JPS58130284A - Corrosion inhibitor - Google Patents

Abstract

PURPOSE:To obtain a corrosion inhibitor which is harmless to man and beast and has an improved corrosion inhibiting effect by adding amine to a mixture of specified acylsarcosine with specified benzotriazole. CONSTITUTION:Amine is added to a mixture of acylsarcosine represented by formulaI(where n is an integer of 4-22) with benzotriazole represented by formula II (where R1 is H, halogen, lower alkyl, hydroxyl or carboxyl; and R2 is H or 7-17C acyl). The resulting corrosion inhibitor maintains its corrosion inhibiting performance to various kinds of metals over a long term, and it is harmless to man and beast.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal rust preventive agent having a sophisticated rust preventive effect.

U.S. Pat. No. 47,1803 describes that various N-acylbenzotriazoles are effective as metal corrosion inhibitors. Furthermore, JP-A-51-15558, U.S. Pat. Are listed.

However, all of these anticorrosion or rust preventive agents are oil-based. Furthermore, German Patent No. 2.42 Sagi No. 512, Japanese Patent Publication No. 15750-15751, No. 15751, No. 15752, and No. 15755 disclose benzo) lyazole in coexistence with an amine salt of a certain carboxylic acid. It is stated that it is effective in preventing rust. However, these rust inhibitors are also oil-soluble rust inhibitors.

On the other hand, acylsarcosine is an acyl derivative of N-methylglycine, and the long-chain acyl derivative is widely used as an excellent surfactant.

It is also known that they are effective as corrosion inhibitors for metals, either as such or in the form of alkali or amine salts.

However, many of the above-mentioned rust preventives or anticorrosives are oil-soluble, and #regional rust preventives are not very effective for non-ferrous metals. It has drawbacks such as ineffectiveness.

Furthermore, conventional rust inhibitors have excellent rust prevention effects while immersed in the solution, but after being removed from the IL solution, rust forms in a short period of time, and discoloration occurs in the treated metal. It has the disadvantage of a high degree of

In addition, for cooling *m in recent internal combustion engines, many types of metals such as aluminum, aluminum castings, cast iron, steel, brass, copper, solder, etc. are used in combination as appropriate. Conventional rust inhibitors for metals are extremely limited in terms of the types of metals to which they can be applied, and few are effective. In reality, in order to prevent corrosion of many kinds of metals, many kinds of rust preventive agents are mixed and used in such soft mud. For example, sodium nitrite is used in a rust preventive agent containing alkanolamines, but it is said that p-soamines, which are thought to be carcinogenic, are produced, and therefore these alkanolamines and T1M4 Caution must be taken when adding sodium chloride to a rust preventive agent.

Therefore, the object of the present invention is to eliminate the drawbacks of the conventional rust preventive agents as described above, thereby providing sufficient anti-corrosion performance against various metals over a long period of time, being suitable for aqueous dilution, and being safe for humans and animals. An object of the present invention is to provide a rust preventive agent that is less harmful.

Here, a rust inhibitor containing an amine addition salt obtained by adding an amine to a mixture of acyl sarcosine and benzotriazole increases the adsorption power and coverage on the metal surface compared to the case of benzotriazole alone or sarcosine alone,
It has been found that the rust prevention effect is synergistically improved. In addition, by making oil-soluble acylsarcosine and benzotriazole water-soluble by forming them into amine addition salts, the range of applications is expanded, and they can be applied to many metals, both ferrous and non-ferrous, such as iron, cast iron, It was found that it exhibits excellent anticorrosion effects on copper, brass, zinc, aluminum, solder, etc. Furthermore, it was found that the rust-preventing effect after the metal was pulled out of the rust-preventing agent solution was extremely excellent because a strong Chereshi film of the rust-preventing component was formed on the metal surface.

It has also been found that such amine addition salts can coexist not only in aqueous applications but also in a large number of 1111II rust-preventing agents, and their rust-preventing effects can be further improved.

Therefore, according to the invention, CHs (CH*) m CON (CHs ) C
Acylsarcosine represented by Ht C00H (where O is an integer from 4 to 22) and the following formula (where 81 represents a hydrogen atom, a Hagen atom, a lower alkyl group, a droxyl group or a carboxyl group, R,
is a hydrogen atom or a Cm-C□ acyl group) A rust inhibitor containing an amine addition salt obtained by adding an amine to a mixture with a benzosilaazole represented by the following is provided.

The acyl of the acylzurcosine of formula (I) used in the present invention includes those having a molecular weight of 4 to 24, preferably 8 to 20. Preferred acyl sarcosines include caproyl sarcosine, bryl sarcosine, cabrinoyl sarcosine, myrisdiyl sarcosine, paratoyl sarcosine, stearyl sarcosine, oleoyl sarcosine, dodecanoyl sarcosine, and the like. These can be used alone or in mixtures. Thus, the acyl may be one derived from coconut oil, such as cocoyl.

The benzotriazoles of formula (■) include benzotriazoles; lower alkylbenzotriazoles such as 1-methylbenzosilaazole, 4-methylbenzosilaazole, and 1-ethylbenzosilaazole; 1-hydroxybenzotriazole, 4-benzotriazole; Lupoxybenzotriazole; H4/benzoF riazoles such as 1-tribenzotriazole, 5-thalbenzotriazole; N
-acetyl, N-butyryl-1N-bipapyru-1N
N-acylbenzotriazoles such as -nonanoyl-1N-capryyl-1N-cabrylyl, N-touroyl-1N-stearyl-1N-oleoyl-benzosyriazole, and the like are used. These may be used alone or as a mixture. Preferred amines for forming amine addition salts include mono-, di- or trialkylamines: cyclopentyl, Schiff-tetrahexyl or sit-p-hebutylamine;
Examples include alkanolamines such as di- or siliethanolamine, mono-, di-, or)banolamine; and cyclic amines such as piperidine, piperazine, and morpholamine.

The rust inhibitor of the present invention comprises an acylsarcosine of formula CI) and an acylsarcosine of formula (CI).
It is produced by adding an amine to the mixture of II) with benzosilaazole. The mixing of the acyl sarcosine and benzotriazole may be facilitated by heating and dissolving if necessary. The addition of the amine to the ampholytic mixture is generally carried out at temperatures above 50°C, preferably between 70°C and 13°C.
This is achieved by heating to about 0°C. The amount of amine added to the mixture of acyl sarcosine and benzosilaazole does not necessarily have to be stoichiometric. Both acyl sarcosine and benzotriazole have anticorrosive effects themselves, and amines can also be effective ingredients of rust preventives, so these three components do not necessarily need to be present in the form of salts in the rust preventive agent of the present invention. Certain components may be present in excess. However, in general, the formula (55 to 85 weight) (
I) Formula of acyl sarcosine and 45-15 weight stroke (■)
45 to 80 parts by weight of amine are added to 100 parts by weight of the mixture with benzotriazole.

In actual use, the rust inhibitor containing the amine addition salt formed in this way has an active ingredient concentration of approximately α.
The rust preventive agent of the present invention can be mixed with various other additives. For example, polyhydric alcohols, partial and total esters of polybasic carpanic acids and their amine derivatives, such as sorbitol, pentaeryth9), esters of alkenylsuccinic acids and C3-CI4 alcohols, C1
~CI4 Aliphatic part or whole ester of alcohol,
It is possible to improve the physical properties by combining a compound produced by reacting an alicyclic or aromatic amine, an alkali metal, an alkaline earth metal, or ammonia, and the synergistic effect thereof. Also, the amine used to form the amine addition salt can be blended again. In addition, commonly used volatile rust preventives can also be used.

Further, depending on the use of the rust preventive agent of the present invention, a lubricity effect may be required. The rust inhibitor of the present invention still maintains the effect as an oil-based agent, but also has wear resistance and
In order to impart extreme pressure resistance, metal organic dithiophosphates (for example 211% Pb5SbsC-), alkyl esters of alkyl or alkenylsuccinic acids (-] such as mono-1-butyl dodobunyl succinate) can be added.

The rust preventive agent of the present invention can be applied to various fields, such as being added to boilers, water storage tanks, and radiators, or being added to water-soluble metal processing oils, water-soluble paints, adhesives, etc. It can be widely used in the field of general rust inhibitors, such as primary rust prevention after metal surface treatment.

Example 1 50 (parts by weight) lauroyl sarcosine is heated to 60-70°C, and benzotriacy, A/10 (parts by weight) is added and completely dissolved. Next) I) Ethanolamine 2
5 (parts by weight) gradually, and when the addition is finished, about 1
The temperature is raised to 10°C, heating is stopped, stirring is continued, and the mixture is allowed to cool down. This yields a rust preventive agent containing an amine addition salt.

The rust preventive thus obtained has a solid content of 15 to 2.0
(% by weight) A rust preventive solution is prepared by adjusting the amount with water so that it becomes an aqueous solution.

A cold-rolled steel plate (5
PCC-B) was polished with #240 emery paper, thoroughly washed with warm Truben F naphtha and warm methanol, immersed in the above rust preventive solution at room temperature for about 5 minutes, and placed in a pulling chamber for 20 minutes.
Table 1 shows the results of a hot-corrosion test conducted for up to 200 hours in accordance with JIS-Z-0256 after being suspended for hours.
Shown below.

Examples 2 to 4 As in Example fi1, various rust inhibitors were manufactured with the starting compositions shown in Table 1 and subjected to SS corrosion tests. The results are shown in Table-1.

Examples 7-9 The rust preventives of Examples 1.2 and 5 were blended with the additives shown in Table 1 and tested as in Example 1.

The results are shown in Table-1.

Comparative Examples 1 and 2 1! A rust inhibitor solution with the starting composition shown in Example 1 was prepared and tested as in Example 1. The results are shown in Table-1.

Example 10 A copper plate, a brass plate, and a zinc plate with a size of 8108Q After being suspended in a pulling chamber for 20 hours, a wet sea bream test was conducted for copper and brass for 200 hours and for zinc for 48 hours in accordance with JIS-Z-0256. The results are shown in Table 2.

Table-2 @: No discoloration, ○: Slight discoloration, Δ: Discoloration.

X: Whole surface discoloration Example 11 A spun iron plate and an alumina lambda plate with a size of 50 x 25 x 1 mm were polished with +240 emery paper, washed with warm solvent naphtha and warm methanol, and the composition solution shown in Example 2 was prepared. Table 3 shows the results of soaking at 50℃ for about 100 hours.
Shown below.

Table-3 ◎: No rusting, ○: Rusting in several spots, Δ: 10 to 30% rusting.

X; 50% or more

Claims (7)

[Claims] (1) The following formula (I) CHm("t)mcON(C)In)(ltcOOI'
1 (I) (where n is an integer of 4 to 22) and the following formula (II) 1 (where R is a hydrogen atom, a halogen atom, a lower alkyl group, a hydroxyl group, or a carboxyl group) Representation, R,
represents a hydrogen atom or a C7-C3, acyl group. (2) Acyl sarcosine is Kabukuro sarcosine,
The rust preventive agent according to claim 1, characterized in that it is Palt)yl sarcosine, lauryl sarcosine, cocoyl de#fucin, oleoyl sarcosine, or hastea gastric sarcosine. (3) The rust preventive agent according to claim 1, wherein the benzotriazole is benzocyriazole, lower alkylbenzo)9azole, or N-acylbenzo)lyazole. (4) The rust inhibitor according to claim 1, wherein the amine is an alkyl or dichloroalkyl amine, an alkanolamine, or a cyclic amine. (5) The rust inhibitor according to claim 4, wherein the amine is cyclohexamine, monoethanolamine, diethanolene, triethanolamine, morpholine, piperazine or piperidine. (6) As-8s weight attack acylsarcosine and 4s-1
Claims 1 to 5 are characterized in that an amine addition salt is formed by adding 45 to 45 parts by weight of an amine to 100 parts by weight of a mixture with benzotriazole of 50% by weight. Rust inhibitor. (7) The rust preventive agent according to any one of claims 1 to 6, which is used after being diluted to a concentration of α01 to 5 by weight.