JPH03260096A - Manufacturing method of zinc-organic polymer composite electroplated steel sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a zinc-organic polymer composite electroplated steel sheet having a zinc-based electroplated film on the surface of which organic polymer fine particles are uniformly dispersed. It relates to a method for manufacturing.

[Conventional technology]

BACKGROUND ART Zinc-organic polymer composite electroplated steel sheets are known, which have a zinc-based electroplated film on the surface of which fine particles of an organic polymer such as a fluororesin or an acrylic resin are dispersed. This composite electroplated steel sheet has excellent coating adhesion, mold releasability, and corrosion resistance.

Excellent wear resistance, etc.

The above-mentioned composite electroplated steel sheet is produced by electroplating using a zinc-based acidic electroplating solution containing organic polymer fine particles and using the steel sheet as a cathode to coat zinc in which organic polymer fine particles are dispersed on the surface of the steel sheet. It can be manufactured by forming a plating film.

[Problem to be solved by the invention]

However, it is not easy to uniformly disperse organic polymer particles in a zinc-based electroplating film. In other words, it is difficult to uniformly disperse organic polymer particles in a zinc-based electroplating film. By electroplating alone, the organic polymer particles are negatively charged and are therefore difficult to deposit on the surface of the steel sheet.

JP-A-61-143591 discloses that a zinc-based acidic electroplating solution containing silica particles is used to electroplate a steel plate as a cathode to form a zinc-silica composite electroplated film on the surface of the steel plate. In order to improve the precipitation of silica particles, a cationic surfactant is added to the electroplating solution, the silica particles are covered with this surfactant, the silica particles are positively charged, and the silica particles are deposited on the surface of the steel sheet. A method for facilitating precipitation is disclosed.

However, it is difficult to apply this method of adding a surfactant to a plating solution to the precipitation of fine particles of various organic polymers because it is difficult to select a suitable surfactant.

Therefore, an object of the present invention is to solve the above-mentioned problems and apply organic polymers 8& When forming a zinc-based plating film in which particles are dispersed, a zinc-organic polymer that improves the precipitation of organic polymer fine particles and has a zinc-based electroplated film on the surface of which organic polymer fine particles are uniformly dispersed. An object of the present invention is to provide a method for manufacturing a molecular composite electroplated steel sheet.

[Means for Solving Problem R] The present inventors have conducted extensive research in order to solve the above-mentioned problems and develop a method for improving the precipitation of organic polymer fine particles on the surface of a steel sheet. Ta.

As a result, the present inventors obtained the following findings. In other words, if the surface of the plating film on which the organic polymer particles are deposited is smooth, the organic polymer particles that come close to the surface of the plating film will be separated by stirring of the plating solution without being embedded in the plating film. Therefore, if fine irregularities are formed in the plating film, the organic polymer fine particles are embedded in the recesses of the plating film, and therefore the precipitation of the organic polymer fine particles can be improved.

This invention was made based on the above findings, and
It consists of forming a zinc-based plating film in which organic polymer fine particles are dispersed on the surface of the steel plate by electroplating using a zinc-based acidic electroplating solution containing organic polymer fine particles and using a steel plate as a cathode. , in the method for producing a zinc-organic polymer composite electroplated steel sheet, in the electroplating solution, together with the organic polymer fine particles,
It is characterized in that it contains a water-soluble aromatic compound and performs electroplating using such an acidic electroplating solution.

In this invention, when a water-soluble aromatic compound is added to a zinc-based acidic electroplating solution containing organic polymer fine particles, fine irregularities are formed on the surface of the plating film. As a result, the organic polymer fine particles are embedded in the recesses of the plating film. Therefore, even when the plating solution is stirred, the organic polymer particles become difficult to separate from the surface of the plating film.
Therefore, precipitation of organic polymer fine particles onto the plating film is improved.

Examples of water-soluble aromatic compounds include nicotinic acid, nicotinamide, henzamide, and sodium benzoate.

Pyridine, ethoxylated-α-naphtholsulfonic acid, etc. are used.

The preferable content of the water-soluble aromatic compound is 0.1 to Lo
g/f. If it is less than 0.1 g/1, the above-mentioned effect cannot be obtained, while if it exceeds 10 g/l, there will be no recesses on the surface, causing a problem that the eutectoid rate of the organic polymer fine particles will decrease.

As the basic galvanizing bath, a conventional sulfuric acid bath, a chlorination bath, or a mixed bath of both can be used. Or conductivity supplements to these basic baths.

The galvanizing bath may contain brighteners, etc.
It is not limited to pure zinc, and may be made of zinc alloys such as zinc-iron, zinc-copal, and zinc-nickel.

Next, the present invention will be explained using examples and comparing with comparative examples.

〔Example〕

A normal zinc-based acidic electroplating solution was used as a basic bath, and organic polymer fine particles and a water-soluble aromatic compound were added to this basic bath to prepare a zinc-based acidic electroplating solution. Using the zinc-based acidic electroplating solution prepared in this way and using a cold-rolled steel sheet as a cathode, the following method C of the present invention shown in Table 1 is carried out.
A zinc-based electroplated film in which organic polymer fine particles were dispersed was formed on the surface of a cold-rolled steel sheet by electroplating according to Nllll-6 (referred to as "method of the present invention").

For comparison, a zinc-based acidic electroplating solution containing organic polymer fine particles to which no water-soluble aromatic compound was added was used, which is outside the scope of this invention. According to the method Nα1 shown in Table 1 (hereinafter referred to as "comparative method"),
A zinc-based electroplated film in which organic polymer fine particles were dispersed was formed on the surface of a cold-rolled steel sheet.

Table 1 shows the types of organic polymer fine particles and water-soluble aromatic compounds, and the matrix metal content in the method of the present invention and the comparative method described above.

As is clear from Table 1, such as the precipitation rate of organic polymer fine particles and the properties of the plated film, the rate of precipitation into the plated film in the case of the comparative method NcLl using a plating solution to which no water-soluble aromatic compound was added. The precipitation rate of organic polymer fine particles was Qvol, χ, whereas the present invention method 11k11 using a plating solution to which a water-soluble aromatic compound was added
In the case of ~6, the precipitation rate of organic polymer fine particles into the plating film is lO~40vol. It has improved to X.

〔Effect of the invention〕

As described above, according to the present invention, organic polymer fine particles are dispersed on the surface of the steel sheet by electroplating using a zinc-based acidic electroplating solution containing organic polymer fine particles and using the steel sheet as a cathode. When forming a zinc-based plating film, the precipitation of organic polymer fine particles is significantly improved. Therefore, it is possible to easily produce a zinc-organic polymer composite electroplated steel sheet having a zinc-based electroplated film on the surface of which organic polymer fine particles are uniformly dispersed, which is an industrially useful effect. It will be done.

Claims (1)

[Scope of Claims] 1. A zinc-based electroplating solution in which organic polymer fine particles are dispersed on the surface of the steel plate by electroplating using a zinc-based acidic electroplating solution containing organic polymer fine particles and using a steel plate as a cathode. In a method for manufacturing a zinc-organic polymer composite electroplated steel sheet, which comprises forming a plating film, in the electroplating solution, together with the organic polymer fine particles,
A method for producing a zinc-organic polymer composite electroplated steel sheet, which comprises containing a water-soluble aromatic compound and performing electroplating using such an acidic electroplating solution.