JPS6117919B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plating method for performing satin-like plating using an additive that forms an organic emulsion in a plating solution. The present invention relates to a satin-like plating method that eliminates the need to stop plating work when replenishing additives by using a plating tank and replenishing additives using an automatic replenishment system using an overflow tank.

Conventionally, the method for obtaining a satin-like nickel electrodeposit is to suspend insoluble inorganic non-conductive particles in an electrolytic nickel plating solution, and eutectoidize the particles during nickel electrodeposition, thereby adding coarseness to the nickel electrodeposit. A method of forming a surface to give a satin-like effect is known (Special Publication No. 43-405). However, this method is difficult to maintain and manage the plating solution, and when treating the plating solution with activated carbon when it is contaminated, insoluble particles must be separated before treatment. Kimono also has the problem that fingerprints are easily attached to it, and furthermore, the low current density portion of the kimono is difficult to form a matte finish. Also,
Barrel plating is difficult with this method.

On the other hand, a method of performing satin-like plating using an additive that forms an organic emulsion in a plating solution is conventionally known. In this plating method, ethylene oxide and propylene oxide compounds that form a finely dispersed emulsion at a temperature of 40 to 75°C are added to the plating solution, and the temperature of the solution is raised during plating to suspend the solution. A method of obtaining a satin-like nickel electrodeposit by plating (Special Publication No. 46-644), a method in which a cationically active or amphoteric substance is added to the plating solution together with an organic anion to contain foreign substances in the plating solution. A method has been proposed for obtaining satin-like nickel or nickel-cobalt electrodeposit (Japanese Unexamined Patent Application Publication No. 50-2093), and each method has various advantages, and the latter method in particular has various advantages. It has the advantages of being able to obtain satin-like plating in various states with excellent appearance and physical properties, requiring no special cooling or heating equipment, and being easy to manage melting. However, in such satin-like plating methods that use additives that form organic emulsions in the plating solution, the additives are consumed during plating, so the additives must be replenished at regular intervals. Each time, it is necessary to stop the plating operation, replenish the plating solution with additives, and stir it using a stirring rod or mechanically. Therefore, there is no problem when plating with a robot-type automatic machine or a manual line, but when replenishing with an elevator-type automatic machine, it is necessary to empty the hanger for several minutes and stop the machine.

The present invention has been made in view of the above circumstances, and is a method for performing satin-like plating using an additive that forms an organic emulsion in a plating solution. When the plating solution overflows from the tank into the overflow tank and the additive is replenished into the plating solution in the plating tank, the additive is mixed with the plating solution in the overflow tank and the additive is replenished. By replenishing the plating liquid in the plating tank with additives by suctioning the liquid with a pump and blowing it out from a number of blow-off holes provided in a blow-off pipe installed at the bottom of the plating tank, To provide a satin-like plating method in which additives are automatically replenished and, therefore, it is not necessary to stop the plating operation when replenishing additives.

In other words, the results of the studies conducted by the present inventors show that when the additive for forming a satin-like plating is directly added to the plating solution during the plating operation, the formation of a satin-like appearance on the object to be plated is uniform. This causes "unevenness" in the appearance of the plated product.In the circulation path where the plating solution is taken out from the plating tank and returned to the plating tank, the plating solution is removed from the bottom of the plating tank. A plating solution outlet may be provided to take out the plating solution, and additives may be replenished during the circulation route, or the plating solution may be simply dispensed into a corner of the plating tank with the replenishment solution added during the circulation route. If the product is returned for a long time, the satin-like appearance will similarly be "uneven", and therefore, with the additive replenishment method described above, continuing plating while replenishing will worsen the plating appearance and, moreover, cause the plating film to deteriorate. This also caused variations in physical properties. In contrast,
The plating solution is taken out from the plating tank using an overflow method, additives for forming matte plating are added to and mixed with the removed plating solution, and the plating solution with the additives is transferred to the lower part of the plating tank. When blowing air from the blow-off pipe installed along the bottom surface, and moreover from the many blow-off holes formed in this pipe, even if you continue the plating work while adopting this replenishment method, the matte appearance and plating physical properties will be maintained. It has been discovered that plating can be performed uniformly with almost no effect on the surface.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

The satin-like plating method according to the present invention is carried out using an additive that forms an organic emulsion in the plating solution.

In this case, as the additive, any additive can be used as long as it forms an organic emulsion in the plating solution and provides a satin-like electrodeposit. substituted or unsubstituted ethylene oxide, or propylene oxide, as formed in the electrolyte of the bath, as well as ethylene oxide-propylene oxide adduct compounds (Japanese Patent Publication No. Sho 46-
644), etc., but in particular, the method of the present invention can be suitably applied to a method that uses a cationically active or amphoteric substance together with an organic anion (Japanese Patent Application Laid-Open No. 1983-20934). For example, Pearl Bright manufactured by Uemura Kogyo Co., Ltd. can be used.

Further, the type of plating liquid used in the present invention is not particularly limited, and is appropriately selected depending on the purpose of satin-like plating. For example, an acidic electrolytic nickel plating solution with a pH of 2.5 to 6, a nickel alloy plating solution such as nickel-cobalt or nickel-iron, a cobalt plating solution, a cobalt alloy plating solution, etc. are used. In this case, the plating solution may be one having a known bath composition, such as a Watt bath, a sulfuric acid bath, a high chloride bath, or a sulfamic acid bath. Furthermore, plating temperature,
Plating conditions such as current density are not particularly limited, and appropriate conditions are adopted depending on the purpose.

The plating method of the present invention uses a plating tank with an overflow tank as the plating tank when performing satin-like plating using the above-mentioned additives, and an automatic replenishment method using the overflow tank is used to replenish the additives. It is something.

That is, to explain in more detail with reference to the drawings,
Fig. 1 shows an example of a plating apparatus used in carrying out the plating method of the present invention. A partition plate 2a between the plating tank 2 and the overflow tank 3 is formed with a low height, and the plating liquid in the plating tank 2 flows through the partition plate 2.
a, the plating solution continuously overflows into the overflow tank 3, and the plating solution is continuously taken out from the plating tank 2. In this apparatus, objects to be plated are plated in the plating tank 2.

In this device, a valve 4, a pump 5, a flow meter 6, and a valve 7 are installed on the bottom wall of the overflow tank 3.
is connected to one end of a liquid feeding pipe 8 in which liquid feeding pipes 8 are successively installed, and the other end of this liquid feeding pipe 8 is connected to a large number of air outlets arranged along the bottom surface of the plating tank 2 at the lower part of the plating tank 2. It is connected to a blowout pipe 10 having a hole 9. Note that an over-bypass 14 is formed in the liquid sending pipe 8 from the upstream side to the downstream side of the valve 4, in which a permeator 13 is interposed between the valves 11 and 12. Further, on the downstream side of the pump 5 of the liquid sending pipe 8, a bypass pipe 15 whose one end is inserted into the plating liquid in the overflow tank 3 is connected to a valve 16.
further connected via the valve 7 of the liquid sending pipe 8.
An air pipe 17 is connected to the downstream side via a valve 18. Note that 19 is a drain pipe connected to the upstream side of the pump 5 of the liquid sending pipe 8 via a valve 20. Further, 21 is an additive storage tank disposed above the plating tank 1, one end of an addition pipe 23 having a valve 22 interposed therein is connected to the additive storage tank 21, and the dripping port at the other end is connected to the additive storage tank 21. It is arranged so as to be located above the plating liquid in the overflow tank 3.

In addition, in the above device, the overflow tank 3
It is preferable that the pump has a capacity of 10 to 20% of that of the plating tank 2, and the pump 5 should be a metering pump capable of pumping 20 to 40% of the plating tank capacity per hour, or a pump with a capacity of 10 to 20% of that of the plating tank 2 should be used. using a pump with the capacity of
It is preferable to adjust the amount of liquid sent by adjusting the valve 16 and using the bypass 15. In this case, the type of pump is not particularly limited, and a type that uses a gland packing or mechanical seal can also be used, but in the present invention, it is avoided to flow the plating liquid in a state where air is involved. In this respect, sealless pumps are preferred. In addition, as the plating tank 2, for example, 500 to 2000
When using a flowmeter 6 having a capacity of 70 to 700/hr, it is preferable to use a flowmeter 6 capable of measuring 70 to 700/hr.

When replenishing the plating liquid in the plating tank 2 with additives in the above device, first adjust the valve 22 to distribute the appropriate amount of the additive in the additive storage tank 21 through the addition pipe 23. It is dripped into the plating liquid in the overflow tank 3 from the dripping port at the other end. Next, the plating liquid in the overflow tank 3 is gently stirred by the stirrer 24 to sufficiently mix the additives into the plating liquid, and the plating liquid replenished with the additives is sucked by the pump 5, and the plating liquid is suctioned by the pump 5. The plating liquid is made to flow through the liquid sending pipe 8 and blown out from the blow-off hole 9 of the blow-off pipe 10, thereby replenishing the plating liquid in the plating tank 2 with additives. In this case, valves 4 and 7 are open and valves 11 and 1
2, 16, 18, and 20 are closed. Further, it is preferable that the amount of the plating liquid sent is adjusted to 20 to 40% of the amount of plating liquid in the plating tank 2 per hour while checking with a flow meter 6.

It should be noted that plating is carried out continuously while replenishing such additives.
According to the above-mentioned replenishment method, even if plating is performed while replenishing the additive, uniform plating is achieved and the plating film is not adversely affected in any way.

In the above device, the plating liquid continuously overflows from the plating tank 2 into the overflow tank 3 and is taken out, and the plating liquid in the overflow tank 3 is continuously blown out from the blow-off hole 9, so that the plating liquid is A continuous flow of plating liquid is applied to the attached object,
Therefore, good liquid flow agitation is performed, and uniform and stable satin-like plating is performed.

In this case, in the above device, the blowout hole 9 is bored at the bottom of the blowout pipe 10, so that the plating liquid replenished with additives is blown out downward, that is, toward the bottom of the plating tank 2. The liquid then rises and is mixed with the plating solution in the plating tank 2.
The additive is uniformly dispersed in the plating liquid in the plating tank 2, and good satin-like plating is achieved. In addition,
Good satin plating can be achieved even if the blow-off hole is provided above the blow-off pipe, but it is preferable to provide the blow-off hole below the pipe from the viewpoint of uniform mixing of additives.

When the blow-off hole is provided on the lower side of the pipe, the blow-off pipe 10 is arranged so that the plating liquid blown out from the blow-off hole 9 is sprayed onto the inner bottom surface of the plating tank 2. It is preferable to arrange the liquid relatively close to the inner bottom surface, for example, at a distance of about 4 to 20% of the height from the inner bottom surface of the plating tank 2 to the liquid level, and in this way it is blown out from the blowing hole 9. By reflecting the plating liquid on the inner bottom surface of the plating tank 2 and then raising it, good satin-like plating can be achieved. Further, the inner lower end edge of the plating tank 2, at least both inner lower end edges along the length direction of the pipe 10, may be formed at an obtuse angle by arranging long plates at an angle, or rounded. Therefore, it is preferable that the plating liquid flows smoothly on these lower edges.

Although the hole diameter, number of holes, and manner of drilling of the blow-off holes 9 are not necessarily limited, it is preferable that the cross-sectional area of each blow-off hole 9 be 0.5 to 3%, particularly 0.6 to 2%, of the flow passage cross-sectional area of the pipe 10.
%, and the number of holes is such that the total cross-sectional area of all the blow-off holes 9 is equal to that of the pipe 3.
The number of holes is preferably set to 20 to 90%, particularly 25 to 75%, of the cross-sectional area of the flow path. Uniform and stable plating can be achieved by setting the diameter and number of the blow-off holes 9 within the above ranges. Furthermore, as shown in FIG. 2, the blow-off holes 9 can be formed in multiple rows (two rows in the drawing) on the left and right sides of the pipe 10, but in this case, the blow-off holes 9 on the left and right sides have approximately the same number. It is preferable that the two be equally distributed. Further, it is preferable that the blow-off holes 9 are formed at approximately equal intervals from each other.

In addition, when blowing out the plating liquid from the blowing holes 9, in order to provide a stable and sufficient flow and stirring effect, the flow rate when the plating liquid blows out from each blowing hole is set to 1 to 12 m/sec, especially 3 to 5 m/sec. /sec, discharge pressure
It is preferably 0.4 to 5 Kg/cm ² , especially 0.6 to 1.2 Kg/cm ² , and the amount of liquid pumped, the discharge head, the diameter of the blowing hole, the number of holes, and the cross-sectional area of the pipe are adjusted as appropriate ( It is preferable to achieve the above-mentioned flow rate by selecting (preferably within the above-mentioned range).

When the flask work is completed using the above device, open the valves 7, 11, 12, and 18, close the valves 4, 16, 20, and 22, and blow air from the air pipe 17 through the blowout hole 9. At the same time, the plating liquid is blown out to perform air agitation, and the pump 5 is operated to transfer the plating liquid to the overpass machine 13 of the overbypass 14.
The liquid is passed through the tank and sent to the plating tank 2 to remove additives.

In addition, in the above device, the blowout pipe 9 is
Although it is made into a book, it may be configured into a plurality of books, and a cathode rocker or the like may be used in combination for stirring.

As described above, in the above-mentioned apparatus, the plating liquid is continuously taken out from the plating tank 2 by overflow, and additives are continuously replenished to the plating liquid in the overflow tank 3. By continuously feeding the liquid to the plating tank 2 and causing the plating liquid in the upper part of the plating tank 2 to overflow, continuous plating work can be performed without stopping the plating equipment. It is possible to replenish the additive while performing this, and by continuously blowing out the plating liquid from the blowing hole 9, good liquid flow and agitation can be achieved.

Therefore, according to the satin-like plating method according to the present invention, in the method of performing satin-like plating using an additive that forms an organic emulsion in a plating solution, an overflow layer is attached to the plating tank; The plating solution is continuously overflowed from the plating tank to the overflow tank, and the additive is continuously or intermittently mixed into the plating solution in the overflow tank, and the plating solution is replenished with the additive. By sucking the additive into the plating solution in the plating tank by suctioning it with a pump and blowing it out from a number of blow-off holes provided in a blow-off pipe installed at the bottom of the plating tank, There is no need to stop the plating operation when replenishing additives, and continuous plating can be performed while replenishing continuously.The replenishment method is also simple, and the current plating line can be modified to implement this system. This can be done easily and inexpensively.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing Examples and Comparative Examples.

Examples, Comparative Examples 1 to 3 A satin-like nickel plating solution having the following composition was prepared.

Nickel sulfate hexahydrate 450 g/ Nickel chloride hexahydrate 35 g/ Boric acid 30 g/ Brightening agent Satucalin 2 g/ Butynediol 50 mg/ Additive Cetyltrimethylammonium chloride
80 mg/〃 2-ethylhexyl sulfate
50 mg/ PH 4.4 Next, using the nickel plating liquid 1000 with the above composition, apply liquid temperature 50 to 10 steel plates of 10 x 10 cm.
°C, cathode current density 5A/dm ² anode/cathode area ratio 2/
1. Satin-like plating was carried out under plating conditions with a plating time of 10 minutes. In this case, plating was performed using various plating devices shown below, and the satin-like plating finish was evaluated. Also include the results.
The evaluation criteria are as follows.

Evaluation criteria 〇: Uniform satin-like plating △: Slightly uneven ×: Unevenness Example device: Same device as shown in Fig. 1 Plating finish: 〇 Comparative example 1 Device: Same as shown in Fig. 1 In the device, the blowout pipe is not arranged along the bottom of the plating tank, but the other end of the liquid pipe is placed at one end of the lower part of the plating tank with the open part facing downward. The plating liquid is blown out from the open part at the other end.

Plating finish: × Comparative example 2 Apparatus: As shown in FIG. At the same time, one end of this liquid feeding pipe 8 is connected to the downstream side of the pump 5, and the other end of an additive pipe 23 is inserted into the additive in the additive storage tank 21, and a valve 22 and a pump 25 are successively interposed therein. Then, the plating liquid in the plating tank 2 is sucked by the pump 5 and circulated in the liquid sending pipe 8, and then
The air is blown out from the many blow-off holes 9 formed on the lower side, the valve 22 is adjusted, and the pump 25
The additives in the additive storage tank 21 are continuously supplied to the plating liquid flowing through the liquid sending pipe 8, and this plating liquid is blown out from the blow-off holes 9 arranged in large numbers on the lower side of the blow-off pipe 10. thing.

Plating finish: △ From the above results, it was confirmed that uniform satin-like plating can be obtained by the satin-like plating method of the present invention. On the other hand, if the additive is replenished during the circulation path of the plating solution without using a blow-off pipe or without using an overflow tank, unevenness will occur and a uniform satin-like plating will not be obtained. It was hot.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional front view showing an example of a plating apparatus used for carrying out the satin-like plating method of the present invention;
The figure is a cross-sectional view of the blow-off pipe of the same apparatus, and FIG. 3 is a schematic cross-sectional front view showing a plating apparatus that does not use an overflow tank and is used as a comparative example. 2...Plating tank, 3...Overflow tank, 5
...Pump, 9...Blowout hole, 10...Blowout pipe.

Claims (1)

[Claims] 1. In a method of performing satin-like plating using an additive that forms an organic emulsion in a plating solution, an overflow layer is attached to the plating tank, and the plating solution is continuously overflowed from the plating tank to the overflow tank. At the same time, the additive was continuously or intermittently replenished and mixed into the plating solution in the overflow tank, and the plating solution replenished with the additive was sucked by a pump and placed in the lower part of the plating tank. A satin-like plating method characterized in that additives are supplied to a plating solution in a plating tank by blowing them out from a large number of blow-off holes provided in a blow-out pipe.