JP4335658B2 - Coated steel sheet for cartridge or electronic information equipment - Google Patents

Description

  The present invention relates to a coated steel sheet suitable as a material for a case of a cartridge inserted in a reader such as a personal computer, a digital camera, an automatic ticket gate, or the inner wall of a cartridge insertion port.

In personal computers, digital cameras, vending machines, automatic ticket gates, etc., a card-like recording medium on which electronic information is recorded is inserted into an insertion slot, and necessary information is recorded or read. For example, a recording medium 10 such as MO is rotatably accommodated in a cartridge 12 having a reading or recording opening 11 (FIG. 1). When the cartridge 12 is inserted into the insertion port 21 provided in the personal computer main body 20 and the personal computer is started up, information is exchanged between the recording medium 10 and the personal computer main body 20.
The insertion port 21 is made by forming a lightweight aluminum plate into a predetermined shape. On the other hand, the case of the cartridge 12 often uses a solid stainless steel plate. When the recording medium 10 accommodated in the stainless steel case is inserted into the insertion slot 21, both the recording medium 10 and the personal computer main body 20 are easily wrinkled by the friction between the stainless steel and the aluminum. In addition to being unfavorable for the appearance of the recording medium 10 and the personal computer main body 20, the wrinkles may cause malfunction.
The occurrence of wrinkles due to the rubbing of the case / insertion wall is eliminated by providing a coating film with good lubricity on the surface of the cartridge 12 to improve the sliding of the cartridge 12. A coating film in which lubricant particles such as polytetrafluoroethylene, cross-linked acrylic resin, melamine resin, and silicone are dispersed in order to obtain necessary lubricating properties is also known (Patent Document 1). Although the lubricity of the coating film surface is improved by the dispersion of the lubricant particles, the lubricant particles may fall off from the coating film when used for a long period of time and may not exhibit the initial performance. If the dropped lubricant particles accumulate in the insertion port 21 of the personal computer main body 20, the reading / writing failure, malfunction, and failure are induced. Similar troubles occur not only in the cartridge 12 containing the recording medium but also in the card-like recording medium made of the metal plate itself.
Japanese Patent Laid-Open No. 10-106215

  The present invention absorbs the stress applied to the lubricant particles during the rubbing of the cartridge / insertion port inner wall by viscoelastic deformation of the coating film by using a coating film having a large elongation as the coating film for dispersing the lubricant particles. It is an object of the present invention to provide a cartridge and a cartridge insertion port which can be used in a personal computer under stable conditions, and maintain a beautiful and highly lubricious surface even after long-term use.

  The coated steel sheet for the cartridge or the electronic information device of the present invention is made of a normal steel plate, a stainless steel plate, a plated steel plate, etc., and a coating film in which organic lubricant particles are dispersed is provided directly or via an undercoat coating film. Yes. Lubricant particles are acrylic beads, nylon beads, polyacrylonitrile beads, polytetrafluoroethylene beads, polyethylene beads, polyurethane beads, polypropylene beads, etc., and organic resin particles of a size that partially protrude from the coating surface are used. The The coating film in which the lubricant particles are dispersed is a coating film exhibiting a high elongation of 50% or more, preferably a fluorine resin having a molecular weight of 10,000 or more, an acrylic resin, a polyester resin, an epoxy resin, an epoxy-modified polyester resin, a urethane resin, A film is formed from a paint based on vinyl chloride resin.

  The coated steel sheet used as the case material of the cartridge is provided with the coating film 2 in which the lubricant particles 1 are dispersed directly on the substrate / steel sheet 3 or through the undercoat coating film 4. The lubricant particles 1 projecting from the surface coating film 2 are in direct contact with the inner wall of the insertion port when the cartridge 12 is inserted into the insertion port 21 and exhibit an excellent lubricating action. Stress F is applied to the lubricant particles 1 by rubbing the inner wall of the case / insertion opening. However, since the lubricant particles 1 are supported by the surface coating film 2 having a large elongation, the stress F is applied as viscoelastic deformation of the surface coating film 2. Is absorbed. Therefore, the shearing force applied to the lubricant particles 1 is reduced, the lubricant particles 1 are prevented from falling off, and the cartridge 12 is smoothly inserted and removed over a long period of time. Even when the cartridge 12 is wrinkled by rubbing the inner wall of the case / insertion opening, the wrinkle occurrence location is limited to the protruding portion of the lubricant particles 1, and the coating film 2 itself is not wrinkled. That is, it is not a continuous eyelid that is easily noticeable, and a beautiful appearance is maintained.

  The action of the lubricant particles 1 projecting from the coating film 2 is utilized even when a coated steel plate is used for the inner wall of the cartridge insertion opening. For example, in a digital camera that requires electric power for electronic control, image display, etc., the battery 32 is inserted into the insertion port 31 provided in the camera body 30, and the engagement recess on the battery 32 side is engaged with the claw 33 on the inner wall of the insertion port. Thus, the battery 32 is positioned and electrically connected to the camera body 30 (FIG. 3). The battery 32 is inserted into the insertion slot 31 while being rubbed against the insertion slot inner wall 34 with a strong force. However, if the insertion slot inner wall 34 is formed of the coated steel sheet of the present invention, the frictional resistance between the insertion slot inner wall 34 and the battery 32 is reduced. Thus, the battery 32 can be easily attached and detached. The use of the coated steel sheet of the present invention enables smooth insertion and removal of the cartridge not only for the battery insertion port 31 of the digital camera but also for the insertion port into which a cartridge such as a memory card, wireless LAN card, PC card or the like is loaded. .

The coating plate includes hot-dip galvanized steel sheet, alloyed hot-dip galvanized steel sheet, zinc alloy-plated steel sheet such as 5% Al-Zn and 6% Al-3% Mg-Zn, and Zn-Al alloy such as 55% Al-Zn. Plated steel plates, stainless steel plates, aluminum plates and the like are also used. The coating original plate is subjected to alkali degreasing, surface adjustment and the like as necessary prior to chemical conversion treatment. For alkali degreasing and surface adjustment, methods commonly used in the production of precoated steel sheets and painted aluminum sheets can be employed.
The coated original plate is subjected to chemical conversion treatment such as chromate treatment, phosphate treatment, and chromium-free treatment as pre-painting treatment.

[Undercoat]
When providing an undercoat film, an undercoat such as polyester, polymer polyester, epoxy, epoxy-modified polyester, or epoxy-modified polymer polyester is used. In the undercoat paint, chromium and non-chromium anticorrosive pigments, pigments such as titanium oxide, calcium carbonate, and silica, and various additives are blended as necessary. Depending on the application of the coated steel sheet, the base resin of the undercoat paint is adjusted to an appropriate molecular weight and glass transition temperature, and the amount of pigment and the like is selected.
Undercoat paint such as roll coat used in continuous coating equipment is applied and baked on the coating original plate according to a conventional method, and an undercoat coating film having a dry film thickness of 1 to 15 μm is formed in the same manner as a normal coated steel plate.

[Surface coating film]
The coating material for forming the surface coating film is based on fluororesin, acrylic resin, polyester resin, epoxy resin, epoxy-modified polyester resin, urethane resin, vinyl chloride resin, etc., and coating film elongation: 50% or more, preferably molecular weight: 10,000 It is prepared by adding resin beads such as acrylic beads, nylon beads, polyacrylonitrile beads, polytetrafluoroethylene beads, polyethylene beads, polyurethane beads, polypropylene beads to the above resin.

  Elongation of coating film: 50% or more absorbs, for example, the stress caused by sliding applied to the memory card inserted into the card insertion slot as the elongation of the surface coating film, and prevents the resin beads from being detached from the surface coating film. Insufficient coating film elongation cannot relieve the stress applied to the resin beads during sliding, and the coating film / resin bead interface peeling or resin bead falling off easily occurs.

The blending amount of the resin beads is preferably selected in the range of 2 to 14 % by mass of the resin solid content. If the resin beads are insufficient, sufficient lubrication characteristics cannot be obtained, but if the amount is too large, adverse effects such as a decrease in paintability tend to appear. In order to obtain sufficient sliding / lubricity, resin beads having a particle size of (0.6-2) × T based on the film thickness T of the surface coating film are preferable. When the particle diameter is less than 0.6T, there are few beads protruding from the surface of the coating film, and a sufficient effect due to the resin bead blending cannot be obtained. On the other hand, when the particle size is too large, there are too many protruding portions from the surface of the coating film, and the resin beads easily fall off. Since the higher the adhesion between the resin beads and the coating film resin component, the more difficult it is to drop off, the adhesion of the resin beads can be improved by surface treatment such as roughening or coating.

In addition to resin beads, extender pigments, colored pigments, aggregates, various additives, and the like can be blended in the coating for forming the surface coating film. An appropriate curing agent is selected according to the target performance such as workability.
The top coating is applied to a coating original plate and baked according to a conventional method, and a surface coating film having a dry film thickness of 5 to 30 μm is preferably formed.

Plate thickness: A hot-dip galvanized steel sheet having a thickness of 0.3 mm was used as a coating original sheet. After the surface of the coated original plate is surface-treated, it is applied with a chromate treatment, and a polyester resin primer (P195: made by Nippon Paint Co., Ltd.) is applied on the generated chromate film, and dried film thickness by baking at 210 ° C for 30 seconds. : An undercoat film of 5 μm was formed.
Next, a top coating (Table 1) containing 8% by mass of resin beads having an average particle size of 5 to 45 μm based on the solid content of the coating is applied, and a dry film thickness is 10 to 25 μm by baking at 230 ° C. for 40 seconds. A coating film was formed.

Each manufactured steel sheet was press-molded to produce a memory card case.
After repeatedly inserting the memory card case 100 to 10,000 times into the card insertion slot having the aluminum cover, the surface of the memory card case was observed to investigate the occurrence of scratches. Scratch resistance was evaluated with a memory card case where no scratches were detected as ◯, a slightly scratched memory card case as △, and a memory card case with clear scratches as ×. The resin beads dispersed in the surface coating film dropped out of the surface coating film as the memory card case with a large amount of scratches occurred, and almost no resin beads dropped in the memory card case without the scratches.

Furthermore, the dynamic friction coefficient was measured according to JIS K7125 using a dynamic friction meter (manufactured by Toyo Seiki Co., Ltd.).
As can be seen from the survey results in Table 2, the test piece in which resin beads were dispersed in a surface coating film with an elongation of 50% or more showed an excellent coefficient of dynamic friction, and after repeated insertion into the card insertion slot many times. However, no scratches were detected on the surface of the memory card case, or very slight scratches were detected.

On the other hand, in the comparative example in which resin beads are dispersed in a surface coating film having a low elongation rate, as a result of most of the resin beads dropping off by repeated insertion over 100 times, the lubricity is impaired. A large amount of scuffing occurred. In Comparative Example 9 in which the resin beads were not dispersed even in the surface layer coating film having a high elongation rate, a large amount of scratches had already occurred when the number of repeated insertions did not reach 100 times.
As is clear from this comparison, it is confirmed that the high lubricity derived from the resin beads is maintained over a long period of time by dispersing the resin beads in the surface coating film having an elongation of 50% or more. In addition, since the falling off of the resin beads is suppressed, there are no troubles such as reading / writing defects, malfunctions and failures due to the accumulation of the dropping particles.

  As described above, since the lubricant particles 1 are dispersed in the surface coating film 2 having a large elongation, the lubricant particles 1 protruding from the surface coating film 2 exhibit good lubricity, and the case / insertion port. The lubricant particles 1 are also prevented from falling off due to the rubbing of the inner wall. Therefore, even after long-term use, it can be smoothly inserted into the insertion port 21 of the electronic information device main body, and there is no generation of debris that adversely affects the electronic information device main body. Even when used on the inner wall of the insertion opening, smooth removal and attachment of the cartridge is ensured over a long period of time.

The perspective view which showed the cartridge with which the personal computer is loaded Sectional view of a coated steel sheet according to the present invention A perspective view showing a battery loaded in a digital camera

Explanation of symbols

1: Lubricant particles 2: Surface coating film 3: Base material / steel plate 4: Undercoat coating film 10: Recording medium 12: Cartridge 20: PC main body 21: Insertion port 30: Camera body 31: Insertion port 32: Battery 33: Claw 34: Inner wall

Claims (5)

A coated steel sheet for a cartridge or electronic information device in which a surface coating film in which organic lubricant particles are dispersed is provided on the steel sheet directly or through an undercoat coating film, and a part of the lubricant particles protrudes from the coating film surface , and the surface layer coating of dry film thickness (T) is 10 to 30 [mu] m, Ri der elongation of 50% or more, average particle diameter of the lubricant particles (0.6 to 2) the range of × T der A coated steel sheet for a cartridge or electronic information device.   The coated steel sheet for cartridges or electronic information equipment according to claim 1, wherein the lubricant particles are one or more of acrylic beads, nylon beads, polyacrylonitrile beads, polytetrafluoroethylene beads, polyethylene beads, polyurethane beads, and polypropylene beads. 3. The cartridge or electronic information device according to claim 1, wherein the surface coating film has a molecular weight of 10,000 or more as a base resin of a fluororesin, an acrylic resin, a polyester resin, an epoxy resin, an epoxy-modified polyester resin, a urethane resin, or a vinyl chloride resin. Painted steel sheet. A cartridge in which a case containing a recording medium is made of the coated steel sheet according to any one of claims 1 to 3 . An electronic information device in which an inner wall of a cartridge insertion slot is formed of the coated steel plate according to any one of claims 1 to 3 .

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