Toyobo ■, product name Vylon RV-200) and a transparent dielectric layer (C) made of the same titanium oxide as the first layer is applied to the third circumference. Prelude consisting of f! There is a layer after birth, a continuous layer,
(A, ) / (B ) / (C) formed by sequentially laminating each layer consisting of a metal thin film layer (B) consisting of a silver thin film layer (A, ) / (B ) / (C)
/(,B)4i optically transparent sheets and sheets were prepared as follows.

The thickness of the metal thin film layer (B) is 10, and the pre-treatment layer and post-treatment layer consisting of a grained titanium layer are 1. Using gold and titanium as targets, a metallic titanium layer was formed by DC magnetron sputtering under an Ar gas pressure of 10-31" orr and exposed to the atmosphere to form a titanium oxide layer.

The silver thin film layer (thickness: 55 mm) of metal thin film layer (B) was formed by DC magnetron sputtering using a silver plate as a target under an argon gas pressure of 5.times.1O@-3 TOrr.

The transparent dielectric layer (G) was prepared by mixing Vylon RV-200i part and Coronate L 0.1 part in a mixed solvent consisting of 3 parts methyl ethyl ketone and 1 part cyclohexanone.
200 was dissolved to a concentration of 2% by weight, coated with a bar coater, and dried at 130° C. for 3 minutes.

The resulting light-transmissive sheet had an integrated visible transmittance of 13% and an integrated near-infrared light transmittance of 39%.

[Example 4] A biaxially stretched polyester film having a thickness of 125 μm was used as the substrate (A), and a metal thin film layer formed of a silver-gold thin film layer containing 20 weight D% of gold to a thickness of 80 mm was formed as a first layer thereon. (B) as a second layer, a transparent dielectric layer (C) made of epoxy resin with a thickness of 750A, and a third layer with the same thickness as the first layer (8A).
Metal with a thin layer of silver and gold containing 20% gold by weight! membrane layer, c
By sequentially stacking B>, and (A>/(,
A light-transmissive sheet having the following structure was prepared as follows. .

The first and third silver-gold thin film layers of the metal thin film layer (B) were prepared using a silver-gold alloy containing 20 parts gold and m% gold, and a target under an At1j pressure of 3 x 107" Torr. D of
A sputtering ring was formed using a C magnetron.

The second transparent dielectric layer (C) made of epoxy resin is made of bisphene 1 nonyl resin, Kikinresin (Shiguru Kagaku).
(manufactured by: product name Epicoli 004) and a polyamide-based curing agent (manufactured by Daiichi General ■: product name, Versamide 125) at the same heavy ratio lv! A mixture consisting of 1 part of dark tonoene and 1 part of hyacetone glycol! 5 x 1,000 boxyresin is added to the paste agent.
．． 5% by weight after coating with @E melt coating ψ bar coater 1
The product was dried at 30°C for 5 minutes.

(The integrated visible light transmittance of the transparent sheet was 68%.
, the integrated near-infrared light transmittance is only 31%. .

[Example 5] A methyl isobutyl ketone solution (A- 31,010 parts, A-102 parts) was coated with a bar coater, air-dried, and then a 25 μm thick polypropylene stretched film was laminated as a protective layer (D). The integral visible light transmittance of the obtained light transmitting sheet laminated with the protective layer (D) was 73%, the integral visible light reflectance was 11%, and the integral near infrared light transmittance was 36%. .

[Example 6] The transparent dielectric layer (C) of Example 4 is formed from a crosslinked polymer of polyester polyurethane resin. Except for this, a light-transmissive sheet similar to that of Example 4 was constructed.

A crosslinked polymer made of polyester polyurethane resin is
1 part of a polyester polyurethane resin with a molecular weight of about 40,000, obtained by chain-extending polyethylene adipate having an average molecular weight of 1300 and having hydroxyl groups at both ends with 2,4-1-lylene diisocyanate, and 0.4 part of the coronate used in Example 3. The polyester polyurethane resin is 1.7
It was obtained by dissolving it in ethyl acetate so as to give a weight percent, coating it with a bar coater, and drying it at IL/130° C. for 3 minutes.

The resulting light-transmissive sheet had an integrated visible transmittance of 72% and an integrated near-infrared light transmittance of 40%.

Claims (1)

[Claims] On at least one side of the organic polymer film (A), a metal, metal, thin film layer (B) having a thickness of 40 to 3QO and a thickness of 2
008 to 30<10. -A Q transparent dielectric layer (C) and transparent protective layer (D>(,A>,/(,,,,B,
,) /(,C)/(B). Or (,A)/ (B,) /(c)/ (B)/
A light-transmitting sheet laminated in the order of (D), characterized in that the transparent dielectric material H and (C) are made of an organic crosslinked polymer.