JPH03146567A - Rustproof pigment composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition usable as a vehicle of various paints having excellent rustproofing effect, white color capable of freely harmonizing color, inducing no environmental pollution, containing no harmful metal comprising a condensed phosphate of hardly soluble in water and zinc compound, etc. CONSTITUTION:Condensed phosphate (preferably aluminum dihydrogen tripolyphosphate or aluminum metaphosphate) of hardly soluble in water regulating the content of particles thereof having >=5mum particle diameter to <=5vol.%, preferably <=1vol.% is mixed with a zinc compound (preferably zinc oxide) and/or alkaline earth compound (e.g. carbonate, phosphate, borate or sulfate, etc., of Mg, Ca or Ba, etc.) to afford the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rust-preventing pigment composition. More specifically, the present invention relates to an anti-w# pigment & II paraboloid that does not contain harmful metals, can be used in various paint vehicles, and has excellent rust-preventing effects.

[Prior Art] Conventionally, anti-rust pigments for oil-based paints and solvent-based paints include chromium-based pigments (e.g., zinc chromate, strontium chromate, etc.), lead-based pigments (e.g., red lead, basic lead chromate, etc.). lead cyanamide, calcium leadate, etc.)
, phosphate pigments (e.g., zinc phosphate, calcium phosphate, etc.), molybdate-based pigments (e.g., zinc molybdate, etc.), boric acid-based pigments (e.g., barium metaborate, etc.), etc. were used (e.g., Japanese Patent Publication No. 53-39894, Japanese Patent Publication No. 50-104799
(Japanese Patent Publication No. 53-31495, etc.).

[Problem to be solved by the invention]

Among these, chromium-based rust-preventing pigments and lead-based rust-preventing pigments have some excellent rust-preventing effects, but since chromium and lead are toxic metals, they pose safety concerns such as harming human health. There was a problem.

On the other hand, phosphoric acid-based rust-preventive pigments, molybdate-based rust-preventive pigments, boric acid-based rust-preventive pigments, etc. are so-called non-polluting rust-preventive pigments that pose few safety problems, but have low rust-preventing effects. However, there were problems in that it lacked versatility, especially in terms of durability and deteriorated some paint resins.

Therefore, an object of the present invention is to provide an anti-M paint composition that does not contain harmful metals such as hexavalent chromium, can be used in various paint vehicles, and has an excellent rust-preventing effect. do.

[Means to solve the problem]

The present invention uses 5% by volume of rust-preventive pigments with a particle size of 5 μm or more.
H in the water below? The above object is achieved by comprising a composition comprising a V-type condensed phosphate, a zinc compound, and/or an alkaline earth compound.

That is, when condensed phosphates dissociate in water, they release polyphosphate ions that have a strong effect of sequestering iron ions, so they have a strong rust-preventing effect.In the present invention, among these condensed phosphates, , by using fine particles with a particle size of 5 μm or more and 5% by volume or less, which has a particularly excellent rust preventive effect, and by using a zinc compound and/or an alkaline earth compound. By neutralizing the pH of the condensed phosphate and preventing the condensed phosphate from degrading the coating resin, we are expanding the scope of use of the coating resin and increasing its versatility. .

The above-mentioned condensed phosphates are, as described below, aluminum salts, iron salts, zinc salts, etc. of condensed phosphates, and do not contain harmful metals such as chromium or lead. &1) Kaimono is white, and when used as an undercoat or brusher, its color can be freely selected.

Examples of the above-mentioned condensed phosphates that are sparingly soluble in water include aluminum dihydrogen tripolyphosphate, aluminum metaphosphate, zinc tripolyphosphate, iron tripolyphosphate, etc. In particular, condensed phosphates such as aluminum dihydrogen tripolyphosphate and aluminum metaphosphate are used. Aluminum phosphate salts are preferably used.

The above aluminum dihydrogen tripolyphosphate has the chemical formula AI
) f, P! O.・It is a substance represented by 2H,O,
For example, it can be manufactured by the method described in Japanese Patent No. 856,386. That is, aluminum or aluminum-containing substances and phosphorus-containing substances are combined with P, O, /
A1.0. A mixture with a molar ratio of 1 to 6 is heated and stirred at 90 to 450'C to form an opaque solid material, which is then reheated at 300 to 450'C to dehydrate and crystallize it. By this, aluminum dihydrogen tripolyphosphate is obtained.

In addition, aluminum metaphosphate has the chemical formula A1 (POs
) The substance represented by s includes A-type, B-type, C-type, D-type, and E-type aluminum metaphosphate.

These aluminum metaphosphates, for example, combine aluminum or aluminum-containing substances with phosphorus-containing substances in P!
The molar ratio of os/A Ito is 1.1 to 3, and the mixture is reacted, dried at 100 to 200°C, fired at 250 to 450"C, and further heated at 450 to 450"C.
It is obtained by firing at 800°C and then pulverizing. In addition, 400% aluminum dihydrogen tripolyphosphate
Aluminum metaphosphate can also be obtained by firing at ~900°C.

The aluminum-containing substances used in the production of aluminum dihydrogen tripolyphosphate and aluminum metaphosphate include aluminum oxide, aluminum hydroxide, and the like, and the phosphorus-containing substances include phosphoric acid, phosphorus pentoxide, and the like.

In order to obtain a water-insoluble condensed phosphate containing 5% by volume or less of particles with a particle size of 5 μm or more, the condensed phosphate such as the above-mentioned aluminum dihydrogen tripolyphosphate or aluminum metaphosphate is wet-pulverized or dry-classified. obtained by.

In the wet pulverization method, for example, the above condensed phosphate is placed in a stainless steel hexel, water and media are added as media, and the particles are dispersed using a shaft with a disc until particles with a diameter of 5 μm or more become 5% by volume or less. do it. For this wet grinding, a sand grinder mill, pingel, etc. are usually used.

As a method of dry classification, a crusher with a classification function,
The operating conditions of a dry classifier or the like may be set appropriately according to the content of particles with a particle size of 5 μm or more, and the particles may be classified until the particles with a particle size of 5 μm or more become 5% by volume or less.

In the present invention, the reason why a condensed phosphate salt which is sparingly soluble in water is used as a component of the anti-w # pigment composition is as described above.
This is because condensed phosphates have a strong sequestering effect on iron ions and the like, and are excellent in rust prevention effects.

In addition, the requirement that it be poorly soluble in water is that if it is poorly soluble, it will gradually exert its rust prevention effect as needed.
This is because the excellent rust prevention effect can be maintained for a long period of time.For example, if it is easily soluble in water, even if the rust prevention effect is excellent, the rust prevention effect will not last for a long time, and if it is insoluble in water, the rust prevention effect will not last for a long time. This is because, in this case, no antirust effect can be exerted at all.

The reason why the amount of condensed phosphates used is less than 5% by volume is those with a particle size of 5 μm or more is because such fine particles have a large surface area and are excellent in rust prevention. It is preferable that the diameter of 5 μm or more is 181% or less.

Examples of zinc compounds used include zinc oxide, basic zinc carbonate, and zinc borate, with zinc oxide being particularly preferred.Alkaline earth compounds include alkaline earth carbonates such as magnesium, calcium, and barium. Salts, phosphates, oxides, borates, sulfates, etc. are used.

As mentioned above, these zinc compounds and alkaline earth compounds neutralize the PH of the condensed phosphate, thereby widening the range of paint resins to choose from when making paints.

In the present invention, a water-insoluble condensed phosphate, a zinc compound, and (
or) the proportion with the alkaline earth compound is 2 by weight.
o: 1-1:20. Special temperature (l: 0゜5~10:
It is preferable to set it to 10. In other words, if the proportion of the condensed phosphate is less than the above range, the excellent rust prevention effect will not be exhibited, and if the proportion of the condensed phosphate exceeds the above range, the acidity will be too strong and may cause deterioration depending on the resin. This is because there is a risk of being exposed.

In preparing the anti-w # pigment composition, the condensed phosphate and the zinc compound and/or alkaline earth compound may be mixed by simple dry mixing, or may be mixed with a coating resin that does not have good stability. In case of dispersion, 40 to 10
It is better to perform a wet reaction in warm water at 0°C, followed by filtration, drying, and pulverization.

When forming a paint using the anticorrosive pigment composition of the present invention, various paint vehicles can be used. For example, various resin faces such as boiled oil, oil face, alkyd resin, phenol resin, amino resin, epoxy resin, urethane resin, vinyl resin, acrylic resin, fluororesin, silicone resin, polyester resin, chlorinated rubber,
Paint vehicles containing rubber derivatives such as cyclized rubber and other cellulose derivatives as main components can be used alone or in combination.

When the anticorrosive pigment composition of the present invention is dispersed in a paint vehicle, the condensed phosphate and the zinc compound and/or alkaline earth compound are not mixed beforehand, but are added separately to the vehicle. They may be mixed in the vehicle, but if it is necessary to disperse them in less stable resins, the condensed phosphates and the zinc compound and/or alkaline earth compound may be wet-reacted beforehand. It is better to leave it alone.

〔Example〕

Next, the present invention will be further explained with reference to Examples, but the present invention is not limited to these Examples. This is based on the standards. Also,
Prior to the Examples, a production example of the condensed phosphate used in the Examples will be shown as a reference example.

Reference example! A raw material containing 49.05 g of α-alumina from aluminum and 500 g of 85% phosphoric acid (molar ratio of P, O, /AI□O1 of 3) was placed in a porcelain crucible and heated under stirring. The temperature of the contents was gradually increased to 220"C in 2 hours. The opaque water-containing semi-solid material thus obtained was heated to 300"C.
Aluminum dihydrogen tripolyphosphate was obtained by dehydration and crystallization by burning for 5 hours in an electric furnace adjusted to .

After washing, dehydrating, drying and pulverizing the aluminum dihydrogen tripolyphosphate obtained as described above, the particle size distribution was measured, and it was found to have a particle size distribution of 0.5 to 21.0 μm. The amount of particles with a particle size of 5 μm or more was about 18% by volume.

Reference Example 2 Menu Aluminum 1 300 kg of aluminum dihydrogen tripolyphosphate obtained in Reference Example 1 was calcined at 800° C. for 2 hours to obtain aluminum metaphosphate.

After the aluminum metaphosphate was pulverized, its particle size distribution was measured, and it was found that it had a particle size distribution of 0.4 to 30 μm. The amount of particles with a particle size of 5 μm or more is about 7
It was 0% by volume.

Example 1 Aluminum dihydrogen tripolyphosphate obtained in Reference Example 1 was processed using a classifier "Acu-Riki 7me 2" manufactured by Nippon Donaldson Co., Ltd. at a rotational speed of 2.00 Orpm and an air flow! 1.5r
The particles were classified at a rate of rr/min to obtain a classified product in which particles with a particle size of 5 μm or more were canted.

80 parts of this classified aluminum dihydrogen tripolyphosphate and 30 parts of zinc oxide were dry mixed to obtain a rust preventive pigment composition.

Example 2 The aluminum metaphosphate obtained in Reference Example 2 was treated using a classifier “Accucut 12j” manufactured by Nippon Donaldson Co., Ltd.
Rotation speed 3.50Orpm, air amount a 1. The particles were classified at Onf/min to obtain a classified product in which particles with a particle size of 5 μm or more were cuffed.

100 parts of this classified aluminum metaphosphate and 40 parts of zinc oxide were dry mixed to obtain a rust preventive pigment composition.

Comparative Example 1 80 parts of aluminum dihydrogen tripolyphosphate having a particle size distribution of 0.5 to 21.0 μm obtained in Reference Example 1 and 3 parts of zinc oxide
0 parts were dry mixed to obtain a rust preventive R'F4Mi composition.

Comparative Example 2 100 parts of aluminum metaphosphate having a particle size distribution of 0.4 to 30 μm obtained in Reference Example 2 and 40 parts of zinc oxide were dry mixed to obtain a rust preventive pigment composition.

Next, a baking-type epoxy resin-based anticorrosion paint was prepared using the anti-TIV pigment compositions of Example 1 and Comparative Example 1,
After the coating film was formed, a salt spray test was conducted to examine its antirust effect. The results are shown in Test Example 1. In addition, test example 1
For comparison purposes, a baking-type epoxy resin-based anticorrosive paint was prepared using zinc phosphate and strontium chromate as anticorrosive pigments, and the same test was conducted.

Furthermore, as for the anticorrosion pigment compositions of Example 2 and Comparative Example 2, they were used to form a room-temperature-drying chlorinated rubber-based anticorrosive agent. After preparing an iI paint and forming a film, a salt spray test was conducted to examine its antirust effect. The results are shown in Test Example 2. Also, in Test Example 2, for comparison purposes, a room temperature drying type chlorinated rubber-based rust preventive paint was prepared using zinc phosphate and zinc chromate as rust preventive pigments, and a similar We conducted the LK experiment.

Test Example 1 A baked-on epoxy resin anti-corrosion paint consisting of an undercoat with the composition shown in Table 1 and a topcoat with the composition shown in Table 2 was prepared, and after the coating film was formed, a salt spray test was conducted to determine its prevention. The rust effect was investigated.

11' As shown in Table 1, dfl type undercoat paints (Example 1, Comparative Product 1, and Control Products 1 to 2) containing anticorrosive pigments were prepared.

The above-mentioned four types of undercoat paints (Executive Product 1, Comparative Product 1, and Comparative Products 1 to 2) were each applied to a plate to be coated under the following coating conditions and baked to form an undercoat film.

Painting: Bar coater painting K16 Board to be coated: Single-sided zinc phosphate treated board JIS G 3141 (SPG) Nippon Test Panel Co., Ltd. Film thickness: 9 ± 1 μm Baking: 200°C at panel temperature 1) min. A top coat of the composition shown in the table was prepared. This top coat does not contain anti-rust pigments, and one type is commonly used for each base coat.

Table (Top coating) Note *4: Trade name of oil-free alkyd resin manufactured by Dainippon Ink and Chemicals Co., Ltd. Its solid content concentration is 60%.

*5: Butylated Mela ξ manufactured by Dainippon Ink and Chemicals Co., Ltd.
It is the trade name of a resin that has a solid content concentration of 60%.

The above-mentioned topcoat paint was applied onto the undercoat film under the following coating conditions and baked to form a topcoat film.

Painting: Barcoater Paint Hidden 24 Film Thickness: 15±2μm Baking: Panel temperature at 200'C for 2 minutes Salt Tamari Natsuta And as above, created by forming a topcoat film on the undercoat film. The prepared test plate was placed in a salt water spray device whose internal temperature was kept at 35°C, and 1 liter of 5% NaCl aqueous solution was added.
The coating film was sprayed at kg/c4 for 28 days, and the occurrence of rust on the test plate and blistering of the coating film were observed.

Table 3 shows the results of the salt spray test for each type of rust-preventing pigment.

The rust prevention effect is evaluated by the rust prevention effect of the test plate and the blistering prevention effect of the paint film, and the evaluation criteria are as follows. The evaluation standard for rust prevention effect is A.
Based on STM D610-68 (1970), the evaluation standard for blister prevention effect is ASTM D714-5.
9 (1965).

Rust 5: Rust occurrence area less than 0.1% 4: Rust occurrence area 0.1% or more - less than 1% 3: Rust occurrence area 1% or more - less than 10% 2: Rust occurrence area 10%
5:8F or less 4: 8M, 6F 3: 8MD, 6M, 4F 2: 8D, 6MD, 4M, 2F 1: 6D, 4MD or more, 2M As shown in Table 3 above, the rust-preventing pigment composition of Example 1 has a high evaluation value for the rust-preventing effect against both rust and blistering, and has an excellent rust-preventing effect comparable to that of strontium chromate. As a result, the rust-preventing effect was far superior to that of zinc phosphate, a conventional non-polluting rust-preventing pigment.

Test Example 2 A room-temperature-drying chlorinated rubber anticorrosive paint having the formulation shown in Table 4 was prepared, and after coating was formed, a salt water spray test was conducted to examine its anticorrosion effect.

Rubber Four types of room temperature drying type chlorinated rubber paints (Executive Product 2, Comparative Product 2, and Comparative Products 3 to 4) were prepared using the formulations shown in Table 4.

■ Chicken - The above four types of room-temperature drying chlorinated rubber paints (execution product 2, comparison product 2, and control products 3 to 4) were each applied to two types of coated boards under the following coating conditions, and dried at room temperature. A coating film was formed.

Painting: Bar coater coating, 70° Coated board: Degreased mild steel Fi (SPCC-5R) galvanized plate (SPG) Nippon Test Panel Co., Ltd. Film thickness: 32 ± 3 μm Drying: Room temperature for 1 week As described above, coated board The test plate prepared by forming a coating film on it was placed in a salt water spraying device whose internal temperature was kept at 35°C, and 1 kg of 5% NaCl aqueous solution was added.
/C- was sprayed on the coating film for 7 days for test plates with one coat of degreased mild steel plate, and for 10 days for test plates with galvanized plate as coated plate1)), test plate. The occurrence of rust and blistering of the paint film were observed.

Table 5 shows the results of the salt spray test for each type of anti-rust pigment when the conventional plate to be coated is a degreased mild steel plate.The evaluation criteria for the anti-rust effect are the same as in Test Example 1. It is.

Table 5 (Degreased Soft W4 Board) As shown in Table 5, the rust-preventive pigment composition of Example 2 has a high evaluation value for the rust-preventive effect against both rust and blisters, and has a high rust-preventive effect. was excellent.

Table 6 shows the results of the salt spray test when the plate to be coated is a galvanized plate, for each type of anti-corrosion pigment.

The evaluation criteria for the rust prevention effect in this case are also the same as in Test Example 1.

Table 6 (Zinc-plated board) As shown in Table 6, the rust-preventing pigment & It had an excellent rust prevention effect.

[Effect of the invention] As explained above, the anti-i+1 pigment composition of the present invention has the following effects:
It did not contain harmful metals such as chromium or lead, was free from pollution, and had excellent rust prevention effects. Furthermore, the anticorrosive pigment composition of the present invention is white and can be freely adjusted in color, and can be used in various paint vehicles.

Claims (3)

[Claims] (1) Slightly water-soluble condensed phosphate containing 5% by volume or less of particles with a particle size of 5 μm or more, a zinc compound, and/or
A rust-preventing pigment composition comprising an alkaline earth compound. (2) The anticorrosive pigment composition according to claim 1, wherein the condensed phosphate that is sparingly soluble in water is aluminum dihydrogen tripolyphosphate or aluminum metaphosphate. (3) The anticorrosive pigment composition according to claim 1, wherein the zinc compound is zinc oxide.