JPH02286324A - Film temperature treatment method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides continuous heating or cooling of a long film by running the film in contact with the circumferential surface of a cylindrical can set at a required temperature. This relates to the temperature treatment method for films.Conventional technologyA thin film is formed on a wide and long polymer film to produce functional films or decorative films that can be used as materials for capacitors, magnetic recording tapes, transparent conductive sheets, etc. For example, a winding type vapor deposition apparatus as shown in the Thin Film Handbook (Japan Society for the Promotion of Science, edited by the 131st Thin Film Committee, 3m, 42, published by Ohmsha) is used.

The outline will be explained with reference to FIG. This FIG. 5 shows only the main parts, and the vacuum chamber housing the structure, intermediate rollers, etc. are omitted. In FIG. 5, a wide and long polymeric film 1 (hereinafter referred to as film) is unwound from a supply roll 2 and transferred to a cylindrical can 3 rotating in the direction of an arrow 16 by a free roller 4.5. The winding is carried out by an angle θ, driven by a can 3 to travel, and wound onto a winding roll 6. The vapor deposition material 7 housed in the crucible 8 is heated and evaporated by a known electron beam 9 or the like, and a part of the vapor passes through the opening of the mask 10 and adheres to the film 1 wrapped around the can 3. Forms a thin film. In the above configuration, although the tension in the longitudinal direction of the film 1 is not shown in the figure, it is controlled to a desired value by the motors attached to the supply roller 2 and the take-up roller 6 using a known current control method or the like. ing. The temperature of the can 3 is controlled to a required temperature by known temperature control, for example, by circulating a heat medium.

With this configuration, for example, when a perpendicular magnetic recording medium made of co-Cr is formed on a polyimide film, it is necessary to heat the film 1 in order to vertically align the medium. Furthermore, it is necessary to heat the film 1 in order to release gas such as moisture in the film 1 and to improve the properties of the magnetic medium and the adhesion to the film 1. As a method for this, a method is used in which the can 3 is sufficiently wrapped around the circumferential surface of the heated can 3 and brought into contact with the can 3 to be driven and run.

In addition, when forming a conductive thin film such as a magnetic recording medium made of a metal film, in order to efficiently dissipate the heat received by the film 1 during vapor deposition to the can 3, it is necessary to contact the thin film formed on the film 1. There is a method in which a potential difference is created between the free roller 5 and the can 3 by a DC power source 15, and the film 1 is strongly stuck to the can 3 by electrostatic attraction acting between the thin film and the can 3, or as shown in the figure. Although not shown, for example, a method is used in which the film is irradiated with electrons using a publicly known piercing type electron gun to charge the film and then stick it on the can 3.

Problems to be Solved by the Invention In the conventional examples described above, when the film is heated on the can, sagging due to thermal expansion in the longitudinal direction does not occur because it is pulled by tension. However, when the film expands in the width direction, it does not spread over the can and partially sag, causing wrinkles in the longitudinal direction. The cooling results in longitudinal wrinkles.

Here, regarding the occurrence of wrinkles on the can, Fig. 6(a) to (
This will be explained using C). In FIG. 6, the film 1 is traveling through the free roller 4 to the cylindrical can 3 in the direction of the arrow 18 in the figure. If the film 1 on the can 3 does not expand or contract due to temperature changes, Fig. 6(a)
As shown in FIG. 2, the width a of the film 1 does not change even along the circumferential surface of the can 3. FIG. 6(b) shows a case where the film 1 travels along the can and expands in the width direction while sliding in the width direction so as not to sag.

If the film 1 slides on the can 3 in the width direction and wrinkles do not occur in the longitudinal direction, the width will be greater than a. However, in reality, there is almost no expansion action in the width direction on the can 3, and the film 1 does not easily slide in the width direction. Therefore, it will sag by the amount of unexpanded elongation, as shown in Figure 6 (
Longitudinal wrinkles 13 as shown in C) are generated on the can 3.

When a thin film is formed on the wrinkles thus generated, they remain as wrinkles. Further, when a potential difference is applied between the formed thin film and the can 3, the film 1 strongly sticks to the can 3, so that the wrinkles further become strongly folded wrinkles.

Such wrinkles not only deteriorate the appearance of the product, but also cause serious functional defects in the case of magnetic recording tapes, such as the inability to record properly because the tape and head do not adhere well. This also caused a significant decrease in yield.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a method for temperature-treating a film that can be stably heated or cooled without causing wrinkles in the film on the can.

Means for Solving the Problems In order to achieve the above object, the present invention provides an elongation equal to the elongation δb in the width direction at a required temperature Tb at a plurality of different temperatures T.
When a long film having properties associated with b1 (+:1, 2...+n) is run in contact with the circumferential surface of a cylindrical can set at the required temperature Tb, it comes into contact with the can. After setting the previous film temperature to a temperature that causes the film to elongate in the width direction greater than or approximately equal to the elongation δb in the film width direction at temperature Tb, the film is brought into contact with a can to heat or cool the film. There are things to do.

Function According to the present invention, the elongation δ in the width direction that occurs in the film when it comes into contact with the cylindrical can set at the required temperature Tb
By causing the film to elongate in the width direction greater than or approximately equal to b using heating means, etc., and then running the film in contact with the circumferential surface of the can,
Partial slack in the width direction of the film on the can can be prevented, and wrinkles caused by this can be completely prevented.

Embodiment A method for temperature treatment of a film in an embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, and 4. Note that the same components as those of the conventional device are given the same numbers and detailed explanations will be omitted.

FIG. 2 is a schematic diagram of the internal configuration of the vacuum evaporation apparatus used in this example. A thermally expandable film 1 (for example, a polyimide film) having a width a (see FIG. 3) is unwound from a supply roll 2 in the direction of an arrow 16, and is heated by an electron beam impact heating device 12 serving as a heating means. expanded, width C
(See FIG. 3), it comes into contact with the outer peripheral surface of the cylindrical can 3, becomes wide, and is driven by the can 3 to travel.

The first and second temperature sensors 25.2B are for detecting the temperature of the film 1, and feed back signals from these sensors 25.2θ to the heating control device 24 that controls the electron beam impact heating device 12. The film temperature is controlled to cause elongation.

FIG. 4 shows a schematic configuration diagram of the electron beam impact heating device 12.

Although the total number of filaments 20 is not shown, the insulating material 2
2' and attached to a box-shaped cathode 19. A grid-shaped anode 21 is supported by the cathode 19 with an insulating material 22 in between. The filament 20 is heated by the power source 17 and emits thermoelectrons. The anode 21 to which a positive potential is applied by the DC power supply 18 accelerates the thermoelectrons toward the film 1 and heats the film 1 by causing them to collide with the film 1. The film 1 is also heated by thermal radiation from the filament 20. Therefore, by controlling the voltage applied to the anode 21 of the electron beam impact heating device 12 or the current flowing through the filament 20 with the heating control device 24, the temperature of the film 1 can be set to a predetermined value. This electron beam impact heating device 12 also has the effect of charging the film 1 and sticking the film 1 to the can 3, so there is a charge removing device (not shown, for example) to remove the charge from the film 1 that has left the can 3. (which utilizes a known glow discharge) is installed immediately after leaving the can 3.

Next, the thermomechanical properties as shown in FIG.
Film 1 with characteristics similar to those with bm = 1.2)
The elongation in the width direction of the film when using the film will be explained with reference to FIG. In addition, in Figure 1, the horizontal axis shows the film 1.
Temperature T1 The vertical axis shows the elongation δ in the width direction per unit width of the film 1 and the width B separately. In addition, the temperature of the film 1 before being heated by the electron beam impact heating device 12 is T.
at the width at that time is al elongation is zero, each of the films 1 on the can 3 is Tb1 bl δb,
The width of the film 1 heated by the electron beam impact heating device 12 to a temperature Tc is expressed as 01, and the elongation is expressed as δC.

The elongation of the film 10 in the width direction will be explained using FIG. Film 1 unwound from supply roll 2 (temperature Ta
z Width a) is heated to a predetermined temperature Tc by the electron beam impact heating device 12, which is a heating means, on the entrance side of the can 3, and thermally expands while being heated 41, and the initial width a is expanded to width C, and remains as it is. It is driven and travels in the direction of arrow 16 while forming a width along the circumferential surface of the cylindrical can 3 which is set at a predetermined temperature Tb. Here, under the film temperature condition where the width of the film 1 is b≦C, the film 1 on the can 3 will shrink from the width C to the width, so it will fit on the can 3 without sagging.
No wrinkles will occur. Therefore, the above conditions can be satisfied by controlling the temperature of the film 1 using the electron beam impact heating device 12 so that the width of the film 1 is elongated such that b≦C.

Therefore, for film 1 above, film 1 on the can
When the temperature is Tb, Tc may be controlled to a temperature within the shaded range in the figure so that the elongation δC is 65 or more. That is, Tb2≦Tc≦Tb or Tb2≦T
If c, then the conditions of b:ac can be titrated.

In this embodiment, a sufficient effect is obtained by making Tc slightly higher than Tbl.

However, even under conditions where the width C of the film 1 just before it enters the can 3 is somewhat narrower than the width of the film 1 on the can 3, the adsorption force of the film 1 to the can 3 as described below In this case, the film 1 does not float up from the can 3, and wrinkles can be prevented. The reason for this is that if the film 1 exerts a strong adhesion force to the screen 73 due to charging during electron beam impact heating or electrostatic adsorption by the power source 15 (depending on the degree of that force), This is because the slight expansion of the film 1 can be suppressed by its adhesion.

In addition, in film 1 having the above characteristics, film 1
If the can temperature is such that the width of is smaller than a,
There is no need for heating with the electron beam impact heating device 12.
Needless to say.

In addition, if δb1 δC is large and difficult to spread in the width direction, it is better to install a known expand roller or the like that has an expanding action in the width direction instead of the free roller 4 shown in FIGS. 2 and 3. Needless to say, this is desirable.

In addition, the temperature sensors 25 and 26 for the film 1 should be non-contact types that do not apply unnecessary force to the film 1, and should be installed in a vacuum container to avoid generation of residual gas and flexibility. Therefore, a compact one is more convenient. In this embodiment, although not shown, a non-contact radiation thermometer using an optical fiber is used. In the above case, since only a portion of the fiber is inserted into the vacuum chamber, the degree of freedom is large and the device is compact.

Additionally, in addition to or instead of the temperature sensor 25, 28, if the actual width of the film 1 is measured using an optical line sensor or the like and this signal is fed back to the heating control device, the condition b≦C can be more reliably satisfied. can be satisfied.

Further, it is preferable to place the electron beam impact heating device 12 and the temperature sensor 25 near the can 3 so that the above condition b≦C is easily satisfied.

It should be noted that the present invention can be configured in various ways other than those shown in the above embodiments. The heating means for heating the film 1 may be infrared heating, a heating roller, or a method of scanning and applying an electron beam of a known piercing type EB gun to the film. A structure in which electrons are applied to the side of the film 1 on which the film 1 is formed, or a structure in which electrons are applied to both sides of the film 1 may be used, and the structure is not limited to the above structure.

Further, in the above embodiment, an example was shown in which the film 1 is heated during vapor deposition, but it goes without saying that the same effect can be obtained even in the case of a heating roll whose purpose is only to degas the film 1. .

Furthermore, if the film 1 running on the cooled can has the property of expanding upon cooling, the same effect can be obtained by using a cooling means (for example, a known cryopanel) as the heating means. be able to.

Effects of the Invention According to the present invention, the elongation in the width direction that is greater than or approximately equal to the elongation in the width direction that occurs in the film when it comes into contact with a cylindrical can set at a required temperature is caused in advance by heating means or the like. After that, by running this film in contact with the circumferential surface of the can, the film is continuously heated or cooled in a stable manner without wrinkles caused by partial sagging in the width direction of the film on the can. This makes it possible to significantly improve quality and yield.

[Brief explanation of the drawing]

FIG. 1 is a characteristic diagram showing the thermomechanical properties of the film used in the film temperature treatment method in one embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing the internal structure of the vacuum evaporation apparatus used in the same embodiment, Figure 3 is an explanatory diagram of the elongation of the film in the same example, Figure 4 is a schematic configuration diagram of the electron beam impact heating device used in the same example, and Figure 5 is a schematic configuration showing the internal structure of the vacuum evaporation device in the conventional example. FIG. 6 is an explanatory diagram of the occurrence of wrinkles in a conventional example. 111. Film, 3. ,,Can, 12. , ,Electron beam impact heating device, 24 , ,Heating control device, 25
, , first temperature sensor, 26. ,,second temperature sensor. Agent's name: Patent attorney Shigetaka Kurino and 1 other person/- Phil A 3...Goin/Z... jV side sz Do--@I Difference 7th ring Tot M Tb Film evenness T Fig. Fig.

Claims (1)

[Claims] When running a long film having a property of elongation equal to the elongation in the width direction at a desired temperature at a plurality of different temperatures in contact with the circumferential surface of a cylindrical can set at the desired temperature, The temperature of the film before contacting the can is set to a temperature that causes the film to elongate in the width direction greater than or approximately equal to the elongation in the width direction of the film at the predetermined temperature, and then the film is brought into contact with the can to elongate the film. A method for temperature treatment of a film, characterized by heating or cooling the film.