CN115216182B - Composite metal pigment composition and method for producing same - Google Patents

Abstract

A composite metallic pigment composition and a method for producing the same, which have high non-volatile component (solid content) content and excellent dispersibility in a paint, and which can give a paint excellent in color tone, brightness, hiding property, etc., and excellent storage stability, and which have a high level of balance in characteristics. The composite metal pigment composition contains composite particles having metal particles and a metal oxide coating formed on the surface thereof, (1) the composite particles are scaly in shape, and (2) the volume-based average particle diameter D at the time of measuring the particle size distribution of the composite particles ₅₀ 1 to 30 [ mu ] m, (3) 20 to 300nm in average particle thickness of composite particles, (4) 70 to 95% by mass of solid content concentration of the composition, (5) 80% by mass or more of a solvent having hydrophilicity and a boiling point of 80 to 150 ℃ which is not less than 80% by mass of non-solid content of the composition, and (6) 0.1% by mass or less of residue of the composition when filtered by a 200-mesh filter.

Description

Composite metal pigment composition and its manufacturing method

technical field

The present invention relates to composite metal pigment compositions comprising composite particles having metal particles and an oxidized metal coating formed on the surface thereof, and to methods of making the same, and more particularly to reducing the amount of volatile organic compounds (VOC) At the same time, it effectively inhibits the aggregation and deformation of composite particles, and is used for low-VOC and water-based paints, such as storage stability, suppression of seeding (Japanese: ブツ, seeding), designability, concealment, etc. Excellent coating film A balanced composite metal pigment composition and a production method thereof are formed at a high level of properties and the like.

Background technique

Conventionally, metallic pigments have been used in metallic paints, printing inks, plastic kneading, etc., in order to obtain cosmetic effects emphasizing a metallic feel.

In recent years, in the paint field, there has been an increasing need to switch to water-based paints that use less organic solvents as measures for saving resources, improving the working environment, and making pollution-free. In order to improve the stability of metal pigments in water-based paints, for example, pigments using composite particles in which metal particles are covered with oxide metals such as amorphous silica have been proposed. For such water-based paints, further reduction of VOC is also required. In order to reduce VOC, it is effective to improve the content of non-volatile components (solid content) in the manufacturing process. If strong centrifugal separation, pressurization under strong pressure, and filtration are performed in the filtration process for this purpose, metal particles such as aluminum will be deformed. , or aggregation, and then defects are generated in the coating of oxidized metals such as silicon dioxide, and the water resistance is deteriorated, and the storage stability may also be reduced. In addition, the content of non-volatile components can also be improved by volatilizing the solvent by heating and reducing pressure, but at this time, the surface is prematurely dried and the particles adhere to each other/aggregate, and cannot be dispersed in solvent or water without agglomeration. Composite metallic pigment compositions with improved non-volatile content by conventional methods in this way have problems such as poor dispersibility during coating preparation, inability to express desired color tone, and poor storage stability. Solving such problems is strongly demanded.

For example, Patent Document 1 describes that PVD metallic effect pigments are provided in the form of powder or in a highly concentrated form, and that the PVD pigment powder does not substantially aggregate, and of course has good redispersibility, etc. However, there is no direct evaluation of aggregation and the like after redispersion, and there is no report on the dispersibility in an aqueous solvent.

Patent Document 2 describes that in the production of coated aluminum effect pigments, suction filtration is performed through a Buchner funnel, and it is also described that the aluminum effect pigments are used to form a water-based paint system, but there is no report on the quality of the dispersibility.

prior art literature

patent documents

Patent Document 1: Japanese PCT Publication No. 2017-533982

Patent Document 2: Japanese PCT Publication No. 2013-518948

Contents of the invention

The problem to be solved by the invention

In view of the limitations of the above-mentioned prior art, the object of the present invention is to provide a composite metallic pigment composition and a manufacturing method thereof, which is a composite metallic pigment composition with a high non-volatile component (solid content) content, It has excellent dispersibility in paints, especially water-based paints, can form a coating film with excellent color tone, brightness, concealment, etc., and can obtain paints, especially water-based paints, which are excellent in storage stability. These characteristics are balanced at a high level .

solutions to problems

The inventors of the present invention conducted in-depth studies and found that, as the solvent constituting the composite metal pigment composition, a specific hydrophilic solvent is used, and/or in the manufacture of the composite metal pigment composition, solvent volatilization is carried out under specific conditions, Accordingly, the above-mentioned problems can be solved, and the present invention has been completed.

That is, the first invention of the present application and various aspects thereof are as follows.

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

(1) The shape of the aforementioned composite particles is scale-like,

(2) The volume-based average particle diameter _D50 when measuring the particle size distribution of the aforementioned composite particles by a laser diffraction particle size distribution meter is 1 to 30 μm,

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

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

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

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

[2] The composite metallic pigment composition according to [1], wherein, in the composite particles, the proportion of unaggregated primary particles is 35% or more on a number basis.

[3] The composite metallic pigment composition according to [1] or [2], wherein, in the composite particles, the ratio of curved 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-containing compound layer.

[5] The composite metal pigment composition according to any one of [1] to [4], wherein the metal oxide coating has an average layer thickness of 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: at least one selected from metals, metal oxides, metal hydrates and resins. Seed cover.

In addition, the second invention and the third invention of the present application and various aspects thereof are as follows.

[8] A method for producing a composite metallic pigment composition, the production method having the following steps 1) to 3),

1) A process of dispersing metal particles in a solvent,

2) the process of covering the aforementioned metal particles with oxidized metal,

3) a step of washing, filtering, and volatilizing the solvent with metal particles and metal oxide-covered composite particles formed on the surface obtained in step 2),

The solvent in step 3) is a mixed solvent of two or more solvents having compatibility with each other and having a boiling point difference of 10° C. or more,

The solvent volatilization in step 3) is performed in the state of a slurry containing the composite particles and the solvent.

[9] A method for producing a composite metallic pigment composition comprising the following steps 1) to 3),

1) A process of dispersing metal particles in a solvent,

2) the process of covering the aforementioned metal particles with oxidized metal,

3) a step of washing, filtering, and volatilizing the solvent with metal particles and metal oxide-covered composite particles formed on the surface obtained in step 2),

The solvent volatilization in step 3) is carried out in three or more stages.

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

The effect of the invention

According to the present invention, a novel composite metallic pigment composition that is not available in the prior art can be obtained.

The composite metal pigment composition of the first invention of the present application reduces the amount of volatile organic compounds (VOC), effectively inhibits the aggregation and deformation of composite particles, and is used for low-VOC, water-based paints, etc. The excellent characteristics of the coating film, such as suppression, designability, concealment, etc., 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, it is possible to effectively manufacture low-VOC, water-based paints, etc. Excellent properties of the coating film such as storage stability, suppression of particle formation, designability, concealability, etc., exceed the limit of the prior art, and form a balanced composite metal pigment composition at a high level.

Detailed ways

Hereinafter, the present invention will be described based on typical or preferred embodiments, but the present invention is not limited by these embodiments. These embodiments can be freely combined within the scope of the present invention defined by the appended claims unless explicitly stated otherwise.

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

(1) The shape of the aforementioned composite particles is scale-like,

(2) The volume-based average particle diameter _D50 when measuring the particle size distribution of the aforementioned composite particles by a laser diffraction particle size distribution meter is 1 to 30 μm,

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

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

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

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

Composite particles constituting a composite metal pigment composition

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

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

The composite metallic pigment composition of the first invention of the present application may contain other components such as an organic treatment agent, a solvent containing water and/or a hydrophilic solvent.

metal particles

The composite particles constituting the composite metal pigment composition of the first invention of the present application include metal particles and metal oxide coatings formed on the surfaces thereof. That is, one or more layers of metal oxide coating are formed on the surface of the metal particle serving as the core of the composite particle. Oxidized metal coatings generally have a layered structure.

The material of the metal particles (core particles) constituting the composite particles is not particularly limited, and for example, known or commercially available materials such as aluminum, aluminum alloy, zinc, iron, magnesium, nickel, copper, silver, tin, chromium, stainless steel, etc. Any kind of metal used in metallic pigments. In the present specification, the metal constituting the metal particles of the composite particles includes not only simple metals but also alloys and intermetallic compounds.

Metal particles may be used alone or in combination of two or more.

The metal particles in the first invention of the present application preferably contain aluminum or an aluminum alloy, and more preferably 95% by mass or more are composed of aluminum element.

The average particle diameter of the metal particles is not particularly limited, but it is preferably an average particle diameter that can realize _D50 in the particle size distribution of the composite particles described later. That is, it is preferable to set the volume average particle diameter ( _D50 ) of the metal particles so that the _D50 of the composite particles when the volume distribution is measured by a laser diffraction particle size distribution meter is 1 to 30 μm, or the _D50 is easily formed. ).

The average particle size of the metal particles can be determined by appropriately adjusting the particle size of the raw material atomized metal powder (such as aluminum powder) and the like in the process of grinding and sieving/filtering the raw material atomized metal powder (such as aluminum powder) using a ball mill, etc. The quality of each grinding ball in the ball mill, the speed of the grinding device, the degree of screening and filter press, etc. are controlled.

The thickness and shape of the metal particles are not particularly limited, and the metal particles are preferably in the form of scales (flakes) with an average particle thickness of 10 to 300 nm. Accordingly, the composite particles constituting the composite metallic pigment composition of the first invention of the present application can also easily have a scaly shape, and as a result, high hiding power and the like can be obtained more reliably.

The average thickness of the metal particles is preferably a thickness that can realize the average thickness of the composite particles described later, and specifically, it is preferably 10 to 300 nm. Thereby, the aggregation and deformation of the composite particles are effectively suppressed, and it is easy to achieve excellent designability in the coating film, gloss, suppression of particle formation, stability in the water-based paint, and the like. The average thickness of the metal particles is preferably from 15 to 250 nm, more preferably from 20 to 200 nm, from the above viewpoint.

Here, the average particle thickness of the metal particles can be measured by a method known in the art, for example, by forming a coating film using a metal pigment composition comprising metal particles and composite particles covered with metal oxide formed on the surface thereof, to obtain The FE-SEM image (field emission type scanning electron microscope image) of the cross section was analyzed and measured. More specifically, it can be measured by the method described in the Examples of the present application.

The aspect ratio (shape factor obtained by dividing the average particle diameter by the average thickness) of the scaly metal particles is preferably 30-1500, more preferably 50-1000, particularly preferably 80-700. When the diameter-to-thickness ratio of the metal particles is 30 or more, a higher glossiness can be obtained. In addition, when the aspect ratio of the metal particles is 1500 or less, the mechanical strength of the sheet is maintained, and a stable color tone can be obtained.

The average thickness of the metal particles is the same as the volume standard _D50 . In the process of grinding and sieving/filtering the raw material atomized metal powder (such as aluminum powder) using a ball mill or the like, the particle size of the raw material atomized metal powder can be appropriately adjusted. The diameter, the quality of each grinding ball when using a ball mill, the speed of the grinding device, the degree of screening and filter press, etc. are controlled.

In addition, the metal particles do not necessarily need to be composed of only metal, and as long as the effect of the first invention of the present application is not inhibited, for example, particles of synthetic resin, particles of inorganic particles such as mica, and glass whose surface is covered with metal, etc. can also be used. In the first invention of the present application, particles containing aluminum or an aluminum alloy are particularly preferred from the viewpoints of high weather resistance, small specific gravity, and ease of acquisition.

The metal particles constituting the composite particles are particularly preferably aluminum flakes which are generally used as pigments for metals. As the aluminum flakes, those having surface properties, particle diameters, and shapes required for metallic pigments such as surface gloss, whiteness, and brilliance are suitable. Aluminum flakes are usually commercially available in a paste state. The pasty aluminum flakes may be used as they are, or may be used after removing fatty acids or the like on the surface with an organic solvent or the like. 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.

oxide metal covering

The composite particles constituting the composite metal pigment composition of the first invention of the present application have metal oxide coatings formed on the surfaces of the metal particles.

The metal oxide coating is a coating composed of a layer containing the metal oxide, and may be formed on the entire surface of the metal particle or only on a part of the surface. It is preferably formed on the entire surface from the viewpoint of water resistance, storage stability when used in paint, and the like.

The metal oxide coating may be entirely made of metal oxide, or only a part thereof may be made of metal oxide and may contain components other than metal oxide.

The oxidized metal constituting the oxidized metal coating is a compound whose constituent elements contain oxygen and at least one metal element.

Therefore, the oxide metal may be an oxide metal in a narrow sense having only oxygen and at least one metal element as its constituent elements, but as long as its constituent elements contain oxygen and at least one metal element, the oxygen and at least one metal element may also be contained in its constituent elements. Elements other than metal elements may be, for example, metal hydroxides, oxide hydrates, oxynitrides, and the like. In addition, an organic group-containing compound may also be used.

In addition, the metal oxide may be a so-called single oxide in which only one metal element is a constituent element, or may be a composite oxide in which two or more metal elements are constituent elements.

At least one metal element that is a constituent element of the metal oxide may be a typical metal or a transition metal. Furthermore, it may be a so-called half-metal element. Among them, silicon oxide as a constituent element is particularly preferable as the oxide metal constituting the oxide metal coating.

Preferable specific examples of 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, oxide Vanadium, their oxide hydrates, their hydroxides, and their mixtures, etc. Among them, silica, alumina, 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 metal oxide coating is particularly advantageous from the viewpoint of achieving good storage stability in water-based paints, improving water resistance when forming a coating film, and suppressing gas generation.

Silicon oxide is used by an oxidized metal coating which generally forms a layer composed of a compound containing Si—O—bonds (siloxane bonds). Such a layer includes, for example, a layer containing at least one of a silane compound and a silicon oxide. Examples _{of such} compounds include SiO _{2 ,} SiO ₂ ·nH ₂ O ( _wherein , n represents an arbitrary positive integer) and the like shown in the silicon oxide. These silane-based compounds and silicon oxides may be either crystalline or amorphous, and are particularly preferably amorphous. Therefore, as a layer containing silicon oxide (silicon dioxide, etc.), for example, a layer containing amorphous silicon dioxide can also be suitably used.

In addition, the metal oxide coating using silicon oxide may be a layer formed from an organosilicon compound (containing a silane coupling agent) as a starting material. In this case, the metal oxide may contain an unreacted organosilicon compound or a component derived therefrom within the range that does not inhibit the effect of the first invention of the present application. In a typical example of this, the oxidized metal coating can be formed by hydrolyzing an organosilicon compound.

The mass of the metal oxide coating layer when silicon oxide is used is not particularly limited, but is preferably 1 to 20 parts by mass, particularly more preferably 2 to 15 parts by mass, based on 100 parts by mass of the metal particles. When the silicon content covered with the metal oxide is 1 part by mass or more with respect to 100 parts by mass of the metal particles, the corrosion resistance, water dispersibility, stability, etc. of the composite metal pigment composition can be maintained high. When the content of silicon coated with the oxidized metal is 20 parts by mass or less with respect to 100 parts by mass of the metal particles, it is possible to prevent aggregation of the composite particles, concealment, and reduction in color tone such as metallic luster.

The metal oxide coating of the composite particles contained in the composite metal pigment composition of the first invention of the present application is particularly preferably hydrophilic. Composite particles usually form a composite metal pigment composition dispersed in an aqueous solvent (water or a mixed solvent containing water and an organic solvent). In the case of a metal oxide coating with a hydrophilic surface, the composite particles can be dispersed in this aqueous solvent. Medium to high dispersion. Furthermore, since metal oxides such as silicon oxides (amorphous silica, etc.) are very stable in aqueous solvents, composite metal pigments containing highly stable composite particles in aqueous solvents can be provided. From this point of view, for the composite particles contained in the composite metal pigment composition of the first invention of the present application, it is preferable that at least one layer, preferably the outermost layer, is a metal oxide coating, particularly preferably a layer containing a silicon compound. (In particular, a layer composed of a compound containing Si—O bonds). Since the metal oxide has excellent affinity with the metal particles, when the composite particle has a coating layer composed of multiple layers, in addition to the outermost layer covered with the metal oxide, as a layer other than the outermost layer, it is particularly preferable to mix with the metal oxide. A metal oxide layer, particularly preferably a silicon-containing compound layer (especially a Si—O-based coating layer) may be formed separately for the layer in contact with the particles.

The metal oxide coating thickness of each composite particle 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 described above. The thickness of the metal oxide coating is generally preferably in the range of about 5 to 200 nm (particularly 10 to 100 nm, further 20 to 70 nm). When the thickness of the oxidized metal coating is 5 nm or more, a coating film having sufficient water resistance and suppressing corrosion of metal particles in the water-based paint and generation of discoloration can be obtained. On the other hand, when the thickness of the metal oxide coating is about 200 nm or less, the brightness, distinctness of image, and hiding power of the coating film can be maintained at high levels.

When the metal oxide coating of each composite particle contains a silicon-containing compound layer, the thickness of the silicon-containing compound 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-containing compound layer is usually in the range of 5 to 200 nm, particularly preferably in the range of 10 to 100 nm, and more preferably in the range of 20 to 70 nm, from the viewpoint of the function of the layer.

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

The organosilicon compound may contain at least one of the organosilicon compounds represented by the following general formula (1), and any one of the following general formulas (2), (3) and (4) At least one of so-called silane coupling agents and their partial condensates.

Si(OR ¹ ) ₄ (1)

(In the formula, ^R1 is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and when there are two or more ^R1s , all of them may be the same, some of them may be the same, or all of them may be different.)

R ² _m Si(OR ³ ) _4-m (2)

(In the formula, R ² is a hydrogen atom, or a hydrocarbon group with 1 to 30 carbon atoms that can optionally contain a halogen group, and R ³ is a hydrogen atom, or a hydrocarbon group with 1 to 8 carbon atoms. R ² and R ³ can be the same or different, when ^R2 or ^R3 is two or more, all of them may be the same, some of them may be the same, or all of them may be different. 1≤m≤3.)

R ⁴ _p R ⁵ _q Si(OR ⁶ ) _4-pq (3)

(In the formula, ^R4 is a group containing a reactive group that can be chemically bonded to other functional groups, ^R5 is a hydrogen atom, or a hydrocarbon group with 1 to 30 carbon atoms that can optionally contain a halogen group, ^R6 is a hydrogen atom, or a hydrocarbon group having 1 to 8 carbon atoms. When ^{R 4} , R ⁵ , or R ⁶ are two or more, all of them may be the same, some of them may be the same, or all of them may be different. 1≤p≤3, 0≤q≤2, 1≤p+q≤3.)

R ⁷ _r SiCl _4-r (4)

(In the formula, R ⁷ is a hydrogen atom or a hydrocarbon group with 1 to 30 carbon atoms that may optionally contain a halogen group. When R ⁷ is two or more, all of them may be the same, some of them may be the same, or all of them may be different. 0≤r ≤3.)

Examples of the hydrocarbon group in R ¹ of the formula (1) include methyl, ethyl, propyl, butyl, hexyl, octyl and the like, which may be branched or linear. Among these hydrocarbon groups, methyl, ethyl, propyl, and butyl groups are particularly preferred. In addition, four R ^1s may be all the same, some of them may be the same, or all of them may be different.

Preferable examples of the organosilicon compound of the formula (1) include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, and the like. Among them, tetraethoxysilane is particularly preferable.

As the example of the hydrocarbon group in R of formula ( ² ), methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, oleyl, stearyl, cyclo Hexyl, phenyl, benzyl, naphthyl, and the like may be branched or linear, and may contain a halogen group such as fluorine, chlorine, or bromine. Among them, a hydrocarbon group having 1 to 18 carbon atoms is particularly preferable. In addition, when there are two or more R ² , all of them may be the same, some of them may be the same, or all of them may be different. The number of R ² in the molecule is m=1-3 in formula (2), that is, 1-3, but m=1 or 2 is more preferable.

Examples of the hydrocarbon group in ^R3 of formula (2) include methyl, ethyl, propyl, butyl, hexyl, octyl, etc., and they may be branched or linear. Among these hydrocarbon groups, methyl, ethyl, propyl, and butyl groups are particularly preferred. In addition, when there are two or more R ^{3 s} , all of them may be the same, some of them may be the same, or all of them may be different.

Preferred examples of organosilicon compounds (silane coupling agents) of the formula (2) include methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, dimethyl Dimethoxysilane, Dimethyldiethoxysilane, Dimethyldibutoxysilane, Trimethylmethoxysilane, Trimethylethoxysilane, n-Propyltrimethoxysilane, n-Propyl N-propyltriethoxysilane, n-propyltributoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltributoxysilane, dibutyldimethoxysilane, dibutyl Diethoxysilane, Dibutyldibutoxysilane, Isobutyltrimethoxysilane, Isobutyltriethoxysilane, Hexyltrimethoxysilane, Hexyltriethoxysilane, Dihexyldimethylsilane oxysilane, dihexyldiethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, dioctyldimethoxysilane, dioctyldiethoxysilane, dioctylethoxysilane Butoxysilane, decyltrimethoxysilane, decyltriethoxysilane, didecyldimethoxysilane, didecyldiethoxysilane, octadecyltrimethoxysilane, octadecyltrimethoxysilane Alkyltriethoxysilane, bis(octadecyl)dimethoxysilane, bis(octadecyl)diethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, di Phenyldimethoxysilane, Diphenyldiethoxysilane, Trifluoropropyltrimethoxysilane, Heptadecafluorodecyltrimethoxysilane, Tridecafluorooctyltrimethoxysilane, Tridecafluorooctyl Triethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropyltributoxysilane, etc.

Examples of reactive groups capable of chemically bonding with other functional groups in R in formula ( ³ ) include vinyl, epoxy, styryl, methacryloxy, acryloxy, amino , ureide group, mercapto group, polysulfide (polysulfide) group, isocyanate group, etc.

In addition, when there are two or more R ^{4 s} , all of them may be the same, some of them may be the same, or all of them may be different. In the formula (3), the number of R ⁴ in the molecule is p=1 to 3, that is, 1 to 3, but p=1 is more preferable.

As the example of ^R5 of formula (3), methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, oleyl, stearyl, cyclohexyl can be enumerated , phenyl, benzyl, naphthyl, etc., which may be branched or linear, and may contain halogen groups such as fluorine, chlorine, and bromine. Among them, a hydrocarbon group having 1 to 18 carbon atoms is particularly preferable. In addition, when there are two or more R ^{5 s} , all of them may be the same, some of them may be the same, or all of them may be different.

Examples of the hydrocarbon group in R ⁶ of formula (3) include methyl, ethyl, propyl, butyl, hexyl, octyl, etc., and they may be branched or linear. Among these hydrocarbon groups, methyl, ethyl, propyl, and butyl groups are particularly preferred. In addition, when there are two or more R ^{6 s} , all of them may be the same, some of them may be the same, or all of them may be different.

Preferable examples of organosilicon compounds (silane coupling agents) of the formula (3) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyl-tris(2-methoxyethyl) oxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyl Trimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methoxysilane Acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloyl Oxypropyltrimethoxysilane, N-methyl-3-aminopropyl-trimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N- 2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethyl Oxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl Trimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 3-ureidepropyltriethoxysilane, 3-mercaptopropyl Methyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyl-triethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanate Propyltriethoxysilane, etc.

As the example of the hydrocarbon group in ^R7 of formula (4), methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, oleyl, stearyl, cyclo Hexyl, phenyl, benzyl, naphthyl, and the like may be branched or linear, and may contain a halogen group such as fluorine, chlorine, or bromine. Among them, a hydrocarbon group having 1 to 12 carbon atoms is particularly preferable. In addition, when there are two or more R ^{7 s} , all of them may be the same, some of them may be the same, or all of them may be different. The number of R ⁷ in the molecule is in formula (4), r=0-3, that is, 0-3, but r=1-3 is more preferable.

Preferable examples of organosilicon compounds (silane coupling agents) of the formula (4) include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and octyldimethylchlorosilane. , phenyltrichlorosilane, vinyltrichlorosilane, tetrachlorosilane, etc.

The organosilicon compound represented by the above general formula (1) may be used alone or in combination of two or more. Moreover, the silane coupling agent represented by any one of General formula (2), (3) and (4) can also be used individually by 1 type or in combination of 2 or more types. When using two or more types in combination, only two or more of the silane coupling agents shown in any one of (2), (3) and (4) may be used in combination, or two or more different types may be used The silane coupling agent represented by the general formula is used in combination.

A hydrolyzate of an organosilicon compound and/or a condensation reaction product thereof is obtained by stirring and mixing an organosilicon compound, water in an amount necessary for the hydrolysis reaction, and a hydrolysis catalyst. At this time, a hydrophilic solvent can also be used as needed. Various conditions for the hydrolysis reaction (ie, the reaction for forming the silicon-containing compound layer) are as described later.

As a raw material for the hydrolysis reaction and/or the condensation reaction to obtain the hydrolyzate of the organosilicon compound and/or its condensation reaction product, an oligomer partially condensed in advance can be used.

The condensation reaction of the hydrolyzate of the organosilicon compound may be carried out simultaneously with the hydrolysis reaction of the organosilicon compound, or may be carried out in a separate process and the catalyst may be replaced as necessary. At this time, the temperature can be increased as needed.

Physical Properties of Composite Particles and Composite Metallic Pigment Composition

In the composite metallic pigment composition of the first invention of the present application, the composite particles constituting it satisfy the following physical property conditions.

(1) The shape of the composite particles is scale-like.

(2) The volume-based average particle diameter D ₅₀ when measuring the particle size distribution of the composite particles 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.

The composite metallic pigment composition of the first invention of the present application further satisfies the following conditions as a composition.

(4) The solid content concentration of the composite metallic pigment composition is 70 to 95% by mass.

(5) The solvent which is hydrophilic and has a boiling point of 80 to 150° C. accounts for 80% by mass or more of the non-solid content of the composite metal pigment composition.

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

Each of these physical property conditions will be described below.

(1) The shape of the composite particles is scale-like.

The composite particles contained in the composite metallic pigment composition of the first invention of the present application have a scaly shape. By containing the scaly composite particles, the composite metallic pigment composition of the first invention of the present application can effectively form a coating film having excellent characteristics such as high hiding power.

Scale-like composite particles are easily deformed in the process of stirring, separating, and filtering during production, especially due to strong centrifugation for increasing the content of non-volatile components (solid content), filtration under strong pressure, etc. However, in the present invention, the deformation of scale-like composite particles can be effectively suppressed while achieving a high non-volatile content (solid content).

Here, the fact that the composite particles are scale-like means that the particles have a shape with a high aspect ratio preferably within a numerical range described later.

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

The scaly composite particles contained in the composite metallic pigment composition of the first invention of the present application preferably have an aspect ratio (shape factor obtained by dividing the average particle diameter by the average thickness) of 30-700. When the aspect ratio of the composite particles is 30 or more, it is easy to obtain a higher glossiness. In addition, when the aspect ratio of the composite particles is 700 or less, the mechanical strength of the composite particles is maintained, and a stable color tone is easily obtained. The aspect ratio is preferably 50-600, more preferably 80-500.

(2) The volume-based average particle diameter _D50 when measuring the particle size distribution of the composite particles with a laser diffraction particle size distribution meter is 1 to 30 μm

The volume-based average particle diameter _D50 when measuring the particle size distribution of the composite particles with a laser diffraction particle size distribution meter is 1 to 30 μm. As a result, the aggregation and deformation of particles are effectively suppressed, and the coating film formed using the composite metallic pigment composition or a water-based paint containing it can achieve excellent design, gloss, suppression of particle formation, and stability in water-based paints. sex etc. This volume-based _D50 is also commonly referred to as the median particle size.

From the viewpoint of obtaining excellent design, gloss, suppression of particle formation, stability in water-based paint, etc., _D50 based on volume when measuring the particle size distribution of composite particles with a laser diffraction particle size distribution meter is preferably 2 to 25 μm , particularly preferably 3 to 20 μm.

The "composite particle" in the condition of physical properties refers to an aggregate (aggregate) thereof when a plurality of composite particles aggregate/adhere.

Here, D ₅₀ on a volume basis when measuring the particle size distribution of composite particles with a laser diffraction particle size distribution meter refers to a particle diameter at which the degree of accumulation is 50% in the volume cumulative particle size distribution. It does not specifically limit as a laser-diffraction particle size distribution meter, For example, "LA-300" (made by Horiba Seisakusho Co., Ltd.) can be used. As the measurement solvent, hydrophilic solvents such as water, isopropanol, and methoxypropanol can be used. For example, for a composite metallic pigment composition containing composite particles of a sample, after performing ultrasonic dispersion for about 2 minutes as a pretreatment, it is put into a dispersion tank, and after confirming proper dispersion, D ₅₀ can be measured.

The D ₅₀ based on the volume of the composite particles constituting the composite metal pigment composition can be appropriately adjusted by, for example, using a ball mill or the like to grind the atomized metal powder (such as aluminum powder) and sieve/filter the raw material. Particle size and input amount of metal powder, amount of grinding solvent such as mineral spirits, type and amount of grinding aids, mass and input amount of each grinding ball when using a ball mill, rotational speed of the grinding device, sieve The degree of separation and filter press, etc., and can be controlled by appropriately adjusting the pH, concentration, stirring temperature, The stirring time, the type of stirring device, the power/degree of stirring (the type and diameter of the stirring blade, the rotational speed, the presence or absence of external stirring, etc.) are controlled.

In addition, there is a tendency for the particle size to increase due to aggregation during the metal oxide coating treatment, but the increase in particle size leads to a decrease in color tone, a decrease in concealment, and a decrease in the appearance of the coating film. It is effective to prevent particle hypertrophy.

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

The average thickness of the composite particles contained in the composite metallic pigment composition of the first invention of the present application is 20 to 300 nm. Thus, combined with satisfying the above conditions (1) and (2), the aggregation and deformation of the composite particles are effectively suppressed, and excellent designability, gloss, and particle formation suppression in the coating film can be achieved, and stability in the water-based paint can be achieved. sex etc.

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

The "composite particle" in the condition of physical properties refers to an aggregate (aggregate) thereof when a plurality of composite particles aggregate/adhere.

As for the average thickness of the composite particles here, the average particle thickness of the metal particles and the thickness of the metal oxide coating can be measured respectively, and calculated from them according to the following formula.

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

The average particle thickness of the metal particles can be measured by the method described in (2) above.

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 of the present application.

The average thickness of the composite particles contained in the composite metal pigment composition is the same as the volume basis _D50 , and can be covered by the metal oxide coating (and other coating layers if necessary) in the process of processing the raw metal powder and covering the silicon-containing compound layer. In the process, etc., the pH, concentration, stirring temperature, stirring time, type of stirring device, stirring power/degree (type of stirring blade and Diameter, rotational speed, presence or absence of external stirring, etc.) etc. to control. In addition, there is a tendency for the particle size to increase due to aggregation during the metal oxide coating treatment, but the increase in particle size leads to a decrease in color tone, a decrease in concealment, and a decrease in the appearance of the coating film. It is effective to prevent particle hypertrophy.

(4) The solid content concentration of the composite metallic pigment composition is 70 to 95% by mass

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

With the composite metallic pigment composition of the first invention of the present application, when the solid content concentration is 70 to 95% by mass, it is possible to achieve low VOC (volatile organic compound) and to form a coating film with a good appearance . More specifically, when the solid content concentration is 70% by mass or more, the content of VOCs such as solvents can be sufficiently reduced, so even when the coating is formed using it, a coating with a sufficiently reduced VOC content can be realized. On the other hand, when the solid content concentration is 95% by mass or less, uniform dispersion at the time of coating formation is facilitated, and generation of particles in the coating film can be effectively suppressed.

The solid content concentration is preferably 75 to 95% by mass, more preferably 80 to 95% by mass, particularly preferably 85 to 95% by mass.

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

The solid content concentration of the composite metal pigment composition can be appropriately adjusted by removing volatile components such as solvents used in the dispersion of metal particles and the formation of the metal oxide film by filtration, volatilization, etc. during the production of the composite metal pigment composition. Adjustment.

In the first invention of the present application, in order to achieve such a specific high solid content concentration, it is preferable to use a solvent with a low boiling point that is easily removed by volatilization. Since such a low-boiling-point solvent may not be suitable for the dispersion of metal particles and the formation of a metal oxide film, it is possible to replace the solvent with a solvent with a lower boiling point after the dispersion of metal particles and the formation of a metal oxide film. .

In addition, it is also preferable to perform volatilization stepwise. For example, after volatilization, an operation of diffusing composite particles into a solvent may be performed, and then volatilization may be performed again.

Furthermore, in order to realize a high solid content concentration, it is also preferable to combine filtration and volatilization, and it is particularly preferable to perform filtration to reduce the amount of volatile components before volatilization.

A high solid content concentration can also be achieved by removing solvents, etc., by centrifugal separation and relatively strong pressure filtration, but it should be noted that this operation may cause scale-like composite particles to aggregate and/or deform, which may be difficult to achieve Other conditions of the first invention of the present application include, for example, a predetermined volume-based average particle diameter D ₅₀ and a predetermined residue amount.

In the first invention of the present application, when realizing the specified solid content concentration, it is particularly preferable to adopt the second invention of the present application, and/or from the viewpoint of effectively preventing aggregation and deformation of the composite particles and allowing sufficient removal of volatile components. The manufacturing method of the 3rd invention of this application.

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

The hydrophilic solvent having a boiling point of 80 to 150° C. (hereinafter also referred to as “specific solvent”) accounts for 80% by mass or more of the non-solid content of the composite metallic pigment composition of the first invention of the present application.

The specific solvent is easy to volatilize because its boiling point is 80-150°C, and extreme high temperature and reduced pressure are not required for volatilization. Therefore, the specific solvent accounts for 80% by mass of the non-solid content, and the composite particles can be removed without agglomeration or adhesion. Improve the solid content of the non-solid content.

In addition, since the specific solvent is hydrophilic, it becomes easier to disperse the composite metallic pigment composition of the first invention of the present application in water when the specific solvent accounts for 80% by mass of the non-solid content, and it becomes easier to form a uniform water-based paint. . In addition, by being hydrophilic, water in the composition can be removed more easily by azeotropy or the like, and aggregation due to moisture can be more effectively suppressed.

The concept of a hydrophilic solvent is commonly understood by those skilled in the art. For example, a solvent having a solubility in water of 20 g/g or more at room temperature can be preferably used 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.

The specific solvent accounts for preferably 80 to 100% by mass of the non-solid content of the composite metallic pigment composition, more preferably 85 to 100% by mass, particularly preferably 90 to 100% by mass.

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

Preferable examples of the specific solvent include methoxypropanol, isobutanol, n-butanol, isopropanol, n-propanol and the like.

These specific solvents may be used alone or in combination of two or more.

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

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

The 200-mesh filter has a pore size of about 74 μm. Therefore, for composite particles with a volume-based average particle diameter _D50 of 1 to 30 μm and an average particle thickness of 20 to 300 nm, most of them pass through 200 mesh if there is no adhesion or aggregation of particles. filter. Therefore, when the composite metallic pigment composition is filtered with a 200-mesh filter, the residue is a composite particle formed by particles adhering to each other and aggregating, and the ratio of the composite metal pigment composition in the solid content is preferably low,

Since the composite metal pigment composition of the first invention of the present application has a residue of 0.1% by mass or less of the solid content when filtered through a 200-mesh filter, the particles are effectively suppressed from adhering to each other and agglomerating, and can be dispersed in a solvent or water to prevent aggregation. In addition, it is possible to form a coating film with excellent appearance such that particle generation is effectively suppressed.

The amount of residue when filtered through a 200-mesh filter is preferably 0.05% by mass or less, more preferably 0.01% by mass or less, particularly preferably 0.005% by mass or less, based on the solid content.

Regarding the amount of residue when filtering with a 200-mesh filter, after the composite metal pigment composition is well dispersed in a solvent, filter with a 200-mesh filter, measure the dry mass of the residue, and combine it with the original composite metal pigment The mass of the solid component in the product determines the ratio of the residue to the solid component. More specifically, it can be measured, for example, by the method described in the Examples of the present application.

The amount of residue when filtering with a 200-mesh filter can be reduced by suppressing adhesion and aggregation of composite particles by various methods described in the specification of the present application. In particular, use of a large amount of the above-mentioned specific solvent is effective for reducing the residue amount. In addition, with the production method of the second invention of the present application and/or the production method of the third invention of the present application, it is also effective to reduce the amount of residue by removing volatile components while effectively preventing aggregation and deformation of the composite particles.

Preferred physical properties of composite particles, etc.

The composite metallic pigment composition of the first invention of the present application preferably has some or all of the following physical properties, characteristics, etc. in addition to the physical property conditions of (1) to (3) above.

The proportion of non-aggregated primary particles in the composite particles is 35% or more on a number basis

In the composite metallic pigment composition of the present embodiment, the ratio of unaggregated primary particles to all composite particles contained in the composite metallic pigment composition is preferably 35% or more on a number basis. The ratio of the primary particles being 35% or more means that the aggregation of each particle is suppressed, and not only the primary particles but also aggregated particles have a smaller degree of aggregation. As a result, the coating film formed using the composite metallic pigment composition exhibits excellent designability, gloss, and suppression of particle formation, and it is further easy to improve stability in water-based coatings and the like.

In addition, since the agglomeration of each particle is suppressed in this way, the agitation for dispersion is mild enough, and thus the deformation of the particles due to agitation can be greatly reduced.

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

The proportion of non-aggregated primary particles in composite particles is usually as high as possible, and in particular, there is no upper limit, and 100% is ideal.

The ratio of non-agglomerated primary particles to the composite particles can be determined by a method known in the art, for example, by using a metal pigment composition comprising an aggregate of metal particles and composite particles covered with oxide metal on the surface thereof Form a coating film, obtain an FE-SEM image (field emission scanning electron microscope image) of its cross section for image analysis, or measure by counting the number of primary particles and aggregated particles in the FE-SEM image by an evaluator . More specifically, it can be measured, for example, by the method described in the Examples of the present application.

The ratio of unaggregated primary particles to composite particles can be improved, for example, by increasing the amount of a specific solvent used, or by adopting the production method of the second invention of the present application and/or the production method of the third invention of the present application.

In addition, it can be controlled by appropriately setting the selection and treatment of the metal particles constituting the composite particles, the type of metal oxide coating formed on the metal particles, and the production conditions. As a prior art, attempts have been made to strengthen mechanical dispersion by increasing the agitation speed during coating treatment and making the Reynolds number more than a certain value, but there is the following problem when using this method: the dispersion of such fine particles is limited in the application. , and scale-like thin particles are broken or deformed due to strong stress during stirring.

On the other hand, before the metal particles are coated with metal oxide, the metal particles are subjected to pretreatment for improving the dispersibility, thereby suppressing the aggregation of the particles during the coating treatment, thereby greatly increasing the number of times that there is no aggregation. particle ratio.

For example, when the metal particles used as raw materials are dispersed in a solvent and supplied, the solvent is replaced with the same solvent as the solvent used in the covering treatment, and then heated for a certain period of time as necessary to make the solvent and the surface of the metal particles Sufficiently compatible, thereby greatly suppressing aggregation during covering processing. Furthermore, adding a small amount of surfactant at this time is also effective for aggregation suppression.

Since the dispersibility of the metal particles themselves is improved by these treatments, it is not necessary to forcibly stir during the covering treatment, and primary particles without agglomeration can be produced even with gentle stirring. Therefore, particle deformation during coating treatment can be significantly reduced, and excellent designability, gloss, and suppression of particle formation in the coating film, stability in water-based paint, and the like can be easily realized.

In addition to the above, as factors that affect the ratio of primary particles that are not aggregated, raw material mist in the process of grinding and sieving/filtering raw material atomized metal powder (for example, aluminum powder) etc. using a ball mill etc. The particle size of metal oxide powder, etc., the mass of each grinding ball when using a ball mill, the rotation speed of the grinding device, the degree of sieving and filter press, and the covering of oxidized metals such as silicon-containing compound layers (and as required other coating layers) during the hydrolysis of raw materials such as organosilicon compounds, concentration, stirring temperature, stirring time, type of stirring device, stirring power/degree (type and diameter of stirring blade, rotational speed, external stirring The presence or absence of, etc.), etc., by adjusting them appropriately, it is also possible to control the ratio of primary particles that are not aggregated.

The proportion of curved composite particles in the composite particles is 10% or less on a number basis.

In the composite metallic pigment composition of the present embodiment, the ratio of curved composite particles to all composite particles contained in the composite metallic pigment composition is preferably 10% or less. As a result, the coating film formed using the composite metallic pigment composition exhibits excellent designability, gloss, and suppression of particle formation, and it is further easy to improve stability in water-based coatings and the like.

The ratio of bent composite particles is understood as an index related to the degree of deformation or breakage of the composite particles. If the ratio of curved composite particles is 10% or less, the degree of deformation or breakage of the composite particles is small, and thus the ratio of the untreated surface (the surface on which the metal oxide film is not formed) of each composite particle is reduced, whereby the water-based paint The stability in the compound metal pigment composition is improved, and in addition, it is easy to form uniform and sufficient coverage on each particle, and the agglomeration of each particle is further reduced, so it is possible to obtain an excellent coating surface formed using a composite metal pigment composition. Coating film with designability, gloss, and particle suppression.

The smaller the proportion of curved composite particles in the aggregate of composite particles, the better. The ratio is preferably 6% or less, more preferably 3% or less. The lower the ratio of bent composite particles is, the more preferable it is, so in particular there is no lower limit, and it is ideally 0%.

The ratio of curved composite particles in a composite metal pigment composition can be determined using methods known in the art, for example, by using a metal pigment composition comprising an aggregate of metal particles and oxidized metal-coated composite particles on the surface thereof. The object forms a coating film, and an FE-SEM image (field emission scanning electron microscope image) of its cross section is obtained for image analysis and measurement. More specifically, the ratio of the linear distance between the two front ends of the cross-section of the metal particle in the FE-SEM image to the path length between the two front ends along the metal particle cross-section can be 0.8 times or less. The particles judged to be curved were obtained and measured by calculating their number ratio. More specifically, it can be measured, for example, by the method described in the Examples of the present application.

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

In addition, it is also possible to appropriately adjust the pretreatment for improving the dispersibility of the raw aluminum paste, the stirring time, the type of stirring device, and the power of stirring in the process of covering the metal oxide coating (and other coating layers as needed). /degree (the type and diameter of the stirring wing, the rotating speed, the presence or absence of external stirring, etc.) etc. to control.

Furthermore, the dispersibility of the particles themselves during the reaction is improved by the pretreatment of the raw material aluminum paste, and thus the stirring for dispersion is mild enough, so the deformation of the particles due to stirring can be greatly reduced.

2nd covering layer

The coating layer of the composite particles contained in the composite metallic pigment composition of the first invention of the present application is not particularly limited except that it has at least one layer of metal oxide coating, and coating layers other than the metal oxide coating can also be formed as needed ( Hereinafter referred to as "second covering layer").

For example, the second covering layer preferably contains metals (alkali metals; alkaline earth metals; metals such as manganese, iron, cobalt, nickel, copper, silver), metal oxides (titanium oxide, zirconium oxide, iron oxides, etc.), metal hydrates , and resins (synthetic resins such as acrylic resins, alkyd resins, polyester resins, polyurethane resins, polyvinyl acetate resins, nitrocellulose resins, and fluororesins). As the second coating layer, for example, a molybdenum-containing film, a phosphate compound film, or the like can be formed. By providing the second coating layer, the corrosion resistance of the metal particles can be improved and the formation of an oxide metal coating such as a silicon-containing compound layer can be accelerated.

The second coating layer (when formed) is particularly preferably formed between the metal particles and the oxide metal coating such as the silicon-containing compound layer. Therefore, for example, a layer structure of "metal particle/second coating layer/oxide metal coating" can be suitably employed. Although not particularly limited, examples of molybdenum-containing coatings include Japanese Patent Laid-Open No. 2003-147226, International Publication No. 2004/096921 pamphlet, Japanese Patent No. 5979788, and Japanese Patent Laid-Open No. 2019-151678 The molybdenum-containing coating disclosed in . As an example of the phosphoric acid compound film, the phosphoric acid compound film disclosed in Japanese Patent No. 4633239 is mentioned. Preferred examples of the molybdenum-containing substance constituting the molybdenum-containing coating include mixed-coordination heteropolyanion compounds disclosed in JP-A-2019-151678.

In another modification, the second coating layer can be formed on the outside of the metal oxide coating such as the metal particles and the silicon-containing compound layer. Moreover, in yet another modified form, the constituent components of the second coating layer (molybdenum-containing compound, phosphoric acid compound, etc.) can be included in the metal oxide coating such as the silicon-containing compound layer together with the silicon compound or the like.

Mixed coordination type heteropolyanion preferably used in the form of forming a second coating layer (a typical example, a molybdenum-containing coating) other than the metal oxide coating of the composite particles contained in the composite metallic pigment composition of the first invention of the present application The compound is not particularly limited, and the following examples are specifically mentioned.

Mixed-coordination heteropolyanion compound that can be used The mixed-coordination heteropolyanion has a structure in which some of the polyatoms of the heteropolyanion formed from one element are replaced by other elements, and exhibits the same structure as that of each heteropolyanion. Mixtures of anions have different physical properties.

In the case of using a chemical formula, if the mixed-coordination heteropolyanion is expressed as [X _p M _q N _r O _s ] ^t , the heteropolyanion becomes [X _p M _q O _s ] ^t , and it is also compatible with the isopolyanion [M _q O _s ] ^t difference. Here, X as a hetero atom represents an element of Group IIIB, IVB, VB such as B, Si, Ge, P, As, etc., and among them, B, Si, and P are preferable. M and N as polyatoms represent transition metals such as Ti, Zr, V, Nb, Ta, Mo, and W, and are preferably Ti, Zr, V, Nb, Mo, or W.

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

Since the heteropolyanion compound has many structures, the mixed-coordination type heteropolyanion compound can have more structures, but as representative and preferable mixed-coordination type heteropolyanion compounds, the following mixed-coordination type 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 (silicon tungstomolybdic acid n hydrate), H _4+x SiV _x Mo _12-x O ₄₀ nH ₂ O (silicon vanadium molybdic acid n hydrate), etc. (where, 1≤x≤11, n≥0)

Among these heteropolyanionic compounds, preferred specific examples 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 O, H ₄ SiW ₉ Mo ₃ O ₄₀ nH ₂ O, H ₅ SiV ₁ Mo ₁₁ O ₄₀ nH ₂ O, H ₇ SiV ₃ Mo ₉ O ₄₀ nH ₂ O and other mixed coordination types Heteropolyacids. (where n≥0)

The mixed-coordination heteropolyanion compound may be used as an acid (so-called mixed-coordination heteropolyacid) or as a (partial or complete) salt using a specific cation as a counterion.

The counter cation source when the mixed coordination heteropolyanion compound is used in the form of a salt with a specific cation as a counter ion includes, for example, alkali metals selected from lithium, sodium, potassium, rubidium, and cesium; magnesium, calcium, At least one of alkaline earth metals such as strontium and barium; metals such as manganese, iron, cobalt, nickel, copper, zinc, silver, cadmium, lead, and aluminum; inorganic components such as ammonia; and amine compounds as organic components. Among the inorganic components, salts of alkali metals, alkaline earth metals, and ammonia are preferred.

Furthermore, in the case of at least one selected from these alkali metals, alkaline earth metals, and ammonia as a source of counter cations, it is more preferable to use a mixture selected from 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 (phosphovanadanomolybdic acid n hydrate), H ₄ SiW _x Mo _12-x O ₄₀ nH ₂ O (silicon tungsten molybdic acid n hydrate), H _4+x SiV _x Mo _12-x O ₄₀ nH ₂ O (silicon vanadium molybdic acid n hydrate) in the form of at least one salt.

In addition, an amine compound as an organic component is also preferably used as a counter cation source of the mixed-coordination heteropolyanion compound, and as a specific example, an amine compound represented by the following general formula (5) is preferable.

(R ⁸ -N(-R ¹⁰ )-) _n -R ⁹ (5)

(In the formula, R ⁸ , R ⁹ and R ¹⁰ can be the same or different, and are hydrogen atoms, or monovalent or divalent monovalent or divalent compounds with 1 to 30 carbon atoms that can optionally contain ether bonds, ester bonds, hydroxyl groups, carbonyl groups, and mercapto groups. Hydrocarbon group, R ⁸ and R ⁹ can be arbitrarily combined to form a 5-membered or 6-membered cycloalkyl group, or a 5-membered or 6-membered ring that can additionally contain nitrogen or oxygen atoms as a crosslinking group, or R ⁸ can be arbitrarily , R ⁹ and R ¹⁰ together form a multi-component multiple ring that can contain more than one additional nitrogen atom and/or oxygen atom as a crosslinking group. R ⁸ , R ⁹ and R ¹⁰ will not form a hydrogen atom at the same time. n Represents an integer from 1 to 2.)

As the above-mentioned amine compound as the counter cation source of the mixed-coordination heteropolyanion compound, primary, secondary, or tertiary amines of straight-chain or branched-chain alkyl groups, tertiary amines having mixed hydrocarbon groups, lipids, etc. Cycloprimary amines, primary amines with aromatic ring substituents, secondary alicyclic amines, secondary amines with aromatic ring substituents, asymmetric secondary amines, alicyclic tertiary amines, tertiary amines with aromatic ring substituents Amines, amines having an ether bond, alkanolamines, diamines, cyclic amines, aromatic amines, etc., or any mixture thereof.

Among these amine compounds, as a preferred specific example, at least one of primary, secondary, or tertiary amines, or alkanolamines selected from linear or branched alkyl groups having 4 to 20 carbon atoms species, such as butylamine, hexylamine, cyclohexylamine, octylamine, tridecylamine, stearylamine, dihexylamine, di-2-ethylhexylamine, linear or branched di( Tridecyl)amine, distearylamine, tributylamine, trioctylamine, linear or branched tri(tridecyl)amine, tristearylamine, N,N-dimethylethanolamine, N-methyldiethanolamine, triethanolamine, morpholine, etc.

More preferably, at least one selected from the amine compounds represented by these general formulas (5), and selected from 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 (phosphovanadanomolybdic 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 (silicon vanadium molybdic acid · n hydrate) in the form of at least one salt.

Among the above mixed coordination type heteropolyanion 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 are most preferred O ₄₀ nH ₂ O (phosphovanadanomolybdic acid n hydrate), H ₄ SiW _x Mo _12-x O ₄₀ nH ₂ O (silicotungstomolybdic acid n hydrate) mixed coordination heteropoly acid, Or organic amine salts of these mixed coordination heteropolyacids.

For the second covering layer other than the oxidized metal covering of the composite particles contained in the composite metallic pigment composition of the present embodiment, in order to further improve the corrosion resistance of the metal particles (preferably aluminum particles or aluminum alloy particles) serving as nuclei, it may be Layers containing other corrosion inhibitors. The corrosion inhibitor to be added is not particularly limited, and any known corrosion inhibitor can be used. The amount used should just be in the range which does not inhibit the desired effect of the 1st invention of this application. Examples of such corrosion inhibitors include acid phosphates, dimer acids, organic phosphorus compounds, metal salts of molybdic acid, and the like.

In the metal oxide coating and/or the second coating layer of the composite particles contained in the composite metal pigment composition, or as another layer, from the viewpoint of adhesion and chemical resistance when forming a coating film, an organic oligomer or polymer.

In addition, the metal oxide coating and/or the second coating layer of the composite particles, or as another layer, may contain a compound selected from inorganic phosphoric acid and its salts, and acidic organic (sub) At least one of the group consisting of phosphate esters and their salts.

These compounds are not particularly limited, and for example, compounds disclosed in JP-A-2019-151678 can be used.

Composite metal pigment composition

The composite metal pigment composition of the first invention of the present application comprises: composite particles containing metal particles and more than one layer of metal oxide coating on the surface thereof, the composite particles satisfy the conditions of (1) to (3) above, the composite metal pigment The composition satisfies the above-mentioned conditions (4) to (6), and does not bear other conditions. However, in addition to the composite particles, unreacted silicone may be contained as a residual part of the solid content (non-volatile content) Compounds, compounds forming the second coating layer, oligomers or polymers derived from them, etc. may contain solvents such as water used in the production process in addition to the specific amount of specific solvents related to the above condition (5).

In the composite metal pigment composition, there can be present as organosilicon compound (for example, at least one of the organosilicon compounds represented by the above-mentioned general formula (1), and selected from the above-mentioned general formula (2), (3) and (4) Any one of the silane coupling agents shown, and at least one of their partial condensates) hydrolyzate and/or silicon compound of its condensate.

In the composite metallic pigment composition, a compound forming an arbitrarily selected second covering layer (for an arbitrarily selected form of forming a molybdenum-containing coating as the second covering layer, a molybdenum-containing compound, such as a mixed coordination type heteropolyanion compound).

In the composite metal pigment composition, any selected organic oligomer or polymer can be present.

In the composite metallic pigment composition, at least one selected from the group consisting of arbitrarily selected inorganic phosphoric acid and its salt, and acid organic (phosphite) ester and its salt can be present.

In the composite metal pigment composition, a solvent containing water/hydrophilic solvent used in the production process can be present.

The composite metallic pigment composition can contain arbitrary selected components other than the above. Examples of optional components include at least one of antioxidants, photostabilizers, and surfactants.

As the antioxidant, antioxidants typified by phenolic compounds, phosphorus compounds, and sulfur compounds can be used.

As the light stabilizer, the light stabilizer used as the above-mentioned antioxidant can also be used, such as benzotriazole-based compounds, benzophenone-based compounds, salicylate (salt)-based compounds, cyanoacrylate Light stabilizers represented by oxalic acid derivatives, hindered amine compounds (HALS), and hindered phenol compounds.

Examples of surfactants include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether. Alkylene alkyl ethers, polyoxyethylene octylphenyl ethers, polyoxyethylene nonylphenyl ethers, polyoxyalkylene alkylphenyl ethers, polyoxyethylene lauryl amino ethers, Polyoxyalkylene alkylamino ether such as polyoxyethylene stearyl amino ether, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, dehydrated Sorbitan fatty acid esters such as sorbitan monooleate; Polyoxyethylene sorbitan monolaurate, Polyoxyethylene sorbitan monopalmitate, Polyoxyethylene dehydrated Sorbitan monostearate, polyoxyethylene sorbitan monooleate and other polyoxyalkylene sorbitan fatty acid esters; polyethylene glycol monolaurate, polyethylene glycol monolaurate Polyalkylene glycol fatty acid esters such as oleate, polyethylene glycol monostearate, polyethylene glycol dilaurate, polyethylene glycol distearate; monoglyceryl laurate, hard Nonionic surfactants represented by glycerin fatty acid esters such as fatty acid monoglyceride and oleic acid monoglyceride include polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene octylphenyl Sodium ether sulfate, sodium polyoxyethylene nonylphenyl ether sulfate, triethanolamine lauryl sulfate, sodium lauryl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate and other sulfate ester salts; sodium dodecylbenzenesulfonate sulfonates such as sodium alkylnaphthalene sulfonate and sodium dialkylsulfosuccinate; anionic surfactants represented by phosphate ester salts such as alkyl potassium phosphate, such as lauryl trimethyl chloride Cationic surfactants such as cationic surfactants represented by quaternary ammonium salts such as ammonium, cetyltrimethylammonium chloride, and stearyltrimethylammonium chloride may be used one or more kinds selected from them. Among them, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether can be exemplified as particularly preferable examples. or their mixtures.

Method for producing composite metallic pigment composition

The method for producing the composite metallic pigment composition of the first invention of the present application is not particularly limited, but it is particularly preferably produced by the production method of the second invention of the present application and/or the production method of the third invention of the present application. The manufacturing method of the 2nd invention of the present application and the manufacturing method of the 3rd invention of the present application can effectively prevent the aggregation and suppression of the composite particles while producing a composite metal pigment composition with a high non-volatile content (solid content), so it is particularly It is suitable for the manufacture of the composite metal pigment composition of the 1st invention of this application.

It should be noted that the applicable objects of the manufacturing method of the second invention of the present application and the manufacturing method of the third invention of the present application are not limited to the manufacture of the composite metallic pigment composition of the first invention of the present application, and are suitable for various composite metallic pigments Composition Manufacture.

The manufacturing method of the 2nd invention of this application is the manufacturing method of the composite metallic pigment composition which has the process of following 1)-3),

1) A process of dispersing metal particles in a solvent,

2) the process of covering the aforementioned metal particles with oxidized metal,

3) a step of washing, filtering, and volatilizing the solvent with metal particles and metal oxide-covered composite particles formed on the surface obtained in step 2),

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

The solvent volatilization in step 3) is performed in the state of a slurry containing the composite particles and the solvent.

The manufacturing method of the 3rd invention of this application is the manufacturing method of the composite metallic pigment composition which has the process of following 1)-3),

1) A process of dispersing metal particles in a solvent,

2) the process of covering the aforementioned metal particles with oxidized metal,

3) a step of washing, filtering, and volatilizing the solvent with metal particles and metal oxide-covered composite particles formed on the surface obtained in step 2),

The solvent volatilization in step 3) is carried out in three or more stages.

That is, the manufacturing method of the 2nd invention of the present application and the manufacturing method of the 3rd invention of the present application both have:

1) A process of dispersing metal particles in a solvent,

2) a process of covering the aforementioned metal particles with an oxidized metal, and

3) A step of washing, filtering, and volatilizing the solvent on the composite particles having the metal particles and the metal oxide coating formed on the surface obtained in step 2).

In the second invention of the present application, the aforementioned solvent is a mixed solvent of two or more solvents having compatibility with each other and having a boiling point difference of 10° C. or higher, and the solvent in step 3) is volatilized in the slurry containing the aforementioned composite particles and the aforementioned solvent. On the other hand, there is no such limitation in the 3rd invention of the present application. In this aspect, the 2nd invention of the present application is different from the 3rd invention of the present application. In the 3rd invention of the present application, the solvent in the step 3) volatilizes On the other hand, the second invention of the present application is not limited to the implementation in three or more stages, and the second invention of the present application is different from the third invention of the present application in this point.

Each of these steps will be described below.

1) Process of dispersing metal particles in a solvent

In step 1), metal particles are dispersed in a solvent. By dispersing the metal particles in the solvent, the aggregation of the particles can be suppressed in the next step 2) covering the metal particles with the oxidized metal. As a result, the dispersibility of the obtained composite particles is also good, and the number of primary particles without aggregation can be greatly increased. particle ratio.

The method of dispersing the metal particles in the solvent is not particularly limited, but methods such as adding the metal particles to the solvent, stirring, and irradiating ultrasonic waves are preferably employed.

In addition, it is also preferable to perform pretreatment in order to improve the dispersibility of the metal particles.

Stirring can be performed using a well-known or commercially available stirring device. For example, kneaders, kneaders, rotating vessel mixers, stirred reaction tanks, V-shaped mixers, double-cone mixers, spiral mixers, zigzag mixers, fast mixers, airflow mixers, ball mills, wheel mills, etc. can be used. at least one of the

Among these stirrers, a stirring blade (impeller) is preferably used. The agitating blade exerts a circulation action to flow the entire system including the metal particles and the solvent, and exerts a pressure shearing action. As a result, aggregation of the metal particles can be suppressed and the metal particles can be dispersed more effectively.

The shape of the stirring blade is not particularly limited, and for example, an anchor type, a propeller shape, a turbine shape, a fan turbine shape, a paddle shape, an inclined paddle shape, and a gate shape can be used. In addition, stirring blades of these shapes may be combined in multiple stages.

The stirring speed is preferably such that the stirring blades are not exposed due to the vortex generated by the stirring. In addition, in order to suppress vortices generated by stirring, a cylindrical tank, a square tank, a tank provided with baffles, or the like can be suitably used.

The linear velocity of the stirring (the tip velocity of the stirring blade) is preferably 0.5 to 30 m/s, more preferably 1 to 20 m/s. When the linear speed of stirring is in the range of 0.5-30m/s, the dispersibility of metal particles can be improved, and it is easier to obtain the aggregation of each particle. It has excellent design, gloss, and appearance of the coating film, and less gas generation. Composite metal pigment composition. In addition, when the linear velocity of stirring is within the above-mentioned range, breakage of metal particles (for example, scaly aluminum powder) can be prevented and aggregation of particles can be effectively suppressed.

Ultrasonic treatment is not particularly limited, and can be performed at usually 10 to 1000 W, preferably 50 to 800 W, and usually for 20 seconds to 10 minutes, preferably about 30 seconds to 5 minutes.

As the pretreatment, for example, when the metal particles used as the raw material are dispersed in an inert solvent and supplied, the solvent may be replaced with the same solvent as that used in the covering treatment. Further, heating treatment for a certain period of time is performed as necessary to make the solvent sufficiently compatible with the surface of the metal particles, thereby greatly suppressing the aggregation that occurs in the step of 2) covering the metal particles with the oxidized metal. The heat treatment temperature is preferably about 30 to 60° C., and the treatment time is preferably optimized within 3 hours to 7 days. In the step of covering treatment, it is preferable to use a hydrophilic solvent such as ethanol, isopropanol, or methoxypropanol, and therefore it is also preferable to use the same hydrophilic solvent as that used in the reaction in the pretreatment.

Furthermore, adding a small amount of surfactant at this time is also effective for aggregation suppression by pretreatment. The surfactant is not particularly limited, but it is preferably a nonionic surfactant or anionic surfactant, and it is particularly preferable to use a nonionic surfactant.

1) The step of dispersing the metal particles in a solvent can be performed usually at 10 to 80°C, preferably at 15 to 70°C, and most preferably around room temperature (around 20 to 60°C). In addition, 1) the step of dispersing metal particles in a solvent (including this treatment when ultrasonic treatment is performed) can be performed for 5 minutes to 20 hours, preferably 10 minutes to 5 hours.

2) Process of covering metal particles with oxidized metal

By carrying out the step of 2) coating the metal particles with the metal oxide after the step of 1) dispersing the metal particles in the solvent, the metal oxide coating can be formed on the metal particles.

As mentioned above, it is preferable to use silicon oxide for the metal oxide coating, so the embodiment in which at least one layer of the metal oxide coating is a silicon-containing compound layer is taken as an example below, and as a specific example of step 2), for the formation of a silicon-containing compound Layer steps will be described.

Step of forming silicon compound layer

For the silicon-containing compound layer, in the formation process, for example, by making a mixture containing metal particles, a silicon-containing raw material containing at least one of organosilicon compounds, a solvent, and other optional components as needed, a mixture containing silicon compound layer.

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

As the metal particles, the above-mentioned metal particles can be used, but particles of aluminum or an aluminum alloy can be used particularly suitably. In addition, as for the particle shape, it is also preferable to use scaly metal particles as described above. As the metal particles, known or commercially available metal particles (typically, paste-like aluminum flakes) can be used.

The content (solid content) of the metal particles in the liquid mixture is not particularly limited, and can be appropriately set according to the type, particle size, and the like of the metal particles to be used.

As the silicon-containing raw material, organosilicon compounds can be used. The organosilicon compound is not limited, but the above-mentioned organosilicon compounds can be preferably used.

An organosilicon compound represented by the above formula (1) (a typical example, tetraalkoxysilane) and/or its condensate, and any one of the above formulas (2) to (4) can be suitably used. At least one of silane coupling agents.

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

When the tetraalkoxysilane represented by the above formula (1) and the silane coupling agent represented by any of the above formulas (2) to (4) are used in combination, a mixture of both can be used. method (referred to as "first method"). Alternatively, a method (referred to as "second method") may be employed including the steps of treating metal particles with one to form a first silicon-containing compound layer, and with the other to form a second silicon-containing compound layer.

As the first method, for example, it is possible to include metal particles, the tetraalkoxysilane represented by the above formula (1) and the silane dioxane represented by any one of the above formulas (2) to (4) through appropriate adjustment. The pH of the mixed solution of the coupling agent, the hydrolysis/condensation reaction of the tetraalkoxysilane and the silane coupling agent to form a silicon-containing compound layer.

As the second method, for example, it may include: by appropriately adjusting the pH of a mixed liquid containing metal particles and tetraalkoxysilane represented by the above formula (1), hydrolyzing/condensing tetraalkoxysilane, thereby A step of forming a first silicon-containing compound layer (for example, a silicon dioxide coating formed of amorphous silicon dioxide) on the surface of the metal particles; The pH of the mixed liquid of the silane coupling agent shown above is the method of the step of causing the silane coupling agent to undergo a hydrolysis/condensation reaction to form a second silicon-containing compound layer on the surface of the first silicon-containing compound layer.

The usage-amount of the tetraalkoxysilane represented by said formula (1) or its condensate can be suitably set according to the kind etc. of the tetraalkoxysilane used. For example, from the viewpoint of the effect of covering treatment, and from the viewpoint of suppressing the aggregation of metal particles or the reduction of glossiness, the amount used can be 2 to 200 parts by mass, more preferably 5 to 200 parts by mass relative to 100 parts by mass of metal particles (solid content). 100 parts by mass.

The amount of the silane coupling agent represented by any one of the above formulas (2) to (4) is not particularly limited, and usually it can be about 0.1 to 20 parts by mass relative to 100 parts by mass of the metal particles (solid content), especially Preferably, it is 1-5 mass parts. When the usage-amount is about 0.1-20 mass parts, desired coating treatment effect and preferable coating-film physical property can be acquired.

As the solvent in the mixed solution, that is, the solvent used for the hydrolysis reaction and/or condensation reaction of the organosilicon compound, it may be appropriately selected according to the type of silicon-containing raw material used, etc., and water, hydrophilic organic solvents can usually be used , or their mixed solvents. By using these solvents, the uniformity of reaction and the uniformity of the obtained hydrolyzate and/or condensation reaction product can be improved. In the aspect in which the silicon-containing compound 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 reaction between the metal particles and water. In the present embodiment, a mixed solvent of water and a hydrophilic organic solvent can be suitably used.

The hydrophilic organic solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, propanol, butanol, isopropanol, and octanol; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether , diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether and other ether alcohols and their esters; ethylene glycol, Diols of propylene glycol, 1,3-butanediol, 1,4-butanediol, polyoxyethylene glycol, polyoxypropylene glycol, ethylenepropylene glycol; ethyl cellosolve, butyl cellosolve solvents, acetone, methoxy propanol, ethoxy propanol, other alkoxy alcohols, etc. These can be used 1 type or 2 or more types.

The amount of solvent used in the formation process of the silicon-containing compound layer (in the case of pre-dispersing the metal particles, except for the amount of solvent used therein) is not limited, and is usually 100 parts by mass relative to 100 parts by mass of the metal particles (solid content). About -10000 mass parts is sufficient, Especially preferably, it is 200-2000 mass parts. When the usage-amount of a solvent is 100 mass parts or more, the viscosity increase of a liquid mixture (slurry) is suppressed, and stirring can be performed appropriately. Moreover, when the usage-amount of a solvent is 10000 mass parts or less, it can prevent recovery and regeneration cost of a processing liquid from increasing. In addition, the usage-amount of the solvent here means the total amount of the solvent used for the formation of the 1st silicon-containing compound layer and the formation of the 2nd silicon-containing compound layer in the case of the said 2nd method.

In the above mixed solution, other additives may be compounded as necessary within the range that does not inhibit the effects of the first invention of the present application. For example, in addition to catalysts such as hydrolysis catalysts and dehydration condensation catalysts, surfactants, metal corrosion inhibitors, and the like can be mentioned.

Among them, a hydrolysis catalyst can be suitably used. By blending a hydrolysis catalyst, the pH of the mixed liquid can be adjusted, and the organosilicon compound can be efficiently hydrolyzed and dehydrated and condensed. As a result, a silicon compound layer can be efficiently and reliably formed on the surface of the metal particles.

The hydrolysis catalyst is not particularly limited as long as a known or commercially available one can be used. As the hydrolysis catalyst, for example, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid; organic acids such as benzoic acid, acetic acid, chloroacetic acid, salicylic acid, oxalic acid, picric acid, phthalic acid, and malonic acid; Phosphonic acids such as phosphonic acid, 2-carboxyethanephosphonic acid, 2-aminoethanephosphonic acid, octanephosphonic acid, and the like. These hydrolysis catalysts can be used individually by 1 type or in combination of 2 or more types.

In addition, as a hydrolysis catalyst, for example, inorganic alkalis such as ammonia, sodium hydroxide, and potassium hydroxide; inorganic alkali salts such as ammonium carbonate, ammonium bicarbonate, sodium carbonate, and sodium bicarbonate; monomethylamine, dimethyl amine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, N,N-dimethylethanolamine, ethylenediamine, pyridine, aniline, bile Amines such as alkali, tetramethylammonium hydroxide, and guanidine; salts of organic acids such as ammonium formate, ammonium acetate, monomethylamine formate, dimethylamine acetate, pyridinium lactate, guanidinoacetic acid, and aniline acetate. These hydrolysis catalysts can use 1 type or 2 or more types.

The addition amount of a hydrolysis catalyst is not specifically limited, Usually, 0.01-20 mass parts is sufficient with respect to 100 mass parts of metal particles (solid content), Especially preferably, it is 0.02-10 mass parts. When the said addition amount is 0.01 mass part or more, the precipitation amount of a silicon-containing compound layer can become sufficient. Moreover, when the said addition amount is 20 mass parts or less, aggregation of metal particle|grains can be suppressed effectively.

In the production of the composite metal pigment composition of the first invention of the present application, it is preferable to carry out the production of the above-mentioned mixed liquid under stirring at an appropriate intensity.

The temperature of the mixed solution may be either at normal temperature or under heating. Usually, the temperature of the mixed solution is only required to be 20°C to 90°C, and it is particularly preferable to control it within the range of 30°C to 80°C. When the aforementioned temperature is 20° C. or higher, the formation speed of the silicon-containing compound layer is increased, and the processing time can be shortened. On the other hand, when the temperature is 90° C. or lower, the reaction can be easily controlled and the probability of obtaining desired composite particles can be increased.

The stirrer for stirring the mixed liquid is not particularly limited, and a known stirrer capable of efficiently and uniformly stirring a mixed liquid containing aluminum particles and an organosilicon compound can be used. Specific examples include a kneader, a kneader, a rotary container mixer, a stirred reaction tank, a V-shaped mixer, a double-conical mixer, a spiral mixer, a zigzag mixer, a rapid mixer, an airflow mixer, a ball mill, Wheel mill etc.

The temperature of the liquid mixture at the time of stirring the liquid mixture containing the metal particles and the organosilicon compound is usually about 10 to 100°C, and particularly preferably 30 to 80°C. When the temperature is 10° C. or higher, the reaction time for obtaining a sufficient treatment effect can be shortened. Moreover, when this temperature is 100 degreeC or less, control of the reaction 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 sufficient time for forming the desired silicon-containing compound layer. The stirring time is, for example, preferably 0.5 to 10 hours, more preferably 1 to 5 hours. When the stirring time is 0.5 hour or more, a sufficient treatment effect can be obtained. In addition, when the stirring time is 10 hours or less, an increase in processing cost can be suppressed.

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

When adjusting the pH, especially in the stage where the silicon-containing compound layer is formed on the surface of the metal particle (or by the second coating layer), the pH of the mixed solution changes, so it is preferable to adjust it appropriately so that the pH can be maintained within a constant range. . At this time, it is preferable to adjust the pH by adding a hydrolysis catalyst, but other acidic or basic compounds may be used to adjust the pH as long as the properties of the composite metal pigment composition of the first invention of the present application are not impaired.

When using a basic hydrolysis catalyst as a hydrolysis catalyst, it is preferable that pH is 7-13. When the pH is 7 or more, the silicon-containing compound layer can be rapidly formed. On the other hand, when the pH is 13 or less, it is possible to suppress aggregation of metal particles and a decrease in glossiness, and to prevent generation of hydrogen gas due to corrosion.

When an acidic hydrolysis catalyst is used as a hydrolysis catalyst, pH is preferably 1.5-7, and 2-6 is more preferable especially. When the pH is at least 1.5, the reaction is appropriately controlled, and it is easy to obtain a composite metal pigment composition containing desired composite particles. On the other hand, when the pH is 7 or less, the deposition rate of the silicon-containing compound layer can be kept high.

When any one of the above-mentioned first method and second method is adopted, it is preferable that the hydrolyzate of the organosilicon compound represented by the above-mentioned general formula (1) and/or its condensate relative to the metal particles (solid content) For 100 parts by mass, 0.01 to 50 parts by mass, more preferably 1 to 30 parts by mass, are added in terms of the state in which the hydrolysis and condensation reactions are completed. In addition, the hydrolyzate and/or condensate derived from the silane coupling agent represented by any one of the above-mentioned general formulas (2) to (4) and/or their partial condensate is relative to the metal particles (solid content ) to 100 parts by mass, a total of 0.01 to 10 parts by mass, more preferably 0.05 to 2 parts by mass, is added in conversion based on the state of completion of the hydrolysis and condensation reactions.

The hydrolyzate of the organosilicon compound shown in general formula (1) and/or its condensate can be multiplied by the quality of the organosilicon compound shown in general formula (1) when making composite metal pigment composition. The organosilicon compound was calculated from the mass ratio before and after the reaction when the hydrolysis and condensation reaction completely proceeded.

For example, when tetraethoxysilane (TEOS) is used as the organosilicon compound represented by the general formula (1), the hydrolyzate of the organosilicon compound and/or its The amount of condensate added.

(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

Before and after the above hydrolysis and condensation reactions, the mass is 60/208 = 0.288 times. Therefore, for example, when using 10 parts by mass of TEOS with respect to 100 parts by mass of metal particles (solid content), the addition of its hydrolyzate and/or its condensate The amount is 0.288 times that, that is, 2.88 parts by mass.

Similarly, the addition amount of hydrolyzate and/or its condensate of the silane coupling agent etc. shown in any one of general formula (2)～(4) also can pass the general formula used when making composite metal pigment composition The mass of the silane coupling agent shown in any one of (2) to (4) and/or its partial condensate is multiplied by the silane coupling agent and/or its partial condensate when it is completely hydrolyzed and condensed The mass ratio before and after the reaction was calculated.

For example, when using methyltrimethoxysilane as the silane coupling agent represented by the general formula (2), the hydrolyzate and/or The amount of its condensate added.

(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

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

3) The process of washing, filtering, and evaporating the solvent for the composite particles

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

When manufacturing the composite metallic pigment composition of the first invention of the present application, it is not essential to carry out step 3), but it is preferably carried out.

In the manufacturing method of the composite metal pigment composition of the second invention of the present application, step 3) is carried out, the solvent at this time is a mixed solvent of two or more solvents having compatibility with each other and a boiling point difference of 10° C. or more, and the step The volatilization of the solvent in 3) is carried out in the state of the slurry containing the aforementioned composite particles and the aforementioned solvent.

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

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

Stirring is preferably performed during washing, and the stirring conditions are not particularly limited, and for example, the same conditions as those described above in connection with step 1) can be used.

The washing temperature and time in step 3) are not particularly limited, and can be carried out usually at 10 to 70°C, preferably 15 to 60°C, for 5 to 180 minutes, preferably 10 to 120 minutes.

For washing, it is preferable to use an organic solvent, and it is more preferable to use a hydrophilic organic solvent from the viewpoints of removal of moisture and convenience when the composite metallic pigment composition is used in an aqueous paint afterward. It is particularly preferable that the hydrophilic organic solvent has a boiling point of 80 to 150°C. By washing with such an organic solvent, it is easier to satisfy the (5) hydrophilicity and the boiling point of the solvent of 80 to 150°C in the first invention of the present application. The condition that the non-solid content of the composite metallic pigment composition is 80% by mass or more. Preferable examples of hydrophilic solvents having a boiling point of 80 to 150° C. include methoxypropanol, isopropanol, isobutanol, n-butanol, n-propanol, and the like.

The number of times of washing is not particularly limited, and washing may be performed only once, or may be performed multiple times, for example, 2 to 5 times. When washing is performed multiple times, washing and filtration may be performed alternately. In addition, washing by continuously or intermittently flowing a washing liquid using a suction filter type filter is also one of the preferable examples.

Filtration in step 3) can be performed by a method commonly used in this technical field. For example, a polypropylene filter cloth with an air permeability of usually 10 to 100 ml/cm ² /min, preferably 20 to 80 ml/cm ² /min, a metal filter of equivalent pore size, a glass filter, For the ceramic filter, etc., a suction filter type filter is used, and filtration is performed by suction filtration or pressure filtration, and methods such as a filter press, a belt press, and a centrifugal filter are appropriately used. By performing filtration, water, unreacted substances, unfavorable solvents in the final composite metal pigment composition, and the like 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. Generally, when a suction filter type filter is used, it can be carried out at a temperature of 10 to 70° C., preferably 15 to 60° C., and a pressure of 0.11 to 0.9 MPa, preferably 0.15 to 60° C. Implemented under the condition of 0.5MPa.

The solid content of the filtered composite particle-containing slurry, filter cake, etc. is preferably 75% by mass or more, more preferably 80 to 98% by mass, particularly preferably 85 to 95% by mass.

From the viewpoint of low VOC, etc., the solid content of the filtered slurry containing composite particles, filter cake, etc. is preferably high, so the pressure at the time of filtration can be set high, but the high pressure at the time of filtration may be Since aggregation and deformation of the composite particles are caused, it is preferable to set the pressure taking this into consideration.

Solid-liquid separation methods other than filtration, such as filtration, centrifugation, and decantation, can be appropriately combined.

The number of times of filtration is not particularly limited, and filtration may be performed only once, or multiple times of washing and filtration may be alternately performed. By alternately performing multiple washings and filtering, water, unreacted substances, unfavorable solvents, etc. in the final composite metal pigment composition can be further effectively removed, and the (5) hydrophilicity and The condition that the solvent having a boiling point of 80 to 150° C. accounts for 80% by mass or more of the non-solid content of the composite metallic pigment composition.

At the time of filtration, it is preferable to simultaneously pass gas through the surface of the slurry, the filter cake, and voids to volatilize the solvent. As a result, it is easy to obtain a composite metal pigment composition having a high solid content in which the low-boiling point solvent volatilizes preferentially and the high-boiling point solvent component mainly remains.

Solvent volatilization in step 3) can be performed by a method commonly used in this technical field. For example, the solvent can be volatilized by heating, reducing pressure, ventilating, a combination thereof, and the like.

By performing solvent volatilization to remove volatile components, the ratio of solid content is improved, so it is possible to efficiently manufacture the composite metal pigment that satisfies the condition (4) that the solid content concentration of the composite metal pigment composition in the first invention of the present application is 70 to 95% by mass. Composite metallic pigment composition. In addition, unfavorable solvents and the like in the composite metallic pigment composition can be removed by solvent volatilization, so it is possible to further easily manufacture a solvent that satisfies (5) hydrophilicity and has a boiling point of 80 to 150° C. A composite metallic pigment composition with a non-solid content of 80% by mass or more.

There are no special restrictions on the temperature, pressure, time, etc. of the solvent volatilization in step 3), usually at a temperature of 15 to 100°C, preferably 20 to 80°C, more preferably 30 to 70°C, and a pressure of 0.1 (usually pressure) to 0.001 MPa, preferably 0.05 to 0.01 MPa, while confirming the degree of solvent volatilization.

When volatilizing the solvent by ventilation, it is preferable to use dry air, and it is appropriate to adjust the dew point and the flow rate of the ventilation appropriately while checking the degree of volatilization of the solvent.

The composite metallic pigment composition can be directly obtained through solvent volatilization, or can be obtained through further steps. The solid content of the composite metallic pigment composition after solvent evaporation is preferably 75% by mass or more, more preferably 80 to 98% by mass, particularly preferably 85 to 95% by mass.

In the method for producing a composite metallic pigment composition according to the second invention of the present application, the solvent in step 3) is a mixed solvent of two or more solvents having compatibility with each other and having a boiling point difference of 10° C. or more. Using a mixed solvent of two or more solvents that are compatible with each other and have a difference in boiling point of 10°C or more, that is, a mixed solvent with a low boiling point, the solvent used in the previous steps is replaced, and the low boiling point The solvent is selectively volatilized, thereby selectively leaving a desired solvent, for example, a hydrophilic solvent having a boiling point of 80 to 150°C. In addition, low-boiling-point solvents are relatively easy to volatilize, and extreme pressure reduction such as high temperature is not required, so the solid content concentration can be improved relatively easily while suppressing deformation and aggregation of composite particles.

The difference between the boiling points of two or more solvents constituting the mixed solvent is preferably 10 to 80°C, particularly preferably 20 to 60°C.

As the solvent on the high boiling point side, methoxypropanol, isobutanol, n-butanol and the like can be preferably used.

As the solvent on the low boiling point side, isopropanol, n-propanol, ethanol, or the like can be preferably used.

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

In addition, in the method for producing a composite metallic pigment composition according to the second invention of the present application, the volatilization of the solvent in step 3) is performed in the state of a slurry containing the composite particles and the solvent.

In step 3), the mixed solvent of two or more solvents having compatibility with each other and having a boiling point difference of 10° C. or more is volatilized in the state of the slurry containing the composite particles and the solvent, and the solvent on the lower boiling point side It becomes more likely that the volatilized and high-boiling-point solvent remains in the composite metal pigment composition.

In addition, in the manufacturing method of the composite metallic pigment composition of the 3rd invention of this application, the solvent volatilization in the process 3) is divided into 3 or more stages and implemented. At this time, the solvent volatilization divided into three or more stages can be performed continuously, but it is preferable to perform a process of uniformizing the entire solvent component contained in the slurry between the solvent volatilization of one stage and the solvent volatilization of the subsequent stage, for example, Stirring, aging, etc. In such a step of making the solvent component uniform, the solvent may be partially replaced by adding a new solvent.

Solvent volatilization is carried out in three or more stages. In addition, it is preferable to perform volatilization and dispersion alternately to suppress the local formation of a part with little solvent and effectively prevent aggregation and deformation of composite particles. This application can be produced relatively easily and effectively. A composite metallic pigment composition having a high solid content and a preferred solvent composition like the composite metallic pigment composition of the first invention.

In the method for producing the composite metallic pigment composition of the second invention of the present application and the third invention of the present application, it is preferable to use a solvent with a low moisture content from the viewpoint of suppressing aggregation of composite particles. In particular, it is preferable that the moisture content of the solvent at the time of volatilization of the solvent in step 3) be low. The moisture content of the solvent is preferably 10% by mass or less, more preferably 5% by mass or less, particularly preferably 1% by mass or less.

The moisture content of the entire system of the composite metal pigment composition obtained at this time can be preferably 0.1% by mass or less, more preferably 0.05% by mass or less, so the residue amount is preferably reduced to 0.1% by mass or less, more preferably 0.003% by mass of the solid content. % below becomes further easier.

other processes

Preferably, when the composite metallic pigment composition of the first invention of the present application is produced by the method for producing the composite metallic pigment composition of the second invention of the present application and/or the composite metallic pigment composition of the third invention of the present application, in addition to the above-mentioned steps 1) to 3), it is possible to There are also steps such as pulverizing metal particles, and a step of forming a coating layer other than the metal oxide coating.

Crushing, sieving, filtering, etc. of metal particles

Before 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 finer, which is preferable from the viewpoint of producing a composite metal pigment composition containing uniform and fine composite particles.

Here, the case of using aluminum powder as the metal particles will be described as an example.

For aluminum powder, usually atomized aluminum powder and/or aluminum foil will use the methods commonly used in the pigment industry such as dry ball mill method, wet ball mill method, attritor method, and pounder method. In the presence of pulverization, so-called scales are formed, and after this step, necessary steps such as sieving (classification), filtration, washing, and mixing are carried out to obtain the above-mentioned aluminum powder.

Examples of the pulverization aid here include fatty acids, aliphatic amines, aliphatic amides, and aliphatic alcohols. Usually, oleic acid, stearic acid, stearylamine and the like are preferred. In addition, examples of the inert solvent include mineral spirits, solvent naphtha, toluene, xylene, and other inert solvents exhibiting hydrophobicity, and these may be used alone or in combination. Pulverization aids and inactive solvents are not limited to them.

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

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

Formation process of the second coating layer

The composite particles constituting the composite metal pigment composition of the first invention of the present application preferably have a coating layer (second coating layer) other than the metal oxide coating in addition to the metal oxide coating, and preferably contain a coating selected from metals, metal oxides A covering layer of at least one of metal hydrate and resin. The second coating layer (when formed) is particularly preferably formed between the metal particles and the oxide metal coating such as the silicon-containing compound layer. Therefore, the layer structure of "metal particle/second coating layer/oxide metal coating" can be suitably used.

The second coating layer is not particularly limited, and may be a molybdenum-containing coating, a phosphate compound coating, or the like. Preferred examples of the molybdenum-containing substance constituting the molybdenum-containing coating include mixed-coordination heteropolyanion compounds disclosed in JP-A-2019-151678. Examples of the constituent components of the second covering layer including the mixed-coordination heteropolyanion compound are as described above.

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

In the case of forming a molybdenum-containing coating between metal particles and an oxide metal coating such as a silicon-containing compound layer as the second coating layer, before forming an oxide metal coating such as a silicon-containing compound layer, the coating containing metal particles and a molybdenum compound (typically Said mixed coordination type heteropolyanion compound) mixed liquid stirring, can form molybdenum-containing film on the surface of metal particles.

The method for forming the molybdenum-containing coating on the surface of the metal particles is not particularly limited as long as it can uniformly stir a mixed solution containing the metal particles and the molybdenum compound 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 liquid mixture containing the metal particles and the molybdenum compound in a slurry state or a paste state. In the mixed solution, the molybdenum compound can be dissolved or dispersed.

The stirrer for stirring the liquid mixture containing the metal particles and the molybdenum compound is not particularly limited, and a known stirrer capable of efficiently and uniformly stirring the liquid mixture containing the metal particles and the molybdenum compound can be used. Specific examples include a kneader, a kneader, a rotary container mixer, a stirred reaction tank, a V-shaped mixer, a double-conical mixer, a spiral mixer, a zigzag mixer, a rapid mixer, an airflow mixer, a ball mill, Wheel mill etc. Examples of the agitating blades of the agitator are not particularly limited, and examples thereof include anchor blades, paddle blades, propeller blades, and turbine blades.

The usage-amount of a molybdenum compound can be suitably set according to the kind of molybdenum compound used, etc. The usage-amount should just be 0.02-20 mass parts normally with respect to 100 mass parts of metal particles (solid content), Especially preferably, it is 0.1-10 mass parts. A sufficient treatment effect can be acquired by the said content being 0.02 mass part or more. Moreover, when the said content is 20 mass parts or less, the brightness of the obtained composite metal pigment composition can be kept high.

As a solvent used for mixing the metal particles and the molybdenum compound, generally water, a hydrophilic organic solvent, or a mixed solvent thereof can be used.

Examples of hydrophilic organic solvents include alcohols such as methanol, ethanol, propanol, butanol, isopropanol, and octanol; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol Monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether and other ether alcohols and their esters; ethylene glycol, propylene glycol, 1, Diols of 3-butanediol, 1,4-butanediol, polyoxyethylene glycol, polyoxypropylene glycol, ethylene propylene glycol; ethyl cellosolve, butyl cellosolve, acetone, Methoxypropanol, ethoxypropanol, other alkoxy alcohols, etc. These can be used 1 type or 2 or more types.

The amount of the solvent used in the forming step of the second covering layer (in the case of pre-dispersing the metal particles, except for the amount of solvent used therefor) is not particularly limited, and is usually relative to 100 parts by mass of the metal particles (solid content) It is 50-5000 mass parts, More preferably, it is 100-2000 mass parts. When the usage-amount of a solvent is 50 mass parts or more, localization 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 the metal particles and the molybdenum compound is usually about 10 to 100°C, and particularly preferably 30 to 80°C. When the temperature is 10° C. or higher, the reaction time for obtaining a sufficient treatment effect can be shortened. Moreover, when this temperature is 100 degreeC or less, control of the reaction 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 sufficient time for forming a desired molybdenum-containing coating. The stirring time is, for example, preferably 0.5 to 10 hours, more preferably 1 to 5 hours. When the stirring time is 0.5 hour or more, a sufficient treatment effect can be obtained. In addition, when the stirring time is 10 hours or less, an increase in processing cost can be suppressed.

After the stirring of the mixed solution containing the metal particles and the molybdenum compound is completed, the particles on which the second coating layer is formed can be collected. At this time, well-known washing, solid-liquid separation, etc. can be implemented suitably as needed. For example, it is preferable to wash the mixed liquid with a hydrophilic organic solvent and then filter it with a filter to remove water and unreacted substances from the filter cake containing the metal particles having a molybdenum-containing coating. In this way, a molybdenum-containing film can be formed as the second covering layer. When forming another second covering layer, it can also be implemented according to the above-mentioned method.

In the form of forming a second coating layer (hereinafter, a molybdenum-containing coating is described as an example) on the metal particles, followed by forming a metal oxide coating (hereinafter, a silicon-containing compound layer is described as an example), metal particles and molybdenum may be included. After the stirring of the mixed solution of the compound is completed, the particles having the second covering layer are not recovered, and in this system, the silicon compound source (typically, the organosilicon compound represented by the above formula (1), Water and/or a hydrophilic organic solvent such as tetraalkoxysilane and/or its condensate, and at least one of the silane coupling agents shown in any one of the above formulas (2) to (4) of the dispersion. At this time, it is also possible to add an organosilicon compound represented by the above formula (1), such as a dispersion of tetraalkoxysilane and/or a condensate thereof, to the system containing the particles on which the second covering layer is formed, and then add / Stir the dispersion liquid of at least one of the silane coupling agents represented by any one of the above formulas (2) to (4).

Uses of composite metallic pigment compositions

The composite metal pigment composition of the first invention of the present application and the composite metal pigment composition produced by the production method of the second invention of the present application and/or the production method of the third invention of the present application can be used in organic solvent-based coatings, inks, and the like. In addition, the composite metal pigment composition can form a metal water-based paint or a metal paint by adding the composite metal pigment composition to a water-based paint or water-based ink obtained by dissolving or dispersing a resin as a coating film forming component (binder) in a medium mainly composed of water. Water-based ink. In addition, the composite metallic pigment composition may be kneaded with a resin or the like to be used as a water-resistant binder or filler. Antioxidants, photostabilizers, and surfactants can be added when compounding the composite metal pigment composition with water-based paints, water-based inks, or resins.

When the composite metallic pigment composition is used for paint or ink, it can be directly added to (aqueous) paint or (aqueous) ink, but it is preferably added after being pre-dispersed in a solvent. Examples of the solvent used include water, dodecyl alcohol ester, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, and the like. In addition, examples of these resins include acrylic resins, polyester resins, polyether resins, epoxy resins, fluororesins, and rosin resins. Moreover, as an example of the binder of paint or ink, rubber|gum can be mentioned besides resin.

These resins are preferably emulsified, dispersed or dissolved in water. For this purpose, carboxyl groups, sulfonic acid groups, etc. contained in resins can be neutralized.

Preferable resins include acrylic resins and polyester resins.

Resins such as a melamine-based curing agent, an isocyanate-based curing agent, and a urethane dispersion may be used in combination as necessary. Furthermore, it can be combined with coloring pigments such as inorganic pigments, organic pigments, and extender pigments, silane coupling agents, titanium coupling agents, dispersants, anti-sedimentation agents, leveling agents, thickeners, and defoamers that are usually added to coatings. . In order to improve the dispersibility to the paint, a surfactant may be further added. In order to improve the storage stability of the paint, an antioxidant, a light stabilizer, and a polymerization inhibitor may be further added.

Examples of coloring pigments include phthalocyanine, quinacridone, isoindolinone, perylene, azo lake, iron oxide, chrome yellow, carbon black, titanium oxide, pearl mica, and the like.

The content of the composite metallic pigment composition of the first invention of the present application or the composite metallic pigment composition produced by the production method of the second invention of the present application or the third invention of the present application in the above-mentioned water-based paint or water-based ink (resin composition) The limit is usually 0.1 to 30% by mass, particularly preferably 1 to 20% by mass. When this content is 0.1 mass % or more, a high decorative (metallic) effect can be acquired. Moreover, when this content is 30 mass % or less, it can prevent that the characteristics of an aqueous paint or an aqueous ink, such as weather resistance, corrosion resistance, mechanical strength, etc. are impaired.

The content of the solvent is not particularly limited, but may be 20 to 200% by mass relative to the binder content. When the content of the solvent is within this range, the viscosity of the paint and ink can be adjusted within an appropriate range, and handling and film formation can be facilitated.

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

A coating film formed by water-based paint or the like may be formed on an undercoat layer or an intermediate coat layer formed by electrodeposition coating or the like. In addition, a top coat etc. may be formed on the coating film formed with the water-based paint etc. as needed.

In the case of these layer structures, each coating layer can be applied and the next coating layer can be applied after curing or drying, or the coating layer can be applied without curing or drying by so-called wet-on-wet coating. Just apply the next coating layer. From the viewpoint of obtaining a coating film with good mirror-like brightness, the composite metal pigment composition containing the first invention of the present application or the composite metal pigment produced by the production method of the second invention of the present application or the production method of the third invention of the present application The water-based paint or the like of the pigment composition preferably employs a method including a step of forming a paint film layer with a water-based paint or the like after applying an undercoat layer and curing or drying it.

The curing method of the coating composition in each coating film layer may be thermal curing or normal temperature curing. In addition, the drying method of the coating composition of each coating film layer can use hot air or natural drying at normal temperature, for example.

The thickness of the coating film layer formed by a water-based paint or the like is not particularly limited, but is generally preferably about 0.5 to 100 μm, more preferably about 1 to 50 μm. When the thickness of the coating film layer is 0.5 μm or more, the concealment effect of the base by the ink or paint can be sufficiently obtained. Moreover, when the thickness of a coating film layer is 100 micrometers or less, drying becomes easy, and generation|occurrence|production of defects, such as a wrinkle and a sag, can be suppressed.

The composite metallic pigment composition of the first invention of the present application, the composite metallic pigment composition obtained by the production method of the second or third invention of the present application, and the coating film obtained by using the same have excellent design at a high level properties, gloss, suppression of particle formation, stability in water-based paints, etc., so it can be suitably used in various applications where metal pigments have been used, such as paints, inks, and resin kneading agents, more specifically, automotive bodies, automotive repairs, etc. Materials, automotive parts, home appliances, etc., plastic parts, coatings for PCM, highly weather-resistant coatings, heat-resistant coatings, anti-corrosion coatings, coatings for ship bottoms, offset printing inks, gravure printing inks, screen printing inks, etc.

Example

Hereinafter, the present invention will be described in more detail through examples. However, it should be noted that these examples are merely illustrations, and the present invention is not limited by the description of these examples.

Example 1

In a reaction tank of 1 m with a diameter of 2 m and an anchor type stirring blade with a blade diameter of ¹ m, a commercially available aluminum paste (manufactured by Asahi Kasei Co., Ltd., trade name "GX-3100 (average particle size: 11 μm, non-volatile content 74 %)) ") 135kg add 465kg of methoxypropanol (hereinafter referred to as "PM"), the mixture is stirred with a stirring blade at 100rpm, and the dispersion liquid of 10L/min drawn out from the bottom is returned from the upper part of the reaction tank to the The external circulation of the reaction tank makes the aluminum paste evenly dispersed in the PM. In the external circulation, 500W ultrasonic waves are irradiated for 1 minute in the middle of the flow path to improve the dispersibility of the particles.

Next, a liquid obtained by dissolving 1 kg of phosphotungstomolybdic acid (H ₃ PW ₆ Mo ₆ O ₄₀ ) hydrate in 5 kg of methoxypropanol was slowly added, and stirred for 1 hour while maintaining the temperature of the slurry at 40°C. During the reaction, the external circulation was continued while ultrasonic waves were irradiated.

Then, after adding 10 kg of tetraethoxysilane as an organosilicon compound, 10 kg of 25% ammonia water and 200 kg of purified water were added over 3 hours. Then, as a silane coupling agent, 1.3 kg of methyltrimethoxysilane was added and stirred for 2 hours. During the reaction, the external circulation was continued while ultrasonic waves were irradiated. After the reaction is finished, the slurry is filtered under pressure after cooling.

The filtered slurry is fully washed with a mixture of isopropanol (hereinafter referred to as "IPA")/PM: 3/2 to replace the solvent, then pressurized and filtered again, and ventilated mainly to volatilize IPA to obtain non-volatile components 90% composite aluminum pigment composition. The water content in the IPA/PM mixed solvent used here was 200 ppm, and pressure filtration and ventilation used dry air with a dew point of -40°C.

Example 2

Change to an aluminum paste (manufactured by Asahi Kasei Co., Ltd., trade name "GX-4100 (average particle size 10 μm, non-volatile content 74%)"), and obtain a composite with a non-volatile content of 90% in the same manner as in Example 1. Aluminum pigment composition.

Example 3

Change to an aluminum paste (manufactured by Asahi Kasei Co., Ltd., trade name "FD-5090 (average particle size 9 μm, non-volatile content 75%)"), and obtain a composite with a non-volatile content of 85% in the same manner as in Example 1. Aluminum pigment composition.

Example 4

Until the reaction was carried out in the same manner as in Example 1, after the reaction was completed, the slurry was cooled and filtered, and the same amount of PM was used to repeat washing/filtration three times to obtain a paste with 50% non-volatile content. Next, the solvent was volatilized at room temperature under reduced pressure, and the non-volatile content was increased by 10%, and the reduced pressure was released to mix the paste so that the paste became uniform, and the mixture was sealed and left to stand for 12 hours. Furthermore, this operation was performed twice to obtain a paste-like composite aluminum pigment composition having a nonvolatile content of 90%.

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 an IPA/PM mixed solvent with a water content of 2000 ppm was used.

Comparative example 1

465 kg of PM was added to 135 kg of a commercially available aluminum paste (manufactured by Asahi Kasei Co., Ltd., trade name "GX-3100 (average particle size: 11 μm, non-volatile content: 74%)") to obtain a slurry, and the slurry was stirred. At the same time, slowly add a liquid obtained by dissolving 1 kg of phosphotungstomolybdic acid (H ₃ PW ₆ Mo ₆ O ₄₀ ) hydrate in 5 kg of PM, and stir for 1 hour while keeping the temperature of the slurry at 40°C. Then, after cooling, the slurry was filtered to obtain a composite aluminum pigment composition with a non-volatile content of 60%.

Comparative example 2

The process after the reaction was completed and filtered was changed to a process of transferring the aluminum pigment composition to another container, heating to 50° C. while depressurizing for 1 hour to remove the solvent in a static state, and the same as the implementation. In Example 1, a composite aluminum pigment composition having a non-volatile content of 80% was obtained in the same manner.

Comparative example 3

A composite aluminum pigment composition having a non-volatile content of 80% was obtained in the same manner as in Example 1, except that the process of filtering after completion of the reaction was changed to a process of extruding with a filter press to remove the solvent.

(Evaluation of Composite Metallic Pigment Composition)

Average particle size: D ₅₀

The average particle diameter (D ₅₀ ) of the composite particles (aluminum particles covered with silicon oxide) in the composite aluminum pigment composition obtained in each of the above Examples/Comparative Examples was measured using a laser diffraction/scattering particle size distribution measuring device (LA-300 / manufactured by Horiba Manufacturing Co., Ltd.) measurement.

As a measurement solvent, isopropanol was used.

The measurement was carried out according to the machine operation manual. As a note, the composite metal pigment composition used as a sample was ultrasonically dispersed for 2 minutes as a pretreatment, and then put into a dispersion tank. After confirming that the dispersion was at an appropriate concentration, the measurement was started.

After the measurement, _D50 is calculated by the software of the machine and displayed automatically.

Solid content concentration

After heating 10 g of the composite aluminum pigment composition obtained in each of the above Examples/Comparative Examples at 105° C. for 3 hours to volatilize the volatile components, the mass was measured, and this was regarded as the mass of the solid content to obtain the ratio.

residue

After 50 g of the composite aluminum pigment composition obtained in the above-mentioned examples/comparative examples were dispersed in 1000 ml of mineral spirits with a spatula, filtered through a 200-mesh nylon mesh (manufactured by NBC Corporation), and the residue was fully washed with acetone, 105 After drying at °C for 10 minutes, the mass was measured, and this was regarded as the mass of the residue to obtain the ratio.

(Evaluation of paint and coating film)

Using the composite aluminum pigment compositions obtained in the above-mentioned Examples and Comparative Examples, water-based metallic paints were produced with the following compositions, and the paints and the coating films obtained therefrom were evaluated by the following methods. It should be noted that their results are shown in Table 1.

A waterborne metallic paint having the following ingredients was produced.

・Composite aluminum pigment composition: 12.0 g as a non-volatile component

·Methoxypropanol: 18.0g

· Polyoxyethylene lauryl ether (nonionic surfactant, manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., brand name "Marpon L5"): 6.0 g

·Purified water: 12.0g

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

・Melamine resin (※ 2): 18.0g

*1: Made by Mitsui Chemicals, Inc., Almatex WA911

*2: Made by Nihon Cytec Industries Inc., Cymel 350

After mixing the above ingredients, use dimethylethanolamine to adjust the pH to 7.7~7.8, and use carboxylic acid thickener and purified water to adjust the viscosity to 650~750mPa·s (B-type viscometer, No.3Low, 60 rpm , 25°C).

The following evaluations were performed using the water-based metallic paint produced in this way.

・Evaluation 1 (storage stability (gas generation))

Collect 200 g of the water-based metallic paint produced by the above formula into a flask, and measure the cumulative hydrogen gas generation in a constant temperature water bath at 60°C until 24 hours. Based on the obtained amount of gas generation, evaluation was performed according to the following criteria, and it was used as an index of the storage stability in the coating material.

○: Less than 2ml

△: More than 2ml and less than 10ml

×: More than 10ml and less than 50ml

××: more than 50ml

・Evaluation 2 (coating film evaluation)

The water-based metallic paint produced by the above formula is air-spray-coated on a 12cm×6cm steel plate (manufactured by Miki coating K.K) for intermediate coating to form a dry film thickness of 6 μm. After pre-drying at 90°C for 10 minutes, After dispersing the organic solvent-based surface coating paint with the following composition for 3 minutes with a spatula, adjust the viscosity of the paint with a Ford Cup No. 4 for 20.0 seconds, and perform air spray coating so that the dry film thickness is 20 μm, at 140°C It dried for 30 minutes, produced the painted board, and used it for the following evaluation.

(Composition of paint for organic solvent-based surface coating)

・ACRYDIC 44-179 (manufactured by DIC Corporation, acrylic transparent resin) 141g

・SUPER BECKAMINE J-820 (manufactured by DIC Corporation, melamine resin) 35.3 g

·Toluene 123.5g

2-i (Particles from coating film)

The particle count of the entire surface of the surface coating film of the obtained painted board was measured, and it evaluated by the following index.

〇: Particles cannot be seen

△: less than 10 particles

×: more than 10 particles

2-ii (brightness)

The obtained painted board was evaluated using Alcope (Alcope) LMR-200, a laser type metallization measuring device manufactured by KANSAI PAINT CO., LTD. As an optical condition, there is a laser light source with an incident angle of 45 degrees and a light receiver at a light receiving angle of 0 degrees and -35 degrees. As the measured value, the IV value was obtained at the light receiving angle -35 degrees at which the maximum light intensity was obtained except for the light in the specular reflection area reflected on the surface of the coating film among the reflected light of the laser light. The IV value is a parameter proportional to the intensity of regular reflection light from the coating film, and represents the magnitude of the brightness.

Evaluation was performed based on the following criteria from the obtained IV value.

〇: The range of decrease from the reference (Comparative Example 1) is less than 20.

Δ: The range of decrease from the reference (Comparative Example 1) is 20 or more and less than 40.

×: The range of decrease from the reference (Comparative Example 1) is 40 or more.

2-iii (Concealment)

The produced water-based metallic paint was applied to a polyethylene terephthalate sheet (PET sheet) with a 2-mil applicator so that the dry film thickness was 15 μm, and it was judged to be dried at 140° C. 30 minutes of film coating.

◯: Same to slightly lower than the standard (Comparative Example 1).

Δ: Decreased compared with the reference (Comparative Example 1).

×: Significantly lower than the reference (comparative example 1).

(Evaluation of Aggregation and Deformation of Composite Particles)

In order to facilitate the determination of the aggregation state of the particles, etc., the amount of the aluminum paste in the compounding of the paint used in the production of the coated panel in Evaluation 2 was set to 1/10, and it was produced under the same conditions. As for the paint, a painted board was produced under the conditions of Evaluation 2.

The above-mentioned coated board was cut into 1 cm squares using a board cutter.

The cross-section of the obtained coating film was set so that ion beam irradiation can be performed using an ion milling device (manufactured by JEOL Ltd./IB-09010CP) up to a part 20 μm away from the cross-section of the coating film. Grind cross-section specimens.

The cross-section of the obtained coating film (coated plate) was observed with FE-SEM (manufactured by HITACHI/S-4700) to observe the overlapping state of the particles and the deformation state of the particles, and evaluate according to the following procedure.

Ratio of primary particles (aggregated state)

First, the degree of overlapping of particles can be easily recognized by observing at a magnification of about 1000 to 3000 times. If the degree of overlap cannot be discerned at this magnification, the degree of overlap is evaluated by appropriately changing the magnification. In this observation method, observation is performed at a maximum magnification of approximately 30,000 times. 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.

It should be noted that, when the particles are close to each other and it is difficult to judge the aggregation, the case where the length of the contact portion between the particles is less than 1/4 of the particle diameter of the smaller particles (particles with short major diameters) is judged as no aggregation, and greater than 1. In the case of /4, it was determined that there was aggregation.

Ratio of bent particles (deformed state)

When the degree of deformation of the particles can be easily distinguished, it is observed at a magnification of about 1000 to 3000 times. When deformation cannot be discerned at this magnification, the degree of deformation is evaluated by appropriately changing the magnification. In this observation method, observation is performed at a maximum magnification of approximately 30,000 times. 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. Regarding the presence or absence of deformation, it was judged that there was deformation when the shortest distance between both ends of the particle was 0.8 times or less with respect to the length of the particle.

Average particle thickness of metal particles

Using the FE-SEM image (10,000 magnification) obtained by the above-mentioned acquisition procedure, and image analysis software Win Roofversion 5.5 (manufactured by MITANI CORPORATION), the measurement of the thickness of the particles in the cross section of the aluminum particles and the calculation of the average thickness were carried out.

Display the FE-SEM image of the particle thickness measurement in the cross section of the aluminum particle, select the ROI line so that the ROI line fits the 5 μm scale of the image, and set it by registering/changing the input length/unit.

Next, the image representing the thickness measurement of the cross-section of the aluminum particle is selected, and the rectangular ROI is selected, and binary processing is performed so that the rectangular ROI fits the cross-section of the particle.

Next, after selecting the measurement item of the vertical chord length to be measured, the measurement is performed, and the automatically measured value (vertical chord length value) obtained by the image analysis software is displayed on the image.

In this way, 300 particles were selected using the aforementioned image analysis software Win Roof version 5.5, and automatic measurement of the thickness and major diameter in the cross section of the aluminum particles was performed. Next, the arithmetic mean value of the thickness was calculated for 300 particles, and the average thickness t of the particles was obtained. It should be noted that the thickness uniformity of the aluminum particles is high, and the variation in the thickness due to the cut portion of the particles is small. The influence of the difference in the cutting position of the particles on the determination of the average particle thickness can thus be ignored.

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

The average thickness of the particle coating layer was measured at a magnification of 200,000 times using a STEM (scanning transmission electron microscope) for the painted plate used for the above-mentioned FE-SEM image acquisition. When there are irregularities on the surface of the coating layer, the area of the coating layer is measured using the image analysis software Win Roof version 5.5, and divided by the perimeter length of the particles covering it, thereby making it the average thickness of the coating layer. In addition, when the particle is large, it is not necessarily necessary to measure the entire area of the coating layer. The area of the coating layer in a region of about 1 μm along the particle surface is measured and divided by the length of the particle surface to obtain the coating layer with sufficient accuracy. average thickness. In addition, since the average thickness of the covering layer is substantially uniform regardless of the particles, an average value was obtained for 10 particles. In addition, the average thickness of the composite particles was obtained from the thickness of the particle coating layer and the average particle thickness of the metal particles obtained above according to the following calculation formula.

Average particle thickness of composite particles = average particle thickness of metal particles + thickness of covering layer × 2 [Table 1]

The evaluation results are shown in Table 1. The composite metal pigment composition of the present invention that satisfies all the conditions of the above-mentioned items (1) to (6) obtained in each embodiment has a high solid content, and has good stability as a coating, and has little gas generation (with Good storage stability), in addition, the brightness and concealment are also excellent, and the graining of the coating film is also effectively suppressed.

Industrial availability

The composite metallic pigment composition of the 1st invention of the present application, the composite metallic pigment composition obtained by the manufacturing method of the 2nd and 3rd inventions of the present application, and the coating films obtained by using them, are due to exceed the limit of the prior art at a high The level of storage stability when used in low-VOC, water-based paints, etc., the suppression of particle formation, designability, concealment, and other excellent characteristics of the coating film, so it can be suitably used in paints, inks, and resin kneading agents Various applications that have traditionally used metallic pigments, more specifically, automotive bodies, automotive repair materials, automotive parts, home appliances, etc., plastic parts, PCM coatings, highly weather-resistant coatings, heat-resistant coatings, anti-corrosion coatings, and ship bottoms Coatings, offset printing inks, gravure printing inks, screen printing inks, etc. are highly usable in various fields such as the transportation machinery industry such as automobiles, the electrical and electronic industries such as home appliances, the paint industry, and the printing industry.

Claims (23)

1. A composite metal pigment composition, which contains composite particles, and the composite particles have metal particles and metal oxide coatings formed on their surfaces, (1) The shape of the composite particle is scale-like, (2) The volume-based average particle diameter _D50 when measuring the particle size distribution of the composite particles by a laser diffraction particle size distribution meter is 1 to 30 μm, (3) The average particle thickness of the composite particles is 20-300nm, (4) The solid content concentration of the composite metal pigment composition is 70 to 95% by mass, (5) a hydrophilic solvent having a boiling point of 80 to 150° C. accounts for more than 80% by mass of the non-solid content of the composite metal pigment composition, (6) The residue when the composite metallic pigment composition is filtered with a 200-mesh filter is 0.1% by mass or less of the solid content, At least one layer of the metal oxide coating is a silicon-containing compound layer. 2 . The composite metallic pigment composition according to claim 1 , wherein the aspect ratio of the composite particles, that is, the shape factor obtained by dividing the average particle diameter by the average thickness, is 30-700. 3 . The composite metallic pigment composition according to claim 2 , wherein the aspect ratio of the composite particles, that is, the shape factor obtained by dividing the average particle diameter by the average thickness, is 80-500. 4 . 4 . The composite metallic pigment composition according to claim 1 , wherein the volume-based average particle diameter D ₅₀ when measuring the particle size distribution of the composite particles with a laser diffraction particle size distribution meter is 3 to 20 μm. 5. The composite metallic pigment composition according to claim 1, wherein the composite particles have an average particle thickness of 20-200 nm. 6. The composite metallic pigment composition according to any one of claims 1 to 5, wherein the solid content concentration of the composite metallic pigment composition is 85 to 95% by mass. 7. The composite metal pigment composition according to any one of claims 1 to 5, wherein the solvent having hydrophilicity and a boiling point of 80 to 150° C. accounts for 90 to 50% of the non-solid content of the composite metal pigment composition. 100% by mass. 8 . The composite metallic pigment composition according to claim 1 , wherein the residue when the composite metallic pigment composition is filtered through a 200-mesh filter is 0.005% by mass or less of the solid content. 9. The composite metallic pigment composition according to any one of claims 1 to 5, wherein in the composite particles, the proportion of unaggregated primary particles is 35% or more on a number basis. 10 . The composite metallic pigment composition according to claim 9 , wherein in the composite particles, the ratio of primary particles that are not aggregated is 50% or more on a number basis. 11 . 11. The composite metallic pigment composition according to any one of claims 1 to 5, wherein, in the composite particles, the ratio of curved composite particles is 10% or less on a number basis. 12 . The composite metallic pigment composition according to claim 11 , wherein in the composite particles, the ratio of curved composite particles is 3% or less on a number basis. 13 . 13. The composite metal pigment composition according to any one of claims 1 to 5, wherein the silicon content covered with the metal oxide is 1 to 20 parts by mass relative to 100 parts by mass of the metal particles. 14. The composite metal pigment composition according to any one of claims 1 to 5, wherein the average layer thickness of the metal oxide coating is 5 to 200 nm. 15. The composite metal pigment composition according to claim 14, wherein the average layer thickness of the metal oxide coating is 20-70 nm. 16. The composite metal pigment composition according to any one of claims 1 to 5, wherein the metal particles contain aluminum or an aluminum alloy. 17. The composite metal pigment composition according to claim 16, wherein at least 95% by mass of the metal particles is composed of aluminum element. 18. The composite metal pigment composition according to any one of claims 1 to 5, wherein the composite particle also has: a compound selected from at least one of metal, metal oxide, metal hydrate and resin overlay. 19. A method for preparing the composite metallic pigment composition according to any one of claims 1 to 18, wherein the method of manufacture has the following steps 1) to 3), 1) A process of dispersing metal particles in a solvent, 2) a process of covering said metal particles with an oxidized metal, 3) a step of washing, filtering, and volatilizing the solvent with metal particles and metal oxide-covered composite particles formed on the surface obtained in step 2), The solvent in step 3) is a mixed solvent of two or more solvents having compatibility with each other and having a boiling point difference of 10° C. or more, The volatilization of the solvent in step 3) is performed in the state of a slurry containing the composite particles and the solvent. 20. A method for preparing the composite metallic pigment composition according to any one of claims 1 to 18, wherein the method of manufacture has the following steps 1) to 3), 1) A process of dispersing metal particles in a solvent, 2) a process of covering said metal particles with an oxidized metal, 3) a step of washing, filtering, and volatilizing the solvent with metal particles and metal oxide-covered composite particles formed on the surface obtained in step 2), The solvent volatilization in step 3) is carried out in three or more stages. 21. The production method according to claim 19, wherein the solvent volatilization in step 3) is performed in three or more stages. 22. The production method according to claim 19 or 20, wherein the moisture content of the solvent when the solvent volatilizes in step 3) is 10% by mass or less. 23. The production method according to claim 22, wherein the moisture content of the solvent when the solvent volatilizes in step 3) is 1% by mass or less.