JPS58174901A - Optical member which is prevented of reflection - Google Patents

Abstract

PURPOSE:To prevent the generation of variation in reflected color and uneven color by providing an intermediate film between a synthetic resin base material having a refractive index of a specific value or above and a thick film of SiO2 in such a way that the refractive index and film thickness satisfy the specific relation with the refractive index of the synthetic resin base material and the SiO2 film. CONSTITUTION:An intermediate film having 0.3-5mu thickness and a refractive index (Nb) and a film thickness (db) is formed on a synthetic resin base material of >=1.56 refractive index (Ns) by using a material satisfying the relation expressed by the equation (lambda is 450-600nm incident wavelength). The adhesive strength between the base material and the thick film of SiO2 is improved if the intermediate layer having the compsn. of 10-80wt% TiO2, 0.1-10wt% Mo and 20-90wt% SiO2 is provided. An optical member of a lens or the like provided with >=2 layers of reflection preventing layers such an SiO2 layer, ZrO2 layer, SiO2 layer or the like successively on the innermost layer ZrO2 is manufactured on the thick film of SiO2. The generation of the ripple (subwave) on the specular reflectivity characteristic which is conspicuous in the case of the synthetic resin base material having a high refractive index is prevented and the generation of the variation in color and uneven color is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin optical member having anti-reflection.

For the purpose of improving the durability of the surface protection or anti-reflection coating on synthetic resin optical members such as lenses, a silicon oxide film with a thickness of 0. It is common practice in the United States to apply an antireflection film after depositing Mt to a thickness of Sμ or more. In this case, the synthetic resin base material is mainly diethylene glycol bisallyl carbonate resin with a refractive index of about 1.50, so-called CR-
59 was used well. However, recently, synthetic resin base materials with a refractive index of 156 or more have become necessary, for example, for W & jump lenses, and in this way, synthetic resin base materials with a refractive index of 156 or higher have become necessary.
- When used for convenience, there is a ripple in the spectral reflectance characteristic graph as shown in section 7 and 31g1.
occurs. However, the base material used in Figure 3 has a refractive index of 1.6.
0 of [2,2-bis(4-7 chloroethoxy5,
5-dibromphenyl) 10pan and chlorstyrene 70/S0 (li amount ratio) copolymer, silicon oxide film thickness is 1 μm, anti-reflection film composition is as follows: ;
The second layer is silicon oxide with a thickness of 27 nm, the third layer is zirconium oxide with a thickness of 6 gams, and the outermost layer is silicon oxide with a thickness of 97 nm. Then, at the position of, for example, the peak of this ripple, a shift occurs due to subtle changes in the silicon oxide film thickness and refractive index. By the way, the formation of silicon oxide 4 film is carried out by vacuum evaporation, etc., but strict control of concentration is difficult, and it is inevitable that there will be strange variations in the product and variations in parts of the same product. It is inevitable that the refractive index will change slightly depending on the product as it absorbs moisture depending on the humidity in the atmosphere when taken out.Therefore, if you leave the ripple as it is, the position of the ripple will change depending on the product. The reflected color may vary due to the grains shifting, and color unevenness may occur in a single product due to uneven thickness, which is not welcomed in terms of IIIs.

It is possible to provide an optical member having an anti-reflection AT that eliminates the ripples on the 4IK spectral reflectance characteristic graph in a synthetic resin base material.

As a result of research, the present inventor found that the reflected light generated at the interface between the base material and the silicon oxide thick film becomes so large that it cannot be ignored as the difference in refractive index between the two increases. After discovering that ripples occur due to interference between the reflected light at the interface between the film and the anti-reflection film, we came up with the idea of eliminating ripples by preventing the reflected light at the interface between the Kr1 base material and silicon oxide. This led to the completion of the present invention.

Therefore, the present invention is designed to improve the substrate and silicon oxide film thickness (film thickness 0.3~
The refractive index (Ml
)) and dense ((LD) t-!).However, Nt is a refractive single tube of silicon oxide cumulative extension, and N- is the refraction at1λ of the base material.

Incident ftf) tlL length < 400 to 600 film m) t, respectively.

The interlayer film of the present invention has the refractive index (nb) and film thickness (ab
) T-, but it is desirable that it has good adhesion to the synthetic resin base material and the silicon oxide thick film,
For this purpose, it is desirable to use a mixture of Tiea and 8101. When using the electron beam heating evaporation method, it is necessary to add metallic molybdenum (MO) to the mixture of Tie and 811 in order to obtain a homogeneous film.
11. Particularly, a vacuum sintered body of a powder mixture having a composition of 5i02: 20-90 weight - TiO: 10-80 weight sack Mo: 0.1-10 weight sack can be used as a vapor deposition source. ill't L < , 81"r
, TlO2, 1.47 to 1 depending on the m#lV4 combined ratio of MO
A stable interlayer film having any refractive index within the range of 0.00 is used.

Silicon oxide film thickness error may be formed by the conventional vacuum evaporation method, but silicon alkoxide 81 (O
R) 4 Apply bath 111 and apply 60 to 110 as necessary.
After pre-firing at C for 5-70 minutes, 7150-500C
It may be formed by firing at a temperature of about 20 to 70 minutes. The latter method is commercially advantageous in that it does not require expensive vacuum deposition equipment.

The antireflection film itself that is laminated on the silicon oxide thick film is well known, and there are, for example, one to five layer structures.

Typical antireflection coatings with multilayer structures can be classified as follows: High, low, and medium refractive index materials.High, low, and medium are used in a relative sense, but specifically, they have a high refractive index. As car material T101%TagO number, Zr01
．． 1lfo! 810 as a low refractive leather material, Mg1F
2 medium refractive index material,! :LteEliO1C@? 8, La#
'4, Y2O.

etc. are used.

Next, the present invention will be specifically explained by referring to FIG.

Example 1 Synthesis 1IW1 base material consisting of a 70/l (weight ratio) copolymer of bis(4-acryloxyethoxy-45-dibromphenyl)globan and chlorstyrene (refraction 41.6)
As shown in FIG. The middle (first layer) in contact with the base material is 5
Mixture t30 consisting of IOA (49,5 1% by weight), Tie (49,51% by weight) and Mo (1,Q by weight -)
After press-forming W (5 sand) on a square frame of X50X20 and vacuum sintering at a temperature of 120 Orr for 6 hours, it was formed by vacuum evaporation at a violent pressure of 5 X 10 Torr by heating with a 1 km beam, but the film thickness was has a refractive index of 84 and a refractive index of 1.54.

The second layer is vacuum evaporated with a thickness of 8102-6 and a film thickness of d1μ.
The refractive index was 1.48. l! 5th layer has a film thickness of 31n
m zirconium oxide (ZrOa), the fourth layer has a film thickness of 27
The 5th layer is ZrO with a thickness of 60 nm and the upper layer is 810. nm with a thickness of 97 rm. It is l. This spectral reflection monochronism is shown in FIG. Point in Figure 2 *ri coat 10
The solid line was measured 24 hours after coating. On the other hand, in FIG. 5, the top layer 8108,
Without applying an interlayer film consisting of a mixture of TiO2 and Mo,
The second layer of 1μ chicken 810 above on top of the synthetic 11m substrate
The spectral reflectance characteristics are shown when layers 3 to 3 are applied in the same manner. The dotted line in the figure was measured after 10 minutes, and the solid line was measured 24 hours after coating.

Example 2 Polystyrene with a refractive index of 1.57 was used as a synthetic resin base material, and a sintered body consisting of polystyrene with a refractive index of 1.57 was used as a vapor deposition source material to form a medium +4 film (refractive index of 1.52). Thickness: 2. The same procedure as in Example 1 was carried out except that the thickness of the interlayer film was t-79 m, and an optical member tf'1Ill L good was produced with the film configuration tV shown in FIG. 4.

The obtained spectral reflection characteristic tMs diagram of the optical member is shown below. Fifth
The dotted line in the figure is the Kll value measured 10 minutes after coating, and the solid line is the value measured 24 hours after coating.

On the other hand, FIG. 6 is a graph showing the fractional reflection characteristics of the optical member in the above example in which the intermediate layer of the present invention in contact with the base material was not provided, in which the dotted line indicates 10 minutes after coating, and the solid line indicates after coating. Measured 24 hours after.

As described above, according to the present invention, ripples in the spectral reflection 411 characteristics can be reduced even for synthetic resin base materials with a refractive index of 1.56 or more, so changes in reflected color over time are small. In addition, anti-reflection II can be effectively applied to reduce unevenness of reflected color due to crawling between products and between products.
- You can get the advantage of

[Brief explanation of drawings]

FIG. 1 shows the layer structure of Example 1. FIG. 2 is a spectral reflectance characteristic graph of Example 1. Figure 3 shows the spectral reflection of a comparative example with respect to Example 1! 4% gender graph graph. FIG. 4 shows membrane structure 4 of Example 2. Figure 5 is a spectral reflection*characteristic graph of Example 2. FIG. 6 is a graph of the public party reflectance characteristics of a comparative example with respect to Example 2. In addition, in the graph, the point - is after 10 minutes of coat, and actually it is coat 2.
The measurement after 4 hours is 6.

Claims (1)

[Claims] 1. An optical device having a silicon oxide film thickness of 1 from Reikoku Hayashi Co., Ltd., manufactured by 4P, 0.3 to 5P, on which an antireflection film is provided on a synthetic resin base material having a refractive index (No.) of 1.56 or more. In the member, between the base material and the thick film, there is a refractive index (Wb) and a film thickness ((Lb) that satisfy the following formula.
An optical member characterized by an interlayer film tW & K.K. 2. The optical member according to claim 1, wherein the intermediate film is made of a mixture of sio, , tie, and MO.