JP2000160375A - Method and pretreating agent for drying metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the unevenness of drying and the occurrence of stains and to obtain a clean metallic surface by treating a metal after surface treatment with an aq. soln. contg. an acetylene alcohol and an alkyl alcohol each having specified carbon atoms. SOLUTION: This pretreating agent is prepd. by using an aq. soln. contg., preferably, a 3-10C acetylene alcohol by 1 to 10,000 wt.ppm and a 1-7C alkyl alcohol by 10 to 60 wt.%. In the process of various metallic surface treatment and metallic cleaning, prior to drying after rinsing by water, a metal is treated by using this treating agent before drying. Or, treating also serving as washing by water is executed by using an aq. soln. obtd. by adding the treating agent before drying to the water for rinsing by water, and, after that, the metal is dried. It is desirable that the time for the treatment before the drying is practically controlled to 10 to 600 sec. As a metal to be subjected to the pretreatment, iron, copper, nickel, chromium, cobalt, lead, zinc, aluminum, titanium, tin, gold, sliver and the alloys thereof are cited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-drying agent for preventing uneven drying and spots in the field of aqueous metal surface treatment and aqueous metal cleaning.

[0002]

2. Description of the Related Art Conventionally, in the field of water-based metal surface treatment and metal cleaning, as a method for preventing metal oxidation in a drying step for preventing drying unevenness and spots, a draining substitution method using a solvent, a vacuum drying method, a nitrogen drying method, Drying in atmosphere, etc. However, the vacuum drying method requires high equipment cost and low work efficiency, and also requires high equipment cost for drying in a nitrogen atmosphere. Further, since a large amount of nitrogen is used, the cost increases. The method is applied to the case of a special product, and generally, the drainage displacement method using a solvent is industrially adopted.

[0003] In many cases, drying when water is adhered,
Discoloration due to oxidation of the metal surface occurs, reducing product value.
For this reason, in the draining replacement method using a solvent, after rinsing (final finish) water washing, treatment with Freon or a chlorine-based solvent is performed to replace and remove water on the metal surface. However, since the used fluorocarbon or chlorinated solvent causes environmental destruction, their use has been regulated worldwide, and there is a strong demand for alternative technologies.

[0004]

DISCLOSURE OF THE INVENTION The present invention prevents drying unevenness and spots by using a chlorine-based solvent that causes environmental destruction and having the same drying property and liquid permeability as a chlorine-based solvent. And at the same time, to provide a dry pretreatment agent for the metal to obtain a clean metal surface.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a pretreatment agent for drying metal, and as a result, have been found to have 3 to 3 carbon atoms.
By treating with a drying pretreatment agent, which is an aqueous solution containing 10 acetylene alcohols and alkyl alcohols having 1 to 7 carbon atoms, even when drying with some water attached, metal oxidation in the drying step is prevented, Drying unevenness,
It has been found that the occurrence of spots is suppressed and a clean metal surface is obtained, and the present invention has been achieved.

That is, the present invention relates to (A) a method comprising:
0 acetylene alcohol 1 to 10,000 weight pp
m, (B) an alkyl alcohol having 1 to 7 carbon atoms 10 to 10
The present invention relates to a pretreatment agent for drying which is an aqueous solution containing 60% by weight.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The metals used in the present invention include iron, copper, nickel, chromium, cobalt, lead, zinc,
It is applicable to aluminum, titanium, tin, gold, silver, and the like, and alloys of these obtained by grinding / cutting, die casting, and sintering. Further, the present invention can also be applied to a resin, glass, ceramics or the like which is metalized by means such as adhesion, pressure bonding, plating, vapor deposition, or ion plating.

The aqueous metal surface treatment process used in the present invention includes electroless plating, electroplating, anodic oxidation,
Pickling, alkali cleaning, chemical polishing, electrolytic polishing, mechanical polishing, metal coloring, etching, chemical conversion, and other processes are included. Examples of aqueous metal cleaning processes include degreasing, acid cleaning,
Processes such as alkali cleaning and electrolytic cleaning are exemplified.

In these various metal surface treatment and metal cleaning processes, the metal is treated with the drying pretreatment agent of the present invention prior to drying after rinsing with water, or the drying pretreatment of the present invention is added to the rinsing water. The metal is dried after a treatment that also serves as water washing with an aqueous solution to which the agent has been added.

The acetylene alcohol used in the present invention preferably has a boiling point or decomposition temperature of 200 ° C. or less. When the boiling point or the decomposition temperature exceeds 200 ° C., the effect of preventing metal oxidation is high, but the components of the drying pretreatment agent adhere to the dried metal surface, causing drying unevenness and spots, and at the same time clean the metal surface. It becomes difficult to obtain. If the drying temperature is increased, this defect can be prevented, but it is not preferable from the viewpoint of handleability and economy.

Specifically, it is an acetylene alcohol having 3 to 10 carbon atoms, preferably 1-propyn-3-ol, 1-butyn-3-ol, 1-butyn-4-ol, 2-butyn-ol. 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-nonine-3
-Ol, 1-decyn-3-ol, 2-butyne-1,
4-diol, 3-hexyne-2,5-diol, 3,
5-dimethyl-3-hexyne-2,5-diol, 4-
Ethyl-1-octin-3-ol. More preferably, 3-methyl-1-pentyn-3-ol (methylpentinol), 3-methyl-1-butyn-3-ol (methylbutinol), 3,5-dimethyl-1-hexyne-3-ol All (dimethylhexynol).

The alkyl alcohol used in the present invention is an alcohol having 1 to 7 carbon atoms, preferably, methanol, ethanol, i-propanol, n-propanol, n-butanol, s-butanol, i-butanol, t-tanol. Butanol, and more preferably methanol, ethanol and i-propanol.

In the pretreatment agent for drying of the present invention, the concentration of acetylene alcohol in the aqueous solution is from 1 to 10,000 ppm by weight, preferably from 1 to 1,000 ppm by weight.
m, and more preferably from 10 to 100 ppm by weight. If the concentration is less than 1 ppm by weight, the effect of drainage and antioxidation is hardly observed, and 10,000 weight pp.
If it exceeds m, a residue may be generated after drying.

The concentration of the alkyl alcohol is from 10 to 60.
%, Preferably 20 to 60% by weight, more preferably 30 to 60% by weight. The alcohol concentration is
High concentration is desirable, but if it is more than 60% by weight, it becomes dangerous.
Explosion-proof equipment for ignition and explosion is required, and the equipment cost is high.

The pre-drying time depends on the type, shape,
There is no particular limitation depending on the processing method and the like. However, practically, 10 to 600 seconds is preferable. If the time is less than 10 seconds, drying unevenness and spots may occur on the product. 60
If the time exceeds 0 second, there is no problem in the processing effect itself, but it causes a problem in terms of productivity and economy. The treatment temperature is not particularly limited, but is preferably room temperature or higher. In order to increase the drying efficiency, there is no problem in the processing effect even if the water is washed at 80 ° C or higher.
Rather, there is an advantage that a metal having an excellent appearance can be obtained.

[0016]

EXAMPLES The present invention will be specifically described below, but it should not be construed that the invention is limited thereto. In addition, ppm is weight ppm and% is weight%.

Example 1 A bearing component (made of SS400) was chemically polished, deburred and brightened, and then washed with water. Next, immersion treatment was performed at room temperature for 60 seconds using an aqueous solution to which an aqueous solution containing 50 ppm of methylpentinol and 50% of methanol was added.
It was dried in a box-shaped drier at ℃.

Example 2 Instead of using an aqueous solution containing methylpentinol and methanol, 1-propyn-3-ol (100 pp) was used.
m and ethanol 50% were used in the same manner as in Example 1.

Example 3 Instead of using an aqueous solution containing methylpentinol and methanol, 3-methyl-1-butyn-3-ol 2
Except that 00 ppm and 50% n-propanol were used.
Performed in the same manner as in Example 1.

Example 4 A test piece (brass) was subjected to chemical polishing, deburring and brightening treatment. Then, at room temperature, dimethylhexynol 1000
The sample was immersed in an aqueous solution containing 20% by mass of methanol and 30 ppm for 30 seconds, and dried with a box-shaped dryer at 100 ° C.

Example 5 Instead of using an aqueous solution containing dimethylhexynol and methanol, 1-heptin-3-ol 10 pp
m, and 30% of ethanol were used in the same manner as in Example 4.

Example 6 Instead of using an aqueous solution containing dimethylhexynol and methanol, 1-hexyn-3-ol 2500p
Example 4 except that pm, n-butanol 40% was used.
The same was done.

Example 7 A molded substrate having a component mounting recess was obtained by injection molding using a liquid crystal polymer (Vectra C-820 manufactured by Polyplastics Co., Ltd.) containing an inorganic filler. Electroless plating was applied to the entire surface of the molded product. Next, a plating resist pattern was formed using an electrodeposition type photoresist. A circuit pattern was formed on the obtained substrate by applying a bright nickel plating of 10 to 30 μm, followed by gold strike plating, and then 0.3 μm by gold plating for wire bonding. Thereafter, the plating resist and the electroless copper plating of the non-circuit portion were removed from the substrate. Lastly, ultrasonic cleaning was performed at room temperature for 30 seconds with an aqueous solution containing 20 ppm of dimethylhexynol and 60% of i-propanol, and dried with a hot air dryer at 70 ° C.

Comparative Example 1 The procedure of Example 1 was repeated, except that the pretreatment for drying was performed with an aqueous solution containing only 50 ppm of methylpentinol.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the pretreatment for drying was carried out with an aqueous solution containing only 50% of methanol.

Comparative Example 3 The same procedure as in Example 4 was carried out except that the pretreatment for drying was performed with an aqueous solution containing only 1000 ppm of dimethylhexynol.

Comparative Example 4 The procedure of Example 4 was repeated, except that the pretreatment for drying was performed with an aqueous solution containing only 20% of methanol.

Comparative Example 5 The same procedure as in Example 7 was carried out except that the pretreatment for drying was carried out with an aqueous solution containing only 20 ppm of dimethylhexynol.

Comparative Example 6 The same procedure as in Example 7 was carried out except that the pretreatment for drying was performed with an aqueous solution containing only 60% of i-propanol.

The surface tension of the above various pretreatment liquids for drying, the time required for the treated metal product to dry, and the dried metal product are visually observed. Was evaluated. Table 1 shows the results. ◎ No appearance defects such as drying unevenness and spots and very excellent. ○ Very few appearance defects such as drying unevenness and spots. × Inferior appearance defects such as drying unevenness and spots

[0031]

The metal dried product according to the method of the present invention has excellent drying properties and liquid permeability as well as the product dried by the drainage replacement method using a chlorofluorocarbon or chlorine-based solvent, and the metal surface is clean after drying. Good appearance without drying unevenness and spots can be obtained.
Therefore, there is no need to use chlorofluorocarbon or a chlorinated solvent that destroys the environment.

[0032]

[Table 1]

Claims (4)

[Claims] (1) 1 to 10,000 ppm by weight of acetylene alcohol having 3 to 10 carbon atoms;
7. A dry pretreatment agent, which is an aqueous solution, comprising 10 to 60% by weight of the alkyl alcohol of 7. 2. The method according to claim 1, wherein the acetylene alcohol is 3-methyl-
1-pentyn-3-ol, 3-methyl-1-butyne-
3-ol and 3,5-dimethyl-1-hexyne-3-
The drying pretreatment agent according to claim 1, which is at least one selected from all. 3. The pretreatment agent according to claim 1, wherein the alkyl alcohol is at least one selected from methanol, ethanol, n-propanol and i-propanol. 4. After treating with a metal surface treating agent or a metal cleaning agent, and then with the drying pretreatment agent according to claim 1,
A method for drying metal, comprising drying without washing with water.