JPH02230201A - Molding for optical article - Google Patents

Abstract

PURPOSE:To provide the optical molding which has excellent transparency and heat resistance and decreases optical distortions by constituting the molding of a resin the main chain of which consists of a specific repeating unit and which has 5,000 to 200,000 number average mol. wt. CONSTITUTION:The molding for optical article is constituted of the resin the main chain of which consists substantially of the repeating unit expressed by formula I and has 5,000 to 200,000 number average mol. wt. In the formula I, R<1> to R<6> respectively denote a hydrogen atom or lower aliphat. hydrocarbon group. This resin has usually >=120 deg.C glass transition point, has a small coefft. of optical elasticity and is small in double refractiveness. The optical molding which has the excellent heat resistance and transparency and the small optical distortions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to optical molded products such as lenses, diffraction gratings, and substrates for optical recording media.

[Conventional technology]

In recent years, there has been a demand for highly transparent resins as materials for various lighting equipment parts, various signboards, various optical parts including lenses, and the like. Currently, polymethyl methacrylate (
Hereinafter, this will be abbreviated as PMMA. ) and bisphenol A polycarbonate (hereinafter abbreviated as PC).
There is.

PMMA has a low glass transition temperature and poor heat resistance, making it difficult to use in applications requiring high heat resistance. On the other hand, although PC has a certain degree of heat resistance, it suffers from optical distortion (birefringence).
However, there are disadvantages in that the number of folds caused by molding distortion increases.

As a polymer having a tetrahydrofuran skeleton, 2,
Polymers obtained by cationic polymerization of 3-dihydrofuran, 2,3-dihydro-5-methylfuran, etc. are known [Journal of Chemical Society
ociety), 1954, 3766 pages; and Polmer Jour.
nal), vol. 16, p. 415 (I984)],
Furthermore, it has been suggested that the polymer obtained by cationic polymerization of 2,3-dihydrofuran has the performance as a separator for RITECUM secondary batteries [Polymer Prepurine 7]
nts), vol. 24, p. 317 (see I983).

[Line problem to be solved by the invention]

As described above, pMMA, which has been conventionally used as a transparent optical material, has the drawback of insufficient heat resistance, and PC has the drawback of large optical distortion (birefringence). Therefore, the use of optical molded products made of PMMA or PC is limited depending on the usage situation, so it is important to develop optical molded products that have excellent transparency and heat resistance and have low optical distortion. The current situation is that this is desired.

An object of the present invention is to provide an optical molded article that has excellent transparency and heat resistance and has low optical distortion.

[Means for Solving the Problems] According to the present invention, the above object is achieved by the main chain consisting essentially of the following repeating units (I) (wherein R1, R2, R3, B4, 几6 and R6 are Each hydrogen atom in front represents a lower aliphatic hydrocarbon group.Number average molecular weight consisting of s,ooo~200,00
This can be achieved by providing an optical molded article made of resin.

R1, R2, R', R in the above repeating unit (I)
The lower aliphatic hydrocarbon graves represented by l', 几6 and R' (hereinafter collectively referred to as R1 to R6) are as follows:
Examples include methyl group, ethyl group, probyl group, improbyl group, and pter group. It is preferable that R1 to 6 represent a hydrogen atom or a methyl group, and all of R1 to 6 represent a hydrogen atom, and any one of R1 to 6 is a mether group, and all others are hydrogen atoms. It is most preferable if there is. Preferred resins in the present invention include those having the following repeating units.

In addition, the resin in the present invention may have only 1 m of repeating units (I), or may have two or more repeating units.

The resin in the present invention is represented by the following general formula (II) 2
．． It can be produced by subjecting 3-dihydrofuran or its derivative to a known cationic polymerization reaction in the presence of an appropriate amount of initiator.

The resin in the present invention has a number average molecular weight of 5,000 to 5,000 as determined by gel permeation chromatography (hereinafter referred to as GPC).
There is a range K of 2 0 0, 0 0 0.

The number average molecular weight of the resin in the present invention is 10,000 to
Preferably it is in the range of 150,000. In the case of resins with a number average molecular weight as small as s, ooo, the mechanical strength of the resulting molded product is not necessarily sufficient, and
In the case of a resin with a diameter larger than 0.000, the moldability when molding optical parts will be insufficient, which is not preferable.

(In the formula, Rl to 6 are as defined above.) Examples of the initiator used in producing the resin in the present invention K include protonic acids such as hydroiodic acid; chromium oxide, molybdenum oxide, etc. Metal oxides: halogens such as iodine, bromine, and iodine bromide; boron halides such as boron trifluoride and boron trifluoride ether complexes; aluminum chloride,
Metal chloride such as aluminum bromide, titanium tetrachloride, titanium tetrabromide, tin tetrachloride, iron mitakaide; ether aluminum dichloride, diethylaluminum chloride,
Organometallic compounds such as diethylaluminum bromide and diethylzinc; triphenylmethyl antimony hexachloride,
Examples include carbonium ion salts such as triphenylmethanetin pentachloride. The initiator is 2,3-dihydro7
Ranman is used in an amount ranging from 0.01 to 10 mol, preferably from 0.05 to 2 mol, based on the derivative thereof.

The polymerization temperature is in the range of -200°C to 100°C,
Preferably, a temperature in the range of -100°C to 50°C is employed. The polymerization reaction is usually carried out under an inert gas atmosphere such as nitrogen, argon, helium or the like. Although the polymerization can be carried out in the absence of a solvent, aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylenium; aliphatic hydrocarbons such as hexane, heptane, and octane; cyclohexane,
Alicyclic hydrocarbons such as cyclooctane; methylene chloride,
It is preferable to carry out the reaction in the presence of a solvent such as a 71-logenated hydrocarbon such as chloroform or tetrachloroethylene, in terms of removal of reaction heat and ease of handling of the produced polymer. Depending on the type of initiator used, in addition to the above solvents, ethers such as diethyl ether, dibutyl ether, dioctele ether, ethylene glycol dimethyl ether, thiethylene glycol dimethyl ether, and tetrahydrofuran; methyl acetate,
The polymerization reaction can be carried out more efficiently by appropriately coexisting esters such as ethyl acetate, Improvil acetate, and methyl benzoate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. The reaction time is usually selected within the range of 1 second to 100 hours. After reaching the desired degree of polymerization, the reaction is stopped using known methods, and the resulting polymer is isolated and purified.

The resin used in the present invention usually has a glass transition temperature of 120"C or higher (a), and depending on the type of repeating unit (I), has a glass transition temperature of 125"C or higher, such as PMMA.
It also has excellent heat resistance. Furthermore, the resin in the present invention has a photoelastic coefficient that is extremely small compared to PC, has extremely low birefringence, has extremely good transparency, and has excellent mechanical properties.

The above resin can be processed into the optical molded article of the present invention by conventional melt molding or cast molding using a suitable solvent.

Examples of the optical molded article of the present invention include the following.

(I) Diffraction gratings for optical disc player pickups, spectroscopic elements, optical low-pass films, etc. (2) Substrates for optical recording media such as optical discs and optical cards (8)
Various lenses for glasses, cameras, loupes, projection televisions, etc. (4) Various optical elements such as prisms, optical waveguides, beam sputters, etc. (5) Covers for automobile headlamps, rear lamps, etc. (6) Various lighting equipment parts ( 7) Glass substitutes for windows, windshields, etc. (8)
Various signboards (actual examples) The present invention will be specifically explained below using examples.

Note that the physical property values were measured according to the following method.

(2) Number average molecular weight and molecular weight distribution: Determined by CPC (polystyrene equivalent).

(2) Glass transition temperature: Measured by differential thermal analysis (in nitrogen, heating rate 10°C/min).

■ Vicat softening temperature: by heat press! ) Measured on a plate molded to a thickness of 1■ by a method according to JIS K7206.

■ Total light transmittance: Measurement was performed on a plate formed to a thickness of 1 mm by heat press according to a method according to ASTM D1003.

■ Photoelastic coefficient: by heat press, 9 100 x 20m
× 1 ■ The method of Soejima et al. using a helium-neon laser as a light source on a plate K formed with a thickness of K [Kobunshi Ishikengaku, edited by the Editorial Committee of the Society of Polymer Science and Technology, Vol. 10, p. 296 (I9
(1983) Kyoritsu Shuppan].

■ Bending strength and bending modulus: heat press 1 0
Measurement was performed on a plate molded to 0 van x 20 wm x 1 tone by a method according to JIS K7203.

Example 1 The inside of a 1 ton glass container equipped with a stirring device was sufficiently replaced with dry nitrogen gas, and then 0.5 A of dehydrated toluene was charged into the container, and 0.01 A of boron trifluoride was added.
After blowing until the concentration reached mol/t, it was cooled to -78°C. While stirring, slowly add dehydrated 2,3-dihydrofuran 932 to the solution over 20 minutes. -78℃
After continuing the reaction at a temperature of 48 hours, 10 d of a 1N methanol solution of aqueous ammonia was added to the reaction mixture to terminate the polymerization. Next, the mixed solution was dropped into 10 tons of methanol and isolated by reprecipitation according to a conventional method to obtain a white product of 37F. When the number average molecular figure of the product was measured by GPC, it was found to be 56,000 in terms of borysterene. Moreover, the molecular weight distribution was 1.70.

The product was made into a deuterated chloroform solution, and its NMR spectrum was measured by 1H-NMR (500 MHz, JEOL JNM GX-500).
．． 9ppm and 3. Two absorptions occupying equal areas were observed on the position K spectrum at 8 ppm. Regarding these absorptions, the latter can be attributed to methine and methylene protons adjacent to oxygen, and the former can be attributed to other methine and methylene protons.

The product was made into a tetrahydrofuran solution, the solution was prepared into a film with a thickness of 8 μm on a Teflon sheet, and the infrared absorption spectrum was measured using a Shimadzu L-Koichi 400. In the case of 2,3-dihydrofuran -C at the wave number 910 m' and 1060 cm-''
Absorption due to -O-C- was observed. In addition, 2,3
In the case of -dihydrofuran, the absorption due to the double bond observed at the 16 30 cm-'' position had disappeared.

These results indicate that the product is a polymer consisting of the following repeating units, and is obtained by polymerizing 2,3-dihydrofuran at the intracyclic double bond without opening the five-membered ring. was confirmed.

The physical properties of the above polymers are summarized in Table 1.

On a smooth substrate molded using this polymer,
According to the method described in No. 2-95525, methacrylic acid 2
- Copolymer of butenyl and methyl methacrylate (copolymerization molar ratio 1:3.3, molecular weight 200,000) 1
After forming a thin film using a composition consisting of 1 part by weight of 1 and 1 part by weight of 3-penzoylbenzophenone, pattern exposure was performed by irradiating ultraviolet rays through a photomask for a diffraction grating. Next, a diffraction grating was prepared by vacuum drying at 95° C. to remove unreacted 3-benzoylbenzophenone. This diffraction grating was heated to 24°C at 100°C.
No change was observed in the wavefront aberration of transmitted light through the diffraction grating after and before the grating was left for a while.

Example 2 The polymerization reaction and isolation operation were carried out in the same manner as in Example 1 except that 2,3-dihydro-2-methylfuran 982 was substituted for 2,3-dihydrofuran 939. ), 439 white product was obtained. This thing'
It was confirmed that H-NM is a reamer consisting of the following repeating units.

The physical properties of the above polymers are summarized in Table 1.

Using this polymer, SIM-474 manufactured by Technoplus Co., Ltd.
A 9A injection molding machine has an outer diameter of 13 m and an inner diameter of 1. 5 as
, thickness 1. The write/read/erase characteristics of the optical disk obtained by injection molding for 2 ms and using the obtained molded body as a base and forming a film of tellurium oxide as a recording layer on the surface of the base by vacuum evaporation method were evaluated. As a result, the performance was exactly the same as in the case of using PMMA as the substrate.

No change was observed in the writing/reading/erasing characteristics of the optical disc after and before the optical disc was left at 100° C. for 24 hours.

Example 3! ! In Example 1, 2,3-dihydrofuran 93f (7
) Substitute D K 2. A white product of 9,43F was obtained by carrying out the polymerization reaction and single trapping operation in the same manner except that 100f of 3-cyhydro-2-ethylfuran was charged. The physical properties of this IH-NMrt repeating unit or the above polymer are summarized in Table 1.

Using this polymer, a diffraction grating was produced in the same manner as in Example 1. This diffraction grating was left at 100° C. for 24 hours, and no change was observed in the wavefront aberration of transmitted light through the diffraction grating before and after leaving it.

Example 4 F), 479 was obtained by carrying out the polymerization and isolation operations in the same manner as in Example 1 except that 2,3-dihydro-3-methylfuran 97V was used instead of 2,3-dihydrofuran 93F. A white product was obtained.

'H-NMR of this product confirmed that it was a polymer consisting of the following repeating units.

The physical properties of the above polymers are summarized in Table 1.

Using this polymer, the writing/reading/erasing characteristics of an optical disk produced using the same method K as in Example 2 were evaluated, and as a result, the performance was completely equivalent to that when PMMA was used as the substrate.

No change was observed in the writing/reading/erasing characteristics of the optical disc after and before the optical disc was left at 100° C. for 24 hours.

Example 5 Ethyl #7 instead of boron trifluoride in Example 1
A white product 402 was obtained by carrying out the polymerization reaction and isolation operation in the same manner except that 17 ml of a 1 mol/L n-hexane solution of /l/j nium dichloride was charged. This polymer was confirmed to be a polymer consisting of repeating units of 'H-NM⇠Yυ order.The physical properties of the above polymer are summarized in Table 1.

Using this polymer, a diffraction grating was produced in the same manner as in Example 1. No change was observed in the wavefront aberration of transmitted light through the diffraction grating between after and before the grating was left at 100° C. for 24 hours.

The glass transition temperature and photoelastic coefficient of PMMA were measured at 97°C and 4X 10, respectively.
Example 1 using 90 PMMA with d/dyne
A diffraction grating made by the same method as in
When it was left for 24 hours at ℃, the shape changed significantly and it became impossible to use it as a diffraction grating.

Comparative Example 2 When an optical disk prepared using PMMA in the same manner as in Example 2 was left at 100° C. for 24 hours, the shape significantly changed and the disk could no longer be used as an optical disk.

Comparative Example 3 When the glass transition temperature and photoelastic coefficient of PC were measured, they were 138°C and -80X10-, respectively.
13ctA/dyne 1? there were.

〔Effect of the invention〕

According to the present invention, there is provided an optical molded article that has excellent transparency and heat resistance, and has minimal optical distortion.

Claims (1)

[Claims] The main chain is substantially the following repeating unit (I) (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1, R^2, R^3, R^ 4, R^5 and R^6 each represent a hydrogen atom or a lower aliphatic hydrocarbon group.Number average molecular weight 5,000~
Optical molded product made of 200,000 resin.