KR20140069837A

KR20140069837A - method of manufacturing reflector sheet

Info

Publication number: KR20140069837A
Application number: KR1020120137605A
Authority: KR
Inventors: 김창건; 박성덕; 김도현
Original assignee: 주식회사 보이트씨앤아이
Priority date: 2012-11-30
Filing date: 2012-11-30
Publication date: 2014-06-10

Abstract

The present invention relates to a manufacturing method for a reflective film. The manufacturing method for a reflective film includes a first step of performing a vacuum thermal deposition process on the surface of a base material by using aluminum at the high production speed (the rate of movement of the film) of 300-500 m/min; and a second step of performing an Ag sputtering process on the surface of the film which went through the vacuum thermal deposition process using aluminum at the speed of 5-15 m/min after mounting a roll on an Ag sputtering apparatus by taking out, from the vacuum chamber, the film roll which completed the deposition.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method for producing a reflective film by vapor deposition. That is, a reflective sheet is manufactured by increasing the surface reflectance by vacuum deposition or sputtering of a coating material (Al, Ag, Zn, Cu, etc.) of a metal material on the surface of a polyethylene terephthalate (PET) film or other plastic film substrate Technology.

Methods for depositing a film material of a metal material as a thin film on a plastic film substrate (adherend) by a physical method include thermal evaporation, sputtering, and the like. The above methods cause the coating material to evaporate inside the vacuum chamber to adhere to the surface of the adherend, thereby forming a coating layer on the surface of the adherend with a thickness of several tens of angstroms (Å) or several thousand angstroms (Å). The thermal evaporation method is a method in which the coating material and the adherend are put into a vacuum chamber and the whole of the coating material mass is heated to evaporate the coating material in an atomic or molecular state To adhere to the surface of the adherend, thereby coating the surface of the adherend with a coating material. Sputtering, on the other hand, uses an electron beam and argon plasma to heat the coating material from the surface of the coating material to evaporate to the atomic or molecular state and adhere to the surface of the coating material, To form a thin film coating.

Aluminum (Al) and silver (Ag) are typically used as a coating material for thermal deposition or sputtering of a surface of an adherend to increase the surface reflectance of an adherend, And the production rate is very slow because the evaporation rate is slower than that of aluminum. On the other hand, aluminum is very cheap in price and evaporation rate is faster than silver, so the production speed is very fast. However, when aluminum is coated with the same thickness, there is a disadvantage that the reflectance is lower than that of silver. Therefore, when deposition or sputtering is performed using aluminum, the productivity is high because the production speed is high, and the production cost is low. However, aluminum has a limitation in reflectivity due to its metallic properties. If aluminum is used for deposition or sputtering, the reflectance is about 94% and it is difficult to obtain a reflectance higher than that. That is, in the case of aluminum, the reflectance does not increase by more than 94% even if the deposition or sputtering speed is lowered to increase the coating thickness. Therefore, the method of performing vapor deposition or sputtering using only aluminum can not be applied to a reflective sheet requiring a reflectance of 97% or more.

On the other hand, when the silver (Ag) is deposited or sputtered, the reflectance of about 97% can be obtained, but the production speed is very slow and the production cost is very high. Accordingly, a problem to be solved by the present invention relates to a method of manufacturing a reflective sheet having a reflectance of 97% or more while remarkably lowering the production cost.

The reflectance of up to 94% can be obtained when the coating is applied to the adherend by vapor deposition or sputtering using aluminum as a coating material. Since aluminum has a very fast evaporation rate, the reflectance can be up to 94% even when deposited at a very high rate by the thermal evaporation method. As shown in Fig. 1, the film 3, which is the adhesive, is connected and mounted in the vacuum chamber 8 across the unwinder 1, the cooling roll 4, and the rewinder 2. When the cooling roll 4 is cooled and the aluminum 6 is heated in the heating furnace 5, the aluminum vapor 7 adheres to the surface of the film as the adherend. Such aluminum can be produced at a high production speed (film transporting speed) of 300 m / min to 500 m / min using a vacuum thermal vapor deposition apparatus, and the reflectance can be obtained to be 94%. As described above, when vacuum thermal deposition is performed at a high speed using aluminum, productivity is high and aluminum is inexpensive. Thus, a deposition coating film having a reflectance of 94% can be obtained at a very low production cost.

However, when the coating is applied to the adherend by thermal deposition or sputtering using silver (Ag), the reflectance up to 97% can be obtained. However, silver (Ag) It is required to be deposited or sputtered at a rate of about 0.5 m / min to 1 m / min. Therefore, since the productivity is only about 1/100 of aluminum, the production cost is increased to about 100 times, which is not economical. Accordingly, the present invention provides a method of manufacturing a reflective sheet having a reflectance of 97% or more and a high productivity.

That is, in the present invention, a reflective film having a reflectance of 94% is produced by performing vacuum thermal deposition at a high speed of 300 m / min to 500 m / min at a production speed (moving speed of the film) using aluminum in one step. The deposited film roll was taken out of the vacuum chamber, and a silver (Ag) sputtering device was attached to the roll in a two-step manner. Silver (Ag) sputtering was performed on the surface of the aluminum vacuum thermal deposited film at a speed of 5 m / min to 15 m / do. The adherend film 11 is mounted through the unwinder 9, the rewinder 10 and the cooling roll 12 in the sputtering housing (FIG. 2). Vacuum is applied to the vacuum chamber 17, and argon gas is injected through the argon (Ar) gas injection ports 13 and 14 while moving the adherend film. Silver (Ag) is coated on the surface of the adherend as the adherend passes the silver (Ag) targets 15 and 16. When the sputtering is performed in this manner, the reflectance is further increased by about 3%, and a reflective film having a reflectance of about 97% or more can be obtained.

As described above, in order to obtain a reflectance of 97% or more by thermal deposition or sputtering using only silver (Ag), the production speed (moving speed of the film) should be about 0.5 m / min to 3 m / min. , A reflective sheet having a reflectance of about 94% is produced by performing aluminum thermal deposition at a high speed of 300 m / min to 500 m / min in a first step, / min, silver (Ag) alone can be used to produce a reflective sheet having a reflectance of 97% at a speed of about 5 times or more higher than the production pitch for obtaining a reflectance of 97%. Thus, a highly reflective reflective sheet can be produced at a very low production cost.

When silver (Ag) is deposited or sputtered, the reflectance of about 97% can be obtained, but the production speed is very slow and the production cost is very high, which is not economical. Therefore, when aluminum is used as a coating material to produce a reflective sheet having a reflectance of 94% at a high-speed production speed in a single step like the method of the present invention, when the silver (Ag) is sputtered as a coating material in two steps, Reflective sheets having 97% or more can be produced at a very low production cost. That is, if the method of the present invention is used, a reflective sheet having a reflectance of 97% or more can be produced at a production cost of about 1/5 of the production cost of a conventional silver reflection sheet.

FIG. 1 is a schematic view of a vacuum evaporator in which aluminum is used as a coating material to deposit on the surface of a film by a thermal evaporation method. FIG. 2 is a schematic view of a vacuum deposition apparatus using silver (Ag) as a coating material by a sputtering method And FIG. 3 is a view showing a step in which aluminum and silver are coated on the surface of an adherend (PET film) by thermal deposition and sputtering, respectively.

(8) using a vacuum thermal evaporation apparatus with aluminum (6) having a purity of 99.9% on a primer-treated optical PET film (H34P of Kolon KK) as a first step, a vacuum degree of 1.0 × 10 ^-4 mbar to a 9.0 × 10 ^-4 mbar and the temperature of the film wrapped around the back cooling roll 4 to -10 ℃ to -20 ℃ deposition speed it was deposited at a rate of 300 m / min to 500 m / min. An evaporated film was prepared under the same conditions as in the following examples, and the surface reflectance was measured using a reflectance meter (Minolta CM-3500d). Table 1 shows the reflectance measurement results of the aluminum vacuum fired film under the above conditions.

Example Example Vacuum degree
(× 10 ^-4 mbar) Cooling roll temperature
(° C) Deposition speed
(m / min) reflectivity
(%, L ^* ) Example 1 7.5 -10 300 89.1 Example 2 7.5 -10 400 88.2 Example 3 7.5 -10 500 83.7 Example 4 5.0 -15 300 94.4 Example 5 5.0 -15 400 91.8 Example 6 5.0 -15 500 90.1 Example 7 2.5 -20 300 94.6 Example 8 2.5 -20 400 93.0 Example 9 2.5 -20 500 92.2

A roll of the sample of Example 4 (vacuum degree of 5.0 x 10 ^-4 mbar, cooling roll temperature of -15 캜, deposition speed of 300 m / min) was mounted on a silver (Ag) sputtering equipment (FIG. 2) Was again sputtered on the deposited surface using silver (Ag). The sputtering conditions are as follows.

The pressure of the inside of the vacuum chamber 17 was fixed to 5.0 x 10 < ^-4 > mbar, and the Ar gas injection holes 13 and 14 were used. The injection rate was 300 sccm (standard cubic centimeter per minute) to 500 sccm, and the sputtering was performed while changing the speed. Table 2 shows an example in which sputtering is performed under these conditions.

Example Adherend Example Vacuum degree
(× 10 ^-4 mbar) Ar infusion rate
(sccm) Sputtering speed
(m / min) reflectivity
(%, L ^* )
H34P
Example 10 5.0 500 0.5 98.1 Example 11 5.0 500 2 71.4 Example 12 5.0 500 10 63.5

Example 4

Example 13 5.0 300 5 98.5 Example 14 5.0 300 10 97.1 Example 15 5.0 300 15 96.0 Example 16 5.0 500 5 98.6 Example 17 5.0 500 10 97.7 Example 18 5.0 500 15 96.8

In Examples 10 to 12, sputtering was performed using an optical PET film (H34P, manufactured by Kolon) subjected to a primer treatment as an adherend, and in Examples 13 to 18, an aluminum vacuum The deposited film was used. That is, in Examples 10 to 12, silver (Ag) sputtering was performed on a transparent PET film on which nothing was deposited, and in Examples 13 to 18, silver (Ag) will be.

The sputtering speed should be as low as 0.5 m / min in order to obtain a reflectance of 97% or more by performing silver (Ag) sputtering on a transparent PET film on which nothing is deposited. However, when secondary silver (Ag) sputtering is again performed on the aluminum vacuum deposited surface, a surface with a reflectance of 97% can be obtained even if the sputtering speed is 5 m / min to 15 m / min and the process proceeds at a very high speed. That is, Example 13 (degree of vacuum: 5.0 x 10-4 mbar, Ar injection rate: 300 sccm, sputtering speed: 5 m / min), Example 14 (degree of vacuum: 5.0 x 10-4 mbar, Ar injection rate: 300 sccm, sputtering speed: Example 14 (vacuum degree of 5.0 x 10 < -4 > mbar, Ar injection rate of 500 sccm, sputtering rate of 500 sccm, sputtering speed of 5 m / min) At a speed of 10 m / min), a reflectance of 97% or more can be obtained.

1,9: un winder
2,10: Rewinder
3, 11, 18: adherend (PET film)
4,12: Cooling roll
5: Boat
6: Aluminum
7: Aluminum steam
8, 17: Vacuum chamber
13, 14: Argon (Ar) gas inlet
15, 16: silver (Ag) target
19: aluminum (Ag) deposition layer
20: silver (Ag) deposition layer

Claims

(Al) on the surface of a PET film or a plastic substrate by a thermal evaporation method, and further coating silver (Ag) on the aluminum thermal deposition coated surface, A method of producing a reflective film including a step of performing a coating by a sputtering method using

Claims 1. A reflective film production method using aluminum having a purity of 90% or more as a coating film material used in thermal evaporation

The silver (Ag) used as the film material used in sputtering in claim 1 has a purity of 90% or more.

A reflective film produced by the method of claim 1 having a reflectance of 97% or more

A method for producing a reflective film having a moving speed of a PET film or a plastic substrate of 5 m / min or more when sputtering is performed with silver (Ag)