KR20220142928A - Composite metal pigment composition and method for producing the same - Google Patents

Abstract

Provided are: a composite metal pigment composition having a high nonvolatile (solid) content, excellent in dispersibility in a coating material, especially water-based paint, capable of forming a coating film excellent in color tone, brightness, concealability, etc., capable of obtaining a coating material, especially water-based paint excellent even in storage stability and capable of balancing these characteristics at a high level; and a method for manufacturing the same. In a composite metal pigment composition including metal particles and composite particles including a metal oxide coating formed on the surface of the metal particle, (1) the shape of the composite particle is scaly; (2) when measuring the particle size distribution of the composite particles by a laser diffraction particle size distribution meter, a volume-based average particle size D_(50) is 1-30 ㎛; (3) the average particle thickness of the composite particles is 20-300 nm; (4) the solid content concentration of the composite metal pigment composition is 70-95 mass%; (5) a hydrophilic solvent having a boiling point of 80-150 ℃ occupies 80 mass% or more of the non-solid content of the composite metal pigment composition; and (6) when filtering the composite metal pigment composition by a filter of 200 meshes, a residue is 0.1 mass% or less of the solid content.

Description

Composite metal pigment composition and its manufacturing method

The present invention relates to a composite metal pigment composition comprising metal particles and composite particles having a metal oxide coating formed on the surface thereof, and a method for producing the same, and more particularly, while reducing the amount of volatile organic compounds (VOCs) , a composite metal pigment that effectively suppresses aggregation and deformation of composite particles, and has a high level of excellent properties such as low VOC, storage stability when used in water-based paints, suppression of particles, designability, and hiding properties of the coating film. It relates to a composition and a method for preparing the same.

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 field of paints, the necessity of switching to a water-based paint with a small amount of organic solvent used is increasing as a measure for saving resources, improving the working environment, and reducing pollution. In order to improve the stability of the metal pigment in an aqueous coating material, for example, a pigment using composite particles in which metal particles are coated with a metal oxide such as amorphous silica has been proposed. Also in such a water-based coating material, further reduction of VOC is calculated|required. In order to reduce VOC, it is effective to improve the nonvolatile matter (solid content) content in the manufacturing process. , agglomerate, and furthermore, defects occur in the coating of metal oxides such as silica, which deteriorates water resistance and deteriorates storage stability. In addition, it is possible to improve the content of non-volatile matter by volatilizing the solvent by heating or under reduced pressure, but in this case, the surface dries prematurely, the particles adhere and aggregate, and it becomes impossible to disperse without agglomeration in the solvent or water. As described above, the composite metal pigment composition in which the content of nonvolatile matter is improved by the conventional method is accompanied by problems such as poor dispersibility during paint production, inability to express a desired color tone, and poor storage stability. This was strongly demanded.

For example, in Patent Document 1, it is described to provide a PVD metal effect pigment present in the form of a powder or in a highly concentrated form, to the effect that the PVD pigment powder should be substantially free of agglomeration, to the effect that it should have good redispersion performance, etc. This is described. However, aggregation after redispersion is not directly evaluated, and dispersibility in an aqueous solvent is not reported either.

In Patent Document 2, suction filtration through a Buchner funnel is described in the production of a coated aluminum effect pigment, and the formation of a water-based paint system using the aluminum effect pigment is described. has not been reported about

Japanese Patent Publication No. 2017-533982 Japanese Patent Publication No. 2013-518948

In view of the limitations of the prior art, an object of the present invention is a composite metal pigment composition with a high non-volatile matter (solid content) content, excellent dispersibility in paints, especially water-based paints, color tone, brightness, hiding properties, etc. It is an object to provide a composite metal pigment composition capable of forming such an excellent coating film and obtaining a coating material having excellent storage stability, particularly an aqueous coating material, and having these properties balanced at a high level, and a method for producing the same.

As a result of intensive research, the present inventors have found that the above object can be achieved by using a specific hydrophilic solvent as a solvent constituting the composite metal pigment composition, and/or performing solvent volatilization under specific conditions in the production of the composite metal pigment composition. Found that it can be done, and came to complete the present invention.

That is, the 1st invention of this application and its 1st aspect are as follows.

[One]

A composite metal pigment composition comprising metal particles and composite particles having a metal oxide coating formed on the surface thereof,

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

(2) a volume-based average particle diameter D ₅₀ when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 1 to 30 μm,

(3) the average particle thickness of the composite particles is 20 to 300 nm,

(4) the solid content concentration of the composite metal pigment composition is 70 to 95 mass %,

(5) 80 mass % or more of the non-solid content of the composite metal pigment composition is hydrophilic and a solvent having a boiling point of 80 to 150 ° C.,

(6) The composite metal pigment composition, wherein residues when the composite metal pigment composition is filtered through a 200-mesh filter are 0.1% by mass or less of the solid content.

[2]

The composite metal pigment composition according to [1], wherein the proportion of non-agglomerated primary particles in the composite particles is 35% or more on a number basis.

[3]

The composite metal pigment composition according to [1] or [2], wherein the ratio of the bent composite particles to the composite particles is 10% or less on a number basis.

[4]

The composite metal pigment composition according to any one of [1] to [3], wherein at least one layer of the metal oxide coating is a silicon compound-containing layer.

[5]

The composite metal pigment composition according to any one of [1] to [4], wherein the average layer thickness of the metal oxide coating is 5 to 200 nm.

[6]

The composite metal pigment composition according to any one of [1] to [5], wherein the metal particles contain aluminum or an aluminum alloy.

[7]

The composite metal pigment composition according to any one of [1] to [6], wherein the composite particles further have a coating layer comprising at least one selected from a metal, a metal oxide, a metal hydrate, and a resin.

In addition, the 2nd invention and 3rd invention of this application, and its 1st aspect are as follows.

[8]

It is a method for producing a composite metal pigment composition having the following steps 1) to 3),

1) The process of dispersing metal particles in a solvent

2) The step of coating the metal particles with a metal oxide

3) A step of washing, filtration and solvent volatilization of the metal particles obtained in step 2) and the composite particles having a metal oxide coating formed on the surface thereof

The solvent in step 3) is a mixed solvent of two or more solvents having mutual compatibility and different boiling points by 10°C or more,

The said manufacturing method in which solvent volatilization in process 3) is performed in the state of the slurry containing the said composite grain|particle and the said solvent.

[9]

It is a method for producing a composite metal pigment composition having the following steps 1) to 3),

1) The process of dispersing metal particles in a solvent

2) The step of coating the metal particles with a metal oxide

3) A step of washing, filtration and solvent volatilization of the metal particles obtained in step 2) and the composite particles having a metal oxide coating formed on the surface thereof

The said manufacturing method which divides and implements the solvent volatilization in process 3) into three or more steps.

[10]

The production method according to [8] or [9], wherein the moisture content of the solvent at the time of solvent volatilization in step 3) is 10% by mass or less.

According to the present invention, a novel composite metal pigment composition not found in the prior art can be obtained.

The composite metal pigment composition of the first invention of the present application, while reducing the amount of volatile organic compounds (VOC), effectively suppresses aggregation, deformation, etc. of composite particles, low VOC, storage stability when used in water-based paints, etc., suppression of particles, Excellent properties of the coating film, such as designability and hiding properties, can be balanced at a high level beyond the limits of the prior art.

According to the production methods of the second and third inventions of the present application, while reducing the amount of volatile organic compounds (VOC), aggregation, deformation, etc. of composite particles are effectively suppressed, storage stability when used for low VOC, water-based paints, etc. It is possible to efficiently produce a composite metal pigment composition in which the excellent properties of the coating film such as suppression, designability, and hiding properties are balanced at a high level beyond the limits of the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below according to 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 as defined in the appended claims.

The first invention of the present application is a composite metal pigment composition comprising metal particles and composite particles having a metal oxide coating formed on the surface thereof,

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

(2) a volume-based average particle diameter D ₅₀ when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 1 to 30 μm,

(3) the average particle thickness of the composite particles is 20 to 300 nm,

(4) the solid content concentration of the composite metal pigment composition is 70 to 95 mass %,

(5) 80 mass % or more of the non-solid content of the composite metal pigment composition is hydrophilic and a solvent having a boiling point of 80 to 150 ° C.,

(6) The said composite metal pigment composition is the said composite metal pigment composition whose residues when the said composite metal pigment composition was filtered with a 200-mesh filter are 0.1 mass % or less of solid content.

Composite particles constituting the composite metal pigment composition

The composite metal pigment composition according to the first invention of the present application includes metal particles and composite particles having a metal oxide coating formed on the surface thereof.

That is, in this specification, the term "composite metal pigment composition" includes metal particles and composite particles having a metal oxide coating formed on the surface thereof as essential components, and further includes a specific non-solid content.

The composite metal pigment composition according to the first invention of the present application may contain components other than that, for example, an organic treatment agent, water, and/or a solvent containing a hydrophilic solvent.

metal particles

The composite particles constituting the composite metal pigment composition according to the first invention of the present application include metal particles and a metal oxide coating formed on the surface thereof. That is, one or more layers of metal oxide coatings are formed on the surface of the metal particles serving as the cores of the composite particles. The metal oxide coating usually has a layered structure.

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. are known. Or any of the metals used as a commercially available metallic 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.

A metal particle may be used individually by 1 type, and may be used in combination of 2 or more type.

It is preferable that aluminum or an aluminum alloy is contained, and, as for the metal particle in 1st invention of this application, it is more preferable that 95 mass % or more is comprised from aluminum element.

Although the average particle diameter in particular of a metal particle is not restrict|limited, It is preferable that it is an average particle _diameter which can lead to D50 in the particle size distribution of the composite particle mentioned later. That is, it is preferable to set the average volume particle diameter (D ₅₀ ) 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 1 to 30 μm or to facilitate it. do.

The average particle diameter of the metal particles is determined by grinding, sieving and filtering the raw material atomized metal powder (for example, aluminum powder) using a ball mill, etc., the particle diameter of the raw material atomized metal powder, etc. In the case of use, 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.

The thickness and shape of the metal particles are not particularly limited, either, but they are preferably flaky (flaky) having an average particle thickness of 10-300 nm. Thereby, as a result that the composite particle which comprises the composite metal pigment composition by 1st invention of this application can also have a scale-like shape easily, high hiding power etc. can be acquired more reliably.

It is preferable that the average thickness of a metal particle is a thickness which can lead to the average thickness of the composite particle mentioned later, and, specifically, it is preferable that it is 10-300 nm. Thereby, aggregation and deformation|transformation of a composite particle are effectively suppressed, and it becomes easy to implement|achieve the outstanding designability in a coating film, glossiness, suppression of particles, stability in an aqueous coating material, etc. The average thickness of a metal particle becomes like this from the said viewpoint, Preferably it is 15-250 nm, More preferably, it is 20-200 nm.

Here, the average particle thickness of the metal particles can be measured by a method known in the art, for example, using a metal pigment composition comprising metal particles and composite particles having a metal oxide coating on the surface thereof. It can measure by forming a coating film, acquiring the FE-SEM image (field emission scanning electron microscope image) of the cross section, and performing image analysis. More specifically, it can be measured by the method described in the Examples of the present application.

It is preferable that it is 30-1500, as for the aspect-ratio (shape factor which divided the average particle diameter by average thickness) of the scale-like metal particle, it is more preferable that it is 50-1000, It is especially preferable that it is 80-700. When the aspect-ratio of a metal particle is 30 or more, a higher luminosity can be acquired. Moreover, when the aspect-ratio of a metal particle is 1500 or less, the mechanical strength of a flake is maintained and a stable color tone can be obtained.

The average thickness of the metal particles is similar to the volume basis D ₅₀ , in the process of grinding, sieving and filtering the raw atomized metal powder (eg, aluminum powder) using a ball mill or the like, It can be controlled by appropriately adjusting the particle size, the mass per one grinding ball in the case of using a ball mill, the rotation speed of the grinding device, the sieve powder, and the degree of the filter press.

In addition, the metal particles do not necessarily consist of only metal, and unless the effect of the first invention of the present application is impaired, for example, particles of synthetic resin, particles of inorganic particles such as mica, glass, etc. Can be used. In the first invention of the present application, particles containing aluminum or an aluminum alloy are particularly preferable from the viewpoints of particularly high weather resistance, small specific gravity, and ease of availability.

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 be used as they are, or may be used after removing the fatty acids on the surface with an organic solvent or the like beforehand. In addition, a so-called aluminum vapor deposition foil having a volume average particle diameter (D ₅₀ ) of 3 to 20 μm and an average thickness (t) of 10 to 110 nm can also be used.

metal oxide coating

The composite particles constituting the composite metal pigment composition of the first invention of the present application have a metal oxide coating formed on the surface of the metal particles.

A metal oxide coating is a film comprised by the layer containing a metal oxide, and may be formed in the whole surface of the surface of a metal particle, and may be formed in only a part of the surface. It is preferable to form in the front surface from viewpoints, such as water resistance and storage stability at the time of using for a paint.

As for the metal oxide coating, all may be comprised by the metal oxide, and only that part is comprised by the metal oxide, and may contain components other than a metal oxide.

The metal oxide constituting the metal oxide coating is a compound containing oxygen and at least one metal element as its constituent elements.

Accordingly, the metal oxide may be a metal oxide in a narrow sense having only oxygen and at least one metal element as its constituent elements, but as long as oxygen and at least one metallic element are included in the constituent elements, the oxygen and the metal An element other than an element may be included in the structural element, for example, a metal hydroxide, oxide hydrate, oxynitride, etc. may be sufficient. Moreover, the compound containing an organic group may be sufficient.

The metal oxide may be a so-called single oxide having only one type of metal element as a constituent element, or may be a complex oxide containing two or more types of metallic elements as constituent elements.

A typical metal may be sufficient as the at least 1 sort(s) of metal element which is a structural element of a metal oxide, and a transition metal may be sufficient as it. Furthermore, a so-called semimetal element may be sufficient. Among them, a metal oxide containing silicon as a constituent element is particularly suitable as a metal oxide constituting the metal oxide coating.

Specific examples of suitable metal oxides as metal oxides constituting the metal oxide coating include silicon oxide, aluminum oxide, boron oxide, zirconium oxide, cerium oxide, iron oxide, titanium oxide, chromium oxide, tin oxide, molybdenum oxide, vanadium oxide, and their oxide hydrates. , their hydroxides, and mixtures thereof. Among them, silicon oxide, aluminum oxide and mixtures thereof, and oxide hydrates and hydroxides thereof are preferably used. Particularly preferably, silicon oxides such as silicon oxide, silicon hydroxide, and/or silicon oxide hydrate can be used.

The use of silicon oxide for the metal oxide coating is particularly advantageous from the viewpoints of realizing good storage stability in a water-based coating material, improving water resistance in a coating film, suppressing gas generation, and the like.

By using silicon oxide for the metal oxide coating, the metal oxide coating is usually 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 compound [H ₃ SiO(H ₂ SiO) nSiH ₃ ] (where n represents an arbitrary positive integer), SiO ₂ , SiO ₂ ·nH ₂ O (provided that n is optional) is a positive integer of .) and the like. 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.

Further, the metal oxide coating using silicon oxide may be a layer formed using an organosilicon compound (including a silane coupling agent) as a starting material. In this case, the metal oxide coating may contain the unreacted organosilicon compound or its derived component within the range which does not impair the effect of 1st invention of this application. In a typical example in this case, the metal oxide coating can be formed by hydrolyzing the organosilicon compound.

Although the mass of the metal oxide coating layer in the case of using a silicon oxide is not specifically limited, It is preferable that it is 1-20 mass parts with respect to 100 mass parts of metal particles, It is more preferable that it is especially 2-15 mass parts. When the silicon content of the metal oxide coating is 1 part by mass or more with respect to 100 parts by mass of the metal particles, the corrosion resistance, water dispersibility, stability, and the like of the composite metal pigment composition can be maintained high. When the silicon content of the metal oxide coating is 20 parts by mass or less with respect to 100 parts by mass of the metal particles, aggregation of the composite particles, and deterioration of color tones such as hiding properties and metallic gloss can be prevented.

The metal oxide coating of the composite particles contained in the composite metal pigment composition according to the first invention of the present application is particularly preferably hydrophilic. The composite particles usually form a composite metal pigment composition in a dispersed form in an aqueous solvent (water or a mixed solvent containing water and an organic solvent). However, when the metal oxide coating has a hydrophilic surface, the composite particles are formed in such an aqueous solvent It can be highly dispersed in Furthermore, since a metal oxide such as silicon oxide (amorphous silica, etc.) is very stable in an aqueous solvent, it is possible to provide a composite metal pigment containing composite particles highly stable in an aqueous solvent. From this point of view, in the composite particles contained in the composite metal pigment composition according to the first invention of the present application, at least one layer, preferably the outermost layer, is preferably a metal oxide film, and a silicon compound-containing layer (particularly including a Si-O bond) It is especially preferable that it is a layer comprised of the compound which Since metal oxide is also excellent in affinity with metal particles, when the composite particle has a coating layer composed of a plurality of layers, in addition to the metal oxide coating of the outermost layer, a layer other than the outermost layer, particularly preferably a layer in contact with the metal particles As such, a metal oxide layer, particularly preferably a silicon compound-containing layer (particularly a Si-O-based coating layer), may be formed separately.

The thickness of the metal oxide coating of the individual composite particles is not particularly limited as long as the average particle thickness of the composite particles is in the range of 20 to 300 nm, as will be described later. The thickness of the metal oxide coating is preferably in the range of usually about 5 to 200 nm (especially 10 to 100 nm, furthermore, 20 to 70 nm). When the thickness of the metal oxide coating is 5 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, when the thickness of the metal oxide coating is about 200 nm or less, the brightness, clarity, and hiding power of the coating film can be maintained at a high level.

When the silicon compound-containing layer is included in the metal oxide coating of the individual composite particles, the thickness of the silicon compound-containing layer is not particularly limited as long as the average thickness of the composite particles is in the range of 2 to 300 nm as described later. The thickness of the silicon compound-containing layer is usually in the range of 5 to 200 nm from the viewpoint of exhibiting the function of the layer, particularly preferably in the range of 10 to 100 nm, and further preferably in the range of 20 to 70 nm.

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

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

Si(OR ¹ ) ₄ ... (One)

(Wherein, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and when R ¹ is two or more, all may be 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 may be the same, some may be the same, or all may be different. 1≤m≤3.)

R ⁴ _pR 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 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 R ⁷ is two or more, all are the same, some are the same, or 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. Among these hydrocarbon groups, methyl, ethyl, propyl and butyl are particularly preferable. In addition, as for four R< ¹ >, all 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, or may contain a halogen group such as fluorine, chlorine or bromine. Among these, a C1-C18 hydrocarbon group is especially preferable. In addition, when there exists two or more R< ² >, they may all be 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. Among these hydrocarbon groups, methyl, ethyl, propyl and butyl are particularly preferable. In addition, when there exists two or more R< ³ >, they may all be 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 the 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 ureido group, a mercapto group, and a polysulfide. group, an isocyanate group, etc. are mentioned.

Moreover, when there exists two or more R< ⁴ >, they may all be 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 a halogen group such as fluorine, chlorine or bromine. Among these, a C1-C18 hydrocarbon group is especially preferable. In addition, when there exists two or more R< ⁵ >, they may all be 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. Among these hydrocarbon groups, methyl, ethyl, propyl and butyl are particularly preferable. In addition, when there exists two or more R< ⁶ >, they may all be 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-styryl trimethoxy 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 -Ureid propyltriethoxysilane, 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, or may contain a halogen group such as fluorine, chlorine or bromine. Among these, a C1-C12 hydrocarbon group is especially preferable. In addition, when there exists two or more R< ⁷ >, they may all be 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 methyl trichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, octyldimethylchlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, tetrachlorosilane, and the like. can be heard

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, you can also use a hydrophilic solvent 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.

Physical properties of composite particles and composite metal pigment composition

In the composite metal pigment composition according to the first invention of the present application, the composite particles constituting it satisfy the following physical property requirements.

(1) The shape of the composite particle is scaly.

(2) The volume-based average particle diameter D ₅₀ when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 1 to 30 µm.

(3) The composite particle has an average particle thickness of 20 to 300 nm.

The composite metal pigment composition according to the first invention of the present application also satisfies the following requirements as a composition.

(4) The composite metal pigment composition has a solid content concentration of 70 to 95% by mass.

(5) A solvent having a boiling point of 80 to 150°C with hydrophilicity occupies 80% by mass or more of the specific solid content of the composite metal pigment composition.

(6) The residue when the composite metal pigment composition is filtered with a 200-mesh filter is 0.1% by mass or less of the solid content.

Hereinafter, each of these physical property requirements is demonstrated.

(1) The shape of the composite particle is scaly.

The composite particles contained in the composite metal pigment composition according to the first invention of the present application have a flaky shape. By containing the scale-like composite particles, the composite metal pigment composition of the first invention of the present application can effectively form a coating film having excellent properties such as high hiding power.

The flaky composite particles are easily deformed in processes such as stirring, separation, and filtration during manufacturing, and in particular, strong centrifugation to increase the nonvolatile matter (solid content) content, or filtration under strong pressure, etc. tend to be more easily deformed. , In the present invention, it is possible to effectively suppress the deformation of the scale-like composite particles while realizing a high non-volatile matter (solid content) content.

Here, that the composite particles are scaly means that the particles are preferably in a shape having a high aspect ratio within a numerical range described later.

The scale-like composite particles can be produced by, for example, using a scale-like metal particle as a raw material in the production of the composite particles. As such metal particles, for example, known or commercially available paste-like aluminum flakes can be used.

It is preferable that the aspect-ratio (shape coefficient obtained by dividing the average particle diameter by the average thickness) of the scale-like composite particles contained in the composite metal pigment composition according to the first invention of the present application is 30 to 700. When the aspect-ratio of a composite particle is 30 or more, it becomes easy to obtain a higher luminosity. Moreover, when the aspect-ratio of a composite particle is 700 or less, the mechanical strength of a composite particle is maintained and it becomes easy to obtain a stable color tone. It is preferable that the aspect-ratio is 50-600, and it is more preferable that it is 80-500.

(2) The volume-based average particle diameter D ₅₀ when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 1 to 30 μm

When the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter, the volume-based average particle diameter D ₅₀ is 1 to 30 µm. Thereby, aggregation and deformation of particles are effectively suppressed, and a coating film formed using a composite metal pigment composition or an aqueous coating material containing the same can realize excellent designability, gloss, particle suppression, stability in aqueous coating materials, etc. can D ₅₀ on a volume basis is also generally referred to as a median diameter.

From the viewpoint of obtaining excellent designability, gloss, particle suppression, stability in water-based paints, etc., 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 preferably 2 to 25 μm, particularly preferably 3 to 20 μm.

The "composite particle" in this physical property requirement 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 refers to a particle diameter 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, "LA-300" (made by Horiba Corporation), etc. can be used. Hydrophilic solvents, such as water, isopropanol, and methoxypropanol, can be used as a measurement solvent. For example, the composite metal pigment composition containing the composite particles of the sample is subjected to ultrasonic dispersion for about 2 minutes as a pretreatment, then put into a dispersion tank and after confirming that it is properly dispersed, D ₅₀ can be measured.

D ₅₀ based on the volume of the composite particles constituting the composite metal pigment composition is, for example, in the step of grinding and sieving and filtering the raw material atomized metal powder (eg, aluminum powder) using a ball mill or the like, Particle size and input amount of atomized metal powder, amount of grinding solvent such as mineral spirit, type and amount of grinding aid, mass and input amount per one grinding ball when using a ball mill, rotation speed of grinding device, sieve powder and filter By appropriately adjusting the degree of press, etc., and in the step of coating the metal oxide coating (and other coating layers if necessary), the pH, concentration, stirring temperature, 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 addition, although the particle size tends to be enlarged due to agglomeration during metal oxide coating treatment, since particle enlargement causes a decrease in color tone, a decrease in hiding properties, and a decrease in the appearance of the coating film, in particular, particles by pretreatment of the raw material aluminum paste used for the treatment. It is effective to prevent hypertrophy.

(3) The average particle thickness of the composite particles is 20 to 300 nm

The average thickness of the composite particles included in the composite metal pigment composition according to the first invention of the present application is 20 to 300 nm. Thereby, while satisfying the above requirements (1) and (2), aggregation and deformation of the composite particles are effectively suppressed, and excellent designability in the coating film, gloss, particle suppression, stability in water-based paints, etc. can be realized

From the above viewpoint, the average thickness of the composite particles is preferably 20 to 250 nm, more preferably 20 to 200 nm.

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

The average thickness of the composite particles here can be calculated by measuring the average particle thickness of the metal particles and the thickness of the metal oxide coating, and from these, according to the following formula.

Average particle thickness of composite particles = average particle thickness of metal particles + thickness of metal oxide coating × 2

The average particle thickness of a metal particle can be measured by the method demonstrated by said (2).

The thickness of the metal oxide coating can be measured by a method known in the art, for example, it can be measured by STEM (scanning transmission electron microscope). More specifically, it can be measured by the method described in the Examples herein.

The average thickness of the composite particles contained in the composite metal pigment composition is, similarly to the volume basis D ₅₀ , a step of treating the raw metal powder, a step of coating a metal oxide coating such as a silicon compound-containing layer (and other coating layers if necessary) etc., pH, concentration, stirring temperature, stirring time, type of stirring device, power/degree of stirring (type and diameter of stirring blade, number of rotations, It can be controlled by appropriately adjusting the presence or absence of external stirring, etc.). In addition, although the particle size tends to be enlarged due to agglomeration during metal oxide coating treatment, since particle enlargement causes a decrease in color tone, a decrease in hiding properties, and a decrease in the appearance of the coating film, in particular, particles by pretreatment of the raw material aluminum paste used for the treatment. It is effective to prevent hypertrophy.

(4) The composite metal pigment composition has a solid content concentration of 70 to 95% by mass.

The solid content concentration of the composite metal pigment composition according to the first invention of the present application is 70 to 95 mass%.

The composite metal pigment composition according to the first invention of the present application has a solid content concentration of 70 to 95 mass %, so that it is possible to realize a coating material capable of forming a coating film of good appearance while realizing a low VOC (volatile organic compound) reduction. have. More specifically, when the solid content concentration is 70% by mass or more, the VOC content such as a solvent can be sufficiently reduced. On the other hand, when solid content concentration is 95 mass % or less, uniform dispersion at the time of forming a coating material is easy, and generation|occurrence|production of the particle in a coating film, etc. can be suppressed effectively.

It is preferable that solid content concentration is 75-95 mass %, It is more preferable that it is 80-95 mass %, It is especially preferable that it is 85-95 mass %.

The solid content concentration of the composite metal pigment composition is a mass ratio of the solid content (non-volatile content) contained in the composite metal pigment composition. The solid content concentration can be determined as a ratio of the mass to the mass before heating by measuring the mass after heating a predetermined amount of the composite metal pigment composition to volatilize the volatile matter. More specifically, it can be measured, for example, by the method described in the Examples herein.

The solid content concentration of the composite metal pigment composition can be appropriately adjusted by filtration, volatilization, or the like, to remove volatiles such as a solvent used for dispersion of metal particles or formation of a metal oxide film in the production of the composite metal pigment composition.

In order to implement|achieve the high solid content concentration as specified in the 1st invention of this application, it is preferable to use the low boiling point solvent which is easy to remove by volatilization. Such a low boiling point solvent is not necessarily suitable for dispersion of metal particles or formation of a metal oxide film. Therefore, after dispersion of metal particles or formation of a metal oxide film, the solvent is replaced with a solvent with a lower boiling point. also be

Moreover, it is also preferable to perform volatilization in stages, for example, after volatilizing, you may perform operation which diffuses a composite particle in a solvent, and volatilize again.

Moreover, in order to implement|achieve a high solid content concentration, it is also preferable to combine filtration and volatilization, and it is especially preferable to volatilize after filtration reduces the amount of volatile matter.

A high solid content concentration can also be realized by removing a solvent or the like by centrifugation or filtration under a relatively strong pressure, but such an operation causes agglomeration and/or deformation of the scale-like composite particles, and another requirement of the first invention of the present application , for example, it should be noted that the average particle diameter D ₅₀ based on a predetermined volume or that there is a possibility of making it difficult to realize a predetermined amount of residue.

In realizing the solid content concentration specified in the first invention of the present application, the production of the second invention of the present application and/or the third invention of the present application in that volatile matter can be sufficiently removed while effectively preventing aggregation and deformation of the composite particles It is particularly preferred to employ a method.

(5) A solvent having a boiling point of 80 to 150°C with hydrophilicity occupies 80% by mass or more of the specific solid content of the composite metal pigment composition

As for the non-solid content of the composite metal pigment composition according to the first invention of the present application, 80 mass % or more of the solvent is hydrophilic and has a boiling point of 80 to 150° C. (hereinafter also referred to as “specific solvent”).

Since the specific solvent has a boiling point of 80 to 150° C., it is easily volatilized, and extreme high temperature or reduced pressure is not required for volatilization. The solid content can be improved by removing non-solid content such as solvent.

In addition, since the specific solvent is hydrophilic, it becomes easier to disperse the composite metal pigment composition according to the first invention of the present application in water because the specific solvent occupies 80% by mass of the non-solid content, and it is much easier to form a uniform water-based paint. becomes Moreover, since it is hydrophilic, it becomes much easier to remove the water in a composition by azeotrope etc., and aggregation caused by water|moisture content can be suppressed still more effectively.

Although the concept of a hydrophilic solvent is common understanding among those skilled in the art, for example, a solvent whose solubility in water is 20 g/g or more at normal temperature can be used suitably as a hydrophilic solvent. In addition, a solvent having an sp value (solubility parameter) of 10.5 or more can be preferably used as the hydrophilic solvent.

It is preferable that a specific solvent occupies 80-100 mass % of the specific solid of a composite metal pigment composition, It is more preferable that it occupies 85-100 mass %, It is especially preferable that it occupies 90-100 mass %.

The quantity (ratio) of a specific solvent can be suitably adjusted by adjusting the composition of the solvent used for manufacture of a composite metal pigment composition. It is usually possible to calculate from the amount (ratio) of a specific solvent, the amount of the various solvents used in the production of the composite metal pigment composition, and the amount of the various solvents removed, but the calculation is complicated due to the complicated process of filtration and volatilization at the time of production In this difficult case, the solvent can be extracted from the obtained composite metal pigment composition with a solvent such as THF (tetrahydrofuran), and measurement can be performed by LC-MS (liquid chromatography mass spectrometer) or the like.

Suitable examples of the specific solvent include methoxypropanol, isobutanol, normal butanol, isopropanol, and normal propanol.

Only one type may be used for these specific solvents, and may be used combining two or more types.

(6) The residue when the composite metal pigment composition is filtered with a 200-mesh filter is 0.1% by mass or less of the solid content.

The residue when the composite metal pigment composition according to the first invention of the present application is filtered with a 200-mesh filter is 0.1% by mass or less of the solid content.

Since the filter eye size of 200 mesh is about 74 μm, the composite particles having an average particle diameter D ₅₀ on a volume basis of 1 to 30 μm and an average particle thickness of 20 to 300 nm are most It passes through this 200 mesh filter. Therefore, the residue when the composite metal pigment composition is filtered with a 200-mesh filter is a composite particle in which particles are adhered and aggregated, and it is preferable that the ratio of the composite metal pigment composition to solid content is low.

In the composite metal pigment composition according to the first invention of the present application, since the residue when filtered through a 200-mesh filter is 0.1% by mass or less of the solid content, adhesion of particles to each other and aggregation are effectively suppressed, and aggregation is prevented by dispersing in a solvent or water It is possible to form a suppressed coating material, and it is possible to form a coating film excellent in appearance such as effectively suppressing particles.

It is preferable that it is 0.05 mass % or less of solid content, and, as for the quantity of the residue at the time of filtering with a 200-mesh filter, it is more preferable that it is 0.01 mass % or less, It is especially preferable that it is 0.005 mass % or less.

The amount of residue when filtered with a 200-mesh filter is determined by dispersing the composite metal pigment composition well in the solvent, then filtering with a 200-mesh filter, measuring the dry mass of the residue, and measuring the dry mass of the residue with this in the original composite metal pigment composition. From the solid content mass, the ratio of the residue to the solid content can be determined. More specifically, it can be measured, for example, by the method described in the Examples herein.

The amount of residue when filtered with a 200-mesh filter can be reduced by suppressing adhesion and aggregation of composite particles to each other by various methods described in the present specification. In particular, it is effective to reduce the amount of residue to use a lot of the said specific solvent. In addition, employing the manufacturing method of the second invention of the present application and/or the third invention of the present application, while effectively preventing aggregation and deformation of the composite particles, removing volatile matter is also effective in reducing the amount of residue.

Preferred physical properties of composite particles, etc.

In the composite metal pigment composition according to the first invention of the present application, it is preferable that the composite particles constituting the composition have some or all of the following physical properties and characteristics in addition to the physical property requirements of (1) to (3) above.

The proportion of non-agglomerated primary particles in the composite particles is 35% or more

In the composite metal pigment composition according to the present embodiment, it is preferable that the ratio of primary particles without aggregation to the total composite particles contained in the composite metal pigment composition is 35% or more on a number basis. When the proportion of primary particles is 35% or more, it means that individual particle aggregation is suppressed, and the degree of aggregation is smaller not only in the primary particles but also in the aggregated particles. Thereby, while the coating film formed using the composite metal pigment composition shows the outstanding designability, glossiness, and suppression of a particle, it becomes still easier to improve stability in an aqueous coating material, etc.

In addition, since individual particle cohesiveness is suppressed in this way, mild stirring for dispersion is sufficient, so that deformation of particles by stirring can be significantly reduced.

From the viewpoint of promoting the above effect, the proportion of non-agglomerated primary particles in the aggregate of composite particles is more preferably 40% or more, particularly preferably 50% or more.

The ratio of primary particles without agglomeration to the composite particles is usually preferably higher, and there is no upper limit in particular, and it is ideal that it is 100%.

The proportion of non-agglomerated primary particles in the composite particles can be measured by a method known in the art, and includes, for example, an aggregate of metal particles and composite particles having a metal oxide coating on the surface thereof. A coating film is formed using a metal pigment composition, and an FE-SEM image (field emission scanning electron microscope image) of the cross section is obtained and image analysis is performed, or an evaluator compares the primary particles and aggregated particles in the FE-SEM image. It can measure by counting a number. More specifically, it can be measured, for example, by the method described in the Examples herein.

The proportion of non-agglomerated primary particles in the composite particles can be improved by, for example, increasing the amount of the specific solvent used, adopting the manufacturing methods of the second invention of the present application and/or the third invention of the present application, etc. .

In addition, it can be controlled by selecting and processing the metal particles constituting the composite particles, and by appropriately setting the type and manufacturing conditions of the metal oxide coating formed on the metal particles. In the existing technology, attempts have been made to enhance mechanical dispersion by increasing the number of stirring rotations during coating treatment and setting the Reynolds number to a certain value or more. There is a problem in that there is a limit and that the scaly thin particles break or deform due to the strong stress at the time of stirring.

On the other hand, by performing a pretreatment for improving the dispersibility on the metal particles before performing the coating treatment with the metal oxide on the metal particles, it is possible to suppress aggregation of the particles during the coating treatment, whereby there is no aggregation 1 The proportion of tea particles can be significantly increased.

For example, when the metal particles used as raw materials are dispersed in a solvent and supplied, the solvent is replaced with the same water as the solvent used for the coating treatment, and if desired, a heating treatment is performed for a certain period of time to apply the solvent to the surface of the metal particles. The aggregation generated at the time of the coating treatment can be significantly suppressed by making it sufficiently suitable for the coating. In addition, adding a small amount of surfactant at this time is also effective for suppressing aggregation.

Since the dispersibility of the metal particles itself is improved by these treatments, there is no need to perform excessive stirring during the coating treatment, and even mild stirring can produce primary particles without agglomeration. For this reason, it becomes possible to significantly reduce the deformation|transformation of the particle|grains at the time of a coating process, and it becomes easy to implement|achieve the outstanding designability in a coating film, glossiness, suppression of particles, stability in a water-based coating material, etc.

As a factor affecting the ratio of primary particles without agglomeration other than the above, in the process of grinding, sieving and filtering the raw material atomized metal powder (eg, aluminum powder) using a ball mill, etc., the raw material atom The particle size of the maized metal powder, etc., 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 the filter press, and the metal oxide coating (and if necessary, the silicon compound-containing layer) In the process of coating other coating layers), pH, concentration, stirring temperature, stirring time, type of stirring device, power/degree of stirring (type and diameter of stirring blades, rotational speed, presence or absence of external stirring, etc.), and the like, and by appropriately adjusting these, the proportion of primary particles without aggregation can be controlled.

The ratio of the bent composite particles to the composite particles is 10% or less by number.

In the composite metal pigment composition according to the present embodiment, it is preferable that the ratio of the bent composite particles to the total composite particles contained in the composite metal pigment composition is 10% or less. Thereby, while the coating film formed using the composite metal pigment composition shows the outstanding designability, glossiness, and suppression of a particle, it becomes still easier to improve stability in an aqueous coating material, etc.

The ratio of the bent composite particles is understood as an index related to the degree of deformation or breakage of the composite particles. When the proportion of the bent composite particles is 10% or less, the degree of deformation or breakage of the composite particles is small, thereby reducing the ratio of the untreated surface (surface on which the metal oxide film is not formed) of each composite particle, so that it is applied to the water-based paint. In addition, since it becomes easy to form a uniform and sufficient coating|coating to individual particle|grains by improving the stability in the individual particle|grains, and individual particle|grain aggregation property becomes still smaller, the excellent designability on the surface of the coating film formed using the composite metal pigment composition , a coating film exhibiting gloss and particle suppression can be obtained.

The smaller the ratio of the bent composite particles to the aggregate of composite particles, the better. This ratio becomes like this. Preferably it is 6 % or less, More preferably, it is 3 % or less. The lower the proportion of the bent composite particles, the more preferable, so there is no particular lower limit, but ideally it is 0%.

The proportion of the bent composite particles in the composite metal pigment composition can be measured by a method known in the art, and includes, for example, an aggregate of metal particles and composite particles having a metal oxide coating on the surface thereof. It can measure by forming a coating film using the metal pigment composition to do, acquiring the FE-SEM image (field emission scanning electron microscope image) of the cross section, and performing image analysis. More specifically, in the FE-SEM image, the ratio of the straight-line distance between both ends of the cross-section of the metal particle to the path length between the two ends along the cross-section of the metal particle is 0.8 times or less, and the particle is determined as a bent particle, It can measure by calculating|requiring the number ratio. More specifically, it can be measured, for example, by the method described in the Examples herein.

The ratio of the bent composite particles to the composite particles can be reduced by, for example, increasing the amount of the specific solvent used, adopting the manufacturing methods of the second invention of the present application and/or the third invention of the present application, or the like.

In addition, in the process of coating the metal oxide coating (and other coating layers if necessary), pretreatment for improving the dispersibility of the raw aluminum paste, stirring time, type of stirring device, power/degree of stirring (type of stirring blade and Diameter, rotation speed, presence or absence of external stirring, etc.), etc. can be controlled by suitably adjusting.

Furthermore, by improving the dispersibility of the particles themselves during the reaction by pre-treatment of the raw material aluminum paste, mild stirring for dispersion is sufficient, so that the deformation of the particles by stirring can be significantly reduced.

second coating layer

The coating layer of the composite particles contained in the composite metal pigment composition according to the first invention of the present application is not particularly limited except for having at least one layer of metal oxide coating, and a coating layer other than the metal oxide coating (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, etc.), a metal oxide (titanium oxide, zirconium oxide, iron oxide, etc.), a metal hydrate and It is preferable that at least 1 sort(s) of resin (synthetic resins, such as an acrylic resin, an alkyd resin, a polyester resin, a polyurethane resin, a polyvinyl acetate resin, a nitrocellulose resin, a fluororesin, etc.) are included. 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 metal oxide coatings, such as a silicon compound containing layer, can be accelerated|stimulated.

It is preferable that a 2nd coating layer is especially formed between metal oxide coating|cover, such as 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/metal oxide coating" can be employ|adopted suitably. Although not particularly limited, examples of the molybdenum-containing coating include those disclosed in Japanese Patent Application Laid-Open No. 2003-147226, International Publication No. 2004/096921 pamphlet, Japanese Patent No. 5979788, and Japanese Patent Application Laid-Open No. 2019-151678. have. 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 Japanese Patent Application Laid-Open No. 2019-151678.

In another modified form, the second coating layer may be formed on the outside of the metal oxide coating such as a layer containing metal particles and a silicon compound. 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 a silicon compound or the like in the metal oxide coating of the silicon compound-containing layer or the like.

A mixed coordination heteropolyvalent anion compound preferably used for forming a second coating layer other than the metal oxide coating of the composite particles contained in the composite metal pigment composition according to the first invention of the present application (a film containing molybdenum as a typical example) is particularly Although not limited, the following examples are specifically mentioned.

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 represented by the formula, when a mixed coordination heteropolyvalent anion is expressed with [X _p M _q N _r O _s ] ^t , the heteropolyvalent anion becomes [X _p M _q O _s ] ^t , and further isopolyanions [M It is also distinguished from _q O _s ] ^t . However, X as a hetero atom represents an element of IIIB, IVB, VB groups, such as B, Si, Ge, P, and As, B, Si, and P are preferable among these. 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 also have numerous structures, but 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 (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 (silicotungstomolybdic acid·n-hydrate), H _4+x SiV _x Mo _12-x O ₄₀ ·nH ₂ O (silicium tungstomolybdic acid·n-hydrate), etc. are examples (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 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 it in the form of a salt with at least 1 sort(s) 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.)

Examples of the amine compound as the counter cation source of the mixed coordination heteropolyvalent anion compound include linear or branched alkyl primary, secondary, or tertiary amines, tertiary amines having a mixed hydrocarbon group, alicyclic primary amines, aromatic ring substituents Primary amines, alicyclic secondary amines, secondary amines having an aromatic ring substituent, asymmetric secondary amines, alicyclic tertiary amines, tertiary amines having an aromatic ring substituent, amines having an ether bond, alkanolamines, diamines, Cyclic amines, aromatic amines, etc., or these arbitrary mixtures are illustrated.

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, trioctyl amines, straight-chain 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 a salt with at least 1 sort(s) selected from _12-x O ₄₀ ·nH ₂ O (silicicavanado molybdic 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 metal oxide coating of the composite particles included in the composite metal pigment composition according to the present embodiment is used in order to further improve the corrosion resistance of the metal particles (preferably aluminum particles or aluminum alloy particles) serving as the core. A layer containing a corrosion inhibitor may be sufficient. It does not specifically limit as a corrosion inhibitor to add, Any well-known corrosion inhibitor can be used. The usage-amount should just be the range which does not impair the desired effect of 1st invention of this application. 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.

From the viewpoint of adhesion and chemical resistance when a coating film is formed in the metal oxide coating and/or the second coating layer or as a separate layer of the composite particles contained in the composite metal pigment composition, an organic oligomer or polymer may be contained. can

In addition, in the metal oxide coating 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) phosphoric acid esters and salts thereof. You may contain at least 1 sort(s) chosen from the group.

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

Composite Metal Pigment Composition

The composite metal pigment composition of the first invention of the present application includes composite particles comprising metal particles and at least one metal oxide coating on the surface thereof, wherein the composite particles meet the requirements of (1) to (3) above, and , The composite metal pigment composition satisfies the requirements of (4) to (6) above, and other requirements are not imposed, but as the remainder of the solid content (non-volatile content) other than the composite particles, unreacted organosilicon compound; In some cases, it contains a compound that forms the second coating layer, an oligomer or polymer derived therefrom, and the like, and further contains a solvent such as water used in the manufacturing process in addition to the specific amount of the specific solvent related to the above requirement (5). there is

In the composite metal pigment composition, an organosilicon compound (for example, at least one organosilicon compound represented by the general formula (1), and any of the general formulas (2), (3) and (4) Hydrolyzate of at least 1 sort(s) and/or the silicon compound which is a condensate of the silane coupling agent used and at least 1 sort(s) selected from their partial condensate may exist.

In the composite metal pigment composition, a compound forming an optional second coating layer (a molybdenum-containing compound in an optional embodiment of forming a molybdenum-containing film as the second coating layer, for example, a mixed coordination heteropolyanion compound) is present. can

Any optional organic oligomers or polymers may be present in the composite metal pigment composition.

In the composite metal pigment composition, at least one selected from the group consisting of optional inorganic phosphoric acids and salts thereof, and acidic organic (phosphorous) esters and salts thereof may be present.

In the composite metal pigment composition, a solvent including water/hydrophilic solvent used in the manufacturing process may be present.

The composite 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, an optical stabilizer, 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), What is typified by a hindered phenol type compound can be used.

Examples of the surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, and poly Polyoxyalkylene alkylphenyl ethers such as oxyethylene nonylphenyl ether, polyoxyalkylene alkylamino ethers such as polyoxyethylene laurylamino ether and polyoxyethylene stearylamino ether, sorbitan monolaurate, and sorbitan monopalmi sorbitan fatty acid esters such as tate, sorbitan monostearate, and sorbitan monooleate; polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate; polyalkylene glycol fatty acid esters such as polyethylene glycol monolaurate, polyethylene glycol monooleate, polyethylene glycol monostearate, polyethylene glycol dilaurate, and polyethylene glycol distearate; Nonionic surfactants typified by glycerin fatty acid esters, such as lauric acid monoglyceride, stearic acid monoglyceride, and oleic acid monoglyceride, are mentioned, Polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene octylphenyl ether sodium sulfate, sulfuric acid ester salts such as polyoxyethylene nonylphenyl ether sodium sulfate, triethanolamine lauryl sulfate, sodium lauryl sulfate, potassium lauryl sulfate, and ammonium lauryl sulfate; sulfonates such as sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, and sodium dialkylsulfosuccinate; Anionic surfactants typified by phosphate ester salts such as potassium alkylphosphate, and cationic surfactants typified by quaternary ammonium salts such as lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, and stearyltrimethylammonium chloride and 1 type or 2 or more types selected from these can be used. Among these, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, or mixtures thereof are exemplified as particularly preferable examples.

Method for producing composite metal pigment composition

Although there is no restriction|limiting in particular in the manufacturing method of the composite metal pigment composition by 1st invention of this application, It is especially preferable to manufacture by the manufacturing method of 2nd invention of this application, and/or the manufacturing method of 3rd invention of this application. The production method of the second invention of the present application and the production method of the third invention of the present application can produce a composite metal pigment composition having a high non-volatile matter (solid content) content while effectively preventing aggregation or suppression of the composite particles, and thus the first invention of the present application It is particularly suitable for the preparation of composite metal pigment compositions by

In addition, the manufacturing method of this application 2 invention and the manufacturing method application object of the 3rd invention of this application are not limited to manufacture of the composite metal pigment composition by the 1st invention of this application, It is used suitably for manufacture of various composite metal pigment compositions.

The manufacturing method of the second invention of the present application,

It is a method for producing a composite metal pigment composition having the following steps 1) to 3),

1) The process of dispersing metal particles in a solvent

2) The step of coating the metal particles with a metal oxide

3) A step of washing, filtration and solvent volatilization of the metal particles obtained in step 2) and the composite particles having a metal oxide coating formed on the surface thereof

The solvent is a mixed solvent of two or more solvents having compatibility with each other and having a boiling point of 10° C. or more different,

It is the said manufacturing method in which the solvent volatilization in process 3) is performed in the state of the slurry containing the said composite particle and the said solvent.

The manufacturing method of the third invention of the present application,

It is a method for producing a composite metal pigment composition having the following steps 1) to 3),

1) The process of dispersing metal particles in a solvent

2) The step of coating the metal particles with a metal oxide

3) A step of washing, filtration and solvent volatilization of the metal particles obtained in step 2) and the composite particles having a metal oxide coating formed on the surface thereof

It is the said manufacturing method which divides and implements the solvent volatilization in process 3) into three or more steps.

That is, the manufacturing method of the 2nd invention of this application and the manufacturing method of the 3rd invention of this application are all,

1) a process of dispersing metal particles in a solvent;

2) coating the metal particles with a metal oxide; and

3) It has the process of washing|cleaning, filtration, and solvent volatilization of the metal particle obtained in process 2), and the composite particle which has the metal oxide coating|coated formed on the surface.

In the second invention of the present application, the solvent is a mixed solvent of two or more solvents having compatibility with each other and having different boiling points of 10°C or more, and the solvent volatilization in step 3) causes the composite particles and the solvent to react with each other. On the other hand, in the third invention of the present application, there is no such limitation, and the second invention of the present application and the third invention of the present application are different from each other, and in the third invention of the present application, in step 3) While the solvent volatilization is carried out in three or more stages, the second invention of the present application is different from the third invention of the present application also in that there is no such limitation in the second invention of the present application.

Hereinafter, each of these steps will be described.

1) The process of dispersing metal particles in a solvent

In process 1), a metal particle is disperse|distributed in a solvent. By dispersing the metal particles in the solvent, it is possible to suppress aggregation of the particles in the subsequent 2) step of coating the metal particles with a metal oxide, and as a result, the dispersibility of the resulting composite particles is also good, and the primary non-agglomeration The proportion of particles can be significantly increased.

Although the method of dispersing a metal particle in a solvent is not specifically limited, Methods, such as adding a metal particle to a solvent, adding stirring, and irradiating an ultrasonic wave, are employ|adopted preferably.

Moreover, it is also preferable to perform pre-processing in order to improve the dispersibility of a metal particle.

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. .

It is preferable to use the apparatus which stirs with a stirring blade (impeller) among these stirrers. As a result of exerting a pressure shearing action as well as a circulating action of flowing the entire system containing the metal particles and the solvent by the stirring blade, the aggregation of the metal particles can be suppressed and the metal particles can be dispersed more effectively.

The shape of a stirring blade is not specifically limited, For example, an anchor type, a propeller type, a turbine type, a fan turbine type, a paddle type, an inclined paddle type, and a gate type can be used. Moreover, it is also possible to combine the stirring blades of these shapes in multiple stages.

It is preferable that the stirring speed is stirred to such an extent that the stirring blade is 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.

It is preferable that it is 0.5-30 m/s, and, as for the linear speed (tip speed of a stirring blade) of stirring, it is more preferable that it is 1-20 m/s. When the linear velocity of the agitation is in the range of 0.5 to 30 m/s, the dispersibility of the metal particles can be improved, and further, individual particle aggregation properties are small, and excellent designability, gloss, and coating film appearance are obtained, and gas is generated. It becomes easier to obtain this little composite metal pigment composition. In addition, when the linear speed of the agitation is within the above range, while the breakage of the metal particles (eg, flaky aluminum powder) is prevented, the aggregation of particles can be effectively suppressed.

Although ultrasonic treatment is not specifically limited, Usually, it is 10-1000 W, Preferably it is 50-800 W, It is 20 second - 10 minutes normally, Preferably it can perform about 30 second - about 5 minutes.

As the pretreatment, for example, when metal particles used as raw materials are dispersed and supplied in an inert solvent, the solvent can be replaced with the same water as the solvent used for the coating treatment. In addition, by performing a heating treatment for a certain period of time as desired to make the solvent sufficiently compatible with the surface of the metal particles, 2) aggregation occurring in the step of coating the metal particles with a metal oxide can be significantly suppressed. The heat treatment temperature is preferably about 30 to 60°C, and the treatment time is preferably optimized between 3 hours and 7 days. Since hydrophilic solvents, such as ethanol, isopropanol, and methoxypropanol, are preferably used in the process of performing a coating process, also in pre-processing, the same hydrophilic solvent used for reaction is used preferably.

In addition, adding a small amount of surfactant at this time is also effective for suppressing aggregation by pretreatment. Although it does not restrict|limit especially as surfactant, A nonionic surfactant and anionic surfactant are preferable, and it is especially preferable to use a nonionic surfactant.

1) The step of dispersing the metal particles in the solvent is usually 10 to 80°C, preferably 15 to 70°C, and most preferably, it can be carried out around room temperature (about 20 to 60°C). Further, 1) the step of dispersing the metal particles in the solvent can be performed for 5 minutes to 20 hours, preferably 10 minutes to 5 hours (including that in the case of performing ultrasonic treatment).

2) Process of coating metal particles with metal oxide

The metal oxide coating can be formed on the metal particles by performing the step of 1) dispersing the metal particles in a solvent and then performing the step of 2) coating the metal particles with a metal oxide.

As described above, since it is preferable to use silicon oxide for the metal oxide coating, an embodiment in which at least one layer of the metal oxide coating is a silicon compound-containing layer is taken as an example, and as a specific example of step 2), a silicon compound-containing layer The forming process will be described.

Formation process of silicon compound-containing layer

The silicon compound-containing layer is formed by reacting, for example, a silicon-containing raw material containing at least one of metal particles, an organosilicon compound, and a solvent, and, if necessary, a mixed solution containing other optional components in the forming step, so that the silicon compound-containing layer is formed. is formed

Since the metal particles are dispersed in the solvent in step 1), a silicon-containing raw material is usually added thereto in step 2).

Although the above-mentioned metal particle can be used as a metal particle, In particular, particle|grains of aluminum or an aluminum alloy can be used suitably. Moreover, as for the particle shape, as mentioned above, it is preferable to use a scale-like metal particle. As the metal particles, known or commercially available ones (typically pasty aluminum flakes) can be used.

Content (solid content) in particular of the metal particle in the said liquid mixture is not restrict|limited, 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 can be 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 suitably used 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 collectively called simply "tetraalkoxysilane" in some cases.

When using together the tetraalkoxysilane represented by said Formula (1), and the silane coupling agent represented by either of said Formulas (2) - (4), the method of mixing and using both (referred to as "the 1st method") can be employed Alternatively, a method including a step of forming a first silicon compound-containing layer by performing a treatment by one of the metal particles and forming a second silicon compound-containing layer by performing a treatment by the other (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 either of said Formula (2)-(4) is adjusted suitably, for example. The method including the process of making a hydrolysis/condensation reaction of tetraalkoxysilane and a silane coupling agent and forming a silicon compound containing layer by carrying out is mentioned.

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, and the first is applied to the surface of the metal particles. A step of forming a silicon compound-containing layer (for example, a silica film made of amorphous silica), and adjusting the pH of a mixed solution containing metal particles and a silane coupling agent represented by any of Formulas (2) to (4) above 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 the aggregation of the metal particles or reduction of the luminosity, 2 to 200 parts by mass with respect to 100 parts by mass of the metal particles (solid content), 5 to It is more preferable that it is 100 mass parts.

Although the usage-amount of the silane coupling agent represented by either of said Formula (2) - (4) is not specifically limited, Usually, 0.1-20 mass parts may be sufficient with respect to 100 mass parts of metal particles (solid content), Especially 1 - It is preferable that it is 5 mass parts. When this usage-amount is about 0.1-20 mass parts, the desired coating process effect and preferable coating-film physical properties can be acquired.

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 silicon-containing raw material used, etc., but usually water, a hydrophilic organic solvent, or these 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 rapid progress of the reaction between the metal particles and water. In this embodiment, the mixed solvent of water and a hydrophilic organic solvent can be used suitably.

Although it does not specifically limit as a hydrophilic organic solvent, For example, Alcohol, such as methanol, ethanol, a propanol, a 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 be used 1 type or 2 or more types.

The amount of the solvent used in the silicon compound-containing layer forming step (in the case of pre-dispersing the metal particles, the amount of the solvent is excluded) is not limited, but usually 100 to 100 parts by mass of the metal particles (solid content). What is necessary is just about 10000 mass parts, and it is preferable that it is especially 200-2000 mass parts. 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. Moreover, when the usage-amount of a solvent is 10000 mass parts or less, it can prevent that collection|recovery and reproduction|regeneration cost of a process liquid become 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 solvent amount 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 1st invention of this application. For example, 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 do

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.

Although the addition amount of a hydrolysis catalyst is not specifically limited, Usually, what is necessary is just to set it as 0.01-20 mass parts with respect to 100 mass parts of metal particles (solid content), It is preferable to set it as 0.02-10 mass parts especially. When the added amount is 0.01 parts by mass or more, the amount of the silicon compound-containing layer precipitated may be sufficient. Moreover, when the said addition amount is 20 mass parts or less, aggregation of a metal particle can be suppressed effectively.

In the production of the composite metal pigment composition according to the first invention of the present application, the preparation of the mixed solution is preferably performed under stirring at an appropriate intensity.

The temperature of the liquid mixture may be at room temperature or under heating. In general, the temperature of the liquid mixture may be set to 20 to 90°C, and particularly preferably to be controlled in the range of 30 to 80°C. 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 is 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.

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 30-80 degreeC 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 composite 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 to 10 hours, and, as for this stirring time, it is more preferable to set it as 1 to 5 hours, for example. When stirring time is 0.5 hour or more, sufficient processing effect can be acquired. 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 via 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, it is preferable to adjust the pH value by adding a hydrolysis catalyst, but as long as the properties of the composite metal pigment composition according to the first invention of the present application are not impaired, the pH value may be adjusted using other acidic or alkaline compounds. do.

When using a basic hydrolysis catalyst as a hydrolysis catalyst, it is preferable to make pH value into 7-13. 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 13 or less, aggregation of 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 1.5-7, and it is more preferable to set it as 2-6 especially. When a pH value is 1.5 or more, reaction is moderately controlled and it becomes easy to obtain the composite metal pigment composition containing a desired composite particle. On the other hand, when the pH value is 7 or less, the deposition rate of the silicon compound-containing layer can be maintained high.

Even when either 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 are 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 hydrolyzate and/or its condensate derived from the silane coupling agent represented by any one of the said General formula (2) - (4) and/or their partial condensate with respect to 100 mass parts of metal particles (solid content). In conversion of the state in which hydrolysis and condensation reaction were completed, 0.01-10 mass parts is added in total, and it is more preferable to add 0.05-2 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 in manufacture of the composite metal pigment composition, the said organosilicon It is computable by multiplying the mass ratio before and behind reaction when all the compounds hydrolyze and carry out a 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 its condensate, such as a silane coupling agent represented by any of the general formulas (2) to (4), is also used in the production of the composite metal pigment composition in the general formulas (2) to (4) Calculated by multiplying the mass ratio of the silane coupling agent and/or its partial condensate represented by any of can do.

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 its mass ratio before and after the following hydrolysis and condensation reactions are used. The addition amount of the condensate 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.

3) Process of washing, filtration and solvent volatilization of composite particles

2) After the step of coating the metal particles with the metal oxide is finished, in order to recover the obtained composite particles and obtain a desired composite metal pigment composition, 3) the steps of washing, filtration and solvent volatilization of the composite particles can be carried out .

In producing the composite metal pigment composition of the first invention of the present application, although it is not essential to carry out step 3), it is preferable to carry out.

In the method for producing the composite metal pigment composition of the second invention of the present application, step 3) is performed, and the solvent at that time is a mixed solvent of two or more solvents having mutual compatibility and different boiling points by 10° C. or more; In addition, the solvent volatilization in process 3) is performed in the state of the slurry containing the said composite particle and the said solvent.

In the manufacturing method of the composite metal pigment composition of this application 3rd invention, process 3) is implemented, and the solvent volatilization in process 3) is divided into three or more steps, and is implemented.

The washing in step 3) can be performed by a method commonly used in this technical field, for example, the slurry or cake containing the composite particles obtained in step 2) can be washed using an organic solvent. By washing, water, unreacted substances, and undesirable solvents in the final composite metal pigment composition can be removed from the slurry, cake, etc. containing the composite particles.

In washing, it is preferable to stir, and although there is no restriction|limiting in particular in the conditions of stirring, For example, the conditions similar to what was demonstrated above with respect to process 1) can be employ|adopted.

Although there is no restriction|limiting in particular in the temperature, time, etc. at the time of washing|cleaning in step 3), Usually, 10-70 degreeC, Preferably it is 15-60 degreeC, 5-180 minutes, Preferably it can carry out for 10-120 minutes. have.

In washing, it is preferable to use an organic solvent, and it is more preferable to use a hydrophilic organic solvent from the viewpoint of the removal of water|moisture content and the convenience at the time of using a composite metal pigment composition for a water-based coating material afterwards. It is particularly preferable that the hydrophilic organic solvent has a boiling point of 80 to 150°C, and by washing with such an organic solvent, 80% by mass or more of the non-solid content of the (5) composite metal pigment composition in the first invention of the present application , it becomes easier to satisfy the requirement that a solvent having a boiling point of 80 to 150° C. is occupied by hydrophilicity. Preferred examples of the hydrophilic solvent having a boiling point of 80 to 150°C include methoxypropanol, isopropanol, isobutanol, normal butanol and normal propanol.

There is no restriction|limiting in particular in the frequency|count of washing|cleaning, You may wash|clean only once, and you may wash|clean in multiple times, for example, 2 to 5 times. When performing washing|cleaning several times, you may perform washing|cleaning and filtration alternately. In addition, it is also one of preferable examples to use a Nutche type filter to continuously or intermittently flow a washing liquid to wash.

Filtration in step 3) can be performed by a method commonly used in this technical field. For example, a polypropylene filter cloth having a normal air permeability of 10 to 100 milliliters/cm 2 /min, preferably 20 to 80 milliliters/cm 2 /min, a metal filter, glass filter, ceramic filter, etc. of the same size Using a Nutsche type filter, filtration by suction filtration or pressure filtration, or methods such as a filter press, a belt press, and a centrifugal filter can be appropriately employed. By performing filtration, water, unreacted substances, and undesirable solvents in the final composite metal pigment composition can be removed from the composite particles obtained in step 2).

The temperature and pressure of the filtration in step 3) are not particularly limited, but when a Nutsche type filter is usually used, the temperature is 10 to 70°C, preferably 15 to 60°C, the pressure is 0.11 to 0.9 MPa, preferably can be carried out at 0.15 to 0.5 MPa.

It is preferable that it is 75 mass % or more, as for the solid content of slurry containing composite particle|grains after filtration, a cake, etc., it is more preferable that it is 80-98 mass %, It is especially preferable that it is 85-95 mass %.

From the viewpoint of low VOC, etc., it is preferable that the solid content of the slurry containing the composite particles after filtration, cake, etc. is high. Therefore, the pressure at the time of filtration can be set high, but the high pressure at the time of filtration can cause aggregation of the composite particles or Since deformation may be caused, it is preferable to set the pressure after taking this point into consideration.

You may combine filtration and a solid-liquid separation method other than filtration, such as centrifugation and decantation, as appropriate.

There is no restriction|limiting in particular in the frequency|count of filtration, You may filter once and may perform washing|cleaning and filtration several times alternately. By alternately washing and filtering a plurality of times, water, unreacted substances, and undesirable solvents in the final composite metal pigment composition are more effectively removed, and (5) composite metal pigment composition according to the first invention of the present application It becomes much easier to satisfy the requirement that 80 mass % or more of the specific solid content of a solvent with a boiling point of 80-150 degreeC is occupied by hydrophilicity.

At the time of filtration, it is preferable to volatilize a solvent by allowing gas to pass through the surface of a slurry or a cake, and a space|gap part together. As a result, the low boiling point solvent volatilizes preferentially, and the high boiling point solvent component mainly made and remained, and it becomes easy to obtain the composite metal pigment composition with high solid content.

The solvent volatilization in step 3) can be performed by the method commonly used in this technical field. For example, by removing volatile matter by performing solvent volatilization capable of performing solvent volatilization by heating, reduced pressure, ventilation, a combination thereof, etc., the ratio of solid content is improved, so (4) composite metal pigment in the first invention of the present application The composite metal pigment composition which satisfies the requirement that the solid content concentration of a composition is 70-95 mass % can be manufactured efficiently. In addition, since solvent volatilization can remove undesirable solvents from the composite metal pigment composition, (5) 80 mass % or more of the non-solid content of the composite metal pigment composition is hydrophilic and has a boiling point of 80 to 150 ° C. A composite metal pigment composition satisfying the requirements occupied by a solvent can be manufactured much more easily.

Although there is no restriction|limiting in particular in the temperature, pressure, time, etc. of solvent volatilization in step 3), Usually, the temperature is 15-100 degreeC, Preferably 20-80 degreeC, More preferably, 30-70 degreeC, and a pressure are absolute pressure. 0.1 (normal pressure) to 0.001 MPa, Preferably it is 0.05 to 0.01 MPa, and can carry out, confirming the degree of solvent volatilization.

When performing solvent volatilization by ventilation, it is preferable to use dry air, and it is good to adjust a dew point and flow volume of ventilation suitably, confirming the volatilization degree of a solvent.

A composite metal pigment composition may be obtained directly by solvent volatilization, and a composite metal pigment composition composition may be obtained through a further process. It is preferable that solid content of the composite metal pigment composition after solvent volatilization is 75 mass % or more, It is more preferable that it is 80-98 mass %, It is especially preferable that it is 85-95 mass %.

In the manufacturing method of the composite metal pigment composition of this application 2nd invention, the solvent in process 3) is mutually compatible, and is a mixed solvent of 2 or more types of solvents which differ in boiling point by 10 degreeC or more. A mixed solvent of two or more solvents that are compatible with each other and have different boiling points of 10° C. or more, that is, a mixed solvent obtained by mixing a solvent with a low boiling point, by substituting the solvent used in each step prior to that, and selectively volatilizing the low boiling point solvent , a solvent to be left, for example, a solvent having a boiling point of 80 to 150° C. due to hydrophilicity can be selectively left. In addition, the low boiling point solvent volatilizes relatively easily, and since high temperature or the like or extreme pressure reduction is not required, the solid content concentration can be improved relatively easily and while suppressing deformation and agglomeration of the composite particles.

It is preferable that it is 10-80 degreeC, and, as for the difference of the boiling point of 2 or more types of solvent which comprises a mixed solvent, it is especially preferable that it is 20-60 degreeC.

As a solvent on the high boiling point side, methoxypropanol, isobutanol, normal butanol, etc. can be used preferably.

As a solvent on the low boiling point side, isopropanol, normal propanol, ethanol, etc. can be used preferably.

It is particularly preferable to use a combination of methoxypropanol as the solvent on the high boiling point side and isopropanol as the solvent on the low boiling point side.

Moreover, in the manufacturing method of the composite metal pigment composition of 2nd invention of this application, the solvent volatilization in process 3) is performed in the state of the slurry containing the said composite particle and the said solvent.

In step 3), the solvent on the low boiling point side is volatilized by volatilizing a mixed solvent of two or more solvents that are compatible with each other and have different boiling points by at least 10°C in the state of a slurry containing the composite particles and the solvent. It becomes much easier to leave the high boiling point side solvent in the composite metal pigment composition.

In addition, in the manufacturing method of the composite metal pigment composition of this application 3rd invention, the solvent volatilization in process 3) is divided into three or more steps, and is implemented. At this time, the solvent volatilization divided into three or more steps may be continued, but between the step 1 solvent volatilization and the solvent volatilization in the step subsequent thereto, a step of homogenizing the solvent components contained in the slurry as a whole, for example, stirring It is preferable to perform the process of performing aging, etc. In the process of homogenizing such a solvent component, you may add a solvent anew and perform solvent substitution partially.

Solvent volatilization is carried out in three or more stages, and preferably by alternately volatilizing and dispersing, while suppressing the occurrence of locally low solvent portions and effectively preventing aggregation and deformation of composite particles, the formulation of the present application A composite metal pigment composition having a desirable solvent composition with a high solid content, such as the composite metal pigment composition of the present invention, can be produced relatively easily and efficiently.

In the manufacturing method of the composite metal pigment composition of the 2nd invention of this application and 3rd invention of this application, it is preferable to use the solvent with a low moisture content from a viewpoint of suppressing aggregation of a composite particle. In particular, it is preferable that the water content of a solvent at the time of solvent volatilization in process 3) is low. It is preferable that the moisture content of a solvent is 10 mass %, It is more preferable that it is 5 mass % or less, It is especially preferable that it is 1 mass % or less.

At this time, the total water content of the composite metal pigment composition obtained can be preferably 0.1 mass% or less, more preferably 0.05 mass% or less, so the residual amount is preferably 0.1 mass% or less of the solid content, more preferably It becomes much easier to reduce to 0.003 mass % or less.

other processes

Preferably, in the production of the composite metal pigment composition of the first invention of the present application by the method for producing the composite metal pigment composition of the second invention and/or the third invention of the present application, in addition to the above steps 1) to 3), a metal You may have the process of grinding|pulverizing particle|grains, etc., the process of forming coating layers other than metal oxide coating, etc.

Grinding of metal particles, sieving, filtration, etc.

Prior to the step of 1) dispersing the metal particles in the solvent, the metal particles may be pulverized, sieved, and/or filtered. By pulverizing, sieving, and/or filtering the metal particles, the particle size of the metal particles becomes more uniform and fine, which is preferable from the viewpoint of producing a composite metal pigment composition containing uniform and fine composite particles.

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

In general, the aluminum powder is prepared by using a method commonly used in the pigment industry such as a dry ball mill method, a wet ball mill method, an attritor method, and a stamp mill method by using atomized aluminum powder and/or aluminum foil to obtain a grinding aid or inert It is grind|pulverized in presence of a solvent, it is set as what is called a scale, and it is obtained through required processes, such as sieving (classification), filtration, washing|cleaning, mixing, after this process further.

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

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

When aluminum particles are employed as the metal particles, commercially available paste-like aluminum flakes obtained through such grinding and sieving and filtration can be used. The paste-like aluminum flakes may be used as they are, or may be used after removing the fatty acids on the surface with an organic solvent or the like beforehand.

Formation process of 2nd coating layer

The composite particles constituting the composite metal pigment composition of the first invention of the present application include, in addition to the metal oxide coating, other coating layers (second coating layer), preferably at least one selected from metals, metal oxides, metal hydrates and resins. It is preferable to further have a coating layer which consists of It is preferable that a 2nd coating layer is especially formed between metal oxide coating|cover, such as a metal particle and a silicon compound containing layer (when it is formed). Therefore, the layered constitution of "metal particle/second coating layer/metal oxide coating" can be employ|adopted suitably.

Although a 2nd coating layer is not specifically limited, A molybdenum containing film, a phosphoric acid compound film, etc. may be sufficient. Preferred examples of the molybdenum-containing material constituting the molybdenum-containing film include a mixed coordination heteropolyanion compound disclosed in Japanese Patent Application Laid-Open No. 2019-151678. Examples of the constituent components of the second coating layer including the mixed coordination heteropolyvalent anion compound are as described above.

Hereinafter, an embodiment in which a molybdenum-containing film is formed as the second coating layer between the metal particles and the metal oxide coating such as the silicon compound-containing layer will be described as an example.

When a molybdenum-containing film is formed as a second coating layer between the metal particles and a metal oxide coating such as a silicon compound-containing layer, the metal particles and a molybdenum compound (typically mixed A molybdenum-containing film can be formed on the surface of the metal particle by stirring the liquid mixture containing the coordination-type heteropolyvalent anion compound).

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 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 metal 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 0.02-20 mass parts with respect to 100 mass parts of metal particles (solid content), and it is preferable to set it as 0.1-10 mass parts especially. 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 composite metal 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 (when the metal particles are pre-dispersed, the amount of the solvent is excluded) 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 it is thru|or 5000 mass parts, and it is more preferable that it is 100-2000 mass parts. 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, the 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 30-80 degreeC 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 composite 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. It is preferable to set it as 0.5 to 10 hours, and, as for this stirring time, it is more preferable to set it as 1 to 5 hours, for example. When stirring time is 0.5 hour or more, sufficient processing effect can be acquired. Moreover, an increase in processing cost can be suppressed by stirring time being 10 hours or less.

After the stirring of the mixed solution containing the metal particles and the molybdenum compound is finished, the particles with the second coating layer formed thereon can be recovered. In this case, well-known washing|cleaning, solid-liquid separation, etc. can be performed suitably as needed. For example, after washing the liquid mixture using a hydrophilic organic solvent, it is preferable to filter using a filter etc., and to remove water and unreacted material with the cake containing the metal particle which has a molybdenum containing film. In this way, the molybdenum-containing film as the second coating layer can be formed. When forming another 2nd coating layer, it can carry out according to the said method.

In an aspect of forming a second coating layer (hereinafter, a molybdenum-containing coating film will be described as an example) on the metal particles, followed by a metal oxide coating (hereinafter, a silicon compound-containing layer will be described as an example) is formed on the metal particles, the metal particles and the molybdenum compound After the stirring of the liquid mixture containing You may directly add and stir the dispersion liquid of water and/or a hydrophilic organic solvent of an alkoxysilane and/or its condensate, and at least 1 sort(s) of the silane coupling agent represented by any of the said Formula (2)-(4). 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 to the system containing the particle|grains with a 2nd coating layer formed, 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 of (4).

Use of Composite Metal Pigment Composition

The composite metal pigment composition of the first invention of the present application and the composite metal pigment composition produced by the manufacturing method of the second invention and/or the third invention of the present application can be used for organic solvent-based paints, inks, and the like. In addition, this composite metal pigment composition is added to a water-based paint or water-based ink in which a resin, which is a coating film forming component (binder), is dissolved or dispersed in a medium mainly containing water, it can be made into a metallic water-based paint or metallic water-based ink. . The composite metal pigment composition can also be used as a water-resistant binder and filler by kneading with a resin or the like. An antioxidant, a light stabilizer, and surfactant may be added when mix|blending a composite metal pigment composition with a water-based paint, water-based ink, resin, etc.

When the composite metal pigment composition is used for a paint or ink, it may be added to the (water-based) paint or (water-based) ink as it is, but it is preferable to add it after dispersing it in a solvent in advance. 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 for 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.

As preferable resins, acrylic resins and polyester resins are mentioned.

If necessary, a resin such as a melamine-based curing agent, an isocyanate-based curing agent, or a urethane dispersion can be used in combination. Furthermore, you may combine it with coloring pigments, such as inorganic pigments, organic pigments, and an extender pigment, generally added to a paint, a silane coupling agent, a titanium coupling agent, a dispersing agent, a settling inhibitor, a leveling agent, a thickener, and an antifoaming agent. In order to improve the dispersibility to a coating material, you may add surfactant further, and in order to improve the storage stability of a coating material, 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.

The content of the composite metal pigment composition according to the first invention of the present application or the composite metal pigment composition produced by the manufacturing method of the second invention or the third invention of the present application in the water-based paint or water-based ink (resin composition) is not limited. However, normally, what is necessary is just to set it as 0.1-30 mass %, and it is preferable to set it as 1-20 mass % especially. When this content is 0.1 mass % or more, a high decoration (metallic) effect can be acquired. In addition, when this content is 30 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, 20-200 mass % 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 suitably 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 topcoat layer etc. may be formed on the coating film formed with the water-based coating material 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. The composite metal pigment composition according to the first invention of the present application, or an aqueous coating material containing the composite metal pigment composition produced by the production method of the second invention or the third invention of the present application, a coating film having a good mirror-like brilliance is obtained. It is preferable to employ|adopt the method which includes the process of forming a coating film layer with a water-based coating material etc. after coating a base coat layer and hardening or drying in that point.

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 a hot air, for example, and natural drying in 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, about 0.5-100 micrometers is preferable, and if it is about 1-50 micrometers, it is more preferable. When the thickness of a coating film layer is 0.5 micrometer or more, the hiding effect of the foundation|substrate by ink or a coating material is fully acquired. In addition, when the thickness of the coating layer is 100 µm or less, drying becomes easy, and the occurrence of defects such as boiling and sagging can be suppressed.

The composite metal pigment composition of the first invention of the present application, the composite metal pigment composition obtained by the production method of the second or third invention of the present application, and a coating film obtained using the same are excellent in designability, gloss, particle suppression, and water-based paint. Since it has a high level of stability, etc. in paints, inks, resin kneading agents, etc., various uses in which metal pigments are conventionally used, more specifically, automobile bodies, automobile repair materials, automobile parts, home appliances, plastic parts, etc. It can be suitably used in paints for PCM, high weather resistance paints, heat resistant paints, anticorrosive paints, paints for ship bottoms, offset printing inks, gravure printing inks, screen printing inks, and the like.

Example

Hereinafter, although an Example demonstrates this invention more concretely, please note that these Examples are mere illustration, and this invention is not limited at all by description of these Examples.

Example 1

A commercially available aluminum paste (manufactured by Asahi Kasei Co., Ltd., trade name "GX-3100 (average particle diameter 11 μm, volatile content 74%)") 135 in a reaction tank of 1 m in diameter and having an anchor-type stirring blade with a blade diameter of 1 m. To kg, 465 kg of methoxypropanol (hereinafter referred to as “PM”) is added, the mixture is stirred with a stirring blade at 100 rpm, and the 10 L/min dispersion extracted from the bottom is returned to the reactor from the top of the reactor. With external circulation, the aluminum paste was uniformly dispersed in the PM. In the external circulation, 500 W ultrasonic waves were irradiated for 1 minute in the middle of the flow path to improve the dispersibility of particles.

Next, a liquid 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 thereto, followed by stirring for 1 hour while maintaining the slurry temperature at 40°C. During the reaction, external circulation was continued while irradiating ultrasonic waves.

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 for 2 hours. During the reaction, external circulation continues while irradiating ultrasonic waves. After completion of the reaction, the slurry was filtered under pressure after cooling.

The filtered slurry is thoroughly washed with a mixed solution of isopropanol (hereinafter referred to as "IPA")/PM: 3/2 to replace the solvent contained therein, then filtered again under pressure and vented to volatilize mainly IPA, non-volatile matter A 90% composite aluminum pigment composition was obtained. The water content in the IPA/PM mixed solvent used here was 200 ppm, and dry air having a dew point of -40°C was used for pressure filtration and ventilation.

Example 2

A composite aluminum pigment composition having a non-volatile content of 90% was prepared in the same manner as in Example 1 except that the aluminum paste was changed to (Asahi Chemical Co., Ltd., trade name “GX-4100 (average particle size 10 µm, volatile content 74%)”). got it

Example 3

A composite aluminum pigment composition having a non-volatile content of 85% was prepared in the same manner as in Example 1 except that the aluminum paste was changed to (manufactured by Asahi Chemical Co., Ltd., trade name “FD-5090 (average particle size 9 μm, volatile content 75%)”). got it

Example 4

The reaction was carried out in the same manner as in Example 1, and after the reaction was completed, the slurry was filtered after cooling, and washing and filtration were repeated 3 times with an equivalent amount of PM to obtain a paste having a nonvolatile content of 50%. Next, the solvent was volatilized at room temperature under reduced pressure to increase the non-volatile content by 10%, the pressure was released and the paste was mixed so as to be uniform, sealed and left to stand for 12 hours. This operation was further performed twice, and the paste-form composite aluminum pigment composition of 90% of non-volatile matter was obtained.

Example 5

As the IPA/PM mixed solvent, a composite aluminum pigment composition having a nonvolatile content of 90% was obtained in the same manner as in Example 1 except that the water content was 2000 ppm.

Comparative Example 1

Intungstomolybdenum in tungstomolybdenum was stirred while stirring the slurry dispersed by adding 465 kg of PM to 135 kg of commercially available aluminum paste (manufactured by Asahi Kasei Co., Ltd., trade name "GX-3100 (average particle size 11 µm, non-volatile content 74%)") The liquid which melt|dissolved 1 kg of hydrates of an acid (H ₃ PW ₆ Mo ₆ O ₄₀ ) in 5 kg of PMs was added gradually, and it stirred for 1 hour, maintaining the slurry temperature at 40 degreeC. Then, after cooling, the slurry was filtered, and the composite aluminum pigment composition of 60% of non-volatile matter was obtained.

Comparative Example 2

The process after completion of the reaction and filtration was similar to Example 1 except that the aluminum pigment composition was transferred to another container, and the aluminum pigment composition was changed to a process of desolving under reduced pressure while heating to 50° C. in a standing state for 1 hour. An 80% composite aluminum pigment composition was obtained.

Comparative Example 3

A composite aluminum pigment composition having a nonvolatile content of 80% was obtained in the same manner as in Example 1 except that the step after the reaction was completed and filtered was changed to a step of desolving by pressure bonding with a filter press.

(Evaluation of composite metal pigment composition)

Average particle diameter: D ₅₀

The average particle diameter (D ₅₀ ) of the composite particles (silicon oxide-coated aluminum particles) in the composite aluminum pigment composition obtained in each of the above Examples/Comparative Examples was measured with a laser diffraction/scattering particle size distribution analyzer (LA-300/Co.) It was measured using the Horiba Seisakusho Co., Ltd.).

As the measurement solvent, isopropanol was used.

The measurement was carried out according to the device instruction manual, but as a precaution, ultrasonic dispersion for 2 minutes was performed as a pretreatment for the composite metal pigment composition to be sampled, and then put into the dispersion tank and after confirming that it was dispersed at an appropriate concentration, the measurement was performed started

After completion of the measurement, D ₅₀ was calculated by the instrument's software and displayed automatically.

solids concentration

10 g of the composite aluminum pigment composition obtained in each of the above Examples/Comparative Examples was heated at 105° C. for 3 hours to volatilize the volatile matter, then the mass was measured, and the ratio was determined as the mass of the solid content.

residue

After dispersing 50 g of the composite aluminum pigment composition obtained in each of the above examples/comparative examples in 1000 ml of mineral spirit with a spatula, it was filtered through a 200 mesh nylon net (manufactured by NBC), and the residue was sufficiently washed with acetone, After drying at 105° C. for 10 minutes, the mass was measured, and this was used as the mass of the residue to determine the ratio.

(Evaluation of paint and film)

Using the composite aluminum pigment composition obtained in each of the above Examples and Comparative Examples, an aqueous metallic paint was prepared with the following composition, and the paint and the coating film obtained therefrom were evaluated by the following method. In addition, those results are shown in Table 1.

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

Composite 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 “Mapon L5”): 6.0 g

Purified water: 12.0g

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

・Melamine resin (※2): 18.0 g

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

※2: Cymel 350, manufactured by Cytec Industries, Ltd., Japan

After mixing the above components, the pH is adjusted from 7.7 to 7.8 with dimethylethanolamine, and the viscosity is adjusted to 650 to 750 mPa·s (B-type viscometer, No. 3, 60 rotations, 25° C.) with a carboxylic acid thickener and purified water. Adjusted.

The following evaluation was performed using the aqueous metallic paint prepared in this way.

・Evaluation 1 (storage stability (gas generation))

200 g of the aqueous metallic paint prepared in the above formulation was collected in a flask, and the cumulative amount of hydrogen gas generated was measured in a constant temperature water bath at 60° C. for 24 hours. Based on the amount of generated gas obtained, evaluation was performed in the same manner as in the following criteria, and it was set as an index of storage stability in the coating material.

○: less than 2ml

△: 2 or more and less than 10 ml

×: 10 ml or more and less than 50 ml

××: 50ml or more

・Evaluation 2 (coating film evaluation)

The water-based metallic paint prepared in the above formulation is air-sprayed to a dry film thickness of 6 µm on a 12 cm x 6 cm steel plate (manufactured by Mickey Coating Co., Ltd.) with an intermediate coating, and pre-dried at 90 ° C. for 10 minutes. Then, the organic solvent type topcoat paint of the following composition is dispersed with a spatula for 3 minutes, the paint viscosity is adjusted to 20.0 seconds in a pod cup No4, and air spray coated to a dry film thickness of 20 µm, and at 140 ° C. It was made to dry for 30 minutes, the coating board was produced, and it used for the following evaluation.

(Composition of organic solvent type topcoat paint)

・Acridic 44-179 (manufactured by DIC, acrylic clear resin) 141 g

・Super Beccamine J-820 (manufactured by DIC, melamine resin) 35.3 g

・Toluene 123.5g

2-i (film particle)

The number of particles on the entire surface of the top coat coating film of the obtained coating plate was measured and evaluated by the following index.

○: Particles cannot be visually recognized

△: 10 or less particles

×: There are more than 10 particles

2-ii (luminance)

About the obtained coating board, it evaluated using the laser-type metallic feeling measuring apparatus Alcop LMR-200 manufactured by Kansai Paint Corporation. The optical condition has a laser light source with an incident angle of 45 degrees and a light receiver with light receiving angles of 0 and -35 degrees. As a measured 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. The IV value is a parameter proportional to the intensity of the specularly reflected light from the coating film, and represents the magnitude of the luminance.

From the obtained IV value, it evaluated based on the following criteria.

(circle): The fall width from the reference|standard (comparative example 1) was less than 20.

(triangle|delta): the fall width from the reference|standard (comparative example 1) was 20 or more and less than 40

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

2-iii (cloaking)

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.

(circle): It was slightly lower than the standard (comparative example 1) and equivalent.

(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).

(Evaluation of agglomeration and deformation of composite particles)

In order to facilitate the determination of the aggregation state of particles, etc., a paint was produced under the same conditions except that the amount of aluminum paste in the formulation of the paint used for the preparation of the paint plate in evaluation 2 was 1/10, and the evaluation was performed. A painted plate was produced under the conditions of 2.

The said coating board was cut|disconnected to 1 cm square using the shearing machine.

The obtained coating film cross section was set so that ion beam irradiation was possible up to a portion 20 μm away from the coating film cross section using an ion milling apparatus (manufactured by Nippon Electronics / IB-09010CP), and a precision polished cross-section sample was produced by ion milling treatment. .

By observing the obtained coating film cross section (coated plate) with FE-SEM (manufactured by HITACHI/S-4700), the overlapping state of the particles and the deformation state of the particles were observed, and the following procedures were evaluated.

Proportion of primary particles (agglomerated state)

First, what can easily determine the degree of overlap of particles was observed at a magnification of about 1000 to 3000 times. When the overlapping degree could not be discriminated by this magnification, the overlapping degree was evaluated by changing the magnification suitably. In this observation method, it observed at a maximum of approximately 30000 times magnification. A plurality of fields of view were observed from the cross section of the same sample piece so that the number of observed particles was 500 or more.

In addition, when the particles are close to each other and it is difficult to determine aggregation, when the length of the contact site between the particles is 1/4 or less of the particle diameter of the smaller particle (the shorter long diameter), it is determined that there is no aggregation, and less than 1/4 In a large case, it was determined that there was aggregation.

Proportion of bending particles (deformed state)

The degree of deformation of the particles was observed at a magnification of about 1000 to 3000 times, which can be easily determined. When the strain could not be discriminated by this magnification, the degree of strain was evaluated by appropriately changing the magnification. In this observation method, it observed at a maximum of approximately 30000 times magnification. A plurality of fields of view were observed from the cross section of the same sample piece so that the number of observed particles was 500 or more. As for the presence or absence of deformation, the case where the shortest distance at both ends of the particle was 0.8 times or less with respect to the length of a particle|grain was judged as having a deformation|transformation.

Average particle thickness of metal particles

Using the FE-SEM image (10,000 times) obtained in the above acquisition procedure and image analysis software Win Roof version 5.5 (manufactured by MITANI CORPORATION), the thickness measurement and average thickness of the particles in the aluminum particle cross section were calculated.

The FE-SEM image for measuring the thickness of the particle in the cross section of the aluminum particle is displayed as an image, the ROI line is selected, the ROI line is aligned with the 5 μm scale of the image, and the length and unit are inputted and set from registration/change did.

Next, the image in which the cross-sectional thickness measurement of the aluminum particle should be measured was displayed, a rectangular ROI was selected, the rectangular ROI was matched with the cross section of the particle|grain, and binary processing was performed.

Next, after selecting the measurement item of the vertical field of measurement, measurement was made, and the automatic measurement value (vertical field value) by the image analysis software was displayed on the image.

In this way, 300 particles were selected using the image analysis software Win Roof version 5.5 described above, and the thickness and long diameter of the aluminum particles were automatically measured in the cross section. Next, the thickness arithmetic mean value was computed about 300 particle|grains, and the average thickness t of the particle|grains was calculated|required. Moreover, the thickness uniformity of the aluminum particle|grains is high, and the difference of the thickness by the cut|disconnected part of particle|grains is small. Therefore, the influence of the difference in the cut region of the particles on the average particle thickness measurement is negligible.

Average particle thickness of composite particles, thickness of metal oxide coating

About the coating board used for the said FE-SEM image acquisition, the average thickness of the particle|grain coating layer was measured at 200,000 times magnification using STEM (scanning transmission electron microscope). When the surface of the coating layer had irregularities, the area of the coating layer was measured using the image analysis software Win Roof version 5.5, and this was divided by the peripheral length of the coated particles to obtain the average thickness of the coating layer. In addition, when the particles are large, it is not necessarily necessary to measure the entire area of the coating layer, and by measuring the area of the coating layer in a region of about 1 μm along the particle surface and dividing this by the particle surface length, the average thickness of the coating layer can be calculated with sufficient precision. is obtained In addition, since the average thickness of the coating layer was almost uniform regardless of particle size, the average value was calculated|required about 10 particle|grains. In addition, from the thickness of this particle|grain coating layer and the average particle thickness of the metal particle obtained above, the average thickness of the composite particle was calculated|required according to the following formula.

Average particle thickness of composite particles = average particle thickness of metal particles + thickness of coating layer x 2

An evaluation result is shown in Table 1. The composite metal pigment composition according to the present invention that satisfies all of the requirements of the above items (1) to (6) obtained in each example has a high solid content, good stability as a paint, and low gas generation (good It has storage stability), and was excellent in brightness|luminance and hiding property, and also the particle|grains of a coating film were suppressed effectively.

The composite metal pigment composition of the first invention of the present application, the composite metal pigment composition obtained by the production methods of the second and third inventions of the present application, and the coating film obtained by using them have low VOC, storage stability when used in water-based coatings, etc. Since it combines excellent properties of coating films such as suppression, designability, and hiding properties at a high level beyond the limits of the prior art, various uses in which metal pigments are conventionally used, such as paints, inks, and resin kneading agents, more specifically Suitable for automobile bodies, automobile repair materials, automobile parts, home appliances, plastic parts, PCM paints, high weather resistance paints, heat resistant paints, anticorrosive paints, ship bottom paints, offset printing inks, gravure printing inks, screen printing inks, etc. It can be used widely, and has high applicability in each field of industries such as transportation machinery industry such as automobiles, electric and electronic industry such as home appliances, paint industry, and printing industry.

Claims (10)

A composite metal pigment composition comprising metal particles and composite particles having a metal oxide coating formed on the surface thereof,
(1) the shape of the composite particles is scaly,
(2) a volume-based average particle diameter D ₅₀ when the particle size distribution of the composite particles is measured with a laser diffraction particle size distribution meter is 1 to 30 μm,
(3) the average particle thickness of the composite particles is 20 to 300 nm,
(4) the solid content concentration of the composite metal pigment composition is 70 to 95 mass %,
(5) 80 mass % or more of the non-solid content of the composite metal pigment composition is hydrophilic and a solvent having a boiling point of 80 to 150 ° C.,
(6) The composite metal pigment composition, wherein the residue when the composite metal pigment composition is filtered with a 200-mesh filter is 0.1% by mass or less of the solid content. The composite metal pigment composition according to claim 1, wherein the ratio of the bent composite particles to the composite particles is 10% or less on a number basis. The composite metal pigment composition according to claim 1 or 2, wherein the proportion of non-agglomerated primary particles in the composite particles is 35% or more on a number basis. The composite metal pigment composition according to claim 1 or 2, wherein at least one layer of the metal oxide coating is a silicon compound-containing layer. The composite metal pigment composition according to claim 1 or 2, wherein the average layer thickness of the metal oxide coating is 5 to 200 nm. The composite metal pigment composition according to claim 1 or 2, wherein the metal particles contain aluminum or an aluminum alloy. The composite metal pigment composition according to claim 1 or 2, wherein the composite particle further has a coating layer comprising at least one selected from a metal, a metal oxide, a metal hydrate, and a resin. It is a method for producing a composite metal pigment composition having the following steps 1) to 3),
1) The process of dispersing metal particles in a solvent
2) The step of coating the metal particles with a metal oxide
3) A step of washing, filtration and solvent volatilization of the metal particles obtained in step 2) and the composite particles having a metal oxide coating formed on the surface thereof
The solvent in step 3) is a mixed solvent of two or more solvents having mutual compatibility and different boiling points by 10°C or more,
The manufacturing method in which the solvent volatilization in process 3) is performed in the state of the slurry containing the said composite grain|particle and the said solvent. It is a method for producing a composite metal pigment composition having the following steps 1) to 3),
1) The process of dispersing metal particles in a solvent
2) The step of coating the metal particles with a metal oxide
3) A step of washing, filtration and solvent volatilization of the metal particles obtained in step 2) and the composite particles having a metal oxide coating formed on the surface thereof
The manufacturing method which divides and implements the solvent volatilization in process 3) into three or more steps. The manufacturing method of Claim 8 or 9 whose moisture content of the said solvent at the time of solvent volatilization in process 3) is 10 mass % or less.