JPH0264032A - Manufacturing method of lump glass - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can be applied to optical components such as lenses for projection exposure devices for integrated circuits, TPT substrates for liquid crystal displays, prisms, and beam splitter-1 spectrometers. The present invention relates to a method for manufacturing quartz glass and various glasses with excellent optical properties by a sol-gel method.

[Prior art 1] In the conventional production of glass by the sol-gel method using fine particles of metal alkoxides and metal oxides as the main raw materials, a liquid sol having the desired glass component composition is gelled in a closed container of a desired shape. The gelation temperature is 25-30℃
It was about.

[Problem to be solved by the invention]

However, in the above-mentioned conventional technology, the wet gel shrinks immediately after gelation, and the active ingredients, metal alkoxide monomers and oligomers with a low degree of polymerization, are released in the wet gel together with the ethanol and water released at this time. It separates from inside the gel. This creates a distribution in the proportion of fine particles and metal alkoxide in the wet gel,
When this is dried, sintered, and vitrified, internal differences occur in the sintering speed, making it extremely difficult to manufacture highly homogeneous glass.

Therefore, the purpose of the present invention is to particularly improve the conditions during gelation,
The objective is to provide a highly homogeneous glass and an easy manufacturing method.

[Means for Solving the Problems] The method for producing glass by the sol-gel method of the present invention involves preparing a liquid sol having a target glass component composition using metal alkoxide and metal oxide fine particles as main raw materials, and In the production method, the liquid sol is gelatinized in a closed container of a desired shape to produce a wet gel, and then the wet gel is subjected to heat treatment such as drying and sintering. When gelling is carried out, the gelling is carried out at 20°C or lower.

[Function 1] The present invention reduces the shrinkage rate after gelation by controlling the gelation temperature, and reduces the amount of metal alkoxide monomers and oligomers that do not participate in the polymerization reaction. Wet gel can be made.

[Example 1 Ethyl silicate, ethanol, water, ammonia water (2
9%) were mixed in a molar ratio of 6.4.008, stirred for about 3 hours, and left to stand at room temperature.
The particles were grown and aged, and then concentrated under reduced pressure to prepare a silica fine particle dispersion with good dispersibility.
In addition, when the particle size distribution was measured by a centrifugal sedimentation method, the average particle size was 0.54 μm.

Next, using 1/4 amount of ethyl silicate than the ethyl silicate used above, 0.02 N hydrochloric acid was added to give a weight ratio of ml, and the hydrolyzed solution was prepared by stirring for about 2 hours while cooling with water. did.

Here, the pH value of the silica fine particle dispersion was adjusted to 4.5 by adding 2N hydrochloric acid, and then mixed with a hydrolyzed solution of ethyl silicate and sufficiently stirred until a homogeneous liquid sol was obtained. After that, 0.2N ammonia water was added to the liquid sol to adjust the pH value to 5.0, and the diameter was 30cm.
The liquid sol was injected into a cylindrical mold of m to a height of loam, and the mold was sealed with a lid and gelatinized at a temperature of 5°C. After gelation, leave it at 5°C for 20 days, and the lO%
Once it had shrunk to a certain extent, it was dried in a constant temperature dryer kept at 70°C, and the drying was completed in about 2 weeks, with a diameter of 21cm,
A white gel with a height of 7 cm was obtained.

The obtained gel body was once heated to 800 °C in an oxygen/nitrogen atmosphere.
℃, and various treatments such as promotion of condensation reaction, dehydration, removal of organic residues, etc., were then heated to 1350℃ under reduced pressure to vitrify, and further raised to 1750℃ in a nitrogen atmosphere for 1'' After holding for 30 minutes, the mixture was slowly cooled.

The glass body thus obtained was a highly transparent colorless cylinder, having a diameter of 15 clTl, a height of 5 cm, and a weight of 1940 g.

In addition, the physical properties of the obtained glass were consistent with those of silica glass, including Vickers hardness, specific gravity, coefficient of thermal expansion, infrared and near-infrared absorption spectra, and refractive index.

[Effects of the Invention] As described above, according to the method of the present invention, it is easy to produce a large lump of glass with excellent optical homogeneity.

Therefore, we believe that its application will expand not only to fields where quartz glass has been used up until now, but also to various other fields that require particularly high quality, such as IC photomask substrates, optical fiber base materials, and special optical applications. .

In addition, in the sol preparation step, B, Ti, Ge, Na,
Ca, Li, A1. Since it is possible to add various elements such as Te, Zr, Ce, Nd, and Cr, it is easy to manufacture a wide variety of multicomponent glasses and glasses that do not have existing compositions.

that's all Applicant: Seiko Epson Corporation

Claims (1)

[Claims] 1) Prepare a liquid sol with the desired glass component composition using metal alkoxide and metal oxide fine particles as main raw materials, gel the liquid sol in a sealed container of a desired shape to produce a wet gel, and then 1. A method for producing bulk glass using a sol-gel method in which a wet gel is vitrified by heat treatment such as drying and sintering, the method comprising gelling the liquid sol at a temperature of 20° C. or lower.