JP7019224B1 - Water-soluble rust inhibitor composition and its usage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rusting of a work in an intermediate rust prevention of a work in a wet state such as when cutting, grinding, plastic working, heat treatment, etc., and staying in a metal processing process, and to improve the quality of the product. Provided are a water-soluble rust preventive composition which is safer for the human body and a method of using the same, which improves productivity. SOLUTION: A water-soluble rust preventive composition containing (A) hydroxycarboxylic acid and / or aromatic nitrated carboxylic acid and (B) an organic amine compound, which is used as a stock solution or diluted with water and coated. A method of using a water-soluble rust preventive composition, which comprises a step of applying to a rust preventive. [Selection diagram] None

Description

The present invention relates to a water-soluble rust inhibitor that is safer for the human body and has excellent metal rust inhibitory properties, and a method for using the same.

Various water-soluble rust preventives have been proposed and used in the intermediate rust preventive of workpieces that are in a wet state when staying in the metal processing process, and currently the mainstream water-soluble rust preventive composition is used. , For example, those using an inorganic salt such as nitrite are known.

However, a formulation containing sodium nitrite as in Patent Document 1 is concerned about its effects on the human body such as acute toxicity (oral) and toxicity to specific target organs, and environmental hazards to aquatic organisms. In addition, water-soluble metalworking oils are often used in the processes before and after application of rust preventives, and there is a problem that carcinogenic nitrosamines may be produced by reaction with amines in the water-soluble metalworking oils. Will be. Further, the composition proposed in Patent Document 2 contains an alkali metal, and the composition proposed in Patent Document 3 contains an aliphatic dibasic acid and an aliphatic monocarboxylic acid. The formation of metal soap affects the next process, such as deterioration of appearance finish and processability. Patent Document 4 shows a rust-preventive cleaning solution for steel pipes after processing, which contains a hydroxycarboxylic acid metal salt, but there is no description or suggestion as to whether the rust-preventive property is improved by using an organic amine compound in combination. ..

As described above, the current situation is that almost no water-soluble rust inhibitor has been obtained, which is highly safe for the human body, exhibits excellent rust preventive power, and is less affected by rust preventive residues.

Japanese Unexamined Patent Publication No. 56-055576 Japanese Patent No. 6674996 Japanese Unexamined Patent Publication No. 60-255896 Japanese Unexamined Patent Publication No. 2019-0233333

An object of the present invention has been made to solve the above problems, and a water-soluble rust preventive composition having high safety to the human body and excellent rust preventive property and use of a rust preventive agent using the same. To provide a method.

As a result of intensive studies to achieve the above object, the present inventor has excellent rust resistance by using a hydroxycarboxylic acid and / or an aromatic nitrated carboxylic acid in combination with a predetermined organic amine compound. It has been found that the above object can be achieved, and further various studies have been made based on this, and the present invention has been completed.

That is, the water-soluble rust preventive agent of the present invention is a hydroxycarboxylic acid and / or an aromatic nitrated carboxylic acid represented by the following general formula (1) and a primary organic amine compound, and a secondary represented by the following general formula (2). It is composed of a complex containing one or more selected from the group consisting of a tertiary organic amine compound and an alkylamine compound represented by the following general formula (3).

A water-soluble rust inhibitor composition, wherein the hydroxycarboxylic acid is malic acid or citric acid and contains one or two of them.

（式（１）中、Ｘは水素またはカルボキシル基を示す。Ｙ１、Ｙ２、Ｙ３、Ｙ４は水素またはニトロ基を示す。Ｙ１、Ｙ２、Ｙ３、Ｙ４は同一でも異なっていてもよいが、Ｙ１、Ｙ２、Ｙ３、Ｙ４が全て水素であることはない。）

(In formula (1), X represents a hydrogen or carboxyl group. Y1, Y2, Y3, Y4 represents a hydrogen or nitro group. Y1, Y2, Y3, Y4 may be the same or different, but Y1, Y2, Y3, and Y4 are not all hydrogen.)

（式（２）中、Ｚ１、Ｚ２は炭素数１～４の直鎖、分岐鎖の炭化水素基を示す。Ｒ１は水素、炭素数１～１２の直鎖、分岐鎖、若しくは環状構造のアルキル基、アルコキシ基、ベンジル基を示す。Ｒ２、Ｒ３は水素、水酸基、フェニル基を示す。Ｒ２、Ｒ３は同一でも異なっていてもよいが、Ｒ２、Ｒ３が全て水素であることはない。）

(In the formula (2), Z1 and Z2 represent a straight chain having 1 to 4 carbon atoms and a hydrocarbon group having a branched chain. R1 is hydrogen, a straight chain having 1 to 12 carbon atoms, a branched chain or an alkyl having a cyclic structure. Indicates a group, an alkoxy group, and a benzyl group. R2 and R3 indicate hydrogen, a hydroxyl group, and a phenyl group. R2 and R3 may be the same or different, but R2 and R3 are not all hydrogen.)

（式（３）中、Ｚ３は炭素数１～１２の直鎖、分岐鎖、若しくは環状構造の炭化水素基を示す。Ｒ４、Ｒ５、Ｒ６、Ｒ７は水素、炭素数１～１２の直鎖、分岐鎖、若しくは環状構造のアルキル基の炭化水素基を示す。Ｒ４、Ｒ５、Ｒ６、Ｒ７は同一でも異なっていてもよいが、Ｒ４、Ｒ５、Ｒ６、Ｒ７が全て水素であることはない。）

(In the formula (3), Z3 represents a straight-chain, branched-chain, or cyclic hydrocarbon group having 1 to 12 carbon atoms. R4, R5, R6, and R7 are hydrogen and a linear chain having 1 to 12 carbon atoms. Indicates a hydrocarbon group of a branched chain or an alkyl group having a cyclic structure. R4, R5, R6 and R7 may be the same or different, but R4, R5, R6 and R7 are not all hydrogen.)

A water-soluble rust preventive composition, wherein the molar ratio of the amount of the organic amine compound added to the amount of the hydroxycarboxylic acid and / and the aromatic nitrated carboxylic acid is 1: 2 to 1:10.

The method of using the rust preventive agent of the present invention is a step of applying the rust preventive agent composition of the present invention to an iron-based material such as stainless steel, alloy steel and carbon steel as it is or by diluting it with water. Shall include.

The pH of the undiluted solution and the diluted water-soluble rust inhibitor is used in the range of 8.0 to 12.0.

According to the present invention, a water-soluble rust preventive composition in which a hydroxycarboxylic acid and / or an aromatic nitrated carboxylic acid and a predetermined organic amine compound are used in combination is diluted with a stock solution or water and applied to an iron-based metal material. Therefore, the rust can be remarkably suppressed. By not blending the alkali metal and the fatty acid in the composition, there is no influence such as deterioration of the appearance finish and processability due to the metal soap produced from the alkali metal and the fatty acid. Therefore, it is safer for the human body, the finishability and workability are not adversely affected, the generation of defective products due to the generation of rust can be suppressed, and the decrease in productivity can be effectively prevented.

Examples of the hydroxycarboxylic acid used in the present invention include malic acid, citric acid and the like. These can be used alone or in combination of the two.

Examples of the aromatic nitrated carboxylic acid represented by the general formula (1) used in the present invention include nitrophthalic acid, nitrobenzoic acid and the like. These aromatic nitrated carboxylic acids can also be used alone, or two or more of them can be used in combination.

Examples of the primary organic amine compound used in the present invention include monoethanolamine, monoisopropanolamine, diglycolamine, 2-amino-2-methyl-1-propanol, benzylamine and the like. The amine salt composed of the above amine has excellent rust resistance, but from the viewpoint of the effect on the human body, it is preferable to use diglycolamine, 2-amino-2-methyl-1-propanol, benzylamine and the like.

Examples of the secondary and tertiary organic amine compounds represented by the general formula (2) used in the present invention include diethanolamine, diisopropanolamine, methylethanolamine, 2- (butylamino) ethanol, and 2-{(1-methylpropyl). ) Amino} ethanol, triethanolamine, triisopropanolamine, methyldiethanolamine, butyldiethanolamine, octyldiethanolamine, cyclohexylamine ethylene oxide adduct and the like can be mentioned. The amine salt composed of the above amines has excellent rust resistance, but from the viewpoint of the effect on the human body, diisopropanolamine, methylethanolamine, 2- (butylamino) ethanol, triethanolamine, triisopropanolamine, butyldiethanolamine, octyl. It is preferable to use diethanolamine, cyclohexylamine ethylene oxide adduct and the like.

Examples of the alkylamine compound represented by the general formula (3) used in the present invention include 2-methylpentamethylenediamine and tetramethylhexamethylenediamine. Although the amine salt composed of the above amine has excellent rust resistance, it is preferable to use 2-methylpentamethylenediamine or the like from the viewpoint of the influence on the human body.

In the present invention, the molar ratio of at least one selected from (A) hydroxycarboxylic acid and / or aromatic nitrated carboxylic acid to (B) at least one selected from a given organic amine compound is (A). : (B) is preferably about 1: 2 to 1:10, more preferably about 1: 3 to 1: 8, and even more preferably about 1: 4 to 1: 6.

The content of the hydroxycarboxylic acid in the rust preventive composition of the present invention is preferably 5 to 25% by weight, more preferably 8 to 20% by weight. If it is less than 5% by weight, a sufficient rust preventive effect cannot be obtained, and if it exceeds 25% by weight, it becomes difficult to maintain a pH of 8.0 or more.

The content of the aromatic nitrated carboxylic acid is preferably 5 to 25% by weight, more preferably 8 to 20% by weight. If it is less than 5% by weight, a sufficient rust preventive effect cannot be obtained, and if it exceeds 25% by weight, the appearance of the liquid becomes brown.

The water-soluble rust preventive agent of the present invention is used by using the water-soluble rust preventive agent composition of the present invention as a stock solution and diluting it with water. When the water-soluble rust inhibitor composition is diluted with water and actually used, it is preferable to dilute the undiluted solution with water so that the concentration is about 1 to 100% by weight, and about 2 to 100% by weight is more preferable. preferable. If it is less than 1% by weight, a sufficient rust preventive effect cannot be obtained, which is not preferable.

As the water-soluble rust inhibitor of the present invention, the water-soluble rust inhibitor composition of the present invention can be used as it is as a stock solution. In that case, the content of the hydroxycarboxylic acid or the aromatic nitrated carboxylic acid is preferably 1 to 15% by weight, more preferably 2 to 10% by weight, based on 100% by weight of the entire water-soluble rust inhibitor composition. Is. If it is less than 1% by weight, a sufficient rust preventive effect cannot be obtained, and if it exceeds 15% by weight, the rust-prevented object may become sticky, and therefore neither is preferable.

The water-soluble rust inhibitor of the present invention preferably has a pH of about 8.0 to 12.0 when the stock solution of the water-soluble rust inhibitor composition of the present invention is diluted with water. It is more preferably about 1 to 11.5, and further preferably about 8.2 to 11.0. If the pH is less than 8.0, a sufficient rust preventive effect cannot be obtained, and if it exceeds 12.0, the working environment may be deteriorated such as rough skin, which is not preferable.

Ingredients other than the above components In addition to the constituents of the present invention, the water-soluble rust preventive composition according to the present invention includes conventional additives such as metal corrosion inhibitors and surfactants within the range not deviating from the object of the present invention. Additives such as activators, preservatives and defoamers can be added. The blending amount of these additives is appropriately determined according to the type of metal processing step.

Examples of the metal corrosion inhibitor include imidazole-based compounds, benzotriazole-based compounds, and triltriazole-based compounds.

As a nonionic surfactant, for example, as a general one,
Examples include HO- (EO) m (PO) n (EO) m-H, RO (EO) n-H, R- (AO) n-H, and the EOPO adduct of glycerin. In each of these formulas, R represents an alkyl group (which may be linear or branched, or may have a cyclic structure, a double bond, a triple bond, etc.) and AO (alkylene oxide). ) Is a mixture of one or two of EO (oxyethylene group) and PO (oxypropylene group), and the sequence in the case of the mixture may be random or block. Further, in each equation, n and m represent integers of about 1 to 500.

Examples of the preservative include triazine compounds, isothiazolin compounds, benzoisothiazolin compounds, morpholin compounds, pyridine compounds, iodine compounds and the like.

Examples of the defoaming agent include silicon-based, higher alcohol-based, polyglycol-based, and mineral oil-based.

Water is blended in the water-soluble rust preventive composition of the present invention. The blending amount of water is usually preferably about 1 to 70% by weight when the entire water-soluble rust preventive composition is 100% by weight. The water used may be tap water, industrial water, ion-exchanged water, distilled water, or the like.

The method of applying the water-soluble rust inhibitor diluted solution to the object is not particularly limited to the work that is in a wet state when it stays during the metal processing process such as cutting, grinding, and quenching, and it is applied by dipping or brushing. , A known method such as dropping in a shower or the like can be used depending on the purpose.
In the water-soluble rust inhibitor composition of the present invention, iron-based materials such as stainless steel, alloy steel, and carbon steel are suitable for the work to be rust-prevented.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to these Examples.

Wet rust prevention test According to the wet test specified in JIS K2246 "Rust preventive oil", after making a hole with a diameter of 5 mm at the corner of the mild steel plate SPCC-SD test piece (80 x 100 x 0.8 mm). It was washed with water, methanol and diethyl ether, and one side was polished with a 100-count abrasive grain polishing cloth. The samples of Examples 1 to 17 shown in Table 1 were diluted with tap water to 5% by weight, and the test piece was completely immersed in the diluted solution. For the samples of Examples 18 and 19, the test piece was completely immersed in the stock solution. After pulling up the fully immersed test piece, passing the hanger through the hole, and hanging it in a constant temperature and humidity chamber (temperature 60 ° C, relative humidity 95%) for one day and night, the 100 grids of the test piece are used as the measurement area. The degree of rusting% was evaluated by the number of grids on which one or more points of rust were generated.

Table 1 shows a water-soluble protective solution in which the (A) hydroxycarboxylic acid and / or the aromatic nitrated carboxylic acid of the present invention and the (B) organic amine compound are blended in a molar ratio of (A) :( B) = 1: 4. The compounding composition of the rust inhibitor composition and the water-soluble rust preventive composition for comparison was concentrated in% by weight, and for the samples of Examples 1 to 17, the pH when the composition was diluted to 5% by weight with water, Example. For the samples 18 and 19, the pH of the undiluted solution is shown. In Example 1, 15% by weight (0.1 mol) of malic acid (molecular weight: 134) and 36% by weight (0.4 mol) of 2-amino-2-methyl-1-propanol (molecular weight: 89) were blended. did.

Table 2 shows the water-soluble rust preventive composition of the present invention and comparison, and for the samples of Examples 1 to 17, the water-soluble rust preventive agent obtained by diluting the composition with water to 5% by weight, Examples 18 and 19. For the sample, the evaluation of the rust preventive performance of the undiluted solution is shown. The determination was made by visually setting 100 grids of the test piece as the measurement range, and the rust degree% was evaluated by the number of grids in which one or more points of rust were generated.

From the results of the degree of rusting of the test piece visually in Table 2, the undiluted solution of the water-soluble rust inhibitor composition of the present invention or the water-soluble rust inhibitor obtained by diluting it with water has a rust preventive effect for comparison with nitrite. It is clear that it is significantly superior to water-soluble rust inhibitors in which sodium-free compositions are diluted with water.

The water-soluble rust preventive composition that is safer for the human body of the present invention is effective in reducing productivity due to rust when a stock solution or a water-soluble rust preventive obtained by diluting the undiluted solution is applied to the work surface. Therefore, it can be used extremely effectively in the metal processing industry and related industries.

Claims (6)

A water-soluble rust preventive composition of an iron-based material containing at least one selected from the group consisting of (A) apple acid and citric acid and (B) an organic amine compound (however, the water-soluble rust preventive composition). Is an aromatic nitrated carboxylic acid, alkali metal, alkaline earth metal, aliphatic dibasic acid other than apple acid, aliphatic monocarboxylic acid, sodium nitrite, phosphorus-containing compound, 2-alkyl-N-carboxymethyl- Does not contain N-hydroxyethyl imidazolinium betaine) . The organic amine compound (B) is selected from the group consisting of a primary organic amine compound, a secondary or tertiary organic amine compound represented by the following general formula (2), and an alkylamine compound represented by the following general formula (3). The water-soluble rust preventive agent composition according to claim 1, which is at least one kind.

(In the formula (2), Z1 and Z2 represent a straight chain having 1 to 4 carbon atoms and a hydrocarbon group having a branched chain. R1 is hydrogen, a straight chain having 1 to 12 carbon atoms, a branched chain or an alkyl having a cyclic structure. Indicates a group, an alkoxy group, and a benzyl group. R2 and R3 indicate hydrogen, a hydroxyl group, and a phenyl group. R2 and R3 may be the same or different, but R2 and R3 are not all hydrogen.)

(In the formula (3), Z3 represents a straight-chain, branched-chain, or cyclic hydrocarbon group having 1 to 12 carbon atoms. R4, R5, R6, and R7 are hydrogen and a linear chain having 1 to 12 carbon atoms. Indicates a hydrocarbon group of a branched chain or an alkyl group having a cyclic structure. R4, R5, R6 and R7 may be the same or different, but R4, R5, R6 and R7 are not all hydrogen.) The water-soluble rust inhibitor composition according to claim 1 or 2, wherein the molar ratio of the addition amount of (B) to the addition amount of (A) is 1: 2 to 1:10. Use of the water-soluble rust preventive composition comprising the step of applying the water-soluble rust preventive composition according to any one of claims 1 to 3 to the rust-prevented object as it is or by diluting it with water. Method. Claim 4 in which the amount of the water-soluble rust inhibitor composition (A) added is 1 to 15% by weight when the total amount of the water-soluble rust inhibitor composition is 100% by weight when used as the undiluted solution. How to use the water-soluble rust inhibitor composition according to. The method for using a water-soluble rust inhibitor composition according to claim 5, wherein the pH of the water-soluble rust inhibitor composition diluted with a stock solution or water is in the range of 8.0 to 12.0.