JPH0619061B2 - Solar heat shielding coating composition and coating structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a solar heat shielding coating composition and a coating structure, and more specifically, it relates to a marine structure, a ship deck or tank, a cylindrical or spherical tank, and the like. Prevents internal temperature rise due to direct sunlight by coating the outer surface of onshore structures, buildings such as houses, buildings, warehouses or gymnasiums, outdoor structures such as automobiles, tank trucks, refrigerating containers, and home appliances such as refrigerators. The present invention relates to a coating composition suitable for saving energy by increasing the effects of cooling and freezing or preventing evaporation of volatile components such as petroleum, and a structure formed by coating the same.

[Conventional technology]

Conventionally, the temperature rise inside buildings, etc. is prevented by the sun's solar radiation to reduce the cost of air conditioning, and the outer surfaces of tankers, tank gas carriers, land tanks, etc. are covered to evaporate the volatile components inside. It is strongly demanded to control the weight loss and improve the freezing effect of tanks and home appliances. For example, the loss of crude oil due to the evaporation of a tanker is enormous, and it is said that it reaches 0.2 to 0.5% of the total load on one voyage from the Middle East to our country.

White pigments and coloring pigments such as titanium oxide that have been conventionally used as a solar heat shielding coating for dealing with such a problem have a certain degree of solar heat shielding effect in white,
Since the solar heat shielding effect is remarkably reduced when it is colored other than white, there has been a demand for a coating composition having a high solar heat shielding effect even if it is colored in any color.

On the other hand, conventionally, as a solar heat shielding coating for the roof of the building and the outer surface of the tank, aluminum paint containing scale-like aluminum powder has been known, but the color is limited and insufficient in terms of durability, In addition, it has a defect that it has poor wear resistance and is not suitable for walking.

In order to solve these problems, a heat-reflecting enamel containing antimony trioxide, antimony dichromate, alkali metal dichromate, etc. has been proposed by JP-A-56-109257, but it is environmentally friendly in that it contains heavy metals. Not good for hygiene.

Further, a metal coated with an emulsion paint containing fine glass particles having a particle size of 20 to 350 μ, a paint containing white pigment-containing synthetic silica particles having a particle size of 300 μ or less, or a paint containing crushed glass particles having a particle size of 5 to 300 μ. Board manufacturing method is Shokoku Sho5
Nos. 5-33828, JP-A-55-120669 and JP-A-55-74862 are proposed.
Although these have an excellent initial solar heat shielding effect, they have the disadvantage that they have an uneven pattern on the surface and have poor stain resistance over time, resulting in a marked decrease in the solar heat shielding effect. It has been difficult to maintain a good solar shading effect for as long as possible.

In view of the present situation, as the substance satisfying such performance, the present inventors have (1) one or more kinds of zirconium oxide, yttrium oxide, or indium oxide, (2) zirconium oxide, indium oxide, titanium oxide, or oxide. It has already been proposed from Japanese Patent Application No. 62-279061 that a compound of at least one kind of silicon and at least one kind of magnesium oxide, yttrium oxide, barium oxide, calcium oxide or zinc oxide is excellent. . With this technology, a composition having a solar radiation reflectance of 90% or more and having a solar heat shielding effect has been made possible, but it is required to have a black color or a low lightness coloring represented by Munsell symbols N-2 to N-6. In that case, a coloring agent such as manganese dioxide or carbon black must be used in combination, and in that case, the solar heat shielding effect must be lowered.

[Problems to be Solved by the Invention]

The object of the present invention is to improve the air-conditioning cost or contents by covering the outer surface of various structures on land and sea that are directly exposed to the sun, ships, buildings, home appliances, etc. and suppressing the rise of the internal temperature thereof. The coating composition and the coating structure by which it is possible to expect a remarkable effect in saving energy by evaporating and deteriorating, and which has excellent long-term durability, no environmental hygiene problems, is colorable, and has an aesthetic appearance To provide things.

[Means for Solving the Problems]

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a coating material containing a solar heat shielding pigment having a particle size of 50 μm or less, which has a high solar radiation reflectance in the ultraviolet region and the near infrared region, in the solid content. The inventors have found that a coating composition containing 2 to 60% by weight has excellent long-term durability and can be colored, and has reached the present invention.

That is, the present invention provides a vehicle with excellent weather resistance in a solar heat shielding coating material containing a vehicle and a pigment as main components, and Si or Si and Al, Fe, Mg, Mn, Ni having a particle size of 50 μm or less as a solar heat shielding pigment, A solar heat-shielding coating composition comprising one or two or more alloys with any one or more of Ti, Cr, and Ca in a coating solid content in a coating solid content, and the coating composition for a structure substrate. At least the outermost coating layer, and a solar heat shielding coating structure characterized in that a coating layer containing a filler excellent in heat insulation and a vehicle excellent in adhesiveness and anticorrosion as main components is provided as a lower layer. It is a thing.

Hereinafter, the present invention will be described in detail.

First, the vehicle having excellent weather resistance used in the coating composition of the present invention means yellowing resistance, color retention resistance, gloss retention and chalking resistance and other excellent heat shielding effect for a long period of time. A vehicle that can be maintained, and as a vehicle that is dried at room temperature, one or more main components of an acrylic resin, a silicon-modified polyester resin, an alkyd resin, a silicon-modified alkyd resin, or a fluorine-containing resin as a main component, and hexamethylenediiso Ianate or an adduct thereof, isophorone diisocyanate or an adduct thereof, hydrogenated xylylene diisocyanate or an adduct thereof, hydrogenated dicyclohexylmethane diisocyanate or an adduct thereof and tetramethylxylylene diisocyanate or a combination of one or more adducts thereof, or Carboxyl group and / or An acrylic resin having an amino group as a main component, a combination of a compound having a glycidyl group as needed is preferred. Further, as a vehicle suitable for forced drying, it is preferable to use one or more kinds of polyester resin, silicon-modified polyester resin, fluorine-containing resin or acrylic resin as a main component and, if necessary, one or more kinds of blocked isocyanate or melamine resin in combination. .

Next, as the solar heat shielding pigment used in the composition of the present invention, the solar heat reflectance calculated by the spectral reflectance (Rλi) specified by JIS A5759 architectural heat ray shielding and glass shatterproof film in a state of being arranged in a paint. Out of
It has a reflectance higher than that of a normal pigment except for visible light of 380 nm or less and 780 nm or more, and is preferably higher, especially in the case of black or a color having low lightness. Further, it is desirable that the solar heat shielding pigment is a component which is safe, has excellent water resistance and weather resistance, and maintains a heat shielding effect for a long period of time. As such a pigment, as a result of examination, metallic Si,
Or Si and Al, Fe, Mg, Mn, Ni, Ti, C
It has been found that the use of one or more alloys of at least one of r and Ca with the alloy can exhibit an excellent heat-shielding effect particularly for dark-colored black-based or gray-based alloys.

As substances that exhibit the same performance as these substances, A
There are metals such as 1 and Ag, and oxides such as tin oxide and manganese dioxide. However, when Al and manganese dioxide are compounded in a paint and exposed outdoors, the solar heat shielding effect is significantly reduced. Further, when Ag, tin oxide or the like is blended in a paint, it is difficult to obtain a paint having medium to low brightness such as N-2 to N-6, which has a large brightness.

Metal Si or Si and Al, Fe, Mg, Mn, Ni,
The reason why such an alloy with any one or more of Ti, Cr, and Ca exerts such an effect is unknown, but when these are compounded in a paint, a paint of medium to low brightness such as N-2 to N-6 is used. It is easy to obtain, and even when exposed outdoors,
Maintains solar heat shielding effect for a long time. The reason why they always exert a stable effect is that they are covered with a strong, thin, dense, and transparent oxide film, which probably has no adverse effect on the effect, and a similar oxide film is formed even when finely dispersed during coating. However, it is considered that this effect is less likely to decrease even when exposed outdoors.

Such effects are not observed at all in metals other than the previous term, metal oxides, alloy powders and carbon black, or become extremely unsatisfactory.

Also, the particle size of the solar heat shielding pigment is 50 from the viewpoint of stain resistance.
It is necessary that the thickness be less than or equal to μ, but it is particularly preferable that it is less than or equal to 20 μ. If a pigment having coarse particles of more than 50 μ is used, fine irregularities are generated in the coating film, especially dust and soot are attached to the concave portions, and the surface of the coating film is contaminated, and it becomes difficult to maintain the solar heat shielding effect.

In addition, if the particle size is in the range of 2 to 60 in the solid content of the paint.
It is an important essence of the present invention that the content of the alloy be included by weight percent. When the amount of the pigment is less than 2% by weight, the solar heat shielding effect is insufficient, and when the amount exceeds 60% by weight, the amount of the pigment in the coating film is large and the resistance to chalking is deteriorated, resulting in lack of weather resistance.

The solid content here means a substance that does not volatilize or evaporate even when heated in the coating composition, and generally refers to a component that should form a coating film, specifically, a pigment,
It refers to the resin component in the vehicle and other additives.

Further, in the present invention, in addition to the above-mentioned metal / alloy powder, titanium dioxide may be used in combination as a white pigment to adjust the brightness. That is, titanium dioxide has a relatively high reflectance in the visible light and near-infrared region, and also has excellent chalking resistance, dispersibility, and hiding power, and when blended in a paint together with the metal / alloy powder described above, It is particularly preferable because a stable solar heat shielding effect can be obtained even when exposed outdoors for a long period of time.

The coating composition of the present invention configured as described above can be dissolved and dispersed in an organic solvent and adjusted to a viscosity suitable for coating before use. As the organic solvent, a hydrocarbon solvent, an alcohol solvent, an ether alcohol solvent, an ether solvent solvent, an ester solvent, an ester alcohol solvent solvent, or a ketone solvent solvent can be used, which is suitable for coating property and drying property.

Further, if necessary, a surface smoothing agent, an ultraviolet absorber, a viscosity modifier, a curing catalyst, a pigment dispersant, a pigment settling inhibitor, a color separation preventing agent and the like can be used.

Next, in the present invention, a coating layer is provided on at least the outermost layer of the structure substrate by the coating composition as described above, and a filler excellent in heat insulating property and a vehicle excellent in adhesive and anticorrosive property are provided under the coating layer. The second important skeleton is to provide a coating layer containing as a main component.

First, the coating composition used for the outermost coating layer is as described above, and excellent performance can be obtained by coating the coating layer with a thickness of 1 μm or more, preferably 10 μm or more. If it is less than 1 μm, the effect of the lower layer coating film appears so much that the sufficient effect cannot be exhibited. The upper limit of the film thickness is good even if the film is considerably thick, but the effect is saturated even if the film is made too thick, so about 10 to 100 μm is preferable.

Next, as the filler having excellent heat insulating properties contained in the lower layer, a flaky substance and / or a spherical hollow body is preferable. First, as the flaky substance, for example, glass flakes, mica or the like having a diameter of 50 μm or less can be used. As the flaky metal, for example, stainless steel, aluminum foil and the like are commercially available, but glass flakes and mica are excellent in terms of thermal conductivity. The size is 50μ or less, especially 20
It is preferably μ or less. When it exceeds 50 μ, the coating film becomes uneven due to the flaky substance, which adversely affects the upper coating film and also reduces the heat insulating effect and the corrosion resistance effect by not flattening the flaky material. Especially when the content of this substance is 20μ or less, the phosphorus pieces are arranged in parallel with the coating surface by setting the ratio with the vehicle to an appropriate value, and as a result, a thick layer is formed and the path of water permeation is extended. Occurs, which improves the corrosion resistance and the heat insulating effect. Alternatively, a spherical hollow body having a diameter of 50 μm or less, preferably 1 μm to 10 μm, such as a glass balloon, a shirasu balloon, or a balloon made of a resin such as polystyrene can be used. Diameter is 5
When it exceeds 0 μ, the coating film becomes uneven as described above, which adversely affects the upper coating film. If the diameter is less than 1 μ, the hollow effect, that is, the effect of heat insulation is deteriorated, which is not preferable.

The vehicle used for the lower layer has excellent adhesion and corrosion resistance, and is one of epoxy resin, epoxy modified resin, phenol modified butyral resin, polyester resin, acrylic resin, silicon modified polyester resin, alkyd resin, fluorine resin and urethane resin. With seeds or more as the main component,
If necessary, a curing agent and a curing accelerator, a surface smoothing agent, a viscosity adjusting agent, a pigment dispersant, a pigment settling inhibitor, a color separation preventing agent and the like can be used. As the curing agent, a compound having an isocyanate group, a compound having an amino group,
Examples include melamine resin.

It is desirable that the above-mentioned filler is contained in the coating film in an amount of 2 to 60% by weight. If it is less than 2%, the heat insulation is not cured, and if it exceeds 60%, the adhesion of the coating film is lowered and the upper layer film is adversely affected. The above vehicle is preferably contained in the lower layer coating in an amount of 20 to 60% by weight. If it is less than 20%, the adhesion of the coating film is inferior, and if it exceeds 60%, the adiabatic and corrosion resistance deteriorates.

As described above, the structure of the present invention has a coating layer having excellent solar heat reflection properties as the outermost layer of the substrate, and the main point is to have a coating layer having excellent heat insulating properties as the lower layer. In this case, the lower coating layer may be directly provided on the structure substrate surface, or is usually used between the lower layer and the substrate surface to improve the adhesion to the lower substrate surface. It goes without saying that a primer layer to be used may be provided.

Examples of the present invention will be described below.

〔Example〕

(Ingredient) Solar Heat Shielding Pigment Solar Heat Shielding Pigment A: Metal Si having an average particle size of 0.5 μ was used.

Solar heat shielding pigment B: Silicon oxide and titanium oxide were melt-reduced using carbon in an electric furnace to prepare an S-Ti alloy.
The weight ratio of Si to Ti of this alloy was 0.8 / 0.2. This alloy was crushed to an average particle size of 5 μm to obtain a solar heat shielding pigment B.

Sunscreen pigment C: Silicon oxide and nickel oxide pigment B
Melt reduction was carried out in the same manner as described above to prepare an Si-Ni alloy. The weight ratio of Si to Ni of this alloy is 0.75 / 0.2.
It was 5. This alloy was crushed to an average particle size of 5μ and pigment C
And

White pigment Taipaque CR-90 (manufactured by Ishihara Sangyo Co., Ltd.) Average particle size 0.4μ Phosphorous flake MP-325 (manufactured by Okabe Mica Co., Ltd.) Average particle size 15μ Spherical hollow body Silica balloon QCEL300 ( Asahi Glass Co., Ltd.) Average particle size 5μ (preparation of paint) Acrydic A-801 (Acrylic polyol manufactured by Dainippon Ink and Chemicals, Inc.) was used as a vehicle in the proportions shown in Table 1, a solar heat shielding pigment, white A pigment was added, and a mixed solvent of xylene and methyl isobutyl ketone 1: 1 was used for dispersion treatment for 20 minutes and then adjusted to 20 to 30 poises. At the time of coating, Takenate D-170N (Hexamethylene diisocyanate adduct manufactured by Takeda Pharmaceutical Co., Ltd.) was added so that the NCO / OH molar ratio was 1: 1 to obtain coatings 1, 2, 3, 4, 5, 6 and 7 were obtained.

Acridic A-801 (Acrylic polyol manufactured by Dainippon Ink and Chemicals, Inc.) was used as a vehicle in a ratio shown in Table 1, a white pigment, a scaly material, and a spherical hollow body were added, and the hue was N-7. To become carbon MA-1
00 (Carbon Black manufactured by Mitsubishi Kasei Co., Ltd.) was added, and a mixed solvent of xylene and methyl isobutyl ketone (1: 1) was used for 20 minutes for dispersion treatment, and then adjusted to 20 to 30 poises. At the time of coating, Takenate D-170N (hexamethylene diisocyanate adduct manufactured by Takeda Pharmaceutical Co., Ltd.) was added so that the NCO / OH molar ratio was 1: 1 to obtain undercoat paints 8 and 9.

Carbon MA-100 (manufactured by Mitsubishi Kasei Co., Ltd., carbon black) was added in the ratio shown in Table 1 in place of the solar heat-shielding pigment so that a predetermined hue was obtained.
0, 11, and 12 were obtained.

(Preparation of test pieces) Paints 8 and 9 were spray-coated on a 1 mm thick mild steel plate to a dry film thickness of 150 µ, dried at 20 ° C for 1 day, and then painted 1, 2, 3, 4, 5, 6 , 7, 10, 11, and 12 were spray-coated to a dry film thickness of 50 μm and dried for 2 weeks to prepare test pieces.

(Preparation of tank) A steel tank with an internal capacity of 10 liters is coated with an epoxy resin-based primer having a film thickness of 20μ, and then paints 8 and 9 are spray-coated so as to have a film thickness of 150μ, followed by drying at 20 ° C for 1 day and further film formation Paint 1, 2, 3, 4, 5, so that the thickness is 50μ
6, 7, 10, 11, 12 were spray-painted to prepare a tank.

(Test Method) The above test piece was irradiated with an incandescent lamp as shown in FIG. 1 to measure the back surface temperature of the test piece. Explaining the backside temperature measuring means of FIG. 1, a steel plate 2 (size 150 × 70 × 1 mm) having a coating film 1 is fitted on a styrofoam plate 3 having a thickness t = 30 mm with the coating film 1 surface facing upward. An incandescent lamp (500w photoreflector lamp) 4 is installed at a position of h = 370 mm on the surface of the coating film, and a power source 5 is connected. On the other hand, a temperature sensor 6 is attached to the back side of the steel plate 2 and a temperature recorder 7 is connected. After setting as above, set the room temperature to 20
The temperature of the incandescent lamp 4 is turned on by adjusting the voltage of the power source 5 to 70 ± 1 V while keeping the temperature at ± 1 ° C., and the temperature at the position of the temperature sensor 6 is recorded by the recorder 7.

Further, the tank prepared as described above was provided with an opening and filled with 1,1,2 trichloroethane, and the tank was kept outdoors for 7 days under direct sunlight to measure the weight loss of the contents.

The above results are also shown in Table 2.

[Effects of the Invention] As is clear from the results of the above examples, when the same hue is compared, the back surface temperature of the test piece and the weight reduction of the contents of the tank show remarkable effects. By covering the outer surface of the receiving vessel and various structures, it shields solar heat for a long time, suppresses the internal temperature rise, improves air conditioning costs or suppresses evaporation and consumption of contents, resulting in remarkable energy savings. It is possible to provide a solar heat shielding coating composition that can be expected to be effective and a coating structure using the same, and there is an extremely great contribution to industrial development.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a means for measuring the back surface temperature of the test piece used in the examples. 1 ... Paint film, 2 ... Steel plate, 3 ... Styrofoam plate, 4
...... Incandescent lamp, 5 ... Power supply, 6 ... Temperature sensor, 7 ...
Temperature recorder.

Claims (3)

[Claims] 1. A solar heat-shielding paint comprising a vehicle and a pigment as main components, the vehicle having excellent weather resistance, and Si or Si and A having a particle size of 50 μm or less as the solar heat-shielding pigment.
1, 1 or 2 or more alloys with any one or more of Fe, Mg, Mn, Ni, Ti, Cr and Ca in the coating solid content in an amount of 2 to 60% by weight. Composition. 2. A vehicle having excellent weather resistance in at least the outermost layer of a structure substrate, and Si or Si having a particle size of 50 μ or less and any one of Al, Fe, Mg, Mn, Ni, Ti, Cr and Ca. One or two or more of the above alloys have a coating layer having excellent solar heat reflection properties, which contains, as a main component, a solar heat shielding pigment contained in the coating solid content in an amount of 2 to 60% by weight, and has a heat insulating property as a lower layer. A solar heat shield coating structure comprising a coating layer containing, as a main component, an excellent filling material and a vehicle having excellent adhesion and anticorrosion properties. 3. A filler having excellent heat insulating properties, which is contained in the lower layer,
The solar heat shield coating structure according to claim 2, which is a flaky material and / or a spherical hollow body.