JPH06124566A - Floppy disk and its production - Google Patents

Abstract

PURPOSE:To obtain the floppy disk having a floppy disk shutter and/or shell subjected to surface ornamentation at a low cost by simple stages. CONSTITUTION:This process for production of the floppy disk has a stage for ornamenting the surface of the floppy disk shutter and/or shell during the production process. The above-mentioned surface ornamenting stage consists in forming laser markings on the surface of the floppy disk shutter and/or shell formed of a thermoplastic resin material with which the laser marking is possible by irradiating the surface with a laser beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a shutter and / or shell of a floppy disk formed of a thermoplastic resin material, the shutter and / or shell surface of which is marked by irradiating it with a laser beam. And a method of manufacturing such a floppy disk at low cost.

[0002]

2. Description of the Related Art Generally, in a floppy disk, a magnetic disk is covered with a shell formed of ABS resin or the like, a window for reading information from the magnetic disk is provided, and a magnetic disk is used. It has a structure in which a sliding shutter is installed on the window so that the disc cannot be touched directly by hand. Conventionally, as the floppy disk shutter, a stainless shutter obtained by pressing a stainless plate has been generally used. However, when the shutter slides during use, the ABS shell is worn by the sliding of the shutter and the shell, and the abrasion powder generated by the abrasion affects the magnetic recording medium in the shell, causing a read error. It was. Therefore, recently, in order to reduce the abrasion powder with the ABS shell, a floppy disk using a resin shutter molded from a thermoplastic resin typified by polyacetal, polybutylene terephthalate, and polypropylene has come to be used. Came. FIG. 1 shows a shell 1, a shutter 2, and an opening 3 provided in the shutter.
1 shows a schematic perspective view of a general floppy disk having On the other hand, the shutter is usually provided with surface decorations such as letters, numbers, symbols, and designs, which are rich in design, for displaying a brand name, a floppy disk type, and the like. Therefore, in addition to the slidability and wear characteristics, printability is required as a characteristic required for this shutter. Generally, in order to mark a desired character, number, pattern, etc. on the surface of a floppy disk shutter molded from such a thermoplastic resin, a marking method using a thermosetting ink typified by polyurethane, epoxy, etc. is used. Has been adopted. However, crystalline thermoplastic resins typified by polyacetal, polybutylene terephthalate, and polypropylene have inadequate ink adhesion due to the inactive surface of the molded product, making it difficult to perform marking with excellent durability. Met. In addition, with the marking of thermosetting ink,
Since a high temperature and long curing process is required to cure the ink, the molded product may be deformed in the case of a thin molded product of about 0.3 mm such as 3.5 inch floppy disk shutter. was there. In addition, surface treatment such as corona discharge treatment, flame treatment, and ultraviolet treatment is generally performed in order to perform imprinting with good adhesion at a temperature that does not deform the same parts, but the imprinting process becomes complicated. However, the cost of stamping increased, and it was difficult to achieve economical and stable mass production. On the other hand, the shell that forms the floppy disk separately from the shutter may be stamped with the serial number, the HD mark indicating the recording capacity, etc. In such a case, use the shutter described above to obtain the final product. Two printing processes were required in addition to the printing process of. At this time, a method of assembling a floppy disk and printing on the shutter and the shell at the same time in order to combine two printing steps into one is conceivable. However, the shutter and the shell are often different thermoplastic resins. On the other hand, it was impossible to perform good printing at the same time. In addition, heat treatment is required to cure the ink, but it was expected to adversely affect the recording disk inside the floppy disk.

[0003]

DISCLOSURE OF THE INVENTION In view of the above-mentioned prior art, the present inventors have proposed a floppy disk provided with a surface-decorated floppy disk shutter and / or shell.
As a result of earnest studies to manufacture at low cost by a simpler process, as a result of focusing on marking by irradiating a laser beam on a floppy disk shutter and / or shell molded of a thermoplastic resin material, especially for this application As a result of further studies on suitable resins and laser marking methods, the present invention has been completed. That is, the present invention provides a floppy disk shutter and / or
Alternatively, in the method of manufacturing a floppy disk including a step of decorating the surface of the shell, the surface decorating step irradiates the surface of the floppy disk shutter and / or shell formed of a thermoplastic resin material capable of laser marking with laser light. A method of manufacturing a floppy disk, which is laser marking, and a floppy disk shutter and / or a floppy disk formed by laser marking the surface of a shell formed of a laser-markable thermoplastic resin material.

The floppy disk referred to in the present invention is typified by a commercially available 3.5-inch floppy disk or mini disk. The information recording disk is covered with a shell formed of a thermoplastic resin material, In order to read information from the information recording disk, the information recording disk is a magnetic recording system if it has a structure that protects the magnetic disk with a sliding shutter so that it cannot be touched directly by hand through the window. It may be a magnetic disk or optical recording type optical disk. Although three representative parts constituting the floppy disk are taken up here, the floppy disk referred to in the present invention is not limited to this number of parts, and includes other parts using other parts.

The method of manufacturing the floppy disk of the present invention will be described below. The shutter and shell forming the floppy disk of the present invention can be formed by conventional injection molding. The thermoplastic resin material used in the present invention is not particularly limited as long as it has a high fluidity capable of forming a thin wall, has excellent friction and wear characteristics, and has excellent laser marking properties, and polypropylene, polyethylene ,
Examples thereof include those mainly containing ABS, AS, acrylic, polyacetal, polybutylene terephthalate, polycarbonate, wholly aromatic polyester, polyarylene sulfide and the like. In the present invention, in particular, frictional wear characteristics,
MI with good physical properties and good fluidity
It is preferable to use a thermoplastic resin material mainly composed of a highly fluid polyacetal resin, a polybutylene terephthalate resin or an ABS resin having a fluidity (melt index) of 9 g / 10 min or more. Here, the polyacetal resin used in the present invention is a polymer compound having (-CH ₂ O-) as a main constituent unit, a polyoxymethylene homopolymer, a copolymer containing a small amount of another constituent unit other than an oxymethylene group. It may be either a terpolymer (including a block copolymer), the molecule is not only linear,
It may have a branched or crosslinked structure. Further, there is no particular limitation on the degree of polymerization or the like. Further, the polybutylene terephthalate resin is a polymer compound obtained by a polycondensation reaction with terephthalic acid or its ester-forming compound and 1,4-butanediol as the main components, and a generally known copolymerization component. It may be a polybutylene terephthalate copolymer contained. The ABS resin is a thermoplastic resin containing acrylonitrile, butadiene, and styrene as main components and basically having acrylonitrile-styrene copolymer grafted on dispersed polybutadiene particles.

Further, as is well known, when marking is performed by irradiating a laser beam, a method of adding a dye and a silicon-containing inorganic compound or a silicon-containing dye to a molding material (Japanese Patent Laid-Open No. 56-14995). ), A method of adding a radiation absorbing substance such as a metal silicate (JP-A-59-118926), a method of adding 20% or more of hydrated alumina as an inorganic filler (JP-A-59-187050), A method of adding a pigment containing a phosphate (JP-A-2-204888), a method of adding a non-black inorganic lead compound (JP-A-2-48984), and a method of adding a non-white metal titanate salt. (JP-A-3-10884), a method of adding a black organic dye (JP-A-60-155493), a method of incorporating a metal hydroxide or / and a metal hydrous compound and a colorant (JP-A-60-60). −16
No. 6488 gazette) and the like are known, and all of these methods use a laser beam to irradiate a resin molded product obtained by adding a specific substance that selectively absorbs the laser beam to the laser beam. The light-irradiated portion is locally heated, and the additive or resin in the resin surface layer is melted, vaporized, carbonized,
Marking is performed by causing a thermal change such as discoloration, and in the present invention, these substances are appropriately blended with the thermoplastic resin to the extent that fluidity is not impaired. Carbon black is particularly preferable, and by containing carbon black in a concentration of 0.005 to 0.5% by weight, marking with recognizable and clear contrast can be performed.

Further, in the present invention, known additives and / or fillers are further added to the above-mentioned polymer organic material depending on the purpose, within the range in which the fluidity and the laser marking property are not significantly impaired. be able to. For example, antioxidants, various stabilizers for improving weather resistance, lubricants, plasticizers,
Nucleating agents, release agents, antistatic agents, surfactants, etc. or glass fibers, metal fibers, potassium titanate, glass flakes, glass beads, mica, talc, wollastonite, calcium carbonate, titanium oxide, alumina, silicon carbide , Boron nitride, ceramics, metal powder, etc.
It is a granular or powdery inorganic compound or the like. Further, a pigment or dye can be added for coloring.

Next, the surface of the floppy disk shutter and / or the shell obtained by molding the laser-markable thermoplastic resin material is laser-marked. At this time, it is possible to assemble the shutter, shell, information recording disk and other parts in the next step after laser marking the floppy disk shutter single body or shell single body or both. When this method is used, a pre-process such as corona treatment and a post-process for curing the ink are unnecessary, and space-saving, unmanned operation, automation and the like enable economical production. The most preferable manufacturing method with a higher economical effect is to assemble an injection-molded shutter, a shell injection-molded in a separate process, and a component such as an information recording disk,
It is a method of laser marking the shutter and / or the shell. Conventionally, the shutter and the shell are imprinted in separate processes, and the assembly process is performed while controlling the number of imprinted samples. On the other hand, according to this method, only one marking step is required, the number of marked samples can be controlled, and the labor for transferring to the assembling step can be saved. Therefore, the manufacturing process can be rationalized, simplified, and space-saving can be realized. The manufacturing method is very economical.

In the present invention, when laser marking is performed on the shutter and / or the shell, clear marking can be easily performed only by irradiating the desired position with the laser beam. In order to perform marking of a desired shape, for example, a method of scanning the surface of an object with a spot of laser light having an appropriate size, or a laser light having a desired shape by masking the laser light Examples include a method of irradiating the surface of an object. The type of laser used is not particularly limited, but for example, carbon dioxide laser, ruby laser, semiconductor laser,
Argon laser, excimer laser, YAG laser and the like can be mentioned. Among them, the Nd: YAG laser having a wavelength of 1.06 μm is preferable. The oscillation mode may be continuous oscillation or pulse oscillation,
Particularly suitable is a scan type Nd: YAG laser which is a continuous oscillation using a Q switch. The laser power in the processed portion is preferably 0.5 W to 20 W, particularly preferably 0.5 W to 5 W. Irradiation with more laser light causes the laser light that has passed through the molded product to damage the internal disk.

[0010]

[Marking conditions]

Device: Laser marker SL475E manufactured by NEC Corporation Marking number of characters: 40 characters Marking method: One-stroke writing method Power at marking part: 1 to 6 W Scan speed: 100 mm / sec Q switch frequency: 1 to 5 kHz Processing time: Approximately 3 seconds [ Evaluation method] Whether or not marking was possible and the contrast of the marking were observed with the naked eye. Marking availability 1 ← ────────────── → 5 Marking is not possible Marking is possible Contrast 1 ← ───────────── →→ 10 Very unclear (Reading of printout) No) Good Examples 10 to 18 and Comparative Examples 6 to 10 Polybutylene terephthalate resin (PBT) was mixed with carbon black or carbon black and various inorganic fillers in the proportions shown in Table 2 to prepare resin compositions, Example 1
9 and Comparative Examples 1 to 5 were molded, laser-marked, and evaluated. The results are shown in Table 2.

[0011]

[Table 1]

[0012]

[Table 2]

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a floppy disk.

[Explanation of reference numerals] 1 shell 2 shutter 3 opening provided in the shutter

Claims (5)

[Claims] 1. A method of manufacturing a floppy disk comprising a step of decorating the surface of a floppy disk shutter and / or a shell during the manufacturing step, wherein the surface decoration step is a floppy formed of a laser-markable thermoplastic resin material. A method for producing a floppy disk, which is laser marking in which the surface of a disk shutter and / or a shell is irradiated with laser light. 2. The method of manufacturing a floppy disk according to claim 1, wherein after the shutter and the shell are assembled, the assembly is laser-marked. 3. The method for producing a floppy disk according to claim 1, wherein the thermoplastic resin material is mainly composed of polyacetal resin, polybutylene terephthalate resin or ABS resin. 4. The laser marking is a scan type N.
d, YAG laser is used to perform the process.
A method for manufacturing the described floppy disk. 5. A floppy disk having a laser marking on the surface of a floppy disk shutter and / or shell formed of a laser-markable thermoplastic resin material.