JPS629417B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a selective light-transmitting laminate in which a metal thin film layer and a titanium oxide thin film layer are laminated on a transparent molded substrate, such as a transparent organic polymer film, and a method for manufacturing the same. More particularly, the present invention relates to an improved laminate having a thin titanium oxide layer chemically formed from an organic titanium compound such as an alkyl titanate, and a method for manufacturing the same. In general, in a laminate in which a transparent high refractive index dielectric layer is laminated or sandwiched between a conductive metal thin film such as gold, silver, copper, palladium, or some alloy thereof, the film of each component thin film is It is known that by controlling the thickness, light in a specific wavelength range can be selectively reflected. In particular, a laminate that selectively reflects infrared wavelength regions is important as a heat ray reflective film from the viewpoint of energy saving in houses and the like and utilization of solar energy. Examples of such a laminate include Bi ₂ O ₃ /Au/Bi ₂ O ₃ , ZnS/
Laminated bodies such as Ag/ZnS and TiO ₂ /Ag/TiO ₂ have been proposed, and conventionally these films have been formed by vacuum evaporation, reactive evaporation, or sputtering. However, although physical methods such as vacuum evaporation and sputtering are effective in forming metal thin films, they are not effective in forming metal oxide thin films.
There are often problems with industrial productivity and adhesion with organic substrates. As a solution to this problem, the present inventors have already proposed a method in which a transparent high refractive index dielectric layer is formed from an organometallic compound by chemical means. That is, to give a typical example, a titanium oxide thin film layer with a high refractive index can be formed by applying an organic solvent solution of alkyl titanate onto a substrate and treating it at a relatively low temperature, and this can be combined with a vapor-deposited metal thin film layer. By combining them, it has become possible to economically produce a TiO ₂ /Ag/TiO ₂ three-layer laminate with an infrared reflectance of 95% or more (10μ) and a visible light (500mμ) transmittance of 75% or more. Moreover, since the processing temperature is low, it is also possible to use an organic polymer (for example, film) substrate such as polyethylene terephthalate as a substrate, and by forming a laminate continuously on the film, it is extremely economical. It became possible to obtain a laminate with good performance. Although the above method is an extremely excellent method, the selective light transmitting laminate formed by this method cannot be said to be perfect and may have insufficient durability depending on the usage conditions. There is. According to research conducted by the present inventors, this drawback in durability was caused by the interaction between the titanium oxide thin film layer and the metal thin film layer. That is, as mentioned above, a laminated structure formed by sandwiching, for example, a silver thin film layer with a titanium oxide thin film layer formed by hydrolyzing an alkyl titanate at a relatively low temperature, will deteriorate during use. Its selective light transmittance, ie, infrared reflectivity and visible transmittance, decrease. This is because silver atoms and titanium atoms diffuse into each other, changing from a clear three-layer structure to an indefinite structure. In order to suppress this phenomenon, the present inventor changed the metal layer from silver alone to an alloy such as a silver-copper alloy or a silver-gold alloy, or added a silver sulfide layer by applying an active sulfur compound to the silver thin film layer. Various methods have been tried to directly change the metal layer, such as by intervening the metal layer. At the same time, in forming a titanium oxide thin film layer, an attempt was made to form a special titanium oxide thin film by adding an organosilicon compound such as an alkyl silicate to alkyl titanate. Although such a method was effective to some extent and could improve the durability of the laminate, as an industrial production method, further improvement was required due to the complexity of the operation, and the durability could be improved. Further improvements were desired. As a result of intensive research to achieve the above object, the present inventor surprisingly found that once a three-dimensional film of titanium oxide is formed, if a moist heat treatment is performed under limited conditions, an extremely excellent laminate can be formed. The present invention was achieved by discovering that it can be made into a titanium oxide thin film. That is, the present invention includes sequentially forming a titanium oxide thin film layer (B), a metal thin film layer containing silver and/or gold as a main component (C), and a titanium oxide thin film layer (D) on at least one side of a transparent molded substrate (A). In the method of laminating to form a selective light transmitting laminate, the titanium oxide thin film layer (B) and/or (D) is
Immediately after the alkyl titanate solution is applied and heat treated to form the layer, or after all layers have been laminated, or after a further protective layer has been laminated, contact treatment with hot water is performed to ensure that the layer is This is a method for producing a selective light transmitting laminate, characterized in that it contains 0.1% to 6.5% by weight of organic groups as measured by specified analysis method B. According to the present invention, it is surprisingly possible to prevent the interaction between the metal thin film layer and the titanium oxide thin film layer by extremely simple means,
The criticality of the interface between both layers can be maintained for a long period of time, making it possible to maintain the desired selective light transmission ability for a long period of time. Furthermore, since the amount of residual organic groups is controlled to a preferable value, excellent effects can be exhibited in terms of adhesiveness, optical properties, and other properties. The components (A), (B), (C), and (D) of the present invention, the protective layer, and the contact treatment with high temperature water will be described in detail below. The transparent molded substrate (A) is a transparent substrate made of inorganic, organic, or a mixture thereof, and preferably a transparent molded substrate containing an organic polymer as a component, particularly an organic polymer film. Any organic polymer film may be used as long as it can withstand the processing conditions of the present invention, but in consideration of practical performance such as coatability, dimensional stability, and durability, polyethylene terephthalate film and the like are preferred. Polyester film, nylon film, polycarbonate film, polyethylene film, polypropylene film, etc. are preferably used. Titanium oxide thin film layers (B) and (D) in the method of the present invention
is provided by using a solution of a solute containing an alkyl titanate as a main component, usually an organic solvent solution. The alkyl group of the tetraalkyl titanate used is not particularly limited and includes ethyl, propyl, isopropyl, butyl, 2-ethylhexyl, stearyl, and the like, among which propyl and butyl are preferably used. These are usually used as tetraalkyl titanates or condensates thereof. These condensates are obtained by condensing two or more tetraalkyl titanates. For example, the expression [However, in the formula, R represents an alkyl group, and m is a positive integer. ] It is a compound represented by the following or a mixture thereof, and from the viewpoint of ease of handling, m is preferably 10 or less. In particular, dimers, tetramers, decamers, etc. of tetra-n-butyl titanate and tetrapropyl titanate are preferably used from the viewpoint of coatability. Moreover, these condensates may be obtained by any method. The titanium oxide thin film according to the present invention can be formed by dissolving a predetermined amount of the alkyl titanate in a solvent, applying a solution obtained on the molded substrate, drying it, and heat-treating the solution. When used in a coating solution, the solvent should have solubility with the solute, evaporability (preferably boiling point below 150°C), inertness (does not react with the solute and deactivate the three-dimensional reticulation reaction), etc. It is sufficient if the conditions are met. Particularly preferred are hydrocarbons such as n-heptane, cyclohexane, toluene, and xylene, general-purpose solvents such as ethyl alcohol, isopropyl alcohol, and butanol, and mixed solvents thereof. In the present invention, as described above, water plays an effective role in promoting three-dimensional reticulation of the coating film. In order to make the hot water or hot water treatment more effective, a small amount of water may be added to the coating solution in advance. In addition, in order to obtain stability of the coating solution, acetylacetone, acetone acetate, diacetone alcohol, lactic acid, glycolic acid, etc. should be added to the above solution.
-It is also effective to add a known chelating agent such as oxyacid. Particularly when the alcoholic solvent contains a small amount of water, the addition of the above-mentioned chelating agent is particularly effective in suppressing hydrolysis of the coating solution and improving coating properties and storage stability. The coating method is not particularly limited and may be a general method, that is, a solution diluted with a solvent may be applied, or a general coating method such as a dipping method, a spray method, a spinner method, or a machine coating method such as gravure coating may be applied as is. I can do it. In addition, in the present invention, titanium oxide thin film layer (B) or (D)
Either one of them may be laminated by, for example, low-temperature sputtering or electron beam evaporation, in addition to the chemical coating method using alkyl titanate. In addition, in the present invention, in order to improve the heat resistance and practicality of the selectively transparent coating, alkyl silicates, alkoxysilanes, silicon compounds such as silane coupling agents, thiourea, etc. are added to the alkyl titanate coating solution. A small amount may be added. In the present invention, the titanium oxide thin film layer is subjected to a contact treatment with high-temperature water, which will be described later, at an appropriate stage, with or without other layers such as a protective layer, so that the titanium oxide thin film layer is not finally formed. The amount of organic matter contained in the titanium oxide layer is controlled to an extremely small amount. The content of such organic matter can be determined by the extraction method, i.e., hydrochloric acid.
The amount is hardly detected by the method of extracting with an alcohol aqueous solution and quantifying the extract by the mass fragment method (see below), but the amount is hardly detected by the EMX method,
That is, according to a method in which carbon atoms in a titanium oxide film formed as a model on aluminum foil are quantified using an X-ray microanalyzer and converted (see below), the amount is only slightly detectable. Therefore, the titanium oxide thin film layer (B) and/or (D) in the present invention has an organic content of 0.1% to 6.5% by weight, preferably 0.5% to 3.5% by weight based on the titanium oxide thin film when analyzed by EMX method. %, particularly preferably from 1.0% to 3.0% by weight. Here, the organic substance means the group R when the alkyl titanate is represented by the above formula. Metal thin film layer used in the laminated film of the present invention
The material (C) consists of a metal whose main component is silver and/or gold. That is, silver or gold may be used alone, an alloy of silver and gold, or an alloy of silver and/or gold with other metals. These metals exhibit high visible light transmittance and infrared light reflectivity, and provide excellent selective light transmittance. Metals other than silver and gold are added to further enhance the above properties or to improve light resistance, heat resistance, color tone, etc. Specifically, for example, copper, aluminum, nickel, palladium, platinum, indium, Examples include tin and cadmium. In particular, combinations of silver-copper, silver-platinum, and gold-platinum are preferably used. The content of the third component is in the range of 1 to 20% by weight, preferably 1 to 15% by weight. The thickness of the metal thin film is not particularly limited as long as it has the required characteristics as a selective light transmission film, but in order to have infrared light reflecting ability, it is necessary to have continuity in at least a certain area. It is. The film thickness is preferably about 40 Å or more as it gives a continuous structure rather than an island structure, and it is preferably 600 Å or less in terms of transparency to solar energy. The thinner the metal thin film layer, the wider the light transmission area, so in order to increase transparency, it is necessary to
A film thickness of 50 Å or more is preferable in order to provide sufficient conductivity or infrared light reflecting ability. The metal thin film layer (A) can be formed by, for example, a vacuum evaporation method, a magnetron sputtering method, a plasma spraying method, a vapor phase plating method, a chemical plating method, or a combination thereof. The vacuum deposition method is particularly suitable from the viewpoints of uniformity, ease of production, and film formation speed. Unlike the case of compounds, vacuum evaporation of metals does not pose any industrial problems. In the present invention, the protective layer (E) used is for protecting the titanium oxide thin film layer on the surface from external mechanical stimulation, ultraviolet rays, etc. Therefore, the type of coating is not particularly limited, but general protective coatings such as polyacrylate paints, saturated polyester paints, ethylene-vinyl acetate copolymer paints, polystyrene paints, polyvinyl formals, polyvinyl butyral paints, polyvinyl chloride paints, etc. , poly(vinyl acetate-vinyl chloride)-based paints, poly(vinyl chloride-vinylidene chloride)-based paints, cellulose-based paints, thermoplastic paints such as epoxy-based paints, polyfunctional polyacrylate-based paints, melamine-based paints, etc. be done. The thickness of the protective layer is not particularly limited, but generally
A range of 0.05μ to 10μ, preferably 0.1μ to 5μ is used. If it is more than that, the protective layer will absorb infrared rays, reducing the heat ray reflection ability, and if it is less than that, it will not exhibit wear resistance and will not fulfill its original role as a protective layer, which is not preferable. Also, although it depends on the refractive index of the protective layer, the range of about 0.5μ to 1.3μ is the so-called interference film thickness, and it may be avoided depending on the purpose because a rainbow-colored interference pattern will occur when exposed to visible light. It's better to The hot water or hot water treatment used in the present invention refers to immersing the selectively transparent laminated film in hot water or hot water before or after providing the protective layer. The temperature of the hot or hot water is 40°C to 100°C, preferably 50°C to 95°C, particularly preferably 70°C to 90°C. If the temperature is lower than that, the hot water treatment effect will be small. This is thought to be because the hydrolysis reaction and reticulation reaction of the alkyl titanate are exceeded, resulting in an imbalance. A high temperature is better for the reaction to proceed. However, when the water is close to boiling, the conditions are severe and the treatment time must be controlled in order to peel off the titanium oxide thin film layer. In that sense, 50℃~95℃ is preferable, and 70℃~
90°C is particularly preferred. The processing time depends on the processing temperature, the presence or absence of a protective layer, and the film thickness. Of course, the higher the treatment temperature, the shorter the treatment time. The more a protective layer is provided and the thicker the protective layer is, the longer the processing time will be. Processing time is 1 second to 100 hours, preferably 2 seconds to
It will take place over a period of 70 hours. The following is a suitable processing time when considering the processing temperature and the presence or absence of a protective layer. 40 when processing without a protective layer
~70℃ for 30 minutes to 1 hour, 70 to 90℃ for 10 minutes to 30 minutes,
Preferably, the temperature is 90 to 100°C for 1 to 10 minutes. If using a protective layer, heat at 40-70℃ for 30 minutes to 2 hours, 70-90℃
The process is carried out for 10 minutes to 1 hour at 90 to 100°C for 5 minutes to 30 minutes. In the present invention, heating may be performed after hot water or hot water treatment, and this heat treatment has the meaning of drying the film after treatment and promoting and completing reticulation. The processing temperature is generally 50 to 200°C, preferably 60 to 150°C, although it depends on the film being handled. The selective light transmitting laminate thus obtained has excellent heat resistance and light resistance, and can be used advantageously for heat ray reflection applications, as well as applications utilizing its conductivity, such as electrodes for liquid crystal displays and electrodes for electroluminescent materials. It is also used in fields such as electronics, such as electrodes for photoconductive photoreceptors, antistatic layers, and surface heating elements. In the present invention, a method for quantifying the amount of organic residue contained in a titanium oxide layer formed from an organic titanium compound will be briefly described below. The analysis method (A) is a method using a chemical extraction method and a gas chromatograph mass spectrometer, and the analysis method (B) is a method using an X-ray microanalyzer and an elemental analysis method. Analysis method A A 100 cm ² molded product in which the TBT layer in the laminate of the present invention is formed on both sides of a polyethylene terephthalate film is made into a small piece approximately 2 to 3 mm square, and this is mixed with 1000 parts by weight of water, ethyl The organic components were sufficiently extracted by immersion in 5 ml of a solution prepared by mixing 20 parts by weight of alcohol and 1 part by weight of hydrochloric acid at room temperature for 24 hours.
The ions were determined by mass fragment graphing using a glass column with a diameter of 3 mm and a length of 3 m filled with 30 parts by weight of PEG20 (60 to 80 mesh). Analysis method B Organic residual amount determination method using X-ray microanalyzer method (EMX method) A TBT layer (titanium oxide layer from tetrabutyl titanate) constituting each laminate of the present invention is placed on an aluminum foil with a purity of 99.9% and a thickness of 50μ. ) were formed in the same manner as in each example. The amounts of carbon atoms (C) and titanium atoms (Ti) contained in the obtained TBT layer were determined as respective counts by the EMX method, and the intensity ratio C/Ti was calculated. On the other hand, the following formula [However, R is

Represents [formula]. ] Using the compound represented by (1) as a standard substance, a chloroform solution of this compound was applied on aluminum foil and dried, and the resulting thin film was analyzed by EMX method.
The Ti intensity ratio and the C/Ti weight % ratio were determined by elemental analysis. Furthermore, using a sputtered TiO ₂ thin film as the reference material (2), the C/Ti intensity ratio by EMX method and the C/Ti weight % ratio by elemental analysis were determined in the same manner as above. Thus, with these two points
A calibration curve (straight line) was created to determine the relationship between the C/Ti intensity ratio determined by the EMX method and the C/Ti weight % ratio determined by elemental analysis. The residual amount of organic matter in the laminate of the present invention can be calculated as the residual amount of butyl groups by determining the C/Ti weight % ratio by elemental analysis using this calibration curve from the C/Ti intensity ratio determined by the EMX method. can. The present invention will be specifically explained below with reference to Examples. Examples 1 to 28 A biaxially stretched polyethylene terephthalate film with a light transmittance of 86% and a film thickness of 50 μm was used as a transparent molded substrate.
(A), (B) a titanium oxide thin film layer with a thickness of 280 Å, and (C) a thin film layer of a silver and copper alloy with a thickness of 170°C (92% silver, 8% copper) Titanium oxide thin film layers with a thickness of 280 Å were sequentially laminated as the (D) layer to obtain a laminate having selective light transmittance. The titanium oxide thin film layers (B) and (D) were each formed by applying a solution consisting of 3 parts of tetrabutyl titanate and 97 parts of isopropyl alcohol using a bar coater and heating at 120°C for 3 minutes. This layer is hereinafter abbreviated as TBT layer. The metal thin film layer was formed by vacuum evaporation using a resistance heating method using a silver-copper alloy (70% silver, 30% copper). The content of butyl groups contained in the TBT layer was determined by the mass fragment graphics method (mass No. 56) to be 4.5.
It was %. The visible light transmittance (0.5μ) of the obtained film is
The infrared reflectance of 4μ, 6μ and 10μ was 98%, 97% and 98%, respectively. The film thus obtained was treated with hot water. Hydrothermal treatment involves placing the body in hot water set at a temperature of 80℃ for 10 seconds.
This was achieved by leaving it in for a selected time from 1 minute, 10 minutes, 30 minutes, or 60 minutes. In addition, either before or after this treatment, the following organic resins (a) acrylate resin [Mitsubishi Rayon Co., Ltd.]
DIANAL LR574], (b) Hexakis[2-acryloyloxy-2-methylethyl]melamine (hereinafter abbreviated as NMA), (c) Pentaerythritol tetraacrylate (tetramethylol methane tetraacrylate) (hereinafter abbreviated as A・TMMT) was applied with a spinner or bar coater to a thickness of 0.2μ or 2μ to form a protective layer. These organic resin films have a film thickness of 0.2μ.
LR574 When using a methyl isobutyl ketone solution containing 1% by weight, a methyl isobutyl ketone solution containing 2% by weight of NMA, or a methyl isobutyl ketone solution containing 2% by weight of A-TMMT, and the film thickness is 2μ, use LR574.
20% by weight methyl isobutyl ketone solution, A-
A methyl isobutyl ketone solution containing 40% by weight of TMMT or a methyl isobutylketone solution containing 40% by weight of NMA was applied and dried to obtain a desired film thickness. The thus obtained laminate was placed in a hot air dryer set at 90°C to perform a heat resistance deterioration acceleration test, and the time until the 10μ infrared light reflectance reached 85% of the initial value was recorded. These treatment conditions and results are summarized in Table 1.
Further, the results of Examples 3 and 5 are shown in FIG. 1, and compared to Comparative Example 1, etc., the effect of improving heat resistance by moist heat treatment is remarkable.

[Table] In addition, the sample used in Example 5 and the sample used in Comparative Example 1, which will be described later, were compared after deterioration (Example 5 was 90%
℃ 1500 hours elapsed, comparative example 1 90℃ 500 hours elapsed)
ESCA (Electron Spectroscopy for Chemical
Table 1-(2) shows the results of the display analysis using ``Analysis''.

[Table] Examples 29 to 40 The selectively transparent laminates having the polyester film/TBT/Ag.Cu/TBT structure used in Examples 1 to 20 were prepared in exactly the same manner as in Examples 1 to 20. The obtained film was subjected to moist heat treatment under various conditions, and at that time, LR574 acrylate resin was applied to a predetermined thickness to form a protective layer before or after the treatment. Characteristic evaluation was performed in the same manner as in Example 1. The results of various hot water treatment conditions and characteristic evaluation are shown in Table 2-(1) and Table 2-
(2).

【table】

[Table] Examples 41 to 44 A laminate having selective light transmittance was obtained in exactly the same manner as in Example 1, except that the metal layer thin film (layer (C)) was composed only of silver. The metal layer thin film was vacuum-deposited using a resistance heating method using silver as a deposition source to form a thin film layer with a thickness of 180 Å. The optical properties of the obtained laminate were as follows: visible light transmittance (0.5μ): 80%; infrared light reflectance: 97%, 96%, and 96% at 4μ, 6μ, and 10μ, respectively. This laminate was subjected to hot water treatment by immersing it in hot water set at a temperature of 95℃, and LR574 was applied to a film thickness of 0.2μ either before or after the hot water treatment.
A heat resistance deterioration acceleration test was conducted at 90°C until the infrared light reflectance decreased to 85% or less, and the deterioration time was measured. These results are shown in Table 3.

[Table] Examples 45 to 48 A laminate having selective light transmittance was obtained in exactly the same manner as in Example 1, except that the metal thin film layer (C) was composed of a metal layer in which gold and silver coexisted. Ta. The metal thin film layer in which gold and silver coexist was formed as a 165 Å thick metal thin film containing 8% gold by magnetron sputtering using a gold-silver alloy containing 8% gold as a target. The optical properties of the obtained laminate are as follows: visible light transmittance (0.5μ) is 79%, and infrared light reflectance is 4μ, 6μ, and 10μ.
They were 98%, 98%, and 98%, respectively. The obtained laminates were treated with hot water in the same manner as in Examples 41 to 44, and the heat resistance was evaluated. Table 4 shows the results.

[Table] Examples 49 to 52 Selective light transmittance was obtained in exactly the same manner as in Example 1, except that an organic silicon compound [X12・917 Shin-Etsu Silicone Co., Ltd.] was added to the titanium oxide layer (D) layer. A laminate having the following properties was obtained. The titanium oxide layer containing an organic silicon compound contains 3 parts of a tetramer of tetrabutyl titanate,
A solution consisting of 3 parts of X12.917, 2 parts of acetylacetone, and 92 parts of isopropanol was coated with a bar coater and heated at 120°C for 5 minutes. The optical properties of the obtained laminate were 73% in visible light transmittance (0.5μ) and 93%, 95%, and 95% in infrared light reflectance at 4μ, 6μ, and 10μ, respectively. The thus obtained laminates were treated with hot water in the same manner as in Examples 41 to 44, and the heat resistance was evaluated. Table 5 shows the results.

[Table] Comparative Examples 1 to 8 Examples 1, 41, and 8 of the laminates with selective light transmittance listed in Examples 1 to 52
45. Laminated polyethylene terephthalate film listed below used in Example 49/
TBT/Ag・Cu/TBT Polyethylene terephthalate film/
TBT/Ag/TBT Polyethylene terephthalate film/
TBT/Ag・Au/TBT polyethylene terephthalate film/
Apply LR574 to TBT/Ag・Cu/TBT+×12・917 with a film thickness of 0.2 μ or A・
TMMT was coated to a film thickness of 0.2μ, placed in a hot air dryer set at 90℃, and a heat resistance deterioration acceleration test was performed. The properties are listed in Table 6. Further, the results of Comparative Example 1 are shown in FIG.

[Table] Comparative Examples 9 to 12 Laminated polyethylene terephthalate films taken up in Comparative Examples 1 to 4/
TBT/Ag・Cu/TBT Polyethylene terephthalate film/
TBT/Ag/TBT Polyethylene terephthalate film/
TBT/Ag・Au/TBT polyethylene terephthalate film/
After coating TBT/Ag・Cu/TBT＋×12・917 with LR574 to a film thickness of 0.2μ, 20
After soaking in water at ℃ for 60 minutes, taking it out and air drying, put it in a hot air dryer set at 90℃ and perform a heat resistance deterioration acceleration test. The characteristics were measured as time and are listed in Table 7.

[Table] Examples 53 to 56 The tetrabutyl titanate solution used to construct the laminate of Example 1 was applied onto the polyethylene terephthalate film used in Example 1 in the same manner as in Example 1, and dried to form a film. A titanium oxide layer with a thickness of 50 Å was obtained. This film was treated with hot water under the conditions shown in Table 8, and the organic residues remaining in the titanium oxide layer were quantified by analytical method (A) and analytical method (B) and expressed in weight %. The results are shown in Table 8.

【table】 [Brief explanation of the drawing]

Figure 1 shows the results of a heat resistance accelerated deterioration test at 90°C. The vertical axis is the infrared light reflectance R (%) at 10μ
, and the horizontal axis is the elapsed time (time). In the figure, symbol A means the result of Comparative Example 1, symbol B means the result of Example 3, and symbol C means the result of Example 5.

Claims (1)

[Claims] 1 A titanium oxide thin film layer (B), a metal thin film layer containing silver and/or gold as a main component (C), and a titanium oxide thin film layer (D) are sequentially laminated on at least one side of a transparent molded substrate (A). In the method of forming a selectively transparent laminate, the titanium oxide thin film layer (B) and/or (D) is
Immediately after the alkyl titanate solution is applied and heat treated to form the layer, or after all layers have been deposited, or after a further protective layer has been deposited, contact treatment with hot water is performed to ensure that the layer is 1. A method for producing a selectively transparent laminate, characterized in that it contains 0.1% to 6.5% by weight of organic groups as measured by specified analytical method B.