JPS60136981A - Magnetic disc - Google Patents

Abstract

PURPOSE:To attain excellent and strong bonding between a liner and a package by fixing the liner made of non-woven fabric on one side of which a synthetic thermoplastic resin film is laminated to the inside face of the package while opposing the synthetic resin film side. CONSTITUTION:The package 1 consists of a plastic-made sheet having left/right both side pieces 2, 3, a folding piece 4 for package circumference melting provided to the right side piece 3, and the left/right both side pieces 2, 3 are provided with an opening 7 corresponding to the center opening 6 of a magnetic disc main body 5 inserted and stored between both the pieces, a magnetic head insertion slit 8 and a sector index port 9. The liner 10 is made of non-woven fabric one side of which a synthetic thermoplastic resin film is laminated, the synthetic thermoplastic resin film 12 laminated onto one side of the unwoven cloth 11 is adhered by thermal melting while the film 12 is opposed to the inner side face of the package 1 so as to improve the bonding performance between the liner 10 and the package 1. The strength of the package is reinformed and strengthened through the insertion of the synthetic thermoplastic resin film 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a magnetic disk in which a magnetic disk body is housed in a storage body so that it can be rotated from the outside and can be recorded and reproduced. An object of the present invention is to provide a magnetic disk that is good in quality and has excellent strength.

A magnetic disk is a device in which the magnetic disk body can be stored in a storage body so that it can be rotated from the outside and can be recorded and played back in order to prevent contamination of the magnetic disk body by dust etc. The magnetic disk body is made of vinyl chloride sheet. A liner such as a non-woven fabric made of rayon fiber or polypropylene fiber is attached by heat welding to a PlusDeck sheet such as , and an opening corresponding to the central opening of the magnetic disk body to be stored, a magnetic head insertion slot, etc. are punched out. After that, it is made by bending and fusing.

However, nonwoven fabrics made of rayon fibers, polypropylene fibers, etc. do not necessarily have sufficient thermal weldability to storage bodies made of plastic materials such as plastic sheets, and if the heat welding conditions are strengthened, the storage bodies may become deformed. This may cause output abnormalities, and on the other hand, if the thermal welding conditions are weak, the adhesive force will decrease and the nonwoven fabric may shift due to the rotation of the magnetic disk body. Furthermore, the strength is not always sufficient and may deform when used or stored for a long time.

The inventor has conducted various studies in view of the current situation.

As a result, when a thermoplastic synthetic resin film is laminated on one side of a nonwoven fabric and this is used as a liner and heat welded with the synthetic resin film side facing the inner surface of the storage body, a thermoplastic synthetic resin film with good heat weldability can be obtained. It was discovered that by intervening, thermal welding can be easily performed even when the heating temperature is low, and the adhesion between the liner and the storage body is sufficiently good, and the strength of the storage body is also improved by exerting a reinforcing effect. , this invention was made.

As the material for the thermoplastic synthetic resin film laminated on one side of the nonwoven fabric, thermoplastic synthetic resins such as vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, polyethylene resin, and polyamide resin are preferably used.
A thermoplastic synthetic resin film made of these materials is laminated on one side of the nonwoven fabric by stacking these films or these films coated with an adhesive on the joint surface with a nonwoven fabric and passing between thermocompression rolls. In this case, the lamination does not require thermocompression bonding of the thermoplastic synthetic resin film and the nonwoven fabric over the entire surface (but may also be partially thermocompression bonded. If the thickness is thinner than 0.01 fin, heat weldability will be poor.
If it is thicker than 0.3 m, part of the resin melted during welding will seep into the nonwoven fabric and ooze out to the other side, contaminating or damaging the magnetic disk body and causing errors, so 0.01 to 0. Preferably, the thickness is within the range of 0.3 fins, more preferably 0.03 to 0.2 fins.

Note that a carbon blank may be included in such a thermoplastic synthetic resin film (if the carbon blank is included, the conductivity of the liner will be improved and the antistatic function will be exhibited, so it will not be magnetic). The generation of static electricity due to sliding contact with the disk body is well prevented.If the content of this carbon blank is less than 5% by weight, the conductivity will not be so good, and the generation of static electricity cannot be effectively prevented, which is the opposite. If the amount exceeds 70% by weight, the heat weldability of the thermoplastic synthetic resin film may deteriorate, so it is preferably contained within the range of 5 to 70% by weight, and preferably within the range of 10 to 50% by weight. A more favorable result can be obtained.

The present invention will be explained below based on the drawings.

FIG. 1 shows an example of the magnetic disk storage body according to the present invention, which is unfolded.
A magnetic disk is made of a plastic sheet such as vinyl chloride and has a bent piece 4 for welding the storage body periphery provided on the right side piece 3, and is inserted and stored between the left and right side pieces 2 and 3. An opening 7 corresponding to the central opening 6 of the main body 5, a magnetic head insertion opening 8, and a sector marking opening 9 are provided to correspond to each other. The storage body 1 is not limited to the plastic sheet as described above, but may be a case made of a molded plastic material, or may be made of paper or metal other than plastic.

Reference numeral 10 denotes a liner attached to the storage body 1 so as not to block the openings described above, and the liner 10 is made of a woven fabric laminated with a thermoplastic synthetic resin film on one side as described above, as shown in FIG. As shown in the nonwoven fabric 11
Thermoplastic synthetic resin film laminated on one side of
It is attached by heat welding with the second side facing the inner surface of the storage body 1. Therefore, the nonwoven fabric 11 is well adhered to the storage body 1 via the thermoplastic synthetic resin film 12 having excellent thermal weldability, and the adhesion between the liner 10 and the storage body 1 is further improved. Furthermore, since the thermoplastic synthetic resin film 12 is interposed between the nonwoven fabric 11 and the storage body 1, the strength of the storage body is reinforced and strengthened, and the storage body 1 does not deform due to long-term use.

As shown in FIG. 3, carbon black 13 may be mixed into the thermoplastic synthetic resin film 12 of the liner 10 made by laminating the thermoplastic synthetic resin film 12 on one side of the nonwoven fabric 11. When such carbon black 13 is contained, the conductivity of the liner 10 becomes good, and electrostatic charging is effectively prevented. Therefore, in the magnetic disk shown in FIG. 3, the adhesion between the liner 1o and the storage body 1 is good, and the strength of the storage body is strengthened.
Furthermore, the antistatic function is fully exhibited.

The magnetic disk of this invention is configured as described above,
After storing the magnetic disk main body 5 in this magnetic disk storage body and installing it in a recording/reproducing device, the magnetic disk main body 5 is rotated at high speed by a drive device guided through the opening 7, and the magnetic head is inserted into the magnetic disk through the magnetic head insertion port 8. , recording and reproduction can be performed by pressing the magnetic disk against the magnetic disk main body 5 which is rotating at high speed.

Next, embodiments of the invention will be described.

Example Cotton made of 100% rayon fiber was blown with water or air to entangle it, and then heat-treated to bind the fibers to make a non-woven fabric with a basis weight of 35 g/n (and a thickness of 0.20 m). Next, a liner was made by laminating a film made of vinyl chloride-vinyl acetate copolymer with a thickness of 0.05 m on one side of this nonwoven fabric.
Heat welded to a 5ui vinyl chloride sheet at a temperature of 200℃,
After punching out a predetermined opening, bending and fusing were performed to produce a magnetic disk storage body.

Comparative Example 1 A liner was made in the same manner as in Example except that the lamination of the vinyl chloride-vinyl acetate copolymer film was omitted, and an attempt was made to thermally weld it to a vinyl chloride sheet, but the welding failed. could not.

Comparative Example 2 In the example, the lamination of the film made of vinyl chloride-vinyl acetate copolymer was omitted, and the welding temperature when thermally welding the liner made of nonwoven fabric to the vinyl chloride sheet was set at 20°C.
A magnetic disk storage body was produced in the same manner as in the example except that the temperature was changed from 0°C to 300°C and heat welding was performed.

The welding strength of the magnetic disk storage bodies obtained in Examples and Comparative Examples was measured using an Instron type tensile tester, and the deformation of the vinyl chloride sheet serving as the storage body was visually observed.

The table below shows the results.

As is clear from the above table, in the case where the liner made only of non-woven fabric was heat-welded to the storage body (Comparative Examples 1 and 2),
If the heating temperature during heat welding is low, at 200°C, the liner will not weld to the storage body, and the heating temperature during heat welding may be raised to 3.
When heated to 00°C, the liner was welded to the storage body, but deformation of the vinyl chloride sheet that was the storage body was observed, whereas in the case of the product obtained by this invention (Example), the heating temperature during thermal welding was 200°C. However, in addition to welding with a stronger welding strength than that obtained in the comparative example, almost no deformation of the vinyl chloride sheet used as the storage body was observed, which indicates that the magnetic disk obtained by this invention can be welded with a stronger welding strength than that obtained in the comparative example. It can be seen that the adhesion to the body has been further improved.

[Brief explanation of drawings]

FIG. 1 is a developed view showing an example of the magnetic disk storage body of the present invention, FIG. 2 is an enlarged sectional view taken along the line A-A in FIG. 1, and FIG. 3 is an enlarged view showing another example of the magnetic disk of the present invention. FIG. 1... Storage body, 5... Magnetic disk body, 10...
・Liner, 11... Nonwoven fabric, 12... Thermoplastic synthetic resin film

Claims (1)

[Claims] (2) In a magnetic disk in which the magnetic disk body is housed in a storage body so as to be rotatably driven and recordable/reproducible from the outside, a synthetic resin liner made of a nonwoven fabric laminated with a thermoplastic synthetic resin film on one side is placed on the inner surface of the storage body. A magnetic disk characterized by being fixed with the film sides facing each other.