KR20220134457A - Metallic pigment composition - Google Patents

Abstract

Provided is a novel metal pigment composition. The metal pigment composition of the present invention comprises: metal particles; and composite particles having one or more coating layers on a surface thereof, wherein (1) the shape of the composite particles is scaly, (2) when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter, the D_50 of a volume basis is 3 μm or more and 30 μm or less, (3) the average thickness of the composite particles is 20 nm or more and 300 nm or less, (4) at least one layer of the coating layer is a silicon compound-containing layer, (5) in the composite particles, the ratio of the metal element content based on the metal particles to the silicon content based on the coating layer is 0.02 or more and 0.3 or less with respect to the ratio of the silicon content to the metal element content, and (6) the number ratio of the composite particles having a particle size of 0.1 μm or more and 1 μm or less is 10 % or less with respect to the total number of the composite particles in the metal pigment composition.

Description

Metal pigment composition {METALLIC PIGMENT COMPOSITION}

The present invention relates to a metal pigment composition comprising novel composite particles. More specifically, the present invention relates to a metal pigment composition comprising novel composite particles having excellent paint stability, storage stability, paint film color tone (specifically, brightness, flip-flop feeling, hiding property) and paint adhesion. .

BACKGROUND ART Conventionally, metallic pigments have been used for metallic paints, printing inks, plastic kneading, and the like, for the purpose of obtaining a plastering effect that emphasizes a metallic feeling.

In recent years, in the paint field, as a resource saving and pollution-free measure, the necessity of switching to a water-based paint with a small amount of organic solvent is increasing. Not enough. For this reason, metal pigments can be easily corroded in water-based paints. When the metal powder is present in the water-based paint or the water-based ink, corrosion by water occurs in any of acidic, neutral, and basic, or a plurality of regions, depending on the properties of various metals, and hydrogen gas is generated. In particular, in the manufacturing process of a paint or ink in a paint maker or an ink maker, and the painting process or printing process in an automobile, a home appliance maker, a printing maker, etc. WHEREIN: It is a very serious problem in terms of safety.

Moreover, since the corrosion resistance of a metal pigment poses a problem in the point of storage stability, the corrosion resistance of a metal pigment can be said in other words to storage stability.

In addition, since the smoothness of the metal surface is lost due to corrosion, the color tone when used as a coating film, that is, a decrease in the color tone of the coating film (specifically, brightness, flip-flop feeling, and hiding property) is unavoidable. In addition, in recent years, there is a high demand for metallic paints that can obtain a finish with strong brilliance from diversification of color designs, and for that reason, a high flip-flop feeling as a paint film color tone (i.e., a property in which brightness changes depending on the observation angle, metal There is also the current situation that is a parameter that depends on the degree of orientation of the pigment) is being sought.

Moreover, when a metallic pigment is used as a coating material, the thing with small cohesiveness of the said pigment (specifically, the cohesiveness of the individual particle|grains which comprise the said pigment), ie, coating material stability is calculated|required.

Moreover, when it is made into a coating film by making a metal pigment into a coating material, it is calculated|required that adhesiveness with a base material, ie, coating material adhesiveness, is not reduced.

In patent document 1 (International Publication No. 2020/21735 pamphlet), in order to solve the problem that adhesiveness with resin in a coating film is low when an aluminum pigment which has not been surface-treated is used as a paint or a printing ink, a predetermined A resin-coated metal pigment having a minute average particle diameter using a copolymer as a coating resin is disclosed.

In addition, in Patent Document 2 (International Publication No. 2019/77904 pamphlet), small-diameter aluminum flakes having a particle size of 1 µm or less are included from the viewpoint of providing new design properties and a high-quality metallic feeling, and a scanning electron microscope is used. and observed under a microscope WHEREIN: The ratio of the number of the said small-diameter aluminum flakes is 35% or less of the aluminum flake pigment with respect to the whole said aluminum flake, The aluminum flake pigment is disclosed.

However, it is difficult to provide sufficiently satisfactory coating material stability, storage stability, coating film color tone (specifically, brightness, flip-flop feeling, hiding property) and coating material adhesion by any of these patent documents, There is a current situation that development of a metal pigment composition containing composite particles is desired.

International Publication No. 2020/21735 pamphlet International Publication No. 2019/77904 Pamphlet

It is an object of the present invention to provide a metal pigment composition comprising novel composite particles not found in the prior art.

Another object of the present invention is to provide novel composite particles in which the problems of the prior art are solved, that is, excellent in paint stability, storage stability, paint film color tone (specifically, brightness, flip-flop feeling, hiding property) and paint adhesion. It is to provide a metal pigment composition comprising.

As a result of intensive research, the present inventors have found a metal pigment composition comprising composite particles having metal particles and a coating layer comprising one or more layers of a silicon compound-containing layer (that is, a silica layer) on the surface thereof, and the composite particles have a scale-like shape. Coating treatment so that the average thickness of the composite particles (specifically, the size (particle diameter) of the metal particles serving as the core of the composite particles and the thickness of the silica layer constituting the coating layer on the surface) is within a certain range, , in addition to controlling the volume-based D ₅₀ in the particle size distribution of the composite particles to be within a predetermined range, the silicon content based on the silica layer relative to the metal element content based on the metal particles serving as the core particles of the composite particle It has been found that the above problems can be solved by a metal pigment composition in which the ratio of and the number ratio of composite particles having a predetermined minute particle size are controlled within a predetermined range.

In the case of forming a coating layer containing one or more silicon compound-containing layers (that is, silica layers) on the surface of the metal particles serving as the core of the composite particles, in the composite particles contained in the metal pigment composition, the present inventors , while a silica layer of a certain thickness is required to exhibit corrosion resistance, when the size (particle diameter) of the composite particles increases, the metal particles that become the core also become smaller, so the thickness of the silica layer becomes relatively large. , the orientation of the metal pigment is inhibited, making it difficult to exert the original optical performance of the metal particles, or if the size (particle diameter) of the composite particles increases, the adhesion between the substrate and the paint is inhibited and the adhesion of the paint resin substrate is reduced. It discovered that the subject, such as lowering, could also be solved according to the said metal pigment composition.

That is, the first aspect of the present invention is as follows.

[Aspect 1]

A metal pigment composition comprising metal particles and composite particles having one or more coating layers on the surface thereof,

(1) the shape of the composite particles is flaky,

(2) D ₅₀ on a volume basis when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 3 µm or more and 30 µm or less,

(3) the average thickness of the composite particles is 20 nm or more and 300 nm or less,

(4) at least one layer of the coating layer is a silicon compound-containing layer,

(5) in the composite particle, the ratio of the metal element content based on the metal particles to the silicon content based on the coating layer is 0.02 or more and 0.3 or less in terms of the ratio of the silicon content to the metal element content,

(6) the number ratio of the composite particles having a particle diameter of 0.1 μm or more and 1 μm or less is 10% or less with respect to the total number of the composite particles occupied in the metal pigment composition;

The metal pigment composition.

[Mode 2]

When the particle size distribution of the composite particles is measured with the above-described laser diffraction particle size distribution meter, the number ratio of the composite particles having a particle size three times or more of D ₅₀ on a volume basis is the composite particle occupied in the metal pigment composition The metal pigment composition according to the above [Aspect 1], which is 3% or less with respect to the total number of .

[Mode 3]

The metal pigment composition according to the above [Aspect 1] or [Aspect 2], wherein the metal particles are aluminum or an aluminum alloy.

[Aspect 4]

The metal pigment composition according to any one of [Aspect 1] to [Aspect 3], further comprising a coating layer comprising at least one of a metal, a metal oxide, a metal hydrate, and a resin.

[Aspect 5]

The metal pigment composition according to any one of [Aspect 1] to [Aspect 4], wherein the at least the silicon compound-containing layer is disposed as an outermost layer.

[Aspect 6]

A water-based metallic paint comprising the metal pigment composition according to any one of [Aspect 1] to [Aspect 5].

[Mode 7]

An aqueous metallic coating film comprising the metal pigment composition according to any one of [Aspect 1] to [Aspect 5].

According to the present invention, it is possible to provide a metal pigment composition comprising novel composite particles that are not in the prior art.

According to one preferred aspect of the present invention, paint stability (specifically, the characteristic that the cohesiveness of individual particles constituting the pigment is small when the pigment is used as a paint), storage stability (specifically, due to corrosion Characteristics that can suppress the generation of hydrogen gas), coating film color tone (specifically, characteristics such as high brightness, flip-flop feeling, and hiding properties), and paint adhesion (specifically, when a metallic pigment is converted into a paint to form a paint film) It is possible to provide a metal pigment composition excellent in adhesiveness to).

Hereinafter, the present invention will be described in accordance with typical or suitable embodiments, but the present invention is not limited by these embodiments. Unless clearly indicated, these embodiments can be freely combined within the scope of the present invention defined by the appended claims.

1. Composite particles included in the metal pigment composition

The metal pigment composition according to the present invention contains metal particles and composite particles having one or more coating layers on the surface thereof.

As used herein, the term "metal pigment composition" means that the composite particles comprising metal particles and one or more coating layers on the surface thereof are dispersed in a solvent containing water and/or a hydrophilic solvent, or the composite particles are water and It refers to a composition that is accompanied by a solvent including / or a hydrophilic solvent, and may optionally include other components.

In addition, in this specification, the composition which added resin with respect to a metal pigment composition may be distinguished from the term "metal pigment composition" and called a "resin composition" or a "resin composition containing a metal pigment composition."

metal particles

The composite particle contained in the metal pigment composition by this invention contains the metal particle and the one or more coating layers currently formed in the surface. That is, one or more coating layers are formed on the surface of the metal particle used as the core of a composite particle.

The material of the metal particles (core particles) constituting the composite particles is not particularly limited, and for example, aluminum, aluminum alloy, zinc, iron, magnesium, nickel, copper, silver, tin, chromium, stainless steel, etc. Any of the metals used as a well-known or commercially available metal pigment may be sufficient. In the present specification, the metal of the metal particles constituting the composite particle includes not only a single metal but also an alloy and an intermetallic compound.

In this way, the metal particles may use a metal containing only one type of metal element alone, or a combination of two or more types of metals containing only one type of metal element (that is, a metal containing two or more types of metal elements). may be used.

The metal which has an aluminum element as a main component is preferable, for example, it is preferable that it is aluminum or an aluminum alloy, and, as for the metal particle in this invention, it is more preferable that it is aluminum.

Although the shape of a metal particle is not restrictive, it is especially preferable that it is flaky form. Thereby, as a result that the composite particle contained in the metal pigment composition by this invention can also have a scale-like shape, high hiding property etc. can be acquired more reliably. From this point of view, it is preferable that the aspect ratio (shape coefficient obtained by dividing the average particle diameter by the average thickness) of the scale-like metal particles is 20 or more and 30 or less. When the aspect-ratio of a metal particle is 20 or more, a higher luminosity can be acquired. Moreover, when the aspect-ratio of a metal particle is 3000 or less, the mechanical strength of a flake is maintained and a stable color tone can be obtained. Here, about the average thickness of the metal particle used for this invention, it is computable from the surface diffusion area and density of a metal particle.

The average particle diameter of the metal particles is not particularly limited as long as it becomes an average particle diameter that can bring D ₅₀ in the particle size distribution of the composite particles described later. That is, it is preferable to set the average particle diameter of the metal particles so that D ₅₀ when the volume distribution is measured with a laser diffraction particle size distribution meter in the composite particles is 3 µm or more and 30 µm or less.

The average particle diameter of the metal particles is determined by using a ball mill or the like to grind, sieve and filter the raw material atomized metal powder (for example, aluminum powder). In this case, it can be controlled by appropriately adjusting the mass per one grinding ball, the rotation speed of the grinding apparatus, the sieve powder, the degree of the filter press, and the like.

In addition, the metal particles do not necessarily consist of only metal, and as long as the effect of the present invention is not impaired, for example, particles of synthetic resin, particles of inorganic particles such as mica, glass, etc., in which the surface is coated with metal, can also be used. have. In this invention, it is preferable that it is the particle|grains formed especially from aluminum or an aluminum alloy from points, such as high weather resistance, a small specific gravity, and easiness of acquisition.

Particularly suitable as the metal particles constituting the composite particles are aluminum flakes, which are commonly used as metallic pigments. As aluminum flakes, those having surface properties, particle size, and shape required for metallic pigments, such as surface gloss, whiteness, and brilliance, are suitable. Aluminum flakes are usually marketed in a paste state. The paste-like aluminum flakes may contain flaky aluminum powder, mineral spirits (aliphatic hydrocarbons) used at the time of pulverization, residual content of fatty acids, and organic solvents such as solvent naphtha and xylene. The paste-like aluminum flakes may be used as it is, or may be used after removing the fatty acids on the surface with an organic solvent or the like in advance.

Moreover, in the state of a composite particle, the volume average particle _diameter (D50) of 3 micrometers or more and 30 micrometers or less, and an average thickness of 20 nm or more and 300 nm or less, so-called aluminum vapor deposition foil can also be used.

2. Preferred physical properties of the metal pigment composition

The metal pigment composition according to the present invention is characterized in that it further satisfies the following physical property requirements.

(1) that the shape of the composite particles is scaly;

(2) D ₅₀ on a volume basis when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 3 µm or more and 30 µm or less;

(3) that the average thickness of the composite particles is 20 nm or more and 300 nm or less;

(4) at least one layer of the coating layer is a silicon compound-containing layer;

(5) the ratio of the metal element content based on the metal particles to the silicon content based on the coating layer in the composite particle is 0.02 or more and 0.3 or less in terms of the ratio of the silicon content to the metal element content;

(6) The number ratio of the composite particles having a particle size of 0.1 µm or more and 1 µm or less is 10% or less with respect to the total number of the composite particles in the metal pigment composition.

Hereinafter, each of these physical property requirements is demonstrated.

(1) The shape of the composite particle is scaly

The shape of the composite particle of the metal pigment composition by this invention is a flaky shape (flaky shape). Thereby, the coating film formed using the metal pigment composition can exhibit high brightness, a high flip-flop feeling, high hiding property, etc. In this specification, that the shape of the composite particle is "flaky" (flake shape) indicates that the composite particle has an average aspect ratio (shape coefficient obtained by dividing the average particle diameter by the average thickness) of 10 or more. From the viewpoint of obtaining high luminance, flip-flop feeling, hiding properties, and the like, it is preferable that the average aspect ratio of the scale-like composite particles is 10 or more and 1500 or less. When the average aspect ratio is 10 or more, a sufficient luminosity can be exhibited, while when the average aspect ratio is 1500 or less, the mechanical strength of the flakes is maintained and a stable color tone can be obtained.

The "composite particle" in this physical property requirement (1) refers to the aggregate (aggregate) when a some composite particle is aggregated and fixed.

Here, the average particle diameter for calculating the average aspect ratio of the composite particles is a volume reference D ₅₀ referred to as the median diameter, and this point will be described in detail in the description of the requirement (2) to be described later. In addition, the average thickness for calculating the average aspect-ratio of a composite grain|particle is demonstrated in detail in the description regarding the requirement (3) mentioned later.

(2) Volume-based D when the particle size distribution of composite particles is measured with a laser diffraction particle size distribution meter ₅₀ This 3 µm or more and 30 µm or less

When the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter, D ₅₀ on a volume basis is 3 µm or more and 30 µm or less. Thereby, the coating film formed using the metal pigment composition exhibits high luminance, high flip-flop feeling, high hiding properties, and the like, and the aggregation of individual particles constituting the metal pigment composition is suppressed, and the aggregation property becomes small. can D ₅₀ on this volume basis is also commonly referred to as the median diameter.

From the viewpoint of obtaining such high luminance, high flip-flop feeling, high hiding properties and small cohesion of individual particles, the volume-based D ₅₀ when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 3 as the lower limit. It is more than micrometer, and as an upper limit, it is 30 micrometers or less, Preferably it is 25 micrometers or less, More preferably, it is 20 micrometers or less.

The "composite particle" in this physical property requirement (2) refers to the aggregate (aggregate) when a some composite particle aggregates and adheres.

Here, D ₅₀ on a volume basis when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter indicates a particle size with a cumulative degree of 50% in the volume cumulative particle size distribution. Although it does not specifically limit as a laser diffraction type particle size distribution meter, For example, "LA-300" (made by Horiba Corporation) can be used. As the measurement solvent, isopropyl alcohol or mineral spirit can be used. For example, after performing ultrasonic dispersion for 2 minutes as a pretreatment with respect to the metal pigment composition containing the composite particle of a sample, it inject|throws-in in a dispersion tank, After confirming that it disperse|distributed moderately, _D50 can be measured.

The particle diameter of the composite particle in the resin composition mentioned later cannot be measured by this method. Therefore, as an alternative method in this case, for example, by photographing the composite particles in the resin composition with an optical microscope, a laser microscope, etc. from the surface of the coating film, and using commercially available image analysis software, by obtaining the distribution of the equivalent circle diameter A method of determining the particle size may be employed.

D ₅₀ based on the volume of the composite particles contained in the metal pigment composition is, in the method for producing a metal pigment composition described later, grinding and sieving the raw material atomized metal powder (eg, aluminum powder) using a ball mill or the like. In the filtration step, by appropriately adjusting the particle size of the raw material atomized metal powder, the mass per one grinding ball in the case of using a ball mill, the number of rotations of the grinding device, the sieve powder and the degree of the filter press, and the like, and silicon compound In the step of coating the content layer (and other coating layers if necessary), the type of the organosilicon compound used, the pH in the coating step (including the step when the organosilicon compound is hydrolyzed and used), concentration, It can be controlled by appropriately adjusting the stirring temperature, the stirring time, the type of stirring device, the power/degree of stirring (the type and diameter of the stirring blade, the number of rotations, the presence or absence of external stirring, etc.).

(3) The average thickness of the composite particles is 20 nm or more and 300 nm or less

It is preferable that the average thickness of the composite particles included in the metal pigment composition according to the present invention is 20 nm or more and 300 nm or less. . Thereby, while satisfying the above requirements (1) to (2), the coating film formed using the metallic pigment composition exhibits still higher luminance, higher flip-flop feeling, high hiding properties, and the like, and the metallic pigment composition The aggregation of individual composite particles constituting the .

In addition, in addition to satisfying the requirements (4) to (6) described later, high corrosion resistance is exhibited even when used for water-based metallic paints or metallic coatings, etc. .

From the above viewpoint, the average thickness of the composite particles is 20 nm or more as a lower limit, and 300 nm or less as an upper limit, preferably 250 nm or less, and more preferably 200 nm or less.

The "composite particle" in this physical property requirement (3) refers to the aggregate (aggregate) when several composite particle aggregates and adheres.

The average thickness of the composite particles here can be calculated from the surface diffusion area and density of the composite particles. The water surface diffusion area refers to the area occupied by the dry composite particles per unit mass when the dried composite particles are uniformly diffused on the water surface by using a ripping phenomenon and coated in a state without gaps. The measurement of the surface diffusion area can be performed according to the regulations of JIS K5906:1998.

However, in the composite particle of this invention, when the hydrophilicity of the surface is strong, it may be difficult to calculate|require the said water surface diffusion area. In this case, the average thickness of the composite particles may be measured according to the method described in Examples to be described later. That is, a film (thin film) is formed using a metal pigment composition in which the composite particles are dispersed in a mixture of an alcohol-based solvent such as methoxypropanol and water, and the thickness of the composite particles (500 or more) is measured with a scanning electron microscope (SEM). The average thickness of the composite particles can be determined by observation.

The average thickness of the composite particles contained in the metal pigment composition is similar to the volume basis D ₅₀ , in the method for producing a metal pigment composition to be described later, the raw material atomized metal powder (eg, aluminum powder) using a ball mill or the like. In the process of grinding and sieving and filtering, by appropriately adjusting the particle size of the raw material atomized metal powder, the mass per one grinding ball when using a ball mill, the number of rotations of the grinding device, the sieve powder and the degree of filter press, etc. and the type of organosilicon compound used in the step of coating the silicon compound-containing layer (and other coating layers, if necessary), the coating step (including the step in the case where the organosilicon compound is hydrolyzed and used) It can be controlled by appropriately adjusting pH, concentration, stirring temperature, stirring time, type of stirring device, power/degree of stirring (eg, type and diameter of stirring blades, rotation speed, presence or absence of external stirring), and the like.

(4) At least one layer of the coating layer is a silicon compound-containing layer

In the metal pigment composition according to the present invention, at least one of the one or more coating layers formed on the surface of the metal particles serving as the cores of the composite particles is a silicon compound-containing layer. Thereby, gas generation in the water-based coating material can be suppressed, good storage stability (that is, corrosion resistance) is obtained, and excellent water resistance is obtained when it is set as a coating film.

In addition, in addition to the satisfaction of the above requirements (1) to (3) and the requirements (5) to (6) to be described later, high luminance, high flip-flop feeling, While exhibiting the excellent coating film color tone by high hiding property, when it uses for coating films, such as a metallic coating film, the outstanding adhesiveness can be exhibited.

The coating layer of the composite particle may have another coating layer (second coating layer) other than the silicon compound-containing layer. Such a second coating layer will be further described later.

The silicon compound-containing layer is particularly preferably a layer composed of a compound containing a Si-O- bond (siloxane bond). As such a layer, the layer containing at least 1 sort(s) of a silane type compound and a silicon oxide is mentioned, for example. As such a compound, in addition to the silane-based compound [H ₃ SiO(H ₂ SiO) _n SiH ₃ ] (provided that n represents an arbitrary positive integer), SiO ₂ , SiO ₂ .nH ₂ O (provided that n is It represents an arbitrary positive integer.) etc. are illustrated. Although either crystalline or amorphous may be sufficient as these silane-type compound and a silicon oxide, it is especially preferable that they are amorphous. Therefore, as a layer containing silicon oxide (silica etc.), for example, a layer containing amorphous silica can also be employ|adopted suitably.

In addition, the layer comprised from the compound containing a Si-O bond should just be a layer formed using an organosilicon compound (a silane coupling agent is included) as a starting material. In this case, the silicon compound-containing layer may contain an organosilicon compound or a component derived therefrom within a range that does not impair the effects of the present invention. As a typical example, a layer composed of a compound containing a Si—O bond can be formed by hydrolyzing an organosilicon compound.

The silicon compound-containing layer may contain additives other than the silicon compound, impurities, and the like, as long as the properties of the present invention are not impaired.

The silicon content contained in the silicon compound-containing layer is not particularly limited as long as it becomes an amount that can satisfy the requirement (5) described later.

It is preferable that the coating layer of the composite particle contained in the metal pigment composition by this invention is especially hydrophilic. The composite particles usually form a metal pigment composition dispersed in an aqueous solvent (water or a mixed solvent containing water and an organic solvent), but when the coating layer has a hydrophilic surface, the composite particles are highly concentrated in this aqueous solvent. can be dispersed. Furthermore, since silicon oxide (amorphous silica, etc.) is very stable in an aqueous solvent, it is possible to provide a metal pigment composition comprising composite particles highly stable in an aqueous solvent. From such a viewpoint, in the composite particles contained in the metal pigment composition according to the present invention, it is preferable that at least the outermost layer is a silicon compound-containing layer (particularly a layer composed of a compound containing a Si-O bond). When the coating layer is composed of a plurality of layers, in addition to the silicon compound-containing layer of the outermost layer, a silicon compound-containing layer (particularly a Si-O-based coating layer) may be separately formed as a layer other than the outermost layer.

The thickness of the coating layer of the individual composite particles is not particularly limited as long as the average thickness of the composite particles is in the range of 20 nm or more and 300 nm or less, but usually about 5 to 50 nm (especially 10 nm or more and 40 nm or less, further 15 nm or more and 30 nm It is preferable to set it as within the range of below). When the thickness of the coating layer is 1 nm or more, it is possible to obtain a coating film having sufficient water resistance and in which corrosion or discoloration of the metal particles in the water-based coating material is suppressed. On the other hand, since the thickness of the coating layer is about 50 nm or less, the brightness, clarity, and hiding properties of the coating film can be maintained at a high level.

The thickness of the silicon compound-containing layer included in the coating layer of the individual composite particles is not particularly limited as long as the average thickness of the composite particles is in the range of 20 nm or more and 300 nm or less as described in the above requirement (3), but the function of the layer From the viewpoint of exhibiting, it is preferable that it is usually in the range of 5 nm or more and 50 nm or less, and particularly preferably in the range of 10 nm or more and 40 nm or less.

Specific examples of the organosilicon compound that can be used in the present invention are further described below, but the organosilicon compound is not limited to these specific examples.

The organosilicon compound includes at least one organosilicon compound represented by the following general formula (1), a silane coupling agent represented by any of the following general formulas (2), (3) and (4), and a portion thereof. You may contain at least 1 sort(s) chosen from a condensate.

Si(OR ¹ ) ₄ · · · (1)

(Wherein, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ¹ may be all the same, some may be the same, or all may be different.)

R ² _m Si(OR ³ ) _4-m · · · · (2)

(Wherein, R ² is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, which may optionally include a halogen group, and R ³ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. R ² and R ³ may be the same or different, and when there are two or more R ² or R ³ , all of them may be the same, some may be the same, or all may be different. 1≤m≤3.)

R ⁴ _p R ⁵ _q Si(OR ⁶ ) _4-pq . . . (3)

(Wherein, R ⁴ is a group containing a reactive group capable of chemical bonding with another functional group, R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, optionally including a halogen group, and R ⁶ is It is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. When there are two or more R ⁴ , R ⁵ or R ⁶ , all of them may be the same, some may be the same, or all may be different. p≤3, 0≤q≤2, and 1≤p+q≤3.)

R ⁷ _r SiCl _4-r · · · · (4)

(Wherein, R ⁷ is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, which may optionally include a halogen group, and when there are two or more R ⁷ , all of them or some of them are the same. , all may be different. 0≤r≤3.)

Methyl, ethyl, propyl, butyl, hexyl, octyl etc. are mentioned as an example of the hydrocarbon group in R< ¹ > of Formula (1), These may be branched or linear may be sufficient as them. Among these hydrocarbon groups, methyl, ethyl, propyl and butyl are particularly preferable. In addition, all four R< ¹ > may be the same, some may be the same, or all may be different.

As a preferable example of such an organosilicon compound of Formula (1), tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, etc. are mentioned. Among these, tetraethoxysilane is especially preferable.

Examples of the hydrocarbon group for R ² in formula (2) include methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, oleyl, stearyl, cyclohexyl, phenyl, benzyl, and naphthyl. These may be branched or linear, and may contain halogen groups, such as fluorine, chlorine, and a bromine. Among these, a hydrocarbon group having 1 to 18 carbon atoms is particularly preferable. In addition, when there exists two or more R< ² >, even if all are the same, some may be the same, or all may be different. Although the number of R< ² > in a molecule|numerator is m=1-3, ie, 1-3 in Formula (2), it is more preferable that it is m=1 or 2.

Methyl, ethyl, propyl, butyl, hexyl, octyl etc. are mentioned as an example of the hydrocarbon group in R< ³ > of Formula (2), These may be branched or linear may be sufficient as them. Among these hydrocarbon groups, methyl, ethyl, propyl and butyl are particularly preferable. In addition, when there exists two or more R< ³ >, even if all are the same, some may be the same, or all may be different.

Preferred examples of the organosilicon compound (silane coupling agent) of the formula (2) include methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and dimethyldibutoxysilane. , trimethylmethoxysilane, trimethylethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltributoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltribu Toxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dibutyldibutoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, dihexyldimethoxysilane Silane, dihexyldiethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, dioctyldimethoxysilane, dioctyldiethoxysilane, dioctylethoxybutoxysilane, decyltrimethoxysilane, decyltriethoxy Silane, didecyldimethoxysilane, didecyldiethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, dioctadecyldimethoxysilane, dioctadecyldiethoxysilane, phenyltrimethoxysilane, phenyltri Ethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluoroox tyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropyltributoxysilane, etc. are mentioned.

Examples of a reactive group capable of chemical bonding with another functional group in R ⁴ in Formula (3) include a vinyl group, an epoxy group, a styryl group, a methacryloxy group, an acryloxy group, an amino group, a ureide group, a mercapto group, and a polysulfur. A feed group, an isocyanate group, etc. are mentioned.

In addition, when there exists two or more R< ⁴ >, even if all are the same, some may be the same, or all may be different. Although the number of R< ⁴ > in a molecule|numerator is p=1-3, ie, 1-3 in Formula (3), it is more preferable that it is p=1.

Examples of the hydrocarbon group for R ⁵ in formula (3) include methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, oleyl, stearyl, cyclohexyl, phenyl, benzyl, naphthyl, and the like. , these may be branched or linear, or may contain halogen groups such as fluorine, chlorine and bromine. Among these, a hydrocarbon group having 1 to 18 carbon atoms is particularly preferable. In addition, when there are two or more R< ⁵ >, even if all are the same, some may be the same, or all may be different.

Methyl, ethyl, propyl, butyl, hexyl, octyl, etc. are mentioned as an example of the hydrocarbon group in R< ⁶ > of Formula (3), These may be branched or linear may be sufficient as them. Among these hydrocarbon groups, methyl, ethyl, propyl and butyl are particularly preferable. In addition, when there exists two or more R< ⁶ >, even if all are the same, some may be the same, or all may be different.

Preferred examples of the organosilicon compound (silane coupling agent) of the formula (3) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyl-tris(2-methoxyethoxy)silane, and 2-(3,4-). Epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxy Silane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxy Propyltrimethoxysilane, N-methyl-3-aminopropyl-trimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-amino Propylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyl Trimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 3 -Ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyl-triethoxysilane, bis(triethoxysilylpropyl)tetrasulf feed, 3-isocyanate propyl triethoxysilane, etc. are mentioned.

Examples of the hydrocarbon group for R ⁷ in formula (4) include methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, oleyl, stearyl, cyclohexyl, phenyl, benzyl, naphthyl, and the like. These may be branched or linear, and may contain halogen groups, such as fluorine, chlorine, and a bromine. Among these, a C1-C12 hydrocarbon group is especially preferable. In addition, when there exists two or more R< ⁷ >, even if all are the same, some may be the same, or all may be different. Although the number of R< ⁷ > in a molecule|numerator is r=0-3, ie, 0-3 in Formula (4), it is more preferable that it is r=1-3.

Preferred examples of the organosilicon compound (silane coupling agent) of the formula (4) include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, octyldimethylchlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, and tetrachlorosilane. Silane etc. are mentioned.

The organosilicon compound represented by the said General formula (1) may be used individually by 1 type, and may be used in combination of 2 or more type. In addition, the silane coupling agent represented by either of General formulas (2), (3) and (4) may be used individually by 1 type, and may be used in combination of 2 or more type. When using in combination of two or more types, only the silane coupling agent represented by any of (2), (3) and (4) may be used in combination of two or more types, and represented by two or more other general formulas You may use combining a silane coupling agent.

The hydrolyzate of the organosilicon compound and/or the condensation product thereof are obtained by stirring and mixing the organosilicon compound, water in an amount required for hydrolysis reaction, and a hydrolysis catalyst. In that case, a hydrophilic solvent can also be used as needed. Various conditions for the hydrolysis reaction (that is, the reaction for forming the silicon compound-containing layer) will be described later.

As a raw material of the hydrolysis reaction for obtaining the hydrolyzate of an organosilicon compound and/or its condensation reaction product, and/or its condensation reaction, you may use the oligomer which previously condensed a part.

Condensation reaction of the hydrolyzate of an organosilicon compound may be performed simultaneously with the hydrolysis reaction of an organosilicon compound, and may divide a process and may change a catalyst and may perform it if necessary. In that case, you may heat as needed.

The coating layer of the composite particles contained in the metal pigment composition according to the present invention is not particularly limited except that at least one layer is a silicon compound-containing layer, but a coating layer other than the above-described silicon compound-containing layer (hereinafter referred to as "second coating layer") may be formed as needed.

The second coating layer is, for example, a metal (alkali metal; alkaline earth metal; metal such as manganese, iron, cobalt, nickel, copper, silver), metal oxide (titanium oxide, zirconium oxide, iron oxide, etc.), metal hydrate, and resin (Synthetic resins, such as an acrylic resin, an alkyd resin, a polyester resin, a polyurethane resin, a polyvinyl acetate resin, a nitrocellulose resin, and a fluororesin), what consists of containing at least 1 sort(s) may be sufficient. As a 2nd coating layer, a molybdenum containing film, a phosphoric acid compound film, etc. can be formed, for example. By providing a 2nd coating layer, while improving the corrosion resistance of a metal particle, formation of a silicon compound containing layer can be accelerated|stimulated.

It is preferable that the 2nd coating layer is especially formed between a metal particle and a silicon compound containing layer (when it is formed). Therefore, for example, the layered constitution of "metal particle/2nd coating layer/silicon compound containing layer" can be employ|adopted suitably. Although it does not specifically limit, As an example of a molybdenum containing film, the thing disclosed by Unexamined-Japanese-Patent No. 2003-147226, International Publication No. 2004/096921 pamphlet, Japanese Patent No. 5979788, and Unexamined-Japanese-Patent No. 2019-151678 are mentioned. can Examples of the phosphoric acid compound film include those disclosed in Japanese Patent No. 4633239. Preferred examples of the molybdenum-containing material constituting the molybdenum-containing film include a mixed coordination heteropolyanion compound disclosed in JP-A-2019-151678.

In another modified form, the second coating layer may be formed on the outside of the metal particle and silicon compound-containing layer. Further, in another modified form, the constituent components of the second coating layer (molybdenum-containing compound, phosphoric acid compound, etc.) may be contained together with the silicon compound in the silicon compound-containing layer.

The mixed coordination heteropolyvalent anion compound used in the aspect of forming the second coating layer (typically a molybdenum-containing film) other than the silicon compound-containing layer of the composite particles contained in the metal pigment composition according to the present invention is not particularly limited. , specifically, the following examples are given.

The mixed coordination heteropolyvalent anion of the mixed coordination heteropolyvalent anion compound that can be used has a structure in which some of the poly atoms of the heteropolyvalent anion containing one element are substituted with other elements, and each heterovalent It shows different physical properties from a mixture of anions.

When expressed by the formula, when the mixed coordination heteropolyanion is expressed as [X _p M _q N _r O _s ] ^t , the hetero polyvalent anion becomes [X _p M _q O _s ] ^t , and isopolyanion [MqOs] It is also distinguished from ^t . However, X which is a hetero atom represents IIIB, IVB, VB group elements, such as B, Si, Ge, P, and As, Among them, B, Si, and P are preferable. M and N which are poly atoms represent transition metals, such as Ti, Zr, V, Nb, Ta, Mo, and W, Ti, Zr, V, Nb, Mo, and W are preferable.

In addition, p, q, r, and s represent the number of atoms, and t represents an oxidation number.

Since the heteropolyvalent anion compound has numerous structures, the mixed coordination heteropolyanion compound may have many more structures. As a representative and preferred mixed coordination heteropolyanion compound, the following mixed coordination heteropolyacid: H ₃ PW _x Mo _12-x O ₄₀ nH ₂ O (phosphomolybdic acid n-hydrate), H _3+x PV _x Mo _12-x O ₄₀ nH ₂ O (phosphovanadomolybdic acid n-hydrate), H ₄ SiW _x Mo _12-x O ₄₀ .nH 2 O (silicotungstomolybdic acid·n-hydrate), H _4+x SiV _x Mo _12-x O ₄₀ ·nH ₂ O (silicium tungstomolybdic acid·n-hydrate), and _the like are exemplified. (However, 1≤x≤11, n≥0)

Preferred examples of these heteropolyanionic compounds include H ₃ PW ₃ Mo ₉ O ₄₀ nH ₂ O, H ₃ PW ₆ Mo ₆ O ₄₀ nH ₂ O, H ₃ PW ₉ Mo ₃ O ₄₀ nH ₂ O, H ₄ PV ₁ Mo ₁₁ O ₄₀ nH ₂ O, H ₆ PV ₃ Mo ₉ O ₄₀ nH ₂ O, H ₄ SiW ₃ Mo ₉ O ₄₀ nH ₂ O, H ₄ SiW ₆ Mo ₆ O ₄₀ nH ₂ Mixed coordination type heteropolyacids, such as O, H ₄ SiW ₉ Mo ₃ O ₄₀ .nH ₂ O, H ₅ SiV ₁ Mo ₁₁ O ₄₀ .nH ₂ O, and H ₇ SiV ₃ Mo ₉ O ₄₀ .nH ₂ O, are exemplified. (however, n≥0)

The mixed coordination heteropolyvalent anion compound may be used in the form of an acid (so-called mixed coordination heteropolyacid), or may be used in the form of a salt (partially or completely) using a specific cation as a counter ion.

Examples of the counter cation source in the case of using the mixed coordination heteropolyvalent anion compound in the form of a salt having a specific cation as a counter ion include alkali metals such as lithium, sodium, potassium, rubidium, and cesium; alkaline earth metals such as magnesium, calcium, strontium, and barium; metals such as manganese, iron, cobalt, nickel, copper, zinc, silver, cadmium, lead, and aluminum; inorganic components such as ammonia; And at least 1 sort(s) selected from the amine compound etc. which are organic components are mentioned. Among the inorganic components, salts of alkali metals, alkaline earth metals and ammonia are preferable.

Moreover, when using at least 1 sort(s) selected from these alkali metals, alkaline-earth metals, and ammonia as a counter cation source, H ₃ PW _x Mo _12-x O ₄₀ nH ₂ O (phosphotungstomolybdic acid n-hydrate), H _{3 +x} PV _x Mo _12-x O ₄₀ nH ₂ O (invanadomolybdic acid n-hydrate), H ₄ SiW _x Mo _12-x O ₄₀ nH ₂ O (silicotomolybdic acid n-hydrate), H ₄ It is more preferable to use in the form of at least one salt selected from _+x SiV _x Mo _12-x O ₄₀ ·nH ₂ O (silicavanadomolybdic acid·n-hydrate).

Moreover, as a counter cation source of a mixed coordination type hetero polyvalent anion compound, the amine compound which is an organic component is also used preferably and what is represented by the following general formula (5) as a specific example is preferable.

(R ⁸ -N(-R ¹⁰ )-) _n -R ⁹ . . . (5)

(In the formula, R ⁸ , R ⁹ and R ¹⁰ may be the same or different, and may be a hydrogen atom or a monovalent group having 1 to 30 carbon atoms, optionally including an ether bond, an ester bond, a hydroxyl group, a carbonyl group, or a thiol group. or a divalent hydrocarbon group, optionally R ⁸ and R ⁹ become one to form a 5- or 6-membered cycloalkyl group, or a 5- or 6-membered ring which may additionally contain a nitrogen or oxygen atom as a bridging member or optionally R ⁸ , R ⁹ and R ¹⁰ may be taken as one to form a multi-membered polycyclic ring which may contain one or more additional nitrogen and/or oxygen atoms as bridging members. ⁸ , R ⁹ and R ¹⁰ do not simultaneously become hydrogen atoms, n represents an integer of 1 to 2.)

Specific examples of the amine compound as the counter cation source of the mixed coordination heteropolyvalent anion compound include, for example, ethylamine, propylamine, butylamine, hexylamine, octylamine, laurylamine, tridecylamine, stearylamine and the same straight-chain primary amines; branched primary amines such as isopropylamine, isobutylamine, 2-ethylhexylamine and branched tridecylamine; straight-chain secondary amines such as dimethylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, dioctylamine, dilaurylamine, ditridecylamine, and distearylamine; branched secondary amines such as diisopropylamine, diisobutylamine, di-2-ethylhexylamine, and dibranched tridecylamine; N-methylbutylamine, N-ethylbutylamine, N-ethylhexylamine, N-ethyllaurylamine, N-ethylstearylamine, N-isopropyloctylamine, N-isobutyl-2-ethylhexylamine and asymmetric secondary amines such as; straight-chain tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tritridecylamine, and tristearylamine; branched tertiary amines such as triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, and tribranched tridecylamine; In addition to tertiary amines having a mixed hydrocarbon group such as N,N-dimethyloctylamine, N,N-dimethyllaurylamine, N,N-dimethylstearylamine, and N,N-diethyllaurylamine, allylamine; amines having an alkenyl group such as diallylamine, triallylamine, and N,N-dimethylarylamine; alicyclic primary amines such as cyclohexylamine and 2-methylcyclohexylamine; primary amines having an aromatic ring substituent such as aniline, benzylamine and 4-methylbenzylamine; alicyclic secondary amines such as N,N-dicyclohexylamine and N,N-di-2-methylcyclohexylamine; secondary amines having an aromatic ring substituent such as dibenzylamine and N,N-di-4-methylbenzylamine; asymmetric secondary amines such as N-cyclohexyl-2-ethylhexylamine, N-cyclohexylbenzylamine, N-stearylbenzylamine and N-2-ethylhexylbenzylamine; alicyclic tertiary amines such as N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine and tricyclohexylamine; tertiary amines having an aromatic ring substituent such as tribenzylamine and tri-4-methylbenzylamine; amines having an ether bond such as morpholine, 3-methoxypropylamine, 3-ethoxypropylamine, 3-butoxypropylamine, 3-decyloxypropylamine, and 3-lauryloxypropylamine; Monoethanolamine, diethanolamine, monoisopropanolamine, monopropanolamine, butanolamine, triethanolamine, N,N-dimethylethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N -Propylethanolamine, N-isopropylethanolamine, N-butylethanolamine, N-cyclohexyl-N-methylaminoethanol, N-benzyl-N-propylaminoethanol, or N-hydroxyethylpyrrolidine, N -alkanolamines such as hydroxyethylpiperazine and N-hydroxyethylmorpholine; Ethylenediamine, N-methylethylenediamine, N,N'-dimethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, N,N -diamines such as dimethyl-1,3-propanediamine, N-cyclohexyl-1,3-propanediamine, N-decyl-1,3-propanediamine, and N-isotridecyl-1,3-propanediamine; N,N'-dimethylpiperazine, N-methoxyphenylpiperazine, N-methylpiperidine, N-ethylpiperidine, quinuclidine, diazabicyclo[2,2,2]octane, 1,8 -cyclic amines such as diazabicyclo[5,4,0]-7-undecene; aromatic amines such as pyridine and quinoline, or any mixture thereof.

Preferred specific examples of these amine compounds include at least one selected from primary, secondary or tertiary amines of straight chain or branched alkyl having 4 to 20 carbon atoms, and alkanolamines, for example, butylamine, Hexylamine, cyclohexylamine, octylamine, tridecylamine, stearylamine, dihexylamine, di-2-ethylhexylamine, straight or branched ditridecylamine, distearylamine, tributylamine, trioctylamine , linear or branched tritridecylamine, tristearylamine, N,N-dimethylethanolamine, N-methyldiethanolamine, triethanolamine, morpholine, and the like.

At least one selected from the amine compounds represented by the general formula (5), H ₃ PW _x Mo _12-x O ₄₀ nH ₂ O (phosphotungstomolybdic acid n-hydrate), H _3+x PV _x Mo _12-x O ₄₀ nH ₂ O (phosphovanadomolybdic acid n-hydrate), H ₄ SiW _x Mo _12-x O ₄₀ nH ₂ O (silicotomolybdic acid n-hydrate), H _4+x SiV _x Mo It is more preferable to use it in the form of at least 1 sort(s) of salt selected from _12-x O ₄₀ .nH ₂ O (silicovadomolybdic acid n-hydrate).

Among the mixed coordination heteropolyanionic compounds, H ₃ PW _x Mo _12-x O ₄₀ nH ₂ O (phosphotungstomolybdic acid n-hydrate), H _3+x PV _x Mo _12-x O ₄₀ nH ₂ O (Invanadomolybdic acid n-hydrate), H ₄ SiW _x Mo _12-x O ₄₀ nH ₂ O (silicotomolybdic acid n-hydrate) mixed coordination heteropolyacids, or organic amine salts of these mixed coordination heteropolyacids Most preferred.

The second coating layer other than the silicon compound-containing layer of the composite particles contained in the metal pigment composition according to the present invention further improves the corrosion resistance of the metal particles (preferably aluminum particles or aluminum alloy particles) serving as the core, other corrosion inhibitors A layer containing It does not specifically limit as a corrosion inhibitor to add, Any well-known corrosion inhibitor can be used. The amount used should just be a range which does not impair the desired effect of this invention. As such a corrosion inhibitor, an acidic phosphoric acid ester, a dimer acid, an organophosphorus compound, the metal salt of molybdic acid, etc. are mentioned, for example.

In the silicon compound-containing layer and/or the second coating layer of the composite particles contained in the metal pigment composition, or as a separate layer, from the viewpoint of adhesion and chemical resistance when a coating film is formed, an organic oligomer or polymer may be further contained. have.

In addition, in the silicon compound-containing layer and/or the second coating layer of the composite particles, or as a separate layer, from the viewpoint of storage stability, inorganic phosphoric acids and their salts, and acidic organic (phosphorous) esters and salts thereof. You may contain at least 1 sort(s) selected from.

Although these compounds are not specifically limited, For example, what is disclosed in Unexamined-Japanese-Patent No. 2019-151678 can be used.

(5) In the composite particle, the ratio of the metal element content based on the metal particles to the silicon content based on the coating layer is 0.02 or more and 0.3 or less in terms of the ratio of the silicon content to the metal element content

The composite particle contained in the metal pigment composition of this invention has the metal particle used as the core, and the one or more coating layers on the surface of the said metal particle. And, as described in detail in the description of the requirement (4) above, at least one layer of the coating layer is a silicon compound-containing layer (so-called silica layer). Therefore, the composite particle of the metal pigment composition according to the present invention comprises a metal element constituting the metal particle serving as the core of the composite particle, and a silicon compound-containing layer (so-called silica layer) constituting the coating layer on the surface of the metal particle. ) from the silicon element as a constituent.

In the composite particle which the metal pigment composition of this invention contains, it is preferable that the ratio of the said silicon element content with respect to the said metal element content is 0.02 or more and 0.3 or less. Here, each element content in a composite particle melt|dissolves, for example, a metal pigment composition, and the content of the metal element and content of the silicon element in the composite particle contained therein is high frequency inductively coupled plasma (ICP) light emission. It can be determined by analysis by spectroscopic analysis.

The content of the metal element constituting the metal particle serving as the core of the composite particle is proportional to the size (ie, particle size) of the metal particle, and a silicon compound-containing layer (so-called silica layer) constituting the coating layer on the surface of the metal particle. The content of the silicon element from the silicon compound is proportional to the thickness of the silicon compound-containing layer (so-called silica layer).

When the ratio is 0.02 or more, the thickness of the silicon compound-containing layer (so-called silica layer) in the coating layer on the surface of the metal particles with respect to the particle size of the metal particles is a thickness that can effectively exhibit corrosion resistance. In addition, when the said ratio is 0.3 or less, the said thickness turns into thickness which the optical performance which a metal particle has can exhibit effectively. As a lower limit, as for the said ratio, it is 0.02 or more, 0.03 or more are preferable, and 0.04 or more are more preferable. As an upper limit, it is 0.3 or less, 0.2 or less are preferable and 0.15 or less are more preferable. That is, in the composite particle of the metal pigment composition according to the present invention, the ratio of the metal element content to the silicon element content is the ratio, so that the corrosion resistance based on the silicon compound-containing layer (so-called silica layer) in the coating layer of the composite particle is obtained. Both optical performance (for example, high luminance, high flip-flop feeling, and excellent color tone of a coating film due to high hiding property) based on the characteristics possessed by the metal particles serving as the core of the composite particles can be effectively exhibited. Specifically, by effectively exhibiting the corrosion resistance based on the silica layer, gas generation is suppressed and good storage stability is obtained even when used as a water-based paint such as a water-based metallic paint or an aqueous ink, and the water resistance when used as a coating film By effectively demonstrating the optical performance based on the intrinsic properties of metal particles, high luminance, high flip-flop feeling, and excellent color tone of the coating film can be obtained even when used for water-based metallic paints or metallic coatings, etc. can also lose

Furthermore, while satisfying the requirements (1) to (4) and the requirements (6) described later, further exhibiting excellent coating film color tones such as high hiding properties and luminance, furthermore, it is applied to coating films such as metallic coating films. Even when used, the excellent adhesiveness can also be exhibited.

The "composite particle" in this physical property requirement (5) refers to the aggregate (aggregate) when a some composite particle is aggregated and fixed.

As the metal particles, as described above, a metal containing only one type of metal element may be used alone, or a combination of two or more types of metals containing only one type of metal element (that is, a combination of two or more types of metal elements containing two or more types of metal elements. metal) may be used. For example, when the metal particle which becomes the core of the composite particle comprises a metal containing one type of metal element, " metal element constituting the said metal particle " in this requirement (5) means the one type of metal It refers to an element, and, for example, when the metal particle used as the core of the composite particle is composed of a metal containing two types of metal elements, " metal element constituting the metal particle " in this requirement (5) means the 2 refers to the metal element of the species. That is, if the metal particle that becomes the core of the composite particle is an aluminum metal particle containing only an aluminum element, " metal element constituting the metal particle " in this requirement (5) refers to an aluminum metal element, and the core of the composite particle is If the metal particle used is a metal particle containing two types of metal elements of an aluminum element and another metal element, it refers to an aluminum metal element and the said other metal element.

As for the metal particle, as mentioned above, it is preferable that it is aluminum or an aluminum alloy, and, as for the metal particle in this invention, it is more preferable that it is aluminum.

The amount of metal particles contained in the composite particles and the silicon content contained in the silicon compound-containing layer constituting the coating layer on the surface of the metal particles are such that the above ratio (that is, this requirement (5)) can be satisfied. As long as it is, it is not particularly limited.

(6) the number ratio of the composite particles having a particle diameter of 0.1 μm or more and 1 μm or less is 10% or less with respect to the total number of the composite particles occupied in the metal pigment composition

The number ratio of the composite particles having a particle diameter of 0.1 μm or more and 1 μm or less (hereinafter also referred to as micro composite particles) to the total number (ie, total number) of the composite particles contained in the metal pigment composition of the present invention is 10% or less to be.

As explained in the above requirement (4), by making at least one layer of the coating layer formed on the surface of the metal particle which becomes the core of the composite particle contained in the metal pigment composition according to the present invention as a silicon compound-containing layer (so-called silica layer), excellent corrosion resistance can be obtained. And, in order to obtain excellent corrosion resistance, this silica layer has a certain thickness which satisfy|fills the above-mentioned requirement (5). However, fine composite particles having a particle diameter of 1 μm or less (specifically, composite particles having a particle diameter of less than 0.1 μm are not recognized as composite particles and excluded because their size is too small and the effect on the performance of the present invention is negligible. Therefore, in composite particles having a particle diameter of 0.1 μm or more and 1 μm or less (that is, it refers to micro composite particles), the ratio of the thickness of the silica layer to the particle diameter of the metal particles serving as the core of the composite particle becomes large, The proportion of the metal itself in the particle is decreasing. Therefore, if the number ratio of the fine composite particles occupied in the metal pigment composition increases, the original optical performance of the metal particles (for example, high luminance, high flip-flop feeling, excellent coating film color due to high hiding property) cannot be exhibited. become Moreover, since the thickness with respect to a particle diameter becomes relatively thick with respect to a particle diameter, such a fine composite particle becomes difficult to orientate, the orientation of the said metal pigment as a whole is inhibited, and it will become impossible to exhibit the original optical performance of a metal particle.

In addition, since the fine composite particles having a particle diameter of 1 μm or less impair the adhesion between the substrate and the coating material, if a large amount of the fine composite particles are present in the metal pigment composition, the adhesion of the coating resin to the substrate is also likely to decrease when used as a coating material. lose

In the metal pigment composition of the present invention, the number ratio of the fine composite particles is 10% or less with respect to the total number of composite particles occupied in the metal pigment composition. Thereby, since the particle size occupied by the whole composite particle contained in the metal pigment composition can suppress the number of fine composite particles, the original optical performance of the metal particle (eg, high luminance, high flip-flop feeling, high hiding property) ) can be achieved.

Furthermore, while satisfying the above requirements (1) to (5), high luminance, high flip-flop feeling, and excellent coating film color tone due to high hiding properties are further exhibited, and individual composites constituting the metal pigment composition Aggregation of particles is suppressed, and furthermore, by effectively exhibiting the corrosion resistance based on the silica layer, gas generation can be suppressed even when used as an aqueous paint such as an aqueous metallic paint or an aqueous ink, and good storage stability is obtained, When used as a coating film, it becomes excellent in water resistance.

The number ratio of the fine composite particles is 10% or less, preferably 5% or less, more preferably 3% or less, and preferably as low as possible from the viewpoint of the total number of composite particles occupied in the metal pigment composition. do.

The "composite particle" in this physical property requirement (6) refers to the aggregate (aggregate) when a some composite particle is aggregated and fixed.

Although there is no restriction|limiting in particular as a measuring method of the number ratio of the composite particle (ie, micro composite particle) which has a particle diameter of 0.1 micrometer or more and 1 micrometer or less, For example, a coating film is produced using the metal pigment composition of this invention, and the said The coating film is photographed with a digital microscope (e.g., KH-3000 manufactured by HiROX) at a magnification such that the total number of particles (i.e., the total number of complex particles) is roughly in the range of 500 or more, and image analysis software (e.g., For example, using Media Cybernetics Co., Ltd.: Image-ProPLUS ver.7.0), from among all the particles contained therein, particles having an equivalent circle diameter of 0.1 μm or more and 1 μm or less are extracted, and this is used as the number with respect to the total number of particles. It can be obtained by measuring. Here, the equivalent circle diameter refers to the diameter of a circle having the same area as the projected area of the particle image, and is generally referred to as the Heywood diameter. For example, even if there are non-circular, distorted particles, if the area is, for example, 78.5 nm ² (corresponding to the area of a circle with a particle diameter = 10 nm), the particle diameter is regarded as 10 nm. In addition, when particles are agglomerated and fixed and the boundary cannot be visually recognized, the equivalent circle diameter can be obtained from the cross-sectional area of the crushed shape in the aggregated and fixed state, What is necessary is just to measure the particle diameter (equivalent circle diameter) of each particle|grain, when a boundary can be visually recognized.

In addition, in the "composite particle" in this physical property requirement (6), as mentioned above, the ultrafine composite particle (specifically, the composite particle with an equivalent circle diameter of less than 0.1 micrometer) has a particle diameter of less than 0.1 micrometer. , because the size is so small that the effect on the performance of the present invention is negligible, it is not recognized as a composite particle and is excluded.

In addition, when the volume distribution of the composite particles is measured with a laser diffraction particle size distribution meter, the number ratio of the composite particles having a particle size of three times or more of the volume-based D ₅₀ (hereinafter, also referred to as coarse composite particles) is, It is preferable that it is 3 % or less with respect to the number (ie, total number) of the whole composite particle which occupies in a metal pigment composition.

Thereby, when it is set as a coating film, it can be set as the metallic coating film with a dense feeling, and the roughness of the surface at the time of setting it as a coating film can be suppressed.

Furthermore, while satisfying the above requirements (1) to (6), further exhibiting excellent color tones such as high hiding properties and luminance, aggregation of individual composite particles constituting the metal pigment composition is suppressed. In addition, even when used as an aqueous paint such as an aqueous metallic paint or an aqueous ink, gas generation can be suppressed, and good storage stability is obtained, and excellent water resistance when used as a coating film, furthermore, a coating film such as a metallic coating film Excellent adhesion can also be exhibited when used for

The number ratio of the coarse composite particles is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less with respect to the total number of composite particles occupied in the metal pigment composition.

The "composite particle" in this physical property requirement refers to the aggregate (aggregate) when a some composite particle aggregates and adheres.

The method for measuring the coarse composite particles is not particularly limited, but for example, a method for obtaining the coating film by observing the coating film with a digital microscope in the same manner as for measuring the fine composite particles, or using a laser diffraction particle size distribution meter or the like. may be saved

The number ratio of the fine composite particles or the coarse composite particles contained in the metal pigment composition of the present invention is mainly determined by appropriately selecting the particle size of the metal particles to be used, and covering the silicon compound-containing layer (and other coating layers if necessary). In the process, it can be controlled by appropriately adjusting the stirring time, the type of the stirring device, the power/degree of stirring (the type and diameter of the stirring blade, the number of rotations, the presence or absence of external stirring, etc.). In particular, the number ratio of the fine composite particles contained in the metal pigment composition of the present invention is, as will be described later, the removal of metal particles with a small particle size before the step of coating the silicon compound-containing layer (and other coating layers if necessary) (mild conditions). grinding and classification), and controlling the silicon compound-containing layer (and other coating layers if necessary) by stirring under mild conditions in the step of coating.

3. Method for preparing metal pigment composition

The metal pigment composition according to the present invention, for example, from a slurry of metal powder, through processes such as grinding, washing, sieving (classification), filtration, concentration, etc. to produce a predetermined flaky (flaky) metal particles, , followed by stirring using a solvent containing water and/or a hydrophilic solvent, it can be suitably manufactured by a manufacturing method including the step of coating the silicon compound-containing layer on the metal particles. More specifically, although the following method is mentioned, It is not limited to this.

The metal pigment composition according to the present invention comprises, for example, (a) metal particles, (b) a silicon-containing raw material comprising at least one of an organosilicon compound, (c) a solvent (water and/or a hydrophilic solvent), and necessary In a mixed solution containing other optional components according to It can be suitably manufactured. This process can usually be carried out under stirring.

(1) Grinding, sieving (classification), filtration process

Here, the case where an aluminum particle is used as a metal particle is mentioned as an example, and it demonstrates.

In general, aluminum particles are prepared by using a method commonly used in the pigment industry such as a dry ball mill method, a wet ball mill method, an atlite method, and a stamp mill method for atomized aluminum powder and/or aluminum foil, and use a grinding aid or inert Grinding in the presence of a solvent to obtain so-called flaky (flaky) aluminum particles, and after this step, removing coarse aluminum particles by sieving (classification), filtration, washing, mixing, etc. A paste-form aluminum particle pigment is obtained through the process of In this specification, this is also called "a paste-form aluminum flake pigment."

Here, the flaky (flaky) aluminum particle with a coarse particle diameter is an aluminum particle which does not pass through the metal mesh of #300 - #800.

In this invention, when grinding|polishing an atomized aluminum powder and/or aluminum foil, it is preferable to carry out on mild conditions. By doing this, thereafter, among the composite particles obtained by forming a coating layer containing at least one silicon compound-containing layer on the surface of the aluminum particles, the composite particles having a fine particle diameter of 1 μm or less (specifically, a particle diameter of less than 0.1 μm) Since the composite particles having a size are too small and the effect on the performance of the present invention is negligible, they are not recognized as composite particles and are excluded. because it can be suppressed.

Here, the mild conditions refer to carrying out in combination by appropriately adjusting conditions such as reducing the mass per one grinding ball and reducing the rotational speed of the grinding device.

In addition to performing the above operation, adjusting the average particle diameter (D ₅₀ ) of the flaky (flaky) aluminum particles to the range of the present embodiment, and also taking into consideration that the productivity is improved, determining the grinding conditions good night.

When it is considered that the average particle diameter (D ₅₀ ) of the flaky (flaky) aluminum particles is in the range of 3 µm or more and 30 µm or less, particularly preferred grinding conditions are as raw materials, preferably Ato with a particle diameter of 1 to 30 µm. Mized aluminum powder is used, the mass per one grinding ball used in the grinding device is preferably 0.08 to 11 mg, and the rotation speed of the grinding device is 33% to 78% with respect to the critical rotation speed (Nc), More preferably, the conditions of 36% to 57% are combined.

The specific gravity of the grinding balls used in a ball mill or the like is preferably 8 or less, more preferably 7.5 or less, and 7 or less from the viewpoint of making it easy to reduce the proportion of fine particles and from the viewpoint of increasing the surface smoothness of the aluminum particles. more preferably.

In addition, it is preferable that the specific gravity of the grinding ball is larger than the specific gravity of the grinding solvent. When the specific gravity of the grinding balls is larger than the specific gravity of the grinding solvent, it is possible to prevent the grinding balls from floating in the solvent, the shear stress between the grinding balls is sufficiently obtained, and grinding tends to proceed sufficiently.

As a grinding ball used in the manufacturing method of the aluminum pigment of this embodiment, one with high surface smoothness, such as a steel ball, a stainless steel ball, a zirconia ball, and a glass ball, from a viewpoint of adjustment of the surface smoothness of aluminum particles and durability of a grinding|polishing ball. desirable.

On the other hand, steel balls, alumina balls, and the like, which have low surface smoothness, are not preferable from the viewpoint of adjustment of the surface smoothness of aluminum particles and durability of the grinding balls.

For this reason, for example, in the case of a steel ball, it is preferable to use the thing whose surface smoothness was improved by mechanical grinding|polishing and chemical grinding|polishing.

As described above, the mass per one grinding ball is preferably 0.08 to 11 mg.

By using the grinding balls with a mass of 0.08 mg/piece or more, the shear stress between the grinding balls is lowered because the grinding balls move in groups or in groups without individual motion, a phenomenon in which grinding does not proceed, the so-called group motion. occurrence can be prevented.

In addition, by using a grinding ball having a mass of 11 mg/piece or less, it is possible to prevent excessive impact force from being applied to the aluminum powder, and to prevent the occurrence of warpage, deformation, cracks, and the like.

As the atomized aluminum powder used as a raw material, a substance with few impurities other than aluminum is preferable.

The purity of the atomized aluminum powder becomes like this. Preferably it is 99 % or more, More preferably, it is 99.5 % or more, More preferably, it is 99.7 % or more.

As for the average particle diameter of the atomized aluminum powder used as a raw material, 2-25 micrometers is preferable.

As a shape of the atomized aluminum powder used as a raw material, things like a spherical powder and a teardrop-like powder are preferable. By using these, there exists a tendency for the shape of the aluminum pigment at the time of grinding|polishing to become brittle. On the other hand, needle-like powder or irregular powder is not preferable because the shape of the aluminum pigment at the time of grinding is brittle.

When manufacturing the aluminum pigment of this embodiment with the grinding|polishing apparatus provided with a ball mill, it is preferable to use the grinding|polishing solvent.

The type of the grinding solvent is not limited to the following, but for example, hydrocarbon solvents such as mineral spirit and solvent naphtha, and low viscosity solvents such as alcohols, ethers, ketones, and esters, which are conventionally used. can be heard

As grinding conditions of the atomized aluminum powder, it is preferable that the volume of the grinding|polishing solvent with respect to the mass of aluminum of the atomized aluminum powder is 1.5-16.0 times, and 2.0-12.0 times are more preferable. When the volume of the grinding solvent with respect to the mass of aluminum of the atomized aluminum powder is 1.5 times or more, warpage, deformation, cracks, etc. accompanying long-time grinding of the atomized aluminum powder can be prevented, and it is preferable.

In addition, when the volume of the grinding solvent relative to the mass of aluminum in the atomized aluminum powder is 16.0 times or less, the uniformity in the mill at the time of grinding is improved, the atomized aluminum powder is efficiently contacted with the grinding media, and grinding is performed. tends to proceed appropriately.

The volume of the grinding balls (volume of grinding balls/volume of grinding solvent) with respect to the volume of the grinding solvent is preferably 0.5 to 3.5 times, more preferably 0.8 to 2.5 times.

When the volume of the grinding balls with respect to the volume of the grinding solvent is 0.5 times or more, the uniformity of the grinding balls in the mill at the time of grinding improves, and grinding tends to proceed appropriately.

In addition, when the volume of the grinding balls with respect to the volume of the grinding solvent is 3.5 times or less, the ratio of the grinding balls in the mill becomes a suitable range, and the stacking of the balls does not become too high, so that the bending and deformation of the particles due to the grinding stress It is preferable because the problem of shape deterioration such as , cracks and the like can be prevented, and a decrease in luminance and strong scattered light can be prevented.

When manufacturing the aluminum pigment of this embodiment with the grinding|polishing apparatus provided with a ball mill, in addition to the grinding|polishing solvent mentioned above, it is preferable to use a grinding|polishing auxiliary agent.

Examples of the grinding aid include fatty acids, aliphatic amines, aliphatic amides and aliphatic alcohols. In general, oleic acid, stearic acid, stearylamine and the like are preferred. Moreover, as an example of an inert solvent, what shows hydrophobicity, such as mineral spirit, solvent naphtha, LAWS, HAWS, toluene, xylene, is mentioned, These can be used individually or in mixture. A grinding aid and an inert solvent are not limited to these.

It is preferable to use a grinding aid in the quantity of 0.2-30 mass % with respect to the mass of the atomized aluminum powder.

It is preferable that the diameter of the ball mill used for the grinding|polishing of atomized aluminum powder is 0.6-2.4 mm.

By using a ball mill having a diameter of 0.6 mm or more, the lamination of the grinding balls does not become too low, the pressure applied to the aluminum particles during grinding processing becomes a suitable range, and grinding tends to proceed appropriately.

In addition, by using a ball mill having a diameter of 2.4 mm or less, the stacking of the grinding balls does not become too high, and the problem of shape deterioration such as warpage, deformation, cracks, etc. It is preferable because it can prevent the scattered light from becoming strong.

As described above, the rotational speed of the ball mill at the time of grinding the atomized aluminum powder is preferably 33% to 78% with respect to the critical rotational speed Nc.

When the rotational speed/critical rotational speed ratio is 33% or more, the aluminum slurry in the ball mill and the uniformity of the ball motion are maintained, which is preferable.

In addition, when the rotation speed/critical rotation speed ratio is 78% or less, the behavior of the grinding ball being swept up or falling under its own weight is prevented, and the impact force applied to the aluminum particles received from the grinding ball does not become too high. It is preferable because the problem of shape deterioration such as warpage, deformation, and cracks is prevented.

In addition, the aluminum pigment of this embodiment can also be manufactured by the vacuum vapor deposition method other than the manufacturing method which has the process of grinding|polishing the atomized aluminum powder mentioned above.

As a grinding|pulverization process, the grinding|pulverization by the wet ball mill method is preferable from a viewpoint of preventing dust explosion and ensuring safety.

Further, in the present invention, before forming a coating layer containing at least one silicon compound-containing layer on the surface of the flaky (flaky) aluminum particles, aluminum particles with a small particle diameter among the aluminum particles are removed in advance by classification. It is preferable to put By doing this, thereafter, among the composite particles obtained by forming a coating layer containing at least one silicon compound-containing layer on the surface of the aluminum particles, the composite particles having a fine particle diameter of 1 μm or less (specifically, a particle diameter of less than 0.1 μm) Since the composite particles having a size are too small and the effect on the performance of the present invention is negligible, they are not recognized as composite particles and are excluded. because it can be suppressed. Specifically, the number ratio of the composite particles having a particle diameter of 0.1 µm or more and 1 µm or less in the aluminum pigment can be suppressed to 10% or less with respect to the total number of composite particles occupied in the aluminum pigment. By using this classification in combination with the grinding under the mild conditions described above, the suppression of the generation of fine composite particles can be further enhanced.

However, the above-mentioned grinding process under mild conditions and the above-mentioned classification for removing flaky (flake-like) aluminum particles with a small particle size do not necessarily have to perform both steps, but only one of them is performed as necessary. also be That is, without performing the grinding step under the mild conditions described above, only a step of removing flaky (flaky) aluminum particles with small particle diameters by classification after the normal grinding step may be used, or the above-mentioned mild conditions may be used. It is good also as a process which does not perform classification only by performing a grinding|polishing process.

As a classification process for removing flaky (flaky) aluminum particles with a small particle size, wet classification is preferable from the viewpoint of ensuring safety, for example, a gravity classifier (sedimentation classifier), Spitz-Casten , a hydraulic classifier, a siphon sizer, a centrifugal classifier, a liquid cyclone, a jet sizer, a rake classifier, an Akins type, a spiral classifier, a ball classifier, a hydro separator, a decanter, and the like.

As metal particles in the production of the metal pigment composition of the present invention, a so-called vapor deposition aluminum pigment produced by peeling and pulverizing a metal layer deposited on a carrier material such as a resin film by physical vapor deposition (PVD) from the carrier material. can also be used. Also in this case, it is important to appropriately adjust the grinding conditions to suppress the generation of fine particles or to remove the fine particles by classification.

(2) Formation step of silicon compound-containing layer

A liquid mixture containing the above-mentioned (a) metal particles, (b) a silicon-containing raw material containing at least one type of organosilicon compound, and (c) a solvent, and optionally other optional components is prepared by mixing these components. can do. The order of mixing is not specifically limited.

As (a) metal particle mentioned above, especially the particle|grains of aluminum or an aluminum alloy can be used suitably. Moreover, the metal particle in the form of a scale (flake form) can be used suitably as the particle shape also mentioned above.

Content (solid content) of the metal particle in the said liquid mixture is not restrict|limited in particular, as long as the metal pigment composition of this invention is obtained, According to the kind, particle size, etc. of the metal particle to be used, it can set suitably.

As the silicon-containing raw material, an organosilicon compound is used. Although it does not restrict|limit as an organosilicon compound, Preferably the thing mentioned above can be used.

At least one of the organosilicon compound represented by the formula (1) (tetraalkoxysilane as a typical example) and/or its condensate, and the silane coupling agent represented by any of the formulas (2) to (4) is suitable can be used

Hereinafter, the case where tetraalkoxysilane is used as an organosilicon compound represented by the said Formula (1) is mentioned as an example, and it demonstrates. In addition, below, tetraalkoxysilane and/or its condensate may be simply collectively called "tetraalkoxysilane".

When using together the tetraalkoxysilane represented by the formula (1) and the silane coupling agent represented by any of the formulas (2) to (4), a method in which both are mixed and used (referred to as a “first method”) can be employed Alternatively, a method including a step of forming a first silicon compound-containing layer by subjecting the metal particles to one treatment and forming a second silicon compound-containing layer by performing the other treatment (referred to as a “second method”) ) may be employed.

As a 1st method, the pH of the liquid mixture containing metal particle|grains, the tetraalkoxysilane represented by said Formula (1), and the silane coupling agent represented by any one of said Formula (2)-(4) is adjusted suitably, for example by and a method including a step of subjecting tetraalkoxysilane and a silane coupling agent to hydrolysis/condensation reaction to form a silicon compound-containing layer.

As the second method, for example, by appropriately adjusting the pH of the mixed solution containing the metal particles and the tetraalkoxysilane represented by the formula (1), the tetraalkoxysilane is hydrolyzed/condensed to form the first surface of the metal particles. A step of forming a silicon compound-containing layer (for example, a silica film containing amorphous silica), and adjusting the pH of a liquid mixture containing metal particles and a silane coupling agent represented by any of the above formulas (2) to (4) and a method including a step of forming a second silicon compound-containing layer on the surface of the first silicon compound-containing layer by subjecting a silane coupling agent to a hydrolysis/condensation reaction.

The usage-amount of the tetraalkoxysilane represented by said Formula (1) or its condensate can be set suitably according to the kind etc. of the tetraalkoxysilane to be used. The amount used is, for example, from the viewpoint of the coating treatment effect, and from the viewpoint of suppressing aggregation of metal particles or a decrease in luminosity, etc., it is 2 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the metal particles (solid content) It is preferable, and it is more preferable that they are 3 mass parts or more and 100 mass parts or less, It is still more preferable that they are 5 mass parts or more and 60 mass parts or less.

Although the usage-amount of the silane coupling agent represented by any one of said Formula (2) - (4) is not specifically limited, From a viewpoint of a desired coating treatment effect, etc., 0.1 mass part or more with respect to 100 mass parts of metal particles (solid content) It is preferable that it is 20 mass parts, It is more preferable that they are 0.5 mass parts or more and 15 mass parts, It is still more preferable that they are 1 mass part or more and 10 mass parts.

The solvent in the liquid mixture, that is, the solvent for the hydrolysis reaction and/or condensation reaction of the organosilicon compound may be appropriately selected according to the type of the silicon-containing raw material used, etc., but usually water, a hydrophilic organic solvent, or a solvent thereof Mixed solvents may be used. By using these solvents, the uniformity of reaction and the uniformity of the hydrolyzate and/or condensation reaction product obtained can be improved. In the aspect in which the silicon compound-containing layer is directly formed on the metal particles, it is particularly preferable that the solvent of the mixed solution contains a hydrophilic organic solvent from the viewpoint of avoiding the rapid reaction between the metal particles and water. In the present invention, a mixed solvent of water and a hydrophilic organic solvent can be suitably used.

Although it does not specifically limit as a hydrophilic organic solvent, For example, Alcohol, such as methanol, ethanol, a propanol, a butanol, isopropanol, octanol; Ether alcohols such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, and dipropylene glycol monomethyl ether; its esters; glycols of ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, polyoxyethylene glycol, polyoxypropylene glycol, and ethylene propylene glycol; and ethyl cellosolve, butyl cellosolve, acetone, methoxypropanol, ethoxypropanol, and other alkoxy alcohols. These can be used 1 type or 2 or more types.

Moreover, when using the mixed solvent of water and a hydrophilic organic solvent as said solvent, as long as the metal pigment composition of this invention is obtained, the ratio of both is not specifically limited.

The amount of the solvent used in the step of forming the silicon compound-containing layer (when pre-dispersing the metal particles, the amount of the solvent is excluded) is not limited, but is usually 100 parts by mass for 100 parts by mass of the metal particles (solid content). It should just be about -10000 mass parts, and it is preferable that they are especially 200 mass parts or more and 1000 mass parts or less. When the usage-amount of a solvent is 100 mass parts or more, the raise of the viscosity of a liquid mixture (slurry) is suppressed, and moderate stirring is attained. In addition, when the amount of the solvent used is 10000 parts by mass or less, it can be prevented that the cost of recovery and regeneration of the treatment liquid becomes high. In addition, in the case of the said 2nd method, the usage-amount of the solvent here points out the sum total of the amount of solvent used for formation of a 1st silicon-compound-containing layer and formation of a 2nd silicon-compound-containing layer.

In the said liquid mixture, you may mix|blend other additives as needed within the range which does not impair the effect of this invention. For example, in addition to catalysts, such as a hydrolysis catalyst and a dehydration-condensation catalyst, surfactant, a metal corrosion inhibitor, etc. are mentioned.

Among these, a hydrolysis catalyst can be used suitably. By mixing the hydrolysis catalyst, the pH of the liquid mixture is adjusted and the organosilicon compound can be efficiently hydrolyzed and dehydrated and condensed, and as a result, a silicon compound-containing layer is efficiently and reliably formed on the surface of the metal particles. it becomes possible to

A known or commercially available hydrolysis catalyst may be used, and it is not specifically limited. As a hydrolysis catalyst, For example, inorganic acids, such as hydrochloric acid, nitric acid, a sulfuric acid, phosphoric acid; organic acids such as benzoic acid, acetic acid, chloroacetic acid, salicylic acid, oxalic acid, picric acid, phthalic acid, and malonic acid; and phosphonic acids such as vinylphosphonic acid, 2-carboxyethanephosphonic acid, 2-aminoethanephosphonic acid, and octanephosphonic acid. These hydrolysis catalysts may be used individually by 1 type, or may be used in combination of 2 or more type.

Moreover, as a hydrolysis catalyst, For example, inorganic alkalis, such as ammonia, sodium hydroxide, potassium hydroxide; inorganic alkali salts such as ammonium carbonate, ammonium hydrogen carbonate, sodium carbonate and sodium hydrogen carbonate; Monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, N,N-dimethylethanolamine, ethylenediamine, pyridine, aniline, choline, amines such as tetramethylammonium hydroxide and guanidine; Salts of organic acids such as ammonium formate, ammonium acetate, monomethylamine formate, dimethylamine acetate, pyridine lactate, guanidinoacetic acid and aniline acetate can also be used. These hydrolysis catalysts can be used 1 type or 2 or more types.

The addition amount of the hydrolysis catalyst is not particularly limited, but is usually 0.01 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the metal particles (solid content), and particularly preferably 0.02 parts by mass or more and 10 parts by mass or less. do. When the amount added is 0.01 parts by mass or more, the amount of the silicon compound-containing layer precipitated may be sufficient. In addition, when the added amount is 20 parts by mass or less, aggregation of the metal particles can be effectively suppressed.

When preparing the mixed solution, each of these components may be mixed uniformly in the mixed solution, and the mixing order is not particularly limited.

It is preferable that preparation of the said liquid mixture is performed under stirring of moderate intensity|strength for manufacture of the metal pigment composition by this invention.

The temperature of the liquid mixture may be at room temperature or under heating. In general, the temperature of the liquid mixture may be 20°C or more and 90°C or less, and it is particularly preferable to control it in the range of 30°C or more and 80°C or less. When the said temperature is 20 degreeC or more, the formation rate of a silicon compound containing layer becomes high, and a process time can be shortened. On the other hand, when the said temperature is 90 degrees C or less, it becomes easy to control reaction, and the probability that a desired composite particle can be obtained can be raised.

It does not specifically limit as a stirrer for stirring a liquid mixture, A well-known stirrer which can stir the liquid mixture containing aluminum particles and an organosilicon compound efficiently and uniformly can be used. Specific examples include a kneader, a kneader, a rotary vessel stirrer, a stirred reactor, a V-shaped stirrer, a double-conical stirrer, a screw mixer, a sigma mixer, a flash mixer, an airflow stirrer, a ball mill, an edge runner, and the like. Further description of the stirrer is given below.

The temperature of the liquid mixture at the time of stirring the liquid mixture containing a metal particle and an organosilicon compound should just be about 10-100 degreeC normally, and it is preferable to set it as 30 degreeC or more and 80 degrees C or less especially. When this temperature is 10 degreeC or more, the reaction time for obtaining a sufficient process effect can be shortened. Moreover, when this temperature is 100 degrees C or less, reaction control for obtaining a desired metal pigment composition becomes easier.

The stirring time of the liquid mixture is not particularly limited as long as it is a time sufficient for the desired silicon compound-containing layer to be formed. It is preferable to set it as 0.5 hour or more and 10 hours or less, for example, and, as for this stirring time, it is more preferable to set it as 1 to 5 hours. When the stirring time is 0.5 hours or more, a sufficient treatment effect can be obtained. Moreover, an increase in processing cost can be suppressed by stirring time being 10 hours or less.

In the liquid mixture, a silicon compound-containing layer is formed on the surface of the metal particles (or through a second coating layer) by hydrolyzing/condensing the silicon-containing raw material. In particular, this hydrolysis/condensation reaction can be carried out by adjusting the pH of the mixed solution or the like.

In the case of pH adjustment, especially in the step in which the silicon compound-containing layer is formed on the surface of the metal particles (or through the second coating layer), the pH value of the mixed solution changes, so that the pH value is appropriately adjusted so that it can be maintained within a certain range. it is preferable In that case, although it is preferable to adjust a pH value by adding a hydrolysis catalyst, unless the characteristic of the metal pigment composition by this invention is impaired, you may adjust a pH value using another acidic or alkaline compound.

When a basic hydrolysis catalyst is used as the hydrolysis catalyst, the pH value is preferably 7 or more and 11 or less, and more preferably 7.5 or more and 10 or less. When the pH value is 7 or more, the silicon compound-containing layer can be formed quickly. On the other hand, when the pH value is 11 or less, aggregation of the metal particles or reduction in luminance can be suppressed, and generation of hydrogen gas due to corrosion can be prevented.

When using an acidic hydrolysis catalyst as a hydrolysis catalyst, it is preferable to make pH value into 1.5 or more and 4 or less, and it is more preferable to set it as 2 or more and 3 or less especially. When a pH value is 1.5 or more, reaction is moderately controlled and it becomes easy to obtain the metal pigment composition containing a desired composite particle. On the other hand, when the pH value is 4 or less, the deposition rate of the silicon compound-containing layer can be maintained high.

Even when any of the first method and the second method are employed, the hydrolyzate of the organosilicon compound represented by the general formula (1) and/or the condensate thereof is contained in an amount of 100 parts by mass of the metal particles (solid content), It is preferable to add 0.01-50 mass parts in conversion of the state in which hydrolysis and condensation reaction were completed, and it is more preferable to add 1-30 mass parts. In addition, the silane coupling agent represented by any one of the said General formulas (2) - (4), and/or the hydrolyzate derived from those partial condensate and/or its condensate is 100 mass parts of metal particles (solid content) On the other hand, in conversion of the state in which hydrolysis and condensation reaction were completed, 0.01-0.8 mass parts is added in total, and it is more preferable to add 0.01-0.7 mass parts.

The addition amount of the hydrolyzate of the organosilicon compound represented by General formula (1) and/or its condensate is to the mass of the organosilicon compound represented by General formula (1) used at the time of manufacture of the metal pigment composition, the said organosilicon compound All of these are hydrolyzed and can be calculated by multiplying the mass ratio before and after the reaction in the case of condensation reaction.

For example, when tetraethoxysilane (TEOS) is used as the organosilicon compound represented by the general formula (1), the hydrolyzate of the organosilicon compound and / using the following mass ratios before and after hydrolysis and condensation reaction Alternatively, the addition amount of the condensate can be calculated.

(hydrolysis)

Si(OC ₂ H ₅ ) ₄ (Molecular Weight: 208) + 4H ₂ O

→Si(OH) ₄ (molecular weight: 96) + (C ₂ H ₅ OH) ₄

(condensation)

Si(OH) ₄ (molecular weight: 96) + Si(OH) ₄ (molecular weight: 96)

→(SiO ₂ ) ₂ (Molecular weight: 60×2)+4H ₂ O

Since the mass becomes 60/208 = 0.288 times before and after the above hydrolysis and condensation reaction, for example, when 10 mass parts of TEOS is used with respect to 100 mass parts of metal particles (solid content), the hydrolyzate and/or its condensation The amount of water added is 0.288 times that, that is, 2.88 parts by mass.

Similarly, the addition amount of a hydrolyzate and/or a condensate thereof such as a silane coupling agent represented by any one of the general formulas (2) to (4) in the general formulas (2) to (4) used in the production of the metal pigment composition By multiplying the mass ratio of the silane coupling agent and/or its partial condensate represented by any of these by the mass ratio before and after the reaction when all of the silane coupling agent and/or its partial condensate are hydrolyzed and subjected to a condensation reaction, it can be calculated can

For example, when methyltrimethoxysilane is used as the silane coupling agent represented by the general formula (2), a hydrolyzate of the silane coupling agent and/or using mass ratios before and after the following hydrolysis and condensation reactions. The amount of the condensate added can be calculated.

(hydrolysis)

CH ₃ Si(OCH ₃ ) ₃ (Molecular Weight: 136) + 3H ₂ O

→CH ₃ Si(OH) ₃ (molecular weight: 94) + (CH ₃ OH) ₃

(condensation)

CH ₃ Si(OH) ₃ (molecular weight: 94) + CH ₃ Si(OH) ₃ (molecular weight: 94)

→(SiCH ₃ O _1.5 ) ₂ (molecular weight: 67×2) + 3H ₂ O

Since the mass becomes 67/136 = 0.49 times before and after the above hydrolysis/condensation reaction, for example, when 1.23 mass parts of methyltrimethoxysilane is used with respect to 100 mass parts of metal particles (solid content), the hydrolyzate and/or the amount of the condensate added is 0.49 times that, that is, 0.60 parts by mass.

In addition, even when either of the said 1st method and the 2nd method are employ|adopted, before combining with the organosilicon compound which is a silicon compound source, a metal particle (or, when forming a 2nd coating layer, before combining with a molybdenum compound) , water, a hydrophilic organic solvent, or a mixed solvent thereof is preferably sufficiently dispersed. In this pre-dispersion (initial dispersion), preferably a part of the dispersion (for example, per minute, 0.5% by mass or more and 30% by mass or less of the entire dispersion, preferably 1% by mass or more and 20% by mass or less, more preferably Preferably, 1 mass % or more and 15 mass % or less) are once withdrawn to the outside of a dispersion tank, and then the degree of dispersion can be raised more by performing external circulation in which it returns again in a dispersion tank. Dispersibility can be further improved by performing ultrasonic treatment outside the dispersion tank in the middle of the flow path of external circulation.

Although ultrasonic treatment is not specifically limited, Usually 10W or more and 1000W or less, Preferably it is 50 or more and 800W or less, Usually 20 seconds or more and 10 minutes or less, Preferably it can perform for about 30 seconds - about 5 minutes. In addition, the amount of the solvent used for this pre-dispersion may be usually about 100 to 10000 parts by mass, 200 parts by mass or more with respect to 100 parts by mass of metal particles (solid content) from the viewpoint of obtaining sufficient dispersion by appropriately adjusting the intensity of stirring. It is preferable that they are 5000 mass parts or less, and it is more preferable that they are 300 mass parts or more and 1000 mass parts or less.

Such pre-dispersion of the metal particles can be usually carried out at 10°C or more and 80°C or less, preferably 15°C or more and 60°C or less, and most preferably around room temperature (about 20 to 30°C). In addition, the pre-dispersion of the metal particles can be carried out for 5 minutes to 10 hours, preferably for 10 minutes to 5 hours (including that in the case of performing ultrasonic treatment).

(3) Formation process of 2nd coating layer

As mentioned above, it is preferable that the 2nd coating layer is especially formed (when formed) between a metal particle and a silicon compound containing layer. Therefore, the layer structure of "metal particle/2nd coating layer/silicon compound containing layer" can be employ|adopted suitably.

Although a 2nd coating layer is not specifically limited, What is necessary is just a molybdenum containing film, a phosphoric acid compound film, etc. Preferred examples of the molybdenum-containing material constituting the molybdenum-containing film include a mixed coordination heteropolyanion compound disclosed in JP-A-2019-151678. Examples of the constituent components of the second coating layer including the mixed coordination heteropolyvalent anion compound are as described above.

Hereinafter, the aspect which forms a molybdenum containing film as a 2nd coating layer between a metal particle and a silicon compound containing layer is mentioned as an example and demonstrated.

When forming a molybdenum-containing film as a second coating layer between the metal particles and the silicon compound-containing layer, prior to the formation of the silicon compound-containing layer, a mixed solution containing the metal particles and a molybdenum compound (typically a mixed coordination heteropolyvalent anion compound) By stirring, a molybdenum containing film can be formed on the surface of a metal particle.

It does not specifically limit as a method of forming a molybdenum containing film on the surface of a metal particle, What is necessary is just a method which can stir the mixture containing a metal particle and a molybdenum compound uniformly in an aqueous solvent. For example, a molybdenum-containing film can be formed on the surface of the metal particles by stirring or kneading a mixture containing the metal particles and the molybdenum compound in a slurry state or a paste state. In the liquid mixture, the molybdenum compound may be dissolved or may be dispersed.

In addition, the stirrer for stirring the mixed solution containing the metal particles and the molybdenum compound is not particularly limited, and a known stirrer capable of efficiently and uniformly stirring the mixed solution containing the aluminum particles and the molybdenum compound can be used. Specific examples include a kneader, a kneader, a rotary vessel stirrer, a stirred reactor, a V-shaped stirrer, a double-conical stirrer, a screw mixer, a sigma mixer, a flash mixer, an airflow stirrer, a ball mill, an edge runner, and the like. Although the example of the stirring blade of a stirrer is not specifically limited, An anchor blade, a paddle blade, a propeller blade, a turbine blade, etc. are mentioned.

The usage-amount of a molybdenum compound can be set suitably according to the kind etc. of the molybdenum compound to be used. Generally, this usage-amount should just be 0.02 mass part or more and 20 mass parts or less with respect to 100 mass parts of metal particles (solid content), and it is especially preferable to set it as 0.1 mass part or more and 10 mass parts or less. When the said content is 0.02 mass part or more, sufficient processing effect can be acquired. Moreover, when the said content is 20 mass parts or less, the brilliance of the metallic pigment composition obtained can be maintained highly.

As a solvent used for mixing a metal particle and a molybdenum compound, water, a hydrophilic organic solvent, or these mixed solvent can be used normally.

Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol, propanol, butanol, isopropanol, and octanol; Ether alcohols such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, and dipropylene glycol monomethyl ether; its esters; glycols of ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, polyoxyethylene glycol, polyoxypropylene glycol, and ethylene propylene glycol; and ethyl cellosolve, butyl cellosolve, acetone, methoxypropanol, ethoxypropanol, and other alkoxy alcohols. These can use 1 type or 2 or more types.

The amount of the solvent used in the formation step of the second coating layer (excluding the amount of the solvent for the pre-dispersion of the metal particles) is not particularly limited, but is usually 50 parts by mass per 100 parts by mass of the metal particles (solid content). It is preferable that they are mass parts or more and 5000 mass parts or less, and it is more preferable that they are 100 mass parts or more and 2000 mass parts or less. When the usage-amount of a solvent is 50 mass parts or more, the uneven distribution of a molybdenum compound and aggregation of a metal particle can be suppressed. Moreover, when the usage-amount of a solvent is 5000 mass parts or less, sufficient processing effect by a molybdenum compound can be acquired with respect to a metal particle.

The temperature of the liquid mixture at the time of stirring the liquid mixture containing a metal particle and a molybdenum compound should just be about 10-100 degreeC normally, and it is preferable to set it as 30 degreeC or more and 80 degrees C or less especially. When this temperature is 10 degreeC or more, the reaction time for obtaining a sufficient process effect can be shortened. Moreover, when this temperature is 100 degrees C or less, reaction control for obtaining a desired metal pigment composition becomes easier.

The stirring time of the mixed solution is not particularly limited as long as it is a time sufficient to form a desired molybdenum-containing film. This stirring time is, for example, preferably 0.5 hours or more and 10 hours or less, more preferably 1 hour or more and 5 hours or less. When the stirring time is 0.5 hours, a sufficient treatment effect can be obtained. Moreover, increase in processing cost can be suppressed because stirring time is 10 hours or less.

After the stirring of the mixed solution containing the metal particles and the molybdenum compound is finished, the particles on which the second coating layer is formed may be recovered. In this case, well-known washing|cleaning, solid-liquid separation, etc. can be performed suitably as needed. For example, it is preferable to wash the liquid mixture using a hydrophilic organic solvent and then filter it using a filter or the like to remove water and unreacted substances from the cake containing the metal particles having the molybdenum-containing film. In this way, the molybdenum-containing film as the second coating layer can be formed. Also when forming another 2nd coating layer, it can carry out according to the said method.

In the aspect of forming the silicon compound-containing layer following the second coating layer (molybdenum-containing film) on the metal particles, after the stirring of the mixed solution containing the metal particles and the molybdenum compound is finished, the particles having the second coating layer are not recovered , in the system, a silicon compound source (typically an organosilicon compound represented by the formula (1), for example, tetraalkoxysilane and/or its condensate, and any of the formulas (2) to (4) You may directly add and stir the dispersion liquid of water and/or a hydrophilic organic solvent of at least 1 sort(s) of the silane coupling agent represented by this. At this time, the dispersion liquid of the organosilicon compound represented by the said Formula (1), for example, tetraalkoxysilane and/or its condensate is added in the system containing the particle|grains with a 2nd coating layer, and then said Formula (2) You may add and stir the dispersion liquid of at least 1 sort(s) of the silane coupling agent represented by any one of thru|or (4) (refer the 2nd method in the above-mentioned "formation process of a silicon compound containing layer").

(4) Stirring conditions

In manufacture of the metal pigment composition which concerns on this invention, it is necessary to perform the formation process of a silicon compound containing layer at least under stirring. Moreover, in manufacture of the metal pigment composition which concerns on this invention, it is preferable to perform not only the formation process of a silicon compound containing layer but also the formation process of a 2nd coating layer under stirring. In the aspect of pre-dispersing the above-mentioned metal particles, it is more preferable to also carry out this under stirring. Further, in the production of the metal pigment composition according to the present invention, it is more preferable to perform the entire process under stirring, including the pre-dispersion of the metal particles, the step of forming the second coating layer, and the step of forming the silicon compound-containing layer.

In the production of the metal pigment composition according to the present invention, at least the step of forming the silicon compound-containing layer is performed under appropriately controlled stirring, whereby the composite particles adhere to each other through the silicon compound-containing layer, or each aggregated particle containing the metal particles It is possible to effectively suppress or prevent the phenomenon covered with the silicon compound-containing layer. In addition, by carrying out the entire process under stirring, including the pre-dispersion of the metal particles, the step of forming the second coating layer, and the step of forming the silicon compound-containing layer (until the time when all the layers to be formed on the surface of the metal particles are formed), It becomes possible to obtain more easily the metal pigment composition which concerns on this invention which satisfies all of the physical-property requirements of (1)-(6).

Description of the stirring conditions demonstrated below can be applied to any process in manufacture of the metal pigment composition which concerns on this invention.

Stirring can be performed with a well-known or commercially available stirring apparatus. For example, at least one of a kneader, a kneader, a rotary vessel stirrer, a stirred reactor, a V-type stirrer, a double cone stirrer, a screw mixer, a sigma mixer, a flash mixer, an airflow stirrer, a ball mill, an edge runner, etc. can be used. .

Agitation is particularly preferably performed under mild conditions.

The mild conditions herein refer to stirring at a low speed in which the tip speed of the stirring blade is 0.5 m/sec or more and 20 m/sec or less, when the silicon compound-containing layer forming step is performed in a stirred reaction tank.

Among the composite particles obtained by forming a coating layer including at least one silicon compound-containing layer on the surface of the metal particles by stirring at such low speed, composite particles having a fine particle diameter (specifically, composite particles having a particle diameter of less than 0.1 µm) Since the particle size is too small and the effect on the performance of the present invention is negligible, it is not considered as a composite particle. to be. Specifically, the number ratio of the composite particles having a particle diameter of 0.1 μm or more and 1 μm or less in the metal pigment composition can be suppressed to 10% or less with respect to the total number of composite particles occupied in the copper metal pigment composition. Agitation under this mild condition can be used in combination with grinding and classification under the mild conditions described above to more effectively reduce the proportion of the composite particles having a fine particle size.

It is preferable to use the apparatus of the stirring tank type|mold which stirs with the stirring blade among the said stirrers. As a result of exerting a pressure shearing action as well as a circulating action for flowing the entire reaction system including a liquid phase by the stirring blade, it is possible to more effectively suppress the generation of agglomeration of the composite particles.

The shape of a stirring blade is not specifically limited, For example, an anchor type, a propeller type, a turbine type, an inclined turbine type, a fan turbine type, a paddle type, an inclined paddle type, and a gate type can be used. Max blend blades (manufactured by Sumitomo Jukai Process Equipment Co., Ltd.) and full zone blades (manufactured by Shinko Kankyo Solutions, Ltd.) are also suitable. Moreover, it is also possible to combine the stirring blades of these shapes in multiple stages.

The stirring speed is preferably stirred to such an extent that the stirring blades are not exposed by the vortex (vortex) generated by the stirring. In addition, in order to suppress the vortex generated by stirring, a cylindrical tank, a square tank, or a tank provided with a baffle plate, etc. can be used suitably.

In the production of the metal pigment composition containing the composite particles according to the present invention, it is preferable to set the optimal size of the stirring tank or stirring blade and the speed of the stirring blade in relation to the amount of the mixed solution and physical properties (density, viscosity, etc.) do. The size of the stirring tank is preferably selected so that the maximum amount of the mixed solution used in the series of steps is 20% or more and 80% or less of the stirring tank. In the case of a cylindrical stirring tank, it is common that the ratio of the height (L) to the inner diameter (D) of the stirring tank is L/D in the range of 0.5 or more and 3.0 or less, and it is usually in the range of 1 or more and 2 or less. In addition, as for the size of a stirring blade, it is common to make a maximum diameter into the range of 0.2 or more and 0.9 or less of the inner diameter of a stirring tank, and it is good to make it into about 0.4 or more and 0.6 or less. The shape (including the length) of the stirring blades is preferably selected appropriately depending on the physical properties of the mixed solution, and it is important that the entire stirring tank is stirred throughout the process. In particular, it is preferable to combine an inclined paddle type, an inclined turbine type, and a propeller type, which are prone to up-and-down flow, in multiple stages, or to use a max blend blade or a full zone blade so as not to generate an unagitated stagnation part near the liquid level or the bottom of the stirring tank. At this time, the distance between the stirring blade and the inner surface of the stirring tank (including the baffle plate) is preferably 5 mm or more apart. By doing in this way, it becomes easy to suppress the damage|damage and deformation|transformation of a metal particle.

The speed of the stirring blade is preferably 0.5 m/s or more and 20 m/s or less at the tip, more preferably 1 m/s or more and 15 m/s or less, and still more preferably 2 m/s or more and 10 m/s or less. When the speed of the tip of the stirring blade is in the range of 0.5 m/s or more and 20 m/s or less, the dispersibility of the composite particles in the resulting metal pigment composition can be increased, and further, individual particle cohesiveness is small, and excellent hiding properties; It has a color tone and it becomes easier to obtain the metal pigment composition with little generation|occurrence|production of a gas. In addition, when the linear speed of stirring is within the above range, damage to metal particles (eg, flaky aluminum powder) is prevented, and the rate of hydrolysis/condensation reaction is appropriately controlled, effectively suppressing aggregation of composite particles. can be

(5) Composite particle recovery process

After the step of forming the silicon compound-containing layer (and optionally the second coating layer) on the metal particles is finished, the obtained composite particles can be recovered. At the time of collection|recovery, you may perform well-known processes, such as washing|cleaning and solid-liquid separation, as needed. For example, it is preferable to wash the dispersion using an organic solvent and then filter it using a filter to remove water and unreacted substances with a cake containing composite particles. In addition, you may heat-process the cake containing composite particle|grains as needed after that at the temperature of the range of 100-500 degreeC, for example. As described later, the recovered composite particles may constitute a metal pigment composition accompanied by a residual solvent containing a small amount of water/hydrophilic solvent used in the production process.

4. Metal Pigment Composition

The metal pigment composition of the present invention obtained as described above contains composite particles comprising metal particles and one or more coating layers on the surface thereof, and is used in the manufacturing process as the remainder of the solid content (non-volatile matter). It can be understood that the metal pigment composition containing a solvent such as water/hydrophilic solvent is constituted.

In a metal pigment composition, an organosilicon compound (For example, at least 1 sort(s) of the organosilicon compound represented by the said General formula (1), and any of the said General formula (2), (3) and (4)) A hydrolyzate of at least one selected from the silane coupling agent and partial condensates thereof) and/or a silicon compound that is a condensate thereof is converted into a state in which the hydrolysis/condensation reaction has been completed with respect to 100 parts by mass of the metal particles 0.02 to 50 parts by mass may be present.

In the metal pigment composition, a compound forming an optional second coating layer (a molybdenum-containing compound in an optional embodiment for forming a molybdenum-containing film as the second coating layer, for example, a mixed coordination heteropolyanion compound) is a metal 0.01 to 10 parts by mass may be present with respect to 100 parts by mass of the particles.

In the metal pigment composition, an optional organic oligomer or polymer may be present in an amount of 0.01 to 50 parts by mass based on 100 parts by mass of the metal particles.

In the metal pigment composition, 0.01 to 20 parts by mass of at least one selected from the group consisting of optional inorganic phosphoric acids and salts thereof, and acidic organic (phosphite) phosphates and salts thereof, based on 100 parts by mass of the metal particles are present in an amount of 0.01 to 20 parts by mass. can

In the metal pigment composition, a solvent including water/hydrophilic solvent used in the manufacturing process may be present as the remainder of the component (non-volatile matter). The quantity of the solvent containing water/hydrophilic solvent may be 0.5 mass % or more and 95 mass % or less of a metal pigment composition, for example. Alternatively, the amount of the solvent containing water/hydrophilic solvent may be 1 mass % or more and 90 mass % or less, or 2 mass % or more and 80 mass % or less, or 5 mass % or more and 70 mass % or less of the metal pigment composition.

The metal pigment composition may optionally include optional components other than the above. As an example of an arbitrary component, at least 1 sort(s) of antioxidant, a light stabilizer, a polymerization inhibitor, and surfactant is mentioned.

As antioxidant, those typified by a phenol-type compound, a phosphorus compound, and a sulfur-type compound can be used.

As the light stabilizer, those used as the antioxidants described above can also be used, but benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylates, oxalic acid derivatives, hindered amine compounds (HALS), Those typified by hindered phenolic compounds can be used.

5. Uses of metal pigment compositions

Such a metal pigment composition can be used for water-based paints, inks, and the like. In addition, this metallic pigment composition can be made into a metallic water-based paint or metallic water-based ink by adding it to a water-based paint or water-based ink in which resins, which are coating film forming components (binders), are dissolved or dispersed in a medium mainly containing water. Moreover, a metal pigment composition can also be used as a water-resistant binder and filler by kneading|mixing with resin etc. You may add antioxidant, a light stabilizer, and surfactant, when mix|blending a metal pigment composition with an aqueous coating material, aqueous ink, resin, etc.

When using a metal pigment composition for a paint or ink, although you may add to a (water-based) paint or (aqueous) ink as it is, it is more preferable to add, after making it disperse|distribute in a solvent beforehand. As a solvent to be used, water, texanol, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, etc. are mentioned. Moreover, as these resins, acrylic resins, polyester resins, polyether resins, epoxy resins, fluororesins, rosin resins, etc. are mentioned, for example. Moreover, as an example of a binder of a paint or ink, rubber is mentioned in addition to resin.

These resins are preferably emulsified, dispersed or dissolved in water. Therefore, a carboxyl group, a sulfone group, etc. contained in resins can be neutralized.

Preferred resins are acrylic resins and polyester resins.

Resins, such as a melamine type hardening|curing agent, an isocyanate type hardening|curing agent, and a urethane dispersion, can be used together as needed. Furthermore, you may combine it with coloring pigments, such as inorganic pigments, organic pigments, and an extender pigment, a silane coupling agent, a titanium coupling agent, a dispersing agent, a settling inhibitor, a leveling agent, a thickener, and an antifoaming agent which are generally added to a paint. In order to make the dispersibility to a coating material favorable, surfactant may be further added, and in order to make storage stability of a coating material favorable, you may add antioxidant, an optical stabilizer, and a polymerization inhibitor further.

Examples of the color pigment include phthalocyanine, quinacridone, isoindolinone, perylene, azolake, iron oxide, yellow lead, carbon black, titanium oxide, pearl mica, and the like.

Although content of the metal pigment composition which concerns on this invention in the said water-based paint or water-based ink (resin composition) is not limited, Usually, what is necessary is just to set it to 0.1 mass % or more and 50 mass % or less, Especially 1 mass % or more and 30 mass % or less is preferable. When this content is 0.1 mass % or more, a high decoration (metallic) effect can be acquired. Moreover, when this content is 50 mass % or less, it can prevent that the characteristic of a water-based paint or water-based ink, for example, weather resistance, corrosion resistance, mechanical strength, etc. is impaired.

Although content of a solvent is not specifically limited, 20 mass % or more and 200 mass % or less may be sufficient with respect to binder content. When the content of the solvent is within this range, the viscosity of the paint and ink is adjusted to an appropriate range, and handling and film formation can be facilitated.

The coating method or printing method of water-based paints etc. is not specifically limited. For example, various coating methods or printing methods can be appropriately employed in consideration of the shape of the water-based paint or the like, the surface shape of the material to be coated, and the like. As a coating method, the spray method, the roll coater method, the brush coating method, the doctor blade method etc. are mentioned, for example. Moreover, as a printing method, gravure printing, screen printing, etc. are mentioned, for example.

The coating film formed with an aqueous coating material etc. may be formed on the undercoat layer by electrodeposition coating etc. or the intermediate|middle layer. Moreover, a top coating layer etc. may be formed on the coating film formed with water-based paint etc. as needed.

In the case of these layer structures, each coat layer is coated, and the next coat layer may be coated after curing or drying. You can do it. In the water-based paint or the like containing the metal pigment composition according to the present invention, a coating film having a good mirror-like brilliance is obtained. It is preferable to employ a method including the step of:

Thermosetting may be sufficient as the hardening method of the coating composition in each coating film layer, and room temperature hardening may be sufficient as it. In addition, the drying method of the coating composition of each coating film layer may use hot air, for example, and natural drying at normal temperature may be sufficient as it.

Although the thickness of the coating film layer by an aqueous coating material etc. is not specifically limited, Usually, 0.5 micrometer or more and 100 micrometers or less are preferable. When the thickness of the coating layer is 0.5 µm or more, the effect of concealing the underlying surface by the ink or the paint is sufficiently obtained. In addition, since the thickness of the coating layer is 100 μm or less, drying is facilitated, and the occurrence of defects such as foaming and sagging can be suppressed.

[Example]

Hereinafter, the present invention will be more specifically described by way of examples, but it should be noted that these examples are merely illustrative, and the present invention is not limited by the description of these examples at all.

1. Evaluation method of various physical properties used in Examples and Comparative Examples

The evaluation methods of various physical properties used in Examples and Comparative Examples are as follows.

(1) Average particle size D ₅₀ measurement of

Using the aluminum pigment composition obtained in each Example and Comparative Example as a sample, the volume-based D ₅₀ of the composite particles contained therein was determined by a laser diffraction particle size distribution meter "LA-300" (manufactured by Horiba Corporation). ) was used for measurement.

As the measurement solvent, isopropanol was used.

About the metal pigment composition containing the composite particle|grains used as a sample, after ultrasonic dispersion for 2 minutes as a pretreatment, it injected|threw-in in a dispersion tank, and after confirming that it became an appropriate concentration, _D50 was measured.

(2) Measurement of the ratio of the Si element to the Al element

The content of the aluminum element and the silicon element in the composite particles contained in the aluminum pigment composition obtained in each Example and Comparative Example was measured by high frequency inductively coupled plasma (ICP) emission spectroscopy.

(3) Measurement of the ratio of the number of composite particles

The number of composite particles (micro composite particles) having a particle diameter of 0.1 μm or more and 1 μm or less in the aluminum pigment compositions obtained in Examples and Comparative Examples, and 3 times or more of D ₅₀ based on the volume of the composite particles as measured above The number of composite particles (coarse composite particles) having a particle size of the size was measured by preparing a metallic paint to prepare a coating film, and measuring the number of composite particles contained in the coating film. Specifically, it is as follows.

First, a metallic paint having the following components was prepared.

Aluminum pigment composition: 0.25 g as a non-volatile matter

Isopropyl alcohol: 18.0 g

Acrylic resin (※1): 24g

Melamine resin (※2): 5g

※1: DIC Co., Ltd., Acrydic 47712

※2: DIC Co., Ltd., Amedia J-820-60

The aluminum pigment composition obtained in each Example and Comparative Example was used.

To prepare a test piece for observation, first, the metallic paint prepared by the above formulation is applied on a polyethylene terephthalate film (PET film) with a 1 mil applicator, left at room temperature for 20 minutes, and then baked at 140° C. for 20 minutes. was performed to prepare a plate.

Next, using a microscope (manufactured by HiROX: KH-3000), the coating film of the produced ceramic plate was photographed at a magnification of 700 times, and using image analysis software (manufactured by Media Cybernetics: Image-ProPLUS ver.7.0), the original equivalent Particles having a diameter of 0.1 µm or more and 1 µm or less, and the equivalent circle diameter of the above-mentioned laser diffraction type particle size distribution meter "LA-300" (manufactured by Horiba, Ltd.) is the volume-based D of the composite particles Particles greater than three times ₅₀ were extracted and counted for each as a number relative to total particles. And, let the former be the number ratio (%) of the composite particles having a particle size of 0.1 μm or more and 1 μm or less, and the latter 3 of the volume basis D ₅₀ when the volume distribution of the composite particles is measured with a laser diffraction particle size distribution meter It was set as the number ratio (%) of the composite particle which has a particle diameter of more than double the size.

In addition, the imaging range was appropriately selected so that the number of particles might be approximately 500.

In addition, particles having an equivalent circle diameter of less than 0.1 µm were excluded from measurement because their size was too small and the effect on the performance of the present invention was negligible.

2. Preparation of aluminum pigment composition

Reference Example 1

In a ball mill having an inner diameter of 2 m and a length of 30 cm, a mixture containing 50 kg of raw material atomized aluminum powder (average particle size: 25 μm), 82.2 kg of mineral spirit, and 1.5 kg of oleic acid is filled, and a steel ball having a diameter of 1.6 mm and a specific gravity of 7.8 was ground using 900 kg.

As for the surface roughness of the steel ball, 0.08 µm (grade G40) or less in the surface roughness Ra (maximum) of JIS B 1501 of the steel ball for ball bearing was used. The ball mill set the rotation speed to 27 rpm, and performed grinding for 6 hours.

After grinding, the slurry in the mill was washed with mineral spirits, filtered through a 400-mesh vibrating sieve, and the slurry was subjected to a liquid cyclone classifier (manufactured by Murata Kogyo Co., Ltd., T-10 Superclone) into fine particles of aluminum pigment. was removed until 2%.

The obtained slurry was filtered and concentrated with a filter, it collect|recovered as an aluminum pigment cake, the non-volatile matter was adjusted, and the aluminum pigment paste (namely, paste-form aluminum flake pigment) of 80 mass % of a non-volatile matter was obtained.

Reference Example 2

Except having used the atomized aluminum powder (average particle diameter: 20 micrometers) as a raw material, operation similar to the reference example 1 was performed, and the aluminum pigment paste of 80 mass % of non-volatile matter was obtained.

Reference Example 3

Using a liquid cyclone classifier (manufactured by Murata Kogyo Co., Ltd., T-10 type Superclone), the same operation as in Reference Example 1 was performed, except that the aluminum pigment of the fine particles was removed until the aluminum pigment became 9%, and non-volatile content of 80% by mass aluminum A pigment paste was obtained.

Example 1

The aluminum pigment paste obtained in Reference Example ¹ (average particle size 16 μm, nonvolatile matter 80% by mass) 465 kg of methoxypropanol (hereinafter also referred to as “PM”) was added to 135 kg, and the mixture was stirred with a stirring blade at 100 rpm (the tip speed of the stirring blade was 2.6 m/sec), Further, the aluminum paste was uniformly dispersed in the PM while performing external circulation in which the 40 L/min dispersion discharged from the bottom was returned to the reactor from the top of the reactor. In the external circulation, ultrasonic waves with a frequency of 20 kHz and an output of 500 W were irradiated for 1 minute in the middle of the flow path to improve the dispersibility of particles.

Then, a solution obtained by dissolving 1 kg of phosphomolybdic acid (H ₃ PW ₆ Mo ₆ O ₄₀ ) hydrate in 5 kg of methoxypropanol was gradually added, and the slurry temperature was maintained at 40° C. and stirred for 1 hour under the same conditions as above. .

Then, after adding 10 kg of tetraethoxysilane as an organosilicon compound, 10 kg of 25% aqueous ammonia and 200 kg of purified water were added over 3 hours. Then, 1.3 kg of methyltrimethoxysilane was further added as a silane coupling agent, and it stirred on the conditions similar to the above for 2 hours. After completion of the reaction, the mixture was cooled and the slurry was filtered.

Thereby, the aluminum pigment composition of 60% of non-volatile matter containing the composite particle|grains which has the metal particle of aluminum and the coating layer which contains the silicon compound-containing layer on the surface was obtained. During the reaction, external circulation while irradiating ultrasonic waves was continued.

Example 2

In the same manner as in Example 1, except that it was changed to the aluminum pigment paste obtained in Reference Example 2 (average particle size of 20 µm, non-volatile content 80% by mass), a composite having aluminum metal particles and a coating layer containing a silicon compound-containing layer on the surface thereof An aluminum pigment composition containing particles and having a non-volatile content of 60% was obtained.

Example 3

In the same manner as in Example 1, except that 3 kg of tetraethoxysilane, 3 kg of 25% aqueous ammonia, 70 kg of purified water, and 0.5 kg of methyltrimethoxysilane were changed, aluminum metal particles and a silicon compound-containing layer were included on the surface The aluminum pigment composition containing the composite particle|grains which has the coating layer which says 60% of non-volatile matter was obtained.

Example 4

50 kg of tetraethoxysilane, 50 kg of 25% aqueous ammonia, 500 kg of purified water, and 6.5 kg of methyltrimethoxysilane. An aluminum pigment composition having a non-volatile content of 60% was obtained, comprising metal particles of and composite particles having a coating layer containing a silicon compound-containing layer on the surface thereof.

Example 5

In the same manner as in Example 1, except that it was changed to the aluminum pigment paste obtained in Reference Example 3 (average particle diameter of 20 µm, non-volatile content 80% by mass), a composite having aluminum metal particles and a coating layer containing a silicon compound-containing layer on the surface thereof An aluminum pigment composition containing particles and having a non-volatile content of 60% was obtained.

Comparative Example 1

Except not having performed reaction with an organosilicon compound and a silane coupling agent, it carried out similarly to Example 1, and obtained the aluminum pigment composition of 60% of non-volatile matter.

Comparative Example 2

Except not having removed microparticles|fine-particles using the liquid cyclone classifier, it carried out similarly to Example 1, and obtained the aluminum pigment composition of 60% of non-volatile matter.

Comparative Example 3

One inclined paddle-type stirring blade having a blade diameter of 0.35 m is disposed at a position of 0.3 m from the bottom, the rotation speed is 1500 rpm, and the operation is performed in the same manner as in Example 1 except that external circulation is not performed, and non-volatile content is 60% of an aluminum pigment composition was obtained.

Comparative Example 4

1.5 kg of tetraethoxysilane, 1.5 kg of 25% aqueous ammonia, 35 kg of purified water, and 0.25 kg of methyltrimethoxysilane was carried out in the same manner as in Example 1 to obtain an aluminum pigment composition having a nonvolatile content of 60%.

Comparative Example 5

100 kg of tetraethoxysilane, 100 kg of 25% aqueous ammonia, 1000 kg of purified water, and 13 kg of methyltrimethoxysilane, and the same procedure as in Example 1 except that the addition time of aqueous ammonia and purified water was 7 hours A 60% aluminum pigment composition was obtained.

Table 1 summarizes the composition and manufacturing conditions of each of the Examples and Comparative Examples.

Moreover, the following coating materials were prepared using the aluminum pigment composition obtained by each said Example and the comparative example, and also the following method evaluated as a coating material. Those results are also shown in Table 1.

3. Preparation of paints and coatings

(1) Preparation of paint

A water-based metallic paint having the following components was prepared.

・Aluminum pigment composition: 12.0 g as a non-volatile matter

·Methoxypropanol: 18.0 g

・Polyoxyethylene lauryl ether (nonionic surfactant, manufactured by Matsumoto Yushi Seyaku Co., Ltd., trade name “Actinol L5”): 6.0 g

Purified water: 12.0g

・Water-soluble acrylic resin (※1): 110.0g

・Melamine resin (※2): 18.0 g

※1: Mitsui Chemical Co., Ltd., Almatex WA911

※2: Nippon Cytech Industries Co., Ltd. Cymel 350

The aluminum pigment composition obtained in each Example and Comparative Example was used.

After mixing the above components, the pH is adjusted to 7.7 to 7.8 with dimethylethanolamine, and the viscosity is measured with a carboxylic acid-based thickener and purified water from 650 to 750 mPa·s (B-type viscometer, No. 3 low, 60 rotations, 25° C.) ) was adjusted. Thereby, a water-based metallic paint was prepared and used for evaluation.

(2) Preparation of coating film

The water-based metallic paint prepared by the above formulation is air-sprayed to a dry film thickness of 4 μm on a 12 cm × 6 cm steel sheet with intermediate coating, and pre-dried at 90° C. for 10 minutes, followed by an organic solvent-type top coating paint , air spray coating was carried out so that it might become a dry film thickness of 20 micrometers, it was made to dry at 140 degreeC for 30 minutes, the coating board was produced, and it was set as the coating film for evaluation.

4. Evaluation method

(1) Evaluation 1 (Paint Stability)

The change of state of the aqueous metallic paint for evaluation prepared according to the above formulation after standing at 23° C. for 24 hours was visually evaluated as follows.

(circle): A change in particular was not recognized.

(triangle|delta): Aggregation of an aluminum pigment is confirmed slightly.

x: Aggregation of an aluminum pigment is confirmed.

(2) Evaluation 2 (storage stability (gas generation) evaluation)

200 g of the aqueous metallic paint prepared by the above prescription was collected in a flask, and the accumulated amount of hydrogen gas was observed in a constant temperature water bath at 60° C. for 24 hours. It evaluated as follows according to the amount of gas generation, and it was set as the parameter|index of the storage stability in a coating material.

○: less than 5ml

△: 5 ml or more and less than 20 ml

×: 20 ml or more

(3) Evaluation 3 (Evaluation of color tone of coating film)

Brightness, flip-flop feeling (FF), and hiding property were evaluated using the said coating film for evaluation.

The organic solvent-type top coating paint was prepared by mixing the following components and dispersing it with a spatula for 3 to 4 minutes, and then adjusting the paint viscosity in a pod cup No. 4 for 20.0 seconds.

・A345 (manufactured by DIC, acrylic clear resin) 420 g

・L-117-60 (manufactured by DIC, melamine resin) 165 g

· Solvesso 100 (manufactured by Exxon Chemical Co., Ltd., aromatic solvent) 228 g

・Brightness

The luminance of the coating film was evaluated using the laser-type metallic feeling measuring apparatus Alcop LMR-200 manufactured by Kansai Paint Corporation. As optical conditions, it has a laser light source with an incident angle of 45 degrees and a light receiver at 0 degrees and -35 degrees of light receiving angles. As a measurement value, the IV value was calculated|required at the light receiving angle -35 degree|times from which the maximum light intensity was obtained except the light of the specular reflection area reflected by the coating-film surface among the reflected light of a laser. IV value is a parameter proportional to the intensity|strength of the specular reflection light from a coating film, and shows the magnitude of luminance. The determination method is as follows.

(circle): The fall width from the reference|standard (comparative example 1) was less than 40.

(triangle|delta): The fall width from the reference|standard (comparative example 1) was 40 or more.

x: The fall width from the reference|standard (comparative example 1) was 40 or more.

・Flip-flop feeling (FF)

It evaluated using the variable angle colorimeter made by Suga Industrial Co., Ltd. The FF value was calculated|required from the logarithmic inclination of the reflected light intensity (L value) in observation angle (light reception angle) 30 degree|times and 80 degree|times with respect to the light source with an incident angle of 45 degree|times. The FF value is a parameter proportional to the degree of orientation of the metallic pigment, and indicates the magnitude of the flip-flop feeling of the pigment. The determination method is as follows.

○: 0.05 or more higher than the standard (Comparative Example 1)

△: the difference from the standard (Comparative Example 1) is less than ±0.05

x: 0.05 or more lower than the reference (Comparative Example 1)

· Concealment

The prepared aqueous metallic paint was applied on a polyethylene terephthalate sheet (PET sheet) with a 2 mil applicator so as to have a dry film thickness of 15 µm, and the coating film dried at 140°C for 30 minutes was visually determined.

○: It was equal to or slightly lower than the standard (Comparative Example 1).

(triangle|delta): It was slightly lower than the reference|standard (comparative example 1).

x: It was significantly lower than the reference|standard (Comparative Example 1).

(4) Evaluation 4 (Paint Adhesiveness/Grid Test)

Cellophane tape (registered trademark: Nichiban Co., Ltd., CT-24) was adhered to the coating film for evaluation formed on the coating plate, pulled at an angle of 45 degrees, and the degree of peeling of the coating film was visually observed. . The judgment criteria are as follows.

○: No peeling

△: there is some peeling

×: with peeling

An evaluation result is shown in Table 1. The composite metal pigment according to the present invention that satisfies all of the above physical property requirements (1) to (6) obtained in each example has good stability as a paint, little gas generation (that is, has good storage stability) Moreover, it was confirmed that high brightness|luminance, a high flip-flop feeling, and high hiding property were shown (that is, it has a favorable coating color tone), and also it was excellent also in adhesiveness as a coating film.

The composite metal pigment of the present invention and a coating film obtained using the same have excellent designability, gloss, bubble suppression, stability in water-based paints, etc., at a high level exceeding the limits of the prior art, so paints and inks , resin kneading agent, etc., various uses in which metal pigments are conventionally used, more specifically, automobile bodies, automobile repair materials, automobile parts, home appliances, plastic parts, PCM paints, high weather resistance paints, heat resistant paints, anticorrosive paints, It can be suitably used in ship-bottom paints, offset printing inks, gravure printing inks, screen printing inks, etc. has the potential to be used.

Claims (7)

A metal pigment composition comprising metal particles and composite particles having one or more coating layers on the surface thereof,
(1) the shape of the composite particles is flaky,
(2) D ₅₀ on a volume basis when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 3 µm or more and 30 µm or less,
(3) the average thickness of the composite particles is 20 nm or more and 300 nm or less,
(4) at least one layer of the coating layer is a silicon compound-containing layer,
(5) in the composite particle, the ratio of the metal element content based on the metal particles to the silicon content based on the coating layer is 0.02 or more and 0.3 or less in terms of the ratio of the silicon content to the metal element content,
(6) the number ratio of the composite particles having a particle diameter of 0.1 μm or more and 1 μm or less is 10% or less with respect to the total number of the composite particles occupied in the metal pigment composition;
The metal pigment composition. The metal pigment according to claim 1, wherein the ratio of the number of the composite particles having a particle size three times or more of D ₅₀ on a volume basis when the particle size distribution of the composite particles is measured by the laser diffraction particle size distribution meter is 3% or less of the total number of the composite particles occupied in the composition. The metal pigment composition according to claim 1, wherein the metal particles are aluminum or an aluminum alloy. The metal pigment composition according to claim 1, further comprising a coating layer comprising at least one of a metal, a metal oxide, a metal hydrate, and a resin. The metallic pigment composition according to claim 1, wherein the at least silicon compound-containing layer is disposed as an outermost layer. A water-based metallic paint comprising the metallic pigment composition according to any one of claims 1 to 5. The metallic coating film containing the metal pigment composition in any one of Claims 1-5.