JPH08153326A - Calender treatment device - Google Patents

Abstract

PURPOSE: To produce a magnetic tape having high accuracy characteristics and to simplify and miniaturize a device by improving the surface characteristic of a coating film of a ferromagnetic material of the magnetic tape. CONSTITUTION: An original sheet of the magnetic tape (magnetic recording medium) 9 coated with a magnetic coating material is passed between multi- stage type rolls 2 combined with revolving rolls in a multi-stage type, by which the coating films is smoothed. The respective revolving rolls 3, 4, 5 of the multi- stage type rolls 2 of the calender treatment device 1 are made of metals so that thermal conductivity is enhanced and a high pressure is obtd. As a result, the multi-stage rolls of a smaller number, such as two stages of the revolving rolls and three stages of the revolving rolls, are constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calendering device for smoothing a coating film by passing a magnetic tape having a magnetic coating film between multi-stage rolls in which rotating rolls are combined in multiple stages.

[0002]

2. Description of the Related Art Conventionally, a magnetic tape as a magnetic recording medium such as a video tape is generally manufactured by kneading a magnetic powder with a binder to form a magnetic paint, and coating this on the base film. Target.

In such a magnetic tape manufacturing method, a surface treatment called calendering is applied to the magnetic tape after coating the base film with a magnetic coating material and drying it.

This process is considered to be an essential process for the recent magnetic tapes which are required to have high performance and short wavelength recording, and it is said that the finish of the process influences the performance of the magnetic tapes. is there.

A calendering apparatus 101 for carrying out this calendering treatment is, for example, as shown in FIGS. 19 and 20, a metal rotating roll 10 made of metal having a mirror-finished surface.
3, 105, 107 and elastic rotating rolls 104, 106 each having a surface coated with a polyester resin are combined to form a five-stage multi-stage roll 102. That is, by interposing the elastic rotation rolls 104, 106 between the metal rotation rolls 103, 105, 107, a plurality of pressure surfaces are formed.

Therefore, the calendar processing device 10
2 is actually used to smooth the coating film 109a of the magnetic tape 109 coated with the magnetic paint,
As shown in FIG. 0, by sandwiching the magnetic tape 109 between the pressure surfaces of the multi-stage roll 102 having the above configuration,
A process of sending out the magnetic tape 109 while applying heat and pressure is performed.

The smoothness of the surface of the magnetic tape 109 when the apparatus having the above-mentioned structure is used is controlled by temperature, pressure, etc. For example, in the case of a high quality magnetic tape 109 such as a metal tape, coating is performed. Since high packing density of the magnetic powder in the film, that is, high packing is required, high temperature treatment and high pressure treatment are required. In calendering, high temperature treatment of 110 ℃ or higher, 350kg
A high-pressure treatment of f / cm or more is required, and the number of stages of the multi-stage roll 102 must be seven stages.

[0008]

As described above, in the above-mentioned conventional calender device 101, since the metal rotary roll and the elastic rotary roll are combined, the processing temperature required for the calendering tends to be high. Therefore, there are various problems as described below.

First, in the case of a long tape 109 for audio which has been developed under the tendency of mass recording of magnetic recording, the tape 109 is deformed, which adversely affects the quality, resulting in high accuracy. There is a problem in that a good magnetic tape 109 cannot be obtained.

Further, when the treatment is carried out at a high temperature, the binder component contained in the coating film of the ferromagnetic material of the magnetic tape 109 may exude and adhere to the respective rotating rolls. Reattachment to the surface caused a surface defect (dropout error).

When the calendering temperature is raised to 110 ° C. or higher and pressure is applied, the multi-stage roll 10
There is a risk that a slip phenomenon of the magnetic tape 109 may occur on the second pressing surface.

Further, if a temperature and a pressure exceeding a certain limit are applied to the elastic rotating rolls 104 and 106, the elastic bodies of these rolls are destroyed, so that the processing temperature, high pressure processing, processing speed, etc. It was necessary to set restrictions on calendar conditions.

Further, if the processing temperature is raised, the surface of the magnetic tape 109 may be excessively smoothed, and in this case, friction may increase and the running performance of the magnetic tape 109 may deteriorate.

Furthermore, if the multi-stage roll 102 is constituted by five or more stages, the apparatus inevitably becomes large in size, but this may further increase the cause of the surface defect (dropout error). .

Therefore, according to the present invention, the surface property of the coating film of the ferromagnetic material of the magnetic tape can be improved, and the magnetic tape having high precision characteristics can be manufactured, and the apparatus can be simplified.
An object of the present invention is to provide a calendar processing device that can be downsized.

[0016]

In order to achieve the above-mentioned object, a calendering apparatus according to the present invention passes a magnetic recording medium coated with a magnetic paint between multi-stage rolls in which rotating rolls are combined in multi-stages. In the calendering device for smoothing the coating film by the above, each rotary roll of the multi-stage roll is made of metal.

Further, the multi-stage roll is constituted by a two-stage rotary roll or a three-stage rotary roll.

[0018]

According to the present invention, since the rotating rolls constituting the multi-stage roll are all metal rotating rolls,
High thermal conductivity and high pressure can be obtained, so that the coating film of the magnetic coating material of the magnetic recording medium is not crushed even at a lower temperature and a lower pressure than the case where the conventional elastic rotating roll is used. By increasing the density, the packing density of the magnetic powder in the coating film is increased to smooth the coating film.

When an audio tape or the like is manufactured by the calendar processing apparatus according to the present invention, the surface of the magnetic recording medium is not excessively smoothed, and the surface property suitable for running can be obtained. That is, for a magnetic recording medium having a rough surface of a base film such as an audio tape, smoothing with a metal rotating roll according to the present invention makes the surface roughness of the base film magnetic coating material. Since it appears in the coating film of, the surface can be made rougher than in the case of the conventional device. As a result, the friction on the surface of the magnetic recording medium is reduced and the running property of the magnetic recording medium is improved.

Further, since each of the rotary rolls constituting the multi-stage roll is a metal rotary roll, it is possible to construct a two-stage or three-stage multi-stage roll having a small number of stages. The simplification and miniaturization of are achieved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording medium to which the present invention is applied and a method for manufacturing the same will be specifically described below.

Structure of Calendering Device As shown in FIGS. 1 and 2, the calendering device 1 according to the present embodiment has a multi-stage roll 2 formed by combining only metal rotating rolls 3, 4 and 5. . That is, the calendering apparatus 1 does not use the elastic rotating rolls that have been conventionally used, and in each case, the metal is used as the material, and the first metal rotating roll 3, the second metal rotating roll 4, and the third metal are used. It has a structure in which the rotating rolls 5 are combined in three stages in the vertical direction. The radius of each of the metal rotating rolls 3, 4 and 5 used in this embodiment is 320 mm and the same type is used.

The magnetic tape original plate 9 having the above-mentioned structure is used to rotate the multi-stage rolls 2 into the rotating rolls 3, 4, 5 respectively.
A plurality of guide members 8 are arranged to guide the pressing surfaces 6 and 7 therebetween.

A calendar device 1 having the above-mentioned structure
The multi-stage roll 2 is a metal rotary roll 3, 4, 5 of the same kind.
It is composed of only one and no elastic rotating roll is used as in the past. Therefore, according to the present embodiment, the device itself can be downsized, and it is sufficient to guide the magnetic tape original plate 9 to the two pressing surfaces 6 and 7, so that the device itself can be simplified.

Further, as shown in FIG. 2, by forming a multi-stage type roll with only the metal rotating rolls 3, 4, and 5 as described above, elastic deformation does not occur unlike a conventional elastic rotating roll, and pressure (in the figure, A large pressure can be obtained by operating in a narrow range (denoted by the symbol "P") (hereinafter referred to as "linear pressure"). Therefore, in order to obtain the density of the ferromagnetic material coating film 9a with the same pressure as in the conventional device (see FIG. 20) in which the elastic roll is incorporated, the number of stages of the multistage roller 2 can be reduced.

That is, in the conventional apparatus, since the elastic rotary roll and the metal rotary roll are combined, there are many stages of five stages or more, and complicated ones having different radii and the like are used. However, in this embodiment, since the multi-stage roll 2 is composed of only the metal rotating rolls 3, 4, and 5, the coating film 9a can be smoothed by the three-stage configuration. .

When the multistage roll 2 is composed of only the metal rotating rolls 3, 4, and 5, another embodiment is as follows.
It is also possible to realize a configuration with only two stages.

Further, in this embodiment, the metal rotating rolls 3,
Since the multi-stage roll 2 is constituted only by 4 and 5, the coating film 9a of the magnetic tape original plate 9 is formed by the deformation of the elastic body of the elastic rotary roll as in the conventional case in which the elastic rotary roll is combined (see FIG. 20). A slip phenomenon occurs between the metal rotating rolls and the metal rotating rolls, so that the rotating rolls are not contaminated.

Method of Calendering Using the calendering apparatus 1 having the above-mentioned structure,
When smoothing the coating film 9a made of a ferromagnetic material, as shown in FIG.
As shown in FIG. 2, the magnetic tape original plate 9 after coating is passed through the pressing members 6 and 7 of the metal rotating rolls 3, 4, and 5 through the guide member 8.

That is, as a method of producing a magnetic recording medium such as a magnetic tape, a step of applying magnetic powder to the base film 9b by kneading the magnetic powder with a binder to form a magnetic paint, and applying the magnetic powder to the base film 9b is calendering. It is performed as a premise of the process.

After that, the magnetic tape original plate 9 on which the coating film 9a is formed is the pressing surface 6 between the first metal rotary roll 3 and the second metal rotary roll 4 of the calendering device 1, and It is sandwiched between the pressure surfaces 7 of the second metal rotary roll 4 and the third metal rotary roll 5, and heat and pressure are applied.
In addition, after the above-mentioned calendar treatment is performed, various treatments are performed as necessary, and then the magnetic tape original plate 9 is used.
Then, a cutting process for cutting into a predetermined width and length is performed.

By the way, the smoothness of the surface 9c of the magnetic tape original plate 9 is controlled by temperature, pressure and speed, but in the present embodiment, these conditions are affected in various ways depending on the apparatus configuration. .

Regarding the specific conditions such as the processing temperature, in the high quality magnetic tape original plate 9 such as a metal tape, since the rotating roll is made of all metal, the thermal conductivity is high and the present embodiment is concerned. The product processed by the calendering device can be manufactured at the same level or higher even if the temperature condition is lower by 20 ° C. than the product processed by the conventional ordinary calendering device. In the figure, "example product" means a product processed by the calendar device according to the present embodiment, and "conventional product" means a product processed by a conventional normal calendar device.

That is, as shown in FIG. 3, the temperature (indicated by T in the figure) at which the magnetic tape original plate 9 is clamped and the pressure acts is 110 ° C. or higher (T in the figure).
Even if the temperature is lowered to 90 ° C, which is 20 ° C lower than 2) (T in the figure
1), the magnetic characteristics of the magnetic tape original plate 9, for example, the high saturation magnetic flux density Br is equal to or higher than the conventional one.

In the audio tape, the surface 9 of the magnetic tape master 109 is used as a substitute for the tape characteristics.
FIG. 4 shows the relationship between the glossiness (Gloss) of c and the surface roughness (SRa).

It can be seen from FIG. 4 that when the tape characteristics G1 of the conventional conventional product are compared, a tape having the same tape characteristics G1 and having a high surface roughness (SRa) can be obtained.

In this respect, originally, since the rotary rolls of the multi-stage roll 2 are all metal rotary rolls 3, 4 and 5, the surface of the magnetic recording medium should be smoother than in the conventional case. However, in a base film 9b such as a magnetic tape original plate 9 having a rough surface such as a base film for an audio tape, the base film 9b shown in FIG.
For the audio shown in FIG. 6, the influence of the base material (protrusion) of the base film 9b is more likely to appear on the surface 9c of the magnetic tape original plate 9 (see FIG. 6). This is a base film for audio 9
Since b is generally rough such as surface roughness SRa ≧ 30 nm, this influence is likely to occur. Therefore, by appropriately roughening the surface 9c of the magnetic tape original plate 9, the friction of the surface 9c of the magnetic tape original plate 109 is reduced,
It is considered that the running property and durability of the magnetic tape original plate 109 are improved.

As described above, according to this embodiment, it is assumed that the surface of the metal rotary rolls 3, 4, and 5 has a lower temperature and a lower maximum pressure than those of the conventional apparatus using the elastic rotary roll. It is possible to smooth the coating film 9a of the magnetic paint while maintaining the magnetic characteristics and physical characteristics at the same level as or higher than the conventional level.

Then, the linear pressure and the maximum pressure (P-max) of the conventional device 101 and the device 1 of the present embodiment were compared and examined. FIG. 7 shows this result. In addition,
Here, the conventional device 101 is a seven-stage type in the case of the metal tape described above, and the radius of each rotating roll of the multi-stage roll 102 is 320 mm, 200 m for the metal rotating roll.
m and 350 mm having different radii are used, and each of the elastic rotating rolls has a radius of 280 mm.

As is apparent from FIG. 7, at the same linear pressure, the maximum pressure (P-max) of the device 1 of this embodiment is significantly higher than that of the conventional device 101.

The reason why such a remarkable difference is observed is as follows.
As shown in FIG. 20, the elastic rotary roll 104 and the like are elastically deformed, but according to the present embodiment, as shown in FIG. 2, the multi-stage roll 2 is constituted by metal rotary rolls 3, 4, and 5 only. Therefore, the conventional elastic deformation does not occur, and the pressure acts in a narrow range. Note that the conventional device 101
Young's modulus of the metal rotating roll of 21000 kg / mm
^2. The Young's modulus of the elastic rotating roll was 350 kg / mm ² .

As described above, since the maximum pressure (P-max) is increased, the amount of crush of the coating film 9a of the magnetic tape original plate 9 is large, the density of the coating film is high, high packing is possible, and high saturation is possible. The magnetic flux density Br will be obtained.

Experimental Results The concrete experimental results will be described below by using different tape types of the first commercial video tape (TL), the second commercial video tape (EDL), and the audio tape (CVS) as described above. It was applied to a calendar processing device and compared with the conventional case. Table 1 shows the types of magnetic tape original plate 9 and the experimental conditions.
Shown in The processing speed was the same as that of the conventional product.

[0044]

[Table 1]

Table 2 shows specific experimental results obtained under the conditions shown in Table 1. In Table 2, ⊚ indicates “good” as compared to the product, ∘ indicates “equivalent” to the product, and Δ indicates “slightly bad”. It should be noted that Table 2 shows that it is possible to lower the temperature condition according to the present embodiment. However, no matter how much the temperature condition is lowered, it is possible to obtain the same or better performance as the conventional one. Is considered.

[0046]

[Table 2]

As is clear from Table 2, the above TL, E
In each case of DL and CVS, the amount of crushing and the glossiness (Gl
oss), the saturation magnetic flux density Br, etc. show that the packing is increased. However, 1 for TL
It can be seen that the same level of characteristics can be obtained even if the temperature is lowered by 0 ° C. Further, in the case of EDL and CVS, it can be seen that even if the temperature is lowered by 20 ° C., the same level of characteristics can be obtained. In addition, CVS
The experimental result that the surface roughness at 70 ° C. is “rough” is obtained, but it is because the influence of the base film 9b base / protrusion of the base film 9b is exerted as described above. Conceivable.

Next, the first commercial video tape (T
L), the second commercial video tape (EDL), and the audio tape (CVS), in order to compare the case where the application device 1 according to the present embodiment is used and the conventional product, The magnetic characteristics (saturation magnetic flux density Br), physical characteristics (adhesion degree), and electrical characteristics (ER) of the magnetic tape original plate 9 produced by the apparatus of the embodiment, and the glossiness (Gloss) of the surface 9c of the magnetic tape original plate 9 And surface roughness (SRa)
The relationship between the temperature condition and the pressure condition was investigated.

First, FIGS. 8 to 10 show the above-mentioned first commercial video tape (TL). As is clear from these figures, even if the temperature and pressure are lowered as compared with the case of the conventional product. It can be seen that magnetic properties, physical properties, and electrical properties at the same level or higher can be obtained.

11 to 13 show the commercial video tape (EDL), and FIGS. 14 to 16 show the audio tape (CVS). As is apparent from these figures, conventional products It can be seen that even if the temperature and the pressure are lowered, the magnetic properties and the glossiness (Gloss) of the surface of the magnetic tape original plate at the same level or higher can be obtained.

Regarding the surface roughness (SRa), as shown in FIGS. 13 and 15, different results were obtained for the above-mentioned tape types depending on the temperature and pressure conditions.

In the case of the present embodiment, the glossiness (Gloss) and surface roughness (SR) of the various tapes described above are used.
FIG. 17 shows the relationship with a), and FIG. 18 shows the sunk thickness of the coating film 9a of the magnetic tape original plate 9 due to crushing.

[0053]

In the calendering apparatus according to the present invention, a calendering apparatus for smoothing the coating film by passing the magnetic tape original plate coated with the magnetic coating material between the multi-stage rolls in which the rotating rolls are combined in a multi-stage manner is used. In the above, since each rotating roll of the multi-stage roll is made of metal, a two-stage or three-stage multi-stage roll having a smaller number of stages than the conventional elastic rotating roll is used. Therefore, simplification and downsizing of the device can be achieved.

Further, in this embodiment, since the multi-stage roll is constituted only by the metal rotary roll, the coating film of the magnetic tape original plate and the metal rotary roll are deformed by the conventional deformation of the elastic body in combination with the elastic rotary roll. The slip phenomenon does not occur between the rotating rolls and the rotating rolls are not soiled.

Furthermore, since each of the rotary rolls constituting the multi-stage roll is a metal rotary roll, high thermal conductivity and high pressure can be obtained, so that the temperature is lower than that of the conventional elastic rotary roll. Even with a low pressure, the coating film of the magnetic paint of the magnetic recording medium is crushed to a large extent, the packing density of the magnetic powder in the coating film is increased, and the coating film is smoothed.

The effect that the temperature can be made low as described above has the following effects, and the magnetic characteristics, electromagnetic conversion characteristics, and physical characteristics are improved, and high accuracy is achieved. It is possible to manufacture a magnetic recording medium such as a magnetic tape.

First, the magnetic tape was deformed under the conventional high temperature treatment, but in the present invention, since the temperature condition can be lowered, the magnetic tape is not deformed.

Secondly, in the conventional apparatus, the binder component in the coating film sometimes oozes out, but in this embodiment, the temperature condition can be lowered, and the rotating roll is made only of metal. Therefore, the binder component and the like do not ooze out, and as a result, surface defects (dropout error) of the magnetic tape can be prevented.

Thirdly, it is not a multi-stage type roll in which an elastic rotating roll and a metal rotating roll are combined as in the conventional case, but
Since it is a multi-stage roll with only metal rotating roll,
The surface roughness of the coating film of the ferromagnetic material can be increased. Therefore, the friction on the surface of the magnetic tape is reduced, and the running property and durability of the magnetic tape can be improved.

Fourth, the crushing of the coating film coated with the magnetic coating material of the magnetic tape is increased, the density of the coating film is increased, and a high saturation magnetic flux density Br is obtained.

As described above, the present invention is highly expected as a next-generation calendar device and calendar system.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a calendar processing apparatus of an embodiment to which the present invention is applied.

FIG. 2 is a schematic diagram showing a state in which a magnetic tape is sandwiched between metal rotating rolls according to the above-described embodiment and a state in which maximum pressure is applied.

FIG. 3 is a diagram showing a comparison between a relationship between a saturation magnetic flux density Br and a temperature condition for an example product manufactured according to the above-described embodiment and a conventional product.

FIG. 4 is a diagram showing a comparison between the surface roughness and the glossiness of the example product manufactured according to the above-described example and the conventional product.

FIG. 5 is a cross-sectional view showing a coating state of a coating film of a ferromagnetic material on a base film in the case of a normal tape.

FIG. 6 is a cross-sectional view showing a coating state of a coating film of a ferromagnetic material on a base film in the case of an audio tape.

FIG. 7 is a graph showing the relationship between the linear pressure and the peak pressure between the present embodiment and a conventional seven-stage type device.

FIG. 8 is a diagram showing a comparison of magnetic characteristics (saturation magnetic flux density Br) of a case where the magnetic tape is TR with respect to a case where the magnetic tape is produced using this example and a conventional product.

FIG. 9 is a diagram showing a comparison between a case where a magnetic tape is TR and a case where a physical property (adhesion degree) is used for production in this example and a conventional product.

FIG. 10 is a diagram showing a comparison between the case where the magnetic tape is TR and the case where the electric characteristic (ER) is produced using this embodiment and the conventional product.

FIG. 11 is a diagram showing a comparison between the case where the magnetic tape is EDL and the case where the glossiness (Gloss) is produced using this example and the conventional product.

FIG. 12 is a diagram showing a comparison of the magnetic characteristics (saturation magnetic flux density Br) of the magnetic tape manufactured by using this example and the conventional product when the magnetic tape is CVC.

FIG. 13 is a diagram showing a comparison between a case where the magnetic tape is EDL and a case where the surface roughness (SRa) is produced using this example and a conventional product.

FIG. 14 is a view showing a comparison between a case where the magnetic tape is CVC and a case where the glossiness (Gloss) is produced using this embodiment and a conventional product.

FIG. 15 is a diagram showing a comparison of the magnetic characteristics (saturation magnetic flux density Br) of the case where the magnetic tape is CVC with respect to the case where the magnetic tape is produced using this example and the conventional product.

FIG. 16 is a diagram showing a comparison between the case where the magnetic tape is CVC and the surface roughness (SRa) produced by using this example and the case where the conventional product is used.

FIG. 17 is a diagram showing the relationship between the surface roughness and the glossiness of a magnetic tape when produced using this example.

FIG. 18 is a diagram showing a submerged thickness of a coating film of a magnetic tape when produced by using this embodiment.

FIG. 19 is a schematic diagram showing a schematic configuration of a conventional calendar processing device.

FIG. 20 is a schematic diagram showing a state in which a magnetic tape is sandwiched between rolls and a state in which maximum pressure is exerted on the conventional calendaring device.

[Explanation of Codes] 1 Calendering device 2 Multi-stage roll 3 First metal rotary roll 4 Second metal rotary roll 5 Third metal rotary roll 6 First metal rotary roll and second metal rotary roll Clamping surface 7 Clamping surface between the second metal rotating roll and the third metal rotating roll 8 Guide member 9 Magnetic tape 9a Coating film of ferromagnetic material of magnetic tape 9b Base film 9c Surface of magnetic tape

Claims (3)

[Claims] 1. A calendering apparatus for smoothing a coating film by passing a magnetic recording medium coated with a magnetic coating between multi-stage rolls in which multi-stage rolls are combined, wherein each rotary roll of the multi-stage rolls A calendar processing device, characterized in that the is made of metal. 2. The calender processing apparatus according to claim 1, wherein the multi-stage roll is composed of two-stage rotating rolls. 3. The calendering apparatus according to claim 1, wherein the multi-stage roll comprises three-stage rotating rolls.