JP2000160376A - 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 in a metal and to obtain a clean metallic surface by treating a metallic surface after surface treatment by using an aq. soln. contg. a hydroxylemine compd. having a specified compsn. and an alkyl alcohol. SOLUTION: This pretreating agent is prepd. with an aq. soln. contg. 10 to 10,000 wt.ppm hydroxylamine compsn. expressed by the formula and 10 to 60 wt.% 1-7C alkyl alcohol. In the formula, R1, R2 and R3 denote hydrogen, an alkyl group, an alkenyl group, an alkanol group or a cycloalkyl group. It is preferable that 1 to 1,000 ppm 3-10C acetylene alcohol is moreover incorporated into this treating agent. In the process of various metallic surface treatments and metallic cleaning treatments, prior to drying after rinsing by water, the metal is treated with an aq. soln. contg. the treating agent before drying or is subjected to treatment serving also as washing by using water with an aq. soln. obtd. by adding the treating agent before drying to the water for rinsing by using water, and after that, the metal is dried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

As an alternative technique, Japanese Patent Laid-Open No. 9-5319 is disclosed.
No. 4 discloses a drying pretreatment agent containing a hydroxylamine compound, and JP-A-9-302325 discloses a drying pretreatment agent containing a hydroxylamine compound and acetylene alcohol. -8
No. 278 discloses a drying pretreatment agent containing acetylene alcohol.

[0005]

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.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies on a metal pre-drying agent, and as a result, have found that a pre-drying agent comprising an aqueous solution containing a hydroxylamine compound and an alkyl alcohol, more preferably an acetylene alcohol. The present invention finds that even when drying with a certain amount of water adhered, metal oxidation in the drying step can be prevented, drying unevenness and generation of spots can be suppressed, and a clean metal surface can be obtained. Reached.

That is, the present invention provides: (A) a hydroxylamine compound represented by the following formula (1): 10 to 10,000 ppm by weight;

Embedded image (Wherein R1, R2, and R3 are hydrogen, an alkyl group, an alkenyl group, an alkanol group, or a cycloalkyl group), and (B) 10 to 60% by weight of an alkyl alcohol having 1 to 7 carbon atoms. And a pretreatment agent for drying, which is an aqueous solution. More preferably, (C) carbon number 3
The present invention relates to a dry pretreatment agent containing 1 to 10,000 weight ppm of acetylene alcohol.

[0008]

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 those obtained by grinding, cutting, die-casting, and sintering these alloys. Alternatively, the present invention can be applied to a product which is metallized on a surface of resin, glass, ceramics, or the like by means of bonding, pressure bonding, plating, vapor deposition, ion plating, or the like.

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, after rinsing water, the metal is treated with an aqueous solution containing a pre-drying agent prior to drying, or the metal is rinsed with water for rinsing. The metal is dried after performing a treatment also serving as water washing with the added aqueous solution.

The boiling point or decomposition temperature of the hydroxylamine compound, alkyl alcohol and acetylene alcohol of the present invention is preferably 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.

As the hydroxylamine compound of the present invention, R1, R2, and R3 in the formula are preferably hydrogen, an alkyl group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, and an alkanol having 1 to 4 carbon atoms. Or a cycloalkyl group. In addition, these groups may have a substituent. Specifically, hydroxylamine, O-methylhydroxylamine, O-ethylhydroxylamine, N-methylhydroxylamine, N, N-dimethylhydroxylamine, N, O-dimethylhydroxylamine, N-ethylhydroxylamine, N, N-diethylhydroxylamine, N, O-diethylhydroxylamine, O,
N, N-trimethylhydroxylamine, N- (2-methoxyethyl) hydroxylamine, N-allylhydroxylamine, N, O-diallylhydroxylamine,
O-cyclohexyl-N, N-dimethylhydroxylamine and the like. More preferred are hydroxylamine and N, N-diethylhydroxylamine.

The alkyl alcohol of 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-butanol. Butanol, and more preferably methanol, ethanol and i-propanol.

The acetylene alcohol of the present invention includes
It is an acetylenic alcohol having 3 to 10 carbon atoms, preferably 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-hexyne-
3-ol, 1-heptin-3-ol, 1-octin-3-ol, 1-nonin-3-ol, 1-decyne-
3-ol, 2-butyne-1,4-diol, 3-hexyne-2,5-diol, 3,5-dimethyl-3-hexyne-2,5-diol, 4-ethyl-1-octyne-
3-ol. More preferably, 3-methyl-1
-Pentin-3-ol (methylpentinol), 3-
Methyl-1-butyn-3-ol (methylbutynol) and 3,5-dimethyl-1-hexyn-3-ol (dimethylhexynol).

The concentration of the hydroxylamine compound of the present invention is 10 to 10,000 ppm by weight. 10 weight pp
If it is less than m, drying unevenness and spots may occur depending on the type, shape, water quality, drying method and the like of the metal. Also, 1
If it exceeds 000 ppm by weight, it is unsuitable in terms of handleability, economy and the like.

The concentration of the alkyl alcohol of the present invention is 1
0 to 60% by weight, preferably 20 to 60% by weight,
More preferably, it is 30 to 60% by weight. The alcohol concentration is desirably high, but if it is 60% by weight or more, it becomes a dangerous substance, and explosion-proof equipment for ignition and explosion is required, and the equipment cost becomes high.

The concentration of the acetylene alcohol of the present invention is:
1 to 10,000 ppm by weight, preferably 1 to
1,000 ppm by weight, more preferably 10 to 10 ppm by weight.
100 ppm by weight. When the concentration is less than 1 ppm by weight, the effect of drainage and antioxidation is hardly observed, and
If it exceeds 10,000 ppm by weight, a residue may be generated after drying.

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.

[0019]

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 containing 500 ppm of hydroxylamine and 50% of methanol, followed by drying in a box-type drier at 80 ° C.

Example 2 500 ppm of hydroxylamine, 100 ppm of N-methylhydroxylamine instead of 50% of methanol,
Example 1 was repeated except that an aqueous solution containing 50% of ethanol was used.

Example 3 A test piece (iron-nickel alloy) was subjected to chemical polishing, deburring and brightening. Then, at room temperature, N, N-dimethylhydroxylamine 10,000 ppm, methanol 2
Immersion treatment in an aqueous solution containing 0% for 30 seconds,
It dried with the box-shaped dryer of ° C.

Example 4 N, N-dimethylhydroxylamine 10,000 pp
m, and the same procedure as in Example 3 except that an aqueous solution containing 5000 ppm of N-ethylhydroxylamine and 40% of n-propanol was used instead of 20% of methanol.

Example 5 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 is 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 using an aqueous solution containing 100 ppm of hydroxylamine and 60% of i-propanol, and dried with a hot-air dryer at 70 ° C.

Example 6 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 500 ppm of hydroxylamine, 50% of methanol, and 50 ppm of methylpentinol was added, followed by drying in a box dryer at 80 ° C.

Example 7 A test piece (iron-nickel alloy) was chemically polished, deburred and brightened. Then, at room temperature, N, N-dimethylhydroxylamine 10,000 ppm, methanol 2
30% with an aqueous solution containing 0% methylbutynol 50ppm
It was immersed for 2 seconds and dried in a 100 ° C. box dryer.

Example 8 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 is 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. Finally, ultrasonic cleaning was performed at room temperature for 30 seconds with an aqueous solution containing 100 ppm of hydroxylamine, 60% of i-propanol, and 20 ppm of dimethylhexynol, 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 500 ppm of hydroxylamine.

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

Comparative Example 3 N, N-dimethylhydroxylamine 1
Except that it was performed in an aqueous solution containing only 000 ppm
Performed in the same manner as in Example 3.

Comparative Example 4 The procedure of Example 3 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 5 was carried out except that the pretreatment for drying was performed with an aqueous solution containing only 100 ppm of hydroxylamine.

Comparative Example 6 The procedure of Example 5 was repeated, except that the pretreatment for drying was carried out with an aqueous solution containing 60% of i-propanol.

Comparative Example 7 Hydroxylamine 500 ppm, methanol 50%,
Example 6 was repeated except that an aqueous solution containing 500 ppm of hydroxylamine, 1000 ppm of methanol and 30 ppm of methylpentinol was used instead of 50 ppm of methylpentinol.

Comparative Example 8 N-dimethylhydroxylamine 500 ppm, methanol 50%, methylbutynol 50 ppm
-Performed in the same manner as in Example 7 except that an aqueous solution containing 500 ppm of dimethylhydroxylamine, 5000 ppm of methanol, and 50 ppm of methylbutynol was used.

Comparative Example 9 100 ppm of hydroxylamine, i-propanol 6
0%, hydroxylamine 500 ppm instead of methylpentinol 20 ppm, i-propanol 3000
Example 8 was carried out except that an aqueous solution containing 10 ppm of dimethylhexynol and 10 ppm of dimethylhexynol was used.

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

[0038]

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.

[0039]

[Table 1]

Claims (6)

[Claims] (A) A hydroxylamine compound represented by the following formula (1): 10 to 10,000 ppm by weight (Wherein R1, R2, and R3 are hydrogen, an alkyl group, an alkenyl group, an alkanol group, or a cycloalkyl group), and (B) 10 to 60% by weight of an alkyl alcohol having 1 to 7 carbon atoms. A drying pretreatment agent, which is an aqueous solution. 2. The dry pretreatment agent according to claim 1, which further comprises (C) 1 to 10,000 ppm by weight of acetylene alcohol having 3 to 10 carbon atoms. 3. The dry pretreatment agent according to claim 1, wherein the hydroxylamine compound is hydroxylamine or N, N-diethylhydroxylamine. 4. The drying pretreatment agent according to claim 1, wherein the alkyl alcohol is at least one selected from methanol, ethanol, n-propanol and i-propanol. 5. The method of claim 1, wherein the acetylene alcohol is 3-methyl-
1-pentyn-3-ol, 3-methyl-1-butyne-
The dry pretreatment agent according to claim 1, which is at least one selected from 3-ol and 3,5-dimethyl-1-hexyn-3-ol. 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 drying pretreatment agent according to claim 1 or 2, followed by drying without washing with water. .