JP2021042344A - Scaly zinc powder-containing composition and manufacturing method of scaly zinc powder - Google Patents

Abstract

To provide a scaly zinc powder-containing composition capable of sufficiently exhibiting corrosion control and whiteness in a coated film.SOLUTION: A scaly zinc powder-containing composition is a composition containing scaly zinc powder and a dispersant, in which the dispersant contains at least one kind selected from the group consisting of a barium compound, a titanium compound and silica, a L* value in a CIELAB color system when the composition is measured by a spectral colorimeter is higher than the L* value of a simple mixture of the scaly zinc powder and the dispersant having the same blending ratio as the composition.SELECTED DRAWING: None

Description

The present invention relates to a composition containing scaly zinc powder and a method for producing scaly zinc powder. More specifically, the present invention relates to a scaly zinc-containing composition and a method for producing scaly zinc powder, which are useful for anticorrosive paints for cars, ships, steel structures and the like.

Zinc powder is suitably used as an anticorrosive undercoat paint for protecting large steel structures such as bridges, factory plants, tanks, and steel towers from corrosion, as well as small and medium-sized steel structures such as cars, ships, and small and medium-sized steel structures. The resin layer containing zinc powder acts as an anticorrosion layer that protects the steel material from rust by sacrificing zinc due to its electrochemical properties. Regarding anticorrosion coating materials, for example, Patent Document 1 describes a reaction solution (a), a zinc-containing powder (b), and a rocking agent (c) obtained by reacting a polyisocyanate compound having a hydrophilic moiety with a secondary amino group-containing alkoxysilane. ), And water (d), and in the reaction, the equivalent ratio of the isocyanate group of the polyisocyanate compound to the secondary amino group of the secondary amino group-containing alkoxysilane (NCO /). A water-based anticorrosion coating composition having an NH) of 1.0 / 0.8 to 1.0 / 1.0 is disclosed. Patent Document 2 describes (A) and (A) and (A) and (D) an inorganic zinc rich paint containing (A) a silicon-based inorganic binder, (B) a polyvinyl butyral resin, (C) an organoboron compound and (D) zinc powder. The compounding ratio of B) is SiO ₂ component in the component (A): component (B) = 85: 15-15: 85 (weight ratio), and the contents of the component (C) are (A) and (B). ) Is 5 to 30% by weight based on the total weight of the components, and the component (D) consists of (d1) zinc powder having an average particle size of 10 to 50 μm and (d2) zinc powder having an average particle size of less than 10 μm. The compounding ratio is (d1) :( d2) = 5:95 to 70:30 (weight ratio), and the content of the component (D) is 60 to 90% by weight in the solid content of the dry coating film. The characteristic inorganic zinc rich paint is disclosed.

In recent years, anticorrosion paints have been required not only to have excellent anticorrosion performance but also to be lead / chrome-free from the viewpoint of global environmental conservation. Furthermore, color tones and metallics are required for building materials that emphasize design that are visible to the public. Designability such as a feeling and a feeling of glitter (a feeling of glitter) is also required. Further, in the zinc powder-containing coating film, there is a case where "whiteness" different from the metallic feeling originally inherent in the metal-based material is required. For example, in Patent Document 3, zinc particles and other metal particles and / or inorganic pigment particles are mixed with an organic solvent and a lubricant using a bead mill and pulverized to form zinc particles into flakes. A method for producing dissimilar metal-containing zinc flakes, which comprises adhering other metal particles and / or inorganic pigment particles to the surface of flaked zinc particles, is disclosed.

Japanese Unexamined Patent Publication No. 2016-12178 Japanese Unexamined Patent Publication No. 2008-31237 Japanese Unexamined Patent Publication No. 2006-348147

As described above, various zinc-containing coating compositions and methods for producing zinc flakes are disclosed. However, for example, the method of mixing metallic aluminum or aluminum flakes with zinc powder to improve the design and the method of mixing pigments to improve the color tone reduce the proportion of zinc in the paint, and thus prevent corrosion. There was a problem that the performance deteriorated. Conventional zinc powder is not sufficient in terms of both anticorrosion performance and whiteness.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a scaly zinc powder-containing composition capable of sufficiently exhibiting both anticorrosion performance and whiteness in a coating film.

As a result of various studies on scaly zinc, the present inventor has found that a predetermined composition containing scaly zinc powder and a dispersant can sufficiently exhibit both anticorrosion performance and whiteness in a coating film. The present invention has been reached with the idea that the above problems can be solved brilliantly.

That is, the present invention is a composition containing a scaly zinc powder and a dispersant, and the dispersant contains at least one selected from the group consisting of a barium compound, a titanium compound and silica, and the above composition is used. A composition containing scaly zinc powder whose L * value in the CIELAB color system measured by a spectral color difference meter is higher than the L * value of a simple mixture of scaly zinc powder having the same compounding ratio as the composition and the above dispersant. It is a thing.

The content of the dispersant is preferably 0.001% by mass or more and less than 10% by mass with respect to 100% by mass of the scaly zinc powder.

It is preferable that the L * value of the scaly zinc powder-containing composition in the CIELAB color system measured by a spectrocolorimeter is 60 or more.

Using the above scaly zinc powder-containing composition, a coating film formed so that the mass ratio of scaly zinc powder to the binder (scaly zinc powder / binder) was 1.2 was measured with a spectrocolorimeter. It is preferable that the L * value in the CIELAB color system is 50 or more.

Using the above scaly zinc powder-containing composition, a coating film formed so that the mass ratio of scaly zinc powder to the binder (scaly zinc powder / binder) was 1.2 was measured with a spectrocolorimeter. Using a simple mixture of scaly zinc powder and dispersant having the same L * value in the CIELAB color system as the composition, the mass ratio of scaly zinc powder to the binder (scaly zinc powder / It is preferably higher than the L * value of the coating film formed so that the binder) is 1.2.

The 60 ° gloss value of the coating film formed by using the scaly zinc powder-containing composition so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) is 1.2 is the said. Using a simple mixture of scaly zinc powder and a dispersant having the same compounding ratio as the composition, the mass ratio of scaly zinc powder to the binder (scaly zinc powder / binder) was formed to be 1.2. It is preferably higher than the 60 ° gloss value of the coating film.

The present invention also includes a step A of obtaining a slurry containing zinc powder and a dispersant, and a step B of performing a scaling treatment on the silica obtained in the above step A, wherein the dispersant is a barium compound or a titanium compound. It is also a method for producing scaly zinc powder containing at least one selected from the group consisting of silica.

The amount of the dispersant used is preferably 0.001% by mass or more and less than 10% by mass with respect to 100% by mass of zinc powder.

The slurry in step A preferably further contains at least one selected from the group consisting of fatty acids and salts thereof.

In the above step B, it is preferable that the media treatment is performed in a time of 200% or less when the media treatment time at which the median diameter (D50) of the obtained zinc powder is maximized is 100%.

The present invention is also a coating material containing the scaly zinc powder-containing composition and a binder.

The content of the scaly zinc powder is preferably 5 to 95% by mass with respect to 100% by mass of the solid content in the coating material.

The paint is preferably used for anticorrosion applications.

The scaly zinc powder-containing composition of the present invention has the above-mentioned structure and can sufficiently exhibit both the anticorrosion performance and the whiteness in the coating film. , Can be suitably used for anticorrosion topcoat paints and the like.

Hereinafter, preferred embodiments of the present invention will be specifically described, but the present invention is not limited to the following description, and can be appropriately modified and applied without changing the gist of the present invention. A form in which two or three or more of the individual preferred forms of the present invention described below are combined also falls under the preferred form of the present invention.

<Composition containing scaly zinc powder>
The scaly zinc powder-containing composition of the present invention contains scaly zinc powder and a dispersant, and the dispersant contains at least one selected from the group consisting of a barium compound, a titanium compound and silica, and the above composition. A simple mixture of scaly zinc powder having the same compounding ratio as the composition and the above-mentioned dispersant (hereinafter, simply "scaly zinc") has an L * value (L1) in the CIELAB color system measured by a spectrocolor difference meter. It is also referred to as a "simple mixture of powder and dispersant"), which is higher than the L * value (L2).
More preferably, L1 / L2 is 1.01 or more, and even more preferably 1.02 or more.
The scaly zinc powder-containing composition of the present invention is preferably a scaly product of a composition containing zinc powder and a dispersant, and is obtained by scaling the composition containing zinc powder and a dispersant. It is more preferable that it is one.

The simple mixture of the scaly zinc powder and the dispersant is a mixture of the dispersant after scaling the zinc powder.
In the simple mixture to be compared, other than mixing the dispersant with the scaly zinc powder, other conditions such as the blending ratio of the scaly zinc powder and the dispersant are the scaly zinc of the present invention. It is the same as the powder-containing composition.
In the scaly zinc powder-containing composition of the present invention, a dispersant is added to zinc powder and scaly by media treatment, so that the dispersant enters between the scaly zinc powders at the time of scaly zinc powder formation, and the scaly zinc powder is formed. It is presumed that by acting as a spacer that suppresses aggregation and sticking of zinc powders, the light reflection area of scaly zinc powders increases and the L * value improves.
On the other hand, when the scaly zinc powder and the dispersant are simply mixed (comparative example), the dispersant only adheres to the surface of the scaly zinc powder once aggregated or fixed, so that the L * value is improved. Is considered to be rarely seen.

The dispersant is not particularly limited as long as it contains at least one selected from the group consisting of barium compounds, titanium compounds and silica.
The barium compound is not particularly limited as long as it contains a barium element, and examples thereof include sulfates, nitrates, hydrochlorides, oxides, hydroxides, carbonates, fatty acid salts, and organic acid salts. Of these, sulfates, fatty acid salts and organic acid salts are preferable, and sulfates are more preferable.
The organic acid in the above organic acid salt is not particularly limited, but the number of carbon atoms of the organic acid is preferably 1 to 22. It is more preferably 1 to 20, and even more preferably 1 to 18.
Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid and isostear. Acids, oleic acid, linoleic acid, linolenic acid, arachidonic acid, psychosapentaenoic acid, docosahexaenoic acid, sorbic acid, lactic acid, malic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, merit Examples thereof include carboxylic acids such as acid, silicic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, aconitic acid, pyruvate and oxaloacetate.

The fatty acid in the fatty acid salt is not particularly limited, but the number of carbon atoms of the fatty acid is preferably 8 to 24. It is more preferably 10 to 22, and even more preferably 12 to 20. Specific examples and preferable examples of fatty acids are as described in the method for producing scaly zinc powder described later.
The form in which the barium compound is barium sulfate is one of the preferred embodiments of the present invention.

The titanium compound is not particularly limited as long as it contains a titanium element, and examples thereof include sulfates, nitrates, hydrochlorides, oxides, hydroxides, carbonates, fatty acids, and organic acid salts. Of these, oxides, sulfates and hydroxides are preferable, and oxides are more preferable. The form in which the titanium compound is titanium oxide is one of the preferred embodiments of the present invention. The fatty acid in the fatty acid salt and the organic acid in the organic acid salt are as described in the barium compound.

The silica is not particularly limited as long as it is a compound represented by _{SiO 2, but hydrophobic dry silica and hydrophobic wet silica are preferable.} More preferably, it is hydrophobic dry silica.

The dispersant is preferably a barium compound and / or a titanium compound, and more preferably a barium compound.

The content (that is, the amount of addition) of the dispersant in the scaly zinc powder-containing composition is not particularly limited, but may be 0.001% by mass or more and less than 10% by mass with respect to 100% by mass of the scaly zinc powder. preferable. As a result, a more sufficient anticorrosion effect can be exhibited while maintaining the whiteness. The content of the dispersant is more preferably 0.005 to 9% by mass, further preferably 0.008 to 7% by mass, and particularly preferably 0.01 to 5% by mass.
When the scaly zinc powder-containing composition contains two or more kinds of dispersants, the content is the total content of the dispersants.

The scaly zinc powder-containing composition preferably has an L * value of 60 or more in the CIELAB color system measured by a spectrocolorimeter. When the L * value is 60 or more, the whiteness becomes more sufficient, and it can be suitably used as a white paint. The L * value is more preferably 63 or more, and even more preferably 65 or more.

The scaly zinc powder-containing composition is obtained by spectroscopically forming a coating film formed by using the composition so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) is 1.2. The L * value in the CIELAB color system as measured by a color difference meter is preferably 50 or more. It is more preferably 52 or more, further preferably 54 or more, and particularly preferably 55 or more.
Examples of the binder include binders contained in paints described later.

The scaly zinc powder-containing composition is obtained by spectroscopically forming a coating film formed by using the composition so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) is 1.2. The L * value (L1') in the CIELAB color system measured by the color difference meter is the mass ratio of the scaly zinc powder to the binder (scaly zinc powder) using a simple mixture of the scaly zinc powder and the dispersant. / Binder) is preferably higher than the L * value (L2') of the coating film formed so as to be 1.2.
More preferably, L1'/ L2'is 1.01 or more, further preferably 1.02 or more, and further preferably 1.03 or more.

The scaly zinc powder-containing composition is a 60 ° coating film formed by using the composition so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) is 1.2. The gloss value is preferably 20 or more. It is more preferably 40 or more, further preferably 50 or more, further preferably 60 or more, particularly preferably 70 or more, and most preferably 80 or more.
The 60 ° gloss value of the coating film can be measured by the method described in Examples.

The scaly zinc powder-containing composition is a 60 ° coating film formed by using the composition so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) is 1.2. The gloss value (G1) was formed so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) was 1.2 using a simple mixture of the scaly zinc powder and the dispersant. It is preferably higher than the 60 ° gloss value (G2) of the coating film.
More preferably, G1 / G2 is 1.05 or more, further preferably 1.10 or more, and further preferably 1.15 or more.

The median diameter (D50) of the scaly zinc powder in the scaly zinc powder-containing composition is preferably 1 to 120 μm. It is more preferably 3 to 100 μm, further preferably 6 to 80 μm, and particularly preferably 10 to 50 μm.
The thickness of the scaly zinc powder is preferably 0.01 to 10 μm. It is more preferably 0.01 to 8 μm, further preferably 0.05 to 6 μm, and particularly preferably 0.1 to 4 μm.

The scaly zinc powder-containing composition may further contain a fatty acid (salt). Specific examples and preferable examples of the fatty acid (salt) are as described in the method for producing scaly zinc powder described later.
When the scaly zinc powder-containing composition also contains a fatty acid (salt), it is preferable that the fatty acid (salt) is supported on the scaly zinc powder.
When the dispersant is a fatty acid salt of barium and / or titanium, the scaly zinc powder-containing composition will contain the dispersant and the fatty acid salt.
The content of the fatty acid (salt) is not particularly limited, but is preferably 0.01 to 5.0% by mass with respect to 100% by mass of the scaly zinc powder. It is more preferably 0.05 to 3.5% by mass, further preferably 0.1 to 2.8% by mass, and particularly preferably 0.2 to 2.3% by mass.

The scaly zinc powder-containing composition may contain other components other than the scaly zinc powder, the dispersant, and the fatty acid (salt).
Examples of other components include solvents, other lubricants (grinding aids) other than fatty acids (salts), barium compounds, titanium compounds, and other dispersants other than silica.
Specific examples and preferred examples thereof are as described in the method for producing scaly zinc powder described later. The preferable range of the content of these components with respect to the scaly zinc powder is the same as the preferable range of the amount and content of these components with respect to the zinc powder in the method for producing scaly zinc powder described later.

<Manufacturing method of scaly zinc powder>
The method for producing the scaly zinc powder-containing composition of the present invention is not particularly limited, but the present invention also provides a step A for obtaining a slurry containing zinc powder and a dispersant, and scaling the slurry obtained in the above step A. The dispersant includes the step B of performing the treatment, and the dispersant is also a method for producing a scaly zinc powder containing at least one selected from the group consisting of a barium compound, a titanium compound and silica.

1. 1. Process A
Step A is a step of obtaining a slurry containing zinc powder and a dispersant, and by using at least one selected from the group consisting of a barium compound, a titanium compound and silica as a dispersant, zinc powders are used as a dispersant in step B. It is considered that the reflectance of visible light can be increased and the whiteness is improved because the agglomeration of zinc powder is sufficiently dispersed and the zinc powder is sufficiently dispersed. In particular, since the reflectance of sunlight is increased, the whiteness is further improved under the irradiation of sunlight.

The amount of the dispersant used is preferably 0.001% by mass or more and less than 10% by mass with respect to 100% by mass of zinc powder. As a result, a more sufficient anticorrosion effect can be exhibited while maintaining the whiteness. The amount of the dispersant used is more preferably 0.005 to 9% by mass, further preferably 0.008 to 7% by mass, and particularly preferably 0.01 to 5% by mass.

The slurry in the above step A preferably further contains at least one selected from the group consisting of fatty acids and salts thereof (hereinafter, also referred to as fatty acids (salts)). By using the fatty acid (salt) as a lubricant, the zinc powders can be sufficiently suppressed from sticking to each other, and the zinc powders can be scaled more efficiently.
When the dispersant is a fatty acid salt of barium and / or titanium, the slurry will contain the dispersant and the fatty acid salt.

The fatty acid (salt) may have a hydrocarbon group and a carboxyl group. Examples of the salt include alkali metal salts such as sodium and potassium; alkaline earth metal salts such as calcium, magnesium and barium; salts such as zinc and aluminum; and the like.

The number of carbon atoms of the fatty acid (salt) is preferably 8 to 24. As a result, the slipperiness as a lubricant is further enhanced, and scaling can be performed more efficiently. The number of carbon atoms is more preferably 10 to 22, and even more preferably 12 to 20.

The hydrocarbon group contained in the fatty acid (salt) is preferably an alkyl group having a linear or branched structure. The number of carbon atoms of the alkyl group is preferably 7 to 23, more preferably 9 to 21, and even more preferably 11 to 19.

The linear alkyl group is not particularly limited, but is limited to a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group (amyl group), an n-hexyl group, an n-heptyl group and an n-octyl group. Group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl Examples thereof include a group, an n-nonadecil group, an n-icosyl group, an n-henicosyl group, an n-docosyl group and the like.

Examples of linear fatty acids include butyric acid (butyl acid), valeric acid (valeric acid, pentanic acid), caproic acid (caproic acid), enanthic acid (heptanic acid), caprylic acid (octanoic acid), and pelargonic acid (nonane). Acid), caproic acid (decanoic acid), lauric acid (dodecanoic acid), valeric acid (tetradecanoic acid), pentadecic acid (pentadecylic acid), palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid), stearic acid (octadecanoic acid) ), Nonadecylic acid, enanthic acid, docosanoic acid, henicosylic acid, hexacosanoic acid and the like.
The form in which the fatty acid (salt) is stearic acid (salt) is one of the preferred embodiments of the present invention.

Specifically, the alkyl group having the above-mentioned branched structure includes an isopropyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a 1-methylbutyl group, a 1-ethylpropyl group, a 2-methylbutyl group, an isoamyl group, and a neopentyl group. , 1,2-dimethylpropyl group, 1,1-dimethylpropyl group, tert-amyl group, 1,3-dimethylbutyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, 2-ethyl-2-methyl Propyl group, 1-methylheptyl group, 2-ethylhexyl group, 1,5-dimethylhexyl group, t-octyl group, isooctyl group, sec-nonyl group, tert-nonyl group, neononyl group, isodecyl group, sec-decyl group , Tert-Decil group, Neodecyl group, Isoundecyl group, sec-Undecyl group, tert-Undecyl group, Neoundecyl group, Isododecyl group, sec-Dodecyl group, tert-Dodecyl group, Neododecyl group, Isotridecyl group, sec-Tridecyl group, tert -Tridecyl group, neotridecyl group, isotetradecyl group, sec-tetradecyl group, tert-tetradecyl group, neotetradecyl group, isopentadecyl group, sec-pentadecyl group, tert-pentadecyl group, neopentadecyl group, isohexadecyl Group, sec-hexadecyl group, tert-hexadecyl group, neohexadecyl group, isoheptadecyl group, sec-heptadecyl group, tert-heptadecyl group, neoheptadecyl group, isooctadecyl (isostearyl) group, sec-octadecyl group, tert-octadecyl group , Neo-octadecyl group, isononadecyl group, sec-nonadesyl group, tert-nonadesyl group, neononadecil group, isoicocil group, sec-icosyl group, tert-icosyl group, neoicosyl group, isohenicosyl group, sec-henicosyl group, tert-henicosyl group, Neohenicosyl group, isodocosyl group, sec-docosyl group, tert-docosyl group, neodocosyl group, isothricosyl group, sec-tricosyl group, tert-tricosyl group, neotricosyl group, isotetracosyl group, sec-tetracosyl group, tert-tetracosyl group, neotetracosyl group , Isopentacosyl group, sec-pentacosyl group, tert-pentacosyl group, neopentacosyl group, isohexacosyl group, sec-hexacosyl group, tert-hexacosyl group, neohexacosyl group, isohepta Cosyl group, sec-heptacosyl group, tert-heptacosyl group, neoheptacosyl group, isooctacosyl group, sec-octacosyl group, tert-octacosyl group, neooctacosyl group, n-nonacosyl group, isononacosyl group, sec-nonacosyl group, tert-nonacosyl group, Examples thereof include a neononacosyl group, an n-triacontyl group, an isotriacontyl group, a sec-triacontyl group, and a tert-triacontyl group.

The fatty acid (salt) preferably has a branched structure.
As a result, the branched chain of the fatty acid (salt) becomes a steric hindrance and the zinc powders are more sufficiently suppressed from sticking to each other, and the zinc powders can be scaled more efficiently in step B.
As a result, it is considered that scaly zinc powder that sufficiently exhibits both anticorrosion performance and designability can be obtained. Further, it is considered that by using a fatty acid (salt) having a branched chain, scaling of the zinc powder proceeds while the fatty acid (salt) having a branched chain is supported on the surface of the zinc powder. As a result, the approach of the zinc powders that are scaly can be effectively suppressed. Therefore, when the beads are used in the scaling step, the collision energy of the beads is applied to the zinc powders to be fixed to each other or the zinc powders to each other. It is considered that each zinc powder can be effectively used as energy for scaling without wasting it as energy for breaking the adhesion. Therefore, by using a fatty acid (salt) having a branched chain, it becomes possible to produce scaly zinc powder with less energy than before.

A preferable branched structure of a fatty acid (salt) having a branched chain is the following formula (1);

(In the formula, R ¹ , R ² , and R ³ represent a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. However, ^{at least two of R 1} , R ² , and R ³ have 1 to 2 carbon atoms. It is a structure represented by 22 alkyl groups).
The ^{alkyl groups in R 1} , R ² and R ³ may have a linear structure or a branched structure.

Specific examples of the above-mentioned alkyl group include the above-mentioned alkyl group.
In the compound represented by the above formula (1), the carbon number of at least two alkyl groups among ^{R 1} , R ² , and R ^{3 is preferably 1 to 18.} It is more preferably 2 to 16, still more preferably 4 to 14, still more preferably 5 to 12, and particularly preferably 6 to 10.

Specific examples of the branched fatty acid (salt) include isobutyric acid, isovaleric acid (isopentanoic acid), 2-ethylbutyric acid, ethylmethylacetic acid, isocaproic acid (isohexanoic acid), isoenant acid (isoheptanic acid), and isocapric acid. (Isooctanoic acid), isoperalgonic acid (isononanoic acid), isocapric acid (isodecanoic acid), isoundecanoic acid, isolauric acid (isododecanic acid), isotridecic acid (isotridecanoic acid), isomyristic acid (isotetradecanoic acid), isopentadecyl Acids (isopentadecanoic acid), isopalmitic acid (isohexadecanoic acid), isomargaric acid (isoheptadecanoic acid), isostearic acid (isooctadecanoic acid, 2-heptylundecanoic acid), isononadecic acid (isononadecanoic acid), isoaraquinic acid (isoicosanoic acid) ), Isodocosanoic acid, Isohexacosanoic acid, 2-ethylhexanoic acid, 2-propylhexanoic acid, 2-butylhexanoic acid, 2-ethylheptanoic acid, 2-propylheptanic acid, 2-butylheptanic acid, 2-ethyloctanoic acid, 2-propyloctanoic acid, 2-butyloctanoic acid, 2-pentyldecanoic acid, 2-heptyloctanoic acid, 2-hexylnonanoic acid, 2-heptylnonanoic acid, 2-hexyldecanoic acid, 2-hexyldodecanoic acid, 2-octyl Decanoic acid, 2-hexyltridecanoic acid, 2-heptyldodecanoic acid, 2-octylundecanoic acid, 13-methyltetradecanoic acid, 12-methyltetradecanoic acid, 15-methylhexadecanoic acid, 14-methylhexadecanoic acid, 10-methylhexadecane Acids, 18-methyleicosanoic acid, phytanic acid, salts thereof and the like can be mentioned.
Of these, isoenantic acid, isocapric acid, isoperalgonic acid, isocapric acid, isounedecanoic acid, isolauric acid, isotridecylic acid, isomyristic acid, isopentadecylic acid, isopalmitic acid, isomargaric acid, isostearic acid, isononadecic acid, isoaraquin Acids, and salts thereof, more preferably isolauric acid, isotridecylic acid, isomyristic acid, isopentadecylic acid, isoparmitic acid, isomargalic acid, isostearic acid, isononadecic acid, isoaraquinic acid, and particularly preferably isostearic acid. It is an acid.

The amount of the fatty acid (salt) used is not particularly limited, but is preferably 0.01 to 5.0% by mass with respect to 100% by mass of zinc powder. When a fatty acid (salt) having a branched chain is used, the effect as a lubricant can be exhibited with a smaller amount than when a linear fatty acid is used. It is more preferably 0.05 to 3.5% by mass, further preferably 0.1 to 2.8% by mass, and particularly preferably 0.2 to 2.3% by mass.

The zinc powder is not particularly limited, but preferably has an average particle size of 0.1 to 80 μm. It is more preferably 0.5 to 60 μm, and even more preferably 1 to 50 μm.
The average particle size can be measured by the particle size distribution measuring device described in the examples.

The amount of water used in the above step A is preferably 10% by mass or less with respect to 100% by mass of zinc powder. As a result, the scaly zinc powders are sufficiently suppressed from sticking to each other, and scaly zinc powders having better design can be obtained. The amount of water used is more preferably 5% by mass or less, further preferably 1% by mass or less, and most preferably 0% by mass.

In the above step A, it is preferable to prepare a slurry using a solvent other than water.
As the solvent, a commonly used solvent can be used, for example, hydrocarbons such as pentane, hexane, heptane, octane, toluene, xylene, mineral tarpen, mineral spirit, solvent naphtha; methanol, ethanol, isopropanol, 2- Alcohols such as methyl-2-propanol, butanol, hexanol, methoxybutanol, methoxymethylbutanol, capryl alcohol, lauryl alcohol, myristyl alcohol, oleyl alcohol, stearyl alcohol, isopalmityl alcohol, isostearyl alcohol, and these alcohols. Acetate esters, propionic acid esters and other esters, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, hexylene glycol, octylene glycol, neopentyl glycol and other glycols, glycerin Examples thereof include trihydric alcohols such as dipropylene glycol monomethyl ether, glycol ethers such as diethylene glycol methyl ether and ethylene glycol hexyl ether, and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone. Hydrocarbons are preferable, and xylene is more preferable.
The amount of the solvent other than water used is preferably 10 to 600% by mass with respect to 100% by mass of the zinc powder. It is more preferably 50 to 400% by mass, and even more preferably 100 to 250% by mass.

In the above step A, the method for preparing the slurry containing the zinc powder and the dispersant is not particularly limited, but it is preferable to suspend the zinc powder and the dispersant in a solvent.
Further, as the slurry containing zinc powder and the dispersant, the slurry containing zinc powder and the slurry containing the dispersant may be prepared separately and then mixed, or the slurry containing either zinc or the dispersant may be used. , The other may be added to prepare. It is preferably in the form of being prepared separately and then mixed.
When the slurry in the above step A contains a fatty acid (salt), the order and method of adding the fatty acid (salt) to the solvent are not particularly limited, but a form in which zinc powder is added to the solvent to which the fatty acid (salt) is added is preferable.

The slurry obtained in the above step A may contain zinc powder, a dispersant, a fatty acid (salt) and other components other than the solvent.
Examples of other components include other lubricants (grinding aids) other than fatty acids (salts), barium compounds, titanium compounds, and other dispersants other than silica.
The content of other components is preferably 0 to 1.0% by mass with respect to 100% by mass of zinc powder. It is more preferably 0.05 to 0.5% by mass, and further preferably 0.1 to 0.3% by mass.

Examples of the other lubricants include solid paraffin, polyethylene wax, aliphatic amines, aliphatic amides, aliphatic esters, fatty alcohols, graphite, talc, zinc phosphate, talc, mica and the like.
The content of the other lubricant is preferably 0 to 1.0% by mass with respect to 100% by mass of the zinc powder. It is more preferably 0 to 0.5% by mass, further preferably 0 to 0.3% by mass, and most preferably 0% by mass.

2. Process B
Step B is a step of scaling the slurry obtained in step A.
The scale treatment method is not particularly limited and can be carried out by a commonly used method.
For example, a planetary mill, a bead mill, a vibration mill, a medialess crusher, or the like can be used. Among these, the method using a bead mill is preferable.

As the beads used in the bead mill, any of glass beads, alumina beads, zirconia beads, titania beads, silicon nitride beads and the like may be used. Zirconia beads and alumina beads are preferable.
When a bead mill is used, it is preferable to use beads having a diameter of 0.03 to 0.5 mm.
When the bead mill is used, the amount of beads used is not particularly limited, but is 10 to 1000% by mass with respect to 100% by mass of zinc powder used. As a result, the zinc powder and the beads sufficiently collide with each other, and the median diameter (D50) of the obtained zinc powder can be set in a more suitable range. The amount of beads used is more preferably 20 to 950% by mass, still more preferably 30 to 900% by mass.
When a bead mill is used, it is preferable to use a rotating disc, and the rotation speed of the rotating disc is preferably 100 to 10,000 rpm. It is more preferably 200 to 6000 rpm, further preferably 250 to 4000 rpm, and particularly preferably 300 to 3500 rpm.
The peripheral speed of the rotating disc is preferably 4 to 50 m / s. It is more preferably 6 to 40 m / s, further preferably 8 to 30 m / s, and particularly preferably 8 to 20 m / s.

In the above step B, as the zinc powder is scaly, the median diameter of the zinc powder (value of D50 of the particle size distribution) increases and reaches a peak.
The present inventor has found that the obtained scaly zinc powder has a large median diameter (D50) to be more excellent in metallic feeling. That is, it is preferable to perform the scaling treatment in a time of 25% or more and 200% or less when the scaling treatment time at which the median diameter (D50) of the zinc powder is maximized is 100%. More preferably 30-180% of the time, even more preferably 40-160% of the time, even more preferably 50-150% of the time, even more preferably 60-130% of the time, in particular. It is preferably 70 to 120% of the time, and even more preferably 80 to 110% of the time.
The median diameter (D50) of the particle size distribution of scaly zinc powder can be determined by the method described in Examples.

The temperature at which step B is performed is not particularly limited, but can be performed at a temperature of 5 to 60 ° C.

The method for producing scaly zinc powder of the present invention may include other steps other than steps A and B. Examples of other steps include a step of removing the solvent and the like contained in the slurry obtained in steps A and / or B, a step of washing and drying, and the like.

<Use of scaly zinc powder>
The scaly zinc powder-containing composition of the present invention and the scaly zinc powder obtained by the production method of the present invention can be used for cars, ships, roads, railways, ports, buildings, elevated bridges, factory equipment, plants, pipelines, etc. It can be suitably used as an anticorrosive undercoat paint, an anticorrosive topcoat paint, etc. for protecting steel structures such as steel towers from corrosion.

<Paint>
The present invention is also a coating material containing the scaly zinc powder-containing composition of the present invention and a binder (hereinafter, also referred to as a resin). A coating material containing scaly zinc powder and a binder obtained by the production method of the present invention is also one of the present inventions.
The above paint is preferably used for undercoating and anticorrosion applications.
The paint preferably has a scaly zinc powder content of 15 to 95% by mass with respect to 100% by mass of the solid content in the paint. It is more preferably 20 to 95% by mass, further preferably 25 to 95% by mass, and particularly preferably 30 to 95% by mass.
The term "solid content" as used herein means a solid or liquid residue at room temperature excluding volatile components such as solvent and water, that is, a so-called non-volatile content, which is dried at 150 ° C. for 1 hour. The solid content can be calculated by measuring the evaporation residue obtained.

The binder content of the above coating material is preferably 1 to 99% by mass as a solid component with respect to 100% by mass of scaly zinc powder. It is more preferably 3 to 90% by mass, and even more preferably 5 to 80% by mass.

Examples of the binder (resin) include silicates such as sodium silicate, potassium silicate, and lithium silicate; alkaline silicone, silicone, silicone emulsion, water-soluble silicone, acrylic resin, acrylic resin emulsion, epoxy resin emulsion, phenol resin emulsion, and silicone resin. , Alkyl silicate, silane coupling agent, polystyrene resin, rubber chloride, epoxy resin, phenol resin, polyurethane resin, polyester resin, phenol-modified alkyd resin, melamine resin, melamine / alkyd resin, alkyd resin, fluororesin, water-based urethane resin , Aqueous acrylic resin, aqueous acrylic resin emulsion, aqueous melamine resin, aqueous modified epoxy resin, aqueous modified epoxy ester resin and the like.
Of these, melamine / alkyd resin, epoxy resin, polyurethane resin, acrylic resin, polyester resin, alkyd resin, silicone resin, water-based urethane resin, water-based acrylic resin, water-based acrylic resin emulsion, water-based melamine resin, water-based modified epoxy resin, and water-based modification Epoxy ester resin is preferred. More preferably, it is a melamine / alkyd resin, an epoxy resin, a polyurethane resin, an acrylic resin, a silicone resin, an aqueous urethane resin, or an aqueous modified epoxy resin, and even more preferably, an epoxy resin, a polyurethane resin, an aqueous urethane resin, an aqueous modified epoxy resin, or melamine. -Alkyd resin.

The paint may contain scaly zinc powder and other components other than the binder.
The total content of the other components in the coating material is preferably 0 to 5% by mass with respect to 100% by mass of the total of the scaly zinc powder and the resin. It is more preferably 0 to 1% by mass, and further preferably 0 to 0.5% by mass.

Examples of the other components include solvents, pigments, dispersants, wetting agents, leveling agents, thixotropy-imparting agents, thickeners, sagging inhibitors, fungicides, film forming aids, stabilizers and the like.
Examples of the solvent include the above-mentioned solvents.
Pigments include, for example, aluminum powder, magnesium powder, nickel powder, cobalt powder, silicon oxide, titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, zirconium oxide, barium sulfate, barium carbonate, silica, calcium carbonate, talc, mica, etc. Examples thereof include clay, kaolin, bentonite, carbon black, aniline black, gunjo, watching red, cyanine blue, and phthalocyanine green.
Dispersants include cationic surfactants such as octadecylamine acetate, alkyltrimethylammonium chloride, and alkyldimethylbenzylammonium chloride; polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl amide, and polyoxy. Examples thereof include nonionic surfactants such as ethylene fatty acid esters.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" shall mean "mass%".

Various measurements (evaluations) were performed as follows.
<Median diameter (D50)>
The volume-based median diameter (D50) was measured by a laser diffraction / scattering particle size distribution measuring device Microtrac MT-3300 EXII (manufactured by Nikki So Co., Ltd.). Xylene was used as the solvent at the time of measurement, 2.4 was used as the refractive index of the scaly zinc powder, and 1.5 was used as the refractive index of the solvent.

<Measurement of L * value>
The L * value in the CIELAB color system was measured with a spectrocolorimeter (manufactured by Nippon Denshoku Kogyo Co., Ltd., SE 6000).

<Evaluation of 60 ° gloss value of coating film>
The 60 ° gloss of the coating film was measured with a gloss meter VG 7000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.).
10 g of scaly zinc powder obtained for each scaly treatment time in Examples and Comparative Examples described later, 9.47 g of thermosetting alkyd resin J-524-A (solid content concentration 50%, manufactured by DIC Corporation), butylated. 3.80 g of melamine resin J-820 (solid content concentration 75%, manufactured by DIC Corporation) and 2.67 g of xylene are shaken with a paint shaker to prepare a paint, a coating film is prepared with a 6 mil applicator, and 30 minutes at room temperature. After allowing to dry, it was baked at 140 ° C. for 20 minutes, and the gloss of the coating film was measured with a gloss meter VG 7000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.).

<Anti-corrosion (rust-prevention) performance evaluation>
Scale-like zinc powder obtained in Examples described later, or 10 g of a comparative example sample, thermosetting alkyd resin J-524-A (solid content concentration 50%, manufactured by DIC Corporation) 1.18 g, butylated melamine resin. 0.40 g of J-820 (solid content concentration 75%, manufactured by DIC Corporation) and 21.72 g of xylene were shaken with a paint shaker to prepare a paint having a zinc concentration of 92% when dried. Subsequently, the prepared paint was applied to one side of an SPCC-SB steel sheet (0.8 t × 35 × 150 mm) using an airbrush MX2370 for hobby (manufactured by Anest Iwata Co., Ltd.), allowed to stand at room temperature for 30 minutes, and then dried. A coating film was formed on the steel sheet by baking at 140 ° C. for 20 minutes, a cross cut extending from the coating film surface to the steel sheet was made with a cutter blade, and an outdoor exposure test was conducted for 336 hours. The test was started on a rainy day, and after the start of the test, red rust generated from the cross-cut portion was visually observed over time, and qualitative evaluation of ○, Δ, and × was performed. ◯ means that no red rust is generated within 336 hours, Δ means that no red rust is generated within 168 hours, but red rust is generated within 336 hours, and × means that red rust is generated within 168 hours.

<Example 1>
Barium sulfate; 1.05 g (1 wt% to Zn) of Varifine BF-10 (manufactured by Sakai Chemical Industry Co., Ltd.) was repulped to 13.65 g of xylene and dispersed for 10 minutes. Further, 2.11 g (2 wt% to Zn) of stearic acid was added to and dissolved in 122.85 g of xylene, and then 105.3 g of zinc powder # 3 (manufactured by Sakai Chemical Industry Co., Ltd.) was repulped to prepare a slurry. The barium sulfate slurry and the zinc powder slurry were mixed, and the slurry was scaled for 240 minutes at 3000 rpm (peripheral speed 8.6 m / s) using a rotating disk and 567 g of φ0.3 mm zirconia beads. After that, it was filtered and dried to obtain highly white scaly zinc powder. The median diameter (D50) of the obtained scaly zinc powder was 27.2 μm. The median diameter (D50) of the zinc powder became maximum after the scaling treatment for 240 minutes. Further, with respect to the obtained powder of scaly zinc powder having a high whiteness, the L * value in the CIELAB color system was measured with a spectrocolorimeter (manufactured by Nippon Denshoku Kogyo Co., Ltd., SE 6000) and found to be 65.1. there were.
Further, 10 g of the obtained scaly zinc powder, 9.47 g of thermosetting alkyd resin J-524-A (N.V. 50%), and butylated melamine resin J-820 (N.V. 75%) 4. 80 g and 2.67 g of xylene were shaken with a paint shaker for 10 minutes to form a paint, and a coating film was prepared with a 6 mil applicator and baked at 140 ° C. for 30 minutes to form a coating film. For the coating film having a powder / binder weight ratio of 0.6 in the obtained coating film, the L * value of the coating film in the CIELAB color system was measured with a spectral color difference meter and found to be 57.4. .. The 60 ° gloss value of the coating film was 83.3.

<Example 2>
The scaly zinc powder was prepared by the same procedure as in Example 1 except that the conditions shown in Table 1 were changed. Titanium oxide; SA-1 (manufactured by Sakai Chemical Industry Co., Ltd.) was used as the titanium compound. The median diameter (D50) of the obtained scaly zinc powder was 26.6 μm.

<Example 3>
The scaly zinc powder was prepared by the same procedure as in Example 1 except that the conditions shown in Table 1 were changed. As the barium compound, barium stearate; SB (manufactured by Sakai Chemical Industry Co., Ltd.) was used. The median diameter (D50) of the obtained scaly zinc powder was 27.3 μm.

<Example 4>
The scaly zinc powder was prepared by the same procedure as in Example 1 except that the conditions shown in Table 1 were changed. As the barium compound, barium sulfate; Varifine BF-21 (manufactured by Sakai Chemical Industry Co., Ltd.) was used. The median diameter (D50) of the obtained scaly zinc powder was 27.2 μm.

<Example 5>
The scaly zinc powder was prepared by the same procedure as in Example 1 except that the conditions shown in Table 1 were changed. As the barium compound, barium stearate; SB (manufactured by Sakai Chemical Industry Co., Ltd.) was used. The median diameter (D50) of the obtained scaly zinc powder was 25.6 μm.

<Example 6>
The scaly zinc powder was prepared by the same procedure as in Example 1 except that the conditions shown in Table 1 were changed. Hydrophobic fumed silica AEROSIL R 972 (manufactured by Aerosil Japan) was used as the silica. The median diameter (D50) of the obtained scaly zinc powder was 26.0 μm.

<Comparative example 1>
In Example 1, scaly zinc powder was prepared without adding a barium compound, and 1.0% of barium sulfate; Varifine BF-10 (manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained scaly zinc powder. A simple mixture of scaly zinc powder and barium sulfate was prepared.

<Comparative example 2>
In Example 2, scaly zinc powder was prepared without adding a titanium compound, and 0.1% of titanium oxide; SA-1 (manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained scaly zinc powder to form scaly zinc powder. A simple mixture of zinc powder and titanium oxide was prepared.

<Comparative example 3>
In Example 3, scaly zinc powder was prepared without adding a barium compound, and 0.1% of barium stearate; SB (manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained scaly zinc powder to add scaly zinc. A simple mixture of powder and barium stearate was prepared.

<Comparative example 4>
In Example 4, scaly zinc powder was prepared without adding a barium compound, and 0.1% of barium sulfate; Varifine BF-21 (manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained scaly zinc powder. A simple mixture of scaly zinc powder and barium sulfate was prepared.

<Comparative example 5>
In Example 5, scaly zinc powder was prepared without adding a barium compound, and 3.0% of barium stearate; SB (manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained scaly zinc powder to add scaly zinc. A simple mixture of powder and barium stearate was prepared.

<Comparative Example 6>
In Example 7, scaly zinc powder was prepared without adding silica, and 0.1% of hydrophobic fumed silica AEROSIL R 972 (manufactured by Aerosil Japan) was added to the obtained scaly zinc powder to add scales. A simple mixture of zinc powder and silica was prepared.

From the results in Table 1, by adding a dispersant to the zinc powder to make it scaly, the L * value in the CIELAB color system becomes higher than when the scaly zinc powder and the dispersant are simply mixed, that is, It was confirmed that the whiteness was high. In the coating film, by adding barium sulfate and stearic acid to the zinc powder to make it scaly, the L * value in the CIELAB color system becomes higher than when the zinc powder and the dispersant are simply mixed, that is, It was confirmed that the whiteness was high, and that the 60 ° gloss value of the coating film was also high. Regarding the 60 ° gloss value of the coating film, it is considered that the 60 ° gloss value was increased because the dispersibility of the scaly zinc powder in the coating film and the coating film was increased and the surface of the coating film was arranged more smoothly.

By adding a dispersant to the zinc powder and scaling it by media treatment, the dispersant enters between the scaly zinc powders during the formation of scaly zinc powders, and as a spacer that suppresses aggregation and adhesion between the scaly zinc powders. By playing the role of, the L * value is improved by increasing the light reflection area of the scaly zinc powder.
On the other hand, when the scaly zinc powder and the dispersant are simply mixed (comparative example), the dispersant only adheres to the surface of the scaly zinc powder once aggregated or fixed, so that the L * value is improved. Is considered to be rarely seen.

Claims (13)

A composition containing scaly zinc powder and a dispersant.
The dispersant contains at least one selected from the group consisting of barium compounds, titanium compounds and silica.
The L * value of the composition in the CIELAB color system measured by a spectrocolorimeter is higher than the L * value of a simple mixture of scaly zinc powder having the same compounding ratio as the composition and the dispersant. A characteristic scaly zinc powder-containing composition. The scaly zinc powder-containing composition according to claim 1, wherein the content of the dispersant is 0.001% by mass or more and less than 10% by mass with respect to 100% by mass of the scaly zinc powder. The scaly zinc powder-containing composition according to claim 1 or 2, wherein the L * value in the CIELAB color system obtained by measuring the scaly zinc powder-containing composition with a spectrocolorimeter is 60 or more. Using the scaly zinc powder-containing composition, a coating film formed so that the mass ratio of scaly zinc powder to the binder (scaly zinc powder / binder) was 1.2 was measured with a spectrocolorimeter. The scaly zinc powder-containing composition according to any one of claims 1 to 3, wherein the L * value in the CIELAB color system at the time is 50 or more. Using the scaly zinc powder-containing composition, a coating film formed so that the mass ratio of scaly zinc powder to the binder (scaly zinc powder / binder) was 1.2 was measured with a spectrocolorimeter. Using a simple mixture of scaly zinc powder and dispersant having the same L * value in the CIELAB color system as the composition, the mass ratio of scaly zinc powder to the binder (scaly zinc powder / The scaly zinc powder-containing composition according to any one of claims 1 to 4, wherein the coating film formed so that the binder) is 1.2 is higher than the L * value. The 60 ° gloss value of the coating film formed by using the scaly zinc powder-containing composition so that the mass ratio of the scaly zinc powder to the binder (scaly zinc powder / binder) is 1.2 is the said. Using a simple mixture of scaly zinc powder and a dispersant having the same compounding ratio as the composition, the mass ratio of scaly zinc powder to the binder (scaly zinc powder / binder) was formed to be 1.2. The scaly zinc powder-containing composition according to any one of claims 1 to 5, wherein the gloss value is higher than the 60 ° gloss value of the coating film. Step A to obtain a slurry containing zinc powder and a dispersant,
Including step B in which the slurry obtained in step A is scaled.
A method for producing scaly zinc powder, wherein the dispersant contains at least one selected from the group consisting of a barium compound, a titanium compound and silica. The method for producing scaly zinc powder according to claim 7, wherein the amount of the dispersant used is 0.001% by mass or more and less than 10% by mass with respect to 100% by mass of the zinc powder. The method for producing scaly zinc powder according to claim 7 or 8, wherein the slurry in the step A further contains at least one selected from the group consisting of fatty acids and salts thereof. The step B is characterized in that the media processing is performed in a time of 200% or less when the media processing time at which the median diameter (D50) of the obtained zinc powder is maximized is 100%. The method for producing scaly zinc powder according to any one. A coating material comprising the scaly zinc powder-containing composition according to claims 1 to 6 and a binder. The coating material according to claim 11, wherein the content of the scaly zinc powder is 5 to 95% by mass with respect to 100% by mass of the solid content in the coating material. The paint according to claim 11 or 12, wherein the paint is used for anticorrosion applications.