JPH0790601A - Surface-treated metal plate with excellent conductivity and processability - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a surface-treated metal plate which can be press-formed without oiling and degreasing steps and has sufficient conductivity. [Structure] Organic resin 10 on the surface of a metal plate or a plated plate
An organic resin mixture containing 5 to 40 parts by weight of carbon black having a specific surface area of 800 m ² / g or more and 0 to 30 parts by weight of a powdery lubricant, and a dry film thickness of 0.05 to 3 A surface-treated metal plate excellent in conductivity and workability, which is formed by forming an organic resin layer having a thickness of 0.0 μm. The powdered lubricant has an average particle size of 0.05 to 10 μm.
m wax and / or fluorine-based resin, and the average particle size thereof is 1.0 to 10 times the dry film thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a metal plate which is processed mainly by press forming and which is required to have conductivity, that is, a surface excellent in workability and conductivity which is used in home appliances, OA equipment, automobiles and the like. Regarding a treated metal plate.

[0002]

2. Description of the Related Art Various metal plates such as steel plates, Zn or Zn alloy plated steel plates, stainless steel plates, copper or copper alloy plates and Al or Al alloy plates are press-formed in the manufacturing process of home appliances, office automation equipment, automobile products, etc. It is often done.

[0003] In general, at the time of these press workings, a lubricating oil is applied to a metal plate for working, and there are the following problems. (1) Lubricating oil is often applied by spraying, which causes the lubricating oil to scatter around and deteriorate the working environment. (2) It is necessary to remove the lubricating oil after pressing,
Since a solvent (Freon, 1-1-1 trichloroethane, etc.) or an alkali cleaner is used in this degreasing step, pollution prevention measures are required, resulting in increased costs and a bad working environment.

Under such a background, a so-called lubricating steel sheet in which a chromate layer is formed on a galvanized steel sheet and a resin layer containing a lubricant is further formed thereon is a technique capable of omitting oiling and degreasing steps. Has been developed.
(For example, JP-B-62-24505 and JP-A-62-73.
No. 938)

However, the above-mentioned prior art has a serious drawback that the conductivity inherent to the metal plate is impaired because the resin layer is formed on the metal plate.

Further, as a technique for improving the conductivity, there is a technique disclosed in Japanese Patent Laid-Open No. 63-83172 in which conductive particles are contained in a resin, but with the recent development of information equipment, the conductivity of a metal surface is improved. However, the required level of groundability is increasing, and it has been difficult with these conventional techniques to secure workability and further improve conductivity.

[0007]

The drawback of the prior art as described above is that the resin layer is uniformly formed on the metal plate in order to improve the workability. Usually, the resin has a very high volume resistivity of about 10 ¹⁵ Ω · cm, and even if it is applied as a thin film of about 1 μm, it exists as a layer having an interlayer resistance of 10 ¹⁰ Ω or more on the metal plate surface. The conductivity and groundability were impaired.

Further, in the method of improving the conductivity by adding conductive particles to these resin layers, it is necessary to add a large amount of particles in order to obtain sufficient conductivity with respect to the recent required level, and the workability is improved. However, there are problems such as a decrease in the oil pressure and a difficulty in the resin application work.

The present invention overcomes the above-mentioned drawbacks of the prior art, and enables press molding without oiling and degreasing steps and has sufficient conductivity.
It is intended to provide a surface-treated metal plate having a grounding property.

[0010]

As a result of intensive studies to overcome the above-mentioned drawbacks of the prior art, the inventors of the present invention have the smallest effect on workability among the conductive agents added to improve conductivity. The present invention was accomplished by discovering that carbon black is a substance and that there is a certain relationship between the specific surface area of carbon black and the processability and conductivity.

That is, the present invention contains 5 to 40 parts by weight of carbon black having a specific surface area of 800 m ² / g or more per 100 parts by weight of an organic resin on the surface of a metal plate or a plated plate, and further, powdered lubricant 1 Provided is a surface-treated metal plate having excellent conductivity and processability, which is formed by forming an organic resin layer having a dry film thickness of 0.05 to 3.0 μm with an organic resin mixture containing 30 to 30 parts by weight. It is a thing.

Here, the powdered lubricant has an average particle size of 0.
It is a wax and / or fluorine-based resin having a thickness of from 05 to 10 μm and an average particle diameter of 1.0 to 10 of the dry film thickness.
It is preferably double.

[0013]

The present invention will be described in more detail below. The metal plate in the present invention is a metal plate processed by press forming for home appliances such as steel plates, plated steel plates, stainless steel plates, aluminum and aluminum alloy plates, copper and copper alloy plates, titanium plates, OA equipment, and automobiles. Alternatively, it broadly includes plated metal plates (hereinafter simply referred to as metal plates). In the present invention, the pretreatment for resin treatment is not particularly specified, but a pretreatment such as a chromate treatment, a non-chromate treatment, an oxide film removal treatment, etc. suitable for each metal material can be appropriately selected and performed.

Next, as the organic resin of the resin layer formed on the metal plate, an epoxy resin, an alkyd resin, an acrylic resin, a urethane resin, a phenol resin, a melamine resin, and a polyvinyl butyral which have good adhesion to the metal plate. One or a mixture or copolymer of two or more kinds of resins and polyester resins is preferable. If the dry film thickness of these resin layers is less than 0.05 μm, sufficient processability cannot be ensured, and if it exceeds 3.0 μm, it becomes difficult to secure conductivity, so the range was limited to 0.05 to 3.0 μm. . A more preferable range is 0.1 to 1.0 μm.

Next, the carbon black added to the resin will be described. When the specific surface area is less than 800 m ² / g, it is difficult to secure sufficient workability and conductivity, and the addition amount is 100 parts by weight of the resin. On the other hand, if it is less than 5 parts by weight, sufficient workability and conductivity are not improved, and if it exceeds 40 parts by weight, the cohesive force of the resin is lowered and powdering easily occurs, so that the specific surface area is 800 m. ^The amount added is limited to ² / g or more and 5 to 40 parts by weight.

As the powdery lubricant, it is preferable to use a synthetic wax, a fluorine-based resin, or a mixture thereof.
Examples of synthetic waxes include polyethylene wax, polypropylene wax, polybutene wax and the like.

Examples of the fluorine-based resin include polytetrafluoroethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin and the like.

The average particle size of these lubricants is 0.05 to 1
It is preferably 0 μm and used in the range of 1.0 to 10 times the dry film thickness. If the average particle size of the lubricant is too small compared to the dry film thickness, the lubricity is insufficient, and if it is too large, the lubricant is likely to fall off and sufficient workability cannot be obtained. A more preferable range is 1.5 to 5 times the dry film thickness.

The addition amount of the powdered lubricant is less than 1 part by weight with respect to 100 parts by weight of the organic resin, the effect of improving the workability and lubricity is not sufficient. Since there is a risk that the cohesive force of the resin may be reduced and powdering may occur and the paint adhesion of the post-coating may be reduced, the amount is limited to the range of 1 to 30 parts by weight.

[0020]

EXAMPLES The present invention will be specifically described below based on examples. (Example) As the test piece, the following steel plate, plated steel plate, stainless steel plate, and aluminum alloy plate were used. The steel sheet materials A to D are SPCC equivalent products. A: Cold rolled steel sheet 1 mm thick B: Electrogalvanized steel sheet Zinc basis weight 20 g / m ²
Plate thickness 1 mm C; Electric zinc-nickel alloy plated steel plate Coating weight 20 g / m ² Nickel content 12% Plate thickness 1 mm D; 5% Aluminum-zinc hot dip galvanized steel plate Coating weight 60 g / m ² Plate thickness 1 mm E; SUS304 Stainless steel plate Skin pass finishing material Plate thickness 1mm F; JIS5182 Aluminum alloy plate Plate thickness 1mm

The metal plate was degreased with 1-1-1 trichloroethane by vapor, coated with a coating type chromate with a spin coater, dried and baked at 120 ° C., and then treated with a resin.

Table 1 shows the chromate treatment conditions, and Table 2 shows the resin treatment conditions. The following chromates, carbon blacks, organic resins and lubricants were used in this example. The following tests and evaluations were performed on the obtained samples. (Chromate) Coating Chromate I; manufactured by Nihon Parkerizing Co., Ltd. 45
13H Coating Chromate II; Kansai Paint Cosmer 15
0

(Carbon black); Mitsubishi Kasei CF9 specific surface area 60 m ² / g; Mitsubishi Kasei MA8 137 m ² / g; Mitsubishi Kasei 1000 200 m ² / g; Mitsubishi Kasei 2400 280 m ² / g; Mitsubishi Kasei 3750 800 m ² / g; Mitsubishi Kasei 3950 1500 m ² / g; Ketjen Black EC 800 m ² / g; Ketjen Black EC 600 JD 1270 m ² / g Homemade acetylene black 560 m ² / g The specific surface area is obtained by the nitrogen adsorption method.

(Organic resin) Epoxy resin; Yuka Shell Epoxy Co., Ltd. Epicoat alkyd resin; Mitsui Toatsu Kagaku Co., Ltd. Urix acrylic resin; Mitsui Toatsu Chemical Co., Ltd. Almatex 749 urethane resin; Mitsui Toatsu Chemical Co., Ltd. Orestar Phenolic resin; Super Beckasite melamine resin manufactured by Dainippon Ink and Chemicals; Uban butyral resin manufactured by Mitsui Toatsu Chemicals; Denka butyral polyester resin manufactured by Denki Kagaku; Almatex P645 manufactured by Mitsui Toatsu Chemicals 50 parts by weight of acrylic resin to 100 parts by weight of epoxy resin, 100 parts by weight of urethane resin for 100 parts by weight of epoxy resin for epoxy + urethane resin, 100 parts by weight of urethane resin for 100 parts by weight of acrylic resin for acrylic + urethane resin age .

(Lubricant) Wax 1 San Nopco SL92 average particle diameter 27 μm Wax 2 San Nopco SL417 14 μm Wax 3 San Nopco SL530 6 μm Wax 4 San Nopco SL600 1.2 μm Fluoro resin 1 Asahi Glass AD1 8 μm Fluorine Resin 2 Lubron 0.2 μm manufactured by Daikin Industries, Ltd.

(Test of Workability and Evaluation Method) The workability of the test piece after the surface treatment was determined by high-speed cylindrical drawing with a diameter of 33 mmφ (processing speed 500 mm / sec) without oiling, and its limiting drawing ratio (LDR). Flat plate sliding test (200 kg / cm ² ,
The friction coefficient (μ) at 100 mm / sec) was used for evaluation.

(1) Steel plate, plated steel plate and stainless steel plate Evaluation by LDR Evaluation by μ ◎; LDR 2.3 or more ◎; 0.15 or less ○; 2.24 or more and less than 2.3 ○; 0.15 or more and 0.25 Less than: Δ; 2.12 or more and less than 2.24 Δ; 0.25 or more and less than 0.4 ×; Less than 2.12 ×; 0.4 or more

(1) Aluminum Alloy Plate Evaluation by LDR Evaluation by μ ◎; LDR 2.12 or more ◎; 0.15 or less ○; 1.96 or more and less than 2.12 ○; 0.15 or more and less than 0.25 △; 1 0.90 or more and less than 1.96 Δ; 0.25 or more and less than 0.4 ×; less than 1.90 ×; 0.4 or more

(Conductivity Test and Evaluation Method) The conductivity was evaluated by measuring the surface resistance value with a surface resistance meter Loresta manufactured by Mitsubishi Yuka. The value was the average of 10 measurements. ⊚: less than 0.1Ω ◯: 0.1Ω or more and less than 0.5Ω Δ; 0.5Ω or more and less than 2Ω ×; 2Ω or more

The results of the above evaluation tests are summarized in Table 3. As is clear from Tables 1 to 3, according to the present invention, excellent workability, slidability, and conductivity can be obtained with any metal plate, while all performances are improved in Comparative Examples outside the scope of the present invention. I can't be satisfied.

In Comparative Examples A-14, E-8 and F-13, since the amount of carbon black added was small, the conductivity was remarkably inferior and the workability was slightly insufficient. In Comparative Examples A-15, E-7, and F-14, since the amount of carbon black added is excessive, the cohesive force of the resin film is reduced and sufficient workability and slidability cannot be obtained. In Comparative Examples A-16, E-9, and F-10, sufficient workability cannot be obtained due to the insufficient amount of the lubricant added, and in A-17, the cohesive force of the resin film decreases due to the excessive amount of the lubricant added. Sufficient workability and slidability cannot be obtained.

Comparative Examples B-6, C-9, D-6, E-6,
Since F-9 has an excessively small specific surface area of carbon black, sufficient conductivity cannot be obtained, and workability and slidability are slightly insufficient. In Comparative Examples B-7 and D-8, the lubricant particle size is too small to obtain sufficient workability and slidability, and in B-8 and D-7, the particle size is too large and they easily fall off. Excellent workability and slidability are not obtained. In Comparative Examples C-7 and F-12, the resin thickness is too large to obtain sufficient conductivity, and in C-8 and F-11, the resin thickness is too thin to provide sufficient workability and slidability. Has not been obtained. Further, FIG. 1 shows the results of investigating the relationship between the specific surface area by determining μ and the surface resistance value by changing only the specific surface area of carbon black under the processing conditions of A-1.

As will be apparent, the specific surface area is 800 m ² /
It can be seen that the sliding property and the conductivity are remarkably improved when the value is g or more.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

[Table 6]

[0040]

[Table 7]

[0041]

[Table 8]

[0042]

[Table 9]

[0043]

[Table 10]

[0044]

[Table 11]

[0045]

[Table 12]

[0046]

Industrial Applicability As described above, according to the present invention, an organic resin layer containing carbon black having a specific surface area of 800 m ² / g or more and a powdery lubricant is formed on the surface of a metal plate, thereby carrying out press working. Property, slidability and conductivity are remarkably improved. As a result, the productivity of home appliances, office automation equipment, automobile parts, etc. processed by press molding can be remarkably improved, and the oiling and degreasing steps can be omitted, which is very effective for environmental improvement. Further, improvement in spot resistance weldability can be expected in view of the remarkable effect of improving conductivity.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a specific surface area of carbon black, slidability (friction coefficient μ), and conductivity (surface resistance value).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location // B32B 7/02 104 7148-4F (72) Inventor Naoki Nishiyama Chuo-ku, Chiba City, Chiba Prefecture Kawasaki-cho 1 Technical Research Headquarters, Kawasaki Steel Co., Ltd. (72) Koichi Hashiguchi Koichi Hashiguchi 1-Kawasaki-cho Chuo-ku, Chiba, Chiba Prefecture Kawasaki Steel Co., Ltd. Technical Research Headquarters (72) Inventor Koji Owawa 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Technical Research Division, Kawasaki Steel Co., Ltd. (72) Inventor, Motohiro Namba 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Aluminum Co., Ltd.

Claims (2)

[Claims] 1. The surface of a metal plate or a plated plate contains 5 to 40 parts by weight of carbon black having a specific surface area of 800 m ² / g or more per 100 parts by weight of an organic resin, and 1 to 30 parts by weight of a powdered lubricant. A surface-treated metal plate having excellent conductivity and processability, which is formed by forming an organic resin layer having a dry film thickness of 0.05 to 3.0 μm with the contained organic resin mixture. 2. The powder lubricant has an average particle size of 0.05.
The surface-treated metal sheet having excellent conductivity and workability according to claim 1, which is a wax and / or a fluorine-based resin having a thickness of 10 μm and an average particle diameter of 1.0 to 10 times the dry film thickness.