JPH0326378A - Production of thin film - Google Patents

Abstract

PURPOSE:To prevent the wrinkling of a polymer substrate due to sudden thermal deformation by blowing a jet of gas on the substrate during travelling along a heating roll when a thin layer is formed on the substrate and the substrate is travelled along the heating roll to produce a thin film. CONSTITUTION:When decorative packing paper obtd. by forming an Al layer on a polymer substrate, e.g. by vacuum deposition is annealed in an atmosphere having an oxygen content equal to or higher than that of the air, the elasticity of the substrate at the inlet side of a heating roll 5 is relatively reduced to increase the mobility on the roll 5 at the time of thermal deformation and the tension of the substrate is relatively increased at the outlet side of the roll 5. A jet of gas from a nozzle 7 is blown on the substrate during travelling along the roll 5. The wrinkling of the substrate is prevented.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a conventional technology relating to a thin film manufacturing method for forming an excellent thin film without wrinkles.In modern society, thin film technology plays a wide variety of roles.Thin film substrates Materials can be classified into flexible substrates such as polymer films and non-flexible substrates such as glass plates based on their mechanical properties, and thin film manufacturing methods are used that match the mechanical properties of the substrates. When using a flexible substrate such as a polymer film, a continuous winding method can be used for mass production of thin films. This is a method in which a roll-shaped polymer substrate is unwound from an unwinding roll, and while it is running, a thin film is formed on the substrate by plating, sputtering, vacuum evaporation, etc., and then the film is wound onto a take-up roll. This method is considered suitable for production. Thin films formed in this way are used in a wide range of fields, including decorative packaging films and magnetic recording media.

In the thin film form precepts, the internal stress relaxation and
A heat treatment called annealing is sometimes performed to improve surface hardness. Although it is possible to solve this process 1 by running the polymer substrate 3 on which a thin film has been formed along the temperature raising roller 5 in the atmosphere using a winding system as shown in FIG. However, when the substrate 3 is thin, the heating roller 5
In order to prevent wrinkles, for example, the tension of the substrate on the entry side of the heating roller 5 should be relatively low to increase the mobility of the film on the roller 5 during heating and thermal deformation. At the same time, it is effective to make the substrate tension relatively high on the exit side of the temperature raising roller 5 so that the film is peeled off from the roller 5 uniformly in the film width direction. However, if the film tensions on both sides of the roller 5 are different, the roller 5
It is difficult to maintain the tension difference between the entrance and exit sides of the roller 5 due to slipping between the film and the roller 5, and at the same time, the film is scratched by sliding, which is not desirable. % Also, in order to prevent slippage between the roller 5 and the film, for example, in the case of a metal thin film, if electrostatic attraction is generated by applying a voltage between the film and the roller 5, However, the present invention aims to solve the problems of the prior art.

Means for Solving the Problems According to the present invention ζ After forming a thin film layer on a polymer substrate directly or via an underlayer, the polymer substrate is heated with a heating roller in the atmosphere or an atmosphere containing oxygen of equal or higher concentration. In the method for producing a thin film, the tension is different between the entrance and exit sides of the temperature-raising roller, and when the polymer substrate is along the temperature-raising roller, the gas flow is caused to run along the circumferential surface of the temperature-raising roller. According to the present invention, it is possible to prevent slippage between the heating roller and the polymer substrate on which the thin film is formed, and also to prevent the film from entering the heating roller. Since this can be ensured without reducing the mobility of the polymer substrate, it is possible to prevent wrinkles caused by rapid thermal deformation of the polymer substrate during annealing.

EXAMPLES Below, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, which differs from FIG. 2 which shows a conventional example in that a nozzle 7 is provided on the side surface of the temperature raising roller 5. A film with a thickness of 30 nm was formed by vacuum evaporation on a polyethylene terephthalate substrate with a thickness of 8 μm and a width of 50 cm.
Flattening (uncurling) of decorative wrapping paper with A'1 layer
In the annealing treatment for the purpose of In some cases, it is possible to create a large tension difference between the entrance and exit sides of the heating roller 5.Wrinkles in the film can be prevented by using a nozzle that causes wrinkles in the film on the heating roller 5. The resulting Figure 2 shows another embodiment of the present invention.The difference from Figure 1 is that the airflow from the nozzle 7 can be made into a superheated airflow by using a superheating device 8. . If the temperature of the temperature rising roller 5 is high but the airflow from the nozzle 7 is low temperature, the annealing temperature will be substantially lowered by blowing the airflow. In such a case, the nozzle airflow should be a heated airflow.Surface oxidation of a perpendicular magnetic recording medium in which a CoCr layer with a thickness of 2'50 nm is provided by vacuum evaporation on a polyimide substrate with a thickness of 10 μm and a width of 20 cm. In the annealing treatment aimed at, the temperature of the heating roller 5 was set at 300 m/min, and the film running speed was set at lm/min. By using the nozzle 7, wrinkles that would occur on the heating roller 5 in the absence of the nozzle 7 can be prevented. When the air flow was not heated, a decrease in the thickness of the surface oxidation layer and an accompanying decrease in film surface hardness were observed.When the temperature of the heated air flow was 160℃ or higher, measured using a thermocouple near the film, the surface Neither a decrease in the thickness of the oxide layer nor a decrease in the film surface hardness was observed.The room temperature at this time was 20°C. In addition, in the range of 150°C to 400°C, k with respect to other heating roller temperatures Difference force between heating air flow temperature and room temperature t Approximately 172 of the difference between heating roller temperature and room temperature
If it is above, neither a decrease in the thickness of the surface oxidation layer nor a decrease in the film surface hardness is observed.
g/cm") was measured using a pressure gauge. Tension on the entry side of the temperature rising roller T+ (g) and tension on the exit side T+
(To maintain g>, ζ friend is approximately 5PLW≧lT+
I found out that it is necessary to be -Tal where W
is the width of the polymer substrate (cm), and L is the contact length between the polymer substrate and the heating roller (cm). It can prevent wrinkles.

[Brief explanation of drawings]

Figure 1 is a front view showing an example of the annealing process in the thin film manufacturing method according to an embodiment of the present invention; Figure 2 is a front view showing another example of the annealing process in the thin film manufacturing method of the present invention; FIG. 3 is a front view showing a conventional example of an annealing process. 1... Rotating box 2... Rolling out rono k 3...
Polymer substrate on which a thin film is formed, 4... Guide roller, 5... Temperature raising roller, 6... Winding port-)L
,, 7...Nozzle, 8...Heat-setting

Claims (4)

[Claims] (1) Production of a thin film by forming a thin film layer directly or via an underlayer on a polymer substrate, and then running the polymer substrate along a heating roller in the atmosphere or an atmosphere containing an equivalent or higher amount of oxygen. The method is characterized in that the tensions on the entry and exit sides of the temperature-raising roller are different, and when the polymer substrate is along the temperature-raising roller, a gas flow is blown from the outside of the circumferential surface of the temperature-raising roller. Method for manufacturing thin films. (2) The method for producing a thin film according to claim 1, wherein the gas flow comprises heated gas. (3) The circumferential surface temperature of the temperature-raising roller is in the range of 150°C to 400°C, and the difference between the gas flow temperature near the circumferential surface of the temperature-raising roller and the room temperature is the same as the temperature of the temperature-raising roller and the room temperature. Claim 2 characterized in that the difference is substantially 1/2 or more.
Method of manufacturing the described thin film. (4) Pressure P (kg/cm^2) of pressing the polymer substrate onto the circumferential surface of the temperature raising roller by gas flow, width W (cm) of the polymer substrate, and the temperature increase between the polymer substrate and the temperature increasing roller. The relationship between the contact length L (cm) of the roller and the tensions T_1 (g) and T_2 (g) on the entry and exit sides of the heating roller is 5.
The method for producing a thin film according to claim 1, 2, or 3, wherein PLW≧|T_1−T_2|.