JP5610751B2 - Metal surface treatment agent and imidazole compound - Google Patents

Description

  The present invention relates to a metal surface treatment agent excellent in rust prevention performance on a metal surface, and more particularly to a surface treatment agent for copper and copper alloy useful for producing a printed wiring board.

Conventionally, a compound having an imidazole skeleton, a benzimidazole skeleton, or a benzotriazole skeleton has been used as a metal surface treatment agent for the purpose of preventing rust on a metal surface.
In particular, the surface of copper is easily corroded and discolored in electrical parts made of copper, printed wiring boards in which circuits are formed of copper, and other parts with copper plating on the surface. In addition, a discoloration inhibitor containing a rust inhibitor is applied to prevent corrosion discoloration.

  As a surface treatment agent having such rust prevention performance, for example, Patent Document 1 describes a rust preventive agent composed of benzotriazole or a derivative thereof, and Patent Document 2 discloses copper and a copper alloy. In particular, an imidazole compound suitable as a preflux treating agent for copper circuit portions of printed wiring boards is described.

  However, although the surface treatment agents described in Patent Documents 1 and 2 exhibit rust prevention effects such as discoloration prevention and corrosion prevention, evaluation on such effects has not been performed. Furthermore, at present, there are a wide variety of uses for metals that have been surface-treated for the purpose of imparting rust prevention properties, and rust prevention performance that can withstand use under more severe conditions is required. Therefore, the rust preventive performance under severe conditions of the surface treatment agents of Patent Documents 1 and 2 has not been sufficient yet.

JP 2005-171366 A JP-A-6-329635

  Therefore, in the present invention, an object of the present invention is to provide a metal surface treatment agent having excellent rust prevention performance when used as a metal surface treatment agent even under high temperature conditions.

  However, as a result of intensive studies in view of such circumstances, the present inventors have identified that the hydrogen on the nitrogen atom has been substituted with a carboxyalkyl group (or an ester thereof) that has not been used as a conventional surface treatment agent. It has been found that a surface treatment agent containing an imidazole compound having a structure exhibits excellent antirust performance even under high temperature conditions, and has completed the present invention.

  That is, the gist of the present invention is a metal surface treating agent containing an imidazole compound represented by the following general formula (1) as an active ingredient.

(Wherein, R ¹ to R ³ represents a hydrogen atom, an alkyl group, a phenyl group, or a halogen atom, which may be the same or different .X is an alkylene group, Y represents a hydrogen atom or an alkyl group .)

  In addition, the imidazole skeleton N atom pair in the metal surface treatment agent coordinates to the vacant orbit of the metal surface, forms a thin organic film, and protects the metal surface to prevent metal oxidation from heat and moisture. It is thought that Since the imidazole compound represented by the general formula (1) in the present invention has a carboxyl group and a carboxylic ester group in the molecule, it forms a salt with a molecule different from the molecule coordinated with the imidazole skeleton. It is thought that it becomes a strong film and contributes to the improvement of rust prevention.

  The surface treatment agent of the present invention is excellent in rust prevention performance such as discoloration prevention and corrosion prevention at high temperatures.

  Hereinafter, although it demonstrates in detail about the structure of this invention, these show an example of a desirable embodiment.

The metal surface treating agent of the present invention comprises an imidazole compound represented by the following general formula (1) (hereinafter sometimes simply referred to as “imidazole compound (A)”) as an active ingredient.
The “active ingredient” in the present invention means that the imidazole compound (A) is usually 0.000001% by weight or more, preferably 0.00001% by weight or more, particularly preferably based on the total amount of the metal surface treatment agent. It contains 0.0001% by weight or more.

(Wherein, R ¹ to R ³ represents a hydrogen atom, an alkyl group, a phenyl group, or a halogen atom, which may be the same or different .X is an alkylene group, Y represents a hydrogen atom or an alkyl group .)

R < ¹ > -R < ³ > in the said General formula (1) is either a hydrogen atom, an alkyl group, a phenyl group, or a halogen atom.

  The alkyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a sulfanyl group, an aryl group, and a heteroaryl group. As such an alkyl group, those having 1 to 20 carbon atoms, preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms are used.

  The phenyl group may have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a sulfanyl group, an aryl group, and a heteroaryl group.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R ¹ , R ² and R ³ may all be the same, or some or all of them may be different.

X in the general formula (1) is an alkylene group, and among them, an alkylene group having 1 to 10 carbon atoms is preferred, and in particular, a methylene group, an ethylene group, a propylene group, a tetramethylene group, or the like. 4 alkylene groups are preferable, and a methylene group and an ethylene group are more preferable.
Such an alkylene group may have a substituent such as a halogen atom, a hydroxyl group, an alkoxy group, an amino group, a sulfanyl group, an aryl group, or a heteroaryl group.

  Y in the general formula (1) is a hydrogen atom or an alkyl group. As the alkyl group, a lower alkyl group is used, and those having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, are used. Among these, a methyl group and an ethyl group are preferable.

  Specific examples of the imidazole compound (A) satisfying the general formula (1) include (1H-2-phenylimidazol-1-yl) acetic acid and (1H-2-phenylimidazol-1-yl) acetic acid. Methyl, (1H-2-phenylimidazol-1-yl) ethyl acetate, (1H-2,4-diphenylimidazol-1-yl) acetic acid, (1H-2,4-diphenylimidazol-1-yl) methyl acetate, (1H-2,4-diphenylimidazol-1-yl) ethyl acetate, (1H-2-methylimidazol-1-yl) acetic acid, (1H-2-methylimidazol-1-yl) methyl acetate, (1H-2 -Methylimidazol-1-yl) ethyl acetate, (1H-2-undecylimidazol-1-yl) acetic acid, (1H-2-undecylimidazol-1-yl) Acid methyl, (1H-2-undecylimidazol-1-yl) ethyl acetate, (1H-2-ethyl-4-methylimidazol-1-yl) acetic acid, (1H-2-ethyl-4-methylimidazole-1) -Yl) methyl acetate, (1H-2-ethyl-4-methylimidazol-1-yl) ethyl acetate, (1H-2,4,5-trimethylimidazol-1-yl) acetic acid, (1H-2,4, 5-trimethylimidazol-1-yl) methyl acetate, (1H-2,4,5-trimethylimidazol-1-yl) ethyl acetate, (1H-2-phenylimidazol-1-yl) propionic acid, (1H-2 -Phenylimidazol-1-yl) methyl propionate, (1H-2-phenylimidazol-1-yl) ethyl propionate, (1H-2,4-diphenyl) (Midazol-1-yl) propionic acid, (1H-2,4-diphenylimidazol-1-yl) methyl propionate, (1H-2,4-diphenylimidazol-1-yl) ethyl propionate, (1H-2- Undecylimidazol-1-yl) propionic acid, methyl (1H-2-undecylimidazol-1-yl) propionate, ethyl (1H-2-undecylimidazol-1-yl) propionate, (1H-2- Ethyl-4-methylimidazol-1-yl) propionic acid, methyl (1H-2-ethyl-4-methylimidazol-1-yl) propionate, (1H-2-ethyl-4-methylimidazol-1-yl) Ethyl propionate, (1H-2,4,5-trimethylimidazol-1-yl) propionic acid, (1H-2,4 , 5-trimethylimidazol-1-yl) methyl propionate, ethyl (1H-2,4,5-trimethylimidazol-1-yl) propionate, and the like. Among these, rust prevention performance is excellent. (1H-2,4-diphenylimidazol-1-yl) acetic acid, (1H-2,4-diphenylimidazol-1-yl) methyl acetate, (1H-2,4,5-trimethylimidazol-1-yl) acetic acid , (1H-2,4,5-trimethylimidazol-1-yl) methyl acetate is preferred.

  The molecular weight of the imidazole compound (A) is usually 100 to 1000, preferably 120 to 800, particularly preferably 150 to 600. If the molecular weight is too small, the heat resistance of the anticorrosive film tends to be inferior, and if it is too large, the solubility of the compound in the solvent tends to be inferior, and the adjustment of the treatment liquid and the antirust treatment tend to be difficult.

  The production method of the imidazole compound (A) is not particularly limited. For example, a 1-position unsubstituted imidazole compound represented by the following reaction formula (see [Chemical Formula 3]) is substituted with a halogenated alkylcarboxylic acid ester. It is produced by alkylating with benzene, then hydrolyzing the ester group, or by forming an imidazole ring by reaction with an amino acid ester, aldehyde compound, ammonia, or α-diketone compound, and then hydrolyzing the ester group. be able to.

Here, the alkylation method will be briefly described.
1-position unsubstituted imidazole compound, inorganic bases such as sodium hydroxide and potassium carbonate, organic bases such as triethylamine, and organic solvents, with stirring, such as methyl chloroacetate, methyl bromoacetate, methyl chloropropionate, etc. A halogenated carboxylic acid ester or a solution of an organic solvent of these compounds is added dropwise, and then reacted with stirring.
Examples of the organic solvent include ethers such as THF (tetrahydrofuran) and dioxane, amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and acetonitrile.

  The amount of the halogenated carboxylic acid ester charged in the alkylation reaction is usually 0.5 to 5 times mol, preferably 0.7 to 3 times mol, more preferably 0.8 to 2 times the amount of the imidazole compound. Is a mole. If the charged amount of the halogenated carboxylic acid ester is too small, the amount of unreacted imidazole compound tends to increase, resulting in a decrease in yield, separation and purification, and if more than this, the imidazole compound is excessive. By-products such as quaternary salts increase, yield tends to decrease.

  The amount of the base charged in the alkylation reaction is usually 0.5 to 10 times mol, preferably 0.7 to 8 times mol, more preferably 0.8 to 6 times mol for the imidazole compound. If the amount of the base used is too small, the yield tends to decrease.

  The reaction solvent used for the alkylation reaction is usually 1 to 50% by weight, preferably 1 to 30% by weight, more preferably 1 to 20% by weight, based on the imidazole compound. If the amount of the solvent used is too small, stirring tends to be difficult and the yield tends to decrease due to the by-product of the quaternary salt. If the amount used is larger than this, the reaction rate decreases and the yield decreases. There is a tendency for the rate to decline.

  The reaction temperature of the alkylation reaction is usually -20 to 150 ° C, preferably -10 to 130 ° C, more preferably 0 to 120 ° C. If the reaction temperature is too low, the reaction cannot be driven and the yield tends to decrease. If the reaction temperature is too high, the yield tends to decrease due to by-product formation of quaternary salts.

  The reaction time of the alkylation reaction is usually 1 minute to 100 hours, preferably 3 minutes to 90 hours, more preferably 5 minutes to 80 hours. If the reaction time is shorter than this, the reaction may not be able to be pursued and tends to decrease, and if the reaction temperature is increased, the compound may tend to decompose.

  The reaction conditions for the alkylation reaction described here are only an example, and can be adjusted as appropriate depending on the imidazole compound and the halogenated carboxylic acid ester used.

  After the completion of the alkylation reaction, it may be hydrolyzed and hydrolyzed as it is, or the ester may be isolated by a method such as filtration, concentration, recrystallization, and then hydrolyzed.

  After the alkylation reaction, when hydrolysis is carried out without isolating the ester, the amount is usually 0.01 to 20% by weight, preferably 0.05 to 15% by weight, based on the imidazole compound charged. More preferably, 0.1 to 10% by weight of water is added. If the amount of water added is too small, the reaction rate is slow, and the yield tends to decrease. If the amount is too large, the imidazole compound may precipitate and the yield may decrease.

  In such a hydrolysis reaction, an inorganic base such as sodium hydroxide is usually added in an amount of 0.5 to 20 times mol, preferably 0.8 to 10 times mol, more preferably 0, relative to the imidazole compound in the reaction system. Add 9 to 5 times mole. If the amount of the base is too small, the hydrolysis reaction does not proceed and the yield tends to decrease. If the amount is too large, the yield tends to decrease due to decomposition of the imidazole compound.

  The reaction temperature of the hydrolysis reaction is usually 0 to 150 ° C, preferably 5 to 120 ° C, more preferably 10 to 100 ° C. When the reaction temperature is too low, the reaction rate is slow and the yield tends to decrease. When the reaction temperature is too high, the yield tends to decrease due to decomposition of the imidazole compound.

  The reaction time for the hydrolysis reaction is usually 1 minute to 100 hours, preferably 3 minutes to 90 hours, and more preferably 5 minutes to 80 hours. When the reaction time is shorter than this, the reaction does not proceed sufficiently and the yield tends to decrease, and when the reaction temperature becomes longer, the compound tends to decompose.

  When the above ester is isolated, the base and water are added in the same manner as when the hydrolysis reaction is performed without isolation, and alcohols such as methanol and ethanol, THF, dioxane, etc. An organic solvent such as ethers is added to conduct a hydrolysis reaction.

  After the hydrolysis, the target imidazole compound (A) is obtained by post-treatment such as neutralization, filtration, extraction, and crystallization of the reaction solution with an acid such as hydrochloric acid.

Next, the metal surface treating agent using the imidazole compound (A) will be described.
The metal surface treatment in the present invention mainly includes a rust preventive treatment on the metal surface, but also includes cleaning of the metal surface, etching treatment, flux treatment and the like.

  When the imidazole compound (A) is used as a surface treatment agent, it is common to use the imidazole compound (A) by dissolving it in a solvent. However, the imidazole compound (A) remains solid or is vaporized, sublimated, etc. It can also be used.

  Such a solvent is not particularly limited as long as it completely dissolves an imidazole compound, and examples thereof include water, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, and ethyl acetate. Examples of such esters include amides such as dimethylformamide, etc. Among these, water or an organic solvent miscible with water or water and an organic solvent in terms of ease of handling and workability. A mixed solvent is particularly preferred.

  The concentration of the imidazole compound (A) in the solvent is usually 0.000001 to 20% by weight, preferably 0.00001 to 10% by weight, and particularly preferably 0.0001 to 5% by weight. If the concentration is too high, it is uneconomical, and if it is too thin, the organic film of the imidazole compound tends not to be sufficiently formed.

  The surface treating agent in the present invention may contain an organic acid, an inorganic acid, an amine compound, an inorganic base, a metal salt, a surfactant, a chelating agent and the like in addition to the imidazole compound (A).

  Examples of such organic acids include formic acid, acetic acid, propionic acid, butyric acid, caproic acid, lauric acid, oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, glycolic acid, glyoxylic acid, lactic acid, malic acid. Benzoic acid, methanesulfonic acid, acrylic acid and the like.

  Examples of such inorganic acids include hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid and the like.

  Examples of the amine compound include alkylamines such as ammonia, methylamine, and ethylamine, and azoles such as benzotriazole, benzimidazole, 2-phenylimidazole, 2,4-diphenylimidazole, and 2-undecylimidazole.

  Examples of such an inorganic base include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and the like.

  Examples of such metal salts include copper salts such as copper acetate, copper chloride, copper bromide, copper sulfate, and copper nitrate, zinc salts such as zinc acetate, zinc chloride, zinc bromide, zinc sulfate, and zinc nitrate, and potassium chloride. And alkali metal halide salts such as potassium bromide and potassium iodide.

  Next, a metal surface treatment method using the metal surface treatment agent of the present invention will be described.

  The metal to be surface-treated using the metal surface treatment agent is not particularly limited, and a known general metal can be used. Among them, copper, nickel, silver, zinc, iron, aluminum or alloys thereof However, it is suitable for the metal surface treatment agent of the present invention, and copper and copper alloys are particularly preferable.

  As for the method of treating the metal surface, impregnating the metal to be treated with the treatment liquid containing the imidazole compound, spraying the treatment liquid containing the imidazole compound on the metal to be treated, or applying the solution using a spin coater. Then, it can be treated by a method such as drying or washing an excess treatment liquid with water or the like and then drying.

  Such a processing temperature is usually 10 to 80 ° C, preferably 15 to 70 ° C, more preferably 20 to 60 ° C. If the treatment temperature is too low, there is a tendency that a sufficient film cannot be formed on the metal surface. If it is too high, decomposition of the imidazole compound may occur.

  Such treatment time is usually 1 second to 30 minutes, preferably 5 seconds to 25 minutes, and more preferably 10 seconds to 20 minutes. If the treatment time is too short, there is a tendency that a sufficient film cannot be formed on the metal surface, and if it is too long, it is uneconomical to form a film more than necessary, or the conductivity due to the thick film There is a tendency to decrease.

  The thickness of the coating film on the metal after the surface treatment is usually 0.1 nm to 2 μm, but depending on the use of the surface-treated metal and the required performance, the film thickness can be changed by appropriately changing the treatment method and conditions. Can be controlled.

  The present invention also provides novel imidazole compounds represented by the following general formulas (2) and (3).

(In the formula, Y is a hydrogen atom or an alkyl group.)

(In the formula, Y is a hydrogen atom or an alkyl group.)

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the examples, “parts” and “%” mean weight basis unless otherwise specified.

<Method for producing compound>
(Production Example 1)
Synthesis of (1H-2,4-diphenylimidazol -1-yl) acetic acid (A-1) To a solution of 8.0 g (27 mmol) of methyl (1H-2,4-diphenylimidazol-1-yl) acetate in 24 mL of methanol 9.2 g (58 mmol) of 25% aqueous sodium hydroxide solution was added and stirred at 25 ° C. for 1.5 hours. After completion of the reaction, the methanol content was distilled off under reduced pressure, and 10.9 g (59 mmol) of 20% aqueous hydrochloric acid solution was added for neutralization. The precipitated crystals were collected by filtration, washed twice with 10 mL of water, and then dried to obtain 6.6 g (yield 86.3%) of imidazole compound (A-1).

LC-MS: [M + 1] = 279
¹ H-NMR (DMSO-d ₆ ): 4.9 (s, 2H), 7.2 to 7.8 (m, 11H)
¹³ C-NMR (DMSO-d ₆ ): 49.1, 120.3, 125.0, 127.4, 129.0, 129.3, 129.4, 129.7, 130.5, 134.3, 139.6, 147.9, 170.3

(Production Example 2)
Synthesis of methyl (1H-2,4-diphenylimidazol-1-yl) acetate (A-2) 22.0 g (0.1 mol) of 2,4-diphenylimidazole and 41.4 g (0.3 mol) of potassium carbonate To a 110 mL solution of acetonitrile, 16.2 g (0.15 mol) of methyl chloroacetate was added and stirred at 70 ° C. for 56 hours. The insoluble material was filtered and washed with acetonitrile, and then the filtrate and the washing solution were combined and concentrated under reduced pressure. The residue was dissolved by adding 60 mL of ethyl acetate, and washed twice with 30 mL of water. The ethyl acetate layer was concentrated under reduced pressure and recrystallized with ethyl acetate. The precipitated crystals were collected by filtration, washed with ethyl acetate and dried to obtain 16.7 g (yield 57.2%) of an imidazole compound (A-2).

LC-MS: [M + 1] = 293
¹ H-NMR (DMSO-d ₆ ): 3.7 (s, 3H), 5.0 (s, 2H), 7.2 to 7.8 (m, 11H)

(Production Example 3)
Synthesis of (1H-2,4,5-trimethylimidazol- 1-yl) acetic acid (A-3) 9.2 g (50 mmol) of methyl (1H-2,4,5-trimethylimidazol-1-yl) acetate in water 20 g of 20% aqueous sodium hydroxide solution (100 mmol) was added to 30 mL of the solution, and the mixture was stirred at 25 ° C. for 4 hours. After completion of the reaction, the reaction solution was neutralized by adding 18.2 g (100 mmol) of 20% aqueous hydrochloric acid solution, and concentrated to dryness under reduced pressure. After adding 200 mL of methanol to the residue and filtering and removing insoluble matter, the filtrate was concentrated to dryness. The residue was washed with 15 mL of methanol and dried to obtain 7.1 g (yield: 83.6%) of imidazole compound (A-3).

LC-MS: [M + 1] = 169
¹ H-NMR (D ₂ O): 2.1 (s, 3H), 2.2 (s, 3H), 2.5 (s, 3H), 4.8 (s, 2H)
¹³ C-NMR (D ₂ O): 10.1, 11.0, 12.8, 50.4, 126.1, 128.6, 144.9

(Production Example 4)
Synthesis of (1H-2,4,5-trimethylimidazol-1-yl) methyl acetate (A-4) 5 mol / L sodium in a 25 mL methanol solution of 11.0 g (0.1 mol) 2,4,5-trimethylimidazole 20 mL (0.1 mol) of a methoxide / methanol solution was added and dissolved, and then concentrated to dryness under reduced pressure. DMF110mL was added to the residue and it cooled in the ice bath. To this was added dropwise 10.9 g (0.1 mol) of methyl chloroacetate over 30 minutes. After completion of the dropping, the ice bath was removed and the mixture was stirred at 23 ° C. for 2 hours, and then the reaction solution was concentrated under reduced pressure. 100 mL of ethyl acetate was added to the residue, the insoluble material was filtered, and washed with 50 mL of ethyl acetate. 200 mL of ethyl acetate was further added to the obtained ethyl acetate layer, and then washed with 25 mL of a saturated aqueous sodium hydrogen carbonate solution and then with 25 mL of water. The obtained organic layer was concentrated under reduced pressure to obtain 10.7 g (yield 58.8%) of an imidazole compound (A-4).

LC-MS: [M + 1] = 183
¹ H-NMR (DMSO-d ₆ ): 1.9 (s, 6H), 2.1 (s, 3H), 3.7 (s, 3H), 4.7 (s, 2H)
¹³ C-NMR (DMSO-d ₆ ): 8.9, 13.1, 13.3, 45.2, 52.9, 122.4, 130.7, 142.9, 169.7

<Metal surface treatment test>
A metal surface treatment test (heat resistance test) was performed on the imidazole compounds (A-1) to (A-4) obtained above and 1,2,3-benzotriazole.

Example 1
After immersing a copper plate (manufactured by Yamamoto plating tester: cathode plate for hull cell; B-60-P05) in a 20% aqueous solution of acidic cleaner: LAC-41 (made by Rohm and Haas) at 40 ° C. for 5 minutes, 1 in pure water It was immersed for 1 minute, and then immersed in a 5% aqueous sulfuric acid solution at 30 ° C. for 1 minute. The obtained copper plate was immersed in an isopropyl alcohol solution of an imidazole compound (A-1) having a concentration of 100 ppm at 30 ° C. for 1 minute, then immersed and washed in pure water for 1 minute, and then dried with a dryer. About the obtained copper plate, the surface treatment test (heat resistance test) was done. The evaluation results are shown in Table 1 below.

(Examples 2 to 4)
In Example 1, instead of the imidazole compound (A-1), imidazole compounds (A-2) to (A-4) were used, and a 100 ppm test solution was prepared with the solvents shown in Table 1. In the same manner, a copper plate was obtained. Next, a surface treatment test (heat resistance test) was performed.

(Comparative Example 1)
A copper plate was obtained in the same manner as in Example 1, except that an aqueous solution of 1,2,3-benzotriazole was used instead of the isopropyl alcohol solution of the imidazole compound (A-1). Next, a surface treatment test (heat resistance test) was performed.

(Heat resistance test)
It heated at 150 degreeC for 1 hour using oven (The product made by SAKURA: HOT-AIR STERILIZER HE-11).
・ Evaluation (visual judgment)
1: No discoloration,
2: Slight discoloration,
3: A little discoloration,
4: Clear discoloration,
5: Severe discoloration

From the results of Table 1 above, it can be seen that the imidazole compounds (A-1) to (A-4) of Examples 1 to 4 exhibit superior rust prevention properties than the benzotriazole compound of Comparative Example 1.
In addition, since the heat resistance test is a surface treatment test under conditions severer than the normal environment, it is considered that the difference in the rust prevention performance of the compounds appears more prominently.

  Since the surface treatment agent of the present invention exhibits excellent rust prevention performance even under high temperature conditions, it is very useful as a copper foil or lead frame treatment agent or preflux treatment agent in the production of printed wiring boards. Useful.

Claims (5)

A metal surface treating agent comprising an imidazole compound represented by the following general formula (1) as an active ingredient.
(Wherein, R ¹ to R ³ represents a hydrogen atom, an alkyl group, a phenyl group, or a halogen atom, which may be the same or different .X is an alkylene group, Y represents a hydrogen atom or an alkyl group .)   2. The metal surface treatment agent according to claim 1, wherein the metal surface treatment agent is used for a metal selected from copper, nickel, silver, zinc, iron, aluminum or an alloy thereof.   3. The metal surface treatment agent according to claim 1, wherein the metal surface treatment agent is used as a metal surface rust inhibitor. An imidazole compound represented by the following general formula (2).
(In the formula, Y is a hydrogen atom or an alkyl group) An imidazole compound represented by the following general formula (3).
(In the formula, Y is a hydrogen atom or an alkyl group)