JPH1046048A - Metallic coating material using metallic pigment excellent in weatherability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject coating material excellent in light resistance, alkali resistance, weatherability and dispersibility, by subjecting metal powder having adsorbed a cationic dispersant on the surface and ultrafine powder of metal oxide having adsorbed an anionic dispersant on the surface in a specific ratio to ionic reaction. SOLUTION: (A) Metal powder such as aluminum, copper, brass, chromium, nickel, cobalt or stainless steel having adsorbed 0.5-5wt.% of a cationic dispersant on the surface and 1.0-100μm particle diameter and (B) ultrafine powder of metal oxide such as titanium oxide or iron oxide having adsorbed 1-5wt.% of an anionic dispersant on the surface and 0.01-0.1μm particle diameter at a ratio of the components A/B of (100/1) to (100/10) are subjected to an ionic reaction so as to give the objective coating material containing a metallic pigment in which the component B is coordinated on the surface of the component A, excellent in coated film performances such as no formation of seediness when a coated film is made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallic paint using a metallic pigment having good weather resistance.

[0002]

2. Description of the Related Art Metallic pigments used in metallic paints have hitherto been used to produce metal flakes or granular metal powders by mechanical methods such as stamp milling, dry ball milling (H
(metatag method), wet ball mill method, etc., and the method of making is known.

[0003]

As a metallic pigment, an aluminum paste is mainly used. However, since the surface of a crushed paste-like aluminum powder is active, fatty acids such as maleic acid and stearic acid and amines are used. Is adsorbed on the surface of aluminum.However, since the activity of aluminum cannot be sufficiently prevented, when a coating film is formed with, for example, a metallic paint, it is exposed after exposure due to deterioration of the coating film due to sunlight. There is a problem that the metallic feeling of the film is rapidly reduced.

Further, instead of aluminum powder which is usually used for metallic paint as a new color, copper, brass,
Metal powders such as chromium, nickel, cobalt, stainless steel, etc. are also being used as metallic pigments, but when they are made into paints, the active points cannot be completely prevented, so the weather resistance is poor and the metal color specific to the metal over time There was a problem that it disappeared.

On the other hand, Japanese Patent Publication No. 59-15152 discloses an organic solvent type flake-like metal pigment composition using a dimer and a higher fatty acid and a method for producing the same. Is not taken into account.

JP-B-59-17142 discloses a novel flaky metal powder pigment, but does not particularly mention deterioration of the pigment when formed into a coating film.

[0007]

Means for Solving the Problems The present inventor pays attention to this point, and selects aluminum powder, copper, brass, chromium, nickel,
Weather resistance by coordinating metal oxide ultrafine particles (particle size 0.01-0.1μ) smaller than visible light (380-780nm) on the surface of metal powders such as cobalt and stainless steel It is thought that this may be improved, and as a result of various studies, the present invention has been achieved.

[0008] In general, metallic pigments adsorb fatty acids and amines on the surface of metal powder, but aluminum powder coated with ultrafine titanium oxide or ultrafine iron oxide produced by the present invention by ionic reaction. Metal powder,
Further, the metallic pigment produced by coating with a synthetic polymer compound having at least one silicon group having a hydrolysis bonded to a side chain in one molecule is combined with the good weather resistance of the resin itself to further improve the weather resistance. Becomes better.

As a secondary effect, the ultrafine metal oxide particles used in the present invention have an average particle size smaller than the wavelength of visible light, and therefore have transparency. For this reason, not only did the gloss of the metallic pigment not be impaired, but also a deep metallic feeling which was not expected at first due to the synergistic action of the metallic feeling and the transparent coloring effect was found in the coating film.

That is, the present invention relates to the following paints. 1. A. B. Metal powder having a particle diameter of 1.0 to 100 μ with a cationic dispersant adsorbed on the surface. Particle diameter 0.0 with anionic dispersant adsorbed on the surface
1 to 0.1 μm of metal oxide ultrafine particles, and the weight ratio of A and B is A / B = 100/1 to 10
A paint containing a metallic pigment in which B is coordinated to the surface of A by ionic reaction at 0/10. 2. The amount of the cationic dispersant used is 0.
5 wt% to 5 wt%, and the amount of the anionic dispersant used is 1 wt% to 5 wt% based on the metal oxide ultrafine powder.
1. A paint containing the metallic pigment described in the above. 3. The metal powder is selected from aluminum, copper, brass, chromium, nickel, cobalt, and stainless steel. Or 2. A paint containing the metallic pigment described in the above. 4. Metal powder is limited to aluminum Or 2. A paint containing the metallic pigment described in the above. 5. Ultrafine metal oxide powder is limited to titanium oxide and iron oxide From 4. A paint containing the metallic pigment according to any one of the above. 6. The main chain is composed of a silyl group-containing vinyl polymer, and is coated with a synthetic polymer compound having at least one silicon group bonded to a hydrolyzable group at a molecular terminal or a side chain in one molecule. To 5. A paint containing the metallic pigment according to any one of the above.

[0011]

Next, the components of the present invention will be described. (1) Metal Powder The metal powder used in the present invention is a treated metal powder which essentially requires the use of a cationic surfactant instead of mineral spirit or higher fatty acid treatment.
The average particle size of the metal powder is not particularly limited and is 1 to 10
Although those having 0 μm can be used, those having 10 μm to 50 μm are particularly preferable. When the particle size is 100 μm or more, when the coating material is used, it tends to settle due to the difference in specific gravity, and when it is 1 μm or less, the metal oxide ultrafine particle powder is hardly adsorbed.

(2) Cationic surfactant As the cationic surfactant adsorbed on the surface of the metal powder of the present invention, N-acyl amino acid salts (dialkyldimethylammonium chloride), alkylpyridium salts and the like can be used. is there. As a method for adsorbing the cationic surfactant to the metal powder, it is sufficient to use a conventional method during a soft texture process (at the time of mechanical pulverization). That is, when producing a treated metal powder by a known method of finely pulverizing the metal powder while spreading the same with a mineral spirit using a ball mill, the cationic surfactant is added in an amount of 0.5 to 5 wt%.
By using it, the cationic surfactant can be adsorbed around the metal powder.

(A) Metal powder on which a cationic dispersant is adsorbed The surface treatment of the metal powder is usually carried out with a mineral spirit, but a ketone solvent or a cellosolve solvent which is partially a polar solvent is used in combination. It does not matter. In this way, a treated metal powder on which the cationic surfactant is adsorbed can be produced, but the amount of the cationic surfactant used is 0.
When the content is 5 wt% or less, the coordination of the metal oxide ultrafine particles is not sufficiently performed, and when the content is 5 wt% or more, the weather resistance of the coating film is reduced.

(3) Ultrafine metal oxide powder Next, the ultrafine metal oxide powder to which the anionic surfactant used in the present invention is adsorbed includes, for example, titanium oxide and iron (III) oxide. , Zinc oxide, cobalt oxide, chromium (III) oxide, alumina and the like. Particularly, the method for producing iron (III) oxide is described in JP-B-52-135.
No. 28, a method of pulverizing lamellar or wiggrain-like coagulating polycrystalline hydrated iron oxide particles at 700 ° C. and then pulverizing them after dehydration, and 55 [1] 13-19 1982 in the following colloid chemistry method Is disclosed, but this is not a limitation of the present invention.

That is, an anion exchange resin is added to an aqueous ferric chloride solution to form a transparent positive hydrated iron oxide sol, and an anionic surfactant is added to the sol to aggregate the colloid particles. By transferring into an organic solvent layer by flushing and removing water and the organic solvent therefrom, metal oxide ultrafine particles having an anionic surfactant adsorbed thereon can be obtained.

As a method for producing titanium oxide, a colloidal chemistry method is used for coloring materials, 57 [6] 305-308,
Although disclosed in 1984, it shows an example of a method for producing ultrafine metal oxide powder used in the present invention, and does not limit the present invention.

That is, an aqueous sodium carbonate solution is added to an aqueous solution of titanyl sulfate to form a hydrosol, and then an anionic surfactant is added to convert the colloidal particles to lipophilicity. By removing the organic solvent, ultrafine titanium oxide to which the anionic surfactant has been adsorbed can be synthesized.

(4) Anionic surfactants Anionic surfactants that can be used in the metal oxide ultrafine particle powder include alkylbenzene sulfonates,
Alkane sulfonates, α-olefin sulfonates,
α-sulfo fatty acid, N-acyl amino acid salt, N- (2-
Sulfo) ethyl-N-methylalkaneamide salt, dialkyl 2-sulfosuccinate, alkylnaphthalene sulfonate and the like. Among them, the alkylbenzene sulfonate and the dialkyl 2-sulfosuccinate are preferable. More specifically, sodium dodecylbenzenesulfonate and sodium (2-ethylhexyl) sulfosuccinate are useful. In the case of the colloidal chemical method as described above, an anionic surfactant can be adsorbed around the metal oxide ultrafine particle powder when used when aggregating the colloidal particles. The use amount of the anionic surfactant is suitably 1 wt% to 5 wt%, and if it is less than 1 wt%, the metal-based ultrafine particles are not completely lipophilic treated and the ionic reaction with the treated metal powder does not proceed smoothly. Also, 5wt
%, The weather resistance of the metallic pigment itself decreases.

(B) Ultrafine metal oxide powder adsorbed with an anionic dispersant The ultrafine metal oxide powder prepared as described above has been subjected to lipophilic treatment on its surface. It is preferable to disperse them. As the solvent, aromatic solvents represented by xylene and toluene, ethyl acetate, ester solvents represented by i-propyl acetate or n-butyl acetate, methyl ethyl ketone, methyl isobutyl ketone,
A ketone solvent represented by cyclohexanone or the like, methyl cellosolve, ethyl cellosolve, or a cellosolve solvent represented by butyl cellosolve is a typical solvent, but a polar solvent to smoothly perform an ion reaction, That is, a ketone solvent or a cellosolve solvent is suitably used.

(I) Metallic Pigment As a method for producing a metallic pigment, a treated metal powder is dispersed in a ketone-based solvent or a cellosolve-based solvent, and then anions are adsorbed on the surface in a range of 1 wt% to 10 wt% of the treated metal powder. Since the reaction proceeds instantaneously by adding the metal oxide ultrafine particle powder, a metallic pigment having good weather resistance can be produced by removing the solvent used after the reaction.

If the metal oxide ultra-fine particle powder is more than 10 wt% of the treated metal powder, free metal oxide ultra-fine particle powder that does not adsorb to the treated metal powder exists in the metallic pigment and the pigment itself is It becomes expensive and hard to produce a deep metallic feeling. If the amount of the metal oxide ultrafine particles is less than 1 wt%, the metal oxide ultrafine particles cannot completely cover the treated metal powder, and the weather resistance of the metallic paint is greatly reduced. I do.

In the ionic reaction of the present invention, a special treatment device is not required, and the reaction can be performed by a stirrer for uniform mixing.

In order to further improve the weather resistance of the metallic pigment used in the present invention, the main chain is composed of a silyl group-containing vinyl polymer or copolymer and is bonded to a molecular terminal or a side chain to a hydrolyzable group. When a metallic pigment is coated with a so-called acrylic silicone resin having at least one silicon group in one molecule, the weather resistance as a pigment is further improved because the resin itself has good weather resistance.

(II) Metallic paint Even when an organic pigment such as anthraquinone, perylene or pyranthrone is added to the paint of the present invention, the storage stability is poor when a usual metallic pigment is used. In addition to the color change and the remarkable change in viscosity, the coating of the present invention has good storage stability. In addition, the occurrence of a bump which was a conventional problem was not observed.

In the metallic coating material of the present invention, the clear reason for the above effect cannot be explained, but it is presumed that the active sites on the surface of the metal powder are probably blocked by the metal oxide ultrafine particles.

The metallic paint of the present invention can be used, for example, as a heat reflective paint, a conductive paint, a decorative paint, or a powder paint. In addition, PC concrete, aluminum die cast board, various siding boards,
When the metallic paint of the present invention was applied to various inorganic building materials such as an extruded molded plate, particularly a molded plate having elaborate design properties, a deep metallic feeling was observed as shown in Table 2.

[0027]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

(Reference Example 1) [How to make aluminum-based treated powder] Atomized aluminum powder (made by Toyo Aluminum)
AA101) 1.0 kg Methyl isobutyl ketone 1.25 l 25 g of a cationic dispersant (stearyldimethylbenzylammonium chloride) was put into a ball mill having a diameter of 50 cm, and pulverized for 2 hours and 30 minutes. After grinding, 8 l of methyl isobutyl ketone
And passed through a 325 mesh screen. Thereafter, solid-liquid separation is performed using a pan filter, and the metal powder 7 is separated.
A filter cake consisting of 0 wt% was obtained. Methyl isobutyl ketone was added to the filter cake so that the metal powder was 65 wt%, and the mixture was kneaded with a kneader for 30 minutes to obtain an aluminum paste. The particle size measured by Microtrac was α = 25.0 (μ).

(Reference Example 2) [How to prepare ultrafine iron oxide powder] An anion exchange resin (Amberlite) was added to 1 liter of a 10% aqueous ferric chloride solution.
IRA-400) was added, and the mixture was allowed to stand for 1 hour and then filtered to produce a transparent positive hydrated iron oxide sol. Next, 50 ml of this positive hydrated iron oxide sol is taken, and 50 ml of an aqueous solution of 3% sodium dodecylbenzenesulfonate is added thereto to aggregate the colloid particles. A flushing operation in which 50 ml of methyl isobutyl ketone was added to the sol and vigorously shaken the sol was transferred to the organic phase of methyl isobutyl ketone and turned into a clear red blood. This sol (ultra-fine metal oxide powder, transparent iron oxide) with an electron microscope
Was measured to be 0.02 to 0.04 (μ).

(Reference Example 3) [How to prepare titanium oxide-based ultrafine particles] While stirring 500 ml of a 1% aqueous solution of titanyl sulfate, the concentration was 15%.
Is added at a rate of 20 ml / min to precipitate titanium hydroxide. After filtration, 80
Add 0 ml of dilute hydrochloric acid and heat to 70 ° C. When this is cooled to room temperature, a transparent titanium hydroxide hydrosol is obtained. Next, 50 ml of this sol was taken out and the concentration was 3%.
Was added to the surface of the colloidal particles, 50 ml of methyl isobutyl ketone was added, and the mixture was transferred to a methyl isobutyl ketone phase by a flushing operation of vigorous shaking. When the organic solvent was removed from the sol by heating under reduced pressure, a titanium oxide-based ultrafine particle powder was obtained. When the size of this powder was measured with an electron microscope, 0.01 to 0.0
2 (μ).

(Synthesis Example 1) 100 g of the aluminum paste of Reference Example 1 in which a cationic dispersant was adsorbed on the surface
3.5 g of ultrafine iron oxide particles having sodium dodecylbenzenesulfonate adsorbed thereto (solid content: 65%, solvent: methyl isobutyl ketone) were gradually added thereto, followed by heating and stirring at 30 ° C. for 10 minutes. The treated paste was filtered and dried to obtain 55 g of a red metallic pigment.

(Synthesis Example 2) 100 g of the aluminum paste of Reference Example 1 in which a cationic dispersant was adsorbed on the surface
(Solid content: 65%, solvent: methyl ethyl ketone) 4 g of titanium oxide ultrafine particles adsorbing sodium 2-ethylhexylsulfosuccinate was gradually added and mixed while stirring. The treated paste was filtered and dried to obtain 58 g of a metallic pigment.

(Synthesis Example 3) 20 g of the metallic pigment obtained in Example 1 was diluted with toluene and the solid content was adjusted to 4%. An acrylic silicon resin solution (Zemrack manufactured by Kaneka Chemical Industry Co., Ltd.) was added for 1 hour. After immersion, filtration and drying yielded 20.2 g of a metallic pigment coated with a resin.

(Synthesis Example 4) 100 g of an aluminum paste having a surface on which a cationic dispersant was adsorbed (solid content: 65
%, Solvent-methyl ethyl ketone), 2.0 g of titanium oxide ultrafine particles having sodium dodecylbenzenesulfonate adsorbed thereon was gradually added thereto, followed by heating and stirring at 35 ° C. for 15 minutes. The treated paste was filtered and dried to obtain 50 g of a metallic pigment.

(Synthesis Example 5) 0.5 g of ultrafine iron oxide powder was added to 100 g of the aluminum paste shown in Example 1 (solid content: 65%, solvent: methyl ethyl ketone).
After heating and stirring at 5 ° C. for 10 minutes, 45 g of a slightly red metallic pigment was obtained by filtration and drying.

(Synthesis Example 6) To 100 g of the aluminum paste shown in Example 1 (solid content: 65%, solvent: methyl ethyl ketone), 7.2 g of iron oxide ultrafine powder was added.
After heating and stirring at 0 ° C for 10 minutes, 62 g of a red metallic pigment was obtained by filtration and drying.

(Synthesis Example 7) A stearic acid was used in place of the cationic dispersant (stearyldimethylbenzylammonium chloride) in Reference Example 1, and the same treatment as in Reference Example 1 was performed to obtain an aluminum paste. The particle diameter measured by Microtrac was α = 32.1 (μ).

(Synthesis Example 8) 100 g of an aluminum paste having a surface on which a cationic dispersant was adsorbed (solid content: 65%)
%, Solvent-methyl isobutyl ketone) adsorbed sodium sulfosuccinate on ultrafine titanium oxide powder 0.4
g was added and the mixture was heated and stirred at 40 ° C. for 30 minutes. By filtering and drying the treated paste, the metallic pigment 60
g was obtained.

[0039]

[Table 1]

<Preparation of Resin> Methyl methacrylate 50
%, N-butyl methacrylate 40%, ethylhexyl methacrylate 8%, and acrylic acid 2% in a mixture of toluene using azobisisobutylnitrile as a polymerization initiator, heating residue 50%, resin viscosity Y (Gardner bubble viscosity (Total 25 ° C.) acrylic resin A was obtained.

(Examples and Comparative Examples) Preparation of Metallic Paint A mixture of acrylic resin A and the metallic pigments of Synthesis Examples 1 to 8 in the following ratio was mixed with a paint shaker to prepare a mixture.
By dispersing with shaking over time, a metallic paint was produced. Acrylic resin A 160 parts, metallic pigment 15 parts, xylene 25 parts (total 200 parts)

Preparation of Primary Color Paint The following formulation was shaken and dispersed with a paint shaker for 1 hour to prepare a blue primary color paint. Acrylic resin A
150 parts, xylene 20 parts, Helion Blue L64
70 (manufactured by BASF) 20 parts (total 190 parts)

The primary color paint and the prepared metallic paint were mixed at a ratio of 10: 1 (weight ratio) to prepare Examples and Comparative Examples.

The results are shown in Table 2.

[Table 2]

[0045]

As is clear from Tables 1 and 2, the overall weather resistance including the light resistance, alkali resistance, etc. of the pigment itself is improved as compared with the case where the conventional metallic pigment is blended in the paint. It was found to be excellent, had good dispersibility, and exhibited excellent coating properties such as no occurrence of bumps even when a coating was formed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C09C 3/12 C09C 3/12 C09D 5/00 C09D 5/00 Z

Claims (6)

[Claims] 1. A. B. Metal powder having a particle diameter of 1.0 to 100 μ with a cationic dispersant adsorbed on the surface. Particle diameter 0.0 with anionic dispersant adsorbed on the surface
1 to 0.1 μm of metal oxide ultrafine particles, and the weight ratio of A and B is A / B = 100/1 to 10
A paint containing a metallic pigment in which B is coordinated to the surface of A by ionic reaction at 0/10. 2. The use amount of the cationic dispersant is 0.5 wt% to 5 wt% based on the metal powder, and the use amount of the anionic dispersant is 1 wt% based on the metal oxide ultrafine powder.
The paint containing the metallic pigment according to claim 1, wherein the content is 5 wt%. 3. A paint containing a metallic pigment according to claim 1, wherein the metal powder is selected from aluminum, copper, brass, chromium, nickel, cobalt and stainless steel. 4. A paint containing a metallic pigment according to claim 1, wherein the metal powder is limited to aluminum. 5. A paint containing the metallic pigment according to claim 1, wherein the metal oxide ultrafine particle powder is limited to titanium oxide and iron oxide. 6. A synthetic polymer compound having a main chain comprising a silyl group-containing vinyl polymer and having at least one silicon group bonded to a hydrolyzable group at a molecular terminal or a side chain per molecule. A paint containing the metallic pigment according to any one of claims 1 to 5.