JPH03111457A - Zinc calcium phosphite, its preparation, and corrosionproof coating material containing it - Google Patents

Abstract

PURPOSE:To obtain a zinc calcium phosphite. compsn. providing a corrosionproof coating material with excellent corrosionproofing power and coating stability and low toxicity by using a specified zinc calcium phosphite. CONSTITUTION:Pref., after H3PO4 is added to a slurry of a zinc compd. (e.g. ZnO) and a Ca compd. (e.g. CaCO3) in water or after the zinc compd., the calcium compd. and a phosphite compd. [e.g. Ca(H2PO3)2 or Zn(H2PO3)2] are made into a slurry with water, the mixture is kneaded by mechanical means in a wet state without heating and reacted mechanochemically to prepare a compsn. contg. zinc calcium phosphite consisting of zinc calcium phosphite of formula CaZn(HPO3)2.nH2O (where (n) is 0-2), and this compd. and zinc phosphite or zinc phosphite and ZnO, or calcium phosphite or calcium phosphite and Ca(OH)2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a novel zinc calcium phosphite, a composition containing the same, a method for producing the same, and a novel anticorrosive paint containing the same. It is.

[Conventional technology]

Zinc phosphite has been well known, but zinc calcium phosphite was completely unknown. It was also unknown how zinc calcium phosphite could be produced.

Furthermore, it is well known that zinc phosphite has effects such as rust prevention, but zinc calcium phosphite has even lower toxicity, good stability, and excellent rust prevention. It was completely unknown that it was happening. Therefore, until now there has been no anti-rust paint containing zinc calcium phosphite.

Conventionally, chromic acid compounds and lead compounds have been widely used as rust-preventing pigments, but although they have excellent rust-preventing properties, they contain chromium and lead in their composition. , its toxicity was a problem. Therefore,
Pigments that do not contain chromium or lead are being developed as pollution-free rust-preventing pigments, and metal phosphates such as silicon phosphate, titanium phosphate, and condensed aluminum phosphate, zinc phosphite, barium phosphite, and zinc phosphite are being developed. Metal phosphites such as manganese phosphate and metal molybdates such as zinc molybdate and calcium molybdate have been investigated.

Among these, the following techniques have been disclosed regarding zinc phosphite, but have not yet been disclosed regarding zinc calcium phosphite.

JP-A No. 50-50297 (Japanese Patent Publication No. 56-9951) discloses that basic zinc phosphite represented by the following formula is used as an agent for suppressing stains caused by tannins on wood surfaces, as a fungicide, and as a flame retardant. It has been disclosed that it is useful as, etc.

XZnO-Zn1lPO* (X=1/2~In) Furthermore, JP-A-58-84109 discloses that a zinc potassium phosphite-containing substance represented by the following formula is useful as a pollution-free rust-preventing pigment. is disclosed.

KtZnt(HPOs)i-IZnl(POs-mZn
o-nHt.

(1 = O ~ 48. m = O ~ (1 + 3), n20 ~ 51) Furthermore, in JP-A-58-194725, a hydroxyzinc phosphite complex represented by the following formula is chemically stable. In terms of properties and dispersibility, the above-mentioned JP-A-50-502
It is disclosed that it is superior to the basic zinc phosphite disclosed in No. 97.

(2Zn(OH)s-ZnHPO3) -XZnO(X
= O~17) On the other hand, regarding mechanochemical reactions, JP-A-64-40563 describes a rust-preventing pigment composition consisting of aluminum dihydrogen tripolyphosphate, a lead compound, and a zinc compound. It is disclosed that when a poorly soluble substance is selected as the lead compound in its production, it is desirable to proceed with the reaction mechanochemically.

[Problem to be solved by the invention]

The above-mentioned non-polluting rust-preventive pigments have poor paint stability to be blended as a substitute for conventional rust-preventive pigments, and their rust-preventive power is also lower than that of conventional rust-preventive pigments. Therefore, it is necessary to develop and blend a new stabilizer, and it is also necessary to increase the blending amount to achieve the same rust prevention effect as conventional pigments. Originally, some of the above-mentioned non-polluting rust-preventing pigments are expensive, and furthermore, the cost of non-polluting rust-preventing paints may increase due to the development and addition of new stabilizers and an increase in the amount of the pigment itself.

The problem to be solved by the present invention is to provide a rust-preventive pigment material that has superior paint stability and superior rust-preventing power at a lower price than the above-mentioned conventional non-polluting rust-preventive paints.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present inventors provide a novel compound, a composition containing the same, a method for producing the same, and an anticorrosive paint containing the same.

This novel compound is zinc calcium phosphite represented by the following formula, and a composition containing it is composed of this zinc calcium phosphite, zinc phosphite or zinc phosphite and zinc oxide, Alternatively, it is a calcium phosphite-containing composition comprising calcium phosphite or calcium phosphite and calcium hydroxide.

CaZn(HPOs)t-nHJ---
(1) Here, n; 0 to 2 This zinc calcium phosphite is characterized by the interplanar spacing d (person) given in powder X-ray diffraction at least according to Table 1.

Table 1 Also, compositions containing zinc calcium phosphite include those shown in the following formula.

acaZn(HPOs)-bZnHPOs-nH2O
-----(21aCaZn (HP 03) t-bZ
n HPO5-cZnO-nHto---(3)
aCaZn(HPOs)*-bcaHPO3-nHHO
2--(4) aCaZn (HPOs) m-bc
aHPOs -cca (DH) t-nHto -(
5) Here, a, b, c are & / (b+c)≧
It represents an integer within 10 that satisfies the relationship of 1/6, and n represents the number of crystal water molecules.

Further, the method for producing zinc calcium phosphite and a composition containing the same according to the present invention includes: (2) adding a zinc compound and a calcium compound to a slurry with water; The above-mentioned calcium zinc phosphite, which is characterized in that a calcium compound and a phosphorous acid compound are slurried with water, and then wet kneaded by mechanical means without heating to cause a mechanochemical reaction. A method for producing a composition containing.

In the production method according to the present invention, the zinc compounds used include zinc oxide (ZnO) and zinc hydroxide (Zn(
OHh), zinc carbonate (ZnCO3), zinc phosphite (ZnHPOs), etc., and calcium compounds include calcium carbonate (CaCOs), calcium oxide (Can), calcium hydroxide (Ca (0 old snow)
, calcium phosphite (CaHPOs), etc. In addition, phosphorous acid compounds include zinc hydrogen phosphite (Z
n(HmPOs) *) Calcium hydrogen phosphite,
(HtPO3h) etc.

The method of the present invention is characterized by wet kneading using mechanical means such as a ball mill, vibration mill, sand grind mill, crusher, etc. without heating, and mechanochemical reaction. This method is essentially different from the method disclosed in JP-A-64-40563, in which only a poorly soluble lead compound is mechanochemically reacted as an aid to the solution reaction.

In addition, the rust-preventive paint containing zinc calcium phosphite according to the present invention refers to a rust-preventive paint containing zinc calcium phosphite according to the present invention or a composition containing the same as a rust-preventive pigment. Refers to paints made into paints.

[Action J] In the method for producing a zinc phosphite calcium compound according to the present invention, during the mechanochemical reaction of a zinc compound, a calcium compound, phosphorous acid, etc., what action is taken to produce phosphorus, which has excellent rust-preventing power? The details of whether acid zinc calcium compounds are formed are unknown, but when solids come into contact, a high-pressure, high-temperature point is instantaneously generated at the point of contact, and energy is concentrated there, resulting in a special reaction that differs from a solution reaction. It is presumed that a reaction is occurring.

In addition, in the rust-preventing paint according to the present invention, the details of how the zinc phosphite calcium compound exhibits its excellent rust-preventing power are unknown, but somehow the combination of zinc phosphite and calcium phosphite is unknown. It is presumed that a synergistic effect, more than an additive effect, is at work.

〔Example〕

■ Production Example 1 of zinc calcium phosphite Zinc oxide (ZnO) 81.4g, calcium carbonate (
After dispersing 100.1 g of CaCOs) in 7501 water to form a slurry, 410.0 g of 40% phosphorous acid aqueous solution
was added over 1 hour with stirring and allowed to react. 1 more
After stirring for an hour, the reaction slurry was transferred to an alumina ball mill and wet kneaded for 6 hours. After wet kneading, the slurry was filtered, and the resulting filter cake was dried at 110°C for 24 hours to form a powder (hereinafter referred to as "powder I").

Example 2 99.4 g of zinc hydroxide (Zn(OH)t) and 112.2 g of calcium monoxide (Can) were mixed with about 120 g of water (1
ml to form a slurry, 547.0 g of a 30% phosphorous acid aqueous solution was added over 1 hour with stirring, and reacted. After further stirring for 1 hour, the reaction slurry was transferred to a vibration mill and wet kneaded for 4 hours. After wet kneading, the slurry was filtered and the resulting filter cake was dried at 110° C. for 24 hours to form a powder (hereinafter referred to as "powder ■").

Example 3 Zinc carbonate (ZnCOs) 125.4g 1 Calcium hydroxide (Ca(OH)s) 148.2g - Phosphorous acid ()
13PO3) 246. (Approximately 5,000 g of 1 g of water was put into a crusher and kneaded for 24 hours. After wet kneading, the slurry was filtered, and the resulting filter cake was heated at 110°C for 2 hours.
It was dried for 4 hours to form a powder (hereinafter referred to as "powder ■").

Example 4 Zinc phosphite (ZnHPOs) 145.4 g Calcium hydroxide (Ca (O former goose) 222.3 g was caught by line fishing at 150
After dispersing in 0 ml to form a slurry, 10.0 g of 40% phosphorus aqueous solution H4 was added over 1 hour with stirring and allowed to react.

After further stirring for 1 hour, the reaction slurry was transferred to a sand grind mill and wet kneaded for 4 hours. After wet kneading, the slurry was filtered and the resulting filter cake was heated at 110°C for 24 hours.
It was dried for a period of time to form a powder (hereinafter referred to as "powder ■").

Example 5 162.8 g of zinc oxide (ZnO) and 147.1 g of calcium phosphite (CaHPO3-'/Rose H*0) were mixed and put into a mixer, and 102.5 g of 80% phosphorous acid aqueous solution was mixed.
was added over 1 hour while kneading and allowed to react. 1 more
After kneading for an hour, 300 g of the reaction product was transferred to an alumina ball mill, 300 liters of fishing rod was added, and wet kneading was carried out for 6 hours. After wet kneading, the slurry was filtered, and the resulting filter cake was dried at 110°C for 24 hours to form a powder (hereinafter referred to as "powder V").

Example 6 Zinc oxide (ZnO) 162.8g, hydration power/I/
Cium (Ca(OHh) 74.1g, Zinc hydrogen phosphite (Zn(H2PO3)*) 227, 4g1 Calcium hydrogen phosphite (Ca(HsPOs)*-6H 0)
310.2g, 50011 fishing rod was put into the vibration mill 4
Wet kneading was carried out for hours. After wet kneading, the slurry was filtered and the resulting filter cake was dried at 110° C. for 24 hours to form a powder (hereinafter referred to as "powder ■").

Example 7 Zinc oxide (ZnO) 244.1g, calcium carbonate (
Mix 100.1g of CaCO3) and put it in a kneader,
While kneading, 307.5 g of 0% phosphorous acid aqueous solution was added over 1 hour and reacted. After further kneading for 1 hour, 300 g of the reaction product was transferred to an alumina ball mill, and Honduri 3001 was added thereto, followed by wet kneading for 4 hours. After wet kneading, the slurry was filtered, and the resulting filter cake was dried at 110°C for 24 hours to form a powder (hereinafter referred to as "powder ■").

Example 8 Zinc oxide (ZnO) 162. '8g, hydration power/l/
148.2g of Numu (Ca(OHh))
After dispersing in 250 ml to form a slurry, 328.0 g of a 50% phosphorous acid aqueous solution was added over 1 hour with stirring and allowed to react. After further stirring for 1 hour, the reaction slurry was transferred to an alumina ball mill and wet kneaded for 6 hours. After wet kneading, the slurry was filtered, and the resulting filter cake was dried at 110°C for 24 hours to form a powder (hereinafter referred to as "powder ■").

Comparative Example 1 Zinc oxide (ZnO) 81.4g, hydration power/l/
Shira A (Ca (0 old snow) 74.1g, real fishing 60
After dispersing the mixture in 0a+I to form a slurry and heating it to 80° C., 328 g of a 50% aqueous phosphorous acid solution was added over 1 hour with stirring and allowed to react. After further stirring for 3 hours while keeping the temperature at 80°C, the slurry was filtered, and the resulting filter cake was dried at 110°C for 24 hours to form a powder (hereinafter referred to as "powder ■").

Tables 2 and 3 show the raw material molar ratios of powders 1 to 1 obtained in Examples 1 to 8 and Comparative Example 1, substances identified by X-ray diffraction, composition molar ratios by chemical analysis, and average grains. Indicates diameter.

Table 2 however, The meanings of the symbols in this table are as follows.

Cl1=Ca(OH)t ZO=ZnOHP=HtP
OzZC= CaZn(HPOs) x CP=
CaHPOt ZP = ZnHPO30 = X-ray diffraction result The presence is recognized.

Δ = As a result of X-ray diffraction, the presence is slightly recognized.

−=Existence not recognized as a result of X-ray diffraction.

Table 3 However, the symbols have the same meanings as in Table 2.

From Tables 2 and 3, in Examples 1 to 8, the desired single-component composition, two-component composition, or three-component composition was obtained by changing the raw material molar ratio, and No impurity components were observed. Comparative example 1 is
As a result, a solution reaction and crystallization occur and the reaction is not completed.
Remaining unreacted substances, which tend to occur in solid solution reactions, were observed.

① Powders I to ① obtained in Examples 1 to 8 were prepared with the following compounding ratio, and dispersed for 1 hour using a Santo mill with 100 g of glass beads (Φ 1.5 mm). The mixture was made into paints to obtain paints 1 to 2, respectively. There were no particular problems in turning it into a paint, and there were no particular problems in the stability of the resulting paint.

Rust preventive pigment (powder I to ■) 6.1 parts by weight Titanium dioxide (rutile type) 6.0 Cal/Rum carbonate 6.7 Talc 13.6 Precipitated barium sulfate 6.7 Resin 55.6 Water
5.3 In addition,
The resin used here is Watersol CD-540, manufactured by Dainippon Ink & Chemicals, which is a water-soluble epochine ester resin with a non-volatile content of 39.2%.

For comparison, a commercially available zinc chromate rust preventive pigment (non-fuchromate JWK-5114) was used as the above rust preventive pigment.
CZP type) (powder X), titanium dioxide (rutile type) (powder XI), zinc phosphite (powder , each was made into a paint by the above method, and paint X
, ~X■ was obtained.

Paints I to ■ thus obtained and paints X-X
IV, cold-rolled steel plate JI manufactured by Nihon Testobaru Industry Co., Ltd.
S G31415PCC-3B 1.0X70X 15
One coat was applied to 0 mm using a barcoder, and the film thickness after drying was 30 μm. After that, it was dried for one week at room temperature, and without topcoating, a salt spray test with 5% salt water was conducted using a salt spray tester 5T-1sO-3 manufactured by Suga Test Instruments ■ to evaluate the rust prevention ability of each paint. Tested. The results are shown in Table 4.

In this table, the evaluation numbers indicate the following results.

100% rust = 75% rust = 50% rust 25% rust = no blistering or rust Table 4 From the table, it is recognized that the zinc calcium phosphite according to the present invention has a rust-preventing power equivalent to or higher than that of zinc chromate, which has been conventionally used as a rust-preventing pigment.

〔Effect of the invention〕

Since the curved lead calcium phosphite, its manufacturing method, and the paint containing the same according to the present invention have the above-mentioned structure and characteristics, they are less toxic and less expensive than conventional pollution-free rust-preventing paints. This makes it possible to provide a rust-preventing paint with excellent paint stability and excellent rust-preventing power.

Claims (3)

[Claims] (1) Zinc calcium phosphite represented by the following formula, and
A zinc calcium phosphite-containing composition CaZn (
HPO_3)_2-nH_2O...(I) Here,
n=0~2 (2) After adding phosphorous acid to a slurry of a zinc compound and a calcium compound with water, or after slurrying a zinc compound, a calcium compound, and a phosphorous acid compound with water, without heating. A method for producing zinc calcium phosphite and a composition containing the same according to claim 1, which comprises wet kneading by mechanical means and mechanochemical reaction. (3) Rust-preventive paint containing zinc calcium phosphite according to claim 1