JPH09180405A - Magnetic tape cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the dropout which is caused by the step of a tape joint and improve the productivity by a method wherein a leader tape which is connected to the tip of a magnetic tape wound in a tape reel in a cassette main part is made of liquid crystal polymer. SOLUTION: A tape reel 3 is housed in a cassette main part 2 consisting of first and second parts 2a and 2b so as to rotate freely. A leader tape 10 is connected to the tip of a magnetic tape 20 which is wound in the reel 3. The tape 10 is made of liquid crystal polymer of polyester system, polycarbonate system, polyamide system, polyurethane system, etc., and the tensile strength of the tape 10 is not less than 15kg/mm<2> . Further, the thickness of the tape 10 and the thickness of the tape 20 in a joint part 40 are equal to each other and the joint part 40 is unified by a splicing tape 30. With this constitution, the step of the joint part 40 is reduced and hence the dropout caused by the step is reduced and, further, the leader tape 10 can be produced by an ordinary extrusion process only, so that the productivity can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cartridge used for a magnetic recording / reproducing device such as a video tape recorder (VTR) or a backup data storage of a computer, and more specifically, to a magnetic tape cartridge having sufficient strength. The present invention relates to a magnetic tape cartridge which has a leader tape and is excellent in productivity.

[0002]

2. Description of the Related Art Conventionally, a single tape has been used as a magnetic tape cartridge used for a magnetic recording / reproducing apparatus such as a video tape recorder (VTR) or a backup data storage of a computer or the like. A magnetic tape cartridge in which a reel is rotatably provided, a magnetic tape is wound around the tape reel, and a leader tape is connected to the tip of the magnetic tape is widely used. And since the leader tape in the conventional magnetic tape cartridge is required to have sufficient strength,
It is formed of biaxially stretched polyethylene terephthalate (PET) having a thickness of about 200 μm.

However, in a magnetic tape cartridge using a leader tape formed of PET having such a thickness, the thickness of the leader tape has a thickness at the connecting portion between the leader tape and the magnetic tape. Since it is thicker than the thickness of 1., there is a problem that a step occurs and the step causes dropout. Therefore, in order to solve such a problem, a magnetic tape cartridge in which the base end side (the end side connected to the magnetic tape) of the leader tape is tapered is proposed. In taper processing,
There is a problem that productivity is low and cost is also high.

Therefore, an object of the present invention is to provide a magnetic tape cartridge which has a small step at the connecting portion between the leader tape and the magnetic tape, has a small dropout, and is excellent in productivity.

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive studies made by the present inventors to solve the above problems, a magnetic tape cartridge having a leader tape formed of a specific material can achieve the above object. I found out.

The present invention has been made on the basis of the above findings, and a single tape reel is rotatably housed in a cassette body composed of a first half and a second half. A magnetic tape cartridge in which a magnetic tape having a leader tape continuously provided at the tip is wound, wherein the leader tape is formed of a liquid crystal polymer.

The present invention also provides the magnetic tape cartridge, wherein the liquid crystal polymer is a polyester liquid crystal polymer. Further, the present invention provides the magnetic tape cartridge, wherein the tensile strength of the leader tape is 15 kgf / mm ² or more.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. The magnetic tape cartridge of the present invention is characterized in that the leader tape is made of a liquid crystal polymer. The liquid crystal polymer used to form the leader tape in the present invention can be used without particular limitation as long as it is a thermotropic liquid crystal polymer which becomes a liquid crystal state in a molten state (or a solution state). Polycarbonate (PC) type liquid crystal polymer, polyester type liquid crystal polymer, polyamide (PA) type liquid crystal polymer, polyurethane (PUR) type liquid crystal polymer and the like can be mentioned.

In the present invention, among the above liquid crystal polymers, the following [Chemical formula 1] is particularly preferable in terms of moldability and industrialization.
Polyester liquid crystal polymers represented by the general formulas (I) to (III) are preferably used.

[0010]

Embedded image

Further, in the present invention, in addition to the above liquid crystal polymer, additives such as a lubricant and a colorant can be added. The leader tape formed of the liquid crystal polymer preferably has a tensile strength of 15 kgf / mm ² or more. Incidentally, the upper limit is preferably higher, and is not particularly limited. If the tensile strength is less than 15 kgf / mm ² , the material strength may be insufficient, resulting in deformation and loss of the function as a leader tape. Here, the tensile strength is determined according to ASTM D638.

To form the leader tape from the liquid crystal polymer, it is possible to easily form it by a generally known extrusion molding method. That is, in the present invention,
Since the above-mentioned liquid crystal polymer is used as the material for forming the leader tape, even if the shape of the leader tape is tapered at its base end, it is easy to improve productivity without using any other molding method. Leader tape can be formed.

Next, one embodiment of a magnetic tape cartridge of the present invention having a leader tape formed of the above liquid crystal polymer will be described with reference to the drawings. Here, FIG.
FIG. 3 is an exploded perspective view showing an embodiment of a magnetic tape cartridge of the present invention, FIG. 2 is a plan view showing a leader tape, and FIG. 3 is an enlarged side view showing a connecting portion between the leader tape and the magnetic tape. It is a figure.

As shown in FIGS. 1 to 3, the magnetic tape cartridge 1 of the present invention includes a first half 2a and a second half 2b.
A single tape reel 3 is rotatably accommodated in a cassette body 2 composed of and a magnetic tape 20 having a leader tape 10 connected in series is wound around the tip of the tape reel 3. More specifically, the tape reel 3 has two
It is composed of two disk-shaped reel flanges 3a and 3b, and a gear portion 3c is formed on the outer periphery of the lower reel flange 3b. Further, the second half is provided with a comb tooth-shaped meshing portion 2c that meshes with the gear portion 3c and a contact portion 2d with a brake release piece that releases the meshing between the gear portion 3c and the meshing portion 2c. . Such a configuration is similar to that of a conventionally known magnetic tape cartridge.

In the magnetic tape cartridge of the present invention, the leader tape is made of a liquid crystal polymer, more specifically, a polyester liquid crystal polymer. As shown in FIGS. 2 and 3, the leader tape 10 is used.
Is formed so that the base end 11 side thereof is tapered (so that the thickness becomes thin), and the thickness of the leader tape 10 at the connecting portion 40 between the leader tape 10 and the magnetic tape 20 is made equal to the thickness of the magnetic tape 20. ing. In addition, the leader tape 10 and the magnetic tape 20 are
The splicing tapes 30 are integrally connected.

The magnetic tape cartridge of the present invention is
The present invention is not limited to the form shown in FIGS.
Various changes can be made without departing from the spirit of the present invention. For example, although the leader tape has been described by exemplifying the one in which the base end side is tapered, the entire thickness of the leader tape is formed to be thin overall (the entire thickness is equal to the thickness of the magnetic tape). You can do the same). That is,
The thickness of the leader tape can be thinned in inverse proportion to the strength of the liquid crystal polymer used (it becomes thinner as the strength becomes higher). In particular, when the thickness is 130 μm or less, the transfer onto the magnetic tape is low, and the occurrence of dropout is suppressed. Therefore, it is not necessary to form the tapered shape as shown in FIG.

[0017]

According to the magnetic tape cartridge of the present invention, the connecting portion between the leader tape and the magnetic tape has few steps so that there are few dropouts and the productivity is excellent. More specifically, in the present invention, since the leader tape is formed of a liquid crystal polymer, it can be formed into a desired shape (the base end portion is tapered by only ordinary extrusion molding, that is, without any other molding step). Shape). Furthermore, when a liquid crystal polymer having a particularly high strength is used, it has sufficient strength even if the thickness is almost the same as the thickness of the magnetic tape, so that it is not necessary to form the tapered shape described above, and the productivity is particularly high. Is.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of a magnetic tape cartridge of the present invention.

FIG. 2 is a plan view showing a leader tape.

FIG. 3 is an enlarged side view particularly showing a connecting portion between a leader tape and a magnetic tape.

[Explanation of symbols]

 1 magnetic tape cartridge 2 cassette body 2a first half 2b second half 3 tape reel 10 leader tape 11 base end 20 magnetic tape 30 splicing tape 40 connection part

Claims (3)

[Claims] 1. A single tape reel is rotatably housed in a cassette body composed of a first half and a second half, and a magnetic tape having a leader tape continuously attached to the tip of the tape reel is wound. A rotating magnetic tape cartridge, wherein the leader tape is formed of a liquid crystal polymer. 2. The magnetic tape cartridge according to claim 1, wherein the liquid crystal polymer is a polyester liquid crystal polymer. 3. The tensile strength of the leader tape is 15
^2. The magnetic tape cartridge according to claim 1, wherein the magnetic tape cartridge has a weight of kgf / mm ² or more.