JPS5947034B2 - anti-rust - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel rust preventive agent that has excellent rust preventive properties and low bubble properties.

Traditionally, rust inhibitors include inorganic compounds such as chromates, linotes, and sodium nitrite, as well as alkylamines, alkylpolyamines, condensates of fatty acids and polyalkylenepolyamines, and adducts of alkylene oxides and amines. Organic compounds such as are mainly used.

Among these, inorganic ones generally have poor lubricity, chromium-based ones are toxic, phosphorus-based ones cause eutrophication of wastewater, and nitrite-based ones are nitrosamines that are concerned about carcinogenicity. Due to pollution problems, their use has begun to be regulated, and the use of organic substances is gradually shifting to organic ones.

However, the rust preventive effect of currently used organic rust preventive agents is still not sufficient, and inorganic compounds such as sodium nitrite are mainly used. However, each of the above-mentioned inorganic rust preventive agents alone does not have a sufficient rust preventive effect, and various organic and inorganic compounds are currently used in combination depending on the purpose. Furthermore, when conventional organic rust preventives are used as water-soluble rust preventive agents, they foam violently, resulting in poor operability in industrial applications. The emergence of organic rust preventive agents is strongly desired. As a result of intensive research to solve the above problems, the inventors of the present invention have developed an organic rust preventive that exhibits excellent rust preventive effects even when used in small amounts and without mixing with other inorganic compounds, and that has low foaming properties. developed a drug.

That is, the rust preventive of the present invention has the general formula [I] HOOCR3(Co-X-C0NHR2COOH・
...It is a rust preventive agent whose essential ingredient is a salt of carboxylic acids represented by [technique].

In the formula [I], X is an aromatic hydrocarbon group, R,...
R2 each represents a hydrocarbon group having 1 to 18 carbon atoms, and may be the same or different, and may be linear or branched. Furthermore, depending on the case, the hydrocarbon group may have an unsaturated bond. The carboxylic acids used in the present invention include N,N'-terephthaloyldiglycine, N,N'-terephthaloyldiaminopropionic acid, N,N'-terephthaloyldiaminocaproic acid, N,
N'-terephthaloyldialanine, N,N'-terephthaloyl disarcosine, and the like, as well as reaction products of pyromellitic anhydride with amino acids such as glycine, sarcosine, and aminocaproic acid, etc., but are not limited to these. It's not a thing.

These carboxylic acids can be easily synthesized from putalol chloride and an amino acid by a known method (for example, Organic Compound Synthesis Method, Vol. 3, p. 66). Next, compounds constituting carboxylic acids and salts include salts of alkali metals and alkaline earth metals such as caustic soda, caustic potash, soda carbonate, and calcium hydroxide, as well as ammonium salts, methylamine, ethylamine, monoethanolamine, Lower amines such as diethanolamine, triethanolamine, and cyclohexylamine are preferably used.

In order to produce carboxylic acid salts (alkali salts),
Both may be mixed and heated and stirred if necessary.

At that time, an organic solvent or water that dissolves both components, or a mixture of both may be used as the reaction solvent. Additionally, the mixing ratio of carboxylic acids and alkalis (the above-mentioned alkali metal and alkaline earth metal salts, amines, etc.) may be equivalent or in excess of 10,000, but in general, an excess of alkali improves solubility in water. becomes good. The method of using the rust preventive of the present invention is not particularly limited, and it can be used by dissolving it in water, oil, or emulsion liquid in the same way as conventional rust preventive agents.

Next, the present invention will be explained in more detail with reference to Examples.

In the examples, parts refer to parts by weight. Example 1 43 parts of aminocaproic acid and 259 parts of sodium hydroxide were placed in a reaction vessel equipped with a condenser and a stirring device. 140 parts of water are mixed and stirred, and while cooling, a solution of 30 parts of terephthaloyl hexachloride dissolved in 70 parts of dioxane is gradually added dropwise so as to maintain the internal temperature at 30° C. or lower.

After the dropwise addition was completed, the mixture was stirred at 30°C for an additional 3 hours, and then neutralized with sulfuric acid while cooling. The white precipitate produced is filtered, washed with water, and purified with isopropyl alcohol to obtain N,N'-terephthaloyldiaminocaproic acid. Next, this N
, N'-terephthaloyldiaminocaproic acid, 26 parts of triethanolamine, and 132 parts of water are heated and mixed to obtain a rust inhibitor containing about 30% of the active ingredient.

Example 2 15 parts of N,N5-terephthaloyldiaminocaproic acid synthesized in Example 1, 3 parts of caustic soda, and 42 parts of water are heated and mixed to obtain a rust inhibitor containing about 30 (fl) of active ingredients.

Example 3 15 parts of N,N'-terephthaloyldiaminocaproic acid synthesized in Example 1, 4.5 parts of caustic potash, and 45.5 parts of water are heated and mixed to obtain a rust preventive having an active ingredient of about 300 I).

Example 4 15 parts of N,N'-terephthaloyldiaminocaproic acid synthesized in Example 1, 8 parts of diethanolamine, and 54 parts of water are heated and mixed to obtain a rust inhibitor containing about 30(f) of active ingredients.

Example 5 15 parts of N,N5-terephthaloyldiaminocaproic acid synthesized in Example 1, 4f of methylamine! f) Heat and mix 44 parts of S water to obtain a rust preventive agent containing about 30% of the active ingredient.

Example 6 15 parts of N,N'-terephthaloyldiaminocaproic acid synthesized in Example 1, 5 parts of monoethanolamine, 47 parts of water
A rust preventive agent having an active ingredient of about 3001) is obtained by heating and mixing the two parts.

Example 7 15 parts of N,Nl-terephthaloyldiaminocaproic acid synthesized in Example 1, 7 parts of cyclohexylamine, 51 parts of water
A rust preventive agent containing about 30 (fl) of active ingredients is obtained by heating and mixing the two parts.

Example 8 Into a reaction vessel similar to Example 1, 165 parts of glycine, 176 parts of sodium hydroxide, and 511 parts of water were mixed and stirred.
While cooling, a solution of 396 parts of terephthaloyl chloride in 800 parts of dioxane is added dropwise over 30 to 60 minutes, taking care to keep the internal temperature below 30°C.

After the completion of the dropwise addition, stirring was continued for another 2 hours at 30 to 40°C, and then acidified with sulfuric acid to precipitate the generated dicarboxylic acid, which was filtered and washed with water to obtain a white powder of N,N5-terephthaloyl diglycine. Next, 50 parts of this N,N'-terephthaloyl diglycine, 60 parts of triethanolamine, 2 parts of water
57 parts were mixed and stirred to obtain a rust preventive agent containing about 30% of the active ingredient.

Example 9 89 parts of DL-alanine, 50 parts of sodium hydroxide, and 200 parts of water were placed in a reaction vessel similar to Example 1, mixed and stirred,
While cooling, add 95 parts of putalol chloride to 100 parts of dioxane.
Add the solution dissolved in the solution dropwise, taking care to keep the internal temperature below 30°C.

After the dropwise addition was completed, stirring was continued for another 2 hours at 30-40°C, then neutralized with sulfuric acid, and the dicarboxylic acid produced was filtered and washed with water. A white powder of N,N5-putarolbis (DL-alanine) is obtained. Next, this N,N5-putarol bis(
30 parts of DL-alanine), 45 parts of triethanolamine, and 175 parts of water were mixed and stirred to obtain a rust inhibitor containing about 300 tons of active ingredients.

Comparative Example 1 100 parts of benzoic acid, 117 parts of triethanolamine, and 506 parts of water are heated and stirred to obtain a rust preventive having an active ingredient of about 3001).

Comparative Example 2 100 parts of oleic acid, 51 parts of triethanolamine, and 352 parts of water are mixed and stirred to obtain a rust preventive agent containing about 30% of active ingredients.

Aqueous solutions of active ingredient 1(f) were prepared from the rust preventives shown in each of these Examples and Comparative Examples, and a rust generation test and a foaming test were conducted. The results are shown in Table 1.

The rust occurrence test was based on JIS-K-2246 (rust-prevention oil wet test), and was carried out using a SOPC-1 steel plate (60×
81×1V. ) in a humid box at 49±1℃, relative humidity 9501) or more, air intake amount 886.5±110.5
A rust generation test was conducted under the condition of 11//Hr.

The degree of rust was determined according to JIS-K-2246 (Method for Measuring the Degree of Rust with Rust Preventive Oils), and the products of the present invention exhibited extremely excellent rust preventive properties as shown in the table. Further, foamability was measured based on the Ross-Clark method.

That is, the inner diameter is 50 degrees and the height is 1000V. Pour 200 m2 of an aqueous rust preventive solution containing 1% active ingredient into a cylinder. Pore diameter 40
Air of 500 me/Mm was continuously blown through a glass filter of ~50 μm, and the height of the bubbles at 20° C. was measured after 60 seconds. Next, as shown in Table 1, the degree of rust occurrence of chips (cast iron powder) was determined for each of the above-mentioned Examples and Comparative Examples.

The method and criteria for this test are as follows. First, a cut 5y of dry cut cast iron (FC-20 and FC-25) was washed with toluene and then with methanol, and then immersed in each sample solution (an aqueous rust preventive solution containing 1% active ingredient) for 1 minute ( After soaking (at room temperature) and draining the liquid, place it in a shear dish (diameter 60V) lined with filter paper, add 1 m2 of each of the above sample solutions, cover it, and incubate at 30°C and 80 (!) R.
Save with H. The time until rusting and the degree of rusting after 24 hours were measured on the filter paper in accordance with JIS-K-2246. However, the pH of each sample solution was adjusted to 9.5 with an aqueous NaOH solution. It can be seen from the table that it exhibits extremely excellent rust prevention against chips. Zhou,
It is said that there are very few rust preventives that satisfy both of these requirements. As described above, the rust preventive agent of the present invention can effectively prevent the rust of both the iron plate and the wetted chips (cast iron powder) in the wet box, and has a wide range of rust preventive effects and low foaming. Because it is a polyester, it does not foam when used in emulsions or aqueous solutions, and its major feature is that foaming does not reduce the rust-preventing effect or make it difficult to handle.

Furthermore, the rust preventive agent of the present invention provides excellent rust preventive effects by itself without the use of inorganic salts such as sodium nitrite; Alternatively, it can be used in combination with an organic rust preventive.

Claims (1)

[Claims] 1 General formula HOOCR_1NHCO-X-CONHR_2COOH
A rust preventive agent containing carboxylic acid salts as an essential ingredient. (In the formula, X is an aromatic hydrocarbon group, R_1, R_
2 each represents a hydrocarbon group having 1 to 18 carbon atoms, and may be the same or different, and may be linear or branched. )