JPS5827346B2 - metal corrosion inhibitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a corrosion inhibitor for metals, more specifically copper, cast iron,
The present invention relates to a novel metal corrosion inhibitor that has excellent durability against a wide range of metals and alloys such as copper, brass, aluminum, and solder.

Metal products, such as steel plates and steel pipes, require a considerable period of time after they are manufactured until they are processed and used for their respective purposes.

In particular, metal surfaces that have been subjected to surface treatments such as degreasing and pickling are extremely susceptible to rust, and rust is generally prevented by spraying or coating with rust preventive oil.

However, in order to completely remove these conventional rust preventive oils from metal surfaces when surface treatments such as plating, painting, and lining are applied, first, solvent degreasing followed by alkaline degreasing is required. It is necessary to do so.

(2) Second, when performing secondary processing such as welding, the electrodes become dirty and smoke is generated, which is undesirable.

For these reasons, there has been a strong demand for anticorrosive agents that are soluble in water and have excellent durability.

In addition, anticorrosion agents containing chromates, phosphates, polymerized phosphates, or nitrites as active ingredients have been widely used to prevent corrosion of metals such as iron and aluminum mainly in water, such as in engine cooling water systems. However, the use of these salts is gradually being regulated from the viewpoint of water pollution problems and carcinogenic substances when discharged outside the system.

In view of the above-mentioned demands and regulations on the use of salts, which have been widely used in the past, the inventors of the present invention have developed a solution that has strong anti-corrosion properties with good durability, and is easy to remove, and which has problems with water pollution and carcinogenic substances. As a result of various studies to obtain a safe and inexpensive anticorrosive agent that does not cause corrosion, the following partial esters of unsaturated polybasic acids and unsaturated alcohols, their alkali metal salts, or their amine addition salts have been developed. Recognizing that it is water-soluble and exhibits a corrosion-preventing effect with excellent durability, especially in a harmful gas atmosphere, they were able to successfully complete the present invention.

The first invention of the present invention is a partial ester of an unsaturated polybasic acid selected from alkenylsuccinic acid and alkenylmaleic acid having 10 to 22 carbon atoms and an unsaturated alcohol having 3 to 8 carbon atoms, or an alkali metal salt thereof, or This is a metal corrosion inhibitor characterized by containing one or more amine salts as an active ingredient.

Alkenyl succinic acid or alkenyl maleic acid with carbon numbers of 9 or less are not preferred because they have poor rust prevention effects, and alkenyl succinic acids or alkenyl maleic acids with carbon numbers of 23 or more are not produced industrially. There are problems with availability, high price, and impractical.

Further, in the case of unsaturated alcohols having 9 or more carbon atoms, foaming is severe, antifoaming agents cannot be used to sufficiently eliminate the foam, and the solubility in water is extremely poor, making it impractical.

As the unsaturated polybasic acid used in the metal corrosion inhibitor in the present invention, aliphatic and aromatic acids having two or more carboxyl groups can be used.

Examples of unsaturated polybasic acids include hexynyl succinic acid,
Examples include dodecynyl succinic acid, decynyl succinic acid, pentadecynyl maleic acid, dodecynyl succinic acid, and oleinyl succinic anhydride.

The unsaturated alcohol used in the metal corrosion inhibitor in the present invention must have three or more carbon atoms, and unsaturated alcohols with triple bonds are more preferable than double bonds among unsaturated bonds. is preferred.

Further, the hydrocarbon group may be a straight chain or a side chain, but a straight chain hydrocarbon group is preferred in most cases.

Polyalcohols or aromatic alcohols may also be used.

Specific examples of preferred unsaturated alcohols include aryl alcohol, propagyl alcohol, methylbutynol, methylpentynol, ethylbutynol, flobylpentynol, butynediol, butynediol, and the like.

It is also possible to use the partial ester of an unsaturated polybasic acid and an unsaturated alcohol used as a corrosion inhibitor for metals according to the present invention in the form of a salt. Mention may be made of alkali metals or amines.

Among the above-mentioned amines that can be used in the present invention, mention may be made of aliphatic, aromatic and heterocyclic amines that are capable of reacting with carboxylic acids to form salts.

For example, primary amines, secondary amines, tertiary amines, polyamines, and guanidine can all be used.

Especially hydrazine; mono-, di- or trimethylamine; mono-, di- or triisopropylamine; mono-
, di- or triisopropanolamine; mono-, di- or dodecylamine; butanolamine; mono-,
Di- or cyclohexylamine: mono-, di- or octylamine; monophorine; piperazine; pyrrolidone; dimethylcoconutamine; oleylamine; tallow amine; ethylhexylamine; diethylenetriamine; hydrazine, tetraethylenepentamine; Examples include guanidine nitrate; guanidine carbonate; guanidine phosphate.

The amine salt of the unsaturated polybasic acid partial ester of the present invention can be produced by various known methods.

For example, alcohol and excess unsaturated polybasic acid are heated and reacted without a catalyst or in the presence of a catalyst such as a metal oxide,
A partial ester can be produced by removing unreacted substances, or it can be produced by heating and reacting equimolar amounts of unsaturated polybasic anhydride and alcohol.

Next, for neutralization, an amine is added to the partial ester produced as described above, and the amount of amine used is adjusted so that the pH of the neutralized salt is 7 to 8.
An amine salt can be obtained by neutralizing the amine salt.

Furthermore, the metal corrosion inhibitor according to the first aspect of the present invention is durable and exhibits a long-lasting corrosion prevention effect, especially in a harmful gas atmosphere, but when used in combination with imidapurines, especially alkylimidacillins. It was recognized that these compounds exert a synergistic effect in terms of anti-corrosion effect and other properties.

The second invention of the present invention uses as active ingredients one or more partial esters of unsaturated polybasic acids and unsaturated alcohols, or one or more alkali metal or amine salts thereof, and one or more imidapurines. It is a metal corrosion inhibitor characterized by containing:

The imidapurines used in the second invention of the present invention include 2-ethylimidabul, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, -benzy-2-methylimidazole, 1 -hydroxyethyl-2-dodecylamitasole,
■-Hydroxyethyl-2-octadecyl imidazole can be mentioned.

Further, it is preferable from the viewpoint of economic value that the imidacillin is used in an amount of o, i to 2.0 parts by weight based on 10 parts by weight of the above-mentioned partial ester, since the synergistic effect is greatest and it is economical.

In addition, the metal corrosion inhibitor of the first and second inventions of the present invention may contain dryazur, thiazole, and amides, and may also contain antioxidants, lubricants, various surfactants, etc. and the effects of each can be exhibited in combination.

The metal corrosion inhibitor of the present invention can be applied to a wide range of metals and alloys such as steel, cast iron, copper, brass aluminum, and solder, and exhibits excellent and durable corrosion prevention effects.

When using the metal corrosion inhibitor of the present invention, it can be dissolved in water and immersed in the aqueous solution to prevent corrosion, or the aqueous solution can be applied to a metal surface to prevent corrosion. .

Furthermore, since the metal corrosion inhibitor of the present invention is soluble in mineral oil,
It can be used by dissolving it in so-called rust preventive oil, lubricating oil, hydraulic oil, cutting oil, heat treatment oil, turbine oil, gear oil, etc.

Next, the present invention will be specifically explained with reference to Examples.

Example I An immersion test was conducted according to the hydraulic oil corrosion test method of JIS K2232.

Aluminum alloy, steel, and copper specimens were immersed in a propylene solution containing the amount of corrosion inhibitor shown in Table 1, and then placed in a constant temperature bath at a temperature of 121°C ± 0.5°C for 168 hours. The dry air was adjusted to 5±0.51/hour and introduced.

The results are shown in Table 1 for the cases in which the metal corrosion inhibitor of the present invention was added, the cases in which the metal corrosion inhibitor of the present invention was not added, and the cases in which other metal corrosion inhibitors were added.

The corrosion weight loss was expressed as the number of square feet per square inch. As is clear from Table 1, the corrosion inhibitor for metals according to the present invention can be applied to steel, aluminum alloy,
Shows excellent corrosion protection against copper, etc.

Example 2 Treatment bath A Two-line aqueous solution treatment bath of dodecynyl succinic acid phlopargyl ester/monoethanolamine salt B Dodecynyl succinic acid phlopargyl ester-1-hydroxyethyl-2-probyl imitator ← Addition of salt 2. Corrosion resistance test conditions and test results of a test piece obtained by immersing a surface-cleaned cold-rolled steel plate to be treated in the above treatment bath and immediately drying it in a dryer under the following conditions. Met.

Example 3 In accordance with the JIS K2525 water-soluble cutting oil corrosion test method, a test piece was placed in an approximately 25 ml test tube, and the solution was poured until the test piece was submerged approximately halfway. After the tube opening was lightly closed with a cork stopper, the test tube was opened. Tilt the test piece to completely moisten it with the sample solution.

The test tube was held vertically and the state was observed after 72 hours at 50°C.

The test results are shown in Table 3 below.

In table 3 ○: No discoloration △ mark: Slight discoloration (liquid interface) × mark: discoloration shows.

Example 4 Table 4 shows the results of a rust prevention test using a rust prevention oil prepared using the metal corrosion inhibitor of the present invention.

Table 4 shows that these oils are very good rust preventive oils.

Example 5 In this test, an immersion test was conducted in accordance with the antifreeze corrosion test method of JIS K2234 as follows.

After dissolving the rust inhibitor shown in Table 5 in a mixed solution (wt/wt) of corrosive water and ethylene glycol (80:20), tests on aluminum, cast iron, brass, steel, solder and copper were carried out. Soak the pieces and blow dry air through the vent tube at 1 minute per minute.
Since the flow rate is 00±10m1, the temperature is 80±2°C×
After holding for 8 hours, heating and ventilation were stopped, and one cycle of 16 hours at room temperature was carried out for 14 cycles.

The results are shown in Table 5.

In Table 5, the corrosion loss rate is expressed in milligrams per square senna.

The composition of the corrosive water is as follows.

Cl 100ppm100pp 0.165g,
/1) CO3200ppm (NaHCO20,27”J
/1) SO4300ppm (Na2S0.0.444
．． 9/l) Senju Cu 1 p pm (CuCl22H200,
00265g/l) From Table 5, it is clear that the metal corrosion inhibitor of the present invention exhibits an excellent corrosion prevention effect.

Example 6 After dissolving the rust preventive agent shown in Table 6 below in #60 spindle oil, a galvanized steel plate was immersed for 30 seconds and then lifted out.
I drained the oil for an hour.

The obtained test piece was subjected to a humidity test at a temperature of 50±1° C. and a humidity of 95% or more.

The results are shown in Table 6. It is clear from Table 6 that the metal anticorrosive agent of the present invention exhibits an excellent anticorrosion effect.

Claims (1)

[Scope of Claims] 1. A partial ester of an unsaturated polybasic acid selected from alkenylsuccinic acid and alkenylmaleic acid having 10 to 22 carbon atoms and an unsaturated alcohol having 3 to 8 carbon atoms, or an alkali metal salt thereof or an amine. A metal corrosion inhibitor characterized by containing one or more salts as an active ingredient. 2 One or two partial esters of unsaturated polybasic acids selected from alkenylsuccinic acid and alkenylmaleic acid having 10 to 22 carbon atoms and unsaturated alcohols having 3 to 8 carbon atoms, or their alkali metal salts or amine salts. 1. A metal corrosion inhibitor characterized by containing as active ingredients one or more types of imidapurines and one or more types of imidapurines.