WO2020021735A1

WO2020021735A1 - Resin-coated metallic pigment

Info

Publication number: WO2020021735A1
Application number: PCT/JP2018/043509
Authority: WO
Inventors: 拓哉大坪; 孝典渡辺; 融石井
Original assignee: Dic株式会社
Priority date: 2018-07-23
Filing date: 2018-11-27
Publication date: 2020-01-30
Also published as: JPWO2020021735A1; JP6809605B2

Abstract

Aluminum pigments not having undergone any surface treatment are high in metallic sensation and appearance attractiveness, but have a drawback in that coating materials or printing inks containing such aluminum pigment give coating films in which adhesion between the aluminum pigment and the resin is low and from which a large amount of aluminum pigment particles separate in an adhesion test based on peeling with cellophane adhesive tape. Thus, the coating films are insufficient in satisfying the adhesion properties required of printed matter produced with inks containing metallic pigments. It was found that a resin-coated metallic pigment having a very small average particle diameter gave a coating material which gave coating films wherein the smaller the number of specific particles contained therein, the higher the adhesion. The resin-coated metallic pigment of the present invention has been thus completed.

Description

Resin-coated metal pigment

(4) The present invention relates to a resin-coated metal pigment coated with a copolymer.

Metallic paints are applied to the body and interior parts of automobiles, household appliances such as refrigerators and washing machines, and portable electronic devices such as smartphones and mobile computers, and are mainly used in metallic colors. It is widely used for the purpose of giving a texture. The metallic paint is usually compounded with a metal powder having a flat shape (also referred to as a scale shape) such as aluminum, copper, nickel, or titanium, or a metal pigment represented by metal oxide particles such as mica.

アルミニウム Conventionally, aluminum pigments have been used for metallic paints, printing inks, kneading plastics, etc. for the purpose of obtaining a cosmetic effect emphasizing the metallic feeling.

However, aluminum pigments that have not been subjected to any surface treatment have a high metallic appearance and design, but when used in paints and printing inks, have low adhesion to the resin in the coating film, for example, adhesion by cellophane tape peeling. It has a drawback that a large amount of exfoliation occurs when a performance test is performed.

を In order to solve these problems, a method of performing a predetermined surface treatment on an aluminum pigment has been proposed as a method for improving the adhesion of the aluminum pigment. However, in recent years, these required characteristics have been further increased, and the situation is that the adhesion cannot be said to be sufficient.

For example, in Patent Document 1, the surface of a metal particle having an average particle diameter (d50) selected from a range of 3 to 40 μm, an average thickness (t) of 0.005 to 2 μm, and an average aspect ratio of 20 to 2500 is chemically coated. It has been reported that a metal pigment composition containing a living radical polymer composition having a bound or adsorbed compound as an initiator has excellent adhesion.

Patent Literature 2 discloses an aluminum pigment to which a copolymer obtained by polymerizing a radical polymerizable monomer and / or oligomer having one or more double bonds in a molecule is attached, and the solid content after washing with chloroform is reduced. The mass ratio (b) / (a) of (a) the insoluble solid content to (b) the dissolved solid content when dispersed in dimethylformamide is 0.0001 to 0.1, and the polymerization average molecular weight of the dissolved solid content is It has been reported that a resin-attached aluminum pigment having a molecular weight of 1,000 to 30,000 is excellent in adhesion.

JP 2012-180492 A JP 2017-57309A

However, the above techniques are not enough to satisfy the recent required characteristics of the level of adhesion to a substrate.

The present inventors have conducted intensive studies to solve the above problems, and as a result, when the resin-coated metal pigment is formed into a coating film by coating the resin-coated metal pigment, the number of particles of a specific size is small. As a result, they found that the adhesiveness was more excellent, and completed the resin-coated metal pigment of the present invention.

That is, the present invention
(1) The resin-coated metal pigment coated with the copolymer was adjusted with an acrylic resin and a solvent so that the average particle diameter was 5 to 15 μm and the content of the resin-coated metal pigment was 0.8% by mass. A resin-coated metal pigment in which the area ratio of the area of particles having a diameter of 2 μm or less to the total particle area is 34% or less per image obtained by applying a 1-mil applicator to paint and drying a dried coating film with a microscope.
(2) The ratio of the area of particles having a diameter of 2 μm or less to the total particle area of an image obtained by photographing a coating film formed in the same manner as described in (1) with a microscope is 33% or less. Resin-coated metal pigment.
(3) A paint, ink or molded article containing the resin-coated metal pigment according to any one of the above.
It is about.

When a coating film is formed using the resin-coated metal pigment, the adhesion is improved, so-called "cohesive peeling" is less likely to occur, and the adhesion to the substrate is good, so that the resin-coated metal pigment having less peelability is used. And a paint, ink, and molded article containing the resin-coated metal pigment.

Here, “cohesive peeling” refers to peeling that occurs not between the substrate and the coating but between the coating layers.

7 is a micrograph of a coating film of a printed matter obtained in Example 7. 16 is a micrograph of a coating film of a printed matter obtained in Comparative Example 5.

≪Resin coated metal pigment≫
In the resin-coated metal pigment of the present embodiment, the flat metal particles or metal oxide particles have a surface in which a monomer (B1) of a radically polymerizable unsaturated carboxylic acid or a radically polymerizable phosphoric acid ester has a molecular weight of 3 per molecule. Coated with a coating resin containing an acrylic copolymer (B) obtained by radical polymerization of up to six monomers (B2) containing a (meth) acryloyloxy group with a polymerization initiator (C) And a resin-coated metal pigment.

<Particle (A)>
The particles according to the embodiment are metal particles or metal oxide particles, and include particles belonging to Groups 1 to 15 of the periodic table except for those in the first and second periods. Specific examples include aluminum powder, silver powder, copper powder, bronze powder, zinc powder, stainless steel powder, nickel powder, silicon oxide powder, aluminum oxide powder, mica powder, glass flake, and the like. Among them, flat (scale-like) metal particles or metal oxide particles are more preferable, aluminum particles are further preferable, and flat (scale-like) aluminum particles are particularly preferable from the viewpoint of glitter. The particles in the present invention may be composed of only one kind, or may be a mixture of plural kinds.

粒子 As the particles according to the embodiment, those manufactured by a conventionally known method can be widely used. When flat aluminum particles are used, substantially spherical aluminum particles may be ground and processed into flat aluminum particles, or may be processed into flat aluminum particles by a method such as vapor deposition. Examples of the processing method include a method using a ball mill and a method using vapor deposition. Examples include aluminum particles and vapor-deposited aluminum particles having a shape called a cone flake or a silver dollar.

(4) Hereinafter, the shape of the particles will be described. Usually, it is not assumed that only one particle is provided as a pigment, so the value shown below may be an average value obtained for a plurality of provided particles.

The average particle diameter of the particles can be calculated as a volume-based median diameter d50 from a volume-based cumulative particle size distribution measured by a laser diffraction particle size distribution analyzer.

において In the present invention, the average particle size of the particles is preferably in the range of 5 to 15 μm from the viewpoint of obtaining excellent glitter and adhesion.

When the particles have a flat shape, the average thickness of the particles may be 1 μm or less, may be 0.001 μm to 1 μm, may be 0.01 to 0.8 μm, and may be 0.01 to 0.5 μm. It may be. The average thickness of the particles is obtained by calculating the average value of the thickness of one particle in a region selected at random, and further setting the average value of the thickness of a plurality of particles. Here, the term “plurality” refers to 10 or more.

The ratio R / t between the average particle diameter (R) and the average thickness (t) of the particles is preferably 5 or more, and may be 5 to 3000, 15 to 1500, and 30 to 750. May be. When the R / t of the particles is within the above range, the particles have an appropriate flake shape, so that excellent glitter can be easily obtained.

表面 The surface roughness Ra of the particles is preferably 20 nm or less, more preferably 15 nm or less. The surface roughness Rc of the particles is preferably 80 nm or less, more preferably 60 nm or less. When the surface roughness Ra and / or Rc is equal to or less than the above upper limit, the surface state of the particles becomes smoother, and excellent glitter is easily exhibited.

Regarding the shape of the particles, it is preferable that two or more of the numerical ranges of the above-described average particle diameter, average thickness, R / t, Ra, and Rc are satisfied.

は Further, the particles (A) used in the present invention are preferably 34 parts by mass or less, more preferably 33 parts by mass or less when the total amount of the particles of 2 μm or less is 100 parts by mass.

<Acrylic copolymer (B)>
The acrylic copolymer (B) according to the embodiment is a monomer (B1) of a radical polymerizable unsaturated carboxylic acid or a radical polymerizable phosphate, a radical polymerizable unsaturated aldehyde, and a radical polymerizable unsaturated alcohol. "Monomer (B1)") and monomer (B2) containing 3 to 6 (meth) acryloyloxy groups per molecule ("monomer (B2)"). May be omitted)). The acrylic copolymer according to the embodiment includes a structural unit derived from the monomer (B1) and a structural unit derived from the monomer (B2).

The monomer (B1) according to the embodiment is a radically polymerizable unsaturated carboxylic acid or a radically polymerizable phosphate, a radically polymerizable unsaturated aldehyde, or a radically polymerizable unsaturated alcohol.

Examples of the radical polymerizable unsaturated carboxylic acid include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, maleic acid, fumaric acid, unsaturated dicarboxylic acids such as itaconic acid and half esters of these unsaturated dicarboxylic acids. Is mentioned. These monomers can be used alone or in combination of two or more.

Examples of the radically polymerizable phosphoric acid ester include 2-methacryloyloxyethyl phosphate, di-2-methacryloyloxyethyl phosphate, tri-2-methacryloyloxyethyl phosphate, 2-acryloyloxyethyl phosphate, di-2-acryloyloxyethyl phosphate, Tri-2-acryloyloxyethyl phosphate, bis (2-hydroxyethyl methacrylate) phosphate, diphenyl-2-methacryloyloxyethyl phosphate, diphenyl-2-acryloyloxyethyl phosphate, dibutyl-2-methacryloyloxyethyl phosphate, dioctyl-2 -Acryloyloxyethyl phosphate, 2-methacryloyloxypropyl phosphate and the like. These monomers can be used alone or in combination of two or more.

General examples of the above-mentioned radical polymerizable unsaturated aldehyde and radical polymerizable unsaturated alcohol include acrolein, methacrolein, 2-ethylacrolein, crotonaldehyde, 2-pentenal, 2-hexenal, 2-heptenal, 2-octenal, -Nonenal, 2-decenal, 2-dodecenal, 2-octadecenal, 3-methyl-2-butenal, 2-ethylbutenal, 2-methylpentenal, 2-ethylpentenal, 2,4-hexadienal, 2,4 -Heptadienal, 2,4-octadienal, cinnamaldehyde, α-amylcinnamaldehyde, α-methylcinnamaldehyde, α-hexylcinnamaldehyde, α-bromocinnamaldehyde, 2-hydroxycinnamaldehyde, 2-nitrocin Namaldehyde, 4-azidocinnamaldehyde, 4-methoxycinnamaldehyde, trans-4-bromocinnamaldehyde, 4-nitrocinnamaldehyde, 4-dimethylaminocinnamaldehyde, 4-fluorocinnamaldehyde, 2-furalacrolein, geranial, Neral, citral, farnesal and the like can be mentioned. These monomers can be used alone or in combination of two or more.

単量体 The monomer (B2) according to the embodiment is a monomer containing 3 to 6 (meth) acryloyloxy groups per molecule.

Monomers containing 3 to 6 (meth) acryloyloxy groups per molecule include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, glycerin triacrylate, ditrimethylolpropanetetramethacrylate, and ditrimethylolpropanetetramethacrylate. Acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ethylene oxide (EO) and / or propylene oxide (PO) adducts of these monomers, or isocyanuric acid EO Modified triacrylate and the like can be mentioned. These monomers can be used alone or in combination of two or more.

In the coated pigment, the molar ratio (B1: B2) of the structural unit derived from the monomer (B1) to the structural unit derived from the monomer (B2) of the acrylic copolymer (B) is determined by the coating resin. From the viewpoint of improving the coating state of, the ratio is preferably 1: 1.5 to 1:10, more preferably 1: 1.5 to 1: 8, and still more preferably 1: 1.5 to 1: 7.

<Polymerization initiator (C)>
The polymerization initiator (C) according to the embodiment is a radical polymerization initiator that generates at least a radical as an active species, and includes, for example, an azo polymerization initiator.

In the case of using an azo polymerization initiator containing a nitrile group as the polymerization initiator (C) according to the embodiment, the monomer (B1) and the monomer (B2) are subjected to a radical polymerization reaction.

Examples of the polymerization initiator (C) according to the embodiment include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2-methylbutyronitrile), and 2,2′-azobis (2, 4-dimethylvaleronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2-methylpropanenitrile) and the like, and 2,2'-azobis (isobutyroyl) Nitrile) and 2,2'-azobis (2-methylbutyronitrile) are preferred.

Other polymerization initiators (C) according to the embodiment include peroxides, such as potassium persulfate, sodium persulfate, ammonium persulfate, benzoyl peroxide, lauroyl peroxide, isobutyl peroxide, methyl ethyl ketone peroxide, and the like. Examples include, but are not limited to, di- (t-butyl) cyclohexylidene diperoxide.

重合 The polymerization initiator (C) according to the embodiment may have a polymerization temperature of 60 to 120 ° C. or 70 to 100 ° C. The half-life time can be appropriately set depending on the polymerization temperature and the type of the initiator.

<Particle (A) and coating resin>
Hereinafter, the particles (A) and the coating resin in the resin-coated metal pigment of the embodiment will be described. Here, usually, it is not assumed that the resin-coated metal pigment is provided by only one pigment particle. Therefore, the value shown below may be obtained as an average value for the provided resin-coated metal pigment. Good.

In the resin-coated metal pigment of the embodiment, the particles (A) are coated with a coating resin containing an acrylic copolymer (B).

The coating resin preferably contains the acrylic copolymer (B) in an amount of 50% by mass or more, more preferably 80% by mass or more, even more preferably 95% by mass or more, and more preferably 99% by mass or more. Is particularly preferred. Alternatively, the coating resin may be composed of only the acrylic copolymer (B).

において In the present specification, the phrase “particle (A) is coated with the coating resin” means a state in which the coating resin is laminated on part or all of the particle surface. It is preferable that the coating resin is directly bonded to the surface of the particle (A). Examples of the type of the bond include a chemical bond such as a covalent bond, a coordinate bond, and an ionic bond. Since the coating resin is bonded to the surface of the particles (A), the coating resin can be hardly peeled off from the particles (A).

に対し Resin content is preferably 0.05% by mass to 30% by mass, more preferably 0.5% by mass to 20% by mass, based on 100% by mass of the total of the particle content and the coating resin content.

こと When the mass ratio between the particles (A) and the coating resin is within the above range, the balance between the glitter of the particles (A) and the adhesion between the coating resin and the coating resin becomes preferable.

In the resin-coated metal pigment of the embodiment, the mass [g] of the acrylic copolymer (B) per the total surface area [m ² ] of the particles (A) is appropriately set according to the surface area of the metal pigment. It is.

When the mass of the acrylic copolymer (B) per the total surface area of the particles is within the appropriate range, the balance between the glitter of the particles (A) and the adhesion of the coating resin to the coating resin is preferable. Become. Further, since the monomer (B1) can be a starting point of polymerization of the acrylic copolymer (B), the mass of the monomer (B1) per the total surface area of the particles (A) is within an appropriate range. It is believed that the radical polymerization on the surface of the particles proceeds in a more uniform state between the regions. As a result, a coating resin having a smooth and uniform thickness can be obtained.

総 The total surface area of the particles (A) can be calculated from the specific surface area of the particles measured using a specific surface area meter and the mass of the particles (A).

The coating resin may have resin particles. The resin particles according to the embodiment can be formed by radical polymerization of the copolymer (B) on the particles (A), and can be a hemispherical copolymer.

<Resin coated metal pigment>
The resin-coated metal pigment according to the embodiment has an average particle size of 5 to 15 μm, and a paint prepared with an acrylic resin and a solvent so that the content of the resin-coated metal pigment is 0.8% by mass. This is a resin-coated metal pigment in which the area ratio of the area of particles having a diameter of 2 μm or less to the total particle area is 34% or less per image obtained by photographing the coating film dried and dried with a microscope.

In the above-mentioned coating film, the resin-coated pigment having better adhesion preferably has an area ratio of particles having a diameter of 2 μm or less to a total particle area of 33% or less per image obtained by photographing the coating film with a microscope.

As the resin-coated metal pigment of the embodiment, particles (A) from which particles having a diameter of 2 μm or less have been removed in advance by classification or resin (A) prepared using particles (A) from which particles having a diameter of 2 μm or less have not been removed You may classify and produce a coating metal pigment. Among them, it is preferable to use particles (A) from which particles having a diameter of 2 μm or less have been removed in advance.

Any of conventionally known methods can be used for the classification, and a gravity classification method, an inertial classification method, and a centrifugal classification method can be used under dry and wet methods. Among them, it is preferable to classify the particles (A) before being coated with the coating resin by any of the above classification methods under a dry system from the viewpoint of production cost.

<Paints and inks>
The resin-coated metal pigment of the embodiment can be used as a paint or an ink. As one embodiment, a paint or ink containing the resin metal pigment of the embodiment can be provided. Examples of the paint include a powder paint, a paint for furniture painting, a paint for electrical appliance painting, a paint for automobile painting, a paint for plastic painting, and the like. Examples of the ink include a printing ink and a packaging material printing ink.

The paint or ink may contain the resin-coated metal pigment of the embodiment, the dispersion medium, and the paint or ink resin. As the dispersion medium, any dispersion medium used for dispersing the pigment can be used, and a conventionally known dispersion medium may be used. Examples of the dispersion medium include alcohol solvents such as ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol and isobutyl alcohol; esters such as ethyl acetate, propyl acetate and butyl acetate. Solvents, ketone solvents such as methyl ethyl ketone, methyl butyl ketone and cyclohexanone; ether ester solvents such as methyl cellosolve acetate and butyl cellosolve acetate; amide solvents such as dimethyl formamide and dimethyl acetamide; aromatic carbonization such as toluene and xylene Hydrogen solvents: aliphatic hydrocarbon solvents such as hexane, heptane, and white spirits; and mixed solvents of aromatic hydrocarbons and aliphatic hydrocarbons such as mineral spirits.

(4) As the resin for paint or ink, any resin blended into paint or ink can be used, and a conventionally known resin may be used. Examples of the resin include an acrylic resin, a polyester resin, an alkyd resin, a urethane resin, an epoxy resin, a vinyl chloride-vinyl acetate copolymer resin, a polyamide resin, a melamine resin, a nitrocellulose resin, and a urethane resin.

In addition, as the paint or ink pigment, in addition to the resin-coated metal pigment of the embodiment, further contains any color pigment or glitter that is not included in the resin-coated metal pigment of the embodiment and is blended into the paint or ink. It is also possible to use conventionally known coloring pigments and glittering materials. Examples of coloring pigments include phthalocyanine pigments, halogenated phthalocyanine pigments, quinacridone pigments, diketopyrrolopyrrol-based pigments, isoindolinone pigments, azo pigments, azomethine metal complex pigments, indanthrone pigments, and perylene pigments. , Perinone pigments, anthraquinone pigments, dioxazine pigments, benzimidazolone pigments, condensed azo pigments, triphenylmethane pigments, quinophthalone pigments, anthrapyrimidine pigments, titanium oxide, iron oxide, carbon black, Bismuth vanadate is mentioned. Examples of the glittering material include aluminum pigments, mica pigments, alumina pigments, and glass flake pigments coated with a metal or metal oxide.

For example, the paint or ink preferably contains the resin-coated metal pigment in an amount of 0.5 to 50% by mass, more preferably 3 to 40% by mass, and even more preferably 5 to 30% by mass.

Paints or inks, in addition to the resin-coated metal pigment of the embodiment, if necessary, an antioxidant, a preservative, a softener, an ultraviolet absorber, an antioxidant, a light stabilizer, a heat stabilizer, an antistatic agent And other various additives.

樹脂 The resin-coated metal pigment of the embodiment is preferably coated with a coating resin containing an acrylic copolymer (B) that has been subjected to a radical polymerization reaction with a polymerization initiator (C). When the monomer (B1) is subjected to a radical polymerization reaction with the monomer 重合 (B2) using the polymerization initiator (C) according to the embodiment, the obtained acrylic copolymer (B) is obtained. The contained coating resin has a smooth and uniform thickness, and the resin-coated metal pigment has good glitter and excellent adhesion.

Examples of the molded article containing the resin-coated metal pigment according to the embodiment include various molded articles to which a paint or ink containing the resin-coated metal pigment according to the embodiment is applied and decorated, such as a packaging container and various plastic coated articles. , Automobile parts and the like. As another form, there is also a molded article in which the resin-coated metal pigment according to the embodiment is internally added. For example, electric equipment housings, automobile parts, plastic containers, base makeup such as makeup and foundation such as nail polish and eye shadow. And the like.

製造 Production method of resin-coated metal pigment≫
As an example, the resin-coated metal pigment of the embodiment can be manufactured by a method for manufacturing a resin-coated metal pigment described below.

The method for producing the resin-coated metal pigment of the embodiment is
(I) reacting the particles (A) with the monomer (B1),
(Ii) The monomer (B1) or a structure derived therefrom and the monomer (B2) are subjected to a radical polymerization reaction with a polymerization initiator (C) to form an acrylic copolymer on the particles (A). Having a step of forming a polymer (B),
The particles (A) are coated with a coating resin containing an acrylic copolymer (B).

末端 The terminal of the acrylic copolymer (B) may include a structure represented by the following general formula (1) derived from the polymerization initiator (C).

[In the formula (1), R1 represents a methyl group, R2 represents an alkyl group having 1 to 5 carbon atoms, a group represented by —C (＝ O) —O—R2a, or —C (＝ O) —NH A group represented by -R2a {R2a represents an alkyl group having 1 to 8 carbon atoms; And may represent a cyclic structure in which R1 and R2 are bonded to each other. ]

In the method for producing a resin-coated metal pigment according to the embodiment, the particles (A), the monomer (B1), the monomer (B2)} and the polymerization initiator (C) are those exemplified in the above {Resin-coated metal pigment}. And a detailed description will be omitted.

The step (i) may be a step of reacting the particle (A) with the monomer (B1) to form a bond between the particle and the monomer. Examples of the type of the bond include a chemical bond such as a covalent bond, a coordinate bond, and an ionic bond.

The step (i) may be a step of forming a bond between an atom on the outermost surface of the particle (A) and the monomer (B1). Examples of the type of the bond include a chemical bond such as a covalent bond, a coordinate bond, and an ionic bond.

According to the step (i), a structure derived from the monomer (B1) or the monomer (B1) resulting from the reaction is bonded to the surface of the particle (A). The monomer (B1) or a structure derived from the monomer (B1) bonded to the surface of the particle (A) can be a starting point for the subsequent radical polymerization.

According to the step (ii), the acrylic copolymer (B) can be formed on the surface of the particles (A).

The acrylic copolymer (B) of the resin-coated metal pigment produced through the steps (i) and (ii) is a structural unit derived from the monomer (B1) from the side of the particles (A). Having structural units derived from the monomer (B2) in this order.

反応 In step (i) and step (ii), the reaction can proceed in a reaction solution. The reaction solution in the step (i) can contain the particles (A), the monomer (B1), a solvent and / or a dispersion medium, and if necessary, other components. The reaction solution in the step (ii) comprises a reaction product of the particles (A) and the monomer (B1), a polymerization initiator (C), a monomer (B2), a solvent and / or a dispersion medium, Other components can be included as needed.

Examples of the solvent and / or dispersion medium include organic solvents. Examples of the organic solvent include ester solvents such as ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as methyl ethyl ketone, methyl butyl ketone and cyclohexanone; ether ester solvents such as methyl cellosolve acetate and butyl cellosolve acetate; toluene and xylene And amide solvents such as dimethylformamide and dimethylacetamide, and petroleum solvents such as mineral spirits. These may be used alone or as a mixture of plural kinds of solvents. Other components include a chain transfer agent for a radical polymerization reaction.

温度 The temperature of the reaction solution in step (i) is, for example, about 80 to 120 ° C.温度 The temperature of the reaction solution in the step (ii) is a reaction temperature of a radical polymerization reaction, and may be, for example, 60 to 120 ° C or 70 to 100 ° C.

According to the method for producing a resin-coated metal pigment of the embodiment, the steps (i) and (ii) are performed to produce the resin-coated metal pigment of the embodiment.

When the monomer (B1) is subjected to a radical polymerization reaction with the monomer (B2) using the polymerization initiator (C) according to the embodiment, the obtained acrylic copolymer (B) is obtained. The contained coating resin has a smooth and uniform thickness, and the resin-coated metal pigment has good glitter and excellent adhesion.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, “parts” and “%” are based on mass.

[Production of resin-coated aluminum pigment]
The resin-coated aluminum pigment according to the present invention was produced as follows.

<Production Example 1>
Raw material A: 114 g of aluminum paste ZQ-405 (manufactured by Shogaoka Co., Ltd., average particle size 11 μm, metal content 76.4 mass%) and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask. The temperature was raised to 100 ° C. in an active gas atmosphere. Next, 1.20 g of raw material C: acrylic acid was added and stirred at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-1) which was a paste-like bright material. The resin coating amount (resin solid content / resin coated pigment solid content) of the particles was 2%.

<Production Example 2>
Raw material A: 107.67 g of aluminum paste ZQ-405 and raw material G: 3.33 g of ZQ-2085 (manufactured by Shogaoka Co., Ltd., average particle diameter 11 μm, metal content 69.9% by mass) in a 3 L four-necked flask, Raw material B: 506.00 g of mineral spirit was added, and the mixture was stirred at room temperature for 1 hour under an inert gas atmosphere. Next, the temperature was raised to 100 ° C., and 1.20 g of raw material C: acrylic acid was added, followed by stirring at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-2) as a paste-like bright material. The resin coating amount of these particles was 2%.

<Production Example 3>
Raw material A: 100.70 g of aluminum paste ZQ-405, raw material G: 5.30 g of ZQ-2085, and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask at room temperature under an inert gas atmosphere. Stirred for hours. Next, the temperature was raised to 100 ° C., and 1.20 g of raw material C: acrylic acid was added, followed by stirring at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-3) as a paste-like bright material. The resin coating amount of these particles was 2%.

<Production Example 4>
Raw material A: 102.30 g of aluminum paste ZQ-405, raw material G: 7.70 g of ZQ-2085, and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask at room temperature under an inert gas atmosphere. Stirred for hours. Next, the temperature was raised to 100 ° C., and 1.20 g of raw material C: acrylic acid was added, followed by stirring at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the reaction solution was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-4) as a paste-like bright material. The resin coating amount of these particles was 2%.

<Production Example 5>
Raw material H: 111.33 g of aluminum paste ZQ-407 (manufactured by Shogaoka Co., Ltd., average particle diameter 7 μm, metal content 74.7% by mass), and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask. The temperature was raised to 100 ° C. in an inert gas atmosphere. Next, 1.20 g of raw material C: acrylic acid was added and stirred at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the reaction solution was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-5) as a paste-like bright material. The resin coating amount of these particles was 2%.

<Production Example 6>
Raw material A: 114 g of aluminum paste ZQ-405 (manufactured by Shogaoka Co., Ltd., average particle size 11 μm, metal content 76.4 mass%) and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask. The temperature was raised to 100 ° C. in an active gas atmosphere. Next, 1.20 g of raw material C: acrylic acid was added and stirred at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material I: 0.01 g of 2,2′-azobis (2-isobutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-6) as a paste-like bright material. The resin coating amount of the particles was 2%.

<Production Example 7>
Raw material A: 1008.00 g of aluminum paste ZQ-405, raw material G: 112.00 g of ZQ-2085, and raw material B: 10603.75 g of mineral spirit were added to a 3 L four-necked flask in an inert gas atmosphere at room temperature. By stirring for an hour, an 8 wt% aluminum slurry was obtained. Fine aluminum pigment particles were removed from the slurry by using a liquid cyclone classifier (T-10 type supercron, manufactured by Murata Industry Co., Ltd.). This solution was filtered to obtain an intermediate aluminum paste (metal content: 71.1 mass) as a paste-like bright material.

Next, 117.16 g of the intermediate aluminum paste and 506.00 g of the raw material B: mineral spirit were added to a 3 L four-necked flask, and the mixture was stirred at room temperature for 1 hour under an inert gas atmosphere. Next, the temperature was raised to 100 ° C., 1.20 g of raw material C: acrylic acid was added, and the mixture was stirred at 100 ° C. for 1 hour.

Further, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-isobutyronitrile) are dissolved in raw material B: mineral spirit. 5% by weight) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-7) as a paste-like bright material. The resin coating amount of the particles was 2%.

<Comparative Production Example 1>
To a 3 L four-necked flask, 150.00 g of the raw material A: ZQ-405 and 300.00 g of the raw material F: normal propyl acetate were added and stirred at room temperature for 1 hour. This solution was filtered to obtain an aluminum paste (X-8) as a paste-like bright material.

<Comparative Production Example 2>
Raw material A: 100.80 g of aluminum paste ZQ-405, raw material G: 11.20 g of ZQ-2085, and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask at room temperature under an inert gas atmosphere. Stirred for hours. Next, the temperature was raised to 100 ° C., and 1.2 g of raw material C: acrylic acid was added, followed by stirring at 100 ° C. for 1 hour.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-9) as a paste-like glittering material. The resin coating amount of these particles was 2%.

<Comparative Production Example 3>
Raw material G: 119.24 g of ZQ-2085 and raw material B: 506.00 g of mineral spirit were added to a 3 L four-necked flask, and the temperature was raised to 100 ° C. Then, raw material C: 1.20 g of acrylic acid was added. The mixture was stirred at 100 ° C. for 1 hour in an active gas atmosphere.

Next, raw material D: 0.35 g of trimethylolpropane trimethacrylate and 0.01 g of an initiator solution (raw material E: 0.01 g of 2,2′-azobis (2-methylbutyronitrile) were dissolved in raw material B: mineral spirit. 0.5% by weight solution) and polymerized at 100 ° C. for 1 hour. After completion of the polymerization, the mixture was cooled to room temperature, and the reaction solution was filtered and washed with a raw material F: normal propyl acetate to obtain a resin-coated aluminum paste (X-10) as a paste-like bright material. The resin coating amount of these particles was 2%.

(Production method of printing ink and printed matter)
A solid content adjusting solvent (ethyl acetate: isopropyl alcohol (IPA) = 38.4 parts by mass: 61.6 parts by mass) was mixed with the aluminum pastes produced in Production Examples 1 to 7 and Comparative Production Examples 1 to 3, and the mixture was mixed with a metal. 39.7 parts by mass of an aluminum paste of 39.7 parts by mass were prepared.
To the obtained aluminum paste, 16.0 parts by mass of a nitrified cotton resin (Nobel NC Company Ltd.), 21.9 parts by mass of isopropyl alcohol, 21.1 parts by mass of ethyl acetate, 3.9 parts by mass of a plasticizer, polyethylene wax ( A printing ink was prepared by mixing 0.6 parts by mass of (PE-WAX).
50.0 parts by mass of a diluting solvent (ethyl acetate: isopropyl alcohol = 60.0 parts by mass: 40.0 parts by mass) was mixed with 100.0 parts by mass of the obtained printing ink to obtain a metallic ink whose viscosity was adjusted. Was. The viscosity-adjusted ink was printed on a one-side coated paper (DMSC, 270 g / m2 in U.S.P.) by a gravure proofing machine equipped with a gravure plate having a depth of 30 μm, and dried at 40 to 50 ° C. to obtain a printed material. The printed materials were (Examples 1 to 7) and (Comparative Examples 1 to 3).

(Evaluation of adhesion)
The printed matter (Examples 1 to 7 and Comparative Examples 1 to 3) obtained by the above-described (printing ink and printed matter production method) is sufficiently dried, and a cellophane tape is stuck on the printed surface, and this is placed in a direction perpendicular to the printed surface. The state of the appearance of the printed film when rapidly peeled off was visually determined. The criteria for determining the adhesion were “Pass”: at least 30% of the portion where the printed film and the coated paper were peeled off at the portion where the cellophane tape was peeled off, and “Fail”: the portion where the printed film was peeled with the cellophane tape. The portion where the coated paper was peeled off was 30% or less, the test was performed 10 times, the number of passed tests was counted, and the relative evaluation was performed in 10 steps. The results are shown in Table 1.

* In the description in the table,
Solid content adjusting solvent: ethyl acetate: isopropyl alcohol = 38.4 parts: 61.6 parts NC resin: nitrified cotton resin (nitrocellulose resin)
IPA: isopropyl alcohol plasticizer: ATBC (Taoka Chemical Industry)
PE-WAX: polyethylene wax diluting solvent: ethyl acetate / isopropyl alcohol = 6/4

わかる As can be seen from the results in Table 1, the printed materials of Examples 1 to 7 had very high adhesion as compared with the printed materials of Comparative Examples 1 to 3. The aluminum paste (X-7) used in Example 7 was obtained by removing fine particles of the aluminum paste (X-9) used in Comparative Example 2. As can be seen from a comparison between Example 7 and Comparative Example 2, even when metal particles from which fine particles were removed and resin-coated were used, metal particles (X-1 to 6) having a small content of fine particles were coated with the resin. It became clear that the adhesiveness was increased in the same manner as in.

(Microscope measurement)
Each of the aluminum pastes prepared in Preparation Examples 1 to 7 and Comparative Preparation Examples 1 to 3 was mixed with 0.25 part as a nonvolatile component, 24 parts of an acrylic resin, 5 parts of a melamine resin, and mixed with ethyl acetate as a solid content adjusting solvent to form a paint. Was spread with a 1 mil applicator and dried at 140 ° C. for 15 minutes to form a coating film. This coating film was photographed at a magnification of 500 times using a microscope (Keyence Corporation: VHX-5000), and particles having a diameter of 2 μm or less were extracted from automatic area measurement, which is one of the functions of VHX-5000. The area ratio of the area of the particles having a diameter of 2 μm or less to the particle area was measured. The photographed image area is adjusted so that the field of view is in the range of 0.20 to 0.40 mm ² , and the automatic area ratio measurement method is to measure each different printed part 20 times or more to eliminate measurement errors, and average The value was determined. Here, the total particle area indicates the area of all the particles obtained from the automatic area measurement, and the area of the particles having a diameter of 2 μm or less indicates the area of only the particles calculated to be 2 μm or less from the result of the automatic area measurement. Printed materials on which the coating films were formed were named (Examples 8 to 14) and (Comparative Examples 4 to 6), and the results are shown in Table 2. FIGS. 1 and 2 show images obtained by photographing the coating films in the printed materials obtained in Example 8 and Comparative Example 5. FIG.

Claims

A paint prepared by using an acrylic resin and a solvent so that the resin-coated metal pigment coated with the copolymer has an average particle size of 5 to 15 μm and the content of the resin-coated metal pigment is 0.8% by mass. A resin-coated metal pigment in which the area ratio of the area of particles having a diameter of 2 μm or less to the total particle area is 34% or less in an image of a coating film which has been colored and dried with a mill applicator and taken by a microscope.
<4> The resin-coated metal pigment according to <1>, wherein particles having a diameter of 2 [mu] m or less with respect to the total particle area are 33% or less in an image obtained by photographing a coating film formed in the same manner as described in [1].
塗料 A paint, ink or molded article containing the resin-coated metal pigment according to claim 1 or 2.