JPH01167255A - Production of oxynite glass - Google Patents

Abstract

PURPOSE:To obtain an oxynite glass, having a high N2 content and excellent water and hydrogen resistance and high-temperature strength characteristics and useful in the field of quartz glass, by heating a specific glass body at a high temperature in an N2-containing gas atmosphere and converting the glass body into transparent glass. CONSTITUTION:A glass-forming raw material is subjected to flame hydrolysis or thermal oxidative reaction with a carbon-containing combustion gas 2, such as methane, to form fine glass particles (A), which are then applied to a support 4 to provide a carboncontaining porous glass body 3 (B). The resultant body 3 (B) is subsequently introduced into a quartz glass furnace core tube 5 having a gas fed port 6, such as N2, a gas discharge port 7 and a carbon heating unit 8 and heated at a high temperature in an N2-containing gas atmosphere to liberate O2 from Si-0 bonds of the body 3 (B) and bind N2 to Si. Thereby the aimed transparent oxynite silica glass sufficiently containing N2 is obtained.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a glass doped with nitrogen to improve water resistance, hydrogen resistance, and high strength properties, and provides a method for increasing the amount of topes. do.

(Prior art) For example, in order to improve the water resistance, hydrogen resistance, and high strength properties of quartz glass, the Sj-0 bond is replaced with a 5i-N bond that is denser and has better bonding properties, resulting in a so-called oxy-oxygen bond. Attempts have been made to make oxynite glass9.As a method for producing this oxynite glass,
q of crow fine particles ((particle size: 101 to 0-1 μm) were prepared by flame hydrolysis or thermal oxidation reaction, and then heated with N2, N
There is a method of obtaining transparent glass by heating to high temperature in a nitrogen-containing gas atmosphere such as H, etc.

(Problem to be solved by this invention) However, the amount of nitrogen tope in the glass obtained by this method is at most about Iwt% even if the treatment concentration, treatment temperature, and treatment time are changed. This did not lead to improvement in strength properties.

(Means for solving the problem) The inventors came up with the idea of reducing the problem with carbon from the viewpoint that the cause of the problem lies in the strong Si-〇 bond. However, glass forming raw materials are subjected to flame hydrolysis or thermal oxidation reaction using combustion gas containing carbon to form a porous glass body containing carbon, which is then heated at high temperature in a nitrogen-containing scum atmosphere to form transparent glass. It is in.

The combustion gas containing carbon may be, for example, a carbon compound gas such as methane, ethane, butane, acetylene, ethanol, or methanol.

Carbon, which is decomposed and produced through combustion, adheres as soot around and in the gaps between glass particles that form porous glass bodies produced by flame hydrolysis or thermal oxidation reactions, and is exposed to high temperatures in a nitrogen compound gas atmosphere. During the treatment, oxygen is removed from the Si-0 bond and dispersed from the porous glass body as carbon monoxide or carbon dioxide. In this way, 5j-N bonding becomes easy and the amount of nitrogen doping can be increased. As nitrogen-containing scum, N2, N1-
1. .

NF, etc. are changed. Furthermore, by introducing helium into the atmosphere, the heat of the heating furnace can be efficiently transferred to the porous glass body, and the gas remaining in the bubbles can be quickly discharged to the outside.

(Example) FIG. 1 is an explanatory drawing for obtaining a porous glass body, which is one step of the method of this invention. In the figure, 1 is a quadruple tube bar with 5icf1. , C2 as a combustion gas is supplied to the second layer, Ar is supplied to the third layer, and O7 is supplied to the fourth layer. 2 is a combustion flame caused by the reaction between C, I-1° and q, and SiO2 glass fine particles are generated by this combustion heat. 93 is a porous glass body consisting of the generated Siq glass particles. Carbon is attached around and between them. In addition, 4 is a support body for supporting this porous glass body, and is supported so that it can rotate and move up and down. Fig. 2 shows a heating furnace for turning the porous glass body 3 obtained by the method shown in Fig. 1 into a transparent glass body containing nitrogen. A supply port 6 for supplying gases such as N and He is provided, and a waste discharge lower is provided on the upper side wall thereof. 8 is a carbon heating element located on the outer periphery of the furnace core tube 5. Thus, when the SiO porous glass body 3 containing carbon C is introduced into the furnace tube 5, the carbon deprives oxygen from the 5i-0 bonds and becomes Cq, which is discharged from the discharge lower. On the other hand, nitrogen is bonded to silicon from which oxygen has been liberated, forming transparent oxynite silica glass containing sufficient nitrogen.

(Specific Example) A porous glass body made of carbon-containing Slq and having a diameter of 60 mm and a length of 30 cm was obtained by the method shown in FIG. The gas supply conditions to the burner and the lifting speed of the support at this time were as shown in Table 1.

Table 1 Next, this porous glass body was made into transparent vitrification using the method shown in Figure 2 under the conditions shown in Table 2.
Oxinite silica glass containing 15 wt% nitrogen and having a size of 5 mm and a length of 15 cm was obtained.

=4− Table 2 When the water resistance, hydrogen resistance, and strength resistance characteristics of the thus obtained glass were measured, the fatigue coefficient n was 35 (8
0°C), the diffusion coefficient of hydrogen molecules was almost O, and the maximum strength was 524 Kg/mm. In the above specific example, an example in which nitrogen is contained in quartz glass has been described, but the invention is not limited to this, and multi-component glass, halogen glass, and even Ge, P, B, Aρ, S, etc.
It can also be applied to glass doped with b or the like.

(Effects of the Invention) This invention obtains a porous glass body containing carbon in a reduced state as described above, and transforms it into a transparent glass in an atmosphere containing nitrogen, thereby removing oxygen in the 5i-0 bond state. It can be easily liberated and replaced with nitrogen, making it possible to obtain glass containing sufficient nitrogen.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1.2 is an explanatory diagram showing the method of this invention. In the figure, 3 is a porous glass body containing carbon, and A is a transparent oxynite glass body containing nitrogen.

Claims (1)

[Claims] Glass forming raw materials are subjected to flame hydrolysis or thermal oxidation reaction using combustion gas containing carbon to form a porous glass body containing carbon, which is then heated to a high temperature in a nitrogen-containing gas atmosphere to form transparent glass. Characteristic method for producing oxynite glass.