JP2002309157A - Infrared light-shielding coating for transparent base material, and coating film-forming method and transparent base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared light-shielding coating for a transparent base material which gives a coating film having a high transmittance in the visible light region, excellent in infrared light-shielding properties and exhibiting excellent performances such as adhesion and the like. SOLUTION: The infrared light-shielding coating for a transparent base material comprises (A) a resin composition containing (A-1) an acrylic resin bearing a hydroxy group with a number-average molecular weight of 1,000-50,000 and (A-2) a tetrafunctional silicon compound represented by the general formula (1) (wherein R is the same of different from each other and is a 1-10C alkyl or alkoxyalkyl group; and n is an integer of 1-20) and/or a condensate thereof, and (B) a tin-containing indium oxide having a primary particle size of 0.01-0.1 μm, where the solid content weight ratio of (A-1) the acrylic resin to (A-2) the tetrafunctional silicon compound and/or a condensate thereof is 10/1-1/3 and the solid content weight ratio of (A) the resin composition to (B) the tin- containing indium oxide is 100/0.5-100/20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared shielding paint for a transparent substrate, and more particularly, to an effect of lowering the internal temperature by shielding infrared rays by applying it to the surface of a transparent substrate such as glass or plastic. There is an infrared shielding paint.

[0002]

2. Description of the Related Art General windows of buildings and buildings, roof materials and wall materials of solariums, and glass of automobiles are constantly exposed to sunlight. There is a need to suppress a rise in temperature and the like, and therefore, development of a paint that blocks sunlight, particularly infrared rays, is desired.
On the other hand, these paints also require visibility inside and outside the room through windows and glass, and therefore are required to have high transmittance in the visible light region.

[0003] Materials having an infrared shielding function and having high transmittance in the visible light region include tin-containing indium oxide (ITO), aluminum-added zinc oxide (AZO), titanium oxide, zinc oxide, cerium oxide, ruthenium oxide. And the like are known.

Japanese Patent Application Laid-Open No. 7-70363 discloses an infrared cut-off film comprising a tin-doped indium oxide powder and an organic resin soluble or dispersible in an organic solvent in a non-alcoholic organic solvent. A forming material is disclosed. JP-A-7-70445 and JP-A-7-70
No. 482 discloses an infrared cutoff film forming material comprising a tin-doped indium oxide powder and a binder soluble or dispersible in water and / or alcohol in water and / or alcohol. It has been disclosed. These include tin-containing indium oxide (ITO), sunlight,
In particular, it has been shown to have an excellent shielding function in the infrared region.

Japanese Patent Application Laid-Open No. 8-41441 discloses a tin-containing indium oxide capable of simultaneously shielding ultraviolet rays and near-infrared rays with a high shielding power and controlling radio wave transmission. 01-0.05 μm, tin content is 1
~ 15% by weight, powder color 20 <Y <50, 0.25 <x
<0.3, 0.25 <y <0.32, dust resistance is 0.0
A tin-containing indium oxide having a density of 5 to 0.5 Ω · cm is disclosed.

[0006] Japanese Patent Application Laid-Open No. 10-120946 discloses that a hydrate of tin oxide and indium oxide obtained by adding an aqueous alkali solution to a solution of a tin salt and an indium salt while maintaining the temperature at 30 ° C. or less is insoluble. An infrared shielding material containing a tin-containing indium oxide fine powder obtained by heat treatment in an active gas atmosphere or a reducing gas atmosphere, a paint binder and a solvent is disclosed. Since the tin-containing indium oxide fine powder has a uniform particle size that does not include coarse particles, a coating film having excellent transparency and infrared shielding properties can be obtained.

[0007] All of the above techniques devise tin-containing indium oxide to improve the transparency and infrared shielding properties of the resulting coating film. However, no consideration has been given to the binder in the paint, and there has been a demand for the development of a paint that is excellent in transparency and infrared shielding properties and also excellent in coating properties such as adhesion and durability.

[0008]

SUMMARY OF THE INVENTION In view of the above situation, the present invention provides a coating composition having a high transmittance in the visible light region, excellent infrared shielding properties, and excellent properties such as adhesion and durability. It is an object of the present invention to provide an infrared shielding paint for a transparent substrate from which a film can be obtained.

[0009]

Means for Solving the Problems The present inventors have prepared a resin composition (A) containing a specific acrylic resin (A-1) and a tetrafunctional silicon compound and / or a condensate thereof (A-2). ,
By using in combination with tin-containing indium oxide (B) having a primary particle size of 0.01 μm to 0.1 μm at a fixed content, when applied to a transparent substrate, the transmittance in the visible light region is high, The inventors have found that it is possible to obtain a coating film having excellent infrared shielding properties and excellent performances such as adhesion and durability, and completed the present invention.

That is, according to the present invention, the number average molecular weight is 1000
Acrylic resin having a hydroxyl group of up to 50,000 (A-
1) and the general formula:

[0011]

Embedded image

(Wherein R is the same or different and is an alkyl group or alkoxyalkyl group having 1 to 10 carbon atoms, and n represents an integer of 1 to 20), and / or Resin composition (A) containing condensate (A-2), and primary particle diameter of 0.01 μm or more
An infrared shielding paint for a transparent substrate, comprising 0.1 μm of tin-containing indium oxide (B), wherein the acrylic resin (A-
The solid content weight ratio of 1) to the tetrafunctional silicon compound and / or its condensate (A-2) is 10/1 to 1/3, and the resin composition (A) and the tin-containing indium oxide are used. The solid content weight ratio with (B) is 100 / 0.5 to 100 /
20 is an infrared shielding paint for a transparent substrate, characterized in that it is 20. The acrylic resin (A-1) has a hydroxyl value of 1
It is preferably from 0 to 200. Further, it is preferable that the acrylic resin (A-1) further has an alkoxysilyl group. The present invention is also a method for forming a coating film, comprising a step of applying the infrared shielding paint for a transparent substrate to a transparent substrate. The present invention is also a transparent substrate having a coating film formed by the above coating film forming method. Hereinafter, the present invention will be described in detail.

The infrared shielding paint for a transparent substrate of the present invention contains the resin composition (A). The resin composition (A) contains the acrylic resin (A-1) as a binder resin. The acrylic resin (A-1) is
The number average molecular weight is 1,000 to 50,000. If the number average molecular weight is less than 1000, the strength of the obtained coating film may be insufficient, and if it exceeds 50,000,
Not only is the handling of the resin difficult, but also the compatibility with the later-described tetrafunctional silicon compound and / or its condensate (A-2) is reduced, resulting in separation or formation of a microdomain structure inside the obtained membrane. The durability of the resulting coating film may be reduced.

The acrylic resin (A-1) has a hydroxyl group. By having a hydroxyl group, a tetrafunctional silicon compound and / or a condensate thereof (A-
2) can be prevented from being separated inside the film and the strength, durability and the like of the coating film obtained by imparting curability can be improved.

The acrylic resin (A-1) preferably has a hydroxyl value of 10 to 200. If it is less than 10, the curability will be insufficient, and the durability of the obtained coating film may decrease. If it exceeds 200, the water resistance and durability of the obtained coating film may decrease. More preferably, it is 20 to 150.

The acrylic resin (A-1) preferably further has an alkoxysilyl group. By having the alkoxysilyl group, the curability can be enhanced, and the durability of the coating film can be further improved. Further, the adhesion to the transparent substrate can be improved.

When the acrylic resin (A-1) has an alkoxysilyl group, the alkoxysilyl value is preferably from 5 to 600. If it is less than 5, the curability will be insufficient, and the durability of the resulting coating film may be reduced. If it exceeds 600, the flexibility of the obtained coating film may be reduced. More preferably, it is 25 to 300. In the present specification, the alkoxysilyl value is
It means the number of mg of potassium hydroxide having the same mole as the alkoxyl group bonded to the silicon atom contained in 1 g of the resin solid content.

The method for obtaining the acrylic resin (A-1) includes a hydroxyl-containing monomer having an unsaturated double bond,
If necessary, a method of polymerizing by an ordinary method using an alkoxysilyl group-containing monomer having an unsaturated double bond and another monomer having an unsaturated double bond as a raw material can be used.

Examples of the hydroxyl group-containing monomer having an unsaturated double bond include 2-hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. Examples of the silyl group-containing monomer include γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth)
Acryloxypropyltriethoxysilane and the like can be mentioned. Examples of the other monomer having an unsaturated double bond include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, )
(Meth) acrylic acid alkyl esters such as n-hexyl acrylate; styrene, α-methylstyrene dimer and the like. Examples of the above-mentioned hydroxyl group-containing monomer having an unsaturated double bond, an alkoxysilyl group-containing monomer having an unsaturated double bond, if necessary, and other monomers having an unsaturated double bond include esters of (meth) acrylic acid. When using, it is preferable that the carbon number of the ester part is 1-20. These may be used alone or in combination of two or more. The acrylic resin (A-1) may be used alone or in combination of two or more.

The resin composition (A) comprises a tetrafunctional silicon compound represented by the above general formula and / or a condensate thereof (A
-2). The tetrafunctional silicon compound and / or its condensate (A-2) reacts with a hydroxyl group contained in the acrylic resin (A-1) and contributes to curing of a coating film. In the above general formula, R is the same or different and is an alkyl group or alkoxyalkyl group having 1 to 10 carbon atoms, and from the viewpoint of stability and hydrolyzability, is an alkyl group or alkoxyalkyl group having 1 to 6 carbon atoms. Is preferred. If the number of carbon atoms exceeds 10, the stability of the paint may be reduced, or the adhesion to the transparent substrate may be reduced. N is an integer of 1 to 20. When the above n exceeds 20, the stability of the coating material may be reduced or the adhesion to the transparent substrate may be reduced. In the present specification, the tetrafunctional silicon compound is a silicon compound having four curable functional groups.

Examples of the tetrafunctional silicon compound and / or its condensate (A-2) include MKC silicate MS-51 (R is a methyl group, average value of n = 5), MKC silicate
Silicate MS-56 (R is a methyl group, average value of n is 1
0) (all manufactured by Mitsubishi Chemical Corporation); ethyl silicate 40
Commercial products such as (R is ethyl group, average value of n is 5) and ethyl silicate 48 (R is ethyl group, average value of n is 10) (all manufactured by Colcoat Co., Ltd.) can be used. The above tetrafunctional silicon compound and / or its condensate (A-2) may be used alone or in combination of two or more.

In the present invention, the acrylic resin (A-
The weight ratio of the solid content of 1) to the tetrafunctional silicon compound and / or its condensate (A-2) is from 10/1 to 1/3. When the amount of the acrylic resin (A-1) is less than this range, the performance such as chemical resistance and the adhesion to the transparent base material are reduced, and the flexibility of the coating film is reduced to cause cracks. If the amount of the acrylic resin (A-1) is too large, the adhesion to the transparent substrate may be poor. In addition, the solid content weight of the tetrafunctional silicon compound and / or its condensate (A-2) in the present specification means the weight of the active ingredient before the hydrolysis occurs.

The infrared shielding paint for a transparent substrate of the present invention contains tin-containing indium oxide (B). Tin-containing indium oxide (B) has a function of shielding infrared rays.
The tin-containing indium oxide (B) has a primary particle size of 0.1.
It is from 01 μm to 0.1 μm. When the thickness is less than 0.01 μm, coagulation is strong, a dispersed state cannot be obtained, and the dispersing step may be hindered.
If it exceeds μm, the transparency to visible light, that is, transparency may be impaired.

In the tin-containing indium oxide (B), the tin doping amount in the powder is preferably such that the molar ratio of Sn / (Sn + In) is 0.01 to 0.15, more preferably 0.04 to 0.15. 0.12.

The method for producing the tin-containing indium oxide (B) is described in JP-A-7-70363 and JP-A-7-70363.
It can be manufactured according to a conventional method described in JP-A-70445, JP-A-7-70482, JP-A-8-41441 and the like. That is, for example, In and a small amount of S
An aqueous solution containing a water-soluble salt of n is reacted with an alkali to co-precipitate a hydroxide of In and Sn, and using this co-precipitate as a raw material,
It is manufactured by heating and baking it in the air to convert it to an oxide. As a raw material, a mixture of a hydroxide and / or an oxide of In and Sn can be used instead of a coprecipitate.

As the tin-containing indium oxide (B), the color tone of the powder has an x value of 0.220 to 0.2 on the xy chromaticity diagram.
295, y value is in the range of 0.235 to 0.325,
It is also possible to use a crystal having a characteristic in which the lattice constant of the crystal is in the range of 10.110 to 10.160 °. By using such tin-containing indium oxide, infrared rays in a region of 1200 nm or less, particularly 1000 nm or less can be cut. Such a tin-containing indium oxide is fired in a pressurized inert gas instead of heating and firing in the air in the above-described production method, or a tin-containing indium oxide powder obtained by firing in the air. Is heat-treated in a pressurized inert gas.

Further, as described in JP-A-10-120946, a solution of tin salt and indium salt is obtained by adding an aqueous alkali solution such as aqueous ammonia while maintaining the temperature at 30 ° C. or lower. Primary particles having a uniform particle size and no coarse particles, obtained by subjecting the hydrated tin oxide and indium oxide hydrates to a heat treatment in an inert gas atmosphere or a reducing gas atmosphere.
It is also possible to use a tin-containing indium oxide fine powder of about 5 μm. In the present invention, a commercially available tin-containing indium oxide powder as a conductive powder can be used as it is. The above-mentioned tin-containing indium oxide (B)
May be used alone or in combination of two or more.

In the present invention, the weight ratio of the solid content of the resin composition (A) and the tin-containing indium oxide (B) is as follows:
100 / 0.5 to 100/20. If the ratio of the tin-containing indium oxide (B) is less than the above range, the infrared ray shielding property is poor, and if it exceeds the above range, the light transmittance of the formed coating film is reduced and the transparency is lost.

The infrared shielding paint for a transparent substrate of the present invention may further contain a curing catalyst. The curing catalyst is used as the tetrafunctional silicon compound and / or a condensate thereof (A-
The hydrolysis of 2) can be promoted, and the adhesion to the transparent substrate can be improved.

Examples of the curing catalyst include organic tin compounds such as dibutyltin laurate, dibutyltin octate, dibutyltin acetate, and dioctyltin laurate; inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid and boric acid;
Organic acids such as acetic acid, formic acid, maleic acid and benzoic acid; phosphoric esters such as monomethyl phosphate; organic titanium compounds such as tetrabutyl titanate and tetrabutoxy titanate; γ-aminopropyltrimethoxysilane;
silane coupling agents such as β-aminoethyl-γ-aminopropyltrimethoxysilane and γ-ureidopropyltriethoxysilane; tris (acetylacetonate)
Organic aluminum compounds such as aluminum and tris (ethylacetoacetate) aluminum; organic zirconium compounds such as tetrabutyl zirconate and butoxytris (acetylacetonate) zirconium; amines such as ethylenediamine, diethylenetriamine, diethanolamine; sodium hydroxide, water Inorganic bases such as potassium oxide; and epoxy compounds.

When the above-mentioned catalyst is contained, its content is defined as 100 parts by weight of the total resin solid content of the above-mentioned acrylic resin (A-1) and the above-mentioned tetrafunctional silicon compound and / or its condensate (A-2). On the other hand, the solid content is preferably 0.01 to 30 parts by weight. If the amount is less than 0.01 part by weight, the effect of improving the hydrolysis is not sufficient, and the durability of the obtained coating film may be reduced. If the amount is more than 30 parts by weight, the adhesion to the transparent substrate is reduced. However, the durability of the coating film may decrease, or the resulting coating film may become cloudy and the finish may deteriorate.

As the solvent, the acrylic resin (A
-1) Any substance capable of dissolving and dispersing a tetrafunctional silicon compound and / or a condensate thereof (A-2) and a tin-containing indium oxide (B) can be used, and methanol, ethanol, n-propanol, i-propanol, n-
Alcohols such as butanol and cyclohexanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; ethers such as methyl cellosolve and ethyl cellosolve; esters such as ethyl acetate and methyl cellosolve acetate; hexane, cyclohexane, toluene and xylene. be able to. The proportion of the solvent used is not particularly limited, and may be set according to the purpose of use. In consideration of dispersion, viscosity, etc., the solid content in the coating material is 5 to 50% by weight, preferably 10 to 20% by weight. You can do so. The method for preparing the infrared shielding paint for a transparent substrate of the present invention is carried out by mixing the above components with a commonly used ball mill, sand mill, paint shaker, three rolls or the like.

The infrared shielding paint for a transparent substrate prepared as described above can be suitably used for a transparent substrate. That is, a coating film forming method including a step of applying the above-mentioned infrared shielding paint for a transparent substrate to a transparent substrate is also one of the present invention.

The coating method is not particularly limited, and examples thereof include a brush coating method, a roller method, a spray method, a bar coating method, a dipping method, and a doctor blade method. Here, among the above application methods,
A roller method is preferable, and a roller method of short hair is more preferable. Then, after coating by this method, it is preferable to remove excess paint with a screver to form a uniform coating film. In conventional brush coating as in the past, the applied paint sagged or the thickness of the applied film varied depending on the applied part, and it was difficult to form a uniform coating film on the entire transparent substrate. The method, particularly the short-haired roller method, is suitable for the present invention since such inconvenience does not occur.

After being applied to the transparent substrate, a coating film can be formed by drying and, if desired, heat treatment. The dry film thickness is not particularly limited.
It is 5 to 50 μm, preferably 1 to 5 μm. The drying can be performed by leaving or heating at 20 to 100 ° C. for 10 minutes to 5 hours.

In the present specification, the term “transparent substrate” is a concept that includes not only a completely colorless and transparent substrate but also a colored and transparent substrate whose inside can be seen through. The transparent substrate is not particularly limited, and includes a substrate composed of an inorganic substance such as glass or an organic substance such as plastic, for example, a general window of a building or a building, a window glass of an automobile, a sunroof, Examples include optical fibers, PET (polyethylene terephthalate) bottles, packaging films, sun visors, glasses, and the like.

The transparent substrate may be coated with a primer in advance, and the infrared shielding paint for a transparent substrate of the present invention can be applied thereon as a clear paint.
It is also possible to apply the infrared shielding paint for a transparent substrate of the present invention as a primer to a transparent substrate, and then overcoat a clear paint thereon. Further, the infrared shielding paint for a transparent substrate of the present invention may be used as a primer and a clear paint, and a coating film may be provided on a lower layer and / or an upper layer thereof as desired.

The infrared shielding paint for a transparent substrate of the present invention comprises a resin composition (A) containing the acrylic resin (A-1) and the tetrafunctional silicon compound and / or a condensate thereof (A-2); Since it contains the above-mentioned tin-containing indium oxide (B), it has excellent physical properties such as curability of the paint, adhesion of the obtained coating film to the transparent substrate, durability, water resistance, flexibility and chemical resistance. And has excellent transmittance in the visible light region and excellent shielding properties against infrared rays. A transparent substrate having a coating film formed by the above coating film forming method is also one of the present invention.

The above-mentioned infrared rays include not only a normal infrared region but also a near infrared region of 750 nm to 2.5 μm,
And a far-infrared region of 20 to 100 μm, and the shielding region is changed by changing the type of the tin-containing indium oxide (B) depending on the application to which the infrared-shielding coating material for a transparent substrate of the present invention is applied. You can choose.
The infrared shielding paint for a transparent substrate of the present invention has a function of suppressing transmission of infrared rays and absorbing heat, and contributes to lowering the perceived temperature inside the transparent substrate.

[0040]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Parts represent parts by weight. Production Example 1 Preparation of Acrylic Resin Having Hydroxyl Group In a reaction vessel, 10 parts of γ-methacryloxypropyltrimethoxysilane, 5 parts of 2-hydroxyethyl methacrylate, 17.5 parts of methyl methacrylate, and 10 parts of n-butyl acrylate 7.5 parts of styrene, 47 parts of xylene, t-butylperoxy-2
-Ethylhexanoate (3 parts) was polymerized by a conventional method to synthesize an acrylic resin having a hydroxyl group. The obtained resin had a solid content of 50% by weight, a glass transition temperature of 35 ° C., an alkoxysilyl value of 135, a hydroxyl value of 48, and a number average molecular weight of 10
000.

Examples 1 and 2, Comparative Examples 1 and 2 Hydroxyl-containing acrylic resin 100 obtained in Production Example 1
Parts by weight, MKC methyl silicate MS-56 (tetramethyl silicate partial hydrolyzate condensate manufactured by Mitsubishi Chemical Corporation, n
= 10) 50 parts by weight, 1 part by weight of dibutyltin laurate, 700 parts by weight of xylene, and 150 parts by weight of isopropyl alcohol are mixed and stirred to obtain a solid content of 10% by weight.
Was prepared. Using a paint obtained by mixing tin-containing indium oxide (X-Iol dispersion, solid content concentration: 10% by weight, primary particle diameter: 0.01 to 0.05 μm, manufactured by C-I Kasei Co., Ltd.) with the varnish, apply isopropyl alcohol to the surface. Washed glass (100 mm x 150 mm x
2.0mm) on one side with a hand roller.
After drying at 60 ° C. for 5 minutes, a glass test piece having a dry film thickness of 5 μm was obtained. The amount of tin-containing indium oxide added was as shown in Table 1, and an acrylic resin having a hydroxyl group and MKC were used.
It was shown by the amount (% by weight) based on the total solid content of methyl silicate MS-56. In Comparative Example 2, only a glass test piece without any coating was used.

The obtained glass test plate was evaluated according to the following method. The results are shown in Table 1. 1. Infrared shielding test The glass test piece was evaluated for heat shielding property using a test apparatus 8 shown in FIG. 1 in which a black vinyl chloride sheet 5 having a thickness of 150 μm was adhered to the inside of a polystyrene foam to form a black box. As shown in FIG. 1, the test piece 1 is placed on the upper surface of a styrofoam box 2 so that the coating film faces upward, and the test piece 1 is irradiated with an incandescent lamp 3 provided above the test piece 1, After 30 minutes and 30 minutes, the temperature was measured. The temperature is measured at two points: the back surface temperature of the test piece 1 and the internal temperature of the styrofoam box 2 (position 7 cm from the lid 4).
The temperature was measured by the temperature sensors 9 and 10 installed respectively, and the measured temperature was recorded by a recorder.

The styrofoam box 2 has a thickness of 25 mm and dimensions (outer dimensions) of 200 mm × 170 mm ×
The thing of 170 mm was used. The lid 4 has a thickness of 7 mm
Then, a test piece 1 was set in the center of the hole using a hole of 80 mm × 130 mm opened in the center. The distance 7 between the test piece 1 and the incandescent lamp 3 was 150 mm.

As the recorder, a thermo recorder R is used.
Incandescent lamp 3 using T-10 (manufactured by Tabai Espec)
Used a Toshiba reflex lamp 150W (for indoor use; manufactured by Toshiba Corporation) which can be turned on by the power supply 6. Also,
The test was carried out in a constant temperature room at 20 ° C. without any wind.

2. Pencil hardness test Using the test pieces of Example 1, Example 2 and Comparative example 1, scratches were evaluated with Mitsubishi Uni pencil.

3. Durability test 3-1. Example 1 and Example 2 and Comparative Example 1 in boiling water
Was immersed for 3 hours, taken out, taken out, and made into 100 squares with a grid of 2 mm width, and subjected to a peeling test with cellophane tape (Nichiban). In addition, the coating film which did not peel was shown as 100/100.

3-2. Moisture Resistance Test Under the conditions of 50 ° C. and 95% humidity, the test pieces of Examples 1, 2 and Comparative Example 1 were left for 30 days, taken out, and taken out.
100 squares were formed on a grid of m width, and a peeling test was performed using cellophane tape (Nichiban). In addition, the coating film which did not peel was shown as 100/100.

3-3. Freeze-thaw resistance test Using the test pieces of Example 1, Example 2 and Comparative Example 1, A
The test was performed according to the STM-B method. That is, -20 ° C ×
After conducting a test of 300 cycles with 3 hours at 10 ° C. × 3 hours as one cycle, 100 squares were made with a grid of 2 mm width, and a peeling test was carried out with cellophane tape (Nichiban). In addition, the coating film which did not peel was 100/100
Displayed.

[0049]

[Table 1]

4. Measurement of Spectral Transmittance Spectral transmittance was measured using the glass test pieces obtained in Example 1 and Comparative Example 1. The measurement is a spectrophotometer (U-3500 spectrophotometer, manufactured by Hitachi, Ltd.)
Using, scan speed: 600 nm / min, sampling interval: automatic setting, slit (visible): fixed 2 m
m, slit (near infrared 700 to 2100 nm): automatic control, Pbs sensitivity: 2, photometric voltage: automatic control, standard plate: barium sulfate. FIG. 2 shows the result of the spectral transmittance.

As shown in Table 1, in Examples 1 and 2, the temperature of the glass test piece increased from those of Comparative Example 2 using a glass test piece without any coating and Comparative Example 1 in which no tin-containing indium oxide was added. And endothermic. In Examples 1 and 2, the temperature inside the test box was clearly reduced. This is because the glass test piece obtained in Example 1 was obtained from FIG.
It can be seen that the internal temperature decreased due to good absorption of light in the infrared region.

[0052]

The infrared shielding paint for a transparent substrate of the present invention comprises:
Since it contains the acrylic resin (A-1) and the resin composition (A) containing the tetrafunctional silicon compound and / or the condensate thereof (A-2), and the tin-containing indium oxide (B), the paint Curability, adhesion of the resulting coating film to the transparent substrate, durability, water resistance, flexibility, excellent properties such as chemical resistance, and excellent transmittance in the visible light region, Excellent shielding properties against infrared rays. Therefore, the infrared shielding paint for a transparent substrate of the present invention can be suitably applied to a transparent substrate intended to shield infrared rays.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an apparatus for evaluating the heat shielding properties of glass test pieces obtained in Examples and Comparative Examples.

FIG. 2 is a graph of the spectral transmittance at a wavelength of 350 to 2100 nm of the glass test pieces obtained in Example 1 and Comparative Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass test piece 2 Styrofoam box 3 Incandescent lamp 4 Styrofoam box lid 5 Black vinyl chloride sheet 6 Power supply 7 Distance between glass test piece and incandescent lamp 8 Thermal barrier test device 9, 10 Temperature sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 7/02 103 B32B 7/02 103 27/30 27/30 A C09D 5/33 C09D 5/33 183 / 02 183/02 C09K 3/00 105 C09K 3/00 105 (72) Inventor Koichi Inoue 19-17 Ikedanakamachi, Neyagawa-shi, Osaka Within Nippon Paint Co., Ltd. (72) Inventor Katsuo Miki Amanuma-cho, Omiya-shi, Saitama 2-Chome 809-4 F-term (reference) 4D075 AC29 CB01 CB06 DA06 DB13 EB22 EB42 EB52 EC02 EC53 4F100 AA33A AK25A AK52A AL05A AR00B BA02 CC00A GB07 GB32 JA07A JD10 JN01B YY00A 4J031 CC021 CH032 DL122 HA216 KA04 KA06 MA12 MA14 NA01 NA03 NA04 NA12 NA19 PB01 PB04 PB05 PB07 PC03 PC08

Claims (6)

[Claims] An acrylic resin having a hydroxyl group having a number average molecular weight of 1,000 to 50,000 (A-1), and
General formula: Wherein R is the same or different and is an alkyl group or an alkoxyalkyl group having 1 to 10 carbon atoms, and n is 1 to 2
A resin composition (A) containing a tetrafunctional silicon compound represented by the following formula:
And an infrared shielding paint for a transparent substrate containing a tin-containing indium oxide (B) having a primary particle diameter of 0.01 μm to 0.1 μm, wherein the acrylic resin (A-1) and the tetrafunctional silicon compound and / or Alternatively, the solid content weight ratio with the condensate (A-2) is 10/1 to 1/3, and the solid content weight ratio of the resin composition (A) and the tin-containing indium oxide (B) is , 100 / 0.5 to 100/20. 2. The hydroxyl value of the acrylic resin (A-1) is:
The infrared shielding paint for a transparent substrate according to claim 1, which is 10 to 200. 3. The infrared shielding paint for a transparent substrate according to claim 1, wherein the acrylic resin (A-1) further has an alkoxysilyl group. 4. A method for forming a coating film, comprising a step of applying the infrared shielding paint for a transparent substrate according to claim 1, 2 or 3 to a transparent substrate. 5. The method according to claim 4, wherein the coating is performed using a short-haired roller. 6. A transparent substrate having a coating film formed by the method of claim 4 or 5.