JPS5848037B2 - Dodenchayakuseihinoseizouhouhou - Google Patents

Description

Detailed Description of the Invention The present invention manufactures a product having a copper plating layer suitable for extremely high-precision engraving, such as mechanically engraving the copper plating surface of a cylinder plate body surface to produce a gravure printing plate. Regarding how to.

Conventionally, many techniques have been reported for improving the hardness and smoothness of a plated surface by adding additives such as brighteners and hardening agents to a copper plating solution.

Examples of curing agents include thiourea, penzotriazole,
These include gelatin and Rothsiel's salt.

However, copper plating layers produced by plating baths containing these additives have many variations in hardness among individual electrodeposited products and are not stable, and may also have extremely high hardness.

In addition, the material is relatively brittle and easily breaks, making it unsuitable for machining.

Furthermore, even if an attempt is made to obtain a plated product with appropriate hardness under extremely severe conditions, extremely large local variations in hardness may occur over a wide area of the plated surface, resulting in problems with reproducibility and the like.

In general, conventional methods have not been able to stably produce copper electrodeposit suitable for mechanical processing such as high-precision engraving and cutting.

The present invention solves the drawbacks of the prior art as described above and is a method for obtaining a product having a copper plating layer suitable for mechanical processing. Specifically, the present invention uses thiourea and alkaloids as additives in an acidic copper plating bath. The purpose is to add in an appropriate amount and ratio.

It is known that thiourea has a large effect on the hardness of copper electrodeposit, but by adding alkaloids together with thiourea to the acid plating bath, copper electrodeposit can be made suitable for high-precision machining. Obtainable.

In other words, when thiourea is used alone at a concentration of 7.6 to 30 μ/l, the hardness of the resulting copper plating layer is unstable, and this instability can be corrected by adding one or more alkaloids. By adding them together, it is possible to stabilize the bath by widening the range of addition, and stably obtain an appropriate hardness suitable for high-precision machining, for example, a hardness in a narrow range of 160 to 180 HV (Vickers hardness). The purpose is to eliminate the brittleness of the plating layer and obtain a copper electrodeposit that does not generate paris during engraving or cutting.

Specific examples of the alkaloids used here are basic nitrogen-containing compounds such as berberine, efuedrine, nicotine, lobeline, and atropine, which are added in extremely small amounts of 15 to 31n9 per liter of plating bath. It has a remarkable effect.

If a copper plating bath containing thiourea and alkaloids is used while being continuously energized, the additives will be consumed, and the Vickers hardness of the electrodeposited material will gradually decrease from 220 Hv to 120 Hv, but individual electrolyte The hardness of the clothed product is such that a stable value without variation can be obtained with respect to the amount of current applied.

On the other hand, the amount of additive consumed relative to the amount of current applied to the plating bath can be known quantitatively, and the change in the hardness of the electrodeposited material relative to the amount of current applied can also be known empirically.

Therefore, by externally supplementing the consumption of additives due to the use of a plating bath, it is possible to obtain copper electrodeposited products with constant hardness.

Comparative examples and examples of the present invention will be described below.

[Comparative example]

Copper sulfate 2201/l and sulfuric acid 60/l as acidic copper plating bath
A plating solution with a concentration of &/l was used, and thiourea was added as an additive to this bath at a rate of 25'Tn9/l.

Copper electrodeposition with a thickness of 100 μm was performed on a copper plate at a current density of 10 A7 dm″, and the hardness was 220 Hv.

When plating is repeated in the same way in the same bath, the initial value is 21.
An electrodeposited material was obtained with a hardness range of 0±10 Hv, but as plating was performed several times, the hardness rapidly decreased to 160 Hv.
Hv, and as the process progressed further, local variations in hardness were observed.

Furthermore, the copper electrodeposited layer thus obtained was relatively brittle and unsuitable for high precision machining.

[Example 1] Thiourea and lobeline were added as additives to an acidic copper plating solution having the same composition as the comparative example at 15 μ/l and 5 1 n9, respectively.
/ 7 to form a plating bath.
The plate cylinder was electrodeposited with copper approximately 100 microns thick.

The change in hardness of the copper electrodeposited surface with respect to the amount of current applied is as shown in the graph of FIG.

From this graph, the change in hardness with respect to the amount of current applied can be determined empirically.

As the amount of current applied increases, that is, as the plating bath is used, the additives are consumed and the hardness gradually decreases, but the variation in hardness of the copper electrodeposit obtained at each amount of current applied is ±10Hv.
It did not exceed the range of , and was extremely stable.

Furthermore, there is no local variation in hardness on the same copper electrodeposited surface, resulting in high quality and good reproducibility.

In addition, the electrodeposited material has good gloss and has a hardness of 220 Hv to 120 Hv, and has relatively little brittleness, making it suitable for machining.

[Example 2] Thiourea and ephedrin were added as additives to an acidic copper plating solution having the same composition as in the comparative example at 151 n9/l and 3 n/l, respectively.
■ Add to make a plating bath at a concentration of 10
130 to the plate cylinder at a current density of "A/dm"
Copper plating with a thickness of μ was performed.

The surface of the obtained electrodeposited copper plating was semi-glossy and smooth, and the surface hardness was 170 Hv on the Vickers hardness.

Even if this copper electrodeposition product is left at room temperature for several weeks, no change in hardness due to deterioration is observed and it is stable.

Further, the electrodeposited copper foil has relatively low brittleness and can withstand two 180° bending tests.

This copper-plated cylinder plate was precisely engraved using an edge ocrysiograph to obtain a gravure cylinder printing plate.

In order to reproducibly obtain the hardness and quality of copper electrodeposited products,
Additives consumed by energization of the plating bath were managed and replenished by the amount of energization.

That is, in this example, thiourea was used at 0.01 cm and ephedrin at 0.
．． By replenishing 002■, a copper electrodeposited product of consistently high quality and suitable for high precision machining was obtained.

[Example 3] Copper sulfate 220g/13 and sulfuric acid 6 as acidic copper plating bath
Using a plating solution with a concentration of 0 g/l, thiourea and berberine were added as additives to this bath to give a concentration of 15 g/l, #1, and 10 g/l, respectively, to prepare a plating bath. 100 to the plate cylinder at a current density of dd
Copper electrodeposition with a thickness of μ was performed.

The surface of the obtained copper electrodeposit is a pale pink copper color, and unlike the copper electrodeposit from a bath containing only thiourea, the surface does not turn blackish brown, but is semi-glossy and smooth, and the surface hardness is 18
It was 0Hv.

Even when this copper electrodeposited product was left at room temperature for several weeks, no change in hardness was observed over time.

Furthermore, when the copper electrodeposition layer was peeled off and the brittleness of the foil was examined, it was found that it could withstand a 180° bending test three times.

The copper-plated cylinder plate thus obtained was suitable for highly mechanical precision engraving.

[Example 4] A plating bath was prepared by adding thiourea and nicotine sulfate as additives to an acidic copper plating solution having the same composition as the comparative example so that the concentrations were 15Tn9/l and 15Tn/l, respectively.
Approximately 100 μ thick copper electrodeposition was performed on the plate cylinder at a current density of 0 A/dm.

The surface of the obtained electrodeposited copper plating was semi-glossy and smooth, and the surface hardness was 160 Hv on the Vickers hardness. In order to reproducibly obtain the hardness of copper electrodeposited products, the additives consumed by energizing the plating bath were The agent was replenished by controlling the amount of current applied.

That is, in this example, thiourea was 0.01 cm and nicotine sulfate was 0.
．． By replenishing 01■, a copper electrodeposited product of consistently high quality and suitable for high precision machining was obtained.

[Example 5] Thiourea and atropine sulfate were added as additives to an acidic copper plating solution having the same composition as in the comparative example at 15 μ/l and 5 μl/l, respectively.
■ Add them together to make a plating bath to a concentration of /l,
IOA/di so that the plate cylinder has a thickness of about 100μ
Copper plating was performed at a current density of .

The surface of the obtained electrodeposited copper plating was semi-glossy and smooth, and the surface hardness was 180 Hv.

Even if this copper electrodeposition product is left at room temperature for several weeks, no change in hardness is observed over time, and it is stable.

Furthermore, when the copper electrodeposition layer was peeled off and the brittleness of the foil was examined, it was found that it could withstand a 180° bending test three times.

As mentioned above, the hardness of copper electrodeposited products obtained by a copper plating bath using a combination of thiourea and alkaloids is extremely stable, and due to this stability, the hardness ranges from 220Hv to 1.
A desired value of hardness can be obtained over a range up to 20 Hv.

Moreover, even though it has moderately high hardness, it is not relatively brittle.
The present invention is extremely excellent in that it is suitable for manufacturing electroformed foil and is also suitable for mechanical processing such as engraving and cutting.

[Brief explanation of drawings]

FIG. 1 is a graph showing the change in hardness with respect to the amount of current applied to the plating bath in Example 1.

Claims (1)

[Claims] 1. To an acidic copper plating bath to which 7.6 to 3Q1 ng/g of thiourea was added as an additive, an alkaloid selected from berberine, ephedrine, nicotine, lobeline, and atropine was added at a rate of 15 to 15 per liter of the plating bath. A method for producing copper electrodeposited products suitable for high-precision machining by plating copper in an acidic plating bath containing 3m9.