KR100696923B1 - Aluminum pigment, process for production thereof and resin composition - Google Patents

Abstract

It provides an aluminum pigment that is excellent in dispersibility and stability and does not generate or agglomerate hydrogen gas during storage. This pigment is a film formed of an aluminum particle, a molybdenum film containing molybdenum oxide and / or molybdenum hydrate covering the surface of the aluminum particle, and a silica film containing amorphous silica covering the molybdenum film and / or a silane coupling agent. It consists of particles having a. Content of molybdenum and content of silicon are in the range of 0.01-5 mass parts with respect to 100 mass parts of aluminum particles, It is preferable that it is 1-20 mass parts.

Description

Aluminum pigment, its manufacturing method, and resin composition {ALUMINUM PIGMENT, PROCESS FOR PRODUCTION THEREOF AND RESIN COMPOSITION}

The present invention relates to an aluminum pigment. More specifically, the present invention relates to an aluminum pigment which is preferably used for an aqueous paint or an aqueous ink, a method for producing the same, and a resin composition containing the same.

Recently, metal paints and metal inks have been used in various fields such as automobile exteriors, electric devices, buildings, stationery, office equipment, communication devices, cosmetics, etc. because of their excellent design.

The coating film formed by the metal coating material reflects the external incident light by the flaky metal pigment contained in the coating film, thereby exhibiting a brilliant design. The reflection of light shows a unique appearance excellent in designability according to each color tone of the coating film.

Since aluminum is easy to handle because of its excellent metallic luster, inexpensiveness, and low specific gravity, metal pigments mainly containing aluminum flakes (hereinafter simply referred to as "aluminum pigments") are generally used for automotive paint finishes and plastics. It is used for the coating finish, the ink for printing, or the metallic design for resin moldings.

On the other hand, in the field of coatings, the use of water-based paints containing no organic solvent is increasing as a resource saving and pollution-free countermeasure. Accordingly, the demand for aluminum pigments having excellent water dispersibility that can be suitably blended into aqueous paints is also expanding.

In order to satisfy these demands, the aluminum flakes are treated with saturated or unsaturated fatty acids such as stearic acid or oleic acid and derivatives thereof, and aluminum pigments having a water-dispersing property by adding a surfactant to them are used as aqueous coatings. It is generally provided as.

However, this water-dispersible aluminum pigment has a problem of low storage stability and weather resistance after coating when blended in an aqueous paint. That is, the water-based paints in which the water-dispersible aluminum pigment is blended have reduced dispersibility of the aluminum pigment during storage, causing seeding, which significantly reduces the properties of the paint, or reacts with the aluminum pigment and water in a large amount. Hydrogen gas is generated to cause a problem such as explosion of the container. If the water-based paint is applied to a part exposed to the harsh environment such as an exterior of an automobile or a building, there is also a problem that the designability is reduced after the painting.

In general, aluminum having a natural oxide protective layer on its surface is stable in an atmosphere containing oxygen and exhibits excellent corrosion resistance to electrolytes contained in neutral water. However, the native oxide protective layer of aluminum may dissolve without showing sufficient corrosion resistance to acidic or alkaline aqueous solutions. In particular, in recent years, metal paints containing aluminum pigments are frequently exposed to environments with harsh acidic conditions due to acid rain and the like, and it is difficult to sufficiently protect the aluminum pigments from corrosion with only the natural oxide protective layer.

In order to solve such a problem, many techniques have been developed, but as a relatively practical recent known technique, Japanese Patent Application Laid-open No. Hei 1-54386, Japanese Patent Application Laid-open No. 59-74201, Japanese Patent Application Laid-open No. 55- 158202, Japanese Patent Application Laid-open No. Hei 4-318181, US Patent No. 5,296,032, Japanese Patent Application Laid-open No. Hei 6-57171, and the like.

For example, Japanese Patent Application Laid-open No. Hei 1-54386 discloses a method of treating an aluminum pigment with chromic acid. According to this method, the chemical stability of the aluminum pigment is improved, but the reactivity of the treatment liquid is too strong, the fine aluminum pigment cannot be treated, and a hexavalent chromium compound is used, which causes labor hygiene or environmental problems.

Japanese Laid-Open Patent Publication No. 59-74201 discloses a method of treating an aluminum pigment with ammonium vanadate. This treatment has not been put to practical use because of the large change in color tone of the aluminum pigment caused by the treatment.

Japanese Laid-Open Patent Publication No. 55-158202 also discloses a method of coating an aluminum pigment with an acidic phosphate ester. The color tone and chemical stability are good according to this method, but in the case of forming a two coat 1-bak or two coat 2 bake coating, the treatment agent has an undesirable effect on the adhesion between the aluminum pigment and the resin. Delamination between the base metal coating layer and the top coat layer is a major problem.

Japanese Laid-Open Patent Publication No. 4-318181 discloses a method of treating an aluminum pigment with a treatment liquid containing an oxidizing agent such as molybdate, an phosphate anion, an alkaline earth metal ion, and the like. Although an aluminum pigment having excellent chemical stability can be formed by this method, phosphate anions or alkaline earth metal ions contained in the treatment liquid tend to lower the physical properties of the coating film such as moisture resistance.

US Pat. No. 5,296,032 discloses a process for treating aluminum pigments with heteropoly anions such as inmolybdic acid, but sufficient chemical stability of aluminum pigments cannot be obtained through such treatments.

In addition, Japanese Laid-Open Patent Publication No. Hei 6-57171 discloses a method of further stabilizing an aluminum pigment by treating the aluminum pigment with ammonium molybdate and then adding molybdate or the like. According to this method, it is possible to obtain an aluminum pigment excellent in chemical stability, and there is no problem with regard to the coating film properties, but there is a problem that the manufacturing process is complicated.

U.S. Patent No. 2,885,366 discloses a method of coating an amorphous silica layer on various core materials, and also describes an embodiment using aluminum powder as the core material. However, this silica coating is carried out in a highly alkaline aqueous solution, and aluminum powder may react during the treatment process to generate a large amount of hydrogen gas, which is very dangerous. Moreover, this patent also discloses the method of supplying the intermediate | middle layer of the basic salt of aluminum and chromium on a core material in order to coat efficiently like an amorphous silica layer, but it is difficult to coat | cover an aluminum pigment uniformly.

Japanese Laid-Open Patent Publication No. 7-3185 discloses a method of coating an siloxane on the surface of an aluminum pigment and coating a synthetic resin to produce an aluminum pigment having excellent corrosion resistance, but having a siloxane coat coated with a synthetic resin. There is a problem that the thickness of the aluminum pigment is increased, thereby decreasing the appearance / gloss due to the protrusion from the coating film or reducing the opacity.

As mentioned above, although it is excellent to provide the aluminum pigment which is excellent in dispersibility and stability, and is excellent in the designability of a coating-film appearance, without generating or aggregating hydrogen gas during storage, well-known technique fully satisfy | fills this request. It is not possible to provide a satisfying aluminum pigment.

Therefore, on the basis of the above situation, the object of the present invention is excellent in dispersibility and stability, and is preferably used for an aqueous paint or an aqueous ink, which is excellent in designability of the appearance of the coating film without generating or aggregating hydrogen gas during storage. It is to provide an aluminum pigment that can be blended.

It is another object of the present invention to provide an aluminum pigment which is excellent in dispersibility and stability, and which can be suitably blended into an aqueous paint or an aqueous ink, which is excellent in designability of a coating film appearance without generating or aggregating hydrogen gas during storage. It is to provide a manufacturing method.

Another object of the present invention is to provide a resin composition which is excellent in dispersibility and stability, and which can be suitably used as an aqueous paint or an aqueous ink, which does not generate or agglomerate hydrogen gas during storage, and is excellent in designability of a coating film appearance. It's there.

Further, another object of the present invention is to provide an aqueous coating and an aqueous ink which are excellent in dispersibility and stability and excellent in designability of the appearance of the coating film without generating or aggregating hydrogen gas during storage.

MEANS TO SOLVE THE PROBLEM In order to achieve the said objective, the present inventors have the property that the surface of each aluminum particle is poor in reactivity with aqueous solution, and does not impair designability of a coating film, and prevents generation | occurrence | production of hydrogen gas etc. during storage. It was thought that it could be coated with a coating having a coating, and experiments covering the surface of aluminum particles with coatings having various compositions were carried out for further study.

As a result of these studies, the inventors found that the surface of each aluminum particle was covered with a molybdenum film containing molybdenum oxide and / or molybdenum hydrate, and the surface of the molybdenum film was coated with a silica film and / or a silane coupling agent containing amorphous silica. It has been found that it can be coated with a coating obtained from Furthermore, the present inventors found that when the film obtained from the silica film and the silane coupling agent is formed together, sufficient effects are obtained without forming a molybdenum film on the surface of each aluminum particle.

In addition, the present inventors have further studied what manufacturing method is preferably used to coat the surface of each aluminum particle with a film formed of molybdenum film, silica film or silane coupling agent. As a result of these studies, the inventors found that the aluminum pigment can be effectively produced using a specific manufacturing method, thus completing the present invention.

The aluminum pigment according to the present invention is an aluminum film, a molybdenum film containing molybdenum oxide and / or molybdenum hydrate covering the surface of each aluminum particle, and a silica film and / or silane comprising amorphous silica further covering the molybdenum film. It has a film formed from a coupling agent.

Another aluminum pigment according to the present invention has a film formed of aluminum particles, a silica film containing amorphous silica covering the surface of each aluminum particle, and a silane coupling agent further covering the silica film.

If the aluminum pigment according to the present invention has a molybdenum film, the content of molybdenum is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of aluminum particles, and the content of silicon is 1 to 20 mass, regardless of the presence or absence of the molybdenum film. It is desirable to disclaim.

The silane coupling agent used in the present invention is preferably one or more selected from compounds having the structure:

R _A -Si (OR _B ) ₃ or R _A -SiR _B (OR _B ) ₂

R _A : C2-C18 alkyl or aryl or alkenyl group

R _B : an alkyl group having 1 to 3 carbon atoms

In the method for producing an aluminum pigment according to the present invention, by stirring a dispersion solution containing aluminum particles and molybdenum compounds, to form a molybdenum film containing any one or both of molybdenum oxide and molybdenum hydrate on the surface of each aluminum particle And pH of the dispersion solution containing each aluminum particle having an molybdenum coating, an organosilicon compound and / or a silane coupling agent, and a hydrolysis catalyst, hydrolyzing the organosilicon compound and / or the silane coupling agent, and each aluminum particle And forming a film formed of a silica film containing amorphous silica and / or a silane coupling agent on the surface of the molybdenum film of.

In another method for producing an aluminum pigment according to the present invention, a dispersion solution containing aluminum particles and a molybdenum compound is stirred to form a molybdenum film containing any one or both of molybdenum oxide and molybdenum hydrate on the surface of each aluminum particle. And adjusting the pH of each aluminum particle having a molybdenum film, an organic silicon compound, and a dispersion solution containing a hydrolysis catalyst to hydrolyze the organosilicon compound to include amorphous silica on the surface of the molybdenum film of each aluminum particle. Forming a silica film, and adjusting the pH of each of the aluminum particles having the silica film, the dispersion solution containing the silane coupling agent and the hydrolysis catalyst, and hydrolyzing the silane coupling agent to obtain the silica film of each aluminum particle. To form a film formed of a silane coupling agent on the surface It includes the system.

Another method for producing an aluminum pigment according to the present invention is to adjust the pH of a dispersion solution containing aluminum particles, an organosilicon compound, a silane coupling agent and a hydrolysis catalyst to hydrolyze the organosilicon compound and the silane coupling agent, Forming a film formed of a silica film containing amorphous silica and a silane coupling agent on the surface of each aluminum particle.

Alternatively, another method for producing an aluminum pigment according to the present invention is to adjust the pH of a dispersion solution containing aluminum particles, an organosilicon compound, and a hydrolysis catalyst, hydrolyze the organosilicon compound, and surface of each aluminum particle. Forming a silica film containing amorphous silica in the < RTI ID = 0.0 > and < / RTI > and adjusting the pH of the dispersion solution containing each aluminum particle having a silica film, a silane coupling agent and a hydrolysis catalyst to hydrolyze the silane coupling agent, thereby producing each aluminum Forming a film formed of a silane coupling agent on the surface of the silica film of particles.

In forming a molybdenum film on the surface of each aluminum particle, it is preferable to use 1 type, or 2 or more types chosen from the group which consists of polymolybdate peroxide, ammonium molybdate, and phosphorus molybdate as a molybdenum compound.

In the above step of forming the silica film, it is preferable to use tetraethoxysilane and / or tetramethoxysilane as the organosilicon compound.

In the above step of forming a film formed of a silica film and / or a silane coupling agent, it is recommended to use a basic catalyst as the hydrolysis catalyst and to adjust the pH to a range of 7.0 to 11.0.

In the above step of forming a film formed of a silica film and / or a silane coupling agent, as the hydrolysis catalyst, one selected from the group consisting of triethanolamine, ammonia, ethylenediamine, and 3-aminopropyl triethoxysilane, or It is preferable to use 2 or more types.

In the above step of forming a film formed of a silica film and / or a silane coupling agent, an acidic catalyst is used as the hydrolysis catalyst, and the pH may be adjusted in the range of 1.5 to 4.0.

In the above step of forming a film formed of a silica film and / or a silane coupling agent, it is preferable to perform a hydrolysis reaction at a temperature of 20 to 90 ° C. for 1 to 48 hours.

In addition, the present invention includes a resin composition containing the aluminum pigment and the resin according to the present invention. It is preferable that the resin composition of this invention contains 0.1-30 mass% of the aluminum pigment which concerns on this invention.

The aluminum pigment according to the present invention is preferably used in combination with an aqueous paint together with a binder and a hydrophilic solvent. In addition, the aluminum pigment which concerns on this invention is mix | blended with an aqueous ink together with a binder and a hydrophilic solvent, and is used preferably.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the manufacturing method of the aluminum pigment which concerns on this invention.

2 is a view showing an example of another method for producing an aluminum pigment according to the present invention.

3 is a view showing an example of another method for producing an aluminum pigment according to the present invention.

4 is a view showing an example of another method for producing an aluminum pigment according to the present invention.

The invention is now described in more detail with reference to examples.

<Description of the Aluminum Pigment According to the Present Invention>

An aluminum pigment according to the present invention is a film containing aluminum particles, a molybdenum oxide and / or molybdenum hydrate covering the surface of each aluminum particle (referred to herein as "molybdenum coating"), and an amorphous coating the molybdenum coating A film formed of a silica film (referred to herein as " silica film ") and / or a silane coupling agent.

Another aluminum pigment of this invention has the film formed from the aluminum particle, the silica film containing amorphous silica which coat | covers the surface of each aluminum particle, and the silane coupling agent which further coats this silica film.

<Description of aluminum particle>

The aluminum pigments according to the invention are based on aluminum particles.

The aluminum particles used in the present invention may be composed of only aluminum, or may be composed of an aluminum-based alloy, and the purity thereof is not particularly limited.

The shape of the aluminum particles, which can be selected from various shapes such as granular, plate, mass, flake (scale scale) and the like used in the present invention, provides a coating film having excellent metallic feel and brightness. For this reason, it is preferable that it is flaky.

Although the average particle diameter of the aluminum particle used for this invention is not specifically limited, It is preferable that it is 2 micrometers or more, More preferably, it is 5 micrometers or more. It is preferable that this average particle diameter is 40 micrometers or less, and it is more preferable if it is especially 30 micrometers or less. If the average particle diameter is smaller than 2 µm, handling in the manufacturing step is difficult, the particles tend to aggregate easily, and if the average particle diameter exceeds 40 µm, the coating film surface becomes rough when aluminum pigment is used as a coating material, which is preferable. Can not be realized.

In addition, the aluminum particles used in the present invention preferably have a shape coefficient (in the present specification, an "aspect ratio") obtained by dividing the average particle diameter by the average thickness, of 5 or more, more preferably 15 or more. It is preferable that this aspect ratio is 1,000 or less, and it is more preferable especially if it is 500 or less. If the aspect ratio is less than 5, the luminance tends to be insufficient, and if the aspect ratio exceeds 1,000, the mechanical strength of the flakes may decrease and the color tone may become unstable.

The average particle diameter of the aluminum particles used in the present invention is determined from particle size distribution measured by known particle size distribution measurement methods such as laser diffraction method, micromesh sheaving method and Coulter counter method. Obtained by calculating the volume average. The average thickness is calculated from the hiding power and density of the metal flake pigments.

Grinding aids may be attached to the surface of the aluminum particles used in the present invention. Unsaturated fatty acids are usually used as grinding aids. For example, examples of the unsaturated fatty acid used herein include oleic acid, linoleic acid, linoleic acid, ricinolic acid, elideic acid, jumarin acid, gadoleic acid or erucic acid.

<Description of Molybdenum Film>

One of the aluminum pigments according to the present invention has a molybdenum film covering the surface of each aluminum particle.

The molybdenum film is a film containing molybdenum oxide and / or molybdenum hydrate, and molybdenum oxide specifically refers to MoO ₃ , Mo ₂ O _3, etc., and molybdenum hydrate specifically refers to MoO ₃ · H ₂ O, MoO ₃ · H Assume that ₂ O ₂ H ₂ O and the like are shown.

When a molybdenum film is formed on the surface of each aluminum particle used in the present invention, this film serves as a nucleus of precipitation and facilitates the formation of a silica film that further covers the surface of the molybdenum film. In addition, since the molybdenum film has a constant corrosion resistance, the aluminum pigment having a molybdenum film improves the corrosion resistance. In addition, the molybdenum film is an abnormality between the treatment solution (solution containing water and strong in alkali or acid) and the respective aluminum particles coated with the molybdenum film during the formation of the film formed of the silica film and / or the silane coupling agent. It also has the effect of preventing the reaction.

It is preferable that it is 0.01 mass part or more with respect to 100 mass parts of aluminum particles, and, as for the quantity of Mo contained in the molybdenum film formed on the surface of each aluminum particle used for this invention, it is more preferable that it is 0.05 mass part or more. Moreover, it is preferable that it is 5.0 mass parts or less, and, as for the quantity of this Mo, it is more preferable that it is 2.0 mass parts or less. The amount of this Mo is preferably changed according to the specific surface area of the aluminum particles to be treated. For aluminum particles having a large or small specific surface area, it is desirable to increase or decrease the amount of Mo.

If the amount of Mo is less than 0.01 part by mass, the chemical stability tends to be lowered. When the amount of Mo exceeds 5.0 parts by mass, the color tone (metal gloss) of the aluminum pigment is significantly reduced, and the aluminum pigment aggregates or Problems such as deterioration of the coating film properties may occur.

The molybdenum film is not only a film composed of molybdenum oxide and / or molybdenum hydrate, but may also contain other additives or impurities within a range that does not impair the characteristics of the present invention.

<Explanation of the silica film>

The silica coating imparted to the aluminum pigment according to the present invention may be further coated on the surface of the molybdenum coating, or may be directly coated on the aluminum surface along the coating formed of the silane coupling agent.

The silica film is a film containing amorphous silica, and it is assumed that the amorphous silica specifically represents siloxane [H ₃ SiO (H ₂ SiO) _n SiH ₃ ], SiO ₂ , SiO ₂ · nH ₂ O, or the like. In the above, it is assumed that n represents any positive integer.

The aluminum pigment according to the present invention having a silica coating covering the surface of the molybdenum coating of each aluminum particle has better corrosion resistance than the case having only a molybdenum coating.

Since amorphous silica has a hydrophilic surface, the aluminum pigment according to the present invention having a silica coating can thereby be easily dispersed in each of an aqueous paint or an aqueous ink. In addition, since amorphous silica is very stable in aqueous solution, the aluminum pigment according to the present invention having a silica coating is thereby very stable in aqueous solution.

Other corrosion inhibitors may be added to the silica coating of the aluminum pigment according to the invention in order to further improve the corrosion resistance of the aluminum pigment. Corrosion inhibitors to be added are not particularly limited, but known corrosion inhibitors may be used in amounts that do not impair the effects of the present invention, and include acidic phosphate esters, diamer acid, organophosphorus compounds, molybdenum Acid metal salts; and the like.

The above-mentioned silica film does not need to be a film consisting only of amorphous silica, and may contain other additives or impurities within a range not impairing the characteristics of the present invention.

<Description of the film formed from a silane coupling agent>

The aluminum pigment according to the present invention may be provided with a molybdenum film or a film formed of a silane coupling agent on a silica film, so that the reactivity with water can be further suppressed, and at the same time, coating properties such as adhesion, moisture resistance and weather resistance Various effects, such as improvement, the improvement of dispersibility in paint, the improvement of the orientation of an aluminum pigment, etc. can be anticipated.

However, although the dispersibility in water can be reduced depending on the type of silane coupling agent used, this can be improved by using a suitable surfactant. The film obtained from a silane coupling agent is obtained by hydrolyzing the following silane coupling agent and reacting with the hydroxyl group in the silica film on each aluminum particle surface.

For example, methyl triethoxysilane, methyl trimethoxysilane, dimethyl dimethoxysilane, trimethyl methoxysilane, dimethyl diethoxysilane, trimethyl ethoxysilane, 3-aminopropyl-trimethoxysilane, n-methyl-3- Aminopropyl-trimethoxysilane, 3-aminopropyl-triethoxysilane, 3-aminopropyl-tris (2-methoxy-epoxy-silane), n-aminoethyl-3-aminopropyl trimethoxysilane, n -Aminoethyl-3-aminopropyl-methyl-dimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-methyl-dimethoxysilane, 3-acryloxypropyl-trimethoxysilane , 3-glycidyloxypropyl-trimethoxysilane, 3-glycidyloxypropyl-methyl-dimethoxysilane, 3-mercaptopropyl-trimethoxysilane, 3-mercaptopropyl-triethoxysilane, 3-mercaptopropyl-methyldimethoxysilane, vinyl trichlorosilane, vinyl trimethoxysilane, Neyl triethoxysilane, vinyl-tris (2-methoxyethoxy) silane, vinyl triacetoxysilane, 3- (3,4-epoxycyclohexyl ethyltrimethoxy) silane, γ-aminopropyl triethoxysilane , N-β- (aminoethyl) -γ-aminopropyl trimethoxysilane, 3-ureidopropyl triethoxysilane, 3-chloropropyl trimethoxysilane, 3-aniridopropyl triethoxysilane, 3- (4,5-dihydroimidazolepropyl triethoxy) silane, n-phenyl-3-aminopropyl trimethoxysilane, heptadecafluorodecyl trimethoxysilane, tridecafluorooctyl trimethoxysilane, tri Fluoropropyl trimethoxysilane, 3-isocyanatepropyl triethoxysilane, p-styryl trimethoxysilane, and the like.

As particularly preferred silane coupling agents the following compounds are used:

R _A -Si (OR _B ) ₃ or R _A -SiR _B (OR _B ) ₂

R _A : C2-C18 alkyl or aryl or alkenyl group

R _B : an alkyl group having 1 to 3 carbon atoms

More specifically, the following compounds are illustrated:

For example, n-propyl trimethoxysilane, isobutyl trimethoxysilane, octyl triethoxysilane, decyl trimethoxysilane, octadecyl triethoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane, diphenyl Diethoxysilane etc. are mentioned.

It is preferable that the total amount of silicon contained in the silica film provided by this invention and the film formed from a silane coupling agent is 1 mass part or more with respect to 100 mass parts of aluminum particles, and it is more preferable that it is 2 mass parts or more. It is preferable that it is 20 mass parts or less, and, as for content of this silicon, it is more preferable that it is 15 mass parts or less.

If the content of this silicon is less than 1 part by mass, corrosion resistance, water dispersibility, stability, etc. tend to decrease, and if the content of this silicon exceeds 20 parts by mass, the aluminum pigment aggregates, the concealability is reduced, or Problems in which color tone, such as metallic glossiness, is damaged may occur.

<Description of Method for Manufacturing Aluminum Pigment According to the Present Invention>

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the manufacturing method of the aluminum pigment which concerns on this invention.

In the method for producing an aluminum pigment according to the present invention, a step of forming a molybdenum film containing molybdenum oxide and / or molybdenum hydrate on the surface of each aluminum particle by stirring a dispersion solution containing aluminum particles and a molybdenum compound (S101) ) And the pH of the dispersion solution containing each aluminum particle having an molybdenum film, an organosilicon compound and / or a silane coupling agent, and a hydrolysis catalyst is adjusted to hydrolyze the organosilicon compound and / or the silane coupling agent to form amorphous silica. Forming a film formed of a silica film and / or a silane coupling agent comprising a on the surface of the molybdenum film of each aluminum particle (S103).

2 is a view showing an example of another method for producing an aluminum pigment according to the present invention.

Method for producing an aluminum pigment according to the present invention, by stirring a dispersion solution containing aluminum particles and molybdenum compound, to form a molybdenum film containing molybdenum oxide and / or molybdenum hydrate on the surface of each aluminum particle (S201) And the pH of each of the aluminum particles having the molybdenum film, the dispersion solution containing the organosilicon compound and the hydrolysis catalyst, and hydrolyzing the organosilicon compound to form a silica film containing amorphous silica. Forming on the surface of (S203) and adjusting the pH of the dispersion solution containing each aluminum particle having a silica film, a silane coupling agent and a hydrolysis catalyst, hydrolyzing the silane coupling agent, the silica of each aluminum particle Forming a film formed of a silane coupling agent on the surface of the film (S205) It should.

3 is a view showing an example of another method for producing an aluminum pigment according to the present invention.

In the method for producing an aluminum pigment according to the present invention, the pH of a dispersion solution containing aluminum particles, an organosilicon compound, a silane coupling agent, and a hydrolysis catalyst is adjusted to hydrolyze the organosilicon compound and the silane coupling agent to form amorphous silica. Forming a film formed of a silica film and a silane coupling agent comprising a on the surface of each aluminum particle (S301).

4 is a view showing an example of another method for producing an aluminum pigment according to the present invention.

Alternatively, in the method for producing an aluminum pigment according to the present invention, the pH of a dispersion solution containing aluminum particles, an organosilicon compound, and a hydrolysis catalyst is adjusted to hydrolyze the organosilicon compound to form a silica coating containing amorphous silica. Forming on the surface of each aluminum particle (S401), pH of the dispersion solution containing each aluminum particle which has a silica film, a silane coupling agent, and a hydrolysis catalyst is adjusted, and a silane coupling agent is hydrolyzed, and each aluminum Forming a film formed of a silane coupling agent on the surface of the silica film of particles (S403).

<Method of coating aluminum particles with molybdenum film>

One method for producing an aluminum pigment according to the present invention has a step of forming a molybdenum film on the surface of each aluminum particle by stirring a dispersion solution containing aluminum particles and a molybdenum compound.

The method of forming a molybdenum film on the surface of each aluminum particle is not specifically limited, What is necessary is just to disperse | distribute the dispersion solution containing aluminum particle and a molybdenum compound uniformly according to this method. More specifically, a method of stirring and kneading a dispersion solution containing aluminum particles and a molybdenum compound in a slurry state or a paste state to form a molybdenum film on the surface of each aluminum particle is mentioned.

The stirrer used in the step of stirring the dispersion solution containing the aluminum particles and the molybdenum compound is not particularly limited, but a known stirrer capable of efficiently and uniformly stirring the dispersion solution containing the aluminum particles and the molybdenum compound may be used. have.

In more detail, a kneader, a kneader, a rotary vessel stirrer, a stirred reactor, a V-stirrer, a double cone stirrer, a screw mixer, a sigma mixer, a flash mixer, an airflow stirrer, a ball mill, an edge runner, etc. are mentioned. .

Although the molybdenum compound used for this invention is not specifically limited, A well-known molybdenum compound which can form a molybdenum film when it is added to the dispersion solution containing aluminum particle and stirred can be used, As a specific example, polymolybdate peroxide , Ammonium molybdate, phosphomolybdic acid and the like. The molybdenum compounds may be used alone, or these molybdenum compounds may be mixed with each other.

Polymolybdate peroxide is generally a compound represented by the following composition formula (1), and can be easily prepared by dissolving a metal molybdenum powder, molybdenum oxide, or the like in a 5 to 40% hydrogen peroxide solution.

_{Mo x O y · mH 2 O} 2 · nH 2 0 ··· (1)

(However, in the composition formula (1), x is 1 or 2; y is an integer of 2 to 5, m, n represents any positive integer.)

Hydrophilic solvents are preferably used as the solvent for the dispersion solution containing the aluminum particles and the molybdenum compound. More specifically, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, t-butyl alcohol, n-butyl alcohol, isobutyl alcohol, ethyl cellosolve, butyl cellosolve, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, propylene glycol monopropyl ether, acetone, etc. are mentioned.

Water may be contained in the said hydrophilic solvent, and water may be used independently as a hydrophilic solvent. Moreover, it is more preferable to mix and use the said hydrophilic solvent and water than to use the said hydrophilic solvent independently. When the hydrophilic solvent and water are mixed with each other, the contact efficiency between the aluminum particles and the molybdenum compound may be further improved. When referred to herein as "hydrophilic solvent", it is assumed to include the hydrophilic solvent, water, a mixture of the hydrophilic solvent and water.

In the dispersion solution containing the aluminum particles and the molybdenum compound, the content of the molybdenum compound is preferably 0.2 part by mass or more, and more preferably 0.1 part by mass or more, based on 100 parts by mass of the aluminum particles. Moreover, it is preferable that content of this molybdenum compound is 20 mass parts or less, and it is more preferable if it is 10 mass parts or less.

When content of a molybdenum compound is less than 0.02 mass part, there exists a tendency for a processing effect to become inadequate, and when content of a molybdenum compound exceeds 20 mass parts, there exists a tendency for the brightness of an aluminum pigment to run short.

In the dispersion solution containing aluminum particle and molybdenum compound, it is preferable that content of a hydrophilic solvent is 50 mass parts or more with respect to 100 mass parts of aluminum particles, and it is more preferable if it is 100 mass parts or more. Moreover, it is preferable that content of this hydrophilic solvent is 5,000 mass parts or less, and it is more preferable if it is 2,000 mass parts or less.

If the content of the hydrophilic solvent is less than 50 parts by mass, the molybdenum compound is unevenly distributed, and the aluminum particles tend to aggregate remarkably. Tends to be insufficient.

In the stirring step of the dispersion solution containing the aluminum particles and the molybdenum compound, the temperature of the dispersion solution in the stirring step is preferably 10 ° C or more, and more preferably 30 ° C or more. Moreover, it is preferable that it is 100 degrees C or less, and, as for the temperature of the dispersion solution in this stirring step, it is more preferable if it is 80 degrees C or less.

If the temperature of the dispersion solution in this stirring step is less than 10 ° C, the reaction time for obtaining a sufficient treatment effect tends to be long, and if the temperature of the dispersion solution in this stirring step exceeds 100 ° C, the risk of acceleration of the reaction increases. Tend to.

In the step of stirring the dispersion solution containing the aluminum particles and the molybdenum compound, the stirring time is preferably 0.5 hours or more, and more preferably 1.0 hours or more. Moreover, it is preferable that this stirring time is 10 hours or less, and it is more preferable if it is 5 hours or less.

If this stirring time is less than 0.5 hour, there exists a tendency for a processing effect to become inadequate, and when this stirring time exceeds 10 hours, there exists a tendency for a process cost to increase.

After this step of stirring the dispersion solution containing the aluminum particles and the molybdenum compound is finished, the dispersion solution is washed with the hydrophilic solvent containing no water, and then filtered through a filter to obtain a molybdenum coating. It is desirable to remove water and unreacted material from the cake containing aluminum particles.

<Method of coating aluminum particles with silica film>

One example of the method for producing an aluminum pigment according to the present invention is to adjust the pH of each aluminum particle with or without a molybdenum film, an organosilicon compound, and a hydrolysis catalyst to hydrolyze the organosilicon compound. To form a silica film on the surface of each aluminum particle or the surface of the molybdenum film.

The method of forming the silica film is not particularly limited, but the pH of the dispersion solution containing each aluminum particle with or without a molybdenum film, an organosilicon compound, and a hydrolysis catalyst is adjusted to hydrolyze the organosilicon compound. Any known method may be used as long as the silica film can be formed on the surface of each aluminum particle or the surface of the molybdenum film.

More specifically, an organosilicon compound is added to a dispersion solution containing each aluminum particle with or without a molybdenum film, and a hydrolysis catalyst is added to adjust the pH value of the dispersion solution to hydrolyze the organosilicon compound. The method of forming a silica film on the surface of each aluminum particle or the surface of a molybdenum film is preferable. At this time, the above-mentioned dispersion solution is preferably stirred at an appropriate rate so that each component is uniformly dispersed or dissolved.

In order to simplify the manufacturing process, the pH value of the dispersion solution is preferably adjusted by adding a hydrolysis catalyst in the above step, but the method of adjusting the pH value of the dispersion solution is particularly limited to the method of adding a hydrolysis catalyst. Although not necessarily, other acidic and / or alkaline compounds may be used to adjust the pH of the dispersion solution.

In this specification, when referred to as an organosilicon compound, it is assumed that it contains the condensate of an organosilicon compound and an organosilicon compound.

Although the organosilicon compound used for this invention is not specifically limited, The pH of the dispersion solution containing each aluminum particle with or without a molybdenum film, an organosilicon compound, and a hydrolysis catalyst is adjusted to make an organosilicon compound hydrolyze. The well-known organosilicon compound which can form a silica film on the surface of each aluminum particle, or the surface of a molybdenum film, and its condensate can be used.

Examples of such organosilicon compounds include tetraethoxysilane, tetramethoxysilane, tetraisopropoxysilane and the like and condensates thereof. An organosilicon compound may be used independently and may be used by stirring 2 or more types of such organosilicon compounds.

Hydrolysis Catalyst

Although the hydrolysis catalyst used for this invention is not specifically limited, When the pH of the dispersion solution containing each aluminum particle, an organosilicon compound, and a hydrolysis catalyst with or without a molybdenum film is adjusted, a silicon oxide compound will be hydrolyzed. A well-known hydrolysis catalyst which decomposes and forms a silica film on the surface of each aluminum particle or the surface of a molybdenum film can be used.

Examples of the hydrolysis catalyst of the organosilicon compound include monoethanolamine, diethanolamine, triethanolamine, ammonia, ethylenediamine, t-butylamine, 3-aminopropyl triethoxysilane, n-2-aminoethyl- Basic hydrolysis catalysts such as 3-aminopropyl triethoxysilane, n-2-aminoethyl-3-aminopropylmethyldimethoxysilane, urea, sodium silicate or sodium hydroxide, oxalic acid, acetic acid, nitric acid, sulfuric acid, phosphoric acid, Or acidic hydrolysis catalysts such as phosphonic acid.

In view of the reaction rate in the above step, it is more preferable to use a basic hydrolysis catalyst rather than an acidic hydrolysis catalyst. Among the basic hydrolysis catalysts described above, triethanolamine, ammonia, ethylenediamine, or 3-aminopropyl triethoxysilane are particularly preferable in view of quality.

<Dispersion solution>

It is preferable to use a hydrophilic solvent as a solvent of each aluminum particle with or without a molybdenum film, an organic silicon compound, and a dispersion solution containing a hydrolysis catalyst. More specifically, in order to avoid adverse reaction between aluminum particles and water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, t-butyl alcohol, n-butyl alcohol, isobutyl alcohol, ethyl cellosolve, Preference is given to using butyl cellosolve, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, acetone and the like.

This hydrophilic solvent may contain water. However, in order to avoid abnormal reaction of aluminum particle and water, it is preferable that content of the water in this hydrophilic solvent is 20 mass% or less.

In a dispersion solution containing aluminum particles with or without a molybdenum film, an organosilicon compound, and a hydrolysis catalyst, the content of the organosilicon compound is preferably 2 parts by mass or more, and 5 parts by mass or more based on 100 parts by mass of aluminum particles. It is more preferable if it is. Moreover, it is preferable that content of this organosilicon compound is 200 mass parts or less, and it is more preferable if it is 100 mass parts or less.

When content of an organosilicon compound is less than 2 mass parts, there exists a tendency for a processing effect to become inadequate, and when content of an organosilicon compound exceeds 200 mass parts, there exists a tendency for the aggregation of aluminum particle and the fall of brightness to become remarkable. The organosilicon compound may be added gradually or all at once.

In a dispersion solution containing aluminum particles with or without a molybdenum coating, an organosilicon compound, and a hydrolysis catalyst, the content of the hydrolysis catalyst is preferably 0.1 parts by mass or more, and 0.5 parts by mass or more based on 100 parts by mass of aluminum particles. It is more preferable if it is. Moreover, it is preferable that content of this hydrolysis catalyst is 20 mass parts or less, and it is more preferable if it is 10 mass parts or less.

When content of a hydrolysis catalyst is less than 0.1 mass part, there exists a tendency for the precipitation amount of a silica layer to become inadequate, and when content of a hydrolysis catalyst exceeds 20 mass parts, there exists a tendency for aggregation of aluminum particle to become remarkable.

In a dispersion solution containing aluminum particles with or without a molybdenum coating, an organosilicon compound, and a hydrolysis catalyst, the content of the hydrophilic solvent is preferably 500 parts by mass or more, and 1,000 parts by mass or more based on 100 parts by mass of aluminum particles. More preferred. Moreover, it is preferable that content of this hydrophilic solvent is 10,000 mass parts or less, and it is more preferable if it is 5,000 mass parts or less.

When the content of the hydrophilic solvent is less than 500 parts by mass, the viscosity of the slurry becomes high and the stirring tends to be difficult. When the content of the hydrophilic solvent exceeds 10,000 parts by mass, the recovery / regeneration cost of the treatment liquid tends to increase.

In the step of forming a silica film on the surface of each aluminum particle with or without a molybdenum film, the temperature of the dispersion solution in this step is preferably 20 ° C or more, more preferably 30 ° C or more. Moreover, it is preferable that the temperature of the dispersion solution in this stirring step is 90 degrees C or less, and it is more preferable if it is 80 degrees C or less.

When the temperature of the dispersion solution in this stirring step is less than 20 ° C, the rate of formation of the silica layer is delayed and the treatment time tends to increase, and when the temperature of the dispersion solution in this stirring step exceeds 90 ° C, the reaction is accelerated. The risk tends to increase.

In the step of forming a silica film on the surface of each aluminum particle with or without a molybdenum film, the reaction time is preferably 1 hour or more, more preferably 3 hours or more. It is preferable that this stirring time is 48 hours or less, and it is more preferable if it is 24 hours or less.

If this stirring time is less than 1 hour, the treatment effect tends to be insufficient, and if this stirring time exceeds 48 hours, the treatment cost tends to increase.

In the step of forming a silica film on the surface of each aluminum particle with or without a molybdenum film, since the pH value of the dispersion solution changes during the reaction, it is necessary to appropriately adjust the pH value. At this time, the pH value is preferably adjusted by adding a hydrolysis catalyst, but the pH of the dispersion solution may be adjusted using other acidic and / or alkaline compounds in a range that does not impair the properties of the aluminum pigment according to the present invention. .

In this dispersion solution containing each aluminum particle with or without a molybdenum coating, an organosilicon compound, and a hydrolysis catalyst, when using a basic hydrolysis catalyst, the pH is preferably 7 or more, and more preferably 7.5 or more. . Moreover, it is preferable that pH of this dispersion solution is 11 or less, and it is more preferable if it is 10 or less.

When the pH of this dispersion solution is less than 7, the formation rate of a silica layer tends to decrease, and when the pH of the dispersion solution in this stirring step exceeds 11, there exists a tendency for the aggregation of aluminum particles and the fall of brightness to increase. .

In the step of forming a silica film on the surface of each aluminum particle with or without a molybdenum film, since the formation rate of the silica film is fast and the productivity is good, a basic hydrolysis catalyst is used rather than an acidic hydrolysis catalyst. More preferred. However, even when an acidic hydrolysis catalyst is used, there is no big difference in quality from the case where a basic hydrolysis catalyst is used.

When using an acidic hydrolysis catalyst in the dispersion solution containing each aluminum particle with or without a molybdenum film, an organosilicon compound, and a hydrolysis catalyst, it is preferable that pH is 1.5 or more, and it is more preferable if it is two or more. Moreover, it is preferable that pH of this dispersion solution is 4 or less, and it is more preferable if it is 3 or less.

When the pH of this dispersion is less than 1.5, the risk of acceleration of the reaction tends to increase, and when the pH of the dispersion solution during this stirring step exceeds 4, the precipitation rate of the silica layer tends to decrease.

<Method for forming a film formed of a silane coupling agent>

In one example of the method for producing an aluminum pigment according to the present invention, the method of forming the film formed of the silane coupling agent is similar to the method of forming the silica film, and includes hydrolyzing the silane coupling agent to form the film.

In one example of the method for producing an aluminum pigment according to the present invention, a film formed of a silane coupling agent and formed on a molybdenum film or a silica film reacts with a hydroxyl group in the silica film and a silane coupling agent when the film is formed on a silica film. Is formed.

When a film formed of a silane coupling agent is directly provided to each aluminum particle having a molybdenum film, the pH of the dispersion solution containing each aluminum particle having a molybdenum film, a silane coupling agent and a hydrolysis catalyst is adjusted to provide a silane coupling agent. Hydrolysis is carried out to form a film formed of a silane coupling agent on the surface of the molybdenum film.

Providing a film formed of a silane coupling agent to the silica film, the pH of the dispersion solution containing each aluminum particle with or without a molybdenum film, an organic silica compound, a silane coupling agent and a hydrolysis catalyst is adjusted to provide an organosilicon compound and The silane coupling agent is hydrolyzed to form a film formed of the silane coupling agent on the surface of the silica film.

At this time, the film formed of the silane coupling agent is temporarily silica by hydrolysis in order to perform the formation of the silica film by hydrolysis of the organic silica compound and the formation of the film by hydrolysis of the silane coupling agent step by step. It may be formed by adding a silane coupling agent after the film is formed and further hydrolyzing it.

The conditions, such as reaction solvent, temperature, a hydrolysis catalyst, for forming the film formed from a silane coupling agent, are similar to the conditions at the time of forming a silica film.

The quantity of a silane coupling agent is 0.1-20 mass parts with respect to 100 mass parts of aluminum particles, More preferably, it is 1-10 mass parts. If the amount is less than the above, the desired effect tends not to be obtained, and if the amount is too large, the amount of unreacted silane coupling agent increases and the coating film properties tend to be lowered.

After the step of forming the film formed of the molybdenum film, the silica film and the silane coupling agent on each aluminum particle is completed, the dispersion solution is washed with the hydrophilic solvent containing no water, and filtered through a filter, thereby It is preferred to remove water and unreacted material from the cake containing the aluminum pigment according to the invention.

Then, if necessary, the cake containing the aluminum pigment according to the present invention may be heat-treated at a temperature in the range of 100 to 500 ° C.

Forming a molybdenum film on the surface of each aluminum particle and forming a film formed of a silica film and / or a silane coupling agent on the surface of the molybdenum film of each aluminum particle may be performed in another dispersion solution, or These steps may also be carried out after appropriate adjustment of the components in the same dispersion solution.

<Description of Resin Composition>

The resin composition according to the present invention contains the aluminum pigment and the resin according to the present invention.

Although the resin which can be mix | blended with the resin composition of this invention is not specifically limited, For example, acrylic resin, alkyd resin, polyester resin, polyurethane resin, polyvinylacetate resin, nitrocellulose resin, a fluororesin etc. are preferable. Can be used.

The coloring pigment which can be mix | blended with the resin composition of this invention other than the aluminum pigment which concerns on this invention is although it does not specifically limit, For example, phthalocyanine, quinacridone, isoindolinone, perylene, azo lake, iron oxide, chromium yellow , Carbon black, titanium oxide, pearl mica and the like.

In addition, the additive which can be mix | blended with the resin composition of this invention is not specifically limited, Surfactant, a hardening | curing agent, a ultraviolet absorber, an electrostatic remover, a thickener, an extender pigment, a dye, a corrosion inhibitor, etc. Can be mentioned.

The resin composition of this invention may contain water, a hydrophilic solvent, an organic solvent, etc. other than said component.

It is preferable that content of the aluminum pigment which concerns on this invention in the resin composition of this invention is 0.1 mass% or more with respect to the whole resin composition, and it is more preferable if it is 1.0 mass% or more. Moreover, it is preferable that content of the aluminum pigment which concerns on this invention is 30 mass% or less, and it is more preferable if it is 20 mass% or less.

If the content of the aluminum pigment according to the present invention is less than 0.1% by mass, the decorative effect (metallic feeling) tends to decrease, and if the content of the aluminum pigment according to the present invention is more than 30% by mass, Properties (weather resistance, corrosion resistance, mechanical strength, etc.) may be insufficient.

The resin composition of this invention containing the aluminum pigment which concerns on this invention can be mix | blended with a paint, ink, etc., and can be used preferably. Moreover, especially when a resin composition is mix | blended with an aqueous paint or an aqueous ink among paints and inks, it can be used especially preferably.

In addition, the resin composition of the present invention has a good appearance with excellent metallic feel, excellent weatherability and stability, and is preferably used as it is without being used as a paint or ink, or mixed with a rubber composition or a plastic composition. Can be.

<Description of an aqueous paint or an aqueous ink>

The aluminum pigment according to the present invention can be suitably formulated into an aqueous paint or an aqueous ink together with a binder and a hydrophilic solvent.

The binder used for the aqueous coating or the aqueous ink containing the aluminum pigment according to the present invention is not particularly limited, but for example, acrylic resins, alkyd resins, polyester resins, polyurethane resins, polyvinylacetate resins, nitrocellulose resins And resins such as fluororesin can be preferably used.

The binder used for the aqueous paint or aqueous ink containing the aluminum pigment according to the present invention is generally used as a binder for an aqueous paint or an aqueous ink, and a binder other than the resin as long as a good coating film can be formed by solidification after coating. This can be used. More specifically, polymer compositions other than resin, such as a rubber composition, a plastic composition, or a natural polymer composition, are mentioned.

Moreover, the coloring pigments other than the aluminum pigment which concerns on this invention which can be mix | blended with the aqueous paint or aqueous ink containing the aluminum pigment which concerns on this invention are not specifically limited, For example, phthalocyanine, quinacridone, isoin Dolnon, perylene, azo lake, iron oxide, chrome yellow, carbon black, titanium oxide, pearl mica and the like.

The additive which can be blended into the aqueous coating or the aqueous ink containing the aluminum pigment according to the present invention is not particularly limited, but may include a surfactant, a curing agent, an ultraviolet absorber, an electrostatic remover, a thickener, a extender pigment, a dye, and the like. .

The hydrophilic solvent that can be blended into the aqueous paint or the aqueous ink containing the aluminum pigment according to the present invention is not particularly limited, but for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, t-butyl alcohol and n-butyl alcohol, isobutyl alcohol, ethyl cellosolve, butyl cellosolve, propylene glycol monobutyl ether, dipropylene glycol motomethyl ether, propylene glycol monopropyl ether, acetone and the like.

Said hydrophilic solvent may contain water, or water may be used independently as a hydrophilic solvent. Moreover, 1 type, or 2 or more types of said hydrophilic solvents may be stirred and used according to a use.

It is preferable that it is 0.1 mass% or more with respect to content of a binder, and, as for content of the aluminum pigment which concerns on this invention in the aqueous paint or aqueous ink containing the aluminum pigment which concerns on this invention, it is more preferable if it is 1.0 mass% or more. Moreover, it is preferable that content of the aluminum pigment which concerns on this invention is 30 mass% or less with respect to content of a binder, and it is more preferable if it is 20 mass% or less.

When the content of the aluminum pigment according to the present invention is less than 0.1% by mass, the decorative effect (metallic feeling) of the coating film of the aqueous coating or the aqueous ink tends to decrease, and the content of the aluminum pigment according to the present invention is more than 30% by mass. In many cases, the characteristic (weather resistance, corrosion resistance, mechanical strength, etc.) of the coating film of aqueous coating or aqueous ink may become inadequate.

It is preferable that it is 20 mass% or more with respect to content of a binder, and, as for content of the hydrophilic solvent in the aqueous paint or aqueous ink containing the aluminum pigment which concerns on this invention, it is more preferable if it is 50 mass% or more. Moreover, it is preferable that it is 200 mass% or less with respect to content of a binder, and, as for content of a hydrophilic solvent, it is more preferable if it is 100 mass% or less.

If the content of the hydrophilic solvent is less than 20% by mass, the viscosity of the paint and ink is high, and handling tends to be difficult. If the content of the hydrophilic solvent is more than 200% by mass, the viscosity of the paint or ink is low, resulting in coating film formation. It tends to be difficult.

The application of the aluminum pigment according to the present invention is not limited to mixing with an aqueous paint or an aqueous ink, but is a paint containing an organic solvent, an ink containing an organic solvent, a powder paint, a rubber composition, a plastic composition, a natural polymer composition, and the like. It can also be preferably used when blending.

The coating method or printing method of the aqueous coating or aqueous ink containing the aluminum pigment according to the present invention is not particularly limited, and various coatings are considered in consideration of the form of the aqueous coating or aqueous ink to be used and the surface shape of the substrate. Method or printing method may be used. For example, the coating method of the aqueous coating containing the aluminum pigment according to the present invention includes a spray method, a roll coater method, a brushing method or a doctor blade method, and the like. As a printing method of the aqueous ink to contain, gravure printing, screen printing, etc. are mentioned.

The coating film formed by the aqueous coating or the aqueous ink containing the aluminum pigment according to the present invention may be formed in an undercoat layer or an intermediate coat layer by electrodeposition coating or the like, or as a topcoat. A layer may be formed in the coating film formed by the aqueous paint or the aqueous ink containing the aluminum pigment according to the present invention.

In this case, the following coating layer may be applied after the respective coating layer is cured or dried, or the next coating layer may be coated by the so-called wet-on-wet coating. It may then be painted without curing or drying. However, in order to obtain a coating film having a good mirror-like brightness, it is preferable to apply a coating film layer of an aqueous paint or an aqueous ink containing the aluminum pigment according to the present invention after coating and curing or drying the basic coating film layer.

The coating composition forming each coating layer may be, for example, thermoset, or may be cold-set. In addition, the coating composition which forms each coating film layer may be dried by hot air, for example, or it may dry naturally at normal temperature.

In this case, the thickness of the coating layer formed by the aqueous coating or the aqueous ink containing the aluminum pigment according to the present invention is not particularly limited, but in general embodiments, the thickness is preferably 2 μm or more, more preferably 5 μm or more. Do. Moreover, it is preferable that the thickness of this coating film layer is 100 micrometers or less, and it is more preferable if it is 50 micrometers or less.

If the thickness of the coating layer is less than 2 µm, the effect of concealing the lower layer by ink or paint tends to be insufficient. When the thickness of the coating layer exceeds 100 µm, drying becomes difficult, and Defects such as sagging tend to be prominent.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

<Example 1>

A solution obtained by adding 0.5 g of metal molybdenum powder little by little to 10 g of hydrogen peroxide containing 30% of hydrogen peroxide and reacting was dissolved in 600 g of isopropyl alcohol, and commercially available aluminum pigment (7640NS manufactured by Toyo Aluminum Co., Ltd., solid content) : 653.8) was added 153.8g (aluminum powder: 100g), and it stirred at 50 degreeC for 1 hour.

Thereafter, monoethanolamine was added to the slurry to adjust the pH value of the slurry to 8.5.

Next, 40 g of tetraethoxysilane (hereinafter referred to as TEOS) was added to the slurry whose pH was adjusted, and further stirred at 50 ° C for 10 hours. The pH value of the slurry was checked every 2 hours during the treatment and adjusted to 8.5 by the addition of monoethanolamine.

After the end of the reaction, the slurry was solid-liquid separated through a filter, and the slurry containing the obtained aluminum pigment was dried at 105 ° C. for 3 hours to obtain a powdered aluminum pigment.

<Examples 2 to 8>

An aluminum pigment according to Examples 2 to 8 was formed similarly to Example 1.

Example 9

153.8 g (aluminum powder: 100 g) and 3 g of 3-aminopropyl triethoxysilane used as catalyst were added to 600 g of IPA at an aluminum pigment (7640NS manufactured by Toyo Aluminum Co., Ltd., solid content: 65%), Stirred for 1 h.

Thereafter, monoethanolamine was added to the slurry to adjust the pH value of the slurry to 8.5.

Next, 30 g of TEOS, and 10 g of decyl trimethoxysilane were added to the pH adjusted slurry, and further stirred at 50 ° C. for 10 hours. The pH value of the slurry was checked every 2 hours during the treatment and adjusted to 8.5 by the addition of monoethanolamine.

After the end of the reaction, the slurry was solid-liquid separated through a filter, and the slurry containing the obtained aluminum pigment was dried at 105 ° C. for 3 hours to obtain a powdered aluminum pigment.

<Example 10>

A solution obtained by gradually adding 0.5 g of metal molybdenum powder to 10 g of hydrogen peroxide containing 30% hydrogen peroxide and reacting was dissolved in 600 g of isopropyl alcohol, and commercially available aluminum pigment (7640 NS manufactured by Toyo Aluminum Co., Ltd.) , Solid content: 65%) was added 153.8 g (aluminum content: 100 g), and it stirred at 50 degreeC for 1 hour.

Thereafter, monoethanolamine was added to the slurry to adjust the pH value of the slurry to 8.5.

Next, 30 g of TEOS and 10 g of phenyl triethoxysilane were added to the pH adjusted slurry and further stirred at 50 ° C. for 10 hours. The slurry pH value was checked every two hours during the treatment and adjusted to a pH value of 8.5 by the addition of monoethanolamine.

After the end of the reaction, the slurry was solid-liquid separated through a filter, and the slurry containing the obtained aluminum pigment was dried at 105 ° C. for 3 hours to obtain a powdered aluminum pigment.

<Comparative Examples 1-3>

An aluminum pigment according to Comparative Examples 1 to 3 was formed similarly to Example 1. However, when forming Comparative Example 2, the aluminum pigment according to Comparative Example 2 was not obtained because the aluminum pigment caused an abnormal reaction during the reaction for forming the silica film and caused hydrogen gas to be remarkably agglomerated. Tables 1-3 show the analysis conditions of the manufacturing conditions and composition of the aluminum pigment of Examples 1-10 and Comparative Examples 1-3.

Table 1: Analytical Values of Manufacturing Conditions and Compositions of Aluminum Pigments

Table 2: Analysis of Manufacturing Conditions and Compositions of Aluminum Pigments

Table 3: Analytical Values of Manufacturing Conditions and Compositions of Aluminum Pigments

In Table 1-Table 3,

_{* 1: H 2 O 2 30} % aq denotes an aqueous solution containing H ₂ O _2% 30 by weight.

* 2: Mo content of phosphomolybdic acid is 47 mass% in terms of Mo metal.

* 3: IPA stands for isopropyl alcohol.

* 4: MFDG stands for dipropylene glycol monomethyl ether.

* 5: TEOS represents tetraethoxysilane.

* 6: DTMS represents decyltrimethoxysilane.

* 7: PTES represents phenyltriethoxysilane.

 <Performance evaluation>

The aluminum pigment obtained by Examples 1-10 and Comparative Examples 1-3 was evaluated for performance according to the following measuring method or evaluation method. Tables 4-6 show evaluation results.

(i) Measurement of content of Si and Mo

The content of Mo and Si of each aluminum pigment was measured by plasma emission analysis by ICPS-8000 manufactured by Shimadzu Corporation through a calibration curve using a liquid extracted by alkali dissolution / extraction method and Mo and Si standard solutions.

(ii) evaluation of stability

100 parts by mass of water was added to 100 parts by mass of the powder of each aluminum pigment, and the mixture was pasteurized, and the paste was stored at 50 ° C. for 1 month, and then by JIS standard sieve having holes of 45 μm. It was wet-screened by hand in water, and evaluated according to the following criteria.

○: Almost no change in aluminum pigment

△: aluminum pigment partially aggregated

×: most aluminum pigment aggregates

(iii) Determination of the amount of gas generated in water-based paints

Each aluminum pigment was used to form an aqueous paint having the following composition.

Water Soluble Acrylic Resin (* 1) 28.2 g

Melamine resin (* 2) 4.4 g

1.1 g of triethanolamine

44.8 g of deionized water

3.0 g of isopropyl alcohol

5.0 g of transparent iron oxide (* 3)

Aluminum pigment 3.0 g (solid content)

(Examples 1-8, Comparative Example 1, Comparative Example 3)

* 1: Mitsui Doatsu Chemical Co., Ltd., Almatex WA911

* 2: Cymel 350, manufactured by Mitsui Toatsu Chemical Co., Ltd.

* 3: Manufactured by BASF, SICOTRANS RED L2175D

In order to measure the cumulative amount of hydrogen gas generated by the mass cylinder method by water displacement, 80 g of the aqueous paint formed by the above method was taken and stored for 7 days in a water bath adjusted to 50 ° C.

(iv) Evaluation of the color tone of the coating film of the aqueous paint containing aluminum pigment

In the measurement of the amount of gas generated in the water-based paint, each water-based paint formed in the above (iii) is air sprayed onto a test copper plate electrodeposited with a primary rust-prevention paint in advance, and the thickness after drying. Was 13 μm, pre-dried at 90 ° C. for 10 minutes, and then the organic solvent type top coat paint having the following composition was air sprayed, and after drying, was 40 μm thick, dried at 140 ° C. for 30 minutes, A paint plate is formed.

140 g of acrylic resin (* 4)

Melamine resin (* 5) 50 g

Solvesso 10O 60 g

* 4: manufactured by Mitsui Doatsu Chemical, Almatex 110

* 5: Mitsui Doatsu Chemical Co., Ltd., Uban 20SE60

The metallic glossiness of the metal coating plate obtained by the above method was evaluated in five steps according to the following criteria. The higher the number is, the better the metallic luster. Flip flop has the property that brightness changes according to the viewing angle, and the stronger the direction, the easier the brightness changes.

5: Very good brightness, very strong directivity

4: excellent brightness, strong directional

3: Both brightness and directionality are normal

2: The brightness is slightly lowered, the direction is slightly weaker

1: The brightness is lowered and the direction is weak

(v) coating film moisture resistance / adhesion test

Each coated plate obtained in the above (iv) was left for one day in an atmosphere of 40 ° C. and a humidity of 100%, and then the adhesion test was carried out according to JIS K5600 5-6: 1999. The obtained result is shown to Tables 4-6. The results are shown by the following five steps of evaluation.

5: no peeling

4: peeling: 10% or less

3: peeling: 10-50%

2: peeling: 50-90%

1: Peeling: 100%

Table 4: Evaluation result items of aluminum pigments and water-based paints

Table 5: Evaluation result items of aluminum pigments and water-based paints

Table 6: Evaluation results of aluminum pigments and aqueous paints

From the results shown in Tables 4 to 6, each of the aqueous paints blended with the aluminum pigments according to Examples 1 to 10 did not generate gas at all compared to the aqueous paints blended with the aluminum pigments according to Comparative Examples 1 to 3. In addition, it can be seen that the color tone of the coating plate and the constitution adhesion of the coating film are remarkably excellent.

The embodiments and examples disclosed herein are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and is intended to include any modifications within the scope and meaning of equivalency of the claims.

From the above results, the aluminum pigment according to the present invention, which is excellent in dispersibility and stability and excellent in designability of the appearance of the coating film without generating or agglomerating hydrogen gas during storage, is suitably blended into an aqueous paint or an aqueous ink. .

It is excellent in dispersibility and stability, and suitably formulated in an aqueous paint or an aqueous ink using the aluminum pigment manufacturing method according to the present invention, which is excellent in designability of the appearance of the coating film without generating or aggregating hydrogen gas during storage. Aluminum pigments can be obtained.

Moreover, the resin composition of this invention which is excellent in dispersibility and stability, and is excellent in the designability of a coating film external appearance, without generating or aggregating hydrogen gas during storage, is mix | blended suitably with an aqueous coating material or an aqueous ink.

In addition, the aqueous coating or aqueous ink containing the aluminum pigment according to the present invention is excellent in water dispersibility and stability, does not generate or agglomerate hydrogen gas during storage, and is excellent in designability of the coating film appearance.

Claims (15)

An aluminum pigment having an aluminum film, a molybdenum film containing any one or both of molybdenum oxide and molybdenum hydrate covering the surface of each aluminum particle, and a silica film containing amorphous silica further covering the molybdenum film. The aluminum pigment according to claim 1, wherein the content of molybdenum is 0.01 to 5 parts by mass with respect to 100 parts by mass of the aluminum particles. The aluminum pigment according to claim 1, wherein the content of silicon is 1 to 20 parts by mass with respect to 100 parts by mass of the aluminum particles. The aluminum pigment according to claim 1, further comprising a film formed of a silane coupling agent on the silica film. The aluminum pigment according to claim 4, wherein the silane coupling agent is at least one member selected from compounds having the following structure. R _A -Si (OR _B ) ₃ or R _A -SiR _B (OR _B ) ₂ R _A : C2-C18 alkyl or aryl or alkenyl group R _B : an alkyl group having 1 to 3 carbon atoms The resin composition containing the aluminum pigment of Claim 1, and resin, Comprising: The content of the said aluminum pigment is 0.1-30 mass% of the whole said resin composition, The resin composition characterized by the above-mentioned. Stirring the dispersion solution containing the aluminum particles and the molybdenum compound to form a molybdenum film containing one or both of molybdenum oxide and molybdenum hydrate on the surface of each aluminum particle, The pH of the dispersion solution containing the aluminum particles having the molybdenum coating, the organic silicon compound, and the hydrolysis catalyst is adjusted to hydrolyze the organic silicon compound, and amorphous silica is applied to the surface of the molybdenum coating of the aluminum particles. Method for producing an aluminum pigment comprising the step of forming a silica film comprising. 8. The method of claim 7, wherein forming a molybdenum film on the surface of each aluminum particle comprises one or two or more selected from the group consisting of polymolybdate peroxide, ammonium molybdate and phosphorus molybdate as the molybdenum compound. Method for producing an aluminum pigment, characterized in that it comprises a step of using. 8. The method of claim 7, wherein the forming of the silica film comprises using one or two or more compounds selected from the group consisting of tetraethoxysilane and tetramethoxysilane as the organosilicon compound. Method for producing an aluminum pigment, characterized in that. 8. The aluminum pigment according to claim 7, wherein the forming of the silica film comprises adjusting the pH of the dispersion solution in the range of 7.0 to 11.0 using a basic catalyst as the hydrolysis catalyst. Manufacturing method. 8. The method of claim 7, wherein the forming of the silica film is used as one or two or more selected from the group consisting of triethanol amine, ammonia, ethylenediamine and 3-aminopropyl triethoxysilane as the hydrolysis catalyst. Method for producing an aluminum pigment, characterized in that it comprises a step. Stirring the dispersion solution containing the aluminum particles and the molybdenum compound to form a molybdenum film containing one or both of molybdenum oxide and molybdenum hydrate on the surface of each aluminum particle, The pH of the dispersion solution containing the aluminum particles having the molybdenum coating, the organic silicon compound, and the hydrolysis catalyst is adjusted to hydrolyze the organic silicon compound, and amorphous silica is applied to the surface of the molybdenum coating of the aluminum particles. Forming a silica film comprising, and The pH of the dispersion solution containing each said aluminum particle which has the said silica film, a silane coupling agent, and a hydrolysis catalyst is adjusted, the said silane coupling agent is hydrolyzed, and the said silane is formed on the surface of the said silica film of each said aluminum particle. A method for producing an aluminum pigment comprising the step of forming a film formed of a coupling agent. PH of a dispersion solution containing aluminum particles, an organosilicon compound, a silane coupling agent and a hydrolysis catalyst is adjusted to hydrolyze the organosilicon compound and the silane coupling agent, and the amorphous silica is included on the surface of each aluminum particle. A method for producing an aluminum pigment comprising forming a film formed of a silica film and the silane coupling agent. Adjusting the pH of a dispersion solution containing aluminum particles, an organosilicon compound, and a hydrolysis catalyst to hydrolyze the organosilicon compound to form a silica film containing amorphous silica on the surface of each aluminum particle, and PH of the dispersion solution containing each said aluminum particle which has the said silica film, a silane coupling agent, and a hydrolysis catalyst is adjusted, hydrolysis of the said silane coupling agent is carried out on the surface of the said silica film of each said aluminum particle, A method for producing an aluminum pigment comprising the step of forming a film formed of a silane coupling agent. PH of the dispersion solution containing each aluminum particle having an molybdenum coating, an organosilicon compound, a silane coupling agent, and a hydrolysis catalyst is adjusted to hydrolyze the organosilicon compound and the silane coupling agent, and the A method for producing an aluminum pigment, wherein a silica film containing amorphous silica is formed on the surface of the molybdenum film and a film formed of the silane coupling agent is formed thereon.

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