JPS5849579B2 - pigment composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel anticorrosive pigment composition.

More specifically, the present invention relates to a novel anticorrosive pigment composition comprising a mixture of aluminum dihydrogen tripolyphosphate and zinc oxide.

Conventional anti-rust pigments include chromium pigments (e.g. zinc chromate, strontium chromate) and lead pigments (e.g. zinc chromate, strontium chromate).
For example, red lead (red lead, lead chromate) has been mainly used, but this has become a problem because it contains chromium and lead, which are toxic metals.

Zinc phosphate, zinc molybdate, which are less toxic,
Calcium molybdate, barium metaborate, etc. have been used, but they are still insufficient in terms of rust prevention.

The researchers of the present invention arrived at the present invention as a result of many years of research on aluminum dihydrogen tripo-IJ.

The present invention relates to a pigment compound that exhibits excellent rust prevention properties and is obtained by mixing aluminum dihydrogen tripolyte and zinc oxide.

That is, the aluminum dihydrogen tripolyphosphate itself is a solid acid, and its pH is usually 2 to 4. When used alone, it is acidic and tends to destabilize the resin and cause problems such as gelation, so it does not exhibit desirable pigment properties. Moreover, since it contains a large amount of water-soluble matter, it tends to swell when formed into a coating film.

On the other hand, zinc oxide is weakly basic and is said to have antirust properties, but its performance is not sufficient and it is not used as a general-purpose antirust pigment.

As a result of detailed studies on aluminum dihydrogen toripo IJ IJ, zinc oxide, and others, the inventors of the present invention have found that excellent protection can be obtained by mixing aluminum dihydrogen tripo IJ IJ and zinc oxide. Efforts have been made to obtain pigments which exhibit rusting effects and which, moreover, do not have any of the above-mentioned troubles that are observed when they are present alone.

That is, the aluminum dihydrogen tripolyphosphate is ZnO
When used in combination with the resin, the acidity is neutralized, so the destabilization of the resin as described above can be effectively avoided, and its solubility is controlled, so that it exhibits appropriate water solubility.

Therefore, from all aspects, it is possible to obtain a general-purpose rust-preventive pigment that accurately solves the problems of using aluminum dihydrogen tripolyte alone and exhibits favorable rust-preventive properties when formed into a coating.

Furthermore, it goes without saying that the insufficient rust prevention caused by using zinc oxide alone is fully covered.

The above-mentioned aluminum dihydrogen tripolyphosphate can be produced, for example, by the method of JP-A-50-52584,
It is a substance with the structural formula H2AlP301o.2H20.

Further, the quality of zinc oxide is not particularly limited, but generally any type of zinc oxide can be used as long as it is of pigment quality.

There is no particular limitation on the ratio when mixing aluminum dihydrogen tripolyphosphate and zinc oxide, but the ratio of zinc oxide/TripoIJ IJ excluding the range that is not much different from the case of aluminum dihydrogen tripolyphosphate and zinc oxide alone. A ratio of aluminum dihydrogen oxide between 1/20 and 10/2 exhibits good rust prevention properties.

Method of mixing aluminum dihydrogen tripolyte and zinc oxide (there is no particular limitation regarding this; simple dry mixing may be used, or a method of wet mixing and then drying may be used).

A coating film using the antirust pigment of the present invention exhibits rust prevention properties that are equivalent to or better than those using a chromium-based antirust pigment or a lead-based antirust pigment.

Although the details of why anti-rust pigments made of aluminum dihydrogen tripolyphosphate and zinc oxide exhibit excellent anti-corrosion properties cannot be completely elucidated, it is difficult to fully elucidate the details of why anti-rust pigments made of aluminum dihydrogen tripolyphosphate and zinc oxide exhibit excellent anti-corrosive properties.
Aluminum dihydrogen chloride alone has considerable rust prevention properties, and by mixing it with zinc oxide, as mentioned above, the problems of using these alone can be effectively solved, and moreover, some kind of synergistic effect occurs. It is thought that the rust prevention properties are further improved.

Also, by mixing with zinc oxide, Tolipo IJ I
There are also advantages such as better storage stability of the paint than when using aluminum dihydrogen chloride alone, and less blistering when submerged in paint test.

To further explain these relationships, trypo IJ I
The pH change when zinc oxide is added to aluminum dihydrogen chloride alone is summarized as shown in the attached drawing; it becomes rapidly neutralized with a small amount of addition, and when ZnO is not added, the pH is below 3. What was there became pH 4.5 with the addition of 5 parts of ZnO, and with 10φ the pH was 5.5, 15%.
In this case, the pH value becomes 6, and if the addition is more than that, the pH value becomes flat.

The solubility is shown in Table 1 below, and Z
When nO was 0%, it was 1.46.9/100g water, but it was 0.46.9/100g water. 0.17g/lOOg with 5% ZnO addition
Sharpen with water.

A specific manufacturing example of the product according to the present invention will be described below.

Production example 1 A mixture of commercially available monoaluminum phosphate type C and diatomite as an extender at a weight ratio of 1:1 was used as a raw material, and heated at 400°C with 1.5 kg of water using a turbo dryer.
After calcining in an atmosphere of /kgair for 1 hour, the mixture was washed with water and crushed to obtain a mixture of trypoIJ aluminum dihydrogen phosphate and diatomaceous earth.

The unit of kg water/kg ir is as follows:
It does not necessarily refer to a mixed gas of only water and air, but is a representation of gases other than water converted to air.

This aluminum dihydrogen tripolyphosphate was dry mixed with zinc white in an amount equivalent to 10% of aluminum dihydrogen tripolyphosphate to obtain a product according to the present invention.

Usage Examples: The product of the present invention and each of the rust-preventive pigments shown in Table 2 below were added in a proportion of 35% by weight to a long oil alkyd resin (Betsukosol P-470 manufactured by Inu Nippon Ink Co., Ltd.), and precipitated barium sulfate and talc were added. Extender pigment was added thereto, and each rust-preventive paint was prepared by dispersion treatment for 45 minutes using a paint conditioner as a dispersion machine.

However, the test panel was made by brush painting on a mild steel plate with 40 μm (
Two coats were applied to a thickness of approximately 100 g/m'') and used after drying.

A salt water spray resistance test (500 hours in 5 cups of salt water) was conducted on the test panel thus obtained.

The results are shown in Table 3.

- Shows the results of measuring blisters in a water immersion test after 500 hours.

In addition, Table 4 below shows that 3 steamed saline solutions are available at room temperature. However, the evaluations in Tables 3 and 4 above are based on ASTM
714-59 (Fukure) and ASTM D610-68
(rust) and are as follows.

In other words, the product of the present invention has the highest evaluation value of "5" for both rust and blistering, and in Table 3, it is completely equivalent to zinc chromate, which is generally considered to have the highest rust prevention effect. Also, in Table 4, it was confirmed that the zinc chromate was higher than that of zinc chromate.

Furthermore, regarding the anti-rust pigments shown in Tables 3 and 4 above, a comparative test was conducted to determine the toxicity of TripoIJ aluminum dihydrogen phosphate itself, which is the material of the product of the present invention, and zinc chromate and red lead as comparison thereof. The results are summarized in Table 5 below.

In other words, the LD5o value is the dose (■
), it is clear that the product of the present invention or its material is more than two orders of magnitude less toxic than zinc chromate or red lead, and has almost no toxicity.

Production Example 2 α-Alumina and 85-line phosphoric acid were mixed so that P205/Al203 was 2.9, and the mixture was evaporated to dryness and used as a raw material.

Using a band dryer using a gas mixture made by mixing this raw material with light oil combustion gas, air, and water, 400' GO. 9kgwater/kga
AlH
Make 2P301o-1, absorb water and crush it to form H2AlP.
301o.2H20 was used as a comparison product, and a product of the present invention was prepared by adding 30 weight more zinc oxide to this product, wet mixing in water, and drying.

The products of the present invention and comparative products obtained as described above were subjected to dispersion treatment by adding 35% of rice cake by weight to the long oil alkyd resin and adding the same extender pigment as in the usage example described in Production Example 1. Each anti-corrosion paint was applied to a test panel and subjected to a salt water spray test (500 hours in 5φ salt water) and immersion in salt water at normal temperature after 500 hours in the same manner as in Production Example 1. The test results (blister) are summarized in Table 6 below.

In this case, the comparative product produced a hard cake in the storage stability test at 40°C for 1 month, similar to the iron phosphate in Example 1, whereas the rust-preventive paint of the present invention was extremely stable. It was something.

Production Example 3 Tolipo IJ, a comparative product in Production Example 2. A paint was prepared with the following formulation using an anti-rust pigment made by mixing aluminum dihydrogen oxide and zinc oxide in a ratio of 2:1.

Rust preventive pigment 17 parts extender pigment
48 parts Watersol (S
-100D) [Solid content 60 buns] 83 parts Dilution water (20 buns) 60 parts Dryer (lead naphthenate 16φ, cobalt naphthenate 2%) 1 part 20
9 parts The results of testing and measuring the rust prevention properties and paint stability of the paint made from the product of the present invention obtained as described above, together with the comparative product in Production Example 2 and the paint made from zinc oxide alone, are as follows.

Immediately apply each of the above paints to a steel plate with a brush to a film thickness of 60 mm.
Table 7 shows the results of a salt spray test after drying at room temperature for 7 days and a storage stability test after storage at room temperature for 1 month.

However, the rust prevention evaluation in Table 7 above is as appended to Table 4 above.

Production Example 4 Using the anticorrosive pigment obtained in the same manner as in Production Example 3, a paint having the following formulation was prepared.

Neutral alkyd resin (Dainippon Ink Co., Ltd. 1334EL (NV50) 100 parts Rust preventive pigment 14 parts Barita (Ba
SO+) 2 5 parts talc
37 parts ocher (Mapico XLO manufactured by Titan Kogyo Co., Ltd.) 14 parts Dryer (24 parts lead naphthenate and 5 parts cobalt naphthenate 2:1) 2.2 parts paint thinner 35 parts 227.2 parts The above paint was coated with a bar coater. It was applied to a mild steel plate to a film thickness of 40 μm, dried for one week, and then subjected to a salt spray test. The results are shown in Table 8 below, along with a comparative product and a single zinc oxide product, as in Production Example 3.

That is, when the above results are taken together, Toripo IJ I
The rust-preventing pigment of the present invention, which is a mixture of aluminum dihydrogen chloride and zinc oxide, is a very excellent rust-preventing pigment, with a corrosion resistance equivalent to (see Table 3) or better than that of zinc chromate (see Table 3).
It has the following properties (see Table 4), has almost no toxicity, is stable in resins, has appropriate solubility, and is favorable in terms of paint stability, and is suitable for industrial use. It is clear that this invention has great effects.

[Brief explanation of the drawing]

The drawing is a chart showing the state of pH change when ZnO is added to TripoIJ aluminum dihydrogen phosphate in the present invention.

Claims (1)

[Claims] 1. Rust-preventing pigment composition consisting of aluminum dihydrogen tripolyphosphate and zinc oxide.