JPH07116482B2 - Aluminum alloy powder and paint for paint - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aluminum alloy powder for paint and a paint containing the alloy powder.

"Prior Art" Conventionally, aluminum powder has been used as a pigment for a dry paint used for outdoor silver paints for the purpose of reflecting heat rays and preventing the transmission of moisture. The shape of this aluminum powder is flakes with a width of 10 μm, a length of 30 μm and a thickness of 0.3 μm. When this powder is mixed with a resin and applied by brushing, spraying, etc., the surface of the aluminum powder produced when the resin hardens It can be laminated by the tension in parallel with the coated surface (leafing phenomenon), and a continuous aluminum coating can be formed to shield the material from the outside air, thereby imparting weather resistance, water resistance and moisture resistance.

However, the above-mentioned aluminum powder is made of crystalline aluminum, and a paint containing this powder cannot obtain sufficient corrosion resistance against acids such as hydrochloric acid, salts such as salt, and alkali such as caustic soda. There was a problem.

"Problems to be solved by the invention" The present invention has been made in view of the problems of the above-mentioned conventional techniques, and the object thereof is to form a good coating film state, as well as more excellent weather resistance and water resistance. Another object of the present invention is to provide an aluminum alloy powder for paint and a paint which can be provided with moisture resistance.

"Means for Solving the Problems" The aluminum alloy powder for coating according to the present invention has the general formula Al
a Mb Xc (where M is V, Cr, Mn, Fe, Co, Ni, C
u, Zr, Ti, Mo, W, Ca, Li, Mg, Si, one or more kinds of metal elements, X is Y, La, Ce, Sm, Nd,
One or more elements selected from Hf, Nb, Ta, and Mm [Misch metal] represent an element, and a, b, and c are 50% by atom.
≦ a ≦ 95, 0.5 ≦ b ≦ 35, 0.5 ≦ C ≦ 25. ), An aluminum alloy powder having a composition of amorphous or a mixed phase of amorphous and fine crystalline and having a thickness of 0.1 to
5 μm, aspect ratio (ratio of major axis to thickness) of 5 or more, minor axis and major axis of 5 to 500 μm.

Further, the paint of the present invention is characterized by containing at least a resin component for paint and the above-mentioned aluminum alloy powder.

"Function" The present inventors examined the corrosion resistance of aluminum alloys having various compositions and structures in order to obtain more excellent aluminum alloy powders for paints. As a result, it was found that an amorphous alloy made by quenching and solidifying a molten aluminum alloy having the above composition or an alloy consisting of a mixed phase of amorphous and fine crystalline has excellent corrosion resistance. It was also found that the surface gloss is excellent because it is made by quenching and solidification directly from the molten metal. As a result, it was found that by using the aluminum alloy powder having the above composition of amorphous or a mixed phase of amorphous and fine crystalline, it is possible to obtain a coating excellent in corrosion resistance such as water resistance, weather resistance, and moisture resistance. It was

The composition of the aluminum alloy is a composition that easily forms an amorphous phase by rapid solidification, and if the composition is out of the above range, it becomes difficult to form the amorphous phase, and as a result, sufficient Corrosion resistance cannot be obtained.

Also, regarding the shape of the powder, as a result of various studies on thickness, aspect ratio, minor axis and major axis dimension, in order to enhance the corrosion resistance effect by effectively causing the leafing phenomenon while maintaining a good coating film state. Was found to be required to fall within the above range. That is, the thickness is 0.1
If the thickness is less than μm, there is a problem in maintaining the corrosion resistance for a long time, and if the thickness exceeds 5 μm, the smoothness of the coating film becomes poor.
On the other hand, if the short diameter is 5 μm or less, the powder particles are not overlapped with each other, and if the long diameter exceeds 500 μm, the strength of the coating film is deteriorated. Further, if the aspect ratio is less than 5, the leafing phenomenon is unlikely to occur.

Since the coating material of the present invention contains the above-mentioned aluminum alloy powder, the surface to be coated is covered with the aluminum alloy powder due to the leafing phenomenon when applied, and excellent water resistance, weather resistance and moisture resistance are obtained. Further, it is also excellent in light reflectivity which is a characteristic of aluminum.

"Preferred Embodiment of the Invention" As a preferred method for producing the aluminum alloy powder of the present invention, a molten metal of the aluminum alloy having the above-described composition is caused to flow out from a nozzle, and a gas is sprayed to the molten metal to generate droplets of the molten metal. There is a method of causing the droplets to collide with the surface of the umbrella-type or horn-type rotary cooling body arranged in the droplet flow direction before solidifying to rapidly solidify the droplets. Then, if necessary, the powder having the above-mentioned shape characteristics may be separated from the obtained powder. According to this method, the aluminum alloy powder having the above-mentioned shape characteristics can be produced in a yield of 70% or more.

In the coating material of the present invention, the aluminum alloy powder is 5 to 20.
It is preferable that the content is vol%. Powder content 5
If it is less than vol%, the amount of the base material coating alone increases in the coating film at the time of coating, and the effect of powder mixing is not obtained. Also,
If it exceeds 20 vol%, the strength of the coating film becomes weak, and cracks, peeling, and the like occur, and processing adhesion deteriorates, which is not preferable.

As the resin component for paint, various synthetic resins used for paint can be freely used, but for example, vinyl resin, acrylic resin, polyurethane resin, epoxy resin and the like are preferably used. However, the resin component for coating material in the present invention is meant to include monomers and oligomers of those resins in the case of being cured after being applied.

In addition to the aluminum alloy powder and the resin component for paint, a solvent, a curing agent, a pigment, a thickener, a dispersant, a stabilizer and the like can be freely added to the paint of the present invention. The solvent is appropriately selected according to the resin used,
For example, xylene, toluene, alcohol, acetone, ethyl acetate, etc. are used. Also, as the type of paint, various types such as solvent type, emulsion type, solventless type, and powder type can be adopted.

The coating material of the present invention can be applied by various methods such as a brush coating method and a spray method. In this case, in order to disperse the aluminum alloy powder and make it adhere well,
Prior to coating, surface treatment may be performed using a surface treatment agent such as a surfactant or a covering agent, or a surface modifier.

"Example" FIG. 1 shows an example of an apparatus for producing the aluminum alloy powder of the present invention. That is, a nozzle 2 for flowing out a molten alloy 1 melted in a crucible (not shown) is installed, and an atomizing nozzle 3 for blowing a high-pressure injection gas to the falling molten metal 1 is installed.
The atomizing nozzle 3 is arranged, for example, in a circular shape so as to surround the nozzle 2, and has a structure for ejecting a high-speed gas from a large number of ejection ports toward the flow of the molten metal 1. Below the nozzle 2, an umbrella-shaped rotary cooling body 4 is disposed with its rotation axis slightly laterally displaced from directly below the nozzle 2.

Therefore, a high-pressure jet gas is sprayed from the atomizing nozzle 3 to the flow of the molten metal 1 flowing out of the nozzle 2 and falling, whereby droplets 5 of the molten metal 1 are formed. The droplets 5 spread and spread downward, collide with the conical surface of the rotary cooling body 4 and rapidly solidify to form flattened flaky alloy powder 6. In this embodiment, as the rotary cooling body 4, an umbrella type as shown in FIG. 2 (a) is used, but a horn type as shown in FIG. 2 (b) may be used. ..

The pressure of the gas injected from the atomizing nozzle 3 is preferably
40kg / cm ² or more. Further, as the injection gas, various kinds such as argon, helium, nitrogen, air or mixed gas can be used. Further, the rotary cooling body 4
Is preferably cooled to at least 50 ° C. or lower by means such as water cooling, and the rotation speed is preferably 1000 to 20000 rpm.

Test Example (Evaluation of Corrosion Resistance of Aluminum Alloy) After vacuum melting various aluminum alloys whose compositions are shown in Table 1, argon gas injection pressure was applied from a quartz nozzle with a hole diameter of 0.4 mm.
It was jetted at 1.0 kg / cm ² , and this molten metal was collided with a single roll rotating at a peripheral speed of 30 m / sec to obtain a ribbon. The obtained ribbon had a width of about 1 mm and a thickness of about 30 μm, and as a result of X-ray diffraction and TEM observation, it was confirmed that both were amorphous or a mixed phase of amorphous and fine crystals.

The various ribbons thus obtained were subjected to a corrosion test after being immersed in 1N-HC1 at 30 ° C for 3 hours and after being immersed in 1N-NaOH at 30 ° C for 3 hours. The evaluation was carried out based on the criteria that x is elution, Δ is surface change, and ◯ is surface change. Further, the toughness of each of the obtained thin strips was evaluated by determining whether or not 180 ° contact bending was possible. From the above-mentioned evaluation results of corrosion resistance and toughness, a comprehensive evaluation was made as ⊚ ... suitable for alloy powder for corrosion-resistant paint, and × unsatisfactory as alloy powder for corrosion-resistant paint.

For comparison, in addition to the above ribbon, commercially available Al (4
N), 2024 alloy, and Al-Si alloy were also subjected to the same test evaluation. These results are shown in Table 1 (described later).
Shown in.

From Table 1, it can be seen that No. 1 to No. 16, which are preferable aluminum alloy compositions in the present invention, can provide sufficient corrosion resistance when used as a powder for paints.

Practical example (1) Preparation of alloy powder Using the apparatus shown in FIG. 1, aluminum alloys having the compositions of sample Nos. 2, 5, 6, 9, 11, 14, and 15 in Table 1 (described later) were prepared. Each was placed in a crucible and melted at 1000 ° C. to obtain a molten metal 1.

This molten metal 1 is made to flow out from the nozzle 2 and dropped, and 100 kg / cm of argon gas is supplied from the atomizing nozzle 3 to the molten metal 1 to be dropped.
^A droplet of 5 is formed by spraying at a pressure of ² , and before the droplet 5 is solidified in the air, the roll diameter is about 200 mmφ and the cone angle is 90.
By colliding with a rotating cooling body having a rotation speed of 7200 rpm, a leaf-shaped flake-shaped alloy powder 6 was obtained.

Of the alloy powder obtained by the above method using the alloy of sample No. 5
A scanning electron micrograph at 90 times magnification is shown in FIG.

The alloy powders of the respective compositions obtained by the above method were classified, and those having the shape characteristics shown in Table 2 were separated. It should be noted that the preferred thickness of the present invention is 0.1 to 5
The yields of powders each having a micrometer, a minor axis, a major axis of 5 to 500 μm, and an aspect ratio (ratio of major axis to thickness) of 5 or more exceeded 70%.

The powder obtained by using the alloy of Sample No. 5 has a thickness of 0.5 to 4 μm, an aspect ratio (ratio of major axis to thickness) of 10 to 100, a minor axis and a major axis of 10 to 400 μm (Sample No. 5). .5-1), thickness less than 0.1 μm, aspect ratio (ratio of major axis to thickness) of 5 or more, minor axis and major axis 10 to
400μm (Sample No.5-2), thickness 0.5-4μm,
Aspect ratio (ratio of major axis to thickness) of less than 5, minor axis and major axis of 5 to 18 μm (Sample No. 9-3), spherical powder (Sample No. 5-4), thickness 0.5 to 4 μm, aspect ratio (ratio of major axis to thickness) of 5 or more, major axis of 500 μm
(Sample No. 5-5) were prepared.

Furthermore, for comparison, Al used in commercial paints
(4N) powder was prepared (Sample No. 19). This powder is
Thickness 0.3 μm, aspect ratio (ratio of major axis to thickness)
It is 5 or more and the minor axis and the major axis are less than 50 μm.

(2) Preparation of paint A paint was prepared by mixing 85 vol% of an acrylic resin as a resin binder and 15 vol% of each of the metal powders obtained above.

(3) Evaluation of coating film performance A SS41 steel plate having a thickness of 3 mm, a width of 20 mm and a length of 50 mm is prepared, subjected to sandblasting, and then ultrasonically cleaned in trichlene,
Each coating prepared above has a coating thickness of 100 μm
Brush painting was applied to the front and back. After drying, the state of the coating film was observed and a corrosion resistance test was conducted. The corrosion resistance test was carried out by immersing it in aqua regia at 20 ° C and examining the time for the base material to elute. The results are shown in Table 2 (described later).

From Table 2, sample Nos. 2 and 5 containing aluminum alloy powder composed of amorphous or mixed phase of amorphous and fine crystal
1, 5-2, 5-3, 5-5, 6, 9, 11, 14, 15 are
It can be seen that superior corrosion resistance can be obtained compared to sample No. 19 containing conventional Al (4N) powder. However, when the state of the coating film and the corrosion resistance were evaluated, Sample No. 2 containing a powder having a thickness of 0.1 to 5 μm, a minor axis and a major axis of 5 to 500 μm, and an aspect ratio (ratio of major axis to thickness) of 5 or more. 5,
It can be seen that -1, 6, 9, 11, 14, 15 are particularly preferable.

"Effects of the Invention" As described above, the aluminum alloy powder according to the present invention has a characteristic composition and is composed of an amorphous phase or a mixed phase of an amorphous phase and a fine crystalline phase, and therefore has excellent corrosion resistance. Also,
Since it has a specific shape characteristic, it is possible to effectively cause the leafing phenomenon while maintaining a good state of the coating film. Therefore, the coating material of the present invention containing this aluminum alloy powder can impart excellent water resistance, weather resistance and moisture resistance while maintaining a good coating film state.
Further, it is also excellent in light reflectivity which is a characteristic of aluminum.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an apparatus for producing the aluminum alloy powder of the present invention, and FIGS. 2 (a) and 2 (b).
Are views showing different examples of the rotary cooling body used in the apparatus, and FIG. 3 is a 90-fold scanning electron micrograph showing the particle structure of the amorphous alloy powder obtained in the example of the present invention. . In the figure, 1 is a molten metal, 2 is a nozzle, 3 is an atomizing nozzle, 4 is a rotary cooling body, 5 is a droplet, and 6 is a flake-like alloy powder.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Akihisa Inoue Kawauchi Muzenchi, Sendai City, Miyagi Prefecture Kawauchi Housing 11-806 (72) Inventor Masahiro Oguchi 1-9-9 Yaesu Chuo-ku, Tokyo Imperial Piston Ring Co., Ltd. (72) Yoshio Harakawa, Inventor, 1-9-9 Yaesu, Chuo-ku, Tokyo Teikoku Piston Ring Co., Ltd.

Claims (4)

[Claims] 1. A general formula Ala Mb Xc (where M is V, C
r, Mn, Fe, Co, Ni, Cu, Zr, Ti, Mo, W, Ca, Li, M
g, one or more metal elements selected from Si, X
Represents one or more elements selected from Y, La, Ce, Sm, Nd, Hf, Nb, Ta and Mm [Misch metal],
a, b, c are atomic% and 50 ≦ a ≦ 95, 0.5 ≦ b ≦ 35, 0.5 ≦
C ≦ 25. ), Which is an aluminum alloy powder having a composition represented by the formula (1) and having an amorphous phase or a mixed phase of amorphous and fine crystalline and having a thickness of 0.1 to 5 μm and an aspect ratio (ratio of major axis to thickness) of 5 or more, Minor axis and major axis 5-500 μm
Aluminum alloy powder for paints, characterized in that 2. A paint comprising at least a resin component for paint and the aluminum alloy powder according to claim 1. 3. The aluminum alloy powder is 5 to 20 vol%
The coating composition according to claim 2, which contains. 4. The paint according to claim 2 or 3, wherein the resin component for paint is selected from vinyl resin, acrylic resin, polyurethane resin, and epoxy resin.