JP3131492B2 - Method for producing white rust preventive pigment composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white rust preventive pigment,
More specifically, it relates to a method for producing an improved zinc-free white rust preventive pigment composition.

[0002]

2. Description of the Related Art Conventionally, lead tin or zinc chromate has been widely used as the most typical rust preventive pigment. These rust-preventive pigments exhibit extremely excellent rust-preventive power, but are toxic to the components such as lead and chromium in the color pigment and the composition thereof. Recently, the use of pigments containing these toxic components has been severely restricted, and new low-toxic or non-polluting white rust preventive pigments have been developed and put to practical use.

To date, non-polluting rust preventive pigments include (a) metal condensed phosphates such as condensed aluminum phosphate;
(b) metal phosphates, such as zinc phosphate, silicon phosphate, titanium phosphate, (c) metal phosphites, such as zinc phosphite, barium salts, magnesium salts, manganese salts, (d) Numerous proposals have been made such as metal hypophosphites such as calcium hypophosphite or iron hypophosphite, and (e) metal molybdates such as zinc salt and calcium salt.

[0004] Among these non-polluting rust preventive pigments, zinc phosphate-based pigments are considered to be highly practical in terms of performance and economy, and the production methods thereof are described, for example, in JP-B-49-2005, These are disclosed in JP-A-52-69898, JP-A-55-36267, JP-A-56-169113, JP-A-59-42297 and JP-A-1-308814. All of these methods aim at improving rust prevention by producing fine zinc phosphate.

On the other hand, a special anticorrosive pigment based on zinc potassium phosphite is used as an organic phosphonic acid (salt) having a chelating ability.
It is known to use (JP-A-60-124660).

[0006]

However, these non-polluting white rust preventive pigments are inferior in rust preventive power to lead tin and chromate pigments and have advantages and disadvantages in the pigment properties when used, so that there are many points to be improved. . In particular, when used as a water-based paint, the rust-preventing power is weak, so that it is not satisfactory as a rust-preventive pigment.

[0007] In particular, zinc phosphate is apt to form coarse primary particles in the form of plate or scale due to its properties, so that it is difficult to make fine particles. Is limited and you can't get what you can expect. Further, potassium zinc phosphite using an organic phosphonic acid having chelating ability is a special pigment as described above, and has various problems in pigmentation and coating, and many improvements are required for practical use. There is a point to be.

[0008] As described above, among the many white rust preventive pigments that have been proposed in the past, only practical ones are extremely limited. In addition, there is no one used alone, and in many cases, In fact, it is used by several composites.

In view of the above-mentioned circumstances, the present inventors have been intensively researching non-polluting white rust-preventive pigments. Rust prevention function is demonstrated. The present invention has been developed based on such knowledge, and an object thereof is to provide a non-polluting zinc phosphate-based white rust-preventive pigment composition having excellent rust-preventive ability.

[0010]

Means for Solving the Problems A method of manufacturing a white anticorrosive pigment composition according to the present invention for achieving the above object, no
Use of potassium compound and inorganic phosphite compound
With zinc oxide slurry, phosphoric acid and chelating ability
The mixed solution with the organic phosphorus compound
Of the zinc phosphate-containing white rust preventive pigment composition obtained by
A method of producing the composition, wherein the zinc phosphate is spherical fine particles.
And features. In addition, inorganic potassium compounds and inorganic lithium
Zinc oxide slurry without the use of acid compounds
, Phosphoric acid, and an organic phosphorus compound having chelating ability
Phosphoric acid obtained by individually mixing and reacting
A method for producing a zinc-containing white rust-preventive pigment composition,
It is characterized in that zincate is spherical fine particles. Also,
Use of inorganic potassium compounds and inorganic phosphite compounds
Chelating ability when preparing zinc oxide slurry
A slurry reacted by adding an organic phosphorus compound having
Phosphorus obtained by mixing and reacting with phosphoric acid
A method for producing a zinc acid-containing white rust-preventive pigment composition,
It is characterized in that zinc phosphate is spherical fine particles. Ma
Use inorganic potassium compounds and inorganic phosphite compounds
Without dissolving zinc salt with alkali phosphate and
The mixed solution with an organic phosphorus compound
Zinc-containing white rust-proof face obtained by
A method for producing a filler composition, wherein the zinc phosphate is spherical fine particles.
The child is a structural feature.

The zinc phosphate constituting the white rust preventive pigment obtained by the production method of the present invention is a fine spherical particle, and the apparent particle is desirably as fine as possible. Here, the term “fine spherical particles” means, in a relative relationship with the conventional coarse plate-like or scale-like primary particles, does not substantially include these, and does not necessarily mean a true sphere, and Round fine particles that can be easily confirmed by microscopic observation.

Although zinc phosphate is like amorphous particles according to electron microscopic observation, it is mainly composed of tetrahydrate [Zn ₃ (PO ₄ ) ₂ · 4H ₂ O] and / or dihydrate [Zn 3 ₃ (P
O ₄ ) ₂ .2H ₂ O], which can be easily confirmed by X-ray diffraction analysis. The zinc phosphate of the present invention also includes a solid solution or a mixed phosphate in which alkaline earth metals such as calcium, magnesium, barium, and strontium are substituted up to about 10%, in addition to zinc phosphate itself.

Next, the organic phosphorus compound having chelating ability in the white rust-preventive pigment obtained by the production method of the present invention is not particularly limited, but for example, aminoalkylenephosphonic acid, ethylenediaminetetraalkylenephosphonic acid, alkylmethane- Representative components include 1-hydroxy-1,1-diphosphonic acid, 2-hydroxyphosphonoacetic acid and their ammonium salts, alkali metal salts, and divalent metal salts such as zinc, calcium, magnesium, barium, and strontium. .

Examples of the aminoalkylene phosphonic acid include nitrilotrismethylene phosphonic acid, nitrilotris ethylene phosphonic acid, nitrilotris propylene phosphonic acid, nitrilo diethyl methylene phosphonic acid, nitrilopropyl bis methylene phosphonic acid, and ethylenediamine tetraalkylene phosphonic acid. Is, for example, ethylenediaminetetramethylenephosphonic acid, ethylenediaminetetraethylenephosphonic acid, ethylenediaminetetrapropylenephosphonic acid or the like, and as alkylmethane-1-hydroxy-1,1-diphosphonic acid, for example, methane-1-hydroxy-1,1- Diphosphonic acid, ethane
1-hydroxy-1,1-diphosphonic acid, propane-1
-Hydroxy-1,1-diphosphonic acid and the like, which may be used alone or in combination of two or more.

The content of the organophosphorus compound having a chelating ability with respect to zinc phosphate varies depending on the type of the compound and the method for preparing a pigment described below, but is 0.1 to 30% by weight based on the total weight of the pigment composition. , Preferably 1 to 10
% By weight. If the content is less than 0.1% by weight, the zinc phosphate is not substantially modified and the rust-preventing ability is insufficient. On the other hand, if the content is more than 30% by weight, not only does the pigment property deteriorate, causing trouble in coating, Economically disadvantaged.

As a method for incorporating an organic phosphorus compound having a chelating ability into zinc phosphate, a wet method and a dry method can be considered, but it is preferable to apply the wet method. The wet method is a method in which the above-mentioned organic phosphorus compound is used as a partial substitute for a phosphoric acid source in the production of zinc phosphate, and includes, for example, the following several embodiments. (1) A method of mixing and reacting a slurry (solution A) of zinc oxide (zinc white) with a mixed solution of phosphoric acid and an organic phosphorus compound. (2) A method in which solution A, phosphoric acid and an organic phosphorus compound are individually mixed and reacted. (3) A method in which a phosphoric acid is mixed with a slurry that has been reacted by adding an organic phosphorus compound during the preparation of the solution A. (4) A method of mixing and reacting a mixed solution of a soluble zinc salt (for example, zinc sulfate and zinc nitrate) with an alkali phosphate and an organic phosphorus compound.

In each of the above reactions, an oxide, hydroxide or soluble salt of an alkaline earth metal may be partially substituted with zinc oxide or zinc salt, if necessary, in an amount of about 10% of zinc.
% Can be used. In the heterogeneous reaction using zinc oxide, a small amount of a dispersant or a sol such as silica, alumina, or zirconia can be used.

The temperature during the reaction does not need to be particularly limited, and may be either normal temperature or heating. However, in the case of a heterogeneous solid-liquid reaction, it is often preferable to heat to a temperature range of 40 to 80 ° C. Reaction times range from 0.5 to 10 hours, preferably from 1 to 6 hours. After the completion of the reaction, if necessary, after wet pulverization, filtration by a conventional method,
Separate, wash, dry and pulverize to a product.

On the other hand, the dry method is a method in which an organic phosphorus compound solution is added to zinc phosphate prepared in advance and reacted with homogenization. In this case, a mixed reaction product of zinc oxide and the organic phosphorus compound is added and blended. You may. The reaction in the dry method is carried out by a mixer having a strong shearing force, for example, a Henschel mixer, a ball mill or a powerful blender, and the product is obtained.

The zinc phosphate rust preventive pigment composition obtained by the production method of the present invention can be subjected to a surface treatment, if necessary, in consideration of handling during use. As a surface treatment agent,
Examples thereof include a silane coupling agent, a higher fatty acid or a derivative such as a metal salt thereof, an acidic phosphate ester or a metal salt thereof. Further, the rust preventive pigment composition according to the present invention,
If necessary, other white rust preventive pigments, such as phosphites,
Hypophosphite-based, aluminum tripolyphosphate-based, molybdate-based blends with anti-rust pigments, or silica, titanium oxide, zinc white, barium sulfate, calcium phosphate,
It can be used as a blend with a bulking agent such as magnesium phosphate.

[0021]

The white rust preventive pigment obtained by the production method of the present invention is
By adding an organic phosphorus compound having a chelating ability to zinc phosphate, a remarkable inhibitory effect and a barrier effect on crystal development are brought about, and fine spherical particles substantially free of plate-like or scale-like coarse primary particles Is generated.
On the other hand, by substituting a part of zinc with an alkaline earth metal in the production of zinc phosphate, it has an effect of similarly producing fine particles. The presence of the organophosphorus compound having a chelating ability together with the zinc phosphate composed of such fine particles functions to exert more rust-preventive ability, resulting in a pollution-free white rust-proof pigment composition.

[0022]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples. In each example, "part" indicates weight.

Example 1 11.1 parts of zinc white (JIS No. 3) was added to 100 parts of water, and the mixture was sufficiently stirred and mixed. Next, a mechanical dispersion operation was performed through a colloid mill to obtain a zinc white slurry (Solution A). The solution A was heated to 50 ° C. while stirring, and 10.3 parts of 75% phosphoric acid and 60% of methane-1-hydroxy-1,1-diphosphonic acid were added thereto.
A mixed solution (solution B) prepared by dissolving 1.4 parts of an aqueous solution in 39.1 parts of water was added to 0.1 part.
It was gradually added at an addition rate of 85 parts / minute. After the addition reaction, stirring was continued for about 1 hour while maintaining the slurry temperature at 50 ° C.
Then, a rust preventive pigment was obtained through filtration, drying, and pulverization steps by a conventional method. The obtained pigment had a white color and was spherical fine particles when observed by an electron microscope photograph.

Example 2 11.1 parts of zinc white (JIS No. 1) was sodium hexametaphosphate
The solution was added to a solution of 1.2 parts and 100 parts of water, and mixed and stirred. Then, the mixture was passed through a homogenizer and subjected to a mechanical dispersion operation to obtain a zinc white slurry (Solution A). 50 ° C while stirring this solution A
And 10.3 parts of 75% phosphoric acid and 1.4 parts of a 60% aqueous solution of methane-1-hydroxy-1,1-diphosphonic acid were added to water.
A mixed solution (solution B) dissolved in 39.1 parts was gradually added at an addition rate of 0.85 part / min. After the addition reaction, stirring was continued for about 1 hour while maintaining the slurry temperature at 50 ° C. Then, a rust preventive pigment was obtained through filtration, drying, and pulverization steps by a conventional method. The obtained pigment was white, and when observed with an electron micrograph, was spherical fine particles.

Example 3 Solution A obtained in the same manner as in Example 1 was heated to 50 ° C. while stirring, and 10.3 parts of 75% phosphoric acid and 1.7 parts of a 50% aqueous solution of nitrilotrismethylenephosphonic acid were added to water. A mixed solution (solution B) dissolved in 39.1 parts was gradually added at an addition rate of 0.85 part / min. After the addition reaction, keep the slurry
Stirring was continued for hours. Then, a rust preventive pigment was obtained through filtration, drying, and pulverization steps by a conventional method. The obtained pigment was white, and it was confirmed by observation with an electron microscope photograph that it was spherical fine particles.

Comparative Example A solution obtained in the same manner as in Example 1 was heated to 50 ° C. while stirring, and a solution (solution B) in which 11.4 of 75% phosphoric acid was dissolved in 63.6 parts of water was added at 1.25 parts / Minutes and slowly added. After that, a white rust preventive pigment was obtained through the same operations as in the examples.
When this pigment was observed with an electron micrograph, it was found to be plate-like coarse particles.

Evaluation of Rust Prevention A rust prevention test was performed on each of the rust prevention pigments obtained in Examples and Comparative Examples and a commercially available pollution-free rust prevention pigment under the following conditions. (1) Preparation of rust preventive paint 5 parts of each rust preventive pigment and 112 parts of alkyd-based water-based varnish [Watersol CD-520, manufactured by Dainippon Ink Industries, Ltd.] were converted to paint using a paint shaker, and a test rust preventive paint was prepared. Prepared. (2) Preparation of coated steel sheet One part of dryer (5% cobalt naphthenate dryer W type: 20%) per 100 parts of the above rust prevention test coating composition
Lead naphthenate dryer W type = 1: 1)
250 × 350 × 1.6 Japan test panel, iron plate SS400
(Former SS41) was coated with a bar coater so that the dry coating film thickness became 20 to 30 μm, and dried at room temperature for one week to obtain a coated steel plate. Next, the dried coated steel sheet was cut into a size of 70 × 150 to obtain six test steel sheets per sheet.

(3) Rust Prevention Test The coated steel sheet prepared in (2) was cross-cut, set on a salt spray tester, and subjected to a rust prevention test. (4) Test evaluation results The results of the salt spray test at 400 hours were evaluated by the following five-step evaluation method, and the rust-preventive effect of the rust-preventive pigment was determined. Rating 5: There is no rust generation other than the cross cut portion, and there is no blister. Rating 4: Rust occurred within 2 mm on one side from the cross cut part.
No blisters. Rating 3: Rust and partial blisters occurred within 6 mm on one side from the cross cut portion. Rating 2: Rust and partial blisters occurred within 12 mm on one side from the cross cut part. Rating 1: Rust and blisters occurred on the entire surface of the steel sheet. Table 1 shows the results of evaluating the rust-preventive ability of each of the obtained rust-preventive pigments.
In addition, the blank of Table 1 is a coated steel plate using a varnish containing no rust preventive pigment.

[0029]

[Table 1]

[0030]

The white rust-preventive pigment composition obtained by the production method of the present invention contains zinc phosphate composed of fine spherical particles as a main component, and contains an organic phosphorus compound having a chelating ability. However, it has remarkably superior rust-preventing ability as compared with the conventional non-polluting white rust-preventive pigment. Since this rust-preventing ability is sufficiently exhibited in a water-based paint system, it can be expected to be highly practical as a pollution-free white rust-preventive pigment.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Yokoyama 3-36-5 Sakashita, Itabashi-ku, Tokyo Toho Pigment Industry Co., Ltd. Research Department (56) Reference JP-A-60-124660 (JP, A) JP-A 53-46336 (JP, A) JP-A-6-49392 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09C 1/00-3/12 C23F 11/00 C09D 5 / 08

Claims (5)

(57) [Claims] 1. An inorganic potassium compound and an inorganic phosphite compound
Without the use of zinc oxide slurry and phosphoric acid
And a mixture of organic phosphorus compound with chelating ability
Containing zinc phosphate obtained by reacting
A method for producing a rust-preventive pigment composition, wherein the zinc phosphate is spherical.
Of a white rust-preventive pigment composition, which is
Manufacturing method . 2. An inorganic potassium compound and an inorganic phosphite compound
Without the use of zinc oxide slurry and phosphoric acid
And an organophosphorus compound having chelating ability
Containing zinc phosphate obtained by combining and reacting
A method for producing a color antirust pigment composition, wherein the zinc phosphate is
White rust preventive pigment composition characterized by spherical fine particles
Manufacturing method . 3. An inorganic potassium compound and an inorganic phosphite compound
When preparing zinc oxide slurries without using
An organophosphorus compound having chelating ability is added to
The mixed slurry and phosphoric acid are mixed and reacted.
For producing zinc phosphate-containing white rust-preventive pigment composition obtained
Wherein the zinc phosphate is spherical fine particles.
A method for producing a white rust-preventive pigment composition . 4. An inorganic potassium compound and an inorganic phosphite compound
Soluble zinc salt and alkali phosphate
And a mixed solution with an organic phosphorus compound having chelating ability.
Contains zinc phosphate obtained by mixing and reacting
A method for producing a white rust-preventive pigment composition, comprising the zinc phosphate
Rust-preventive pigment composition, wherein is a spherical fine particle
Method of manufacturing a product . 5. The organic phosphorus compound having a chelating ability,
Amino alkylene phosphonic acid, ethylene diamine tetra alkylene phosphonic acid, alkyl methane-1-hydroxy-1,1-diphosphonic acid, 2-hydroxy phosphono acetic acid or claim 1 is one or more selected from salts thereof The method for producing a white rust-preventive pigment composition according to any one of Items 1 to 4 .