JPH0868901A - Resin optical parts - Google Patents

Abstract

PURPOSE: To form thick hard coating layers on resin optical parts so as to obtain required hardness and to improve the hard coating performance. CONSTITUTION: Two or more hard coating layers comprising SiO reaction vapor deposition layers are formed on the surface of a base body of optical parts and an intermediate layer comprising ALn Osn-1 which is thin enough not to act as a reflection enhancing film is formed between the hard coating layers. Difference in the refractive index between the hard coating layers and the base body is within ±0.5%. By this method, the layers are formed to obtain the total thickness to obtain the required hardness while the thickness of the unit film is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-made optical component forming a part of OA equipment, optical communication equipment, optical information processing equipment, optical application manufacturing equipment, measuring equipment, cameras and the like.

[0002]

2. Description of the Related Art A resin optical component has a lower surface hardness than a glass optical component, and therefore has a drawback that it is easily damaged. Further, as in the case of the optical component made of glass, it is necessary to perform antireflection treatment in order to improve its optical characteristics.

Hardness characteristics cannot be improved only by forming an antireflection layer consisting of a plurality of protective layers on the surface of a base material of a resin optical component. Further, when an SiO ₂ film or a MgF ₂ film having a certain thickness or more is formed to improve the surface hardness, if the film thickness is made too large to obtain sufficient hardness (about 5000 angstroms or more). , Cracks easily occur in the film in the heated state. Further, when the film thickness is large, if the difference in the refractive index from the base material is large, a bleeding phenomenon occurs and the appearance is deteriorated, and if the film thickness is large, the adhesion to the base material also deteriorates.

In order to solve this problem, the present applicant has previously proposed, as a hard coat structure for a resin optical component, an antireflective coating consisting of a SiO reactive vapor deposition layer and a SiO ₂ film or a MgF ₂ film on a substrate of the optical component. A method for sequentially forming films has been proposed (JP-A-5-173002).

According to this structure, as compared with the coating structure known before that, it is excellent in abrasion resistance, adhesion to the substrate, and durability, and no bleeding phenomenon due to film formation is observed. Is obtained.

[0006]

In the above-mentioned prior invention of the present applicant, a SiO reactive vapor deposition layer is deposited and formed to a thickness of 15000 to 20000 angstroms to provide performance as a hard coat.

However, this prior invention has a limitation that the hard coat performance cannot be further improved when the SiO reactive vapor deposition layer has a film thickness of 20000 Å or more because cracks occur in the adhered layer.

When the base material of the optical component is polymethylmethacrylate (PMMA), it is 1 at 60 ° to 70 ° C.
When heated for a time, it had a defect that cracks were generated in the coat film.

Therefore, an object of the present invention is to provide a coating structure for a resin-made optical component, which has a feature that the hard coat performance can be further improved and cracks are less likely to occur even under heating conditions.

[0010]

In the resin optical component provided by the present invention, SiO having a refractive index on the surface of its base material, the difference from the refractive index of this base material is ± 0.5% or less. A hard coat layer made of a reactive vapor deposition layer is formed between the hard coat layers, and is thin Al _n O _{2n- 1} (for example, Al ₂ O ₃ including Al ₃ O ₅ etc.) so as not to serve as a reflection _enhancing film. Two or more layers are laminated with an intermediate layer made of (3) sandwiched therebetween.

The preferred film thickness of each layer is 5000 to 15000 angstroms for the hard coat layer made of SiO reactive vapor deposition layer and 50 to 10 for the intermediate layer made of Al _n O _2n-1.
It is 0 angstrom.

By overlaying an antireflection film made of MgF ₂ or SiO _{2 on} the uppermost layer of the hard coat layer made of the SiO reactive vapor deposition layer, necessary antireflection performance can be provided.

The resin used as the base material of the optical component targeted by the present invention is not particularly limited as long as it is any resin used in the art, and specifically, polymethylmethacrylate (PMMA). , Polycarbonate (P
C), polyamide, polystyrene, diethylene glycol bisallyl carbonate resin and the like are exemplified as typical materials.

The hard coat layer composed of the SiO reactive vapor deposition layer is such that the optical parts are arranged in a vacuum vapor deposition apparatus, and SiO is heated in the vacuum vapor deposition apparatus in the presence of O ₂ to irradiate it with an electron beam to obtain a resin optical layer. It is obtained by forming a SiO reaction vapor deposition film on the surface of a component. When forming it, the difference between the refractive index of the resin optical component and the refractive index of the SiO reaction vapor deposition layer is ±
The partial pressure of O ₂ and the vapor deposition rate are adjusted so that the film thickness becomes 0.5 or less and the film thickness becomes 5000 to 15000 Å. These conditions will vary depending on the type of resin constituting the optical component, but can be readily determined empirically, partial pressure 1 to 3 × 10 ^{over 4} Toor approximately normal O _2, the deposition rate 10 It is about 14 Å / sec.

Al _n formed between SiO reactive vapor deposition layers
As for the intermediate layer made of O _2n-1 , the optical parts are arranged in a vacuum vapor deposition apparatus, and the heated aluminum material is irradiated with an electron beam in the presence of O ₂ , similarly to the formation of the SiO reaction vapor deposition layer.
It is obtained by depositing aluminum oxide Al _n O _2n-1 on the surface of the SiO reaction deposited layer. During its formation, O ₂ is added so that the film thickness becomes 50 to 100 Å.
Adjust the partial pressure and deposition rate of. This is because when the thickness is less than 50 angstroms, the function of preventing cracks in the hard coat layer is lost, and when the thickness exceeds 100 angstroms, the refractive index of Al ₂ O ₃ is as large as (1.6), so that the increased reflection effect occurs. This is to prevent it.

Further, an antireflection M formed on the uppermost layer.
gF ₂ or SiO ₂ deposited layers may be formed according to a conventional method. The thickness and the number of layers are not particularly limited, but usually the thickness is about 800 to 1200 angstroms.

[0017]

In the above manufacturing method, by interposing the aluminum oxide layer Al _n O _2n-1 layer, the unit thickness of the SiO reaction layer is kept within a range in which cracks are unlikely to occur, and the required hardness is obtained. Lamination can be done until the thickness is reached.
The antireflection film can be formed on these laminated layers,
The required antireflection performance is also obtained.

[0018]

Embodiments of the present invention will be described below.

Example 1 Polymethylmethacrylate (PMMA) flat plate having a thickness of 3 mm (refractive index = 1.49)
Mounting in a vacuum evaporation apparatus was evacuated up to 5 × 10 ^-5 Toor, after introducing O ₂ into the apparatus while the partial pressure of O ₂ is adjusted to 2 × 10 ^-4 Toor, heated SiO By the EB method of irradiating the substrate with an electron beam, S
Deposition of io at a deposition rate of 12 angstroms / second 7
A 500 angstrom first hard coat layer is formed. Further, while keeping the partial pressure of O ₂ at 1 × 10 ⁻⁴ TOOR, the same EB method is used to form an intermediate layer of 100 Å at a deposition rate of Al ₂ O ₃ of 2 Å / sec. Further, SiO is vapor-deposited by the same method as that for the first layer.
A second hard coat layer of 00 Å is formed. Next, a SiO ₂ layer having an optical film thickness (= physical film thickness × refractive index) of 138 nm is formed as an antireflection film by a usual method.

[Example 2] The same polymethylmethacrylate (PMMA) as in Example 1 was used, and each layer was formed in the same process. However, the first and second layers of hard coat are
The film thickness is set to 15,000 angstroms, which is twice that of the first embodiment.

[Example 3] Each layer is formed in the same manner as in Example 2 using a flat plate (refractive index = 1.58) of polycarbonate (PC) having a thickness of 2 mm. However, hard court first
Layer, the O ₂ partial pressure 1 × 10 ^-4 for forming the second layer TOOR
And the amount of oxygen supply is reduced. Next, Comparative Example 1,
No. 2 is the previous proposal of the applicant described in the conventional example (Japanese Patent Laid-Open No. Hei 5 (1999) -58242)
No. 173002) is applied to the flat plate base materials used in Examples 1 to 3.

COMPARATIVE EXAMPLE 1 The same polymethylmethacrylate (PMMA) flat plate as in Example 1 was used, the partial pressure of O ₂ was set to 2 × 10 ⁻⁴ TOOR, and the deposition rate was 12 Å / sec by the EB method to 10000 Å. Thick Si
Only one O vapor deposition layer is formed. After that, a SiO ₂ layer having an optical thickness of 138 nm is formed as an antireflection film by a usual method.

Comparative Example 2 Each layer is formed in the same manner as in Comparative Example 1 on the same polycarbonate (PC) flat plate as in Example 3. However, the film thickness of the SiO vapor deposition layer is set to 15000 Å, and the O ₂ partial pressure when forming this layer is 1 ×.
It is 10 ^-4 TOOR. When the physical properties of the hard coats of Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated, the following results were obtained.

[Table 1] The evaluation of each item is as follows. -Adhesion: A cellophane tape is used to perform a peeling test five times. -Surface hardness: According to pencil hardness test. -Abrasion resistance: Steel wool is reciprocated 5 times under a load of 300 g, and the number of scratches is counted with the naked eye. In addition, PMMA and PC in the bottom column of the above table are results for a flat plate as it is as a raw material on which no coating layer is formed.

The above-mentioned evaluation shows that the hard coat performance of the example of the present invention is improved as a whole for the substrate of the same material as compared with the comparative example of the prior invention. ing.

When the thickness of the hard coat layer of the present invention is increased, abrasion resistance is improved, but cracks tend to occur during heating. Therefore, instead of using only two hard coat layers as in these examples, the total thickness can be increased by increasing the number of layers while reducing the unit thickness of each hard coat layer to prevent cracking. Hard coat performance can be further improved by increasing the size to improve wear resistance.

[0026]

The present invention has a structure in which two or more hard coat layers made of SiO vapor deposition layers are laminated with an intermediate layer made of thin Al _n O _2n-1 sandwiched between them. It is possible to increase the total thickness to a size at which the required hardness can be obtained, while suppressing the thickness that does not easily occur. Therefore, the applicant's prior invention (Japanese Patent Laid-Open No. 17300/1993)
It is possible to realize a hard coat performance exceeding that of Japanese Patent No. 2).

Claims (3)

[Claims] 1. A hard coat layer made of a SiO reactive vapor deposition layer having a refractive index of which the difference from the refractive index of this substrate is ± 0.5% or less is formed on the surface of a resin optical component substrate. Between the hard coat layers, thin Al that does not serve as a reflection enhancing film
A resin-made optical component, characterized in that two or more layers are laminated with an intermediate layer made of _n O _2n-1 sandwiched therebetween. 2. A hard coat layer comprising a SiO reactive vapor deposition layer having a thickness of 5000 to 15000 angstroms, A
l _n O plastic optical component according to claim 1 in which the _2n-1 consists of intermediate layer thickness, characterized in that a 50 to 100 angstrom. 3. The resin according to claim 1, wherein an antireflection film made of MgF ₂ or SiO ₂ is formed on the uppermost layer of the hard coat layer made of a SiO reactive vapor deposition layer. Optical components.