JPH01208785A - Tape cassette and its box body - Google Patents

Abstract

PURPOSE:To secure the reliability of high-packing-density recording even in a highly corrosive environment by providing trap layers whose corrosive property is equivalent to or higher than that of the magnetic recording layer of a magnetic tape housed in a tape cassette at part of the area in the vicinity of the magnetic tape stretched between both reels of the cassette. CONSTITUTION:Trap layers 23 and 24 whose corrosive property is equivalent to or higher than that of the magnetic recording layer 17 of a magnetic tape 16 are provided at part of the area in the vicinity of the magnetic tape 16 stretched between both reels. The corrosive gas entering and diffused into a tape cassette through gaps of the cassette is caught by the trap layers 23 and 24 when the gas makes a selective absorptive reaction with the layers 23 and 24. Since the successively entering gas flows toward the trap layers 23 and 24 because of the diffusion governed by the concentration gradient, the deterioration which takes place in the magnetic tape 16 can be maintained at such a level that at which the tape 16 is not practically affected even the magnetic tape 16 is used in the environment of a high-corrosive gas. Therefore, the magnetic recording layer 17 made of a metallic material can be used for high-packing-density recording even in a severe environment where a corrosive gas exists.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a tape cassette for storing a metal-based magnetic tape suitable for high-density magnetic recording.

Conventional technology The magnetic recording system that is currently gaining popularity is based on the magnetic flux differential type, which uses magnetic tape, which exchanges signals,
It is no exaggeration to say that the industry has developed based on advances in magnetic head systems.

In order to continue developing magnetic recording in the future, it is essential to improve the recording density of the negative layer, and tape and head systems are transitioning from conventional oxide-based to metal-based systems. Active development is underway.

Metal-based magnetic tape consists of so-called MP tape, which is coated on a polymer film with ferromagnetic metal powder such as iron or cobalt dispersed in a binder, and a Go-Ni-0 obliquely vapor-deposited film coated with a polymer film. placed on film. It is broadly categorized into so-called ME tapes, and is beginning to play a role in increasing the density of 8mm video and broadcast recording equipment. Furthermore, such metal-based magnetic tapes are expected to be essential for increasing the density of digital recording from analog recording, and are expected to solve various problems brought about by the shortening of the wavelength of recording signals and the problems inherent to the materials themselves. However, studies are continuing to find solutions at a higher level.

Among the above, an important issue is the so-called tribology, which is how to impart durability to a magnetic recording layer with good smoothness in order to minimize spacing loss, which is a big problem with short wavelength signals. In addition to the above issues, how to ensure the total magnetic flux when the film is made thinner and the short wavelength characteristics are improved, and how to take measures against the problem of aging deterioration due to corrosion.

The proposals that have been made so far to solve these problems can be summarized into the following (a) to (e): (a) Improving friction, wear, etc. by arranging minute protrusions on the magnetic recording layer. [For example, IEE Transactions on Magnetics ([[TRANSACTIO
NS ON MAGNETZC3) vol MA
C-21, No. 6.1524-1526 (1985
), JP-A-59-207422, JP-A No. 61-284
[Patent No. 829] (a) Corrosion resistance without exposing the metal part responsible for magnetism.

Partially oxidized layers are effectively used to improve wear resistance etc. [For example, Japanese Patent Publication No. 67-2391, Japanese Patent Publication No. 57-1999]
No. 29770, Japanese Unexamined Patent Publication No. 61-163856] (1) Make the material structure of the magnetic recording layer hard and have good corrosion resistance [For example, Japanese Unexamined Patent Publication No. 69-119632, Unexamined Japanese Patent Application No. 81/1982 -139920 Publication] (1) Avoid direct sliding between the magnetic recording layer and the magnetic head, etc.
The essential role of the magnetic recording layer itself and ensuring durability against sliding are shared by providing another protective lubricant layer [for example, Japanese Patent Laid-Open Nos. 60-93635 and 61-131.
No. 231, No. 61-142525, No. 61-
No. 151830, No. 61-242323, No. 61-284829, No. 61-280019, No. 62-8325.

Special Publication No. 61-61444] No. Publication A combination of the above proposals, Either one is adopted.

Magnetic tapes improved by the above technology generally have
It is placed in a tape cassette and put into practical use.

The vast majority of tape cassettes currently in practical use are assembled from molded parts made of synthetic resin, and the materials, design, ease of assembly, mechanical properties, weather resistance, etc. are determined according to various standards. Many efforts have been made to ensure the necessary airtightness, especially for recent high-density recording applications, to prevent foreign matter from entering and to prevent problems such as dropouts and clogging. [For example, Japanese Utility Model Publication No. 57-9983, Japanese Utility Model Application Publication No. 58-109875, Japanese Unexamined Utility Model Publication No. 61-54]
Publication No. 87, Japanese Utility Model Publication No. 1987-48481, Japanese Patent Application Publication No. 1983
No. 1-162290, Japanese Utility Model Application Publication No. 118175/1982]. The above-mentioned one with good airtightness, specifically the commercially available 8
Cassettes such as MilliVideo, R-DAT, and Ml format for broadcasting are preferable in terms of improving the weather resistance of metal magnetic tapes, helping to improve the magnetic tape itself and making it possible to put it into practical use. This is what is considered to be.

Problems to be Solved by the Invention However, the spread of video in recent years has been remarkable, and the scope of recording has expanded for both consumer and professional use, and it has become difficult to withstand harsh environmental conditions such as high temperature and high humidity, high temperature and low humidity, etc. as well as various corrosive gases, such as H2S, So□,
There is a growing demand for it to withstand practical use under harsher conditions in which C12, NOx, etc. are added.

Even if the tape cassette is completely harmless under normal usage conditions, in special environments where the above gases exist in high concentrations, even short exposure can cause signal loss and clogging. It was hoped that the points would be improved.

The present invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to propose an improved tape cassette that makes it possible to ensure the reliability of high-density recording even under highly corrosive and special environmental conditions.

Means for Solving All the Problems In order to solve all the above problems, the tape cassette of the present invention has a trap layer having a corrosivity equal to or higher than that of the magnetic recording layer of the magnetic tape to be stored, at least between both reels of the cassette. The magnetic tape is placed in a part of the vicinity of the magnetic tape that is stretched over the magnetic tape.

Function: The metal magnetic tape disposed in the tape cassette of the present invention traps corrosive gas that diffuses and enters through gaps existing in the tape cassette in a stored state by selectively adsorbing and reacting with the trap layer. The invading gases flow toward the trap layer due to concentration-enclosed diffusion, so that even in a highly corrosive gas atmosphere, there is no practical problem with deterioration on the magnetic tape side. You can keep it. The above effect is particularly strong because the cassette is highly sealed and the gas inside moves by diffusion.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is an enlarged sectional view of an ME tape that was placed in a tape cassette according to an embodiment of the present invention and whose practicality was evaluated. In Fig. 2, 1 is a polymer film such as polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, etc., and 2 is a film of 1205.5 in2. Eu
This is a fine particle coating layer coated with fine particles of 2O3, CaO, ZrO□, etc. 3 is Go-0, Go-Ni, Co
-Or, Go-Ti, Go-Si.

A magnetic recording layer is made of a ferromagnetic metal thin film such as Go-Or-Wb or Go-Ni-0, and 4 is a protective lubricating layer made of fatty acid.

Lubricants such as perfluorocarboxylic acid and perfluoropolyether, Sin, membrane, and plasma polymerized membrane.

A protective film such as a BN film or an amorphous carbon film is arranged with an optimum film thickness while taking into consideration spacing loss. 6 is a so-called bank coat layer in which fillers such as carbon and calcium carbide are dispersed and fixed in resin to improve running properties.0 The magnetic tape having the above structure is approximately 8 mm in diameter.

3.8 Mi! J or other predetermined width if necessary, wound around a reel to the required length via a leader tape and a trailer tape, and then assembled into a cassette.

The tape cassette that is the subject of an embodiment of the present invention has a relatively good airtightness, and is similar to the tape cassette for home video tapes of 1 inch, which are currently widely used. Since it is difficult to obtain sufficient operation and effect if the airtightness is low, we will explain in detail the external view of the 8mm video, R-
This is based on the assumption that the structure is hermetically sealed, as is typical for DAT.

Figure 3 is an external view showing the tape force set for 8mm video, where 6 is the magnetic tape, 7 is the main case, 8 is the case (hereinafter referred to as bottom), and 9 is the case B. (Hereinafter, referred to as upper part 79), 10 is a front cover that is pivotally supported on upper part 79 so as to be openable and closable, and covers the front surface of main body case 7. 1
Reference numeral 1 denotes a rear cover for protecting the magnetic tape 6 to be drawn out.

Figure 4 is an external view of the tape cassette for R-DAT.
2 is the upper case, 13 is the lower case, 14 is the slider, 1
6 is a lid.

A more specific example will be described in detail below.

The magnetic tapes used to examine the effects of this example were ME tape and MP tape. Regarding MP tape, as a result of preliminary experiments, no particular difference was observed between tapes currently on the market. minute tape was used.

On the other hand, for the MK tape, 10 μm diameter Eu2O
After applying an average of 10 particles per 1 (μm), 6×1o (Torr) was applied along a cylindrical can with a diameter of 1 m.
Minimum angle of incidence 45 in oxygen at ~1X10 (Torr)
0.1 μm of Go-Ni (Ni 20 wt%) was deposited at
:1, dispersed in polyurethane resin at 20% by weight, mixed with isocyanate and a solvent, coated and dried to form a 0.
A back coat layer of 5 μm was arranged, and on the Go-Ni layer, “KRYTOX-157, FS-M” manufactured by DuPont, which is commercially available as a perfluorocarboxylic acid, was coated with f approximately 1o.
An 8 mm wide tape was used.

Before explaining how one embodiment of the present invention is superior in practicality to a comparative example when both tapes are placed in a tape cassette and exposed to various environments, we will explain the requirements of the present invention. A trap layer having a corrosive property equal to or higher than that will be described in detail.

Generally a test method for corrosion resistance of bulk materials.

It would be good if standards etc. could be used, but as will be described later in an example, magnetic tape has a problem with corrosion of either the thin film or the coating, so corrosive gas placed on the cassette side should be used. Traps that have the function of reactive adsorption come in the form of bulk, thin film, coating, molded material, etc., and are rated as corrosive by an evaluation method that addresses problems that occur during the recording and playback process when attached to a deck and used as described below. We judged that it would be practical to investigate the following, and proceeded with the study using the scale described below.

2o that can control temperature, humidity, and corrosive gas concentration
Prepare a glass container, place the magnetic tape and trap in a cassette, fix the test pieces on a holder 10 cm apart, and after exposing them for a certain period of time, use an optical microscope (100x magnification) to observe the progress of corrosion. The area was evaluated in terms of surface fraction (%), and if the surface fraction was the same, it was considered that the corrosion resistance was equivalent. In order to reduce errors, temperature, humidity, type and concentration of corrosive gases were confirmed over a wide range in the experiment, but in the example described later,
, m It was represented by the corroded surface fraction in 3 minutes. Depending on the material, manufacturing method, and structural requirements of the trap layer, for example, the concentration dependence may not necessarily match the concentration dependence of the magnetic tape. However, the above representative values are sufficient for determining the structural requirements of the present invention. These values are treated as representative values because they can be managed.

[Embodiment 1] FIG. 1 is a longitudinal sectional side view of the main parts of an 8 mm tape cassette used in a first embodiment of the present invention.

In FIG. 4, 16 is an ME tape, and 17 is a G o -N i-0 magnetic layer obtained by a vapor deposition method. 18 is reel 7 lunge 19 is lower half, 20 is upper half, 21 is front lid, 2
2 is the rear lid. 23 is a trap layer A324 is a trap layer B.

That is, in this example, the trap layers were placed on the inner surfaces and some side surfaces of the rear cover and front cover, as shown in the figure, and the effects of forming layers of various materials by high-frequency magnetron sputtering were evaluated. Talk about.

In addition, the corrosiveness investigation was carried out with a thickness of 2 fins, 9 widths, and 20. A with length 10G
BS resin was prepared as a test piece, and the trap layer was placed on the cassette part under the time conditions for placing the trap layer.

Before depositing various thin films by sputtering method, Ar pressure 3
13.56 (M) 12) at X 10 (Torr)
A glow discharge treatment of 0.8 (KW) was performed for 3 seconds. The trap layer material, structural thickness, corrosivity investigation results, examples in which ME tape was incorporated using these cassette parts, and comparative examples were prepared in two volumes each at 35°C, 80-83% RH,
After leaving it in a HCl s op, p, m desiccator for 1 hour, a commercially available 8 mm video (Sony = C0D-V
2O) 2 each on the front and back of the position that corresponds to the tape drawer
Recording and reproduction were performed in a range of m.

In the table, dropout was evaluated by the increase rate, and clogging was evaluated by the total time, and the worse value of the two volumes was shown. MP tapes were also used in combination with some cassettes. The conditions and results are summarized in Table 1.

Among the materials shown in Table 1, for example, the material shown as Ni-0 is
The thin film was formed under conditions of partial oxidation with Ar+02 gas during sputtering.

In addition, FIG. 5 shows Ni and Ni- other than those shown in Table 1.
A characteristic diagram summarizing the experimental results of the A/ and Mul-0 systems, including the experimental results of the 0 system, and the relationship between corrosivity and clogging time, which is a major defect, is shown. (In addition, what is shown in the characteristic diagram is an example in which the experiment was carried out with trap waste in one location.) 0 , :: ・ , C″ ・−] As can be seen from the results in Table 1, Compared to 13°14, ME tapes and MP tapes used in cassettes are protected even in highly corrosive environments because they are equipped with a trap layer that has a corrosivity equal to or higher than that of the sample tape. If the corrosion resistance is too thick, the sustainability of the effect may be lost, but according to the conditions of this comparison, it is recommended that the corrosion resistance be the same or higher, and that the corrosion resistance should be up to 3 times higher. It can be seen that this is preferable.In addition, from FIG. 5, it can be confirmed that there is a range suitable for implementation, and at the same time, the action and effect of the Ni system is better than that of the human 4 system.

[Example 2] The trap layer was entirely formed at the same location where the trap layer was placed in Example-1 using a different manufacturing method, and the ME tape and MP tape were formed into a cassette, 30'C 80% RH, H2S 16
After being exposed to p, p, and m environments for 30 minutes, the recording and reproducing characteristics of the OME tape were compared under the same conditions as in Example 1. The corrosiveness of the OME tape was 3.6 to 3.6, which was almost the same as that of the MP tape by adjusting the amount of oxygen. 4
．． 4 (%) was used.

Cassette 2 - For both trap layer A and wrap layer B,
N1(Co4)ga, ;', f 13.56 (MHz
) 1 (KW) was decomposed by glow discharge and coated with a 3 μm Ni film by so-called chemical vapor deposition.

The cassette 2-B used was one in which a Ni film of 1.5 μm was formed by electron beam evaporation with a deflection of 270 degrees at 16 KW (7) at 10 Kv in a 1×10 (Torr) (D vacuum).

Cassette) 2-C is a 3-μm baked coating under the condition that urethane resin, Ni powder, and urethanized oil are mixed and dispersed, and Ni fine particles with an average particle size of 0.2 μm are contained in a volume fraction of 50% of the resin at the time of curing. Use the one you made fc, o case 7
2 D f3, Ni, C1,, eH20, 30g
/l, NaH2PO2,10911l N&C:2
Using an acidic Ni bath with H505+50 f/l and pH 4 to 6, a masking process was performed to form electroless Ni plating of 2.5 μm in a predetermined area. If necessary, the external dimensions of the cassette parts were adjusted according to the plating thickness so that these cassettes could be attached to and removed from the video main body.

As a comparative example, a fully metal-plated cassette including the plated portion of the example was also prototyped and evaluated, although the technical idea, purpose, and effect were different from the cassette that was not subjected to the above-described treatment.

That is, as disclosed in Japanese Unexamined Patent Publication No. 49-27214, a cassette case was prepared in which a nickel/chromium plating layer was deposited to a thickness of 6.6 .mu.m on the inside and 17 .mu.m on the outside. Also, based on the technical idea disclosed in the above publication, since nickel has a lower Young's modulus than nickel chrome, the plating thickness is increased and the entire surface is plated with nickel. That is, 8 μm inside the cassette housing.
, and one in which the outside was plated with a thickness of 20 μm was also prepared.

Table 2 shows the results of comparative evaluation using the above-mentioned cassettes.

(The following is a blank space) From Table 2, it is clear that the Examples have superior effects to the Comparative Examples without a trap layer in both cases of ME tape and MP tape. Furthermore, Ni
It was also found that the plating applied to the entire surface was inferior in effectiveness, even though it included trap debris and the B part. This is because the trap layer placed on the outside traps corrosive gases, which effectively increases the flow of corrosive gases surrounding the cassette, creating a highly concentrated environment that prevents them from penetrating inside. It is presumed that this is because the amount of gas also increases, increasing the probability of attacking the tape.

Figure 6 shows a characteristic diagram showing the protection performance against ME tape in relation to the blinding time when the same Ni plating and Go plating are arranged in the trap layer B with different thicknesses. Indicated. It can be seen that there is a preferable thickness range even when it is arranged on the inner surface or a part of the side surface.

However, the preferred range of this thickness varies depending on the surface area and location, as described in the following example.

Since it varies depending on the manufacturing method, it can be selected as appropriate. However, generally speaking, if the thickness is increased, the cassette parts will be deformed due to distortion problems, creating gaps and increasing variations, so overall the appropriate thickness is 0.1 to 4μ.
A range of m is preferred. Another reason why the properties vary when the thickness is increased is thought to be that the trap layer changes and peels off.

Moreover, if it is less than 0.1 μm, the area will be insufficient and the trapping effect will be insufficient.

[Example-3] A front lid formed by the Nif ion blating method and ion-blated at the same site as in Example-1,
The effect of changing the surface area of the rear lid will be explained.

3 cassettes - standard 3 x 1 flat configuration
13.56 (MH) in argon at 0 (Torr)
z) 1 (KW) A knobblow discharge is generated and Ni is ion-blated to a thickness of 1.5 μm.
3-B is 10 pieces per 1i, depth 100μm and width 60μm.
Ni61. with grooves arranged under the above conditions. sμm ion blating, cassette) 3-C is the same (Ni il, 5 μm ion blating) on the surface with 10 recesses of 60 μm in diameter and 60 μm in depth. Corrosive 4.
Incorporating 1 to 5.1 (%) ME tape and MP tape, 16 nitrous acid gas (No2) at 30 ° C and 75% RH.
Table 3 summarizes the results of examining the recording and reproducing characteristics after being exposed to a corrosive atmosphere containing p, p, m and 1 p, p, m for one hour. Note that the corrosivity of the N1 ion blating film is 6.2 to 6.9 (%).

(Leave blank below) To ::1 ri1to country
Mountain .

≧ 1 Foll 1 inch OQl Within the range of the representative examples shown in Table 3, there is almost no difference in the constituent surface area of the trapping agent, but naturally, if the area becomes too small, the characteristic diagram shown in Figure 7 The effect is weakened. Although it varies depending on the thickness of the trap layer, as a first guideline, the area should be approximately the same as the surface area of the magnetic tape in an open state without being wound. This is a rough guideline, taking into account the degree of sealing of the cassette, the actual exposure atmosphere, the exposure time, and the fact that the opening position changes as the tape is fed. .

Optimization may be carried out depending on the cassette structure, degree of sealing, etc., taking economic efficiency into consideration as appropriate.

Other methods of changing the surface area include changing the surface roughness of the cassette parts, making the film of the trap material porous, plating the film with fine lips for reinforcement, and Other preferable methods include a method of plating and then roughening it by etching, a method of plating with an embossed structure, a method of arranging metal whiskers on the surface, etc., and it has been confirmed that these methods can be employed as appropriate and have sufficient effects.

[Example-4] Electroless wind plating with a thickness of 2 μm [Corrosivity 6.6-7.
2 (%)], placed in different parts, corrosiveness 3.3-4.1
(%) of MR tape was incorporated and S
02 gas 2. Op-p-m environment and 40”C83%R
HteCa12 gas5. The recording and reproducing characteristics were examined after exposure to Op, p, and m environments for 46 hours, and the results are summarized in Table 4 for each plating site condition of the cassette. The fourth person's cassette 4-me is located in section a of the front lid 21 in FIG.

Part b, part 0, and part (j) of the surface facing the tape stretched on the side of the lower half shown in Figure 9 are plated by L = 1 on.Cassette 4-B is the same as cassette 4-person L
= Cassette 4 under the same conditions except that it was 3 cm
-C is the one in which parts a, b, and 0 of the front cover 21, part j in Fig. 9 of L=31, and the side surface corresponding to part j of the upper half (the plating length is 3α) are plated, and the cassette is plated. ) 4-D is the one in which, in addition to the conditions of cassette 1-4-C, the g part of the upper half and the d part of the lower half are plated, cassette) 4-IC
cassette 4-F has plated parts a and b of the front lid 21 and parts 0 and d of the lower half, and cassette 4-F has plated parts of the tape winding part of the reel flange, part 1 (this is Cassette) 4-G is the one with plating on the d, e, f, and g parts of the upper half and lower half, and the cassette E is the one with plating on the d, e, f, and g parts of the upper half and lower half. Only the 9g portion was plated.

(The following is a margin) From Table 4, it can be seen that even if Ni plating is applied, a sufficient effect cannot be obtained depending on the plating area.

That is, although the tape cassette 6 is considerably improved over the unplated tape cassette 8, a plating layer, that is, a trap layer is arranged in a region near the magnetic tape stretched between both reels. The fourth thing that is preferable is that
This is clear from the table.

When forming a trap layer using the plating method or ion blating method, partial plating is often expensive from a cost perspective, and depending on the area, for example, the inner part of the back cover may be
Of course, it is also possible to use one whose entire outer surface is plated.

[Example 6] FIG. 10 shows a longitudinal sectional side view of the main parts of the cassette for 8 mm tape used in the sixth example. The same parts as in FIG. 4 are indicated by the same numbers. In this example, the results of comparing the cases where the trap layer is disposed on a flat surface so as to be easily applied among various current techniques for metallizing surfaces will be described in detail. Reference numeral 25 designates a trap portion a disposed on one flat surface of the inner surface of the front lid 21, and reference numeral 26 represents a trap portion a disposed on one flat surface of the inner surface of the rear lid 22. In addition, trap parts a and b
Of course, it is possible to freely decide whether to increase the number of flat parts or select a plurality of flat parts within the range permitted by the standard, and the design based on the technical idea disclosed in this example The scope of improvements is considered to be within the scope of the present invention. That is, if necessary, it is possible to change the material composition and installation method of traps a and b, and to combine them as appropriate. b uses the same material composition and the same installation method.

Cassette 5-A uses transfer foil, so-called hot stamp foil, to transfer Ni, SUS, Cr.
Cassette 5-B is a so-called in-mold molded cassette in which approximately 1000 Ni particles are placed, using transfer foil at the same time as injection molding.
-C is a metal spraying method in which metal is melted by arc discharge, atomized with high-pressure argon gas, and then sprayed, with an average film thickness of 0.7 μm. Cassette) 5-D is a nonwoven fabric. 2 people, 5. The ME tape used has a corrosivity of 4.3 to 6.1 (%). Since it was not possible to evaluate the corrosivity of the non-woven fabric, the evaporated film was deposited on the resin surface of the cassette (3000 people thick) at the same time as the metal woven fabric, and the values obtained were recorded.

Incorporate the ME tape into the above cassette and heat at 35°C.
283%RH, CI2.10 p, p, m, SO
Table 6 shows the results of comparing the recording and reproducing characteristics after being exposed to corrosive atmospheres of 2°12p, p, and ffl for 24 hours.

(Left below) 24 - Kasumi 1': l j i'
1 l 1 1, 1
′.

+1'' Mirror: ・、、、：jt
l=1ku
(i Eo ・0) As is clear from Table 6, the properties are controlled more by the material than by the construction method.

Therefore, other methods such as plating method, painting method, vacuum deposition method, chemical vapor deposition method.

Optimize the material conditions for other molding methods, taking into account not only economical aspects, but also processing reproducibility, difficulty in changing the dimensions of the cassette during processing, and the degree of difficulty in adapting the shape of the processed part. [Example-6] An external view is shown in Fig. 3, and an example carried out with R-DAT will be described in detail.The trapping agent was applied to the lid 16 part in Fig. 3 under different conditions. ME tape (corrosivity 3.8-4.
3%) and MP tape, 30'CB3%R
HH2S 3 p, p, m HCI es p, p, m
The rate of change in block error rate was measured after 4 hours of exposure to a corrosive environment.

Cassette 6-A has a 1.6 μm layer of electroless N1-P mesochira on the inner surface of the lid, and cassette 6-B has a coating developed for electromagnetic shielding made by Shinto Chemitron Co., Ltd., coated by a spray method. One of the things I did was
One is coated with an acrylic paint using a copper-based filler (product number: Cintron!-3316) to a thickness of approximately 6 μm, and the other is coated with a nickel-based filler (Cintron X-3063) to a thickness of approximately 6 μm. -C
Ni-Ti (Ni:
6-D is a conductive BS resin using Ni powder and Al powder as fillers (filler content is % by weight). This is a case where a lid molded with 26% to 27% of the resin is used.

Regarding the results of comparison between the above-mentioned cassette and comparative example, the sixth
They are summarized in the table. The R-DAT used for measurements is a testing machine with the same functions as commercially available products, and the head is easy to clean, and it is initialized each time the tape is run to avoid errors due to measurement order. It was evaluated based on the following.

As can be seen from Table 6, tapes 1.3 and 4°6.7 show the measured values themselves, but at a level that can be said to be almost unchanged, and tapes 2 and 8.8 also show the measured values when compared to the comparative example. As described above, the present invention has an excellent effect in that high-density magnetic recording using a metal-based magnetic recording layer can be put to practical use even in a harsh environment where corrosive gas exists. effective.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of the main parts of an 8 mm tape cassette used in the first embodiment of the present invention, FIG. 2 is an enlarged sectional view of the MR tape used in one embodiment of the present invention, and FIG. 3 is a perspective view of an 8mm video magnetic tape cassette, and Figure 4 is an R-DAT.
A perspective view of a magnetic tape cassette, Figure 6 shows corrosive properties. ,! Figure 6 is a characteristic diagram showing the plating thickness and clogging time, Figure 7 is a characteristic diagram showing the trap surface area and clogging time, and Figure 8 is a characteristic diagram showing the relationship between plating thickness and clogging time. FIG. 9 is a perspective view of the main part of the lower nozzle, and FIG. 10 is a longitudinal side view of the main part of the 8 mm tape cassette. DESCRIPTION OF SYMBOLS 1...Polymer film, 3...Magnetic recording layer consisting of a ferromagnetic metal thin film, 6...Magnetic tape, 7...Main body case, 10. ...Front lid, 11...Rear cover, 12...Top case,
14...Slider, 15...Lid, 16...ME tape, 21...Front lid, 22...Rear lid, 23, 24, 25. 26...
...Trap layer 0 Name of agent: Patent attorney Toshio Nakao and 1 other person/6
- ME Teig? l-front 1 22-back i th. 3.24--1 Trap Layer/°-Polymer Film 3-Wi Sho Wood Eating Sheet Thin Film B R6 Ru Removal W Hai Layer Fig. 2 6-Magnetic Tag Fig. 5 Corrosion (” /-J Fig. 6 Thickness of wood (Jim) Fig. 7 Surface type of tiger and whelk (cm2) Fig. 8 25.2 Mu Trap country

Claims (6)

[Claims] (1) It has a casing that houses a magnetic tape having a magnetic recording layer made of a metal magnetic material and two reels wound with the magnetic tape, and at least one part near the magnetic tape stretched between the two reels. 1. A tape cassette comprising a trap layer having a corrosivity equal to or higher than that of the magnetic recording layer. (2) It has a casing that houses a magnetic tape with a magnetic recording layer made of a metallic magnetic material and two reels wound with the magnetic tape. 1. A tape cassette, characterized in that a trap layer having a corrosivity equal to or higher than that of the magnetic recording layer is provided on the inner surface of a lid that closes the tape in a casing, at least in a portion facing the stretched magnetic tape. (3) The tape cassette according to claim 2, wherein the lid is comprised of two rotating lids configured to close the stretched magnetic tape from the front and back when closed. (4) The lid has a rotating lid that covers the front surface of the stretched magnetic tape and a sliding lid that is slidably provided on the lower surface of the housing, and the rotating lid and the sliding lid cover the housing. The tape cassette according to claim 2, which is configured to close the body. (5) It has a casing that houses a magnetic tape having a magnetic recording layer made of a metal magnetic material and two reels wound with the magnetic tape, and at least the inner surface of the lid that constitutes a part of the casing A trap layer having a corrosive property equal to or higher than that of the magnetic recording layer is provided in a portion facing the stretched magnetic tape, and a jacket is provided to accommodate the casing, so that the magnetic tape is substantially blocked in the accommodated state. A tape cassette characterized by having a configuration in which: (6) A housing for a tape cassette that can store two reels, and the inner surface of the lid that forms a part of the housing has a corrosivity equivalent to or higher than the magnetic recording layer of the magnetic tape to be built in. A tape cassette casing characterized by having a trap layer.