JPH1192979A - Rust preventive agent and rust preventive coating material and rust preventive liquid using the agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the rust preventing effect by incorporating a salt prepared by neutralizing dioxycarboxylic acid or its deriv. with a base such as alkali metals. SOLUTION: This rust preventive consists of one or more kinds of salts prepared by neutralizing an acid expressed by the formula with a base. When m is 1 and R1 is hydrogen in the formula, the salt is prepared by neutralizing with >=2 equiv. of a base comprising compds. of alkali metals or alkaline earth metals, monoethanol amines, etc. When m is 1 and R1 is not hydrogen, the salt is prepared by neutralizing with >=1 equiv. base above descrivbed. When m is 0, R1 is -NR2R3. In the formula. R1 is hydrogen, 1 to 8C alkyl group, 3 to 8C alkenyl group, phenyl group, phenyl group having 1 to 4C alkyl group, 2 to 4C alkenyl group or -NR2R3 (wherein R2 and R3 are independently hydrogen, 1 to 6C alkyl groups or the like), n is 1 or 2 and m is 0 or 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel rust inhibitor, a rust preventive paint and a rust preventive liquid using the same.

[0002]

2. Description of the Related Art For example, in a factory, machined iron and steel parts (for example, various parts from small parts such as bolts and nuts to large parts such as pressed steel sheets for automobiles) are used in the next process. In order to temporarily prevent rusting until sending or product completion, or in assembling ships, bridges, etc., temporarily assemble various thickness steel plates, steel pipes, etc. Various rust inhibitors are used to rust.

[0003] The temporary rust inhibitor must be easily removable with, for example, water or hot water, and therefore, a water-soluble rust inhibitor is preferably used. As such a water-soluble rust inhibitor, for example, disodium phosphate, trisodium phosphate, sodium carbonate, sodium tripolyphosphate and the like are generally used instead of the conventional chromium compound.

Further, as a new water-soluble rust inhibitor,
For example, JP-A-53-31737 discloses triazine derivatives such as 2-anilino-4,6-dithiol-S-triazine monosodium and 2-benzylamino-4,6-dithiol-S-triazine monosodium. Is disclosed in Japanese Patent Application Laid-Open No. Sho 54-8642.
A compound is disclosed in which a compound obtained by esterifying moles of 1,6-hexanediol and 2 moles of thioglycolic acid and having two or more thiol groups in a molecule is further added to an olefin compound.

Further, Japanese Patent Laid-Open No. Hei 6-93213 discloses that
A water-soluble organic reducing agent having a mercapto group and a carboxy group in the molecule, such as thiopropionate, thioglycolate, and thiomalate, and neutralizing only the carboxy group, is used as a water-soluble rust. It is disclosed for use as a stopping agent.

[0006]

However, none of the above-mentioned conventional rust preventive agents has a sufficient anti-rust effect yet, and it is presently required to further improve the anti-rust effect. A main object of the present invention is to provide a novel rust inhibitor excellent in rust inhibitory effect as compared with conventional rust inhibitors, a rust inhibitor paint and a rust inhibitor liquid using the same.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have proposed dithiodiglycolic acid, dithiodipropionic acid (hereinafter referred to as dithiocarboxylic acid) represented by the general formula (I) and derivatives thereof ( (Hereinafter referred to as a derivative), and revealed that a salt neutralized (total neutralization) with a specific base such as an alkali metal, an alkaline earth metal, or an amine has excellent rust inhibiting performance. Further, the rust preventive paint of the present invention contains the above rust inhibitor and a resin as a film-forming element, and the rust preventive solution of the present invention contains water or a mixed solvent of water and a polar solvent. One or two or more of the above rust inhibitors are dissolved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below. As described above, the rust inhibitor of the present invention neutralizes a salt obtained by neutralizing dithiocarboxylic acid with two or more equivalents of base (hereinafter referred to as "total neutralization") or a derivative with one or more equivalents of base. It is characterized by containing one or more salts.

The base having a molar equivalent of 2 or more is preferably a monovalent base having a molar ratio of at least twice that of dithiocarboxylic acid, or a divalent base having a molar equivalent of dithiocarboxylic acid or more. The amount of the monovalent base or the base is preferably at least 1/2 mole amount, and examples of the monovalent base include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide. And amines such as monoethanolamine, diethanolamine, triethanolamine and dichlorohexylamine. Examples of the divalent base include, for example, magnesium hydroxide, calcium hydroxide, strontium hydroxide,
Hydroxides of alkaline earth metals such as barium hydroxide. Alternatively, dithiocarboxylic acid may be saponified and then double-decomposed with a halide or sulfate of an alkaline earth metal. The divalent base may form a salt between the molecules, or may form a salt within the molecule. Also, a mixture of both may be used.

Among the above, the total neutralized salt with an alkali metal atom such as lithium, sodium, potassium or the like can capture calcium in water, which is one of the causes of scale, and even if it becomes calcium salt, it is rustproof. Since it has an effect, it is particularly useful as a rust inhibitor. In addition, as described above, the dithiocarboxylic acid totally neutralized salt is prepared by using dithiocarboxylic acid and a derivative as a starting material, neutralizing the carboxy group in the molecule with a base, and preparing the above dithiocarboxylic acid. A neutralized salt of a dithiocarboxylic acid or a neutralized salt of a derivative obtained from the production process may be used.

The derivative represents a case where R1 is not hydrogen in the general formula (I). For example, when m is 1, dithiodiglycolic acid monoethyl ester, dithiodiglycolic acid monobutyl ester, dithiodiglycolic acid monooctyl ester, dithiodiglycolic acid monophenyl ester, dithiodipropionic acid monomethyl ester, dithiodipropionic acid Monobutyl ester, monooctyl dithiodipropionate, monoallyl dithiodipropionate, mono-p-methylphenyl dithiodipropionate, and m is 0,
Represents dithiodipropionic acid monoethanolamide, dithiodipropionic acid monopropylamide, dithiodiglycolic acid monoamide and the like.

The rust inhibitor of the present invention containing one or more of the above-mentioned neutralized salts of all dithiocarboxylic acids and neutralized salts of derivatives can be used, for example, in combination with a water-soluble resin as a film-forming element. As an anticorrosive paint, or alone, dissolved in water or a mixed solvent of water and a polar solvent, as an anticorrosive liquid, in addition to being used for the temporary anticorrosion, taking advantage of its water solubility, Can be used for rust preventives such as boiler water and cooling water in chemical factory plants, compounded in concrete for rust preventives such as reinforcing steel, or compounded in emulsion paint for semi-permanent rust preventive paints. It is.

Among the above, the concentration of the rust inhibitor in the rust inhibitor obtained by dissolving the rust inhibitor alone in water or a mixed solvent of water and a polar solvent is not particularly limited.
It is preferably from 0.01 to 60% by weight. When the concentration of the rust inhibitor is less than the above range, the effect of adding the rust inhibitor becomes insufficient, and rust may occur on iron or steel parts, and conversely, when the concentration exceeds the above range. Is inconvenient to handle due to high viscosity of the liquid, and is not desirable in terms of economy. In addition, the concentration of the rust inhibitor is preferably 0.01 to
It is preferably about 40% by weight.

On the other hand, an anticorrosive paint containing an anticorrosive agent and a water-soluble resin is usually supplied in a liquid form in which both are dissolved in a predetermined amount of water or a mixed solvent of water and a polar solvent in advance. Not containing such a solvent, may be supplied in the form of a solid such as powder or granules containing a rust inhibitor in a water-soluble polymer, or in the form of a concentrated solution containing a small amount of water or a mixed solvent. In the latter two cases, a predetermined amount of water or a mixed solvent may be added for use to dilute the mixture to a predetermined concentration.

The concentration of the rust inhibitor and the water-soluble resin (the concentration at the time of final use) is not particularly limited, and may be an appropriate range which does not impair the rust preventing property, the uniformity of the coating film, and the adhesion. Although it is possible, the concentration of the rust inhibitor is preferably about 0.01 to 30% by weight, more preferably 0.01 to 10% by weight. When the concentration of the rust inhibitor is less than the above range, the effect of adding the rust inhibitor becomes insufficient, and rust may occur on iron or steel parts, and conversely, when the concentration exceeds the above range. This may be because the uniformity and adhesion of the coating film are reduced, or rust may be generated on the above parts.

The concentration of the water-soluble resin is preferably about 0.01 to 60% by weight. If the concentration of the water-soluble resin is less than the above range, the uniformity of the coating film, there is a possibility that the adhesion is reduced, and if it exceeds the above range, the viscosity of the paint is too high, the coating operation is difficult. It may not be easy. The concentration of the water-soluble resin is particularly preferably about 0.1 to 40% by weight in the above range.

When the rust preventive paint is supplied in a solid state as described above, the concentration of the rust preventive agent and the water-soluble resin at the time of final use by adding water or a mixed solvent is within the above range. Thus, both may be blended. For example,
The rust inhibitor A and the water-soluble resin B are mixed at a weight ratio of A / B = 0.
What is necessary is just to mix in the ratio of 01/60 to 10 / 0.01.

Among the rust preventive paints, a liquid paint obtained by dissolving a rust inhibitor and a water-soluble resin in water or a mixed solvent,
For example, it is manufactured by first dissolving a predetermined amount of a water-soluble resin in water or a mixed solvent heated to about 70 to 80 ° C., and then dissolving a predetermined amount of a rust inhibitor. Also, the solid thing, by drying or removing water or a mixed solvent from the liquid thing produced as described above, or a rust inhibitor and a water-soluble resin, melt kneading in a solventless system, or by mixing Manufactured.

Examples of the water-soluble resin include, but are not limited to, alkyd resins, amino resins, phenol resins, acrylic resins, acrylate resins, epoxy ester resins, acrylamide resins, melamine resins, and the like.
Bisphenol type epoxy resin, polyvinyl alcohol resin, maleated oil-modified resin, maleated fatty acid-modified polyester resin, special phenol resin-modified resin, trimellitic acid-modified alkyd resin, polyethylene glycol resin, polypropylene glycol resin, polyethyleneimine resin, various polycarboxylic acids Any of various conventionally known water-soluble resins, such as a resin obtained by salting an acid resin with an organic amine, ammonia or the like, can be used.

Examples of the polar solvent constituting a mixed solvent with water include alcohols such as methanol, ethanol, isopropanol, amyl alcohol and ethylene oxide-added alcohol, esters such as methyl acetate, amyl acetate and octyl acetate, acetone and methyl acetone. And ketones and ethers such as ethylene glycol.

The rust preventive paint may be colored by adding a pigment such as titanium white, calcium carbonate, barium sulfate, phthalocyanine blue, helio red, or carbon black. A surfactant as a dispersant for such a pigment,
Alternatively, it may contain various conventionally known additives such as a viscosity modifier, a plasticizer, a drying accelerator, a defoamer, and an anti-skinning agent. Further, when machining a part with the rust preventive paint applied, various conventionally known organic phosphorus compounds, organic sulfur compounds, halogen compounds and the like may be added as an antiwear agent for processing. The amounts of these additives may be the same as in the prior art.

When the anticorrosive agent of the present invention is used in a semi-permanent anticorrosive paint by blending it in an emulsion paint, examples of resins for the emulsion paint include vinyl acetate resin, styrene-butadiene resin, and maleic acid. Ester-acrylate copolymer resins, vinyl chloride resins, vinyl chloride-vinylidene chloride resins, butadiene-acrylonitrile resins, urethane resins, and the like.

Various additives similar to those described above may be added to the emulsion paint.

[0024]

The present invention will be described below with reference to examples and comparative examples. Examples 1 to 15 The following rust preventive agents (A) to (O) were each dissolved in water to prepare an aqueous solution having a concentration of 1% by weight. (A) Dilithium dithiodipropionate (B) Disodium dithiodipropionate (C) Dipotassium dithiodipropionate (D) Calcium dithiodipropionate (E) Magnesium dithiodipropionate (F) Dithio Strontium dipropionate (G) Barium dithiodipropionate (H) Bis (triethanolamine) dithiodipropionate (I) Bis (diethanolamine) dithiodipropionate (J) Bis (monodithiodipropionate) (Ethanolamine) salt (K) Bis (diclohexyl) amine dithiodipropionate (L) Monomethyl dithiodipropionate sodium salt (M) Monobutyl dithiodipropionate Monoethanolamine salt (N) Dithiodipropionic acid Monoethanol Amide Sodium Salt (O) Dithiodiglycolic Acid Disodium Salt

Comparative Examples 1 to 10 Each of the following rust preventive agents (a) to (j) was dissolved in water to prepare an aqueous solution having a concentration of 1% by weight. (I) Commercial rust inhibitor (a) dithiodipropionic acid (b) monoammonium dithiodipropionate (c) monosodium dithiodipropionate (d) disodium thiodithiodipropionate (e) dithio Monopropylamine dipropionate (f) Mono (dipropyl) amine dithiodipropionate (g) Mono (tripropyl) amine dithiodipropionate (h) Mono (2-ethylhexyl) amine dithiodipropionate ( i) Commercial rust inhibitor

Comparative Example 10 was prepared by adding water to which no rust inhibitor was added.
And

Antirust Test-1 (Immersion Test) An iron plate (SPCC) as a test piece was immersed in the aqueous solution prepared in each of the above Examples and Comparative Examples, pulled up and drained, and then at room temperature for 30 days. After standing, the rust inhibiting properties of the rust inhibitor were evaluated according to the following five criteria.

A: No rust was observed. Particularly good rust resistance. ：: Rust was observed, but the area was 1% on the surface of the test piece.
It was less than 0%. Good rust prevention. Δ: Rust was observed in a range of 10% or more and less than 50% of the surface of the test piece. Slightly poor rust resistance.

×: Rust was observed in a range of 50% or more and less than 90% of the surface of the test piece. Poor rust resistance. XX: Rust was observed in a range of 90% or more of the surface of the test piece. Extremely poor rust resistance. Table 1 shows the above results.

[0030]

[Table 1]

An alkali metal of the dithicarboxylic acid of the present invention,
It was found that, among all neutralized salts of alkaline earth metals and amines, all neutralized salts of monoethanolamine, ditanolamine, triethanolamine and dicyclohexylamine were excellent in rust inhibitory performance. Also, it was found that the sodium salt of thiodipropionic acid (total neutralization) was completely different from dithiopropionic acid and had no rust-preventing performance at all.

Examples 16 to 22 Except that the addition amount of the rust inhibitor of B was set to the value shown in Table 2, a rust inhibitor was prepared in the same manner as in Example 1-15. The rust preventive liquid of each of the above examples was subjected to the above rust preventive test, and the results were evaluated based on the same five-point criteria as above.

[0033]

[Table 2] From Table 2, it was confirmed that when the added amount was less than 0.01 part by weight, the rust inhibitory effect was slightly reduced, but when the added amount was more than 0.01 part by weight, a sufficient effect could be exhibited.

Examples 23-25 Comparative Example 11-
14. After adding and dissolving 10.0 parts by weight of polyvinyl alcohol (molecular weight 1700) to 89.0 parts by weight of water heated to 70 to 80 ° C., the above (B), (J), (K) and (a)
(C) 1.0 part by weight of each of the rust inhibitors of (d) and the condensed phosphoric acid was further added and dissolved to prepare a total of 100 parts by weight of a rust preventive paint.

Comparative Example 15 Example 23-2 except that no rust inhibitor was added.
5. In the same manner as in Comparative Examples 11 to 14, rust preventive paints were produced. For each of the above Examples and Comparative Examples,
The following rust preventive test-2 was performed, and the results were evaluated based on the same five-point criteria as above. Table 3 shows the results.

[0036]

[Table 3] Rust prevention test-2 An iron plate (SPCC) as a test piece was immersed in the aqueous solution prepared in each of the above Examples and Comparative Examples, pulled up, drained, and then dried at 50 ° C for 1 hour. Then, this test piece is compliant with JIS K2246 “Wet test method”,
1 in a thermo-hygrostat set at a temperature of 50 ° C and a humidity of 95%
After standing for 8 hours, the surface of the test piece was observed.
The rust inhibitory properties of the rust inhibitor were evaluated on a scale basis.

Examples 26 to 28 Comparative Example 16
-19 The added amount of the rust inhibitor for (B), (J), (K), (a), (c), and (d) and the condensed phosphoric acid was respectively dissolved in water to prepare a 1.0% concentration aqueous solution. . Comparative Example 20 Example 26-2 except that no rust inhibitor was added
8. A rust inhibitor was prepared in the same manner as in Comparative Example 6-19. For the rust preventive liquid of each of the above Examples and Comparative Examples, the above-described rust preventive test-2 was performed, and the results were evaluated based on the same five-point criteria as above. Table 4 shows the results.

[0038]

[Table 4] In Examples 23 to 28, it was found that the anticorrosive agent of the present invention exhibited an excellent anticorrosive effect even in the anticorrosive test-2 (wet test). Examples 29-30 Dithiodipropionic acid obtained from a residue obtained by adding sodium hydrogen sulfide and acrylonitrile and then hydrolyzing to synthesize 3-mercaptopropionic acid, followed by distillation to remove 3-mercaptopropionic acid. Is completely neutralized with sodium hydroxide, and the rust inhibitor of (B) is completely neutralized with monoethanolamine, and the rust inhibitor of (J) is completely neutralized with Examples (2) and (10). Rust prevention test-1
Was done. Table 5 shows the results.

[0039]

[Table 5] From Table 5, it was confirmed that the compounds (B) and (J) belonging to the rust inhibitor of the present invention also had a high rust inhibitor effect regardless of the method of synthesizing the starting materials.

[0040]

As described above in detail, according to the present invention, there is provided a novel rust inhibitor having a remarkably excellent rust inhibitory effect, and a unique effect of providing a rust inhibitor paint and a rust inhibitor solution using the same. It works.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akio Sakamoto 5-1-1 Ebisshimacho, Sakai City, Osaka Prefecture Sakai Chemical Industry Co., Ltd. (72) Inventor Yoshiki Takenaka 3-27-16 Chikushinmachi, Sakai City, Osaka Prefecture Inside Tomioka Chemical Co., Ltd. (72) Inventor Shinji Ikeshita Tomioka Chemical Co., Ltd.

Claims (7)

[Claims] 1. A compound of the general formula (I) Wherein at least one of m is 1 and R1 is hydrogen, a compound comprising at least 2 equivalents of an alkali metal or an alkaline earth metal, A salt neutralized with a base consisting of monoethanolamine, diethanolamine, triethanolamine or dicyclohexylamine; and when m is 1 and R1 is not hydrogen, a salt neutralized with one or more equivalents of the above base, When m is 0, R1 is a -NR2R3 group. In the formula, R1: hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 3 to 8 carbon atoms, a phenyl group, an alkyl group having 1 to 4 carbon atoms, a phenyl group having an alkenyl group having 2 to 4 carbon atoms,- NR2R3 groups (R2 and R3 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted by a hydroxyl group, 6 to 18 carbon atoms A phenyl group). n represents 1 or 2. m represents 0 or 1. 2. A rust preventive paint comprising the rust inhibitor according to claim 1 and a resin as a film-forming element. 3. The rust preventive paint according to claim 2, wherein the resin is a water-soluble resin. 4. The rust preventive paint according to claim 3, wherein the water-soluble resin and the rust inhibitor are dissolved in water or a mixed solvent of water and a polar solvent. 5. A rust inhibitor having a concentration of 0.01 to 30% by weight.
The rust preventive paint according to claim 4, which is: 6. In water or a mixed solvent of water and a polar solvent,
A rust preventive solution in which the rust inhibitor according to claim 1 is dissolved. 7. A rust inhibitor having a concentration of 0.01 to 60% by weight.
7. The rust inhibitor according to claim 6, wherein