JPH02235275A - Floppy disk - Google Patents

Abstract

PURPOSE: To provide a floppy disk which is superior in media durability, media error generation rate, etc., by using an oil-repellent nonwoven fabric for the liner which is in contact with the surface of magnetic layer. CONSTITUTION: The magnetic disk medium 1 is covered with a jacket 5; liners 3, 4 in contact with the surface of the medium 1 is equipped on the inner face of the lifter section of the jacket 5; and the central section of the medium 1 is installed with a fixing hub 2. An rectangular opening 6 is installed to bring the magnetic head in contact with the medium 1. Oil-repellent nonwoven fabrics composing the liners, 3, 4, have the nature of repelling lubricants and is made by a method that an oil-repellent disk 8 is installed by spray-coating oil-repellent solution pertaining to the rayon family, the polyethylene terephtalate family, etc., to installed an oil-repellent disk 8 to the nonwoven fabrics and thereby reducing the surface tension of the fabric. By this, a floppy disk which is excellent in media durability, media error generation rate, etc., is obtained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a floppy disk with improved performance such as media durability and media error rate.

[Conventional technology]

A conventional floppy disk, as shown in Figure 2,
A magnetic disk medium 1 is provided with a magnetic layer on a disc-shaped non-magnetic support and has a lubricant on the surface of the magnetic layer.
The inner surface of the jacket 5 is fitted with liners 3 and 4 made of non-woven fabric.

A magnetic disk medium 1 is fixed with a disk 2. The liners 3 and 4 cover the surface facing the magnetic disk medium 10, except for a notch 7 facing a rectangular opening 6 for bringing the magnetic head and the magnetic disk medium 1 into contact (for example, Publication No. 61-255682, Japanese Unexamined Patent Publication No. 62-5
Publication No. 1027).

[Problem that the invention seeks to solve]

However, in conventional floppy disks, no matter how the material of the nonwoven fabric that is the liner is selected, the nonwoven fabric has capillary action, so it is difficult to reduce the transfer speed to prevent lubricant from transferring from the magnetic layer of the magnetic disk medium to the liner. It was difficult to reduce it. As a result, the lubricant is quickly lost from the magnetic layer, causing wear of the magnetic layer during running of the N1 floppy disk, which in turn causes a decrease in the durability of the floppy disk media.

SUMMARY OF THE INVENTION An object of the present invention is to provide an economical floppy disk with excellent durability.

[Means for solving problems]

According to the present invention, a magnetic disk medium 1 is provided with a magnetic layer on one or both surfaces of a disc-shaped non-magnetic support and has a lubricant on the surface of the magnetic layer, a liner 3 that can come into contact with the surface of the magnetic layer, There is provided a floppy disk comprising a jacket 5 having an inner surface κ and a jacket 5, characterized in that the liners 3 and 4 are made of an oil-repellent non-woven fabric. In another embodiment, in the floppy disk K, the oil-repellent nonwoven fabric is a nonwoven fabric having an acrylic polymer coating containing a perfluoroalkyl group, a nonwoven fabric having a urethane oligomer coating containing a perfluoroalkyl group, or a nonwoven fabric having a perfluoroalkyl group-containing urethane oligomer coating. Provided are nonwoven fabrics having an acid coating or a nonwoven fabric having a metal salt coating of a perfluoroorganic acid.

FIG. 1 is an exploded perspective view of a floppy disk according to an embodiment of the present invention. As explained with reference to FIG. 1, the floppy disk of the present invention is constructed by covering a magnetic disk medium 1 with a jacket 5. As shown in FIG. Liners 3 and 4 that come into contact with the surface of the magnetic disk medium 1 are attached to the inner surface of a portion of the lifter of the jacket 5, and a blade 2 for fixing the liners is provided at the center of the magnetic disk medium 1. The rectangular opening 6 is
K to bring the magnetic head into contact with the magnetic disk medium 1
establish.

The magnetic disk medium 1 is made of a base material such as a polymer film, provided with κ magnetic layers on both sides, and has a lubricant held on both surfaces. The lubricant improves the durability of the floppy disk by preventing wear of the magnetic layer at the contact area between the magnetic head and the magnetic layer during running of the floppy disk. For this reason, the lubricant is preferably one that exists stably as a liquid in the usage environment (0 to 60° C.) and is less susceptible to physical and chemical influences such as adsorption and decomposition in the magnetic layer. Lubricants that can be used for this purpose include alcohols, silicone oils, higher fatty acids, paraffinic hydrocarbons, fatty acid esters, esters of glycerin, perfluoroalkyl ethers, per7lolo fatty acid esters, silicate esters, phosphate esters, and polyesters. Examples include glycol and the like. In the present invention, in particular,
The following general formula: RICOH2 0 C-R3 (The above formula % Rl "" R4 is
Fatty acid esters (representing 1-C21J alkyl groups) can be preferably used.

Liners 3 and 4 in the floppy disk K of the present invention
The oil-repellent nonwoven fabric is a nonwoven fabric that has the property of repelling the lubricant. The oil-repellent non-woven fabric in the present invention may be any known non-woven fabric, such as a rayon-based, polyethylene terephthalate-based, nylon-based non-woven fabric, or a blend thereof, by spray coating with a 9K oil repellent solution, or by spray coating with a 9K oil repellent solution. The surface tension of the nonwoven fabric is lowered by providing an oil repellent coating 8 by a method such as dipping the nonwoven fabric in an oil solution. The critical surface tension of the above-mentioned known nonwoven fabrics is about 40 to 45 dyn/crt, and the critical surface tension of the nonwoven fabrics having the oil repellent coating of the present invention is about 20 dyn/crt1 or less. For reference, in order to determine the critical surface tension of a nonwoven fabric, that is, the surface energy of a plastic, droplets of multiple liquids with known surface tensions are attached to the solid surface to be measured), and the contact angle θ From the straight line obtained by plotting a series of values,
Determine the surface tension that gives the contact angle O. This n is called the critical surface pressure rσ, and is estimated to be the surface energy of the solid.

(For details, see "Tribology" by Kiyoshi Matsubara, published by Sangyo Tosho Publishing Co., Ltd. in 1980, p. 106) As the oil repellent used in the oil repellent treatment of nonwoven fabric in the present invention, for example, (
b) Formula: (In the formula, each of Rl and R2 is an independent K hydrogen atom or a methyl group, and n is an integer of 7 to 13.) Perfluoroalkyl group-containing acrylic polymer with a molecular weight of 10[]00
(mouth) Polyfunctional isocyanate such as tolylene diisocyanate and hexamethylene diisocyanate and the formula; c(1
p, n+ISO2NH-CH2CH20H (wherein, n
is an integer from 7 to 13), a compound represented by the formula: CnF2
n+1802NCH2CH20H (wherein, n is 7 to 1
3 Ordinary CH. Perfluoroalkyl group-containing urethane IJ 1''mer which is a condensation compound with a perfluoroalkyl group-containing compound such as a compound represented by the formula (CnF2)
n+ 1(CH2)mCOOHC where n is 7
m is an integer of 2 to 6) or (d) the above par-7
Examples include salts (including complex salts) of fluorocarboxylic acid and zinc, zirconium, etc., and gold maple.

Finally, the oil repellent in the present invention has a surface tension lower than that of the lubricant (specifically, critical surface tension: 1 5
dyn/an), it has the property of repelling lubricants.

[Effect]

The liner of the present invention is made of an oil-repellent nonwoven fabric, which is different from conventional liners made of nonwoven fabric.

In the conventional liner K, the lubricant is transferred to the nonwoven fabric as the running time of the floppy disk passes due to capillary action existing in the gaps between the nonwoven fabrics. Compared to conventional liners, the nonwoven fabric in the liner of the present invention has a lower surface tension, which inhibits capillary action and prevents or reduces lubricant migration to the nonwoven fabric. For this reason. , the lubricating effect of the lubricant on the surface of the magnetic disk medium will last significantly longer. Moreover, the liner of the present invention does not lose its original effect of preventing charging of the entire magnetic disk medium and cleaning the surface thereof.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these Examples.

Cobalt-containing gamma iron monoxide carbon plaque alumina nitrocellulose (A" {*RSI manufactured by A4) Polyurethane (HI-2000 manufactured by Dainippon Ink Co., Ltd.) Lubricant cyclohexane methyl ethyl ketone 100 parts by weight 15 I 14 l 200 N 200 l Composed of the above composition A friend who adjusts magnetic paint.

This was applied to both sides of a polyethylene terephthalate film with a thickness of 7.5 μm, and after drying thoroughly, it was calendered.
A film having a magnetic layer with a thickness of 1.0 to 1.3 μm was obtained. After leaving this at 60℃ K for 2 days in Oden,
A magnetic disk medium was manufactured by punching and polishing into a disk shape. ◎ Additionally, a nonwoven fabric 1 with a thickness of approximately 0.1 to 0.6 fl was placed on both sides of the inner surface of the jacket made of AB8 resin, which has a portion of the lifter.
An oil-repellent non-woven fabric formed by spray-coating an oil-repellent solution was attached so that about 80 m9 of solid oil repellent was coated per cI1''.The above-mentioned magnetic disk medium was loaded into this jacket, and 3 .5# floppy disk was manufactured.

On the other hand, for comparison, 3. was carried out in the same manner as above except that a nonwoven fabric without an oil repellent coating was used as the liner.
A 5s float T-disk was manufactured.

These floppy disks have: (1) O tensile strength in the vertical direction of the liner (k9/ff”), (21 Oil repellency of the liner, (3) lubricant transfer rate to the liner (%)
), (4) media durability (10,000 passes), and (5) media error occurrence rate (%) were measured. Here, the above (2
) The oil repellency of the liner is determined by dropping one drop (0.05 to 0.1114) of lubricant onto the liner placed horizontally, and visually checking how wet the liner is after about 1 minute. (○: The lubricant droplets did not penetrate into the liner at all, and no κ stain was observed. ). The transfer rate (%) of the lubricant to the liner in (3) above was determined by determining the amount of lubricant transferred to the liner after 15 million passes by gas chromatography, and calculating its ratio to the initial value κ. . The media durability (10,000 passes) in (4) above was determined by determining the number of passes until the magnetic layer wears out. The media error occurrence rate (%) in (5) above was determined by counting the number of signals initially recorded after storage at 40° C. and 80% RH for 6 days using an actual device.

The results of Kohori et al. are shown in No. 18 on the next page.

It should be noted that, as shown in Table 1, the urethane orico97 formula (11) shows that the liner in the floppy disk of the present invention is oil-repellent, unlike the liner in the floppy disk of the comparative example, so the transfer rate of the lubricant to the liner is low. is low, and has good tensile strength in both the longitudinal and longitudinal directions.
The media durability of the floppy disk of the present invention is as follows. Both have over 60 million buses, which is enough for practical purposes. Moreover, the floppy disk of the present invention does not cause any media errors.

In the floppy disk of the present invention, Scotchgard FC-905 manufactured by Sumitomo 3M Co., Ltd. is particularly preferred because it has a strong bonding force to the rayon nonwoven fabric.

〔Effect of the invention〕

In view of the above, it is possible to provide a floppy disk with significantly superior performance in various properties such as media durability and media error rate, and whose practical value has been dramatically improved by the present invention. It became.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a floppy disk according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a conventional floppy disk. 1...Magnetic disk medium 2...Hub 3 and 4...Liner 5...Jacket 6...Opening 7...Notch 8...Oil repellent treated surface

Claims (2)

[Claims] (1) A magnetic disk medium having a magnetic layer on one or both surfaces of a disc-shaped non-magnetic support and having a lubricant on the surface of the magnetic layer, and a jacket equipped with a liner on the inner surface that can come into contact with the surface of the magnetic layer. 1. A floppy disk comprising: a floppy disk, wherein the liner is made of an oil-repellent nonwoven fabric. (2) The oil-repellent nonwoven fabric is a nonwoven fabric having a perfluoroalkyl group-containing acrylic polymer coating, a nonwoven fabric having a perfluoroalkyl group-containing urethane oligomer coating, a nonwoven fabric having a perfluorocarboxylic acid coating, or a metal salt of perfluorocarboxylic acid. A floppy disk according to claim 1, which is a nonwoven fabric having a coating.