WO1998012362A1

WO1998012362A1 - Post-treating solution of plated steel sheet having improved solderability, post-treated plate and method of production thereof

Info

Publication number: WO1998012362A1
Application number: PCT/JP1997/003313
Authority: WO
Inventors: Masahiro Kai; Jun-Ichi Fujimoto; Masanori Yoshikawa; Yoshiyuki Sugimoto
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1996-09-20
Filing date: 1997-09-19
Publication date: 1998-03-26
Also published as: JP3502393B2; AU4319097A

Abstract

A post-treating solution which has high solder wettability and, moreover, excellent corrosion resistance, even when a flux not containing a chlorine is used. This invention provides also a post-treating method using this solution, a post-treated plate obtained by applying this post-treating solution and a production method thereof. This post-treating solution, containing 100 to 600 g/1 of an aqueous type acrylic resin having an acid value of not higher than 150, 1 to 30 g/1 of a rust-proofing pigment, 1 to 100 g/1 of a water-solubilized rosin and/or 1 to 30 g/1 of a cross-linking agent, is applied so that a dry thickness is 0.05 to 2 νm.

Description

Specification

Post-treatment liquid of plated steel sheet for improving solderability, post-treatment plate and method for producing the same

TECHNICAL FIELD The present invention relates to post-treatment of a steel sheet for solder, and relates to a post-treatment liquid, a post-treatment plate, and a method for producing the same, which improve the wettability, aging, and corrosion resistance of solder. Background art

In general, tinned steel, lead-tinned steel, copper-plated steel, and zinc-plated steel that can be soldered change their appearance when exposed to the environment in which they are used, and are red.锖 occurs. Therefore, there is a need for a post-treatment method for a plated steel sheet to suppress a decrease in solderability due to the growth of an oxide film over time. In the field of recent electronic components, the use of highly corrosive, active fluxes containing chlorine tends to be refused in order to prevent the deterioration of corrosion resistance of substrates and the like. Even when used, a material with excellent solder wettability is required. If a weakly active or inactive flux that does not contain chlorine is used, the solder will adhere to the metal substrate, but it will take a long time to uniformly wet the metal substrate, and the solder will have poor wettability. The tendency becomes remarkable as the metal plate increases over time. Further, there is a need for a plated steel sheet having a soldering property on one side and an electrical insulating property on the other side, such as a liquid crystal frame. On the other hand, as a method of imparting electrical insulation to a plated steel sheet, there is a method in which a film made of a vinyl chloride resin, a polyester resin, a polypropylene resin, a polyethylene resin, or the like is coated on the steel sheet. When these resin films are coated on a plated steel sheet, 180 to 250. The sheet must be heated to C. Even in this case, if the other side of the plated steel sheet is still plated, solderability and corrosion resistance are poor.

The present invention has excellent solder wettability even when a flux containing no chlorine is used on one side of a plated steel sheet, and the wettability of the solder does not deteriorate over time or even when heated. A post-treatment liquid capable of obtaining a film having excellent corrosion resistance, a post-treatment plate obtained by applying the post-treatment liquid to a plating steel plate and drying the plate, and a method for producing the post-treatment plate; It is intended to provide a post-treated plate in which this post-treatment liquid is applied to one side of a plating steel sheet, dried, and the other side is coated with a resin film having electrical insulation, and a method for producing the same. Disclosure of the invention

The present invention provides a post-treatment liquid for a plated steel sheet comprising an aqueous acryl resin having an acid value of 150 or less, or

A post-treatment solution for a coated steel sheet containing 100 to 600 g of an aqueous acryl resin having an acid value of 150 or less, 1 to 30 g of a water-proof pigment, and 1 to 100 1 of a water-soluble rosin.

100-600 g of water-based acrylic resin with acid value of 150 or less, l-30 g / l of water-resistant pigment, water-soluble rosin :! ~ 100 gZ and a post-treatment liquid for a plated steel sheet containing 1-30 g / 1 of a crosslinking agent.

The anti-reflective pigment is characterized in that it is any one of ammonium chromate, sodium chromate, and barium metaborate.

The present invention also provides a post-treated plate obtained by applying the above-mentioned post-treatment solution to a plated steel sheet so that the dry thickness is 0.05 to 2 m.

Further, the present invention provides a post-treated plate in which one side of a plated steel sheet is coated with the above-mentioned post-treatment liquid so that the dry thickness becomes 0.05 to 2 μm, and the other side is coated with a resin film. Is also an object of the invention.

• Still further, the present invention also relates to a method for manufacturing a post-treated plate, characterized in that the above-mentioned post-treatment liquid is applied to a plated steel sheet so as to have a dry thickness of 0.05 to 2 m and dried. I do.

Further, in the present invention, it is preferable that the above-mentioned post-treatment liquid is applied to one side of the plated steel sheet so as to have a dry thickness of 0.05 to 2 and dried, and then the other side is coated with a resin film. A method of manufacturing a post-processed plate characterized by the above is also an object of the invention. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the acid value of the aqueous acryl resin contained in the post-treatment liquid of the present invention and the solder wetting. It is a figure which shows the relationship with sex. BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, a post-treatment liquid containing an aqueous acryl resin having an acid value of 150 or less as a main component is applied to a plated steel sheet so as to have a dry thickness of 0.05 to 2 m and dried. And a method of manufacturing the same, and a steel sheet in which one side of a plated steel sheet is subjected to the above-mentioned post-treatment and the other side is coated with a resin film having electrical insulating properties, and a method of manufacturing the same. The treated plated steel sheet has excellent solderability even when chlorine-free flux is used, does not deteriorate the solder wettability even after aging or heating, and also has excellent corrosion resistance.

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

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

When corrosion resistance is particularly required, an anti-pigment pigment must be added to the acrylic resin. However, in this case, although corrosion resistance is improved, there is a disadvantage that solder wettability is reduced. The present inventors have found that the addition of a water-soluble rosin to an acrylic resin improves solder wettability again. At that time, since the viscosity increases, it is necessary to limit the amount of the acrylic resin to be added. The added amount is preferably from 100 to 600 g Z1. If it is less than 100 g Zl, there is no effect of improving the solderability and the corrosion resistance is reduced. On the other hand, when the amount exceeds 600 g Zl, the effect of improving the solderability is saturated, and when mixed with a water-soluble resin, the viscosity increases, and gelation may occur, which is not preferable.

Waterproof pigments include ammonium chromate, sodium chromate, and barium metaborate , Ammonium dichromate, sodium dichromate, potassium dichromate, etc. It is preferably one of barium. The added amount is preferably 1 to 30 g / 1. If it is less than 1 g1, there is no effect of improving the corrosion resistance, and if it exceeds 3 Og, the effect of improving the corrosion resistance is saturated, the solderability is remarkably reduced, the viscosity is increased, and gelation may occur. • Addition of anti-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 mouth gin is obtained by a method of neutralizing the sulfonic acid group in the abietic acid molecule, which is a main component of the mouth gin, with an amine salt or the like to obtain rosin stone. The added amount is preferably 1 to 100 g Z1. If it is less than 1 g / 1, there is no effect of improving the solderability, and if it exceeds 100 g Z1, the film becomes sticky and the film formability and corrosion resistance are poor.

Further, a crosslinking agent may be added in order to improve solvent resistance and fingerprint resistance. Examples of the cross-linking agent include an epoxy group, an aziridine group, a carbodiimide group, an isocyanate group, a compound containing a polyvalent hydroxyl group, and an amino resin, and any of them may be used. The addition amount is preferably from 1 to 30 g / 1. If it is less than 1 g / 1, there is no effect of improving the solvent resistance and fingerprint resistance, and if it exceeds 30 g Z1, the processing solution may solidify over time.

The pH of the post-treatment solution is suitably in the range of 3 to 10. If it is less than 3, the stability of the treatment liquid is poor, and if it exceeds 10, the drying property of the treated film is poor.

The post-treatment liquid obtained as described above is applied to one or both sides of a steel sheet. The application method is not particularly limited, such as an immersion method, a roll coating method, a curtain flow coating method, and a spray coating method. However, when performing double-sided coating, it is easy and economical to apply immersion and squeezing in the subsequent process of the continuous plating line, taking advantage of the fact that the treatment liquid is aqueous.

The post-treatment liquid is applied so that the film thickness after drying is 0.05 to 2 m. The coated steel sheet to which the post-treatment solution is applied is heated and dried at a temperature of 50 to 250 ° C. to evaporate moisture in order to form a post-treatment film. As for the drying temperature, 50 to 15 CTC is sufficient if it is only necessary to evaporate the water. However, drying at a high temperature of 150 to 250 C There is no problem in sex. However, when the temperature exceeds 250 ° C, the temperature at which the acrylic resin starts to decompose into monomers is reached, and the corrosion resistance is slightly inferior. If the thickness of the film is less than 0.05 ^ m, not only sufficient solderability and fingerprint resistance cannot be obtained, but also corrosion resistance is remarkably poor. If the thickness exceeds 2 m, the effect of improving the characteristics is saturated and the cost advantage is lost.

The specifications of the plated steel sheet are not particularly limited. Either method, such as hot-dip plating or electric plating, can provide a plating having a sufficient effect. In addition, the type of plating applied to the steel sheet, such as copper plating, nickel plating, tin plating, lead-tin alloy plating, zinc plating, alloy zinc plating, and composite zinc plating, is also selected according to the application. You.

When one side of a plated steel sheet is subjected to the above post-treatment and the other side is coated with a resin film to provide electrical insulation, the applicable resin film may be polyester having a thickness of 5 to 300 m, Includes films made of vinyl chloride, polypropylene, and polyethylene. In particular, a polyester film is particularly preferable because it has excellent electrical insulation properties over a wide range of temperatures. If the thickness of the resin film is less than 5 m, little effect is obtained in terms of electrical insulation, and if it exceeds 300 m, it is not preferable in terms of economy.

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

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

Examples and comparative examples

An annealed and temper rolled steel sheet (sheet thickness 0.5 mm) is used as After performing degreasing and cleaning treatment by sulfuric acid pickling, electro-zinc plating, electro-zinc alloy plating, or nickel plating was performed. The post-treatment liquids shown in Tables 1 and 2 were applied to both sides or one side of these plated steel sheets by a roll coating method, and dried at 90 temperatures. In the case of a plated steel sheet coated with a post-treatment solution on both sides, this was used as the test material. In the case of a plated steel sheet having only one side coated with a post-treatment liquid, the steel sheet was further heated to a sheet temperature of 200 ° C., and a resin film was laminated on the other side to obtain a test material. Tables 1 to 3 show the conditions for sample preparation, and Tables 4 to 6 show the evaluation results. The evaluation was performed for the following items.

1) Solder wettability:

Using a meniscograph method (MI L-STD-883B), S ODERCHE CKER (MODEL SAT-2000, manufactured by RHE SCA) was used. % Solder flux (Lapix RA, manufactured by Nippon Handa Kogyo) or a weak active flux containing no chlorine (Lapix RMA, manufactured by Nippon Handa Kogyo), and then held at 230 ° C in a solder bath (JISZ 3282: A sample in which the above flux was applied to H60A) was immersed in 2 mm, the length of the solder wetted was measured, and the solder wettability was evaluated based on the following criteria. The test was performed in two ways: immediately after sample preparation and after 500 hours of aging at constant temperature and humidity (60 ° C, 95% RH).

◎: 3 mm or more, 〇: 2-3 mm, △: 1-2 mm ^ X: 1 mm or less 2) Corrosion resistance:

A salt spray test was conducted for 96 hours in accordance with JIS Z 2371, and the occurrence of redness was visually observed, and the corrosion resistance was evaluated based on the following criteria.

〇: No red 発生, Δ: Partially red 、, X: Red に generated over the entire surface

3) Fingerprint resistance:

Based on JISK 2246, artificial sweat (pH: 3.3) was pressed onto the surface of the post-treatment film, and the degree of fingerprint attachment was evaluated according to the following criteria. In addition, the appearance of the post-processed plate with fingerprints after 500 hours of aging at constant temperature and humidity (60 ° (:, RH: 95%)) was visually observed, and the degree of discoloration was evaluated according to the following criteria. .

◎: No fingerprint attached, no discoloration 〇: Slight fingerprint attached, slightly discolored

Δ: Significant fingerprint adhered, discolored considerably

X: Fingerprint adhesion remarkable, discoloration over the entire surface

4) Processing adhesion with resin film

For the test material in which the post-treatment liquid was applied to only one side and the resin film was laminated on the other side, Ericksen overhang (Er = 6 mm) was performed, and the processing adhesion of the resin film was evaluated as follows. Evaluation was based on criteria.

〇: No peeling

X: Peeling

As shown in Tables 4 to 6, those according to the present invention exhibited good properties in terms of solder wettability and corrosion resistance. On the other hand, as in the case of the comparative example, when the range greatly deviated from the scope of the present invention, the performance was inferior in any of the items. Post-treatment conditions (Part 1) Treatment solution composition (g, l) Acrylic skin resin

Cloth Resin film Film number Acrylic water-soluble Cross-linking preventive pigment surface Acid value Thickness Thickness resin Resin resin mm

1 1000 Both 65 1.0 None

2 100 1 Sodium B-borate 1 Both 54 0.05 None

3 600 75 Lithium metaborate 30 Cars 75 2.0 None

4 300 15 Nummonic acid 10 Cars 150 0.5 None None 5 300 100 Harium metaborate 5 Cars 100 0.5 None Example 6 400 15 1 Harium metaborate 5 Cars 83 1.0 None

7 400 15 30 Sodium chromate 10 Both 83 1.0 None

8 400 15 10 Sodium chromate 10 Both 83 2.0 None

9 400 30 5 Sodium chromate 10 Both 65 1.0 None Table 2 Post-treatment conditions (Part 2)

Note) PET: polyethylene phthalate, ΡΡ: rif Dk ren, PE: polyethylene

Table 3 Post-treatment conditions (part 3)

Section p3¾ Treatment solution composition (g c) Acrylic leather Resin cloth Resin film Film number Acrylic water-soluble water-proof pigment Surface acid value Thickness thickness Resin resin βm μm

1 1000 ―

Both 160 1.0 None

2 400 15 30 Sodium chromate 10 Both 83 0.02 None Ratio 3 300 100 15 Hadium helium metaborate 5 Both 160 0.5 None

4 300 0.5 15 Λ'lium metaborate 5 Both 100 1.5 None

5 300 120 15 Halium metaborate 5 Cars 100 1,5 None Compare

6 90 50 5 Metaborate / lium 5 Both 100 0.5 None

7 700 50 10 Chromate ammonium 5 both 100 0.5 None Example 8 300 50 10 Sodium chromate 0.5 Both 100 0.5 None

9 300 50 10 Sodium chromate 40 Both 100 1.0 None

10 300 50 40 Sodium chromate 10 Both 100 1.0 None

Table 4 t (i-equivalent results (part 1)

Ward <Haneda wettability

Material Resin film Flux: RA Flux: RMA Corrosion resistance Fingerprint resistance

Immediately after aging Immediately after aging

1 ◎ ◎ ◎ 〇 Δ 〇 No parity

2 ◎ ◎ 〇〇〇せ Not evaluated

3 ◎ ◎ ® ◎ 〇 C Not evaluated

4 ◎ ◎ ◎ ◎ 〇〇 g No parity provided 5 ◎ ◎ ◎ ◎ 〇せ Not rated

7 ◎ ◎ ◎ ◎ ◎ Not evaluated

8 ◎ ◎ ◎ 〇 ® Not evaluated

9 ◎ ◎ ◎ ◎ 〇 ◎ Not evaluated

Table 5 Evaluation Results (Part 2) Ward Haneda

teiT] says No Nolem No. Flux: RA Flux: RMA Corrosion resistance Fingerprint resistance

Immediately after aging Immediately after aging

10 ◎ ◎ ◎ ◎ 〇〇〇

11 ◎ ◎ ◎ ◎ 〇〇〇

12 ◎ ◎ ◎ 〇 ◎ 〇施

13 ◎ ◎ ◎ ◎ 〇 ◎ 例 Example

14 ◎ ◎ ◎ ◎ 〇〇〇

15 ◎ ◎ ◎ ◎ ◎ 〇 Table 6 Evaluation Results (Part 3)

Mouth

Minute processing adhesion immediately after aging immediately after aging

1 Δ X X X Δ せ Not evaluated

2 Δ X X X X X Not evaluated Ratio 3 〇 Δ Δ X 〇 ◎ Not evaluated

4 Δ X X X 〇 ◎ Not evaluated

6 ◎ 〇〇 △ X ◎ Not evaluated

7 Processing solution gelled, not evaluated due to coating failure

Example 8 ◎ ◎ ◎ ◎ X ◎ Not evaluated

9 〇 Δ Δ X ◎ ◎ Not evaluated

10 Not evaluated because treatment liquid gels and coating is impossible Industrial applicability

The plated steel sheet coated with the post-treatment liquid of the present invention has excellent solder wettability even when a flux containing no chlorine is used, which is not inferior even with time, and also excellent in corrosion resistance. Further, the post-treatment liquid of the present invention is applied to one side of a plated steel sheet, and the other side is coated with a resin film having electrical insulation properties. The coated steel sheet has excellent solderability and corrosion resistance of the above-described various types. Also, since it is excellent in processing adhesion of a resin film, it can be very advantageously applied to precision electronic equipment.

Claims

The scope of the claims

1. A post-treatment solution for plated steel sheets containing an aqueous acryl resin with an acid value of 150 or less.

2. Post-treatment of a plated steel plate containing 100 to 600 gZ1 of aqueous acrylic resin with an acid value of 150 or less, 1 to 30 gZ1 of protective pigment, and 1 to 100 gZ1 of water-soluble gin liquid.

3. Contains 100 to 600 1, water-based acrylic resin with acid value of 150 or less, 1 to 30 g of protective pigment, 1 to 100 1 of water-soluble rosin, and 1 to 30 gZ1 of crosslinking agent. Post-treatment liquid for coated steel sheets.

4. The post-treatment liquid according to claim 2, wherein the pigment is any one of ammonium chromate, sodium chromate, and barium metaborate.

5. A post-treatment plate obtained by applying the post-treatment solution according to any one of claims 1 to 4 to a plated steel sheet so that the dry thickness is 0.05 to 2 j «m.

6. Coating the post-treatment liquid according to any one of claims 1 to 4 on one side of the plated steel sheet so that the dry thickness becomes 0.05 to 2 im, and coat the other side with a resin film. Post-processing plate.

7. A method for producing a post-treated plate, characterized in that the post-treatment solution according to any one of claims 1 to 4 is applied to a plated steel sheet so as to have a dry thickness of 0.05 to 2 jum and dried. C

8. Apply the post-treatment solution according to any one of claims 1 to 4 to one side of the plated steel sheet so that the dry thickness is 0.05 to 2 mm, and then dry. A method for producing a post-processed plate, which comprises coating a film.