JPS63218727A - Optical material - Google Patents

Abstract

PURPOSE:To provide an optical material outstanding in transparency, water resistance, thermal characteristics, etc., suitable for compact discs, video discs, etc., consisting of a hydrogenated product from a polymer prepared by ring opening polymerization of dicyclopentadiene. CONSTITUTION:The objective optical material can be obtained by hydrogenation (pref., with a hydrogenation rate >=90%), using a catalyst such as niekel, of a polymer prepared by ring opening polymerization, in a solvent such as benzene, using a catalyst such as titanium, of dicyclopentadiene. This material is constituted of structural unit of formula.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to optical materials, more particularly transparency,
This invention relates to optical materials with excellent water resistance and thermal properties.

Glass or polymer materials are generally used as the surface protective layer of optical recording materials such as compact discs, video discs, computer discs, etc., but for mass production, plastic materials are used due to their ease of molding processability. In this case, the properties required of the plastic are: ■ Good optical properties such as transparency, high light transmittance, stable refractive index, and low birefringence; ■ Plastic protection. It has properties such as having heat deformation resistance to the extent that it can protect recording substrates such as aluminum or silver-plated aluminum as a layer, withstanding long-term deterioration, not discoloring, and not corroding the substrate due to moisture absorption. and (2) good moldability. Currently, polycarbonate, polymethyl methacrylate, etc. are used as plastics that can relatively satisfy these characteristics, but polycarbonate has a high glass transition temperature (Tg) and has good heat resistance, but has poor moisture absorption. It is somewhat high, tends to cause birefringence, and has hydrolyzability due to its molecular structure. On the other hand, polymethyl methacrylate is transparent and has excellent optical properties such as low birefringence, but it is highly hygroscopic and may cause corrosion of the substrate.
Warpage may occur on the disk surface due to changes in size and shape. Furthermore, since the Tg is around 100°C, deformation at high temperatures cannot be ignored.

Problems to be Solved by the Invention The inventors of the present invention have conducted extensive research in order to obtain optical materials that solve these problems, particularly plastics for optical recording materials. It was discovered that the above-mentioned drawbacks could be solved by using a compound as a constituent component, and based on this knowledge, the present invention was completed.

Means for Solving the Problems The gist of the present invention is an optical material comprising a hydrogenated ring-opening polymer of dicyclopentadiene as a constituent component. The hydrogenated product of this dicyclopentadiene ring-opening polymer is the following [I]
It is a polymer having a structural unit represented by the formula, and is a conventionally known substance (see, for example, Japanese Patent Publication No. 58-43412).

(However, in the formula, - indicates a single bond or a double bond.) The ring-opening polymer used as a raw material is produced by a known ring-opening polymerization method for cyclic olefins using dicyclopentadiene as a monomer. be able to. Further, the hydrogenation of this ring-opened polymer is also carried out using a conventional hydrogenation reaction method.

Each component of the present invention will be explained in detail below.

(Polymerization catalyst) The ring-opening polymer of dicyclopentadiene is produced by the usual polymerization method of norbornenes. These catalyst systems include metal compounds (for example, Japanese Patent Publication No. 46-14910) or systems of transition metal compounds such as titanium, vanadium, molybdenum, and tungsten and organometallic compounds of No. 1-1'ir of the periodic table. may be combined with a third component (for example, Japanese Patent Publication No. 41-20111, Japanese Patent Publication No. 57
-17883, Japanese Patent Publication No. 57-61044, Japanese Patent Publication No. 57-61044
4-86600, JP-A-58-127728, etc.)
.

The polymerization catalyst is not particularly limited as long as it is a metal compound capable of ring-opening polymerization of dicyclopentadiene, but preferably,
A catalyst system containing a transition metal compound and an organic metal, or a catalyst system containing molecular oxygen, alcohol, ether, peroxide, carboxylic acid, acid anhydride, acid chloride, ester, ketone, nitrogen-containing compound, sulfur-containing compound, or halogen-containing compound. It is a catalyst system that combines a third component such as a chemical compound, molecular iodine, and other Lewis acids.

(Solvent) Ring-opening polymerization can be carried out without using a solvent, but it can also be carried out in an inert organic solvent.

Specific examples include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as n-pentane, hexane, and heptane, alicyclic hydrocarbons such as cyclohexane, methylene dichloride, dichloroethane, dichloroethylene, and tetrachlor. Examples include halogenated hydrocarbons such as ethane, chlorobenzene, dichlorobenzene, and trichlorobenzene, and two or more of these may be used in combination.

(Polymerization temperature) There are no particular restrictions on the temperature conditions for ring-opening polymerization, but -
It is usual to select any temperature between 20°C and 100°C.

(Polymerization Pressure) The polymerization pressure condition is usually preferably selected from the range of O' to 50 Kg/crrI'.

(Ring-opening polymer) The molecular weight of the polymer is usually 0.05 to 0.05 in terms of intrinsic viscosity [η].
10du/gr, preferably O01-5dJL/gr.

In addition, when carrying out one polymerization, chain monoolefins, chain non-conjugated diolefins, cycloolefins, etc. are added.
TlR1 molecular weight and physical properties! ! You can also. Specific examples include butene-1, pentene-1, hexene-1, octene-1, butene-2, pentene-2,1,4-hexadiene, cyclopentene, norbornene, and the like.

(Hydrogenation) The hydride used in the present invention is one in which the ring-opened polymer described above is hydrogenated to saturate all or a portion of its double bonds to improve heat deterioration resistance and light deterioration resistance. . The hydrogenation rate is at least 50%, assuming that all double bonds in the ring-opened polymer are saturated by hydrogenation, and is 80% in order to further improve heat resistance and light resistance. % or more, particularly preferably 90% or more.

This hydrogenation reaction of the ring-opening polymer is carried out by a conventional method (for example, see Japanese Patent Publication No. 58-43412). As the hydrogenation catalyst, any catalyst commonly used in the hydrogenation of olefin compounds can be used. Examples include, but are not limited to, the following: Heterogeneous catalysts include nickel, palladium, platinum, or solid catalysts in which these metals are supported on supports such as carbon, silica, diatomaceous earth, alumina, and fermented titanium, such as nickel/silica, nickel/diatomaceous earth, and palladium. /
Examples include carbon, palladium/silica, palladium/diatomaceous earth, palladium/alumina, and the like. Homogeneous catalysts include catalysts based on metals in Group 1 of the periodic table, such as nickel naphthenate/triethylaluminum, cobalt octate/n-butyllithium, nickel acetylacetonate/triethylaluminum, etc. , a Co compound and an organometallic compound of a group 1-m metal of the periodic table, or a Rh compound.

The hydrogenation reaction is carried out in a homogeneous or heterogeneous system depending on the type of catalyst under a hydrogen pressure of 1 to 150 atmospheres at 0 to 200°C, preferably 20 to 150°C. The hydrogenation rate can be arbitrarily adjusted by changing hydrogen pressure, reaction temperature, reaction time, catalyst concentration, etc.

In the present invention, in order to further improve the oxidative deterioration resistance of the hydrogenated product, a stabilizer such as an ultraviolet absorber may be added within a range that does not reduce transparency. Also,
It is also possible to mix and use other polymers that are compatible with this.

Examples of methods for molding the hydrogenated product of the present invention as an optical material include common molding methods such as compression molding, injection molding, casting, and spin cording.

The obtained molded products can be used as optical recording materials such as compact discs, video discs, and computer discs, as well as photomask retention MW, optical fibers, optical fiber connectors, etc. by taking advantage of their properties such as transparency, moisture resistance, and heat resistance. It can also be used in the fields of optical communication and lenses such as prisms and plastic lenses.

EXAMPLES The present invention will be explained in more detail with reference to Examples and Reference Examples below.

Reference Example 1 Into an OJl autoclave that had been sufficiently dried and replaced with nitrogen,
400ml of dehydrated and purified toluene and 100mJl of dicyclopentadiene were charged, and 1ml was added as a molecular weight regulator.
- 0.37 mmol of hexene.

0.370 mmol of tungsten hexachloride and 0.74 mmol of tetraethyltin were added and polymerized at room temperature for 5 hours. After the reaction was completed, 5 ml of monoethanolamine was added and 2,6-ditertiarybutylphenol (BIT) was added as a stabilizer.
After adding Ig, the reaction solution was poured into a large amount of methanol to precipitate a polymer, and the mixture was vacuum-dried to obtain a toluene-soluble polymer (Polymer A). Yield is 62
%Met.

As a result of proton NMR analysis of the obtained polymer, δ
= 5.0 to 5.4 ppm, absorption due to olefin double bond protons was observed, and the absorption intensity almost matched the theoretical value (33.3%) for the absorption intensity derived from all protons. It was confirmed that ring-opening polymerization occurred. The glass transition temperature (DS
C) was 129°C, and the intrinsic viscosity measured in toluene at 25°C was 0.90 db/g.

Reference Example 2 11 400 g of a cyclohexane solution (concentration 5%) of (polymer A obtained in Reference Example 1) in cyclohexane and 2 g of palladium carbon were placed in an autoclave, and the inside of the reactor was filled with hydrogen, and the temperature was raised to a predetermined temperature while stirring. When the temperature inside the vessel became constant, the hydrogen pressure was increased to 70 atm, and the hydrogen consumed by the zero reaction was replenished, and the reaction was continued for a predetermined period of time.The catalyst in one reactant was passed through the mouth, and a large amount of acetone-isopropyl alcohol : 1) Precipitated in a mixed solvent, filtered, and dried.

Proton NMR analysis was performed on the obtained product,
Absorption due to olefin double bond protons (δ=5.
The hydrogenation rate was calculated from a comparison of the values (0 to 5.4 ppm).

The results are shown in Table 1.

(Margin below) Table 1 Example 1 The glass transition point (Tg) of the various polymers obtained in Reference Examples 18 and 2 was measured and
Press-formed under g/ctn' conditions to 30mm x 30m
Create a test piece of m x 1 mm.

Using this, we evaluated the characteristic values necessary for an optical material.

The results are shown in Table 2, for comparison.

Polycarbonate (Nipilon MR, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and polymethyl methacrylate (Acrylite, manufactured by Mitsubishi Rayon Co., Ltd.), which have been conventionally used as optical materials, were evaluated in the same manner.

Example 2 Intrinsic viscosity 0.72d synthesized according to Reference Examples 1 and 2
When a polymer (polymer E) with a hydrogenation rate of 98% and a hydrogenation rate of 98% was evaluated in the same manner as in Example 1, the Tg was 128°C,
The light transmittance was 92% and the water absorption rate was 0.02%.

From the above results, the hydrogenated product of the present invention has good transparency.

It can be seen that it is extremely useful as an optical material because of its excellent moisture absorption resistance.

Effects of the Invention According to the present invention, an optical material having excellent transparency, water resistance, thermal properties, etc. can be obtained.

Claims (2)

[Claims] (1) An optical material containing a hydride of a ring-opening polymer of dicyclopentadiene as a constituent component. (2) The optical material according to claim (1), wherein the hydrogenation rate of the hydride of the ring-opening polymer of dicyclopentadiene is 80% or more.