JPS61120386A - Magnetic sheet cassette - Google Patents

Abstract

PURPOSE:To prevent a decrease in the density of the lubricant of a magnetic sheet by a simple method by treating a liner sheet with a lubricant of the same kind with a magnetic layer and incorporating at least a hydrocarbon lubricant in the liner sheet. CONSTITUTION:The magnetic sheet has the magnetic layer formed on a nonmagnetic base and the liner sheet is provided in contact with the surface of the magnetic sheet and treated with the lubricant of the magnetic sheet, and contains at least the hydrocarbon lubricant. This hydrocarbon lubricant used, for example, a petroleum, lubricant, a synthetic lubricant, and others. Consequently, a decrease in the density of the lubricant of the magnetic sheet is prevented securely and effectively and various troubles resulting from that the lubricant of the magnetic sheet decreases below a necessary amount are therefore prevented.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a magnetic sheet having a magnetic sheet having a magnetic layer formed on a non-magnetic support, and a liner sheet in contact with the surface of the magnetic sheet. Regarding cassettes.

[Conventional technology]

A magnetic sheet is usually formed into a circular flat plate shape, and is used, for example, as a so-called floppy disk, a combi disk, a floppy disk, and other recording means.

, Flo, and Bidiscs are popular because they allow a large amount of information to be stored on a small disk.
In recent years, it has been rapidly used as an external recording device for computers, personal computers, etc. On the other hand, along with this, there has been a strong demand for ensuring durability, etc., and it is required that no errors occur even when used for a long time.

Conventionally, the ninth step to extending the life of a magnetic sheet is to apply a lubricant internally to the surface to form a lubricant layer, thereby suppressing wear caused by friction with magnetic fields, pads, etc. is being carried out.

By the way, as shown in FIG. 1, a floppy disk cassette consists of a sheet 1 called a liner sheet placed inside a jacket 2, and the surface of the floppy disk is in contact with the liner sheet 1. It is stored in The liner sheet is made of non-woven fabric, etc., and has the effect of cleaning the surface of the Flo and Pidisc by wiping it in contact with the surface. This removes dust and the like that adheres during recording and playback, and plays a role in reducing dropouts.

Therefore, the lubricant present on the disk surface is used not only to lubricate the disk, pad, etc., but also to lubricate the liner sheet. However, as a result of this, the lubricant on the floppy disk is transferred to the liner sheet side due to contact with the liner sheet, and the lubricant on the disk surface may be reduced compared to a predetermined square.

This tendency is particularly strong for low-molecular-weight lubricants that tend to migrate, and the amount of lubricant required on the disk surface may be significantly reduced from the specified amount. After all, for example, if a magnetic sheet is stored for a long period of time, and the storage conditions are relatively high at about 45°C, the lubricant present on the surface of the magnetic sheet will transfer to the liner sheet, and the surface of the magnetic sheet will be transferred to the liner sheet. The amount of lubricant is reduced and the lubricant becomes less effective. If this is excessive, there is a risk that the magnetic sheet will be damaged when the magnetic head and the magnetic sheet come into sliding contact. Alternatively, the frictional force between the magnetic sheet and the magnetic field may become excessive, causing an abnormal overload phenomenon in the motor of the floppy disk drive, increasing the torque, and causing troubles such as stopping the entire device.

Under these circumstances, a technique has been proposed in which the same or the same type of lubricant as the lubricant mixed on the disk surface is mixed into the liner material in order to maintain a constant lubricant concentration on the surface of the floppy disk. (U.S. Pat. No. 4,354,213). However, as mentioned above, the situation in which the lubricant migrates differs depending on the type of lubricant, and cannot be said to be a rule, so this concept alone will not necessarily solve the above problem. Rather, unless some kind of lubricant is identified, it is thought that no specific effect will occur. In this conventional technology, long-chain fatty acids and their esters are assumed as lubricants, and depending on the type of fibers in the liner sheet, these are mixed in advance into the fiber raw material or mixed into a binder solution that fixes the fibers. It has become so. However, both methods require work steps at the initial stage of liner sheet manufacturing (fiber manufacturing stage and sheet-forming stage), are complicated processes, and require advanced work techniques.

[Purpose of the invention]

An object of the present invention is to prevent the concentration of the lubricant on the magnetic sheet from decreasing with a simple means, and to further ensure this effect by specifying all the lubricants on the liner sheet. To provide a magnetic sheet cassette and toe which can prevent various troubles caused by lowering the required amount of lubricant, thereby improving the performance of the magnetic sheet and improving its durability and reliability. It is in.

[Structure and operation of the invention]

The magnetic sheet cassette of the present invention includes a magnetic sheet having a magnetic layer formed on a non-magnetic support, and a liner sheet in contact with the surface of the magnetic sheet, and the liner sheet is of the same type as the magnetic layer of the magnetic sheet. However, this liner sheet contains at least a hydrocarbon-based lubricant as the lubricant.

Because of this structure, 1. In the present invention, the liner sheet is treated with the same type of lubricant as the magnetic layer of the magnetic sheet, and as a result, the transfer of the lubricant from the magnetic layer to the liner sheet is suppressed, and the magnetic layer always have the necessary lubricant. In addition, since the liner sheet contains at least a hydrocarbon lubricant as a lubricant, the lubricant in the magnetic layer is more reliably retained and functions effectively. Moreover, the liner sheet exhibits this effect by being treated with the same type of lubricant as the magnetic layer.
No complicated steps are required, and the present invention is simple and easy to apply.

In the present invention, the liner sheet only needs to be treated with the same type of lubricant as the magnetic layer, and does not necessarily have to be a hydrocarbon-based lubricant. However, if a type of lubricant other than a hydrocarbon lubricant is used in common, the liner sheet must contain the hydrocarbon lubricant. Of course, the same type of lubricant may be the same substance, but it also may be the same type of lubricant. Any material may be used as long as it can prevent the lubricant from migrating to the surface.

For example, if the magnetic layer has a hydrocarbon-based lubricant, it can exhibit this effect even if it is not the same material as long as the liner sheet is treated with a hydrocarbon-based lubricant.
It may also be fatty acids or their esters. magnetic layer,
When there are two or more lubricants in any of the liner sheets, at least one of the lubricants must be of the same type; in short, it is sufficient that the same type of lubricant is present in common.

When a plurality of lubricants are included in the magnetic layer, it goes without saying that it is preferable to use the lubricant component for liner treatment in the same ratio.

Hydrocarbon-based lubricants that can be used as liner sheet lubricants in the present invention include, for example, petroleum-based lubricating oils, synthetic lubricating oils, and others. Petroleum-based lubricating oils contain hydrocarbon components such as high molecular weight hydrocarbons, as well as S and N.

Although it may contain elements such as 0, such elements are also included in the present invention. Liquid paraffin and the like can be preferably used. Synthetic lubricating oils include, for example, olefin polymerized oils obtained from ethylene, butylene, and the like.

Others, Suhwara/(2゜6.10,15,19,23
-hexamethyltetracosane) and the like can also be suitably used.

In addition to hydrocarbon-based lubricants, the liner sheet lubricant can be used in combination with other lubricants. For example, hydrocarbons and fatty acid esters may be combined. Using squalane as a hydrocarbon lubricant,
Examples include combinations thereof with butyl stearate (fi), octyl myristate (n), octyl palmitate (i), or octyl stearate (i).

Moreover, a combination of hydrocarbon and glyceride can also be used. Examples include a combination of liquid paraffin as a hydrocarbon lubricant and triolein glyceride, olive oil, or trimyristine glyceride. Any of the combinations exemplified above can be used at a concentration of 0.3 wt% by mixing them at a ratio of 1:1, for example. A combination of a hydrocarbon and an unsaturated fatty acid ester can also be used, such as squalane and oleyl oleate, myristyl oleate, lauryl oleate, or instearyl oleate.

Further, lubricants that can be used in combination with hydrocarbon lubricants include fatty acids, fatty acid amides, metal soaps, aliphatic alcohols, paraffins, silicones, fluorosurfactants, and other fatty acid esters other than those listed above.

As the fatty acid, those having 12 or more carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, and lilunic acid can be preferably used.

As the fatty acid ester, in addition to those exemplified above, ethyl stearate, butyl stearate, amyl stearate, stearic acid monoglyceride, oleic acid monoglyceride, etc. can be used.

Fatty acid amides include caproic acid amide, capric acid amide, lauric acid amide, no(lumitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, linoleic acid amide, ethylene bisstearic acid amide, ethylene bis stearic acid amide) etc. can be used.

Examples of metal soaps include Zn) Pb such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, and linuric acid.

Ni, Oo, Fe, kl, Mg, Sr,
Salts of O, etc., salts of carboxylic acids such as lauryl, palmityl, myristyl, stearyl, behenyl, oleyl, linole, linole, etc. and the above metals, etc. can be used.

As the aliphatic alcohol, cetyl alcohol, stearyl alcohol, etc. can be used.

As the paraffin, saturated hydrocarbons such as n-nonadecane, n-), 'lysocane, and n-tocosan can be used.

As silicones, polysiloxanes in which hydrogen is partially substituted with alkyl groups or phenyl groups, and those modified with fatty acids, aliphatic alcohols, monofatty acid amides, etc. can be used.As fluorine-based surfactants, Par 70 loalkylcarbo7tj and par70roalkylsulfonic acid and Na,
, Mg, Zn, t'+, l, Fe, Co, N
salts with per-70-roalkyl phosphates, perfluoroargyl betaines, per-70-roalkyltrimethylammonium salts, per-70-sethylene oxide, per-70-roalkyl aliphatic esters, etc. can be used.

Each of the above-described lubricants can be used singly or in combination as a lubricant for the magnetic layer.

The amount of lubricant added to the magnetic layer may be 5-30 parts by weight, preferably 1G-20 parts by weight, based on 100 parts by weight of the register.

The non-magnetic support and magnetic layer constituting the magnetic sheet can have any known configuration (υ), and the shape, material, etc. can be selected as appropriate.

The second inner sheet may be made of non-woven fabric, or may be made of other appropriate materials.

[Embodiments of the invention]

Hereinafter, some examples of the embodiments of the present invention will be illustrated and explained.

Example 1 In this example, a liner sheet made of nonwoven fabric was used. The liner sheet was treated with a lubricant that was a mixture of squalane and butyl stearate. On the other hand, the magnetic layer of this example contained butyl stearate as a lubricant. Therefore, in this example, the liner sheet is treated with butyl stearate, which is common to the magnetic layer, and therefore treated with the same type of lubricant, and the liner sheet is treated with a hydrocarbon-based lubricant. It contains a certain squalane.

・Vinyl chloride-vinyl acetate copolymer m, manufactured by O, O, Inc., trade name VAGH) (binder) 7
0O acrylonitrile-butadiene copolymer (trade name N
-1432J) (Binder) 300 Isocyanate Hardening Agent (Product Name: Coronet) L)
100 Carbon Black (manufactured by Asahi Carbon Co., Ltd., trade name Ha-500) (antistatic agent)
30'0r103 abrasive
100 Lubricant Butyl stearate 20 0 Toluene 4000 Methyl ethyl ketone 400 The above composition was kneaded in a ball mill for 48 hours, and then foreign matter was removed by a filter, and then coated on a polyester base (75 μm), which is a non-magnetic support, to a coating thickness of 3 μm. It was applied so that The magnetic sheet was then punched out into a disk shape to obtain a magnetic sheet.

Next, the lubricant treatment on the liner sheet will be described.

There are various treatment methods such as a dipping method, a spray method, a coating method, and a centrifugation method, and any of them can be employed. In this example, the treatment was performed by a dipping method.

The treatment solution was prepared as follows.

By using this treatment solution and changing the treatment concentration, the adhesion amount on the liner sheet was 3q/1 (Example 1-1), 6q/2 (Example 1-2), and 12q/l (Example 1). -3),
tswI9/r (Example t-4).

18K/2 (Example 1-5), 24mf/f (Example 1
-6) The liner sheet was treated so as to have the following properties.

The running durability of the 70-tube disk made in the above example was investigated. The test was conducted as follows. 70
The Tsupi disk was attached to the recording/reproducing device, and the magnetic head was brought into sliding contact with the head pressure of 25 f, and the circumferential speed at that time was 2.5 m.
/sec.

Under these conditions, a 10 million bus run test was conducted on the same track, and the load torque of the drive motor and the playback output level (the playback output level immediately after recording was 1009?;
) was measured. A comparative example (Comparative Example 1) in which a magnetic layer was formed in the same manner as in Example 1 and the liner sheet was not treated with a lubricant was also tested.

The results are shown in Table 1.

Table 1 As is clear from Table 1, the 70 disks of this example, in which the liner sheet was treated with a lubricant, all showed better results than the comparative examples, and the present invention is applicable to them. It can be seen that this is effective in extending the life of the magnetic sheet. Also, from Table 1, in this example, the treatment concentration of the liner 7-t is such that the amount of lubricant attached to the liner is 6.
■/l~18m1/? It is particularly preferable that the lubricant falls within the range of , however, it can be seen that the effect of lubricant treatment on the liner appears regardless of the amount of adhesion.

Example 2 In this example, the lubricant in the material composition of the magnetic layer of Example 1 was changed from butyl stearate to SQUA 2/. As in Example 1, the liner sheet was treated using a 1:1 mixture of squalane and butyl stearate. In this example, the hydrocarbon lubricant contained in the liner 7 is squalane, and the lubricant common to the magnetic layer is also squalane.

When the test was conducted in the same manner as in the example above,
Good results similar to those in Example 1 were obtained.

Example 3 In this example, squalane was used as the lubricant in the material composition of the magnetic layer of Actual IF+Example 1, and squalane was used as the treatment liquid for the thinner sheet, using toluene as a solvent.

The treatment was carried out using a lubricant of 127 i/2 (liner 7-tashi). A test similar to that described above was conducted with one stage (ratio fv row 2) in which the liner 7-t was not treated with lubricant. The results are shown in Table 2.Table 2 From Table 2, it can be seen that the life of the magnetic sheet was significantly improved in this example as well.

Example 4 As in Example 3, squalane was used as the 14 lubricant in the magnetic layer. In this series, a 1=1 mixture of squalane and olive oil was used as the treatment liquid for the liner sheet. When treated in the same manner as in Example 3, the results are shown in Table 3 together with Comparative Example 2.

From the upper table of Table 3, it can be seen that good results were obtained in this example as well.

Example 5 In this example, a magnetic layer was formed by changing the lubricant from butyl stearate to fluid fin in the material composition of the magnetic layer in Example 1. The liner sheet was treated by a dipping method using liquid paraffin as a lubricant and a treatment solution prepared as Freon 112 as a solvent. Therefore, in this example, the magnetic layer and the liner sheet use liquid paraffin as a common lubricant, and the liner sheet contains liquid paraffin, which is a hydrocarbon-based lubricant.

In this example, the concentration of the liner treatment liquid is changed to
7470.1% (Example 5-1), 0.2% (Example 5-1)
-2), 0.3% (Example 5-3), and the liner sheet was treated. Comparative Example 3 is a case in which the same magnetic layer is used and a liner sheet is not treated with a lubricant.

Regarding such Examples and Comparative Examples, the same tests as in Example 1 were conducted. The results are shown in Table 4.

Table 4 From Table 4, it can be seen that the life of the magnetic sheet is significantly improved in this example as well.

It should be noted that, as a matter of course, the present invention is not limited only to the embodiments and illustrations described above.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reliably and effectively prevent the concentration of the lubricant in the magnetic sheet from decreasing with a simple means, and therefore, various troubles caused by the lubricant in the magnetic sheet being less than the required amount can be prevented. It can be prevented. Therefore, the magnetic sheet cassette of the present invention has the effect of improving the performance of the magnetic sheet and improving durability and reliability.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a general magnetic seven-piece cassette. 1...Liner sort, 2...Jacket.

Claims (1)

[Claims] A magnetic sheet cassette comprising a magnetic sheet having a magnetic layer formed on a non-magnetic support and a liner sheet in contact with the surface of the magnetic sheet, wherein the liner sheet is treated with the same type of lubricant as the magnetic layer. A magnetic sheet cassette characterized in that the liner sheet contains at least a hydrocarbon lubricant as a lubricant.