JPH0230747A - Formation of film on plastic substrate - Google Patents

Abstract

PURPOSE:To increase the bonding force of vacuum-deposited particles to a plastic substrate and to improve the adhesion and durability of a film formed on the substrate by vacuum deposition by irradiating the surface of the substrate with excimer laser light before or during vacuum deposition to remove water and impurities on the surface. CONSTITUTION:When a film of SiO2, Al2O3, MgF2, etc., is formed on a plastic substrate by vacuum deposition, the surface of the substrate is irradiated with excimer laser light before or during vacuum deposition to remove water and impurities on the surface and to activate molecules. The bonding force of vacuum-deposited particles to the substrate is increased, the adhesion and durability of a formed film are improved and the wear and scratch resistances are enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming a thin film on a plastic substrate in order to improve wear resistance, scratch resistance, etc.

[Conventional technology]

In recent years, plastics have been increasingly used instead of inorganic glass as materials for optical components such as lenses, mirrors, and prisms. The main reason for this is that it has the advantage of being lightweight, low-cost to manufacture, and having a large degree of freedom in shape. Furthermore, because of these advantages, it has recently been widely used in various parts other than optical parts.

However, parts made of these plastics have inferior wear and scratch resistance compared to glass or metal, so
There are many practical problems unless some kind of surface treatment is performed. Especially when using plastic as optical components,
As with optical glass, there is a need to form optical thin films. However, in the case of optical glass, it is possible to vapor-deposit it by heating the optical glass, which improves the adhesion between the optical glass and the optical thin film, but in the case of plastic, it is not possible to vapor-deposit it by heating the substrate. Since it is difficult to deposit the thin film, it must be deposited at room temperature, resulting in poor adhesion and adhesion of the thin film to the plastic substrate, resulting in poor durability.

Therefore, in order to solve the above problems, from the point of view of the vapor deposition material, the layer in contact with the plastic substrate is made of Sin.

The structure using A11z Ox and Ce Fs is also a spin code with an organic material as a brimer coat.

A method has been used in which a dielectric film is formed using a dip coating method and a dielectric film is deposited thereon. A technique similar to this technique is disclosed in Japanese Patent Laid-Open No. 61-64301. Other methods that have been adopted include subjecting the plastic substrate to plasma treatment or irradiating it with an ion beam to modify the surface before vapor deposition.

[Problem to be solved by the invention]

A common drawback of the above-mentioned conventional film deposition methods on plastic substrates is that the materials that can be deposited on the first layer are limited. There was a problem in that it was extremely difficult to satisfy desired characteristics when designing. In addition, in pretreatment methods using organic materials such as primer coating, good reproducibility cannot be obtained unless sufficient attention is paid to liquid management and working environment, and furthermore, complicated processes are required before vapor deposition. Because of the high cost, there are disadvantages in terms of both cost and yield. Further, in the method of plasma processing the substrate surface, it is not a good method because there is a risk of contamination due to dirt in the chamber. In addition, in methods of modifying the substrate surface by ion beam irradiation, etc., the adhesion between the film and the plastic substrate is not sufficient, and furthermore, the deposition of a dielectric film causes a charge-up phenomenon on the film-forming surface. This is not a preferable method for film formation.

The present invention has been made in view of the problems of the prior art described above, and provides a thin film that has good adhesion and durability to plastic substrates and has properties equivalent to those when deposited on glass materials. It is an object of the present invention to provide a method for forming a film on a plastic substrate that allows film formation.

, [Means and effects for solving the problem] The method of forming a film on a plastic substrate according to the present invention is a method of forming a film on a plastic substrate by a vacuum evaporation method, and the method includes:
``Vacuum deposition is performed by irradiating the plastic substrate surface with excimer laser light before and during vapor deposition. According to this method, water and contaminated impurities on the plastic substrate surface are removed, and molecular As a result, the bonding force of the vapor deposited particles to the substrate increases, making it possible to form a dense film.

〔Example〕

Embodiments of the present invention will be described in detail below, using drawings as necessary.

(First Embodiment) FIG. 1 shows an apparatus (vacuum evaporation apparatus) 1 for carrying out the method of forming a film on a plastic substrate according to the present invention.

In the figure, 2 is a plastic substrate on which a thin film is to be deposited (evaporated), and in this embodiment, a molded acrylic lens (acrylic lens) is used. The acrylic lens 2 is attached to a rotating dome 4 placed in a vacuum deposition chamber 3 in the vacuum deposition apparatus 1 .

5 is an evaporation material, and in this example, Sin
, was used. Reference numeral 6 designates an electron gun for heating and evaporating the evaporation material 5.

7 is an excimer laser light emitting device, and mirror 8
．． The setting is such that the entire surface of the rotating dome 4 can be irradiated with excimer laser light 10 via a diffusion lens 9.

Next, using the device 1 described above, the acrylic lens 2 is coated with Sin,
A method for forming a thin film will be explained.

First, the acrylic lens 2 is set on the rotating dome 4, and the inside of the vacuum deposition chamber 3 is evacuated.

Then, the degree of vacuum in the vacuum deposition chamber 3 is IX I
When the temperature becomes O-'Torr or less, excimer laser light (λ-248 nm) is emitted from the excimer laser light emitting device 7.
Fire 10. The excimer laser light 10 is transmitted to a mirror 8. The entire surface of the rotating dome 4 is diffused and irradiated via the diffusion lens 9. The intensity of the excimer laser light 10 at this time is
The irradiation time was set to 10 mJ/c or less on the surface of the acrylic lens 2, and the irradiation time was 5 minutes at 10 pulses/second.

After irradiating the excimer laser beam 10, when the degree of vacuum in the vacuum deposition chamber 3 reaches the desired degree of vacuum, S
The iO 5 is deposited by electron beam evaporation using an electron gun 6 to form a film.

In order to investigate the performance of the Sin film formed on the acrylic lens 2 through the above process, scratching tests, tape peeling tests, etc. were conducted on the film-formed surface of the Sin film, and the results showed that The same performance as that obtained by applying a thin layer of SiO□ was obtained. Furthermore, under the conditions of 30°C to 80'C, 2
After carrying out the 00 hour durability test, a test similar to the above was carried out, and no problems were found. This result occurs because in the surface treatment method using excimer laser light 10, the photon energy is much larger than that of laser light in the normal visible range, so water adhering to the surface of the acrylic lens 2 is and contaminated impurities are removed,
As the molecules are activated, the bonding force (adhesive force) of the vapor deposited particles to the acrylic lens 2 increases and a dense (
This is because a film with high density and high filling rate) is formed. Therefore, according to the film forming method of this example, it is possible to form a film that has high adhesion and high durability equivalent to that of a film formed on a glass lens, and is sufficiently durable for practical use.

(Second Example) In this example, M g F t is used as the vapor deposition material 5.
As a pretreatment for vapor-depositing MgF, the acrylic lens 2 was diffusely irradiated with excimer laser light (λ=193 nm) 10 as in the first embodiment. 5 m on the lens surface
It was set to be below J/cd and irradiated for 5 minutes at 10 pulses/sec.

Then, a film of M g F z was formed on the acrylic lens 2 by electron beam evaporation.

The durability of the film formed by the method of this example was examined in the same manner as in the first example.
The same results as in the case of g were obtained.

Therefore, the same effect as the first embodiment can be achieved.

(Third Example) In this example, excimer laser light 10 is irradiated before vapor deposition (before film formation) under the same conditions as in the first example, and excimer laser light 10 is also applied during film formation. Assisted vapor deposition was performed while irradiating. The membrane structure is A in the IN eye.
l z○1.An antireflection film was formed by electron beam evaporation using ZrO□ for the second layer and MgF for the third layer.

The optical properties of the film formed in this example are as follows:
The reflectance at 650 nm was 0.8% or less, and performance equivalent to that of a glass lens was obtained. Also, in terms of durability in scratch tests, tape peel tests, etc., results sufficient for practical use were obtained, similar to the first example.

(Fourth Example) In this example, vapor deposition was performed under the same conditions as in the second example while irradiating excimer laser light 10 before and during film formation. In the case of this example, the film structure is such that SiO□ is applied to the IN layer, Sing is applied to the odd-numbered layers, and T is applied to the even-numbered layers.
iO□ was evaporated to form an infrared cut filter laminated with a total thickness of 14N.

The optical properties of the film formed in this example were similar to those of a film adhered to a normal glass substrate, and there was almost no change in the properties after the durability test. Furthermore, with regard to durability, in tests such as scratch test 5 and tape peeling, both initial performance and durability performance were similar to those of the above examples, and results sufficient for practical use were obtained.

〔Effect of the invention〕

As described above, according to the film forming method of the present invention, water and contaminated impurities on the surface of a plastic substrate can be removed and molecules can be activated, thereby increasing the bonding force of vapor deposited particles to the substrate and forming a dense layer. Film formation becomes possible. As a result, it is possible to form a film on a plastic substrate with high adhesion and durability equivalent to that on a glass material.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an apparatus for carrying out various embodiments of the method according to the present invention. 2... Acrylic lens (plastic substrate) 5...
Vapor deposition material 6...Electron gun 10...Excimer laser light

Claims (1)

[Claims] A method of forming a film on a plastic substrate by vacuum evaporation, characterized by performing vacuum evaporation by irradiating the surface of the plastic substrate with excimer laser light before, or before and during the evaporation. A method for forming a film on a plastic substrate.