HK1056200A - Process for producing part made of magnesium and/or magnesium alloy - Google Patents

Description

Method for producing magnesium and/or magnesium alloy member

Technical Field

The present invention relates to a method for producing a magnesium and/or magnesium alloy member.

Technical Field

Magnesium is the lightest in weight among metals for practical structural materials, has high specific strength, and is easy to machine, and therefore is widely used for automobile parts, electric products such as computers and audio equipment, aircraft parts, and the like. Further, molded articles of magnesium and magnesium alloys are generally produced mainly by die casting, extrusion molding, or calender molding, and recently, a so-called molding method using an injection molding machine has been established in the art, and the freedom of shape and physical properties of the molded articles can be improved, and the range of applications thereof is further expanded.

Conventionally, general steps from the production of a molded article by die casting or molding to the production of a magnesium alloy part are as follows.

1. A mechanical treatment process: a polishing step of removing burrs, removing solid oxides, extruding lubricants, mold release agents, casting sand or general dirt, and removing surface roughness by using a sanding belt, a sand paper, a brush, barrel polishing, buffing, spray cleaning, or the like.

2. Degreasing step

(1) Solvent degreasing: pre-degreasing and washing the cutting oil, grease, etc. with a solvent such as petroleum, aromatic hydrocarbon, chlorine, etc.

(2) Alkali degreasing: degreasing and washing are performed by removing general dirt, a sintered graphite lubricant cutting agent, and the like with an alkali solution such as caustic soda.

(3) Degreasing emulsion: and (3) cleaning to emulsify and remove dirt on the metal surface.

3. An acid washing process: a washing step of removing the oxide film, corrosion products, sintered lubricant, pressed abrasive, blasting sand, casting sand and other contaminants which are not removed in the degreasing step with a pure acid or a mixed solution of hydrofluoric acid, nitric acid, sulfuric acid, phosphoric acid, chromic acid, etc., activating the molding, and removing the segregation phase.

4. Chromic acid treatment process: in order to impart corrosion resistance, a chromate coating is generally applied to the surface of a molded article using a chromic acid-based treating agent.

5. A washing procedure: and alkali washing and water washing for removing the chromate film.

6. Drying step

7. Coating or plating treatment step

8. Assembling procedure

The treatment in step 4 is generally carried out by chromate treatment (for example, Japanese patent publication No. 61-17911). However, chromate treatment is difficult to set treatment conditions, and a simpler rust prevention method is desired. Further, in the case of chromate treatment, there are disadvantages of discoloration of the surface and loss of metallic luster, and recently, there is a growing demand for environmental protection, and there is a tendency that use of chromium compounds is restricted or all chromium compounds are eliminated, and a treatment method with a small environmental load is desired.

Several treatments have been proposed to replace chromate treatment. For example, there may be mentioned a method of treating potassium permanganate under alkaline conditions and a method of treating manganese phosphate under acidic conditions. However, although the rust preventive effect can be obtained even when any manganese is coated on the surface of magnesium, the effect is still insufficient.

The purpose of the present invention is to provide a method for producing a magnesium and/or magnesium alloy member having excellent corrosion resistance, coating adhesion, and electromagnetic wave shielding properties.

Disclosure of the invention

The present invention relates to:

(1) a method for producing a magnesium and/or magnesium alloy member to be treated, characterized by treating a magnesium and/or magnesium alloy member with (A) a surface treating agent containing a phosphate and (B) an anticorrosive pretreating agent.

(2) A method for producing a magnesium and/or magnesium alloy member to be treated, characterized in that a magnesium and/or magnesium alloy member is treated with (A) a surface treating agent containing a phosphate, (B) a rust-preventive pretreating agent, and then (D) a magnesium rust preventive agent.

(3) A method for producing a magnesium and/or magnesium alloy member to be treated, characterized in that a magnesium and/or magnesium alloy member is treated with (A) a surface treating agent containing a phosphate and then with (B) an anticorrosive pretreating agent, (C) a detergent containing at least 1 kind selected from aromatic carboxylic acids and salts thereof and a surfactant, and then (D) a magnesium member is treated with an anticorrosive agent.

(4) The production process according to the above (1) to (3), wherein the treating agent (A) is a phosphate salt containing at least 1 selected from aromatic carboxylic acids and salts thereof, or a phosphate salt containing at least 1 selected from pyrazole compounds and triazole compounds.

(5) The production process according to the above (1) to (4), wherein at least 1 selected from the group consisting of aromatic carboxylic acids and salts thereof, or at least 1 selected from the group consisting of pyrazole compounds and triazole compounds is added as the treating agent of (D).

(6) The production process according to the above (1) to (5), wherein at least 1 of the steps (A), (B), (C) and (D) is carried out under the generation of ultrasonic waves.

(7) The production process according to the above (1) to (6), wherein a washing step is added to the subsequent step of at least 1 step of the steps (A), (B), (C) and (D).

The present invention also relates to a method for producing a magnesium and/or magnesium alloy part to be treated, which comprises the steps of (1) removing burrs if necessary, (2) treating the magnesium and/or magnesium alloy part with a surface treatment agent containing a phosphate, (3) treating the magnesium and/or magnesium alloy part with a rust-preventive pretreatment agent, (4) performing a rust-preventive treatment with a rust-preventive agent for magnesium, (5) drying, (6) applying or plating, and (7) assembling.

The present inventors have variously studied an alternative reagent to the chromate treatment agent. It has been found in the research that one of the main factors contributing to the improvement of corrosion resistance, coating adhesion and electromagnetic wave shielding property is the treatment before the rust-proof treatment.

The present inventors have proposed in PCT/JP00/00019 a surface treatment agent containing a phosphate and at least 1 selected from aromatic carboxylic acids and salts thereof, which is useful for molded articles of magnesium and/or magnesium alloys. The present inventors have made intensive studies on the use of the surface-treating agent for further improving the rust-preventing effect, paint adhesion and electromagnetic wave shielding properties. As a result, they have found that the effects of rust prevention treatment and coating or plating treatment after treating a magnesium and/or magnesium alloy molded article with a surface treating agent containing a phosphate or a phosphate and at least 1 kind selected from aromatic carboxylic acids and salts thereof are remarkably improved by treating the magnesium and/or magnesium alloy molded article with a rust prevention pretreatment agent, and have completed the present invention. The same effect can be obtained by using a surface treatment agent containing the phosphate, at least 1 selected from the group consisting of aromatic carboxylic acids and salts thereof, and at least 1 selected from the group consisting of pyrazole compounds and triazole compounds.

The surface treatment agent used in the present invention contains a phosphate.

Examples of the phosphate include orthophosphoric acid, ammonium salts of condensed phosphoric acids, and alkanolamine salts.

Examples of the condensed phosphoric acid include metaphosphoric acid and polyphosphoric acid. Examples of metaphosphoric acid include trimetaphosphoric acid and tetrametaphosphoric acid. Examples of the polyphosphoric acid include pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, and the like.

Specifically, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium phosphate, monoethanolammonium phosphate, diethanolammonium phosphate, triethanolammonium phosphate, isopropanolammonium phosphate, trimetaphosphate ammonium salt, tetrametammonium phosphate, ethoxalylammonium triphosphate, ammonium tetraphosphate and the like can be cited. These phosphates may be used alone or in combination of two or more.

Among these, ammonium salts and alkanolamine salts of phosphoric acids are preferable from the viewpoint of having a moderate corrosion effect and causing less stain after washing, and condensed ammonium phosphate is most preferable from the viewpoint of having high safety, being easy to handle waste water, being easy to corrode the surface of magnesium and/or magnesium alloy, preventing excessive corrosion, and the like.

The condensed ammonium phosphate is a known compound, and can be produced, for example, by heat-condensing orthophosphoric acid with urea. In this case, the molar ratio of orthophosphoric acid to urea is preferably 1: 0.5 to 1: 5, and orthophosphoric acid and urea, which are unreacted raw materials in the reaction product, may be contained as the surface treatment agent, and may be used for the effect of the present invention without any problem.

The concentration of the phosphate in the surface treatment of a magnesium and/or magnesium alloy member with the surface treatment agent of the present invention is usually about 0.001 to 90% by weight, preferably about 0.5 to 50% by weight, and more preferably about 1 to 40% by weight. When the concentration exceeds 50 wt%, the surface of the magnesium after washing becomes black, while when the concentration is less than 0.5 wt%, corrosion is insufficient, and the degreasing effect tends to be insufficient.

However, when the concentration of the phosphate is less than about 0.5% by weight, even if the corrosion is relatively insufficient or the degreasing effect is insufficient, the shortage can be completely compensated by the rust-preventive pretreating agent of the next step, and when the magnesium surface is blackened, the shortage can be solved by the rust-preventive pretreating agent of the next step after the treatment.

The present invention can use a surface treatment agent having a phosphate concentration in a wide range, and when the phosphate concentration is low, the surface treatment agent is advantageous in terms of cost, can perform a milder surface treatment, can make the surface dense, and has an advantage of easy control of the treatment state, while when the phosphate concentration is high, the surface treatment agent has an advantage of improving the corrosion resistance, coating adhesion, and electromagnetic wave shielding property to the final product while shortening the treatment time.

Such a phenomenon that the surface is blackened when the phosphate exceeds 50% by weight is a phenomenon peculiar to magnesium. However, the production of the present invention for metals such as aluminum and zinc cannot provide sufficient effects.

In the present invention, the phosphate may be mixed with at least 1 selected from aromatic carboxylic acids and salts thereof, or further mixed with at least 1 selected from pyrazole compounds and triazole compounds.

As the aromatic carboxylic acid, R at the 1-position of the benzene ring of the formula (1) can be preferably used¹And any position of 2-6 is R²、R³、R⁴Substituted compounds, or R in position 1 of the naphthalene ring of formula (2)¹8-position R⁸And 2 to 7-position R²、R³、R⁴、R⁵、R⁶、R⁷A substituted compound.

(in the formula, R¹Represents a carboxyl group, a carboxymethyl group or a carboxyvinyl group, R²、R³、R⁴、R⁵、R⁶And R⁷The same or different represent a hydrogen atom, C₁～C₈Alkyl, nitro, halogen atoms or amino groups, R⁸Represents a hydrogen atom, a carboxyl group, a carboxymethyl group or a carboxyvinyl group)

Specific examples of such aromatic carboxylic acids include benzoic acid, p-isopropylbenzoic acid, o-isopropylbenzoic acid, m-isopropylbenzoic acid, p-tert-butylbenzoic acid, m-toluic acid, o-toluic acid, p-toluic acid, hydroxytoluenic acid, mononitrobenzoic acid, dinitrobenzoic acid, nitrotoluic acid, nitrobenzoic acid, chlorobenzoic acid, p-nitrophenylacetic acid, nitrocinnamic acid, naphthoic acid, 2-hydroxynaphthoic acid, and naphthalenedicarboxylic acid.

As the salts, salts with various organic bases and inorganic bases can be used. Specific examples of the organic base include alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine, aliphatic amines such as methylamine, ethylamine and cyclohexylamine, aliphatic diamines such as 1, 3-bis (aminomethyl) cyclohexane (1, 3-BAMCH) and ethylenediamine, ammonium salts such as TMAH (tetramethylammonium hydroxide), tetraethylammonium hydroxide and tetramethylammonium nitrate, cyclic amines such as DBU (1, 8-diazabicyclo [5.4.0] -7-undecene), DBN (1, 5-diazabicyclo [4.3.0] -5-nonene), 1-aminopyrrolidine and morpholine. Specific examples of the inorganic base include alkali metal hydroxides such as ammonia, hydrazine, sodium hydroxide, and potassium hydroxide. These salts may be used alone in 1 kind, or in combination of 2 or more kinds. These salts are more preferable because they have better solubility in water and have better rust-proofing ability than those obtained by using an aromatic carboxylic acid without forming a salt.

Among these salts, organic amine salts such as alkanolamines and aliphatic diamines, ammonium salts and hydrazine salts are most preferable from the viewpoint of imparting good surface properties to the surface of the object to be treated without sticking the crystals to the surface after the treatment.

The most preferred aromatic carboxylic acids and salts thereof in the present invention include p-isopropylbenzoic acid, o-isopropylbenzoic acid, m-isopropylbenzoic acid, p-tert-butylbenzoic acid, m-toluic acid, o-toluic acid and alkanolamine salts of p-toluic acid.

From the viewpoint of improving rust-proofing performance, it is preferable to use a pyrazole-based compound or a triazole-based compound in combination with an aromatic carboxylic acid. Specific examples of pyrazole compounds include pyrazole, 3, 5-dimethylpyrazole, 3-methyl-5-hydroxypyrazole and 4-aminopyrazole. Examples of the triazole-based compound include triazole compounds such as 1, 2, 3-triazole, 1, 2, 4-triazole and benzotriazole, and compounds having a C group at any position of the triazole compounds₁～C₈And alkyl, mercapto, hydroxy, etc. substituted triazole derivatives.

Specific examples of such triazole-based compounds include 1, 2, 3-triazole, 1, 2, 4-triazole, 3-mercapto-1, 2, 4-triazole, 3-hydroxy-1, 2, 4-triazole, 3-methyl-1, 2, 4-triazole, 1-methyl-3-mercapto-1, 2, 4-triazole, 4-methyl-1, 2, 3-triazole, benzotriazole, and 1-hydroxybenzotriazole. Among these, 1, 2, 3-triazole, 1, 2, 4-triazole, benzotriazole, 3-mercapto-1, 2, 4-triazole, and 3-hydroxy-1, 2, 4-triazole are preferable, and 1, 2, 3-triazole, 1, 2, 4-triazole, and 3-mercapto-1, 2, 4-triazole are most preferable. These pyrazole-based compounds and triazole-based compounds may be used singly or in combination of 2 or more.

Examples of the rust-preventive pretreating agent of the present invention include alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine, aliphatic amines such as methylamine, ethylamine and cyclohexylamine, aliphatic diamines such as 1, 3-BAMCH and ethylenediamine, ammonium salts such as TMAH, tetraethylammonium hydroxide and tetramethylammonium nitrate, cyclic amines such as DBU, DBN, 1-aminopyrrolidine and morpholine, alkali metal hydroxides such as ammonia, hydrazine, sodium hydroxide and potassium hydroxide, alkali metal salts of silicic acid such as sodium orthosilicate, potassium orthosilicate, sodium metasilicate and potassium metasilicate, and the like. These rust-preventive pretreating agents may be used singly in 1 kind or in combination in 2 or more kinds. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and ammonium salts such as TMAH are most preferable.

The concentration of the rust-proofing pretreating agent is about 1 to 50 wt%, preferably about 5 to 35 wt%. The rust-preventive pretreating agent is a treating agent used before the treatment with the rust-preventive agent, and may be treated by spraying or coating with a sprayer or a roll coater, or by immersing in a treating liquid.

As the rust inhibitor for magnesium of the present invention, there can be used a rust inhibitor for magnesium and/or magnesium alloy containing at least 1 selected from chromic acid, dichromate, manganese phosphate, potassium permanganate, modified chromic acid, ferric nitrate, stannic acid, zirconium phosphate, stannous chloride and aromatic carboxylic acids and salts thereof proposed by the present inventors in PCT/JP00/00019, and the like, but from the viewpoint of non-chromate, it is preferable to treat with a rust inhibitor for magnesium and/or magnesium alloy containing at least 1 selected from manganese phosphate, potassium permanganate, ferric nitrate, stannic acid, zirconium phosphate, stannous chloride and aromatic carboxylic acids and salts thereof. When the aromatic carboxylic acid or its salt is used, the concentration thereof may be appropriately set, but the total amount is usually about 0.01 to 30% by weight, preferably about 0.1 to 10% by weight. In addition, at least 1 selected from the pyrazole-based compounds or triazole-based compounds described above may be used in combination. When a pyrazole compound or a triazole compound is used in combination, the concentration of the pyrazole compound or triazole compound in the treating agent is about 0.01 to 30 wt%, preferably about 0.1 to 10 wt%, and the ratio of (aromatic carboxylic acid or salt thereof) to (pyrazole compound or triazole compound) is about 10: 1 to 1: 10 by weight.

As the detergent of the present invention, a detergent containing at least 1 kind selected from the above aromatic carboxylic acids or salts thereof and a surfactant can be used. In addition, the detergent may also be used by combination of the pyrazole compounds or triazole compounds selected from at least 1.

As the surfactant, a known surfactant can be used, and for example, a nonionic surfactant, an amphoteric surfactant, or the like can be preferably used, and an anionic surfactant or a cationic surfactant can also be used.

The nonionic surfactant is not particularly limited, and specifically includes: for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene higher alcohol ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octyl phenyl ether, polyethylene glycol fatty acid esters such as polyethylene glycol monostearate, sorbitan fatty acid esters such as sorbitan monolaurate and polyoxyethylene sorbitan monolaurate, glycol fatty acid esters such as ethylene glycol monostearate, and fatty acid monoglycerides. Among them, polyoxyethylene alkyl ethers and polyoxyethylene alkylphenyl ethers are preferable, and surfactants having an HLB value of 13 to 15 are most preferable.

The amphoteric surfactant is not particularly limited, and specific examples thereof include alkyl B-amino propionic acids, alkyl β -imino dipropionic acids, aminocarboxylic acids such as β -amino propionic acids, and betaines such as trimethylglycine, and among them, β -amino propionic acid and betaines are preferable.

The anionic surfactant is not particularly limited, and specific examples thereof include fatty acid salts, alkyl sulfate ester salts, alkylsulfonic acid salts, alkylarylsulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkylsulfosuccinic acid salts, alkyldiphenylether disulfonic acid salts, alkylphosphates, polyoxyethylene alkylsulfuric acid ester salts, and sulfosuccinic acid ester salts. Among them, fatty acid salts, alkyl sulfosuccinate salts and the like are preferable.

The cationic surfactant is also not particularly limited, and specific examples thereof include halogen acid salts of aliphatic amines, alkyl pyridinium halides, and quaternary ammonium salts, and among them, halogen acid salts of aliphatic amines and quaternary ammonium salts are preferable.

The surfactants may be used alone, or 2 or more of them may be used in combination. The amount of the surfactant is usually about 0.001 to 50% by weight, preferably about 0.01 to 10% by weight based on the total weight of the composition.

The surface treatment agent, rust preventive pretreatment agent, detergent and rust preventive agent used in the present invention may be used as they are, or may be dissolved in an appropriate solvent, and among them, they are preferably used in the form of an aqueous solution.

The concentration of the aromatic carboxylic acid and its salt in the surface treatment agent and the detergent may be appropriately set, and the total amount is usually about 0.01 to 30% by weight, preferably about 0.1 to 10% by weight.

When a pyrazole compound or triazole compound is used in combination with a surface treatment agent or a detergent, the concentration of the pyrazole compound or triazole compound in the surface treatment agent is about 0.01 to 30 wt%, preferably about 0.1 to 10 wt%, and the ratio of (aromatic carboxylic acid or salt thereof) to (pyrazole compound or triazole compound) is about 10: 1 to 1: 10 by weight based on the weight ratio of the aromatic carboxylic acid or salt thereof, and the content of these compounds is increased to improve the rust-proofing effect, but when it exceeds 30 wt%, the coating adhesion tends to be deteriorated.

In the surface treatment agent, the rust-preventive pretreatment agent, the detergent and the rust preventive, various additives such as a surfactant, a chelating agent and an antifoaming agent may be used as required.

The surface treatment agent, rust-preventive pretreating agent, detergent and rust preventive used in the present invention may be used as they are, but may be used after being diluted or concentrated as desired.

The surface treatment agent, rust-preventive pretreating agent, detergent and rust preventive for use in the present invention may be applied by spraying or coating the activated surface of a molded article formed by molding or die casting using a sprayer, a roll coater or the like, or by immersing the article in a treating liquid.

The magnesium or magnesium alloy as a material to which the surface treatment agent of the present invention is applied is not particularly limited, and a simple magnesium substance, an alloy of magnesium and other metals, a composite material, and the like can be widely used. The other metal includes 1 or 2 or more metals selected from aluminum, zinc, manganese, iron, nickel, copper, lead, tin, and calcium.

Of course, an acid washing step may be added between the treatment with the surface treatment agent and the treatment with the rust-preventive pretreatment agent. As the reagent for the pickling step, a reagent for pickling a conventional magnesium alloy can be mentioned. Specifically, there may be mentioned aqueous solutions of nitric acid-sulfuric acid, phosphoric acid, sulfuric acid, chromic acid-nitric acid-hydrofluoric acid, chromic acid, ferric nitrate, hydrofluoric acid, nitric acid, acetic acid-sodium nitrate, chromic acid-sulfuric acid, and the like.

Further, before the treatment with the surface treatment agent, a mechanical treatment or degreasing treatment step of a molded article produced by a die casting method or a molding method may be performed. The mechanical treatment includes deburring, removal of various contaminants, and various polishing steps. The barrel polishing, which is one of the polishing steps, includes, for example, magnetic barrel polishing. Therefore, the unevenness of the surface is small, and the fraction defective can be reduced even when the coating is performed with a thin film thickness, for example, in a mobile phone.

The degreasing treatment step includes solvent degreasing, alkali degreasing, and emulsion degreasing, as described above. These steps may be carried out in 1 or more combinations.

After the treatment with the rust-preventive pretreating agent of the present invention, the treatment is carried out by rust-preventive treatment, electrochemical treatment, or plating treatment, and if necessary, coating and assembling are carried out.

When at least 1 or more of the steps (a), (B), (C) and (D) of the present invention are performed under the generation of ultrasonic waves, a processing tank equipped with an ultrasonic transmitter may be used. By performing the treatment under the generation of such ultrasonic waves, the treatment time can be shortened, and uniformity (stability) of corrosion resistance, coating adhesion, and electromagnetic wave shielding properties can be obtained in the case of a large amount of treatment.

In the present invention, a washing step may be added to the subsequent step of at least 1 step of each of the steps (A), (B), (C) and (D). The water wash may be performed using a solution containing a suitable rust inhibitor. Such washing with water or washing with a solution containing an appropriate rust inhibitor is preferably followed by drying.

When the alkali degreasing treatment is (E), the acid pickling treatment is (F), the rust preventing treatment is (D), the surface treatment agent treatment is (A), the rust preventing pretreatment is (B), and the detergent treatment is (C), the conventional general parts made of magnesium and/or magnesium alloy are produced by coating and assembling via (E) → (F) → (D).

Specific examples of the embodiments of the present invention include

1.(A)→(B)→(D)

2.(A)→(B)→(C)→(D)

3.(A)→(F)→(B)→(D)

4.(A)→(F)→(B)→(C)→(D)

5.(E)→(A)→(B)→(D)

6.(E)→(A)→(B)→(C)→(D)

7.(E)→(A)→(F)→(B)→(D)

8.(E)→(A)→(F)→(B)→(C)→(D)

Best mode for carrying out the invention

The following description will be given by way of examples and comparative examples, but the present invention is not limited to these examples. In addition, the term "part" is used to indicate "part by weight". Reference example 1 preparation of surface treating agent (1)

Mixing orthophosphoric acid and urea according to the molar ratio of 1: 2, and carrying out condensation reaction for 2 hours at the temperature of 150-160 ℃ to prepare the condensed ammonium phosphate. The condensed ammonium phosphate contains unreacted urea and orthophosphoric acid. Deionized water is added into the condensed ammonium phosphate to prepare 55% (w/w) condensed ammonium phosphate water solution. The following examples and comparative examples are also condensed ammonium phosphates.

A surface treatment agent (1) was prepared by dissolving 5 parts of an aqueous 55% (w/w) condensed ammonium phosphate solution, 5 parts of p-tert-butylbenzoic acid, 1 part of 1, 2, 4-triazole, 5 parts of diethanolamine, 5 parts of ラオ - ル XA60/50(ライオソ, nonionic surfactant), 2.5 parts of パイオニソ C (ampholytic surfactant, manufactured by bamboo & fat Co., Ltd.), and 0.5 part of テトロニツク TR913R (antifoaming agent, manufactured by Asahi Denka Co., Ltd.) in deionized water to obtain 100 parts of an aqueous solution and diluting the aqueous solution by 5 times. Reference example 2 preparation of surface treating agent (2)

A surface treatment agent (2) was prepared by dissolving 10 parts of an aqueous 55% (w/w) condensed ammonium phosphate solution, 5 parts of p-tert-butylbenzoic acid, 5 parts of 3-mercapto-1, 2, 4-triazole, 5 parts of isopropanolamine, and ラオ - ル XA 60/502.5 parts in deionized water to obtain 100 parts of an aqueous solution and diluting the aqueous solution by 5 times. Reference example 3 preparation of surface treating agent (3)

A surface treatment agent (3) was prepared by dissolving 10 parts of an aqueous 55% (w/w) condensed ammonium phosphate solution and ラオ - ル XA 60/502.5 parts of deionized water to obtain 100 parts of an aqueous solution and diluting the solution 500 times. Reference example 4 preparation of surface treating agent (4)

ラオ - ル XA 60/5010 parts were added to 100 parts of an aqueous 55% (w/w) condensed ammonium phosphate solution to prepare a surface treating agent (4). Reference example 5 preparation of surface treating agent (5)

100 parts of a 55% by weight aqueous condensed ammonium phosphate solution was diluted 2.5 times to prepare a surface-treating agent (5). Reference example 6 preparation of anticorrosive agent (1)

100 parts of the rust inhibitor (1) is prepared by dissolving 1.5 parts of m-toluic acid, 1.5 parts of 3-mercapto-1, 2, 4-triazole and 1.5 parts of isopropanolamine in deionized water. Reference example 7 preparation of anticorrosive agent (2)

5 parts of p-tert-butylbenzoic acid, 5 parts of 3-mercapto-1, 2, 4-triazole and 5 parts of isopropanolamine are put into deionized water and dissolved to prepare 100 parts of solution, and the solution is diluted by 10 times by using the deionized water to prepare the antirust agent (2). Reference example 8 preparation of anticorrosive agent (3)

5 parts of m-toluic acid, 5 parts of 3-mercapto-1, 2, 4-triazole and 5 parts of 1, 3-bis (aminomethyl) cyclohexane are put into deionized water, dissolved to obtain 100 parts of solution, and then diluted by 10 times with the deionized water to obtain the antirust agent (3). Reference example 9 preparation of detergent (1)

5 parts of p-tert-butylbenzoic acid, 1 part of 1, 2, 4-triazole, 5 parts of diethanolamine, ラオ - ル XA60/505 parts, パイオニソ C2.5 parts, and テトロニツク TR913R 0.5.5 parts were put into deionized water, and dissolved to obtain 100 parts of an aqueous solution, which was diluted 5 times to obtain detergent (1).

Example 1

A plate-shaped molded article (10X 15X 0.2cm) was used, which was obtained by coating a mold release agent (キヤスタ - エ - ス 225, manufactured by Nimi corporation) in a mold and molding a magnesium alloy AZ91D (containing 90% magnesium, 9% aluminum and 1% zinc) using a die casting molding machine (manufactured by Toshiba). The same applies to the following examples.

The plate-like molded article was immersed in the surface treating agent (1) prepared in reference example 1 at 40 ℃ for 10 minutes, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide as an anticorrosive pretreating agent at 60 ℃ for 15 minutes, and washed with deionized water for 1 minute (hereinafter, this operation is referred to as step 1). Subsequently, the sample was immersed in an aqueous manganese phosphate solution 1L containing 100g of ammonium dihydrogen phosphate and 20g of potassium permanganate and adjusted to ph3.5 with orthophosphoric acid at 40 ℃ for 15 minutes (hereinafter, this operation is referred to as "manganese treatment", and after washing and drying, a test piece 1 was obtained.

Example 2

After the plate-like molded article was subjected to step 1, the plate-like molded article obtained was immersed in the detergent (1) prepared in reference example 9 at 50 ℃ for 15 minutes, washed with water, immersed in the rust inhibitor (1) prepared in reference example 6 at room temperature for 1 minute, and dried to obtain a test piece 2.

Example 3

Test piece 1 obtained in example 1 was immersed in rust inhibitor (1) prepared in reference example 6 at room temperature for 1 minute, and dried to obtain test piece 3.

Example 4

A plate-like molded article was immersed in the surface treating agent (1) prepared in reference example 1 at 40 ℃ for 10 minutes, washed with deionized water for 1 minute, immersed in 5% (w/v) phosphoric acid at room temperature for 0.5 minute, washed with water for 1 minute, immersed in 10% (w/v) potassium hydroxide aqueous solution as an anticorrosive pretreating agent at 60 ℃ for 15 minutes, and washed with deionized water for 1 minute (hereinafter, this operation is referred to as "step 2"). Subsequently, manganese treatment, water washing and drying were performed to obtain a test piece 4.

Example 5

After the plate-like molded article was subjected to step 2, the plate-like molded article obtained was immersed in the detergent (1) prepared in reference example 9 at 50 ℃ for 15 minutes, washed with water, immersed in the rust inhibitor (1) prepared in reference example 6 at room temperature for 1 minute, and dried to obtain a test piece 5.

Example 6

Test piece 4 obtained in example 4 was immersed in rust inhibitor (1) prepared in reference example 6 at room temperature for 1 minute, and dried to obtain test piece 6.

Example 7

A plate-like molded article was immersed in a 5% (w/v) aqueous solution of sodium monohydrogen phosphate at 50 to 70 ℃ for 5 minutes, washed with water for 1 minute, immersed in the surface treatment agent (1) prepared in reference example 1 at 40 ℃ for 10 minutes, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide as an anticorrosive pretreatment agent at 60 ℃ for 15 minutes, and washed with deionized water for 1 minute (hereinafter, this operation is referred to as "step 3"). Subsequently, manganese treatment, washing and drying were performed to obtain a test piece 7.

Example 8

After the plate-like molded article was subjected to step 3, the obtained plate-like molded article was immersed in the detergent (1) prepared in reference example 9 at 50 ℃ for 15 minutes, washed with water, immersed in the rust inhibitor (1) prepared in reference example 6 at room temperature for 1 minute, and dried to obtain a test piece 8.

Example 9

Test piece 7 obtained in example 7 was immersed in rust inhibitor (1) prepared in reference example 6 at room temperature for 1 minute, and dried to obtain test piece 9.

Example 10

The plate-like molded article was immersed in the surface treating agent (2) prepared in reference example 2 at 40 ℃ for 1 minute under ultrasonic wave generation, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide as an anticorrosive pretreating agent at 60 ℃ for 5 minutes under ultrasonic wave generation, and washed with deionized water for 1 minute. Next, the rust inhibitor (2) prepared in reference example 7 was immersed in the ultrasonic wave at 40 ℃ for 1 minute, and dried to obtain a test piece 10.

Furthermore, ultrasonic wave was generated by using an ultrasonic washer (C-6356N model manufactured by Togaku Kogyo カイジヨ Co., Ltd., oscillator 26KHz, 600W). The same applies below.

Example 11

The plate-like molded article was immersed in the surface treating agent (3) prepared in reference example 3 at 40 ℃ for 30 minutes under ultrasonic wave generation, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide at 60 ℃ for 5 minutes under ultrasonic wave generation, and washed with deionized water for 1 minute. Next, the rust inhibitor (2) prepared in reference example 7 was immersed in ultrasonic waves at 40 ℃ for 1 minute, and dried to obtain a test piece 11.

Example 12

The plate-like molded article was immersed in the surface treatment agent (4) prepared in reference example 4 at 40 ℃ for 1 minute under ultrasonic wave generation, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide at 60 ℃ for 5 minutes under ultrasonic wave generation, and washed with deionized water for 1 minute. Next, the rust inhibitor (2) prepared in reference example 7 was immersed in the ultrasonic wave at 40 ℃ for 1 minute, and dried to obtain a test piece 12.

Example 13

The plate-like molded article was immersed in the surface treating agent (5) prepared in reference example 5 at 40 ℃ for 1 minute under ultrasonic wave generation, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide as an anticorrosive pretreating agent at 60 ℃ for 10 minutes under ultrasonic wave generation, and washed with deionized water for 1 minute. The resulting plate-like molded article was immersed in the detergent (1) prepared in reference example 9 at 50 ℃ for 5 minutes under ultrasonic wave generation, washed with water, immersed in the rust inhibitor (2) prepared in reference example 7 at 40 ℃ for 1 minute, and dried to obtain a test piece 13.

Example 14

A test piece 14 was produced in the same manner as in example 13, except that the rust inhibitor (3) prepared in reference example 8 was used in place of the rust inhibitor (2) prepared in reference example 7.

Example 15

A test piece 15 was produced in the same manner as in example 13 except that 25% (w/v) tetramethylammonium hydroxide was used in place of the 10% (w/v) aqueous solution of potassium hydroxide as the rust-preventive pretreatment agent. Comparative example 1

A plate-like molded article is immersed in a 5% (w/v) aqueous solution of sodium monohydrogen phosphate at 50 to 70 ℃ for 5 minutes, washed with water for 1 minute, then immersed in a 10% (w/v) aqueous solution of potassium hydroxide at 60 ℃ for 15 minutes, and washed with water for 1 minute. Subsequently, manganese treatment, water washing and drying were performed to obtain comparative test piece 1. Comparative example 2

The plate-like molded article was immersed in the surface treatment agent (1) prepared in reference example 1 at 40 ℃ for 10 minutes, and washed with deionized water for 1 minute. Subsequently, manganese treatment, water washing and drying were performed to obtain comparative test piece 2. Comparative example 3

The plate-like molded article was immersed in a 10% (w/v) aqueous solution of potassium hydroxide at 60 ℃ for 15 minutes, washed with deionized water for 1 minute, and then immersed in the detergent (1) prepared in reference example 9 at 50 ℃ for 15 minutes. After washing with water, the surface-treating agent (1) prepared in reference example 1 was immersed at 40 ℃ for 10 minutes and washed with deionized water for 1 minute. Comparative test piece 3 was prepared by immersing rust inhibitor (1) prepared in reference example 6 in water at room temperature for 1 minute and drying. Comparative example 4

A plate-like molded article was immersed in the surface treatment agent (2) prepared in reference example 2 at 40 ℃ for 1 minute under ultrasonic wave generation, washed with deionized water for 1 minute, immersed in the rust inhibitor (2) prepared in reference example 7 at 40 ℃ for 1 minute under ultrasonic wave generation, and dried to obtain a comparative test piece 4. Comparative example 5

A plate-like molded article was immersed in a 10% (w/v) aqueous potassium hydroxide solution at 60 ℃ for 5 minutes under ultrasonic wave generation, washed with deionized water for 1 minute, then immersed in a rust inhibitor (2) prepared in reference example 7 at 40 ℃ for 1 minute under ultrasonic wave generation, and dried to obtain a comparative test piece 5. Comparative example 6

A plate-like molded article was immersed in 100 parts of an aqueous solution composed of 5 parts of sodium monohydrogen phosphate, 1 part of m-toluic acid, 1 part of 1, 2, 4-triazole, 2 parts of isopropanolamine and the balance of water at 40 ℃ for 1 minute with ultrasonic waves, washed with deionized water for 1 minute, immersed in a 10% (w/v) aqueous solution of potassium hydroxide at 60 ℃ for 5 minutes with ultrasonic waves, and washed with deionized water for 1 minute. Then, the rust inhibitor (2) prepared in reference example 7 was immersed in the ultrasonic wave at 40 ℃ for 1 minute, and dried to obtain comparative test piece 6. Test example 1 (salt spray test)

On each of the test pieces obtained in examples 1 to 15 and comparative examples 1 to 6, 5% (w/v) of a saline solution was sprayed at 35 ℃ for 8 hours to confirm rusting.

The surface area of the test piece was evaluated as 0% for rust less than 0 to 3%, as Δ for rust less than 3 to 11%, and as X for rust more than 11%, and the rust status is shown in Table 1. Test example 2 (resistivity test)

The resistance value of any 5 points (repeated 3 times) on the surface of each test piece was measured by a two-probe method (プロ - ブ: ロレスタ -MP manufactured by Mitsubishi chemical Co., Ltd.) using a contact resistance meter ロレスタ -MP (manufactured by ダイアイソスツルメソツ Co., Ltd.). The measurement was performed before and after the salt spray test of test example 1.

The resistance values were 0.6 Ω or less, x greater than 0.6 Ω, o less than 1.0 Ω, and x greater than 1.0 Ω before the salt water spray test. The results are shown in Table 1.

[ Table 1]

	Test example 1	Test example 2
				Salt spray test	Before salt water spray test	After salt spray test
	Test piece 1	○	○				○
Test piece 2				○	○	○
	Test piece 3	○	○				○
Test piece 4				○	○	○
	Test piece 5	○	○				○
Test piece 6				○	○	○
	Test piece 7	○	○				○
Test piece 8				○	○	○
	Test piece 9	○	○				○
Test piece 10				○	○	○
	Test piece 11	○	○				○
Test piece 12				○	○	○
	Test piece 13	○	○				○
Test piece 14				○	○	○
	Test piece 15	○	○				○
Comparative test piece 1				○	×	×
	Comparative test piece 2	△	○				×
Comparative test piece 3				△	○	×
	Comparative test piece 4	△	○				×
Comparative test piece 5				×	×	×
	Comparative test piece 6	○	×				×

Test example 3 (initial adhesion test)

Each of the test pieces obtained in examples 2 and 10 to 13 was coated with a metallic satin powder coating by a coater (manufactured by Japan パ - カライジソグ), subjected to a sintering treatment (200 ℃ C., 15 minutes), and subjected to a checkerboard test, the results of which are shown in Table 2.

TABLE 2

	Initial adhesion test
		Checkerboard test
	Test piece 2		100/100
Test piece 10		100/100
	Test piece 11		100/100
Test piece 12		100/100
	Test piece 13		100/100

Test example 4 (Secondary adhesion test)

Test pieces 2 and 10 were transversely cut, and after the adhesive tape (18 mm in width) was completely adhered along the cut portion by continuously spraying 5% aqueous sodium chloride solution at 35 ℃ for 120 hours, the peeling state of the coating film was measured.

The peeled state was evaluated by the number of points of evaluation by the X-cut tape method (JIS K54008.5.3). The results are shown in Table 3.

TABLE 3

	2 adhesion tests
				Peeled state	Width of peeling
Test piece 2 test piece 10	1010	0mm0mm

Possibility of industrial utilization

The present invention can produce magnesium and/or magnesium alloy parts with excellent corrosion resistance, coating adhesion and electromagnetic wave shielding performance.

In the present invention, as a result of intensive studies aiming at improvement of corrosion resistance, coating adhesion and electromagnetic wave shielding properties, the effects of rust prevention treatment and coating or plating treatment after treating a magnesium and/or magnesium alloy molded article with a surface treatment agent containing a phosphate, or containing a phosphate and at least 1 selected from aromatic carboxylic acids and salts thereof, or further containing at least 1 selected from pyrazole compounds and triazole compounds are remarkably improved by treating the article with a rust prevention pretreatment agent.

Claims (17)

1. A method for producing a magnesium and/or magnesium alloy member to be treated, characterized by treating a magnesium and/or magnesium alloy member with (A) a surface treating agent containing a phosphate and (B) a rust-preventive pretreating agent.

2. A method for producing a treated magnesium and/or magnesium alloy member, characterized in that a magnesium and/or magnesium alloy member is treated with (A) a surface treatment agent containing a phosphate, (B) a rust-preventive pretreatment agent, and then (D) a rust-preventive treatment agent for magnesium.

3. A method for producing a magnesium and/or magnesium alloy member to be treated, characterized in that the magnesium and/or magnesium alloy member is treated with (A) a surface treating agent containing a phosphate, (B) a rust-preventive pretreating agent, (C) a detergent containing at least 1 kind selected from aromatic carboxylic acids or salts thereof and a surfactant, and (D) a rust-preventive agent for magnesium.

4. The process according to claim 1 to 3, wherein the treating agent (A) is at least 1 selected from aromatic carboxylic acids and salts thereof mixed with phosphate, or at least 1 selected from pyrazole compounds and triazole compounds mixed with phosphate.

5. The process according to claim 2 to 3, wherein at least 1 kind selected from aromatic carboxylic acids and salts thereof is used as the rust inhibitor for magnesium (D).

6. The process according to claim 2 to 3, wherein the rust inhibitor for magnesium (D) is obtained by blending at least 1 treating agent selected from a pyrazole compound and a triazole compound with at least 1 selected from an aromatic carboxylic acid or a salt thereof.

7. The process according to claim 3, wherein the detergent (C) comprises at least 1 selected from the group consisting of aromatic carboxylic acids and salts thereof, at least 1 selected from the group consisting of pyrazole compounds and triazole compounds, and a surfactant.

8. The process according to claim 1 to 7, wherein at least 1 or more of the steps (A), (B), (C) and (D) is carried out under the generation of ultrasonic waves.

9. The process according to claim 1 to 8, wherein a washing step is added in at least one or more steps subsequent to the steps (A), (B), (C) and (D).

10. The process according to claim 1 to 9, wherein the phosphate is at least 1 of ammonium salts and alkanolamine salts of phosphoric acids.

11. The method according to claim 1 to 10, wherein the phosphate is condensed ammonium phosphate.

12. The process according to claim 1 to 11, wherein the aromatic carboxylic acid or a salt thereof is p-isopropylbenzoic acid, o-isopropylbenzoic acid, m-isopropylbenzoic acid, p-tert-butylbenzoic acid, o-toluic acid, m-toluic acid, p-toluic acid or an alkanolamine salt thereof.

13. A production method according to claim 1 to 12, wherein the rust-preventive pretreating agent is at least 1 selected from the group consisting of alkali metal hydroxides and tetraalkylammonium hydroxides.

14. The process according to claim 4, 6 or 7, wherein the triazole-based compound is 1, 2, 3-triazole, 1, 2, 4-triazole or 3-mercapto-1, 2, 4-triazole.

15. A method for producing a treated magnesium and/or magnesium alloy part, characterized by comprising (1) removing burrs if necessary, (2) treating the magnesium and/or magnesium alloy part with a surface treatment agent containing a phosphate salt, (3) treating the magnesium and/or magnesium alloy part with a rust-preventive pretreatment agent, (4) subjecting the magnesium part to a rust-preventive treatment with a rust-preventive agent, (5) drying the magnesium part, (6) coating or plating the magnesium part with a rust-preventive treatment, and (7) assembling the magnesium part and/or magnesium alloy part.

16. A process for producing a treated magnesium and/or magnesium alloy part, characterized by comprising (1) removing burrs if necessary, (2) treating the magnesium and/or magnesium alloy part with a surface treating agent containing a phosphate salt, (2-1) washing with water, (3) treating the magnesium and/or magnesium alloy part with an anticorrosive pretreating agent, (3-1) washing with water, (4) subjecting the magnesium part to an anticorrosive treatment with an anticorrosive agent, (4-1) optionally washing with water, (5) drying, (6) coating or plating, and (7) assembling.

17. A method for producing a treated magnesium and/or magnesium alloy part, characterized by comprising (1) removing burrs if necessary, (2) treating the magnesium and/or magnesium alloy part with a surface treating agent containing a phosphate salt, (2-1) washing with water, (3) treating with a rust-preventive pretreating agent, (3-2) washing with a detergent containing at least 1 kind selected from aromatic carboxylic acids and salts thereof and a surfactant, (4) performing rust-preventive treatment with a rust-preventive agent for magnesium, (4-1) washing with water, (5) drying, (6) coating or plating, and then (7) assembling.