JP2020157507A - Coating product, and thermosetting powder coating - Google Patents

Abstract

To provide a coating product having a coating surface with an excellent moist feeling.SOLUTION: There is provided a coating product in which a standard deviation σ of a peak position of a scattering angle on a coating surface is 13° or less which is measured by a light scattering measuring device equipped with a surface emitting laser as a light source, and the standard deviation σ of a peak intensity of the scattering angle is 0.85 or less, and a glossiness on the coating surface measured by a glossimeter under a condition of an incident angle of 60° is 70° or less, and having a coating layer of a thermosetting powder coating having powder particles containing thermosetting resin, thermosetting agent, and crosslinked resin particles.SELECTED DRAWING: None

Description

The present invention relates to coated products and thermosetting powder coating materials.

In recent years, powder coating technology using powder coatings has been used to produce powder coatings that emit less volatile organic compounds (VOCs) in the coating process and do not adhere to the object to be coated after coating. Since it can be collected and reused, it is attracting attention in terms of protecting the global environment.

On the other hand, the following documents are known as techniques for conventional projection screens, writing boards, decorative sheets, or interior interior wall materials.

For example, Patent Document 1 states that "a whiteboard having a substrate and a colored layer provided on the substrate, and a light diffusing layer containing transparent particles is provided on the colored layer. A whiteboard characterized by. ”Is disclosed.

Further, Patent Document 2 states that "a reflective screen that reflects image light projected from an image source and displays it in an observable manner, and a unit lens having a lens surface and a non-lens surface is the screen surface of the reflective screen. A lens layer having a plurality of Fresnel lens shapes arranged along the line on the back side, a reflection layer formed on the lens surface of at least the unit lens and reflecting light, and an arrangement on the image source side of the lens layer. Then, in a direction parallel to the arrangement direction of the unit lens, the magnitude of the diffusion action on the light incident at the incident angle in a specific angle range including the direction orthogonal to the screen surface of the reflective screen is determined from other angles. The optical control layer includes an optical control layer that is larger than the diffuser action on incident light, and the optical control layer has a convex portion that is convex toward the image source side and a convex portion that is convex toward the image source side, and the lens layer side of the convex portion. The recesses located are alternately arranged along the screen surface in a direction parallel to the arrangement direction of the unit lens.
The convex portion has a substantially quadrangular cross-sectional shape in a cross section parallel to the arrangement direction and orthogonal to the screen surface, and diffuses light on the top surface of the convex portion on the image source side and the surface of the concave portion. A reflective screen characterized by the formation of a fine uneven shape. Is disclosed.

Further, Patent Document 3 states, "For a writing board, the surface layer of a reflective film made of an aliphatic polyester resin containing a fine powdery filler and having voids inside so that the void ratio is 50% or less. A writing board / reflective screen dual-purpose film, characterized in that a light-diffusing and transmissive layer that can be written and erased by a marker is provided. "

Further, Patent Document 4 describes, "A method for manufacturing a projection screen having a base material and a coating film layer laminated on the base material, and the surface of the base material on at least the coating film layer side of the base material. A step of forming the coating film into an uneven shape, a step of preparing a coating film stock solution to be the coating film layer by mixing a plurality of fine particles with a synthetic resin having a thixo property, and a step of forming the substrate surface into the uneven shape. A method for manufacturing a projection screen, which comprises a step of forming the undiluted solution for a coating film in a laminated state so as to have a substantially constant thickness along the same line. ”

Further, Patent Document 5 states that "a reflective screen having transparency, reflecting at least a part of the image light projected from an image source to display an image, and transmitting a part of the image light. A first screen portion and a second screen portion provided on the back side of the first screen portion are provided, and these are integrally laminated, and the first screen portion has light transmission and is the first. A first optical shape layer in which a plurality of 1-unit optical shapes are arranged on the back surface side and at least a part of the first unit optical shape are formed, and the surface thereof has a fine and irregular uneven shape and is incident. The second screen portion includes a first reflective layer having a function of reflecting a part of the light to be transmitted and transmitting a part of the light, and the second screen portion has a light transmitting property, and the second unit optical shape is a surface on the back side. It is formed on at least a part of the second optical shape layer and the second unit optical shape arranged in a plurality of the above, and has a fine and irregular uneven shape on the surface thereof, and reflects a part of the incident light. The display area of the first screen portion and the display area of the second screen portion are provided with a second reflective layer having a function of transmitting a part thereof and viewed from the normal direction of the screen surface of the reflective screen. A reflective screen characterized by at least some overlap. "

Further, Patent Document 6 states that "a projection screen having a base material and a coating film layer formed on the surface of the base material, wherein the coating film layer includes a binder resin, a plurality of fine particles, and the like. The exposed surface of the coating film layer, which contains a surface conditioner, contains at least a silicon-based polymer having an acrylic group, and is opposite to the surface of the coating layer in contact with the substrate, is formed by the plurality of fine particles. A projection screen characterized by being formed in an uneven shape. ”Is disclosed.

Further, Patent Document 7 states that "a decorative sheet having a surface protective layer composed of a film base material and a crosslinked cured product of an ionizing radiation curable resin composition, (1) the surface protective layer is used as a leveling agent. A resin having an acrylic skeleton is contained in a ratio of 0.1 to 4.0 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin, and (2) a hydroxy group is used as a constituent unit of the resin having the acrylic skeleton. A decorative sheet containing a (meth) acrylic acid alkyl ester which does not have, and which is a poly (meth) acrylate containing at least one selected from a (meth) acrylic acid hydroxyalkyl ester and an aromatic vinyl compound. Is disclosed.

Further, Patent Document 8 states, "Tetrahydrophthalic acid, trimethylolpropane or pentaerythritol, (meth) acrylic containing two or more (meth) acryloyl groups in one molecule and having a (meth) acryloyl group equivalent of 500 or less. The first component is oligo (meth) acrylate obtained by esterifying the three components of the acid, and ethylene glycol dimethacrylate and diethylene glycol having two or more methacryloyl groups in one molecule and having a methacryloyl group equivalent of 121 or less. One type of polyhydric alcohol methacrylate selected from dimethacrylate and trimethylolpropane trimethacrylate is used as the second component, and the blending ratio of the first component and the second component is 1st component / 2nd component = 1/0. 5 to 1/2 (weight ratio), and 100 parts by weight of these, 1 to 40 parts by weight of glass powder having a volume of 6.5 × 104 μm3 or less as the third component, and aluminum having a radius of 1 to 50 μm as the fourth component. A coating material obtained by adding 1 to 20 parts by weight of powder and / or stainless powder is applied to an object to be coated, and this is cured by electron beam irradiation in an atmosphere having an oxygen concentration of 1% or less. In the layer, the stain resistance is formed by forming the coating layer on any of a metal plate, a hard board, a particle board, a wood plate such as wood, an asbestos plate, a rock wool plate, an inorganic plate such as gypsum plate, and a plastic plate. , Interior interior wall material with a writing board function with excellent projection and anti-glare properties. "

Japanese Unexamined Patent Publication No. 2006-334850 Japanese Unexamined Patent Publication No. 2012-226103 Japanese Unexamined Patent Publication No. 2006-51792 Japanese Unexamined Patent Publication No. 2013-238705 JP-A-2018-040892 Japanese Unexamined Patent Publication No. 2013-235149 Japanese Unexamined Patent Publication No. 2012-213933 Japanese Unexamined Patent Publication No. 08-253988

An object of the present invention is a coated surface having an excellent moist feeling as compared with the case where the standard deviation σ of the peak position of the scattering angle on the coated surface measured by a light scattering measuring device provided with a surface emitting laser as a light source exceeds 13 °. Is to provide a painted product having.

Means for solving the above problems include the following aspects.
<1> A painted product in which the standard deviation σ of the peak position of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser as a light source is 13 ° or less.
<2>
The coated product according to <1>, wherein the standard deviation σ of the peak position of the scattering angle is 10 ° or less.
<3>
The coated product according to <1> or <2>, wherein the standard deviation σ of the peak intensity of the scattering angle on the coated surface measured by a light scattering measuring device including a surface emitting laser as a light source is 0.85 or less.
<4>
The coated product according to <3>, wherein the standard deviation σ of the peak intensity of the scattering angle is 0.5 or less.
<5>
The coated product according to any one of <1> to <4>, wherein the glossiness on the painted surface measured by a glossiness meter under the condition of an incident angle of 60 ° is 70 ° or less.
<6>
The coated product according to any one of <1> to <5>, which has a coating film of a thermosetting powder coating material having powder particles containing thermosetting resin, thermosetting agent, and crosslinked resin particles.
<7>
The cross-linked resin particles are at least one selected from styrene-based resin particles, (meth) acrylic-based resin particles, styrene- (meth) acrylic-based copolymer resin particles, and polyester resin particles. Painted.
<8>
Thermosetting powder having powder particles containing a thermosetting resin and a thermosetting agent, and an external additive having an external addition amount of 0.3 parts by mass or more and 4 parts by mass or less with respect to 100 parts by mass of the powder particles. The coated product according to any one of <1> to <7>, which has a coating film of paint.
<9>
A thermosetting powder coating material having powder particles containing a thermosetting resin, a thermosetting agent, and crosslinked resin particles.
<10>
The thermosetting powder coating material according to <9>, wherein the crosslinked resin particles are at least one selected from (meth) acrylic resin particles and polyester resin particles.
<11>
Thermosetting resin, powder particles containing a thermosetting agent,
An external additive having an external addition amount of 0.3 parts by mass or more and 4 parts by mass or less with respect to 100 parts by mass of the powder particles.
Thermosetting powder paint with.
<12>
Of <9> to <11>, the volume average particle size D50v of the powder particles is 3 μm or more and 10 μm or less, the volume particle size distribution index GSDv is 1.30 or less, and the average circularity is 0.96 or more. The thermosetting powder coating according to any one of the items.

According to the invention according to <1> or <2>, when the standard deviation σ of the peak position of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser as a light source exceeds 13 °. In comparison, a painted product having a painted surface having an excellent moist feeling is provided.

According to the invention according to <3> or <4>, the standard deviation σ of the peak intensity of the scattering angle on the painted surface measured by a light scattering measuring device provided with a surface emitting laser as a light source is more than 0.85. A coated product having a coated surface having an excellent moist feeling is provided.

According to the invention according to <5>, a painted product having a painted surface having an excellent moist feeling as compared with the case where the glossiness on the painted surface measured by a gloss meter under the condition of an incident angle of 60 ° exceeds 70 °. Is provided.

According to the invention according to <6> or <7>, it has a coating film of a thermosetting powder coating material having powder particles containing a thermosetting resin and a thermosetting agent and not containing crosslinked resin particles. A coated product having a coated surface having an excellent moist feeling is provided as compared with the case.

According to the invention according to <8>, the powder particles containing a thermosetting resin and a thermosetting agent, and an external additive having an external addition amount of less than 0.3 parts by mass with respect to 100 parts by mass of the powder particles. Provided is a coated product having a coated surface having an excellent moist feeling as compared with the case of having a coating film of a thermosetting powder coating having.

According to the invention according to <9> or <10>, a moist feeling is compared with a thermosetting powder coating material having powder particles containing a thermosetting resin and a thermosetting agent and not containing crosslinked resin particles. Provided is a thermosetting powder coating which can obtain a coated product having an excellent coated surface.

According to the invention according to <11>, the powder particles containing a thermosetting resin and a thermosetting agent, and an external additive having an external addition amount of less than 0.3 parts by mass with respect to 100 parts by mass of the powder particles. Provided is a thermosetting powder coating material capable of obtaining a coated product having a coated surface having an excellent moist feeling as compared with the thermosetting powder coating material having.

According to the invention according to <12>, as compared with the case where the volume average particle size D50v of the powder particles exceeds 10 μm, the volume particle size distribution index GSDv exceeds 1.30, or the average circularity is less than 0.96. Provided is a thermosetting powder coating that can obtain a coated product having a coated surface having an excellent moist feeling.

It is a schematic block diagram which shows the inspection apparatus as a light scattering measuring apparatus. It is a schematic block diagram which shows the inspection apparatus as a light scattering measuring apparatus. (A) (B) It is a process chart which showed the inspection process at the time of inspecting an inspection object using the inspection apparatus as a light scattering measuring apparatus. (A) (B) It is a process chart which showed the inspection process at the time of inspecting an inspection object using the inspection apparatus as a light scattering measuring apparatus. It is a block diagram which showed the inspection part which uses the inspection apparatus as a light scattering measurement apparatus, and the light receiving element. The relationship between the scattering angle and the light intensity on the painted surface of the painted product according to the present embodiment measured by a light scattering measuring device provided with a surface emitting laser as a light source is shown. The relationship between the scattering angle and the light intensity on the painted surface of a conventional painted product measured by a light scattering measuring device equipped with a surface emitting laser as a light source is shown.

Hereinafter, preferred embodiments of the present invention will be described in detail.

<Painted product>
In the coated product of the present embodiment, the standard deviation σ of the peak position of the scattering angle on the coated surface measured by a light scattering measuring device including a surface emitting laser as a light source is 13 ° or less.

Here, conventionally, for example, the painted surface of a painted product such as a projection screen, a writing board, a decorative sheet, and an interior interior wall material is moist because many fine contrasts of light and dark are visually recognized and the reflected light is glaring. The texture (also called "moist feeling") is low.
The reason is presumed as follows.

In the conventional surface roughness measurement of the painted surface, the evaluation length is about 400 μm, and the measurement is performed by the on-line stylus type of about 10 mm (defined by JIS B0601-2001, center line average roughness Ra, filter wave center line swell). Wca, arithmetic mean height Rz of roughness curve, etc.). Therefore, with an evaluation length of about 400 μm, an average value of about 10 mm is obtained, and even if a low surface roughness value is shown, minute irregularities are present.
In particular, a pattern (shadow, black and white, etc.) in which the size of the unevenness of the painted surface (specifically, the length between the protrusions) is in the range of 100 μm or more and 1 mm or less has high visibility. That is, since the light pattern created from the unevenness of this size has high luminosity factor, many fine contrasts of light and dark are visually recognized, and the reflected light due to the contrast of light and dark is felt as glare. Therefore, the painted surface has a low moist feeling.

On the other hand, the coated product according to the present embodiment is moist because the standard deviation σ of the peak position of the scattering angle on the coated surface measured by a light scattering measuring device provided with a surface emitting laser as a light source is 13 ° or less. It is a painted product with a painted surface that has an excellent feeling.
The reason is presumed as follows.

In a light scattering measuring device equipped with a surface emitting laser, light scattering measurement of a painted surface is performed with an irradiation spot diameter of 50 μm as fine as 50 μm, and the size (specifically, the length between protrusions) is microscopic. Unevenness information can also be obtained. Specifically, since it is said that the resolution of the human eye at a reading distance of a book is about 60 μm, a light scattering measuring device equipped with a surface emitting laser has microscopic unevenness of a resolution that can be visually recognized by the human eye. Information is also available.

With a light scattering measuring device equipped with a light emitting laser, the standard deviation σ of the peak position of the scattering angle on the coated surface of a conventional coated product having a pattern with high visibility in the range of 100 μm or more and 1 mm or less of the unevenness of the coated surface is obtained. When measured, the standard deviation σ of the peak position of the scattering angle exceeds 13 ° (see FIG. 7).
On the other hand, a light scattering measuring device equipped with a surface emitting laser measures the standard deviation σ of the peak position of the scattering angle on the coated surface of a coated product having a pattern with low visibility in the range where the size of the unevenness of the coated surface is less than 100 μm. Then, the standard deviation σ of the peak position of the scattering angle becomes 13 ° or less (see FIG. 6).

That is, a painted product having a standard deviation σ of the peak position of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser of 13 ° or less has irregularities of a size that makes it difficult for humans to see the painted surface. ing. This uneven shape is an example, but it is a shape in which the center is recessed surrounded by a fine circular (specifically, for example, donut-shaped) convex portion, and the diameter of the convex circle is in the range of 15 μm or more and 20 μm or less. It has become.
Therefore, the uneven shape of the painted surface has a fine size that is difficult for humans to see, and it is difficult to see the fine contrast between light and dark. In addition, since the reflected light itself due to the contrast between light and dark is difficult to see, it is difficult to feel the glare of the reflected light.

From the above, it is presumed that the painted product according to the present embodiment is a painted product having a painted surface having an excellent moist feeling.

Further, since the painted product according to the present embodiment has fine irregularities formed on the painted surface, it is excellent in marker erasability, repeated writing and erasing durability with a marker, and projector projection property.

The painted product according to the present embodiment is suitable for a painted product such as a projection screen, a writing board, a decorative sheet, and an interior interior wall material.

Hereinafter, the details of the painted product according to this embodiment will be described.

In the coated product according to the present embodiment, the standard deviation σ of the peak position of the scattering angle on the coated surface measured by a light scattering measuring device provided with a surface emitting laser as a light source is 13 ° or less, but the coated surface has a moist feeling. , 10 ° or less is preferable, and 4 ° or less is more preferable, from the viewpoint of improving marker erasability, repeated writing and erasing durability by a marker, and projector projectability.
Ideally, the lower limit of the standard deviation σ of the peak position of the scattering angle is 0, but from the viewpoint that the refractive indexes of the coating film and air are different and reflection at the interface always occurs, for example, 2 ° or more. And.

The average value of the peak position of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser as a light source is the moist feeling of the painted surface, marker erasability, repeated writing and erasing durability by markers, and a projector. From the viewpoint of improving the projectability, 4 ° or more and 6 ° or less are preferable, and 2 ° or more and 4 ° or less are more preferable.

The standard deviation σ of the peak intensity of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser as a light source is the moist feeling of the painted surface, marker erasability, repeated writing and erasing durability by the marker, and From the viewpoint of improving the projectability of the projector, 0.85 or less is preferable, 0.5 or less is more preferable, and 0.2 or less is further preferable.
Ideally, the lower limit of the standard deviation σ of the peak intensity of the scattering angle is 0, but from the viewpoint that the refractive indexes of the coating film and air are different and reflection always occurs at the interface, for example, 0.05 ° That's all.

The average value of the peak intensity of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser as a light source is the moist feeling of the painted surface, marker erasability, repeated writing and erasing durability by markers, and a projector. From the viewpoint of improving the projectability, it is preferably 2 or more and 4 or less, and more preferably 0.05 or more and 0.2 or less.

The measurement of the peak position and peak intensity of the scattering angle on the coated surface by a light scattering measuring device provided with a surface emitting laser as a light source is an inspection device of JP2015-072175 (specifically, an inspection according to the first embodiment). It is carried out according to the method using the device). Specifically, it is as follows.

First, the inspection device will be described with reference to FIGS. 1 to 5. The arrow H shown inside indicates the device vertical direction (vertical direction), the arrow W indicates the device width direction (horizontal direction), and the arrow D indicates the device depth direction (horizontal direction).

(Constitution)
The inspection device 10 is a device that inspects the light scattering characteristics of the inspection object OB by irradiating the inspection object OB moving in the depth direction of the device with a luminous flux (light flux). Then, as shown in FIGS. 1 and 5, the inspection device 10 includes a light emitter 14 having a plurality of light sources 12, a light receiver 18 having a plurality of light receiving elements 16, and an inspection unit 20. ..

Further, the inspection device 10 is provided between the light emitter 14 and the inspection object OB, and includes an optical system 30 that guides the light flux emitted from the light source 12 to the inspection object OB.

(Photophore)
As shown in FIG. 1, the light emitter 14 is arranged above the device in the vertical direction with respect to the inspection area T through which the inspection object OB moving in the device depth direction passes. Further, the light emitter 14 is mounted on a substrate and includes a plurality of light sources 12 that are arranged in the width direction of the device and emit light light in the vertical direction of the device. In this way, the light sources 12 are arranged in a direction intersecting (for example, orthogonal to) the moving direction of the inspection object OB (that is, the device depth direction).

Further, from the light source 12A arranged at one end in the device width direction (that is, the right end in the figure) to the light source 12B arranged at the other end in the device width direction (that is, the left end in the figure), each light source 12 is inspected with a time lag. A light source is emitted toward the object OB. Then, while the inspection object OB is moving in the inspection area T, light emission from the light source 12A to the light source 12B is repeated.

(Optical system)
The optical system 30 is a so-called bilateral telecentric lens, and as shown in FIG. 1, a lens 32 as a first lens and a lens 34 as a second lens are arranged in order from the light emitter 14 toward the inspection object OB. And have. Further, the optical system 30 is arranged between the lens 32 and the lens 34, and includes a diaphragm member 40 that narrows the luminous flux.

The optical axis of the lens 32 and the optical axis of the lens 34 are the same, and the lens 32 and the lens 34 are arranged so that the optical axis M of the lens 32 and the lens 34 faces the device in the vertical direction. Further, in the above-mentioned light source 12, the light source 12C arranged at the center in the device width direction is arranged on the optical axis M.

The lens 32 is a circular convex lens in a plan view, and the dimension of the lens 32 in the device width direction (that is, the J dimension in the drawing) is the dimension in the device width direction from the light source 12A to the light source 12B (that is, the D dimension in the drawing). ) Has been made longer. As a result, the luminous flux emitted from each light source 12 passes through the lens 32, so that the lens 32 changes the degree of divergence of the transmitted luminous flux and directs the luminous flux toward the lens 34 as parallel light.

Similarly, the lens 34 is a circular convex lens in a plan view, and the dimension of the lens 34 in the device width direction (that is, the G dimension in the drawing) is longer than the dimension of the lens 32 in the device width direction. Then, the lens 34 is adapted to focus the light flux emitted from the lens 32 and transmitted through the lens 34 toward the inspection object OB.

The diaphragm member 40 is arranged between the lens 32 and the lens 34, and the diaphragm member 40 is formed with a circular opening 42 for narrowing the light flux that passes through the lens 32 and is incident on the lens 34. .. Specifically, the diaphragm member 40 has a plate shape in which the plate surface faces the device in the vertical direction, and the diaphragm member 40 has a tip portion that is bent toward the lens 34 around the optical axis M and is tapered. It is formed. The tip portion is an opening edge 42A constituting the opening 42, and the circular shape formed by the opening 42 has the optical axis M as the central axis.

Then, in the vertical direction of the device, the distance between the aperture edge 42A and the lens 32 (that is, F1 in the drawing) is the same as the focal length of the lens 32, and the distance between the aperture edge 42A and the lens 34 (that is, that is). In the figure, F2) is the same as the focal length of the lens 34. Therefore, the irradiation angle (θ1 in FIG. 1) of the light beam emitted from each light source 12 to the inspection object OB is defined.

(Receiver)
The receiver 18 is arranged between the lens 32 and the lens 34 on the lower side of the diaphragm member 40 in the vertical direction of the device, and is arranged on the right side in the drawing with the optical axis M in between, and the receiver 18A on the left side in the drawing. It is composed of a receiver 18B to be arranged. Since the receiver 18A and the receiver 18B have the same configuration, the receiver 18A will be mainly described.

The light receiver 18A is mounted on a substrate and includes a plurality of light receiving elements 16 arranged in the width direction of the device. Since the light receiving device 18 is arranged between the lens 32 and the lens 34, the light receiving element 16 is also arranged between the lens 32 and the lens 34.

Here, the fact that the light receiving element 16 is arranged between the lens 32 and the lens 34 means that, as shown in FIG. 1, the other lens having an outer diameter larger than that of one lens (lens 34 in this embodiment) It means that the light receiving element 16 is arranged inside the device width direction with respect to the line P (cylindrical surface) extending in the vertical direction of the device through the outer diameter end (virtual contact between the front surface R (radius) and the back surface R). .. When determining the outer diameter end, if there are a plurality of Rs on the front surface R or the back surface R, the outer diameter end is determined by using R having the largest value.

Further, the light receiving surface of the light receiving element 16 and the aperture edge 42A are arranged at the same positions, and the distance between the light receiving surface of each light receiving element 16 and the lens 34 (optical path length: F2 in the drawing) is the focal length of the lens 34. It is said to be the same as the distance.

Further, the light receiving element 16 and the opening 42 are arranged at the same positions in the depth direction of the device. Therefore, the light receiving element 16 cannot be arranged at the position of the opening 42 in the width direction of the device, and the light receiving element 16 arranged at the left end in the drawing in the light receiver 18A and the right end in the drawing in the light receiver 18B. The pitch with the light receiving element 16 arranged in the above is wider than the pitch between the other light receiving elements 16. In other words, the light receiving element 16 to be arranged between the light receiving device 18A and the light receiving device 18B is missing.

In this configuration, the light receiving element 16 is adapted to receive at least a part of the light flux emitted from the lens 34, reflected from the inspection object OB, and transmitted through the lens 34 (see the diffused light LB in FIG. 2). ..

(Inspection unit)
The inspection unit 20 receives the light receiving result of the light receiving element 16. Then, the inspection unit 20 detects the reflection characteristic of the inspection object OB based on the light receiving result of the light receiving element 16.

(motion)
Next, the operation of the inspection device 10 will be described. In addition, FIG. 1, FIG. 3 (A) (B) and FIG. 4 (A) (B) show the luminous flux irradiated to the inspection object OB, and FIG. 2 shows the luminous flux reflected by the inspection object OB. Shown.

First, when the inspection object OB moves in the depth direction of the device and the tip of the inspection object OB enters the inspection area T, as shown in FIGS. 3 (A) (B) and 4 (A) (B). From the light source 12A arranged at one end in the width direction of the apparatus to the light source 12B arranged at the other end, a luminous flux is emitted from each light source 12 toward the inspection object OB with a time lag. Then, light emission is repeated from the light source 12A to the light source 12B until the rear end of the inspection object OB passes through the inspection region T.

Further, the lens 32 changes the degree of divergence of the luminous flux emitted from each light source 12 and transmitted through the lens 32 so as to face the lens 34. Further, the diaphragm member 40 throttles (limits) the luminous flux whose degree of divergence is changed by the lens 32. Further, the lens 34 emits light flux incident on the lens 34, which is focused by the diaphragm member 40, so as to irradiate the inspection object OB from the vertical direction (optical axis direction) of the device.

The luminous flux applied to the inspection target OB is reflected by the surface 200 of the inspection target OB. The lens 34 changes the degree of divergence of the luminous flux (hereinafter referred to as “reflected luminous flux”) reflected by the inspection object OB and transmitted through the lens 34 so as to face each light receiving element 16. Then, each light receiving element 16 receives the reflected light flux transmitted through the lens 34. Further, the inspection unit 20 detects the light scattering information of the inspection object OB based on the light reception result of the light receiving element 16.
As shown in FIGS. 1 and 2, the specularly reflected light LA1 (see FIG. 2) that is emitted from the light source 12C and is specularly reflected at the central portion C in the device width direction on the surface 200 of the inspection object OB. Since it passes through the lens 34 and passes through the opening 42, it is not received by the light receiving element 16. In other words, the light reception result by the specularly reflected light LA1 at the central portion C cannot be obtained.

The detection device 10 described above is used, and the peak position and peak intensity of the scattering angle on the painted surface are measured under the following conditions.

− Light emitter 14−
Light source 12: Vertical Cavity Surface Emitting Laser (VCSEL) with an irradiation light wavelength of 850 nm.
-Number of light sources 12: 40-Arrangement pitch of light sources 12: Surface emitting lasers are arranged alternately at intervals of 4.8 mm and 5.2 mm by alternating the directions of the surface emitting lasers.

-Optical system 30-
-Lens 32: Telecentric optical system lens, diameter 50 mmφ, focal length f50 mm, aperture 2.0 mmφ
-Lens 34: Telecentric optical system lens, diameter 50 mmφ, focal length f50 mm, aperture 2.0 mmφ

-Receiver 18 (Receiver 18A, 18B)-
-Light receiving element 16: Hamamatsu Photonics Co., Ltd. "S12158-01CT", sensitivity 0.7 A / W
-Number of light-receiving elements 16: 40-Placement pitch of light-receiving elements 16: 0.25 mm intervals

-Other measurement conditions-
・ Irradiation spot diameter of surface emitting laser: 50 μmφ
-Measurement points: Measure 40 points by shifting the measurement points by 25 μm in one direction (that is, measure 40 points at intervals of 25 μm and measurement length of 1 mm).
・ 40 light sources (VCSEL) x 10 times = 400 are rearranged in a row and graphed.

With the above inspection device 10 and conditions, the average value of the peak position and peak intensity of the scattering angle measured at 40 points is calculated, and the standard deviation σ is calculated using the average value.
Specifically, the standard deviation σ of the peak position and peak intensity of the scattering angle is the sum of the squares of the difference between the average value (n number = 250) of the peak position and peak intensity of the scattering angle and each value. Is (1/2) squared.

As an example of the method in which the standard deviation σ of the peak position of the coated surface is within the above range, 1) coating of a thermosetting powder coating material having powder particles containing thermosetting resin, thermosetting agent, and crosslinked resin particles. Method of forming a film 2) Powder particles containing a thermosetting resin and a thermosetting agent, and an external additive having an external addition amount of 0.3 parts by mass or more and 4 parts by mass or less with respect to 100 parts by mass of the powder particles. Examples thereof include a method of forming a coating film of a thermosetting powder coating having, 3) a method of controlling baking conditions of the powder coating.

The reason why these methods are suitable as the method in which the standard deviation σ of the peak position of the painted surface is within the above range is not clear, but it is presumed as follows.

In the method 1), the crosslinked resin particles are blended with the powder particles of the powder coating, so that the central portion of the powder particles is larger than the surface layer of the powder particles during heating and melting during baking of the powder coating. Since the viscosity is high, the flow due to heat is slowed down. Therefore, the boundary portion of the powder particles is melted, and the melt hardening proceeds in a raised shape. As a result, it is considered that fine and nearly uniform unevenness is formed on the surface of the coating film (that is, the coated surface).

On the contrary, in the method 2), by blending a large amount of external additives, the surface layer of the powder particles has a higher viscosity than the central portion of the powder particles, so that the flow due to heat becomes slow. Therefore, the central portion of the powder particles is melted, and the melt hardening proceeds in a raised shape. As a result, it is considered that fine and nearly uniform unevenness is formed on the surface of the coating film (that is, the coated surface).

In the method of 3), the melt hardening of the powder particles described in 1) or 2) can be realized by adjusting the baking temperature and the baking time.

These methods are also suitable for setting the average value of the peak positions of the painted surface and the standard deviation σ and the average value of the peak intensity of the painted surface within the above ranges.

In the painted product according to the present embodiment, from the viewpoint of improving the moist feeling of the painted surface, the marker erasability, the repeated durability of writing and erasing with the marker, and the projector projection property, the glossiness meter is used under the condition of an incident angle of 60 °. The glossiness on the painted surface measured by the above is preferably 70 ° or less, more preferably 1 ° or more and 50 ° or less, and more preferably 4 ° or more and 25 ° or less.

The method for measuring the glossiness is a value measured at an incident angle of 60 ° according to the method for measuring the mirror surface glossiness (JIS Z 87411 1997).

In the painted product according to the present embodiment, the center line average roughness Ra of the painted surface is determined from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection. , 0.05 μm or more and 1.0 μm or less, more preferably 0.10 μm or more and 0.50 μm or less.
From the same viewpoint, the wave center line waviness Wca of the painted surface is preferably 0.05 μm or more and 1.50 μm or less, and more preferably 0.1 μm or more and 0.4 μm or less.

The center line average roughness Ra of the painted surface and the wave center line waviness Wca are values measured by a surface roughness measuring machine (SURFCOM 1400A, Tokyo Seimitsu) according to JIS B 0601-1982. The measurement conditions are as follows.
・ Measurement length 10 mm
-Cutoff wavelength 0.25 mm to 0.8 mm
・ Measurement speed 0.3mm / s
・ Inclination correction by calculating the least squares straight line

In the coated product according to the present embodiment, the pencil hardness of the coating film is H or higher from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection. Preferably, 3H or more is more preferable.

Pencil hardness is measured according to JIS K 5600-5-4: 1999 "General paint test method-Part 5: Mechanical properties of coating film-Section 4: Scratch hardness (pencil method)".

<Powder paint>
Next, a powder coating material (hereinafter, “according to the present embodiment) suitable for obtaining a coated product (specifically, a coating film thereof) according to the present embodiment will be described.

The powder coating material according to this embodiment has a powder coating material. The powder coating material may have an external additive, if necessary.
The powder coating material according to the present embodiment is either a transparent powder coating material containing no coloring agent in the powder particles (so-called clear coating material) or a colored powder coating material containing a coloring agent in the powder particles. You may. However, since a painted product having a painted surface with an excellent moist feeling is suitable for a projection screen, a writing board, a decorative sheet, an interior interior wall material, etc., the powder paint does not contain a colorant in the powder particles. A clear powder coating material or a white powder coating material containing a white colorant in powder particles is preferable.

(Powder particles)
The powder particles include a thermosetting resin and a thermosetting agent. The powder particles may contain a curing catalyst, a colorant, crosslinked resin particles, and other additives, if necessary.
In particular, the powder particles are crosslinked resin particles from the viewpoint of forming a coating film having a coated surface having a moist feeling, marker erasability, repeated writing and erasing durability by a marker, and a coated surface having excellent projector projection property. Is preferably included.

-Thermosetting resin-
The thermosetting resin is a resin having a thermosetting reactive group. Examples of the thermosetting resin include various types of resins conventionally used as powder particles of powder coating materials.
The thermosetting resin is preferably a water-insoluble (hydrophobic) resin. When a water-insoluble (in other words, hydrophobic) resin is applied as the thermosetting resin, the environmental dependence of the charging characteristics of the powder coating material is reduced. Further, when the powder particles are produced by the aggregation and coalescence method, the thermosetting resin is preferably a water-insoluble (hydrophobic) resin from the viewpoint of realizing emulsification and dispersion in an aqueous medium. The water-insoluble (in other words, hydrophobic) means that the amount of the target substance dissolved in 100 parts by mass of water at 25 ° C. is less than 5 parts by mass.

Examples of the thermosetting resin include at least one selected from the group consisting of a thermosetting (meth) acrylic resin and a thermosetting polyester resin.

-Thermosetting polyester resin The thermosetting polyester resin is a polyester resin having a curing reactive group. Examples of the thermosetting reactive group contained in the thermosetting polyester resin include an epoxy group, a carboxyl group, a hydroxyl group, an amide group, an amino group, an acid anhydride group, a blocked isocyanate group, and the like, but from the viewpoint of easy synthesis. , Carboxyl groups, and hydroxyl groups are preferred.

The thermosetting polyester resin is, for example, a polycondensate obtained by at least polycondensing a polybasic acid and a polyhydric alcohol.
The thermosetting reactive group of the thermosetting polyester resin is introduced by adjusting the amount of the polybasic acid and the polyhydric alcohol used in synthesizing the polyester resin. By this adjustment, a thermosetting polyester resin having at least one of a carboxyl group and a hydroxyl group can be obtained as a thermosetting reactive group.
Further, after synthesizing the polyester resin, a thermosetting reactive group may be introduced to obtain a thermosetting polyester resin.

Examples of polybasic acids include terephthalic acid, isophthalic acid, phthalic acid, methylterephthalic acid, trimellitic acid, pyromellitic acid, and anhydrides of these acids; succinic acid, adipic acid, azelaic acid, sebatic acid, and these acids. Anhydrous; maleic acid, itaconic acid, anhydrides of these acids; fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid hexahydrophthalic acid, methylhexahydrophthalic acid, anhydrides of these acids; cyclohexanedicarboxylic acid, 2,6 -Naphthalenedicarboxylic acid and the like can be mentioned.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and neopentyl. Glycol, triethylene glycol, bis (hydroxyethyl) terephthalate, cyclohexanedimethanol, octanediol, diethylpropanediol, butylethylpropanediol, 2-methyl-1,3-propanediol, 2,2,4-trimethylpentanediol, Hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide adduct of hydrogenated bisphenol A, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, trishydroxyethylisocyanurate, hydroxypivalylhydroxypivalate And so on.

The thermosetting polyester resin may be polycondensed with a monomer other than the polybasic acid and the polyhydric alcohol.
Examples of other monomers include a compound having both a carboxyl group and a fatty acid in one molecule (for example, dimethanol propionic acid, hydroxypivalate, etc.) and a monoepoxy compound (for example, "Cadura E10 (manufactured by Shell)". (Glycidyl ester of branched aliphatic carboxylic acid, etc.), various monovalent alcohols (eg, methanol, propanol, butanol, benzyl alcohol, etc.), various monovalent basic acids (eg, benzoic acid, p-tert-butylbenzoic acid, etc.) Acids, etc.), various fatty acids (for example, castor oil fatty acid, coconut oil fatty acid, soybean oil fatty acid, etc.) and the like.

The structure of the thermosetting polyester resin may be a branched structure or a linear structure.

The thermosetting polyester resin preferably has a total acid value and hydroxyl value of 10 mgKOH / g or more and 250 mgKOH / g or less, and a number average molecular weight of 1000 or more and 100,000 or less.
When the total of the acid value and the hydroxyl value is within the above range, the smoothness and mechanical properties of the coating film are likely to be improved. When the number average molecular weight is within the above range, the smoothness and mechanical properties of the coating film are improved, and the storage stability of the powder coating material is also likely to be improved.

The measurement of the acid value and the hydroxyl value of the thermosetting polyester resin conforms to JIS K-0070-1992. Further, the measurement of the number average molecular weight of the thermosetting polyester resin is the same as the measurement of the number average molecular weight of the thermosetting (meth) acrylic resin described later.

-Thermosetting (meth) acrylic resin The thermosetting (meth) acrylic resin is a (meth) acrylic resin having a thermosetting reactive group. For the introduction of the thermosetting reactive group into the thermosetting (meth) acrylic resin, it is preferable to use a vinyl monomer having a thermosetting reactive group. The vinyl monomer having a thermosetting reactive group may be a (meth) acrylic monomer (a monomer having a (meth) acryloyl group) or a vinyl simple substance other than the (meth) acrylic monomer. It may be a metric.

Here, examples of the thermosetting reactive group of the thermosetting (meth) acrylic resin include an epoxy group, a carboxyl group, a hydroxyl group, an amide group, an amino group, an acid anhydride group, and a (block) isocyanate group. .. Among these, the thermosetting reactive group of the (meth) acrylic resin is at least one selected from the group consisting of an epoxy group, a carboxyl group, and a hydroxyl group from the viewpoint of easy production of the (meth) acrylic resin. Is preferable. In particular, at least one of the thermosetting reactive groups is more preferably an epoxy group from the viewpoint of excellent storage stability of the powder coating material and the appearance of the coating film.

Examples of the vinyl monomer having an epoxy group as a curable reactive group include various chain epoxy group-containing monomers (for example, glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, glycidyl vinyl ether, and allyl). (Glysidyl ether, etc.), various (2-oxo-1,3-oxolane) group-containing vinyl monomers (for example, (2-oxo-1,3-oxolane) methyl (meth) acrylate, etc.), various alicyclic types Examples thereof include an epoxy group-containing vinyl monomer (for example, 3,4-epoxide cyclohexyl (meth) acrylate, 3,4-epoxide cyclohexylmethyl (meth) acrylate, 3,4-epoxide cyclohexylethyl (meth) acrylate, etc.).

Examples of vinyl monomers having a carboxyl group as a curable reactive group include various carboxyl group-containing monomers (for example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, etc.). Monoesters of α, β-unsaturated dicarboxylic acid and monovalent alcohol having 1 or more and 18 or less carbon atoms (for example, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monoisobutyl fumarate, monotert-butyl fumarate) , Monohexyl fumarate, monooctyl fumarate, mono2-ethylhexyl fumarate, monomethyl maleate, monoethyl maleate, monobutyl maleate, monoisobutyl maleate, monotert-butyl maleate, monohexyl maleate, monooctyl maleate, Mono2-ethylhexyl maleate, etc.), monoalkyl ester of itaconic acid (eg monomethyl itaconate, monoethyl itacone, monobutyl itacone, monoisobutyl itacone, monohexyl itaconic acid, monooctyl itaconic acid, mono2-ethylhexyl itacone, etc.) And so on.

Examples of the vinyl monomer having a hydroxyl group as a curable reactive group include various hydroxyl group-containing (meth) acrylates (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-hydroxy. Propyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, etc.) , Addition reaction products of the above various hydroxyl group-containing (meth) acrylates and ε-caprolactone, various hydroxyl group-containing vinyl ethers (for example, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl Vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, etc.), addition reaction products of the above various hydroxyl group-containing vinyl ethers and ε-caprolactone, various Hydroxy hydroxyl-containing allyl ethers (eg, 2-hydroxyethyl (meth) allyl ether, 3-hydroxypropyl (meth) allyl ether, 2-hydroxypropyl (meth) allyl ether, 4-hydroxybutyl (meth) allyl ether, 3- Hydroxybutyl (meth) allyl ether, 2-hydroxy-2-methylpropyl (meth) allyl ether, 5-hydroxypentyl (meth) allyl ether, 6-hydroxyhexyl (meth) allyl ether, etc.), various hydroxyl group-containing alleles described above Examples thereof include addition reaction products of ether and ε-caprolactone.

In addition to the (meth) acrylic monomer, the thermosetting (meth) acrylic resin may be copolymerized with another vinyl monomer having no thermosetting reactive group.
Other vinyl monomers include various α-olefins (eg ethylene, propylene, butene-1, etc.), various halogenated olefins other than fluoroolefins (eg vinyl chloride, vinylidene chloride, etc.), and various aromatic vinyls. Diesters of monomers (eg, styrene, α-methylstyrene, vinyltoluene, etc.), various unsaturated dicarboxylic acids and monovalent alcohols with 1 to 18 carbon atoms (eg, dimethyl fumarate, diethyl fumarate, dibutyl fumarate) , Dioctyl fumarate, dimethyl maleate, diethyl maleate, dibutyl maleate, dioctyl maleate, dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid, dioctyl itaconic acid, etc.), various acid anhydride group-containing monomers ( For example, maleic anhydride, itaconic anhydride, citraconic anhydride, (meth) acrylic acid, tetrahydrophthalic anhydride, etc.), various steal phosphate group-containing monomers (eg, diethyl-2- (meth) acryloyloxyethyl phosphate) , Dibutyl-2- (meth) acryloyloxybutyl phosphate, dioctyl-2- (meacryloyloxyethyl phosphate, diphenyl-2- (meth) acryloyloxyethyl phosphate, etc.), various hydrolyzable silyl group-containing singles Metrics (eg, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, etc.), various aliphatic vinyl carboxylates ( For example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, branched aliphatic carboxylate vinyl having 9 or more and 11 or less carbon atoms, vinyl stearate. Etc.), various vinyl esters of carboxylic acids having a cyclic structure (for example, vinyl cyclohexanecarboxylate, vinyl methylcyclohexanecarboxylate, vinyl benzoate, vinyl p-tert-butyl benzoate, etc.) and the like.

In the thermosetting (meth) acrylic resin, when a vinyl monomer other than the (meth) acrylic monomer is used as the vinyl monomer having a thermosetting reactive group, the thermosetting (meth) acrylic resin has a curable reactive group. Do not use acrylic monomer.
Examples of the acrylic monomer having no curable reactive group include (meth) acrylic acid alkyl ester (for example, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, and (meth). ) Isopropyl acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic 2-ethylhexyl acid, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethyloctyl (meth) acrylate, dodecyl (meth) acrylate, isodecyl (meth) acrylate, (meth) acrylic acid Lauryl, stearyl (meth) acrylate, etc.), various (meth) acrylic acid aryl esters (eg, benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, etc.), various alkylcarbi Thor (meth) acrylate (eg ethylcarbitol (meth) acrylate, etc.), various other (meth) acrylic acid esters (eg, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth)) Acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, etc.), various amino group-containing amide-based unsaturated monomers (for example, N-dimethylaminoethyl (meth) acrylamide, N- Diethylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide, N-diethylaminopropyl (meth) acrylamide, etc.), various dialkylaminoalkyl (meth) acrylates (eg, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (eg, dimethylaminoethyl (meth) acrylate) (Meta) acrylate, etc.), various amino group-containing monomers (for example, tert-butylaminoethyl (meth) acrylate, tert-butylaminopropyl (meth) acrylate, aziridinyl ethyl (meth) acrylate, pyrrolidinyl ethyl (eg Meta) acrylate, piperidinyl ethyl (meth) acrylate, etc.).

The thermosetting (meth) acrylic resin is preferably an acrylic resin having a number average molecular weight of 1,000 or more and 20,000 or less (preferably 1,500 or more and 15,000 or less).
When the number average molecular weight is within the above range, the smoothness and mechanical properties of the coating film are likely to be improved.

The weight average molecular weight and the number average molecular weight of the thermosetting (meth) acrylic resin are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out by using GPC / HLC-8120GPC manufactured by Tosoh Corporation as a measuring device and column / TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation in a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The thermosetting resin may be used alone or in combination of two or more.

The content of the thermosetting resin is preferably 20% by mass or more and 99% by mass or less, and preferably 30% by mass or more and 95% by mass or less with respect to the entire powder particles.
As will be described later, when the powder particles are core-shell type particles and a thermosetting resin is applied as the resin of the resin coating portion, the content of the thermosetting resin is the core portion. And the content of the total thermosetting resin in the resin coating part.

-Preferable curable resin Here, as the thermosetting resin, carbon is used from the viewpoints of moist feeling, marker erasability, repeated writing and erasing durability with markers, and improvement of projector projectability of the obtained coated surface. It is preferable to contain an acrylic resin (also referred to as "specific acrylic resin") having a side chain having an alkyl group and a hydroxy group of several 4 or more.

The specific acrylic resin may be at least a resin obtained by polymerizing a (meth) acrylic compound, and has 5 masses of a structural unit derived from the (meth) acrylic compound (also referred to as "a structural unit formed of the (meth) acrylic compound"). A resin having% or more and 100% by mass or less is preferable, and a resin having 10% by mass or more and 100% by mass or less of a constituent unit derived from a (meth) acrylic compound is more preferable, and a constituent unit derived from a (meth) acrylic compound. It is more preferable that the resin has 20% by mass or more and 100% by mass or less, and it is particularly preferable that the resin has 30% by mass or more and 100% by mass or less of the structural unit derived from the (meth) acrylic compound.
Here, examples of the (meth) acrylic compound include an acrylate compound, a methacrylate compound, an acrylic acid, a methacrylic acid, an acrylamide compound, a methacrylicamide compound, an acrylonitrile compound, and a methacrylonitrile compound.

Among these, the specific acrylic resin preferably has at least a structural unit derived from at least one compound selected from the group consisting of an acrylate compound, a methacrylate compound, an acrylic acid, and methacrylic acid, and the acrylate compound and It is more preferable to have a structural unit derived from at least one compound selected from the group consisting of methacrylate compounds.

The specific acrylic resin may have the acrylic group and the hydroxy group having 4 or more carbon atoms in one side chain or in another side chain, respectively.
However, from the viewpoints of moist feeling, marker erasability, repeated writing and erasing durability with markers, and improvement of projector projectability of the obtained painted surface, the specific acrylic resin is an acrylic group having 4 or more carbon atoms and hydroxy. It is preferable to have a group in another side chain, and it is more preferable to have a structural unit having an alkyl group having 4 or more carbon atoms in the side chain and a structural unit having a hydroxy group in the side chain.
Further, it is preferable that the structural unit having an alkyl group having 4 or more carbon atoms in the side chain and the structural unit having a hydroxy group in the side chain are each a structural unit derived from a (meth) acrylate compound.

The structural unit having an alkyl group having 4 or more carbon atoms in the side chain is preferably a structural unit represented by the following formula (A).

Wherein ^{(A), R A1} represents an alkyl group having 4 or more carbon ^{atoms, R A2} represents a hydrogen atom or a methyl group.

R ^A1 in formula (A), the painted surface obtained, the coated surface, moist feel, marker erasability, repetition durability writing and erasure by the marker, and from the viewpoint of improvement of the projector projection property, 6 or more carbon atoms It is preferably an alkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 7 to 16 carbon atoms, and an alkyl group having 8 to 12 carbon atoms. Is particularly preferable.
The alkyl group for R ^A1 may be a straight-chain alkyl group, even branched alkyl group, or is also an alkyl group having a cyclic structure, a linear alkyl group, or, branched alkyl group Is preferable.
The Specific examples ^{R A1,} n- butyl group, n- pentyl group, n- hexyl, n- heptyl, n- octyl, 2-ethylhexyl, n- nonyl, n- decyl group, Examples thereof include an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group (cetyl group) and an n-octadecyl group (stearyl group).
Among them, n-octyl group, 2-ethylhexyl group, n from the viewpoint of the moist feeling of the obtained painted surface, the marker erasability, the repeated durability of writing and erasing with the marker, and the improvement of projector projection. It is preferably a nonyl group, an n-decyl group, or an n-dodecyl group, and more preferably a 2-ethylhexyl group, an n-decyl group, or an n-dodecyl group.

The specific acrylic resin may have one type of structural unit having an alkyl group having 4 or more carbon atoms in the side chain alone, or may have two or more types.
The content of the structural unit having an alkyl group having 4 or more carbon atoms in the side chain of the specific acrylic resin is the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection property of the obtained coated surface. From the viewpoint of improvement, it is preferably 2% by mass or more and 50% by mass or less, preferably 5% by mass or more and 40% by mass or less, and 10% by mass or more and 30% by mass or less, based on the total mass of the specific acrylic resin. The following is particularly preferable.

The specific acrylic resin may have a hydroxyalkyl group as the hydroxy group from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projectability of the obtained coated surface. It is more preferable to have a hydroxyalkyl group having 3 or more carbon atoms, further preferably to have a hydroxyalkyl group having 3 or more and 12 or less carbon atoms, and particularly preferably to have a hydroxyalkyl group having 4 or more and 8 or less carbon atoms. ..

Here, the hydroxy group may be any of a primary to tertiary hydroxy group.
However, the hydroxy group is a secondary or tertiary hydroxy group from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection of the obtained painted surface. It is preferable, and it is more preferable that it is a secondary hydroxy group.

Examples of the ethylenically unsaturated compound having a hydroxy group used for producing a specific acrylic resin include various hydroxy group-containing (meth) acrylate compounds (for example, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). ) Acrylic, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene. Glycol mono (meth) acrylate, etc.), addition reaction products of the various hydroxy group-containing (meth) acrylates and ε-caprolactone, various hydroxy group-containing vinyl ether compounds (eg, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl) Vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, etc.), various hydroxy Addition reaction products of group-containing vinyl ether and ε-caprolactone, various hydroxy group-containing allyl ether compounds (eg, 2-hydroxyethyl (meth) allyl ether, 3-hydroxypropyl (meth) allyl ether, 2-hydroxypropyl ( Meta) allyl ether, 4-hydroxybutyl (meth) allyl ether, 3-hydroxybutyl (meth) allyl ether, 2-hydroxy-2-methylpropyl (meth) allyl ether, 5-hydroxypentyl (meth) allyl ether, and , 6-Hydroxyhexyl (meth) allyl ether, etc.), and addition reaction products of the various hydroxy group-containing allyl ethers and ε-caprolactone.
Of these, a hydroxy group-containing (meth) acrylate compound is preferable.

The structural unit having a hydroxy group in the side chain is preferably a structural unit having a hydroxyalkyl group in the side chain, and more preferably a structural unit having a hydroxyalkyl group having 3 or more carbon atoms in the side chain. It is particularly preferable that the structural unit is represented by the formula (H).

Wherein ^{(H), R H1} represents an alkylene group ^{and R H2,} represent a hydrogen atom or a methyl group.

The alkylene group in ^RH1 of the formula (H) may be linear, has a branch, or has a ring structure, but is a branched alkylene group or an alkylene group having a ring structure. It is preferably present, and more preferably it is a branched alkylene group.

The carbon number of ^RH1 in the formula (H) shall be 2 or more from the viewpoint of moist feeling, marker erasability, repeated writing and erasing durability by markers, and improvement of projector projection property of the obtained painted surface. Is more preferable, 3 or more is more preferable, 3 or more and 12 or less is further preferable, and 4 or more and 8 or less is particularly preferable.

The ^-RH1- OH in the formula (H) is 2-hydroxyethyl from the viewpoint of moisturizing the obtained coated surface, marker erasability, repeated writing and erasing durability with markers, and improvement of projector projectability. Group, 2-hydroxypropyl group, 3-hydroxypropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group, 2-hydroxypentyl group, 5-hydroxypentyl group, 2-hydroxyhexyl group, It is preferably a 6-hydroxyhexyl group, a 2-hydroxyheptyl group, a 7-hydroxyheptyl group, a 2-hydroxyoctyl group, or an 8-hydroxyoctyl group, preferably a 2-hydroxypropyl group, a 2-hydroxybutyl group, or 3 -Hydroxybutyl group, 2-hydroxypentyl group, 2-hydroxyhexyl group, 2-hydroxyheptyl group, 2-hydroxyheptyl group, or 2-hydroxyoctyl group is more preferable, and 2-hydroxybutyl group is preferable. Is particularly preferred.

The specific acrylic resin may have one type of structural unit having a hydroxy group in the side chain alone, or may have two or more types.
The content of the structural unit having a hydroxy group in the side chain in the specific acrylic resin is determined from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projectability of the obtained coated surface. , 2% by mass or more and 50% by mass or less, preferably 5% by mass or more and 40% by mass or less, and 10% by mass or more and 30% by mass or less with respect to the total mass of the specific acrylic resin. Especially preferable.

The specific acrylic resin preferably further has a structural unit having an acid group from the viewpoint of moist feeling and dispersibility of the obtained coated surface, particularly dispersibility in an aqueous medium.
Examples of the acid group include a carboxy group, a sulfo group, a phosphonic acid group, a phosphoric acid group, a sulfate group and the like. Of these, a carboxy group is preferable.

The specific acrylic resin preferably further has a structural unit represented by the following formula (AC) from the viewpoint of moist feeling and dispersibility of the obtained coated surface, particularly dispersibility in an aqueous medium.

In formula (AC), ^RAC represents a hydrogen atom or a methyl group.

The specific acrylic resin may have one type of structural unit having an acid group alone, or may have two or more types.
The content of the constituent unit having an acid group in the specific acrylic resin is 0.01 with respect to the total mass of the specific acrylic resin from the viewpoint of moist feeling and dispersibility of the obtained coating film surface, particularly dispersibility in an aqueous medium. It is preferably mass% or more and 10 mass% or less, preferably 0.1 mass% or more and 5 mass% or less, and particularly preferably 0.5 mass% or more and 2 mass% or less.

The specific acrylic resin may be a copolymer obtained by copolymerizing a vinyl compound other than the (meth) acrylic compound.
Examples of the vinyl compound include aromatic vinyl compounds, vinyl ether compounds, vinyl ester compounds, allyl compounds, olefin compounds and the like, but aromatic vinyl compounds are preferable, styrene compounds are more preferable, and styrene is particularly preferable.
That is, the specific acrylic resin is particularly preferably a styrene-acrylic copolymer.

The specific acrylic resin preferably has a structural unit represented by the following formula (S).

The content of the structural unit represented by the above formula (S) in the specific acrylic resin improves the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projectability of the obtained painted surface. From the viewpoint, it is preferably 10% by mass or more and 95% by mass or less, more preferably 20% by mass or more and 90% by mass or less, and 30% by mass or more and 80% by mass or less with respect to the total mass of the specific acrylic resin. It is more preferably 50% by mass or more and 75% by mass or less.

The weight average molecular weight of the specific acrylic resin is 10,000 to 100,000 from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection of the obtained painted surface. It is preferably 20,000 to 80,000, more preferably 30,000 to 70,000.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the resin are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out by using GPC / HLC-8120GPC manufactured by Tosoh Corporation as a measuring device and column / TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation in a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The powder coating material according to the present embodiment may contain one type of the specific acrylic resin alone, or may contain two or more types of the specific acrylic resin.
The powder coating material according to the present embodiment may have powder particles containing only one type of specific acrylic resin, or may have powder particles containing two or more types of specific acrylic resin. Further, powder particles of different types of the specific acrylic resin contained may be used in combination.

The content of the specific acrylic resin is based on the total mass of the powder coating material from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection of the obtained painted surface. , 20% by mass or more and 99% by mass or less is preferable, and 30% by mass or more and 95% by mass or less is more preferable.
In addition, the content of the specific acrylic resin is the total mass of the powder particles from the viewpoint of improving the moist feeling, marker erasability, repeated writing and erasing durability by the marker, and projector projection of the obtained coated surface. On the other hand, 20% by mass or more and 99% by mass or less is preferable, and 30% by mass or more and 95% by mass or less is more preferable.

-Thermosetting agent-
The thermosetting agent is selected according to the type of thermosetting reactive group of the thermosetting resin.
Here, the thermosetting agent means a compound having a functional group capable of reacting with a thermosetting reactive group which is a terminal group of a thermosetting resin.

When the thermosetting reactive group of the thermosetting resin is a carboxyl group, examples of the thermosetting agent include various epoxy resins (for example, polyglycidyl ether of bisphenol A) and epoxy group-containing acrylic resins (for example, glycidyl group-containing acrylic). Resins, etc.), polyglycidyl ethers of various polyvalent alcohols (eg, 1,6-hexanediol, trimethylolpropane, trimethylolethane, etc.), various polyvalent carboxylic acids (eg, phthalic acid, terephthalic acid, isophthalic acid, hexa). Polyglycidyl esters of hydrophthalic acid, methylhexahydrophthalic acid, trimellitic acid, pyromellitic acid, etc., various alicyclic epoxy group-containing compounds (eg, bis (3,4-epoxycyclohexyl) methyladipate, etc.), hydroxy Examples thereof include amides (for example, triglycidyl isocyanurate, β-hydroxyalkylamide, etc.).

When the thermosetting reactive group of the thermosetting resin is a hydroxyl group, examples of the thermosetting agent include polyblock isocyanate and aminoplast. Examples of the polyblock polyisocyanate include various aliphatic diisocyanates (for example, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, etc.), various cyclic aliphatic diisocyanates (for example, xylylene diisocyanate, isophorone diisocyanate, etc.), and various aromatic diisocyanates (for example, xylylene diisocyanate, isophorone diisocyanate, etc.). Organic diisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, etc.; adjuncts of these organic diisocyanates to polyhydric alcohols, low molecular weight polyester resins (eg polyester polyols), water, etc .; Polymers (polymers also containing isocyanurate-type polyisocyanate compounds); various polyisocyanate compounds such as isocyanate biuret compounds blocked with a known and commonly used blocking agent; self-blocking having a uretdione bond as a structural unit Examples thereof include polyisocyanate compounds.

When the thermosetting reactive group of the thermosetting resin is an epoxy group, the thermosetting agents include, for example, succinic acid, glutaric acid, adipic acid, pimeric acid, suberic acid, azelaic acid, sebatic acid, dodecanedioic acid, and aikosan. Diacid, maleic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, trimellitic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexene-1,2-dicarboxylic acid, trimellitic acid, pyromerit Acids such as acids; anhydrides of these acids; urethane modified products of these acids and the like can be mentioned. Among these, as the thermosetting agent, an aliphatic dibasic acid is preferable from the viewpoint of physical properties of the coating film and storage stability, and dodecane diic acid is particularly preferable from the viewpoint of the physical properties of the coating film.

The thermosetting agent may be used alone or in combination of two or more.

The content of the thermosetting agent is preferably 1% by mass or more and 30% by mass or less, and preferably 3% by mass or more and 20% by mass or less, based on the thermosetting resin.
As will be described later, when the powder particles are core-shell type particles and a thermosetting resin is applied as the resin of the resin coating portion, the content of the above thermosetting agent is the core portion and the content of the thermosetting agent. It means the content of the resin coating part with respect to the total thermosetting resin.

-Curing catalyst-
The curing catalyst is preferably contained in the powder particles from the viewpoint of the curing temperature and the suppression of color change during the formation of the coating film. When the powder particles are core-shell type particles, it is more preferable that the curing catalyst contains a curing catalyst in the core portion.

The curing catalyst is not particularly limited, but is preferably at least one compound selected from the group consisting of metal acetylacetonates and quaternary ammonium salts. When the at least one compound is contained, the decomposition temperature of the thermosetting agent having a uretdione structure is particularly lowered.

Specific examples of metal acetylacetonates include aluminum acetylacetonate, chromium acetylacetonate, iron (III) acetylacetonate, zinc (II) acetylacetonate, zirconium (IV) acetylacetonate, and nickel (II). ) Acetylacetonate can be mentioned.
As the quaternary ammonium salt, a tetraalkylammonium salt is preferable, and a compound selected from the group consisting of a tetraethylammonium salt and a tetrabutylammonium salt is more preferable, and tetraethylammonium carboxylate, tetraethylammonium chloride, tetraethylammonium bromide, etc. Compounds selected from the group consisting of tetraethylammonium fluoride, tetrabutylammonium carboxylate, tetrabutylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium fluoride are more preferred.
Among these, as the curing catalyst, a compound selected from the group consisting of tetraethylammonium carboxylate and tetrabutylammonium carboxylate is particularly preferable.

The curing catalyst may be used alone or in combination of two or more.

The content of the curing catalyst (particularly, the total content of metal acetylacetonates and the quaternary ammonium salt) is preferably 0.05% by mass or more and 10% by mass or less with respect to the total mass of the powder particles. More preferably, it is 1% by mass or more and 5% by mass or less. Within the above range, the change in color at the time of forming the coating film becomes smaller.

-Colorant-
Examples of the colorant include pigments. As the colorant, a dye may be used in combination with the pigment.
Pigments include, for example, inorganic pigments such as iron oxide (for example, red iron oxide), titanium oxide, titanium yellow, zinc white, lead white, zinc sulfide, lithopone, antimony oxide, cobalt blue, carbon black; quinacridone red, phthalocyanine blue, etc. Examples thereof include organic pigments such as phthalocyanine green, permanent red, Hansa yellow, indanthrone blue, brilliant first scarlet, and benzimidazolone yellow.
Other pigments include bright pigments. Examples of the brilliant pigment include metal powders such as pearl pigments, aluminum powders, and stainless steel powders; metal flakes; glass beads; glass flakes; mica; phosphorescent iron oxide (MIO) and the like.

The colorant may be used alone or in combination of two or more.

The content of the colorant is selected according to the type of pigment and the color, brightness, depth and the like required for the coating film.
For example, the content of the colorant is preferably 1% by mass or more and 70% by mass or less, and more preferably 2% by mass or more and 60% by mass or less, based on the total resin constituting the powder particles.

Here, in the case of colored powder particles other than white, the powder particles may contain a coloring pigment other than the white pigment together with the white pigment as the coloring agent. When the powder particles contain a white pigment together with the coloring pigment, the color of the surface of the object to be coated is concealed by the coating film, and the color developing property of the coloring pigment is improved. Examples of the white pigment include well-known white pigments such as titanium oxide, barium sulfate, zinc oxide, and calcium carbonate, but titanium oxide is preferable in terms of high whiteness (that is, high hiding power).

When the powder coating material is a clear coating material, the content of titanium oxide is preferably less than 25% by mass, more preferably less than 20% by mass, based on the total mass of the powder particles. It is more preferably less than mass%, particularly preferably less than 5% by mass, and most preferably less than 1% by mass. The lower limit is not particularly limited and may be 0% by mass.
When the powder coating material is used as a coloring coating material, the content of titanium oxide is preferably 25% by mass or more and 50% by mass or less, and more preferably 30% by mass or more and 50% by mass or less.

-Crosslinked resin particles-
The crosslinked resin particles are contained in the powder particles from the viewpoint of forming a coating film having a coating surface having a moist feeling, marker erasability, repeated writing and erasing durability by a marker, and a projector projection property. It is preferable to do so.

Examples of the crosslinked resin particles include crosslinked resin particles crosslinked by an ionic bond (ionic crosslinked resin particles), crosslinked resin particles crosslinked by a covalent bond (covalently bonded crosslinked resin particles), and the like. Among these, the crosslinked resin particles are preferably crosslinked resin particles crosslinked by covalent bonds.

Types of resins used for the crosslinked resin particles include polyolefin resins (polyethylene, polypropylene, etc.), styrene resins (polystyrene, α-polymethylstyrene, etc.), (meth) acrylic resins (polymethylmethacrylate, polyacrylonitrile, etc.). ), Epoxy resin, polyurethane resin, polyurea resin, polyamide resin, polyamide resin, polycarbonate resin, polyether resin, polyester resin and copolymer resins thereof. These resins may be used alone or in combination of two or more, if necessary.

As the resin used for the crosslinked resin particles, at least one selected from the styrene resin, the (meth) acrylic resin, the styrene- (meth) acrylic copolymer resin, and the polyester resin is preferable among the above resins. , Styrene-based resin, (meth) acrylic-based resin, and styrene- (meth) acrylic-based copolymer resin are more preferable.
That is, as the crosslinked resin particles, at least one selected from styrene resin particles, (meth) acrylic resin particles, styrene- (meth) acrylic copolymer resin particles, and polyester resin particles is preferable, and styrene resin. At least one selected from particles, (meth) acrylic resin particles, and styrene- (meth) acrylic copolymer resin particles is more preferable.

Examples of the polyester resin include a resin obtained by polycondensing a polyvalent carboxylic acid and a polyhydric alcohol.
Examples of polyvalent carboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid. , Aliphite carboxylic acids such as alkenyl succinic acid anhydride and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid; One or more of these polyvalent carboxylic acids are used.
Among these polyvalent carboxylic acids, it is preferable to use terephthalic acid, fumaric acid, and alkenyl succinic anhydride.

Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated. Alicyclic diols such as bisphenol A; aromatic diols such as ethylene oxide adduct of bisphenol A and propylene oxide adduct of bisphenol A can be mentioned. One or more of these polyhydric alcohols may be used.
Among these polyhydric alcohols, it is preferable to use an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, propylene glycol, butanediol.

Examples of the styrene resin, the (meth) acrylic resin, and the styrene- (meth) acrylic copolymer resin include resins obtained by polymerizing the following polymerizable monomers by radical polymerization.

Examples of the styrene-based monomer include styrene, α-methylstyrene, vinylnaphthalene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, and 4-ethylstyrene. Alkyl-substituted styrene having an alkyl chain such as 2-chlorostyrene, 3-chlorostyrene, halogen-substituted styrene such as 4-chlorostyrene, fluorine-substituted styrene such as 4-fluorostyrene and 2,5-difluorostyrene and the like can be mentioned. .. Among them, styrene and α-methylstyrene are preferable.

Examples of the (meth) acrylic acid-based monomer include (meth) acrylic acid, (meth) acrylic acid n-methyl, (meth) acrylic acid n-ethyl, (meth) acrylic acid n-propyl, and (meth) acrylic acid. n-butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, ( N-dodecyl (meth) acrylate, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate , (Meta) isobutyl acrylate, (meth) t-butyl acrylate, (meth) isopentyl acrylate, (meth) amyl acrylate, neopentyl (meth) acrylate, isohexyl (meth) acrylate, (meth) acrylate Isoheptyl, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, biphenyl (meth) acrylate, diphenylethyl (meth) acrylate, t-butylphenyl (meth) acrylate, Tarphenyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, methoxyethyl (meth) acrylate, Examples thereof include 2-hydroxyethyl (meth) acrylic acid, -βcarboxyethyl (meth) acrylic acid, (meth) acrylonitrile, and (meth) acrylamide. Among them, n-butyl (meth) acrylate and -β-carboxyethyl (meth) acrylate are preferable.

Examples of the cross-linking agent for cross-linking the resin in the cross-linked resin particles include aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene; divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, and trimesin. Polyvinyl esters of aromatic polyvalent carboxylic acids such as divinyl acid acid, trivinyl trimesicate, divinyl naphthalenedicarboxylate, and divinyl biphenylcarboxylic acid; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridinedicarboxylic acid; vinyl pyromute, Vinyl esters of unsaturated heterocyclic compounds such as vinyl furancarboxylate, vinyl pyrrol-2-carboxylate, vinyl thiophene carboxylate; vinyl esters of butanediol methacrylate, hexanediol acrylate, octanediol methacrylate, decanediol acrylate, dodecanediol methacrylate (Meta) acrylic acid esters of linear polyvalent alcohols such as; branches of neopentylglycoldimethacrylate, 2-hydroxy, 1,3-diacryloxypropane, etc., (meth) acrylic acid esters of substituted polyhydric alcohols, etc. Kind: Polyethylene glycol di (meth) acrylate, polypropylene Polyethylene glycol di (meth) acrylate, divinyl succinate, divinyl fumarate, vinyl maleate, divinyl maleate, divinyl diglycolate, vinyl itacone, divinyl itaconate, acetone Divinyl dicarboxylic acid, divinyl glutarate, divinyl 3,3'-thiodipropionate, trans-divinyl aconite, trivinyl aconite, divinyl adipate, divinyl pimerate, divinyl sverate, divinyl azelate, divinyl sebacate , Divinyldodecanedioate, polyvinyl esters of polyvalent carboxylic acids such as divinyl brushate, and the like. The cross-linking agent may be used alone or in combination of two or more.

The crosslinked resin particles preferably contain a gel component from the viewpoint of improving the moist feeling of the painted surface, the marker erasability, the repeated durability of writing and erasing with the marker, and the projector projection property.
From the same viewpoint, the content of the gel component of the crosslinked resin particles is preferably 2% by mass or more, more preferably 2% by mass or more and 50% by mass or less, and further preferably 5% by mass or more and 20% by mass or more.

As a method for measuring the content of the gel component, the crosslinked resin particles to be measured are placed in an Erlenmeyer flask, tetrahydrofuran (THF) heated to 45 ° C. is added, sealed, and allowed to stand for 24 hours. At this time, it is preferable to use a constant temperature bath capable of maintaining 45 ° C. Then, all the contents of the Erlenmeyer flask are transferred to a glass tube for centrifugation, and centrifugation is performed for 30 minutes at a rotation speed of 20,000 rpm (revolutions per minute) and −10 ° C. After centrifugation, all the contents are taken out and allowed to stand in a constant temperature bath at 45 ° C., and then the supernatant liquid which is a THF-dissolved portion and the THF-insoluble component which is a precipitate at 45 ° C. are separated. The obtained THF-insoluble component is washed with THF and dried to quantify it, and the content of the gel component is calculated.

The volume average particle size of the crosslinked resin particles shall be 5 nm or more and 1,000 nm or less from the viewpoint of improving the moist feeling of the coated surface, marker erasability, repeated writing and erasing durability with markers, and projector projection. It is more preferably 10 nm or more and 300 nm or less, further preferably 10 nm or more and 200 nm or less, and particularly preferably 15 nm or more and 100 nm or less.

The volume average particle diameter of the crosslinked resin particles is measured by the following method.
First, the cross section of the powder particles to be measured is observed with a scanning electron microscope (SEM). Then, the circle-equivalent diameter of each of the 100 crosslinked resin particles to be measured is obtained by image analysis, and the volume-based particle diameter is defined as the volume-based cumulative 50% circle-equivalent diameter from the small diameter side in the volume-based distribution. ..
For image analysis to obtain the equivalent circle diameter of 100 crosslinked resin particles to be measured, a two-dimensional image with a magnification of 10,000 times is taken using an analysis device (ERA-8900: manufactured by Elionix Inc.), and image analysis software is used. Using WinROOF (manufactured by Mitani Shoji Co., Ltd.), the projected area is calculated under the condition of 0.010000 μm / pixel, and the equivalent circle diameter is calculated by the formula: circle equivalent diameter = 2 × (projected area / π) ^1/2 .

The crosslinked resin particles in the powder particles are identified by observation with an atomic force microscope (AFM: Atomic Force Microscope).

The crosslinked resin particles may be used alone or in combination of two or more.

The content of the crosslinked resin particles is 0.1 mass with respect to the powder particles from the viewpoint of improving the moist feeling of the coated surface, the marker erasability, the repeated writing and erasing durability by the marker, and the projector projection property. % Or more and 50% by mass or less is preferable, and 2% by mass or more and 25% by mass or less is more preferable.

-Metal ions of valence or higher-
The powder particles may contain divalent or higher valent metal ions (hereinafter, also simply referred to as “metal ions”). As will be described later, this metal ion is a component contained in both the core portion and the resin coating portion of the powder particles when the powder particles are core-shell type particles.
When the powder particles contain metal ions having a valence of 2 or more, the powder particles form an ion bridge with the metal ions. For example, the functional group of the thermosetting resin (for example, when the thermosetting polyester resin is used as the thermosetting resin, the carboxyl group or the hydroxyl group of the thermosetting polyester resin) and the metal ion interact with each other to crosslink the ions. To form. Due to this ion cross-linking, inclusions of powder particles (thermosetting agent, colorant added as needed in addition to the thermosetting agent, other additives, etc.) are deposited on the surface of the powder particles (so-called). , Bleed) is suppressed, and the storability is likely to be improved. Further, in this ion cross-linking, the bond of the ion cross-linking is broken by heating during thermosetting after coating the powder coating material, so that the melt viscosity of the powder particles is lowered and a highly smooth coating film is formed. It will be easier to do.

Examples of the metal ion include a metal ion having a divalent value or more and a tetravalence or less. Specifically, examples of the metal ion include at least one metal ion selected from the group consisting of aluminum ion, magnesium ion, iron ion, zinc ion, and calcium ion.

Examples of the source of metal ions (compounds contained in powder particles as additives) include metal salts, inorganic metal salt polymers, metal complexes and the like. This metal salt and the inorganic metal salt polymer are added to the powder particles as a coagulant, for example, when the powder particles are produced by the coagulation coalescence method.
Examples of the metal salt include aluminum sulfate, aluminum chloride, magnesium chloride, magnesium sulfate, iron (II) chloride, zinc chloride, calcium chloride, calcium sulfate and the like.
Examples of the inorganic metal salt polymer include polyaluminum chloride, polyaluminum hydroxide, polyiron (II) sulfate, calcium polysulfide and the like.
Examples of the metal complex include a metal salt of an aminocarboxylic acid. Specific examples of the metal complex include known chelate-based metal salts such as ethylenediaminetetraacetic acid, propanediaminetetraacetic acid, nitrile triacetic acid, triethylenetetramine-6 acetic acid, and diethylenetriamine5 acetic acid (eg, calcium salt, Magnesium salt, iron salt, aluminum salt, etc.) and the like.

The source of these metal ions may be added as a mere additive, not as a flocculant.

The higher the valence of the metal ion, the easier it is to form a mesh-like ion crosslink, which is preferable in terms of the smoothness of the coating film and the storability of the powder coating material. Therefore, Al ion is preferable as the metal ion. That is, as a source of metal ions, aluminum salts (for example, aluminum sulfate, aluminum chloride, etc.) and aluminum salt polymers (for example, polyaluminum chloride, polyaluminum hydroxide, etc.) are preferable. Further, in terms of the smoothness of the coating film and the storability of the powder coating material, even if the valence of the metal ions is the same among the sources of the metal ions, the inorganic metal salt polymer is compared with the metal salt. preferable. Therefore, as a source of metal ions, an aluminum salt polymer (for example, polyaluminum chloride, polyaluminum hydroxide, etc.) is particularly preferable.

The content of metal ions is preferably 0.002% by mass or more and 0.2% by mass or less, preferably 0.005% by mass, based on the entire powder particles, in terms of the smoothness of the coating film and the storage property of the powder coating material. % Or more and 0.15% by mass or less is more preferable.
When the content of the metal ions is 0.002% by mass or more, appropriate ion cross-linking by the metal ions is formed, bleeding of the powder particles is suppressed, and the storability of the coating paint is easily improved. On the other hand, when the content of the metal ions is 0.2% by mass or less, the formation of excessive ion crosslinks due to the metal ions is suppressed, and the smoothness of the coating film is likely to be improved.

Here, when the powder particles are produced by the aggregation and coalescence method, the source of metal ions (metal salt, metal salt polymer) added as an aggregating agent contributes to the control of the particle size distribution and shape of the powder particles. To do.

Specifically, the higher the valence of the metal ion, the more suitable it is to obtain a narrower particle size distribution. Further, in terms of obtaining a narrow particle size distribution, a metal salt polymer is preferable to a metal salt even if the valences of the metal ions are the same. Therefore, from these points as well, aluminum salts (for example, aluminum sulfate, aluminum chloride, etc.) and aluminum salt polymers (for example, polyaluminum chloride, polyaluminum hydroxide, etc.) are preferable as the source of metal ions, and the aluminum salt weight is preferable. Coalescence (eg polyaluminum chloride, polyaluminum hydroxide, etc.) is particularly preferred.

Further, when the aggregating agent is added so that the content of the metal ions is 0.002% by mass or more, the agglomeration of the resin particles in the aqueous medium proceeds, which contributes to the realization of a narrow particle size distribution. Further, the agglomeration of the resin particles to be the resin coating portion proceeds with respect to the agglomerated particles to be the core portion, which contributes to the realization of the formation of the resin coating portion on the entire surface of the core portion. On the other hand, when a flocculant is added so that the content of metal ions is 0.2% by mass or less, excessive formation of ion crosslinks in the agglomerated particles is suppressed, and the powder produced when fusion and coalescence are performed. The shape of the particles tends to approach a spherical shape. Therefore, from these points as well, the content of the metal ion is preferably 0.002% by mass or more and 0.2% by mass or less, and more preferably 0.005% by mass or more and 0.15% by mass or less.

The content of metal ions is measured by quantitatively analyzing the fluorescent X-ray intensity of the powder particles. Specifically, for example, first, a resin and a source of metal ions are mixed to obtain a resin mixture having a known concentration of metal ions. A pellet sample of 200 mg of this resin mixture is obtained using a tablet molding machine having a diameter of 13 mm. The mass of this pellet sample is precisely weighed, and the fluorescence X-ray intensity of the pellet sample is measured to obtain the peak intensity. Similarly, the pellet sample in which the amount of the metal ion source added is changed is also measured, and a calibration curve is prepared from these results. Then, using this calibration curve, the content of metal ions in the powder particles to be measured is quantitatively analyzed.

As a method for adjusting the content of the metal ion, for example, 1) a method for adjusting the addition amount of the metal ion source, and 2) when the powder particles are produced by the aggregation and coalescence method, the metal ion content is adjusted in the aggregation step. After adding a flocculant (eg, a metal salt or metal salt polymer) as a source, a chelating agent (eg, EDTA (ethylenediaminetetraacetic acid), DTPA (diethylenetriaminepentaacetic acid), NTA (nitrillotriacetic acid)) is added at the end of the flocculation step. Etc.) is added to form a complex with the metal ion with a chelating agent, and the complex salt formed in the subsequent washing step or the like is removed to adjust the content of the metal ion.

-Other additives-
Other additives include various additives used in powder coatings.
Specifically, as other additives, for example, a foaming (armpit) inhibitor (for example, benzoin, a benzoin derivative, etc.), a curing accelerator (amine compound, an imidazole compound, a cationic polymerization catalyst, etc.), a surface conditioner (for example, a surface conditioner). Leveling agents), plasticizers, charge control agents, antioxidants, pigment dispersants, flame retardants, fluidizers and the like.

(Core-shell type particles)
The powder particles according to the present embodiment may be core-shell type particles having a core portion containing a thermosetting resin and a thermosetting agent, and a resin coating portion that covers the surface of the core portion. ..
At this time, in addition to the thermosetting resin and the thermosetting agent, the core portion may contain the above-mentioned colloidal silica, colorant, and other additives, if necessary.

Further, the resin coating portion of the core-shell type particles will be described below.
The resin coating portion may be composed of only the resin, or may contain other components (thermosetting agent, other additives, etc. described as the components constituting the core portion).
However, from the viewpoint of reducing bleeding, the resin coating portion is preferably made of only resin. Even when the resin coating portion contains components other than the resin, the resin may occupy 90% by mass or more (preferably 95% by mass or more) of the entire resin coating portion.

The resin constituting the resin coating portion may be a non-curable resin or a thermosetting resin, but is a thermosetting resin from the viewpoint of improving the curing density (crosslinking density) of the coating film. That is good.
When a thermosetting resin is applied as the resin of the resin coating portion, examples of the thermosetting resin are the same as those of the thermosetting resin of the core portion, and preferred examples thereof are also the same. However, the thermosetting resin of the resin coating portion may be the same type of resin as the thermosetting resin of the core portion, or may be a different resin.
When a non-curable resin is applied as the resin of the resin coating portion, at least one selected from the group consisting of an acrylic resin and a polyester resin is preferably used as the non-curable resin.

The coverage of the resin coating portion is preferably 30% or more and 100% or less, and more preferably 50% or more and 100% or less from the viewpoint of suppressing bleeding.

The coverage of the resin coating is a value obtained by XPS (X-ray photoelectron spectroscopy) measurement for the coverage of the resin coating on the surface of the powder particles.
Specifically, XPS measurement is carried out by using JPS-9000MX manufactured by JEOL Ltd. as a measuring device, using MgKα ray as an X-ray source, setting an acceleration voltage of 10 kV and an emission current of 30 mA. ..
From the spectrum obtained under the above conditions, the coverage of the resin coating on the surface of the powder particles is achieved by peak-separating the component caused by the material of the core on the surface of the powder particles and the component caused by the material of the coating resin. Quantify. Peak separation separates the measured spectrum into components using curve fitting by the least squares method.
As the component spectrum that is the basis of the separation, the spectrum obtained by independently measuring the thermosetting resin, the curing agent, the pigment, the additive, and the coating resin used for producing the powder particles is used. Then, the coating ratio is obtained from the ratio of the spectral intensities caused by the coating resin to the total of the total spectral intensities obtained from the powder particles.

The thickness of the resin coating portion is preferably 0.2 μm or more and 4 μm or less, and more preferably 0.3 μm or more and 3 μm or less from the viewpoint of suppressing bleeding.
The thickness of the resin coating portion is a value measured by the following method. Thin sections are prepared by embedding powder particles in epoxy resin or the like and cutting them with a diamond knife or the like. This thin section is observed with a transmission electron microscope (TEM) or the like, and cross-sectional images of a plurality of powder particles are taken. The thickness of the resin coating portion is measured at 20 points from the cross-sectional image of the powder particles, and the average value is adopted. When it is difficult to observe the resin coating portion in the cross-sectional image with a clear powder coating material or the like, the measurement can be facilitated by observing the resin coating portion by dyeing.

(Preferable properties of powder particles)
The volume average particle size D50v, volume particle size distribution index GSDv, and average circularity of the powder particles improve the moist feeling of the coated surface, marker erasability, repeated writing and erasing durability by markers, and projector projection. From the viewpoint, the following range is preferable. In particular, it is preferable that the volume average particle size D50v of the powder particles is 3 μm or more and 10 μm or less, the volume particle size distribution index GSDv is 1.30 or less, and the average circularity is 0.96 or more.

-Volume average particle size D50v-
The volume average particle size D50v of the powder particles is preferably 1 μm or more and 25 μm or less, more preferably 2 μm or more and 20 μm or less, further preferably 3 μm or more and 15 μm or less, and even more preferably 3 μm or more and 10 μm or less.

-Volume particle size distribution index GSDv-
The volume particle size distribution index GSDv of the powder particles is preferably 1.50 or less, more preferably 1.40 or less, further preferably 1.30 or less, and particularly preferably 1.25 or less.

-Average circularity-
The average circularity of the powder particles is preferably 0.96 or more, more preferably 0.97 or more, further preferably 0.98 or more, and particularly preferably 0.99 or more.

Here, Coulter Multisizer II (manufactured by Beckman Coulter) is used for the volume average particle size D50v of the powder particles and the volume particle size distribution index GSDv, and ISOTON-II (manufactured by Beckman Coulter) is used as the electrolytic solution. Is measured.
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using an aperture with an aperture diameter of 100 μm by Coulter Multisizer II. Measure. The number of particles to be sampled is 50,000.
The cumulative distribution of the volume is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative particle size of 16% is the volume particle size D16v and the cumulative 50%. The particle size is defined as the volume average particle size D50v, and the particle size with a cumulative total of 84% is defined as the volume particle size D84v.
Then, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 .

The average circularity of the powder particles is measured by using a flow type particle image analyzer "FPIA-3000 (manufactured by Sysmex Corporation)". Specifically, 0.1 ml or more and 0.5 ml or less of a surfactant (alkylbenzene sulfonate) as a dispersant is added to 100 ml or more and 150 ml or less of water from which the impure solid matter has been removed in advance, and the measurement sample is further added to 0. Add 1 g or more and 0.5 g or less. The suspension in which the measurement sample is dispersed is subjected to a dispersion treatment for 1 minute or more and 3 minutes or less with an ultrasonic disperser to bring the dispersion liquid concentration to 3,000 pieces / μl or more and 10,000 pieces / μl or less. The average circularity of the powder particles is measured for this dispersion using a flow-type particle image analyzer.

Here, the average circularity of the powder particles is a value calculated by obtaining the circularity (Ci) of each of the n particles measured for the powder particles and then calculating by the following formula. However, in the following formula, Ci indicates circularity (= circumference of a circle equal to the projected area of particles / circumference of a projected particle image), and fi indicates the frequency of powder particles.

(External additive)
The external additive is a particle that is externally added to the surface of the powder particle.
The external addition method is not particularly limited, and an external addition method known in the field of powder coating can be used.

Inorganic particles can be mentioned as external additives.
Examples of the inorganic particles include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. particles comprising _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 may preferably be mentioned.
Inorganic particles may be used alone or in combination of two or more.

The volume average particle size of the external additive is preferably 10 nm or more and 100 nm or less, more preferably 15 nm or more and 90 nm or less, and further preferably 20 nm or more and 80 nm or less.
When the volume average particle size of the external additive is within the above range, the adhesiveness to the powder particles is excellent, and the smoothness of the coating film obtained by the powder coating material is further improved.

The volume average particle diameter of the external additive is measured by the following method.
First, the powder coating material to be measured is observed with a scanning electron microscope (SEM). Then, the circle-equivalent diameter of each of the 100 external additives to be measured is obtained by image analysis, and the volume-based particle diameter is defined as the volume-based cumulative 50% circle-equivalent diameter from the small diameter side in the volume-based distribution. ..
For image analysis to obtain the equivalent circle diameter of 100 external additives to be measured, a two-dimensional image with a magnification of 10,000 times is taken using an analysis device (ERA-8900: manufactured by Elionix Inc.), and image analysis software. Using WinROOF (manufactured by Mitani Shoji Co., Ltd.), the projected area is calculated under the condition of 0.010000 μm / pixel, and the equivalent circle diameter is calculated by the formula: circle equivalent diameter = 2 × (projected area / π) ^1/2 .
In order to measure the volume average particle diameter of a plurality of types of external additives from powder coating materials, it is necessary to distinguish each external additive. Specifically, for each type of external additive, element mapping is performed by SEM-EDX (scanning electron microscope equipped with an energy dispersive X-ray analyzer), and the element derived from each type of external additive is applicable. Distinguish by associating with an external additive.

The surface of the external additive may be hydrophobized.
The hydrophobizing agent is not particularly limited, and examples thereof include a silane coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.

The content of the external additive is preferably 0.1 part by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the powder particles, from the viewpoint of improving the smoothness of the coating film obtained by the powder coating material. More preferably, it is 3 parts by mass or more and 1.5 parts by mass or less.

In particular, from the viewpoint of forming a coating film having a coated surface having a moist feeling, marker erasability, repeated writing and erasing durability with a marker, and a coated surface having excellent projector projection property, an external additive is excessively used. Is preferably included. Specifically, the content of the external additive is preferably 0.3 parts by mass or more and 4 parts by mass or less, and more preferably 0.5 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the powder particles. More preferably, it is 0.7 parts by mass or more and 2.5 parts by mass or less.
When the content of the external additive is 0.3 parts by mass or more, the powder coating material (specifically, powder particles) is dispersed in the primary particles during coating and is coated, and the coating film tends to be close to uniform. Become. As a result, it becomes easy to form a coating film having a coated surface having an excellent moist feeling, marker erasability, repeated writing and erasing durability by a marker, and projector projection.
On the other hand, when the content of the external additive is 4 parts by mass or less, the insufficient strength of the coating film due to the external additive is suppressed.

(Characteristics of powder paint)
(Manufacturing method of powder paint)
Next, a method for producing the powder coating material according to the present embodiment will be described.
The powder coating material according to the present embodiment can be obtained by externally adding an external additive to the powder particles after producing the powder particles.

The powder particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an agglomeration and coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The manufacturing method of the powder particles is not particularly limited to these manufacturing methods, and a well-known manufacturing method is adopted.

For example, in the dry manufacturing method, 1) a kneading crushing method in which a thermosetting resin and other raw materials are kneaded, crushed, and classified, and particles obtained by the kneading crushing method are changed in shape by mechanical impact force or thermal energy. There is a dry manufacturing method to make it.
On the other hand, in the wet production method, for example, 1) a dispersion obtained by emulsion polymerization of a polymerizable monomer for obtaining a thermosetting resin and a dispersion solution of another raw material are mixed, aggregated and heat-fused. , Aggregation coalescence method to obtain powder particles, 2) Suspension polymerization method in which a polymerizable monomer for obtaining a thermosetting resin and a solution of another raw material are suspended in an aqueous solvent for polymerization, 3. ) There is a dissolution suspension method in which a thermosetting resin and a solution of another raw material are suspended in an aqueous solvent for granulation. The wet method can be preferably used because it has a smaller thermal effect.
Further, the powder particles obtained by the above-mentioned production method may be used as a core, and resin particles may be further adhered and heat-fused to obtain powder particles which are core-shell type particles.

Among these, powder particles are preferably obtained by the aggregation and coalescence method from the viewpoint that the volume particle size distribution index GSDv, the volume average particle size D50v, and the average circularity can be easily controlled within the above preferable ranges.

Hereinafter, the aggregation and coalescence method for producing powder particles, which are core-shell type particles, will be described as an example.
In particular,
In the dispersion liquid in which the first resin particles containing the thermosetting resin and the thermosetting agent are dispersed, the first resin particles and the thermosetting agent are aggregated, or the thermosetting resin and the thermosetting agent are heat-cured. A step of aggregating the composite particles to form first agglomerated particles (first agglomerated particle forming step) in a dispersion liquid in which composite particles containing an agent are dispersed.
The first agglomerated particle dispersion liquid in which the first agglomerated particles are dispersed and the second resin particle dispersion liquid in which the second resin particles containing a resin are dispersed are mixed, and the second agglomerated particles are surfaced on the surface of the first agglomerated particles. A step of aggregating the resin particles and forming the second agglomerated particles in which the second resin particles adhere to the surface of the first agglomerated particles (second agglomerated particle forming step).
A step of heating the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed to fuse and coalesce the second agglomerated particles (fusion unification step).
It is preferable to produce powder particles through the above.
In the powder particles produced by this agglomeration and coalescence method, the portion where the first agglomerated particles are fused and coalesced becomes the core portion, and the portion where the second resin particles adhering to the surface of the first aggregated particles are fused and coalesced. Is the resin coating part.
Therefore, if the first agglomerated particles formed in the first agglomerated particle forming step are subjected to the fusion union step without going through the second agglomerated particle forming step, and fused and united instead of the second agglomerated particles, Powder particles having a single layer structure can be obtained.

The details of each step will be described below.
In the following description, a method for producing powder particles containing a colorant will be described, but the colorant is contained as needed.

-Each dispersion preparation process-
First, each dispersion used in the aggregation and coalescence method is prepared.
Specifically, a first resin particle dispersion liquid in which first resin particles containing a thermosetting resin in the core are dispersed, a thermosetting agent dispersion liquid in which a thermosetting agent is dispersed, and a colorant in which a colorant is dispersed. A dispersion liquid and a second resin particle dispersion liquid in which the second resin particles containing the resin of the resin coating portion are dispersed are prepared.
Further, instead of the first resin particle dispersion liquid and the thermosetting agent dispersion liquid, a heat curable resin for the core portion and a composite particle dispersion liquid in which composite particles containing the thermosetting agent are dispersed are prepared.
In each step of the powder coating manufacturing method, the first resin particles, the second resin particles, and the composite particles are generally referred to as "resin particles", and the dispersion liquid of these resin particles is referred to as "resin particle dispersion liquid". It will be described as.

Here, the resin particle dispersion liquid is prepared, for example, by dispersing the resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion-exchanged water; alcohols and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; Examples thereof include nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, and polyhydric alcohol-based. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by, for example, a phase inversion emulsification method.
In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the resin, and then an aqueous medium is used. By adding (W phase), the resin is converted from W / O to O / W (so-called phase inversion) to make the phase discontinuous, and the resin is dispersed in an aqueous medium in the form of particles. is there.

Specifically, there are the following methods as a method for preparing the resin particle dispersion liquid.
For example, when the resin particle dispersion is a polyester resin particle dispersion in which polyester resin particles are dispersed, the polyester resin particle dispersion is obtained by heating and melting the raw material monomer and polycondensing it under reduced pressure. The condensate is dissolved by adding a solvent (for example, ethyl acetate), and further, stirring and phase inversion emulsification are performed while adding a weakly alkaline aqueous solution to the obtained solution.

When the resin particle dispersion liquid is a composite particle dispersion liquid, the thermosetting resin and the thermosetting agent are mixed and dispersed in a dispersion medium (for example, emulsification such as phase inversion emulsification) to disperse the composite particles. Get the liquid

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 1 μm or less, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and 0.1 μm or more. 0.6 μm is more preferable.
The volume average particle size of the resin particles is determined by using the particle size distribution obtained by the measurement of a laser diffraction type particle size distribution measuring device (for example, manufactured by Horiba Seisakusho, LA-700) with respect to the divided particle size range (channel). , The cumulative distribution is subtracted from the small particle size side for the volume, and the particle size that is cumulatively 50% of all particles is measured as the volume average particle size D50v. The volume average particle diameter of the particles in the other dispersion is also measured in the same manner.

Here, a known emulsification method can be used to prepare the resin particle dispersion, but the obtained particle size distribution is narrow and the volume average particle size is 1 μm or less (particularly 0.08 μm or more and 0.40 μm or less). ) Is effective in the phase inversion emulsification method.

In the phase inversion emulsification method, the resin is dissolved in an organic solvent that dissolves the resin, or an amphipathic organic solvent alone or in a mixed solvent to obtain an oil phase. A small amount of the basic compound is added dropwise while stirring the oil phase, and water is gradually added dropwise while further stirring, and water droplets are incorporated into the oil phase. Next, when the amount of water dropped exceeds a certain amount, the oil phase and the water phase are reversed and the oil phase becomes oil droplets. After that, the aqueous dispersion is obtained through the solvent removal step of reducing the pressure.

The amphipathic organic solvent means a solvent having a solubility in water at 20 ° C. of at least 5 g / L or more, preferably 10 g / L or more. If the solubility is less than 5 g / L, the effect of accelerating the aqueous treatment rate is poor, and the obtained aqueous dispersion is also inferior in storage stability. Examples of the amphoteric organic solvent include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol and tert-amyl. Alcohols, alcohols such as 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, tetrahydrofuran, dioxane Ethers such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, -3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate, etc. Esters such as dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Glycol derivatives such as monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate, dipropylene glycol monobutyl ether, and further. , 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. These solvents can be used alone or in admixture of two or more.

The thermosetting polyester resin as the thermosetting resin is neutralized with a basic compound when dispersed in an aqueous medium. The neutralization reaction of the thermosetting polyester resin with the carboxyl group is the starting force for water-forming, and the electric repulsive force between the generated carboxyl anions makes it easier to suppress the aggregation between the particles.
Examples of the basic compound include ammonia and an organic amine compound having a boiling point of 250 ° C. or lower. Examples of preferred organic amine compounds are triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine. , Diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, Examples thereof include triethanolamine, morpholin, N-methylmorpholin, N-ethylmorpholin and the like.
The basic compound is added in an amount capable of at least partially neutralizing, that is, 0.2 times equivalent or more and 9.0 times equivalent or less with respect to the carboxyl group, depending on the carboxyl group contained in the thermosetting polyester resin. It is preferable, and it is more preferable to add 0.6 times equivalent or more and 2.0 times equivalent or less. When the equivalent is 0.2 times or more, the effect of adding the basic compound is easily recognized. If the equivalent is 9.0 times or less, it is considered that the excessive increase in hydrophilicity of the oil phase is suppressed, but the particle size distribution is difficult to be widened and a good dispersion can be easily obtained.

The content of the resin particles contained in the resin particle dispersion is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

Similar to the resin particle dispersion, for example, a thermosetting agent dispersion and a colorant dispersion are also prepared. That is, regarding the volume average particle size, dispersion medium, dispersion method, and particle content of the resin particles in the resin particle dispersion liquid, the particles are dispersed in the colorant particles dispersed in the colorant dispersion liquid and the curing agent dispersion liquid. The same applies to the particles of the curing agent.

-First aggregate particle formation step-
Next, the first resin particle dispersion liquid, the thermosetting agent dispersion liquid, and the colorant dispersion liquid are mixed.
Then, in the mixed dispersion, the first resin particles, the thermosetting agent, and the colorant are heteroaggregated, and the first resin particles, the thermosetting agent, and the colorant have a diameter close to the diameter of the target powder particles. The first aggregated particles containing and are formed.
By further adding colloidal silica to the above-mentioned mixed dispersion, the first aggregated particles can contain colloidal silica.

Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, the pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. Particles dispersed in a mixed dispersion liquid heated to a temperature of the glass transition temperature of the first resin particles (specifically, for example, the glass transition temperature of the first resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower). To agglomerate to form first agglomerated particles.

In the first aggregate particle forming step, the composite particle dispersion containing the thermosetting resin and the thermosetting agent and the colorant dispersion are mixed, and the composite particles and the colorant are mixed in the mixed dispersion. May be heteroaggregated to form first aggregated particles.

In the first agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear type homogenizer, the above-mentioned flocculant is added at room temperature (for example, 25 ° C.), and the pH of the mixed dispersion is acidic (for example, pH is 2 or more). 5 or less), and if necessary, a dispersion stabilizer may be added, and then the above heating may be performed.

Examples of the flocculant include surfactants having the opposite polarity to the surfactant used as the dispersant added to the mixed dispersion, metal salts, metal salt polymers, and metal complexes. When a metal complex is used as the flocculant, the amount of the surfactant used is reduced and the charging characteristics are improved.
After the completion of aggregation, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used as necessary. As this additive, a chelating agent is preferably used. By adding this chelating agent, when the flocculant is added excessively, the metal ion content of the powder particles can be adjusted.

Here, the metal salt, the metal salt polymer, and the metal complex as the flocculant are used as a source of metal ions. These examples are as described above.

Examples of the chelating agent include a water-soluble chelating agent. Specific examples of the chelating agent include oxycarboxylic acids such as tartrate acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 part by mass or more and 5.0 parts by mass or less, and preferably 0.1 part by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-Second aggregate particle formation step-
Next, the first agglomerated particle dispersion liquid in which the obtained first agglomerated particles are dispersed and the second resin particle dispersion liquid are mixed.
The second resin particles may be of the same type as the first resin particles or may be of different types.

Then, in the mixed dispersion in which the first agglomerated particles and the second resin particles are dispersed, the second resin particles are agglomerated so as to adhere to the surface of the first agglomerated particles, and the first agglomerated particles are attached to the surface of the first agglomerated particles. 2 Form second agglomerated particles to which resin particles are attached.

Specifically, for example, in the first agglomerated particle forming step, when the first agglomerated particles reach the target particle size, the second resin particle dispersion liquid is mixed with the first agglomerated particle dispersion liquid, and this The mixed dispersion is heated below the glass transition temperature of the second resin particles.
Then, by setting the pH of the mixed dispersion in the range of, for example, 6.5 or more and 8.5 or less, the progress of aggregation is stopped.

As a result, the second agglomerated particles that are agglomerated so that the second resin particles adhere to the surface of the first agglomerated particles can be obtained.

-Fusion unification process-
Next, with respect to the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed, for example, 10 than the glass transition temperature of the first and second resin particles (for example, 10 from the glass transition temperature of the first and second resin particles). By heating to a temperature higher than 30 ° C.), the second aggregated particles are fused and united to form powder particles.

Through the above steps, powder particles are obtained.

Here, after the fusion and coalescence step is completed, the powder particles formed in the dispersion liquid are subjected to a known washing step, solid-liquid separation step, and drying step to obtain powder particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, airflow-type drying, fluid-flow drying, vibration-type fluid-drying, and the like may be performed.

Then, the powder coating material according to the present embodiment is produced by adding inorganic particles to the obtained dry powder particles as needed and mixing them.
The above mixing may be performed by, for example, a V blender, a Henschel mixer, a Reedige mixer or the like.
Further, if necessary, coarse particles of powder particles may be removed by using a vibration sieving machine, a wind sieving machine or the like.

(Electrostatic powder coating method)
The electrostatic powder coating method according to the present embodiment is the powder coating material according to the present embodiment, which is a step of discharging the charged powder coating material to electrostatically adhere the powder coating material to the object to be coated (hereinafter referred to as). It has a step of forming a coating film by heating a powder coating material electrostatically adhered to an object to be coated (hereinafter referred to as a “baking step”).

The powder coating material may be either a transparent powder coating material (clear coating material) in which the powder particles do not contain a coloring agent, or a colored powder coating material in which the powder particles contain a coloring agent.

-Adhesion process-
The adhesion step is the powder coating material according to the present embodiment, in which the charged powder coating material is discharged to electrostatically adhere the powder coating material to the object to be coated.
Specifically, in the adhesion step, for example, electrostatic powder is formed in a state where an electrostatic field is formed between the discharge port of the electrostatic powder coating machine and the coated surface (the surface having conductivity) of the object to be coated. A charged powder coating material is discharged from the discharge port of the coating machine, and the powder coating material is electrostatically adhered to the surface to be coated to form a film of the powder coating material. That is, for example, a voltage is applied by using the surface to be coated of the grounded object to be coated as an anode and an electrostatic powder coating machine as a cathode to form an electrostatic field (electrostatic field) on both poles to cause the charged powder coating material to fly. Then, it electrostatically adheres to the coated surface of the object to be coated to form a film of powder coating material.
The bonding step may be performed while relatively moving the discharge port of the electrostatic powder coating machine and the painted surface of the object to be coated.

Here, examples of the electrostatic powder coating machine include corona gun (coating machine that discharges powder coating charged by corona discharge), tribogan (coating machine that discharges powder coating by triboelectric charging), and bergan (corona discharge). Alternatively, a well-known electrostatic powder coating machine such as a coating machine that centrifugally discharges and discharges powder coating material charged by triboelectric charging can be used. The discharge condition for good coating may be in the setting range of each gun.

The amount of powder coating adhered to the coated surface of the object to be coated is 40 g / m ² or more and 200 g / m ² or less (preferably 50 g / m ² or more and 100 g / m /) from the viewpoint of suppressing fluctuations in the smoothness of the coating film. m ² or less) is good.

-Baking process-
In the baking step, the powder coating material electrostatically adhered to the object to be coated is heated to form a coating film. Specifically, the coating film is formed by melting and curing the powder particles of the powder coating film by heating.
The heating temperature (baking temperature) is selected according to the type of powder coating material. As an example, the heating temperature (baking temperature) is, for example, preferably 90 ° C. or higher and 250 ° C. or lower, more preferably 100 ° C. or higher and 220 ° C. or lower, and further preferably 120 ° C. or higher and 200 ° C. or lower. The heating time (baking time) is adjusted according to the heating temperature (baking temperature).

Through the above steps, the coating film is formed, that is, the object to be coated is coated. The powder coating material may be attached and heated (baked) all at once.

Here, the object to be coated, which is the object to be coated with the powder coating material, is not particularly limited, and examples thereof include various metal parts, ceramic parts, resin parts, and the like. These target articles may be unmolded articles before molding into each article such as plate-shaped articles and linear articles, or molded articles for electronic parts, road vehicles, building interior / exterior materials, and the like. It may be a product. Further, the target article may be an article in which the surface to be coated is previously subjected to surface treatment such as primer treatment, plating treatment, electrodeposition coating and the like.

(Use of painted products)
The painted product according to the present embodiment is a writing board or a projection board from the viewpoint that the painted surface is excellent in moist feeling, marker erasability, repeated writing and erasing durability by markers, and projector projection. It is preferably present, more preferably a writing board, and particularly preferably a projection writing board.
Specifically, the writing board or projection board according to the present embodiment is preferably a writing board or projection board having a coating film of a thermosetting powder coating on the outermost layer. The coating film of the thermosetting powder coating material is preferably a colorless transparent layer (clear layer) or a white layer.
In addition, "colorless and transparent" means that the transmittance of light having a wavelength of 400 nm to 750 nm is 80% or more.

Hereinafter, the present embodiment will be described in detail with reference to Examples, but the present embodiment is not limited to these Examples. In the following description, unless otherwise specified, "parts" and "%" are all based on mass.

[Preparation of various dispersions]
<Preparation of white pigment dispersion (W1)>
-Titanium oxide (A-220 manufactured by Ishihara Sangyo Co., Ltd.): 200 parts by mass-Anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK): 30 parts by mass-Ion-exchanged water: 290 parts by mass-0.3 mol / l Nitrate: A white pigment dispersion (9 parts by mass or more) is mixed, dissolved, and dispersed for 3 hours using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to disperse titanium oxide. W1) was prepared.
When measured using a laser diffraction particle size measuring instrument, the volume average particle size of titanium oxide in the white pigment dispersion was 0.25 μm, and the solid content ratio of the white pigment dispersion was 40%.

<Preparation of acrylic resin dispersion (A1)>
・ Styrene: 373 parts by weight ・ n-Butyl acrylate: 115 parts by weight ・ 2-Hydroxybutyl methacrylate: 104 parts by weight ・ Acrylic acid: 8 parts by weight ・ Dodecane thiol: 3.9 parts by weight Mix and dissolve the above components to prepare a solution. Prepare. On the other hand, 10 parts by weight of an anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) was dissolved in 220 parts by weight of ion-exchanged water, the above solution was added, and the solution was dispersed and emulsified in a flask (monomeric emulsion A). ) Was adjusted.
Further, 1 part by weight of the anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) is dissolved in 476 parts by weight of ion-exchanged water and charged in a polymerization flask.
The polymerization flask is sealed, a reflux tube is installed, and the polymerization flask is heated and held in a water bath to 75 ° C. while slowly stirring while injecting nitrogen. 9 parts by weight of ammonium persulfate was dissolved in 37 parts by weight of ion-exchanged water, and the mixture was added dropwise to the polymerization flask via a metering pump over 20 minutes, and then the monomeric emulsion A was also added via the metering pump for 200 minutes. Sprinkle and drop. Then, the polymerization flask was held at 75 ° C. for 3 hours while slowly stirring to complete the polymerization.
As a result, an acrylic resin dispersion (A1) having a particle center diameter of 230 nm, a glass transition point of 54 ° C., a weight average molecular weight of 51,000, and a solid content of 45% was obtained.

<Preparation of acrylic resin dispersion (A2)>
・ Styrene: 343 parts by weight ・ n-Butyl acrylate: 109 parts by weight ・ 2-Hydroxybutyl methacrylate: 140 parts by weight ・ Acrylic acid: 8 parts by weight ・ Dodecane thiol: 3.8 parts by weight Mix and dissolve the above components to prepare a solution. Prepare. On the other hand, 10 parts by weight of an anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) was dissolved in 220 parts by weight of ion-exchanged water, the above solution was added, and the solution was dispersed and emulsified in a flask (monomeric emulsion A). ) Was adjusted.
Further, 1 part by weight of the anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) is dissolved in 476 parts by weight of ion-exchanged water and charged in a polymerization flask.
The polymerization flask is sealed, a reflux tube is installed, and the polymerization flask is heated and held in a water bath to 75 ° C. while slowly stirring while injecting nitrogen. 9 parts by weight of ammonium persulfate was dissolved in 37 parts by weight of ion-exchanged water, and the mixture was added dropwise to the polymerization flask via a metering pump over 20 minutes, and then the monomeric emulsion A was also added via the metering pump for 200 minutes. Sprinkle and drop. Then, the polymerization flask is held at 75 ° C. for 3 hours while slowly stirring to complete the polymerization.
As a result, an acrylic resin dispersion (A2) having a particle center diameter of 220 nm, a glass transition point of 54 ° C., a weight average molecular weight of 52000, and a solid content of 45% was obtained.

<Preparation of acrylic resin dispersion (A3)>
・ Styrene: 230 parts by weight ・ n-Butyl acrylate: 46 parts by weight ・ 2-Hydroxybutyl methacrylate: 315 parts by weight ・ Acrylic acid: 9 parts by weight ・ Dodecane thiol: 3.7 parts by weight Mix and dissolve the above components to prepare a solution. Prepare. On the other hand, 10 parts by weight of an anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) was dissolved in 220 parts by weight of ion-exchanged water, the above solution was added, and the solution was dispersed and emulsified in a flask (monomeric emulsion A). ) Was adjusted.
Further, 1 part by weight of the anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) is dissolved in 476 parts by weight of ion-exchanged water and charged in a polymerization flask.
The polymerization flask is sealed, a reflux tube is installed, and the polymerization flask is heated and held in a water bath to 75 ° C. while slowly stirring while injecting nitrogen. 9 parts by weight of ammonium persulfate was dissolved in 37 parts by weight of ion-exchanged water, and the mixture was added dropwise to the polymerization flask via a metering pump over 20 minutes, and then the monomeric emulsion A was also added via the metering pump for 200 minutes. Sprinkle and drop. Then, the polymerization flask is held at 75 ° C. for 3 hours while slowly stirring to complete the polymerization.
As a result, an acrylic resin dispersion (A3) having a particle center diameter of 230 nm, a glass transition point of 62 ° C., a weight average molecular weight of 55,000, and a solid content of 45% was obtained.

<Preparation of hardener dispersion (B1)>
-Block isocyanate hardener VESTAGON B1530 (manufactured by EVONIK): 150 parts by mass-Anionic surfactant (sodium dodecylbenzene sulfonate): 1 part by mass-Ion-exchanged water: 350 parts by mass or more, high-pressure impact disperser Ultima A curing agent dispersion (B1) was prepared by dispersing the curing agent for 3 hours using an isocyanate (manufactured by Sugino Machine Co., Ltd., HJP30006).
When measured using a laser diffraction particle size measuring instrument, the volume average particle size of the curing agent in the curing agent dispersion was 0.6 μm, and the solid content ratio of the curing agent dispersion was 25%.

<Preparation of acrylic resin / curing agent composite dispersion (M1)>
A 3-liter reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor blade is maintained at 40 ° C. in a water circulation type constant temperature bath. A mixed solvent of 180 parts by mass of ethyl acetate and 80 parts by mass of isopropyl alcohol was added thereto, and the following composition was added thereto.
Acrylic resin (1) [Polymer of styrene / n-butyl acrylate / 2-hydroxybutyl methacrylate / acrylic acid (molar ratio = 100/18/25/4 (mol%), weight average molecular weight (Mw) = 42, 000, number average molecular weight (Mn) = 15,000]: 208 parts by mass ・ Block isocyanate hardener VESTAGON B1530 (manufactured by EVONIK): 92 parts by mass ・ Acrylic oligomer (Acronal 4F BASF): 3 parts by mass

After charging, the mixture was stirred at 150 rpm using a three-one motor and dissolved to obtain an oil phase. A mixed solution of 1 part by mass of a 10 mass% aqueous ammonia solution and 47 parts by mass of a 5 mass% sodium hydroxide aqueous solution was added dropwise to the stirred oil phase in 5 minutes, mixed for 10 minutes, and then further ion exchanged. 900 parts by mass of water was added dropwise at a rate of 5 parts by mass per minute to invert the phase, and an emulsion was obtained.
Immediately, 800 parts by mass of the obtained emulsion and 700 parts by mass of ion-exchanged water were placed in a 2 liter eggplant flask and placed in an evaporator (manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. I set it. While rotating the eggplant flask, it was heated in a hot water bath at 60 ° C., and the pressure was reduced to 7 kPa while paying attention to sudden boiling to remove the solvent. When the amount of solvent recovered reached 1100 parts by mass, the pressure was returned to normal pressure, and the eggplant flask was water-cooled to obtain a dispersion. The obtained dispersion had no solvent odor. The volume average particle diameter of the resin particles in this dispersion was 145 nm. Then, an anionic surfactant (Dowfax2A1, manufactured by Dow Chemical Co., Ltd., active ingredient amount 45% by mass) was added and mixed as an active ingredient with respect to the resin content in the dispersion liquid, and ion-exchanged water was added to add the solid content. The concentration was adjusted to 38% by mass. This was designated as an acrylic resin / hardener composite dispersion (M1).

<Preparation of polyester resin / curing agent composite dispersion (E1)>
A 3-liter reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing is maintained at 40 ° C in a water circulation type constant temperature bath. A mixed solvent of 180 parts of ethyl acetate and 30 parts of isopropyl alcohol was added thereto, and the following composition was added thereto.
Polyester resin (PES1) [polycondensate of terephthalic acid / ethylene glycol / neopentyl glycol / trimethylolpropane (molar ratio = 100/60/38/2 (mol%), glass transition temperature = 62 ° C., acid value ( Av) = 12 mgKOH / g, hydroxyl value (OHv) = 55 mgKOH / g, weight average molecular weight (Mw) = 12,000, number average molecular weight (Mn) = 4,000]: 240 parts-Block isocyanate curing agent VESTAGONB1530 (EVONIK) (Manufactured by): 60 parts ・ Benzoin: 1.5 parts ・ Acrylic oligomer (Acronal 4F, BASF): 3 parts

After charging, the mixture was stirred at 150 rpm using a three-one motor and dissolved to obtain an oil phase. To this agitated oil phase, 10 parts of a 10 mass% aqueous ammonia solution was added dropwise over 5 minutes, mixed for 10 minutes, and then 900 parts of ion-exchanged water was further added dropwise at a rate of 5 parts per minute to invert the phase. , An emulsion was obtained.
Immediately, 1215 parts of the obtained emulsion was placed in a 2 liter eggplant flask and set in an evaporator (manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. While rotating the eggplant flask, it was heated in a hot water bath at 60 ° C., and the pressure was reduced to 7 kPa while paying attention to sudden boiling to remove the solvent. When the amount of solvent recovered reached 350 parts, the pressure was returned to normal pressure (1 atm), and the eggplant flask was water-cooled to obtain a dispersion. The obtained dispersion had no solvent odor. The volume average particle diameter of the resin particles in this dispersion was 145 nm. Then, an anionic surfactant (Dowfax2A1, manufactured by Dow Chemical Co., Ltd., active ingredient amount 45% by mass) was added and mixed as an active ingredient with respect to the resin content in the dispersion liquid, and ion-exchanged water was added to add the solid content. The concentration was adjusted to 25% by mass. This was designated as a polyester resin / curing agent composite dispersion (E1).

[Preparation of powder particles]
<Preparation of white powder particles (PC1)>
-Agglomeration process-
-Acrylic resin dispersion (A1): 200 parts by mass (solid content 45% by mass)
-Hardener dispersion liquid (B1): 119 parts by mass (solid content 25% by mass)
-White pigment dispersion (W1): 161 parts by mass (solid content 40% by mass)
-Ion-exchanged water: 335 parts by mass or more was mixed and dispersed in a round stainless steel flask using a homogenizer (Ultratarax T50 manufactured by IKA). 0.75 parts by mass of a 10 mass% polyaluminum chloride aqueous solution was added thereto, and the dispersion operation was continued with Ultratarax.
A stirrer and a mantle heater are installed, and the temperature is raised to 50 ° C. while adjusting the stirring speed so that the slurry is sufficiently agitated, and after holding at 50 ° C. for 15 minutes, a Coulter counter [TA-II] type The particle size of the agglomerated particles was measured with (aperture diameter: 50 μm, manufactured by Beckman-Coulter), and when the volume average particle size was 6.5 μm, the shell was cured with 54 parts by weight of the acrylic resin dispersion (A1). A mixed solution of 38 parts by mass of the agent dispersion liquid (B1) and 75 parts by mass of ion-exchanged water was slowly added.

-Fusion unification process-
After holding for 30 minutes after the addition, the pH in the system was adjusted to 6.5 with a 0.5 mol / liter aqueous sodium hydroxide solution. Then, the mixture was heated to 95 ° C. while continuing stirring and kept for 2 hours.

-Filtration, cleaning and drying processes-
After completion of the reaction, the solution in the flask was cooled and filtered to obtain a solid content. Next, this solid content was washed with ion-exchanged water and then solid-liquid separated by Nucci-type suction filtration to obtain a solid content again.
Next, this solid content was redistributed in 3 liters of ion-exchanged water at 40 ° C., and the mixture was stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, and the solid content obtained by solid-liquid separation by Nucci-type suction filtration was vacuum-dried for 12 hours to obtain white powder particles (PC1).
When the particle size of the white powder particles (PC1) was measured, the volume average particle size D50v was 7.1 μm, and the volume average particle size distribution index GSDv was 1.25. The average circularity was 0.98.

<Preparation of clear powder particles (PC2)>
Clear powder in the same manner as the white powder particles (PC1) except that the white pigment dispersion (W1) was not used and only the acrylic resin dispersion (A1) and the curing agent dispersion (B1) were used. Particles (PC2) were prepared.
When the particle size of the clear powder particles (PC2) was measured, the volume average particle size D50v was 7.2 μm, and the volume average particle size distribution index GSDv was 1.26. The average circularity was 0.97.

<Preparation of white powder particles (PC3)>
-Agglomeration process-
-Acrylic resin / curing agent composite dispersion (M1): 316 parts by mass (solid content 38% by mass)
-White pigment dispersion (W1): 161 parts by mass (solid content 40% by mass)
-Ion-exchanged water: 340 parts by mass or more was mixed and dispersed in a round stainless steel flask using a homogenizer (Ultratarax T50 manufactured by IKA). Then, a 1.0 mass% nitric acid aqueous solution was used to adjust the pH to 3.5. 0.75 parts by mass of a 10 mass% polyaluminum chloride aqueous solution was added thereto, and the dispersion operation was continued with Ultratarax.
A stirrer and a mantle heater are installed, and the temperature is raised to 50 ° C. while adjusting the stirring speed so that the slurry is sufficiently agitated, and after holding at 50 ° C. for 15 minutes, a Coulter counter [TA-II] type The particle size of the aggregated particles was measured with (aperture diameter: 50 μm, manufactured by Beckman-Coulter), and when the volume average particle size was 6.5 μm, 92 mass of acrylic resin curing agent composite dispersion (M1) was used as the shell. A mixed solution of 75 parts by mass of ion-exchanged water was slowly added.

-Fusion unification process-
After holding for 30 minutes after the addition, the pH in the system was adjusted to 7.0 with a 0.5 mol / liter aqueous sodium hydroxide solution. Then, the mixture was heated to 95 ° C. while continuing stirring and kept for 2 hours.

-Filtration, cleaning and drying processes-
After completion of the reaction, the solution in the flask was cooled and filtered to obtain a solid content. Next, this solid content was washed with ion-exchanged water and then solid-liquid separated by Nucci-type suction filtration to obtain a solid content again.
Next, this solid content was redistributed in 3 liters of ion-exchanged water at 40 ° C., and the mixture was stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, and the solid content obtained by solid-liquid separation by Nucci-type suction filtration was vacuum-dried for 12 hours to obtain white powder particles (PC3).
When the particle size of the white powder particles (PC3) was measured, the volume average particle size D50v was 7.5 μm, and the volume particle size distribution index GSDv was 1.27. The average circularity was 0.97.

<Preparation of clear powder particles (PC4)>
Clear powder particles (PC4) were produced in the same manner as the white powder particles (PC3) except that the white pigment dispersion liquid (W1) was not used and only the acrylic resin / curing agent composite dispersion liquid (M1) was used. did.
When the particle size of the clear powder particles (PC4) was measured, the volume average particle size D50v was 7.4 μm, and the volume particle size distribution index GSDv was 1.25. The average circularity was 0.98.

<Preparation of white powder particles (PC5)>
In the aggregation step of producing white powder particles (PC1), a stirrer and a mantle heater are installed, and the temperature is raised to 52 ° C. at 52 ° C. while adjusting the stirring rotation speed so that the slurry is sufficiently agitated. After holding for 15 minutes, the particle size of the agglomerated particles was measured with a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Beckman-Coulter), except that the volume average particle size was 13.6 μm. , White powder particles (PC5) having a volume average particle size D50v15 μm, a volume particle size distribution index GSDv1.23, and an average circularity 0.97 were obtained in the same manner as the white powder particles (PC1).

<Preparation of white powder particles (PC6)>
In the coagulation step of producing white powder particles (PC1), a stirrer and a mantle heater are installed, and the temperature is raised to 57 ° C. at 52 ° C. while adjusting the stirring speed so that the slurry is sufficiently agitated. After holding for 15 minutes, the particle size of the agglomerated particles was measured with a Coulter counter [TA-II] type (aperture diameter: 50 μm, manufactured by Beckman-Coulter), except that the volume average particle size was 22.8 μm. , White powder particles (PC5) having a volume average particle size D50v25 μm, a volume particle size distribution index GSDv1.23, and an average circularity 0.97 were obtained in the same manner as the white powder particles (PC1).

<Preparation of white powder particles (PC7)>
-Agglomeration process-
-Acrylic resin dispersion (A2): 185 parts by mass (solid content 45% by mass)
-Hardener dispersion liquid (B1): 147 parts by mass (solid content 25% by mass)
-White pigment dispersion (W1): 161 parts by mass (solid content 40% by mass)
-Ion-exchanged water: 320 parts by mass or more was mixed and dispersed in a round stainless steel flask using a homogenizer (Ultratarax T50 manufactured by IKA). 0.75 parts by mass of a 10 mass% polyaluminum chloride aqueous solution was added thereto, and the dispersion operation was continued with Ultratarax.
A stirrer and a mantle heater are installed, and the temperature is raised to 50 ° C. while adjusting the stirring speed so that the slurry is sufficiently agitated, and after holding at 50 ° C. for 15 minutes, a Coulter counter [TA-II] type The particle size of the agglomerated particles was measured with (aperture diameter: 50 μm, manufactured by Beckman-Coulter), and when the volume average particle size was 6.5 μm, the shell was cured with 54 parts by weight of the acrylic resin dispersion (A2). A mixed solution of 38 parts by mass of the agent dispersion liquid (B1) and 75 parts by mass of ion-exchanged water was slowly added.

-Fusion unification process-
After holding for 30 minutes after the addition, the pH in the system was adjusted to 6.5 with a 0.5 mol / liter aqueous sodium hydroxide solution. Then, the mixture was heated to 95 ° C. while continuing stirring and kept for 2 hours.

-Filtration, cleaning and drying processes-
After completion of the reaction, the solution in the flask was cooled and filtered to obtain a solid content. Next, this solid content was washed with ion-exchanged water and then solid-liquid separated by Nucci-type suction filtration to obtain a solid content again.
Next, this solid content was redistributed in 3 liters of ion-exchanged water at 40 ° C., and the mixture was stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, and the solid content obtained by solid-liquid separation by Nucci-type suction filtration was vacuum-dried for 12 hours to obtain white powder particles (PC7).
When the particle size of the white powder particles (PC7) was measured, the volume average particle size D50v was 8.3 μm, and the volume particle size distribution index GSDv was 1.22. The average circularity was 0.98.

<Preparation of white powder particles (PC8)>
-Agglomeration process-
-Acrylic resin dispersion (A3): 134 parts by mass (solid content 45% by mass)
-Hardener dispersion liquid (B1): 238 parts by mass (solid content 25% by mass)
-White pigment dispersion (W1): 161 parts by mass (solid content 40% by mass)
-Ion-exchanged water: 280 parts by mass or more was mixed and dispersed in a round stainless steel flask using a homogenizer (Ultratarax T50 manufactured by IKA). 0.75 parts by mass of a 10 mass% polyaluminum chloride aqueous solution was added thereto, and the dispersion operation was continued with Ultratarax.
A stirrer and a mantle heater are installed, and the temperature is raised to 50 ° C. while adjusting the stirring speed so that the slurry is sufficiently agitated, and after holding at 50 ° C. for 15 minutes, a Coulter counter [TA-II] type The particle size of the aggregated particles was measured with (aperture diameter: 50 μm, manufactured by Beckman-Coulter), and when the volume average particle size was 6.5 μm, the shell was cured with 54 parts by weight of acrylic resin dispersion (A3). A mixed solution of 38 parts by mass of the agent dispersion liquid (B1) and 75 parts by mass of ion-exchanged water was slowly added.

-Fusion unification process-
After holding for 30 minutes after the addition, the pH in the system was adjusted to 6.5 with a 0.5 mol / liter aqueous sodium hydroxide solution. Then, the mixture was heated to 95 ° C. while continuing stirring and kept for 2 hours.

-Filtration, cleaning and drying processes-
After completion of the reaction, the solution in the flask was cooled and filtered to obtain a solid content. Next, this solid content was washed with ion-exchanged water and then solid-liquid separated by Nucci-type suction filtration to obtain a solid content again.
Next, this solid content was redistributed in 3 liters of ion-exchanged water at 40 ° C., and the mixture was stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, and the solid content obtained by solid-liquid separation by Nucci type suction filtration was vacuum-dried for 12 hours to obtain white powder particles (PC8).
When the particle size of the white powder particles (PC8) was measured, the volume average particle size D50v was 7.3 μm, and the volume particle size distribution index GSDv was 1.24. The average circularity was 0.98.

<Preparation of white powder particles (CPC1)>
-Agglomeration process-
-Polyester resin / curing agent composite dispersion (E1): 180 parts by mass (solid content 45% by mass)
-White pigment dispersion (W1): 160 parts by mass (solid content 40% by mass)
-Ion-exchanged water: 200 parts by mass or more was mixed and dispersed in a round stainless steel flask using a homogenizer (Ultratarax T50 manufactured by IKA). Then, a 1.0 mass% nitric acid aqueous solution was used to adjust the pH to 3.5. To this, 0.50 parts by mass of a 10 mass% polyaluminum chloride aqueous solution was added, and the dispersion operation was continued with Ultratarax.
A stirrer and a mantle heater are installed, and the temperature is raised to 50 ° C. while adjusting the stirring speed so that the slurry is sufficiently agitated, and after holding at 50 ° C. for 15 minutes, a Coulter counter [TA-II] type is used. The particle size of the aggregated particles was measured with (aperture diameter: 50 μm, manufactured by Beckman-Coulter), and when the volume average particle size was 7.5 μm, the polyester resin / curing agent composite dispersion (E1) 60 was used as the shell. The mass part was slowly added. (Shell input).

-Fusion unification process-
After holding for 30 minutes after charging, the pH was adjusted to 7.0 using a 5% aqueous sodium hydroxide solution. Then, the temperature was raised to 85 ° C. and maintained for 2 hours.

-Filtration, cleaning and drying processes-
After completion of the reaction, the solution in the flask was cooled and filtered to obtain a solid content. Next, this solid content was washed with ion-exchanged water and then solid-liquid separated by Nucci-type suction filtration to obtain a solid content again.
Next, this solid content was redistributed in 3 liters of ion-exchanged water at 40 ° C., and the mixture was stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, and the solid content obtained by solid-liquid separation by Nucci type suction filtration was vacuum-dried for 12 hours to obtain white powder particles (CPC1).
When the particle size of the white powder particles (CPC1) was measured, the volume average particle size D50v was 8.1 μm, and the volume particle size distribution index GSDv was 1.28. The average circularity was 0.98.

<Preparation of kneaded and crushed white powder particles (CPC2)>
-Titanium oxide (A-220 manufactured by Ishihara Sangyo): 186 parts by mass-Acrylic resin (2) [Polymer of styrene / n-butyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid (molar ratio = 100/20/24 /) 1 (mol%), weight average molecular weight (Mw) = 18,000, number average molecular weight (Mn) = 6,000]: 240 parts by mass, blocked isocyanate hardener VESTAGON B1530 (manufactured by EVONIK): 105 parts by mass, acrylic particles : 5 parts by mass, benzoin: 1.5 parts by mass, acrylic oligomer (Acronal 4F BASF): Premix 3 parts by mass or more with a mixer, and then knead while heating to 100 ° C with an extruder. Then, it was coarsely pulverized and placed on flakes. Next, fine pulverization was carried out using a turbo mill aiming at a particle size of 30 μm, and classification was carried out to obtain kneaded and pulverized white powder particles (CPC2).
When the particle size of the kneaded and pulverized white powder particles (CPC2) was measured, the volume average particle size D50v was 30.2 μm, and the volume particle size distribution index GSDv was 1.28. The average circularity was 0.91.

<Preparation of kneaded and crushed white powder particles (CPC3)>
-Titanium oxide (A-220 manufactured by Ishihara Sangyo): 173 parts by mass-Acrylic resin (3) [Polymer of styrene / n-butyl acrylate / glycidyl methacrylate / acrylic acid (molar ratio = 100/20/60/1 (mol)) %), Weight average molecular weight (Mw) = 22,000, Number average molecular weight (Mn) = 8,000]: 240 parts by mass, blocked isocyanate curing agent dodecanedioic acid: 83 parts by mass, acrylic particles: 5 parts by mass, benzoin : 1.5 parts by mass ・ Acrylic oligomer (Acronal 4F BASF): Premix 3 parts by mass or more with a mixer, then knead while heating to 100 ° C with an extruder, coarsely crush and put on flakes. Next, fine pulverization was carried out using a turbo mill aiming at a particle size of 30 μm, and classification was carried out to obtain kneaded pulverized white powder particles (CPC3).
When the particle size of the kneaded and pulverized white powder particles (CPC3) was measured, the volume average particle size D50v was 31.1 μm, and the volume particle size distribution index GSDv was 1.27. The average circularity was 0.91.

[Examples 1 to 8, Comparative Examples 1 to 3, 5 to 6]
According to Table 1, hydrophobic silica particles (RX300, hydrophobic fumed silica surface-modified with hexamethyldisilazane, Nippon Aerosil Co., Ltd.) were added as an external additive to 100 parts by mass of the powder particles, and sample mill (SK-) was used. Using M10, Kyoritsu Riko), the mixture was stirred and mixed at a rotation speed of 13000 rpm for 30 seconds. Then, the powder coating materials (CP1) to (CP8) and (CPC1) to (CPC5) were obtained by sieving with a vibrating sieve of 200 mesh (opening 45 μm).

Then, each powder coating is applied to a test panel of a 1.0 mm thick aluminum plate by an electrostatic coating method, and then heated (baked) at a heating temperature of 180 ° C. and a heating time of 1 hour to obtain a coating film having a thickness of 40 μm. Was formed, and a sample of a painted product was obtained.

[Comparative Example 4]
The following liquid paint (CLC1) is applied to a test panel of a 1.0 mm thick aluminum plate, and then heated (baked) at a heating temperature of 180 ° C. and a heating time of 1 hour to form a coating film with a thickness of 40 μm. A sample of the product was obtained.

<Making liquid paint (CLC1)>
-Titanium oxide (A-220 manufactured by Ishihara Sangyo): 200 parts by mass, 50% acrylic resin solution (2) [Polymer of styrene / n-butyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid (molar ratio = 100/60) / 34/2 (mol%), weight average molecular weight (Mw) = 42,000, number average molecular weight (Mn) = 15,000]: 480 parts by mass, blocked isocyanate curing agent Duranate TPA-B80E: 129 parts by mass, acrylic Particles: 5 parts by mass, leveling agent Polyflow No. 75: 1 part by mass, butyl acetate: 129 parts by mass or more are mixed and dispersed in a round stainless steel flask using a homogenizer (Ultratarax T50 manufactured by IKA) to make a liquid. A paint (CLC1) was obtained.

[Evaluation]
<Various measurements>
For each example, the following characteristics were measured according to the method described above.
・ Temperature showing the minimum value of the storage elastic modulus of paint ・ Standard deviation σ of the peak position of the scattering angle on the painted surface
-Average value of the peak position of the scattering angle on the painted surface (indicated as "average" in the table)
・ Standard deviation σ of the peak intensity of the scattering angle on the painted surface
-Average value of the peak intensity of the scattering angle on the painted surface (indicated as "average" in the table)
-Glossiness on the painted surface-Average roughness Ra on the center line of the painted surface and swell Wca on the filter wave center line
-Pencil hardness of painted surface (that is, painted film)

<Evaluation of moist feeling on painted surface>
The painted surface of the painted product of each example was visually observed and judged according to the following evaluation criteria.
As for the observation conditions, the degree of contrast intensity in the range of 100 μm or more and 400 μm or less was observed based on the spatial frequency of the visual system at a place 30 cm to 45 cm away from the painted surface under an indoor fluorescent lamp (). If the surface unevenness is large, the shadow will be dark and the contrast will be strong.)
A: The painted surface had no contrast between light and dark, and soft reflected light that was almost uniform as a whole was observed.
B: It was a painted surface in which a slight contrast between light and dark was observed, and a slight amount of uneven and glaring reflected light was observed.
C: It was a painted surface in which a lot of fine contrast between light and dark was observed, and a lot of uneven and glaring reflected light was observed.
D: It was a painted surface in which a large amount of fine contrast between light and dark was observed, and a large amount of uneven and glaring reflected light was observed.

<Evaluation of marker erasability>
Using a commercially available whiteboard marker and eraser manufactured by KOKUYO Co., Ltd., write on the painted surface, leave it for one day in a room temperature environment, and then erase the writing area by reciprocating the eraser three times. Judgment was made according to the following criteria.
A: No stain B: Slight stain C: More than half disappeared D: More than half ink remains

<Repeated durability evaluation by writing with a marker>
Written using a commercially available whiteboard marker and eraser manufactured by KOKUYO Co., Ltd., erasing was performed with an eraser having a load of 500 g, and ink stains after 10,000 rotations were judged according to the following criteria. The device used was a tabletop robot (manufactured by IAI).
A: No stains and film thickness reduction is 0.5 μm or less B: Slight stains or film thickness reduction exceeds 0.5 μm and 1 μm or less C: More than half disappears or film thickness reduction is 1 μm More than 2 μm D: Half or more ink remains, or film thickness change is 2 μm or more

<Evaluation of erasability over time after leaving the marker description at high temperature>
About the ink residue after writing on the painted surface using a commercially available whiteboard marker and eraser manufactured by KOKUYO Co., Ltd., leaving it in an environment of 60 ° C. for 8 hours, and then erasing the writing part by reciprocating the eraser 10 times. , Judgment was made according to the following criteria.
A: No stain B: Slight stain C: More than half disappeared D: More than half ink remains

<Projector projectability evaluation>
It was projected onto a painted surface using a commercially available projector, and the glare caused by the irradiation light was judged according to the following criteria.
A: Almost no irradiation light is confirmed B: The irradiation light looks blurry, but no glare is felt C: Some glare is felt D: Very glare is felt

From the above results, it can be seen that the painted product of this example is superior to the painted product of the comparative example in the moist feeling of the painted surface.
It can be seen that the painted product of this embodiment is also excellent in marker erasability, repeated writing and erasing durability with a marker, and projector projection property.

10 Inspection device 12 Light source 16 Light receiving element 20 Inspection unit 32 Lens 34 Lens 40 Aperture member

Claims (12)

A painted product in which the standard deviation σ of the peak position of the scattering angle on the painted surface measured by a light scattering measuring device equipped with a surface emitting laser as a light source is 13 ° or less. The coated product according to claim 1, wherein the standard deviation σ of the peak position of the scattering angle is 10 ° or less. The coated product according to claim 1 or 2, wherein the standard deviation σ of the peak intensity of the scattering angle on the coated surface measured by a light scattering measuring device including a surface emitting laser as a light source is 0.85 or less. The coated product according to claim 3, wherein the standard deviation σ of the peak intensity of the scattering angle is 0.5 or less. The coated product according to any one of claims 1 to 4, wherein the glossiness on the coated surface measured by a glossiness meter under the condition of an incident angle of 60 ° is 70 ° or less. The coated product according to any one of claims 1 to 5, which has a coating film of a thermosetting powder coating material having powder particles containing thermosetting resin, thermosetting agent, and crosslinked resin particles. The sixth aspect of claim 6, wherein the crosslinked resin particles are at least one selected from styrene resin particles, (meth) acrylic resin particles, styrene- (meth) acrylic copolymer resin particles, and polyester resin particles. Painted. Thermosetting powder having powder particles containing a thermosetting resin and a thermosetting agent, and an external additive having an external addition amount of 0.3 parts by mass or more and 4 parts by mass or less with respect to 100 parts by mass of the powder particles. The coated product according to any one of claims 1 to 7, which has a coating film of paint. A thermosetting powder coating material having powder particles containing a thermosetting resin, a thermosetting agent, and crosslinked resin particles. The thermosetting powder coating material according to claim 9, wherein the crosslinked resin particles are at least one selected from (meth) acrylic resin particles and polyester resin particles. Thermosetting resin, powder particles containing a thermosetting agent,
An external additive having an external addition amount of 0.3 parts by mass or more and 4 parts by mass or less with respect to 100 parts by mass of the powder particles.
Thermosetting powder paint with. The 9th to 11th claims, wherein the volume average particle size D50v of the powder particles is 3 μm or more and 10 μm or less, the volume particle size distribution index GSDv is 1.30 or less, and the average circularity is 0.96 or more. The thermosetting powder coating according to any one of the items.