JPS6154084A - Floppy disc - Google Patents

Abstract

PURPOSE:To enhance the cleaning efficiency against a disc of a jacket by sticking a liner and a plastic sheet in the vicinity of a punched opening part. CONSTITUTION:A jacket is constituted of a plastic sheet and a liner of an unweaving fabric on the back surface. According to the opening part punched in the specified position provided in the jacket, the liner is sticked with the plastic sheet in the vicinity of the punched opening part. Therefore, in the vicinity of the opening part, the falling of a fibre from the liner is decreased and in the other part, the cleaning efficiency to the disc is enhanced because of the small amount of a binder.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Application The present invention relates to a floppy disk, and more specifically to a 70-inch disk consisting of a flexible disk in which a magnetic recording medium is formed on a base film, and a jacket containing the disk. Regarding improved technology.

b. Prior Art With the spread of 0Aill devices, floppy disks, which serve as the storage portion of computers and word processors, have come into wide use.

In the past, floppy disks were used in computer environments that were controlled under certain conditions, but these days they are used in general offices, workplaces, and stores.

They are increasingly being used in environments with a wide range of temperature and humidity conditions, such as homes, and with poor cleanliness.

It is necessary for floppy disks to operate with high reliability even under such severe conditions, and quality improvement to increase the reliability of floppy disks has become an important issue.

As mentioned above, a floppy disk consists of a flexible disk (hereinafter referred to as a disk), which is a magnetic recording medium punched out in the shape of a disk, and a jacket that houses it. It is lined with a liner that has a removal function.

When the disk rotates, the liner and disk come into appropriate contact, and foreign matter on the medium is efficiently removed.

Incidentally, foreign substances that can adhere to the disk include sand, dust, fibrous dust, etc. that enter from the outside through the openings.

On the other hand, dust and fiber fragments generated from the jacket liner itself have a great effect on the reliability of floppy disks.

Liners are non-woven fabrics made of fibers mainly made of rayon, but when roughly classified based on manufacturing method, non-woven liners are classified into binder-based non-woven fabrics that use a latex binder, and non-woven fabrics that use virtually no binder (no binder). Binder-based non-woven fabric [The binder-based non-woven fabric has a length of 50
Shun carded the fibers after mm@ and made them into a web.
Since the fibers are processed with a rubber-based resin emulsion, the fibers are intertwined with high density. When used as a liner, there is little fibrous material falling off, and the openings formed by punching the jacket are free of falling material and fluff, which is good.

However, because the wear is hard, its performance in wiping away dust, that is, its cleaning performance, is poor, and when used under conditions with a lot of dust, it may cause temporary errors (transient).
error) is likely to occur.

On the other hand, binder-free nonwoven fabrics are made by, for example, rayon and polypropylene fibers that are mechanically bonded using a water jet or partially subjected to heat embossing treatment, and mNI!
! Since the I is coarsely entangled, fiber waste is likely to be generated due to frictional action, and fluff is often generated at the jacket opening, and furthermore, fibers are likely to fall off from the batting cut surface.

On the other hand, ware with a soft and rough structure exhibits good dust wiping properties, and results in a reduction in temporary errors have been obtained depending on the usage environment or in some types of floppy disk drives.

Conventional technology includes binder-based nonwoven fabric binder I!
Although there have been attempts to reduce 11th (3) as much as possible, there is a tendency for the occurrence of fluff to increase as cleaning performance improves.

J3, punching fuzz impairs the quality of the floppy disk and lowers its commercial value.In addition, if the fuzz is of better quality, it may get caught in the head, causing not only errors but also precision problems. There is a risk that this may cause the position of the head set to shift.

In order to suppress the generation of fuzz at the opening, attempts have been made to increase the shoeing density around the opening, but the effect is not necessarily sufficient.

C0 Purpose of the Invention The present invention was made in view of the above points, and was made as a result of the discovery that the jacket and liner play an important role when conducting studies to improve the reliability of floppy disks. SUMMARY OF THE INVENTION It is an object of the present invention to provide a floppy disk with an improved jacket.

d, # (7) 4M 1751° The present invention is
A floppy disk consisting of a flexible magnetic recording disk and a jacket containing the disk,
In particular, the jacket part has been improved.

The improved jacket of the present invention is mainly composed of a plastic sheet and a non-woven liner provided on the back side of the plastic sheet, and in particular, the jacket has openings punched in a predetermined shape at a predetermined position on the jacket. The liner is attached to the plastic sheet near the punching opening, and the liner is attached to the plastic sheet in the vicinity of the punching opening.
The liner portion is not substantively bonded to the plastic sheet or is weakly bonded. It's also. In the present invention, the plastic sheet and ll8i1 are used, and the liner part that is sealed is the DI of the inner part! The adhesion rate of the binder contained in the non-woven fabric is low. In short, the amount of binder contained in the non-saddle fabric forming the liner is larger in the vicinity of the punched opening of the jacket than in the inner part. As a result, from the liner near the opening W! The cleaning effect on the disk is high because there is little falling off of lll1t and there is little or no binder eruption in other parts.

In the floppy disk of the present invention, a part of the liner corresponding to a part or all of the vicinity of the punched opening of the jacket has a
The jacket can be obtained by pre-treating with a binder and then applying a liner to the plastic sheet.

The nonwoven fabric used for the liner of the present invention is a so-called spunbond type nonwoven fabric that does not use a binder (binderless nonwoven fabric) and a nonwoven fabric with a small amount of binder, preferably 16
A binder nonwoven fabric having a weight of ω% or less can be used.

When the liner is attached to the plastic sheet,
Jacket punching part and its vicinity (17t TO part 1
7) Outside 111 (1) 5-10# about 1 ton? 7K) Ha, the binder is highly concentrated. Here, being attached at a high concentration means that l114 um is greater than m in the binder in other parts of the nonwoven IT forming the liner. The low content of binder refers to the amount of binder contained in the nonwoven base material itself, and does not mean that the binder is specifically excluded.

By applying the binder to the handling opening and its vicinity in the manner described above, the liner consists of a region with a high binder content and a region with a low temperature. Note that the liner and plastic sheet may be adhered in areas other than the punched opening and its vicinity as appropriate, and can be bonded entirely or partially (adhesion by dots), and the adhesion resistance of the binder in this adhered area is Is it about the same level as near the opening? The binder content may be 2 degrees or lower than this.

To perform binder treatment on a predetermined portion of the liner, it is possible to apply a resin liquid (binder) on a continuous web (nonwoven fabric) using a printing method such as gravure, or it is possible to apply a resin liquid (binder) to a continuous web (nonwoven fabric) using a printing method such as gravure, or to apply a binder treatment on a garment cut into sheets. The resin liquid can also be applied in a predetermined pattern using the method described above.

Alternatively, the resin can be applied to predetermined areas by spraying or using a roller after masking the unnecessary parts.

In either case, the supply of wear can be selected as needed, such as continuous running of continuous wear, intermittent running of continuous wear, or intermittent supply of cut sheets.Resin liquid (binder)
As such, an aqueous emulsion in which a resin having a hydrophilic group introduced into its molecule is emulsified and dispersed in an aqueous solution, a solution of a resin soluble in the solution, a liquid reactive hexamer or a prepolymer, etc. can be used.

The aqueous emulsion resin used in the present invention includes:
Copolymers of vinyl chloride or vinylidene chloride with vinyl acetate, acrylic esters, etc., water-soluble acrylic resins, ethylene/vinyl acetate copolymer resins, water-soluble epoxy resins, polyester resins, ethylene/butadiene rubber, acrylonitrile/butadiene rubber, etc. Further examples include resins used as various water-soluble adhesives.

Examples of solvent-soluble resins include vinyl chloride or vinylidene chloride resins, ethylene/vinylacetate copolymer resins, cellulose nitrate, cellulose acetate, and acrylonitrile/styrene copolymer resins (ABS).

As, AES, AA8, etc.), 'Phenoxy resin.

Polyurethane resins and the like; further examples include acrylonitrile rubber, styrene-butadiene rubber, and natural rubber.

Paid solvents used for this removal include methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran,
Aretone, ethyl acetate, cyclohexanone, toluene,
Examples include isopropyl alcohol, which can be used alone or in combination.

Examples of the reactive monomer or prepolymer include epoxy resin adhesives and cyanoacrylate adhesives.

Other examples include a method in which a radical polymer or oligomer is oxidized using a radical reaction initiator, light, or an electron beam cross-plate.

These resins may be used alone or in combination.

A curing crosslinking agent, a filler, a plasticizer, a lubricant, etc. are added to these resin components as necessary.

After the resin liquid thus obtained is applied to a predetermined portion of the liner, it is lightly smeared if necessary, and then air-dried or heated.

The predetermined area of the liner (near the opening) refers to the inside surrounded by a line 5 to 10 inches from the edge of the opening when the liner is attached to a plastic sheet and punched out. say. The inner region II may be treated, and the central portion removed by punching may not be treated.

Note that, depending on the case, the processing may be limited to only a specific part of the opening, for example, a head window.

As the plastic sheet for the jacket, polyvinyl chloride, post-chlorinated polyvinyl chloride, polypropylene, polyester, polycarbonate, etc. can be used.

As the liner, a binder-free nonwoven fabric or a binder nonwoven fabric with a binder adhesion m of 1 G% or less can be used. These nonwovens have excellent liner cleaning performance, but on the other hand, they tend to generate fuzz, which can be a problem, especially at the batting opening of the jacket.

The partial pre-resin treatment of the present invention provides a balanced improvement in liner cleanability and fuzziness.

Next, examples of the present invention will be described.

In the following examples, all parts refer to parts by weight.

<Implementation VA1> Polyurethane resin (Q oodrich “Nistan”)
) was prepared in 20% tetrahydrofuran solution.

A commercially available binder-free nonwoven fabric for a liner made of rayon and polypropylene fibers was cut into a rectangular shape with a size for a 51/4 inch jacket, that is, an outer size of 264 mm x 130 mm.

A paper pattern cut out from the dotted line area in Figure 1 was made using polyester film, and after overlapping it on the liner, the resin solution was applied to the area corresponding to the hatched area in the figure using a brush, and air-dried for 10 minutes.
After an hour, it was heated and dried at 50°C for 2 hours.

The treated liner was heated and adhered to a 0.21 mm thick polyvinyl chloride sheet, bent, and an opening was punched out to create a jacket. Next, a flexible disk was inserted and further bent to obtain a floppy disk.

Regarding the floppy disk created in this way,
The punching fuzz at the opening, which is related to the quality of the jacket, and the temporary error, which is related to the reliability of signal reading, were evaluated as follows.

(1) Approximately 1 mtm of exposed fluff is removed from each opening of the punched fluff.
Count in 3 categories: around 3IRrR and over 5m+.

Front and back sides of floppy disk (side O and side 1)
The number of fuzz is calculated by taking the average of the measurements of 10 samples.

(2) Using a 96TPI floppy disk device with a temporary error of 51/4 inches, all initialized signals are retried.
ry) Repeated reading at 0 times up to 500 times, and counted the number of times a CRC error occurred in each sector. Measurements were made on 10 samples, and the total evaluation was made.

The measurements were conducted in a semi-clean environment at 23°C and 55%.

Comparative Example 1 As a comparative example, a floppy disk was obtained in exactly the same manner as in Example 1, except that the same liner as in Example 1 was used and no resin liquid treatment was performed.

Table 1 (blank below) Nut IM Examples 2, 3, 4.5> A floppy disk was obtained in the same manner as in Example 1 except that the resin liquid in Table 2 was prepared instead of the resin liquid in Example 1. .

The results for fuzz and temporary errors are shown in Table 3.

(Margin below) Table 2 Table 3 <Example 5, 6.7> and Comparative Examples 2, 3, 4.5>
A binder-based nonwoven fabric made of rayon and polypropylene fibers was used as the nonwoven fabric for the liner. The binder is an acrylic resin type, and the resin adhesion resistance m varies as shown in Table 4.

The same NBR solution as in Example 2 was used as the resin liquid used in the treatment in Examples 5 and 6.7. In Comparative Example 2°3.4.5, no resin liquid treatment was performed.

A floppy disk was obtained in the same manner as in Example 1 except for the liner type and the resin liquid. The results of fluff and temporary errors are also listed in Table 4.

(Margins below) Table 4 Example 8.9 and Comparative Example 6.7 A binder-based liner using rayon fiber and a binder-free liner using polyester fiber were used as the nonwoven fabric.

Examples 8I3 and 9 were treated with a resin liquid, whereas Comparative Examples 6 and 7 were not treated with a resin liquid.

The results for fuzz and temporary errors are shown in Table 5.

(Leaving space below) Table 5 ``Work'' 115m As mentioned above, the cleaning effect is excellent, but the liner that generates a lot of dust and fuzz easily appears at the jacket opening, whereas By pre-treating the area corresponding to the periphery of σ with a resin solution, it was possible to reduce fuzz at the opening and also to reduce temporary errors.

It is presumed that the decrease in fluff at the opening is due to sufficient intertwining between the fibers due to the resin.

The reason for the decrease in temporary errors is not clear, but the dust falling from the periphery of the head window is
It is presumed that this was suppressed by the resin treatment.

If the entire surface of the jacket is treated with resin, such as with a binder-based liner, the cleaning effect of the jacket as a whole will be poor and temporary errors will easily occur, but by applying resin treatment only around the opening of the liner in advance as in the present invention, , has an excellent cleaning effect and removes interlayers from around the opening.

This means that a jacket with less shedding was obtained.

[Brief explanation of drawings]

Figure 1 shows the area near the handling opening (shaded) where the binder of the liner in the example of the present invention is coated with a high concentration of binder.
FIG. Patent Applicant: Teijin Memorex Ltd. No. 1, Masanori Neyama) October 2, 1980

Claims (1)

[Claims] 1) A floppy disk consisting of a flexible magnetic recording disk and a jacket containing the disk, the jacket consisting of a plastic sheet and a liner made of fiber material, and a 1. A floppy disk having a punched opening in the shape of a floppy disk, the liner being attached to the plastic sheet in the vicinity of the punching opening. 2) The fibrous liner is a nonwoven fabric that does not contain a binder or has a low binder content;
2. The floppy disk according to claim 1, wherein the part where the plastic sheet and the liner are attached is provided with a jacket having a high binder content. 3) In a jacket whose liner is a nonwoven fabric with a low binder content, the nonwoven fabric has a binder content of 16% by weight or less, according to claim 1 or 2. floppy disk.