JPS61239426A - Method for removing deformation of magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent the generation of cracks in a ferromagnetic film and the generation of creases on a substrate by slowly increasing and decreasing the temp. of a magnetic recording medium. CONSTITUTION:The first roll part is formed by heating rolls 10 and 11 and a magnetic recording medium 9 is slowly heated at this part. The second roll part is formed by a heating roll 12 and the magnetic recording medium 9 is heated to a temp. necessary for removing deformation at this part. The third roll part is formed by heating rolls 13 and 14 and the magnetic recording medium 9 is slowly cooled at this part. The magnetic recording medium 9 is sent out from a supply roll 8, slowly heated at the first roll part 10 and 11, further heated at the second roll part 12 to remove the deformation and then slowly cooled at the third roll part. The medium is traveled successively on the 5 rolls 10, 11, 12, 13 and 14 while being brought into close contact with each roll and wound by a take-up roll 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for removing deformation of a magnetic recording medium in which a ferromagnetic film is formed on a base material made of an organic polymer material.

[Conventional technology]

In recent years, in order to meet the demands for high-density recording, progress has been made in the development of magnetic tape, in particular magnetic tape, which uses vacuum evaporation. This is the process of continuously forming a ferromagnetic thin film on a base material of an organic polymer material. When forming a magnetic thin film 1: Strain occurs between the base material made of an organic polymer material and the ferromagnetic thin film, and deformation occurs with the C2 ferromagnetic film on the inside as shown in the cross-sectional view of the magnetic recording medium in Figure 3. ,
Or curls occur. In the figure, (1) is a base material made of an organic polymer material, (2) is a ferromagnetic film, and h represents the amount of curl. This curl is a magnetic recording medium,
In particular, curls have a large effect on the running properties of magnetic tapes, and it is necessary to remove curls in order to improve running properties.

[Problem that the invention seeks to solve]

Conventionally, the method for removing curls from this type of magnetic recording medium has been to run the curled magnetic recording medium while keeping it in close contact with one heating roll using the apparatus shown in the schematic diagram of FIG. There is a method of heat shrinking a base material made of an organic polymer material.

In the figure, (3) is a supply roll, (4) is a magnetic recording medium, (5) is a heating roll, +61 is an auxiliary roll, (
7) is a winding roll, and the magnetic recording medium (4) sent out from the supply row (31) is a heating roll +511 m.
The magnetic recording medium runs in close contact with the heating roll (71+) and is wound up through the auxiliary roll (6). Because of the steepness, rapid thermal contraction of the base material made of organic polymer material occurs, which may cause cracks in the ferromagnetic thin film and damage to the base material made of organic polymer material Cl.
There were some problems, such as the occurrence of a rash.

This invention has been made to solve the above-mentioned problems, and provides a method for removing deformation of a magnetic recording medium that prevents cracks from occurring in a ferromagnetic film and also prevents wrinkles from forming on a base material. This is what we are trying to provide.

[Means for solving problems]

The method for removing deformation of a magnetic recording medium according to the present invention involves removing deformation by running a magnetic recording medium, which has a ferromagnetic film attached to a base material made of an organic polymer material, in close contact with a heating roll. Place the heating roll in order ■: At least,
A first roll part, a second roll part, a third roll part, and a first roll part.
It is preheated in the roll section, deformed and removed (heated to the required temperature) in the second roll section, and slowly cooled in the third roll section.

[Effect]

In this invention, the heating roll is provided with at least a first roll part, a second roll part, and a 9J3 roll part in the running order of the magnetic recording medium, and the first roll part is preheated, and the second roll part is heated to a temperature necessary for removing deformation. Since the magnetic recording medium is heated and slowly cooled in the third roll section, the temperature of the magnetic recording medium can be gradually increased and decreased, and cracks in the ferromagnetic film are prevented. : The generation of wrinkles on the base material is prevented.

〔Example〕

Next, a method for removing deformation of a magnetic recording medium according to the present invention will be specifically explained using examples.

FIG. 1 is a schematic diagram of an apparatus used in an embodiment of the present invention, which has five heating rolls. is formed. Note that the first roll part, the second roll part, the third roll part
Each roll portion may be formed by a plurality of heating rolls. In the figure, (9) is a magnetic recording medium, (8) is an output supply roll for feeding the magnetic recording medium (9), and 111.(
11), αa, (13, a4) are heating rolls, the first roll part is formed of a heating roll (101αD), the magnetic recording medium (91) is gradually heated in this part, and the second roll part is The magnetic recording medium +97 is heated to a temperature of 1 necessary for deforming the magnetic recording medium +97 at this part.
The third roll part is formed by a heating roll (13 (141),
In this part, the magnetic recording medium +91 is gradually cooled down.

The scream is a take-up roll.

Next, operation 1: will be explained. The magnetic recording medium +91 is sent out from the supply roll (8) and transferred to the first roll portion α1 (11
) is gradually heated, the second roll part is heated to remove the deformation, and the third roll part is gradually cooled. Like this (; 5 heating rolls (lQ, cll).

rl, (13, (14) - runs in close contact with the winding roll (lQ (takes up twice).

〔Example〕

Base material of organic polymer material (width 150 m1 as II. Thickness 1
2μ polyethylene terephthalate film (glass transition point 69”C, melting point 263’O, heat shrinkage rate 150°C9
4% in the longitudinal direction and 2% in the width direction) for 30 minutes, and then
At a vacuum degree of C2 at
O=80, dζ%, Ni:2Qg7r%) at 0.1/g
A ferromagnetic film (21) was formed by FL evaporation to form a magnetic recording medium.

The diameter of each of the five heating rolls is 20C11, the temperature of the roll αα that the magnetic recording medium (9) contacts first is 70°C, and the temperature of the heating roll αυ that comes into contact with the second one is 90"Ci. , third heated roll sauce to 120°0.4
The amount of deformation or curling was measured by changing the running speed of the magnetic recording medium while setting the heating roll 0 of the sth to cJa and the heating roll α of the sth to 70°O. :, the amount of curl was 0 when the running speed was 2'' Ain. At that time, no cracks were observed in the ferromagnetic film (2) of the magnetic recording medium, and the wrinkles in the base material [11] Of the amount of curl in the figure, the case where the ferromagnetic film +21 is deformed or curled inside is shown as a positive curl f+-), and the opposite is shown as a reverse curl ←).

Note that the number of heating rolls may be three or more, and the number 1 is not particularly critical.

〔Effect of the invention〕

As described above, according to the present invention, in a magnetic recording medium having a ferromagnetic film attached to a base material formed of an organic polymer material, the deformation is removed by running the magnetic recording medium in close contact with a heating roll. The heating roll is sequentially equipped with at least a first roll part, a second roll part, and a third roll part, and is preheated with 9J10 parts, heated to a temperature necessary for removing deformation in the second roll part,
Since the third roll section cools the magnetic recording medium slowly, the temperature of the magnetic recording medium increases and decreases slowly, preventing cracks in the ferromagnetic film and wrinkles in the base material. The present invention has the effect of providing a method for removing deformation of a magnetic recording medium, which allows a magnetic recording medium with good runnability to be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus used in a method for removing deformation of a magnetic recording medium according to an embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view of a magnetic recording medium in which deformation has occurred after the formation of a ferromagnetic film, and FIG. 4 is a schematic diagram of an apparatus used in a conventional deformation removal method. (11...Base material, (21...Ferromagnetic film, (; pull, (
81... Supply roll, +41. (9)...magnetic recording medium, 151. α [, α sword, α2. α3゜■...With heating rolls, σα, υ is the first roll part, α is the second roll part, 惺3. α is the third roll part, (6)... auxiliary roll, +71, (1!9... winding o-ru).

Claims (1)

[Claims] A magnetic recording medium having a ferromagnetic film attached to a base material made of an organic polymer material is run in close contact with a heating roll to remove deformation, and the heating roll is sequentially moved to at least a first roll portion, a first roll portion, a second roll portion, and a second roll portion. To remove deformation of a magnetic recording medium, which has two roll parts and a third roll part, the first roll part is preheated, the second roll part is heated to a temperature necessary for removing deformation, and the third roll part is slowly cooled. Method.