CN104073112B - Heat-insulative light extinction aqueous coating composition and method for forming heat-insulative light extinction coating - Google Patents

Abstract

The present invention provides a heat-insulating matte water-based coating composition and a method for forming a heat-insulating matte coating film. The composition has good weather resistance and/or paint storage stability, and can maintain heat-insulating and matting properties for a long period of time. It can also be preferably used on the outer walls of buildings and the like for its fine appearance. The composition comprises a water-based resin (A) with an acid value per solid content in the range of 2.5 to 30 mgKOH/g, a pigment component (B) and a nonionic surfactant (C) with an HLB value of 10 or more, and the pigment component (B) Contains inorganic white pigment (b1), flaky extender pigment (b2) and extender pigment (b3) other than (b2), the pigment volume concentration of the pigment component (B) is 45 to 80%, and the pigment (b1) , The volume ratio of pigment (b2) and pigment (b3) in the total volume of pigment component (B) is: (b1) is 60-15%, (b2) is 5-70%, (b3) is 20- 80%, and the content of the surfactant (C) is 0.3-10% by mass based on the solid content of the resin (A).

Description

Heat-shielding matte aqueous paint composition and heat-shielding matte coating film forming method

technical field

The present invention relates to a heat-shielding matte water-based coating composition which can obtain a harmonious fine appearance and has high heat-shielding property and a heat-shielding matte coating film forming method using the same.

Background technique

In recent years, in order to suppress the temperature rise of buildings and/or structures caused by thermal energy such as sunlight, people apply heat-insulating coatings on roofs and/or outer walls to perform heat-insulating treatment, and many heat-insulating coatings or coatings have been developed. Inventions such as a coating method using heat-shielding paint.

For example, Patent Document 1 discloses a paint composition comprising a black pigment composition in which two or more kinds of pigments exhibiting absorption in the visible light region and having a reflectance of 35% in the near-infrared region are mixed. In the above colored organic pigment, the black pigment composition has a black color of Munsell notation (N-1).

In addition, Patent Document 2 discloses a coating method in which a heat-insulating white paint is applied to an exterior wall material, and then a heat-insulating color paint obtained by combining a plurality of colored paints is applied.

In the conventional heat-shielding paints and coating methods described in Patent Documents 1 and 2, especially when the film thickness is thin, the concealment performance may be poor, and the absorption amount of infrared rays by the base material may be increased. Sufficient heat insulation cannot be obtained.

In addition, these conventional heat-shielding paints are assumed to be used for glossy coating films applied to roofs, for example, but development of heat-shielding paints that can obtain a fine appearance with matte harmony has been desired.

As a solution to these problems, for example, Patent Document 3 discloses an aqueous coating composition comprising titanium dioxide, calcium carbonate as a porous medium, and an aqueous resin.

The water-based coating composition described in Patent Document 3 has low gloss and can obtain a coating film with high scattering reflectance, so it can also contribute to energy saving of light sources by coating on interior decoration surfaces of buildings. However, this coating contains a large amount of calcium carbonate as a porous medium, so the coating film is prone to cracks. In order to prevent this problem, it is conceivable to use a resin with a low glass transition temperature (Tg). In the case of the outer wall and/or roof of an object, there is a problem that the coating film is stained to impair the reflective function, or whitening and/or discoloration occur. In addition, there is a problem that it is difficult to maintain the stability of the paint for a long period of time and thicken with time.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2002-20647

Patent Document 2: Japanese Patent Laid-Open No. 2002-320912

Patent Document 3: Japanese Patent Laid-Open No. 2012-92289

Contents of the invention

The problem to be solved by the invention

The object of the present invention is to provide a heat-insulating matte water-based coating composition and a method for forming a heat-insulating matte coating film using the same, the weather resistance of the heat-insulating matte water-based coating composition and/or the storage stability of the paint, etc. Good, maintains a fine appearance with thermal insulation and matting properties for a long period of time, and can be preferably used for outer walls of buildings, etc.

solutions to problems

The inventors of the present invention conducted intensive studies on the above-mentioned subject, and as a result, found the following fact, thereby achieving the present invention: by blending a specific pigment component and a specific surfactant in an aqueous resin having a specific range of acid value, Thereby, a coating film having good storage stability and having both a matte feeling and heat-shielding property can be obtained.

That is, the present invention relates to a heat-shielding matte water-based coating composition characterized by comprising an aqueous resin (A) and a pigment component (B) within the range of an acid value per solid content of 2.5 to 30 mgKOH/g. and an aqueous coating composition of a nonionic surfactant (C) having an HLB value of 10 or more, wherein the pigment component (B) includes an inorganic white pigment (b1), a flaky extender (b2) and an extender other than (b2) The pigment (b3), the pigment volume concentration of the pigment component (B) is in the range of 45% to 80%, the inorganic white pigment (b1), the flaky extender (b2) and the extender (b3) are all in the pigment component (B) The proportion of volume in the volume is: 60-15% for inorganic white pigment (b1), 5-70% for flaky extender pigment (b2), 20-80% for extender pigment (b3), non-ionic surface active The content of the agent (C) is based on the solid content of the water-based resin (A) in the range of 0.3 to 10% by mass,

The present invention also relates to a method for forming a heat-insulating matte coating film, which is characterized in that, coating the heat-insulating matte water-based coating composition,

The present invention also relates to a method for suppressing the temperature rise inside the building, by coating the heat-insulating matting water-based paint composition on the outer wall of the building so as to suppress the temperature rise inside the building,

The present invention also relates to a coated article obtained by coating the heat-shielding matte aqueous coating composition.

The effect of the invention

The coating composition of the present invention has a matte feeling and can form a coating film excellent in heat insulation, so it can be applied to buildings, etc., for example, to obtain a harmonious appearance, and can contribute to the maintenance of heating and cooling equipment and/or light sources, etc. energy saving.

In addition, the composition of the present invention is excellent in long-term storage stability.

Moreover, regarding the coating film formed by the water-based matting coating composition of the present invention, it is difficult to generate strain inside the coating film, and even in severe environments such as outdoor exposure, it will not cause cracks, etc., and the appearance and heat insulation of the object to be coated can be maintained for a long time. performance.

detailed description

The heat-shielding matte water-based paint composition of the present invention contains a water-based resin (A), a pigment component (B), and a nonionic surfactant (C) having an HLB value of 10 or more.

<Water-based resin (A)>

The water-based resin (A) in the present invention is a resin that can be dissolved or dispersed in water. As the type of the resin, it is not particularly limited as long as it has the ability to form a coating film. Conventionally known resins can be used, such as: Acrylic resin, silicone resin, polyurethane resin, fluorine resin, polyvinyl acetate resin, epoxy resin, phenolic resin, polyester resin, alkyd resin, polycarbonate resin, melamine resin etc. These can be used individually or in combination of 2 or more types, respectively. In addition, these resins may be modified like urethane-modified acrylic resins, or resins obtained by graft polymerization, or may be in the form of dispersed particles, for example.

Regarding the water-based resin (A), in the form of dispersed particles, it may have a multilayer structure such as a single-layer structure (homogeneous granular) or a core/shell structure. In the case of a core/shell structure, the core and/or The shell can also be crosslinked.

Regarding the water-based resin (A), it is preferably an acrylic resin from the viewpoints of the durability and weather resistance of the coating film formed by the water-based paint composition of the present invention. A resin obtained by (co)polymerizing a (meth)acryloyl group-containing compound together with other polymerizable unsaturated monomers that can be copolymerized as needed.

As a (meth)acryloyl group-containing compound, as a compound having one (meth)acryloyl group in one molecule, for example, methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylate, ) Propyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate , lauryl (meth)acrylate, stearyl (meth)acrylate and other (meth)acryloyl monomers containing linear or branched alkyl groups; cyclohexyl (meth)acrylate, (meth)acrylic acid (meth)acryloyl monomers containing alicyclic alkyl groups such as isobornyl acrylate; (meth)acryloyl monomers containing aralkyl groups such as benzyl (meth)acrylate; (meth)acrylic acid (meth)acryloyl monomers containing alkoxyalkyl groups such as 2-methoxyethyl ester and 2-ethoxyethyl (meth)acrylate; hexafluoroisopropyl (meth)acrylate, (meth)acrylic acid fluorine-containing (meth)acryloyl monomers such as perfluorooctylmethyl acrylate and perfluorooctylethyl (meth)acrylate; N,N-diethylaminoethyl (meth)acrylate Amino-containing (meth)acryloyl monomer; (meth)acrylamide; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate Hydroxyalkyl (meth)acrylates such as esters, hydroxybutyl (meth)acrylate, ε-caprolactone-modified products of the above-mentioned hydroxyalkyl (meth)acrylates, polyethylene oxide containing hydroxyl groups at molecular terminals Chain (meth)acrylate and other hydroxyl-containing (meth)acryloyl monomers; (meth)acrylic acid, β-carboxyethyl acrylate and other carboxyl-containing (meth)acryloyl monomers; (meth) Carbonyl-containing (meth)acryloyl monomers such as acetoacetoxyethyl acrylate and diacetone (meth)acrylamide; glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 3,4-epoxycyclohexylpropyl (meth)acrylate (meth)acryloyl monomers containing epoxy groups; (meth)acryloyl monomers containing isocyanate groups such as isocyanatoethyl (meth)acrylate; γ-methacryloyloxy Propyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane and other alkoxysilyl-containing (meth)acryloyl monomers; (meth)acrylate dicyclopentenyloxy Oxidation-curable group-containing (meth)acryloyl monomers such as ethyl ester, dicyclopentenyloxypropyl (meth)acrylate, and dicyclopentenyl (meth)acrylate, etc.

Examples of compounds having at least two (meth)acryloyl groups in one molecule include: allyl (meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, Glycol ester, tetraethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, di(meth)acrylic acid 1,4-Butanediol, Neopentyl Glycol Di(meth)acrylate, 1,6-Hexanediol Di(meth)acrylate, Pentaerythritol Di(meth)acrylate, Pentaerythritol Tetra(methyl) ) acrylate, glycerol di(meth)acrylate, 1,1,1-trihydroxymethylethane di(meth)acrylate, 1,1,1-trihydroxymethylethane tri(meth)acrylate base) acrylate, 1,1,1-trihydroxymethylpropane tri(meth)acrylate, etc.

These (meth)acryloyl group-containing compounds can be used individually or in combination of 2 or more types, respectively.

In addition, examples of other polymerizable unsaturated monomers that can be copolymerized include: (meth)acrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl ester compounds such as styrene and α-methylstyrene; Aromatic compounds; triallyl isocyanurate, diallyl terephthalate, divinylbenzene and other polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule; Allyl alcohol; carboxyl-containing polymerizable unsaturated monomers such as maleic acid and crotonic acid; (meth)acrolein, formyl styrene, vinyl alkyl ketones with 4 to 7 carbon atoms (such as vinyl methyl carbonyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), carbonyl-containing polymerizable unsaturated monomers such as acetoacetoxyallyl ester; epoxy-group-containing polymerizable unsaturated monomers such as allyl glycidyl ether Unsaturated monomers; polymerizable unsaturated monomers containing isocyanate groups such as m-isopropenyl-α, α-dimethylbenzyl isocyanate; vinyltrimethoxysilane, vinyltriethoxysilane, etc. Alkoxysilyl polymerizable unsaturated monomers; fluoroalkyl trifluorovinyl ethers, perfluoroalkyl trifluorovinyl ethers and other fluorovinyl ethers; the above-mentioned epoxy group-containing polymerizable unsaturated monomers Or an oxidatively curable group-containing polymerizable unsaturated monomer such as a reaction product of a hydroxyl group-containing polymerizable unsaturated monomer and an unsaturated fatty acid, etc., and these may be used alone or in combination of two or more.

In this invention, the acid value of the unit solid content of the said aqueous resin (A) exists in the range of 2.5-30 mgKOH/g, Preferably it is 3-25 mgKOH/g.

When the acid value per solid of the water-based resin (A) is less than 2.5 mgKOH/g, aggregates are formed when the water-based paint composition is stored for a long period of time, or the color stability when mixing multiple colors deteriorates, which is not preferable.

On the other hand, when the acid value per solid content exceeds 30 mgKOH/g, since the water resistance of a coating film will be inferior, it is unpreferable.

As an acidic group which gives an acid value to an aqueous resin (A), a carboxyl group, a sulfonic acid group, a phosphoric acid group etc. are mentioned, Among them, a carboxyl group is preferable.

In addition, these acid groups can also be derived from methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propane Substances obtained by partially or substantially completely neutralizing amines such as alcohols and bases such as ammonia.

Examples of functional groups other than acid groups contained in the above-mentioned water-based resin (A) include hydroxyl groups, isocyanate groups, amino groups, amidocarbonyl groups, etc., and from the viewpoint of weather resistance under severe conditions such as outdoors, especially It preferably has a carbonyl group.

In the case where the water-based resin (A) has a carboxyl group and a carbonyl group, for example, it can be obtained by using (meth)acrylic acid and/or other carboxyl group-containing polymerizable unsaturated monomers as described above and a carbonyl group-containing ( Meth)acryloyl monomers and/or other carbonyl-containing polymerizable unsaturated monomers, as at least a part of the monomer components, and other (meth)acryloyl-containing compounds and/or other polymerizable unsaturated monomers Copolymerization is performed to manufacture the water-based resin (A).

Regarding the amount of related (meth)acrylic acid and other carboxyl-containing polymerizable unsaturated monomers and carbonyl-containing (meth)acryloyl monomers and other carbonyl-containing polymerizable unsaturated Based on the total mass of all polymerizable unsaturated monomers, (meth)acrylic acid and other carboxyl-containing polymerizable unsaturated monomers are usually 0.05 to 10% by mass, preferably in the range of 0.1 to 3% by mass, while The carbonyl group-containing (meth)acryloyl monomer and the carbonyl group-containing polymerizable unsaturated monomer are usually 0.2 to 30% by mass, preferably within the range of 0.3 to 15% by mass.

The polymerization method of the above-mentioned monomers is not particularly limited, and can be carried out, for example, by (co)polymerizing the above-mentioned monomers in the presence of a polymerization initiator and an emulsifier according to a general emulsion polymerization method.

In (co)polymerization of a monomer, a chain transfer agent, a pH adjuster, and a solvent can also be used as needed.

As the emulsifier, known emulsifiers can be used. Specifically, for example, anionic surfactants, nonionic surfactants, and zwitterionic surfactants can be used. In addition, emulsifiers containing A reactive surfactant of both a polymerizable unsaturated group and an anionic group or a nonionic group, and the like.

The amount used is based on the total mass of all polymerizable unsaturated monomers, and is usually within a range of 0.5 to 6% by mass, preferably within a range of 1 to 4% by mass. The produced emulsion particles usually have an average particle diameter in the range of 50 to 500 nm, preferably in the range of 100 to 400 nm, more preferably in the range of 100 to 300 nm.

In addition, in the water-based resin (A), polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, sodium polyacrylate, ethylene-maleic anhydride copolymer, etc. Water-soluble polymer compounds, etc.

In this specification, the average particle diameter of the water-based resin (A) is: using a submicron particle analyzer N4 (trade name, manufactured by Beckman Coulter, Inc., particle size distribution measuring device), using deionized water to dilute the sample to an appropriate The measured concentration is the value measured at normal temperature (about 20°C).

The polymerization initiator is a polymerization initiator that undergoes radical decomposition in the presence of heat or a reducing agent to initiate monomer addition polymerization, and any of inorganic initiators and organic initiators can be used.

<Pigment Component (B)>

The pigment component (B) used for the water-based paint composition of this invention contains an inorganic white pigment (b1), a flaky extender (b2), and an extender (b3) other than (b2).

In the present invention, the inorganic white pigment (b1) is an essential component for imparting heat-shielding properties to the coating film formed from the water-based paint composition of the present invention, and specific examples thereof include titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, and antimony oxide. , zirconia, aluminum nitride, boron nitride, lead white (zinc carbonate), etc., and these may be used alone or in combination of two or more.

Examples of the flaky extender (b2) include talc, mica, glass flakes, and the like, and these can be used alone or in combination of two or more.

By using this flaky extender (b2), there is an effect that a heat-shielding matte coating film excellent in crack resistance can be obtained even under severe conditions such as outdoors.

Pigment extenders (b3) other than (b2) are pigment extenders used to impart a matte feeling to the formed coating film, and known pigment extenders can be used as the pigment extender, specifically calcium carbonate, silica, barium sulfate, and kaolin. Clay etc. can be used individually or in combination of 2 or more types.

In addition, the said pigment component (B) may contain other well-known pigments other than pigments (b1), (b2), and (b3) as needed. This is because a desired color tone and/or luster can be imparted to a matte coating film of a pastel color based on white derived from the pigment (b1) in the present invention.

Specific examples of other pigments include iron oxide, perylene pigment, azo pigment, yellow lead, iron oxide red, cinnabar, titanium red, cadmium red, quinacridone red, isoindolinone, benzimidazolone Coloring pigments such as ketone, phthalocyanine green, phthalocyanine blue, cobalt blue, indanthrene blue, ultramarine blue, and iron blue, aluminum pigments, copper, zinc, brass, nickel, covered with titanium oxide and/or iron oxide Bright pigments such as aluminum oxide, mica covered with titanium oxide and/or iron oxide, holographic pigments, zinc phosphate, zinc phosphosilicate, aluminum zinc phosphate, calcium zinc phosphate, calcium phosphate, aluminum pyrophosphate, calcium pyrophosphate, Antirust pigments such as aluminum dihydrogen tripolyphosphate, aluminum metaphosphate, calcium metaphosphate, zinc oxide, zinc phosphomolybdate, aluminum phosphomolybdate, and the like can be used alone or in combination of two or more.

In addition, carbon black is not included in other pigments, or its content is suppressed to a small amount (for example, according to the ratio of pigment volume concentration of 5% or less, especially 1% or less), this is from the viewpoint of heat insulation of the coating film. Consideration is required.

In the present invention, the pigment volume concentration of the pigment component (B) is in the range of 45-80%, preferably 50-75%.

When the pigment volume concentration is less than 45%, the matting effect will become insufficient. On the other hand, when it exceeds 80%, cracks will occur in the coating film, or pigment sedimentation will be found when the aqueous coating composition of the present invention is stored for a long time, so it is not preferable.

In this specification, "pigment volume concentration" refers to the volume ratio of the pigment component among all the resin components in the paint and the total solids of all the pigments.

The pigment specific gravity used as a basis for calculating the pigment volume is the specific gravity of the pigment based on the "Paint Material Handbook 6th Edition" (Nippon Paint Industry Association), and the specific gravity of the resin solids is a value approximately 1.

In addition, in the present invention, the pigment component (B) contains the above-mentioned pigments (b1), (b2) and (b3), and also contains the nonionic surfactant (C) described later, so the pigment component (B) may contain ) is stabilized at such an amount as to become more than the critical pigment volume concentration.

In this specification, the critical pigment volume concentration refers to the volume concentration of the pigment when the resin just fills the gap between the pigments when the pigment and the resin are mixed, and is calculated by the following formula.

Critical pigment volume concentration = volume of pigment component (B) in paint × l00/(oil absorption of pigment component (B) in paint + volume of pigment component (B) in paint)

In addition, the oil absorption (ml/100g) means the value calculated|required by the method prescribed|regulated by JISK5101-13-2:2004, and the value represented by the ml of boiled linseed oil absorbed in 100g of pigments.

In addition, as the volume ratio of the inorganic white pigment (b1), flake-shaped extender (b2) and extender (b3) in the total volume of the pigment component (B),

Inorganic white pigment (b1) is 60-15%, preferably in the range of 50-20%,

The flaky extender (b2) is 5 to 70%, preferably in the range of 10 to 60%,

The extender pigment (b3) is 20 to 80%, preferably in the range of 30 to 65%,

Other pigments are 0 to 25%, preferably in the range of 0 to 20%.

This is because, by making the pigments (b1), (b2) and (b3) within this range, the storage stability of the aqueous coating composition of the present invention, the color stability during toning, the durability of the coating film, Excellent heat insulation and concealment.

＜Nonionic Surfactant (C)＞

The aqueous coating composition of this invention contains the nonionic surfactant (C) whose HLB value is 10 or more. By including the surfactant (C), the wettability to the pigment can be improved, aggregation can be suppressed when the aqueous coating composition of the present invention containing a large amount of the pigment is stored, and the color stability at the time of toning can be improved. .

Specific examples of such nonionic surfactants (C) include polyoxyethylene alkylphenyl ethers such as polyoxyethylene nonylphenyl ether and polyoxyethylene oxypropylene octylphenyl ether; polyoxyethylene Lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether and other polyoxyalkylene alkyl ethers; polyoxyethylene distyrenated phenyl ether and other polyoxyethylene Ethylene oxide polycyclic phenyl ether; polyoxyethylene alkylamide; glycerin alkyl ester; sorbitan alkyl ester, etc., may be used alone or in combination of two or more.

In this invention, the HLB value of the said nonionic surfactant (C) is 10 or more, Preferably it exists in the range of 11-18.

The HLB value in this specification is an index of the balance of the hydrophilicity and hydrophobicity of a nonionic surfactant, and can be calculated|required by Griffin equation (Griffin equation). Specifically, it is a value obtained by multiplying a value obtained by dividing the molecular weight of a hydrophilic portion such as an oxyalkylene group by the molecular weight of the entire nonionic surfactant by 20.

Moreover, as content of a nonionic surfactant (C), it exists in the range of 0.3-10 mass % based on the solid content of an aqueous resin (A), Preferably it exists in the range of 0.5-6 mass %.

If the content of the nonionic surfactant (C) is less than 0.3% by mass, the pigment component (B) will be poorly integrated into the paint, and the storage stability and/or the color stability when toning the paint will decrease. On the other hand, since the water resistance of a coating film will fall when it exceeds 10 mass %, it is unpreferable.

In the water-based coating composition of the present invention, especially in the case where the aforementioned water-based resin (A) has a carbonyl group, in order to obtain a coating film that can be cross-linked even when it is dried at room temperature, it can be cross-linked even under severe outdoor conditions. The heat-shielding matte coating film that is also excellent in long-term durability preferably contains a hydrazine derivative.

Examples of related hydrazine derivatives include hydrazine, hydrazine hydrate, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipate dihydrazide, sebacic acid Dihydrazides of saturated aliphatic carboxylic acids with 2 to 18 carbon atoms such as dihydrazides; monoethylenically unsaturated dicarboxylic acids such as maleic acid dihydrazides, fumaric acid dihydrazides, and itaconic acid dihydrazides dihydrazide of phthalic acid, terephthalic acid or isophthalic acid; dihydrazide, trihydrazide or tetrahydrazide of pyromellitic acid; trihydrazide of nitrogen triacetate, Citric acid trihydrazide, 1,2,4-benzenetrihydrazide; ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid tetrahydrazide; Polyhydrazide, etc. formed by the reaction of low polymer with hydrazine or hydrazine hydrate; dihydrazide carbonate, bisemicarbazide; N,N-dimethylhydrazine and/or N,N-substituted hydrazine and/or A polyfunctional semicarbazide obtained by excessively reacting the hydrazides exemplified above with diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and polyisocyanate compounds derived therefrom; The polyisocyanate compound is an aqueous polyfunctional amino group obtained by excessively reacting the isocyanate group in the reactant of an active hydrogen compound containing a hydrophilic group such as polyether polyols and/or polyethylene glycol monoalkyl ethers. Urea; a mixture of the polyfunctional semicarbazide and a water-based polyfunctional semicarbazide; diacetyl dihydrazone, and the like can be used alone or in combination of two or more.

In the water-based coating composition of the present invention, hollow particles, alkyl silicates, aggregates, fibers, plasticizers, leveling agents, anti-sagging agents, fluorescent whitening agents, and silane coupling agents can be further included as needed , thickener, neutralizer, antistatic agent, softener, antibacterial agent, fragrance, curing catalyst, pH regulator, humidity regulator, powdery or granular activated carbon, photocatalyst titanium oxide, water-based waterproofing agent, dispersion agent, defoamer, preservative, antifungal agent, antifreeze, ultraviolet absorber, light stabilizer, film-forming aid, zinc whisker, curing accelerator, aldehyde adsorbent, wax, antimony trioxide, pentoxide Known additives for coatings such as flame retardants such as antimony and aluminum hydroxide.

Among them, hollow inorganic particles and hollow resin particles are exemplified.

By including hollow particles, the water-based paint composition of the present invention can make the coating film more reflective of sunlight and the like, or can have a heat-shielding effect, thereby suppressing an increase in the temperature of the base material.

Examples of inorganic substances constituting the hollow inorganic particles include glasses such as sodium silicate glass, aluminosilicate glass, and sodium silicate glass, fly ash, alumina, zirconia, titania or titania, silicon boride, white sand ( Silas), obsidian, etc.

Examples of the resin component 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 resin, acrylic-acrylonitrile-methacrylonitrile copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, etc.

Any of air, a gas other than air, and a vacuum may be contained in the hollow particles.

The average particle diameter of the hollow particles is preferably 5 to 150 μm from the viewpoint of the appearance of the coating film, the physical properties of the coating film, and the heat-shielding effect.

The average particle diameter of the hollow particles can be determined by taking a transmission electron micrograph (TEM), measuring the particle diameters of 50 particles, and averaging them.

In the case of hollow particles, the content thereof is 2 to 50% by mass, preferably 5 to 30% by mass, based on the resin solids contained in the aqueous coating composition. , The viewpoint of crack resistance of the coating film is appropriate.

In addition, the composition of the present invention may contain an alkyl silicate compound for the purpose of imparting stain resistance to the formed coating film.

As an alkyl silicate compound, the compound represented by the following formula, and its partial hydrolysis and condensate are mentioned, for example,

Si(-OR ¹ ) ₄

(wherein, R ¹ is the same or different monovalent hydrocarbon groups selected from alkyl, aryl and aralkyl).

In the above formula, R ¹ is preferably an alkyl group having 1 to 4 carbon atoms.

Examples of alkyl silicate compounds include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane Silane, tetra-tert-butoxysilane, and any combination thereof, and their partial hydrolysis and condensate. In addition, compounds obtained by modifying these exemplified compounds with polyoxyalkylene compounds and the like are also included as alkyl silicate compounds.

In addition, when the above-mentioned alkyl silicate compound is included, catalysts such as organic tin compounds, organic titanate compounds, phosphoric acid compounds, acid anhydrides, and amines may be used in combination.

In addition, when the water-based paint composition of the present invention contains the above-mentioned alkyl silicate compound, it is preferable to make the paint composition a two-component type, and immediately before using the components containing the alkyl silicate compound, Compounded with other ingredients.

When the water-based coating composition of the present invention contains an alkyl silicate compound, from the viewpoint of stain resistance and crack resistance of the formed coating film, the content thereof is based on the resin solid content contained in the coating, It can be made into the range of 3-20 mass %, Preferably it can be made into the range of 5-15 mass %.

<Coating film forming method using heat-shielding matte water-based paint composition>

By applying the heat-shielding matte water-based paint composition of the present invention to the surface of a substrate, a matte coating film excellent in heat-shielding properties can be formed.

The substrate surface to which the water-based paint composition of the present invention can be applied is not particularly limited, but examples include gypsum boards, concrete boards, concrete blocks, exterior wall decorative boards, mortar boards, slate boards, PC boards, ALC boards, cement boards, etc. Acrylic resin, acrylic Polyurethane resins, polyurethane resins, fluororesins, silicone resins, silicone acrylic resins, vinyl acetate resins, epoxy resins, etc., are coated with polyvinyl chloride, polyolefin, paper cloth, etc. Formed wallpaper surface, etc.

The surface of these substrates may also be pre-treated with a sealer or the like.

The water-based paint composition of the present invention can be coated by using its own known coating means, for example, from a roller, an air spray, an airless spray, a sandblasting gun, a universal gun ( Universal gun), brush, roller coater and other coating methods are selected and used. In addition, the water-based coating composition of the present invention may be repeatedly applied multiple times within the range not to impair the appearance of the coating film.

Drying to form a coating film can be carried out by normal temperature drying, but heat drying or forced drying can also be performed depending on the components of the coating composition used, the coating environment, and the like.

The dry film thickness can be appropriately adjusted according to the applicable substrate and/or the coating environment, but in order to obtain sufficient heat insulation, it is generally 35 to 5000 μm, preferably 50 to 3000 μm.

The present invention also provides a method of suppressing a rise in temperature inside a building by applying the above-mentioned water-based paint composition to the outer wall surface of the building.

The water-based coating composition of the present invention can form a coating film having thermal insulation properties and a moderate matte feeling, and thus can impart a harmonious appearance to the outer wall of a building and impart a thermal insulation function by coating the substance.

Specific examples of building exterior walls include, for example, the exterior walls of various buildings such as buildings, houses, facilities, and warehouses, and the materials constituting the exterior walls include general exterior wall materials, such as ceramic exterior wall panels. Inorganic exterior materials such as mortar, concrete, and slate, or metal exterior materials such as iron, aluminum, and metal exterior materials, or wooden exterior materials such as natural wood and plywood, etc., also include old coatings on the surface Material.

Regarding the water-based coating composition of the present invention, a base coating material may be previously coated on the surface of the substrate according to circumstances, and then coated on the formed base coating surface.

As the above-mentioned primer coating material, it can be appropriately selected according to the type and/or state of the substrate surface, etc., for example, a coating formed by including a water-based resin or a solvent-based resin as a resin binder, the water-based resin or solvent-based resin The resin contains acrylic resin, acrylic silicon resin, fluorine resin, polyvinyl acetate resin, polyolefin resin, silicon resin, polyurethane resin, epoxy resin, phenolic resin, polyester resin , alkyd resin, melamine resin, biodegradable resin and other water-based resins or solvent-based resins, it is preferable to use a water-based paint containing a water-based resin.

In particular, when a heat-shielding paint known as a primer is used, the heat-shielding performance of the substrate surface can be further improved together with a coating film obtained from the water-based paint composition of the present invention.

The coating of the above-mentioned base-forming paint can be carried out by using known coating means, such as roller, air spray, airless spray, sandblasting gun, universal gun, brush, roller, etc., according to the use of the substrate. Appropriate selection and use in coating methods such as coaters. Drying of the formed primer coating film is preferably room temperature drying, but heat drying or forced drying may be performed depending on the type of primer coating material and/or the coating environment and the like.

Example

Hereafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples. In addition, "parts" and "%" in the following examples represent "parts by mass" and "% by mass", respectively.

Manufacture of Waterborne Resin Dispersions

Manufacturing example 1

Add 35 parts of deionized water and 1 part of Newcol 707SF (Note 1) to a reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a dropping device, stir and mix in a nitrogen stream, and raise the temperature to 85°C. Next, 3% of the pre-emulsion and 10 parts of a 2.5% ammonium persulfate aqueous solution were added to the reaction vessel and kept at 85° C. for 20 minutes.

Thereafter, 20 parts of the remaining pre-emulsion and 2.5% ammonium persulfate aqueous solution were added dropwise in the reaction container over 4 hours, and aging was performed for 2 hours after the dropwise addition was completed. Thereafter, it was cooled to 30° C., and adjusted so that the solid content was 50% and the pH was 8.0 using ammonia water and deionized water. Then, it is discharged while filtering with 200-mesh nylon cloth to obtain an average particle diameter of 180 nm (using a submicron particle size distribution measuring device "COULTER N4 type" manufactured by Beckman Coulter, Inc., dilute with deionized water and measure at 20°C out), an aqueous resin dispersion (A-1) with an acid value of 13 mgKOH/g per unit solid.

(Note 1) Newcol 707SF: brand name, manufactured by Nippon Emulsifier Co., Ltd., anionic surfactant having a polyoxyethylene chain, 30% of non-volatile content.

Production examples 2 to 5

In the above-mentioned production example 1, the monomer component was set as the formula shown in the following table 1, except that, it was synthesized in the same manner as in the production example 1, and the aqueous resin dispersions (A-2) to (A-2) were obtained. 5).

Table 1

Manufacture of Pigment Dispersion Paste

Manufacturing example 6

The components shown below were sequentially added to a stainless steel container under stirring, and the stirring was continued for 30 minutes until uniformity was obtained using a homodisper manufactured by PRIMIX Co., Ltd. to obtain a pigment dispersion paste (B-1).

(Note 2) Suraoff72N: trade name, manufactured by Japan Enviro Chemicals, Ltd., preservative,

(Note 3) SP-600: trade name, manufactured by Daicel Chemical Industries, Ltd., hydroxyethylcellulose-based thickener,

(Note 4) DISPER BYK-190: trade name, manufactured by BYK-Chemie, pigment dispersant,

(Note 5) BYK-028: trade name, manufactured by BYK-Chemie, antifoaming agent,

(Note 6) TI-PURE R-706: trade name, manufactured by DuPont, titanium dioxide, specific gravity 4.0, oil absorption 14 (ml/100g),

(Note 7) Super S: Trade name, manufactured by Maruo Calcium Co., Ltd., heavy calcium carbonate, specific gravity 2.7, oil absorption 23 (ml/100g),

(Note 8) MS-P: trade name, manufactured by Nippon Talc Co., Ltd., talc, specific gravity 2.7, oil absorption 28 (ml/100g).

Manufacturing Examples 7-11

In the above-mentioned Production Example 6, the pigment dispersion pastes (B-2) to (B-6) were obtained in the same manner as in Production Example 6 except that the pigment components were set to the formulations shown in Table 2 below. .

Table 2

Manufacture of water-based paint

Examples 1-8 and Comparative Examples 1-7

Add the components shown in the following Table 3 to a stainless steel container in a stirring state, and continue stirring for 15 minutes using a homodisperser made by PRIMIX until it becomes uniform to obtain water-based coatings (C-1) to (C-1). -15).

(Note 9) CS-12: trade name, manufactured by Chisso Corporation, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, film-forming aid,

(Note 10) Emulgen A-90: trade name, manufactured by Kao Corporation, polyoxyethylene distyrenated phenyl ether, nonionic surfactant, HLB value 14.5,

(Note 11) Emulgen 103: trade name, manufactured by Kao Corporation, polyoxyethylene lauryl ether, nonionic activator, HLB value 8.1,

(Note 12) Silicate45: trade name, manufactured by Tama Chemical Industry Co., Ltd., partially hydrolyzed condensate of tetraethoxysilane, decontamination agent,

(Note 13) S38: trade name, manufactured by Sumitomo3M Limited, glass hollow microspheres, average particle diameter 40 μm,

(Note 14) SN Thickener 612N: trade name, manufactured by SAN NOPCO LIMITED, polyurethane associative thickener.

evaluation test

The water-based paints obtained in Examples and Comparative Examples were subjected to the following evaluations. The results are shown in Table 3 together.

(*1)Storage stability

Each evaluation paint was put into a 1 L glass bottle with a cap, and it was left to stand in a 40 degreeC thermostat for 30 days, and the state of the paint after storage was visually confirmed.

◎: No pigment sedimentation, no viscosity change,

○: There is no pigment sedimentation, and a slight change in viscosity is confirmed,

△: Although there is pigment sedimentation, it recovers when stirred,

x: The pigment was found to settle, and it did not recover even with stirring, and aggregates remained.

(*2) Appearance of coating film

On a flexible board (according to JIS A5430), use a brush to coat "EcoCation Sealer" (manufactured by Kansai Paint Co., Ltd., a water-based cationic emulsion sealer) at a coating amount of 100 g/m ² at a temperature of 23 °C and a relative humidity of 50% for 18 hours, and then use a brush to apply the evaluation paint twice with a coating interval of 4 hours in such a way that the coating amount per application is 100 g/m ² . Thereafter, it was dried for 24 hours under conditions of a temperature of 23° C. and a relative humidity of 50%, and the state of the surface of the coating film was visually observed.

◎: No gloss unevenness, sufficient harmonious matte feeling,

○: There is no uneven gloss, and there is a matte feeling but a slight gloss is confirmed,

△: Glossy unevenness is confirmed,

×: Abnormalities such as remarkable gloss unevenness, cracks, shrinkage, and pinholes were confirmed.

(*3) Color stability

To 200 g of the paint for evaluation, 2 g of the khaki paste and the red rust paste of UNIRANT77 (trade name, Yokohama Chemicals Co., Ltd., manufactured by Yokohama Chemicals Co., Ltd., color paste for water-based paints) were added, and homogeneously dispersed by PRIMIX Co., Ltd. The mixture was stirred for 5 minutes, and then diluted with water so that the viscosity at 25° C. based on a Stormer Viscometer (Stormer Viscometer) was 75 KU to obtain a color palette for the evaluation paint. Next, "Eco Cation Sealer" (manufactured by Kansai Paint Co., Ltd., water-based cationic emulsion type sealer) was coated on the flexible board (in accordance with JIS A5430) using a brush so that the coating amount became 100 g/m ² On the coated panel, which has been dried for 18 hours at a temperature of 23°C and a relative humidity of 50%, use a medium wool roller to apply the diluted evaluation paint to the entire surface once, and then apply it at a temperature of 23°C and a relative humidity of 50%. It was dried for 4 hours at a relative humidity of 50%. Next, for the second coating, half was coated with a brush, and the remaining half was coated with a medium wool roller, and then dried for 24 hours at a temperature of 23° C. and a relative humidity of 50%, and visually observed The difference in glossiness and color difference between the part painted by the brush and the part painted by the roller.

◎: There is no change in gloss and color difference, and the boundary cannot be confirmed,

○: There is no change in glossiness, but there is slight color difference,

△: There is no change in glossiness, but there is color difference,

×: Changes in glossiness and chromatic aberration are remarkable, and boundaries can be clearly confirmed.

(*4) Promotes weather resistance

On the flexible board (according to JIS A5430), "EcoCation Sealer" (manufactured by Kansai Paint Co., Ltd., water-based cationic emulsion type sealer) is coated with brush hair in such a way that the coating amount is 100g/m ² , and the temperature is After drying at 23°C and a relative humidity of 50% for 18 hours, the evaluation paint was repeatedly applied twice with a brush at an interval of 4 hours so that the amount of application per application was 100 g/m ² . After that, dry for 7 days under the conditions of temperature 23°C and relative humidity 50%, and make accelerated weather resistance test panel, and use the xenon lamp method stipulated in JIS K5600-7-7 to visually observe the coating film after irradiating for 1000 hours state of the surface. In the following standards, the degree of whitening was evaluated in accordance with JIS K5600-8-6.

◎: The whitening grade is below 1, there is no swelling, peeling, cracking, etc., and there is no major color change compared with the sample board,

○: The whitening level is 2 or less, there is no swelling, peeling, cracking, etc., and there is a slight color change compared with the sample plate,

△: The whitening level is 3, there is no swelling, peeling, cracking, etc., and the color change is large compared with the sample plate,

×: The whitening grade is 4 or more, and there is a significant color change compared with the sample plate, or abnormalities such as swelling, peeling, and cracking are confirmed.

(*5) Pollution resistance

On the flexible board (according to JIS A5430), "EcoCation Sealer" (manufactured by Kansai Paint Co., Ltd., water-based cationic emulsion type sealer) is coated with brush hair in such a way that the coating amount is 100g/m ² , and the temperature is After drying at 23°C and a relative humidity of 50% for 18 hours, the evaluation paint was repeatedly applied twice with a brush at an interval of 4 hours so that the amount of application per application was 100 g/m ² . After drying for 7 days at a temperature of 23°C and a relative humidity of 50%, an outdoor exposure test was carried out for 12 months with the painted surface facing south in Hiratsuka City, Japan, with the painted surface inclined upward at 30°, and the painted surface passed the visual evaluation test. of smudges.

◎: Almost no stain was found,

○: Stains are slightly recognized,

△: Stained,

X: Stain is conspicuous.

(*6)Crack resistance

On the flexible board (according to JIS A5430), "EcoCation Sealer" (manufactured by Kansai Paint Co., Ltd., water-based cationic emulsion type sealer) is coated with brush hair in such a way that the coating amount is 100g/m ² , and the temperature is After drying at 23°C and a relative humidity of 50% for 18 hours, the evaluation paint was repeatedly applied twice with a brush at an interval of 4 hours so that the amount of application per application was 100 g/m ² . Thereafter, it was dried for 7 days at a temperature of 23°C and a relative humidity of 50%. According to JIS A6909, it was subjected to a temperature-cooling repeated test in which a total of 24 hours was set as one cycle: immersed in water at 20°C for 18 hours, Immediately thereafter, it was cooled in a thermostat at -20°C for 3 hours, and then heated in a thermostat at 50°C for 3 hours. The state of the coating film surface after five cycles was observed visually.

◎: Crack was not confirmed at all,

○: Slight cracking was confirmed, but it was not clear when viewed from a distance of 50 cm,

△: Cracks were confirmed, and they were clear even at a distance of 50 cm.

×: Remarkable cracks were observed on the entire surface.

(*7) Thermal insulation

In accordance with JIS K5602-2008, the evaluation paint was coated on the white and black concealment rate test paper so that the dry film thickness became 80 μm. Next, the reflectance of the coating film of the black part of the white-black concealment rate test paper was measured using the spectrophotometer (UV-3100: Shimadzu Corporation make) in the wavelength range of 300-2500 nm. Then, in accordance with JIS K5602-2008, the solar reflectance in the wavelength region was calculated from the sum of the product of the spectral reflectance (spectral reflectance) and the weighting coefficients (weighting coefficients) at a wavelength of 300 to 2500 nm, and the thermal insulation performance was evaluated. Evaluation.

Claims (8)

1. A heat-insulating matting water-based paint composition, characterized in that it is a water-based resin (A), a pigment component (B) and an HLB value comprising a unit solid acid value in the range of 2.5 to 30 mgKOH/g Be the aqueous coating composition of 10 or more nonionic surfactant (C), Wherein, the pigment component (B) includes an inorganic white pigment (b1), a flake-shaped extender pigment (b2) and an extender pigment (b3) other than (b2), and the pigment volume concentration of the pigment component (B) is 45 to 80%. Within the range, the volume ratio of the inorganic white pigment (b1), the flaky extender pigment (b2) and the extender pigment (b3) in the total volume of the pigment component (B) is: the inorganic white pigment (b1) is 60-15% , the flake-shaped extender (b2) is 5-60%, the extender (b3) is 20-80%, and the content of the nonionic surfactant (C) is based on the solid content of the water-based resin (A) at 0.3-60%. 10% by mass. 2. The heat-shielding matte water-based paint composition according to claim 1, wherein the pigment volume concentration of the pigment component (B) is greater than or equal to the critical pigment volume concentration. 3. The heat-shielding matte aqueous coating composition according to claim 1 or 2, further comprising hollow particles. 4. The heat-shielding matte water-based paint composition according to claim 1 or 2, further comprising a hydrazine derivative, wherein the water-based resin (A) is a water-based resin having a carbonyl group. 5. The heat-shielding matte aqueous coating composition according to claim 1 or 2, further comprising an alkyl silicate compound. 6. A method for forming a heat-insulating matte coating film, characterized in that the surface of a substrate is coated with the heat-insulating matte water-based coating composition according to any one of claims 1 to 5. 7. A method for suppressing the temperature rise inside the building, by coating the heat-insulating matting water-based paint composition described in any one of claims 1 to 5 on the outer wall of the building so as to suppress the temperature inside the building The temperature rises. A painted article obtained by the method according to claim 6 or 7.