JPH1087349A - Non-iridescent infrared-ray reflecting glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain IR reflecting glass excellent in appearance and weather resistance without assuming iridescent appearance peculiar to IR reflecting glass by forming a transparent electrically conductive film on the surface of glass and an outer coating film of fluorine-contg. polyimide on the outside of the electrically conductive film. SOLUTION: A transparent electrically conductive film is formed on the surface of plate glass preferably having 0.5-10mm thickness and an outer coating film of fluorine-contg. polyimide is formed on the outside of the electrically conductive film. The electrically conductive film is not especially limited if it practically transmits visible radiation but the film is preferably a film of a material having a refractive index of 1.6-2.8, especially antimony or fluorine doped tin oxide. The film has about 80-800nm thickness, about >=70% visible light transmissivity in the wavelength range of 0.38-0.70μm, about >= 60% average IR reflectance at about 107μm wavelength and about 10-20θ/sq. sheet resistance. The polyimide has a refractive index 0.85-1.15 times the square root of the refractive index of the electrically conductive film and concretely has a refractive index of 1.45-1.70. The transmissivity of the polyimide is >= 60% in the visible light region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared-reflective glass for use in windows of buildings and vehicles, and more particularly to an infrared-reflective glass which prevents the pearly appearance of such glass.

[0002]

2. Description of the Related Art In recent years, infrared reflecting glass has been adopted as window glass for buildings and vehicles in order to cut off radiant energy from the sun flowing into the room or inside the vehicle through the glass, and to reduce internal temperature rise and cooling load. Have been.

[0003] It is known that a conductive substance reflects infrared light. A transparent conductive film is formed on the surface of a glass substrate, and light having a wavelength longer than that of visible light can be obtained without reducing the transmittance of visible light. It has been done to reflect light. However, the glass having such a structure has a higher refractive index on the glass surface and has a thin film having a thickness of about 0.1 to 1 μm. Often appear, which impairs the aesthetics of glass. Therefore, various proposals have been made to prevent such glow.

[0004] For example, Japanese Patent Publication No. 63-39535 describes an achromatic glass structure, in which at least one transparent glass sheet and an infrared-reflective material placed on the sheet are used. In a structure including a first inorganic coating layer, wherein the infrared-reflective substance is a transparent semiconductor and is a type of substance that shows a glow in daylight illumination, the second coating layer is made of a glass sheet. A second coating layer disposed between the first coating layer and the second coating layer for reflecting and refracting light so as to substantially reduce the visibility of the first coating layer in daylight illumination. Providing a means for substantially reducing glow by providing at least two interfaces which form with the body of the second coating layer, wherein the second coating layer has a refractive index of the glass sheet and a first Defined as the square root of the product of the refractive index of the coating layer of To have Oriritsu, and a second coating layer is disclosed to have a thickness of 1/4 wavelength of light having a wavelength in vacuum of 500 nm.

[0005] Among them, for example, the second coating layer is 1.7
The first coating layer has a refractive index of 2, the glass sheet has a refractive index of 1.5, and the second coating layer has a refractive index of 1.5 to 1.8, and has a thickness of 64 to 80 nm. Is a metal oxide, a metal nitride or a mixture thereof,
₂ O ₃ , SiO ₂ , ZnO, MgO, SnO ₂ , In ₂ O ₃ ,
Being selected from the group consisting of GeO ₂ and Ga ₂ O ₃ , wherein the thickness of the semiconductor layer, for example, stannic oxide, is less than 0.4 μm, and the total thickness of the first coating layer and the second coating layer is 0.1
１1 μm and the like.

[0006] For example, Japanese Patent Publication No. 3-72586 describes a non-luminous glass structure.
(A) a transparent substrate, (b) an infrared-reflective transparent semiconductor coating having a thickness of 0.1 to 1.0 micron, and (c) a substrate and an infrared-reflective transparent semiconductor coating. An intermediate layer member that suppresses glow between
In a transparent sheet structure, the structure comprises a first intermediate layer component and a second intermediate layer component between the infrared-reflective transparent semiconductor coating and the transparent substrate, that is,
(1) close to the base material, and wherein ^{_{d 1 = (1/720) cos -1}} ((r 1 2 + r 2 2 -r 3 2) / 2
r ₁ r ₂₎ (wherein _{r 1 = (n 1 -n g} ) / (n 1 + n g), r 2 = (n 1
−n ₂ ) / (n ₁ + n ₂ ), r ₃ = (n _c −n ₂ ) / (n _c +
n _2), the refractive index of n _g = substrate, n ₁ = refractive index of the first intermediate layer components, n ₂ = refractive index of the second intermediate layer components, n _c = infrared reflective transparent semiconductor co - refraction Teingu (2) a first intermediate layer component having an optical thickness d ₁ given by (ratio) and (2) a relation between the first intermediate layer component and the semiconductor: d ₂ = (1/720) cos ⁻¹ (( _{^{r 2 2 + r 3 2 -r}} 1 2)
/ Second intermediate layer components having an optical thickness d ₂ given by 2r ₂ r _3), those containing intermediate layer consisting disclosed.

For example, Japanese Patent Laid-Open Publication No. Hei 3-164449 discloses an achromatic glass, and a high refractive index transparent glass having a refractive index n of 1.8 or more and a thickness d of 0.15 μm or more on a glass substrate. A thin film is formed, and a transparent underlayer film having n = 1.65 to 1.8 is formed between the high refractive index transparent thin film and the glass substrate to have an optical thickness nd of 0.1 to 0.18 μm. Achromatic glass, wherein the transparent lower layer film is made of Zr, T
It is disclosed that the film is composed mainly of a composite oxide containing at least one of i, Ta, Hf, Mo, W, Nb, Sn, La, and Cr and Si.

[0008] Among them, it is described that in the case of non-colored (colorless unevenness) glass, indium tin oxide, fluorine-doped tin oxide, zinc oxide and the like are used as the high refractive index transparent thin film.

For example, Japanese Patent Application Laid-Open No. Hei 4-270136 describes a method for producing a film composed of an oxide of aluminum and tin or titanium, and a product thereof, which comprises a non-hydrolyzable aluminum chelate, at least one organic tin compound, or Chitankire - bets and Chitan'arukora - DOO, a solution consisting of capital, by pyrolysis on a glass of high temperature, Al ₂ O ₃ -SnO ₂ (e.g. refractive index 1.66 to 1 .76) or Al ₂ O ₃ —TiO
₂ (e.g., refractive index 1.73 to 1.80) are disclosed to obtain a film of, between the glass substrate and the semiconductor metal oxide film (e.g., thickness 100 to 800 nm) of Al ₂ O ₃ - reflected light by using a SnO ₂ or Al ₂ O ₃ -TiO ₂ film (thickness, for example 80 to 100 nm) have been described to be obtained window glass with a semiconductor film is achromatic.

[0010] For example, Japanese Patent Application Laid-Open No. Hei 5-1166992 discloses an anti-glossy transparent body, in which a transparent thin film having a refractive index of 1.6 or more and a film thickness of 0.15 µm or more is formed on a transparent substrate. A transparent layer having an underlayer formed at the interface between the transparent thin film and the transparent substrate; the underlayer is an absorptive film having an extinction coefficient k other than 0; A transparent thin film having a thickness of not less than 1.6 and a thickness of not less than 0.15 [mu] m, and an anti-glue transparent body having an upper layer formed on the transparent thin film, wherein the upper layer is an absorbing film having an extinction coefficient k other than 0 A transparent thin film having a refractive index of 1.6 or more and a film thickness of 0.15 μm or more is formed on the transparent substrate, an underlayer is formed at an interface between the transparent thin film and the transparent substrate, and an upper layer is formed on the transparent thin film. An anti-glare transparent body with a stratum formed. k that are disclosed respectively the absorption of the film not zero. Among them, for example, the refractive index ng of the transparent substrate is 1.4 to 1.6, and the “transparent thin film” means that the extinction coefficient k is a small value (k = about 0), wherein the refractive index n
f is 1.6 to 2.3, specifically, ITO, SnO
₂ : F, ZnO: Al, ZnO and the like. Further, as the absorbent underlayer or upper layer, the film thickness is 10 to 50.
0 Å, a metal simple substance, a nitride, a carbide, or a composite thereof, preferably at least one of titanium, chromium, zirconium, a metal simple substance, a nitride, a carbide, or a composite thereof,
Specifically, TiN, CrN, CrC,
ZrN, TiN / Cr, TiN / Ti / T as underlayer
iN and Cr / TiN, Cr / ZrN, etc. as the upper layer are mentioned.

For example, Japanese Patent Application Laid-Open No. Hei 5-193994 discloses an anti-iridescent transparent fitting having an anti-iridescent coating which is tolerant to deviations in thickness and refractive index of the optically functional coating. Window glass article and Japanese Patent Laid-Open No. 5-19
Japanese Patent No. 3995 discloses an iridescent-prevention-coated transparent glazing article having a gradient refractive index and having an iridescent-preventing layer that is tolerable to variations in the thickness and refractive index of the iridescent-preventing layer and the optical functional layer Are respectively disclosed.

Further, for example, Japanese Patent Application Laid-Open No. 7-41337 discloses an anti-glossy transparent body, which has a transparent conductive film on a transparent substrate, and a base film between the transparent substrate and the transparent conductive film. In the transparent body, a mixed layer composed of the components of the transparent conductive film and the base film is interposed between the transparent conductive film and the base film, and the mixed layer is formed between the base film and the transparent conductive film. It is disclosed that the refractive index is formed so as to gradually increase from the side closer to the transparent conductive film to the side closer to the transparent conductive film.

Further, for example, Japanese Patent Application Laid-Open No. 7-10607
Discloses a glass article having a colorless coating giving a low emissivity and a method for producing the same, wherein the glass article having a colorless coating giving a low emissivity includes: a. A transparent substrate having a refractive index in the range of about 1.5 to 1.6; b. A first transparent coating layer having a refractive index in the range of about 1.66 to 1.73 and a thickness in the range of about 400 to 600 °; c. A second transparent coating layer having a refractive index in the range of about 1.76 to 1.83 and a thickness in the range of about 350 to 550 °; d. At least 1.86
A metal oxide coating layer having a thickness sufficient to lower the emissivity of the coated substrate below the refractive index of the uncoated substrate. I have.

[0014] In addition, in order to obtain at least non-gloss, at least an oxide film such as SiO _{2 is} coated as a base layer. Gazette, JP-A-5-294
672 and JP-A-4-265253.

[0015]

In any of the above non-light-colored glasses, there is provided a method for reducing the interference of visible light by providing a transparent conductive film formed on a glass substrate with a transparent film made of an inorganic material having a different composition. I am taking. These inorganic films are formed by physical means such as sputtering, ion plating, and vacuum deposition, or by thermally decomposing compounds such as metal alkoxides, metal chelates, and metal salts. Physical means have a lot of restrictions on equipment such as usually requiring a vacuum state, and there is a problem that high-temperature sintering is indispensable to obtain a stable oxide in the thermal decomposition method.

[0016]

Means for Solving the Problems The present inventors have proposed an achromatic infrared reflective glass comprising a transparent conductive film formed on glass and a second film having a different refractive index laminated thereon. After examining a method for forming a stable film at a relatively low temperature, which is industrially preferable, the second film was found to be obtained by coating a specific organic polymer on the outside of the transparent conductive film. Completed.

That is, according to the present invention, a transparent conductive film is provided on the glass surface and an external coating having a refractive index of 0.85 to 1.15 times the square root of the refractive index of the transparent conductive film is provided outside the transparent conductive film. An infrared reflective glass comprising an outer coating made of a fluorinated polyimide.

The glass according to the present invention is a soda lime glass, a borosilicate glass, an alkali-free glass, a quartz glass, etc., for example, a transparent colorless or colored plate glass, a green glass manufactured by a float method. And bronze glass, gray glass, blue glass and the like.

The infrared reflective glass of the present invention is a single plate, various types of double-glazed glass, laminated glass, glass with a shade band,
It can also be used as bilayer glass, tempered glass, or as a flat or bent plate. In addition, it goes without saying that it can be used in applications where a glass plate with an achromatic transparent conductive film is conventionally used, but in particular it is used for a multi-layer glass or the like, and specifically, a fluorine-containing polyimide is used on the inner side of the multi-layer glass or the like. It is mentioned as a preferable example that a film is arranged and used. The thickness of the single glass plate is, for example, preferably about 0.5 mm or more and about 10 mm or less, more preferably about 2.0 mm or more and about 5.0 mm.
Less than or equal.

The transparent conductive film according to the present invention is not particularly limited as long as it is substantially transparent in the visible light region.
A substance having a refractive index of 6 to 2.8, for example, ITO (In
₂ O ₃ + Sn dope) film (1.8 to 2.0), NESA
(SnO ₂ , SnO ₂ + Sb doped, SnO ₂ + F doped) film (1.85-2.1), AZO (zinc + Al ₂ O ₃₎
Dope) film (1.9 to 2.0), other ZnInO _4-x
Film, MgInO _4-x film, MgGaO _4-x film, SbInO
_4-x film, ZrGa ₂ O ₄ film, Cd ₂ SnO ₄ film, CdGa ₂ O
₄ film, CdSb ₂ O ₄ film, Zn ₄ InSbO ₄ based film, Sb ₂ Z
n ₇ O ₁₂ based film, ZnSb ₂ O ₆ based film, ZnO—Ga based film,
An MgIn ₂ O ₄ film, various metal fluoride films and the like can be mentioned, and an antimony-doped tin oxide film and a fluorine-doped tin oxide film can be mentioned as the most preferable ones. It is well known to those skilled in the art that the numerical values of the refractive index in the parentheses are typical values and vary depending on the forming method.

The method of forming these transparent conductive films is not particularly limited, and physical coating methods such as sputtering, reactive sputtering, vacuum deposition, and ion plating, chemical vapor deposition using an organometallic compound, and metal compounds And a chemical coating method such as a coating and baking method.

The thickness of the transparent conductive film is 80 nm to 800 nm.
An average visible light transmittance between about 0.38 μm and about 0.70 μm is about 70% or more;
The average infrared reflectance at a wavelength of about 10 μm is preferably about 60% or more, and more preferably about 70% or more.
It is desirable that the sheet resistance is low, but usually 1 to 100
Ω / □ is used, and preferably 10 to 50 Ω / □, for example, a transparent conductive film of about 10 to 20 Ω / □ is used.

The fluorine-containing polyimide film according to the present invention comprises:
The value is preferably the square root of the refractive index of the transparent conductive film, but a polyimide having a refractive index of 0.85 to 1.15 times that value in practical use may be used.
It is a polyimide of 45 to 1.70. Further, the fluorine-containing polyimide film according to the present invention is a substantially transparent film in a visible light region. Polyimide is often colored from yellow to brown, but substantially transparent means that when the infrared reflective glass of the present invention is prepared, a transmittance of 60% or more, more preferably about 70% or more, in the visible light region is obtained. If it is a rate, it is good. The fluorine-containing polyimide film according to the present invention has a thickness of 75
Outside the range of 150 nm, the phase shift between the reflected light on the fluorinated polyimide film surface and the reflected light on the lower surface (the upper surface of the transparent conductive film) is small, and it is not preferable because achromaticity due to cancellation by interference cannot be achieved. . The specific film thickness is the refractive index,
Although it can be determined by calculation based on optical constants such as reflectance and absorptance, it can be easily determined based on preliminary experiments.

The fluorine-containing polyimide according to the present invention has the following formula (1):

[0025]

Embedded image

(Wherein A represents a divalent organic group, B represents a tetravalent organic group, and at least one of A and B is a fluorine-containing organic group). In general, the organic group of A is introduced by a diamine, and the organic group of B is introduced by a tetracarboxylic acid.

As the divalent organic group A, the following formula (2):

[0028]

Embedded image

(In the formula, 1 is an integer of 3 to 7, and m is an integer of 1 to 8.) or a residue obtained by removing two amino groups from a diamine exemplified later. In this specification, structural units derived from a diamine component and a tetracarboxylic acid component will be described as those based on a diamine or a tetracarboxylic acid. Sex derivatives can be used.

The diamine according to the present invention is not particularly limited as long as it is a fluorine-containing amine.
1,3-bis (anilino) hexafluoropropane,
1,4-bis (anilino) octafluorobutane, 1,
5-bis (anilino) decafluoropentane, 1,7-
Bis (anilino) tetradecafluoroheptane, 2,2
-Bis (p-aminophenyl) hexafluoropropane, 2- (p-aminophenyl) -2- (m-aminophenyl) hexafluoropropane, tetrafluoro-p
-Phenylenediamine, tetrafluoro-m-phenylenediamine, 4,4'-bis (4-aminophenoxy)
Tetrafluorobenzene, 4,4′-bis (4-aminophenoxy) octafluorobiphenyl, 1,4-bis (3-aminophenoxy) tetrafluorobenzene,
4,4'-bis (3-aminophenoxy) octafluorobiphenyl, 2,2'-bis (trifluoromethyl)
-4,4'-diaminobiphenyl, 3,3'-bis (trifluoromethyl) -4,4'-diaminobiphenyl,
2,5-diaminobenzotrifluoride, 2,4-diaminobenzotrifluoride, 3,5-diaminobenzotrifluoride, 1,4-diamino-2-pentafluoroethylbenzene, 2,4-diamino-2-pentafluoroethylbenzene , 3,5-diamino-2-pentafluoroethylbenzene, 1,4-, 2,4- or 3,5-diamino-2-perfluoroalkylbenzene (a perfluoroalkyl group is a linear perfluoroalkyl group having 3 to 8 carbon atoms) Fluoroalkyl group and perfluoroisopropyl group.), 4,4'-diamino-2,2'3,3 ', 5
5 ', 6,6'-octafluorodiphenyl ether,
4,4′-diamino-2,2′3,3 ′, 5,5 ′,
6,6′-octafluorodiphenylmethane, bis (fluorinated alkoxy) -4,4′-diaminodiphenyl,
4,4'-bis (4-aminotetrafluorophenoxy) tetrafluorobenzene, 4,4'-bis (4-aminotetrafluorophenoxy) octafluorobiphenyl, 1,4-bis (3-aminotetrafluorophenoxy) tetra Fluorobenzene, 4,4'-bis (3-
Aminotetrafluorophenoxy) octafluorobiphenyl, 2,2-bis (4- (4-aminophenoxy)
Phenyl) hexafluoropropane, 2,2-bis (4
-(3-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (4-amino-2-trifluoromethylphenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (3- Amino-5-trifluoromethylphenoxy) phenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-methylphenyl)
Hexafluoropropane, 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl ether and the like can be mentioned. These can be used in combination. As the fluorinated diamine, an aromatic fluorinated diamine is preferable, and in particular, a hydrogen in an alkyl group is substituted by fluorine, a perfluoroalkyl group such as a trifluoromethyl group or a pentafluoroethyl group, or a fluoroalkyl group such as a trifluoroethyl group. Those in which a fluorine atom is introduced in the form of a group or the like are preferable. Examples of such are 2, 2 '
-Bis (trifluoromethyl) -4,4'-diaminobiphenyl and the like.

As the tetravalent organic group B, the following formula (3):
(Where n is an integer of 2-10, p is an integer of 0-2, q
Is an integer of 1 to 10. )

[0032]

Embedded image

Alternatively, there may be mentioned a residue obtained by removing four carboxyl groups from the tetracarboxylic acid exemplified later. The fluorinated tetracarboxylic acid according to the present invention is not particularly limited, but specifically, for example, 1-trifluoromethyl-2,3,5,6-tetracarboxylic acid, 1,4-bis (trifluoromethyl ) Tetracarboxylic acid, hexafluoroisopropylidene diphthalic acid, bis (2,2,2-
Trifluoroethyl) pyromellitic acid, 2,2,2-trifluoroethylpyromellitic acid, bis (1H, 1H-
Perfluorobutyl) pyromellitic acid, bis (1H, 1
H, 2H, 2H-perfluorooctyl) pyromellitic acid, (1H, 1H, 2H, 2H-perfluorododecylpyromellitic acid, 1,5-diphenoxydecafluoropentane-3 ′, 3 ″, 4 ′, 4 "-Tetracarboxylic acid,
9,9-bis (trifluoromethyl) xanthene-2,
3,6,7-tetracarboxylic acid and the like.

The fluorine-containing polyimide according to the present invention only needs to contain fluorine in the diamine structural unit or the tetracarboxylic acid structural unit, and either the diamine component or the tetracarboxylic acid component may not contain fluorine. In such a case, for example, as the diamine component, p-phenylenediamine,
m-phenylenediamine, o-phenylenediamine, o
-Toluidine, bis (4-diaminophenyl) ether, bis (4-diaminophenyl) methane, 2,2-bis (diaminophenyl) propane, bis (4-diaminophenyl) sulfone, etc. Examples include pyromellitic acid, isopropylidene diphthalic acid, oxydiphthalic acid, and benzophenonetetracarboxylic acid. Naturally, a fluorine-containing and fluorine-free diamine or a fluorine-containing and fluorine-free tetracarboxylic acid can be used in combination.

From the above-mentioned fluorinated diamine and fluorinated tetracarboxylic acid, a polyimide having a low refractive index is preferably obtained, and for example, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl A particularly preferred example is a polyimide obtained by polycondensing hexafluorodiphthalic dianhydride, di (1H, 1H-perfluorobutyl) pyromellitic dianhydride, and trifluoromethylpyromellitic acid. These polyimides generally have a refractive index of about 1.5, but the refractive index can be adjusted by substituting a diamine component and / or tetracarboxylic acid with another diamine or tetracarboxylic acid.

As the diamine component, those in which 1 mol% or more and 10 mol% or less of all diamine components are siloxydiamine are preferable because the adhesion to a substrate is improved when a coating film is formed. Such siloxydiamines are not particularly limited, but include 1,3-bis (3-aminopropyl) -1,1,2,2-tetramethyldisiloxane, 1,3-bis (3-aminobutyl) -1, 1,2,
Examples thereof include 2-tetramethyldisiloxane, bis (4-aminophenoxy) dimethylsilane, and 1,3-bis (4-aminophenoxy) tetramethyldisiloxane, and two or more of these can be used in combination.

The polyimide used in the present invention can be used by blending a maleimide compound. Among the maleimide compounds, bismaleimide is preferred, and particularly preferred are, for example, 2,2'-bis (4-maleimidophenyl) hexafluoropropane and 2,2'-bis (4- (4-maleimidophenoxy) phenyl) hexa Fluoropropane, 2,2'-bis (4- (2-trifluoromethyl-4-maleimidophenoxy) phenyl)
Fluorine-containing bismaleimides such as hexafluoropropane and 4,4′-bis (4-maleimidophenoxy) octafluorobiphenyl can be exemplified. Other usable bismaleimides include, for example, 4,4′-bismaleimidodiphenylmethane, , 4'-Bismaleimide diphenyl ether, 4,4'-Bismaleimidobenzanilide, 2,2'-bis (4- (4-maleimidophenoxy) phenyl) propane, and the like. It is also possible to use two or more of the above bismaleimides in combination.

Here, maleimide can also be used as a maleimide prepolymer, and the maleimide prepolymer is preferably a bismaleimide prepolymer such as bismaleimide alone, bismaleimide-diamine, bismaleimide-biscyanate or bismaleimide-biscyanamide. Especially fluorinated bismaleimide, fluorinated diamine,
1 of fluorinated biscyanate and fluorinated biscyanamide
Fluorine-containing maleimide prepolymers of two or more species are preferred.

The amount of the maleimide compound or maleimide prepolymer used is less than 30 parts by weight, preferably less than 20 parts by weight, based on 100 parts by weight of the resin solid content as the total amount of the tetracarboxylic acid component and the diamine component. . Up to 30 parts by weight, the adhesive effect appears with an increase in the amount of addition, but if it is more than 30 parts by weight, the adhesive effect is not particularly improved, and the mechanical properties of the formed film are undesirably reduced.

The addition of the maleimide compound in the polyimide precursor solution according to the present invention may be carried out by using a material other than metal,
For example, it is particularly effective in improving the adhesiveness to glass, ceramics, organic materials, and the like, but fluorine-containing bismaleimide having particularly high solubility is preferred from the viewpoints of increasing the concentration and forming a film.

The polyimide precursor composition of the present invention may contain an unsaturated compound such as a vinyl compound or an allyl compound, which is expected to have the same effect as the maleimide compound.

The fluorinated polyimide film according to the present invention comprises:
Polyamide acid, which is a polyimide precursor obtained by mixing and polymerizing the above diamine component and tetracarboxylic acid component and optionally the above maleimide compound at 10 to 100 ° C., or a solution of a polyimide obtained by condensation polymerization of the polyamic acid with a heating or dehydrating agent Is applied to a substrate, dried and / or baked.

As a solvent for polyimide or polyamic acid, N-methylpyrrolidone, dimethylacetamide,
Dimethylformamide, 1,3-dimethyl-3,4,
5,6-tetrahydro-2 (1H) -pyrimidinone,
Nitrogen-containing compounds such as 1,3-dimethyl-2-imidazolidinone, sulfur-containing compounds such as sulfolane and dimethylsulfoxide, γ-butyrolactone, α-methyl-γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ -Caprolactone, lactones such as ε-caprolactone, and the like.Other than these, carbonates such as ethylene carbonate and propylene carbonate, butyl acetate, ethyl cellosolve acetate, esters such as butyl cellosolve acetate, dibutyl ether,
Starting from ethers such as diethylene glycol dimethyl ether and triethylene glycol dimethyl ether, ketones such as methyl isobutyl ketone, cyclohexanone and acetophenone, alcohols such as butanol, octanol and ethyl cellosolve, as well as linear or cyclic amides, ureas and sulfoxides Systems, sulfones, hydrocarbons, halogen-based solvents, and the like can be added in a range that does not affect the stability of the polyamic acid solution or the polyimide precursor composition.

The fluorine-containing polyimide according to the present invention can also form a film by adding an ultraviolet absorber and / or a light stabilizer when forming a coating film.

[0045]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should not be construed that the invention is limited thereto.

[Measurement and Evaluation Methods] Optical properties: Visible light reflectance (380 nm to 780 n)
m), emissivity (ε) is JISZ8722 and JISR
It was measured with a 340-type self-recording spectrophotometer (manufactured by Hitachi, Ltd.) in accordance with 3106, and the intensity of the glow was visually observed.

Electrical characteristics: The surface resistance (Ω / □) was measured by a surface resistance meter (Loresta-AP) manufactured by Mitsubishi Yuka. Weather resistance: The appearance after 1000 hours was visually observed with a sunshine weatherometer.

Acid resistance: 0.1 N H ₂ SO ₄ at about 25 ° C.
After immersing the glass plate in the aqueous solution for 24 hours, the appearance was visually observed. Alkali resistance: The glass plate was immersed in a 0.1N NaOH aqueous solution at about 25 ° C. for 24 hours, and the appearance was visually observed.

Film thickness: The transparent conductive film was etched with an aqueous solution of caustic soda, the fluorine-containing polyimide film was scratched mechanically, and the level difference was measured with a surface roughness meter (DEKTAK30-30, manufactured by SLOAN).

Refractive index: Measured by an ellipsometer (DVA-36L, Mizojiri Optical Co., Ltd.). [Preparation example] Size of about 300 mm x 300 mm, thickness of about 3
mm soda-lime glass float glass plate (FL5)
Was washed sequentially with a neutral detergent, water rinse, and isopropyl alcohol, and dried to obtain a glass plate for coating.

Monobutyl trichlorotin [(C ₄ H ₉ ) S
nCl ₃ ] 100 g and ammonium fluoride 3 g
It was dissolved in a mixed solvent of 550 g of dichloromethane, about 300 g of ethanol, and about 50 g of pure water to make about 1000 g to prepare a coating solution.

The obtained coating solution was sprayed on the float glass plate which had been heated to about 550 ° C. in advance by a two-fluid spray gun at a coating amount of about 250 g / min for about 10 seconds. After cooling to room temperature, a tin oxide-coated glass plate having a fluorine-doped tin oxide film having a thickness of about 400 nm and a refractive index of about 2.0 was obtained.

The obtained tin oxide-coated glass plate had a sheet resistance of 18 Ω / □ and an emissivity of 0.18. Example 1 A four-neck separable flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen insertion tube was charged with 32.0 g.
g of 2,2′-bis (trifluoromethyl) -4,4 ′
-Diaminobiphenyl, 44.4 g of hexafluoroisopropylidene diphthalic dianhydride was charged, and 687.
6 g of dimethylacetamide was added, and the mixture was stirred at room temperature for 24 hours under a nitrogen stream to obtain a viscous transparent solution. Dimethylacetamide was further added thereto to prepare a 3% by weight polyimide precursor solution.

A polyimide precursor solution was applied to the previously prepared tin oxide-coated glass plate with a spin coater,
After evaporating the solvent with, the mixture was baked at 350 ° C. for 1 hour to obtain a colorless and transparent polyimide film having a thickness of 90.5 nm and a refractive index of 1.52.

The average reflectance of visible light of the obtained glass plate coated with a polyimide film was 6.5%, the reflection color tone was colorless and transparent, and the iridescent reflection color had disappeared. Note that the tin oxide-coated glass plate before coating with the polyimide film exhibited a strong rainbow-colored strong reflection color.

FIG. 1 shows a spectrum of reflectance (%) between wavelengths 380 to 780 (nm). No change was observed in any of the weather resistance, acid resistance, and alkali resistance tests.

Example 2 32.0 g of 2,2'-bis (trifluoromethyl) -4,4 'was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen insertion tube. -Diaminobiphenyl, 28.6 g of trifluoromethylpyromellitic dianhydride was charged, and 6
91.1 g of dimethylacetamide was added, and the mixture was stirred at room temperature for 24 hours under a nitrogen stream to obtain a viscous transparent solution. Dimethylacetamide was further added thereto to prepare a 3% by weight polyimide precursor solution.

A polyimide precursor solution was applied to the previously prepared tin oxide-coated glass plate by a spin coater,
After the solvent was volatilized, the mixture was baked at 350 ° C. for 1 hour to obtain a colorless and transparent polyimide film having a thickness of 88.3 nm and a refractive index of 1.49.

The average reflectance of visible light of the obtained glass plate coated with a polyimide film was 6.3%, the reflection color tone was colorless and transparent, and the iridescent reflection color had disappeared. No change was observed in any of the weather resistance, acid resistance, and alkali resistance tests.

Example 3 32.0 g of 2,2'-bis (trifluoromethyl) -4,4 'was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen insertion tube. -Diaminobiphenyl, 46.8 g of bis (1H, 1H-perfluorobutyl) pyromellitic dianhydride were charged, 691.1 g of dimethylacetamide was added, and the mixture was stirred at room temperature for 24 hours under a nitrogen stream to give a viscous solution. A solution was obtained. Dimethylacetamide was further added thereto to prepare a 3% by weight polyimide precursor solution.

A polyimide precursor solution was applied to the previously prepared tin oxide-coated glass plate by a spin coater,
After the solvent was volatilized, the mixture was baked at 350 ° C. for 1 hour to obtain a colorless and transparent polyimide film having a thickness of 89.1 nm and a refractive index of 1.47.

The average reflectance of visible light of the obtained glass plate coated with a polyimide film was 6.2%, the reflection color tone was colorless and transparent, and the iridescent reflection color had disappeared. No change was observed in any of the weather resistance, acid resistance, and alkali resistance tests.

Comparative Example 1 32.0 g of 2,2′-bis (trifluoromethyl) -4,4 ′ was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen insertion tube. -Diaminobiphenyl and 32.2 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride were added, 690.5 g of dimethylacetamide was added, and the mixture was stirred at room temperature for 24 hours under a nitrogen stream to give a viscous solution. A clear solution was obtained. Dimethylacetamide was further added thereto to prepare a 3% by weight polyimide precursor solution.

A polyimide precursor solution was applied to the previously prepared tin oxide-coated glass plate with a spin coater,
After the solvent was volatilized, the mixture was baked at 350 ° C. for 1 hour to obtain a transparent polyimide film having a thickness of 90.5 nm and a refractive index of 1.67.

The average reflectance of visible light of the obtained glass plate coated with a polyimide film was 9.5%, and the reflection color tone was iridescent. FIG. 1 shows a spectrum of reflectance (%) between wavelengths 380 to 780 (nm).

[Comparative Example 2] The polyimide precursor solution used in Example 1 was applied to the previously prepared tin oxide-coated glass plate by a spin coater, and the solvent was evaporated at 70 ° C. This was repeated and baked at 350 ° C. for 1 hour to obtain a colorless and transparent polyimide film having a thickness of 185.9 nm.

The average reflectance of visible light of the obtained glass plate coated with a polyimide film was 12.9%, and the color tone exhibited a unique strong iridescent reflection color. Wavelength 380-780 (nm)
FIG. 1 shows the spectrum of the reflectance (%) during the period between.

REFERENCE EXAMPLE As a reference example, the reflection spectra of a glass plate having no film formed thereon and a glass plate coated with only the tin oxide film prepared in the adjustment example are shown. The visible light reflectance was 8.2% and 13.8%, respectively.

[0069]

According to the present invention, the achromatic infrared reflective glass of the present invention does not exhibit the iridescent appearance peculiar to the infrared reflective glass as shown in the embodiment and FIG.
Moreover, since it has excellent weather resistance, it is useful as a window glass for architecture or vehicles.

[Brief description of the drawings]

FIG. 1 shows wavelengths of 380 to 780 for an infrared reflective glass of Example 1 of the present invention, a glass plate of a reference example, a glass plate coated with tin oxide, and an infrared reflective glass of each comparative example.
It is a diagram showing a spectrum of a reflectance (%) between (nm).

Claims (7)

[Claims] 1. A transparent conductive film on a glass surface and an outer surface of the transparent conductive film having a square root of a refractive index of 0.85 to 0.85.
1. An infrared reflecting glass provided with an external coating having a refractive index of 1.15 times, wherein the external coating is made of fluorine-containing polyimide. 2. The infrared reflecting glass according to claim 1, wherein the transparent conductive film has a refractive index of 1.6 to 2.8 and a thickness of 80 to 800 nm. 3. The film according to claim 1, wherein the transparent conductive film is a film made of a substance selected from indium tin oxide, antimony-doped tin oxide, fluorine-doped tin oxide, and aluminum-doped zinc oxide. Infrared reflective glass. 4. The infrared reflecting glass according to claim 1, wherein the transparent conductive film is a film made of antimony-doped tin oxide or fluorine-doped tin oxide. 5. The infrared reflecting glass according to claim 1, wherein the outer coating is made of a fluorine-containing polyimide having a refractive index of 1.45 to 1.70 and a thickness of 75 to 150 nm. 6. The polyimide according to claim 1, wherein the fluorinated polyimide is a polyimide having a structural unit derived from 2,2′-bis (trifluoromethyl) -4,4′-diaminodiphenyl. Infrared reflective glass. 7. A polyimide comprising a structural unit derived from 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl and a structural unit derived from hexafluoroisopropylidene diphthalic acid. The infrared reflective glass according to claim 1, wherein: