JP2016204741A - Method for partially plating magnesium alloy member by peeling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for partially plating a magnesium alloy member by a peeling system.SOLUTION: A magnesium alloy member is provided with plating and, thereafter, a necessary plated portion is masked with a masking tape or an ink coating. An unnecessary plated portion is peeled and removed by immersing only the plating on the magnesium alloy member in a peeling liquid (hereafter, referred to as a magnesium peeling liquid). Finally, the tape or the ink coating required for masking is peeled and removed, resulting in presence of a magnesium alloy portion and a plated portion on the same member.SELECTED DRAWING: None

Description

The present invention relates to partial plating by a peeling method on a magnesium alloy member.

There are two methods for partial plating using masking.
A plating method in which masking for plating is applied to parts that do not want to be plated and other parts are plated.
A peeling method in which plating is applied to the entire surface, and then plating is masked on the portion where plating is to be left to peel off the plating.
In the case of a magnesium alloy member, for example, when performing plating after masking for plating, most of the pretreatment is performed with high-temperature strong alkalinity, so that the masking tape or ink paint is peeled off and partial plating cannot be performed. .
Next, when the entire plating is performed and then the masking is performed and the plating is peeled off, the plating stripping solution is often a strong alkali type having a high temperature, and the tape and ink paint for masking are still not provided.
If it is an acidic type stripper, the masking tape and ink paint can withstand almost all. However, magnesium is corroded and is not useful.

Since there is almost no patent literature on partial plating of magnesium alloy members, the following literature is shown as a related reference.

Related technical literature

Patent Literature

JP 2000-297386 Waiting 2014-025142

Problems to be solved by the invention

In patent document 1, it is the system which peels off all the plating on magnesium for recycling. The peeling method uses an alkaline electrolysis method.

Patent Document 2 discloses a plating and etching method using a masking solution containing paraffin.
The masking liquid containing paraffin is always kept above the melting point and loaded into the ink jet apparatus, and the masking liquid melted at about 120 ° C. is printed on the base material to form a pattern for masking.

The present invention has been made to solve a combination of a magnesium alloy member and an unknown plating, and provides a peeling type partial plating method using a general masking tape and ink paint.

Means for solving the problem

In order to solve the above problems, the present invention is characterized by a plating stripping method using the magnesium stripping solution of the present invention in which a general masking tape and ink paint can be used.

Tapes and paints that are commercially available for plating masking can be used as they are. For example, the tape is a general masking tape for plating in which an adhesive is applied on one side with polypropylene or polyethylene as a base material. For example, the ink paint is a general resist ink paint for plating of pitch type or tar type.

Examples of the types of plating that can be peeled include, but are not limited to, copper, nickel, zinc, and the like.

Effect of the invention

According to the present invention, partial plating can be performed on a magnesium alloy member.

Conventional equipment can be used without the need for special equipment or masking materials.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In addition, although target material is AZ91 and AZ31, it is not limited to this.

In the present invention, two types of plating on magnesium with good adhesion are assumed.
First, after pre-treatment, zinc substitution is performed, copper bronze plating, and if necessary, electrolytic nickel plating.
The other is to apply electroless nickel directly after pretreatment, and if necessary, combine other plating.

A masking tape is applied to a member that has been subjected to a target plating, such as copper plating or nickel plating. Alternatively, there are methods such as applying ink paint for masking with a brush or by silk printing. In addition, about the method of application | coating, it is not limited to these.
In some cases, the ink paint can be accelerated at 100 to 150 ° C. to shorten the time.

The magnesium stripping solution is preliminarily placed in an FRP tank, a stainless steel tank, or the like.
An alkaline aqueous solution containing 20 to 200 g / L of an aromatic nitro compound, 50 to 150 g / L of sodium cyanide, 5 to 10 g / L of an inhibitor, and an appropriate amount of a pH adjusting agent.
The pH is adjusted to 12 or less. 12 or more is diluted with pyrophosphoric acid diluted water, and 11 or less is diluted with sodium hydroxide diluted water. When the pH is 12 or more, a general masking tape and ink paint are likely to be peeled off during processing.

The temperature of the stripping solution is set to 20 to 50 ° C. depending on the type of plating metal to be stripped and the plating thickness. The peeling time is about 10 to 60 minutes. However, the peeling time is not limited.

The peeled member is immediately washed thoroughly with water. In the case of a tape, it is peeled off by hand while it is wet, and once washed with alkaline electrolysis or the like and dried. In the case of ink paint, it is dried as it is.

The member masked with the ink paint is peeled off with the organic solvent.
Common ones such as thinner, toluene, chlorinated solvents are sufficient.

If necessary, the surface of the magnesium alloy surface after plating peeling is adjusted.
Adjust with the following solution.
Acetic acid 200ml / L, Sodium nitrate 30g / L
Processing while checking visually at room temperature for 10-60 seconds.

Claims (6)

After the zinc substitution, copper bromide, and electrolytic nickel are plated on the entire magnesium alloy member, or the electroless nickel plating is directly applied to the entire magnesium alloy member, a portion where the plating is to be left is masked. Tape or ink paint is used as a masking material, or a combination of both. The masking tape and ink paint are characterized by general materials used for plating masking. The exposed plating surface other than the masked plating portion is dipped in a magnesium peeling solution, and only the plating is peeled off without attacking the magnesium alloy member. The stripping solution for magnesium is characterized by an alkaline aqueous solution containing 20 to 200 g / L of an aromatic nitro compound, 50 to 150 g / L of sodium cyanide, 5 to 10 g / L of an inhibitor, and an appropriate amount of a pH adjusting agent. A stripping solution for magnesium characterized by a pH of 12 or less. The stripping solution for magnesium is a stripping solution used for stripping and removing zinc, copper, nickel, or electroless nickel, which will be the base plating of the magnesium alloy member. In some cases, an oxide film, a work-affected layer, or the like is generated on the surface of the magnesium alloy after the unnecessary plating portion is peeled and removed with the stripping solution for magnesium. Surface conditioning treatment and treatment liquid to remove these.
An aqueous solution of 200 ml / L acetic acid and 30 g / L sodium nitrate is used at room temperature and has a treatment time of about 10 to 60 seconds.