coating film

Abstract

The object of the present invention is to provide a coating film that reduces proximity gloss, depth gloss, and gloss unevenness, and also exhibits excellent surface smoothness. [Solution] A coating film which is a cured product of a topcoat paint composition, wherein the topcoat paint composition comprises a resin, an inorganic pigment, and a solvent, the amount of the inorganic pigment is 60 to 250 parts by mass per 100 parts by mass of the solid content of the resin, and the surface roughness of the coating film is Sa such that the surface roughness Sa1 of wavelengths of 8 μm or less is 0.07 to 1.44 μm, the surface roughness Sa2 of wavelengths of 250 μm or less is 1.4 to 5.5 μm, and the ratio of Sa1 to Sa2 (Sa2 / Sa1) is 50 or less.

Description

Technical Field

[0001] The present invention relates to a coating film.

Background Art

[0002] In buildings, in order to obtain a high-class and calming space, a matte coating film may be formed on the interior or exterior finish. The paint used to form this matte coating film may contain a resin and an inorganic pigment. (For example, see Patent Document 1.)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A matte coating film with reduced gloss of the coating film can be obtained by forming fine irregularities on the surface of the coating film. The roughness of the coating film surface can be adjusted by the particle diameter of the pigment used.

[0005] A matte coating film using only pigments with a small particle diameter has small irregularities on the coating film surface, so it has a dense matte appearance when observed from a direction perpendicular to the coating film, but when the coating film is observed from an angle close to an angle parallel to the coating film, there is a problem that a glossiness occurs, that is, so-called depth gloss remains.

[0006] On the other hand, with respect to the depth gloss, by blending a pigment with a large particle diameter into the coating film, the roughness of the coating film can be increased to reduce the depth gloss.

[0007] However, when a pigment with a large particle diameter is blended, there is a problem that the surface (texture) of the coating film becomes rough and the smoothness of the coating film decreases.

[0008] Furthermore, with matte finishes, uneven gloss is also a problem because it degrades the appearance quality of the finish. Uneven gloss is a phenomenon in which gloss appears in certain areas on the surface of the finish, and it is likely to occur in areas where paint is applied using rollers or other methods.

[0009] Therefore, the present invention aims to provide a coating film that reduces gloss (near-view gloss) when the coating film is observed from a vertical direction, depth gloss and gloss unevenness when the coating film is observed from a parallel direction, and also has excellent surface smoothness. [Means for solving the problem]

[0010] The coating film according to the present invention is A coating film which is a cured product of a topcoat paint composition, The topcoat paint composition comprises a resin, an inorganic pigment, and a solvent. The amount of the inorganic pigment is 60 to 250 parts by mass per 100 parts by mass of the solid content of the resin. If the surface roughness of the coating film is denoted as Sa, The surface roughness Sa1 for wavelengths of 8 μm or less is 0.07 to 1.44 μm. The surface roughness Sa2 for wavelengths below 250 μm is 1.4 to 5.5 μm. The ratio of Sa1 to Sa2 (Sa2 / Sa1) is 50 or less. It is a coating film. This reduces proximity gloss, depth gloss, and gloss unevenness, and also provides excellent smoothness of the coating film surface.

[0011] In one embodiment of the coating film according to the present invention, the inorganic pigment is An inorganic pigment (1) having an average particle size of 3 μm or more and less than 7 μm, Inorganic pigment (2) having an average particle size of 7 μm or more and less than 19 μm, The material comprises an inorganic pigment (3) having an average particle size of 19 μm or more and 29 μm or less, Each of the inorganic pigments (1) to (3) is independently one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, talc, and diatomaceous earth.

[0012] In one embodiment of the coating film according to the present invention, the amounts of the inorganic pigments (1) to (3) are as follows with respect to 100 parts by mass of the solid content of the resin: Inorganic pigment (1): 10 to 70 parts by mass, Inorganic pigment (2): 5 to 120 parts by mass, and Inorganic pigment (3): 25 to 150 parts by mass.

[0013] In one embodiment of the coating film according to the present invention, the oil absorption amounts of the inorganic pigments (1) to (3) are as follows: Inorganic pigment (1): 5 to 260 (g / 100g), Inorganic pigment (2): 20 to 40 (g / 100g) and Inorganic pigment (3): 10 to 150 (g / 100g).

[0014] In one embodiment of the coating film according to the present invention, the ratio (Sa2 / Sa1) is 20 or less.

Effects of the Invention

[0015] According to the present invention, it is possible to provide a coating film that reduces the surface gloss, the depth of gloss, and the gloss unevenness, and also has excellent smoothness on the surface of the coating film.

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described. These descriptions are for the purpose of exemplifying the present invention and do not limit the present invention in any way.

[0017] In the present invention, two or more embodiments can be arbitrarily combined.

[0018] The materials, components, compounds, resins, inorganic pigments, and solvents described in this specification may each be used alone or in combination of two or more, unless otherwise specified.

[0019] In the present invention, paints and paint compositions can be used interchangeably.

[0020] In this invention, the term "solids" is a concept that includes both solids and non-volatiles.

[0021] In this specification, numerical ranges are intended to include the upper and lower limits of the range unless otherwise specified. For example, 60 to 250 parts by mass means 60 parts by mass or more and 250 parts by mass or less.

[0022] In the present invention, the surface roughness Sa1 of the coating film with a wavelength of 8 μm or less and the surface roughness Sa2 with a wavelength of 250 μm or less are measured by the method described in the examples.

[0023] In the present invention, the average particle size is measured by the method described in the examples.

[0024] In this invention, the oil absorption amount of the inorganic pigment is measured by the method described in the examples. (coating film) The coating film according to the present invention is A coating film which is a cured product of a topcoat paint composition, The topcoat paint composition comprises a resin, an inorganic pigment, and a solvent. The amount of the inorganic pigment is 60 to 250 parts by mass per 100 parts by mass of the solid content of the resin. If the surface roughness of the coating film is denoted as Sa, The surface roughness Sa1 for wavelengths of 8 μm or less is 0.07 to 1.44 μm. The surface roughness Sa2 for wavelengths below 250 μm is 1.4 to 5.5 μm. The coating film has a ratio of Sa1 to Sa2 (Sa2 / Sa1) of 50 or less.

[0025] ·Surface roughness Sa If the surface roughness of the coating film of the present invention is denoted as Sa, The surface roughness Sa1 for wavelengths of 8 μm or less is 0.07 to 1.44 μm. The surface roughness Sa2 for wavelengths below 250 μm is 1.4 to 5.5 μm. The ratio of Sa1 to Sa2 (Sa2 / Sa1) is 50 or less.

[0026] In this invention, surface roughness Sa is a concept that extends the arithmetic mean roughness Ra, which relates to the roughness curve at a reference length, to a two-dimensional surface. The smoothness (texture) of the coating film surface can be evaluated using surface roughness Sa.

[0027] The inventors have found that the appearance of the coating can be improved by satisfying the above-mentioned predetermined ranges of Sa1, Sa2, and ratio (Sa2 / Sa1).

[0028] In this invention, surface roughness Sa1 represents the surface roughness of the coating film surface at wavelengths of 8 μm or less. The reason for focusing on surface roughness at wavelengths of 8 μm or less is that there is a strong correlation between surface roughness at wavelengths of 8 μm or less and proximity gloss, and the greater the surface roughness at wavelengths of 8 μm or less, the better the proximity gloss becomes (gloss is suppressed). In one embodiment, the wavelength at which surface roughness Sa1 is measured is 1.6 μm or more due to the limitations of the device resolution.

[0029] In the coating film of the present invention, the surface roughness Sa1 for wavelengths of 8 μm or less is 0.07 to 1.44 μm. If the surface roughness Sa1 is less than 0.07 μm, uneven gloss is noticeable, and the appearance of the coating film cannot be improved. On the other hand, if the surface roughness Sa1 exceeds 1.44 μm, there are many fine edges on the surface of the coating film, and the smoothness or texture cannot be improved. In one embodiment, the surface roughness Sa1 is 0.07 μm or more, 0.10 μm or more, 0.13 μm or more, 0.20 μm or more, 0.30 μm or more, 0.40 μm or more, 0.50 μm or more, 0.60 μm or more, 0.70 μm or more, 0.80 μm or more, 0.90 μm or more, 1.00 μm or more, 1.10 μm or more, 1.20 μm or more, 1.30 μm or more, or 1.40 μm or more. In another embodiment, the surface roughness Sa1 is 1.44 μm or less, 1.40 μm or less, 1.30 μm or less, 1.20 μm or less, 1.10 μm or less, 1.00 μm or less, 0.90 μm or less, 0.80 μm or less, 0.70 μm or less, 0.60 μm or less, 0.50 μm or less, 0.40 μm or less, 0.30 μm or less, 0.20 μm or less, or 0.10 μm or less.

[0030] Examples of methods for adjusting the surface roughness Sa1 include the following: The surface roughness Sa1 can be increased by reducing the amount of inorganic pigment (1), described later, that is, inorganic pigment with a relatively small average particle size, in the coating film. Conversely, the surface roughness Sa1 can be increased by increasing the amount of inorganic pigment (2) or (3), described later, that is, inorganic pigment with a relatively large average particle size, in the coating film. On the other hand, if you want to decrease the surface roughness Sa1, you can, for example, increase the amount of inorganic pigment with a relatively small average particle size in the coating film, or decrease the amount of inorganic pigment with a relatively large average particle size in the coating film.

[0031] In this invention, surface roughness Sa2 represents the surface roughness of the coating film surface at wavelengths of 250 μm or less. The reason for focusing on surface roughness at wavelengths of 250 μm or less is that there is a strong correlation between surface roughness at wavelengths of 250 μm or less and deep gloss, and deep gloss is suppressed as the surface roughness at wavelengths of 250 μm or less increases. In one embodiment, the wavelength at which surface roughness Sa2 is measured is 1.6 μm or more due to the limitations of the device resolution.

[0032] In the coating film of the present invention, the surface roughness Sa2 at a wavelength of 250 μm or less is 1.4 to 5.5 μm. If the surface roughness Sa2 is less than 1.4 μm, uneven gloss is noticeable or a deep gloss remains, and the appearance of the coating film cannot be improved. On the other hand, if the surface roughness Sa2 exceeds 5.5 μm, the surface of the coating film becomes rough, and the smoothness or texture cannot be improved. In one embodiment, the surface roughness Sa2 is 1.4 μm or more, 1.5 μm or more, 1.6 μm or more, 1.7 μm or more, 1.8 μm or more, 1.9 μm or more, 2.0 μm or more, 2.1 μm or more, 2.2 μm or more. Top, 2.3μm or more, 2.4μm or more, 2.5μm or more, 2.6μm or more, 2.7μm or more, 2.8μm or more, 2.9μm or more, 3.0μm or more, 3.1μm or more, 3.2μm or more, 3.3μm or more The above are 3.4 μm or larger, 3.5 μm or larger, 3.6 μm or larger, 3.7 μm or larger, 3.8 μm or larger, 3.9 μm or larger, 4.0 μm or larger, 4.1 μm or larger, 4.2 μm or larger, 4.3 μm or larger, 4.4 μm or larger, 4.5 μm or larger, 4.6 μm or larger, 4.7 μm or larger, 4.8 μm or larger, 4.9 μm or larger, 5.0 μm or larger, 5.1 μm or larger, 5.2 μm or larger, 5.3 μm or larger, or 5.4 μm or larger. In another embodiment, the surface roughness Sa2 is 5.5 μm or less, 5.4 μm or less, 5.3 μm or less, 5.2 μm or less, 5.1 μm or less, 5.0 μm or less, 4.9 μm or less, 4.8 μm or less, 4.7 μm Below, 4.6μm or less, 4.5μm or less, 4.4μm or less, 4.3μm or less, 4.2μm or less, 4.1μm or less, 4.0μm or less, 3.9μm or less, 3.8μm or less, 3.7μm or less, 3.6μm The following are the minimum and maximum sizes: 3.5 μm or less, 3.4 μm or less, 3.3 μm or less, 3.2 μm or less, 3.1 μm or less, 3.0 μm or less, 2.9 μm or less, 2.8 μm or less, 2.7 μm or less, 2.6 μm or less, 2.5 μm or less, 2.4 μm or less, 2.3 μm or less, 2.2 μm or less, 2.1 μm or less, 2.0 μm or less, 1.9 μm or less, 1.8 μm or less, 1.7 μm or less, 1.6 μm or less, or 1.5 μm or less.

[0033] Examples of methods for adjusting the surface roughness Sa2 include the following: The surface roughness Sa2 can be increased by reducing the amount of inorganic pigment (1), described later, that is, inorganic pigment with a relatively small average particle size, in the coating film. Conversely, the surface roughness Sa2 can be increased by increasing the amount of inorganic pigment (2) or (3), described later, that is, inorganic pigment with a relatively large average particle size, in the coating film. On the other hand, if you want to decrease the surface roughness Sa2, for example, you can increase the amount of inorganic pigment with a relatively small average particle size in the coating film, or decrease the amount of inorganic pigment with a relatively large average particle size in the coating film. Also, increasing the amount of inorganic pigment (3), described later, in the coating film increases both the surface roughness Sa1 and Sa2, but in this case, the increase in Sa2 tends to be greater than that of Sa1.

[0034] In the coating film of the present invention, the ratio of Sa1 to Sa2 (Sa2 / Sa1) is 50 or less. If the ratio (Sa2 / Sa1) exceeds 50, gloss unevenness becomes noticeable, and the appearance of the coating film cannot be improved. In one embodiment, the ratio (Sa2 / Sa1) is 50 or less, 40 or less, 30 or less, 20 or less, 19 or less, 18 or less, 17 or less, 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, 2 or less, or 1 or less. In another embodiment, the ratio (Sa2 / Sa1) is 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater, 11 or greater, 12 or greater, 13 or greater, 14 or greater, 15 or greater, 16 or greater, 17 or greater, 18 or greater, 19 or greater, 20 or greater, 30 or greater, or 40 or greater.

[0035] • Topcoat paint composition The coating film of the present invention is a cured product of a topcoat paint composition, the topcoat paint composition comprising a resin, an inorganic pigment, and a solvent. The topcoat paint composition will be described below.

[0036] The topcoat paint composition contains a resin. The resin can be a film-forming resin used in paints such as known topcoats. Examples of resins include acrylic resins, polyester resins, polyurethane resins, alkyd resins, polyether resins, fluororesins, epoxy resins, silicone resins, and urea resins.

[0037] The topcoat paint composition contains an inorganic pigment. Known inorganic pigments can be used.

[0038] Examples of inorganic pigments include silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, talc, diatomaceous earth, and bentonite. In one embodiment, the inorganic pigment is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, talc, and diatomaceous earth.

[0039] The amount of inorganic pigment in the topcoat paint composition is 60 to 250 parts by mass per 100 parts by mass of the resin solids. If the amount of inorganic pigment is less than 60 parts by mass, the deep gloss cannot be reduced. If the amount of inorganic pigment exceeds 250 parts by mass, the smoothness of the coating film decreases. In one embodiment, the amount of inorganic pigment is 60 parts by mass or more, 70 parts by mass or more, 80 parts by mass or more, 90 parts by mass or more, 100 parts by mass or more, 110 parts by mass or more, 120 parts by mass or more, 130 parts by mass or more, 140 parts by mass or more, 150 parts by mass or more, 160 parts by mass or more, 170 parts by mass or more, 180 parts by mass or more, 190 parts by mass or more, 200 parts by mass or more, 210 parts by mass or more, 220 parts by mass or more, 230 parts by mass or more, or 240 parts by mass or more per 100 parts by mass of the resin solids. In another embodiment, the amount of inorganic pigment is 250 parts by mass or less, 240 parts by mass or less, 230 parts by mass or less, 220 parts by mass or less, 210 parts by mass or less, 200 parts by mass or less, 190 parts by mass or less, 180 parts by mass or less, 170 parts by mass or less, 160 parts by mass or less, 150 parts by mass or less, 140 parts by mass or less, 130 parts by mass or less, 120 parts by mass or less, 110 parts by mass or less, 100 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, or 70 parts by mass or less, per 100 parts by mass of the solid content of the resin.

[0040] In one embodiment, the inorganic pigment is An inorganic pigment (1) having an average particle size of 3 μm or more and less than 7 μm, Inorganic pigment (2) having an average particle size of 7 μm or more and less than 19 μm, The material contains an inorganic pigment (3) having an average particle size of 19 μm or more and 29 μm or less. This makes it easier to adjust Sa1 and Sa2. Furthermore, using this inorganic pigment (1) makes it easier to suppress uneven gloss. Furthermore, using this inorganic pigment (3) makes it easier to suppress uneven gloss and improve the smoothness of the coating film.

[0041] • Inorganic pigments (1) As described above, inorganic pigments (1) with an average particle size of 3 μm or more and less than 7 μm have a relatively small average particle size, so by increasing the amount of inorganic pigments (1) in the coating film, Sa1 and Sa2 can be reduced.

[0042] The average particle size of the inorganic pigment (1) is 3 μm or more and less than 7 μm. In one embodiment, the average particle size of the inorganic pigment (1) is 3.0 μm or more, 3.5 μm or more, 4.0 μm or more, 4.5 μm or more, 5.0 μm or more, 5.5 μm or more, 6.0 μm or more, or 6.5 μm or more. In another embodiment, the average particle size of the inorganic pigment (1) is less than 7.0 μm, 6.5 μm or less, 6.0 μm or less, 5.5 μm or less, 5.0 μm or less, 4.5 μm or less, 4.0 μm or less, or 3.5 μm or less. In yet another embodiment, the average particle size of the inorganic pigment (1) is 4.0 to 6.0 μm.

[0043] The amount of inorganic pigment (1) in the topcoat paint composition can be adjusted so that the total amount of inorganic pigment is in the range of 60 to 250 parts by mass, for example, 5 to 100 parts by mass per 100 parts by mass of resin solids. In one embodiment, the amount of inorganic pigment (1) is 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, 50 parts by mass or more, 55 parts by mass or more, 60 parts by mass or more, 65 parts by mass or more, 70 parts by mass or more, 75 parts by mass or more, 80 parts by mass or more, 85 parts by mass or more, 90 parts by mass or more, or 95 parts by mass or more per 100 parts by mass of resin solids. In another embodiment, the amount of inorganic pigment (1) is 100 parts by mass or less, 95 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, 55 parts by mass or less, 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, or 10 parts by mass or less, per 100 parts by mass of the solid content of the resin. In yet another embodiment, the amount of inorganic pigment (1) is 10 to 70 parts by mass per 100 parts by mass of the solid content of the resin.

[0044] The oil absorption amount of the inorganic pigment (1) (g of linseed oil (refined linseed oil) absorbed per 100g of pigment) is not particularly limited and can be any known oil absorption amount. The oil absorption amount of the inorganic pigment (1) is, for example, 1 to 300 (g / 100g). In one embodiment, the oil absorption amount of the inorganic pigment (1) is 5 to 260 (g / 100g).

[0045] Examples of commercially available inorganic pigments (1) include the NipSeal series such as "NipSeal (registered trademark) E-170" (silica) from Tosoh Silica Co., Ltd.; the Barite Powder series such as "Barite Powder FBA" (barium sulfate) from Takehara Chemical Industry Co., Ltd.; the Satinton series such as "Satinton W Whitetex" (kaolin) from BASF Inc.; and the Fine Grade series such as "KGP-H65" (wollastonite) from Kansai Matec Co., Ltd.

[0046] • Inorganic pigments (2) As described above, Sa1 and Sa2 can be increased by increasing the amount of inorganic pigment (2) in the coating film.

[0047] The average particle size of the inorganic pigment (2) is 7 μm or more and less than 19 μm. In one embodiment, the average particle size of the inorganic pigment (2) is 7.0 μm or more, 7.5 μm or more, 8.0 μm or more, 8.5 μm or more, 9.0 μm or more, 9.5 μm or more, 10.0 μm or more, 10.5 μm or more, 11.0 μm or more, 11.5 μm or more, 12.0 μm or more, 12.5 μm or more, 13.0 μm or more, 13.5 μm or more, 14.0 μm or more, 14.5 μm or more, 15.0 μm or more, 15.5 μm or more, 16.0 μm or more, 16.5 μm or more, 17.0 μm or more, 17.5 μm or more, 18.0 μm or more, or 18.5 μm or more. In another embodiment, the average particle size of the inorganic pigment (2) is less than 19.0 μm, 18.5 μm or less, 18.0 μm or less, 17.5 μm or less, 17.0 μm or less, 16.5 μm or less, 16.0 μm or less, 15.5 μm or less, 15.0 μm or less, 14.5 μm or less, 14.0 μm or less, 13.5 μm or less, 13.0 μm or less, 12.5 μm or less, 12.0 μm or less, 11.5 μm or less, 11.0 μm or less, 10.5 μm or less, 10.0 μm or less, 9.5 μm or less, 9.0 μm or less, 8.5 μm or less, 8.0 μm or less, or 7.5 μm or less. In yet another embodiment, the average particle size of the inorganic pigment (2) is 12.0 to 17.0 μm.

[0048] The amount of inorganic pigment (2) in the topcoat paint composition can be adjusted so that the total amount of inorganic pigment is in the range of 60 to 250 parts by mass, for example, 1 to 150 parts by mass per 100 parts by mass of resin solids. In one embodiment, the amount of inorganic pigment (2) is 1 part by mass or more, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, 50 parts by mass or more, 55 parts by mass or more, 60 parts by mass or more, 70 parts by mass or more, 80 parts by mass or more, 90 parts by mass or more, 100 parts by mass or more, 110 parts by mass or more, 120 parts by mass or more, 130 parts by mass or more, or 140 parts by mass or more per 100 parts by mass of resin solids. In another embodiment, the amount of inorganic pigment (2) is 150 parts by mass or less, 140 parts by mass or less, 130 parts by mass or less, 120 parts by mass or less, 110 parts by mass or less, 100 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, 55 parts by mass or less, 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less, per 100 parts by mass of the solid content of the resin. In yet another embodiment, the amount of inorganic pigment (2) is 5 to 120 parts by mass per 100 parts by mass of the solid content of the resin.

[0049] The oil absorption amount of the inorganic pigment (2) is not particularly limited and can be any known oil absorption amount. The oil absorption amount of the inorganic pigment (2) is, for example, 10 to 60 (g / 100g). In one embodiment, the oil absorption amount of the inorganic pigment (2) is 20 to 40 (g / 100g).

[0050] Examples of commercially available inorganic pigments (2) include the general-purpose talc series such as "SWE" (talc) from Nippon Talc Co., Ltd.; the general-purpose grade series such as "RS413A" (talc) from Fuji Talc Industrial Co., Ltd.; and "R-30" (calcium carbonate) from Maruo Calcium Co., Ltd.

[0051] • Inorganic pigments (3) As described above, inorganic pigments (3) with an average particle size of 19 μm or more and 29 μm or less have a relatively large average particle size, so by increasing the amount of inorganic pigment (1) in the coating film, Sa1 and Sa2 can be increased. In this case, Sa2 tends to increase by a larger percentage than Sa1.

[0052] The average particle size of the inorganic pigment (3) is 19 μm or more and 29 μm or less. In one embodiment, the average particle size of the inorganic pigment (3) is 19.0 μm or more, 19.5 μm or more, 20.0 μm or more, 20.5 μm or more, 21.0 μm or more, 21.5 μm or more, 22.0 μm or more, 22.5 μm or more, 23.0 μm or more, 23.5 μm or more, 24.0 μm or more, 24.5 μm or more, 25.0 μm or more, 25.5 μm or more, 26.0 μm or more, 26.5 μm or more, 27.0 μm or more, 27.5 μm or more, 28.0 μm or more, or 28.5 μm or more. In another embodiment, the average particle size of the inorganic pigment (3) is 29.0 μm or less, 28.5 μm or less, 28.0 μm or less, 27.5 μm or less, 27.0 μm or less, 26.5 μm or less, 26.0 μm or less, 25.5 μm or less, 25.0 μm or less, 24.5 μm or less, 24.0 μm or less, 23.5 μm or less, 23.0 μm or less, 22.5 μm or less, 22.0 μm or less, 21.5 μm or less, 21.0 μm or less, 20.5 μm or less, 20.0 μm or less, or 19.5 μm or less. In yet another embodiment, the average particle size of the inorganic pigment (3) is 20.0 to 25.0 μm.

[0053] The amount of inorganic pigment (3) in the topcoat paint composition can be adjusted so that the total amount of inorganic pigment is in the range of 60 to 250 parts by mass, for example, 15 to 200 parts by mass per 100 parts by mass of resin solids. In one embodiment, the amount of inorganic pigment (3) is 15 parts by mass or more, 20 parts by mass or more, 30 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, 50 parts by mass or more, 55 parts by mass or more, 60 parts by mass or more, 65 parts by mass or more, 70 parts by mass or more, 75 parts by mass or more, 80 parts by mass or more, 85 parts by mass or more, 90 parts by mass or more, 95 parts by mass or more, 100 parts by mass or more, 110 parts by mass or more, 120 parts by mass or more, 130 parts by mass or more, 140 parts by mass or more, 150 parts by mass or more, 160 parts by mass or more, 170 parts by mass or more, 180 parts by mass or more, or 190 parts by mass or more per 100 parts by mass of resin solids. In another embodiment, the amount of inorganic pigment (3) is 200 parts by mass or less, 190 parts by mass or less, 180 parts by mass or less, 170 parts by mass or less, 160 parts by mass or less, 150 parts by mass or less, 140 parts by mass or less, 130 parts by mass or less, 120 parts by mass or less, 110 parts by mass or less, 100 parts by mass or less, 95 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, 55 parts by mass or less, 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less, per 100 parts by mass of the solid content of the resin.

[0054] In one embodiment of the coating film according to the present invention, the amount of the inorganic pigments (1) to (3) is such that, relative to 100 parts by mass of the solid content of the resin, Inorganic pigment (1): 10 to 70 parts by mass, Inorganic pigment (2): 5 to 120 parts by mass, and Inorganic pigment (3): 25 to 150 parts by mass.

[0055] The oil absorption amount of the inorganic pigment (3) is not particularly limited and can be any known oil absorption amount. The oil absorption amount of the inorganic pigment (3) is, for example, 5 to 200 (g / 100g). In one embodiment, the oil absorption amount of the inorganic pigment (3) is 10 to 150 (g / 100g).

[0056] Examples of commercially available inorganic pigments (3) include the Radiolite series such as "Radiolite F" (diatomaceous earth) and "Radiolite FA" (diatomaceous earth) manufactured by Showa Chemical Industry Co., Ltd., and "R-70H" (heavy calcium carbonate) manufactured by Maruo Calcium Co., Ltd.

[0057] In one embodiment, the inorganic pigments (1), (2), and (3) are each independently one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, talc, and diatomaceous earth.

[0058] The types of inorganic pigments (1), (2), and (3) may all be the same, two may be the same and one different, or all three may be different.

[0059] In one embodiment, the inorganic pigments (1) to (3) satisfy any of the following conditions. The inorganic pigment (1) is one or more selected from the group consisting of silica, barite, kaolin, barium sulfate, calcium carbonate, talc, and diatomaceous earth; The inorganic pigment (2) is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, and diatomaceous earth; or The inorganic pigment (3) is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, talc, and diatomaceous earth.

[0060] In another embodiment, the inorganic pigments (1) to (3) satisfy any of the following conditions. The inorganic pigment (1) is one or more selected from the group consisting of silica, barite, kaolin, barium sulfate, calcium carbonate, talc, and diatomaceous earth; The inorganic pigment (2) is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, talc, and diatomaceous earth; or The inorganic pigment (3) is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, talc, and diatomaceous earth.

[0061] In another embodiment, the inorganic pigments (1) to (3) satisfy any of the following conditions. The inorganic pigment (1) is one or more selected from the group consisting of silica, barite, wollastonite, barium sulfate, calcium carbonate, talc, and diatomaceous earth; The inorganic pigment (2) is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, and diatomaceous earth; or The inorganic pigment (3) is one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, and talc.

[0062] In one embodiment of the coating film according to the present invention, the inorganic pigment is An inorganic pigment (1) having an average particle size of 3 μm or more and less than 7 μm, Inorganic pigment (2) having an average particle size of 7 μm or more and less than 19 μm, The material comprises an inorganic pigment (3) having an average particle size of 19 μm or more and 29 μm or less, Each of the inorganic pigments (1) to (3) is independently selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, talc, and diatomaceous earth. This makes it easier to adjust Sa1 and Sa2. Furthermore, using inorganic pigment (1) makes it easier to suppress uneven gloss. Furthermore, using inorganic pigment (3) makes it easier to suppress uneven gloss and improve the smoothness of the coating film.

[0063] In one embodiment of the coating film according to the present invention, the oil absorption amount of the inorganic pigments (1) to (3) is Inorganic pigment (1): 5-260 (g / 100g) Inorganic pigments (2): 20-40 (g / 100g) and Inorganic pigment (3): 10-150 (g / 100g).

[0064] The topcoat paint composition contains a solvent. The solvent can be any solvent known from paint compositions. Examples of solvents include aqueous solvents and organic solvents.

[0065] Examples of aqueous solvents include water, glycol-based solvents such as ethylene glycol and propylene glycol; glycol ether-based solvents such as ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate; alcohol-based solvents such as methanol, ethanol, and isopropyl alcohol; ketone-based solvents such as acetone; and N-methyl-2-pyrrolidone.

[0066] Examples of organic solvents include ether-based solvents such as dioxane and tetrahydrofuran; ester-based solvents such as ethyl acetate and butyl acetate; ketone-based solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbon-based solvents such as toluene and xylene; and hydrocarbon-based solvents such as pentane, hexane, and cyclohexane.

[0067] The amount of solvent can be adjusted as appropriate; for example, it is 30 to 60% by mass of the total mass of the paint composition.

[0068] Other ingredients The topcoat paint composition may optionally contain other components besides resin, inorganic pigment, and solvent. Examples of other components include dispersants, curing catalysts, viscosity modifiers, film-forming aids, ultraviolet absorbers, light stabilizers, antioxidants, defoamers, surface modifiers, pinhole inhibitors, rust inhibitors, and the like.

[0069] The weather resistance of the coating can be improved by including a light stabilizer or UV absorber in the topcoat paint composition.

[0070] Method for preparing topcoat paint composition The method for preparing the topcoat paint composition is not particularly limited, and known methods for preparing paint compositions can be used. For example, it can be prepared by mixing essential components such as resin, inorganic pigment, and solvent, as well as other components as needed. Dispersers, ball mills, roll mills, planetary mixers, etc., can be used to mix the components.

[0071] • Method for forming a coating film The method for forming the coating film is not particularly limited, and known coating methods can be used. For example, dipping, brushing, rollers, roll coaters, air sprayers, airless sprayers, curtain flow coaters, roller curtain coaters, die coaters, etc., can be used.

[0072] The drying temperature after applying the topcoat paint composition can be adjusted as appropriate depending on the solvent and other factors. For example, if drying is required in a short time, such as 10 seconds to 30 minutes, the temperature can be set to 30 to 200°C, with 40 to 160°C being preferred. If drying is required in a short time, energy rays such as ultraviolet light may be used. If drying is not required in a short time, drying may be done at room temperature, for example.

[0073] The film thickness of the coating can be adjusted as appropriate depending on the application, for example, the dry film thickness is 25 to 60 μm.

[0074] Other layers on the object to be coated, to which the coating film of the present invention is applied, are not particularly limited and may be selected as appropriate. Examples of such other layers include a primer film using an undercoat paint or surface preparation agent, and an intermediate coating film using an intermediate coating paint.

[0075] The material of the object to be coated is not particularly limited and includes, for example, mortar, concrete, siding board, autoclaved lightweight concrete (ALC), iron, aluminum, hot-dip galvanized steel, stainless steel, wood, FRP, gypsum board, extruded cement board, porcelain tile, calcium silicate board, slate, rigid PVC, and chromate-treated galvanized steel.

[0076] (Goods) The article of this embodiment is an article having the coating film of the present invention.

[0077] Articles having a coating are not particularly limited and include, for example, buildings, ships, vehicles, aircraft, bridges, offshore structures, plants, tanks, pipes, steel pipes, cast iron pipes, etc. [Examples]

[0078] The present invention will be described in more detail below with reference to examples, but these examples are for illustrative purposes only and do not limit the present invention in any way.

[0079] The materials and apparatus used in the examples are as follows: ·resin Resin 1: Weakly solvent-soluble acrylic resin, product name "Acrydic® A-870" manufactured by DIC Corporation, acid value: 2-4 mg KOH / g, solids content: 55% Resin 2: Weakly solvent-soluble acrylic resin, product name "Hariakron 8730" manufactured by Harima Chemicals, acid value: 3 mg KOH / g or higher, solids content: 55% Resin 3: Water-based emulsion resin, manufactured by Saiden Chemical Co., Ltd., product name "Saibinol (registered trademark) EC-201", pH: 8.5, solids content: 46% • Inorganic pigments (1) Silica: Product name "NipSeal (registered trademark) E-170" manufactured by Tosoh Silica Co., Ltd., average particle size 4 μm, oil absorption capacity 250 g / 100 g, labeled as "Inorganic Pigment 1-1" in the table. Barium sulfate: Product name "Barite Powder FBA" manufactured by Takehara Chemical Industry Co., Ltd., average particle size 5 μm, oil absorption 8 g / 100 g, labeled as "Inorganic Pigment 1-2" in the table. Wollastonite: Product name "KGP-H65" manufactured by Kansai Matec Co., Ltd., average particle size 6 μm, oil absorption 65 g / 100 g, labeled as "Inorganic Pigment 1-3" in the table. • Inorganic pigments (2) Talc 1: Product name "SWE" manufactured by Nippon Talc Co., Ltd., average particle size 17 μm, oil absorption 24 g / 100 g, labeled as "Inorganic Pigment 2-1" in the table. Talc 2: Product name "RS413A" manufactured by Fuji Talc Industrial Co., Ltd., average particle size 12 μm, oil absorption 29 g / 100 g, labeled as "Inorganic Pigment 2-2" in the table. Calcium carbonate: Product name "R-30" manufactured by Maruo Calcium Co., Ltd., average particle size 11 μm, oil absorption 27 g / 100 g, labeled as "Inorganic Pigment 2-3" in the table. • Inorganic pigments (3) Diatomaceous earth 1: Product name "Radiolite F" manufactured by Showa Chemical Industry Co., Ltd., average particle size 23 μm, oil absorption capacity 150 g / 100 g, labeled as "Inorganic Pigment 3-1" in the table. Diatomaceous earth 2: Product name "Radiolite FA" manufactured by Showa Chemical Industry Co., Ltd., average particle size 21 μm, oil absorption capacity 150 g / 100 g, labeled as "Inorganic Pigment 3-2" in the table. Heavy calcium carbonate: Product name "R-70H" manufactured by Maruo Calcium Co., Ltd., average particle size 29 μm, oil absorption 18 g / 100 g, labeled as "Inorganic Pigment 3-3" in the table. Other inorganic pigments Silica O1: Product name "Nipgel (registered trademark) AZ-201" manufactured by Tosoh Silica Co., Ltd., average particle size 2 μm, oil absorption capacity 280-370 g / 100 g, indicated as "Silica O1" in the table. Talc O1: Product name "RS313" manufactured by Fuji Talc Industries Co., Ltd., average particle size 12 μm, oil absorption capacity 18 g / 100 g, labeled as "Talc O1" in the table. Silica O2: Product name "Silica Sand No. 8" manufactured by Yamamori Civil Engineering & Mining Co., Ltd., average particle size 120 μm, oil absorption 0.1 g (g / 100 g), labeled as "Silica O2" in the table.

[0080] • Measurement of surface roughness Sa of the coating film The surface roughness Sa of the coating film was measured under the following conditions, and the average value of 5 measurements was used. Equipment: Taylor Hobson's non-contact surface texture analyzer "CCI MP-HS" Lens magnification: 10x, WD=7.4mm lens used. Measurement speed: 1x Stitch measurement: None Shape removal: 1 time Number of measurements: 5

[0081] • Measurement of average particle diameter The average particle size of inorganic pigments was measured under the following conditions. Equipment: LS 13 320 (manufactured by BECKMAN COULTER) Measurement sample: A solution prepared by dispersing an inorganic pigment in 12 ml of water was used. Number of measurements: 3 Calculation method: After measuring D50 three times, calculate the average value.

[0082] • Measuring oil absorption The oil absorption of inorganic pigments was measured under the following conditions. Reagent: Purified linseed oil (acid value 5.0-7.0 mg KOH / g) Sample mass: Any amount between 1 and 20 g Measurement: In accordance with JIS K 5101-13-1, add linseed oil drop by drop to the sample using a burette and knead. Continue this process until the resulting paste reaches a smooth consistency (endpoint). Calculation formula: Oil absorption amount (g / 100g)=(93×V) / m In the formula, V is the volume of linseed oil consumed (mL), and m is the mass of the sample (g).

[0083] • Measurement of gloss level The gloss value was measured under the following conditions. Gloss measuring instrument: Konica Minolta's "MULTI GLOSS 268A" Measurement area: 2 x 4mm Number of measurements: 3 Calculation method: After taking three measurements, calculate the average value.

[0084] • Undercoat application An epoxy-based rust-inhibiting paint was applied as a primer to a tin plate used as the base material, to a dry film thickness of 45 μm, and dried at 23°C for 24 hours to form a primer film on one side of the base material.

[0085] (Example 1) A topcoat paint composition was prepared by mixing resin, inorganic pigments (1) to (3), and mineral spirits as a solvent according to the formulations shown in Table 1.

[0086] (Examples 2-5, Comparative Examples 1-8) The topcoat paint composition was prepared in the same manner as in Example 1, except that the type or amount of inorganic pigment was changed as shown in Table 1.

[0087] (Examples 6, 8-16) As shown in Table 2, the topcoat paint composition was prepared in the same manner as in Example 1, except that the resin and inorganic pigment were changed.

[0088] (Example 7) As shown in Table 2, the resin and inorganic pigment were changed, and water was mixed as the solvent to prepare the topcoat paint composition.

[0089] • Top coat formation A substrate with a primer coating was prepared. The topcoat coating composition of each example or comparative example was applied to the primer coating to a dry film thickness of 45 μm to form a topcoat coating.

[0090] (Appearance evaluation) For each example and comparative example, the coated panels with the topcoat film obtained were evaluated in the following four ways. The coated panels were placed on a stand so that their surfaces were parallel to the horizontal. All evaluations were performed by nine individuals with more than 10 years of experience in painting work. The evaluation results of these nine individuals were then arranged in order of score, and the median score was adopted. For near gloss and deep gloss, the corresponding gloss value measured with a gloss meter from the same angle as the visual observation was also noted.

[0091] • Close-up gloss The intensity of specularly reflected light was evaluated visually from a distance of approximately 20 cm from the painted board, at an angle of 60° from the perpendicular to the board, according to the following criteria. A score of 5 is the best. 5 points: No reflected light is observed (60° gloss value: 0.5 or less) 4 points: Reflected light is barely observable (60° gloss value: 0.6~1.0) 3 points: Slight reflection is observed (60° gloss value: 1.1~2.0) Points 2: Clearly visible reflected light (60° gloss value: 2.1~3.0) 1 point: Significant reflected light is observed (60° gloss value: 3.1 or higher)

[0092] • Deep luster (glossy appearance when viewed from a distance) The intensity of specularly reflected light was evaluated by visual observation from a distance of approximately 50 cm from the coated board, at an angle of 5° from the board surface, according to the following criteria. A score of 5 is the best. 5 points: No reflected light is observed (5° gloss value: 1.5 or less) 4 points: Reflected light is barely observable (5° gloss value: 1.6~2.0) 3 points: Slight reflection is observed (5° gloss value: 2.1~3.0) Points 2: Clearly visible reflected light (5° gloss value: 3.1~4.0) 1 point: Significant reflected light is observed (5° gloss value: 4.1 or higher)

[0093] • Glossy The paint film was observed visually from a distance of approximately 50 cm, at an angle of 60° from the perpendicular to the painted board, and the difference between the gloss at close range and the gloss at depth was compared for each part. The gloss unevenness was evaluated according to the following criteria. A score of 5 is the best. 5 points: No unevenness in gloss was observed. 4 points: Slight unevenness in gloss is visible, though barely. 3 points: Slight unevenness in gloss is noticeable. 2 points: Clear unevenness in gloss is visible. 1 point: Significant unevenness in gloss is observed.

[0094] ·Smoothness Light was incident on the coated panel at an angle of 85° to the perpendicular to the panel. Then, the smoothness (surface irregularities) was evaluated by visual inspection from the direction perpendicular to the panel, according to the following criteria. A score of 5 is the best. 5 points: No pigment particles are visible on the surface of the coating when the coating is visually inspected. 4 points: When the paint film is visually inspected, pigment particles can be barely observed on the surface of the paint film. 3. When the paint film was visually inspected, tiny particles of pigment were observed on the surface of the paint film. 2. When the paint film was visually inspected, pigment particles were clearly visible on the surface of the paint film. 1. When the paint film was visually inspected, a significant amount of pigment particles were observed on the surface of the paint film.

[0095] [Table 1]

[0096] [Table 2]

[0097] According to the present invention, it is possible to provide a coating film that reduces proximity gloss, depth gloss, and gloss unevenness, and also exhibits excellent surface smoothness. [Industrial applicability]

[0098] According to the present invention, it is possible to provide a coating film that reduces proximity gloss, depth gloss, and gloss unevenness, and also exhibits excellent smoothness of the coating film surface.

Claims

1. A coating film which is a cured product of a topcoat paint composition, The topcoat paint composition comprises a resin, an inorganic pigment, and a solvent. The amount of the inorganic pigment is 60 to 250 parts by mass per 100 parts by mass of the solid content of the resin. If the surface roughness of the coating film is Sa, The surface roughness Sa1 of the wavelength 8 μm or less is 0.07 to 1.44 μm. The surface roughness Sa2 at wavelengths of 250 μm or less is 1.4 to 5.5 μm. The ratio of Sa1 to Sa2 (Sa2 / Sa1) is 50 or less. Coating film.

2. The inorganic pigment, An inorganic pigment (1) having an average particle size of 3 μm or more and less than 7 μm, Inorganic pigment (2) having an average particle size of 7 μm or more and less than 19 μm, The material comprises an inorganic pigment (3) having an average particle size of 19 μm or more and 29 μm or less, The coating film according to claim 1, wherein each of the inorganic pigments (1) to (3) is independently one or more selected from the group consisting of silica, barite, kaolin, wollastonite, barium sulfate, calcium carbonate, talc, and diatomaceous earth.

3. The amount of the inorganic pigments (1) to (3) is such that, relative to 100 parts by mass of the solid content of the resin, Inorganic pigment (1): 10 to 70 parts by mass, Inorganic pigment (2): 5 to 120 parts by mass, and The coating film according to claim 2, wherein the inorganic pigment (3) is 25 to 150 parts by mass.

4. The oil absorption amounts of the inorganic pigments (1) to (3) are, Inorganic pigment (1): 5-260 (g / 100g) Inorganic pigment (2): 20-40 (g / 100g) and The coating film according to claim 2, wherein the inorganic pigment (3) is 10 to 150 (g / 100g).

5. The coating film according to claim 1, wherein the ratio (Sa2 / Sa1) is 20 or less.

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