JP2696874B2 - Heat shielding material and heat shielding glass - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat-shielding glass (here, glass is formed of a glass material, a transparent plastic material) applied to a building, an automobile window, or the like. , And further used in a broad sense, including those composed of a composite of the two).

2. Description of the Related Art Recently, it has been required to use heat ray shielding glass for windows of buildings and automobiles from the viewpoint of energy saving and the like. Requires a material that transmits visible light well while effectively shielding near-infrared to mid-far infrared rays (heat rays).

Conventionally, as a method of realizing a steep change in transmittance, an interference method using a precision multilayer film is known, but this method is mainly applied to precision optical equipment and the like, and the building which is being considered now However, it is difficult to apply it to a large area such as a window of an automobile at low cost.

Therefore, as a heat ray shielding glass used for such an application, a thin metal layer (several hundred square meters) such as a glass material or a transparent plastic material is formed on the surface thereof. However, although the glass having such a thin metal layer has a large heat ray shielding effect, it also impedes the transmission of visible light at the same time, so that the surface on which the thin metal layer is formed looks shiny like a mirror surface. The use of, for example, in building windows causes certain types of pollution, such as the entire building shining brightly.

On the other hand, unlike such a metal thin film, a transparent conductive film is expected to have a heat ray shielding effect while maintaining high transmittance in the visible light region, and typical examples thereof include SnO ₂ and indium tin. -Oxide (ITO) is known. However, SnO ₂ has problems such as high resistivity (-310 ⁻³ Ω · cm), that is, low conductivity, and ITO is expensive.
For this reason, zinc oxide (ZnO) has recently attracted attention as a transparent conductive film replacing SnO ₂ and ITO.

In addition, a transparent conductive film in which Zn or the like is added to Al or the like has been conventionally known [Reference A, “Japanese Journal of Applied Physics (Jpn. J. Appl. Phys, Let)”.
t.) 24 (1985) L781 ”; Reference B“ Preparation of ZnO transparent conductive film by magnetron sputtering ”(IEICE CPM84)
-8); Reference C "Thin Solid Films (Thin Sol
id Films) 124 (1985) 43 "; JP-A-61-96609.

However, although the above-mentioned literature describes the properties of the transparent conductive film, the use of a ZnO film containing Al or the like as a heat ray shielding material merely suggests the possibility, and contains such Al and the like. No specific heat ray shielding material using a ZnO film, or material parameters when a ZnO film actually containing Al or the like is used as the heat ray shielding material is disclosed.

In fact, according to the study of the present inventors, when such a ZnO film containing Al or the like is used as a heat ray shielding material, 400 nm or more
Although the transmittance in the visible region of 800 nm is good,
2 μm near-infrared wavelength is considerably transmitted, and 2 μm
It was found that the mid-infrared region of 4 μm to 4 μm to 1 mm may not have sufficient shielding properties for wavelengths in the far-infrared region, and the effect may still be insufficient.

Even if it says a heat ray, the spectrum distribution of the intensity is spread over a very wide wavelength range by a heat source, for example, in the sunlight, it extends not only to a visible range but also to a near infrared range of 800 to 2 μm. It spreads from the mid-infrared region to the far-infrared region.Thus, as a heat-shielding material, it effectively shields mid- and far-infrared rays while maintaining transparency in the visible region, while transmitting in the near-infrared region, which has a large thermal effect. It is desired to block as much as possible.

Means and Actions for Solving the Problems In response to the above demands, the present inventors have conducted various studies on heat ray shielding materials that achieve both high transparency of visible light and high heat ray shielding properties. One or more metal elements selected from group IV elements and group IV
It is effective to use a ZnO film containing up to 10 atomic% in combination with a near-infrared absorber. In this case, in particular, a ZnO film containing a Group III element and a Group IV element having a thickness of 2,000 mm or more is used. Has been found to give excellent effects.

That is, conventionally, it is considered that the thickness of a ZnO film containing Al or the like is not related to the electron density even though it is related to the volume resistivity, which is an electrical property, and is therefore not related to the heat ray shielding property, which is an optical property. According to the study of the present inventors, ZnO containing a Group III metal element or a Group IV metal element in addition to the above, as is clear from the results of the experiments described below,
The film thickness largely defines the heat-ray shielding characteristics. In this case, if the film thickness is thinner than 2000 mm, it is not only in the near infrared region but also
Despite not having a sufficient heat-ray shielding effect even in the far-infrared region, the heat-ray shielding characteristics are sharply improved when the film thickness is 2,000 mm or more, especially at 3000 mm or more. It has been found that short near-infrared rays are effectively shielded. Furthermore, when the film thickness is smaller than 2000 mm, the volume resistivity is as large as 10 ^-2 to 10 ^-3 Ωcm, but when the film thickness is more than 2000 mm, the conductivity is suddenly improved, and it is on the order of 10 ^-4 Ωcm, From the measurement of the electron density, it was found that the electron density of the group III or group IV metal element-containing ZnO film has a high film thickness dependency. × 10 ²⁰ / cm ³ or more, therefore, the Group III or Group IV metal element-containing ZnO film is completely different from the prior art expectation, and its thickness and electron density have a positive correlation, When the film thickness becomes 2000 mm or more, the electron density also increases to 5 × 10 ²⁰ / cm ³ or more, the heat ray shielding effect increases remarkably, and even when the film thickness becomes 2000 mm or more, the visible light transmittance is maintained, 60
It was found that even at a thickness of 00 °, it was 90% or more.

Therefore, when the thickness of the group III or group IV metal element-containing ZnO film is set to 2000 mm or more, the heat ray shielding property is dramatically improved, the mid / far infrared rays can be effectively shielded, and the near-infrared region is further improved. Has a considerable shielding effect. However,
It should be noted that there is room for improvement in terms of shielding effect in the near infrared region near the visible region, and particularly when a Group III or Group IV metal element-containing ZnO film having a thickness of 2000 mm or less is used, It is desired to improve the infrared shielding effect, but by using a near-infrared absorber having a maximum absorbance in the wavelength range of 800 nm to 2 μm, the near-infrared shielding effect is significantly improved, and The present inventors have found that an effective heat ray shielding material can be obtained for heating appliances as well, and have accomplished the present invention.

That is, the present invention provides one or more metal elements selected from Group III elements and Group IV
Near-infrared absorbing agent is blended on both sides of a glass or transparent plastic material on which a zinc oxide film containing up to 10 atomic% is formed, or a thermoplastic or light or thermosetting transparent organic polymer film is disposed on the surface. In addition, the present invention provides a heat ray shielding material and a heat ray shielding glass made of the material, wherein a glass plate is arranged outside each of these films.

As shown in FIG. 3, the heat ray shielding material of the present invention
A thermoplastic or light or thermosetting transparent organic polymer film in which near-infrared absorbers are blended on both sides of a glass material or a transparent plastic material 1 on which a zinc oxide film 2 containing a group I or group IV element is formed 3, 3 and a glass plate 4, 4 on the outside of each of the films 3, 3 or, as shown in FIG.
Near-infrared absorbing agent is applied to the outer surface of both sides of a glass material or a transparent plastic material 1 on which a zinc oxide film 2 containing a group V element is formed to form a near-infrared absorbing layer 3 ", 3". A plastic or light- or thermosetting transparent organic polymer film 3 ', 3' is arranged, and the near-infrared absorbing layer 3 ", 3 ', 3', 3 '
The glass plates 4, 4 are arranged with the 3 ″ interposed therebetween. The heat ray shielding material of the present invention thus comprises a Group III metal element and a Group I metal element.
A group V metal element is contained in the ZnO film, and as such a metal element, Al, In, Ga, Si, Ti, Zr, Hf, Ge, etc. are preferably used, and among them, Al, Si, Ti, Ge is most preferred. Note that these metal elements may be contained as an element alone or as a compound such as an oxide. The content of these elements is 0.1 to 10 atomic%, but more preferably 2 to 10 atomic%.
４4 at%. Further, the film thickness is preferably 2000 ° or more, more preferably 3000 ° or more, especially 3500 ° or more.

Here, as a method of forming a ZnO film containing a Group III or Group IV metal element such as Al, a plasma dry process is excellent, and for example, a vapor deposition method, an ion plating method, and a CVD method are also used. Although included, various sputtering methods are particularly preferably employed. Examples of the sputtering method include a DC two-pole, three-pole, or four-pole sputtering method, a high-frequency sputtering method, a DC or high-frequency magnetron sputtering method, and an ion beam sputtering method.

As a method for adding a Group III or Group IV metal element to ZnO, a sputtering method is performed by adding a metal element to a target in advance. In this case, when the target is a ZnO sintered body, it is preferable to add in the form of an oxide such as Al ₂ O ₃ , and when the target is metal Zn, it is preferable to add the target in the form of a single metal element such as metal Al. Alternatively, the sputtering is performed at a high frequency, but when the target is the former, it is preferable to perform sputtering with Ar gas, and in the latter case, it is preferable to perform reactive sputtering with a mixed gas of Ar and O ₂ .

Incidentally, as a method of adding a metal element, Zn
It is also possible to adopt a method in which an O film is formed and a metal element such as A is vapor-deposited on the surface and thermally diffused, or a method in which a compound gas such as tetramethylaluminum or tetraethylaluminum is introduced into the film during the film formation. it can.

The above-mentioned group III or group IV metal element-containing ZnO film is used after being formed on an appropriate substrate according to its use or the like.
For example, when obtaining a heat ray shielding glass for a building or a window for an automobile, the film can be formed on a glass material or a transparent plastic material. In this case, when the film is formed by using the sputtering method, the film can be easily formed on a low-temperature substrate as compared with SnO ₂ or ITO, so that the film can be easily formed on a plastic film. For example, on a transparent plastic film having a thickness of 1 mm or less, such as a polyester film,
It is easy to form a group III or group IV metal element-containing ZnO film having a thickness of 00 ° or more. The plastic materials usable as the substrate material include polyester, polyamide, polyvinyl chloride, polyvinylidene chloride, polyethylene, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, polymethyl methacrylate, Polyvinyl butyral, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, metal ion crosslinked ethylene-methacrylic acid copolymer, polystyrene, polyurethane, polycarbonate,
Although a cellulose derivative and the like are included, the most preferred are a polyester film and a polyamide film.

The near-infrared absorber used in combination with the above-mentioned group III or group IV metal element-containing ZnO is a substance having a maximum absorbance in a wavelength range of 800 nm to 2 μm, and has absorption as much as possible in the visible region. Any compound may be used. When such an absorber is used in combination with the Al-containing ZnO film, a heat ray shielding material whose transmittance changes rapidly in the near infrared region can be obtained.

Examples of such near-infrared absorbing agents include cyanine dyes, quinone dyes, metal complex dyes, indoaniline dyes, azulene dyes, nitrogen-containing polycyclic dyes, and sulfur-containing polycyclic dyes. . Here, the cyanine dyes include chalcogenopyrrolomethine dyes and squarium dyes, and the quinone dyes include naphthoquinone dyes and anthraquinone dyes.
In addition, phthalocyanine dyes, as metal complex dyes,
Benzenethiol nickel complex dyes and the like are included.

More specifically, the following general formula (1) (Wherein, R ^{1 to} R ⁴ represent an alkyl group or an aryl group, R represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 4.) , 2-Benzenedithiolato) nickelate derivative, the following general formula (2) (Wherein, R ¹ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and R ² and R ⁵ may be the same or different from each other. Represents a hydrogen atom or a group capable of substituting the same, R ³ and R ⁴ may be the same or different from each other, and represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkyl group And R ⁶
And R ⁷ may be the same or different from each other, and may be a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, an acyl group, a sulfonyl group, or a 5-membered ring wherein R ⁶ and R ⁷ are linked to each other. Or a group of non-metallic atoms necessary for forming a 6-membered ring. However, R ³ and R ⁴ are not hydrogen atoms at the same time. ) The compound represented by these.

The following general formula (3) (Wherein, R ¹ and R ² may be the same or different from each other, and represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkenyl group). A compound represented by the following general formula (4) (Where R is hydrogen or a lower alkyl group, X is an anion selected from the group consisting of hexafluoroarsenate ion, hexafluoroantimonate ion, fluoroborate ion and perchlorate ion, and m is 0 or an integer of 1, 2. A is And n is an integer of 1 or 2. N), N, N ', N'-tetrakis (p-substituted phenyl) -p-phenylenediamines, benzidines and their aluminum salts and diimonium salts represented by the following formula (5) Bis (dithiobenzyl) nickel represented by the following formula, of course, but is not limited thereto. In addition,
All of these near infrared absorbers are commercially available,
Among these, those having low absorption in the visible region are preferable.

Even if the absorbent is colored, it can be sufficiently diluted when actually used, so that the visible light transmittance can be maintained at 80 to 85% or more.

When the heat ray shielding material is desired to be colored blue, a blue pigment may be added together with or in place of the above-mentioned near infrared absorber. In this case, as the blue pigment, anthraquinone pigments and phthalocyanine pigments are preferably used, which can effectively block light of about 800 nm.

Here, when using a near-infrared absorbing agent, the near-infrared absorbing agent is often in the form of a powder, which is kneaded into a thermoplastic or heat or photocurable transparent organic polymer resin to have a thickness. Is preferably formed into a film having a thickness of 1 mm or less, or an absorbent is dissolved in an appropriate solvent in advance, a transparent organic polymer film is dipped in the film, and the absorbent is attached to the film. in this case,
The amount of the absorbent used is not particularly limited, but can be 0.05 to 1% by weight, particularly 0.1 to 0.5% by weight of the film weight.

In addition, as the thermoplastic transparent film, the above-described organic polymer resin described for the ZnO coating containing a Group III or Group IV metal element can be used. Also,
Examples of the heat or photocurable transparent film include metal ion crosslinked ethylene- (meth) acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene- (meth) acrylic acid copolymer, and ethylene-ethyl acrylate. Polymers, ethylene-vinyl acetate copolymers, and polymer materials having an unsaturated double bond in the molecule modified with (meth) acrylic acid and its derivatives, organic peroxides or photosensitizers And those to which 50% by weight or less of an acryloxy group or meryloxy group-containing compound is added as a curing aid. Here, any organic peroxide can be used as long as it decomposes at a temperature of 100 ° C. or higher, and as a photosensitizer, directly by irradiation with light,
Any material may be used as long as it generates a radical indirectly.

The heat ray shielding material according to the present invention is a combination of a Group III or Group IV metal-containing ZnO film and a near-infrared absorbing agent.In this case, the glass or the glass on which the Al-containing ZnO film described above is formed. It can be used in combination with a transparent plastic film and a thermoplastic or light or thermosetting transparent organic polymer film blended or coated on the surface with a near-infrared absorber, or Al can be directly applied to the film surface blended or coated with the absorber. The contained ZnO can be used after being formed into a film, and its use mode can be variously selected.

Further, as a specific method of using the heat ray shielding material, there is a use as a heat ray shielding glass. In this case, a transparent organic polymer film such as an ethylene-vinyl acetate copolymer or the like is blended with a near-infrared absorbing agent.
Create a laminate with a transparent plastic interposed between the intermediate material layers of the layer containing a Group III or Group IV metal element-containing ZnO,
In addition, it is preferable that the laminated body is interposed between two glass plates to be integrated, and the intermediate layer is cured as necessary to produce a heat ray shielding glass.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

[Example 1] (a) Preparation of organic polymer film containing near-infrared absorbing agent Commercially available ethylene-vinyl acetate copolymer (EVA)
(Vinyl acetate 26%) 100 parts by weight of 1 part by weight of dicumyl peroxide as an organic peroxide and 0.3 part by weight of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent are mixed uniformly with a V-type mixer. After that, a 0.4 mm thick EVA sheet was extruded by an extruder for plastic (set at 80 ° C. to 100 ° C.).

With respect to 100 parts by weight of this EVA sheet, 0.25 parts by weight of a near-infrared absorbing agent of the above formula (4) (IRG-002, manufactured by Nippon Kayaku Co., Ltd.) was blended with a rubber kneading roll at a temperature setting of 80 to 85 ° C.

Next, a 0.3 mm sheet (hereinafter, referred to as sheet S) was prepared by sandwiching the EVA containing the above absorbent between polyethylene terephthalate films and using a press set at 90 ° C. This was placed in an oven at 150 ° C. for 20 minutes to be cured, and then allowed to cool. After reaching room temperature, the polyethylene terephthalate film was peeled off. On the other hand, an EVA sheet without a near-infrared absorber as a standard (hereinafter referred to as sheet R)
) And a 0.3 mm sheet was produced in the same manner as above.

(B) Preparation of Al-containing ZnO film A magnetron sputtering device was used to form a circular shape with a diameter of 10 cm.
Using a ZnO sintered target containing 3.4Al / Zn atomic% of Al ₂ O ₃ under argon gas flow rate of 50cc / min and pressure of 5mTorr
Sputtering was performed with a direct current of 500 V × 0.5 A. In this case, the substrate is disposed at the end of the target vertically to the target, the sheet S is attached thereto, and the process is performed without particularly heating.
A 4,000 mm thick film was formed on the surface.

Similarly, a 4000 ° Al-containing ZnO film was formed on the surface of the sheet R.

The volume resistivity of these films was measured using a four-probe method surface resistance meter Loresta MPC-TESTER manufactured by Mitsubishi Yuka Co., Ltd., and it was found to be about 5 × 10 ⁻⁴ Ωcm in both cases.

(C) Measurement of optical transmittance Next, in order to examine the optical characteristics of each heat ray absorbing material obtained above, a Shimadzu multi-purpose automatic spectrophotometer MPS-5000 was used.
Was used to measure the transmittance in the visible and near infrared regions.

The results are shown in FIG. 1 (visible range) and FIG. 2 (near infrared range).

In the figure, A (dashed line) indicates the Zn-containing ZnO on the sheet R.
(Therefore, only Al-containing ZnO, comparative example), B (broken line) indicates the sheet S only (accordingly, near infrared absorbing agent only, comparative example), C (solid line)
Is a visible light transmission spectrum of a sheet S coated with Al-containing ZnO (accordingly, a combination of Al-containing ZnO and a near-infrared absorbing agent, Example). Further, D (dotted line) is a commercially available heat ray reflective film having Ag deposited on the surface (comparative example).

From the results of FIGS. 1 and 2, it can be seen that the heat ray shielding material using the Al-containing ZnO film and the near-infrared absorber according to the present invention has excellent visible light transmittance and can effectively shield near-infrared rays. Was observed.

Example 2 (a) Preparation of Near-Infrared Absorber-Added Organic Polymer Film A film was prepared in the same manner as in Example 1, except that the curing agent was benzoyl as a photosensitizer instead of organic peroxide. 1 part by weight of isopropyl ether was used. As the near-infrared absorbing agent, the absorbing agent of the above formula (1) (IRF-905 manufactured by Fuji Photo Film Co., Ltd.) and the absorbing agent of the formula (3) (PA-1001 manufactured by Mitsui Toatsu Fine Co., Ltd.) Each of the absorbents of formulas (4) (IRG-002 and IRG-003 manufactured by Nippon Kayaku Co., Ltd.) was used, and 0.25 parts by weight of each was added to prepare a sheet.

It should be noted that curing was not performed at this stage, but a laminated glass was prepared as described later, and then cured by UV irradiation.

(B) Preparation of Al-containing ZnO film A ZnO film of about 3000 ° was formed on a 100 μm-thick polyethylene terephthalate film in the same manner as in Example 1. At this time, the volume resistivity was 7 × 10 ⁻⁴ Ωcm.

(C) Preparation of heat-shielding laminated glass The polyethylene terephthalate film coated with Al-containing ZnO film prepared in (b) is sandwiched between the two EVA sheets containing the absorbent prepared in (a), and the laminated body is further laminated. It was sandwiched between two 3 mm-thick float glasses that had been washed and dried in advance, placed in a rubber bag, and degassed under vacuum at a temperature of 100 ° C. for 15 minutes (in this state, a laminate completely free of bubbles). Immediately apply this with a 4KWUV irradiation device at a distance of 15 cm on one side 3
Ultraviolet rays were irradiated for 0 seconds each for a total of 1 minute to produce a heat ray shielding laminated glass of the example.

EVA without added near infrared absorber as standard
A laminated glass was prepared by sandwiching a sheet with a polyethylene terephthalate film coated with an Al-containing ZnO film (comparative example).

Further, for comparison, a commercially available heat ray reflective film was sandwiched between EVA sheets to which a near-infrared ray absorbent was not added, to produce a laminated glass (Comparative Example).

(D) Measurement of Solar Energy Shielding Effect Using each of the above-mentioned heat ray shielding laminated glasses, the sunlight shielding effect of the laminated glass was measured by a wavelength-based light energy analyzer LI-1800C manufactured by Leiger U.S.A.

In this case, first, sunlight is directly incident on the device,
The total radiant heat of 100 nm light energy was determined.

Next, using each laminated glass prepared in (c), sunlight was transmitted through each of the laminated glasses, and thereafter, was incident on the device, and the total radiant heat was determined. The results are shown in Table 1.

As can be seen from the above table, the laminated glass using only No. 6 transparent conductive film Al-containing ZnO compared to the No. 1 sunlight original only cuts about 20%, but this is due to the near infrared It can be seen that about 50% is cut by using the absorbent together. This is comparable to the shielding properties of a laminated glass using a commercially available Ag-coated No. 7 commercial product with poor visible light transmittance.

[Example 3] The shielding effect against the energy from the incandescent lamp was measured using various heat ray shielding laminated glasses produced in Example 2. The measurement was performed using a light energy absolute measurement device manufactured by Nozaki Sangyo Co., Ltd., and a laminated glass sample was placed just before the entrance of the device, and a 100 V × 60 W incandescent light source was placed 50 cm away from the sample and irradiated with light. went. The measurement wavelength was 300 nm to 30 μm, and the total radiant heat in this region was determined.
The results are shown in Table 2.

In the table, the results of the incandescent light bulb original are measured by directly entering light without opening the laminated glass.

Unlike sunlight, incandescent light bulbs mainly emit near-infrared and mid-far infrared rays, so the No. 6 transparent conductive film Al-containing ZnO
70% is cut even with laminated glass using only the film, but by using this together with near-infrared absorbers,
It was confirmed from the results in Table 2 that the cut in% was possible.

 Next, a reference example will be described.

(Reference example)

The magnetron sputtering device, using ZnO sintered target containing 3.4Al / Zn atomic% of Al ₂ O ₃ in a circular shape having a diameter of 10 cm, under conditions of pressure 5 m Torr at DC 500V × 0.5A 3
Sputtering for ~ 30 minutes, 3rd on a transparent polyethylene terephthalate (PET) substrate (100mm x 100mm x 100μm)
A heat ray shielding material made of a ZnO film containing Al having a film thickness shown in the table was formed. In this case, the substrate was placed perpendicular to the target at the end of the target, and a film was formed without performing heating and pre-sputtering.

Next, an optical measurement was performed on each of the obtained heat ray shielding materials. That is, Shimadzu multipurpose automatic spectrophotometer MP
400-800 nm visible light region and 800-2500 using S-5000
The transmittance in the near-infrared region of 2.5 nm was measured.
3, and the reflectance was measured using a regular reflection measuring device RF-11.
The results are shown in Tables 3 to 5.

From the results of Tables 3 to 5, the heat ray shielding material composed of the Al-containing ZnO film shows that the optical properties, particularly the optical properties in the infrared region, show the film thickness dependence, and the film thickness is made 2000 mm or more, especially 3000 mm or more. Is effective in blocking mid- and far-infrared rays, and it is recognized that near-infrared rays also have a wavelength that is quite close to the visible range. In this case, even if the film thickness is increased, visible light is transmitted well. It was found that there was no problem such as coloring.

Next, a sample of 10 mm × 10 mm was cut out from each heat ray shielding material, and the volume resistivity ρ and the mobility μ of each heat ray shielding material were determined by a van der Pauw method using an apparatus of HALLMEASUREMENT SYSTEM HL200 manufactured by BIORAD. It was measured. The results are shown in Table 6.

Further, the electron density N of each heat ray shielding material was measured, and the plasma wavelength λp was calculated from the measured value. In this case, the effective mass of electrons was calculated for two cases of m * = 0.4 and m * = 1.0. The results are shown in Table 7.

As is clear from the results of Tables 6 and 7, the volume resistivity of the heat ray shielding material composed of the Al-containing ZnO film has a large thickness dependency, and the mobility changes with the change of the volume resistivity, The electron density also depends on the film thickness. When the film thickness exceeds 2000 mm, the volume resistivity becomes very small, the mobility becomes large, and the electron density becomes large. It can be seen that there is a large shift to about 1 μ.

Therefore, as can be seen from the results of the optical characteristics described above, contrary to the conventional expectation, the film thickness and the electron density have a positive correlation, and the electron density increases as the film thickness increases, and the volume resistivity increases. It was found that the heat ray shielding effect was significantly increased by setting the film thickness to 2000 mm or more.

Effects of the Invention The heat ray shielding material according to the present invention has both high transparency of visible light and high heat ray shielding property, and thus is suitably used for a heat ray shielding glass and the like, and the obtained heat ray shielding glass is Exhibits excellent visible light transmission and heat ray shielding effects.

[Brief description of the drawings]

FIG. 1 is a graph showing the transmittance of various heat ray shielding materials in the visible region, FIG. 2 is a graph showing the transmittance of the material in the near infrared region, and FIG. 3 is an embodiment of the heat ray shielding glass of the present invention. FIG. 4 is a cross-sectional view showing another example of the heat ray shielding glass of the present invention. DESCRIPTION OF SYMBOLS 1 ... Glass material or transparent plastic material 2 ... Zinc oxide film containing group III or IV element 3 ... Transparent organic polymer film containing near-infrared absorbing agent 3 '... Transparent organic polymer film 3 "... Near-infrared absorbing layer 4 ... Glass plate

Claims (2)

(57) [Claims] 1. A glass material or a transparent plastic on which a zinc oxide film containing one or more metal elements selected from Group III elements and Group IV elements in an amount of 0.1 to 10 atomic% with respect to zinc is formed. A thermoplastic or light- or thermosetting transparent organic polymer film with a near-infrared absorber mixed or coated on the surface on both sides of the material, and a glass plate body placed on the outside of each of these films A heat ray shielding material characterized by the following. 2. A heat ray shielding glass comprising the heat ray shielding material according to claim 1.