TW200414953A - Method of preparing Zn/A1 metal powder - Google Patents

Abstract

A method of preparing Zn/Al metal powder comprises mounting an aluminum powder in a zincate aqueous solution to perform a zinc substitution reaction in order to prepare a Zn/Al metal powder, in which water used to prepare the zincate aqueous solution has been subjected to an oxygen removal treatment, and the zinc substitution reaction is carried out in an oxygen-free environment, and/or, on completion of the zinc substitution reaction, the Zn/Al metal powder is subjected to a perhydrogen reduction reaction in a hydrogen-containing gas. A Zn/Al metal powder produced according to the invented method is applicable on a coating having anti-corrosion and anti-oxidation effects.

Description

200414953 发明 发明, description of the invention (the description of the invention should state: invention: power, prior technology, content, implementation and simple description of the drawings) The technical field of Dengming belongs to the present invention is mainly related to a method for preparing a composite metal powder, In detail, it relates to a method for preparing an inscription metal powder 'and the use for making an inscription zinc metal powder. Prior art Among various coatings, zinc-rich paints ’ZRP have a better anti-corrosive effect than other coatings. The corrosion resistance provided by zinc coatings is closely related to the metal powders contained in them. Among metal powders, the particle size of the powder, the zinc metal substitution ratio, and the reactivity of zinc metal all affect the properties of the coating containing the metal powder. Among zinc-containing metal powders, aluminum-zinc metal powders are the most commonly used by users, because zinc metal is more active than iron metal. In addition to being able to isolate substrates (such as steel) from external corrosive environments, it can also be used as an electrical source. Insulation protection, but due to the poor reaction between pure zinc metal powder and the binding agent in the coating, and the coating using pure zinc powder, with time, the surface color of the pure zinc powder coating will gradually become white and affect the appearance; Aluminum metal can form a durable aluminum oxide on its surface, which can provide substrate protection in most environments (Friel, JJ and Townsend, Η.E., Corrosion resistance of zinc and zinc aluminium alloy coating. Sheet Metal Industries, September 1983: 506-507), so the inscription metal powder is the main component of the current paint. Traditionally, the preparation of zinc-containing metal powders is made by processing zinc alloy blocks into powders (Leclercq, M., Production of zinc and zinc-alloyed dusts by 200414953

fine-atomization. JOCCA, 1987 (1 0): 290-299; Townsend, HE and Borzillo, AR, Thirty-year atmospheric corrosion performance of 5 5% aluminum-zinc alloy-coated sheet steel. MP, April 1996: 30- 36) ^ The process uses smelting. After melting the metal material at high temperature, it is cooled to form a metal alloy ingot and ground to a powder state under the protection of water spray. However, this method cannot obtain high-purity metal powder and consumes extremely energy. If you want to produce zinc metal aluminum zinc metal powder directly on the surface of aluminum powder, you can use (1) mechanical metallurgy: use the collision of grinding ball-powder-grinding ball to produce repetition of welding, cracking and re-welding between powder mixture Step 骡 to achieve the effect of alloying metal powder; and (2) impregnation reaction method: the redox reaction of the metal with cations in the solution is used to oxidize and dissolve the metal surface atoms, and to reduce the precipitation of cations in the solution. Also known as displacement reaction. In the replacement reaction of aluminum-zinc metal powder, because aluminum and zinc are both amphoteric elements, and aluminum is more active than zinc, zinc substitution reaction can be used to generate zinc on the aluminum surface. The reaction is as follows: Anode reaction: A1 + 30H · □ Al (OH) 3 + 3e · Α1 (ΟΗ) 3 □ Α102 · + Η2〇 + Η + Cathode reaction: Zη (ΟΗ) 42- □ Zη2 + + 40Η-Zη2 + + 2e · □ Zη Η + + e * □ 1/2 Η2 The general zinc replacement reaction is performed with an experimental zincate solution. Different crystal sizes can be obtained by adjusting the concentration of zincate. Among them, the reaction with a lower concentration zincate solution can Zinc with coarser grains and a dendritic structure is obtained, and when reacted with a higher concentration of zincate, fine grains can be formed. 200414953

(3) Consistent and tightly adhered zinc. In addition, the zinc replacement reaction can adjust the reaction time to control the proportion of the zinc layer to be formed. Although the anti-corrosion effect of zinc coatings is better than other forms of coatings, however, as the service life of the substrate increases, more and more anti-corrosion effects and longer-life coatings are needed. This anti-corrosion effect is similar to that of composite aluminum. Whether the two metals of zinc metal powder can be closely adhered to each other and the anti-corrosion ability of the surface metal layer are related. Based on this, the present invention is devoted to the development of a novel and progressive method for preparing aluminum zinc metal powder and aluminum zinc metal powder. And coatings to achieve the purpose of increasing the anti-corrosion effect and extending the service life. SUMMARY OF THE INVENTION The object of the present invention is to provide a method for preparing an aluminum-zinc metal powder, which comprises placing a powder in a zincate solution prepared with water and performing a zinc replacement reaction to obtain the aluminum-zinc metal powder, which is used for blending. The water system of the zincate solution is deoxidized, and the zinc replacement reaction is performed in an anaerobic environment. Another object of the present invention is to provide a method for preparing aluminum-zinc metal powder, which comprises placing aluminum powder in a zincate solution prepared with water to perform a zinc replacement reaction to obtain the aluminum-zinc metal powder. The aluminum-zinc metal powder undergoes hydrogen reduction reaction in a gas containing hydrogen. Still another object of the present invention is to provide a method for preparing aluminum-zinc metal powder, which comprises placing aluminum powder in a zincate solution prepared with water to perform a zinc replacement reaction, thereby preparing the aluminum-zinc metal powder, which is used for The water system in which the zincate solution is prepared is deoxidized. The zinc replacement reaction is performed in an anaerobic environment. After the zinc replacement reaction is completed, the aluminum-zinc metal powder is subjected to hydrogen reduction in a gas containing hydrogen. reaction. 200414953 (4) _speak_continued embodiment Embodiment The method for preparing the aluminum-zinc metal powder provided by the present invention is characterized in that the reaction is performed in an oxygen-free environment, and / or a hydrogen reduction reaction is performed after the reaction is completed to reduce the metal The oxides on the surface of the powder can be reacted and reduced by hydrogen in the absence of oxygen in the method of the present invention. The method for preparing the aluminum-zinc metal powder according to the present invention is performed by a zinc replacement reaction, and the reaction solution of the zinc replacement reaction is a zincate solution prepared with water, wherein the water system is subjected to deoxidation treatment. The deaeration treatment of the present invention may be any conventional method, and the method of implementation is determined by those skilled in the art. In one embodiment of the present invention, the deoxidizing treatment of the water is to reduce the oxygen content in the water by heating, and at the same time, an inert gas, preferably argon, is passed, and zinc is formulated with the deoxidized water. Set and change the reaction solution. In one embodiment of the present invention, the zinc replacement reaction solution is an alkaline zincate solution to provide zinc ions, such as an aqueous zinc oxide solution containing sodium hydroxide. The concentration of the test zincate solution can be adjusted according to the desired grain size. According to the present invention, the zinc replacement reaction is performed in an oxygen-free environment. In one embodiment, in order to continuously introduce an inert gas into the reaction solution, argon is preferably used to maintain the oxygen-free environment. On the other hand, the proportion of the zinc layer to be formed can be determined by the time of the zinc replacement reaction. At the beginning of the reaction, the amount of zinc replacement increases with the increase of the reaction time. However, in the middle and late stages of the reaction, the zinc replacement reaction solution is strongly alkaline. It will corrode aluminum on the surface of metal powder and cause irregular changes in the content of zinc and aluminum. The relationship curve between the replacement reaction time and the replacement ratio of zinc layer can be quickly obtained by those skilled in the technology through simple experiments. The displacement reaction can be easily changed by changing the pH of the reaction solution, such as ^ 414953

It is known that a large amount of water is added to the reaction solution to neutralize pH and terminate. After the reaction of the metal powder, the water on the surface of the metal powder can be removed with an appropriate organic solvent, such as propylene, after neutralizing its acidity. Another feature of the present invention is that after the zinc replacement reaction, the reaction is reduced by perhydrogen: the oxide content of the zinc layer on the surface, which is to place the ... powder on the surface of the aluminum zinc metal powder by using hydrogen The oxide also

In this case, the only preferred example is that the hydrogen reduction reaction is performed at a temperature of about 350 ° C and 5500 ° C, and more preferably at about 40 ° C to promote and accelerate the reaction. According to the invention, according to the reaction time required for the reduction of the zinc metal powder surface, in one embodiment, the hydrogen reduction reaction is performed for about 1 hour under heating. μ According to the present invention, in order to maintain the reducing center of the metal surface after the hydrogen reduction treatment, the metal powder of the present invention is preferably stored in an oxygen-free environment, and the far metal powder is stored in isopropanol (is〇pr). 〇pyl alc〇h〇i) to isolate the oxygen in the environment. Aluminum-zinc metal powder manufactured according to the method of the present invention

The genus are closely adhered to each other, and no interface is generated, and the oxidization of the aluminum-zinc metal powder is much lower than that of the conventional aluminum-zinc metal powder. The method for preparing the zinc zinc metal powder of the present invention is preferably applied to coatings. Because the aluminum-zinc metal powder aluminum prepared by the present invention adheres tightly to each other and has a relatively low oxidation state, the coating has better corrosion effect than conventional coatings, and has a longer service life. New coating with great advantages. The invention is explained in detail, but does not mean the invention -10-200414953

(6) Limited to what is disclosed in these examples. Example 1: Preparation of Mingsai Metal Powder Co., Ltd. 7 lC oxygen removal treatment. • Distilled water is heated to boiling, and argon gas is continuously introduced during heating to remove oxygen in distilled water. Distilled water after deaeration is sealed and cooled to room temperature for later use.

Weng replacement reaction solution: The zinc replacement reaction solution in the example is zinc oxide (211〇) 7.5§ / [and sodium hydroxide ^ & 011) 8 (^ / 1 ^, which is the County preparation reaction: 40 g of aluminum complex powder is added to 1 L of water after deoxidation treatment, and a small amount of neutral wetting agent is added, and then the zinc replacement reaction solution is slowly added and stirred uniformly, the reaction time is 15 seconds to 10 Within 5 seconds, when the reaction time was stopped, a large amount of steam was added to replace the acidity of the zinc to replace the reaction solution, and then the reaction was completed to obtain the aluminum-zinc metal powder by filtration, and the powder was washed with water until the pH was neutral, and then acetone The metal powder is washed to remove moisture. During this part of the operation, argon gas must be introduced into the liquid throughout the process to drive out oxygen.

Passing by .. and friends ... The aluminum-zinc metal powder prepared in the above step was heated to 400 □ for 1 hour in hydrogen to carry out the hydrogen reduction reaction, and the powder obtained was treated differently. Preserved in propanol. Example 2: Fe zinc .. The rest of the powder is more susceptible to germination-should be a plasma __ mass spec analysis:% fixed weight aluminum zinc metal powder is added to 1: 1 nitric acid to fully dissolve The metal powder is then heated to dryness to remove nitric acid, deionized water is added, and then evaporated. After repeating this operation several times, the solution is diluted with deionized water to a concentration of 40 ppm. -11-200414953 The results of the inductively coupled plasma mass spectrometry analysis are listed in Table 1 below. At the beginning of the zinc replacement reaction, the weight percentage of zinc increased from 17.80% to 51.46%, and the weight percentage of aluminum decreased from 82.20% to 48.54%. It can be seen that with the reaction time With the increase, the amount of zinc substituted aluminum also increased. However, in the middle and late stages of the reaction, the zinc replacement reaction tended to ease. Also, the aluminum on which the zinc replacement reaction did not occur on the surface of the metal powder was attacked by a strong alkali, and the amounts of zinc and aluminum did not Rule change 0 Table 1: Reaction time (seconds) Zinc weight percentage (%) Zinc weight percentage (%) 15 17.80 82.20 30 3 1.73 68.27 45 5 1.46 48.54 60 46.20 53.80 75 40.03 59.97 90 40.88 59.12 105 50.98 49.02 X-ray X-ray diffraction analysis of the structure and phase composition of aluminum-zinc metal powder using copper as the material 'Scanning electric dust is 30 KV' Current is 2011 8 and scanning rate is 3 ° / 11 ^ 11, the range is 30. to 50. See Figure 1. There are only two aluminum crystal surfaces of the unreacted aluminum powder, which are (1 1 2) and (2 0 0). After the zinc replacement reaction, the zinc grains Began to grow in a nucleus and grow in four directions (002), (100), (101), and (102). Between 15 seconds and 45 seconds of reaction time, the intensity of zinc on the surface of aluminum powder increased with the increase of reaction time. The intensity of aluminum is relatively weakened. This result is inductively coupled plasma mass spectrometry 200414953

⑻ The analysis results are similar. Scanning electron microscope and energy dispersive spectrum analysis: The high-resolution field emission scanning electron microscope (Hitachi S-4 10 0) was used to analyze the aluminum-zinc metal powder to observe the surface shape of the powder, and the energy dispersive spectrum analysis The instrument performs qualitative, semi-quantitative and surface analysis of surface elements.

At the initial stage of the reaction, the surface shape of the metal powder was slightly pitted due to strong alkali attack, and at this time, the aluminum element was more than zinc; as the reaction time increased, see Figure 2, the appearance of the powder gradually became smooth, and the zinc The proportion gradually increases; at the middle and late stages of the reaction, the powder surface begins to become rough again, and the pits and pits are more and more. The entire appearance is irregular, and the proportion of zinc is greater than the proportion of aluminum. The principle and effect of the invention are not intended to limit the present invention. Therefore, the modifications and changes made by those skilled in the art to the above embodiments still do not depart from the spirit of the present invention. The scope of rights of the present invention should be listed in the patent application scope mentioned later. Simple illustration

The present invention will be further illustrated by the following diagrams, wherein FIG. 1 shows X-ray diffraction analysis diagrams of aluminum powder and aluminum-zinc metal powder under different reaction times; and FIG. 2 shows aluminum-zinc metal that undergoes zinc replacement reaction for 45 seconds. Scanning electron micrograph of powder surface shape. Description of component symbols 1 represents the curve of zinc replacement reaction 4 5 seconds 2 represents the curve of zinc replacement reaction 30 seconds -13-200414953

(9) 3 shows the curve of zinc replacement reaction for 15 seconds 4 shows the curve of unreacted powder

Claims (1)

200414953 Scope of application and patent application 1. A method for preparing aluminum-zinc metal powder, which comprises placing aluminum powder in a zincate solution prepared with water to perform a zinc replacement reaction to obtain the zinc-zinc metal powder, wherein: The water system in which the zincate solution is prepared is deoxidized, and the zinc replacement reaction is performed in an anaerobic environment. 2. The method according to item 1 of the scope of patent application, wherein the zincate solution is an experimental zincate solution. 3. The method according to item 1 of the scope of patent application, wherein the oxygen removal treatment of the water is heating the water, and an inert gas is passed during the heating. 4. The method according to item 1 of the scope of the patent application, wherein the zinc replacement reaction performed in an oxygen-free soil is to introduce an inert gas to drive out oxygen during the reaction. 5. The method according to claim 3 or 4, wherein the inert gas is argon. 6. The method according to item 1 of the scope of patent application, wherein the produced aluminum-zinc metal powder is used for preparing coatings. 7. A method for preparing an aluminum-zinc metal powder, comprising placing the aluminum powder in a zincate solution prepared with water to perform a zinc replacement reaction, thereby obtaining the aluminum-zinc metal powder, and then subjecting the aluminum-zinc metal powder to The hydrogen reduction reaction is performed in a gas containing hydrogen. 8. The method according to item 7 of the scope of patent application, wherein the hydrogen reduction reaction of the aluminum-zinc metal powder is heated in a gas containing hydrogen to 350 ° C to 550 ° C. 200414953 Patent Application Continued 9. The method according to item 7 of the scope of patent application, wherein the hydrogen reduction reaction of the aluminum-zinc metal powder is heated to 400 in a gas containing hydrogen. (:. 1 10. The method according to item 7 of the scope of patent application, wherein the reaction time of the hydrogen reduction reaction is sufficient to reduce the oxide on the surface of the aluminum zinc metal powder. 1 1. The method according to item 7 of the scope of patent application The aluminum-zinc metal powder prepared therein is used for preparing coatings. 1 2. A method for preparing aluminum-zinc metal powder, which comprises placing aluminum powder in a zincate solution prepared with water to perform a zinc replacement reaction, and The aluminum-zinc metal powder is prepared, wherein: the water system used for preparing the zincate solution is subjected to deoxidation treatment, the zinc replacement reaction is performed in an oxygen-free environment, and after the zinc replacement reaction is completed, the aluminum The zinc metal powder is subjected to hydrogen reduction reaction in a gas containing hydrogen. 1 3. The method according to item 14 of the scope of the patent application, wherein the zincate solution is an experimental zincate solution. 1 4. According to the patent application The method according to item 14 of the scope, wherein the oxygen removal treatment of the water is to heat the water and pass in an inert gas during the heating. 1 5. The method according to item 14 of the scope of patent application, wherein the method is performed in an oxygen-free environment. Zinc The reaction is to introduce an inert gas to expel oxygen during the reaction. 16. The method according to item 14 or 15 of the scope of the patent application, wherein the inert gas is nitrogen. 200414953 Round yeast. Page. 1 7. According to the scope of patent application The method according to item 14, wherein the aluminum-zinc metal powder is heated in a gas containing hydrogen to 350 ° C to 55 ° C. 18. The method according to item 19 in the scope of patent application, wherein The aluminum-zinc metal powder is heated to 400 ° C in a gas containing hydrogen. 1 9. The method according to item 14 of the scope of the patent application, wherein the reaction time of the perchloride reduction reaction is sufficient to reduce the surface of the aluminum-zinc metal powder. Oxide 2 0. The method according to item 14 of the scope of the patent application, wherein the produced aluminum zinc metal powder is used for preparing coatings.