JPH02188441A - Production of quartz glass doped with functional organic molecule - Google Patents

Abstract

PURPOSE:To stably and efficiently use the high-performance functional org. molecule and to obtain the silica glass useful in optoelectronics by adding the functional org. molecule when a silicon alkoxide is hydrolyzed, dehydrating, and condensing the molecule. CONSTITUTION:Water and alcohol are added to the silicon alkoxide shown by Si(OR)4 (R is an alkyl) to obtain a liq. mixture. An amount of water to be used is about 4-10 times of the silicon alkoxide. The functional org. molecule such as a nonlinear optical functional org. molecule (e.g. 2-methyl-4-nitroaniline), a photochromism functional org. molecule (e.g. spiropyrane), an electrochromism functional org. molecule (e.g. polyxylylviologen), and a liq. crystal (p- methoxybenzylidene-p'-butylaniline) is added to the liq. mixture. The mixture is hydrolyzed, dehydrated, and condensed while applying ultrasonic vibration to obtain the quartz glass doped with the functional org. molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing functional organic molecule-doped quartz glass having functionality that can be used in optoelectronics.

[Conventional technology]

In recent years, the development of highly functional organic materials has been active in the field of optoelectronics.

For example, organic dye lasers, organic photoconductors, organic electroluminescence, organic electromic displays,
Various sensors, semiconductor laser second harmonic generation devices,
Nonlinear optical elements such as optical bistable memories and photoelectronic ICs, organic photochromism, and the like are known. In particular, as materials having nonlinear optical functions, organic materials have been found to have performance orders of magnitude greater than inorganic materials. Such organic nonlinear optical materials include organic crystals, polymer compounds, liquid crystals, and the like.

Here, a nonlinear optical material is a material that exhibits an optical phenomenon (nonlinear effect) that is not proportional to the amplitude of incident light and exhibits a high-order effect of the square or higher order, and is induced by light that enters the material. The polarization is expressed as the following equation (11, P = t, z"'E+ ε.
"・= + ε, x''E"-(11χtx+ is called second-order nonlinear susceptibility, and χln is called third-order nonlinear susceptibility.

As such a nonlinear optical material, LIN is an inorganic material.
bOs, KIIzPO4, BaTiOs, etc., and organic materials such as 2-methyl-4-nitroaniline, urea,
At-nitroaniline and the like are known. organic crystal 2
-Methyl-4-nitroaniline (MNΔ) is famous as a second-order nonlinear material. Among polymer materials, polyvinylidene fluoride is known to have a third-order nonlinear effect.

It is known that liquid crystals also have third-order nonlinear effects.

Such nonlinear optical materials are expected to be applied to higher information storage densities and optical computers, and interest in optical materials is increasing.

[Problem to be solved by the invention]

Conventionally, this type of organic material is used as a solution dissolved in a solvent as in the case of organic dye lasers, adsorbed on single crystal glass, or dispersed in organic polymers. There are many.

However, such conventional usage forms have not been able to fully utilize the functionality of organic molecules. This is because liquid devices are more inconvenient to handle than solid devices, and also have poor optical transparency, which limits their range of use as optical components. Similarly, when a polymeric material is used as a medium for organic molecules, the durability of the polymer is also a problem. Although functional organic molecules have high functionality, they are currently not fully utilized due to the lack of suitable media, and an immediate solution to this problem is a major issue.

In view of the above-mentioned current situation, the present invention has discovered a new and suitable medium for functional organic molecules, and provides a method for producing the same.
This was done with the aim of opening up possibilities for a wide range of uses as engineering parts.

[Means and effects for solving the problem] As a result of intensive research efforts in accordance with the above-mentioned objective, the present inventors have achieved the following by using silica glass, which has excellent durability and translucency, as a medium for functional organic molecules. It was found that the functions of functional organic molecules can be utilized stably and with high performance. Furthermore, in order to achieve this objective, it was found that a glass synthesis method called the sol-gel method is most suitable because it allows for stable and uniform dispersion.

That is, the present invention relates to the general formula Si To R11 (however, R
In a method of synthesizing silica glass by adding water and alcohol to a silicon alkoxide represented by an alkyl group to form a mixed solution, and performing hydrolysis and dehydration condensation, functional organic molecules are added to the mixed solution during the hydrolysis. This is a method for producing functional organic molecule-doped quartz glass, characterized in that the quartz glass is doped with functional organic molecules.

In the present invention, it is particularly preferable that the functional organic molecule is a nonlinear optical functional organic molecule, a photochromic functional organic molecule, an electromic functional organic molecule, or a liquid crystal, and the mixed liquid is hydrolyzed while applying ultrasonic vibration. The above manufacturing method is a particularly preferred embodiment.

According to the present invention, functional organic molecules can be dispersed and added into silica glass without modifying their structure. Furthermore, by applying ultrasonic vibration when adding functional organic molecules, the functional organic molecules can be dispersed very uniformly in the solution.
We also discovered that functional organic molecules that are insoluble in water and alcohol can be uniformly dispersed in monomolecular form.

Below, the circumstances leading to the present invention and the details of the present invention will be specifically explained.

It is considered desirable to use glass as a medium for functional organic molecules, especially when the functional organic molecules are optically functional organic molecules, but organic molecules are generally sensitive to heat, and functional organic molecules can also be heated up to 300°C. There is a problem with disassembling the front and rear parts.

Silica glass has been used as a highly durable engineering material since ancient times, and its manufacturing method involves melting natural quartz at high temperatures of over 2,000 degrees Celsius, which is called the fusion method.
It depends on the method of cooling.

Organic molecules cannot be dispersed in such a high temperature process.

Incidentally, in recent years, a low-temperature glass synthesis process called the sol-gel method has been developed. This sol-gel method is based on the general formula 5
A gel body is synthesized by hydrolyzing a silicon alkoxide represented by l(OR+4 (where R is an alkyl group), and this reaction proceeds in a solution at room temperature.

Therefore, in the case of the sol-gel method, there is no fear of decomposition even if functional organic molecules are dispersed in a gel body. Based on this idea, the inventors conducted repeated experiments and found that by adding functional organic molecules when hydrolyzing silicon alkoxide, it is possible to disperse and add functional organic molecules into silica glass without changing the structure of the functional organic molecules. Furthermore, by applying ultrasonic vibration when adding functional organic molecules,
We have discovered that functional organic molecules can be dispersed very uniformly in a solution, and that functional organic molecules that are insoluble in water and alcohol can also be uniformly dispersed in monomolecular form.

However, in order to obtain a glass of the same quality as silica glass synthesized by the melting method by the sol-gel method, the gel body must be
It is necessary to heat it to 00°C. As a result of further investigation into this point, the present inventors found that sufficiently transparent gel glass can be obtained even with heat treatment at about 100°C.
The present invention was based on the knowledge that although it has a higher water and alcohol content and a lower density than ordinary silica glass, its translucency and mechanical strength are quite close to those of silica glass.

In the present invention, water for hydrolysis and alcohol as a solvent for silicon alkoxide and water are added to silicon alkoxide represented by the general formula St to R14 (where R is an alkyl group) to form a mixed solution, and the silicon alkoxide is hydrolyzed. At the same time, functional organic molecules are added. When the functional organic molecule is soluble in water or alcohol, it is also possible to add a solution in which the functional organic molecule is dissolved in advance to the alkoxide. When this functional organic molecule-added mixture is allowed to stand at room temperature, silicon alkoxide is hydrolyzed into silica SiOx, and this silica is dehydrated and condensed to become a solid called gel.

In this reaction, the functional organic molecule does not change its structure and is converted into silica, SiO! It is thought that the system will be incorporated into the network. By further drying this gel body, a silica glass analog called gel glass is obtained. It was confirmed by spectroscopic analysis that the functional organic molecules in this gel glass were monomolecularly dispersed.

In order to more uniformly disperse the functional organic molecules in the glass, it is effective to apply ultrasonic vibration to the solution during the hydrolysis reaction. When synthesizing a substance with an isotropic structure such as glass, uniformity within the solution is essential, and generally, in the case of a mixture of only soluble solutes, a homogeneous solution can be obtained by stirring. However, hydrophobic functional organic molecules with large molecular weights such as liquid crystals are insoluble in water and alcohols such as ethanol, and such insoluble substances associate even in solution and are not uniformly dispersed.

Even if such a mixed solution is gelled, gel glass doped with functional organic molecules cannot be obtained. In such cases, applying ultrasonic vibration to the liquid mixture can prevent the association of functional organic molecules by directly applying mechanical vibration to the molecules of the liquid, and can also prevent functional organic molecules such as liquid crystals. Can be uniformly dispersed in the solution.

By allowing the gel body to stand still at a temperature of 100° C. or lower, sufficiently dry gel glass can be obtained.

As described above, the present invention enables functional organic molecules to coexist within the glass synthesis reaction process by carrying out the synthesis reaction in a solution reaction at a low temperature of 100°C.

Examples of the silicon alkoxide of the present invention represented by the general formula Si 10 R14 (where R is an alkyl group) include those in which R is a methyl group, an ethyl group, a propyl group, a butyl group, and the like.

The water added to hydrolyze the silicon alkoxide has a molar ratio of 4 to 10 to the silicon alkoxide.
The amount is preferably within the range of about twice that, because if it is less than the above range, cracks will occur in the gel during drying, and if it is too much, gelation will not proceed.

Examples of alcohol include methanol, ethanol,
Propatool, etc. is preferable, and the amount added is preferably within a range of about 2 to 4 times the molar ratio of silicon alkoxide.The reason for this is that if it is less than the above range, precipitation of 6 molecules will occur, which is too much. This is because gelation is delayed in some cases.

Various functional organic molecules can be used as the functional organic molecules according to the present invention. Functional organic molecules are particularly preferred because the excellent properties of the functional organic molecules themselves can be very advantageously exhibited by using glass as a medium for the functional organic molecules.

The amount of the organic molecule that provides this functionality must be less than the saturated amount dissolved in the solvent.The reason for this is that if more than the saturated amount is added, the organic molecule will precipitate during gelation, resulting in dissolution within the gel glass. This is because it is not added uniformly.

Examples of nonlinear optically functional organic molecules according to the present invention include 2-methyl-4-nitroaniline, 3-methyl-4
・Nitropyridine-N-oxide, urea 9m-nitroaniline, etc. are mentioned, and photochromic functional organic molecules include, for example, spiropyran, azobenzene, cis-dirubene, nitrone-oxacyridine, 1-phenoxyanthraquinone, etc. Examples of organic molecules include polyxylyl viologen and polystyrene sulfonic acid, and examples of liquid crystals include paramethoxybenzylideneparadibutylaniline.

Examples include cholesterol, terephthal bisbutylaniline, and the like. However, it goes without saying that it is not limited to these.

In the experiments conducted by the present inventors, the conditions of ultrasonic vibration were oscillation frequency of 45 K Ilz and duration of 1 to 5 hours. The reaction temperature for hydrolysis is 30 to 50°C, the hydrolysis time is about 10 to 20 hours, the gel dehydration and condensation conditions are 50 to 80°C, held for 1 to 3 days, and the further drying conditions for the gel body are 80 to 80°C. ℃ to 150
Conditions were adopted in which the temperature was raised at 1 to 1.degree. C. and maintained at 150.degree. C. for 5 to 15 hours. However, it is not limited to this.

〔Example〕

Example 1 Silicon methoxide 4m/, I+! 02.3rn1.
HCj70.06rnt, ethanol 5.7d and 2-methyl-4-nitroaniline 17, a nonlinear organic molecule.
Dissolve ■, leave this mixed solution at room temperature for one week,
A disc-shaped gel glass with a radius of 20 mm and a thickness of 2 mm was obtained.

This was a yellow transparent glass, and when observed with the naked eye, no localized organic matter was observed. When spectroscopic analysis was performed in the solution state and in the gel glass state, there was no difference in the spectra between the two, so it is considered that the additives were uniformly dispersed.

Example 2 Silicon methoxide 7rn1. H snow 04mZ, HC
fO.

1+J, ethanol 6-, one of the nematic liquid crystals,
p-methoxybenzylidene-po-alkylaniline 0
．． 25 rn! , added. This mixed solution was homogenized in an ultrasonic vibration tank for 1 hour, and then left to stand at room temperature for 1 week. A gel glass in which white liquid crystal molecules are uniformly dispersed was obtained.

Example 3 Silicon methoxide 7 nl, IIto 4 ml
0.25 ml of p-methoxybenzylidene-po-alkylaniline, one of the nematic liquid crystals, was added to I C10°1 m/, 6 d of ethanol, and the mixture was vigorously stirred with a stirrer and then allowed to stand at room temperature. After three days, the liquid crystal was separated from the glass component, and cracks had appeared in the gel glass. This is probably because the liquid crystal was not sufficiently uniformly dissolved in the solution.

The gel glass of the present invention obtained in the above examples had a density of about 1.6 (/ctn3), a light transmittance of about 90%, and a mechanical strength (Vickers hardness) of about 20 kg/mm''.

Incidentally, the density, translucency, and mechanical strength of normal silica glass are 2.2 g/cm' 100% and 600 g/cm', respectively.
kg/am”.

In the above examples, the functional organic molecules used were organic compounds exhibiting nonlinear optical properties and liquid crystals, but the functional organic molecules are of course not limited to these, and exhibit photochromic properties, electrochromic properties, etc. Functional organic molecules can also be dispersed in the glass, resulting in a glass doped with functional organic molecules that effectively exhibits its functions.

〔Effect of the invention〕

As explained above, the present invention makes it possible to disperse and add functional organic molecules into gel glass of silica component, and is effective when used for the synthesis of glass having high functionality.

Claims (3)

[Claims] (1) General formula Si(OR)_4 (R is an alkyl group)
In a method of synthesizing silica glass by adding water and alcohol to a silicon alkoxide represented by the formula to form a mixed solution and subjecting the mixture to hydrolysis and dehydration condensation, a functional organic molecule is added to the mixed solution during the hydrolysis. A method for producing quartz glass doped with functional organic molecules. (2) The functional organic molecule dope according to claim 1, wherein the functional organic molecule is a nonlinear optically functional organic molecule, a photochromic functional organic molecule, an electromic functional organic molecule, or a liquid crystal. Method for manufacturing quartz glass. (3) The method for producing functional organic molecule-doped quartz glass according to claim (1), wherein the liquid mixture is hydrolyzed while applying ultrasonic vibrations.