JPS6241629B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a Zn alloy powder rust-preventing pigment for rust-preventing paints that can impart outstanding corrosion resistance simply by applying it to the surface of metal materials, particularly steel materials. In general, methods of melt-plating metals such as Zn or Zn alloys on the surface of metal materials, and methods of applying anti-rust paint are known as cheap and simple methods to improve the corrosion resistance of metal materials, especially steel materials. It is being However, the former method, fusion plating, requires a large amount of equipment and work space, and involves high-temperature work, so there are problems in that complicated operations and environmental measures must be taken. On the other hand, the latter method of applying a rust preventive paint has the advantage of simple equipment and work processes, but has the problem that the corrosion resistance of the resulting product is inferior to that of hot-dip plating products. In other words, rust-preventing paints often contain rust-preventing pigments to enhance their rust-preventing effects through chemical and electrochemical actions. , metal lead powder, aluminum powder, stainless steel powder, manganese powder, etc. Among these, zinc-rich paints, which contain more than 70% by weight of metallic Zn in their pigments, have recently attracted a lot of attention due to their high corrosion resistance, and are used for applications such as inside and outside fresh water tanks and water pipes that require long-term corrosion resistance, and other areas that are constantly submerged in water. It is put to practical use in a variety of areas, including corrosion protection of zinc materials such as chemical factory sashes, ship bottoms, and galvanized steel sheets. However, even with this highly corrosion-resistant zinc-rich paint, although it is easy to apply, it is currently unable to impart satisfactory corrosion resistance to steel materials in harsh usage environments. Therefore, from the above-mentioned viewpoint, the inventors of the present invention have developed a method for achieving excellent corrosion resistance by simply applying it to the surface of metal materials, especially steel materials, without requiring a large amount of equipment, work space, or difficult work. As a result of conducting various studies to find rust-preventing pigments that can impart
When Al and further Si are added, the corrosion resistance of the resulting Zn alloy is significantly improved due to the coexistence of Ti, Al, and Si. This is due to the fact that Zn alloy powder is uniformly and finely dispersed and precipitated, and the glossiness is also increased. Therefore, the powder of the Zn alloy is used as a rust preventive pigment, and is applied to various organic paints and inorganic paints. They discovered that when the surface of a material is coated with a paint as a binder, it exhibits significantly superior corrosion resistance even in a severe corrosive environment. Therefore, the present invention was made based on the above knowledge, and the rust preventive pigment was prepared using Ti: 0.1.
~6.0%, Mn: 0.1~6.0%, Al: 0.1~3.8%, and if necessary, Si: 0.01~0.7%, with the remainder consisting of Zn and unavoidable impurities (wt%) This Zn alloy powder has
By applying the alloy powder anti-rust pigment to the surface of metal materials, especially steel materials, with any binder,
It is characterized by maintaining extremely excellent corrosion resistance over a long period of time even under harsh and harsh environments. Next, the reason why the composition range of the Zn alloy powder rust preventive pigment of the present invention is limited as described above will be explained. (a) Ti The Ti component has the effect of improving corrosion resistance, but if the content is less than 0.1%, the desired excellent corrosion resistance cannot be secured, while if the content exceeds 6.0%, it will cause pulverization. Workability deteriorates rapidly,
Since it would be difficult to form it into powder, its content was set at 0.1 to 6.0%. Note that the content is preferably 0.5 to 4.0%. (b) Mn The Mn component has the effect of dissolving Ti in the Zn matrix, finely and uniformly dispersing partially precipitated Ti compounds, and further refining crystal grains to improve corrosion resistance. However, if its content is less than 0.1%, the desired effect cannot be obtained;
If the content exceeds 0.1%, the grinding workability will drop sharply like Ti, so the content was set at 0.1% to 6.0%. Note that the content is preferably 0.5 to 4.0%. (c) Al Al component has the effect of further improving corrosion resistance, especially in coexistence with Ti, and ensuring excellent corrosion resistance in severe corrosive environments, but its content is
If the content is less than 0.1%, the desired excellent corrosion resistance cannot be ensured, while if the content exceeds 3.8%, the corrosion resistance tends to deteriorate, so the content was set at 0.1 to 3.8%. In addition, 0.3
A content of ~2.0% is desirable. (d) Si The Si component has the effect of improving the fluidity of the molten Zn alloy, improving workability during powder compaction, and further improving the corrosion resistance of the Zn alloy powder.
It is included as necessary when these properties are required, but if the content is less than 0.01%, the desired effect of improving the above function cannot be obtained, while if it is added in excess of 0.7%, the molten metal will be damaged again. Since the fluidity decreases, the content is set at 0.01 to 0.7%. Note that the content is preferably 0.03 to 0.30%. The Zn alloy powder rust preventive pigment of the present invention is used together with organic paints and binders such as polyester, epoxy, phenol, and urethane, as well as inorganic paints and binders such as ethyl silicate. Of course, it may be used by directly adding it to various commercially available paints, and in either case it exhibits excellent corrosion resistance. Also, the amount of this Zn alloy powder rust preventive pigment added to the above paints and binders is
70 to 90% is good; if the amount added is less than 70%, satisfactory corrosion resistance cannot be obtained, while if the amount added exceeds 90%, the strength of the coating film will decrease. Further, the particle size of the Zn alloy powder rust preventive pigment is desirably 325 mesh or less in terms of spreadability and corrosion resistance when applied to the surface of the material. Next, the Zn alloy powder rust preventive pigment of the present invention will be explained using examples and comparison with conventional examples. Examples Each of the ingredients had the composition shown in Table 1.
Prepare molten Zn alloy by normal melting method and use spray method.

【table】

【table】

【table】

[Table] Zn alloy powder pigments 1 to 25 of the present invention and comparative Zn alloy powder pigments 1 to 4, each having a particle size of -325 mesh, were produced by powdering and adjusting the particle size using a sieve. In addition, comparison Zn
Alloy powder pigments 1 to 4 have a composition in which the content of one of the constituent components (those marked with * in Table 1) is outside the scope of the present invention.
It is manufactured from Zn alloy. Next, predetermined amounts of the resulting Zn alloy powder pigments 1 to 25 of the present invention, comparative Zn alloy powder pigments 1 to 4, and commercially available zinc powder pigments were added to various paints in the proportions shown in Table 1. added to,
The coating was applied to the surface of an acid-washed steel plate with a thickness of 0.6 mm by spraying so that the film thickness was 20 μm. Subsequently, on the steel plate with the coating film formed in this way,
We conducted a salt spray test based on JIS Z2371,
The time required for red rust to appear on the painted surface of the steel plate was measured. The measurement results are also shown in Table 1. From the results shown in Table 1, the steel sheets coated with paints containing Zn alloy powder pigments 1 to 25 of the present invention are significantly superior to the steel sheets coated with paints containing commercially available zinc powder. It is clear that the material exhibits excellent corrosion resistance. Furthermore, as seen in the steel sheets coated with paints containing Comparative Zn alloy powder pigments 1 to 4, if the content of any of the constituent components deviates from the range of the present invention, the desired excellent corrosion resistance may not be achieved. I know that I can't get it. As mentioned above, the Zn alloy powder rust preventive pigment of the present invention does not require a large amount of equipment or work space, nor does it require complicated work or environmental measures, and can be used on metal materials in any location. In particular, it brings about industrially useful effects such as being able to impart outstanding corrosion resistance just by applying it to the surface of steel materials.

Claims (1)

[Claims] 1 Ti: 0.1 to 6.0%, Mn: 0.1 to 6.0%, Al: 0.1
A Zn alloy powder rust-preventing pigment for highly corrosion-resistant rust-preventing paints, characterized in that it consists of a Zn alloy powder having a composition (by weight) of ~3.8% and the remainder consisting of Zn and unavoidable impurities. 2 Ti: 0.1-6.0%, Mn: 0.1-6.0%, Al: 0.1
High corrosion resistance characterized by being made of a Zn alloy powder having a composition (by weight) of ~3.8%, Si: 0.01~0.7%, and the remainder consisting of Zn and unavoidable impurities. Zn alloy powder rust prevention pigment for rust prevention paint.