WO2023120295A1 - Aqueous coating composition, method for producing coating film, method for using aqueous coating composition, and coated article - Google Patents

Aqueous coating composition, method for producing coating film, method for using aqueous coating composition, and coated article Download PDF

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Publication number
WO2023120295A1
WO2023120295A1 PCT/JP2022/045807 JP2022045807W WO2023120295A1 WO 2023120295 A1 WO2023120295 A1 WO 2023120295A1 JP 2022045807 W JP2022045807 W JP 2022045807W WO 2023120295 A1 WO2023120295 A1 WO 2023120295A1
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WIPO (PCT)
Prior art keywords
water
coating composition
titanate
aqueous
titanium dioxide
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PCT/JP2022/045807
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French (fr)
Japanese (ja)
Inventor
隆寛 三島
陽子 富永
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大塚化学株式会社
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Publication of WO2023120295A1 publication Critical patent/WO2023120295A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
    • C09D183/04—Polysiloxanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D201/00—Coating compositions based on unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/004—Reflecting paints; Signal paints
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/02—Emulsion paints including aerosols
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/61—Additives non-macromolecular inorganic
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
    • E04F13/00—Coverings or linings, e.g. for walls or ceilings
    • E04F13/02—Coverings or linings, e.g. for walls or ceilings of plastic materials hardening after applying, e.g. plaster

Definitions

  • the present invention relates to a heat-shielding water-based coating composition, a method for producing a coating film using the water-based coating composition, a method for using the water-based coating composition, and a coated article using the water-based coating composition.
  • Patent Document 1 describes a thermal shielding material having a black color of Munsell symbol (N-1), which is a mixture of two or more colored organic pigments exhibiting absorption in the visible region and having a reflectance of 35% or more in the near-infrared region.
  • N-1 Munsell symbol
  • a chromogenic black pigment composition is disclosed.
  • Patent Document 2 discloses a method of applying a heat-shielding color paint to a siding material.
  • Patent Document 2 describes that the heat-shielding color paint is prepared by combining two or more primary color paints having a solar reflectance of 20% or more in the wavelength range of 780 nm to 2100 nm. .
  • Patent Document 3 discloses a water-based coating composition containing titanium dioxide as a pigment, porous calcium carbonate, and a water-based resin.
  • a general thermal barrier paint that uses titanium dioxide as a pigment with thermal barrier performance has a glossy finished appearance, and in many cases it is not possible to obtain the low-gloss, calm appearance that is preferred for exterior walls.
  • the thermal barrier paints described in Patent Documents 1 and 2 also have the problem of not being able to provide a matte finished appearance because they are intended to be a glossy coating film for painting on roofs and the like. .
  • the heat-shielding paints described in Patent Documents 1 and 2 may not provide sufficient heat-shielding properties.
  • Patent Document 3 also describes that a coating film with high diffuse reflectance and low glossiness can be formed by using a specific calcium carbonate.
  • the film formability becomes insufficient in terms of particle size and shape. Therefore, the water-based coating composition as disclosed in Patent Document 3 has a problem that the film-forming property is not sufficient and the mechanical strength of the coating film cannot be sufficiently increased. Therefore, cracking of the coating film is likely to occur, and there is a problem that it is difficult to maintain the excellent appearance and heat shielding function of the coating film over a long period of time.
  • An object of the present invention is to solve such problems, and an aqueous coating composition that can form a coating film having excellent film-forming properties, high heat-shielding properties, and low gloss, and the aqueous coating composition using the above-mentioned aqueous coating composition.
  • An object of the present invention is to provide a method for producing a coating film, a method for using the water-based coating composition, and a coated article using the water-based coating composition.
  • the present inventors have made intensive studies to solve the above problems, and as a result, in a water-based coating composition having heat-shielding properties, titanium dioxide (A), titanate (B), an aqueous medium (C), and an aqueous By containing the resin (D), it was found that a coating film having excellent film-forming properties, high heat-shielding properties, and low gloss can be obtained, and the present invention was completed. .
  • the gist of the present invention is as follows.
  • Item 1 An aqueous coating composition having heat-shielding properties, containing titanium dioxide (A), titanate (B), aqueous medium (C), and aqueous resin (D).
  • Item 2 The aqueous coating composition according to Item 1, wherein the titanium dioxide (A) is non-fibrous particles, and the titanate (B) is fibrous particles or non-fibrous particles.
  • the titanate (B) is A 2 Ti n O (2n+1) [wherein A is one or more alkali metals excluding Li, n is a number from 2 to 11], A x M y Ti (2-y) O 4 [In the formula, A is one or more alkali metals excluding Li, and M is selected from Li, Mg, Zn, Ga, Ni, Cu, Fe, Al, and Mn. one or more, x is 0.5 to 1.0, y is a number of 0.25 to 1.0], and A 0.2 to 0.8 Li 0.2 to 0.4 Ti 1.
  • Item 4 Item 1, wherein the total content of the titanium dioxide (A) and the titanate (B) is 5% by mass or more and 70% by mass or less with respect to the total amount of 100% by mass of the aqueous coating composition. 3.
  • the water-based coating composition according to any one of items 3 to 4.
  • Item 5 Items 1 to 3, wherein the mass ratio of titanate (B) to titanium dioxide (A) (titanate (B)/titanium dioxide (A)) is 0.1 or more and 9.0 or less 5.
  • the aqueous coating composition according to any one of 4.
  • Item 6 The aqueous coating composition according to any one of Items 1 to 5, wherein the aqueous resin (D) is an acrylic resin.
  • Item 7 The aqueous coating composition according to any one of Items 1 to 6, wherein the aqueous resin (D) is an acrylic silicone emulsion resin.
  • Item 8 The aqueous coating composition according to any one of Items 1 to 7, further containing hollow particles.
  • Item 9 A method for producing a coating film, wherein the aqueous coating composition according to any one of Items 1 to 8 is applied to the surface of a substrate.
  • Item 10 A water-based paint composition that suppresses the temperature rise inside the building by coating the roof, exterior wall surface, and/or interior surface of the building with the water-based paint composition according to any one of Items 1 to 8. A method of using the coating composition.
  • Item 11 A method of using a water-based coating composition, wherein the water-based coating composition according to any one of Items 1 to 8 is applied to the paved surface of the road to suppress the temperature rise of the road surface.
  • Item 12 A method of using a water-based paint composition, wherein the water-based paint composition according to any one of Items 1 to 8 is applied to the outer wall surface of the tank to suppress the temperature rise inside the tank.
  • Item 13 A coated article comprising a substrate and a coating film of the aqueous coating composition according to any one of Items 1 to 8 provided on the surface of the substrate.
  • Item 14 The coated article according to Item 13, wherein the solar radiation penetration ratio is 0.01 to 0.4.
  • a water-based coating composition that is excellent in film-forming properties, can form a low-gloss coating film with high heat-shielding properties, a method for producing a coating film using the water-based coating composition, and the water-based A method of using the coating composition and a coated article using the aqueous coating composition can be provided.
  • the water-based coating composition of the present invention is a heat-insulating water-based coating composition containing titanium dioxide (A), a titanate (B), an aqueous medium (C), and an aqueous resin (D), Other additives can be further contained as necessary.
  • the water-based coating composition according to the present invention has the above-described structure, it can form a coating film with excellent film-forming properties, high heat-shielding properties, and low gloss. This can be explained as follows.
  • the water-based coating composition of the present invention contains titanate (B) in addition to titanium dioxide (A), it is possible to improve the film-forming properties of the coating film. Regarding this point, it is considered that the surface of the ionizable titanate (B) functions as a film-forming aid. It is considered that the mechanical strength of the coating film can be enhanced thereby.
  • titanate (B) is added instead of part of the titanium dioxide (A), it is possible to form a coating film with excellent heat shielding properties and low gloss.
  • a paint such as the water-based paint composition of the present invention is a semi-finished product.
  • the above paints function only when they form a coating film as designed without any problems during coating and drying.
  • the titanate (B) used in the water-based paint composition of the present invention usually has the same water content as titanium dioxide, and may have reduced fluidity as a paint. Therefore, when the fluidity is to be improved only with the titanate (B), it is desirable to increase the water content. However, when the moisture content is increased, drying is slowed down, and problems such as filler sinking may occur, resulting in a non-uniform coating film composition. In this case, the designed film performance may not be exhibited.
  • the water-based coating composition of the present invention contains titanium dioxide (A) in addition to titanate (B), so that the above-mentioned required amount of water can be reduced and fluidity is improved. can be enhanced. It is believed that this is because the gaps in the titanate (B) can be filled with titanium dioxide (A), and it is thought that durability such as strength and hardness of the resulting coating film can be improved. be done. In addition, since the gaps in the titanate (B) can be filled with the titanium dioxide (A), the opacity of the obtained coating film is improved, and the heat shielding performance is also enhanced.
  • the coating film formed from the water-based coating composition of the present invention is resistant to cracking even in severe environments such as outdoor exposure, and the coating film has excellent appearance and heat shielding function over a long period of time. can be maintained.
  • the aqueous coating composition of the present invention contains titanium dioxide (A).
  • titanium dioxide (A) By containing titanium dioxide (A), the water-based coating composition of the present invention can form a coating film having a small solar radiation penetration ratio and excellent heat shielding properties.
  • titanium dioxide (A) examples include the sulfuric acid method and the chlorine method. Titanium dioxide (A) is preferably produced by the chlorine method. When the water-based coating composition contains titanium dioxide (A) produced by the chlorine method, it is possible to form a coating film having a lower solar radiation penetration ratio and a more excellent heat shielding property.
  • Crystal forms of titanium dioxide (A) include rutile type, anatase type, and brookite type.
  • the crystal form of titanium dioxide (A) is preferably rutile. Since rutile-type titanium dioxide (A) has a high refractive index, it is possible to form a coating film with even better heat shielding properties.
  • the particle shape of titanium dioxide (A) is preferably non-fibrous.
  • non-fibrous titanium dioxide (A) is used, a coating film in which the particles are more closely packed can be formed.
  • the oil absorption of titanium dioxide (A) is preferably 10 g/100 g to 40 g/100 g, more preferably 13 g/100 g to 40 g/100 g, still more preferably 15 g/100 g to 40 g/100 g.
  • Titanium dioxide (A) having an oil absorption in the above range can be obtained, for example, by surface-treating with alumina, silica, zircon, zinc, or the like to form a surface-treated layer to increase the specific surface area.
  • titanium dioxide (A) is, for example, preferably surface-treated with at least one metal selected from the group consisting of alumina, silica, zircon, and zinc. More preferably, the surface is treated with at least one kind of metal selected from the group consisting of alumina, silica and zinc.
  • the air lowers the average refractive index of the vehicle. Therefore, it is believed that in a coating film that incorporates air, the difference between the refractive index of titanium dioxide (A) and the average refractive index of the vehicle becomes greater, resulting in a smaller solar penetration ratio. Moreover, it is thought that the heat-shielding property of the formed coating film is further enhanced thereby.
  • titanium dioxide (A) oil absorption of titanium dioxide (A) is large, the affinity between titanium dioxide (A) and the water-based resin (D) is improved, and the dispersibility of titanium dioxide (A) can be further enhanced. As a result, it is possible to obtain a coating film having a smaller solar radiation penetration ratio and a more excellent heat shielding property.
  • the surface treatment layer is thin and the titanium dioxide particles tend to aggregate, so the solar radiation penetration ratio may increase and the heat shielding property may decrease, and the gloss of the coating film may increase. There is a risk.
  • the oil absorption is a value obtained by measuring by a method according to JIS K-5101.
  • the average particle size of titanium dioxide (A) is not particularly limited, and is preferably 0.1 ⁇ m to 5 ⁇ m, more preferably 0.15 ⁇ m to 3 ⁇ m, and more preferably 0.2 ⁇ m to 1.5 ⁇ m. More preferred. When the average particle size of titanium dioxide (A) is within the above range, the heat shielding properties of the resulting coating film can be further enhanced and the gloss can be further reduced.
  • the average particle size is the particle size at 50% volume-based accumulation in the particle size distribution measured by the laser diffraction method.
  • the pH of the titanium dioxide (A) is preferably 5.5 to 10 from the viewpoint of enhancing the film-forming properties of the resulting coating film and further improving the mechanical strength. 0.8 to 9.5 is more preferred.
  • the pH of the above-mentioned titanium dioxide (A) can be determined, for example, by adding 1 g of a test sample of titanium dioxide to 100 mL of distilled water to prepare a slurry of 1% by mass, and measuring the pH of the obtained slurry (at a temperature of 20° C.) with a pH meter ( Horiba, Ltd., product number "F21”), and the measurement result can be calculated as pH.
  • the specific gravity of titanium dioxide (A) is not particularly limited, and is preferably 3 g/cm 3 to 5 g/cm 3 , more preferably 3.2 g/cm 3 to 4.8 g/cm 3 . It is more preferably 0.5 g/cm 3 to 4.5 g/cm 3 .
  • the content of titanium dioxide (A) is preferably 1% by mass to 40% by mass, more preferably 2% by mass to 30% by mass, with respect to 100% by mass of the total amount of the aqueous coating composition. , more preferably 3% by mass to 20% by mass, and particularly preferably 4% by mass to 15% by mass.
  • the content of titanium dioxide (A) is at least the above lower limit, the heat shielding properties of the resulting coating film can be further enhanced.
  • the content of titanium dioxide (A) is equal to or less than the above upper limit, it is possible to make it more difficult to cause distortion inside the coating film in the obtained coating film, and even under severe environments such as outdoor exposure, the coating film It is possible to make it even more difficult for cracks to occur. That is, it is possible to further improve the film-forming properties of the water-based coating composition.
  • the aqueous coating composition of the present invention contains titanate (B).
  • the titanate (B) include potassium titanate, sodium titanate, magnesium potassium titanate, lithium potassium titanate, calcium titanate, strontium titanate, and barium titanate.
  • a 2 Ti n O (2n+1) [wherein A is one or more alkali metals excluding Li, n is a number from 2 to 11]
  • a x M y Ti (2-y) O 4 [wherein A is one or more alkali metals excluding Li, M is selected from Li, Mg, Zn, Ga, Ni, Cu, Fe, Al and Mn.
  • x is 0.5 to 1.0
  • y is a number of 0.25 to 1.0
  • A is one or more alkali metals excluding Li
  • a 2 Ti n O (2n+1) is preferred
  • A is one or more alkali metals other than Li
  • n is a number from 2 to 11] is more preferred.
  • n in the above formula is preferably a number of 5 to 9, more preferably a number of 6 to 8, and even more preferably 8 from the viewpoint of further improving the film-forming properties, and from the viewpoint of further lowering the glossiness. is 6 from .
  • the pH of the titanate (B) is preferably 7 to 12 from the viewpoint of further improving the film-forming properties of the resulting coating film and further improving the mechanical strength. ⁇ 10 is more preferred.
  • the pH of the titanate (B) described above can be obtained, for example, by adding 1 g of a test sample of the titanate (B) to 100 mL of distilled water to prepare a slurry of 1% by mass, and the pH of the obtained slurry (temperature: 20° C. ) can be measured with a pH meter (manufactured by Horiba Ltd., product number “F21”), and the measurement result can be calculated as pH.
  • the particle shape of the titanate (B) may be fibrous, spherical (including those with slightly uneven surfaces, or those having a substantially spherical shape such as an elliptical cross section), columnar (rod-like, columnar, angular, etc.). Columnar, strip-shaped, approximately circular columnar, approximately strip-shaped, etc.), plate-shaped, block-shaped, and having a plurality of protrusions (ameba-shaped, boomerang-shaped, cross-shaped, confetti) shape, etc.), irregular shape, and the like.
  • the particle shape of the titanate (B) is preferably plate-like or fibrous, more preferably fibrous.
  • Each particle shape of these titanates (B) can be arbitrarily controlled by manufacturing conditions, particularly raw material composition, firing conditions, and the like. Also, the particle shape can be determined, for example, from scanning electron microscope (SEM) observation.
  • SEM scanning electron microscope
  • the average particle size of the titanate (B) is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, and still more preferably 2 ⁇ m or more, It is preferably 100 ⁇ m or less, more preferably 50 ⁇ m or less, and even more preferably 30 ⁇ m or less.
  • the average particle size is the particle size at 50% volume-based accumulation in the particle size distribution measured by the laser diffraction method.
  • the average fiber diameter of the titanate (B) is preferably 0.01 ⁇ m to 1 ⁇ m, more preferably 0.05 ⁇ m to 0.8 ⁇ m. More preferably, it is 0.1 ⁇ m to 0.7 ⁇ m.
  • the average fiber length of the titanate (B) is preferably 1 ⁇ m to 50 ⁇ m, more preferably 3 ⁇ m to 30 ⁇ m, even more preferably 10 ⁇ m to 20 ⁇ m.
  • the average aspect ratio of the titanate (B) is preferably 10 or more, more preferably 10-100, even more preferably 15-35.
  • the average fiber length and average fiber diameter of titanate (B) can be measured by observation with a scanning electron microscope (SEM).
  • the average aspect ratio (average fiber length/average fiber diameter) of the titanate (B) can be calculated from the average fiber length and average fiber diameter. For example, a plurality of titanates (B) are photographed with a scanning electron microscope (SEM), 300 titanates (B) are arbitrarily selected from the observation image, and their fiber lengths and fiber diameters are measured.
  • An average fiber length can be obtained by accumulating all fiber lengths and dividing by the number, and an average fiber diameter can be obtained by accumulating all fiber diameters and dividing by the number.
  • a fibrous particle is a rectangular parallelepiped having the smallest volume among the rectangular parallelepipeds circumscribing the particle (circumscribing rectangular parallelepiped).
  • thickness T B>T
  • the major axis L corresponds to the fiber length
  • the minor axis B corresponds to the fiber diameter.
  • non-fibrous particles refer to particles having an L/B ratio of less than 3.
  • particles having an L/B of less than 3 and an L/T of 3 or more are called plate-like particles.
  • the true specific gravity of the titanate (B) is not particularly limited, but is preferably 3 g/cm 3 to 4.5 g/cm 3 , more preferably 3.2 g/cm 3 to 4.3 g/cm 3 . More preferably, it is 3.3 g/cm 3 to 4 g/cm 3 .
  • the total content of titanium dioxide (A) and titanate (B) in the aqueous coating composition of the present invention is 5% by mass to 70% by mass with respect to 100% by mass of the total amount of the aqueous coating composition. is preferred, more preferably 6% to 50% by mass, even more preferably 7% to 35% by mass, and particularly preferably 10% to 20% by mass.
  • the film-forming properties of the water-based coating composition can be further improved, and a coating film with even higher heat-shielding properties and lower gloss can be formed. .
  • the content of the titanate (B) in the aqueous coating composition of the present invention is preferably 1% by mass to 40% by mass with respect to 100% by mass of the total amount of the aqueous coating composition, and 3% by mass to It is more preferably 30% by mass, even more preferably 5% to 20% by mass, and particularly preferably 5% to 15% by mass.
  • the content of the titanate (B) is at least the above lower limit, the film-forming properties of the aqueous coating composition can be further improved, and the mechanical strength of the resulting coating film can be further improved. can.
  • the content of the titanate (B) is equal to or less than the above upper limit, it is possible to form a coating film with even higher heat shielding properties and lower glossiness.
  • the content ratio of titanate (B) to titanium dioxide (A) is 0.1 to 9.0 in mass ratio (titanate (B)/titanium dioxide (A)). It is preferably from 0.25 to 4.0, even more preferably from 0.30 to 3.0, and particularly preferably from 0.40 to 2.4.
  • the mass ratio (titanate (B)/titanium dioxide (A)) is at least the above lower limit, the film-forming properties of the water-based coating composition can be further improved, resulting in a coating film with even lower gloss. can be formed.
  • the mass ratio (titanate (B)/titanium dioxide (A)) is equal to or less than the above upper limit, a coating film having even better heat shielding properties can be formed.
  • the content ratio of titanate (B) to titanium dioxide (A) is 0.07 to 15.0 in terms of volume ratio (titanate (B)/titanium dioxide (A)). It is preferably 0.15 to 6.8, even more preferably 0.25 to 4.0.
  • the volume ratio (titanate (B)/titanium dioxide (A)) is at least the above lower limit, the film-forming properties of the water-based coating composition can be further improved, resulting in a coating film with even lower gloss. can be formed.
  • the volume ratio (titanate (B)/titanium dioxide (A)) is equal to or less than the above upper limit, a coating film with even better heat shielding properties can be formed.
  • the aqueous coating composition of the present invention contains an aqueous medium (C).
  • aqueous medium includes water, an organic solvent miscible with water, or a mixture thereof.
  • the organic solvent miscible with water is not particularly limited, but for example, alcohol solvents such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; ketones such as acetone; ethers such as tetrahydrofuran and dioxane; nitriles such as acetonitrile; Esters such as ethyl and propylene carbonate can be mentioned.
  • the water-based resin (D), which will be described later, is represented only by the resin solid content. Therefore, when an emulsion resin, for example, is used as a raw material for the aqueous resin (D), water, which is a dispersion medium for the emulsion resin, is included in the aqueous medium (C).
  • water which can be contained in the raw material of the aqueous resin (D)
  • examples of water that can be used as the aqueous medium (C) include tap water, ion-exchanged water, purified water, pure water, and the like.
  • the content of the aqueous medium (C) is preferably 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass, with respect to 100% by mass of the total amount of the aqueous coating composition. . If the content of the aqueous medium (C) is less than the above lower limit, the aqueous resin (D) may not be dispersed satisfactorily, resulting in poor fluidity. If the content of the aqueous medium (C) is larger than the above upper limit, problems may occur during drying of the coating film (deterioration of leveling, separation, etc.), and the coating film-forming ability and adhesion to the substrate may deteriorate. be.
  • Aqueous resin (D) The aqueous coating composition of the present invention contains an aqueous resin (D).
  • Aqueous resin (D) is a resin that can be dissolved or dispersed in water.
  • the resin species of the water-based resin (D) is not particularly limited as long as it has a coating film-forming ability.
  • aqueous resin (D) examples include water-insoluble acrylic resins, silicone resins, urethane resins, fluorine resins, vinyl acetate resins, epoxy resins, phenol resins, polyester resins, polycarbonate resins, Ethylene-based resins, vinyl chloride-based resins, alkyd-based resins, melamine-based resins, and the like can be mentioned. These may be used individually by 1 type, and may use multiple types together. These resins may be modified, for example, urethane-modified acrylic resins, may be graft-polymerized, or may be used in the form of dispersed particles.
  • water-based resin (D) it is preferable to use an "emulsion resin" in which fine particles of resin are dispersed in water, which is usually used as a coating material.
  • the emulsion resin is an acrylic silicone emulsion resin or a fluorine emulsion resin from the viewpoint of making the coating film lower gloss, further improving the design property, and further improving the weather resistance and durability. is preferred, and an acrylic silicone emulsion resin is more preferred.
  • the water-based resin (D) is preferably an emulsion resin as described above, from the viewpoint of being easier to mix during the production of the water-based coating composition of the present invention.
  • the resin concentration of the emulsion resin is preferably 15% by mass to 65% by mass from the viewpoint of lowering the glossiness of the coating film and further enhancing the design. Among them, emulsion resins having a resin concentration of 30% by mass to 60% by mass, which are suitably used in the field of paints, are more preferable.
  • the main dispersion medium of the emulsion resin is water, and the water becomes part of the aqueous medium (C), which is the dispersion medium of the aqueous coating composition of the present invention.
  • the aqueous resin (D) When the aqueous resin (D) is in the form of dispersed particles, it can have a monolayer structure (homogeneous particles) or a multilayer structure such as a core-shell structure. In the case of core-shell structures, the core and/or shell may be crosslinked.
  • the aqueous resin (D) is preferably an acrylic resin from the viewpoint of further improving the durability and weather resistance of the resulting coating film.
  • acrylic resins include resins obtained by (co)polymerizing at least one (meth)acryloyl group-containing compound, optionally with other copolymerizable unsaturated monomers. can.
  • (meth)acryloyl refers to methacryloyl or acryloyl.
  • (Meth)acrylate refers to methacrylate or acrylate.
  • (meth)acryl refers to methacryl or acryl.
  • (Meth)acryloyl group-containing compounds include compounds having one (meth)acryloyl group in one molecule or compounds having at least two (meth)acryloyl groups in one molecule.
  • Compounds having one (meth)acryloyl group in one molecule include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth) linear or branched alkyl group-containing (meth)acryloyl monomers such as acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate; Alicyclic alkyl group-containing (meth)acryloyl monomers such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate; aralkyl group-containing (meth)acryloyl monomers such as benzyl (meth)acrylate; 2-methoxyethyl (meth)acryl
  • Compounds having at least two (meth)acryloyl groups in one molecule include, for example, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth) Acrylates, 1,3-butylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerol di(meth)acrylate, 1,1,1-trishydroxymethylethane di(meth)acrylate, 1,1,1 -trishydroxymethylethane tri(meth)acrylate, 1,1,1-tri
  • polymerizable unsaturated monomers that can be copolymerized include (meth)acrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl aromatic compounds such as styrene and ⁇ -methylstyrene; , diallyl terephthalate, divinylbenzene and the like polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule; allyl alcohol; carboxyl group-containing polymerizable unsaturated monomers such as maleic acid and crotonic acid; (meth)acrolein , formyl styrene, vinyl alkyl ketones having 4 to 7 carbon atoms (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), carbonyl group-containing polymerizable unsaturated monomers such as acetoacetoxy allyl ester; epoxy group-containing polymerizable unsaturated monomers; isocyana
  • the aqueous resin (D) also includes water-soluble polymer compounds such as polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, sodium polyacrylate, and ethylene-maleic anhydride copolymer. be.
  • the viscosity of the aqueous resin (D) is not particularly limited, but is preferably 50 mPa ⁇ s or more, more preferably 100 mPa ⁇ s or more, still more preferably 200 mPa ⁇ s or more, particularly preferably 300 mPa ⁇ s or more, preferably 10000 mPa ⁇ s. Below, it is more preferably 5000 mPa ⁇ s or less, still more preferably 3000 mPa ⁇ s or less, and particularly preferably 2500 mPa ⁇ s or less.
  • the viscosity of the aqueous resin (D) can be measured, for example, at 25°C with a viscosity measuring device such as an ultrasonic viscometer, a B-type viscometer, or an E-type viscometer.
  • a viscosity measuring device such as an ultrasonic viscometer, a B-type viscometer, or an E-type viscometer.
  • the content of the aqueous resin (D) is preferably in the range of 2% by mass to 50% by mass, preferably 10% by mass to 30% by mass, as a resin solid content with respect to 100% by mass of the total amount of the aqueous coating composition. % range is more preferable. If the content of the water-based resin (D) is less than the above lower limit, it may not be possible to obtain a low-gloss coating film with good design. On the other hand, if the content of the aqueous resin (D) exceeds the above upper limit, the resin content may be too large, making it difficult to produce the aqueous coating composition.
  • the water-based paint composition of the present invention may contain other additives commonly used in paints, as long as the effects of the present invention are not impaired.
  • Other additives include, if necessary, hollow particles, alkyl silicates, aggregates, fibers, plasticizers, leveling agents, anti-sagging agents, fluorescent brightening agents, coloring pigments, silane coupling agents, and neutralizing agents.
  • antistatic agent such as flame retardants can be included as optional ingredients.
  • hollow particles include hollow inorganic particles and hollow resin particles.
  • the formed coating film can more efficiently reflect solar radiation and the like, and can further enhance the heat insulating effect. Therefore, the temperature rise of the substrate can be further suppressed. In addition, when the water-based coating composition contains hollow particles, the glossiness of the formed coating film can be further lowered.
  • inorganic substances that make up the hollow inorganic particles include glasses such as sodium silicate glass, aluminum silicate glass, and sodium borosilicate glass; fly ash, alumina, zirconia/titania, silicon boride, shirasu, and obsidian.
  • resin components constituting the hollow resin particles include acrylic resins, styrene resins, acrylic-styrene copolymer resins, acrylic-acrylonitrile copolymer resins, acrylic-styrene-acrylonitrile copolymer resins, acrylonitrile-methacrylonitrile copolymer resins, Acryl-acrylonitrile-methacrylonitrile copolymer resin, vinylidene chloride-acrylonitrile copolymer resin and the like can be mentioned.
  • the inside of the hollow particles may be air, a gas other than air, or a vacuum.
  • the average particle diameter of the hollow particles is preferably 5 ⁇ m to 150 ⁇ m, more preferably 10 ⁇ m to 100 ⁇ m, from the viewpoint of further improving the coating film appearance, coating film physical properties, and heat shielding effect.
  • the average particle size of the hollow particles can be obtained by taking scanning electron microscope (SEM) photographs, measuring the particle sizes of 50 particles, and averaging them.
  • the bulk density of the hollow particles is preferably 0.01 g/cm 3 to 1.0 g/cm 3 . Further, the true density is preferably 0.01 g/cm 3 to 1.2 g/cm 3 .
  • the content thereof is preferably 1% by mass to 50% by mass, more preferably 1% by mass, based on the resin solid content contained in the aqueous coating composition. 30% by mass, more preferably 1.5% by mass to 15% by mass, particularly preferably 1.5% by mass to 10% by mass, and even more preferably 1.5% by mass to 4.0% by mass. 5% by mass.
  • the storage stability of the water-based paint and the crack resistance of the resulting coating film can be further enhanced.
  • the water-based paint composition may contain an alkylsilicate compound for the purpose of imparting stain resistance to the formed coating film.
  • Alkylsilicate compounds include, for example, compounds represented by the formula: Si(--OR 1 ) 4 and partial hydrolysates and condensates thereof. (Wherein, R 1 is the same or different monovalent hydrocarbon group selected from an alkyl group, an aryl group and an aralkyl group.)
  • R 1 is preferably an alkyl group having 1 to 4 carbon atoms.
  • alkylsilicate compounds include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-isopropoxysilane, tetra-n-butoxysilane, tetra-isobutoxysilane, tetra-t-butoxysilane, and Any combination thereof, as well as partial hydrolysates and condensates thereof are included. Further, compounds obtained by further modifying these exemplified compounds with polyoxyalkylene compounds or the like are also included as alkylsilicate compounds.
  • a catalyst such as an organic tin compound, an organic titanate compound, a phosphoric acid compound, an acid anhydride, or an amine may be used in combination.
  • the water-based paint composition of the present invention contains the above alkylsilicate compound, it is desirable to make the paint composition a two-pack type and mix the component containing the alkylsilicate compound with other components immediately before use.
  • the content is based on the resin solid content contained in the coating. , preferably 3% by mass to 20% by mass, more preferably 5% by mass to 15% by mass.
  • film-forming aids include isobutyric acid ester-based, ethylene glycol-based, and propylene glycol-based film-forming aids.
  • film-forming aids that can be used include 2,2,4-trimethyl-1,3-pentanediol-2-methylpropanoate and butyl cellosolve.
  • the coating film can be crosslinked even under normal temperature drying conditions, and even under severe outdoor conditions.
  • a coating film having excellent long-term durability can be formed.
  • dispersants include water-based wetting and dispersing agents such as block copolymers and random copolymers that have affinity for pigments.
  • the water-based wetting and dispersing agent may be a resin having a certain amount of acid value shown below, or may be a resin not having a certain amount of acid value.
  • the resin having an acid value has an acid value per solid within the range of 2.5 mgKOH/g to 30 mgKOH/g, preferably within the range of 3 mgKOH/g to 25 mgKOH/g.
  • the acid value per solid content of the resin having an acid value is less than the above lower limit, aggregates may form when the water-based coating composition is stored for a long period of time, and color stability may deteriorate when multiple colors are mixed. Sometimes inferior.
  • the formed coating film may have poor water resistance.
  • a carboxyl group, a sulfonic acid group, a phosphoric acid group, etc. can be mentioned as acid groups that give an acid value to a resin having an acid value.
  • a carboxyl group is preferable as an acid group that imparts an acid value to a resin having an acid value.
  • these acid groups are partially or It may be substantially completely neutralized.
  • functional groups other than acid groups possessed by water-based wetting and dispersing agents include, for example, hydroxyl groups, isocyanato groups, amino groups, amide groups, and carbonyl groups.
  • hydroxyl groups for example, hydroxyl groups, isocyanato groups, amino groups, amide groups, and carbonyl groups.
  • carbonyl groups from the viewpoint of further improving weather resistance under severe conditions such as outdoors, it is desirable to have a carbonyl group as another functional group.
  • the water-based wetting and dispersing agent has a carboxyl group and a carbonyl group
  • (meth)acrylic acid and/or other carboxyl group-containing polymerizable unsaturated monomers described above are used as at least part of the monomer components, using a carbonyl group-containing (meth)acryloyl monomer and/or other carbonyl group-containing polymerizable unsaturated monomer and copolymerizing it with another (meth)acryloyl group-containing compound and/or other polymerizable unsaturated monomer can produce a water-based wetting and dispersing agent.
  • the content of the dispersant in the aqueous coating composition of the present invention is 0.1% by mass to 10% with respect to 100% by mass of the total amount of the aqueous coating composition. It is preferably 0.2% by mass to 8% by mass, more preferably 0.2% by mass to 8% by mass. If the content of the dispersant is less than the above lower limit, the titanium dioxide and titanate cannot be dispersed well, causing aggregation and segregation in the coating film, which may deteriorate the mechanical strength of the coating film. . If the content of the dispersant is larger than the above upper limit, the film-forming properties may deteriorate.
  • antifoaming agents include a mixed solution in polyglycol containing foam-breaking polysiloxane and hydrophobic particles.
  • an inorganic thickener may be used, or an organic thickener may be used.
  • inorganic thickeners include silica-based, clay mineral-based, and calcium carbonate-based thickeners.
  • organic thickeners include wax-based, polyurethane-based, cellulose derivative-based, and polyacrylic acid-based thickeners.
  • organic thickeners include montmorillonite, polyethylene oxide, hydroxyethyl cellulose, and polyacrylic acid.
  • the water-based paint composition of the present invention may further contain any appropriate color pigment as necessary, as long as it does not impair its preferred physical properties.
  • coloring pigments include inorganic pigments such as yellow lead, yellow iron oxide, iron oxide, and carbon black; azochelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, dioxane-based pigments, quinacridone-based pigments, isoindolinone-based pigments, metal complex pigments, and the like. These may be used alone or in combination of two or more.
  • the content of the coloring pigment is preferably 0.5% by mass relative to the content of titanium dioxide (A).
  • the water-based paint composition of the present invention may further contain other pigments to the extent that the effects of the present invention are not impaired.
  • Other pigments include, for example, silica; barium sulfate; alumina; whisker white pigment; and magnesium carbonate.
  • examples of aggregates include sand, gravel, powdered stone, resin particles, and the like.
  • aggregates used in paints include, for example, silica sand, kansuiseki, perlite, ceramics, shells, and the like.
  • the role of aggregates is to prevent cracks, suppress shrinkage, improve abrasion resistance, adjust film thickness, and prevent slippage.
  • the particle size is not particularly limited as long as it does not impair the effect in each application.
  • the average particle size is 150 ⁇ m or less, it is preferably used for walls and roofs of buildings from the viewpoint of mechanical addition during spray coating and surface finish.
  • the water-based coating composition of the present invention can form a matte coating film with excellent heat-shielding properties by coating it on the surface of a substrate.
  • the substrate surface to which the aqueous coating composition of the present invention can be applied is not particularly limited.
  • ALC plate cement calcium silicate plate, brick, glass, wood, stone, plastic molded product, ceramics, porcelain tile, iron part, surface of base material such as metal processing material such as aluminum sash;
  • Acrylic resin acrylic urethane resin, polyurethane resin, fluorine resin, silicone resin, silicone acrylic resin, vinyl acetate resin, epoxy resin, etc., polyvinyl chloride, polyolefin, paper, cloth
  • a wall paper surface or the like made of a material such as The surface of these substrates may be previously treated with a sealer or the like.
  • the water-based coating composition of the present invention can be applied using known coating means. It can be appropriately selected and used according to the type, application, and the like. In addition, the water-based coating composition of the present invention can be applied multiple times within a range that does not impair the appearance of the coating film.
  • the formed coating film can be dried at room temperature.
  • the formed coating film may be heat-dried or forced-dried depending on the composition of the coating composition used, the coating environment, and the like.
  • the dry film thickness can be appropriately adjusted depending on the substrate to be applied and the coating environment, but from the viewpoint of obtaining more sufficient heat shielding properties, it is, for example, 35 ⁇ m to 5000 ⁇ m, preferably 50 ⁇ m to 3000 ⁇ m.
  • the method of using the water-based coating composition of the present invention is a method of suppressing the temperature rise inside a building by applying the water-based coating composition to the roof, exterior wall surface, and/or interior surface of the building.
  • the water-based coating composition of the present invention has heat-shielding properties and can form a coating film having an appropriate matt feeling. It gives the surface a calm appearance and maintains the heat shielding function for a long period of time.
  • Exterior wall surfaces of buildings include exterior wall surfaces of various buildings such as buildings, houses, facilities, and warehouses.
  • Common exterior wall materials that constitute the exterior walls of buildings include inorganic exterior materials such as ceramic siding boards, mortar, concrete, and slate, and metal materials such as iron, aluminum, and metal siding.
  • Exterior materials, wood-based exterior materials such as natural wood and plywood, and the like can be used.
  • the method of using the water-based coating composition of the present invention is a method of suppressing the temperature rise on the outer surface of the building by coating the roof and/or the outer wall surface of the building with the water-based coating composition. good too.
  • the water-based paint composition of the present invention is less likely to crack even on the outer surface of a building exposed to a harsh environment, gives a calm appearance for a long time and maintains a heat-shielding function.
  • the heat island phenomenon can be suppressed because the temperature rise in can be suppressed for a long period of time.
  • the method of using the aqueous coating composition of the present invention may be a method of suppressing the temperature rise of the road surface by coating the paved surface of the road with the aqueous coating composition.
  • the water-based coating composition of the present invention does not easily crack even on road surfaces exposed to harsh environments, provides a calm appearance for a long period of time, maintains a heat-shielding function, and prevents the temperature rise of the road surface for a long period of time. Since it can be suppressed, the heat island phenomenon can be suppressed.
  • the method of using the aqueous coating composition of the present invention may be a method of suppressing temperature rise inside the tank by coating the outer wall surface of the tank with the aqueous coating composition.
  • the water-based coating composition of the present invention is less likely to crack even on the outer wall surface of the tank exposed to harsh environments, and can maintain the heat shielding function for a long period of time, so volatilization of the contents of the tank is suppressed. can do.
  • the content of the tank here includes, for example, a volatile organic solvent, a liquid such as water, a mixture of these liquids, or a volatile gas.
  • the water-based coating composition of the present invention can optionally be applied onto the surface of the base that is formed after the surface of the substrate has been previously coated with an undercoat.
  • the undercoat paint can be appropriately selected according to the type and condition of the base material surface.
  • the undercoat paint include acrylic resins, acrylic silicone resins, fluorine resins, polyvinyl acetate resins, polyolefin resins, silicone resins, polyurethane resins, epoxy resins, phenol resins, polyester resins, Coatings containing water-based or solvent-based resins such as alkyd-based resins, melamine-based resins and biodegradable resins as resin binders can be mentioned.
  • the undercoat paint it is preferable to use a water-based paint containing a water-based resin.
  • the heat-shielding performance of the substrate surface can be further enhanced together with the coating film of the water-based coating composition of the present invention.
  • the application of the undercoat paint can be performed using known painting means.
  • the undercoat paint can be applied by appropriately selecting from coating methods such as roller, air spray, airless spray, lysing gun, all-purpose gun, brush, and roll coater, depending on the intended use of the base material. Drying of the undercoat film to be formed is preferably carried out at room temperature, but depending on the type of undercoat paint and the coating environment, heat drying or forced drying can be carried out.
  • the water-based coating composition of the present invention by applying the water-based coating composition of the present invention to the outer wall surface of a building, it is possible to suppress the temperature rise inside the building.
  • the method for producing the aqueous coating composition of the present invention is not particularly limited, and any appropriate method can be adopted.
  • a method for producing the aqueous coating composition of the present invention for example, titanium dioxide (A), titanate (B), aqueous medium (C), aqueous resin (D), and, if necessary, other components can be kneaded and dispersed using an SG mill, shaker, disper, or the like.
  • the titanium dioxide (A) is preferably prepared as a pigment paste in advance and then mixed with the water-based resin (D) and other components to disperse.
  • the pigment titanium dioxide (A) can be dispersed more stably and sufficiently.
  • the coated part of the present invention can be produced by forming a coating film on the substrate surface by the method for producing a coating film using the aqueous coating composition described above.
  • the roof, outer wall surface and/or interior surface of a building with the water-based coating composition described above, it is possible to suppress the temperature rise inside the building.
  • the temperature rise on the outer surface of the building can be suppressed for a long period of time, so the heat island phenomenon can be suppressed. .
  • the pavement surface of the road with the water-based coating composition described above, it is possible to suppress the temperature rise of the road surface over a long period of time, thereby suppressing the heat island phenomenon. Furthermore, by coating the outer wall surface of the tank with the above-described water-based paint composition, cracks are less likely to occur and the heat shielding function can be maintained for a long period of time, so volatilization of the contents of the tank is suppressed. be able to.
  • a coated article having a solar radiation penetration ratio of 0.01 to 0.4 can be produced.
  • the coated article of the present invention can be suitably used, for example, for roofs and interiors of buildings that have a low environmental load and require weather resistance.
  • Titanium dioxide crystalline rutile, average particle size: 0.30 ⁇ m, oil absorption: 18 g/100 g, specific gravity: 4.1 g/cm 3 , pH: 6.0 to 8.0, manufactured by Tayca, trade name: JR -701"
  • Fibrous titanate 1 fibrous potassium hexatitanate, average fiber length: 15 ⁇ m, average fiber diameter: 0.5 ⁇ m, true specific gravity: 3.4 g/cm 3 to 3.6 g/cm 3 , pH: 7 to 8 , manufactured by Otsuka Chemical Co., Ltd., trade name: "TISMO N"
  • Fibrous titanate 2 fibrous potassium octatitanate, average fiber length: 15 ⁇ m, average fiber diameter: 0.5 ⁇ m, true specific gravity: 3.4 g/cm 3 to 3.6 g/cm 3 , pH: 9 to 10 , manufactured by Otsuka Chemical Co., Ltd., trade name: "TISMO D"
  • Example 1 Preparation of water-based paint composition> 0.78 g of titanium dioxide, 1.82 g of fibrous titanate (fibrous titanate 1), 5.60 g of deionized water, 0.49 g of dispersant and 0.015 g of antifoaming agent were mixed. Next, the mixture was stirred for 5 minutes at 3000 rpm with a high-speed disperser Homodisper Model 2.5 (manufactured by PRIMIX) to obtain a pigment paste.
  • a high-speed disperser Homodisper Model 2.5 manufactured by PRIMIX
  • Example 2 2.07 g of titanium dioxide, 0.52 g of fibrous titanate (fibrous titanate 1), 3.23 g of ion-exchanged water, 0.49 g of dispersant, and 0.015 g of antifoaming agent were mixed.
  • a water-based coating composition was obtained in the same manner as in Example 1, except that the composition shown in .
  • Example 3 1.82 g of titanium dioxide, 0.78 g of fibrous titanate (fibrous titanate 1), 3.50 g of ion-exchanged water, 0.49 g of dispersant, and 0.015 g of antifoaming agent were mixed and mixed.
  • a water-based coating composition was obtained in the same manner as in Example 1, except that the composition shown in 1 was used.
  • Example 4 1.25 g of titanium dioxide, 1.10 g of fibrous titanate (fibrous titanate 1), 3.57 g of ion-exchanged water, 0.24 g of dispersant, and 0.047 g of antifoaming agent were mixed.
  • a pigment paste was obtained in the same manner as in Example 1, except that the composition shown in 1 was used.
  • Example 1 except that 8.62 g of an aqueous resin, 0.862 g of a film-forming aid, and 0.025 g of a thickener were added to the obtained pigment paste while stirring to obtain the composition shown in Table 1 below.
  • a water-based coating composition was obtained in the same manner.
  • Example 5 Water-based paint was prepared in the same manner as in Example 4, except that fibrous titanate (fibrous titanate 2) was used instead of fibrous titanate (fibrous titanate 1) in Example 4. A composition was obtained.
  • Example 6 1.37 g of titanium dioxide, 1.21 g of fibrous titanate (fibrous titanate 1), 0.45 g of hollow particles, 3.35 g of deionized water, 0.49 g of dispersant, and 0.015 g of antifoaming agent are mixed.
  • a water-based coating composition was obtained in the same manner as in Example 1, except that the composition shown in Table 1 below was used.
  • Example 7 A water-based coating composition was obtained in the same manner as in Example 4, except that the fibrous titanate (fibrous titanate 1) of Example 4 was replaced with a non-fibrous titanate.
  • Table 1 shows the formulation and evaluation results of each paint of Examples 1 to 7 and Comparative Example 1.
  • the coated article produced using the water-based coating composition of Comparative Example 1 has a glossy coating film appearance, feels dazzling, has a glossiness of 77, and is glossy.
  • the film-forming property was poor, the tensile strength was 1.67 N/mm 2 , the pencil hardness was 3B, and the cross-cut test was class 2, indicating that the strength, hardness and adhesiveness of the coating film were weak.
  • the coated article produced using the water-based coating composition of Example 1 there was no gloss unevenness, and a sufficiently calm matte feeling was felt, and the glossiness was 21, which was low gloss.
  • it has excellent film-forming properties, a tensile strength of 3.83 N/mm 2 , a pencil hardness of 6H, and a cross-cut test of class 0, indicating that the strength, hardness, and adhesion of the coating film are improved.
  • the same tendency as in Example 1 is observed in Examples 2 to 7 as well.
  • Comparative Example 1 in which only titanium dioxide was blended in the water-based coating composition and no titanate was blended, the coating film appearance was glossy, felt dazzling, and was glossy, and had film-forming properties. Poor mechanical strength (tensile strength, hardness, adhesion) was lowered.
  • a water-based coating composition containing both titanium dioxide and titanate it is possible to provide a coated article with excellent heat shielding properties (solar reflectance and solar radiation penetration ratio) and a good coating film appearance. becomes.
  • the aqueous coating composition and coated article of the present invention can form a low-gloss coating film with excellent film-forming properties, it can be used, for example, for roofs, exterior walls, and / or interiors of buildings. It is thought that the application of this material will give the appearance of a building with a calm atmosphere, and will also contribute to energy conservation in air conditioning, light sources, and the like.
  • the coating film formed from the water-based coating composition of the present invention is less likely to crack even in severe environments such as outdoor exposure, and maintains the excellent appearance and heat shielding function of the coating film for a long period of time. Therefore, for example, it can be applied to the paved surface of a road, the outer wall surface of a tank, etc., which are exposed to severe environments such as outdoor exposure.

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Abstract

Provided is an aqueous coating composition which has excellent film-forming properties and high heat-shielding properties, and can form a low-gloss coating film.　The aqueous coating composition has heat-shielding properties, and contains a titanium dioxide (A), a titanate (B), an aqueous medium (C), and an aqueous resin (D).

Description

水性塗料組成物、塗膜の製造方法、水性塗料組成物の使用方法、および塗装物品Water-based paint composition, method for producing coating film, method for using water-based paint composition, and coated article
　本発明は、遮熱性を有する水性塗料組成物、上記水性塗料組成物を用いた塗膜の製造方法、上記水性塗料組成物の使用方法、および上記水性塗料組成物を用いた塗装物品に関する。 The present invention relates to a heat-shielding water-based coating composition, a method for producing a coating film using the water-based coating composition, a method for using the water-based coating composition, and a coated article using the water-based coating composition.
　近年、建築物や建造物においては、太陽光等の熱エネルギーによる温度上昇を抑制することを目的として、屋根や外壁等に遮熱塗料を塗布することにより遮熱処理が施されることが多い。また、空調費用低減などの省エネルギーの観点から、遮熱塗料の需要は高まってきている。そのため、遮熱処理に用いられる遮熱塗料についても、さまざまな検討がなされている。 In recent years, buildings and structures are often subjected to heat shielding by applying heat shielding paint to roofs and outer walls, etc., with the aim of suppressing temperature rise due to thermal energy such as sunlight. In addition, from the viewpoint of energy saving such as air conditioning cost reduction, the demand for thermal insulation paint is increasing. Therefore, various studies have been made on heat-shielding paints used for heat-shielding heat treatment.
　下記の特許文献１には、可視領域で吸収を示し、近赤外領域では反射率３５％以上の有色有機顔料の２種以上を混合した、マンセル記号（Ｎ－１）の黒色を有する熱遮へい性黒色顔料組成物が開示されている。 Patent Document 1 below describes a thermal shielding material having a black color of Munsell symbol (N-1), which is a mixture of two or more colored organic pigments exhibiting absorption in the visible region and having a reflectance of 35% or more in the near-infrared region. A chromogenic black pigment composition is disclosed.
　下記の特許文献２には、サイディング材に遮熱性カラー塗料を塗布する方法が開示されている。特許文献２では、遮熱性カラー塗料が、７８０ｎｍ～２１００ｎｍの波長域における日射反射率が２０％以上である、２種以上の原色塗料を組み合わせることにより調製されるものであることが記載されている。 Patent Document 2 below discloses a method of applying a heat-shielding color paint to a siding material. Patent Document 2 describes that the heat-shielding color paint is prepared by combining two or more primary color paints having a solar reflectance of 20% or more in the wavelength range of 780 nm to 2100 nm. .
　また、下記の特許文献３には、顔料としての二酸化チタンおよび多孔質の炭酸カルシウムと、水性樹脂とを含む、水性塗料組成物が開示されている。 In addition, Patent Document 3 below discloses a water-based coating composition containing titanium dioxide as a pigment, porous calcium carbonate, and a water-based resin.
特開２００２－２０６４７号公報JP-A-2002-20647 特開２００２－３２０９１２号公報JP-A-2002-320912 特開２０１２－９２２８９号公報JP 2012-92289 A
　遮熱性能を有する顔料として二酸化チタンを用いた一般的な遮熱塗料は、艶のある仕上がり外観となり、外壁等で好まれる低光沢な落ち着きのある外観が得られない場合が多い。特許文献１および２に記載の遮熱塗料においても、屋根などに塗装するための艶有り塗膜を想定したものであることから、艶消しの落ち着きのある仕上がり外観が得られないという問題がある。また、特許文献１および２に記載の遮熱塗料では、十分な遮熱性が得られない場合がある。 A general thermal barrier paint that uses titanium dioxide as a pigment with thermal barrier performance has a glossy finished appearance, and in many cases it is not possible to obtain the low-gloss, calm appearance that is preferred for exterior walls. The thermal barrier paints described in Patent Documents 1 and 2 also have the problem of not being able to provide a matte finished appearance because they are intended to be a glossy coating film for painting on roofs and the like. . Moreover, the heat-shielding paints described in Patent Documents 1 and 2 may not provide sufficient heat-shielding properties.
　また、低光沢な塗膜を形成するために粒径の大きな顔料や炭酸カルシウムなどが用いられることがある。特許文献３においても、特定の炭酸カルシウムを用いることで、光の拡散反射率が高く、低光沢の塗膜を形成できることが記載されている。しかしながら、この場合、粒径や形状の面から造膜性が不十分になる。そのため、特許文献３のような水性塗料組成物では、造膜性が十分ではなく、塗膜の機械的強度を十分に高めることができないという問題がある。そのため、塗膜のひび割れも発生し易く、塗膜の優れた外観や遮熱機能を長期に亘って維持することが難しいという問題がある。 In addition, pigments with a large particle size, calcium carbonate, etc. are sometimes used to form a low-gloss coating film. Patent Document 3 also describes that a coating film with high diffuse reflectance and low glossiness can be formed by using a specific calcium carbonate. However, in this case, the film formability becomes insufficient in terms of particle size and shape. Therefore, the water-based coating composition as disclosed in Patent Document 3 has a problem that the film-forming property is not sufficient and the mechanical strength of the coating film cannot be sufficiently increased. Therefore, cracking of the coating film is likely to occur, and there is a problem that it is difficult to maintain the excellent appearance and heat shielding function of the coating film over a long period of time.
　本発明は、かかる問題を解決することを目的とし、造膜性に優れ、遮熱性が高くかつ低光沢の塗膜を形成することができる、水性塗料組成物、上記水性塗料組成物を用いた塗膜の製造方法、上記水性塗料組成物の使用方法、および上記水性塗料組成物を用いた塗装物品を提供することを目的とする。 An object of the present invention is to solve such problems, and an aqueous coating composition that can form a coating film having excellent film-forming properties, high heat-shielding properties, and low gloss, and the aqueous coating composition using the above-mentioned aqueous coating composition. An object of the present invention is to provide a method for producing a coating film, a method for using the water-based coating composition, and a coated article using the water-based coating composition.
　本発明者らは、上記課題を解決するべく鋭意検討を重ねた結果、遮熱性を有する水性塗料組成物において、二酸化チタン（Ａ）、チタン酸塩（Ｂ）、水性媒体（Ｃ）、および水性樹脂（Ｄ）を含有することにより、造膜性に優れ、遮熱性が高くかつ低光沢の塗膜を形成することができる、塗膜が得られることを見出し、本発明を完成するに至った。 The present inventors have made intensive studies to solve the above problems, and as a result, in a water-based coating composition having heat-shielding properties, titanium dioxide (A), titanate (B), an aqueous medium (C), and an aqueous By containing the resin (D), it was found that a coating film having excellent film-forming properties, high heat-shielding properties, and low gloss can be obtained, and the present invention was completed. .
　即ち、本発明の要旨は以下の通りである。 That is, the gist of the present invention is as follows.
　項１　遮熱性を有する水性塗料組成物であって、二酸化チタン（Ａ）、チタン酸塩（Ｂ）、水性媒体（Ｃ）、および水性樹脂（Ｄ）を含有する、水性塗料組成物。 Item 1. An aqueous coating composition having heat-shielding properties, containing titanium dioxide (A), titanate (B), aqueous medium (C), and aqueous resin (D).
　項２　前記二酸化チタン（Ａ）が非繊維状粒子であり、前記チタン酸塩（Ｂ）が繊維状粒子または非繊維状粒子である、項１に記載の水性塗料組成物。 Item 2 The aqueous coating composition according to Item 1, wherein the titanium dioxide (A) is non-fibrous particles, and the titanate (B) is fibrous particles or non-fibrous particles.
　項３　前記チタン酸塩（Ｂ）が、Ａ２ＴｉｎＯ（２ｎ＋１）〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ｎは２～１１の数〕、ＡｘＭｙＴｉ（２－ｙ）Ｏ４〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ＭはＬｉ、Ｍｇ、Ｚｎ、Ｇａ、Ｎｉ、Ｃｕ、Ｆｅ、Ａｌ、Ｍｎより選ばれる１種または２種以上、ｘは０．５～１．０、ｙは０．２５～１．０の数〕、およびＡ０．２～０．８Ｌｉ０．２～０．４Ｔｉ１．６～１．８Ｏ３．７～３．９５〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上〕、Ａ０．２～０．８Ｍｇ０．３～０．５Ｔｉ１．５～１．７Ｏ３．７～３．９５〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上〕よりなる群から選択される１種または２種以上である、項１または項２に記載の水性塗料組成物。 Item 3 The titanate (B) is A 2 Ti n O (2n+1) [wherein A is one or more alkali metals excluding Li, n is a number from 2 to 11], A x M y Ti (2-y) O 4 [In the formula, A is one or more alkali metals excluding Li, and M is selected from Li, Mg, Zn, Ga, Ni, Cu, Fe, Al, and Mn. one or more, x is 0.5 to 1.0, y is a number of 0.25 to 1.0], and A 0.2 to 0.8 Li 0.2 to 0.4 Ti 1. 6-1.8 O 3.7-3.95 [wherein A is one or more alkali metals excluding Li], A 0.2-0.8 Mg 0.3-0.5 Ti 1.5-1.7 O 3.7-3.95 [wherein A is one or more alkali metals excluding Li], 3. The water-based coating composition according to item 1 or item 2.
　項４　前記二酸化チタン（Ａ）と前記チタン酸塩（Ｂ）の合計含有量が、水性塗料組成物の合計量１００質量％に対して、５質量％以上、７０質量％以下である、項１～項３のいずれか一項に記載の水性塗料組成物。 Item 4 Item 1, wherein the total content of the titanium dioxide (A) and the titanate (B) is 5% by mass or more and 70% by mass or less with respect to the total amount of 100% by mass of the aqueous coating composition. 3. The water-based coating composition according to any one of items 3 to 4.
　項５　前記二酸化チタン（Ａ）に対するチタン酸塩（Ｂ）の質量比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））が、０．１以上、９．０以下である、項１～項４のいずれか一項に記載の水性塗料組成物。 Item 5 Items 1 to 3, wherein the mass ratio of titanate (B) to titanium dioxide (A) (titanate (B)/titanium dioxide (A)) is 0.1 or more and 9.0 or less 5. The aqueous coating composition according to any one of 4.
　項６　前記水性樹脂（Ｄ）が、アクリル系樹脂である、項１～項５のいずれか一項に記載の水性塗料組成物。 Item 6 The aqueous coating composition according to any one of Items 1 to 5, wherein the aqueous resin (D) is an acrylic resin.
　項７　前記水性樹脂（Ｄ）が、アクリルシリコーン系エマルジョン樹脂である、項１～項６のいずれか一項に記載の水性塗料組成物。 Item 7 The aqueous coating composition according to any one of Items 1 to 6, wherein the aqueous resin (D) is an acrylic silicone emulsion resin.
　項８　中空粒子をさらに含有する、項１～項７のいずれか一項に記載の水性塗料組成物。 Item 8 The aqueous coating composition according to any one of Items 1 to 7, further containing hollow particles.
　項９　基材表面に、項１～項８のいずれか一項に記載の水性塗料組成物を塗装する、塗膜の製造方法。 Item 9. A method for producing a coating film, wherein the aqueous coating composition according to any one of Items 1 to 8 is applied to the surface of a substrate.
　項１０　建築物の屋根、外壁面、および／または内装面に、項１～項８のいずれか一項に記載の水性塗料組成物を塗装することにより建築物内部の温度上昇を抑制する、水性塗料組成物の使用方法。 Item 10. A water-based paint composition that suppresses the temperature rise inside the building by coating the roof, exterior wall surface, and/or interior surface of the building with the water-based paint composition according to any one of Items 1 to 8. A method of using the coating composition.
　項１１　道路の舗装面に、項１～項８のいずれか一項に記載の水性塗料組成物を塗装することにより路面の温度上昇を抑制する、水性塗料組成物の使用方法。 Item 11 A method of using a water-based coating composition, wherein the water-based coating composition according to any one of Items 1 to 8 is applied to the paved surface of the road to suppress the temperature rise of the road surface.
　項１２　タンクの外壁面に、項１～項８のいずれか一項に記載の水性塗料組成物を塗装することによりタンク内部の温度上昇を抑制する、水性塗料組成物の使用方法。 Item 12 A method of using a water-based paint composition, wherein the water-based paint composition according to any one of Items 1 to 8 is applied to the outer wall surface of the tank to suppress the temperature rise inside the tank.
　項１３　基材と、前記基材表面に設けられている、項１～項８のいずれか一項に記載の水性塗料組成物の塗膜と、を備える、塗装物品。 Item 13 A coated article comprising a substrate and a coating film of the aqueous coating composition according to any one of Items 1 to 8 provided on the surface of the substrate.
　項１４　日射侵入比が０．０１～０．４である、項１３に記載の塗装物品。 Item 14 The coated article according to Item 13, wherein the solar radiation penetration ratio is 0.01 to 0.4.
　本発明によれば、造膜性に優れ、遮熱性が高くかつ低光沢の塗膜を形成することができる、水性塗料組成物、上記水性塗料組成物を用いた塗膜の製造方法、上記水性塗料組成物の使用方法、および上記水性塗料組成物を用いた塗装物品を提供することができる。 According to the present invention, a water-based coating composition that is excellent in film-forming properties, can form a low-gloss coating film with high heat-shielding properties, a method for producing a coating film using the water-based coating composition, and the water-based A method of using the coating composition and a coated article using the aqueous coating composition can be provided.
　以下、本発明を実施した好ましい形態の一例について説明する。ただし、以下の実施形態は単なる例示である。本発明は、以下の実施形態に何ら限定されない。 An example of a preferred embodiment of the present invention will be described below. However, the following embodiments are merely examples. The present invention is by no means limited to the following embodiments.
　＜水性塗料組成物＞
　本発明の水性塗料組成物は、遮熱性を有する水性塗料組成物であって、二酸化チタン（Ａ）、チタン酸塩（Ｂ）、水性媒体（Ｃ）、および水性樹脂（Ｄ）を含有し、必要に応じて、その他添加剤をさらに含有することができる。 <Aqueous paint composition>
The water-based coating composition of the present invention is a heat-insulating water-based coating composition containing titanium dioxide (A), a titanate (B), an aqueous medium (C), and an aqueous resin (D), Other additives can be further contained as necessary.
　本発明に係る水性塗料組成物は、上記の構成を備えるので、造膜性に優れ、遮熱性が高くかつ低光沢の塗膜を形成することができる。これについては、以下のようにして説明することができる。 Since the water-based coating composition according to the present invention has the above-described structure, it can form a coating film with excellent film-forming properties, high heat-shielding properties, and low gloss. This can be explained as follows.
　エマルジョンのような塗料の造膜では、粒子が相互に近接して最密状態に充填されるプロセス、粒子表面の保護層が破壊され、露出したポリマー粒子同士の接触により変形・融着が起こるプロセス、融着粒子間のポリマー鎖自由末端の相互拡散が進行して、より均質な膜を形成するプロセスを経て造膜されることが知られている。ここで、溶剤系塗料では、有機溶剤が粒子表面の保護層を溶解することにより、造膜されるが、水ではそのような効果が期待できないことから、従来の水系塗料は造膜性が悪い（塗膜の機械的強度が十分でない）という問題がある。 In the film formation of emulsion-like paints, a process in which particles are closely packed to close each other, a process in which the protective layer on the surface of the particles is destroyed and the exposed polymer particles come into contact with each other, causing deformation and fusion. It is known that a film is formed through a process in which interdiffusion of polymer chain free ends between fused particles progresses to form a more homogeneous film. Here, in solvent-based paints, the organic solvent dissolves the protective layer on the particle surface to form a film, but such an effect cannot be expected with water, so conventional water-based paints have poor film-forming properties. There is a problem that (mechanical strength of the coating film is not sufficient).
　これに対して、本発明の水性塗料組成物は、二酸化チタン（Ａ）に加えて、チタン酸塩（Ｂ）を含むので、塗膜の造膜性を向上させることができる。なお、この点については、電離し得るチタン酸塩（Ｂ）の表面が造膜助剤として機能しているものと考えられる。それによって、塗膜の機械的強度を高められるものと考えられる。 On the other hand, since the water-based coating composition of the present invention contains titanate (B) in addition to titanium dioxide (A), it is possible to improve the film-forming properties of the coating film. Regarding this point, it is considered that the surface of the ionizable titanate (B) functions as a film-forming aid. It is considered that the mechanical strength of the coating film can be enhanced thereby.
　また、二酸化チタン（Ａ）の一部の代わりにチタン酸塩（Ｂ）を加えた場合においても、遮熱性に優れ、低光沢の塗膜を形成することができる。 Also, even when the titanate (B) is added instead of part of the titanium dioxide (A), it is possible to form a coating film with excellent heat shielding properties and low gloss.
　なお、本発明の水性塗料組成物において、上記の効果が得られる理由は、以下のように説明することもできる。 The reason why the above effects are obtained in the aqueous coating composition of the present invention can also be explained as follows.
　本発明の水性塗料組成物のような塗料は、半製品である。すなわち、上記塗料は、塗装および乾燥中に不具合なく、設計通りの塗膜になってはじめて機能するものである。 A paint such as the water-based paint composition of the present invention is a semi-finished product. In other words, the above paints function only when they form a coating film as designed without any problems during coating and drying.
　本発明の水性塗料組成物で用いられるようなチタン酸塩（Ｂ）は、通常、二酸化チタンと同じ水分量だと、塗料として流動性が低下する場合がある。そのため、チタン酸塩（Ｂ）のみで流動性を向上させる場合には、水分量を多くすることが望ましい。しかしながら、水分量を多くすると乾燥時に乾きが遅く、フィラーの沈み込みといった不具合が起こる場合があり、塗膜組成が不均一になる。この場合、設計した塗膜性能が発揮できないことがある。 The titanate (B) used in the water-based paint composition of the present invention usually has the same water content as titanium dioxide, and may have reduced fluidity as a paint. Therefore, when the fluidity is to be improved only with the titanate (B), it is desirable to increase the water content. However, when the moisture content is increased, drying is slowed down, and problems such as filler sinking may occur, resulting in a non-uniform coating film composition. In this case, the designed film performance may not be exhibited.
　これに対して、本発明の水性塗料組成物では、チタン酸塩（Ｂ）に加えて、二酸化チタン（Ａ）を含んでいるので、上記の必要水分量を少なくすることができ、流動性を高めることができる。これは、チタン酸塩（Ｂ）の隙間を二酸化チタン（Ａ）で埋めることができるためであると考えられ、それによって得られる塗膜の強度、硬度といった耐久性を向上させることもできると考えられる。また、チタン酸塩（Ｂ）の隙間を二酸化チタン（Ａ）で埋めることができるため、得られる塗膜の隠ぺい性が向上し、遮熱性能も高められるものと考えられる。 On the other hand, the water-based coating composition of the present invention contains titanium dioxide (A) in addition to titanate (B), so that the above-mentioned required amount of water can be reduced and fluidity is improved. can be enhanced. It is believed that this is because the gaps in the titanate (B) can be filled with titanium dioxide (A), and it is thought that durability such as strength and hardness of the resulting coating film can be improved. be done. In addition, since the gaps in the titanate (B) can be filled with the titanium dioxide (A), the opacity of the obtained coating film is improved, and the heat shielding performance is also enhanced.
　以上のように、本発明の水性塗料組成物により形成された塗膜は、屋外暴露等の厳しい環境下においても、ひび割れが発生し難く、塗膜の優れた外観や遮熱機能を長期に亘って維持することができる。 As described above, the coating film formed from the water-based coating composition of the present invention is resistant to cracking even in severe environments such as outdoor exposure, and the coating film has excellent appearance and heat shielding function over a long period of time. can be maintained.
　以下、本発明の水性塗料組成物の各構成成分等について、より詳細に説明する。 Each constituent component of the water-based coating composition of the present invention will be described in more detail below.
　＜水性塗料組成物の必須成分＞
　（二酸化チタン（Ａ））
　本発明の水性塗料組成物は、二酸化チタン（Ａ）を含有する。本発明の水性塗料組成物は、二酸化チタン（Ａ）を含むことにより、日射侵入比が小さく、遮熱性に優れた塗膜を形成することができる。 <Essential components of water-based paint composition>
(Titanium dioxide (A))
The aqueous coating composition of the present invention contains titanium dioxide (A). By containing titanium dioxide (A), the water-based coating composition of the present invention can form a coating film having a small solar radiation penetration ratio and excellent heat shielding properties.
　二酸化チタン（Ａ）の製造方法としては、硫酸法、塩素法等が挙げられる。二酸化チタン（Ａ）は、好ましくは、塩素法により製造される。上記水性塗料組成物が、塩素法で製造された二酸化チタン（Ａ）を含む場合、日射侵入比がより小さく、遮熱性により一層優れた塗膜を形成することができる。 Examples of methods for producing titanium dioxide (A) include the sulfuric acid method and the chlorine method. Titanium dioxide (A) is preferably produced by the chlorine method. When the water-based coating composition contains titanium dioxide (A) produced by the chlorine method, it is possible to form a coating film having a lower solar radiation penetration ratio and a more excellent heat shielding property.
　二酸化チタン（Ａ）の結晶形としては、ルチル型、アナターゼ型、ブルッカイト型等が挙げられる。二酸化チタン（Ａ）の結晶形は、好ましくは、ルチル型である。ルチル型の二酸化チタン（Ａ）は、屈折率が高いことから、遮熱性により一層優れた塗膜を形成することができる。 Crystal forms of titanium dioxide (A) include rutile type, anatase type, and brookite type. The crystal form of titanium dioxide (A) is preferably rutile. Since rutile-type titanium dioxide (A) has a high refractive index, it is possible to form a coating film with even better heat shielding properties.
　二酸化チタン（Ａ）の粒子形状は、非繊維状であることが好ましい。非繊維状の二酸化チタン（Ａ）を用いた場合、粒子がより最密充填された塗膜を形成することができる。 The particle shape of titanium dioxide (A) is preferably non-fibrous. When non-fibrous titanium dioxide (A) is used, a coating film in which the particles are more closely packed can be formed.
　二酸化チタン（Ａ）の吸油量は、好ましくは１０ｇ／１００ｇ～４０ｇ／１００ｇであり、より好ましくは１３ｇ／１００ｇ～４０ｇ／１００ｇであり、さらに好ましくは１５ｇ／１００ｇ～４０ｇ／１００ｇである。 The oil absorption of titanium dioxide (A) is preferably 10 g/100 g to 40 g/100 g, more preferably 13 g/100 g to 40 g/100 g, still more preferably 15 g/100 g to 40 g/100 g.
　上記範囲の吸油量を有する二酸化チタン（Ａ）は、例えば、アルミナ、シリカ、ジルコン、亜鉛等で表面処理することにより表面処理層を形成し、比表面積を大きくすることにより得ることができる。このような観点から、二酸化チタン（Ａ）は、例えば、アルミナ、シリカ、ジルコン、および亜鉛からなる群より選ばれる少なくとも一種の金属種で表面処理されていることが好ましく、アルミナ、シリカおよび亜鉛からなる群より選ばれる少なくとも一種の金属種で表面処理されていることがより好ましく、アルミナ、シリカ及び亜鉛から構成される金属種で表面処理されていることがさらに好ましい。 Titanium dioxide (A) having an oil absorption in the above range can be obtained, for example, by surface-treating with alumina, silica, zircon, zinc, or the like to form a surface-treated layer to increase the specific surface area. From such a viewpoint, titanium dioxide (A) is, for example, preferably surface-treated with at least one metal selected from the group consisting of alumina, silica, zircon, and zinc. More preferably, the surface is treated with at least one kind of metal selected from the group consisting of alumina, silica and zinc.
　また、二酸化チタン（Ａ）の吸油量が上記のような範囲であれば、遮熱性がより高く、かつより低光沢な塗膜を形成することができる。 In addition, if the oil absorption of titanium dioxide (A) is within the above range, it is possible to form a coating film with higher heat shielding properties and lower glossiness.
　より詳細には、二酸化チタン（Ａ）の吸油量が多ければ、水性塗料組成物の臨界顔料体積濃度（ＣＰＶＣ）が低くなり、より多くの空気が取り込まれた塗膜を形成することができる。この際、空気はビヒクルの平均屈折率を低下させる。そのため、空気を取り込んだ塗膜では、二酸化チタン（Ａ）の屈折率とビヒクルの平均屈折率との差がより大きくなり、日射侵入比がより小さくなると考えられる。また、それによって、形成される塗膜の遮熱性がより一層高められると考えられる。 More specifically, the higher the oil absorption of titanium dioxide (A), the lower the critical pigment volume concentration (CPVC) of the water-based coating composition, and the more air-entrained coating film can be formed. At this time, the air lowers the average refractive index of the vehicle. Therefore, it is believed that in a coating film that incorporates air, the difference between the refractive index of titanium dioxide (A) and the average refractive index of the vehicle becomes greater, resulting in a smaller solar penetration ratio. Moreover, it is thought that the heat-shielding property of the formed coating film is further enhanced thereby.
　また、二酸化チタン（Ａ）の吸油量が多ければ、二酸化チタン（Ａ）と水性樹脂（Ｄ）とのなじみが良くなり、二酸化チタン（Ａ）の分散性をより一層高めることができる。その結果、日射侵入比がより小さく、遮熱性により一層優れた塗膜を得ることができる。 Also, if the oil absorption of titanium dioxide (A) is large, the affinity between titanium dioxide (A) and the water-based resin (D) is improved, and the dispersibility of titanium dioxide (A) can be further enhanced. As a result, it is possible to obtain a coating film having a smaller solar radiation penetration ratio and a more excellent heat shielding property.
　なお、吸油量が上記下限値未満である場合、表面処理層が薄く二酸化チタン粒子が凝集しやすくなることから、日射侵入比が大きくなり遮熱性が低下するおそれや、塗膜の光沢が高くなるおそれがある。 If the oil absorption is less than the above lower limit, the surface treatment layer is thin and the titanium dioxide particles tend to aggregate, so the solar radiation penetration ratio may increase and the heat shielding property may decrease, and the gloss of the coating film may increase. There is a risk.
　一方、吸油量が上記上限値より多く、表面処理層が厚すぎる場合、一定体積中の二酸化チタン粒子数が少なくなるため、日射侵入比が大きくなり、遮熱性が低下するおそれがある。また、吸油量が上記上限値より多い場合、得られる塗膜にクラック欠陥等が生じるおそれがある。なお、本明細書において、上記吸油量は、ＪＩＳ　Ｋ－５１０１に準じる方法で測定を行い、得られる値である。 On the other hand, if the oil absorption is greater than the above upper limit and the surface treatment layer is too thick, the number of titanium dioxide particles in a given volume will decrease, so the solar radiation penetration ratio will increase and the heat shielding property may decrease. If the oil absorption is more than the above upper limit, cracks and the like may occur in the resulting coating film. In this specification, the oil absorption is a value obtained by measuring by a method according to JIS K-5101.
　二酸化チタン（Ａ）の平均粒子径は、特に限定されず、０．１μｍ～５μｍであることが好ましく、０．１５μｍ～３μｍであることがより好ましく、０．２μｍ～１．５μｍであることがさらに好ましい。二酸化チタン（Ａ）の平均粒子径が上記範囲内にある場合、得られる塗膜の遮熱性をより一層高めることができ、かつ光沢をより一層低めることができる。なお、上記平均粒子径は、レーザー回折法により計測される粒度分布における体積基準累積５０％時の粒子径である。 The average particle size of titanium dioxide (A) is not particularly limited, and is preferably 0.1 μm to 5 μm, more preferably 0.15 μm to 3 μm, and more preferably 0.2 μm to 1.5 μm. More preferred. When the average particle size of titanium dioxide (A) is within the above range, the heat shielding properties of the resulting coating film can be further enhanced and the gloss can be further reduced. The average particle size is the particle size at 50% volume-based accumulation in the particle size distribution measured by the laser diffraction method.
　本発明においては、得られる塗膜の造膜性を高め、機械的強度をより一層向上させるという観点から、上記二酸化チタン（Ａ）のｐＨが、５．５～１０であることが好ましく、５．８～９．５であることがより好ましい。 In the present invention, the pH of the titanium dioxide (A) is preferably 5.5 to 10 from the viewpoint of enhancing the film-forming properties of the resulting coating film and further improving the mechanical strength. 0.8 to 9.5 is more preferred.
　上述の二酸化チタン（Ａ）のｐＨは、例えば、二酸化チタンの試験サンプル１ｇを蒸留水１００ｍＬに加えて１質量％のスラリーを調製し、得られたスラリーのｐＨ（温度２０℃）をｐＨメーター（堀場製作所社製、品番「Ｆ２１」）にて測定し、その測定結果をｐＨとして算出することができる。 The pH of the above-mentioned titanium dioxide (A) can be determined, for example, by adding 1 g of a test sample of titanium dioxide to 100 mL of distilled water to prepare a slurry of 1% by mass, and measuring the pH of the obtained slurry (at a temperature of 20° C.) with a pH meter ( Horiba, Ltd., product number "F21"), and the measurement result can be calculated as pH.
　二酸化チタン（Ａ）の比重は、特に限定されず、３ｇ／ｃｍ３～５ｇ／ｃｍ３であることが好ましく、３．２ｇ／ｃｍ３～４．８ｇ／ｃｍ３であることがより好ましく、３．５ｇ／ｃｍ３～４．５ｇ／ｃｍ３であることがさらに好ましい。 The specific gravity of titanium dioxide (A) is not particularly limited, and is preferably 3 g/cm 3 to 5 g/cm 3 , more preferably 3.2 g/cm 3 to 4.8 g/cm 3 . It is more preferably 0.5 g/cm 3 to 4.5 g/cm 3 .
　二酸化チタン（Ａ）の含有量は、水性塗料組成物の合計量１００質量％に対して、１質量％～４０質量％であることが好ましく、２質量％～３０質量％であることがより好ましく、３質量％～２０質量％であることがさらに好ましく、４質量％～１５質量％であることが特に好ましい。二酸化チタン（Ａ）の含有量が上記下限値以上である場合、得られる塗膜の遮熱性をより一層高めることができる。また、二酸化チタン（Ａ）の含有量が上記上限値以下である場合、得られる塗膜における塗膜内部のひずみをより一層生じ難くすることができ、屋外暴露等の厳しい環境下においても塗膜のひび割れをより一層生じ難くすることができる。すなわち、水性塗料組成物の造膜性をより一層向上させることができる。 The content of titanium dioxide (A) is preferably 1% by mass to 40% by mass, more preferably 2% by mass to 30% by mass, with respect to 100% by mass of the total amount of the aqueous coating composition. , more preferably 3% by mass to 20% by mass, and particularly preferably 4% by mass to 15% by mass. When the content of titanium dioxide (A) is at least the above lower limit, the heat shielding properties of the resulting coating film can be further enhanced. In addition, when the content of titanium dioxide (A) is equal to or less than the above upper limit, it is possible to make it more difficult to cause distortion inside the coating film in the obtained coating film, and even under severe environments such as outdoor exposure, the coating film It is possible to make it even more difficult for cracks to occur. That is, it is possible to further improve the film-forming properties of the water-based coating composition.
　（チタン酸塩（Ｂ））
　本発明の水性塗料組成物は、チタン酸塩（Ｂ）を含有する。チタン酸塩（Ｂ）としては、例えば、チタン酸カリウム、チタン酸ナトリウム、チタン酸マグネシウムカリウム、チタン酸リチウムカリウム、チタン酸カルシウム、チタン酸ストロンチウム、チタン酸バリウム等を挙げることができる。なかでも、チタン酸塩（Ｂ）としては、Ａ２ＴｉｎＯ（２ｎ＋１）〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ｎは２～１１の数〕、ＡｘＭｙＴｉ（２－ｙ）Ｏ４〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ＭはＬｉ、Ｍｇ、Ｚｎ、Ｇａ、Ｎｉ、Ｃｕ、Ｆｅ、Ａｌ、Ｍｎより選ばれる１種または２種以上、ｘは０．５～１．０、ｙは０．２５～１．０の数〕、またはＡ０．２～０．８Ｌｉ０．２～０．４Ｔｉ１．６～１．８Ｏ３．７～３．９５〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上〕、Ａ０．２～０．８Ｍｇ０．３～０．５Ｔｉ１．５～１．７Ｏ３．７～３．９５〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上〕で表されるチタン酸塩が好ましく、Ａ２ＴｉｎＯ（２ｎ＋１）〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ｎは２～１１の数〕で表されるチタン酸塩がより好ましい。また、上記式中のｎは、好ましくは５～９の数、より好ましくは６～８の数、さらにより好ましくは造膜性をより一層向上させる観点から８であり、光沢度をより低める観点からは６である。 (Titanate (B))
The aqueous coating composition of the present invention contains titanate (B). Examples of the titanate (B) include potassium titanate, sodium titanate, magnesium potassium titanate, lithium potassium titanate, calcium titanate, strontium titanate, and barium titanate. Among them, as the titanate (B), A 2 Ti n O (2n+1) [wherein A is one or more alkali metals excluding Li, n is a number from 2 to 11], A x M y Ti (2-y) O 4 [wherein A is one or more alkali metals excluding Li, M is selected from Li, Mg, Zn, Ga, Ni, Cu, Fe, Al and Mn. 1 or 2 or more, x is 0.5 to 1.0, y is a number of 0.25 to 1.0], or A 0.2 to 0.8 Li 0.2 to 0.4 Ti 1 .6-1.8 O 3.7-3.95 [wherein A is one or more alkali metals excluding Li], A 0.2-0.8 Mg 0.3-0.5 Titanates represented by Ti 1.5-1.7 O 3.7-3.95 [wherein A is one or more alkali metals excluding Li] are preferred, and A 2 Ti n O (2n+1) [In the formula, A is one or more alkali metals other than Li, and n is a number from 2 to 11] is more preferred. Further, n in the above formula is preferably a number of 5 to 9, more preferably a number of 6 to 8, and even more preferably 8 from the viewpoint of further improving the film-forming properties, and from the viewpoint of further lowering the glossiness. is 6 from .
　本発明においては、得られる塗膜の造膜性をより一層高め、機械的強度をより一層向上させるという観点から、チタン酸塩（Ｂ）のｐＨは、７～１２であることが好ましく、７～１０であることがより好ましい。 In the present invention, the pH of the titanate (B) is preferably 7 to 12 from the viewpoint of further improving the film-forming properties of the resulting coating film and further improving the mechanical strength. ~10 is more preferred.
　上述のチタン酸塩（Ｂ）のｐＨは、例えば、チタン酸塩（Ｂ）の試験サンプル１ｇを蒸留水１００ｍＬに加えて１質量％のスラリーを調製し、得られたスラリーのｐＨ（温度２０℃）をｐＨメーター（堀場製作所社製、品番「Ｆ２１」）にて測定し、その測定結果をｐＨとして算出することができる。 The pH of the titanate (B) described above can be obtained, for example, by adding 1 g of a test sample of the titanate (B) to 100 mL of distilled water to prepare a slurry of 1% by mass, and the pH of the obtained slurry (temperature: 20° C. ) can be measured with a pH meter (manufactured by Horiba Ltd., product number “F21”), and the measurement result can be calculated as pH.
　チタン酸塩（Ｂ）の粒子形状は、繊維状、球状（表面に若干の凹凸があるものや、断面が楕円状等の形状が略球状のものも含む）、柱状（棒状、円柱状、角柱状、短冊状、略円柱形状、略短冊形状等の全体として形状が略柱状のものも含む）、板状、ブロック状、複数の凸部を有する形状（アメーバ状、ブーメラン状、十字架状、金平糖状等）、不定形状等の粒子形状等を挙げることができる。チタン酸塩（Ｂ）の粒子形状は、好ましくは板状または繊維状であり、より好ましくは繊維状である。 The particle shape of the titanate (B) may be fibrous, spherical (including those with slightly uneven surfaces, or those having a substantially spherical shape such as an elliptical cross section), columnar (rod-like, columnar, angular, etc.). Columnar, strip-shaped, approximately circular columnar, approximately strip-shaped, etc.), plate-shaped, block-shaped, and having a plurality of protrusions (ameba-shaped, boomerang-shaped, cross-shaped, confetti) shape, etc.), irregular shape, and the like. The particle shape of the titanate (B) is preferably plate-like or fibrous, more preferably fibrous.
　これらのチタン酸塩（Ｂ）の各粒子形状は、製造条件、特に原料組成、焼成条件等により任意に制御することができる。また、粒子形状は、例えば走査型電子顕微鏡（ＳＥＭ）観察から判別することができる。 Each particle shape of these titanates (B) can be arbitrarily controlled by manufacturing conditions, particularly raw material composition, firing conditions, and the like. Also, the particle shape can be determined, for example, from scanning electron microscope (SEM) observation.
　チタン酸塩（Ｂ）の粒子形状が非繊維状である場合、チタン酸塩（Ｂ）の平均粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは２μｍ以上であり、好ましくは１００μｍ以下、より好ましくは５０μｍ以下、さらに好ましくは３０μｍ以下である。なお、上記平均粒子径は、レーザー回折法により計測される粒度分布における体積基準累積５０％時の粒子径である。 When the particle shape of the titanate (B) is non-fibrous, the average particle size of the titanate (B) is preferably 0.1 μm or more, more preferably 1 μm or more, and still more preferably 2 μm or more, It is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The average particle size is the particle size at 50% volume-based accumulation in the particle size distribution measured by the laser diffraction method.
　チタン酸塩（Ｂ）の粒子形状が繊維状である場合、チタン酸塩（Ｂ）の平均繊維径は、０．０１μｍ～１μｍであることが好ましく、０．０５μｍ～０．８μｍであることがより好ましく、０．１μｍ～０．７μｍであることがさらに好ましい。また、チタン酸塩（Ｂ）の平均繊維長は、１μｍ～５０μｍであることが好ましく、３μｍ～３０μｍであることがより好ましく、１０μｍ～２０μｍであることがさらに好ましい。また、チタン酸塩（Ｂ）の平均アスペクト比は、１０以上であることが好ましく、１０～１００であることがより好ましく、１５～３５であることがさらに好ましい。 When the particle shape of the titanate (B) is fibrous, the average fiber diameter of the titanate (B) is preferably 0.01 μm to 1 μm, more preferably 0.05 μm to 0.8 μm. More preferably, it is 0.1 μm to 0.7 μm. The average fiber length of the titanate (B) is preferably 1 μm to 50 μm, more preferably 3 μm to 30 μm, even more preferably 10 μm to 20 μm. Further, the average aspect ratio of the titanate (B) is preferably 10 or more, more preferably 10-100, even more preferably 15-35.
　チタン酸塩（Ｂ）の平均繊維長および平均繊維径は、走査型電子顕微鏡（ＳＥＭ）の観察により測定することができる。チタン酸塩（Ｂ）の平均アスペクト比（平均繊維長／平均繊維径）は、平均繊維長および平均繊維径より算出することできる。例えば、走査型電子顕微鏡（ＳＥＭ）により、複数のチタン酸塩（Ｂ）を撮影し、その観察像からチタン酸塩（Ｂ）を任意に３００個選択して、それらの繊維長および繊維径を測定し、繊維長の全てを積算し個数で除したものを平均繊維長とし、繊維径の全てを積算し個数で除したものを平均繊維径とすることができる。 The average fiber length and average fiber diameter of titanate (B) can be measured by observation with a scanning electron microscope (SEM). The average aspect ratio (average fiber length/average fiber diameter) of the titanate (B) can be calculated from the average fiber length and average fiber diameter. For example, a plurality of titanates (B) are photographed with a scanning electron microscope (SEM), 300 titanates (B) are arbitrarily selected from the observation image, and their fiber lengths and fiber diameters are measured. An average fiber length can be obtained by accumulating all fiber lengths and dividing by the number, and an average fiber diameter can be obtained by accumulating all fiber diameters and dividing by the number.
　本発明において繊維状の粒子とは、粒子に外接する直方体のうち最小の体積をもつ直方体（外接直方体）の最も長い辺を長径Ｌとし、次に長い辺を短径Ｂとし、最も短い辺を厚さＴ（Ｂ＞Ｔ）と定義したときに、Ｌ／ＢおよびＬ／Ｔがいずれも３以上の粒子のことをいう。このとき、長径Ｌが繊維長に相当し、短径Ｂが繊維径に相当する。また、非繊維状の粒子とは、Ｌ／Ｂが３より小さい粒子のことをいう。なかでも、非繊維状の粒子のうちＬ／Ｂが３より小さく、Ｌ／Ｔが３以上の粒子を板状の粒子という。 In the present invention, a fibrous particle is a rectangular parallelepiped having the smallest volume among the rectangular parallelepipeds circumscribing the particle (circumscribing rectangular parallelepiped). When defined as thickness T (B>T), it refers to grains in which both L/B and L/T are 3 or more. At this time, the major axis L corresponds to the fiber length, and the minor axis B corresponds to the fiber diameter. In addition, non-fibrous particles refer to particles having an L/B ratio of less than 3. Among non-fibrous particles, particles having an L/B of less than 3 and an L/T of 3 or more are called plate-like particles.
　チタン酸塩（Ｂ）の真比重は、特に限定されず、３ｇ／ｃｍ３～４．５ｇ／ｃｍ３であることが好ましく、３．２ｇ／ｃｍ３～４．３ｇ／ｃｍ３であることがより好ましく、３．３ｇ／ｃｍ３～４ｇ／ｃｍ３であることがさらに好ましい。 The true specific gravity of the titanate (B) is not particularly limited, but is preferably 3 g/cm 3 to 4.5 g/cm 3 , more preferably 3.2 g/cm 3 to 4.3 g/cm 3 . More preferably, it is 3.3 g/cm 3 to 4 g/cm 3 .
　本発明の水性塗料組成物における二酸化チタン（Ａ）とチタン酸塩（Ｂ）の合計含有量は、水性塗料組成物の合計量１００質量％に対して、５質量％～７０質量％であることが好ましく、６質量％～５０質量％であることがより好ましく、７質量％～３５質量％であることがさらに好ましく、１０質量％～２０質量％であることが特に好ましい。上記合計含有量が上記範囲内にある場合、水性塗料組成物の造膜性をより一層向上させることができ、しかも遮熱性がより一層高く、かつより低光沢の塗膜を形成することができる。 The total content of titanium dioxide (A) and titanate (B) in the aqueous coating composition of the present invention is 5% by mass to 70% by mass with respect to 100% by mass of the total amount of the aqueous coating composition. is preferred, more preferably 6% to 50% by mass, even more preferably 7% to 35% by mass, and particularly preferably 10% to 20% by mass. When the total content is within the above range, the film-forming properties of the water-based coating composition can be further improved, and a coating film with even higher heat-shielding properties and lower gloss can be formed. .
　本発明の水性塗料組成物におけるチタン酸塩（Ｂ）の含有量は、水性塗料組成物の合計量１００質量％に対して、１質量％～４０質量％であることが好ましく、３質量％～３０質量％であることがより好ましく、５質量％～２０質量％であることがさらに好ましく、５質量％～１５質量％であることが特に好ましい。チタン酸塩（Ｂ）の含有量が上記下限値以上である場合、水性塗料組成物の造膜性をより一層向上させることができ、得られる塗膜の機械的強度をより一層向上させることができる。チタン酸塩（Ｂ）の含有量が上記上限値以下である場合、遮熱性がより一層高く、かつより低光沢の塗膜を形成することができる。 The content of the titanate (B) in the aqueous coating composition of the present invention is preferably 1% by mass to 40% by mass with respect to 100% by mass of the total amount of the aqueous coating composition, and 3% by mass to It is more preferably 30% by mass, even more preferably 5% to 20% by mass, and particularly preferably 5% to 15% by mass. When the content of the titanate (B) is at least the above lower limit, the film-forming properties of the aqueous coating composition can be further improved, and the mechanical strength of the resulting coating film can be further improved. can. When the content of the titanate (B) is equal to or less than the above upper limit, it is possible to form a coating film with even higher heat shielding properties and lower glossiness.
　本発明において、二酸化チタン（Ａ）に対するチタン酸塩（Ｂ）の含有比率は、質量比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））で、０．１～９．０であることが好ましく、０．２５～４．０であることがより好ましく、０．３０～３．０であることがさらに好ましく、０．４０～２．４であることが特に好ましい。質量比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））が上記下限値以上である場合、水性塗料組成物の造膜性をより一層向上させることができ、より一層低光沢である塗膜を形成することができる。また、質量比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））が上記上限値以下である場合、遮熱性により一層優れる塗膜を形成することができる。 In the present invention, the content ratio of titanate (B) to titanium dioxide (A) is 0.1 to 9.0 in mass ratio (titanate (B)/titanium dioxide (A)). It is preferably from 0.25 to 4.0, even more preferably from 0.30 to 3.0, and particularly preferably from 0.40 to 2.4. When the mass ratio (titanate (B)/titanium dioxide (A)) is at least the above lower limit, the film-forming properties of the water-based coating composition can be further improved, resulting in a coating film with even lower gloss. can be formed. Moreover, when the mass ratio (titanate (B)/titanium dioxide (A)) is equal to or less than the above upper limit, a coating film having even better heat shielding properties can be formed.
　本発明において、二酸化チタン（Ａ）に対するチタン酸塩（Ｂ）の含有比率は、容積比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））で、０．０７～１５．０であることが好ましく、０．１５～６．８であることがより好ましく、０．２５～４．０であることがさらに好ましい。容積比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））が上記下限値以上である場合、水性塗料組成物の造膜性をより一層向上させることができ、より一層低光沢である塗膜を形成することができる。また、容積比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））が上記上限値以下である場合、遮熱性により一層優れる塗膜を形成することができる。 In the present invention, the content ratio of titanate (B) to titanium dioxide (A) is 0.07 to 15.0 in terms of volume ratio (titanate (B)/titanium dioxide (A)). It is preferably 0.15 to 6.8, even more preferably 0.25 to 4.0. When the volume ratio (titanate (B)/titanium dioxide (A)) is at least the above lower limit, the film-forming properties of the water-based coating composition can be further improved, resulting in a coating film with even lower gloss. can be formed. In addition, when the volume ratio (titanate (B)/titanium dioxide (A)) is equal to or less than the above upper limit, a coating film with even better heat shielding properties can be formed.
　（水性媒体（Ｃ））
　本発明の水性塗料組成物は、水性媒体（Ｃ）を含有する。本明細書において、「水性媒体」とは、水、水と混和する有機溶媒、またはこれらの混合物が挙げられる。水と混和する有機溶媒としては、特に限定されないが、例えばメチルアルコール、エチルアルコール、イソプロピルアルコール等のアルコール系溶媒；アセトン等のケトン類；テトラヒドロフラン、ジオキサン等のエーテル類；アセトニトリル等のニトリル類；酢酸エチル、プロピレンカーボネート等のエステル類を挙げることができる。 (Aqueous medium (C))
The aqueous coating composition of the present invention contains an aqueous medium (C). As used herein, the term "aqueous medium" includes water, an organic solvent miscible with water, or a mixture thereof. The organic solvent miscible with water is not particularly limited, but for example, alcohol solvents such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; ketones such as acetone; ethers such as tetrahydrofuran and dioxane; nitriles such as acetonitrile; Esters such as ethyl and propylene carbonate can be mentioned.
　後述する水性樹脂（Ｄ）は、樹脂固形分のみで表すものとする。そのため、水性樹脂（Ｄ）の原料として、例えば、エマルジョン樹脂を使用する場合、エマルジョン樹脂の分散媒である水は、水性媒体（Ｃ）に算入するものとする。水性樹脂（Ｄ）の原料に含まれ得る水以外に、水性媒体（Ｃ）として使用可能な水としては、上水、イオン交換水、精製水、純水等が挙げられる。 The water-based resin (D), which will be described later, is represented only by the resin solid content. Therefore, when an emulsion resin, for example, is used as a raw material for the aqueous resin (D), water, which is a dispersion medium for the emulsion resin, is included in the aqueous medium (C). In addition to the water that can be contained in the raw material of the aqueous resin (D), examples of water that can be used as the aqueous medium (C) include tap water, ion-exchanged water, purified water, pure water, and the like.
　水性媒体（Ｃ）の含有量は、水性塗料組成物の合計量１００質量％に対して、１０質量％～８０質量％であることが好ましく、２０質量％～７０質量％であることがより好ましい。水性媒体（Ｃ）の含有量が、上記下限値未満であると、水性樹脂（Ｄ）を良好に分散できずに流動性が悪い場合がある。水性媒体（Ｃ）の含有量が、上記上限値より大きいと、塗膜乾燥中に不具合（レベリング性の悪化、分離等）が生じ、塗膜形成能や下地との付着性が悪くなる場合がある。 The content of the aqueous medium (C) is preferably 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass, with respect to 100% by mass of the total amount of the aqueous coating composition. . If the content of the aqueous medium (C) is less than the above lower limit, the aqueous resin (D) may not be dispersed satisfactorily, resulting in poor fluidity. If the content of the aqueous medium (C) is larger than the above upper limit, problems may occur during drying of the coating film (deterioration of leveling, separation, etc.), and the coating film-forming ability and adhesion to the substrate may deteriorate. be.
　（水性樹脂（Ｄ））
　本発明の水性塗料組成物は、水性樹脂（Ｄ）を含有する。水性樹脂（Ｄ）は、水中に溶解または分散可能な樹脂である。水性樹脂（Ｄ）の樹脂種としては、塗膜形成能を有するものであれば、特に限定されない。 (Aqueous resin (D))
The aqueous coating composition of the present invention contains an aqueous resin (D). Aqueous resin (D) is a resin that can be dissolved or dispersed in water. The resin species of the water-based resin (D) is not particularly limited as long as it has a coating film-forming ability.
　水性樹脂（Ｄ）としては、例えば、水不溶性のアクリル系樹脂、シリコーン系樹脂、ウレタン系樹脂、フッ素系樹脂、酢酸ビニル系樹脂、エポキシ系樹脂、フェノール系樹脂、ポリエステル系樹脂、ポリカーボネート系樹脂、エチレン系樹脂、塩化ビニル系樹脂、アルキド系樹脂、メラミン系樹脂等が挙げられる。これらは、１種を単独で用いてもよく、複数種を併用してもよい。また、これらの樹脂は、例えば、ウレタン変性アクリル樹脂のように変性されていてもよく、グラフト重合されたものであってもよく、分散粒子の形態で用いられるものであってもよい。 Examples of the aqueous resin (D) include water-insoluble acrylic resins, silicone resins, urethane resins, fluorine resins, vinyl acetate resins, epoxy resins, phenol resins, polyester resins, polycarbonate resins, Ethylene-based resins, vinyl chloride-based resins, alkyd-based resins, melamine-based resins, and the like can be mentioned. These may be used individually by 1 type, and may use multiple types together. These resins may be modified, for example, urethane-modified acrylic resins, may be graft-polymerized, or may be used in the form of dispersed particles.
　また、水性樹脂（Ｄ）としては、通常塗料原料として使用される、樹脂の微粒子が水中に分散した「エマルジョン樹脂」であることが好ましい。 Further, as the water-based resin (D), it is preferable to use an "emulsion resin" in which fine particles of resin are dispersed in water, which is usually used as a coating material.
　なかでも、エマルジョン樹脂としては、塗膜をより低光沢とし、意匠性をより一層高める観点や、耐候性および耐久性をより一層高める観点から、アクリルシリコーン系エマルジョン樹脂またはフッ素系エマルジョン樹脂であることが好ましく、アクリルシリコーン系エマルジョン樹脂であることがより好ましい。本発明の水性塗料組成物の製造時により一層配合しやすい観点から、水性樹脂（Ｄ）は、上記のようなエマルジョン樹脂であることが好ましい。 Among them, the emulsion resin is an acrylic silicone emulsion resin or a fluorine emulsion resin from the viewpoint of making the coating film lower gloss, further improving the design property, and further improving the weather resistance and durability. is preferred, and an acrylic silicone emulsion resin is more preferred. The water-based resin (D) is preferably an emulsion resin as described above, from the viewpoint of being easier to mix during the production of the water-based coating composition of the present invention.
　エマルジョン樹脂の樹脂濃度は、塗膜をより低光沢とし、意匠性をより一層高める観点から、１５質量％～６５質量％であることが好ましい。なかでも、塗料分野で好適に使用される３０質量％～６０質量％の樹脂濃度のエマルジョン樹脂であることがより好ましい。エマルジョン樹脂の主分散媒は水であり、当該水は本発明の水性塗料組成物の分散媒である水性媒体（Ｃ）の一部となる。 The resin concentration of the emulsion resin is preferably 15% by mass to 65% by mass from the viewpoint of lowering the glossiness of the coating film and further enhancing the design. Among them, emulsion resins having a resin concentration of 30% by mass to 60% by mass, which are suitably used in the field of paints, are more preferable. The main dispersion medium of the emulsion resin is water, and the water becomes part of the aqueous medium (C), which is the dispersion medium of the aqueous coating composition of the present invention.
　水性樹脂（Ｄ）は、分散粒子の形態である場合には、単層構造（均質な粒状）またはコア・シェル構造等の多層構造を有することができる。コア・シェル構造の場合、コアおよび／またはシェルは架橋されていてもよい。 When the aqueous resin (D) is in the form of dispersed particles, it can have a monolayer structure (homogeneous particles) or a multilayer structure such as a core-shell structure. In the case of core-shell structures, the core and/or shell may be crosslinked.
　水性樹脂（Ｄ）は、得られる塗膜の耐久性および耐候性をより一層向上させる観点から、アクリル系樹脂であることが好ましい。アクリル系樹脂としては、少なくとも１種の（メタ）アクリロイル基含有化合物を、必要に応じて共重合可能な他の重合性不飽和モノマーとともに、（共）重合することにより得られる樹脂を挙げることができる。なお、本明細書において、（メタ）アクリロイルとは、メタクリロイルまたはアクリロイルのことをいう。（メタ）アクリレートとは、メタクリレートまたはアクリレートのことをいう。また、（メタ）アクリルとは、メタクリルまたはアクリルのことをいう。 The aqueous resin (D) is preferably an acrylic resin from the viewpoint of further improving the durability and weather resistance of the resulting coating film. Examples of acrylic resins include resins obtained by (co)polymerizing at least one (meth)acryloyl group-containing compound, optionally with other copolymerizable unsaturated monomers. can. In this specification, (meth)acryloyl refers to methacryloyl or acryloyl. (Meth)acrylate refers to methacrylate or acrylate. Moreover, (meth)acryl refers to methacryl or acryl.
　（メタ）アクリロイル基含有化合物としては、１分子中に１個の（メタ）アクリロイル基を有する化合物または１分子中に少なくとも２個の（メタ）アクリロイル基を有する化合物等が挙げられる。 (Meth)acryloyl group-containing compounds include compounds having one (meth)acryloyl group in one molecule or compounds having at least two (meth)acryloyl groups in one molecule.
　１分子中に１個の（メタ）アクリロイル基を有する化合物としては、例えば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ｎ－ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ペンチル（メタ）アクリレート、ヘキシル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ラウリル（メタ）アクリレート、ステアリル（メタ）アクリレート等の直鎖または分岐状のアルキル基含有（メタ）アクリロイルモノマー；シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート等の脂環式アルキル基含有（メタ）アクリロイルモノマー；ベンジル（メタ）アクリレート等のアラルキル基含有（メタ）アクリロイルモノマー；２－メトキシエチル（メタ）アクリレート、２－エトキシエチル（メタ）アクリレート等のアルコキシアルキル基含有（メタ）アクリロイルモノマー；ヘキサフルオロイソプロピル（メタ）アクリレート、パーフルオロオクチルメチル（メタ）アクリレート、パーフルオロオクチルエチル（メタ）アクリレート等のフッ素含有（メタ）アクリロイルモノマー；Ｎ，Ｎ－ジエチルアミノエチル（メタ）アクリレートのようなアミノ基含有（メタ）アクリロイルモノマー；（メタ）アクリルアミド；２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、ヒドロキシブチル（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート、上記ヒドロキシアルキル（メタ）アクリレートのε－カプロラクトン変性体、分子末端が水酸基であるポリオキシエチレン鎖含有（メタ）アクリレート等の水酸基含有（メタ）アクリロイルモノマー；（メタ）アクリル酸、β－カルボキシエチルアクリレート等のカルボキシル基含有（メタ）アクリロイルモノマー；アセトアセトキシエチル（メタ）アクリレート、ダイアセトン（メタ）アクリルアミド等のカルボニル基含有（メタ）アクリロイルモノマー；グリシジル（メタ）アクリレート、β－メチルグリシジル（メタ）アクリレート、３，４－エポキシシクロヘキシルメチル（メタ）アクリレート、３，４－エポキシシクロヘキシルエチル（メタ）アクリレート、３，４－エポキシシクロヘキシルプロピル（メタ）アクリレート等のエポキシ基含有（メタ）アクリロイルモノマー；イソシアナトエチル（メタ）アクリレート等のイソシアナト基含有（メタ）アクリロイルモノマー；γ－メタクリロイルオキシプロピルトリメトキシシラン、γ－メタクリロイルオキシプロピルトリエトキシシラン等のアルコキシシリル基含有（メタ）アクリロイルモノマー；ジシクロペンテニルオキシエチル（メタ）アクリレート、ジシクロペンテニルオキシプロピル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート等の酸化硬化性基含有（メタ）アクリロイルモノマー等が挙げられる。 Compounds having one (meth)acryloyl group in one molecule include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth) linear or branched alkyl group-containing (meth)acryloyl monomers such as acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate; Alicyclic alkyl group-containing (meth)acryloyl monomers such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate; aralkyl group-containing (meth)acryloyl monomers such as benzyl (meth)acrylate; 2-methoxyethyl (meth)acrylate, Alkoxyalkyl group-containing (meth)acryloyl monomers such as 2-ethoxyethyl (meth)acrylate; fluorine-containing (meth)acrylates such as hexafluoroisopropyl (meth)acrylate, perfluorooctylmethyl (meth)acrylate, and perfluorooctylethyl (meth)acrylate meth)acryloyl monomer; amino group-containing (meth)acryloyl monomer such as N,N-diethylaminoethyl (meth)acrylate; (meth)acrylamide; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, Hydroxyalkyl (meth)acrylates such as 3-hydroxypropyl (meth)acrylate and hydroxybutyl (meth)acrylate, ε-caprolactone modified hydroxyalkyl (meth)acrylates, and polyoxyethylene chains containing hydroxyl groups at the molecular ends ( hydroxyl group-containing (meth)acryloyl monomers such as meth)acrylate; carboxyl group-containing (meth)acryloyl monomers such as (meth)acrylic acid and β-carboxyethyl acrylate; acetoacetoxyethyl (meth)acrylate, diacetone (meth)acrylamide, etc. carbonyl group-containing (meth)acryloyl monomers; glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 3 Epoxy group-containing (meth)acryloyl monomers such as 4-epoxycyclohexylpropyl (meth)acrylate; isocyanato group-containing (meth)acryloyl monomers such as isocyanatoethyl (meth)acrylate; γ-methacryloyloxypropyltrimethoxysilane, γ- Alkoxysilyl group-containing (meth)acryloyl monomers such as methacryloyloxypropyltriethoxysilane; oxidative curing properties such as dicyclopentenyloxyethyl (meth)acrylate, dicyclopentenyloxypropyl (meth)acrylate, and dicyclopentenyl (meth)acrylate group-containing (meth)acryloyl monomers, and the like.
　１分子中に少なくとも２個の（メタ）アクリロイル基を有する化合物としては、例えばアリル（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、トリエチレングリコールジ（メタ）アクリレート、テトラエチレングリコールジ（メタ）アクリレート、１，３－ブチレングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、１，４－ブタンジオールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、グリセロールジ（メタ）アクリレート、１，１，１－トリスヒドロキシメチルエタンジ（メタ）アクリレート、１，１，１－トリスヒドロキシメチルエタントリ（メタ）アクリレート、１，１，１－トリスヒドロキシメチルプロパントリ（メタ）アクリレート等が挙げられる。 Compounds having at least two (meth)acryloyl groups in one molecule include, for example, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth) Acrylates, 1,3-butylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerol di(meth)acrylate, 1,1,1-trishydroxymethylethane di(meth)acrylate, 1,1,1 -trishydroxymethylethane tri(meth)acrylate, 1,1,1-trishydroxymethylpropane tri(meth)acrylate and the like.
　これら（メタ）アクリロイル基含有化合物は、１種を単独で用いてもよく、複数種を併用してもよい。 These (meth)acryloyl group-containing compounds may be used singly or in combination.
　また、共重合可能な他の重合性不飽和モノマーとしては、（メタ）アクリロニトリル；酢酸ビニル、プロピオン酸ビニル等のビニルエステル化合物；スチレン、α－メチルスチレン等のビニル芳香族化合物；トリアリルイソシアヌレート、ジアリルテレフタレート、ジビニルベンゼン等の１分子中に少なくとも２個の重合性不飽和基を有する多ビニル化合物；アリルアルコール；マレイン酸、クロトン酸等のカルボキシル基含有重合性不飽和モノマー；（メタ）アクロレイン、ホルミルスチロール、炭素数４～７のビニルアルキルケトン（例えば、ビニルメチルケトン、ビニルエチルケトン、ビニルブチルケトン等）、アセトアセトキシアリルエステル等のカルボニル基含有重合性不飽和モノマー；アリルグリシジルエーテル等のエポキシ基含有重合性不飽和モノマー；ｍ－イソプロペニル－α，α－ジメチルベンジルイソシアネート等のイソシアナト基含有重合性不飽和モノマー；ビニルトリメトキシシラン、ビニルトリエトキシシラン等のアルコキシシリル基含有重合性不飽和モノマー；フルオロアルキルトリフルオロビニルエーテル、パーフルオロアルキルトリフルオロビニルエーテル等のフルオロビニルエーテル；上記エポキシ基含有重合性不飽和モノマーまたは水酸基含有重合性不飽和モノマーと不飽和脂肪酸との反応生成物等の酸化硬化性基含有重合性不飽和モノマー等が挙げられる。これらは、１種を単独で用いてもよく、複数種を併用してもよい。 Other polymerizable unsaturated monomers that can be copolymerized include (meth)acrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl aromatic compounds such as styrene and α-methylstyrene; , diallyl terephthalate, divinylbenzene and the like polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule; allyl alcohol; carboxyl group-containing polymerizable unsaturated monomers such as maleic acid and crotonic acid; (meth)acrolein , formyl styrene, vinyl alkyl ketones having 4 to 7 carbon atoms (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), carbonyl group-containing polymerizable unsaturated monomers such as acetoacetoxy allyl ester; epoxy group-containing polymerizable unsaturated monomers; isocyanato group-containing polymerizable unsaturated monomers such as m-isopropenyl-α,α-dimethylbenzyl isocyanate; alkoxysilyl group-containing polymerizable unsaturated monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; Saturated monomers; fluorovinyl ethers such as fluoroalkyltrifluorovinyl ethers and perfluoroalkyltrifluorovinyl ethers; oxidative curing of reaction products of the above epoxy group-containing polymerizable unsaturated monomers or hydroxyl group-containing polymerizable unsaturated monomers and unsaturated fatty acids a functional group-containing polymerizable unsaturated monomer, and the like. These may be used individually by 1 type, and may use multiple types together.
　なお、水性樹脂（Ｄ）には、ポリビニルアルコール、ポリビニルピロリドン、ヒドロキシエチルセルロース、メチルセルロース、ヒドロキシプロピルセルロース、ポリアクリル酸ナトリウム、エチレン－無水マレイン酸共重合体などの水溶解性高分子化合物等も包含される。 The aqueous resin (D) also includes water-soluble polymer compounds such as polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, sodium polyacrylate, and ethylene-maleic anhydride copolymer. be.
　水性樹脂（Ｄ）の粘度は、特に限定されないが、好ましくは５０ｍＰａ・ｓ以上、より好ましくは１００ｍＰａ・ｓ以上、さらに好ましくは２００ｍＰａ・ｓ以上、特に好ましくは３００ｍＰａ・ｓ以上、好ましくは１００００ｍＰａ・ｓ以下、より好ましくは５０００ｍＰａ・ｓ以下、さらに好ましくは３０００ｍＰａ・ｓ以下、特に好ましくは２５００ｍＰａ・ｓ以下である。 The viscosity of the aqueous resin (D) is not particularly limited, but is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, still more preferably 200 mPa·s or more, particularly preferably 300 mPa·s or more, preferably 10000 mPa·s. Below, it is more preferably 5000 mPa·s or less, still more preferably 3000 mPa·s or less, and particularly preferably 2500 mPa·s or less.
　なお、水性樹脂（Ｄ）の粘度は、例えば、２５℃において、超音波粘度計、Ｂ型粘度計、Ｅ型粘度計などの粘度測定装置により測定することができる。 The viscosity of the aqueous resin (D) can be measured, for example, at 25°C with a viscosity measuring device such as an ultrasonic viscometer, a B-type viscometer, or an E-type viscometer.
　水性樹脂（Ｄ）の含有量は、水性塗料組成物の合計量１００質量％に対して、樹脂固形分として、２質量％～５０質量％の範囲であることが好ましく、１０質量％～３０質量％の範囲であることがより好ましい。水性樹脂（Ｄ）の含有量が上記下限値未満であると、低光沢な塗膜の意匠性が得られない場合がある。また、水性樹脂（Ｄ）の含有量が上記上限値を超えると、樹脂分が多すぎて水性塗料組成物の製造が困難となる場合がある。 The content of the aqueous resin (D) is preferably in the range of 2% by mass to 50% by mass, preferably 10% by mass to 30% by mass, as a resin solid content with respect to 100% by mass of the total amount of the aqueous coating composition. % range is more preferable. If the content of the water-based resin (D) is less than the above lower limit, it may not be possible to obtain a low-gloss coating film with good design. On the other hand, if the content of the aqueous resin (D) exceeds the above upper limit, the resin content may be too large, making it difficult to produce the aqueous coating composition.
　＜水性塗料組成物の任意成分＞
　（その他添加剤）
　本発明の水性塗料組成物は、本発明の効果を妨げない範囲で、塗料に通常使用されるその他添加剤を含有することができる。その他添加剤としては、必要に応じて、例えば、中空粒子、アルキルシリケート、骨材、繊維、可塑剤、レベリング剤、タレ防止剤、蛍光増白剤、着色顔料、シランカップリング剤、中和剤、帯電防止剤、軟化剤、抗菌剤、香料、硬化触媒、ｐＨ調整剤、調湿剤、粉状もしくは微粒子状の活性炭、水性撥水剤、造膜助剤、分散剤、消泡剤、増粘剤、防腐剤、防カビ剤、凍結防止剤、紫外線吸収剤、光安定化剤、亜鉛ウィスカ、硬化促進剤、アルデヒド吸着剤、ワックス、三酸化アンチモン、五酸化アンチモン、水酸化アルミニウム等の難燃化剤等の公知の塗料用添加剤を任意成分として含ませることができる。 <Optional components of water-based paint composition>
(Other additives)
The water-based paint composition of the present invention may contain other additives commonly used in paints, as long as the effects of the present invention are not impaired. Other additives include, if necessary, hollow particles, alkyl silicates, aggregates, fibers, plasticizers, leveling agents, anti-sagging agents, fluorescent brightening agents, coloring pigments, silane coupling agents, and neutralizing agents. , antistatic agent, softening agent, antibacterial agent, perfume, curing catalyst, pH adjuster, humidity control agent, powdery or particulate activated carbon, water repellent agent, film forming aid, dispersant, antifoaming agent, thickener Adhesives, preservatives, antifungal agents, antifreeze agents, UV absorbers, light stabilizers, zinc whiskers, curing accelerators, aldehyde adsorbents, waxes, antimony trioxide, antimony pentoxide, aluminum hydroxide, etc. Known paint additives such as flame retardants can be included as optional ingredients.
　これらのうち、中空粒子としては、中空無機粒子、中空樹脂粒子が挙げられる。 Among these, hollow particles include hollow inorganic particles and hollow resin particles.
　水性塗料組成物が中空粒子を含む場合、形成される塗膜が日射等をより一層効率よく反射したり、断熱効果をより高めたりすることができる。そのため、基材の温度上昇をより一層抑えることができる。また、水性塗料組成物が中空粒子を含む場合、形成される塗膜の光沢度もより低めることができる。 When the water-based coating composition contains hollow particles, the formed coating film can more efficiently reflect solar radiation and the like, and can further enhance the heat insulating effect. Therefore, the temperature rise of the substrate can be further suppressed. In addition, when the water-based coating composition contains hollow particles, the glossiness of the formed coating film can be further lowered.
　中空無機粒子を構成する無機物質としては、例えば、珪酸ソーダガラス、アルミ珪酸ガラス、硼珪酸ソーダガラス等のガラス；フライアッシュ、アルミナ、ジルコニア・チタニア、ホウ化ケイ素、シラス、黒曜石等が挙げられる。 Examples of inorganic substances that make up the hollow inorganic particles include glasses such as sodium silicate glass, aluminum silicate glass, and sodium borosilicate glass; fly ash, alumina, zirconia/titania, silicon boride, shirasu, and obsidian.
　中空樹脂粒子を構成する樹脂成分としては、例えば、アクリル樹脂、スチレン樹脂、アクリル－スチレン共重合樹脂、アクリル－アクリロニトリル共重合樹脂、アクリル－スチレン－アクリロニトリル共重合樹脂、アクリロニトリル－メタアクリロニトリル共重合樹脂、アクリル－アクリロニトリル－メタアクリロニトリル共重合樹脂、塩化ビニリデン－アクリロニトリル共重合樹脂等が挙げられる。 Examples of resin components constituting the hollow resin particles include acrylic resins, styrene resins, acrylic-styrene copolymer resins, acrylic-acrylonitrile copolymer resins, acrylic-styrene-acrylonitrile copolymer resins, acrylonitrile-methacrylonitrile copolymer resins, Acryl-acrylonitrile-methacrylonitrile copolymer resin, vinylidene chloride-acrylonitrile copolymer resin and the like can be mentioned.
　上記中空粒子内は、空気、空気以外の気体、真空のいずれでもよい。 The inside of the hollow particles may be air, a gas other than air, or a vacuum.
　中空粒子の平均粒子径としては、塗膜外観、塗膜物性、遮熱効果をより一層向上させる観点から、５μｍ～１５０μｍであることが好ましく、１０μｍ～１００μｍであることがより好ましい。 The average particle diameter of the hollow particles is preferably 5 μm to 150 μm, more preferably 10 μm to 100 μm, from the viewpoint of further improving the coating film appearance, coating film physical properties, and heat shielding effect.
　中空粒子の平均粒子径は、走査型電子顕微鏡（ＳＥＭ）写真を撮影し、５０個の粒子について粒子径を測定し、これを平均して求めることができる。 The average particle size of the hollow particles can be obtained by taking scanning electron microscope (SEM) photographs, measuring the particle sizes of 50 particles, and averaging them.
　なお、中空粒子のかさ密度としては、０．０１ｇ／ｃｍ３～１．０ｇ／ｃｍ３であることが好ましい。また、真密度としては０．０１ｇ／ｃｍ３～１．２ｇ／ｃｍ３であることが好ましい。 The bulk density of the hollow particles is preferably 0.01 g/cm 3 to 1.0 g/cm 3 . Further, the true density is preferably 0.01 g/cm 3 to 1.2 g/cm 3 .
　水性塗料組成物が中空粒子を含有する場合、その含有量としては、水性塗料組成物に含まれる樹脂固形分を基準として、好ましくは１質量％～５０質量％であり、より好ましくは１質量％～３０質量％であり、さらにより好ましくは１．５質量％～１５質量％であり、特に好ましくは１．５質量％～１０質量％であり、特により好ましくは１．５質量％～４．５質量％である。この場合、水性塗料の貯蔵安定性や、得られる塗膜の耐ワレ性をより一層高めることができる。 When the aqueous coating composition contains hollow particles, the content thereof is preferably 1% by mass to 50% by mass, more preferably 1% by mass, based on the resin solid content contained in the aqueous coating composition. 30% by mass, more preferably 1.5% by mass to 15% by mass, particularly preferably 1.5% by mass to 10% by mass, and even more preferably 1.5% by mass to 4.0% by mass. 5% by mass. In this case, the storage stability of the water-based paint and the crack resistance of the resulting coating film can be further enhanced.
　また、水性塗料組成物は、形成される塗膜に耐汚染性を付与することを目的として、アルキルシリケート化合物を含有していてもよい。 In addition, the water-based paint composition may contain an alkylsilicate compound for the purpose of imparting stain resistance to the formed coating film.
　アルキルシリケート化合物としては、例えば、式：Ｓｉ（－ＯＲ１）４で示される化合物、並びにその部分加水分解および縮合物が挙げられる。
　（式中、Ｒ１は、アルキル基、アリール基およびアラルキル基から選択される、同一または異なる１価の炭化水素基である。） Alkylsilicate compounds include, for example, compounds represented by the formula: Si(--OR 1 ) 4 and partial hydrolysates and condensates thereof.
(Wherein, R 1 is the same or different monovalent hydrocarbon group selected from an alkyl group, an aryl group and an aralkyl group.)
　上記式において、Ｒ１は、炭素数１～４のアルキル基であることが好ましい。 In the above formula, R 1 is preferably an alkyl group having 1 to 4 carbon atoms.
　アルキルシリケート化合物の例としては、テトラメトキシシラン、テトラエトキシシラン、テトラ－ｎ－プロポキシシラン、テトラ－イソプロポキシシラン、テトラ－ｎ－ブトキシシラン、テトラ－イソブトキシシラン、テトラ－ｔ－ブトキシシラン、およびそれらの任意の組み合わせ、並びにそれらの部分加水分解および縮合物が挙げられる。また、これら例示の化合物をさらにポリオキシアルキレン化合物などで変性した化合物もアルキルシリケート化合物として包含される。 Examples of alkylsilicate compounds include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-isopropoxysilane, tetra-n-butoxysilane, tetra-isobutoxysilane, tetra-t-butoxysilane, and Any combination thereof, as well as partial hydrolysates and condensates thereof are included. Further, compounds obtained by further modifying these exemplified compounds with polyoxyalkylene compounds or the like are also included as alkylsilicate compounds.
　また、上記アルキルシリケート化合物を含ませる場合には、有機スズ化合物、有機チタネート化合物、リン酸化合物、酸無水物、アミン類等の触媒を併用させてもよい。 In addition, when the alkylsilicate compound is included, a catalyst such as an organic tin compound, an organic titanate compound, a phosphoric acid compound, an acid anhydride, or an amine may be used in combination.
　また、本発明の水性塗料組成物が上記アルキルシリケート化合物を含む場合、塗料組成物を２液型とし、該アルキルシリケート化合物を含む成分を使用直前にそれ以外の成分と配合混合することが望ましい。 In addition, when the water-based paint composition of the present invention contains the above alkylsilicate compound, it is desirable to make the paint composition a two-pack type and mix the component containing the alkylsilicate compound with other components immediately before use.
　本発明の水性塗料組成物がアルキルシリケート化合物を含む場合、得られる塗膜の耐汚染性や耐ひび割れ性をより一層向上させる観点から、その含有量としては塗料中に含まれる樹脂固形分を基準として、好ましくは３質量％～２０質量％であり、より好ましくは５質量％～１５質量％である。 When the water-based coating composition of the present invention contains an alkylsilicate compound, from the viewpoint of further improving the stain resistance and crack resistance of the resulting coating film, the content is based on the resin solid content contained in the coating. , preferably 3% by mass to 20% by mass, more preferably 5% by mass to 15% by mass.
　造膜助剤としては、イソ酪酸エステル系、エチレングリコール系、プロピレングリコール系等の造膜助剤が挙げられる。造膜助剤としては、例えば、２，２，４－トリメチル－１，３－ペンタンジオール－２－メチルプロパノアート、ブチルセロソルブ等を用いることができる。 Examples of film-forming aids include isobutyric acid ester-based, ethylene glycol-based, and propylene glycol-based film-forming aids. Examples of film-forming aids that can be used include 2,2,4-trimethyl-1,3-pentanediol-2-methylpropanoate and butyl cellosolve.
　本発明の水性塗料組成物において、特に水性樹脂（Ｄ）がカルボニル基を有する場合、造膜助剤と併用することにより、常温乾燥の条件でも塗膜が架橋でき、且つ、屋外の厳しい条件でも長期耐久性により優れた塗膜を形成することができる。 In the water-based coating composition of the present invention, particularly when the water-based resin (D) has a carbonyl group, by using it in combination with a film-forming aid, the coating film can be crosslinked even under normal temperature drying conditions, and even under severe outdoor conditions. A coating film having excellent long-term durability can be formed.
　分散剤としては、例えば、顔料に親和性のあるブロック共重合物、ランダム共重合物等の水系用湿潤分散剤が挙げられる。 Examples of dispersants include water-based wetting and dispersing agents such as block copolymers and random copolymers that have affinity for pigments.
　本発明において、水系用湿潤分散剤は、下記に示す一定量の酸価を有する樹脂であってもよく、一定量の酸価を有さない樹脂であってもよい。 In the present invention, the water-based wetting and dispersing agent may be a resin having a certain amount of acid value shown below, or may be a resin not having a certain amount of acid value.
　酸価を有する樹脂は、固形分当たりの酸価が２．５ｍｇＫＯＨ／ｇ～３０ｍｇＫＯＨ／ｇの範囲内にあり、好ましくは３ｍｇＫＯＨ／ｇ～２５ｍｇＫＯＨ／ｇの範囲内にある。 The resin having an acid value has an acid value per solid within the range of 2.5 mgKOH/g to 30 mgKOH/g, preferably within the range of 3 mgKOH/g to 25 mgKOH/g.
　酸価を有する樹脂の固形分当たりの酸価が上記下限値未満である場合、水性塗料組成物を長期間貯蔵したときに凝集物が生じたり、複数色を混ぜ合わせたときの色安定性が劣ったりすることがある。 If the acid value per solid content of the resin having an acid value is less than the above lower limit, aggregates may form when the water-based coating composition is stored for a long period of time, and color stability may deteriorate when multiple colors are mixed. Sometimes inferior.
　一方、酸価を有する樹脂の酸価が上記上限値を超えると、形成される塗膜の耐水性が劣ることがある。 On the other hand, if the acid value of the resin having an acid value exceeds the above upper limit, the formed coating film may have poor water resistance.
　酸価を有する樹脂に酸価を与える酸基としては、カルボキシル基、スルホン酸基、リン酸基などが挙げられる。なかでも、酸価を有する樹脂に酸価を与える酸基としては、カルボキシル基が好ましい。 A carboxyl group, a sulfonic acid group, a phosphoric acid group, etc., can be mentioned as acid groups that give an acid value to a resin having an acid value. Among them, a carboxyl group is preferable as an acid group that imparts an acid value to a resin having an acid value.
　また、これら酸基は、メチルアミン、ジメチルアミン、トリメチルアミン、エチルアミン、ジエチルアミン、トリエチルアミン、ジメチルアミノエタノール、２－メチル－２－アミノ－１－プロパノール等のアミン類；アンモニア等の塩基で部分的にまたは実質的に完全に中和されたものであってもよい。 In addition, these acid groups are partially or It may be substantially completely neutralized.
　本発明において、水系用湿潤分散剤が有する酸基以外の他の官能基としては、例えば、水酸基、イソシアナト基、アミノ基、アミド基、カルボニル基等が挙げられる。なかでも、屋外等の厳しい条件における耐候性をより一層向上させる観点から、他の官能基として、カルボニル基を有するものであることが望ましい。 In the present invention, functional groups other than acid groups possessed by water-based wetting and dispersing agents include, for example, hydroxyl groups, isocyanato groups, amino groups, amide groups, and carbonyl groups. Among others, from the viewpoint of further improving weather resistance under severe conditions such as outdoors, it is desirable to have a carbonyl group as another functional group.
　水系用湿潤分散剤がカルボキシ基およびカルボニル基を有する場合には、例えば、モノマー成分の少なくとも一部として、（メタ）アクリル酸および／または上述した他のカルボキシル基含有重合性不飽和モノマーと、上述したカルボニル基含有（メタ）アクリロイルモノマーおよび／または他のカルボニル基含有重合性不飽和モノマーを使用し、その他の（メタ）アクリロイル基含有化合物および／またはその他の重合性不飽和モノマーと共重合させることにより、水系用湿潤分散剤を製造することができる。 When the water-based wetting and dispersing agent has a carboxyl group and a carbonyl group, for example, (meth)acrylic acid and/or other carboxyl group-containing polymerizable unsaturated monomers described above are used as at least part of the monomer components, using a carbonyl group-containing (meth)acryloyl monomer and/or other carbonyl group-containing polymerizable unsaturated monomer and copolymerizing it with another (meth)acryloyl group-containing compound and/or other polymerizable unsaturated monomer can produce a water-based wetting and dispersing agent.
　本発明の水性塗料組成物が分散剤を含む場合、本発明の水性塗料組成物における分散剤の含有量は、水性塗料組成物の合計量１００質量％に対して、０．１質量％～１０質量％であることが好ましく、０．２質量％～８質量％であることがより好ましい。分散剤の含有量が、上記下限値未満であると、二酸化チタンとチタン酸塩を良好に分散できずに塗膜中で凝集や偏析を起こし、塗膜の機械的強度が悪くなる場合がある。分散剤の含有量が、上記上限値より大きいと、造膜性が悪くなる場合がある。 When the aqueous coating composition of the present invention contains a dispersant, the content of the dispersant in the aqueous coating composition of the present invention is 0.1% by mass to 10% with respect to 100% by mass of the total amount of the aqueous coating composition. It is preferably 0.2% by mass to 8% by mass, more preferably 0.2% by mass to 8% by mass. If the content of the dispersant is less than the above lower limit, the titanium dioxide and titanate cannot be dispersed well, causing aggregation and segregation in the coating film, which may deteriorate the mechanical strength of the coating film. . If the content of the dispersant is larger than the above upper limit, the film-forming properties may deteriorate.
　消泡剤としては、例えば、破泡性ポリシロキサンと疎水性粒子とを含有する、ポリグリコール中の混合液等が挙げられる。 Examples of antifoaming agents include a mixed solution in polyglycol containing foam-breaking polysiloxane and hydrophobic particles.
　増粘剤としては、無機系増粘剤を用いてもよく、有機系増粘剤を用いてもよい。無機系増粘剤としては、シリカ系、粘土鉱物系、炭酸カルシウム系の増粘剤が挙げられる。有機系増粘剤としては、ワックス系、ポリウレタン系、セルロース誘導体系、ポリアクリル酸系の増粘剤が挙げられる。有機系増粘剤としては、例えば、モンモリロナイト、酸化ポリエチレン系、ヒドロキシエチルセルロース、ポリアクリル酸等が挙げられる。 As the thickener, an inorganic thickener may be used, or an organic thickener may be used. Examples of inorganic thickeners include silica-based, clay mineral-based, and calcium carbonate-based thickeners. Examples of organic thickeners include wax-based, polyurethane-based, cellulose derivative-based, and polyacrylic acid-based thickeners. Examples of organic thickeners include montmorillonite, polyethylene oxide, hydroxyethyl cellulose, and polyacrylic acid.
　本発明の水性塗料組成物は、その好ましい物性を損なわない範囲において、必要に応じて、任意の適切な着色顔料をさらに含み得る。着色顔料としては、例えば、黄鉛、黄色酸化鉄、酸化鉄、カーボンブラック等の無機顔料；アゾキレート系顔料、不溶性アゾ系顔料、縮合アゾ系顔料、フタロシアニン系顔料、インジゴ顔料、ペリノン系顔料、ペリレン系顔料、ジオキサン系顔料、キナクリドン系顔料、イソインドリノン系顔料、金属錯体顔料等が挙げられる。これらは、単独で用いてもよく、２種以上を組み合わせて用いてもよい。着色顔料の含有割合は、二酸化チタン（Ａ）の含有量に対して、好ましくは０．５質量％である。 The water-based paint composition of the present invention may further contain any appropriate color pigment as necessary, as long as it does not impair its preferred physical properties. Examples of coloring pigments include inorganic pigments such as yellow lead, yellow iron oxide, iron oxide, and carbon black; azochelate pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, dioxane-based pigments, quinacridone-based pigments, isoindolinone-based pigments, metal complex pigments, and the like. These may be used alone or in combination of two or more. The content of the coloring pigment is preferably 0.5% by mass relative to the content of titanium dioxide (A).
　本発明の水性塗料組成物は、本発明の効果を損なわない範囲で、さらに他の顔料を含んでいてもよい。その他の顔料としては、例えば、シリカ；硫酸バリウム；アルミナ；ウイスカ白色顔料；炭酸マグネシウム等が挙げられる。 The water-based paint composition of the present invention may further contain other pigments to the extent that the effects of the present invention are not impaired. Other pigments include, for example, silica; barium sulfate; alumina; whisker white pigment; and magnesium carbonate.
　本発明において、骨材としては、例えば、砂、砂利、粉石、樹脂粒子等が挙げられる。なかでも、塗料に使用される骨材としては、例えば、硅砂、寒水石、パーライト、セラミック、貝殻等が挙げられる。また、骨材の役割としては、一般的にひび割れの防止、収縮の抑制、耐摩耗性の向上、膜厚の調整、滑り止めなどの役割が挙げられる。各用途においてその効果を損なわない範囲であれば、粒子サイズは特に限定されないが、例えば、平均粒子径の大きさが１５０μｍ以上のものであれば、塗膜強度の観点から路面用途での使用が好ましく、平均粒子径の大きさが１５０μｍ以下のものであれば、スプレー塗装時の機械的付加や表面仕上がりの観点から建築物の壁面や屋根用途での使用が好ましい。 In the present invention, examples of aggregates include sand, gravel, powdered stone, resin particles, and the like. Among others, aggregates used in paints include, for example, silica sand, kansuiseki, perlite, ceramics, shells, and the like. In general, the role of aggregates is to prevent cracks, suppress shrinkage, improve abrasion resistance, adjust film thickness, and prevent slippage. The particle size is not particularly limited as long as it does not impair the effect in each application. Preferably, if the average particle size is 150 μm or less, it is preferably used for walls and roofs of buildings from the viewpoint of mechanical addition during spray coating and surface finish.
　＜塗膜の製造方法＞
　本発明の水性塗料組成物は、基材表面に塗装することにより、遮熱性に優れた艶消し塗膜を形成することができる。本発明の水性塗料組成物を適用することができる基材表面としては、特に制限されるものではないが、例えば、石膏ボード、コンクリート板、コンクリートブロック、サイディングボード、モルタル板、スレート板、ＰＣ板、ＡＬＣ板、セメント珪酸カルシウム板、レンガ、ガラス、木材、石材、プラスチック成形物、陶磁器、磁器タイル、鉄部、アルミサッシ等の金属加工材等の基材の表面；これら基材上に設けられたアクリル樹脂系、アクリルウレタン樹脂系、ポリウレタン樹脂系、フッ素樹脂系、シリコーン樹脂系、シリコーンアクリル樹脂系、酢酸ビニル樹脂系、エポキシ樹脂系等の塗膜面、ポリ塩化ビニル、ポリオレフィン、紙、布等の材質からなる壁紙面等を挙げることができる。これら基材表面はシーラー等であらかじめ処理したものであってもよい。 <Method for producing coating film>
The water-based coating composition of the present invention can form a matte coating film with excellent heat-shielding properties by coating it on the surface of a substrate. The substrate surface to which the aqueous coating composition of the present invention can be applied is not particularly limited. , ALC plate, cement calcium silicate plate, brick, glass, wood, stone, plastic molded product, ceramics, porcelain tile, iron part, surface of base material such as metal processing material such as aluminum sash; Acrylic resin, acrylic urethane resin, polyurethane resin, fluorine resin, silicone resin, silicone acrylic resin, vinyl acetate resin, epoxy resin, etc., polyvinyl chloride, polyolefin, paper, cloth A wall paper surface or the like made of a material such as The surface of these substrates may be previously treated with a sealer or the like.
　本発明の水性塗料組成物は、既知の塗装手段を用いて塗装を行うことができ、例えば、ローラー、エアスプレー、エアレススプレー、リシンガン、万能ガン、ハケ、ロールコーター等の塗装法から基材の種類、用途等に応じて適宜選択して使用することができる。また、本発明の水性塗料組成物は、塗膜外観を損なわない範囲で複数回塗り重ねることもできる。 The water-based coating composition of the present invention can be applied using known coating means. It can be appropriately selected and used according to the type, application, and the like. In addition, the water-based coating composition of the present invention can be applied multiple times within a range that does not impair the appearance of the coating film.
　形成塗膜の乾燥は、常温乾燥で行うことができる。形成塗膜は、使用した塗料組成物の組成や塗装環境等に応じて、加熱乾燥または強制乾燥してもよい。 The formed coating film can be dried at room temperature. The formed coating film may be heat-dried or forced-dried depending on the composition of the coating composition used, the coating environment, and the like.
　乾燥膜厚は、適用基材や塗装環境によって適宜調整できるが、より十分な遮熱性を得る観点からは、例えば、３５μｍ～５０００μｍであり、好ましくは５０μｍ～３０００μｍである。 The dry film thickness can be appropriately adjusted depending on the substrate to be applied and the coating environment, but from the viewpoint of obtaining more sufficient heat shielding properties, it is, for example, 35 μm to 5000 μm, preferably 50 μm to 3000 μm.
　＜水性塗料組成物の使用方法＞
　本発明の水性塗料組成物の使用方法は、建築物の屋根、外壁面、および／または内装面に上記水性塗料組成物を塗装することにより、建築物内部の温度上昇を抑制する方法である。 <How to use the water-based paint composition>
The method of using the water-based coating composition of the present invention is a method of suppressing the temperature rise inside a building by applying the water-based coating composition to the roof, exterior wall surface, and/or interior surface of the building.
　本発明の水性塗料組成物は、遮熱性を有し、かつ適度な艶消し感を有する塗膜を形成することができるため、これを塗装することによって建築物の屋根、外壁、および／または内装面に落ち着いた外観を与えるとともに遮熱機能を長期に亘って維持することができる。 The water-based coating composition of the present invention has heat-shielding properties and can form a coating film having an appropriate matt feeling. It gives the surface a calm appearance and maintains the heat shielding function for a long period of time.
　建築物の外壁面としては、例えば、ビル、家屋、施設、倉庫等の各種建築物の外壁面を挙げることができる。建築物の外壁面を構成するものとしては、一般的な外壁材であり、例えば、窯業系サイディングボード、モルタル、コンクリート、スレートなどの無機系外装材や、鉄、アルミニウム、金属サイディング等の金属系外装材や、天然木、合板等の木質系外装材等を挙げることができる。 Examples of exterior wall surfaces of buildings include exterior wall surfaces of various buildings such as buildings, houses, facilities, and warehouses. Common exterior wall materials that constitute the exterior walls of buildings include inorganic exterior materials such as ceramic siding boards, mortar, concrete, and slate, and metal materials such as iron, aluminum, and metal siding. Exterior materials, wood-based exterior materials such as natural wood and plywood, and the like can be used.
　なお、本発明の水性塗料組成物の使用方法は、建築物の屋根および／または外壁面に上記水性塗料組成物を塗装することにより、建築物の外表面における温度上昇を抑制する方法であってもよい。 The method of using the water-based coating composition of the present invention is a method of suppressing the temperature rise on the outer surface of the building by coating the roof and/or the outer wall surface of the building with the water-based coating composition. good too.
　本発明の水性塗料組成物は、厳しい環境に晒される建築物の外表面においても、ひび割れが発生し難く、長期に亘って落ち着いた外観を与えるとともに遮熱機能を維持し、建築物の外表面における温度上昇を長期に亘って抑制できるので、ヒートアイランド現象を抑制することができる。 The water-based paint composition of the present invention is less likely to crack even on the outer surface of a building exposed to a harsh environment, gives a calm appearance for a long time and maintains a heat-shielding function. The heat island phenomenon can be suppressed because the temperature rise in can be suppressed for a long period of time.
　本発明の水性塗料組成物の使用方法は、道路の舗装面に上記水性塗料組成物を塗装することにより、路面の温度上昇を抑制する方法であってもよい。 The method of using the aqueous coating composition of the present invention may be a method of suppressing the temperature rise of the road surface by coating the paved surface of the road with the aqueous coating composition.
　本発明の水性塗料組成物は、厳しい環境に晒される路面においても、ひび割れが発生し難く、長期に亘って落ち着いた外観を与えるとともに遮熱機能を維持し、路面の温度上昇を長期に亘って抑制できるので、ヒートアイランド現象を抑制することができる。 The water-based coating composition of the present invention does not easily crack even on road surfaces exposed to harsh environments, provides a calm appearance for a long period of time, maintains a heat-shielding function, and prevents the temperature rise of the road surface for a long period of time. Since it can be suppressed, the heat island phenomenon can be suppressed.
　本発明の水性塗料組成物の使用方法は、タンクの外壁面に上記水性塗料組成物を塗装することにより、タンク内部の温度上昇を抑制する方法であってもよい。 The method of using the aqueous coating composition of the present invention may be a method of suppressing temperature rise inside the tank by coating the outer wall surface of the tank with the aqueous coating composition.
　本発明の水性塗料組成物は、厳しい環境に晒されるタンクの外壁面においても、ひび割れが発生し難く、遮熱機能を長期に亘って維持することができるので、タンクの内容物の揮発を抑制することができる。ここでいうタンクの内容物とは、例えば、揮発性の有機溶媒や水等の液体、これらの液体の混合物、あるいは揮発性の気体等が挙げられる。 The water-based coating composition of the present invention is less likely to crack even on the outer wall surface of the tank exposed to harsh environments, and can maintain the heat shielding function for a long period of time, so volatilization of the contents of the tank is suppressed. can do. The content of the tank here includes, for example, a volatile organic solvent, a liquid such as water, a mixture of these liquids, or a volatile gas.
　本発明の水性塗料組成物は、場合により、基材表面にあらかじめ下塗り塗料を塗装した後、形成される下塗り塗面上に塗装することができる。 The water-based coating composition of the present invention can optionally be applied onto the surface of the base that is formed after the surface of the substrate has been previously coated with an undercoat.
　下塗り塗料としては、基材表面の種類や状態等に応じて適宜選択することができる。下塗り塗料としては、例えば、アクリル系樹脂、アクリルシリコーン系樹脂、フッ素系樹脂、ポリ酢酸ビニル系樹脂、ポリオレフィン系樹脂、シリコーン系樹脂、ポリウレタン系樹脂、エポキシ系樹脂、フェノール系樹脂、ポリエステル系樹脂、アルキド系樹脂、メラミン系樹脂、生分解性樹脂等の樹脂種よりなる水系または溶剤系の樹脂を樹脂バインダーとして含んでなる塗料を挙げることができる。なかでも、下塗り塗料としては、水系の樹脂を含んでなる水性塗料を使用することが好ましい。 The undercoat paint can be appropriately selected according to the type and condition of the base material surface. Examples of the undercoat paint include acrylic resins, acrylic silicone resins, fluorine resins, polyvinyl acetate resins, polyolefin resins, silicone resins, polyurethane resins, epoxy resins, phenol resins, polyester resins, Coatings containing water-based or solvent-based resins such as alkyd-based resins, melamine-based resins and biodegradable resins as resin binders can be mentioned. Among them, as the undercoat paint, it is preferable to use a water-based paint containing a water-based resin.
　特に下塗り塗料として、公知の遮熱塗料を使用すると、本発明の水性塗料組成物による塗膜と共に基材面の遮熱性能をより一層高めることができる。 In particular, if a known heat-shielding paint is used as the undercoat, the heat-shielding performance of the substrate surface can be further enhanced together with the coating film of the water-based coating composition of the present invention.
　下塗り塗料の塗装は、既知の塗装手段を用いて行うことができる。下塗り塗料の塗装は、例えば、ローラー、エアスプレー、エアレススプレー、リシンガン、万能ガン、ハケ、ロールコーター等の塗装法から基材の用途等に応じて適宜選択して使用することができる。形成される下塗り塗膜の乾燥は、常温乾燥が好ましいが、下塗り塗料の種類や塗装環境等に応じて、加熱乾燥または強制乾燥を行うことができる。 The application of the undercoat paint can be performed using known painting means. The undercoat paint can be applied by appropriately selecting from coating methods such as roller, air spray, airless spray, lysing gun, all-purpose gun, brush, and roll coater, depending on the intended use of the base material. Drying of the undercoat film to be formed is preferably carried out at room temperature, but depending on the type of undercoat paint and the coating environment, heat drying or forced drying can be carried out.
　また、建築物の外壁面に、本発明の水性塗料組成物を塗装することにより、建築物内部の温度上昇を抑制することができる。 In addition, by applying the water-based coating composition of the present invention to the outer wall surface of a building, it is possible to suppress the temperature rise inside the building.
　＜水性塗料組成物の製造方法＞
　本発明の水性塗料組成物を製造する方法としては、特に限定されず、任意の適切な方法を採用することができる。本発明の水性塗料組成物を製造する方法としては、例えば、二酸化チタン（Ａ）、チタン酸塩（Ｂ）、水性媒体（Ｃ）、水性樹脂（Ｄ）、および必要に応じて、その他の成分を、ＳＧミル、シェーカー、ディスパーなどを用いて混練、分散するなどの方法が用いられ得る。 <Method for producing aqueous coating composition>
The method for producing the aqueous coating composition of the present invention is not particularly limited, and any appropriate method can be adopted. As a method for producing the aqueous coating composition of the present invention, for example, titanium dioxide (A), titanate (B), aqueous medium (C), aqueous resin (D), and, if necessary, other components can be kneaded and dispersed using an SG mill, shaker, disper, or the like.
　二酸化チタン（Ａ）は、あらかじめ顔料ペーストとして調製した後、水性樹脂（Ｄ）およびその他の成分と混合し、分散させることが好ましい。この場合、顔料である二酸化チタン（Ａ）をより安定にかつ十分に分散させることができる。 The titanium dioxide (A) is preferably prepared as a pigment paste in advance and then mixed with the water-based resin (D) and other components to disperse. In this case, the pigment titanium dioxide (A) can be dispersed more stably and sufficiently.
　＜塗装物品と該塗装物品の製造方法および用途＞
　本発明の塗装部品は、基材表面に上記に記載した水性塗料組成物を用いた塗膜の製造方法により、塗膜を形成することで、製造することができる。建築物の屋根、外壁面、および／または内装面に、上述した水性塗料組成物を塗装することにより、建築物内部の温度上昇を抑制することができる。また、建築物の屋根および／または外壁面に、上述した水性塗料組成物を塗装することにより、建築物の外表面における温度上昇を長期に亘って抑制できるので、ヒートアイランド現象を抑制することができる。 <Coated article and method for producing and use of the coated article>
The coated part of the present invention can be produced by forming a coating film on the substrate surface by the method for producing a coating film using the aqueous coating composition described above. By coating the roof, outer wall surface and/or interior surface of a building with the water-based coating composition described above, it is possible to suppress the temperature rise inside the building. In addition, by coating the roof and/or the outer wall surface of the building with the water-based coating composition described above, the temperature rise on the outer surface of the building can be suppressed for a long period of time, so the heat island phenomenon can be suppressed. .
　また、道路の舗装面に、上述した水性塗料組成物を塗装することにより、路面の温度上昇を長期に亘って抑制できるので、ヒートアイランド現象を抑制することができる。さらに、タンクの外壁面に、上述した水性塗料組成物を塗装することにより、ひび割れが発生し難く、遮熱機能を長期に亘って維持することができるので、タンクの内容物の揮発を抑制することができる。 In addition, by coating the pavement surface of the road with the water-based coating composition described above, it is possible to suppress the temperature rise of the road surface over a long period of time, thereby suppressing the heat island phenomenon. Furthermore, by coating the outer wall surface of the tank with the above-described water-based paint composition, cracks are less likely to occur and the heat shielding function can be maintained for a long period of time, so volatilization of the contents of the tank is suppressed. be able to.
　また、これらの方法により塗装物品を製造することにより、日射侵入比が０．０１～０．４の塗装物品を製造することができる。本発明の塗装物品は、例えば、環境負荷が少なく、耐候性が求められる建築物の屋根や内装に好適に用いることができる。なお、日射侵入比は、「ＪＩＳ　Ｋ　５６０３：２０１７　塗膜の熱性能－熱流計測法による日射吸収率の求め方　７．６　測定」により測定することができる。あるいは、日本塗料工業会が定める「遮熱塗料（屋根用）自主管理要領」に記載されている近似式（日射侵入比＝１－全日射反射率（％）/１００）により算出することができる。 Also, by producing a coated article by these methods, a coated article having a solar radiation penetration ratio of 0.01 to 0.4 can be produced. The coated article of the present invention can be suitably used, for example, for roofs and interiors of buildings that have a low environmental load and require weather resistance. The solar radiation penetration ratio can be measured according to "JIS K 5603:2017 Thermal performance of coating film - Determination of solar radiation absorption rate by heat flow measurement method 7.6 Measurement". Alternatively, it can be calculated by the approximate formula (solar penetration ratio = 1 - total solar reflectance (%) / 100) described in the "Thermal barrier paint (roofing) voluntary management guidelines" stipulated by the Japan Paint Manufacturers Association. .
　以下に実施例および比較例に基づいて、本発明を具体的に説明するが、本発明は何らこれに限定されるものではない。なお、本実施例および比較例で使用した原材料は具体的には以下の通りである。 The present invention will be specifically described below based on Examples and Comparative Examples, but the present invention is not limited thereto. In addition, the raw materials used in the present examples and comparative examples are specifically as follows.
　二酸化チタン：結晶形ルチル、平均粒子径：０．３０μｍ、吸油量：１８ｇ／１００ｇ、比重：４．１ｇ／ｃｍ３、ｐＨ：６．０～８．０、テイカ社製、商品名：「ＪＲ－７０１」
　繊維状チタン酸塩１：繊維状６チタン酸カリウム、平均繊維長：１５μｍ、平均繊維径：０．５μｍ、真比重：３．４ｇ／ｃｍ３～３．６ｇ／ｃｍ３、ｐＨ：７～８、大塚化学社製、商品名：「ＴＩＳＭＯ　Ｎ」
　繊維状チタン酸塩２：繊維状８チタン酸カリウム、平均繊維長：１５μｍ、平均繊維径：０．５μｍ、真比重：３．４ｇ／ｃｍ３～３．６ｇ／ｃｍ３、ｐＨ：９～１０、大塚化学社製、商品名：「ＴＩＳＭＯ　Ｄ」
　非繊維状チタン酸塩：非繊維状８チタン酸カリウム、平均粒子径：３μｍ、真比重：３．４ｇ／ｃｍ３、ｐＨ：８．５～１０．５、大塚化学社製、商品名：「ＴＥＲＲＡＣＥＳＳ　ＴＦ－ＳＳ」
　中空粒子：中空樹脂粒子、平均粒子径：２５μｍ、真密度：０．０３６±０．００４ｇ／ｃｍ３、Ｎｏｕｒｙｏｎ社製、商品名：「Ｅｘｐａｎｃｅｌ　４６１ＷＥ２０ｄ３６」
　水性媒体：イオン交換水
　分散剤：顔料に親和性のあるブロック共重合物からなる水系用湿潤分散剤、酸価：１０ｍｇＫＯＨ／ｇ、ＢＹＫ社製、商品名：「ＤＩＳＰＥＲＢＹＫ－１９０」
　消泡剤：ＢＹＫ社製、商品名：「ＤＩＳＰＥＲＢＹＫ－０２２」
　水性樹脂：アクリルシリコーン系エマルジョン樹脂、ガラス転移温度（Ｔｇ）２０℃、ｐＨ８．５～１０、粘度３００ｍＰａ・ｓ～２５００ｍＰａ・ｓ、ＤＩＣ社製、商品名：「ボンコートＳＡ－６３４０」
　造膜助剤：Ａｌｆａ　Ａｅｓａｒ社製、商品名：「テキサノール（ＣＳ１２）」
　増粘剤：ダイセルミライズ社製、商品名：「ＨＥＣ　ＳＰ－６００」 Titanium dioxide: crystalline rutile, average particle size: 0.30 μm, oil absorption: 18 g/100 g, specific gravity: 4.1 g/cm 3 , pH: 6.0 to 8.0, manufactured by Tayca, trade name: JR -701"
Fibrous titanate 1: fibrous potassium hexatitanate, average fiber length: 15 μm, average fiber diameter: 0.5 μm, true specific gravity: 3.4 g/cm 3 to 3.6 g/cm 3 , pH: 7 to 8 , manufactured by Otsuka Chemical Co., Ltd., trade name: "TISMO N"
Fibrous titanate 2: fibrous potassium octatitanate, average fiber length: 15 μm, average fiber diameter: 0.5 μm, true specific gravity: 3.4 g/cm 3 to 3.6 g/cm 3 , pH: 9 to 10 , manufactured by Otsuka Chemical Co., Ltd., trade name: "TISMO D"
Non-fibrous titanate: non-fibrous potassium octatitanate, average particle size: 3 μm, true specific gravity: 3.4 g/cm 3 , pH: 8.5 to 10.5, manufactured by Otsuka Chemical Co., Ltd., trade name: " TERRACE TF-SS"
Hollow particles: hollow resin particles, average particle diameter: 25 μm, true density: 0.036±0.004 g/cm 3 , manufactured by Nouryon, trade name: “Expancel 461WE20d36”
Aqueous medium: ion-exchanged water Dispersant: Water-based wetting and dispersing agent composed of block copolymer having affinity for pigment, acid value: 10 mgKOH/g, manufactured by BYK, trade name: "DISPERBYK-190"
Defoamer: manufactured by BYK, trade name: "DISPERBYK-022"
Water-based resin: acrylic silicone emulsion resin, glass transition temperature (Tg) 20°C, pH 8.5-10, viscosity 300mPa s-2500mPa s, manufactured by DIC, trade name: "Boncoat SA-6340"
Film-forming aid: manufactured by Alfa Aesar, trade name: "Texanol (CS12)"
Thickener: manufactured by Daicel Miraise, trade name: "HEC SP-600"
　＜水性塗料組成物の作製＞
　［実施例１］
　二酸化チタン０．７８ｇ、繊維状チタン酸塩（繊維状チタン酸塩１）１．８２ｇ、イオン交換水５．６０ｇ、分散剤０．４９ｇ、消泡剤０．０１５ｇを混合した。次に、高速分散機ホモディスパー２．５型（ＰＲＩＭＩＸ社製）にて回転数３０００ｒｐｍで５分間撹拌し、顔料ペーストを得た。 <Preparation of water-based paint composition>
[Example 1]
0.78 g of titanium dioxide, 1.82 g of fibrous titanate (fibrous titanate 1), 5.60 g of deionized water, 0.49 g of dispersant and 0.015 g of antifoaming agent were mixed. Next, the mixture was stirred for 5 minutes at 3000 rpm with a high-speed disperser Homodisper Model 2.5 (manufactured by PRIMIX) to obtain a pigment paste.
　得られた顔料ペーストに水性樹脂７．００ｇ、造膜助剤０．７０ｇ、および増粘剤０．０２５ｇを撹拌しながら添加した。撹拌後、高速分散機ホモディスパー２．５型にて回転数３０００ｒｐｍでさらに５分間撹拌することにより、水性塗料組成物を得た。 7.00 g of a water-based resin, 0.70 g of a film-forming aid, and 0.025 g of a thickener were added to the resulting pigment paste while stirring. After stirring, the mixture was further stirred for 5 minutes at 3000 rpm with a high-speed disperser Homodisper 2.5 to obtain a water-based coating composition.
　[実施例２］
　二酸化チタン２．０７ｇ、繊維状チタン酸塩（繊維状チタン酸塩１）０．５２ｇ、イオン交換水３．２３ｇ、分散剤０．４９ｇ、消泡剤０．０１５ｇを混合し、下記の表１に示す組成としたこと以外は、実施例１と同様にして、水性塗料組成物を得た。 [Example 2]
2.07 g of titanium dioxide, 0.52 g of fibrous titanate (fibrous titanate 1), 3.23 g of ion-exchanged water, 0.49 g of dispersant, and 0.015 g of antifoaming agent were mixed. A water-based coating composition was obtained in the same manner as in Example 1, except that the composition shown in .
　[実施例３］
　二酸化チタン１．８２ｇ、繊維状チタン酸塩（繊維状チタン酸塩１）を０．７８ｇ、イオン交換水３．５０ｇ、分散剤０．４９ｇ、消泡剤０．０１５ｇを混合し、下記の表１に示す組成としたこと以外は、実施例１と同様にして、水性塗料組成物を得た。 [Example 3]
1.82 g of titanium dioxide, 0.78 g of fibrous titanate (fibrous titanate 1), 3.50 g of ion-exchanged water, 0.49 g of dispersant, and 0.015 g of antifoaming agent were mixed and mixed. A water-based coating composition was obtained in the same manner as in Example 1, except that the composition shown in 1 was used.
　[実施例４］
　二酸化チタン１．２５ｇ、繊維状チタン酸塩（繊維状チタン酸塩１）１．１０ｇ、イオン交換水３．５７ｇ、分散剤０．２４ｇ、消泡剤０．０４７ｇを混合し、下記の表１に示す組成としたこと以外は、実施例１と同様にして、顔料ペーストを得た。得られた顔料ペーストに水性樹脂８．６２ｇ、造膜助剤０．８６２ｇ、および増粘剤０．０２５ｇを撹拌しながら添加し、下記の表１に示す組成としたこと以外は、実施例１と同様にして、水性塗料組成物を得た。 [Example 4]
1.25 g of titanium dioxide, 1.10 g of fibrous titanate (fibrous titanate 1), 3.57 g of ion-exchanged water, 0.24 g of dispersant, and 0.047 g of antifoaming agent were mixed. A pigment paste was obtained in the same manner as in Example 1, except that the composition shown in 1 was used. Example 1 except that 8.62 g of an aqueous resin, 0.862 g of a film-forming aid, and 0.025 g of a thickener were added to the obtained pigment paste while stirring to obtain the composition shown in Table 1 below. A water-based coating composition was obtained in the same manner.
　[実施例５］
　実施例４の繊維状チタン酸塩（繊維状チタン酸塩１）の代わりに繊維状チタン酸塩（繊維状チタン酸塩２）を用いたこと以外は、実施例４と同様にして、水性塗料組成物を得た。 [Example 5]
Water-based paint was prepared in the same manner as in Example 4, except that fibrous titanate (fibrous titanate 2) was used instead of fibrous titanate (fibrous titanate 1) in Example 4. A composition was obtained.
　[実施例６］
　二酸化チタン１．３７ｇ、繊維状チタン酸塩（繊維状チタン酸塩１）１．２１ｇ、中空粒子０．４５ｇ、イオン交換水３．３５ｇ、分散剤０．４９ｇ、消泡剤０．０１５ｇを混合し、下記の表１に示す組成としたこと以外は、実施例１と同様にして、水性塗料組成物を得た。 [Example 6]
1.37 g of titanium dioxide, 1.21 g of fibrous titanate (fibrous titanate 1), 0.45 g of hollow particles, 3.35 g of deionized water, 0.49 g of dispersant, and 0.015 g of antifoaming agent are mixed. A water-based coating composition was obtained in the same manner as in Example 1, except that the composition shown in Table 1 below was used.
　[実施例７］
　実施例４の繊維状チタン酸塩（繊維状チタン酸塩１）の代わりに非繊維状チタン酸塩を用いたこと以外は、実施例４と同様にして、水性塗料組成物を得た。 [Example 7]
A water-based coating composition was obtained in the same manner as in Example 4, except that the fibrous titanate (fibrous titanate 1) of Example 4 was replaced with a non-fibrous titanate.
　［比較例１］
　二酸化チタン２．５９ｇ、イオン交換水２．８０ｇ、分散剤０．４９ｇ、消泡剤０．０１５ｇを混合した。次に、高速分散機ホモディスパー２．５型にて回転数３０００ｒｐｍで５分間撹拌し、顔料ペーストを得た。 [Comparative Example 1]
2.59 g of titanium dioxide, 2.80 g of deionized water, 0.49 g of dispersant and 0.015 g of antifoaming agent were mixed. Next, the mixture was stirred for 5 minutes at 3000 rpm with a high-speed disperser Homodisper 2.5 to obtain a pigment paste.
　得られた顔料ペーストに水性樹脂７．００ｇ、造膜助剤０．７０ｇ、増粘剤０．０２ｇを撹拌しながら添加した。撹拌後、高速分散機ホモディスパー２．５型にて回転数３０００ｒｐｍでさらに５分間撹拌することにより、水性塗料組成物を得た。 7.00 g of a water-based resin, 0.70 g of a film-forming aid, and 0.02 g of a thickener were added to the resulting pigment paste while stirring. After stirring, the mixture was further stirred for 5 minutes at 3000 rpm with a high-speed disperser Homodisper 2.5 to obtain a water-based coating composition.
　＜塗膜の作製と評価＞
　［塗膜外観］
　実施例１～７および比較例１で得られた各水性塗料組成物をそれぞれ基材（ＴＰ技研製、塗装溶融５５％アルミニウム亜鉛合金メッキ鋼板（ＪＩＳ　Ｇ　３３２２）１５０ｍｍ×７０ｍｍ×０．８ｍｍ）に乾燥膜厚１００μｍとなるように、クリアランス５０μｍおよび２００μｍのフィルムアプリケーターで数回塗布した。上記工程において１回塗装毎に室温乾燥させ、指触乾燥後に塗り重ねた。得られた塗膜の外観を目視観察して、以下に示す基準で評価した。 <Preparation and evaluation of coating film>
[Appearance of coating film]
Each water-based paint composition obtained in Examples 1 to 7 and Comparative Example 1 was applied to a substrate (manufactured by TP Giken, 55% aluminum zinc alloy coated steel sheet (JIS G 3322) 150 mm × 70 mm × 0.8 mm). It was applied several times with a film applicator with a clearance of 50 µm and 200 µm so that the dry film thickness was 100 µm. In the above process, each coat was dried at room temperature, and after being dried to the touch, it was recoated. The appearance of the obtained coating film was visually observed and evaluated according to the following criteria.
　◎：Ｌ値：５０未満
　〇：Ｌ値：５０以上７０未満
　×：Ｌ値：７０以上 ◎: L value: less than 50 ○: L value: 50 or more and less than 70 ×: L value: 70 or more
　［光沢度］
　上記塗膜外観の評価で作製した塗膜を評価サンプルとし、光沢計（ＨＯＲＩＢＡ社製、ＩＧ－３３０）を用いて６０°入射角における光沢度を測定した。 [Glossiness]
The coating film prepared in the evaluation of coating film appearance was used as an evaluation sample, and the glossiness at an incident angle of 60° was measured using a gloss meter (IG-330 manufactured by HORIBA).
　［日射反射率（全日射反射率および赤外反射率）］
　上記塗膜外観の評価で作製した塗膜を評価サンプルとし、「ＪＩＳ　Ｋ　５６０２：２００８　塗膜の日射反射率の求め方　７　分光反射率の測定および　８　日射反射率の求め方」に準じ、日射反射率を求めた。また、「ＪＩＳ　Ｚ　８７２２：２００９　色の測定方法－反射および透過物体色　５．３　反射物体の測定方法　５．３．１　照射および受光の幾何条件　ｄ［記号：８°（ｄｅ）］」に準じ、試験面の三刺激値を測定し、「ＪＩＳ　Ｚ　８７８１－４：２０１３　測色－第４部：ＣＩＥ　１９７６　Ｌ＊ａ＊ｂ＊色空間　４　計算方法　４．１　基本座標」に準じ、Ｄ６５光源におけるＬ＊ａ＊ｂ＊を算出した。 [Solar reflectance (total solar reflectance and infrared reflectance)]
The coating film prepared in the evaluation of the coating film appearance was used as an evaluation sample, and the solar radiation A reflectance was obtained. In addition, according to "JIS Z 8722: 2009 Color measurement method-Reflective and transmissive object color 5.3 Reflective object measurement method 5.3.1 Geometric conditions for irradiation and light reception d [symbol: 8° (de)]" , Measure the tristimulus values of the test surface, and measure the D65 light source according to "JIS Z 8781-4: 2013 Colorimetry-Part 4: CIE 1976 L * a * b * color space 4 calculation method 4.1 basic coordinates" L * a * b * in was calculated.
　［日射侵入比］
　実施例１，４および比較例１で得られた各水性塗料組成物をそれぞれ基材（アルミ板）に乾燥後の単位面積当たりの塗膜質量が同等になるように数回スプレー塗装し、２３±２℃、５０±５％ＲＨで７日間養生した。得られた塗膜が形成された基材を評価サンプルとし、「ＪＩＳ　Ｋ　５６０３：２０１７　塗膜の熱性能－熱流計測法による日射吸収率の求め方　７．６　測定」により、塗膜の日射侵入比を求めた。 [Solar penetration ratio]
Each water-based coating composition obtained in Examples 1 and 4 and Comparative Example 1 was spray-coated several times on a base material (aluminum plate) so that the coating mass per unit area after drying was equivalent, and 23 Cured for 7 days at ±2° C. and 50±5% RH. The base material on which the obtained coating film was formed was used as an evaluation sample, and the solar radiation penetration of the coating film was measured according to "JIS K 5603: 2017 Thermal performance of coating film - Determination of solar absorption rate by heat flow measurement method 7.6 measurement". I asked for a ratio.
　[引張強度]
　実施例１～７および比較例１で得られた水性塗料組成物を、厚さ１ｍｍの型枠に充填した。２３±２℃、５０±５％ＲＨで９６時間養生させた後、塗膜を裏返し、さらに７２時間養生し、試験体を得た。養生後の各試験体をダンベル状３号形に打ち抜き、ダンベル状試験片を得た。得られた各試験片について、「ＪＩＳ　Ａ　６９０９：２０１４　建築用仕上塗材　７．２６　伸び試験」に準じ、引張強度および破断時の伸び率を測定した。 [Tensile strength]
The water-based coating compositions obtained in Examples 1 to 7 and Comparative Example 1 were filled in a mold with a thickness of 1 mm. After curing for 96 hours at 23±2° C. and 50±5% RH, the coating film was turned over and further cured for 72 hours to obtain a specimen. Each specimen after curing was punched into a dumbbell-shaped No. 3 shape to obtain a dumbbell-shaped test piece. Tensile strength and elongation at break were measured for each test piece obtained according to "JIS A 6909:2014 Architectural finish coating material 7.26 elongation test".
　[鉛筆硬度]
　上記塗膜外観の評価で作製した塗膜を評価サンプルとし、「ＪＩＳ　Ｋ　５６００－５－４：１９９９　引っかき硬度（鉛筆法）」に準じ、塗膜の鉛筆硬度を測定した。 [Pencil hardness]
The coating film prepared in the above coating film appearance evaluation was used as an evaluation sample, and the pencil hardness of the coating film was measured according to "JIS K 5600-5-4: 1999 scratch hardness (pencil method)".
　[碁盤目]
　上記塗膜外観の評価で作製した塗膜を評価サンプルとし、「ＪＩＳ　Ｋ　５６００－５－６：１９９９　付着性（クロスカット法）」に準じ、塗膜の付着性を測定した。なお、碁盤目試験では、分類される数字が小さいほど塗膜の密着性が高いことを意味している。 [Grid]
The coating film prepared in the evaluation of coating film appearance was used as an evaluation sample, and the coating film adhesion was measured according to "JIS K 5600-5-6: 1999 Adhesion (cross-cut method)". In the cross-cut test, the smaller the classified number, the higher the adhesion of the coating film.
　実施例１～７および比較例１の各塗料の配合および評価結果を表１に示す。 Table 1 shows the formulation and evaluation results of each paint of Examples 1 to 7 and Comparative Example 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１から明らかなように、比較例１の水性塗料組成物を使用して作製した塗装物品では、塗膜外観に艶があり、眩しさを感じ、光沢度が７７と光沢があり、かつ、造膜性が悪く、引張強度が１．６７Ｎ/ｍｍ２、鉛筆硬度が３Ｂ、碁盤目試験が分類２と、塗膜の強度、硬度、付着性が弱かった。 As is clear from Table 1, the coated article produced using the water-based coating composition of Comparative Example 1 has a glossy coating film appearance, feels dazzling, has a glossiness of 77, and is glossy. The film-forming property was poor, the tensile strength was 1.67 N/mm 2 , the pencil hardness was 3B, and the cross-cut test was class 2, indicating that the strength, hardness and adhesiveness of the coating film were weak.
　一方、実施例１の水性塗料組成物を使用して作製した塗装物品では、艶むらがなく、落ち着いた艶消し感が十分にあるのを感じ、光沢度が２１と低光沢となっており、かつ、造膜性に優れ、引張強度が３．８３Ｎ/ｍｍ２、鉛筆硬度が６Ｈ、碁盤目試験が分類０と、塗膜の強度、硬度、付着性が向上していることがわかる。また、実施例２～７についても実施例１と同様の傾向がみられていることがわかる。 On the other hand, in the coated article produced using the water-based coating composition of Example 1, there was no gloss unevenness, and a sufficiently calm matte feeling was felt, and the glossiness was 21, which was low gloss. In addition, it has excellent film-forming properties, a tensile strength of 3.83 N/mm 2 , a pencil hardness of 6H, and a cross-cut test of class 0, indicating that the strength, hardness, and adhesion of the coating film are improved. Moreover, it can be seen that the same tendency as in Example 1 is observed in Examples 2 to 7 as well.
　このように、水性塗料組成物に二酸化チタンのみを配合し、チタン酸塩を配合しない比較例１では、塗膜外観に艶があり、眩しさを感じ、光沢があり、かつ、造膜性が悪く機械的強度（引張強度、硬度、付着性）が低下していた。 Thus, in Comparative Example 1, in which only titanium dioxide was blended in the water-based coating composition and no titanate was blended, the coating film appearance was glossy, felt dazzling, and was glossy, and had film-forming properties. Poor mechanical strength (tensile strength, hardness, adhesion) was lowered.
　これに対して、二酸化チタンとチタン酸塩を併用して配合した実施例１～７では、比較例１と同等程度に遮熱性（日射反射率および日射侵入比）を維持しつつ、塗膜外観は良好で、光沢は低光沢となっており、かつ、特に造膜性に優れ機械的強度（引張強度、硬度、付着性）が顕著に高められているという効果が得られていることが確認できた。 On the other hand, in Examples 1 to 7, in which titanium dioxide and titanate were used in combination, while maintaining the heat shielding properties (solar reflectance and solar penetration ratio) to the same extent as in Comparative Example 1, the appearance of the coating film was is good, the gloss is low, and it is particularly excellent in film-forming properties, and the mechanical strength (tensile strength, hardness, adhesion) is remarkably enhanced. did it.
　従って、二酸化チタンとチタン酸塩を併用して配合した水性塗料組成物を使用することで、遮熱性（日射反射率および日射侵入比）に優れ、塗膜外観が良好な塗装物品の提供が可能となる。また、本発明の水性塗料組成物および塗装物品は、造膜性に優れた低光沢の塗膜を形成し得るので、例えば、その用途としては建築物の屋根、外壁、および／または内装等に適用することによって落ち着いた雰囲気の建築物の外観が得られ、かつ、冷暖房や光源などの省エネルギーにも貢献することができると考えられる。 Therefore, by using a water-based coating composition containing both titanium dioxide and titanate, it is possible to provide a coated article with excellent heat shielding properties (solar reflectance and solar radiation penetration ratio) and a good coating film appearance. becomes. In addition, since the aqueous coating composition and coated article of the present invention can form a low-gloss coating film with excellent film-forming properties, it can be used, for example, for roofs, exterior walls, and / or interiors of buildings. It is thought that the application of this material will give the appearance of a building with a calm atmosphere, and will also contribute to energy conservation in air conditioning, light sources, and the like.
　また、本発明の水性塗料組成物により形成された塗膜は、屋外暴露等の厳しい環境下においても、ひび割れが発生し難く、塗膜の優れた外観や遮熱機能を長期に亘って維持することができるので、例えば、その用途として、屋外暴露等の厳しい環境下に晒される道路の舗装面やタンクの外壁面等においても、適用することができる。 In addition, the coating film formed from the water-based coating composition of the present invention is less likely to crack even in severe environments such as outdoor exposure, and maintains the excellent appearance and heat shielding function of the coating film for a long period of time. Therefore, for example, it can be applied to the paved surface of a road, the outer wall surface of a tank, etc., which are exposed to severe environments such as outdoor exposure.

Claims (14)

  1. 　遮熱性を有する水性塗料組成物であって、
    　二酸化チタン（Ａ）、チタン酸塩（Ｂ）、水性媒体（Ｃ）、および水性樹脂（Ｄ）を含有する、水性塗料組成物。     A water-based coating composition having heat-shielding properties,
    An aqueous coating composition containing titanium dioxide (A), titanate (B), aqueous medium (C), and aqueous resin (D).
  2. 　前記二酸化チタン（Ａ）が非繊維状粒子であり、前記チタン酸塩（Ｂ）が繊維状粒子または非繊維状粒子である、請求項１に記載の水性塗料組成物。 The aqueous coating composition according to claim 1, wherein the titanium dioxide (A) is non-fibrous particles and the titanate (B) is fibrous particles or non-fibrous particles.
  3. 　前記チタン酸塩（Ｂ）が、Ａ２ＴｉｎＯ（２ｎ＋１）〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ｎは２～１１の数〕、ＡｘＭｙＴｉ（２－ｙ）Ｏ４〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上、ＭはＬｉ、Ｍｇ、Ｚｎ、Ｇａ、Ｎｉ、Ｃｕ、Ｆｅ、Ａｌ、Ｍｎより選ばれる１種または２種以上、ｘは０．５～１．０、ｙは０．２５～１．０の数〕、およびＡ０．２～０．８Ｌｉ０．２～０．４Ｔｉ１．６～１．８Ｏ３．７～３．９５〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上〕、Ａ０．２～０．８Ｍｇ０．３～０．５Ｔｉ１．５～１．７Ｏ３．７～３．９５〔式中、ＡはＬｉを除くアルカリ金属の１種または２種以上〕よりなる群から選択される１種または２種以上である、請求項１または請求項２に記載の水性塗料組成物。 The titanate (B) is A 2 Ti n O (2n+1) [wherein A is one or more alkali metals excluding Li, n is a number from 2 to 11], A x M y Ti (2-y) O 4 [Wherein, A is one or more alkali metals excluding Li, M is one selected from Li, Mg, Zn, Ga, Ni, Cu, Fe, Al, and Mn or two or more, x is 0.5 to 1.0, y is a number of 0.25 to 1.0], and A 0.2 to 0.8 Li 0.2 to 0.4 Ti 1.6 to 1.8 O 3.7-3.95 [In the formula, A is one or more alkali metals excluding Li], A 0.2-0.8 Mg 0.3-0.5 Ti 1. 5-1.7 O 3.7-3.95 wherein A is one or more alkali metals excluding Li] The aqueous coating composition according to claim 1 or claim 2.
  4. 　前記二酸化チタン（Ａ）と前記チタン酸塩（Ｂ）の合計含有量が、水性塗料組成物の合計量１００質量％に対して、５質量％以上、７０質量％以下である、請求項１または請求項２に記載の水性塗料組成物。 The total content of the titanium dioxide (A) and the titanate (B) is 5% by mass or more and 70% by mass or less with respect to 100% by mass of the total amount of the aqueous coating composition, or The aqueous coating composition according to claim 2.
  5. 　前記二酸化チタン（Ａ）に対するチタン酸塩（Ｂ）の質量比（チタン酸塩（Ｂ）／二酸化チタン（Ａ））が、０．１以上、９．０以下である、請求項１または請求項２に記載の水性塗料組成物。 1 or 2, wherein the mass ratio of titanate (B) to titanium dioxide (A) (titanate (B)/titanium dioxide (A)) is 0.1 or more and 9.0 or less. 2. The water-based coating composition according to 2.
  6. 　前記水性樹脂（Ｄ）が、アクリル系樹脂である、請求項１または請求項２に記載の水性塗料組成物。 The water-based coating composition according to claim 1 or 2, wherein the water-based resin (D) is an acrylic resin.
  7. 　前記水性樹脂（Ｄ）が、アクリルシリコーン系エマルジョン樹脂である、請求項１または請求項２に記載の水性塗料組成物。 The water-based coating composition according to claim 1 or 2, wherein the water-based resin (D) is an acrylic silicone emulsion resin.
  8. 　中空粒子をさらに含有する、請求項１または請求項２に記載の水性塗料組成物。 The aqueous coating composition according to claim 1 or claim 2, further containing hollow particles.
  9. 　基材表面に、請求項１または請求項２に記載の水性塗料組成物を塗装する、塗膜の製造方法。 A method for producing a coating film, comprising coating the water-based coating composition according to claim 1 or claim 2 on the surface of a substrate.
  10. 　建築物の屋根、外壁面、および／または内装面に、請求項１または請求項２に記載の水性塗料組成物を塗装することにより建築物内部の温度上昇を抑制する、水性塗料組成物の使用方法。 Use of a water-based coating composition for suppressing temperature rise inside a building by coating the water-based coating composition according to claim 1 or 2 on the roof, exterior wall surface, and/or interior surface of the building. Method.
  11. 　道路の舗装面に、請求項１または請求項２に記載の水性塗料組成物を塗装することにより路面の温度上昇を抑制する、水性塗料組成物の使用方法。 A method of using a water-based paint composition, in which the temperature rise of the road surface is suppressed by applying the water-based paint composition according to claim 1 or claim 2 to the paved surface of the road.
  12. 　タンクの外壁面に、請求項１または請求項２に記載の水性塗料組成物を塗装することによりタンク内部の温度上昇を抑制する、水性塗料組成物の使用方法。 A method of using a water-based coating composition, wherein the temperature rise inside the tank is suppressed by coating the water-based coating composition according to claim 1 or claim 2 on the outer wall surface of the tank.
  13. 　基材と、
    　前記基材表面に設けられている、請求項１または請求項２に記載の水性塗料組成物の塗膜と、
    を備える、塗装物品。     a substrate;
    A coating film of the aqueous coating composition according to claim 1 or 2 provided on the substrate surface;
    A coated article comprising:
  14. 　日射侵入比が０．０１～０．４である、請求項１２に記載の塗装物品。 The coated article according to claim 12, which has a solar radiation penetration ratio of 0.01 to 0.4.
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