JPH0987653A - Water-soluble cutting oil solution for aluminum having discoloration preventing character and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-soluble aluminum cutting oil solution capable of perfectly inhibiting the corrosion and discoloration of aluminum even if the water-soluble cutting oil solution remians on the surface of the machine processed aluminum and its production method. SOLUTION: This water-soluble cutting oil solution having aluminum discoloration preventing character constituted of a water-soluble cutting oil solution containing copper ion, is charged in an electrolytic bath having a pair of electrodes in which at least the positive pole is made from copper. The electric power is supplied between the poles to generate copper ion and the copper ion is allowed to elute into the water-soluble cutting oil solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum discoloration-preventing water-soluble cutting fluid and a method for producing the same.

[0002]

2. Description of the Related Art When aluminum products are machined by machine tools, a large amount of water-soluble cutting fluid that has both a lubricating action and a cooling action is used.

The water-soluble cutting fluid can be classified into the following three types in terms of appearance.

[0004] Milky emulsion type. Semi-transparent solver type. Transparent solution type Among these, water-soluble cutting oil agents of translucent solvel type with milky white emulsion type are oil (mineral oil or synthetic oil), fatty acid, extreme pressure additive, inorganic alkaline compound, surfactant, anticorrosive agent. Made of preservatives, etc.

Transparent solution type water-soluble cutting fluids for these are amine compounds, inorganic builders,
It consists of organic builders, surfactants, anticorrosives, preservatives, etc.

As described above, the water-soluble cutting fluid contains a corrosion inhibitor and an antiseptic agent, but since it essentially contains a large amount of water that causes corrosion, there is a great concern that it will corrode the machined metal. It was

Especially when the machined metal is aluminum,
If left with the water-soluble cutting oil attached, it will turn black and cause corrosion failure.

For this reason, it is necessary to thoroughly wash and remove the water-soluble cutting oil agent adhering to the surface of the aluminum member to which the water-soluble cutting oil agent has adhered, after the completion of machining. As a result, there is a drawback that the machining efficiency of aluminum is reduced. In this case, if the washing time is shortened, discoloration defects frequently occur.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its object is to solve the above-mentioned drawbacks of the prior art and to use aluminum as a water-soluble cutting fluid. An aluminum discoloration-preventing water-soluble cutting oil capable of completely suppressing corrosion and discoloration even if a water-soluble cutting oil remains on a machined aluminum surface when machined, and a method for producing the same. .

[0010]

The gist of the present invention lies in the following two points.

[0011] An aluminum discoloration-preventing water-soluble cutting oil, characterized in that the water-soluble cutting oil contains copper ions.

[0012] After putting a water-soluble cutting fluid in an electrolytic cell in which a pair of electrodes, at least the anodes of which are made of copper, are installed, electricity is applied between the pair of electrodes to generate copper ions and the copper ions are water-soluble. A method for producing a water-soluble cutting fluid for aluminum discoloration prevention, which comprises eluting into a cutting fluid.

That is, the aluminum discoloration-preventing water-soluble cutting fluid produced by the above-mentioned method surprisingly can completely suppress the oxidation of aluminum by the trace amount of copper ions, and as a result, even if the machined aluminum surface is processed. Even if the water-soluble cutting oil remains in, the corrosion and discoloration can be completely suppressed.

In the present invention, the amount of copper ions contained in the aluminum discoloration-preventing water-soluble cutting fluid is preferably 20 ppm or more from the viewpoint of discoloration prevention.

Aluminum discoloration preventive property The discoloration preventive action of the water-soluble cutting fluid is effective not only for aluminum but also for aluminum alloys.

In the method for producing the aluminum discoloration-preventing water-soluble cutting fluid according to the present invention, it is essential that at least the anode side of the pair of electrodes is a copper electrode, but the cathode side is preferably a copper electrode if possible.

Further, in the method for producing the aluminum discoloration-preventing water-soluble cutting fluid of the present invention, the conduction current may be either direct current or alternating current.

Furthermore, in the method for producing a water-soluble cutting fluid for aluminum discoloration prevention according to the present invention, it is desirable that the inside of the electrolytic cell is vigorously stirred and ultrasonic waves are applied.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the aluminum discoloration-preventing water-soluble cutting fluid of the present invention and a method for producing the same will be described.

(One Example of Method for Producing Aluminum Discoloration-Preventing Water-Soluble Cutting Oil of the Present Invention) First, one example of the method for producing the aluminum discoloration-preventing water-soluble cutting oil of the present invention will be described.

FIG. 1 is a partial cross-sectional explanatory view showing an embodiment of a method for producing an aluminum discoloration-preventing water-soluble cutting fluid according to the present invention.

In FIG. 1, 1 is an electrolytic bath, 2 is a water-soluble cutting fluid, 3 is a pair of copper electrodes, 4 is an ultrasonic vibrator, 5 is a power supply device, and 6 is an ultrasonic transmitter.

First, a pair of copper electrodes 3 and 3 are placed in the electrolytic cell 1.
Are separated by 2 cm.

Next, a 2% 5% solution 2 of KT-100, a water-soluble cutting fluid manufactured by Kyodo Yushi Co., Ltd., is placed in an electrolytic cell 1 in which a pair of copper electrodes 3 and 3 are installed at a distance of 2 cm.

Next, the ultrasonic transmitter 6 is turned on to generate ultrasonic waves, and the water-soluble cutting oil KT-1 in the electrolytic bath 1 is generated.
The ultrasonic wave is applied to the 2.5% liquid 2 of the water-soluble cutting fluid KT-100 via the ultrasonic vibrator 4 contained in the 2.5% liquid 2 of 00.

Next, a direct current is applied to the anode current density of 1 A / dm.
^It was electrolyzed so as to be ² and electrolyzed until the copper ion became 400 ppm.

Thus, a stock solution of the aluminum discoloration-preventing water-soluble cutting fluid of the present invention containing 400 ppm of copper ions was obtained.

Next, examples of the water-soluble cutting oil of the comparative example and the aluminum discoloration-preventing water-soluble cutting oil of the present invention will be described.

(Comparative Example 1) In Comparative Example 1, 2.5% of KT-100 which is a water-soluble cutting fluid manufactured by Kyodo Yushi Co., Ltd. which does not electrolyze
It is a liquid.

Comparative Example 2 Water-soluble cutting fluid of Comparative Example 3 because copper sulfate was added to a 2.5% solution of KT-100, a water-soluble cutting fluid of Kyodo Yushi Co. Got

Comparative Example 3 Water-soluble cutting oil of Comparative Example 4 because copper sulfate was added to a 2.5% solution of KT-100, a water-soluble cutting oil manufactured by Kyodo Yushi Co., Ltd. that does not electrolyze, and copper ion was 101 ppm. Got (Comparative Example 4) KT-100, a water-soluble cutting fluid manufactured by Kyodo Yushi Co., Ltd., was prepared by taking a calculated amount of a stock solution of the aluminum discoloration-preventing water-soluble cutting fluid of the present invention having a copper ion content of 400 ppm obtained above and then not electrolyzing. To obtain a water-soluble cutting oil of Comparative Example 2 containing 10 ppm of copper ions.

(Example 1 of aluminum discoloration-preventing water-soluble cutting fluid) Similarly, the copper ion obtained above was 400 ppm.
The calculated amount of the undiluted solution of the aluminum discoloration-preventing water-soluble cutting fluid of the present invention is taken, and then diluted with a 2.5% solution of the water-soluble cutting fluid KT-100 of Kyodo Yushi Co. 20 ppm of the aluminum tarnish-preventing water-soluble cutting fluid of Example 1 was obtained.

(Example 2 of aluminum discoloration-preventing water-soluble cutting fluid) Similarly, the copper ion obtained above was 400 ppm.
The calculated amount of the undiluted solution of the aluminum discoloration-preventing water-soluble cutting fluid of the present invention is taken, and then diluted with a 2.5% solution of the water-soluble cutting fluid KT-100 of Kyodo Yushi Co. An aluminum discoloration-preventing water-soluble cutting fluid of Example 2 of 100 ppm was obtained.

(Discoloration Test) Next, regarding the water-soluble cutting fluids of Comparative Example 1 and Comparative Example 2 thus obtained and the water-soluble cutting fluids of Examples 1 and 2 which have anti-tarnish properties, A color change experiment was conducted.

(Preparation of Processed Aluminum) A plurality of aluminum plates were prepared, and the surfaces thereof were polished with emery paper having a roughness of 1000, immersed in a cleaning agent, and then ultrasonically cleaned.

(Discoloration Test Method and Results) Next, one of each of these aluminum plates obtained above was used as the water-soluble cutting fluid of Comparative Examples 1 to 4 and the aluminum discoloration-preventive water solution of Examples 1 and 2. It was immersed in a water-soluble cutting fluid and left for 3 months.

For the evaluation, the discoloration resistance and the appearance change of the surface were observed.

The discoloration resistance is indicated by x when the color changed to black, and by o when there was no discoloration.

The visual inspection was based on the observation of the surface condition by SEM and the degree of oxygen detection by EDS.

Table 1 shows the results of these tests.

[0041]

[Table 1]

FIG. 2 shows the results of appearance measurement by EDS of an aluminum plate immersed in a water-soluble cutting oil of Comparative Example 4 for 3 months in an aluminum discoloration-preventing water-soluble cutting oil.

As can be seen from Table 1, an aluminum plate immersed in a water-soluble cutting fluid of Comparative Example 1 having an electrolytic copper ion concentration of 0 ppm for 3 months, and a water-soluble cutting fluid of Comparative Example 2 having a copper sulfate ion of 20 ppm in a water-soluble cutting fluid for 3 months. 4 of the aluminum plate, the aluminum plate immersed in 100 ppm of copper sulfate ion water-soluble cutting fluid of Comparative Example 3 for 3 months, and the aluminum plate of Comparative Example 4 immersed in water-soluble cutting fluid agent of 10 ppm electrolytic copper ion concentration for 3 months The workers turned black and oxygen was detected on their surfaces respectively.

On the other hand, an aluminum plate which was immersed in an aluminum discoloration-preventing water-soluble cutting oil having an electrolytic copper ion concentration of 20 ppm in Example 1 for 3 months and an aluminum discoloration-preventing water-soluble agent having an electrolytic copper ion concentration of 100 ppm in Example 2 were used. Two of the aluminum plates immersed in cutting fluid for 3 months showed no discoloration and no oxygen was detected at all. As described above, the aluminum discoloration-preventing water-soluble cutting fluid containing electrolytic copper ions of 20 ppm or more of the present invention does not corrode aluminum, and as a result, discoloration does not occur even when aluminum is dipped.

[0045]

The aluminum discoloration-preventing, water-soluble cutting fluid containing electrolytic copper ions obtained by the method for producing an aluminum discoloration-preventing, water-soluble cutting fluid of the present invention does not corrode aluminum and consequently adheres to the aluminum surface. However, it does not cause discoloration of aluminum and is industrially useful.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional explanatory view showing an example of a method for producing an aluminum discoloration-preventing water-soluble cutting fluid according to the present invention.

FIG. 2 is a result of EDS appearance measurement of an aluminum plate immersed in a water-soluble cutting oil for aluminum discoloration prevention of a water-soluble cutting oil of Comparative Example 4 for 3 months.

[Explanation of symbols]

 1 Electrolyzer 2 Water-soluble cutting oil 3 Copper electrode 4 Ultrasonic vibrator 5 Power supply device 6 Ultrasonic transmitter

Claims (4)

[Claims] 1. An aluminum discoloration-preventing water-soluble cutting oil, characterized in that the water-soluble cutting oil contains copper ions. 2. The aluminum discoloration-preventing water-soluble cutting fluid according to claim 1, wherein the amount of copper ion added is 20 ppm or more. 3. A water-soluble cutting fluid is placed in an electrolytic cell in which a pair of electrodes, at least an anode of which is made of copper, is installed, and then a current is applied between the pair of electrodes to generate copper ions and the copper A process for producing an aluminum discoloration-preventing water-soluble cutting oil, characterized in that ions are eluted into the water-soluble cutting oil. 4. The method for producing an aluminum discoloration-preventing water-soluble cutting fluid according to claim 3, wherein ultrasonic waves are applied while stirring the inside of the electrolytic cell.