JPH1180977A - Rust preventive agent having good hydro-extraction for metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of nonuniformity and blot, which may cause undesired appearance of the product in the drying process, to control oxidation and discoloring during storage, and to maintain good appearance of the product by treating the surface with an aqueous solution containing an acetylenic alcohol having a specific number of carbon atoms and a specific benzotriazole derivative. SOLUTION: The acetylenic alcohol having 3-10 carbon atoms and the benzotriazole derivative of the formula wherein R is hydrogen or methyl group are preferably used as the rust preventive agent. When the hydro-extraction is carried out, the surface is treated with the solution containing an amount of not less than 1 ppm of the acetylenic alcohol and an amount of 0.1-50 ppm or more of the benzotriazole derivative, and then dried. After this treatment, no washing with water is needed. The acetylenic alcohol having a boiling point or a decomposition point more than 200 deg.C is preferably used. The compound selected from 1, 2, 3-benzotriazole, 4-methyl-1H-benzotriazole and 5-methyl-1H- benzotriazole is preferably used as the benzotriazole derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based metal surface treatment and a water-based metal cleaning field, which are intended to prevent unevenness and stains due to a drying step and to suppress oxidation of a metal surface during storage after drying. It relates to a draining rust inhibitor.

[0002]

2. Description of the Related Art In the field of conventional water-based metal surface treatment and metal cleaning, if water is dried while adhering to water, in many cases, drying unevenness and stains are generated on the metal surface, the appearance is impaired, and the product value decreases. . Therefore, as a method for preventing metal oxidation in the drying step for preventing drying unevenness and stains, a draining replacement method using a solvent, vacuum drying, drying in a nitrogen atmosphere, and the like can be mentioned. However, the vacuum drying method requires high equipment costs and low work efficiency. Drying in a nitrogen atmosphere is also expensive in equipment cost, and the cost is increased because more nitrogen is used. These drying methods are applied only to special products. In general, a draining replacement method is used, in which after rinsing (final finish) water treatment, treatment with freon or a chlorine-based solvent is performed to replace and remove water on the metal surface.

However, since the use of chlorofluorocarbon or chlorinated solvents used in the above-mentioned solvent drainage replacement method causes environmental destruction, their use has been regulated worldwide, and alternative technologies are strongly required. ing. As an alternative technology, the use of low-toxic solvents such as isopropyl alcohol has been proposed, but these solvents are flammable (flammable) and have a problem in safety as compared with chlorofluorocarbon or chlorinated solvents, and the equipment cost is high. There is a disadvantage.

[0004] There is also a method of using a corrosion inhibitor to uniformly adsorb and coat an inhibitor component on a metal surface and cutting off contact between the metal and oxygen to prevent metal oxidation. An amine compound is used as a general corrosion inhibitor.

For example, JP-A-60-208487, JP-A-61-91379, and JP-B-61-54.
No. 873 proposes a composition using acetylene alcohol as a corrosion inhibitor for pickling and treating metals with acid, and this composition is used for boiler piping, water-cooled piping, oil wells and the like. The purpose is to suppress metal corrosion in the acid cleaning solution, not to oxidize the metal in the drying step.If these compositions are used in the drying step, the metal The corrosion-inhibiting component remains on the surface, causing uneven spots and poor appearance.

In Japanese Patent Publication No. 61-47909 and Japanese Patent Publication No. Hei 3-30640, acetylene alcohol is used as a metal rust preventive component. 2
It has a high concentration of 0%, which is clearly different from a treating agent which is used at a low concentration such that it does not remain on the metal surface after the completion of the drying step and obtains a rust preventive effect at a high temperature as in the present invention. It is. In these prior inventions, there is no disclosure about prevention of unevenness or stains on the metal surface during the drying step.

On the other hand, the fact that a benzotriazole derivative has a rust-preventing effect is described in "Corrosion Inhibition Mechanism of Benzotriazole Inhibitors and Its Application" (Takeno Notoya,
Benzotriazole and its derivatives are actually commercially available from various manufacturers as rust preventives. However, in order to use it as a rust preventive, the usual use concentration is 0.1%.
Since the concentration is as high as 1 to 1%, when used as a treating agent during the drying step, the benzotriazole derivative precipitates on the metal surface and causes drying unevenness and stains.

On the other hand, in the present invention, the acetylene alcohol and the benzotriazole derivative have the minimum concentration at which the antioxidant performance and drainage performance are exhibited,
By using as a pre-drying agent containing acetylene alcohol and a benzotriazole derivative between the maximum concentration at which no residue remains on the metal surface after the drying step, even if the treatment liquid is dried without rinsing, In addition to preventing the occurrence of unevenness and stains on the metal surface during drying, it also prevents oxidation of the metal surface during storage after drying.

[0009]

SUMMARY OF THE INVENTION The present invention does not require a drainage replacement step using a solvent that causes environmental destruction, and prevents the occurrence of spots and stains even when drying with a treatment liquid attached. It is an object of the present invention to provide a metal draining rust preventive agent for preventing oxidation of the metal surface even when storing.

[0010]

Means for Solving the Problems There is a strong demand for an alternative technique to the drying method by drainage replacement using chlorofluorocarbon or a chlorinated solvent which causes environmental destruction. Thus, the present inventors have proposed a drying pretreatment agent using an aqueous solution containing an acetylene alcohol and a benzotriazole derivative, which can effectively prevent the occurrence of uneven spots in the drying step, and at the time of storage after drying. Also found that metal oxidation can be prevented. That is, the present invention relates to a metal draining rust preventive comprising an aqueous solution containing an acetylene alcohol having 3 to 10 carbon atoms and a benzotriazole derivative represented by the general formula (1).

[0011]

Embedded image (Wherein R is hydrogen or a methyl group)

In various processes used for aqueous metal surface treatment and aqueous metal cleaning, if the metal is dried with water attached, in many cases, discoloration due to metal oxidation occurs and drying unevenness and stains occur. However, after the treatment with the metal surface treatment agent or the metal cleaning agent, prior to the drying step, the metal is treated with the metal drainage rust preventive agent of the present invention, so that even if it is dried with water attached, it is dried. Since the occurrence of unevenness and stains in the process can be suppressed, the appearance of the metal becomes good, and also during storage after drying, the metal can be prevented from being oxidized and the good appearance can be maintained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The aqueous metal surface treatment process used in the present invention includes electroless plating, electroplating, anodic oxidation, pickling, alkali washing, chemical polishing, electrolytic polishing, mechanical polishing, metal coloring, etching, and the like. , Chemical conversion process, etc., as the aqueous metal cleaning process, degreasing,
Processes such as acid cleaning, alkali cleaning, and electrolytic cleaning are exemplified.

In these various metal surface treatments and metal washing processes, the metal is treated with an aqueous solution containing acetylene alcohol and a benzotriazole derivative after rinsing, and before drying, or acetylene alcohol is added to the rinsing water. After a treatment that also serves as water washing with an aqueous solution to which the benzotriazole derivative has been added, the metal is dried. As a result, the occurrence of drying unevenness and spots in the drying step is suppressed, and the metal oxidation is suppressed even during storage after drying, so that it is possible to maintain a good state of the metal appearance.

Although the boiling point or decomposition temperature of the acetylene alcohol used in the present invention varies depending on the drying conditions, a compound having a temperature of 200 ° C. or lower is preferable, and a compound having a temperature of 150 ° C. or lower is usually optimum. A compound having a boiling point or a decomposition temperature exceeding 200 ° C. has a high effect of preventing metal oxidation, but causes a component of a drying pretreatment agent to adhere to a dried metal surface and causes drying unevenness and stains. If the drying temperature is increased, this defect can be prevented, but it is not preferable from the viewpoint of handleability and economy. Fifteen
Compounds having a boiling point or decomposition temperature of 0 ° C. or lower have a high effect of preventing metal oxidation and can provide a good appearance without drying unevenness and spots.

As acetylene alcohols, 1-propyn-3-ol, 1-butyn-3-ol, 1-butyn-4-ol, 2-butyn-1-ol, 3-methyl-1-butyn-3 -Ol, 3-methyl-1-butyn-4-ol, 1-pentyn-3-ol, 3-methyl-1-pentyn-3-ol, 1-hexyn-3-ol, 3,5-dimethyl-1 -Hexyn-3-ol, 1
-Heptin-3-ol, 1-octin-3-ol,
1-nonin-3-ol, 1-decin-3-ol, 2
-Butyne-1,4-diol, 3-hexyne-2,5-
Diol, 3,5-dimethyl-3-hexyne-2,5-
An acetylene alcohol having 3 to 10 carbon atoms such as a diol and 4-ethyl-1-octin-3-ol is preferable,
Among these, in particular, 3-methyl-1-pentyne-3-
All (methylpentinol), 3-methyl-1-butyn-3-ol (methylbutynol), 3,5-dimethyl-1-hexyn-3-ol (dimethylhexynol) and the like are preferred.

The benzotriazole derivatives include 1,1
2,3-benzotriazole, 4-methyl-1H-benzotriazole and 5-methyl-1H-benzotriazole are preferred.

In practicing the present invention, the concentration of acetylene alcohol in the aqueous solution is generally at least 1 ppm or more. Even if it is less than 1 ppm, there is an effect, but depending on the type, shape, water quality and drying method of the metal, drying unevenness and spots may occur. Therefore, it is generally inappropriate to use a concentration exceeding 50,000 ppm for the drying unevenness / stain in consideration of handleability, economy and the like. Practically, in consideration of handling properties, economic efficiency, etc., and the type, shape, water quality, drying method, etc. of the metal to be treated, it is usually 5 ppm or more, preferably 10 to 10 ppm.
Preferably, it is kept at 1,000 ppm. In addition,
In the present invention, ppm means ppm by weight.

The concentration of the benzotriazole derivative is
0.1-50 ppm is preferred. Although effective even at less than 0.1 ppm, depending on the type, shape, water quality and drying method of the metal, drying unevenness and spots, and oxidation during long-term storage may occur. When the concentration exceeds 50 ppm, the benzotriazole derivative precipitates on the metal surface and causes drying unevenness and stains.

The treatment with an aqueous solution containing acetylene alcohol and a benzotriazole derivative is performed by means such as immersion or spraying. In the case where the number of treatment steps is multi-stage, the concentration of the other rinsing tanks is not particularly limited within the above range and is arbitrary, provided that the acetylene alcohol concentration in the final rinsing tank is at least 1 ppm.

The processing time varies depending on the type, shape, processing method and the like of the metal, and is not particularly limited. However, practically 10
~ 600 seconds is preferred. If the time is less than 10 seconds, drying unevenness and spots may occur on the product. Even if it exceeds 600 seconds, there is no problem in the processing effect itself, but it is inappropriate from the viewpoint of productivity and economy. The treatment temperature is not particularly limited, but is preferably room temperature or higher. 80 to increase drying efficiency
There is no problem in the treatment effect even if the bath is washed with water at a temperature of not less than ℃, and there is an advantage that a metal having an excellent appearance can be obtained.

The metal used in the present invention is iron,
Adhesion and pressure bonding to the surface of copper, nickel, chromium, cobalt, lead, zinc, aluminum, titanium, tin, gold, silver, etc., and their alloys, resins, glass, ceramics, etc.
The present invention can be applied to products metallized by means such as plating, vapor deposition, and ion plating. Among these metals, particularly, copper and copper alloys such as copper, brass, phosphor bronze, white bronze, and nickel silver have a remarkable effect of preventing stains and discoloration peculiar to copper.

The acetylene alcohol and the benzotriazole derivative can suppress the occurrence of uneven drying and stains in the drying step and the oxidation of the metal surface during storage after drying, even when used as an aqueous solution containing two or more acetylene alcohols. it can.

It is also effective to use a mixture of an acetylene alcohol and a benzotriazole derivative in an aqueous solution containing an alcohol, a glycol ether or the like as an additive of the third component. In the drying step, these components mainly provide an effect such as improvement of water drainage, and those having a boiling point or a decomposition temperature of 200 ° C. or less are preferable.

As the alcohol, an alcohol having about 1 to 10 carbon atoms is preferable, and particularly, methanol, ethanol, i-propanol, n-propanol, n-butanol, s-butanol, t-butanol and the like are preferable.

As the glycol ether, monoalkyl ethers or dialkyl ethers of glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol are preferable, and among these, diethylene glycol monoalkyl ether, Diethylene glycol dialkyl ether,
Dipropylene glycol monoalkyl, dipropylene glycol dialkyl ether and the like are preferred.

[0027]

By using the treating agent of the present invention as a pre-drying treating agent, it is possible to suppress the occurrence of uneven drying and stains on the metal surface even if drying is performed with the liquid attached without rinsing after the treatment. Appearance is improved, and even after storage after drying, oxidation of the metal surface can be suppressed, so that a good appearance can be maintained.

[0028]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1 A test piece (brass) is subjected to chemical polishing, deburring and brightening. Next, it is immersed in an aqueous solution containing 10 ppm dimethylhexynol and 0.5 ppm 1,2,3-benzotriazole for 60 seconds at room temperature. The test piece is pulled out of the aqueous solution, and dried with a blow dryer at 80 ° C. while a slight amount of the aqueous solution remains.

Example 2 A test piece (phosphor bronze) is chemically polished, and deburred and brightened. Then, at room temperature, 100 ppm methylbutynol and 1 ppm tolyltriazole (4-methyl-1H
-A mixture of benzotriazole and 5-methyl-1H-benzotriazole) for 90 seconds. After this is drained by air blow, it is dried with a blow dryer at 80 ° C. with some aqueous solution attached.

Example 3 A test piece (iron: SS-400) is subjected to chemical polishing, deburring and brightening. Then, at room temperature, 1,000 ppm
Methylpentinol and 5 ppm tolyltriazole (4
-Methyl-1H-benzotriazole and 5-methyl-1
(H-benzotriazole mixture) -containing aqueous solution for 30 seconds. After this is drained by air blow, it is dried with a blow dryer at 100 ° C. with some aqueous solution attached.

Example 4 After adjusting the surface of the copper-clad laminate, a water-soluble dry film was pressed, and the pattern film was overlaid and exposed. Next, development is performed with a 1% by weight aqueous solution of sodium carbonate on a continuous conveyor line to dissolve and remove the uncured portion of the dry film, thereby exposing the unnecessary portion of metallic copper. Next, the exposed metallic copper is dissolved and removed with a copper chloride etching solution, and then the dry film of the hardened portion is dissolved and removed with a 3% by weight aqueous sodium hydroxide solution. Next, a 500 ppm aqueous solution of methylpentinol and a 0.5 ppm aqueous solution of 5-methyl-1H-benzotriazole are spray-washed at room temperature for 15 seconds using a spray water washing machine. Next, the liquid is drained by a squeezing roll and an air knife, and then dried by a conveyor hot air dryer. Thus, a printed circuit board was manufactured.

Comparative Example 1 50 ppm dimethylhexynol and 0.5 ppm
The same operation as in Example 1 was performed except that the pretreatment for drying with the 2,3-benzotriazole-containing aqueous solution was not performed.

Comparative Example 2 The procedure of Example 1 was repeated, except that the pretreatment for drying with an aqueous solution containing 50 ppm dimethylhexynol was not performed.

Comparative Example 3 The procedure of Example 1 was repeated, except that the pretreatment for drying with an aqueous solution containing 0.5 ppm of 1,2,3-benzotriazole was not performed.

Comparative Example 4 The same procedure as in Example 1 was carried out except that a pretreatment for drying was carried out using an aqueous solution containing 100 ppm 1,2,3-benzotriazole instead of 0.5 ppm 1,2,3-benzotriazole.

Comparative Example 5 The procedure of Example 2 was repeated except that the pretreatment for drying with an aqueous solution containing 100 ppm of methylbutynol was not performed.

Comparative Example 6 The procedure of Example 2 was repeated except that the pretreatment for drying with an aqueous solution containing 1 ppm tolyltriazole was not performed.

Comparative Example 7 The same procedure as in Example 3 was carried out except that the pretreatment for drying with an aqueous solution containing 1,000 ppm of methylpentinol was not carried out.

Comparative Example 8 The procedure of Example 3 was repeated except that the pretreatment for drying with an aqueous solution containing 5 ppm tolyltriazole was not performed.

Comparative Example 9 The procedure of Example 4 was repeated except that the pretreatment for drying with an aqueous solution containing 500 ppm of methylbutynol was not carried out.

Comparative Example 10 The procedure of Example 4 was repeated except that the pretreatment for drying with an aqueous solution containing 0.5 ppm of 5-methyl-1H-benzotriazole was not performed.

The metal products immediately after each of the above-mentioned treatments were visually observed, and the appearance such as uneven drying and spots was evaluated on a four-point scale according to the following criteria. ：: Excellent appearance without defects such as drying unevenness and spots. 殆 ど: Very few defects in appearance such as drying unevenness and spots. △: Slight appearance defects such as drying unevenness and stains. Poor ×: Inferior appearance defects such as drying unevenness and spots are inconspicuous.

Further, the metal product after each of the above treatments was
It was stored for 24 hours under the conditions of 0 ° C. and 90% RH, and the rusting state was evaluated in four stages. ：: no rusting ○: rusting area 1 to less than 5% △: rusting area 5 to less than 20% ×: rusting area 20% or more The above results are shown in Table 1.

[0045]

[Table 1]

Claims (6)

[Claims] 1. A rust preventive for metal drainage comprising an aqueous solution containing an acetylene alcohol having 3 to 10 carbon atoms and a benzotriazole derivative represented by the general formula (1). Embedded image (Wherein R is hydrogen or a methyl group) 2. The acetylenic alcohol is 3-methyl-1-pentyn-3-ol, 3-methyl-1-butyn-3-ol or 3,5-dimethyl-1-hexyne-3.
The rust preventive for draining metal according to claim 1, which is an all. 3. The method according to claim 1, wherein the benzotriazole derivative is 1,2,2.
The draining rust inhibitor for metals according to claim 1, which is 3-benzotriazole, 4-methyl-1H-benzotriazole or 5-methyl-1H-benzotriazole. 4. An acetylene alcohol comprising at least one
The rust preventive for drainage of metals according to claim 1, which contains ppm. 5. A benzotriazole derivative in an amount of 0.1 to 5
The draining rust inhibitor for metals according to claim 1, which contains 0 ppm. 6. A method for drying a metal, comprising: treating with a metal surface treating agent or a metal cleaning agent, followed by treating with the metal draining rust inhibitor according to claim 1, and drying without washing with water. Method.