JP2001311049A - Heat radiation-shielding coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat radiation-shielding coating containing a black pigment capable of obtaining a coating film having excellent radiation-shielding properties. SOLUTION: This heat radiation shielding coating composition contains a black pigment having >=8.0% solar radiation reflectance in 780-2,100 nm wave length region and the black pigment may have <=15% reflectance at any wave length in a visible light region of 400-700 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray shielding paint which can be applied to a roof and an outer wall of a building, a vehicle, a ship, a plant, a shed, a barn and the like.

[0002]

2. Description of the Related Art Paints having various colors are used for various structures such as roofs of buildings. However, carbon black usually used as a black pigment for producing various hues easily absorbs solar energy. For this reason, in structures where a coating film obtained from a paint containing carbon black is installed, the internal temperature must be raised, which not only impairs the comfort of living spaces and the storability of articles, but also reduces air conditioning. It consumes a huge amount of energy.

[0003] JP-A-1-121371 and JP-A-1-261466 each disclose the use of various metal oxide and composite oxide pigments as solar heat shielding pigments. In order to obtain carbon black, conventional carbon black must be used, and the heat ray shielding effect is small. Japanese Patent Application Laid-Open No. 2-185572 proposes a composite oxide pigment as a black pigment. However, the solar reflectance of this pigment is less than 8%, and the heat ray shielding effect is small.

On the other hand, Japanese Patent No. 2593968 and Japanese Patent Application Laid-Open No. 05-293434 disclose red, orange, yellow, green, blue, and blue, which have high solar radiation reflectance in the ultraviolet and near infrared regions.
There has been proposed a solar heat-shielding black paint composition which is colored achromatic black by mixing a purple chromatic pigment. However, there has been a problem that a part of the coloring pigment is deteriorated due to long-term use, the color balance is lost, and the color is easily discolored.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat ray shielding paint containing a black pigment, which can provide a coating film having excellent heat ray shielding performance.

[0006]

The heat ray shielding coating composition of the present invention contains a black pigment having a solar reflectance of 8.0% or more in a wavelength range of 780 to 2100 nm.

It is preferable that the black pigment has a reflectance of 15% or less at any wavelength from 400 to 700 nm in the visible region. The black pigment is Fe ₂ O ₃ , Cr ₂ O ₃ and / or Mn.
A calcined pigment containing 20 to 100% by weight of ₂ O ₃ may be used.

[0008] The heat ray shielding coating composition may contain the black pigment in an amount of 0.1% by weight or more. In addition, the above black pigment accounts for 0.5% by weight in all the pigment components.
It is preferable that it is contained above.

The heat ray shielding coating composition preferably contains a polyester resin, an acrylic resin, a fluorine resin or a chlorine resin as a binder component, and further contains a melamine resin and / or a blocked isocyanate as required. You may. Further, the heat ray shielding plate of the present invention is coated with the above heat ray shielding paint composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The heat ray shielding coating composition of the present invention comprises:
It contains a black pigment having a solar reflectance of 8.0% or more in a wavelength range of 780 to 2100 nm.

The black pigment used in the above-mentioned heat ray shielding paint has a solar reflectance of 8.0% or more, preferably 1% or more.
5.0% or more. The solar reflectance is JIS A 575
9 is the reflectance described in FIG.
The reflectance is weighted according to the intensity of each wavelength in the wavelength range of 0 nm. If the solar reflectance is less than 8.0%, sufficient heat ray shielding properties cannot be obtained, and when the paint is applied to a roof or an outer wall of a building, a vehicle, a ship, a plant, a shed, a barn, etc., the internal temperature is reduced. Cannot be sufficiently reduced.

Here, the black pigment refers to a pigment whose appearance looks from black to brown. Black pigment having a solar reflectance as described above, the Fe ₂ O _3, Cr ₂ O ₃ and / or Mn ₂ shall O ₃ and which is a fired inorganic pigments containing 20 to 100% by weight being preferred. That is, this calcined pigment contains Fe ₂ O ₃ as an essential component, and contains Cr ₂ O ₃ and M
characterized in that it contains at least one of n ₂ O ₃ , and the baked pigment contains 20 to 100% by weight, preferably 30 to 100% by weight of these components in total. . When the content is less than 20% by weight, the heat ray shielding performance may not be sufficiently exhibited.

Here, the calcined pigment is usually at 600 ° C.
It is manufactured by crushing after firing as described above. The heat ray shielding coating composition of the present invention contains the above-mentioned black pigment as an essential component. However, in order to meet the hue, intended use, required performance, and the like of the target coating material, the extender pigment is used as another coloring pigment and other pigment. Or a pigment containing a brilliant pigment. In that case, the black pigment was added to the coating composition in an amount of 0.1%.
It is preferred that the content be at least 10 wt%. If the amount is less than 0.1% by weight, the heat ray shielding performance may not be sufficiently exhibited. In addition, the above-mentioned black pigment is preferably contained in all the pigment components in an amount of 0.5% by weight or more, and the larger the content, the more the difference in the heat shielding performance can be increased as compared with the conventional paint of the same hue. . If the amount is less than 0.5% by weight, the same hue may not be able to sufficiently exhibit the shielding performance.

The heat ray shielding coating composition of the present invention may contain a coloring pigment other than the above black pigment and other pigments. The coloring pigment is used for adjusting the hue of the paint, and includes an organic coloring pigment and an inorganic coloring pigment. Organic color pigments include phthalocyanine, azo, condensed azo, anthraquinone, perinone / perylene, indigo / thioindigo, isoindolinone, azomethineazo, dioxazine, quinacridone, aniline black, triphenyl Methane-based and the like, as inorganic color pigments, titanium oxide-based, iron oxide-based, iron hydroxide-based, chromium oxide-based, spinel type fired pigment,
Examples thereof include lead chromate, permilion chromate, navy blue, aluminum powder, and bronze powder.

Examples of the extender include calcium carbonate, barium sulfate, silicon oxide, and aluminum hydroxide. Further, organic crosslinked particles and inorganic particles can also be blended as extenders.

On the other hand, examples of the glitter pigment include mica pigments, aluminum foil, tin foil, gold foil, silver foil, titanium gold foil, stainless steel foil, and metal foil pigments such as nickel and copper.

The type and form of the heat ray shielding coating composition of the present invention are not particularly limited, and examples thereof include thermosetting coatings, thermoplastic coatings, room temperature drying coatings, room temperature curing coatings, and active energy ray curing coatings. It can also be used in the form of paint such as solvent-based paint, water-based paint, non-aqueous emulsion-type paint,
Any of a solventless paint, a powder paint and the like may be used.

The coating composition of the present invention comprises, for example, an acrylic resin, an alkyd resin, a polyester resin, a silicone-modified polyester resin, a silicone-modified acrylic resin, an epoxy resin, a polycarbonate resin, a silicate resin, a fluorine-based resin, and a chlorine-based resin as binder components. It may contain a resin or the like. Among these, a polyester resin, an acrylic resin, a fluororesin or a chlorine-based resin is preferable.

Further, if necessary, the curing agent may contain an amino resin such as a melamine resin, a crosslinking resin such as an isocyanate or a block isocyanate.
The heat ray shielding coating composition of the present invention may contain a particulate filler, an additive, a solvent, and the like, if necessary.

The particulate filler is not particularly restricted but includes, for example, SiO ₂ , TiO ₂ , Al ₂ O ₃ , Cr _{2
O 3, ZrO 2, Al 2} O 3 · SiO 2, 3Al 2 O 3 · 2S
Examples thereof include fine particles made of iO ₂ , zirconia silicate, and the like, and fibrous or granular fine glass.

The additives are not particularly restricted but include, for example, matting agents such as silica and alumina, defoaming agents, leveling agents, anti-dripping agents, surface conditioners, viscosity adjusters, dispersants,
Conventional additives such as ultraviolet absorbers and waxes can be used.

The solvent is not particularly limited as long as it is generally used for paints. For example, toluene, xylene, Solvesso 100, Solvesso 15
Aromatic hydrocarbons such as 0; esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone; and water. These are appropriately selected in consideration of solubility, evaporation rate, safety, and the like. They are,
They may be used alone or in combination of two or more.

The heat ray shielding paint of the present invention contains a black pigment having a solar reflectance in consideration of the intensity of each wavelength in sunlight as described above, and has a wavelength of 780 to 2100 nm as a heat source in the sunlight. Since it effectively reflects near-infrared rays in the region, it can exert an excellent effect particularly as a solar heat shielding paint.

The coating composition of the present invention can be produced, for example, as follows. Using a machine generally used for dispersing pigments such as a roller mill, paint shaker, pot mill, disper, sand grind mill, etc., the pigment is mixed with a pigment dispersing resin to prepare a pigment dispersing paste, and the above binder is prepared. By adding a melamine resin and / or a blocked isocyanate, an additive, a solvent and the like, a coating composition can be obtained.

The coating method of the above-mentioned coating composition is not particularly limited. Coating method. These are appropriately selected according to the purpose of use of the base material.

The heat ray shielding plate of the present invention is coated with the above-mentioned heat ray shielding coating composition of the present invention.
The thickness of the coating film formed on the coating varies depending on the type of the coating material and the application, but is usually 5 to 300 μm in dry film thickness.
It is.

The substrate on which the heat ray shielding paint of the present invention is applied is not particularly limited, and examples thereof include a metal substrate, a plastic substrate, and an inorganic material substrate. Examples of the metal substrate include an aluminum plate, an iron plate, a galvanized steel plate, an aluminum-galvanized steel plate, a stainless steel plate, and a tin plate. Examples of the plastic substrate include substrates such as acrylic, PVC, polycarbonate, ABS, polyethylene terephthalate, and polyolefin. Examples of the inorganic substrate include a ceramic substrate and a glass substrate described in JIS A 5422 and A 5430.

The above-mentioned substrate may be subjected to a surface treatment for imparting adhesion and rust prevention. The undercoat may be coated, or the back of the substrate may be coated with a back paint.

[0029]

As EXAMPLES black pigment black pigment was prepared following pigments. (1) Black pigment A Fe ₂ O ₃ 75 wt%, Cr ₂ O ₃ 25 wt% of the composite oxide calcined pigment (2) Black Pigment B Fe ₂ O ₃ 40 wt%, Cr ₂ O ₃ 60 wt% of composite oxide calcined pigments (3) black pigment C Fe ₂ O ₃ 80 wt%, Mn ₂ O ₃ 20 wt% of the composite oxide calcined pigment (4) black pigment D Fe ₂ O ₃ 15 wt%, Cr ₂ O ₃ 25% by weight, Mn ₂ O ₃ 1
(5) Black pigment E 63% by weight of Cr ₂ O ₃ , 5% by weight of MnO ₂ , 32% by weight of CuO ₂ ) Black pigment F cr ₂ O ₃ 59 wt%, the composite oxide calcined pigment (7) of CuO41 wt% black pigment G Fe ₂ O ₃ 54 wt%, MnO ₂ 28% by weight, CuO18
(8) Black pigment H Carbon black pigment (trade name “Monarch 1300”,
The spectral reflection spectrum of each of the above black pigments was measured. A coating film obtained by dispersing each pigment in a binder at a concentration of 20 to 40 parts by weight (phr) (film thickness of 20 to 40 μm).
m), a spectrophotometer (U-350, manufactured by Hitachi, Ltd.)
0 spectrophotometer).

FIG. 3 shows the spectral spectra of pigments A and D and pigments E and H. Here, pigments A and D are 780
It shows a high reflectance in the near infrared region of ２2100 nm.

The 7 of each black pigment measured as described above
The reflectance in the wavelength range of 80 to 2100 nm is measured according to JIS.
A The solar reflectance was calculated according to the method described in A 5759. The solar reflectance of each pigment is as follows. Black pigment A: 54% Black pigment B: 48% Black pigment C: 21% Black pigment D: 20% Black pigment E: 7% Black pigment F: 6% Black pigment G: 5% Black pigment H: 1%

Example 1 <Preparation of paint> 107 parts by weight of a methyl methacrylate-based acrylic resin (25% of non-volatile content) and 80 parts by weight of black pigment A were charged into a container, stirred, mixed until uniform, and then painted. It was transferred to a shaker and dispersed for 2 hours. To this dispersion, 127 parts by weight of polyvinylidene fluoride powder, 110 parts by weight of the above-mentioned acrylic resin, and 76 parts by weight of isophorone were added with stirring to prepare a coating composition.

<Preparation of Test Specimen> The coating material obtained as described above was applied on a base material of an aluminum plate having a thickness of 0.8 mm using a bar coater so as to have a dry film thickness of 20 μm. Then, the coating was formed by drying at 250 ° C. for 2 minutes to prepare a test piece.

<Evaluation of Coating Film> The Munsell value of the obtained coating film on the test piece was measured by a color difference meter of Hunter manufactured by Suga Test Instruments Co., Ltd., and the gloss was measured by a gloss meter UGK-5K manufactured by Suga Test Instruments Co., Ltd. . In addition, the spectral reflectance spectrum was measured, and the solar reflectance was calculated. The spectral reflection spectrum is
Based on high reflectance barium sulfate white paint (reflectance 10
0%), the reflection spectrum of the coating film of the test piece was measured using a spectrophotometer (U-3500 spectrophotometer, manufactured by Hitachi, Ltd.). Based on the spectral reflectance spectrum measured as described above, the reflectance of the coating film was calculated in the same manner as the solar reflectance of the pigment. Table 1 shows the measurement results.

<Evaluation of Heat Ray Shielding Property> The above test piece was evaluated for heat ray shielding property using a test apparatus 10 shown in FIG. As shown in FIG. 2, the test piece 1 is fitted on the upper surface of the styrofoam box 7 with the coating film facing upward, and the test piece 1 is irradiated by an incandescent lamp 2 provided above the test piece 1.
Temperature sensor 3 and test box 7 installed on the back of test piece 1
The temperature was measured by a temperature sensor 4 installed in the inside, and the measured temperature was recorded by a recorder 5.

The incandescent lamp 2 was turned on by the power supply 6. As the test piece, a size of 320 mm × 230 mm was used. As the test box 7, a styrene foam box having a thickness of 30 mm and dimensions of 350 mm × 250 mm × 250 mm was used. Further, the distance 8 between the test piece 1 and the incandescent lamp 2 is set to 1
It was 50 mm.

The recorder 5 includes a thermo recorder RT
-10 (manufactured by Tabai Espec) and the incandescent lamp 2 used was a Toshiba reflex lamp RF110V200W (manufactured by Toshiba Corporation). Further, the test was performed in a constant temperature room at 20 ° C. in a state of no wind. FIG. 1 shows the measurement temperature results. In Table 1,
This shows the temperature at the time when a certain temperature is reached.

Examples 2, 3, 4 and 5 A paint was prepared in the same manner as in Example 1 except that the black pigment shown in Table 1 was used, and sunlight was used outdoors instead of an incandescent lamp. Except for using, evaluation of the coating film and evaluation of heat ray shielding property were performed in the same manner as in Example 1. Table 1 shows the results. FIG. 1 shows the measurement temperature results in Example 4.

Example 6 A colored paint was prepared in the same manner as in Example 1 except that titanium oxide, ferric oxide, cobalt blue, and chromium titanium yellow were used as coloring pigments instead of the black pigment of Example 1. 1, 2, 3, and 4 were prepared. Colored paints obtained using titanium oxide, ferric oxide, cobalt blue, and chromium titanium yellow are referred to as colored paints 1, 2, 3, and 4, respectively. Next, using the black paint of Example 4 and the above-mentioned colored paints 1 to 4, the Munsell value H = 0.19B, V = 3.43, and C =
The color was adjusted to 0.48 to prepare a gray paint, and the coating film and the heat ray shielding property were evaluated. FIG. 4 shows the spectral reflection spectrum of the coating film.

Example 7 Similarly to Example 6, the Munsell value H = 0.43 PB, V was obtained using the black paint of Example 4 and the above-mentioned colored paints 1 to 4.
= 3.55 A color was adjusted so that C = 0.81 to prepare a blue paint, and the coating film and the heat ray shielding property were evaluated.

Example 8 Next, using the black paint of Example 4 and the above-mentioned colored paints 1 to 4, the Munsell value H = 2.05YR, V = 2.84, C =
The color was adjusted to 6.01 to prepare a rust-colored paint, and the coating film and the heat ray shielding property were evaluated.

Embodiments 9 and 10 In Embodiment 9, a galvanized steel sheet was used for the substrate.
Then, in the same manner as in Example 1 except that the film thickness was changed to 80 μm, the evaluation of the coating film and the evaluation of the heat ray shielding property were performed.

Example 11 A container was charged with 195 parts by weight of a polyester resin (65% of nonvolatile content: 65%) and 80 parts by weight of a pigment A, mixed by stirring until uniform, then transferred to a paint shaker and dispersed for 2 hours. A methylated melamine resin (non-volatile content 70
%) And 83 parts by weight of cyclohexanone were added with stirring to prepare a coating material, and the coating film and the heat ray shielding property were evaluated.

Example 12 A silica-based matting agent (Nip Seal E-2) was added to the prepared paint.
00, manufactured by Nippon Silica Kogyo Co., Ltd.) was prepared in the same manner as in Example 11 except that 5% by weight was added, and the coating film and the heat ray shielding property were evaluated.

Comparative Examples 1-4 Paints were prepared in the same manner as in Example 1 except that the pigments shown in Table 2 were used as black pigments, and the coating films and the heat ray shielding property were evaluated. FIG. 1 shows the evaluation results of the heat ray shielding property.

Comparative Example 5 A paint was prepared in the same manner as in Example 1 except that the pigments shown in Table 2 were used as the black pigment, and the coating film was evaluated and heat rays were shielded by using sunlight instead of incandescent lamps. The sex was evaluated.

Comparative Example 6 A gray paint was prepared in the same manner as in Example 6 using the black paint of Comparative Example 1, and the coating film and the heat ray shielding property were evaluated. FIG. 4 shows the spectral reflection spectrum of the coating film.

Comparative Example 7 A blue paint was prepared in the same manner as in Example 7 using the black paint of Comparative Example 1, and the coating film and the heat ray shielding property were evaluated.

Comparative Example 8 A rust-colored paint was prepared using the black paint of Comparative Example 1 in the same manner as in Example 8, and the evaluation of the coating film and the evaluation of the heat ray shielding property were performed in the same manner as in Example 1. went.

Comparative Examples 9 and 10 In the same manner as in Example 1 except that the black paint of Comparative Example 1 was used, the galvanized steel sheet was used for the substrate in Comparative Example 9, and the film thickness was 80 μm in Comparative Example 10. Then, the coating film and the heat ray shielding property were evaluated.

Comparative Example 11 A coating material was prepared in the same manner as in Example 11 using the black pigment E, and the coating film and the heat ray shielding property were evaluated.

Comparative Example 12 A coating material was prepared in the same manner as in Comparative Example 11 except that a silica-based matting agent (Nip Seal E-200, manufactured by Nippon Silica Industry Co., Ltd.) was added to the prepared coating material in an amount of 5% by weight. Then, the coating film and the heat ray shielding property were evaluated.

[0053]

[Table 1]

[0054]

[Table 2]

FIG. 1 is a graph showing the measured temperature results of Examples 1 and 4 and Comparative Example 1 obtained as described above. As shown in FIG. 1, the temperature inside the test piece and the inside of the test box reached a substantially constant temperature with the passage of time. Are lower by about 29 ° C. and 13 ° C., respectively. Also in the test box, the coating films of Examples 1 and 4 are 6 ° C. and 3 ° C. lower than Comparative Example 1, respectively.

Tables 1 and 2 show the temperature of each test piece when it reached a certain temperature. As is clear from the results of Tables 1 and 2, the black pigments A, B, C, and D used in Examples have a solar reflectance of 8% or more in a wavelength range of 780 to 2100 nm. The solar reflectance of the blended coating film was higher than that of the coating film of the comparative example.

When the coating film of each example was used, the temperature in the back surface of the substrate (the back surface of the test piece) and the temperature in the box were lower than those in the comparative example. In particular, the temperature in the box varies depending on the hue.
The temperature became lower by about ℃. This temperature difference, when applied to buildings such as dwellings and warehouses, is a value that is not negligible from the comfort of the living space, the cooling efficiency of the room, and the storability of the storage items. Therefore, it was found that the coating films of the examples had excellent heat shielding properties or solar heat shielding properties.

[0058]

The heat ray shielding paint of the present invention has a black pigment having a specific composition, so that a coating film having excellent heat ray shielding performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing heat ray shielding properties of coating films formed from paints of Examples and Comparative Examples of the present invention.

FIG. 2 is a simplified diagram showing an apparatus for evaluating the heat ray shielding property of a coating film.

FIG. 3 is a graph showing spectral reflection spectra of black pigments in Examples and Comparative Examples of the present invention.

FIG. 4 is a graph showing a spectral reflection spectrum of a coating film formed from paints of Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Test piece 2 ... Incandescent lamp 3, 4 ... Temperature sensor 5 ... Recorder 6 ... Power supply 7 ... Styrofoam test box 8 ... Test piece and incandescent lamp Distance 10: Heat ray shielding evaluation device

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ryoji Ishihara 2-1-2, Oyodo-kita, Kita-ku, Osaka City, Osaka Nippon Paint Co., Ltd. F-term (reference) 4J038 CG001 DA162 DD001 DG302 HA216 KA08 NA19

Claims (8)

[Claims] 1. A heat ray shielding coating composition comprising a black pigment having a solar reflectance of 8.0% or more in a wavelength range of 780 to 2100 nm. 2. The method according to claim 1, wherein the black pigment has a wavelength of 400 to 400 in the visible region.
The heat ray shielding coating composition according to claim 1, wherein the reflectance at any wavelength of 700 nm is 15% or less. 3. The heat ray shielding according to claim 1, wherein the black pigment is a fired pigment containing 20 to 100% by weight of Fe ₂ O ₃ and Cr ₂ O ₃ and / or Mn ₂ O _3. Paint composition. 4. The heat ray shielding coating composition according to claim 1, which comprises the black pigment in an amount of 0.1% by weight or more. 5. The black pigment according to claim 1, wherein said black pigment is contained in said total pigment component in an amount of 0.1%.
The heat ray shielding coating composition according to any one of claims 1 to 4, which contains 5% by weight or more. 6. The heat ray shielding coating composition according to claim 1, wherein the binder component contains a polyester resin, an acrylic resin, a fluorine resin or a chlorine resin. 7. The heat ray shielding coating composition according to claim 6, further comprising a melamine resin and / or a blocked isocyanate. 8. A heat ray shielding plate coated with the heat ray shielding coating composition according to any one of claims 1 to 7.