JPS6255601A - Antireflection optical parts - Google Patents

Abstract

PURPOSE:To improve the heat resisting property which is a peculiarly inferior property of an inorg. thin film and to improve the anti-scratching property of the titled parts by laminating the plasma-polymerization film of a specific silicon compd. and the plasma-polymerization film obtd. by a mixed gas composed of an aliphatic hydrocarbon and/or an aromatic hydrocarbon and a hydrogen gas and/or an argon gas on at least one of surfaces of the optical parts made of a plastics in order. CONSTITUTION:The main composition of the anti-reflection film is composed of the following 1st and 2nd layers laminated on at least one of surfaces of the optical parts made of the plastics in order. The 1st layer is formed of the plasma-polymerization film of the silicon compd. shown by the formula wherein R<1> is 1-6C a hydrocarbon, a vinyl, a methacryloxy, an aryl, an epoxy, an amino, a mercapto or an isocyano group and a fluorine atom or a chlorine atom, R<2> is a hydrogen atom, an alkoxy, an alkoxyalkoxy or an acetoxy group and a chlorine atom, (n) is 0-4. The 2nd layer is formed of the film having a high refractive index and obtd. by the plasma-polymerization of the mixed gas composed of 1 or >=2 kinds among the aliphatic hydrocarbon and/or the aromatic hydrocarbon and the hydrogen gas and/or the argon gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antireflection plastic optical component having excellent scratch resistance, heat resistance, and hot water resistance.

[Prior art]

The optical component refers to something used to transmit light from the opposite side, such as a lens or a flat sheet material, and in recent years, synthetic polymers have been used in such fields. It's happening more and more often. However, such plastics have the drawback of poor scratch resistance and solvent resistance, and various efforts have been made to compensate for these drawbacks. In other words, methods for modifying the surface of such plastic include laminating it with glass or forming a thin film of metal oxide or fluoride using vacuum evaporation, ion blasting, sputtering, CVD, etc. It is known to apply a curable resin paint, dry it, and then rinse it off.

In addition, even if glass is considered to have sufficient scratch resistance, its reflection is as strong as that of plastic, and imparting anti-reflection function is a challenge along with synthetic polymers, and in this case, vacuum evaporation It is considered that this can be achieved by forming a thin film of metal oxide or fluoride using methods such as ion blasting, sputtering, CVD, etc. In the case of plastics, it also improves surface hardness.

Regarding the anti-reflection function, a considerable part of its technology is publicly known, for example, Tokukosho! ;3-3.06, JP-A-ShojJ-370II! ; , j'J-427≠j J
J-10! ;2'19 and others disclose techniques regarding antireflection coatings. Furthermore, there are many products that have such functions. All of these methods involve forming thin films of metal oxides or fluorides using methods such as vacuum evaporation, and are mainly inorganic thin films.

[Problem that the invention seeks to solve]

However, when the substrate is made of plastic, its heat resistance is poor and its hardness is not sufficient. For example, when such an optical component is immersed in hot water, cracks occur within one minute, which is thought to be due to the inorganic thin film being laminated onto the organic plastic substrate. That is, the brittle inorganic thin film cracks due to stress caused by the difference in thermal expansion coefficient with the plastic substrate. Furthermore, one of the reasons for the insufficient scratch resistance is that the adhesiveness between the organic plastic substrate and the inorganic thin film is insufficient.

[Means for solving problems]

In the present invention, the poor heat resistance peculiar to such an inorganic thin film coated on a plastic substrate is improved, and the scratch resistance is also dramatically improved.

That is, the above-mentioned various performances are improved by making the thin film having an antireflection function an organic-inorganic hybrid.

The basic structure of the antireflection film of the present invention is as follows. First, a plasma-polymerized film of a silicon compound represented by the following general formula (1) is formed on at least seven surfaces of a plastic optical or scientific component to form a first layer.

1SiR2 n 4-n (1) (In the formula, R1 is a hydrocarbon group having 1 to 2 carbon atoms, a vinyl group, a methacryloxy group, an allyl group, an epoxy group, an amino group, a mercapto group, an isocyano group, an organic group containing fluorine or chlorine) group, R2 is a hydrogen element, an alkoxy group, an alkoxyalfoxy group, an acetoxy group, and a chlorine element, and n
is 0-<<. ) Silicon compounds represented by general formula (1) include tetrachlorosilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, tetramethoxysilane, methyltrimethoxysilane, dimethyl Dimethoxysilane, trimethylmethoxysilane, tetrafluorosilane, phenyltrimethoxysilane, vinyltrimethoxysilane,
Examples include γ-methacryloxypropyltrimethoxysilane, allylsilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-chloropropyltrichlorosilane, and the like. These silicon compounds can also be used in combination of seven types or two or more types. When using a compound with a relatively low vapor pressure, it is preferable to heat the compound to promote its vaporization.

Further, when forming the first layer, the silicon compound may be subjected to plasma polymerization with a mixed gas of seven or more gases selected from oxygen, nitrogen, argon, and ammonia. The structure and refractive index of the silicon compound plasma polymerized film obtained in this way vary depending on the silicon compound used and the plasma polymerization conditions, but the film structure usually contains monohydroxyl groups, methylene groups, methyl groups, etc. in addition to siloxane groups. have.

The refractive index can be controlled within the range of 832 to 1, and can be used as a low refractive index layer forming an antireflection film. In addition, the physical thickness of this first layer is the optical thickness λ/l (λ
is determined from the refractive index of the first layer film.

Next, the second layer forming a high refractive index layer formed on the first layer will be described.

The second layer having a high refractive index is formed by plasma polymerization of a mixed gas of one or more selected from aliphatic hydrocarbons and/or aromatic hydrocarbons and hydrogen and/or argon. Examples of the aliphatic hydrocarbons and/or aromatic hydrocarbons used here include methane, ethane, propane, butane, ethylene, acetylene, and benzene. These compounds may be used alone or in combination of two or more. Plasma polymerization is carried out using these aliphatic hydrocarbons and/or aromatic hydrocarbons as a mixed gas with hydrogen and/or argon, and the mixing ratio is 1:0 in terms of flow rate gas ratio. ! r/:
! l;00. More preferably l:5 to:100, and a good film with a high refractive index can be obtained by making the flow rate of hydrogen and/or argon gas higher than the flow rate of aliphatic hydrocarbon and/or aromatic hydrocarbon. .

The structure and refractive index of the plasma-polymerized film obtained in this way differ depending on the monomers used and the plasma polymerization conditions, but the film structure usually has methyl groups, methylene groups, and carbon-carbon double bonds based on infrared absorption spectroscopy. It has a slight amount of The refractive index is /, 1! It is in the range of r~2,≠, and is useful as a high refractive index layer forming an antireflection film. The second layer film obtained by this plasma polymerization appears to be an amorphous carbon film having an organic group based on the film structure and refractive index. This second
The physical thickness of the layer is determined from the refractive index of the second layer so that the optical thickness is λ/2 (λ is the wavelength).

Plastic substrate obtained in this way/first layer/second layer
An antireflection plastic optical component is obtained by further forming a third layer of low refractive index layer on the layer in the same manner as in the case of forming the first layer coating. As mentioned above, the basic structure of the anti-recoil coating consisting of the three-layer structure has been shown, but in order to further improve the scratch resistance or anti-reflection function, it is necessary to add a plastic substrate and a first coating.
Wet or dry undercoating or multilayering of one or more antireflection films can also be performed between the layers. In any case, compared to conventional antireflection films made of metal oxide films formed by vacuum evaporation, the low refractive index film and the high refractive index film of the present invention both have an inorganic-organic hybrid structure, so they can be easily coated on plastic substrates. It appears to have good heat resistance and hot water resistance.

Next, plasma polymerization conditions used for forming the first and third layer coatings forming the low refractive index layer and for forming the second layer coating forming the high refractive index layer will be explained.

The plasma polymerization apparatus used may be a known one, for example, as described in the Journal of Applied Polymer Sci.
X (Journal of Applied po
lymerScience) Volume 17, tZS page (/9
Apparatuses such as the Pelger type internal electrode system described in 73) and the tube type electrodeless system described in the same magazine, Vol. 1s, p. 2277 C/97/)K can be used. A plasma polymerization apparatus particularly suitable for carrying out the invention is shown in the figure. No.
- For forming the 7th layer and the 3rd layer coating, the polymerization apparatus shown in FIG. 1 is used. For the formation of the 2nd layer coating, the polymerization apparatus shown in FIG.
2 was particularly suitable.

Plasma polymerization conditions depend on the size of the apparatus used, the type of monomer used, the discharge power, etc., but suitable conditions when the apparatus shown in the figure was used were as follows. That is, the plasma polymerization for forming the first layer and the third layer of silicon compound using polymerization device 7 is carried out at a discharge power of 3 to 30 watts, a gas pressure of 0.5 to 0.0 liters, and a silicon compound monomer flow rate of 1 liter to 0.0 cc. (STP)/min, also oxygen,
When one or more gases selected from nitrogen, argon, and ammonia are used together, the flow rate of the combined gases is 0.00% of that of the gas above the silicon compound. A ratio of t-jO times, especially 2 to 20 times, was suitable.

Plasma polymerization for forming the second layer film using polymerization device-2 uses discharge power! ;-JO watts, gas pressure 0. /~OJ
) IJ Che IJ-1 Flow rate of one or more monomers selected from aliphatic hydrocarbons and aromatic hydrocarbons: 0.
/ zcc (STP)/min, the hydrogen and/or argon gas flow rate is 2~jO
Double was suitable.

The optimal thickness of the laminated film formed on the plastic substrate in this way is as follows.

That is, if the refractive index of the first layer and the third layer, which are low refractive index coatings, are both 8 lIO, the physical thickness is 1000 angstroms, and the refractive index of the second layer, which is a high refractive index coating, is 2.00. In this case, the physical thickness is /1)00A.

〔Effect of the invention〕

According to the present invention, an antireflection film with excellent scratch resistance, hot water resistance, and hot water resistance can be formed on the surface of a plastic optical component.

〔Example〕

This will be explained below using examples.

Example 1 A first layer, which is a low refractive index coating, was formed by plasma polymerization using a tubular electrodeless plasma polymerization apparatus shown in FIG. 1 using an 0R-j9 flat plate as a base material under the following conditions.

Dimethyldimethoxysilane monomer gas flow rate 0623c
c(STP)/min Oxygen gas flow rate /JJCC(STP)/Gas generation pressure 0.31 trich discharge frequency /
3. ! ; 6 MHz Discharge power: 30 Watts Discharge time: 5 minutes The refractive index and film thickness of the first layer coating thus obtained were 1) 3; and /100 angstroms, respectively. Next, using the plasma polymerization apparatus shown in FIG. 2, a second layer, which is a high refractive index coating, was formed on the first layer by plasma polymerization under the following conditions.

Methane gas flow rate 0.77cc (STP)/min Hydrogen gas flow rate #, 4 (700 (STP)/Gas generation pressure o, is Torichly discharge frequency /3
．． ! ; AMHz Discharge power: 35 Watts Discharge time: 4 hours The refractive index and film thickness of the second layer film thus obtained were 1# and /200 angstroms, respectively. Furthermore, plasma polymerization was performed on the first and second layer laminated coatings using plasma polymerization apparatus 7 under the same conditions as for forming the first layer to form a third layer coating.

The refractive index and film thickness of the third layer film are respectively t.

It was 1000 angstroms. The sto nm of the anti-reflection 0R-39 optical component obtained in this way
The reflectance at
No cracks were observed even after immersion.

The reflectance of untreated 0R-39 at 540 nm is 7%.
Met.

Example 1 The same procedure as Example 1 was carried out except that the third layer coating was formed by plasma polymerization under the following conditions. The refractive index and film thickness of the third layer were JJ and 960 angstroms, respectively. The reflectance of the obtained anti-reflection 0R-J optical component at j60 nm was 2.0%, and it was placed in a hot air drying oven at 100°C.
No cracks were observed even after holding for 0 minutes.

Tetrafluorosilane monomer gas amount 6.0 cc (STP) / minute Oxygen gas flow rate 20 cc (STP) / gas generation pressure 0. tl) Richery discharge frequency
/J, 56MH2 Emission N power l! Watt discharge time: 60 minutes Example 3 The same procedure as Example 2 was carried out except that polycarbonate was used for the substrate.

The obtained antireflection optical component had a reflectance of 8 g% in stonm, and had good heat resistance and hot water resistance.

Comparative example/ Commercially available anti-reflection optical component (OR-39 board) s t
The reflectance at o nm was about /%, but at ♂0°C
Immerse in warm water for 10 minutes or in a hot air drying oven at 100"C for 7 minutes.
Cracks were observed to occur after holding for 0 minutes.

[Brief explanation of drawings]

FIGS. 1 and 2 are side sectional views schematically showing an example of a plasma polymerization apparatus for carrying out the present invention, respectively. OSC: High frequency oscillator w: IT force meter IMC + tuning circuit = Vacuum pump A, carrier gas inlet M, monomer S e substrate, T Nidrap, P: Vacuum pump cw, cooling water Vl +V3+V5: Store half V2 +V
4 +V6 ' Needle valve F1) F21F3
'Flow! Total M12M2 +M3' Monomer and carrier gas E: Electrode

Claims (5)

[Claims] (1) A plasma polymerized film of a silicon compound represented by the following general formula (1) and a mixed gas of aliphatic hydrocarbon and/or aromatic and hydrogen and/or argon are coated on at least one surface of the plastic optical component. Anti-reflection optical component made by laminating plasma polymerized films, R^1_nSiR^2_
4_-_n(1) (in the formula, R^1 is a hydrocarbon group having 1 to 6 carbon atoms, a vinyl group,
Methacryloxy group, allyl group, epoxy group, amino group,
It is a mercapto group, an isocyano group, a fluorine element, an organic group containing fluorine or chlorine, R^2 is a hydrogen element, an alkoxy group, an alkoxyalkoxy group, an acetoxy group, and a chlorine element, and n is 0 to 4. ) (2) The silicon compound represented by the general formula (1) is tetrachlorosilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, tetrafluorosilane, tetramethoxysilane,
The antireflection optical component according to claim 1, which is one or more selected from methyltrimethoxysilane, dimethyldimethoxysilane, and trimethylmethoxysilane. (3) the aliphatic hydrocarbon and aromatic hydrocarbon are methane;
The antireflection optical component according to claim 1, which is one or more selected from ethane, propane, butane, ethylene, acetylene, and benzene. (4) the plastic is polymethyl methacrylate;
The antireflection optical component according to claim 1, which is a plastic selected from polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, and polydiethylene glycol bisallyl carbonate (CR-39). (5) The mixed gas is a mixture of aliphatic hydrocarbon and/or aromatic hydrocarbon and hydrogen and/or argon at a flow rate ratio of 1:0.5 to 1:500. Antireflection optical component according to scope 1.