JPS63168888A - Floppy disk - Google Patents

Abstract

PURPOSE:To attain improve durability, a reduced frictional coefficient and the stable traveling performance of a floppy disk under a wide range of environmental conditions, by sticking and impregnating a solution having specific concentration of traialkylester phosphate into a liner. CONSTITUTION:A both-face recordable magnetic disk 5 is provided together with a hub 6 set at the center of the disk 5 and an approximately C-shaped liner 7 made of an unwoven fabric of rayon, etc. a solution of 0.5-1.5% trialkylester phosphate is impregnated into the disk rubbing surface part of the liner 7 attached to the inner surface of a hard case which stores the disk 5 so that it can be rotated and recorded/reproduced. The trialkylester phosphate has a solid state at room temperature and therefore the frictional coefficient of the liner 7 is reduced when such trialkylester phosphate is impregnated into the liner 7. As a result, the rotational torque of the disk 5 is reduced and the travelling performance of the disk 5 is improved.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is a hard case (hereinafter referred to as a hard case) made of hard plastic, etc., in which a magnetic disk is housed in a manner that allows it to be rotated, recorded and reproduced, and used in information terminal equipment. The present invention relates to a small-sized floppy disk that can be used, and particularly to a floppy disk that has excellent wear resistance and runnability.

Conventional technology Conventionally, this type of hard case has been lined with a non-woven fabric called a liner, made of extremely high porosity rayon or other non-woven fabric. The purpose of this was to improve reliability by eliminating adverse effects such as recording and reproducing defects such as missing pulses and extra pulses.

However, with the recent trend towards higher density recording, the cleaning effect of floppy disks has tended to increase.

Furthermore, in order to reduce the size and weight of disk drives, motors with low driving torque are increasingly being used as drives.

In such floppy disks, when trying to increase the cleaning effect, the contact pressure between the liner and the disk tends to become excessive, and as a result, the rotational torque of the disk increases, which adversely affects the running performance and durability of the disk. There is a risk.

Therefore, as a countermeasure to this problem, it has been proposed to attach and impregnate the liner with a lubricant to improve the slippage of the disk.

Various lubricants are used for this purpose, such as silicone oil and fluorine-containing silicone oil.
5. Japanese Unexamined Patent Publication No. 61-158085 is known.

Problems to be Solved by the Invention However, with the conventional measures as described above, although the wear resistance of the disk is certainly improved by the action of the lubricant, the friction coefficient of the liner is not improved at all, so the rotational torque of the disk is large. The running performance of small floppy disks is not fully satisfactory.

In addition, lubricants such as silicone oil and fluorine-containing silicone oil that have traditionally been used in the liner's lubricating layer are uniformly dispersed and difficult to apply and impregnate, impairing their original cleaning effect and causing missing pulses and There is a possibility that an adverse effect of recording/reproduction failure due to extra pulses etc. may occur.

In view of the above-mentioned problems, the present invention provides a floppy disk in which the friction coefficient is lowered without impairing the cleaning action of the liner, and the wear resistance and runnability of the disk are greatly improved.

Means for Solving the Problems In order to solve the above problems, the floppy disk of the present invention has a phosphoric acid trialkyl ester concentration of 0.6% or more and 1.6% or less on the disk sliding surface of the liner. It is attached and impregnated with a solution of

The phosphoric acid trialkyl ester used in the present invention is a triester consisting of a saturated aliphatic alcohol having about 14 to 20 carbon atoms and phosphoric acid, and specific examples thereof include tritetradecyl phosphate, trihexadecyl phosphate, Examples include stearyl phosphate.

These exhibit a solid state at room temperature.

In order to adhere and impregnate the sliding contact surface of the liner with the above phosphoric acid trialkyl ester, dissolve it in a suitable solvent such as trichlorotrifluoroethane and apply or spray the resulting solution onto the liner, or apply the above solution to the liner. This can be done by immersing it in the liquid, and an appropriate method can be adopted as necessary.

The mixing ratio of the phosphoric acid trialkyl ester and the solvent is preferably within the range of 6:995 to 12:988 by weight.

Function The phosphoric acid trialkyl ester used in the present invention is solid at room temperature, and when adhered and impregnated into a liner, the friction coefficient of the liner is reduced, the rotational torque of the disk is small, and it is effective in improving running performance.

The reason for this is not necessarily clear, but phosphoric acid trialkyl ester acts as a dispersant, so it can be uniformly dispersed into the liner, making it easy to apply and impregnate it.Moreover, because it has a lubricating effect, it transfers to the discs that are in sliding contact. The effect is fully exhibited, and wear resistance and running performance can be greatly improved.

However, if the blending ratio of phosphoric acid trialkyl ester is too small, such as 0.5% or less, the friction coefficient of the liner will not be sufficiently improved and the amount of disk transfer will be small, so that the lubrication sustaining effect will not be sufficiently exhibited.

On the other hand, if the amount is too high (1.6% or more), there is a risk that the disk or head will be contaminated, the output will be reduced, and missing pulses or extra pulses will be generated, and the effect of the present invention will be lost.

As described above, the present invention provides a floppy disk whose durability and runnability are ensured by the above-described structure.

Examples Examples and comparative examples of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing an example of a floppy disk according to the present invention, and FIG. 2 is a cross-sectional view thereof, in which 1 is a hard case, 2 is an opening for inserting a head, 3 is a center opening for inserting a rotational drive shaft, 4 is an index hole detection opening, 6 is a magnetic disk that can record on both sides, 6 is a hub provided in the center of the magnetic disk, and 7 is a substantially C-shaped liner made of nonwoven fabric such as rayon. It is.

Examples and comparative examples of the present invention using such a floppy disk will be described in detail below. Note that all parts below refer to parts by weight.

(Example 1) Tristearyl phosphate 11 parts Trichlorotrifluoroethane 1000 parts A liner was immersed for a short time in a solution prepared by thoroughly mixing and dispersing the above composition in a ball mill, and after drying, it was attached to a node case. I inserted a magnetic disk inside and assembled a floppy disk.

(Example 2) A floppy disk was assembled using the same composition as in Example 1 except that the amount of tristearyl phosphate used was changed to 7 parts, and all the conditions were the same.

(Example 3) A floppy disk was assembled using the same composition as in Example 1 except that tritetradecyl phosphate was used instead of tristearyl phosphate.

(Comparative Example 1) A floppy disk was assembled under the same conditions as in Example 1 except that silicone oil was used instead of tristearyl phosphate.

(Comparative Example 2) A floppy disk was assembled using the same composition as in Example 1 except that trilauryl phosphate was used instead of tristearyl phosphate.

(Comparative Example 3) A floppy disk was assembled using the same composition as in Example 1, except that fluorine-based silicone oil was used instead of tristearyl phosphate, which was used in the past, and all the conditions were the same.

(Comparative Example 4) A floppy disk was assembled under the same conditions as in Example 1 except that tristearyl phosphate was omitted.

The floppy disks of the above Examples and Comparative Examples were loaded into a recording/reproducing device at -6°C and 40''C 80%RH.
While running on the same track in an environment of
Acceleration durability was examined by sliding contact in seconds and measuring the running time until the reproduction output reached 70% of the initial value.

Further, the above disk was installed in a 3-inch compact floppy disk drive under an environment of 40'080% RH, the same track was operated 24 hours a day, and the starting torque (T!) after stopping for 6 hours was investigated.

Furthermore, after measuring the starting torque, the static friction coefficient (μS) between the liner and the magnetic disk was measured using a cursor-type static friction coefficient measuring device (manufactured by Kyowa Kagaku Co., Ltd.) under an environment of 23°Css%RH.

Table 1 summarizes the results.

As is clear from the results in Table 1, the floppy disks obtained in the Examples have a longer running time than the Comparative Examples, and have a low starting torque with no adhesion between the disk and the head. Furthermore, it can be seen that the friction coefficient between the liner and the magnetic disk is low, so the wear resistance and running performance of the disk are well balanced.

Table 1 Effects of the Invention As described above, according to the present invention, by adhering and impregnating the liner with a solution having a concentration of phosphoric acid trialkyl ester of 0.6% or more, the durability and friction coefficient under a wide range of environmental conditions can be improved. A highly reliable floppy disk with low runnability and stable running properties can be obtained. Therefore, it has great practical value.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a floppy disk using the liner of the present invention, and FIG. 2 is a cross-sectional view of FIG. 1. 1...r...Hard case, 2...Opening for head insertion, 3...Center opening, 4...
- Index hole detection opening, 5...magnetic disk, 6...hub, 7...liner. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] The concentration of trialkyl ester of phosphate is 0 on the disk sliding surface of the liner attached to the inner surface of the hard case that houses the magnetic disk so that it can be rotated from the outside and recorded and played back.
．． A floppy disk characterized in that it is adhered and impregnated with a solution of 5% or more and 1.5% or less.