JPS6065732A - Production of quartz glass - Google Patents

Abstract

PURPOSE:To shorten the days required for manufacturing dry gels, by placing a lid having one or more holes thereon on a container for manufacturing the dry gel and allowing the dry gel to stand at a high temperature of the room temperature or above in the method for synthesizing the dry gel at low temperature by the sol-gel method. CONSTITUTION:Aqueous hydrochloric acid is added to hydrolyze ethyl silicate under vigorous agitation, and fine powdery silica is then added to the resultant solution, uniformly dispersed and adjusted to 4-6pH to form a sol solution 4. The resultant sol solution 4 is then contained in a container 3, and a lid 2 having one or more holes 1 is placed on the container 3. The covered container 3 is then allowed to stand at a temperature of room temperature or above and 100 deg.C or below to give a dry gel, which is then sintered to afford the aimed quartz glass. The area ratio between the holes 1 of the lid 2 and the whole lid 2 (opening ratio) is <=50%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses gold-stripe alkoxide and finely powdered silica as raw materials, and uses a sol-gel method with a pH of 4 to 6 to produce quartz glass at a low temperature. All about how to make dry gel.

Quartz glass became VC as it was used for 3-pieces, boards, diffusion furnaces, etc. during the engineering process, and its usefulness was recognized, and products with fewer hydroxyl groups and those with good optical uniformity were developed. As a result, quartz glass fibers have come to be used for various optical applications, and quartz glass fibers for optical transmitters have recently been attracting attention. In this way, quartz glass is used in individual fields, and its scope of use is expanding.

Made of quartz glass! l! ! Manufacturing cost, i%
The problem is that it's only one song.

Therefore, an inexpensive method of manufacturing quartz glass is desired.

Two methods have been tried: one using 'C1 Kanagawa alkoxide as a raw material and the other using ultrafine Norica powder as a raw material.

Next, I would like to outline each.

Nogami et al. (Ceramics Journal, 87, 37, 1979) and Jiki et al. .1979).

This sol-gel method has the advantage that it is possible to obtain commercially available quartz glass because the raw material alkoxide is of high quality, and that it is cheaper to manufacture than the conventional method. Teii.

The outline of this method is as follows. i.e. silicon tetraalcogides, water, alcohol.

Mix a suitable catalyst (hydrochloric acid, ammonia, etc.), hydrolyze it, promote polymerization reaction, gel it, shrink and dry it to make a dry gel, and then heat it to about 1000℃ (sintering). Can be used with quartz crow.

Problems with this method include the fact that cracks occur during dry gel preparation, and it is difficult to obtain large dry gels.
At this time, cracks and cracks also occurred, making it difficult to create large quartz glass.

On the other hand, if ultrafine powdered silica is used in the yA$+ method, Bell Labs' Labinovicb EM et al.
Journal of Non-Crystalline
5O1ide 47 (1982) 435-459)
is being attempted by This is super-imitation powdered silica (C
ab-o-8i1. (Cabnt, Inc.) was soaked in water, hydrosil-bound, gelled, shrink-dried to form a dry gel, and then sintered to form quartz glass. The drawback of this method is that, unlike the metal alkoxide method described above, cracks and cranks may occur during dry gel preparation and sintering.
This means that it is possible to manufacture quartz glass as large as the sword.

There are two big drawbacks to this method? have.

In other words, the sintering temperature is 1,450 degrees Celsius or so, and there are many air bubbles in the gel, and many air bubbles remain in the quartz glass that is created. In addition, because the SiO□ yield in hydrosil is too cylindrical, it is difficult to
In some cases, it may cause cracks. However, this method has fatal disadvantages in that it is difficult to achieve optical homogeneity due to the presence of air bubbles, and it is also difficult to achieve mechanical homogeneity due to the non-uniformity of the hydrosil. .

In order to manufacture quartz glass, which has a heavy responsibility such as optical and memorabilia, it seems impossible to use the metal alkoxide method described above7. For this reason, there is a desire for a method to obtain large quartz glass with a high yield using the metal alkoxide method.
). One such method is a ``method for manufacturing quartz glass'' filed on May 23, 1977. This is a product in which metal alkoxide is mixed with water, super-powdered wood powder is added to the sol, and the pH is adjusted to 4-6. Between cracks and cracks 'rM = solved at the same time. By using this chance, 9 large quartz glass (
41 nchφ or larger) can be produced at low cost.
This method has the disadvantage that it takes 10 days or more to prepare the dry gel, and the production time is not long.

'Also, if you create a dry gel at room temperature, the room temperature will be 10℃.
Since the temperature varies within the above temperature range, cracking may occur due to this temperature change. For this reason, the yield is slightly lower, and
Due to the low temperature, the yield rate is slightly low, probably due to the low temperature of the dry gel in the structure of the dry gel, even if it is a cooling factor. As mentioned above, when producing dry gel, there are problems in that the production time is long and the production rate is somewhat slow.

Therefore, an object of the present invention is to provide a method for producing a dry gel that shortens the production time and further improves the speed of production.

In other words, Showa 5'? Filed on December 23, 2013
Similarly to the method for manufacturing quartz glass, salt e is added to ethyl silicate.
” + Add (add ethanol if necessary at this time).

Shun, Asroeil (Pegula), which was stirred well and hydrolyzed,
ssa), Cab-o-sil (Oabot)
Ultrafine powder bed silica which is white carbon such as? In addition, the pH was adjusted to 4 to 6 in total, and the sol thus obtained was coated with a hydrophobic material (polypropylene, Teflon.

This method involves adding a ritual vessel made of vinyl chloride, polyethylene, etc.), a lid with a suitable through hole (Fig. 1), and leaving it at an appropriate temperature to form a dry gel.

In this way, when the temperature is raised above room temperature, the evaporation rate of the solvent becomes faster and the drying time can be shortened, resulting in a shorter dry gel preparation time. Furthermore, when left at high temperatures, crosslinking in the gel structure occurs even more rapidly, resulting in 1. Since it is thought to be a strong residue, cracks are less likely to occur during gel contraction, and it is expected that the yield will be improved.

However, at high temperatures, the evaporation rate of the solvent is fast, so gelation r
If the drying process is carried out in an open state as shown in FIG. 2 without an excessive lid, the drying speed will be significantly faster, but on the other hand, it will be more likely to crack at random, resulting in a poor yield. Therefore, in order to control the evaporation rate of the solvent at still temperature,
As shown in Figure 1, there is always a woman who puts a lid on the through hole rM.

Here, the value calculated by dividing the area of the through hole by the area of the lid is taken as the aperture ratio. Hereinafter, the value of the aperture ratio will be 11BL.

In this way, by appropriately controlling the lid opening rate and controlling the evaporation rate, the dry gel production time can be shortened and the yield can be improved at the same time.

In order to create a dry gel with a high yield of 9, there is an important correlation between the dry gel creation temperature and the aperture ratio. In the case of room temperature, (as in Toki's special plan in December, the opening rate is 100%)
In this case, the yield will change to 9 depending on the weather, temperature, humidity, etc. during the creation period, and the change in the environment is also one of the reasons why the yield decreases by 9. In most cases, the percentage of words exceeds 50%. (In some cases, the yield increases by about 90% by chance, but the reproducibility of this is almost unmatched.)The yield became very good after using a lid tray with an opening ratio of about 20 inches. In most cases, 60% of the walking errors occur.

And the aperture ratio is 20%L! When the yield is lowered by 11 to less than 10%, the yield 9 becomes approximately 80% or more, and becomes close to 100%.

In this case, the binding diary for making the dry gel should have an aperture ratio of 〒1
If you leave it at 0 and do it at 1, it will take about 2 weeks at 1 7>7)>
10 days iW at 100% aperture ratio], but even with an aperture ratio of 10, after about 6 days, the aperture ratio is 9 by removing the lid, etc., and the temperature is 30%. ~1
With the operation of the temple to raise the temperature at around 00℃, 8 days and 1
You can talk to Dreigel in a group conversation. With this elaborate act of worship, we can increase the yield to nearly 9 to 100 cm, and add Dreigel's work to history.

*I When raising the grapes to 30-100℃ If you raise the temperature to 30 to 100 degrees Celsius, you can make the grapes into 4i11 types. That is, gelation is performed at room temperature (gelation temperature), and the temperature is increased at a rate of 2°C/min or less.
The temperature is raised at a certain temperature between about 30 and 100 degrees Celsius (shrinkage temperature) in a box, and the product is left at that temperature for an excessive period of time to shrink. The temperature of the shrinking oven is approximately 300℃ (drying temperature) at a heating rate of less than ℃/min.
Raise the temperature at 1, leave the excess ball Jii41 at that temperature and roll it with dry gel. If you use this method wisely, it is possible to make the fibers even shorter than in the previous period, and we have an example in which the fibers were made in 4 days using 11 reeds. In this case, the yield was 90 cm or more. Yes, 100chi is also unroman f1
It's not a stop.

In this method, since the gelling temperature and the shrinking temperature are changed, it takes time and effort to raise the temperature during this time. A very simple method is to perform gelation at the same temperature as the shrinkage temperature, then shrink, and that's 7D! Another possible method is to raise the temperature from - to the drying temperature; even with this method, we were able to produce it in a short period of 3 days, and the yield was close to 100%.

In addition, the gelling temperature, shrinkage temperature, and dry wet hair are all kept at the same temperature, and the sol state is left at a high temperature above room temperature.
It is also possible to do the same with wet hair. This method also allows dry gel to be obtained in a short period of time and with good yield.

However, the gelling temperature is 60℃! If the temperature is too high, air bubbles will occur in the dry gel, so the gelling temperature was set at 60°C.
I can't do more than that. Therefore, in order to make it in a short period of time, it is necessary to keep the gelling temperature below 60℃ and the shrinkage and drying temperature [k
It is desirable that the temperature be 60°C or higher.

In the above various cases t4! :However, even if the shrinkage temperature and drying temperature were the same, it would not work.

By using the method according to the present invention as described above, it is possible to shorten the dry gel production time by 1, +ti, and the yield is also the same. Tomorrow.

Example 1 Commercially available ethyl chloride 208057 (40 mol)
0.1 regulation salt water bath basin 1800-sword I", 60
Stir vigorously for 15 minutes to complete the hydrolysis reaction, add 1000ml of water to this solution, and add ultrafine powder silica (
Cab-〇-5il (Oa, t+ot company) k 750
Under V stirring, homogenization was carried out for 730 minutes using ultrasonic vibration, and the cab-o-six was uniformly ground and thick.
Solid or garbage? I passed it through p to remove it. C
1 step down, measure to PH'z4.4, lζ, this sol? Each was added to a 1011ml polypropylene container (inner diameter 23cmφ) so that the thickness was 1 tyrr, and the opening ratio was 6.
Cover all 210 candy lids with 7 lids. I'll leave it alone all night with all these tau jokes. These gelatinized and began to converge a little.

Put these 7 isothermal IlvMVCs at room temperature to 6001 5
The temperature was raised at a heating rate of 10°C/hour, left at 60°C for 5 days, and then heated to 80°C at a heating rate of 10°C/hour.
The temperature was raised in the °C trench. 15.0cr after being left at 80℃ for 2 days
The white dry gel of nψ was 101 hard and 1+. These dry gels became transparent when heated to 21200° C. by a conventional method, and all became quartz glass with a diameter of 10.4 an. This quartz crow @+yy22, Vickers hard i
i, 800K? / +nA T, the infrared absorption spectrum and near-infrared absorption spectrum match those of commercially available quartz glass made by conventional methods.In this way, the number of days required for producing one dry gel can be shortened to 8 days, and the yield and pi1oo I was able to make it into %.

Example 2 In the same manner as in Example 1, 1800 Tnl of 01N hydrochloric acid was added to 20 BOr of Keishin ethyl, and the mixture was stirred vigorously for 30 minutes for hydrolysis. Oa'b-o-8il' (+:
After stirring for 100 minutes, the remaining operations were carried out in the same manner as in Example 1. In other words, super fv vibration, p overexcitation, ammonia water metal〃■ePH? ! : The solution was weighed to 4.4 ml, placed in a 101-firm polybrovisone'd vessel (25C1nφ), allowed to gel, and left to stand overnight. After that, the same operation as in Example 1 was repeated. However, sintering was done in a trench at 1150°C. By doing this, the yield was 910 in 8 days for one dry gel.
I was able to get a stone capsule glass meeting with 0%.

Practical ν135 Cab-o-sil nt-r4oor was used and the operation was exactly the same as in Example 2 except for the IC. 10 dry gels (15 mφ) were obtained in this way, and heated at 1150°C in a reed according to the usual method. When heated, 10 quartz crows (10,2zψ) were obtained.

In the same way, four dry gels were made with a yield of 100% in 78 days.

As described in the examples above, gelation 'T: carried out at room temperature, yield #a 'tlAIJj';
linj, dry gel preparation temperature [780℃ and leave it for 2 days 1-], it is possible to achieve 1' to 1' to 100' yield, and of course the sintering yield is 100's, so quartz Yield v in glass manufacturing is 1
It can be set to 00%. In addition, the number of days required to prepare the dry gel was shortened to 8 days, and this simple effect was demonstrated in Examples 1 to 3.
As shown in Figure 2, it can be seen that this does not depend on children with 0ab=o-611.In our experiment, Ti"l, Cab-
7C0ab divided by final 5ift it before o-sil
-The yield of o-sil lids is 9 in any case between 10% and 60%. ! ``It can be made 100% 7t, and if the ratio of Cab-o7sil is less than 10,
The rate of production of dry gel is 100%, but the yield during sintering is poor, so is it really meaningful? Don't do it. At 60% or more, the low brightness of dry gel preparation deteriorates rapidly.

In this case, the amount of Cab-o-sil is 10%.
If the amount of μCab-o-sil is between 60% and 60%, it is thought that the same result will be obtained by using the same program as Kenichisei program r for dry gel creation.
6% field (composition of Example 1) K is written as a representative.

Therefore, please consider that other Cab-o-sil children will have similar results.

Also, although Sol's PH'i 1st ward V is tricky, (12
As stated in Toki's patent published in the month), the pH is 4.
~60, the same result is obtained in any case, so we will use PH4,4klt'& for PH.Also, in Examples 1 to 6, if the opening rate is t5 or more, the yield will be poor. <No, the yield is 910 in all cases below 5%.
0% and 1 piece.

implementation? l14 In the same manner as in Example 1, add 71,800ml of 0.1N hydrochloric acid to Keishi Ethyl 2080F, stir vigorously for 50 minutes,
The power U water screen reaction meeting is over, there is 71000 water in this sol.
The mixture was further stirred using Cab-o-sil'z 750 f, and subjected to ultra-high wave filtration, and the pH was adjusted to 4.4 with 0.1N aqueous ammonia. This sol? Inner diameter 25cmφ
Prepared in polypropylene um 10 j161,
It was covered with a lid with an open area ratio of 3% and immediately placed in a constant temperature bath at 60°C. After leaving it at 60℃ for 6 days, 10 dry gels were obtained. 11 m of these dry gels were heat treated to 1200° C. to become quartz glass.

In other words, with this method, the number of days required to prepare the dry gel can be reduced to 6 days, and the walking distance can be increased to 100%.
c.

Example 5 The procedure was carried out in the same manner as in Example 4, but the IA degree (dry gel creation temperature) of the constant temperature oven and the opening ratio of the lid were changed to 1 cNfi as shown in Table 1.The number of days required to create the dry gel at that time was The yield of dry gel preparation is shown in 9 & 1.

Table 1 1i 17) h C) Min 7) It can be seen that, depending on the dry gel preparation temperature, there is an upper limit to the aperture ratio at a yield of 9'1100%. In other words, it must be less than 6 inches at 60℃, 4% at 50℃, and 7% at 40℃.
H. At 50°C, it must be less than 10°.

In such a pattern of dry gel 1' cutting, D,
Drive 11 creation date Morimata 76 days with yield 100chi, U
I can do it at once.

1. Dry gel creation temperature: 70°C. Air bubbles are present in the gel. Since these air bubbles are mostly only on the surface, when creating the dry gel at this temperature, It is also sufficiently practical that it is possible to maintain a high temperature of 670'C or higher for up to 6 days.

None of these dry gels can be mixed with sintered quartz glass.

implementation? 1j6 Perform in the same manner as in row 4, sol r inner diameter of PH4,4 25c
The mixture was placed in 10 mφ polypropylene containers. It was left to stand under the conditions shown in Table 2 to form a dry gel. That is, 1. A lid with an opening ratio of 10 was used, left at room temperature for several days to shrink, replaced with a lid with an opening ratio of 2, and heated to various drying tFa degrees. Leave it for a specified number of days to obtain a dry gel at 7C.

The total yield at that time is shown in Table 2.

In this way, if you gel at room temperature, shrink to some extent at room temperature, heat it to a high temperature and put it on a drying path, you can achieve a yield of 9 to 100%, and the dry gel will last for several days. 6 pieces of short wood can be made on the 8th.

By heating and sintering the thus obtained dry gel at 1200° C., it can be made into quartz glass.

Example 7 Performed in the same manner as Example 4, with a pH of 4.4 and a sol grape inner diameter of 23c.
The mixture was placed in a polypropylene container 101 having a diameter of mφ. These were left under the conditions shown in Table 6 to form a dry gel.

In other words, the lid kL has an opening ratio of 2 to 5%, (if the opening ratio is less than 2, it will take too long to create a dry gel, and if the opening ratio is 5% or more, the yield of dry gel creation will decrease). [It gets worse.] It turns into a kelp, settles, and collapses when heated, then it is heated to a high temperature and then dried and treated with dry gel.

In this way, the gelation and retention of the pongee was confirmed.
2.9, Dry gel 113 days 4 days 11nJ 'E
As shown in Table 6 above, we have shown examples of warm programs with ridge patterns. Temperature program of pattern? Even when used, it is possible to shorten the number of days required for dry gel production and achieve a yield rate of nearly 100%.

In this way, by using 10,000 liters of quartz glass according to the present invention, the dry gel can be produced in a few days, and therefore the quartz glass can be produced in a short period of time.

At the same time, the production cost of quartz glass can be further reduced because the yield can be kept low. , furnace LB control, laboratory equipment, etc.) and 1, because conventional quartz glass could not be used at commercial prices!
l! 1-, it greatly contributed to f! ,/).

[Brief explanation of the drawing]

lj! Figure 1 shows dry gel 1 in the production method of the present invention.
It is a container for the preparation, 1 is a hole, 2 is a lid, the filter is a container made of holiflopyrene, and 4 is the number of sol baths. Figure 2 shows a container for making dry gel without a lid. 1 indicates poor condition with no lid, 2 indicates polypropylene,! ! '6 vessel, 6 VJ, Sol de Ana.

Claims (1)

[Claims] (Creation of dry gel in the low-temperature synthesis method of silica glass by sol-gel method using 11 gold m alkoxide as ultrafine powder bed silica raw material and VA Himesu with a sol pH of 4 to 6) Sometimes, the lid has at least one or more through holes,
Furthermore, a method for producing quartz glass characterized by leaving it at a high temperature higher than room temperature. (2) In a lid with a through hole, the ratio of the area of the through hole to the entire lid (opening ratio) is 50% or less.
A method for producing quartz glass according to claim 1. (3) The method for manufacturing quartz glass according to claim 1, characterized in that the temperature at which the glass is left to stand is between room temperature and 100°C. (4) Kelization is carried out at a certain temperature from room temperature to 60°C,
Leave the gelatinizer at a certain temperature between 60℃ and 100℃1.
After shrinking the bale, let it dry again from its shrinkage temperature to a temperature of 300℃ with reeds. )
The method for producing quartz glass described in (5) The heating speed from the gelling temperature to the yield temperature is 2°C/min or less, and the heating rate from the rice harvesting temperature to the drying temperature is 73°C/min. The method for manufacturing quartz glass as set forth in claim 4.