JPH04281402A - High visible transmitted heat ray reflecting laminate - 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate having a so-called high visible heat ray reflection function that efficiently reflects heat rays and efficiently transmits visible light.

0002

2. Description of the Related Art Heat-reflecting glass is a glass that transmits visible light and reflects near-infrared rays, and is used as window glass for architectural buildings and residences. By using this heat-reflecting glass, of the visible light and near-infrared rays that make up the majority of the radiation that reaches the earth's surface from the sun, it is possible to block the near-infrared rays and let in only the useful visible light. It is possible to reduce the cooling load.

[0003] Heat-reflecting glasses are classified into reflection-enhancing film types and interference filter types. Reflection-enhancing film types can be manufactured relatively easily and have been put to practical use by thermal decomposition methods (spray, CVD), vacuum methods (evaporation, sputtering), plating methods, and the like. Heat-reflecting glass produced by such a method has a high reflectance in a wide band, mainly in the near-infrared rays, and can largely block the heat rays of sunlight. On the other hand, since part of the reflected wavelength range extends to visible light, part of the visible light is also reflected, resulting in coloring and a decrease in the overall transmittance of visible light.

0004

[Problems to be Solved by the Invention] The conventional reflection increasing film type heat ray reflective glass described above does not have a sharp cut-off performance in the near-infrared region, and when the near-infrared reflectance is increased, the visible light reflectance also increases. Therefore, it was not suitable for use in applications requiring high transmittance for visible light, such as automobile glass. Further, when the visible light transmittance is increased, the near-infrared transmittance also increases, and there is a problem that the heat ray reflection function is decreased. An object of the present invention is to provide a laminate having a high visible transmission heat ray reflection function that reflects near infrared rays with high efficiency without lowering the transmittance of visible light.

[0005]

[Means for Solving the Problems] The present invention provides a transparent substrate coated with a reflection increasing film that reflects heat rays in a wide range while not reflecting visible light, and a transparent substrate coated with a reflection increasing film that reflects heat rays in a wide range while not reflecting visible light, and in a wavelength range in which the short wavelength side of the reflection range does not overlap with the visible range. This is a laminate that reflects near-infrared rays over a wide range and has high visible light transmittance, in which wavelength filters that reflect near-infrared rays with sharp wavelength selectivity are laminated.

The present invention will be explained in detail below. The reflection increasing film used in the present invention is produced using conventionally known techniques such as thermal decomposition, vacuum, plating, etc., to reflect a wide band in the near-infrared region and to have high transmittance in the visible region. Create something that is. In other words, in this reflection increasing film, the reflectance gradually increases from zero in the long wavelength band from around 800 nm, which is the boundary between the visible region and the near-infrared region, and the reflectance increases to about 80% at a certain wavelength, for example, around 1500 nm. It has a high reflectance of about 80% or more even at longer wavelengths. For example, the manufacturing method is
For example, a method of producing a tin-doped indium oxide layer as shown in No. 524 is heat-treated at about 380 to 500° C. in an atmosphere controlled to have an oxygen partial pressure lower than 10 −7 atmospheres. In this method, from about 800 nm to about 15
It is possible to obtain a reflection increasing film having a spectral reflectance in which the reflectance gradually increases in the range of 0.00 nm. In addition to the tin-doped indium oxide layer described above, a tungsten oxide layer can also be used.

The substrate on which the reflection increasing film is coated may be any transparent film or sheet that can be coated with the reflection increasing film. Examples include commonly used so-called inorganic glasses such as soda glass and low thermal expansion heat-resistant glass, and organic glasses such as acrylic, polyester, and polycarbonate.

[0008] A wavelength filter is used that reflects near-infrared rays in a wavelength range in which the short wavelength side of the reflection range does not overlap with the visible range, with sharp wavelength selectivity. That is, a wavelength filter is used that can reflect near-infrared rays in the range of about 800 nm to about 1500 nm, which cannot be reflected sufficiently by the reflection increasing film. Wavelength filters with such optical characteristics are, for example, multilayer filters made by alternately stacking layers with different refractive indexes, or filters with a full width at half maximum (hereinafter simply referred to as half width) obtained by holography of 50 to 500.
A nm reflection hologram can be used.

Since the reflection hologram has sharp wavelength selectivity as shown in FIG. 1, it is possible to transmit visible light and reflect the shortest wavelength portion in the infrared region. As a method for producing this reflection hologram, it is possible to use, for example, the recording material described in Japanese Patent Application No. 2-236132 previously filed by the applicant of the present application. When a reflective hologram made from this type of recording material is laminated with a polyvinyl butyral film as an interlayer film, the hologram swells due to the plasticizer present in the polyvinyl butyral film, and the reproduction wavelength becomes longer than the recording wavelength. Therefore, from about 800nm to about 1500n
It has a reflectance of about 80% or more within the range of m and a half-width of about 7.
A wavelength filter of 0 nm can be produced. When the wavelength band of a reflection hologram is narrow, the band can be widened by stacking holograms that reflect two or more different wavelength bands.

[0010] Since the light absorption of these wavelength filters in visible light is close to zero, from about 800 nm to about 1500 nm
A laminate in which a reflection increasing film whose reflectance gradually increases in the range of m and a wavelength filter which has a reflectance of about 80% or more in this range and reflects with sharp wavelength selectivity is:
It shows a high reflectance for light with a wavelength of about 800 nm or more, and has a reflectance of about 7% for visible light of about 400 to about 750 nm.
Shows high transmittance of 0% or more.

[0011] The reflection increasing film and the wavelength filter are laminated, but an intermediate film may be interposed between them. The interlayer film is used to control the reproduction wavelength of the hologram, for example, to increase adhesive strength, or to add an ultraviolet absorber to block ultraviolet rays. Examples of the laminate include glass plate with reflection increasing film/polyvinyl butyral film/wavelength filter/polyvinyl butyral film/glass plate (however, the reflection increasing film faces polyvinyl butyral), polyester film with reflection increasing film/wavelength filter/ Examples include acrylic plate (however, the reflection increasing film faces the wavelength filter), glass with reflection increasing film/wavelength filter, etc.

0012

Effects of the Invention According to the present invention, a high visible light transmittance heat ray reflective laminate having high visible light transmittance without impairing the near infrared reflective function, for example, about 70% or more for light in the range of about 800 nm to about 2000 nm. with a high average reflectance of approximately 400
It has become possible to produce a laminate that exhibits a high transmittance of approximately 70% or more for visible light of ~750 nm.

[0013]

EXAMPLES The present invention will be explained in more detail by examples below, but the present invention is not limited to these examples. Example 1 4 cc of tin chloride (SnCl4) was added to a solution of 100 gr of indium oxide (InCl3) in 1 liter of acetic acid n-butyl ester. This solution was atomized with oxygen using an atomizing nozzle and sprayed onto a 2 mm x 20 cm x 20 cm glass substrate at about 500°C to form a layer of about 0.3 μm. Furthermore, this coated substrate was placed in a container and heated to 450°C.
Evacuate to below 0-4 mmHg, then reduce the oxygen partial pressure to 10-
In order to reduce the pressure to 7 atm or less, CO gas was introduced until the pressure reached 15 mmHg, and after 30 minutes, the container was evacuated again and cooled.
It is possible to obtain a glass coated with a reflection increasing film having a spectral reflectance in which the reflectance increases in the range of .

Using the photoreceptor for hologram recording shown in Example 1 of Japanese Patent Application No. 2-236132, 514.5 nm
Using the two-beam interference exposure method shown in FIG. 4, the 514.5 nm light emitted from the argon ion laser 5 is transmitted through the beam expander 7 and the collimator lens 8 so that the total exposure amount is about 500 mJ/cm2. The light is made into parallel light and further divided into two by the beam splitter 9, and the total reflection mirrors 10 and 10' are adjusted so that the incident angle θ=
Three photoreceptors 11 were exposed at three different angles: 50°, 60°, and 75°. Thereafter, the entire surface of the photosensitive material is exposed for about 20 minutes from a distance of 3 cm using a 30 W fluorescent lamp to complete polymerization and fixation, resulting in a film having center wavelengths of about 580 nm, about 615 nm, and about 650 nm and a half-width of about 70 nm. Reflection holograms 1, 2, and 3 each having a thickness of 23 μm were produced.

The glass with the reflection increasing film and the three types of holograms are mounted on a 2 mm thick glass plate and two 0.5 mm thick polyvinyl butyral films as interlayer films (
(manufactured by Sekisui Chemical Co., Ltd.) under autoclave conditions of 150° C. and 15 atm, and at the same time, the reflection wavelength bands of the reflection holograms were changed to about 800 nm, about 875 nm, and about 950 nm, respectively.

As a result, as shown in FIG. 3, the glass plate with reflection increasing film 1/polyvinyl butyral film 3/three wavelength filters 4/polyvinyl butyral film 3/glass plate 1
(However, the reflection increasing film 2 faces the polyvinyl butyral), and has a thickness of about 5 mm and has a spectral reflectance shown in FIG.
A laminate of mm was obtained.

Example 2 A commercially available multilayer filter having the spectral reflectance shown in FIG. 6 and the glass with the reflection increasing film obtained in Example 1 were combined with a polyvinyl butyral film (manufactured by Sekisui Chemical Co., Ltd.) as an interlayer film. A laminate was prepared under autoclave conditions of 150° C. and 15 atm. As a result, a laminate having the spectral reflectance shown in FIG. 7 was obtained.

[Brief explanation of the drawing]

FIG. 1 shows the spectral reflectance of a hologram used in one example of the present invention.

FIG. 2 shows the spectral reflectance of the reflection increasing film used in one example of the present invention.

FIG. 3 is a cross-sectional view showing the structure of a laminate according to Example 1 of the present invention.

FIG. 4 shows a hologram recording optical system for manufacturing a hologram used in manufacturing the laminate of the present invention.

FIG. 5 shows the spectral reflectance of the laminate of Example 1.

FIG. 6 shows the spectral reflectance of the multilayer filter used in Example 2 of the present invention.

FIG. 7 shows the spectral reflectance of the laminate of Example 2.

[Explanation of symbols]

1. ．． glass 2. ．． reflection increasing film 3. ．． polyvinyl butyral 4. ．． Reflection hologram (3 layers) 5. ．． argon ion laser 6. ．． shutter 7. ．． beam expander 8. ．． collimator lens 9. ．． beam splitter 10,10'. ．． Total reflection mirror 11. ．． Photoreceptor for hologram recording

Claims (5)

[Claims] 1. A laminate having high heat ray reflectance and high visible light transmittance, comprising a transparent substrate coated with a thin film that reflects near-infrared light in a wide band and a wavelength filter having sharp wavelength-selective reflection. 2. The laminate according to claim 1, wherein the transparent substrate is made of inorganic glass or organic glass. 3. The laminate according to claim 2, wherein the organic glass is a film or sheet made of acrylic, polyester, or polycarbonate. 4. The laminate according to claim 1, wherein the wavelength filter is produced by holography. 5. The laminate according to claim 1, wherein the wavelength filter is made of a multilayer filter.