JPH08157227A - Production of capillary and capillary - Google Patents

Abstract

PURPOSE: To obtain a capillary having an extremely small diameter, easy to handle and appropriate to be used as a Kerr medium element by sealing a nonlinear medium into the capillary by thermally drawing a glass tube with the inner diameter, outer diameter and ratio of the inner diameter to outer diameter specified. CONSTITUTION: A glass tube having 0.1-3mm inner diameter and 2-50mm outer diameter and with the ratio of the inner diameter to outer diameter controlled to 0.002-0.75 is thermally drawn to produce a capillary. A glass tube consisting of a glass having <=850 deg.C softening temp. is preferably used as the glass tube. A lead-glass tube is preferably used especially when a capillary for the Kerr medium element to be used for an optical Kerr shutter, etc., is produced. Further, when the glass tube is thermally down, the glass tube is preferably heated so that the viscosity of the glass for the tube is controlled to 10<3.5> -10<7.5> ps. A glass tube produced by inserting a glass forming material into a specified die, heating, softening and then extrusion-molding the material is appropriately used as the glass tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capillary manufacturing method and a capillary, and more particularly to a glass capillary manufacturing method and a capillary suitable for use as a Kerr medium element by enclosing a nonlinear medium therein. The present invention also relates to a method of manufacturing a glass tube suitable for use as a material for the capillary when manufacturing the glass capillary.

[0002]

2. Description of the Related Art An all-optical optical switch using an optical gate is considered to be one of the key devices for future information / communication systems, and research and development of an optical gate optical switch such as an optical car shutter is underway. The optical car shutter is a deflector,
The probe light and the gate pulse light are made incident on the optical system that combines the Kerr medium element, the analyzer, etc., and the change of the refractive index of the nonlinear medium by the gate pulse light is used to output the probe light corresponding to the time waveform of the gate pulse. It seeks to obtain light. Here, as the Kerr medium element, an organic material having a large nonlinear optical effect, for example, 4- (N, N-diethylamino) -β-nitrostyrene (hereinafter, DEAN) is used.
Abbreviated as ST) and 4'-dimethylamino-N-methyl-4-stilbazolium methylsulfate (hereinafter D
It is known that a charge transfer type low molecular weight material such as MSM) is dissolved in an organic solvent and the resulting solution is enclosed in a glass capillary.

As the glass capillaries for the above-mentioned applications, those obtained by heating and stretching a quartz glass tube manufactured by a chemical method such as CVD are known, and the manufacturing method thereof is special. The method disclosed in Japanese Patent Laid-Open No. 21537/1992 is known. The method disclosed in the above-mentioned publication is to obtain a capillary by drawing an inert gas such as N ₂ gas into a glass tube made of quartz glass with one end open and drawing the glass tube. In this method, by adjusting the temperature and / or the pulling speed of the heating furnace, the ratio of the inner diameter to the outer diameter (the value of the inner diameter / outer diameter, hereinafter referred to as the inner / outer diameter ratio) in the finally obtained capillary is adjusted. To do. And in the above publication, the inner diameter is 5 m.
m, an outer diameter of 18 mm or 22 mm, using a quartz glass tube as a preform, an inner diameter of about 5 to 50 μm,
Capillary with an outer diameter of about 200 μm (ratio of inner to outer diameter is 0.02
About 5 to 0.25) is specifically described.

[0004]

However, it is desired to improve the efficiency of, for example, an optical car shutter, and for that purpose, lead glass, which has excellent optical properties, is used instead of quartz glass and the inner diameter is It is necessary to obtain a smaller capillary and use this capillary to construct a Kerr medium element. In addition, in order to reduce the driving power,
It is desired to make the inner diameter of the capillary smaller. Capillaries used in optical car shutters are specifically required to have an inner diameter of less than 1 μm to several μm, while an outer diameter of 250 μm or more is required for easy handling. The inner / outer diameter ratio is about 0.0002 to 0.02.

Since glass other than quartz glass cannot be manufactured by the CVD method, capillaries satisfying the above requirements cannot be manufactured by the conventional method. Further, in the conventional method, when a glass tube made of quartz glass is drawn to obtain a capillary, an inert gas must be introduced into the glass tube, so that the manufacturing process is relatively complicated.

A first object of the present invention is to provide a capillary manufacturing method capable of manufacturing a capillary having an extremely fine inner diameter and easy to handle by using a glass other than quartz glass by a relatively simple process. To provide.

A second object of the present invention is to provide a capillary which has an extremely fine inner diameter and is easy to handle.

The third object of the present invention is to provide the above-mentioned first object.
It is an object of the present invention to provide a method for producing a glass tube suitable for use as a material for a capillary when producing a capillary by the method for achieving the above object.

[0009]

According to the method of manufacturing a capillary of the present invention which achieves the first object, the inner diameter is 0.1 to 3
mm, outer diameter 2 to 50 mm, inner to outer diameter ratio 0.002
A glass tube of 0.75 is heated and drawn to obtain a capillary.

The capillary of the present invention which achieves the above-mentioned second object is made of glass having a softening point temperature of 850 ° C. or less, and has an inner diameter of 0.5 to 5 μm and an outer diameter of 250 to 3000.
[mu] m and the ratio of inner diameter to outer diameter is 0.0002 to 0.02.

The method of manufacturing a glass tube of the present invention which achieves the third object is manufactured by an extrusion molding method including an extrusion molding step in which a glass molding raw material is inserted into a predetermined molding die, heated and softened, and then extruded. It is characterized by doing.

The present invention will be described in detail below. First, the method of manufacturing the capillary of the present invention will be described. In this method, the inner diameter is 0.1 to 3 mm and the outer diameter is 2 as described above.
A glass tube having a diameter of -50 mm and an inner / outer diameter ratio of 0.002 to 0.75 is heated and drawn to produce a capillary. Here, the reason why the inner diameter of the glass tube is limited to 0.1 to 3 mm is that it is difficult to obtain a capillary having a desired inner diameter when the inner diameter is smaller than 0.1 mm, and the conventional method is used when the inner diameter is larger than 3 mm. This is because the inner diameter may be collapsed unless a complicated process such as introducing a gas at the time of heating and stretching is performed. The reason for limiting the outer diameter of the glass tube to 2 to 50 mm is
When the outer diameter is out of this range, it is difficult to obtain a capillary by the extrusion molding method, and it is also difficult to obtain a capillary having a desired size. The reason for limiting the inner / outer diameter ratio of the glass tube to 0.002 to 0.75 is that if the inner / outer diameter ratio is smaller than 0.002, it becomes difficult to obtain a capillary with a desired wall thickness, and 0 .75
If it is larger than the above range, the inner diameter may be collapsed during the heat drawing. As the glass tube used in the method for producing a capillary of the present invention, one having an inner diameter of 0.1 to 1.0 mm, an outer diameter of 8 to 20 mm, and an inner to outer diameter ratio of 0.005 to 0.125 is particularly preferable.

The above glass tube is made of glass having a softening point temperature of 850 ° C. or lower, such as lead glass, phosphate glass, borosilicate glass, aluminosilicate glass and non-oxide glass. In particular, when manufacturing a capillary for a Kerr medium element used in an optical Kerr shutter or the like, a lead glass is preferable. A glass tube made of the above glass and having the above-mentioned inner diameter, outer diameter and inner-outer diameter ratio can be obtained by, for example, the method for producing a glass tube of the present invention described later.

In the method for manufacturing a capillary of the present invention, the above-mentioned glass tube is heated and drawn to obtain a capillary. The heat drawing at this time can be performed in the same manner as the drawing at the time of manufacturing the optical fiber, and it is not necessary to introduce gas into the glass tube. The inner diameter and outer diameter of the finally obtained capillary are selected by selecting the inner diameter and outer diameter of the glass tube to be heated and drawn, and also by adjusting the heating temperature and the drawing speed or drawing tension when the glass tube is heated and drawn. It can be controlled by Therefore, the heating temperature and the drawing speed or drawing tension during heating and drawing are the inner diameter of the glass tube used as the material of the capillary, the outer diameter and the inner-outer diameter ratio, and the inner diameter of the capillary to be produced,
It is appropriately selected according to the outer diameter and the inner-outer diameter ratio.

For example, a glass tube having the above-mentioned inner diameter, outer diameter and inner-outer diameter ratio is heated and drawn to have an inner diameter of 0.5 to 5 μm.
m, outer diameter 250 to 3000 μm, inner / outer diameter ratio 0.0002
In order to obtain a capillary of 0.02 to 0.02, the glass tube is heated to a temperature at which the viscosity of the material glass of the glass tube is 10 ^3.5 to 10 ^7.5 ps, and 0.05 to 5.0 mm /
It is preferable to heat and draw at a drawing speed of 5 minutes or a drawing tension of 5 to 50 g, and in particular, the glass tube is heated to a temperature at which the viscosity of the material glass of the glass tube is 10 ^4.5 to 10 ^6.5 ps, and 0.1 to 3 Stretching speed of 0.0 mm / min or 8
It is preferable to heat and stretch with a stretching tension of -40 g.

According to the method for manufacturing a capillary of the present invention in which the above-mentioned glass tube is heated and drawn as described above, a capillary having an extremely fine inner diameter and easy to handle is manufactured using a glass other than quartz glass. It becomes possible to do.
The manufacturing process at this time is relatively simple because it is not necessary to introduce gas into the glass tube.

Next, the capillary of the present invention will be described. As described above, the capillary of the present invention is made of glass having a softening point temperature of 850 ° C. or lower, and has an inner diameter of 0.5 to 5 μm.
m, outer diameter is 250 to 3000 μm, and inner / outer diameter ratio is 0.00
It is characterized by being 02 to 0.02. Here, as specific examples of the glass having a softening point temperature of 850 ° C. or lower, lead glass, phosphate glass, borosilicate glass,
Examples thereof include aluminosilicate glass and non-oxide glass. A capillary made of lead glass is particularly preferable as a capillary for a Kerr medium element used in an optical Kerr shutter or the like.

The reason why the inner diameter of the capillaries of the present invention is limited to 0.5 to 5 μm is that it is difficult to manufacture an inner diameter of less than 0.5 μm, and an inner diameter of more than 5 μm is used in an optical shutter or the like. This is because it is difficult to reduce the driving power of the element even when it is used as a capillary for a Kerr medium element. In addition, the outer diameter of the capillary is 250
The reason why it is limited to ˜3000 μm is that if the outer diameter is less than 250 μm, the wall thickness of the capillary becomes too thin, making it difficult to handle, and if it exceeds 3,000 μm, it is not practical to manufacture. The reason for limiting the inner / outer diameter ratio of the capillaries to 0.0002 to 0.02 is that if the inner / outer diameter ratio is less than 0.0002, it is difficult to manufacture even if the inner and outer diameters are within the above ranges. This is because it is difficult to handle, and there is no case where the inner diameter and the outer diameter exceed 0.02 when the inner diameter and the outer diameter are within the above ranges. In the capillary of the present invention, the inner diameter is 1 to 3 μm, the outer diameter is 250 to 2500 μm, and the inner to outer diameter ratio is 0.0004 to 0.
012 is particularly preferable.

The capillary of the present invention having the above-mentioned inner diameter, outer diameter, and inner-outer diameter ratio has an extremely small inner diameter of 0.5 to 5 μm, and therefore, a Kerr medium element for obtaining an optical Kerr shutter with low driving power. Suitable as a capillary for
Among them, those made of lead glass are suitable as capillaries for Kerr medium elements for obtaining an optical Kerr shutter having high efficiency and low driving power. Further, the capillary of the present invention has an outer diameter of 250 to 3000 μm and an inner / outer diameter ratio of 0.0002 to
Since it is as thick as 0.02, it is easy to handle.

Next, a method of manufacturing the glass tube of the present invention will be described. The method for producing a glass tube of the present invention is a method suitable for producing a glass tube used in the method for producing a capillary of the present invention described above, and in the method, as described above, the glass forming raw material is inserted into a predetermined forming die. Then, a glass tube is manufactured by an extrusion molding method including an extrusion molding step of extruding after heating and softening. Here, the glass forming raw material includes glass having a softening point temperature of 850 ° C. or lower, such as lead glass, phosphate glass, borosilicate glass, aluminosilicate glass and non-oxide glass. It is preferable to use a glass billet. In particular, when manufacturing a glass tube for obtaining a capillary for a Kerr medium element used in an optical Kerr shutter or the like, it is preferable to use a glass billet made of lead glass.

In the extrusion molding step, the above-mentioned glass forming raw material is inserted into a predetermined molding die, heated and softened, and then extruded. The "predetermined molding die" here means a predetermined molding die. It means an extrusion mold equipped with a nozzle having a bore, a mandrel having a predetermined diameter, a container for containing a glass billet, and a pressure plunger. The nozzle diameter and mandrel diameter in this molding die are appropriately selected according to the inner diameter and outer diameter of the desired glass tube and the viscosity of the glass forming raw material at the time of extrusion, and the inner diameter of the container and the diameter of the plunger are used as the forming raw material. It is determined by the size of the glass billet used.

The viscosity of the glass forming raw material at the time of extrusion molding is preferably 10 ⁶ to 10 ¹¹ ps when the glass tube used in the method for producing a capillary of the present invention described above is obtained. The viscosity of the glass forming raw material is 10 ⁶ to 10
^{When the} pressure is ¹¹ ps, the nozzle diameter in the above mold should be within ± 15% of the outer diameter of the target glass tube, and the mandrel diameter should be within + 60% of the inner diameter of the target glass tube. Each is preferred.

The viscosity of the glass forming raw material at the time of extrusion is 10 ^7.6 to obtain the desired glass tube with high dimensional accuracy.
Particularly preferably, it is set to 10 ¹¹ ps. In addition, the extrusion speed (movement speed of the plunger) is approximately 0.8 to 3.5 mm.
It can be appropriately selected within the range of / minute.

The desired glass tube is obtained by extruding the above-mentioned glass forming raw material by using the above-mentioned forming die as described above and allowing the extruded product obtained in this extrusion forming step to cool. However, in order to obtain a glass tube with higher dimensional accuracy, it is preferable to provide a cooling step for forcibly cooling the extruded product. This cooling step is preferably performed so that the temperature decrease rate of the extruded product is 8 to 20 ° C./minute, and particularly preferably 10 to 15 ° C./minute. Further, if dust or the like adheres to the surface of the extruded product in the cooling step, the strength of the finally obtained glass tube is likely to deteriorate, so that the extruded product is cooled by cooling the extruded product with a clean cooling gas (for example, N 2 ₂ gas, clean dry air, etc.) is preferably sprayed.

According to the method for producing a glass tube of the present invention, which can include the above-mentioned extrusion molding step as an essential step and the above-described cooling step as an optional step, the method for producing a capillary of the present invention described above A glass tube suitable for use can be easily obtained.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. Examples 1 to 4 (Production of glass tube) First, as a glass forming raw material, a diameter of 50 mm and a height of 50 m.
m high columnar glass (lead content 75 wt%,
A billet having a softening point temperature of 520 ° C.) was prepared, and this high-lead glass billet was inserted into the cylindrical container 2 of the extrusion molding die 1 shown in FIG. The container 2 is erected, and a band heater 3 for heating the container 2 is mounted around the container 2. A nozzle 4 having a diameter of 15 mm is arranged on the lower end side inside the container 2, and a mandrel 5 having a diameter of 1 mm (diameter at the center of the opening) is arranged at the center of the opening of the nozzle 4. It is set up. The diameter of the mandrel 5 increases as it goes upward from the center of the opening. The horizontal cross section of the upper part of the mandrel 5 has a cross shape, and the end of the cross-shaped portion is locked to the upper part of the nozzle 4.

Next, the plunger 6 (see FIG. 1) was placed above the high lead glass billet inserted into the container 2, and the container 2 was heated by the heater 3 in this state. The heating temperature of the container 2 by the heater 3 at this time was changed for each example as shown in Table 1 so that the viscosity of the high lead glass billet (the viscosity after heating) would be the value shown in Table 1.

After the heating temperature shown in Table 1 was maintained for about 1 hour, the plunger 6 was heated to 50 to 4 while continuing heating.
A load was applied between 50 kg / cm ² and the glass forming raw material softened at an average extrusion rate (downward velocity of the plunger 6) of 2.5 mm / min was extruded from the nozzle 4. At this time, the glass forming raw material 10 softened by heating (see FIGS. 1 and 2).
(See (a)) is pushed downward by the plunger 6, and since the horizontal cross section of the location at the upper part of the mandrel 5 has a cross shape, it is divided into four (see FIG. 2 (b)), and then the mandrel 5 is surrounded. Then, they are merged (see FIG. 2C), and thereafter, they are extruded from the opening of the nozzle 4 to the outside.
The extruded product 11 extruded in this manner is shown in FIG.
It has a tubular shape as shown in (d). The extrusion mold 1 shown in FIG. 1 is provided with a cylindrical clean cold air camper 7 that is continuously provided at the end on the nozzle 4 side. A large number of through holes 8 are provided on the wall surface of the clean cold air camper 7.
If necessary, clean cooling gas from a clean cold air source (not shown) is supplied to the inside of the clean cold air camper 7 from the through hole 8.

After that, the extruded product 11 was naturally cooled to room temperature to obtain a glass tube having a length of 400 to 600 mm. With respect to the glass tubes obtained in each example, the inner diameter and the roundness thereof were measured with an optical microscope, and the outer diameter and the roundness thereof were measured with a micrometer. Also,
The inner / outer diameter ratio was determined. Table 1 shows the results. In addition,
The inner diameter referred to in the present specification means an average value obtained from values measured for all directions orthogonal to the length direction at any number of positions in the length direction of the glass tube, and the circularity of the inner diameter. Means the average value of the values obtained by dividing the difference between the maximum value and the minimum value of the measured values at the above-mentioned points by 2. Further, the outer diameter referred to in the present specification means an average value obtained from the values measured in all directions orthogonal to the length direction at any number of positions in the length direction of the glass tube, and the outer diameter. The roundness of means the average value of the values obtained by dividing the difference between the maximum value and the minimum value of the measured values at the above points by 2.

Example 5 to Example 6 (Manufacture of Glass Tube) A glass billet having the same shape and composition as the high lead glass billet used in Example 1 to Example 4 was used as a glass forming raw material and shown in FIG. After extrusion molding with the extrusion molding die 1, the extruded product was naturally cooled to room temperature to obtain target glass tubes. At this time, in Example 5, the heating temperature of the container 2 was 610 ° C. (the viscosity of the glass forming raw material was 10 ⁵ ps), and in Example 6, the heating temperature of the container 2 was 460 ° C. (the viscosity of the glass forming raw material was 10 ¹² ps). )
And In addition, the average extrusion rate was 2.
Although it was set to 5 mm / min, due to the difference in viscosity of the glass forming raw material,
The load applied to the plunger 6 is 35 to 250 in the fifth embodiment.
It varies between kg / cm ² , and in Example 6, 365-90.
It varied between 0 kg / cm ² . For each glass tube obtained as described above, the inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity were measured in the same manner as in Examples 1 to 4. Further, the inner-outer diameter ratio was determined. Table 1 shows the results.

[0031]

[Table 1]

As shown in Table 1, Examples 1 to 6
The inner diameter of each glass tube obtained in 1. is 0.75-0.86 m
m, outer diameter 14.8 to 16.5 mm, inner-outer diameter ratio 0.0
It was 46-0.058. Although these glass tubes were extruded from the same composition of glass forming raw material using the same extrusion mold, the inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity were slightly different. This is mainly due to the difference in viscosity of the glass forming raw materials during extrusion molding.

The glass tube of Example 5 obtained by setting the viscosity of the glass forming raw material to 10 ⁵ ps had a low forming viscosity, so that the shape retention of the extruded product was relatively low. It was inferior to each glass tube in the example. Also,
Example 6 obtained by setting the viscosity of the glass forming raw material to 10 ¹² ps
In the glass tube of No. 1, since the molding viscosity was high, the frictional resistance at the time of extrusion molding was large, and some bending was observed in the obtained glass tube, and the roundness of each of Examples 1 to 4 was found. It was inferior to the glass tube. From the above Examples 1 to 6, it is understood that it is preferable to set the viscosity of the glass forming raw material at the time of extrusion molding to 10 ⁶ to 10 ¹¹ ps in order to obtain a glass tube having high circularity.

Examples 7 to 10 (Manufacture of glass tubes) The same shape as the high lead glass billets used in Examples 1 to 4, the lead content is about 50 wt% and the softening point temperature is 55.
Extrusion molding having the same structure as the extrusion molding die 1 shown in FIG. 1 except that a glass billet made of lead glass at 5 ° C. is used as a glass forming raw material and the nozzle 4 has a diameter of 25 mm and the mandrel 5 has a diameter of 0.65 mm. After extrusion molding with a mold, the extruded product was naturally cooled to room temperature to obtain target glass tubes. The heating temperature of the container 2 at this time, as shown in Table 2, is 10 ⁶
605 ° C., 575 ° C., 535 in order to obtain 10 ¹¹ ps
Or 520 ° C. Further, in each of the examples, the average extrusion speed was 2.8 mm / min, and the load applied to the plunger 6 varied between 90 and 600 kg / cm ² . For each glass tube obtained as described above, Example 1
In the same manner as in Example 4, the inner diameter, the inner diameter circularity, the outer diameter, and the outer diameter circularity were measured. Further, the inner-outer diameter ratio was determined. Table 2 shows the results.

Examples 11 to 12 (Production of glass tube
Structure)  Same as the lead glass billet used in Examples 7 to 10.
A glass billet of one shape and the same composition
Extrusion composition used in Examples 7 to 10
After extrusion molding with an extrusion mold of the same structure as the
The molded glass is left to cool naturally to room temperature and the desired glass tube
Respectively obtained. At this time, in the eleventh embodiment, the container 2
Heating temperature of 645 ° C (viscosity of the glass forming raw material is 10^Five
ps), and the heating temperature of the container 2 is 5 in Example 12.
05 ° C (viscosity of glass forming raw material is 10¹²ps).
Further, in any of the examples, the average extrusion rate was 2.8 mm /
Minutes For each glass tube obtained as described above,
Then, in the same manner as in Examples 1 to 4,
The roundness, the outer diameter, and the roundness of the outer diameter were measured. Also, within
The outer diameter ratio was determined. Table 2 shows the results.

[0036]

[Table 2]

As shown in Table 2, Examples 7 to 1
The inner diameter of each glass tube obtained in 2 is 0.43 to 0.53 m
m, outer diameter 24.2 to 25.6 mm, inner-outer diameter ratio 0.0
It was 168-0.0219. The difference in inner diameter, inner diameter circularity, outer diameter and outer diameter circularity between each glass tube is
Similar to Examples 1 to 6, this is mainly due to the difference in the viscosity of the glass forming raw material at the time of extrusion molding.

Each of the glass tubes of Examples 7 to 10 had good dimensional accuracy and inner and outer surface accuracy, and had excellent inner surface accuracy. On the other hand, for the same reason as in Example 5, the dimensional accuracy of the glass tube of Example 11 obtained by setting the viscosity of the glass forming raw material to 10 ⁵ ps is from Example 7 to Example 10.
And it was inferior to each glass tube of Example 12. For the same reason as in Example 6, the viscosity of the glass forming raw material was set to 1
The roundness of the glass tube of Example 12 obtained as 0 ¹² ps was inferior to that of each of the glass tubes of Examples 7 to 10.

Examples 13 to 16 (Production of Glass Tube) Diameter 3 made of phosphate glass having a softening point temperature of 650 ° C.
Extrusion having the same structure as the extrusion molding die 1 shown in FIG. 1 except that a glass billet having a height of 5 mm and a height of 60 mm was used as a glass forming raw material, the nozzle 4 had a diameter of 11.6 mm, and the mandrel 5 had a diameter of 0.28 mm. After extrusion molding with a molding die, the extruded product was naturally cooled to room temperature to obtain target glass tubes. The heating temperature of the container 2 at this time, as shown in Table 3, is 1
740 ° C., 670 ° C., 6 to obtain 0 ⁶ to 10 ¹¹ ps
The temperature was 40 ° C or 620 ° C. In each of the examples, the average extrusion rate was 2.8 mm / min, and the load applied to the plunger 6 varied between 150 and 650 kg / cm ² . For each glass tube obtained as described above, the inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity were measured in the same manner as in Examples 1 to 4. Further, the inner-outer diameter ratio was determined. Table 3 shows the results.

Examples 17 to 18 (manufacturing glass tubes
Structure)  Same as the glass billet used in Examples 13 to 16.
A glass billet of one shape and the same composition
Extruded as used in Examples 13 to 16
After extrusion molding with an extrusion mold with the same structure as the mold
Allow the extruded product to cool naturally to room temperature to obtain the desired glass
Each tube was obtained. At this time, in Example 17, the container
The heating temperature of 2 is 800 ° C (the viscosity of the glass forming raw material is 10
^Fiveps), in Example 18, the heating temperature of the container 2 is
600 ° C (viscosity of glass forming raw material is 10¹²ps)
Was. Also, in any of the examples, the average extrusion speed was 2.8 m.
m / min. In each glass tube obtained as described above
About the inner diameter and inner diameter in the same manner as in Examples 1 to 4,
The roundness of the diameter, the outer diameter, and the roundness of the outer diameter were measured. Well
Also, the inner-outer diameter ratio was determined. The results are shown in Table 3.

[0041]

[Table 3]

As shown in Table 3, the inner diameters of the glass tubes obtained in Examples 13 to 18 were 0.1240 to 0.
The outer diameter was 1252 mm, the outer diameter was 11.8 to 12.3 mm, and the inner / outer diameter ratio was 0.0102 to 0.0106. The difference in the inner diameter, the inner diameter circularity, the outer diameter, and the outer diameter circularity between the glass tubes is mainly the same as in Examples 1 to 6 in that the viscosity of the glass forming raw material at the time of extrusion molding This is due to the difference.

In each of the glass tubes of Examples 13 to 16, the dimensional accuracy and the inner and outer surface accuracy were good, and especially the inner surface accuracy was extremely excellent. On the other hand, for the same reason as in Example 5, the dimensional accuracy of the glass tube of Example 17 obtained by setting the viscosity of the glass forming raw material to 10 ⁵ ps is better than that of each of the glass tubes of Examples 13 to 16 and 18. It was inferior. Further, for the same reason as in Example 6, the dimensional accuracy of the glass tube of Example 18 obtained by setting the viscosity of the glass forming raw material to 10 ¹² ps was inferior to that of each of the glass tubes of Example 13 to Example 16.

Examples 19 to 22 (Manufacture of glass tubes) Glass billets having the same shape and composition as the glass billets used in Examples 7 to 10 were used as glass forming raw materials, and the nozzle 4 had a diameter of 15 The target glass tube was obtained by an extrusion mold having the same structure as the extrusion mold used in Examples 7 to 10 except that the diameter of the mandrel 5 was 0.0 mm and the diameter of the mandrel 5 was 0.6 mm. At this time, the heating temperature of the container 2 is 535 ° C. in any of the examples.
(The viscosity of the glass forming raw material was 10 ⁹ ps), and the average extrusion rate was 2.8 mm / min in all the examples. Further, in Examples 19 to 20, dry air of class 100 at 10 ° C. from a clean cold air source (spot air conditioner manufactured by Hitachi, Ltd.) through a large number of through holes 8 provided on the wall surface of the clean cold air camper 7. Was blown inside to force the extruded product to cool to room temperature at a temperature decrease rate of 13.5 ° C./min. On the other hand, in Examples 21 to 22, a clean cold air source (Hitachi Ltd.) is provided through a large number of through holes 8 provided in the wall surface of the clean cold air camper 7.
25 ° C class 100 dry air is blown into the interior of the product from a spot air conditioner manufactured by
The extrudate was forced to cool to room temperature at a ramp rate of minutes. For each glass tube obtained as described above, the inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity were measured in the same manner as in Examples 1 to 4. Further, the inner-outer diameter ratio was determined. The results are shown in Table 4.

Examples 23 to 24 (Manufacture of glass tubes) The extruded products were naturally cooled to room temperature (cooling rate was 4.8 ° C /
The desired glass tube was obtained under the same conditions as in Examples 19 to 22 except for the above. For each glass tube thus obtained, the inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity were measured in the same manner as in Examples 1 to 4. Further, the inner-outer diameter ratio was determined. The results are shown in Table 4.

[0046]

[Table 4]

As shown in Table 4, the inner diameter of each glass tube obtained in Examples 19 to 24 is 0.400 to 0.4.
The outer diameter was 25 mm, the outer diameter was 15.5 to 16.2 mm, and the inner / outer diameter ratio was 0.0258 to 0.0263. The inner diameter between the glass tubes, the circularity of the inner diameter, the difference in the outer diameter and the circularity of the outer diameter is due to the difference in the cooling rate of the extruded product, the composition of the glass forming raw material is the same, Moreover, it can be seen that if the extrusion conditions are the same, it is easier to obtain a glass tube with higher dimensional accuracy when the extruded product is forcibly cooled than when it is naturally cooled.

As is clear from Examples 1 to 24 described above, when the glass tube is manufactured by the extrusion molding method, the dimensional accuracy of the obtained glass tube mainly depends on the molding viscosity, and the glass molding is performed. The influence of raw materials is quite small. Also,
In order to obtain a glass tube having good dimensional accuracy, the viscosity of the glass forming raw material at the time of extrusion is preferably 10 ⁶ to 10 ¹¹ ps, and particularly preferably 10 ^7.6 to 10 ¹¹ ps. Furthermore, in order to obtain a glass tube having good dimensional accuracy, it is preferable to forcibly cool the extruded product. It was confirmed that the extrusion molding method can relatively easily manufacture a glass tube having a thick wall and a small inner diameter, which cannot be obtained by other methods.

Example 25 (Production of Capillary) The glass tube made of the high lead glass obtained in Example 3 (inner diameter: 0.
80 mm, outer diameter 16.0 mm) is cut into a length of 200 mm, and this (hereinafter referred to as preform) is washed, and then the above-mentioned preform 21 is heat-stretched by the heat-stretching device 20 having the configuration shown in FIG. Thus, the target capillary 22 was obtained. At this time, the preform 21
One end of the preform 21 is fixed by a chuck 24 provided above the heating furnace 23, and the other end of the preform 21 is connected to the heating furnace 2
3 was inserted inside. Chuck 24 is a lot feeder 25
It is possible to move up and down freely. The temperature in the heating furnace 23 (hereinafter referred to as the furnace temperature) was set to 635 ° C. so that the viscosity of the preform 21 was 10 ⁴ ps. Then, after the preform 21 begins to deform, the preform 21 has a diameter of 1.5 mm and an inner diameter of 3.0 μm measured by an inner and outer diameter measuring device 26 provided below the heating furnace 23. The feed rate is 5.0 mm / min,
The capillary 22 was obtained by stretching at a stretching speed of 0.6 m / min. In the heating and stretching device 20 shown in FIG. 2, the capillary 22 can be wound by the winding device 27 as needed. Further, the heating and stretching apparatus 20 shown in FIG. 2 has a coating layer made of a photocurable resin or the like and having a thickness of about 50 to 100 μm on the outer periphery of the capillary 22 as needed for the purpose of protecting the surface of the capillary 22. A coating jig 28 for forming and an ultraviolet irradiation furnace 29 for curing the above-mentioned photocurable resin are provided.
The inner diameter of the thus obtained capillary, the circularity of the inner diameter, the outer diameter and the circularity of the outer diameter were measured in the same manner as in Examples 1 to 4, and the inner diameter was 3.0 μm. The roundness was 0.02 μm, the outer diameter was 1.5 mm, the roundness of the outer diameter was 1.2 μm, and the inner-outer diameter ratio was 0.002.
Table 5 shows a list of these measurement results. The surface condition inside and outside the capillary was good.

Example 26 (Production of Capillary) The lead glass glass tube obtained in Example 9 (inner diameter 0.4
7 mm, outer diameter 25.0 mm) cut into a length of 200 mm is used as a preform 21, and the preform 21 is washed and then heated and stretched by the apparatus 2 shown in FIG.
The preform 21 was heated and stretched at 0 to obtain the target capillary 22. Heating furnace 23 at this time
The temperature inside the furnace was set to 645 ° C. so that the viscosity of the preform 21 was 10 ⁵ ps. The feed rate and the drawing rate of the preform 21 are 1.0 mm / min so that the outer diameter and the inner diameter of the capillary 22 measured by the inner / outer diameter measuring device 26 are 1.0 mm and 1.0 μm, respectively.
It was set to 0.65 m / min. When the inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity of the thus obtained capillary were measured in the same manner as in Example 25, the inner diameter was 1.0.
μm, circularity of inner diameter is 0.01 μm, outer diameter is 1.0 m
m, the circularity of the outer diameter is 1.0 μm, and the inner / outer diameter ratio is 0.
It was 001. Table 5 shows a list of these measurement results. Further, the surface condition inside and outside the capillary and the inner surface accuracy were extremely good.

Example 27 (Production of Capillary) The glass tube made of the phosphate glass obtained in Example 15 (inner diameter 0.1245 mm, outer diameter 12.0 mm) was set to 200 mm.
After cutting the preform 21 into pieces, the preform 21 is washed, and then the preform 21 is heated and drawn by the heating and drawing apparatus 20 having the configuration shown in FIG. Obtained. At this time, the temperature inside the heating furnace 23 was set to 765 ° C. so that the viscosity of the preform 21 was 10 ⁶ ps. Also,
The feed rate and the drawing rate of the preform 21 were 0.
4 mm, each with an inner diameter of 0.5 μm, 3 m
m / min and 2.8 m / min. The inner diameter, the inner diameter circularity, the outer diameter, and the outer diameter circularity of the thus obtained capillary were measured in the same manner as in Example 25. As a result, the inner diameter was 0.5 μm, and the circularity of the inner diameter was The outer diameter was 0.005 μm, the outer diameter was 0.4 mm, the circularity of the outer diameter was 0.5 μm, and the inner / outer diameter ratio was 0.00125. Thus, a product having extremely high dimensional accuracy and an extremely fine inner diameter was obtained. Table 5 shows a list of these measurement results.

Example 28 (Production of Capillary) The glass tube made of the phosphate glass obtained in Example 15 (inner diameter 0.1245 mm, outer diameter 12.0 mm) was set to 200 mm.
After cutting the preform 21 into pieces, the preform 21 is washed, and then the preform 21 is heated and drawn by the heating and drawing apparatus 20 having the configuration shown in FIG. Obtained. At this time, the temperature inside the heating furnace 23 was set to 740 ° C. so that the viscosity of the preform 21 was 10 ⁷ ps. Also,
Regarding the feed rate and the drawing rate of the preform 21, the outer diameter of the capillary 22 measured by the inner / outer diameter measuring device 26 was 2.
0 mm and an inner diameter of 5.0 μm.
It was set to 0 mm / min and 0.08 m / min. The inner diameter, the inner diameter circularity, the outer diameter and the outer diameter circularity of the thus obtained capillary were measured in the same manner as in Example 25.
The inner diameter was 5.0 μm, the inner diameter circularity was 0.025 μm, the outer diameter was 2.0 mm, the outer diameter circularity was 1.5 μm, and the inner-outer diameter ratio was 0.0025. The dimensional accuracy was slightly inferior to the capillaries obtained in No. 27. From this, it is considered that the viscosity of the preform in this example is close to the viscous limit at which stretching is possible. Table 5 shows a list of these measurement results.

[0053]

[Table 5]

[0054]

As described above, according to the method of manufacturing a capillary of the present invention, a glass other than quartz glass is used as the capillary which has an extremely small inner diameter and is easy to handle because of its large wall thickness. Can be manufactured by a relatively simple process, and the glass tube used in this method can be manufactured by the method for manufacturing a glass tube of the present invention. Further, the capillary of the present invention has an extremely thin inner diameter and is thick and therefore easy to handle. When a Kerr medium element is constructed using such a capillary, for example, high efficiency and low driving are possible. It becomes possible to provide a powerful optical car shutter.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an outline of an extrusion molding die used in Example 1.

2 (a) is a horizontal sectional view of the extrusion mold used in Example 1 taken along the line AA shown in FIG. 1, and FIG. 2 (b) is a view of the extrusion mold used in Example 1. 1 is a horizontal sectional view taken along line B-B shown in FIG. 1, (c) is a horizontal sectional view taken along line C-C shown in FIG. 1 of the extrusion molding die used in Example 1,
(D) shows the extrusion mold used in Example 1 shown in FIG.
It is a horizontal sectional view when it cuts by the D line.

FIG. 3 is a schematic view of a heating and stretching apparatus used in Example 25.

[Explanation of symbols]

 1 Extrusion Mold 2 Container 3 Heating Band Heater 4 Nozzle 5 Mandrel 6 Plunger 7 Clean Cold Air Camper 10 Softened Glass Molding Material 11 Extruded Product 20 Heat Stretching Device 21 Preform 22 Capillary 23 Heating Furnace 24 Chuck 25 Preform Feed Machine 26 Inner and outer diameter measuring instrument 27 Winding device 28 Coating jig 29 Ultraviolet irradiation furnace

Claims (8)

[Claims] 1. An inner diameter of 0.1 to 3 mm and an outer diameter of 2 to 50
A method for producing a capillary, wherein a glass tube having an inner diameter / outer diameter ratio of 0.002 to 0.75 is heated and drawn to obtain a capillary. 2. The method according to claim 1, wherein, when the glass tube is heated and drawn, the glass tube is heated so that the viscosity of the material glass of the glass tube is 10 ^3.5 to 10 ^7.5 ps. 3. The method according to claim 1, wherein a glass tube having a softening point temperature of 850 ° C. or lower is used. 4. A glass having a softening point temperature of 850 ° C. or lower, having an inner diameter of 0.5 to 5 μm and an outer diameter of 250 to 3000.
A capillary characterized in that the inner and outer diameter ratio is 0.0002 to 0.02. 5. The capillary according to claim 4, which is used as a Kerr medium element by enclosing a nonlinear medium therein. 6. A method for producing a glass tube used in the method according to claim 1, wherein the glass forming raw material is inserted into a predetermined forming die, heated and softened, and then extruded. A method for manufacturing a glass tube, characterized by being manufactured by an extrusion molding method including an extrusion molding step. 7. The method according to claim 6, wherein in the extrusion molding step, the glass forming raw material inserted into a predetermined forming die is heated so that the viscosity of the glass forming raw material becomes 10 ⁶ to 10 ¹¹ ps. 8. The method according to claim 6 or 7, comprising a step of cooling the extruded product obtained in the extrusion molding step.