Water-based matte paint composition and multi-layer coating film

Abstract

The present invention provides a matte paint composition that has an excellent matte finish and yields a coating film that is resistant to condensation stains. [Solution] The present invention relates to an aqueous matte paint composition comprising an emulsion resin (A) and a pigment (B), wherein the pigment volume concentration (PVC) is 30 to 65% by volume. Furthermore, it contains an amino-modified polysiloxane resin (C) and a hydrocarbon solvent (D), The amino-modified polysiloxane resin (C) is blended in an amount of 5 to 15% by mass relative to the solid content of the emulsion resin (A). The hydrocarbon solvent (D) is a hydrocarbon solvent with an aniline point of 40 to 90°C, and is blended in an amount of 230% by mass or more relative to the solid content of the amino-modified polysiloxane resin (C). The present invention provides a water-based matte paint composition characterized by the above. The present invention also provides a multi-layer coating film using the above water-based matte paint composition.

Description

Technical Field

[0001] The present invention relates to an aqueous matte paint composition and a multilayer coating film.

Background Art

[0002] A matte exterior wall gives an impression of stability to a building and enhances a sense of luxury. A matte exterior wall is generally formed by painting with a paint composition containing a filler. For example, Patent Documents 1 and 2 propose aqueous paint compositions that provide matte coating films having excellent performance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an aqueous matte paint composition, rainwater and dew condensation water easily enter the coating film, and hydrophilic substances tend to bleed out onto the coating film, resulting in deterioration of a performance called dew condensation bleeding property.

[0005] The present invention has been made in view of the above, and an object thereof is to provide an aqueous matte paint composition that has an excellent matte feeling and can obtain a coating film in which dew condensation bleeding hardly occurs.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention provides the following aspects. [1] An aqueous matte paint composition containing an emulsion resin (A) and a pigment (B), having a pigment volume concentration (PVC) of 30 to 65% by volume, Furthermore, it contains an amino-modified polysiloxane resin (C) and a hydrocarbon solvent (D), The amino-modified polysiloxane resin (C) is blended in an amount of 5 to 15% by mass relative to the solid content of the emulsion resin (A). The hydrocarbon solvent (D) is a hydrocarbon solvent with an aniline point of 40 to 90°C, and is blended in an amount of 230% by mass or more relative to the solid content of the amino-modified polysiloxane resin (C). A water-based matte paint composition characterized by the following. [2] The aqueous matte paint composition according to [1], wherein the amino-modified polysiloxane resin (C) has a functional group equivalent of 300 to 100,000 amino groups. [3] One or more primer coatings, The system comprises a topcoat coating provided on the aforementioned undercoat coating, The topcoat film is a multi-layered coating formed by the aqueous matte paint composition described in [1]. [4] The multi-layer coating film according to [3], wherein the topcoat film has a specular gloss of 3 or less at both 60 degrees and 85 degrees. [Effects of the Invention]

[0007] The present invention provides a matte paint composition that provides a coating film with excellent matte finish and is resistant to condensation stains, and a multi-layer coating film comprising the coating film. [Modes for carrying out the invention]

[0008] The aqueous matte paint composition of the present invention comprises an emulsion resin (A) and a pigment (B), and further comprises an amino-modified polysiloxane resin (C) and a hydrocarbon solvent (D). The matte paint composition may also contain a crosslinking agent (E). In the present invention, the matte paint film is given water repellency to prevent condensation stains, and for this purpose, an amino-modified polysiloxane resin (C) is added. However, the addition of the amino-modified polysiloxane resin (C) may destabilize the paint. By controlling the amount of amino-modified polysiloxane resin (C) blended, selecting a specific hydrocarbon solvent (D), and further controlling the amount of hydrocarbon solvent (C) added, it is possible to give the paint film an excellent matte finish while simultaneously making it less prone to condensation stains. Each component will be explained below.

[0009] (Emulsion resin (A)) Emulsion resin (A) is a particulate resin dispersed in a solvent, and can also be called dispersed resin particles. Emulsion resin (A) is obtained, for example, by emulsion polymerization of raw material monomers in an aqueous solvent. Hereinafter, the liquid containing dispersed resin particles and aqueous solvent may be referred to as resin emulsion.

[0010] The emulsion resin (A) has a glass transition temperature (Tg) of 0°C to 20°C. A Tg of 0°C or higher improves the strength of the matte coating. A Tg of 20°C or lower improves the flexibility of the coating. Having a matte coating that is both flexible and has a certain degree of strength contributes to suppressing cracking and / or blistering of the matte coating when the coating composition is applied to an elastic (stretchable) substrate or undercoat layer, for example.

[0011] The Tg of emulsion resin (A) may be 5°C or higher, 10°C or higher, or 15°C or higher. The Tg of the above resin may be 19°C or lower, or 18°C ​​or lower.

[0012] The Tg of the emulsion resin (A) can be determined by actual measurement. Alternatively, the Tg of the emulsion resin (A) may be calculated in consideration of the types and blending amounts of the raw material monomers. In this specification, the Tg is calculated in consideration of the types and blending amounts of the raw material monomers.

[0013] Specifically, the Tg of the emulsion resin (A) made from n types of monomers as raw materials is determined by the following FOX formula (Formula (1)). In Formula (1), Tgn is the glass transition temperature (°C) of the homopolymer of each monomer, Wn is the mass fraction of each monomer, and W1 + W2 + ··· + Wn = 1. (Formula 1) 1 / Tg = W1 / Tg1 + W2 / Tg2 + ··· + Wn / Tgn

[0014] The average particle diameter of the emulsion resin (A) may be, for example, 50 nm or more and 500 nm or less. The average particle diameter of the emulsion resin (A) may be 100 nm or more, and may be 120 nm or more. The average particle diameter of the emulsion resin (A) may be 400 nm or less, may be 300 nm or less, and may be 200 nm or less.

[0015] The average particle diameter of the emulsion resin (A) is the 50% average particle diameter (D50) in the volume-based particle size distribution using a particle size distribution measuring device of the laser diffraction / scattering method.

[0016] The number average molecular weight of the emulsion resin (A) may be, for example, 5,000 or more and 30,000 or less. The number average molecular weight of the emulsion resin (A) may be 7,000 or more. The number average molecular weight of the emulsion resin (A) may be 28,000 or less.

[0017] The number average molecular weight can be determined by the GPC method with polystyrene as the standard.

[0018] From the perspective of the mechanical stability of the emulsion resin, the acid value of the emulsion resin (A) may be, for example, 3 mgKOH / g or more and 50 mgKOH / g or less. The acid value of the emulsion resin (A) may be 4 mgKOH / g or more, and may be 5 mgKOH / g or more. The acid value of the emulsion resin (A) may be 40 mgKOH / g or less, and may be 30 mgKOH / g or less.

[0019] The acid value of the emulsion resin (A) can be determined by actual measurement. Alternatively, the acid value of the emulsion resin (A) may be calculated in consideration of the blending amount of the unsaturated monomer in the raw material monomer. In the present invention, the acid value can be determined by a neutral titration method using an aqueous potassium hydroxide solution described in JIS K 0070.

[0020] The emulsion resin (A) is obtained, for example, by emulsion polymerization of a raw material monomer. Emulsion polymerization is carried out by a method generally used by those skilled in the art. Specifically, an emulsifier is mixed in an aqueous medium containing an organic solvent such as alcohol as necessary, and while heating and stirring the resulting mixture, the raw material monomer and the polymerization initiator are dropped. An emulsified mixture obtained by previously emulsifying the raw material monomer, the emulsifier, and water may be dropped into the aqueous medium. The emulsion resin (A) is typically an acrylic resin in an emulsion state.

[0021] When the aqueous matte paint composition of the present invention contains a crosslinking agent (E), a monomer having a functional group that can react with the crosslinking agent (E) is used as one of the raw material monomers used in the synthesis of the emulsion resin (A). When the crosslinking agent (E) is a compound having two or more hydrazide groups in one molecule, a monomer containing a ketone group or an aldehyde group is used as one of the raw material monomers. Examples of monomers containing a ketone group or an aldehyde group include acrolein, diacetone (meth)acrylamide, formyl styrene, vinyl alkyl ketones having 4 to 7 carbon atoms (specifically vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), and acetoacetoxyethyl methacrylate. These can be used individually or in combination of two or more. Among these, diacetone (meth)acrylamide may be used due to its high reactivity.

[0022] When the crosslinking agent (E) is a compound having two or more carbodiimide groups, aziridine groups, or oxazoline groups in one molecule, a carboxyl group-containing monomer can be used as one of the starting monomers. Examples of carboxyl group-containing monomers include (meth)acrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and crotonic acid. These can be used individually or in combination of two or more. Among these, (meth)acrylic acid may be used due to its high reactivity.

[0023] Other raw material monomers include, for example, α,β-ethylenically unsaturated monomers. Examples of α,β-ethylenically unsaturated monomers include (meth)acrylic acid esters (e.g., methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl methacrylate, phenyl acrylate, isobornyl (meth)acrylate, cyclohexyl methacrylate, t-butylcyclohexyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, dihydrodicyclopentadienyl (meth)acrylate, etc.), and hydroxyl group-containing unsaturated monomers (e.g., (meth) Examples include hydroxyethyl acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, allyl alcohol, methacrylic alcohol, ε-caprolactone adduct of hydroxyethyl (meth)acrylate, polymerizable aromatic compounds (e.g., styrene (ST), α-methylstyrene, vinyl ketones, t-butylstyrene, parachlorostyrene, and vinylnaphthalene), polymerizable nitriles (e.g., acrylonitrile, methacrylonitrile), α-olefins (e.g., ethylene, propylene), vinyl esters (e.g., vinyl acetate, vinyl propionate), and dienes (e.g., butadiene, isoprene). These can be used individually or in combination of two or more.

[0024] Emulsion polymerization may be a one-step polymerization, a two-step polymerization, or a multi-step polymerization of three or more steps. In two-step polymerization, a portion of the raw material monomers are emulsion polymerized, and then the remaining raw material monomers are added to carry out emulsion polymerization.

[0025] Examples of polymerization initiators include, for example, azo-based oily compounds or aqueous compounds, and redox-based oily peroxides or aqueous peroxides. Examples of azo-based oily compounds include azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). Examples of azo-based aqueous compounds include the anionic compounds 4,4'-azobis(4-cyanovaleric acid) and 2,2-azobis(N-(2-carboxyethyl)-2-methylpropionamidine), and the cationic compound 2,2'-azobis(2-methylpropionamidine). Examples of redox-based oily peroxides include benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, and t-butyl perbenzoate. Examples of redox-based aqueous peroxides include potassium persulfate and ammonium persulfate. These can be used individually or in combination of two or more.

[0026] The emulsifier can be one that is commonly used by those skilled in the art. The emulsifier may be a reactive emulsifier. Examples of reactive emulsifiers include Antox MS-60 (manufactured by Nippon Emulsifier Co., Ltd.), Eleminor JS-20 (manufactured by Sanyo Chemical Industries, Ltd.), Adekarya Soap NE-20 (manufactured by ADEKA Corporation), Ramtel PD-104 (manufactured by Kao Corporation), and Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0027] To adjust the molecular weight, mercaptan compounds such as lauryl mercaptan and chain transfer agents such as α-methylstyrene dimer can be used as needed.

[0028] The reaction temperature is determined by the polymerization initiator; for example, with azo-based polymerization initiators, the reaction can be carried out at 60°C to 90°C, and with redox-based polymerization initiators, at 30°C to 70°C. Generally, the reaction time is 1 hour to 8 hours. The amount of polymerization initiator relative to the total amount of monomer is generally 0.1% to 5% by mass, and may be 0.2% to 2% by mass.

[0029] The emulsion resin (A) may be neutralized with a base if necessary.

[0030] The matte paint composition may contain resins other than emulsion resin (A). Other resins include, for example, resins with a Tg of less than 0°C, resins with a Tg of more than 20°C, resin particles with an average particle diameter of less than 50 nm, and resin particles with an average particle diameter of more than 200 nm. However, it is desirable that their content be low. For example, the content of other resins may be 5% by mass or less, 3% by mass or less, or 0% by mass of the mass of resin solids in the matte paint composition.

[0031] (Pigment (B)) The pigment (B) used in the present invention includes a coloring pigment and a filler. Examples of coloring pigments include organic coloring pigments such as azo chelate pigments, insoluble azo pigments, condensed azo pigments, diketopyrrolopyrrole pigments, benzimidazolon pigments, phthalocyanine pigments, indigo pigments, perinone pigments, perylene pigments, dioxane pigments, quinacridone pigments, isoindolinone pigments, and metal complex pigments; and inorganic coloring pigments such as lead yellow, yellow iron oxide, red iron oxide, carbon black, and titanium dioxide. These can be used individually or in combination of two or more.

[0032] The matte paint composition may contain fillers. The fillers may include needle-shaped fillers with an aspect ratio (length / diameter) of 3 or more, and non-needle-shaped fillers with an oil absorption capacity of 50g / 100g or less.

[0033] Fillers are particles excluding coloring pigments and gloss pigments, and may include extender pigments. In this specification, the terms extender pigment, coloring pigment, and gloss pigment are used with definitions familiar to those skilled in the art. For example, extender pigments are typically transparent in the coating and are mainly used for reinforcing the coating or adjusting its gloss. Coloring pigments are used to color the coating and have color themselves. Gloss pigments can reflect light and impart gloss to the coating.

[0034] Needle-shaped filler Needle-shaped refers to a shape that resembles a needle, as well as a thin, elongated shape like a rod or fiber. Needle-shaped includes not only straight shapes but also branched shapes. Needle-shaped fillers may be straight.

[0035] The aspect ratio (maximum length / diameter) of the needle-shaped filler is 3 or greater. In other words, a needle-shaped filler is one with an aspect ratio of 3 or greater. The needle-shaped filler improves the strength of the matte coating and suppresses cracking and / or blistering of the matte coating.

[0036] The aspect ratio and average aspect ratio of the needle-shaped filler may be those published by the supplier. The aspect ratio of the needle-shaped filler may also be obtained by dividing the maximum length by its diameter. The maximum length and diameter of the needle-shaped filler may be those published by the supplier. Similarly, other physical properties of the needle-shaped filler and the physical properties of the non-needle-shaped filler may be those published as appropriate.

[0037] The maximum length and diameter of the filler material may be obtained by observing the sample (e.g., the surface of a matte coating, or the surface of a coating obtained by applying a matte paint composition to a glass plate) with a video microscope (e.g., Keyence VK-X 250). Twenty particles other than the coloring pigments and luminous pigments are arbitrarily selected, their maximum length and diameter are measured, and the maximum length is divided by the diameter.

[0038] Particles with a maximum length / diameter of 3 or more are needle-shaped fillers in this disclosure. Particles that are spherical, plate-shaped, or flaky and therefore cannot be measured in length, or particles with a maximum length / diameter of less than 3 and an oil absorption capacity of 50 g / 100 g or less are non-needle-shaped fillers. Particles that are not classified as either needle-shaped or non-needle-shaped fillers are other fillers.

[0039] The average length of the needle-shaped filler may be, for example, 5 μm or more and 60 μm or less. This makes it easier to improve the strength of the matte coating and suppress cracking and / or blistering. The average length of the needle-shaped filler may be 10 μm or more, or 15 μm or more. The average length of the needle-shaped filler may be 50 μm or less, or 40 μm or less.

[0040] The average diameter of the needle-shaped filler may be, for example, 4 μm or more and 20 μm or less. The average diameter of the needle-shaped filler may be 5 μm or more and 6 μm or more. The average diameter of the needle-shaped filler may be 15 μm or less and 10 μm or less.

[0041] The average length and average diameter of the needle-shaped fillers can be obtained, for example, by averaging the maximum length and diameter of any 20 needle-shaped fillers determined as described above. If fewer than 20 needle-shaped fillers are observed in one field of view, a total of 20 needle-shaped fillers are selected by combining them with other fields of view. Alternatively, the field of view may be widened so that 20 or more needle-shaped fillers can be observed in one field of view.

[0042] The average aspect ratio of the needle-shaped filler may be between 5 and 23. If the average aspect ratio of the needle-shaped filler is 5 or higher, the matte effect is further improved. If the average aspect ratio of the needle-shaped filler is 23 or lower, the amount of oil absorbed may also be reduced, making it easier for the emulsion resin (A) to form a film. Furthermore, touch-up properties are improved. The average aspect ratio of the needle-shaped filler may be 6 or higher, or 8 or higher. The average aspect ratio of the needle-shaped filler may be 20 or lower, or 15 or lower.

[0043] "Touch-up" refers to partial painting, such as painting areas that were missed during normal painting or painting to repair scratches. "Touch-up properties" refer to the characteristic that the partially painted area blends well with the underlying paint film formed by the normal paint, making the boundary between them difficult to discern. Touch-up properties are particularly important in exterior painting. Touch-up properties can be mainly influenced by the shape and amount of needle-shaped filler used.

[0044] Fillers with an average aspect ratio of 3 or higher may be considered needle-shaped fillers. The average aspect ratio of needle-shaped fillers is obtained by averaging the aspect ratios of any 20 needle-shaped fillers, which are calculated individually as described above.

[0045] The oil absorption of the needle-shaped filler may be 100g / 100g or less, or 75g / 100g or less, from the viewpoint of forming a film with emulsion resin (A). The oil absorption of the needle-shaped filler may be 30g / 100g or more.

[0046] Examples of raw materials or materials for needle-shaped fillers include calcium silicate, aluminum borate, zinc oxide, sepiolite, atabulgite, zonolite, wollastonite, glass fiber, ceramic fiber, potassium titanate fiber, carbon fiber, and calcium carbonate. These can be used individually or in combination of two or more. Needle-shaped fillers contain extender pigments, but do not contain coloring pigments or luminescence pigments.

[0047] The amount of needle-shaped filler may be, for example, 7 parts by mass or more and 75 parts by mass or less per 100 parts by mass of resin solids contained in the matte paint composition. When the amount of needle-shaped filler is 7 parts by mass or more, cracking and / or blistering of the matte paint film can be further suppressed. When the amount of needle-shaped filler is 75 parts by mass or less, touch-up properties can be further improved. The effect of the needle-shaped filler becomes easier to exert. The amount of needle-shaped filler may be 10 parts by mass or more and 13 parts by mass or more. The amount of needle-shaped filler may be 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, and 50 parts by mass or less.

[0048] The resin solids refer to the emulsion resin (A) contained in the matte paint composition, which is present in the paint film after drying.

[0049] The mass ratio of needle-shaped filler to non-needle-shaped filler (needle-shaped filler / non-needle-shaped filler) may be, for example, 0.02 or more and 0.5 or less. This makes it easier to achieve both a matte finish and high durability. The needle-shaped filler / non-needle-shaped filler ratio may be 0.03 or more and 0.06 or more. The needle-shaped filler / non-needle-shaped filler ratio may be 0.45 or less and 0.35 or less.

[0050] 《Non-acicular filler》 Non-needle-shaped refers to any shape other than needle-shaped, such as spherical, plate-shaped, or flake-shaped. In this disclosure, non-needle-shaped fillers are particles other than colored pigments and luminous pigments, are not classified as needle-shaped fillers, and have an oil absorption capacity of 50 g / 100 g or less.

[0051] The oil absorption rate of the non-needle-shaped packing material may be 45g / 100g or less, 40g / 100g or less, 35g / 100g or less, 30g / 100g or less, or 28g / 100g or less.

[0052] The average particle size of the non-acupuncture filler may be, for example, 5 μm or more and 50 μm or less. If the average particle size of the non-acupuncture filler is 5 μm or more, irregularities are more easily formed in the coating film, and the matte effect is enhanced. If the average particle size of the non-acupuncture filler is 50 μm or less, the strength of the matte coating film is less likely to decrease.

[0053] The average particle size of the non-needle packing material may be 6 μm or more, or 7 μm or more. The average particle size of the non-needle packing material may be 35 μm or less, 32 μm or less, 28 μm or less, 26 μm or less, or 20 μm or less.

[0054] The average particle diameter is the primary particle diameter, which is the 50% mean particle diameter (D50) in the volume-based particle size distribution obtained by laser diffraction and scattering. The average particle diameter may also be calculated by observation with a video microscope as described above. Specifically, 20 non-acupuncture fillers are arbitrarily selected from the observation field of the video microscope. For each of these, its area is determined, and the diameter of a circle with the same area (equivalent circle) is considered to be the diameter of the non-acupuncture filler. The average of the diameters of the 20 non-acupuncture fillers is the average particle diameter of the non-acupuncture fillers.

[0055] Examples of raw materials or materials for non-needle-shaped fillers include calcium carbonate, kaolin, clay, earthenware clay, china clay, talc, mica, barite powder, barium sulfate, barium carbonate, magnesium carbonate, and aluminum hydroxide. These can be used individually or in combination of two or more. Non-needle-shaped fillers contain extender pigments, but do not contain coloring pigments or luminescence pigments.

[0056] The content of the non-needle-shaped filler may be, for example, 70 parts by mass or more and 400 parts by mass per 100 parts by mass of resin solids contained in the matte paint composition. This makes it easier to achieve both a matte effect and high durability. The above content of the non-needle-shaped filler may be 160 parts by mass or more, and 170 parts by mass or more. The above content of the non-needle-shaped filler may be 290 parts by mass or less, and 280 parts by mass or less.

[0057] Other fillers The matte paint composition may include fillers other than coloring pigments and glossy pigments that are not classified as either needle-shaped or non-needle-shaped fillers.

[0058] Other fillers are particles other than needle-shaped fillers that have an oil absorption capacity of more than 50g / 100g. Other fillers include extender pigments, but do not include coloring pigments or luminescence pigments. Typical examples of other fillers include diatomaceous earth, silica, and zeolite.

[0059] The content of other fillers is not particularly limited as long as the effects of this disclosure are not impaired. The content of other fillers may be, for example, 30 parts by mass or less, or 20 parts by mass or less, per 100 parts by mass of resin solids contained in the matte paint composition.

[0060] The pigment volume concentration of pigment (B) (the total volume percentage of the entire pigment (B); hereinafter referred to as PVC) is 30% by volume or more and 65% by volume or less. A PVC concentration of 30% by volume or more provides an excellent matte finish. A PVC concentration of 65% by volume or more prevents the achievement of high durability. The PVC may be 31% by volume or more, 33% by volume or more, or 38% by volume or more. The PVC may be 64% by volume or less, 62% by volume or less, or 55% by volume or less.

[0061] PVC is synonymous with the pigment volume percentage (%) defined in JIS K 5500 Paint Terminology No. 1029, as follows: "The percentage of the total volume of solid particles of pigments, and / or extender pigments, and / or other non-film-forming elements, within the total volume of non-volatile matter in the paint. Useful for comparing the properties of paint films among similar types of paints."

[0062] In this specification, PVC is expressed using the following formula, where Vp is the total volume of pigment (B) and Vb is the volume of emulsion resin (A): PVC (%) = 100 × Vp / (Vp + Vb) It is determined by [method].

[0063] (Amino-modified polysiloxane resin (C)) The aqueous matte coating composition of the present invention contains an amino-modified polysiloxane resin (C). The amino-modified polysiloxane resin (C) makes the coating surface water-repellent. The amino-modified polysiloxane resin is obtained by modifying a water-repellent polysiloxane resin with an amine compound, and commercially available products are often used. Many water-repellent polysiloxane resins are commercially available from specific companies, and their polymer structures and other details are often not clearly defined.

[0064] The amino-modified polysiloxane resin (C) may be any resin having one or more amino groups in its polysiloxane resin skeleton. The functional group equivalent of the amino groups in the amino-modified polysiloxane resin has a lower limit of 300, more preferably a lower limit of 500, an upper limit of preferably 100,000, and more preferably an upper limit of 10,000. If the functional group equivalent of the amino groups is lower than 300, the amino-modified polysiloxane resin is difficult to transfer to the surface of the coating film, resulting in a lack of water repellency (small contact angle). Conversely, if the functional group equivalent of the amino groups exceeds 10,000, the viscosity of the amino-modified polysiloxane resin is high, the viscosity of the paint itself is high, and it is difficult to obtain a uniform finished coating film.

[0065] Specific examples of amino-modified polysiloxane resins are, therefore, often identified below by their sales company and product name, including the commercially available TEGO Phobe 1500N and 1505 from Evonik Industries AG; the KF series from Shin-Etsu Chemical Co., Ltd.; RUCOSIL B-LS from Rudolf; and the commercially available DOWSIL BY series from Dow Toray Industries, Inc. The amino-modified polysiloxane resin (C) is blended into the paint at a concentration of 5 to 15% by mass, preferably 6 to 13% by mass, and more preferably 7 to 11% by mass, relative to the resin solids content. If the amount of amino-modified polysiloxane resin (C) is less than 5% by mass, sufficient water repellency (contact angle of 100° or more) cannot be obtained. If it is greater than 15% by mass, not only will the water repellency (contact angle) plateau (the contact angle will not increase), but on-site application will also become difficult. Specifically, masking tape (adhesive tape) will not be able to be applied, and problems will arise with the storage stability of the paint.

[0066] (Hydroxide-based solvent (D)) The hydrocarbon solvent (D) incorporated in this invention is added to maintain the balance between paint components that has been disrupted by the addition of the amino-modified polysiloxane resin (C). Specifically, the hydrocarbon solvent (D) needs to have an aniline point of 40°C to 90°C. The aniline point (also called the mixed aniline point) is one of the indicators used when examining the solubility of oils and fats. It refers to the temperature at which the sample (the substance used as the object of inspection) and aniline separate when mixed in an equal volume and cooled. Generally, the lower the aniline point, the higher the solubility. If the aniline point of the hydrocarbon solvent (D) exceeds 90°C, the molecular weight of the hydrocarbon solvent increases, and the boiling point tends to rise. This can make it difficult for the solvent in the paint film to volatilize, causing it to remain in the paint film and resulting in problems. When the aniline point of a hydrocarbon solvent is lower than 40°C, its high dissolving power means that during long-term storage of the paint, additives contained in the paint dissolve, impairing the paint's stability. Furthermore, water-repellent agents become unevenly distributed within the water-based paint, failing to form fine particles, thus compromising the stability of the water-repellent properties.

[0067] The hydrocarbon solvent (D) preferably has a boiling point of 130°C or higher. Examples of usable hydrocarbon solvents include mineral spirits (aniline point 43°C, boiling point 130-230°C), A solvent (aniline point 44.5°C, boiling point 150-200°C), cactus solvent P20 (aniline point 43°C, boiling point 150-200°C), IP solvent 1620 (aniline point 81°C, boiling point 166-202°C), and IP solvent 2028 (aniline point 89°C, boiling point 213-262°C).

[0068] The amount of hydrocarbon solvent (D) blended is preferably 230% by mass, more preferably 300% by mass or more, and preferably 800% by mass or less, and more preferably 600% by mass or less, relative to the solid content mass of the amino-modified polysiloxane resin (C). If the amount of hydrocarbon solvent (D) blended is less than 230% by mass relative to the mass of the amino-modified polysiloxane resin (C), the hydrophilic-hydrophobic balance of the amino-modified polysiloxane resin (C) will be disrupted, and the water-repellent effect will not be maintained over time. Conversely, if the amount of hydrocarbon solvent (D) blended is more than 800% by mass relative to the mass of the amino-modified polysiloxane resin (C), the uniformity of the water-based paint composition will be disrupted, and a strong solvent odor will be generated, which has the disadvantage of creating a negative image for the body and the environment.

[0069] (Crosslinking agent (E)) The matte coating composition of the present invention may contain a crosslinking agent (E). Crosslinking of the emulsion resin (A) improves the strength of the coating film. Examples of crosslinking agents (E) include hydrazide compounds, carbodiimide compounds, aziridine compounds, and oxazoline compounds.

[0070] Examples of hydrazide compounds include oxalate dihydrazide, malonic acid dihydrazide, succinate dihydrazide, glutarate dihydrazide, adipic acid dihydrazide, sebacate dihydrazide, dodecanoic acid dihydrazide, carbonate dihydrazide, phthalate dihydrazide, terephthalate dihydrazide, isophthalate dihydrazide, pyromellitic acid dihydrazide, polyhydrazides of polyacrylic acid having 20 to 100 hydrazide groups, nitrilotriacetic acid trihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, ditrihydrazine-triazine, trihydrazine-triazine. Examples include thiocarbozides, N,N'-diaminoguanidine, 2-hydrazinopyridine-5-carboxylic acid hydrazides, 3-chlor-2-hydrazinopyridine-5-carboxylic acid hydrazides, 6-chlor-2-hydrazinopyridine-4-carboxylic acid hydrazides, 2,5-dihydrazinopyridine-4-carboxylic acid, 1,4-dihydrazinobenzol, 1,3-dihydrazinobenzol, 2,3-dihydrazinenaphthalene, maleate dihydrazide, fumarate dihydrazide, itaconic acid dihydrazide, and 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin. These can be used individually or in combination of two or more. Among these, adipic acid dihydrazide is particularly suitable due to its availability.

[0071] Examples of carbodiimide compounds include modified polycarbodiimide compounds. Modified polycarbodiimide compounds have at least two carbodiimide groups in one molecule and a polyalkylene oxide unit with one end sealed by a monoalkoxy group having four or more carbon atoms. The number of carbodiimide groups in one molecule may be between two and twenty. Examples of commercially available carbodiimide compounds include Carbodilite V-02-L2 and Carbodilite E-02 (both polyvalent carbodiimides, manufactured by Nisshinbo Chemical Co., Ltd.).

[0072] Examples of aziridine compounds include bisphenylmethane-bis,4,4'-N,N'-ethyleneurea. A commercially available aziridine compound is Chemitite DZ-22E (divalent aziridine, manufactured by Nippon Shokubai Co., Ltd.).

[0073] Examples of oxazoline compounds include low molecular weight poly(1,3-oxazoline) compounds such as 2,2'-p-phenylene-bis-(1,3-oxazoline) and 2,2'-tetramethylene-bis-(1,3-oxazoline); and homopolymers of 1,3-oxazoline group-containing vinyl monomers such as 2-isopropenyl-1,3-oxazoline. Examples of commercially available oxazoline compounds include Epocross K-2010E and Epocross WS-500 (both oxazoline group-containing polymer polymers, manufactured by Nippon Shokubai Co., Ltd.).

[0074] The matte paint composition of the present invention, by incorporating the above-mentioned components, yields a coating film that combines excellent matte finish with high durability.

[0075] In this specification, "excellent matte finish" means that the gloss of the matte coating is low. For example, if the 60-degree specular gloss and the 85-degree specular gloss, measured in accordance with K 5600-4-7:2008 specular gloss, are both 3 or less, then the coating can be said to have an excellent matte finish. According to the matte coating composition of this disclosure, the above specular gloss can be 2 or less in both cases.

[0076] The specular gloss of a matte coating can be measured using a coating obtained by applying a matte paint composition to a glass plate and leaving it to stand at room temperature under standard conditions (temperature 23°C and relative humidity 50%) (for example, for one day).

[0077] High durability means that the appearance of the matte coating is unlikely to change even after a long period of time. For example, in a test conforming to JIS A 6909:2021 7.11 repeated hot and cold test, if there are no cracks, peeling, or blistering on the surface of the matte coating, it can be said to have high durability. The matte coating composition of this disclosure also exhibits high durability when the coating composition is applied to an elastic (stretchable) substrate or undercoat layer and subjected to repeated hot and cold tests.

[0078] The viscosity η of the matte paint composition, as measured by a Stormer viscometer under conditions of 25°C, is, for example, between 70 KU (Krebs Unit value) and 120 KU. The viscosity η may be 75 KU or higher, or 70 KU or higher. The viscosity η may be 115 KU or lower, or 110 KU or lower.

[0079] (Other ingredients) Matte paint compositions may contain other components, such as viscosity agents, defoaming agents, UV absorbers, light stabilizers (e.g., hindered amines), antioxidants, surface modifiers, film-forming aids, and rust inhibitors.

[0080] (Application) The matte paint composition of the present invention is suitable for painting the exterior of buildings because it provides a highly durable coating film. Examples of building exteriors include floors, walls, and roofs. The matte paint composition can be applied by methods such as spray painting, roller painting, and brush painting. The matte paint composition may also be used for repairing (including touch-ups) the exterior paint of buildings.

[0081] (Preparation method) Matte paint compositions are prepared by methods commonly used by those skilled in the art. For example, a matte paint composition may be prepared by mixing an emulsion resin (A), a pigment (B), an amino-modified polysiloxane resin (C), a hydrocarbon solvent (D), and other components as needed, using a disperser, ball mill, SG mill, roll mill, planetary mixer, etc.

[0082] [Multi-layer coating] The multilayer coating according to this disclosure comprises one or more undercoat coatings and a topcoat coating (matte coating) formed on the undercoat coatings using the above-mentioned matte paint composition. As described above, the topcoat coating (matte coating) has a 60-degree specular gloss and an 85-degree specular gloss of 3 or less, and may be 2 or less. If the 60-degree specular gloss and 85-degree specular gloss of the matte coating alone (for example, a coating obtained by painting a matte paint composition onto a glass plate) are 3 or less, then the 60-degree specular gloss and 85-degree specular gloss of the topcoat coating in the multilayer coating can also be said to be 3 or less, and if the former is 2 or less, then the latter can also be said to be 2 or less.

[0083] (Undercoat film) A multi-layer coating comprises one or more undercoat coatings. The undercoat coating includes, for example, a first undercoat coating applied on the object to be coated and a second undercoat coating applied on the first undercoat coating.

[0084] At least one of the undercoat films may be elastic (stretchable). Because matte finish films have excellent strength, cracking and / or blistering are suppressed even if the undercoat film is elastic. Being elastic means, for example, that the elongation rate under standard conditions, measured in accordance with JIS A 6909:2021 7.26, is 120% or more.

[0085] The standard elongation of the undercoat film, measured in accordance with JIS A 6909:2021 7.26, may be 150% or more, and may be 200% or more.

[0086] Examples of elastic undercoat films include those building finishing coatings specified in JIS A6909:2021 that exhibit flexibility or waterproofing properties.

[0087] Examples of elastic primer coatings include flexible polymer cement-based multi-layer finishing coatings (flexible multi-layer coating CE), waterproof polymer cement-based multi-layer finishing coatings (waterproof multi-layer coating CE), waterproof synthetic resin emulsion-based multi-layer finishing coatings (waterproof multi-layer coating E), waterproof reactive curing synthetic resin emulsion-based multi-layer finishing coatings (waterproof multi-layer coating RE), flexible synthetic resin emulsion-based finishing coatings for repair (flexible repair coating E), flexible reactive curing synthetic resin emulsion-based finishing coatings for repair (flexible repair coating RE), and flexible polymer cement-based finishing coatings for repair (flexible repair coating CE).

[0088] 《First undercoat film》 The first undercoat film is formed by a first undercoat paint that corresponds to "Undercoat material: Used primarily for adjusting the absorption of the main material to the substrate and improving adhesion" in JIS A 6909. The first undercoat film may be an elastic film as described above.

[0089] As the first primer, a conventionally known primer as specified in JIS A 6909 can be used. Examples of the first primer include water-based acrylic resin emulsion paint, epoxy / Michael curing paint, epoxy / amine paint, epoxy dispersion paint, and two-component urethane curing paint. The first primer may be solvent-based or water-based. From the viewpoint of reducing environmental impact, the first primer may be water-based.

[0090] The thickness of the first undercoat film after drying is, for example, 3 μm or more and 80 μm or less. The thickness of the first undercoat film after drying may be 4 μm or more. The thickness of the first undercoat film after drying may be 75 μm or less.

[0091] 《Second undercoat film》 The second undercoat film is formed by a second undercoat paint corresponding to "Main material: Used primarily for the purpose of forming three-dimensional or flat patterns on the finished surface" in JIS A 6909. The second undercoat film may be an elastic coating as described above.

[0092] As the second primer, conventionally known materials as the main material in JIS A 6909 can be used. Examples of the second primer include water-based acrylic resin emulsion paints, epoxy / amine-based paints, two-component urethane-curing paints, one-component urethane-curing paints, carbodiimide-curing paints, acrylic resin-based paints, alkyd resin-based paints, and silicone resin-based paints. From the viewpoint of reducing environmental impact, the second primer may be water-based.

[0093] The thickness of the second undercoat film after drying is, for example, 0.1 mm or more and 10 mm or less. The thickness of the second undercoat film after drying may be 1 mm or more. The thickness of the second undercoat film after drying may be 5 mm or less.

[0094] (Topcoat film) The topcoat film (matte finish) is formed by the matte paint composition according to this disclosure. The thickness of the topcoat film after drying is, for example, 50 μm or more and 200 μm or less. The thickness of the topcoat film after drying may be 60 μm or more. The thickness of the topcoat film after drying may be 180 μm or less. The thickness of the topcoat film after drying may be 70 μm or more. The thickness of the topcoat film after drying may be 175 μm or less. The thickness of the topcoat film after drying is the average value of any 10 points in the thickest part (the recessed part of the unevenness).

[0095] The first and second primers and matte paint compositions are applied by methods such as brushes, rollers, air sprayers (typically tile guns), airless sprayers, and trowels. The application amount is set appropriately depending on the application, purpose, and type of substrate.

[0096] Each coating can be air-dried. Air-drying may take place at room temperature (23°C ± 3°C) for 2 hours or more, 24 hours or more, or even 1 week or more.

[0097] (subject to be coated) Examples of substrates on which a multi-layer coating film is formed include metal substrates, other inorganic substrates, and plastic substrates. Examples of metal substrates include aluminum plates, iron plates, galvanized steel plates, aluminum-galvanized steel plates, stainless steel plates, and tinplate plates. Examples of other inorganic substrates include concrete, mortar, cement boards, extruded boards, slate boards, PC boards, ALC boards, ceramic building materials such as ceramic siding materials or fiber-reinforced cement boards as described in JIS A5422 and JIS A 5430, and glass substrates. Examples of plastic substrates include acrylic plates, polyvinyl chloride plates, polycarbonate plates, ABS plates, polyethylene terephthalate plates, and polyolefin plates.

[0098] The object to be coated may have the above-mentioned substrate and an old coating film (which may be a multi-layer coating) covering the substrate. That is, the multi-layer coating of this disclosure may be provided for repair purposes. [Examples]

[0099] The present invention will be further described by the following examples, but the present invention is not limited thereto. In the examples, "parts" and "%" are on a mass basis unless otherwise specified. Details of the components listed in Tables 1 to 4 are as follows.

[0100] Synthesis of emulsion resin (A) Emulsion resin A1 was manufactured as follows. The amounts of the raw material monomers are shown in Table 1. In the table, the amounts are shown as solid content mass.

[0101] [Manufacturing of emulsion resin A1] A separable flask equipped with a dropping funnel, thermometer, nitrogen inlet tube, reflux condenser, and stirrer was charged with 34.5 parts of deionized water and 0.3 parts of reactive emulsifier (Kao Corporation, product name: Ramtel PD-104, ammonium polyoxyalkylene ether sulfate), and the mixture was heated to 80°C under a nitrogen atmosphere.

[0102] A monomer mixture consisting of 14.75 parts styrene (ST), 29.5 parts 2-ethylhexyl acrylate (2EHA), 24.58 parts methyl methacrylate (MMA), 29.5 parts n-butyl methacrylate (BMA), and 1.67 parts acrylic acid (AA) was prepared separately. A solution of this monomer mixture with 0.6 parts dodecyl mercaptan was added, and this solution was then added to an aqueous solution of Ramtel PD-104 and 50 parts deionized water, and emulsified using a mixer to prepare a preemulsion.

[0103] The above pre-emulsion and an initiator aqueous solution prepared by dissolving 0.3 parts of ammonium persulfate in 13 parts of deionized water were simultaneously added dropwise to the above separable flask from separate dropping funnels. The former was added evenly dropwise for 120 minutes, and the latter for 150 minutes. After the addition was complete, the reaction was continued for another 120 minutes at a temperature of 80 degrees Celsius. After cooling, aqueous ammonia equivalent to 10 mol% of the acrylic acid used was added to neutralize the mixture. The neutralized mixture was filtered through a 200-mesh wire mesh to obtain an emulsion (50% resin solids) containing emulsion resin A1 with a Tg of 8.5°C, an acid value of 13, and an average particle size of 130 nm.

[0104] [Table 1]

[0105] The components used in the preparation of the paint composition are listed below. Pigment (B) Pigment B1: Coloring pigment (black) (carbon black: specific gravity 1.8, commercially available carbon black MA-220 from Mitsubishi Chemical Corporation) Pigment B2: Coloring pigment (blue) (copper phthalocyanine blue: specific gravity 1.6, commercially available MEGHAFAST BLURE BD 909 BMR-L from MEGHMANI ORGANICS LIMITED.) Pigment B3: Filler (Heavy calcium carbonate: specific gravity 2.7, commercially available N heavy carbon from Maruo Marsium Co., Ltd.) Pigment B4: Filler (Heavy calcium carbonate: specific gravity 2.7, commercially available R-70H from Maruo Calcium Co., Ltd.) Pigment B5: Filler (Diatomaceous earth: specific gravity 2.2, commercially available Radiolite F from Showa Chemical Industry Co., Ltd.) Pigment B6: Filler (Wollastonite: specific gravity 2.92, commercially available Wollastonite KGP-H65 from Kansai Matec Co., Ltd.)

[0106] Amino-modified polysiloxane resin (C) Amino-modified polysiloxane resin (C1): Amino-modified polysiloxane resin (TEGO Phobe1500N, commercially available from Evonik Industries AG), resin solids content 48% by mass. Amino-modified polysiloxane resin (C2): Amino-modified polysiloxane resin (RUCOSIL B-LS, commercially available from Rudolf), resin solids content 100% by mass.

[0107] Hydrocarbon solvents (D) Hydrocarbon solvent D1: Mineral spirits (aniline point 43°C) Hydrocarbon solvent D2: IP Solvent 1620 (aniline point 81°C), commercially available from Idemitsu Kosan Co., Ltd. Hydrocarbon solvent D3: Cyclohexane (aniline point 30.2°C)

[0108] Other additives Dispersant: BYK-190, commercially available from BIC CHEMI Corporation. Film-forming aid: CS-12, commercially available from JNC Corporation. Thickening agent: Adekanol UH420, commercially available from ADEKA Corporation. Antifoaming agent: TEGO, commercially available from Evonik Industries AG. R FOAMEX26

[0109] [Example 1] (1) Preparation of matte paint composition A matte paint composition was prepared by mixing 200 parts emulsion resin A1, 12 parts pigment B1, 60 parts pigment B3, 153 parts pigment B4, 16 parts pigment B6, 10.41 parts amino-modified polysiloxane resin C1, 18.99 parts hydrocarbon solvent D1, 19 parts dispersant, 16 parts film-forming aid, 3 parts thickener, 1 part defoamer, and 131 parts tap water.

[0110] (2) Preparation of multi-layer coating A slate board (300cm long, 200cm wide, 3cm thick) was coated with a first primer (product name: Water-based Cation Sealer Transparent, manufactured by Nippon Paint Co., Ltd.) using a medium-pile roller (pile length 13mm) to obtain the first primer film. Next, a second water-based primer (product name: Nippe DAN Filler Epoxy, Waterproof Multi-layer Coating Material RE, manufactured by Nippon Paint Co., Ltd.) was applied to the first primer film using a textured roller (standard texture), and cured for 1 day at a temperature of 23°C and a relative humidity of 50% (hereinafter referred to as standard conditions) to obtain the second primer film. Finally, the matte paint composition of Example 1 was applied twice with a medium-pile roller (pile length 13mm), and cured for 7 days under standard conditions to form a multi-layer coating with a matte finish. The first and second coats of the matte paint composition were applied with a 3-hour interval between them. The resulting matte coating had an excellent appearance.

[0111] [Examples 2-13 and Comparative Examples 1-8] The matte paint compositions of Examples 2-13 and Comparative Examples 1-8 were prepared by mixing each component in the amounts shown in Tables 2-4, in the same manner as in Example 1. Table 2 also lists the formulation for Example 1.

[0112] Tables 2-4 also show the blending amount of amino-modified polysiloxane resin (amount relative to the mass of resin solids), the blending amount of hydrocarbon solvent (D) (amount relative to the solids of amino-modified polysiloxane resin), and the volume %) of PVC (volume %) of pigment (extender pigments and, if necessary, special pigments) relative to the volume of paint solids).

[0113] [evaluation] The matte paint composition and coating film were evaluated as follows. The coating film was evaluated using test panels prepared as described below. The evaluation results are shown in Tables 2 to 4. In the tables, the blending amounts represent mass.

[0114] (a) Water contact angle Each coating composition was applied to one side of a glass plate (15 cm long, 10 cm wide, 0.2 cm thick) using a film applicator with a 6 mil gap. The coated surface was placed horizontally and dried under standard conditions for 72 hours to prepare the test specimen. 4 μl of deionized water was dropped onto the surface of the prepared test specimen, and the contact angle immediately after dropping was measured using a DM-501H contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd. This was defined as the initial contact angle. Next, each coating composition was stored at 50°C for 14 days, and then test specimens were prepared in the same manner, the contact angle was measured, and this was defined as the post-storage contact angle. Contact angle stability was evaluated by checking how much the contact angle after storage at 50°C decreased compared to the initial contact angle, according to the following evaluation criteria.

[0115] Criteria for evaluating contact angle stability ○: The difference between the initial contact angle and the contact angle after storage is less than 10 degrees. △: The difference between the initial contact angle and the contact angle after storage is 10 degrees or more but less than 15 degrees. ×: The difference between the initial contact angle and the contact angle after storage is 15 degrees or more.

[0116] (b) Stain resistance to condensation This test method simulates condensation and evaluates areas where condensed water has accumulated on the paint film surface (spots) and traces where the water has flowed (stains). On a slate board (90cm long, 45cm wide, 0.3cm thick), apply the first undercoat paint (product name: Water-based Cation Sealer Clear, manufactured by Nippon Paint Co., Ltd.) using a medium-pile roller (pile length 13mm) at a rate of 0.12kg / m². 2The sample was painted once and allowed to dry for 24 hours under standard conditions. Next, a second water-based primer (product name: Nippon Paint Underfiller Elastic Excel, Flexible Repair Coating Material E, manufactured by Nippon Paint Co., Ltd.) was applied once with a medium-pile roller (pile length 13 mm) to a dry film thickness of approximately 150 μm, and allowed to dry for 24 hours under standard conditions. Then, the paint composition was applied twice with a medium-pile roller (pile length 13 mm) to a dry film thickness of approximately 90 μm, and allowed to dry for 3 hours under standard conditions to prepare the test specimen. The prepared test specimens were placed vertically, and water was sprayed onto the top 20% of the surface area of ​​the coating using a spray bottle until the water flowed down to the bottom of the specimen. Water was sprayed a total of three times at 30-minute intervals. After drying for 24 hours under standard conditions, the condition of the coating was visually observed, and water stains and spots were evaluated. The same evaluation was also performed on paint compositions stored at 50°C for 14 days. The evaluation criteria are as follows.

[0117] Criteria for evaluating condensation stain resistance ◎ There are no water stains or spots. ○ There are slight traces of water (stains) and spots. × Water stains and spots are noticeable.

[0118] (c) repeated hot and cold tests On a slate board (15cm long, 7cm wide, 0.4cm thick), apply the first undercoat paint (product name: Water-based Cation Sealer Clear, manufactured by Nippon Paint Co., Ltd.) using a medium-pile roller (pile length 13mm) at a rate of 0.12kg / m². 2 After applying one coat, allow it to dry for 24 hours under standard conditions. Then, apply a second water-based primer (product name: NIPPON PAINT DAN Filler Epoxy, Waterproof Multi-Layer Coating Material RE, manufactured by Nippon Paint Co., Ltd.) with a textured roller (standard grit) at a rate of 1.0 kg / m² per coat. 2The substrate was painted twice to achieve the desired finish, dried for 24 hours under standard conditions, and then each paint composition was applied twice using a medium-pile roller (pile length 13 mm) to achieve a dry film thickness of approximately 90 μm. Furthermore, a solvent-based two-component paint was sealed to the sides and back of the substrate to prepare the test specimens. These specimens were dried for 14 days under standard conditions. The prepared test specimens were then immersed in water at 23°C for 18 hours in accordance with JIS A6909:2021 7.11, immediately cooled in a constant-temperature bath maintained at -20°C for 3 hours, and then heated in another constant-temperature bath maintained at 50°C for 3 hours. This procedure was repeated 10 times, and after being left under standard conditions for 1 hour, the condition of the paint film surface was observed visually and with a magnifying glass to evaluate the paint film condition. The evaluation criteria are as follows.

[0119] Evaluation criteria for repeated hot and cold cycle tests ◎: No cracks, blisters, or peeling are visible to the naked eye or under a magnifying glass. ○: No cracks, blisters, or peeling are visible to the naked eye, but one of these is visible under magnification. ×: Visually, one of the following is visible: cracks, blistering, or peeling.

[0120] (d) Specular gloss Each coating composition was applied to one side of a glass plate (15 cm long, 10 cm wide, 0.2 cm thick) using a film applicator with a 6 mil gap. The coated surface was placed horizontally and dried under standard conditions for 24 hours to prepare test specimens. The specular gloss of the obtained test specimens (measurement angles of 60 and 85 degrees) was measured using a specular gloss meter specified in JIS K5600-4-7:2008. The evaluation criteria are as follows.

[0121] Gloss evaluation criteria ○: Both the 60-degree and 85-degree specular gloss levels are 3 or less. ×: Both / or either of the 60-degree specular gloss and 85-degree specular gloss are greater than 3.

[0122] (e) Adhesion of masking tape On a slate board (30cm long, 20cm wide, 0.3cm thick), apply the first undercoat paint (product name: Water-based Cation Sealer Clear, manufactured by Nippon Paint Co., Ltd.) using a medium-pile roller (pile length 13mm) at a rate of 0.12kg / m². 2 The sample was painted once and allowed to dry under standard conditions for 24 hours. Next, a second water-based primer (Nippe Underfiller Elastic Excel, Flexible Repair Coating Material E, manufactured by Nippon Paint Co., Ltd.) was applied once with a medium-pile roller (pile length 13 mm) to a dry film thickness of approximately 150 μm, and allowed to dry under standard conditions for 24 hours. Then, each paint composition was applied twice with a medium-pile roller (pile length 13 mm) to a dry film thickness of approximately 90 μm, and allowed to dry under standard conditions for 24 hours to prepare the test specimens. The following two types of masking tape were applied to the prepared test specimens. Masking tape (1) 25mm wide masking cloth tape (manufactured by Teraoka Seisakusho Co., Ltd.) Masking tape (2) Corona masking tape with cloth tape (manufactured by Otsuka Brush Manufacturing Co., Ltd.) Paste it. The adhesive strength of the tape was subjectively evaluated based on the resistance felt when peeling it off by hand. The evaluation criteria were as follows:

[0123] Evaluation criteria for the adhesion of masking tape ○: There is some resistance when peeling off the tape, but this does not pose a problem in terms of marketability. ×: The tape offers no resistance when peeling it off, which is a problem from a marketability standpoint.

[0124] [Table 2]

[0125] [Table 3]

[0126] [Table 4]

[0127] In Examples 1 to 13 of the present invention, all requirements (range of pigment volume concentration (PVC), amount of amino-modified polysiloxane resin, range and amount of aniline point of hydrocarbon solvent) are satisfied, resulting in high contact angle stability, good condensation stain resistance both initially and after storage, no cracking, blistering, or peeling in repeated hot and cold tests, low specular gloss, and high adhesion to the masking tape with both types of tape (Tape (1) and Tape (2)). On the other hand, in Comparative Example 1, the amount of amino-modified polysiloxane resin added was large, resulting in poor adhesion to the masking tape with both Tape (1) and Tape (2). In Comparative Example 2, conversely, the amount of amino-modified polysiloxane resin added was small, resulting in very poor condensation stain resistance both initially and after storage. In Comparative Example 3, a hydrocarbon solvent with an aniline point below 40°C (30.2°C) was used, so contact angle stability could not be ensured. Comparative Example 4 is an example where no hydrocarbon solvent was added, resulting in poor contact angle stability and particularly poor condensation stain resistance after storage. Comparative Examples 5 and 6 contain small amounts of hydrocarbon solvent, resulting in poor contact angle stability and particularly poor condensation stain resistance after storage, similar to Comparative Example 4. Comparative Examples 7 and 8 are examples outside the range of pigment volume concentration (PVC), with Comparative Example 7 having a small PVC and Comparative Example 8 having a large PVC. Comparative Example 7 shows poor specular gloss and particularly poor condensation stain resistance after storage. Comparative Example 8 shows poor results in the repeated hot and cold cycle test.

[0128] This disclosure includes the following aspects: [1] A water-based matte paint composition comprising an emulsion resin (A) and a pigment (B), wherein the pigment volume concentration (PVC) is 30 to 65% by volume, Furthermore, it contains an amino-modified polysiloxane resin (C) and a hydrocarbon solvent (D), The amino-modified polysiloxane resin (C) is blended in an amount of 5 to 15% by mass relative to the solid content of the emulsion resin (A). The hydrocarbon solvent (D) is a hydrocarbon solvent with an aniline point of 40 to 90°C, and is blended in an amount of 230% by mass or more relative to the solid content of the amino-modified polysiloxane resin (C). A water-based matte paint composition characterized by the following. [2] The aqueous matte paint composition according to [1], wherein the amino-modified polysiloxane resin (C) has a functional group equivalent of 300 to 100,000 amino groups. [3] One or more primer coatings, The system comprises a topcoat coating provided on the aforementioned undercoat coating, The topcoat film is a multi-layer film formed by the aqueous matte paint composition described in [1] or [2]. [4] The multi-layer coating film according to [3], wherein the topcoat film has a specular gloss of 3 or less at both 60 degrees and 85 degrees. [Industrial applicability]

[0129] The matte paint composition of the present invention provides a paint film with excellent matte finish and resistance to condensation stains, making it particularly useful for painting the exteriors of buildings.

Claims

1. An aqueous matte paint composition comprising an emulsion resin (A) and a pigment (B), wherein the pigment volume concentration (PVC) is 30 to 65% by volume, Furthermore, it contains an amino-modified polysiloxane resin (C) and a hydrocarbon solvent (D), The amino-modified polysiloxane resin (C) is blended in an amount of 5 to 15% by mass relative to the solid content of the emulsion resin (A). The hydrocarbon solvent (D) is a hydrocarbon solvent with an aniline point of 40 to 90°C, and is blended in an amount of 230% by mass or more relative to the solid content of the amino-modified polysiloxane resin (C). A water-based matte paint composition characterized by the following.

2. The aqueous matte paint composition according to claim 1, wherein the amino-modified polysiloxane resin (C) has a functional group equivalent of 300 to 100,000 amino groups.

3. One or more primer coatings, The system comprises a topcoat coating provided on the aforementioned undercoat coating, The topcoat film is a multi-layered coating formed by the aqueous matte paint composition described in claim 1.

4. The multi-layer coating film according to claim 3, wherein the topcoat film has a specular gloss of 3 or less at both 60 degrees and 85 degrees.

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