JPS5939665B2 - Method of forming a solar heat absorption film on the surface of metal foil - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a method for forming a solar heat selective absorption film on the surface of metal foil, and its purpose is to form a solar heat selective absorption film that has a small solar interference effect and a high heat absorption rate. The object of the present invention is to provide a method that can be formed easily and in a short time.

This invention will be explained below with reference to the drawings.

In FIG. 1, the method according to the invention includes an upper part K in a vacuum chamber 1, an unwinding reel 3 equipped with a coiled metal foil 2;
and a take-up reel 5 for winding the metal foil 4 from the coiled metal foil 2 attached to the unwind reel 3 are arranged in the same horizontal plane and parallel to each other, and the unwind reel 3 and the take-up reel 5 A vapor deposition material 8 (hereinafter referred to as the first vapor deposition material) made of metal or semiconductor is placed below the reels 3 and 5.
an evaporation source 6 (hereinafter referred to as a first evaporation source) having a evaporation source 6 and a evaporation material 9 made of a metal oxide (hereinafter referred to as a second evaporation material)
An evaporation source 7 (hereinafter referred to as a second evaporation source) having a metal foil 4
The metal foil 4 is placed at a predetermined interval in the winding direction and the former is placed on the unwinding reel 3 side, and a partition plate 10 is placed between the metal foil 4 and the unwinding reel 3 in a vacuum. The method is characterized in that the metal foil 4 is evaporated with the evaporation substances 8.9 while the metal foil 4 is being wound around the metal foil 4 so that the evaporation ranges of the two evaporation substances 8 and 9 do not overlap.

As the metal foil 4, for example, aluminum foil is used.

The spontaneous emission sources 6 and 7 each have an electron beam heating device and the like for heating the vapor deposition substances 8 and 9 in addition to the vapor deposition substances 8 and 9, respectively.

The first vapor deposited substance 8 includes Cr, Ni, Fe, Co, and A1 whose vapor deposited layer acts as a heat absorber.
metals such as Si, Ge, etc. are used.

Further, as the second vapor deposition substance 9, Cr2O3, Ni2O, etc., whose vapor deposition layer is a dielectric layer having an antireflection effect, are used.
3, Al2O3, 5in2. Metal oxides such as SiO are used.

The partition plate 10 is for preventing the vapor deposition ranges of the first vapor deposition substance 8 of the first vaporization source 6 and the second vapor deposition substance 9 of the second vaporization source 7 from overlapping on the metal foil 4 .

The substance evaporated from the first evaporation substance 8 spreads upward, but the evaporation substance that spreads towards the second evaporation source 7 hits the partition plate 10 and evaporates there, so that the first evaporation substance 8 is vapor-deposited on the metal foil 4 in a range a closer to the unwinding reel 3 than the partition plate 10.

On the other hand, the substance evaporated from the second evaporation substance 9 also spreads upward, but the evaporation substance that spreads and spreads toward the first evaporation source 6 hits the partition plate 10 and is deposited thereon, so that the second evaporation substance 9 The vapor deposition substance 9 is vapor deposited on the metal foil 4 in an area closer to the take-up reel 5 than the partition plate 10 .

Therefore, on the metal foil 4 wound from the coiled metal foil 2 mounted on the unwinding reel 3 to the take-up reel 5, the first vapor deposition substance 8 is first vapor-deposited in the area a, and then the first vapor deposition substance 8 is vapor-deposited in the entire area. A second vapor deposition substance 9 is vapor deposited.

As a result, on the surface of the metal foil 40, as shown in FIG.
A coating 13 is formed with a vapor deposited layer 12 of vapor deposited substance 9.

In this film 13, the vapor deposited layer 11 functions as a heat absorber,
Since the vapor deposited layer 12 functions to prevent reflection of sunlight, the coating 13 has sufficient performance as a solar heat selective absorption coating.

The method for depositing the vapor deposition substances 8 and 9 on the metal foil 4 is as follows:
There are vacuum evaporation methods, ion blating methods, sputtering methods, etc.

Solar heat selective absorption film 13 obtained by the method of this invention
The thickness is preferably within the range of 0.05μ to 0.2μ, particularly preferably about 0.1μ.

The reason why the thickness of the film 13 is set within the range of 0.05 to 0.2μ is that if it is less than 0.05μ, the heat absorption rate is insufficient;
．． This is because if it exceeds 2 μ, the emissivity increases and the film 13 does not have sufficient performance as a solar heat selective absorption film.

Next, examples of this invention will be shown.

A coiled aluminum foil 2 is attached to the unwinding reel 3 in the vacuum chamber 1, and the oxide film on the surface thereof has been removed by pretreatment such as sputter cleaning in the vacuum chamber 1.

The aluminum foil has a thickness of 0.1 mm, a width of 100 plates, and a length of 20 m.

Further, the distance between the winding surface of the aluminum foil 40 and the first evaporation source 6 and the second evaporation source 7 is set to 250 plates, and the first evaporation material 8 made of Cr is placed in the first evaporation source 6 and the second evaporation source A second vapor deposition material 9 made of Cr2O3 is provided at 7 and 7, respectively.

Then, while winding up the aluminum foil 4 from the coiled aluminum foil 2 with the take-up reel 5 at a speed of 0.3 m/min, Cr and Cr2O3 are applied to the aluminum foil 4 at a speed of 30 A/sec by vacuum evaporation. Deposited.

The film 13 formed in this way to a thickness of about 0.1μ
The solar energy absorption rate is 0.92, and the emissivity is 0.06.
It has sufficient performance as a solar heat selective absorption film.

As described above, according to the method of the present invention, once the inside of the vacuum chamber 1 is brought into a vacuum state, the surface of the metal foil 40 is coated with metal or semiconductor material while maintaining the vacuum state and in one operation. A solar heat selective absorption film 13 can be formed that includes a vapor deposition layer 11 of vapor deposition material 8 and a vapor deposition layer 12 of vapor deposition material 9 made of a metal oxide, with the former facing the metal foil 4 side.

Moreover, this work can be done in a short time.

In addition, in the solar heat selective absorption film 13 formed by the method of the present invention, the vapor deposited layer 11 made of metal or semiconductor on the metal foil 4 side acts as a heat absorber, and the vapor deposited layer 12 made of metal oxide on the surface side acts as a heat absorber. It functions to prevent the reflection of sunlight, and moreover, after forming the vapor deposited layer on the metal foil 4 side, the vacuum state in the vacuum chamber 1 is temporarily released to form the vapor deposited layer on the surface side. No oxide film is formed between 11 and 12.

Therefore, in this solar heat selective absorption film 13, the interference effect of sunlight is reduced and the heat absorption rate is increased.

Moreover, the adhesion between the two vapor deposited layers 11 and 12 is good, and the durability is excellent.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the method of this invention, and FIG. 2 is a sectional view showing the structure of a solar heat selective absorption film formed by the method according to this invention. DESCRIPTION OF SYMBOLS 1... Vacuum chamber, 2... Coiled metal foil, 3... Unwinding reel, 4... Metal foil, 5... Take-up reel,
6,7... Evaporation source, 8,9... Evaporation substance, 10...
- Partition plate, 13...Solar heat selective absorption film.

Claims (1)

[Claims] 1 The unwinding reel 3 on which the coiled metal foil 2 is attached to the upper part of the vacuum chamber 1 and the take-up reel 5 that winds the metal foil 4 from the coiled metal foil 2 attached to the unwinding reel 3 are the same. The unwinding reels 3 are arranged in a horizontal plane and parallel to each other.
Below the take-up reel 5 and between both reels 3 and 50, an evaporation source 6 having an evaporation substance 8 made of a metal or a semiconductor and an evaporation source 7 having an evaporation substance 9 made of a metal oxide are connected to a metal foil 40. They are arranged at a predetermined interval in the winding direction and the former is on the unwinding reel 3 side.
A partition plate 10 is placed between the metal foils 1 and 1, and while the metal foil 4 is being wound onto the take-up reel 5 in a vacuum atmosphere, the partition plate 10 is used to prevent the vapor deposition ranges of the clearly deposited substances 8 and 9 on the metal foil 4 from overlapping. A method for forming a solar heat selective absorption film on the surface of a metal foil, the method comprising depositing vapor deposition substances 8 and 9 on the metal foil 4.