JPH0562417A - Liner for floppy disk - Google Patents

Abstract

PURPOSE:To lessen the generation of errors by sticking a high-polymer resin for adhesion gradually at <=5wt.% from the rear surface to the front surface of the non-thermocompression bonded parts of the liner and sticking the high- polymer resin for smoothing gradually at <=2wt.% from the front surface to the rear surface. CONSTITUTION:A web disposed with titanium oxide-contg. rayon fibers in the outside layer and blended fibers composed of 50% rayon fibers and 50% hot meltable polyester composite fiber in the inside layer is formed. A non-woven fabric having the thermocompression bonded parts and the non- thermocompression bonded parts is formed by subjecting this web to thermocompression bonding by using a roll having surface ruggedness and a thermocompression bonding roll consisting of a flat surface. An acrylic polyurethane resin is stuck at 5wt.% by foam coating on the rear surface of this non- woven fabric and is dried. A polysilicone resin is stuck at 2wt.% by foam coating on the surface of the non-woven fabric and is cured after predrying. The liner which maintains cleanability without impairment, lessens the generation of lint and has excellent durability is obtd. in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved liner for floppy disks.

[0002]

Floppy disks used as external recording media for computers are generally made of vinyl chloride resin or AB.
It is housed in a case consisting of a jacket molded from S-based resin, and a fiber liner is attached to the inner surface of the case. Regarding the performance required as a liner for a floppy disk, the disk protection property and the disk cleaning property are important, and various liners have been conventionally proposed.

For example, Japanese Unexamined Patent Publication (Kokai) No. 58-7705 discloses a non-woven liner made of polyester fiber.
Japanese Unexamined Patent Publication (Kokai) No. 54-49115 discloses a non-woven liner made of polypropylene fiber.
Japanese Unexamined Patent Publication No. 1280 discloses a non-woven liner made of recycled fiber, and Japanese Unexamined Patent Publication No. 64-70985 discloses a non-woven liner having a polymer resin attached thereto. In order to stabilize the morphology, methods such as fusing fibers together or adhering and fixing the fibers with an adhesive are used.

[0004]

However, when a general non-woven fabric according to a known technique is used as a liner for a floppy disk, fiber waste (lint) is generated due to the dropping of adhesives, fibers, etc., and adheres or is damaged on the floppy disk surface. It may cause a disc playback failure. As a particularly prominent example, lint, dust, etc. adhering to the liner due to ultrasonic welding when attaching the liner to the 3.5 inch floppy disk jacket and ultrasonic welding when sealing the jacket fall onto the disk and reproduce. There is a problem that causes a drop in output.

A liner for a floppy disk produced by a method of adhering and fixing fibers with an adhesive is less hard to produce lint but is not sufficient in cleaning effect.
In addition, friction and wear occur between the adhesive and the floppy disk, and the adhesive transfers to the floppy disk, which causes disk reproduction failure. A particularly notable example is a non-thermoplastic fiber such as a rayon liner, which has no affinity for the disk and does not adhere to the disk, but the disk rotates and comes into contact with the liner to cause friction and wear. It may break, which causes a temporary error and is a problem as a liner for a floppy disk. In particular, recently, the floppy disk has been largely changed to the direction of miniaturization, high density, and high speed rotation, and development of a high-performance floppy disk liner capable of coping with this has been strongly desired.

In view of the above situation, the present invention provides a liner for a floppy disk which does not impair the cleaning property and does not cause lint or transfer of resin to the floppy disk.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a liner for a floppy disk, which comprises a thermoplastic fiber, has a thermocompression bonding portion and a non-thermocompression bonding portion, and is made of a nonwoven fabric whose shape is retained by the thermocompression bonding portion, 5% by weight or less of the polymer resin A, which is indirectly attached to the constituent fibers, gradually adheres from the back surface (surface contacting the jacket) to the surface (surface contacting the disk) of the non-thermocompression-bonded portion of the liner. A gist of a liner for a floppy disk is characterized in that a polymer resin B having a smoothness gradually decreases from the front surface to the back surface of a non-thermocompression bonding portion by 2% by weight or less.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a partially enlarged view of a cross section of a liner having a large number of thermocompression bonding parts. In FIG. 1, 1 is the surface of the liner (the surface that contacts the disk), 2 is the back surface (the surface that contacts the jacket), and 3 is the non-thermocompression bonding. 2 is a thermocompression bonding portion. In FIG. 2, the non-thermocompression bonding portion 3 of the liner shown in FIG. 1 is cut along the line XX ', and the intersections of the liner front surface 1 and the back surface 2 are defined as a and b. It is explanatory drawing which showed the distribution example of the attachment fiber of polymeric resin A, B in a liner cross section in a case.

The liner of the present invention has a distribution of the polymer resin A-adhering fibers and the smooth polymer resin B-adhering fibers indirectly attached to the fibers in the cross section of the non-thermocompression bonding portion 3 of the liner having a large number of thermocompression bonding portions 4 shown in FIG. As shown in FIG. 2, a large amount of polymer resin A-attached fibers are distributed on the back surface, and a large amount of polymer resin B-attached fibers are distributed on the front surface. The conventional liner has a structure in which even if a large number of partial thermocompression bonding portions are provided, the fibers forming the non-thermocompression bonding portions are not constrained to each other, and fiber waste (lint) or the like is likely to occur during cutting. On the other hand, in a conventional chemical bond type liner that is entirely resin-processed, when used for a long time, friction and wear occur at the interface where the disc and the liner come into contact, and the adhered resin component adheres to the disc or damages it. However, in the liner of the present invention, the constituent fibers are adhered to each other by the polymer resin A in a point or line shape on the side in contact with the jacket in the non-thermocompression bonding portion, and the surface of the constituent fibers on the side in contact with the disk is a smooth resin. By coating with, it is possible to reduce the lint that causes an error and prevent the resin from adhering to the disc or damaging the disc. The distribution state of the polymer resin A-adhered fibers in the liner of the present invention will be described with reference to FIG. 2. The vertical axes a and b in FIG. The intersection of the front surface 1 and the back surface 2 is shown. The position where the distribution ratio of the polymer resin A-attached fiber becomes maximum is b, that is, the back surface of the liner. In order to enhance the adhesion between the constituent fibers of the non-thermocompression-bonded portion, it is preferable that the polymer resin A also adheres to the fibers on the surface of the liner. It is desirable that they are attached only to the fibers. Distribution 5 in FIG. 2 is an example in which the fibers to which the polymer resin A adheres are gradually distributed in the surface direction from the back surface of the liner to the range of 30% to 50% of the cloth thickness. As the polymer resin A, an acrylic or polyester thermosetting resin is preferably used, and its adhesion amount is 5% by weight or less, preferably 1 to 5% by weight, and when it exceeds 5% by weight, the liner becomes hard. Therefore, there arises a problem that the cleaning performance is deteriorated.

On the other hand, the position where the distribution ratio of the polymer resin B-adhered fiber becomes the maximum is the liner a, that is, the surface, which is used for smoothing with the disc, and lint generation due to friction and wear and the disc of the resin are produced. To prevent the transition to. As the polymer resin B, a high molecular weight polysilicon resin or a polyfluorinated resin is preferably used, and the adhesion amount thereof is 2% by weight or less, preferably 0.5 to 2% by weight.
The distribution 6 in FIG. 2 is an example in which the fibers to which the polymer resin B is attached are gradually distributed from the front surface of the liner to the back surface in the range of 20% to 50% of the cloth thickness.

In the liner of the present invention, the polymer resin A is adhered to the back surface of the non-woven fabric obtained by heat embossing a web containing thermoplastic fibers and partially thermocompression-bonding it, followed by drying and curing, Then, the polymer resin B can be obtained by similarly attaching, drying and curing the polymer resin B on the surface of the non-woven fabric. In this case, by adjusting the viscosity and the coating amount of the polymer resin, the attachment distribution of each polymer resin can be obtained. It can be controlled appropriately.

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Various evaluations and tests in the examples will be carried out by the following methods. (A) Measurement of amount of lint The liner cut into a size of 90 cm ² is subjected to ultrasonic vibration in water for 1 minute, the fiber waste dispersed in water is filtered by a filter, and the amount of the amount is visually judged. (B) Transfer test of polymer resin to disk 21 Place the liner on a commercially available floppy disk and
A load of g / cm ² is applied, the mixture is allowed to stand in an environment of 70 ° C. and 90% RH for 20 hours, and then the presence or absence of transfer of resin to a disk after conditioning for 5 hours under standard conditions is determined.

(C) Yield test A disk is incorporated into a shell provided with a floppy disk liner to prepare 100 pieces of each, and the measurements are repeated a certain number of times using a Drop-IN-OUT counter manufactured by Tokyo Engineering Co., Ltd. (D) Durability test The durability is evaluated by measuring the reproduction output after rotating a shell incorporating a floppy disk having a reproduction output above a certain level for 10 million passes.

Example 1 Titanium oxide-containing rayon fiber (1.5 denier, 51 mm) was placed in the outer layer, and 50% of the rayon fiber and heat-fusible polyester composite fiber (2.0 denier, 51 mm) were placed in the inner layer. A thermocompression-bonding roll comprising a roll having a surface irregularity and a roll having a flat surface on a web in which a mixed fiber of core component melting point 265 ° C., sheath component melting point 200 ° C .: core component / sheath component = 1/1) 50% is arranged. By performing thermocompression bonding at a roll temperature of 220 ° C. using
A nonwoven fabric having a basis weight of 40 g / m ² having a thermocompression bonding portion and a non-thermocompression bonding portion was formed.

Acrylic polyurethane resin (polymer resin A) was applied on the back surface (the surface contacting the flat roll during thermocompression bonding) of 5% by weight by foam coating to 100 ° C.
By pre-drying for 1 minute in the following manner, and then 2% by weight of a poly-silicon resin (polymer resin B) is applied to the surface of the non-woven fabric (the surface in contact with the roll having surface irregularities during thermocompression bonding) by foam coating,
Preliminary drying was performed at 100 ° C. for 1 minute and then curing treatment was performed at 160 ° C. for 1 minute to obtain a liner A.

When the liner A thus obtained was dyed and observed under a microscope, it was found that the acrylic polyurethane resin was gradually attached within the range of 50% of the cloth thickness from the back surface to the surface of the non-thermocompression bonded portion. , And the cloth thickness is 4 from the front to the back.
It was confirmed that the polysilicon resin was gradually attached within the range of 0%. Various evaluations of this liner A are shown in Table 1.

Comparative Example 1 The same thermocompression-bonded nonwoven fabric used in the examples was impregnated with an acrylic polyurethane resin, dried and cured to obtain a liner B having a resin adhesion amount of 6% by weight. Various evaluations of this liner B are also shown in Table 1. [Comparative Example 2] The same thermocompression-bonded nonwoven fabric (without resin adhesion) used in the examples was used as the liner C, and various evaluations thereof are also shown in Table 1.

[0018]

[Table 1]

[0019]

The liner of the present invention constructed as described above does not impair the cleaning property, generates less lint that causes an error, does not transfer the resin to the disk, and has a good yield and durability. It has a great effect such as being excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a floppy disk liner according to the present invention.

FIG. 2 is an explanatory view showing an example of distribution of fibers to which polymer resins A and B are attached in a non-thermocompression-bonded portion of the floppy disk liner of FIG.

[Explanation of symbols]

1 surface of liner (surface in contact with floppy disk) 2 back surface of liner (surface in contact with jacket) 3 non-thermocompression bonding part 4 thermocompression bonding part 5 distribution curve of polymer resin A adhered fiber 6 distribution curve of polymer resin B adhered fiber

Front Page Continuation (72) Inventor Hisako Toda 4-60 Sunadabashi, Higashi-ku, Nagoya, Aichi Prefecture Mitsubishi Rayon Co., Ltd. Product Development Laboratory

Claims (2)

[Claims] 1. A floppy disk liner made of a non-woven fabric containing thermoplastic fibers, having a thermocompression bonding portion and a non-thermocompression bonding portion, the shape of which is retained by the thermocompression bonding portion, the back surface of the non-thermocompression bonding portion of the liner. 5% by weight or less of the polymer resin A, which is indirectly attached to the constituent fibers, gradually adheres to the front surface of the liner, and the polymer resin B having smoothness from the front surface to the back surface of the non-thermocompression-bonded portion of the liner is A liner for a floppy disk, which is characterized by gradually adhering 2% by weight or less. 2. The polymer resin A is an acrylic or polyester thermosetting resin, and its adhesion amount is 1 to 5% by weight, and the polymer resin B is a polysilicon resin or a polyfluorinated resin, and its adhesion amount. Is 0.5 to 2% by weight, and the floppy disk liner according to claim 1.