JPS58118034A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To produce easily magnetic recording medium which has reduced disturbance of winding, e.g., excellent travelling performance, by controlling the form of the surface at the side where a ferromagnetic layer of a substrate is not formed by means of a vapor-deposited tape which uses a metallic ferromagnetic layer on a substrate of a macromolecular molded material. CONSTITUTION:A substrate 1 is vapor-deposited while it receives a partial limitation of the incident angle with a mask 6 and by a steam current radiated from an evaporating source 5 when the substrate is shifted to a take-up shaft 4 from a supply shaft 3 along a rotating supporter 2. For a rotary supporter 2, a medium is circulated at the inside of the supporter 2 to keep the surface temperature at a certain level. Thus the supporter 2 serves to perform a cooling operation in order to reduce the thermal effect given to the substrate 1. A heat roll 7 has an important role and is formed with a surface having, e.g., 0.06mu means coarseness of the center line. At the same time, the surface temperature of the roll 7 is kept at >=1.3Tg (Tg: temperature of plastic substrate at glass transition point). As a result, the high traveling performance is secured for a magnetic recording medium. The surface temperature of an auxiliary roll 8 is set lower than the Tg in order to prevent the generation of lines.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a magnetic recording medium such as a vapor-deposited tape in which a metal ferromagnetic layer on a polymer molded substrate is used as a magnetic recording layer. The purpose is to provide a method suitable for manufacturing recording media.

In order to realize short wavelength recording, efforts have been made to increase the saturation magnetic flux density, increase the coercive force, and reduce the thickness of the magnetic layer of the recording medium. Vapor-deposited tape, which has long been said to be the ultimate form of tape, has come into use in recent years, and improvements in performance and manufacturing methods are being made in various fields.

Among these, improving running performance remains a difficult task as conventional coating-type technology cannot be used.

The most common method is to form a coating layer containing a lubricant on the side with the magnetic surface and the opposite side of the substrate.
1 (1: Satisfactory results have not been obtained.

In other words, it is difficult to add fine particles such as acclimatized zinc or charcoal 1# calcium and expect a shape effect in the case of vapor-deposited tapes. That is, since such fine particles cannot be made to protrude only from the back surface, the surface roughness of the magnetic surface increases, impairing the electromagnetic conversion characteristics.

The present invention has been made in view of this point, and the cross-sectional configuration is represented by that shown in FIG.

In the figure, the substrate 9 is a plastic film made of polyethylene terephthalate or the like, and may have a coating layer in the shape of earthworm-like minute protrusions on one or both surfaces in advance.

On one surface thereof, a magnetic recording layer 1o is disposed, which has a multilayer structure including a ferromagnetic all-metallic layer and a nonmagnetic layer if necessary.

11 (d [This schematically shows a rough surface. This rough surface 1
1 is 1% due to the manufacturing method described below,
In some cases, it is also possible to coat this rough surface with a lubricant to further improve its practical properties. FIG. 1(d) shows the configuration of the main parts of the apparatus for carrying out the present invention.

As shown in the figure: the substrate 1 is placed along the rotating support 2,
Move from the feed shaft 3 to the take-up shaft 4! At this time, the vapor is deposited on the vapor flow emitted from the evaporation source 5 with the angle of incidence partially limited by the remask 6.

The rotating support body 2 circulates a medium therein to keep the surface temperature at a certain level, and also has a cooling effect in order to reduce the thermal influence on the substrate. 7 is a hot roll which is an important element in the present invention. By setting this roll γ at a surface with a centerline average phase of, for example, o, oeμ, and maintaining the surface temperature at 1.3 Tq or higher, where Tq is the glass transition temperature of the plastic substrate, The driving performance described below can be obtained. The auxiliary roll 8 has a rolling point temperature Tq
Set it lower to prevent wrinkles from forming.

Although some effect is seen at the transition point temperature Tq, it lacks stability, so 1.3 Tg is used as a guideline.

The upper limit is rather determined from aspects other than the problem of wrinkle generation, and up to 2 Tg is probably sufficient to stably obtain the effects of the present invention, but it may be necessary to set a value within an appropriate range depending on the moving speed of the film and the tension applied to the film. should be selected.

Next, the present invention will be specifically explained in detail.

[Example 1] Polyethylene terephthalate film (J19.5μ
, Tg = 69.5℃) and α on 5 x 10”T
The film was deposited to a thickness of 0.15 μm in an oxygen atmosphere of 0.0 m.

The incident angle was 4o0 or more, the film moving speed was 35-n, the temperature of the rotating support (diameter 1 m) was controlled at 15 °C ± 1 °C, and the surface of the heating roll (diameter 116 ms) was adjusted to the centerline average a'rt. The diameter is 0.07μ, the temperature is 90℃, B
= 110"C, C = 130"C (7) 3 levels were selected,
The results of examining the occurrence of winding disorder due to fast forwarding using the same winding system are shown in the first column. The tape width is 7-2 and the length is 10.
It is 0m. The conventional example is a case where the temperature of the heat roll is maintained at room temperature. The polyethylene terephthalate film used has a surface thickness of 0.01 μ in terms of C, L, and A values.

Table 1 [Example 2] Table 1 ■ Polyethylene terephthalate film with roughness C, L, and A values of 0.007 μ (T (J near 1°C, thickness 10.5
μ) − to 6′ − to Co80%N′i 20% to oxygen partial pressure 2×1O−5T
The film was deposited to a thickness of 0.12 μm in a vacuum of 0.03 m. Other conditions were the same as in Example 1, box: 96°C, B: 120°C.

(: In addition to the three levels of 135°C, under conditions A and B, a resin containing a lubricant was applied to a thickness of approximately 0.1μ using a reverse coater.The resin was not polystyrene 2 epoxy, etc. In addition, as a lubricant, regardless of the type of saturated fatty acid, results were obtained that seemed to have a preferential effect on the shape of the present invention.The results are shown in Table 2. show.

Table 2 Others: center line of silent roll, average value O, OSμ0.1
Similar effects are obtained for both μ, 0.14μ, and 0.2μ.

As a substrate, polyethylene naphthalate, polyacetate
The same was true for the valley films of 1., polyamide, and polyimide. In addition, it has been found that no effect is required when the thickness of the vapor deposited layer is within the range of 0.05 μm to 0.3 μm. It is effective to improve the regularity of the hot rolls by engineering, but even randomness is sufficient for Amagawa.

In either case, the center arm is an average rough illusion: there is a +1 direction where it becomes less than the forceps of the heat roll, but it acts as an old one and the curved surface shape JjW is the same as the glass stick. Therefore, the so-called shape transfer caused by winding can also be ignored.

As described above, according to the misfire 1, it is possible to easily produce a magnetic recording medium with little winding disorder, that is, with excellent running properties, and its engineering value is outstanding.

[Brief explanation of the drawing]

11] is a diagram showing a main part of an example of a manufacturing equipment drawer used in the embodiment of the invention, and FIG. 2 is a cross-sectional view of a magnetic recording medium manufactured using the embodiment of the invention. It is. 1.9... Substrate, 2-... Rotating support, 6
...Mask, 7...Heat roll, 10...
・・・Magnetograph layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
"Illustrate". Figure 2-19! , f.

Claims (1)

[Claims] After forming a ferromagnetic layer by vapor deposition on one side of a polymer molded substrate moving along a rotating support, the surface temperature is 1°3Tg, where the glass transition point of the substrate is Tq. With the heat roller controlled as above, the ferromagnetic layer of the substrate 2 is not formed! 1. A method of manufacturing a magnetic recording medium, comprising controlling the shape of a surface of l.