JP3502393B2 - Post-processing plate and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a post-treatment of a steel plate for soldering, and relates to a post-treatment plate of a plated steel plate for improving solder wettability, aging property and corrosion resistance, and a method for manufacturing the same.

BACKGROUND ART Generally, tin-plated steel sheets, lead-tin-plated steel sheets, copper-plated steel sheets, and zinc-plated steel sheets that can be soldered have a change in the appearance of plating when exposed to the environment in which they are used,
Red rust occurs. Therefore, there is a need for a post-treatment method for a plated steel sheet that suppresses the deterioration of solderability due to the growth of an oxide film over time. In addition, in the field of recent electronic components, in order to prevent deterioration of corrosion resistance of substrates, etc., there is a tendency to reject the use of chlorine-containing, highly corrosive, active fluxes. Even in such a case, a material having excellent solder wettability is required. When using a weakly active or inactive flux that does not contain chlorine, the solder adheres to the metal substrate, but it takes a long time to evenly wet the metal substrate, resulting in poor solder wettability. Becomes more remarkable as the metal plate ages. Further, there is a need for a plated steel plate having a soldering property on one side and an electrically insulating property on the other side like a liquid crystal frame.

On the other hand, as a method of imparting electric insulation to the plated steel sheet, there is a method of coating the plated steel sheet with a film made of vinyl chloride resin, polyester resin, polypropylene resin, polyethylene resin or the like. When coating these resin films on a plated steel sheet, the plate must be heated to 180 to 250 ° C, and in this case also, if the other side of the plated steel sheet is still plated, soldering is performed. Inferior in corrosion resistance and corrosion resistance.

The present invention is excellent in solder wettability even when a flux containing no chlorine is used on one surface of a plated steel sheet, and the solder wettability does not deteriorate even after a lapse of time or by heating, and further, in corrosion resistance. To provide a post-treatment plate obtained by applying a post-treatment liquid capable of obtaining an excellent film onto one surface of a plated steel sheet, drying the same, and coating the other surface with a resin film having an electrically insulating property, and a method for producing the same. .

DISCLOSURE OF THE INVENTION The post-treatment plate of the present invention has a water-based acrylic resin having an acid value of 150 or less of 100 to 600 g / l,
1-30 g / l barium metaborate and 1-1 solubilized rosin
00g / l, and a post-treatment solution of a plated steel sheet containing 1 to 30g / l of a crosslinking agent, a dry thickness of 0.05 to 1 on one side of the plated steel sheet.
It is characterized in that it is formed by coating so as to have a thickness of 2 μm, and the other side is covered with a resin film.

The manufacturing method of the post-treatment plate of the present invention is 100-600 g / l of an aqueous acrylic resin having an acid value of 150 or less,
1-30 g / l barium metaborate and 1-1 solubilized rosin
00g / l, and a post-treatment solution of a plated steel sheet containing 1 to 30g / l of a crosslinking agent, a dry thickness of 0.05 to 1 on one side of the plated steel sheet.
It is characterized in that it is applied to have a thickness of 2 μm, dried, and the other surface is coated with a resin film.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a plated steel sheet, an acid value is a post-treatment liquid containing a water-based acrylic resin as a main component of 150 or less, a dry thickness of 0.
It is a steel sheet obtained by coating a resin film having an electric insulating property on one side of a steel sheet applied to have a thickness of 05 to 2 μm, and a manufacturing method thereof. Even if a chlorine-based flux is used, the solderability is excellent, the wettability of the solder is not deteriorated even with the passage of time or heating, and the corrosion resistance is also excellent.

  Hereinafter, the present invention will be described in more detail.

The water-based acrylic resin is a polymer or copolymer of an acrylic monomer having a carboxylic acid, and does not particularly limit a polymerization method such as aqueous solution polymerization or emulsion polymerization. However, it is important that the acid value of the water-based acrylic resin (the number of milligrams of potassium hydroxide required to neutralize the free fatty acid contained in 1 g of the resin) is 150 or less. As shown in FIG. 1, the present inventor has found that the acid value of the water-based acrylic resin has a great influence on the solder wettability, which is a particularly important characteristic in the present invention, and when the acid value exceeds 150, the solder wettability is extremely high. However, on the other hand, when it is 150 or less, the inventors have found that the solder wettability is remarkably excellent, and arrived at the present invention.

If corrosion resistance is particularly required, a rust preventive pigment must be added to the acrylic resin. But in that case,
Although the corrosion resistance is improved, there is a drawback that the solder wettability is lowered. The present inventor has found that the solder wettability is improved again by adding the water-soluble rosin to the acrylic resin. At that time, since the viscosity becomes high, it is necessary to limit the addition amount of the acrylic resin. The amount added is 100-600 g /
It is preferably l. If it is less than 100 g / l, there is no effect of improving the solderability and the corrosion resistance also decreases. On the other hand, when it exceeds 600 g / l, the effect of improving the solderability is saturated, and when mixed with water-soluble rosin, the viscosity becomes high and gelation may occur, which is not preferable.

Anti-rust pigments include ammonium chromate, sodium chromate, barium metaborate, ammonium dichromate,
Although sodium dichromate, potassium dichromate, or the like may be used, it is preferably any of ammonium chromate, sodium chromate, and barium metaborate in view of compatibility with an acrylic resin and stability. The addition amount is preferably 1 to 30 g / l. If it is less than 1 g / l, there is no effect of improving the corrosion resistance, and if it exceeds 30 g / l, the effect of improving the corrosion resistance is saturated, the solderability is remarkably lowered, and the viscosity may be increased to cause gelation.

Addition of anticorrosive pigment to acrylic resin reduces solder wettability. However, we have found that the addition of water-soluble rosin significantly improves solder wettability. The water-solubilized rosin is obtained by a method in which the carboxylic acid group in the abietic acid molecule, which is the main component of rosin, is neutralized with an amine salt or the like to obtain a rosin soap. The added amount is preferably 1 to 100 g / l. If it is less than 1 g / l, there is no effect of improving the solderability, and if it exceeds 100 g / l, the film becomes sticky and the film forming property and corrosion resistance are poor.

Further, a crosslinking agent may be added to improve solvent resistance and fingerprint resistance. Examples of the cross-linking agent include compounds containing an epoxy group, an aziridine group, a carbodiimide group, an isocyanate group, a polyvalent hydroxyl group, and an amino resin, and any of these may be used. The addition amount is 1
It is preferably ˜30 g / l. If it is less than 1 g / l, the effect of improving solvent resistance and fingerprint resistance is not obtained, and if it exceeds 30 g / l, the treatment liquid may coagulate with time.

The pH of the post-treatment liquid is suitably in the range of 3-10. When it is less than 3, the stability of the treatment liquid is poor, and when it exceeds 10, the drying property of the treatment film is poor.

The post-treatment liquid obtained as described above is applied to one side or both sides of the plated steel sheet. As a method of applying,
The immersion method, the roll coating method, the curtain flow coating method, the spray coating method and the like are not particularly limited. However, when performing double-sided coating, taking advantage of the fact that this treatment liquid is water-based, the dipping and
The method of applying by squeezing is easy and economical.

The post-treatment liquid is applied so that the film thickness after drying is 0.05 to 2 μm. The plated steel sheet coated with the post-treatment liquid is heated and dried at a temperature of 50 to 250 ° C. to evaporate the water in order to form a post-treatment film. A drying temperature of 50 to 150 ° C is sufficient if only water is evaporated, but 150 to 250 ° C
Even if it is dried at a high temperature, there is no problem in terms of characteristics. However, when the temperature exceeds 250 ° C and is dried, the temperature becomes a temperature at which the acrylic resin starts to decompose into monomers, and thus the corrosion resistance is slightly deteriorated. When the thickness of the film is less than 0.05 μm, not only sufficient solderability and anti-fingerprint property cannot be obtained, but also the corrosion resistance is significantly deteriorated. 2μ
If it exceeds m, the effect of improving the characteristics is saturated and the cost merit is lost.

The specifications of the plated steel sheet are not particularly limited. Plating having a sufficient effect can be obtained by using any method such as hot dipping or electroplating. Also, copper plating, nickel plating, tin plating, lead-tin alloy plating,
The type of plating applied on the steel sheet, such as zinc plating, alloy zinc plating, and composite zinc plating, is also selected according to the application.

When one side of the plated steel sheet is subjected to the above-mentioned post-treatment and the other side is covered with a resin film for imparting electric insulation, the resin film to be applied has a thickness of 5 to 300 μm.
Includes films of polyester, vinyl chloride, polypropylene, and polyethylene. In particular, the polyester film is particularly preferable because it has excellent electric insulation over a wide range of temperatures. If the thickness of the resin film is less than 5 μm, almost no effect can be obtained in terms of electrical insulation.
If it exceeds m, it is not preferable in terms of economy.

The method for coating the resin film on the plated steel sheet may be any known method and is not particularly limited.
The resin film may be bonded to the plated surface of the plated steel sheet via an adhesive. For example, it may contain one or more of acrylic resin, epoxy resin, nylon resin, urethane resin, vinyl resin, synthetic rubber resin, phenol resin, olefin resin, or polyester resin. . The thickness of the adhesive is 0.1-10μ in dry thickness.
A range of m is preferred. If it is less than 0.1 μm, the adhesive strength is extremely lowered, and if it exceeds 10 μm, it is not preferable in terms of economy.
The adhesive may be in any form of solution, powder, paste or film, and a resin film coated with an adhesive may be used.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

Examples and Comparative Examples Using a steel plate (plate thickness 0.5 mm) that has been annealed and temper-rolled as a plating base plate, after performing alkali degreasing and cleaning treatment by sulfuric acid pickling, electrolytic zinc plating, electrolytic zinc alloy plating, Alternatively, nickel plating is applied. Both sides or one side of these plated steel sheets are coated by a roll coating method from Table 1
After the post-treatment liquid shown in 2 was applied, it was dried at a temperature of 90 ° C. In the case of a plated steel sheet whose both surfaces were coated with the post-treatment liquid, this was used as the test material. In the case of a plated steel sheet in which the post-treatment liquid was applied to only one surface, it was further heated so that the plate temperature was 200 ° C., and a resin film was laminated on the other surface, which was used as a test material. Tables 1 to 3 show conditions for sample preparation, and Tables 4 to 6 show the evaluation results. The following items were evaluated.

1) Solder wettability: Meniscograph method (MIL-STD-883B)
SOLDERCHECKER (MODELSAT-2000, made by RHESCA)
A sample with a width of 10 mm cut out from the test material above was used as an active latex containing 0.25% chlorine (LAPIX R
A, manufactured by Nippon Handa Industry Co., Ltd.) or a weakly active flux containing no chlorine (Lapix RMA, manufactured by Nippon Handa Industry Co., Ltd.) and then held at 230 ° C (JIS Z3282: H60A)
The sample coated with the above-mentioned flux was dipped in 2 mm, the length of the solder wetted was measured, and the solder wettability was evaluated according to the following criteria. The test was carried out in two ways, immediately after the preparation of the sample and after constant temperature and humidity (60 ° C., 95% RH) for 500 hours.

◎: 3 mm or more, ○: 2 to 3 mm, △: 1 to 2 mm, ×: 1 mm or less 2) Corrosion resistance: A salt spray test was conducted for 96 hours in accordance with JIS Z 2371, and the degree of red rust was visually observed. The corrosion resistance was evaluated according to the criteria shown below.

○: No red rust was generated, △: Partial red rust was generated, ×: Red rust was generated on the entire surface 3) Fingerprint resistance: Based on JIS K2246, artificial sweat (pH: 3.3) was pressed against the surface of the post-treatment film to attach fingerprints. The degree was evaluated according to the following criteria. In addition, the post-treatment plate having a fingerprint was aged for 500 hours at a constant temperature and humidity (60 ° C., RH: 95%), the appearance was visually observed, and the degree of discoloration was evaluated according to the following criteria.

◎: No fingerprints attached, no discoloration ○: Slight fingerprints attached, slight discoloration △: Significant fingerprints attached, considerable discoloration ×: Significant fingerprint attachments, discoloration on the whole surface 4) Processing adhesion with resin film For the test material in which the post-treatment liquid was applied only on one side and the resin film was laminated on the other side, Erichsen overhang (Er = 6 mm)
Then, the processing adhesion of the resin film was evaluated according to the following criteria.

◯: No peeling, ×: Peeling As shown in Tables 4 to 6, the products according to the present invention showed good properties in terms of solder wettability and corrosion resistance.

On the other hand, as in Comparative Example, when the range of the present invention was largely deviated, the performance was poor in any of the items.

INDUSTRIAL APPLICABILITY The plated steel sheet coated with the post-treatment liquid of the present invention has excellent solder wettability even when a chlorine-free flux is used, and it is not inferior over time and also has corrosion resistance. Are better.

Furthermore, the post-treatment liquid of the present invention is applied to one side of a plated steel sheet, and the plated steel sheet coated with a resin film having electrical insulation on the other side is excellent in the above various solderability and corrosion resistance, and a resin film. Since it is also excellent in processing adhesion, it can be applied extremely advantageously to precision electronic equipment applications.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-197881 (JP, A) JP-A 61-23767 (JP, A) JP-A 9-310060 (JP, A) JP-B 6- 45902 (JP, B2) JP-B 2-48183 (JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C23C 22/00 C09K 3/00 B05D 3 / 00,7 / 14 B23K 1/20

Claims (2)

(57) [Claims] 1. A water-based acrylic resin having an acid value of 150 or less
00-600 g / l, barium metaborate 1-30 g / l, water-solubilized rosin 1-100 g / l, and cross-linking agent 1-30 g / l A post-treatment plate which is formed by coating on one side so as to have a dry thickness of 0.05 to 2 μm, and by coating the other side with a resin film. 2. A water-based acrylic resin having an acid value of 150 or less
00-600 g / l, barium metaborate 1-30 g / l, water-solubilized rosin 1-100 g / l, and cross-linking agent 1-30 g / l A method for producing a post-treatment plate, which comprises applying to one surface a dry thickness of 0.05 to 2 μm, drying and coating the other surface with a resin film.