TW202311180A - Column glass, method for producing column glass, and device for producing column glass - Google Patents

Abstract

The purpose of the present invention is to provide: a method whereby a columnar glass having a small cross-sectional area can be manufactured without polishing or abrading the side surfaces; a manufacturing device therefor; and a columnar glass obtained by the manufacturing method. A method for manufacturing columnar glass from a glass material includes: a step for preparing a cylindrical mold having a first opening and a second opening that communicates with the first opening and has an opening area smaller than that of the first opening; a step for disposing a glass material in the cylindrical mold; a step in which the prepared glass material is heated and softened; a step in which a first mold having a glass pressing surface is inserted from the first opening so that the glass pressing surface is brought into contact with the glass material; and pressing the softened glass material by moving at least one of the first mold and the cylindrical mold, and discharging the glass from the second opening to form columnar glass.

Description

Columnar glass, manufacturing method of columnar glass, and manufacturing apparatus of columnar glass

The invention relates to columnar glass with a small cross section, a columnar glass manufacturing method and a columnar glass manufacturing device.

Optical glass is generally available as ribbon material or as elongated sheet material known as E-bars, which are formed into glass articles of defined shape. Specifically, first, a small glass piece with a relatively simple shape is produced with the same glass volume as the target object, and then the small glass piece is precisely molded. From the viewpoint of industrial convenience, it is desired to be able to mass-produce products of the same shape for optical glass, and therefore, it is desired to be able to mass-produce small glass pieces of the same shape even when producing such small glass pieces.

As an example of the method for manufacturing such a small glass piece, the following method can be cited: prepare a long and slender rectangular parallelepiped glass whose sides are sufficiently longer than the other sides, mold the rectangular parallelepiped glass into a cylindrical round rod glass, and then, It is cut in the direction perpendicular to the height of the cylinder to obtain small glass pieces in the shape of a flat plate (referred to here as a disk or cylinder). Plate-like small glass pieces are preferably used as a material for optical lenses due to their similarity in shape.

As a method of manufacturing such a flat glass platelet, the method of patent document 1 is mentioned, for example. Patent Document 1 discloses "a manufacturing method of a lens, which is characterized in that: a glass block heated to a temperature above the softening temperature and below the flow temperature is placed between three or more rollers rotating in parallel to the same direction, and formed into a A glass round rod of a prescribed diameter that can be sandwiched based on the interval of the rotating rollers, and then the glass round rod is cut, shaped, and polished to form a lens with a prescribed radius of curvature."

In addition, Patent Document 2 discloses "a method of manufacturing a glass round rod, which is characterized in that a glass material whose surface is heated to a viscosity below ¹⁰¹⁰ poise is moved on a guide slope (chute) to be introduced into mutually parallel arrangements and On a plurality of rollers rotating in the same direction, the guide slope (chute) is arranged parallel to the rotation axis of the roller, and the glass material is rotated in the opposite direction to the rotation direction of the roller, and the glass The material is formed into a round rod shape with a circular cross section, and the movement of the glass material on the guide inclined surface (chute) is performed by rolling down the glass material along the guide inclined surface (chute). ".

Patent Document 3 discloses "a method of manufacturing a small piece of glass material for lenses, which is characterized in that when manufacturing a plurality of small pieces of glass material for lenses from a glass rod, a glass circle is inserted between two rollers rotating in the same direction. Rod, reduce the distance between the two rollers, squeeze the glass round rod heated to above the softening temperature from both sides, and set a plurality of flanges at equal intervals in the axial direction on at least one of the two rollers. The blade simultaneously forms a plurality of grooves in the circumferential direction on the glass rod, and then cuts each groove of the glass rod to form a small piece of glass material of equal weight suitable for the lens." [Prior art literature] [Patent Document]

Patent Document 1: Japanese Patent Application Laid-Open No. 54-117514; Patent Document 2: Japanese Patent Application Laid-Open No. 2000-16822; Patent Document 3: Japanese Patent Application Laid-Open No. 2002-114532.

[Problem to be solved by the invention]

As shown in Patent Documents 1 to 3, development of a method for producing round rod glass (hereinafter, also referred to as round rod glass) as a material of a plate-shaped small glass piece is widely underway. On the other hand, there is a great demand for downsized glass products as glass products, and in the field of optical lenses, reduction in the diameter of lenses is also required. If the cross-sectional diameter of the round rod glass as the optical lens material can be made close to the diameter of the optical lens as the final product, the time and amount of cutting the glass on the side of the round rod glass can be reduced, so the glass manufacturing cost can be suppressed, and It is possible to suppress the waste amount of glass slag (swarf) discharged along with the cutting of glass, which is also beneficial to the environment.

Patent Document 1 does not describe the diameter of the round rod glass immediately after the round rod is formed. Furthermore, although a round rod glass having a diameter of 6 mm is disclosed in paragraph [0061] of Patent Document 2, a round rod glass having a diameter smaller than this is not disclosed. Also, although a round rod glass having a diameter of 7 mm is disclosed in paragraph [0029] of Patent Document 3, a round rod glass having a diameter smaller than this is not disclosed. In addition, as mentioned above, Patent Documents 1 to 3 do not disclose round rod glass of 6 mm or less, because a round rod glass of 6 mm or less (for example, 3.5 mm or less) cannot be produced only by the technology of Patent Documents 1 to 3 . In the case of forming with three rollers, when the diameter of the rollers is 40mm, only a minimum 6.5mm round rod glass can be produced structurally, and when the roller diameter is 20mm, only a minimum 3.5mm round rod glass can be produced structurally . However, it is considered that when the diameter of the roll is 20 mm, the roll itself is damaged by the pressure. It is conceivable to shorten the length of the roll to withstand the pressure, but in such a case, it is impossible to manufacture a long round rod glass. Therefore, in the inventions described in Patent Documents 1 to 3, it is impossible to manufacture a round rod glass having a diameter of 3.5 mm or less and a predetermined length.

Moreover, in the techniques of Patent Documents 1 to 3, only round rod glass with a circular cross section can be manufactured, and if columnar glass with a triangular or quadrangular cross section can also be manufactured, the application range of the manufacturing device will become larger, and it is better. [Scheme for solving the problem]

The inventors of the present invention have conducted research focusing on the above problems, and as a result, have developed a method of manufacturing columnar glass with a small cross-sectional area from bulk solidified glass without cutting, and can be molded into various cross-sectional shapes, thereby completing the present invention. invention. That is, the present invention includes the following matters. [1] A columnar glass manufacturing method, manufacturing columnar glass from a glass material, comprising: a step of preparing a cylindrical mold having a first opening and a second opening communicating with the first opening and having an opening area smaller than that of the first opening; a step of disposing glass material in said barrel mold; a step of heating the configured glass material to soften it; inserting a first mold having a glass pressing face through the first opening so that the glass pressing face contacts the glass material; and A step of pressing the softened glass material by moving at least one of the first mold and the barrel mold to discharge the glass from the second opening to become columnar glass. [2] The columnar glass manufacturing method according to [1], wherein The cylindrical mold has a second mold inside, and the second mold has a glass channel through which the softened glass material is discharged from the second opening to become the columnar glass. [3] The columnar glass manufacturing method according to [2], wherein The second mold has one or more of the glass channels. [4] The method for producing columnar glass according to any one of [1] to [3], wherein The cross-section of the columnar glass has a polygonal, circular or elliptical cross-sectional shape. [5] A columnar glass manufacturing apparatus having: a cylindrical mold having a first opening and a second opening, the second opening communicates with the first opening and has an opening area smaller than that of the first opening; The first mold is used for extruding the glass material arranged inside the cylindrical mold, and has a glass extrusion surface capable of being inserted into the cylindrical mold from the first opening; an extruding unit for extruding the first mold toward the glass material; and A heating unit is used to soften the glass material. [6] The columnar glass manufacturing apparatus according to [5], wherein The barrel mold has a second mold inside, the second mold has a glass channel, the second mold is configured such that the softened glass material is discharged from the second opening through the glass channel to become the columnar glass. [7] A columnar glass having a side surface having an arithmetic average roughness Ra of 0.001 to 0.20 μm and a ten-point average roughness Rz of 0.01 to 1.2 μm. [8] The columnar glass according to [7], wherein The difference between the crystallization peak temperature Tc and the temperature at logη=5.3 ((crystallization peak temperature Tc)−(temperature at logη=5.3)) is 0° C. or higher. [9] The columnar glass according to [7] or [8], wherein The shape of the vertical section with respect to the length direction is the same or substantially the same. [10] A columnar glass manufacturing method, manufacturing columnar glass from a glass material, comprising: the step of preparing a cylindrical mold having at least one opening; a step of inserting a mold having a glass pressing surface into the cylindrical mold in a state where the glass pressing surface is in contact with the glass material through the opening; the step of heating, softening the glass material; and A step of pressing the glass material by moving at least one of the mold or the cylindrical mold, and discharging it as columnar glass from a glass discharge port provided in the mold. [11] The columnar glass manufacturing method according to [10], wherein The mold has a glass channel through which the pressed glass is discharged from the glass discharge port as the columnar glass. [12] The columnar glass manufacturing method according to [11], wherein The mold has one or more of the glass channels. [13] The columnar glass manufacturing method according to [10], wherein The cross-section of the columnar glass has a polygonal, circular or elliptical cross-sectional shape. [14] A columnar glass manufacturing apparatus having: a cylindrical mold having at least one opening; a die for extruding a glass material to the inside of the barrel mold, insertable into the barrel mold from the opening, and having a glass discharge port that discharges the glass upon extrusion; an extruding unit for extruding the glass material by the mold; and A heating unit is used to soften the glass material. [15] A columnar glass manufacturing method, manufacturing columnar glass from a glass material, comprising: the step of preparing a cylindrical mold having a first opening and a second opening communicating with the first opening, having a second mold inside the cylindrical mold; a step of disposing glass material in said barrel mold; a step of heating the configured glass material to soften it; inserting a first mold having a glass pressing face through the first opening so that the glass pressing face contacts the glass material; and A step of pressing the softened glass material by moving at least one of the first mold and the barrel mold to discharge the glass from the second opening to become columnar glass. [16] The columnar glass manufacturing method according to [15], wherein The second mold has a glass channel through which softened glass is discharged from the second opening to become the columnar glass. [17] The columnar glass manufacturing method according to [16], wherein The second mold has one or more of the glass channels. [18] The columnar glass manufacturing method according to [16], wherein The cross-section of the columnar glass has a polygonal, circular or elliptical cross-sectional shape. [19] A columnar glass manufacturing apparatus having: a cylindrical mold having a first opening and a second opening communicating with the first opening; The first mold is used for extruding the glass material disposed inside the cylindrical mold, and has a glass extrusion surface capable of being inserted into the cylindrical mold through the first opening; an extruding unit, configured to extrude the first mold to the glass material; a second mold configured inside the barrel mold; and A heating unit is used to soften the glass material. [20] The columnar glass manufacturing apparatus according to [19], wherein The second mold has glass channels for discharging glass material. [21] The columnar glass manufacturing apparatus according to [20], wherein The second mold has one or more of the glass channels. [Invention effect]

The manufacturing method of the columnar glass of this invention can manufacture columnar glass without grinding or polishing a side surface. In addition, by changing the shape of the second opening for discharge and the shape of the glass channel, the cross-sectional shape of the obtained columnar glass can be changed. Furthermore, by increasing the number of second openings and glass channels, multiple columnar glasses can be obtained simultaneously. The columnar glass thus obtained is naturally free from grinding damage and can be shipped directly from the factory. By making the cross section circular and cutting the columnar glass approximately perpendicular to the longitudinal direction, the cut glass can be used as a lens material as it is, and the amount of cut glass, that is, the amount of glass waste can be suppressed, and the specified glass can be manufactured. The size of the glass lens material. Furthermore, since the columnar glass production method of the present invention can produce columnar glass without raising the temperature to a temperature at which crystallization is easy, crystallization inside the glass can be suppressed and high-quality columnar glass can be obtained.

Detailed ways

In the present specification, unless otherwise specified, "˜" used when specifying a numerical range means that both the upper limit and the lower limit are included in the range.

[Manufacturing method and manufacturing apparatus of columnar glass] The method for producing columnar glass of the present invention produces columnar glass from a solidified glass material, comprising: a step of preparing a cylindrical cylindrical mold having a first opening and a second opening, the second opening and the first opening One opening is connected and has an opening area smaller than that of the first opening; a step of disposing glass material in the cylindrical mold; a step of heating the configured glass material to soften it; will have a step of inserting a first mold of a glass pressing face from said first opening in such a manner that said glass pressing face is in contact with said glass material; At least one of them is moved to squeeze the softened glass material out of the second opening as columnar glass. Hereinafter, it will describe in detail with reference to drawings.

As shown in FIG. 1 and FIG. 2 , in the manufacturing apparatuses D1 and D2 of the present invention, there is a cylindrical mold 3 in which a glass material 1 in a solid state can be placed as a material. The cylindrical mold 3 can be a whole, and can also be divided into a cylindrical mold side part 31 and a cylindrical mold discharge part 32 as shown in the first figure and the second figure. In addition, the cylindrical mold discharge part 32 can be a manufacturing device The member having the glass discharge channel 35 communicated with the glass channel 41 of the second mold 4 as in D1 and D2 can also be a cylindrical cavity as the manufacturing device D4 of the 10th FIG. 10 and the manufacturing device D5 of the 11th FIG. .

The cylinder mold 3 may have the container 5 inside the cylinder mold 3 as shown in FIG. 1 , or may not have a container as shown in FIG. 2 . For convenience of description, first, the manufacturing apparatus D2 (FIG. 2 ) of a mode not having a container will be described, and then the container 5 will be described using FIG. 1 . As shown in FIG. 2 , the cylindrical mold 3 has a first opening 33 and a second opening 34 , and the second opening 34 communicates with the first opening 33 and has an opening area smaller than that of the first opening 33 . That is, the cylindrical mold 3 has two openings, and has an internal space in which the first opening 33 and the second opening 34 communicate and the material glass 1 can be disposed. The cross-sectional shape of the inner space can be circular, elliptical, or polygonal. In order to reduce the glass remaining inside after molding, it is preferably circular. In addition, the shape of the outer side of the cylindrical mold 3 is not particularly limited, but is preferably a cylindrical shape or a polygonal cylindrical shape.

The first opening 33 is an opening for inserting the glass material 1 in a solid state, and the first opening 33 is also an opening for inserting the first mold 2 after inserting the glass 1 . The second opening 34 is an opening for discharging the softened glass material 1 from the cylindrical mold 3 into a columnar shape. Therefore, in the embodiments of D1 and D2, the shape of the second opening 34 is preferably the same shape as the cross-sectional shape of the discharged columnar glass 11 . For example, if the columnar glass is made of round rod glass, the cross-sectional shape of the second opening 34 is preferably circular. The cross-sectional area of the second opening 34 is preferably such that the material glass 1 thrown in as a material does not fall downward. In addition, there may be one or more second openings 34 . For producing columnar glass, it is preferred to have a glass discharge channel 35 communicating with the second opening 34 . The shape of the glass at the time of discharge can be stabilized by the glass discharge path 35 having a predetermined length.

In this invention, the container 5 can be provided as needed. The manufacturing apparatus D1 in FIG. 1 is an embodiment having a container 5 . The container 5 can be installed inside the cylindrical mold 3 in a tightly fitted state. For example, if the internal space cross section of the cylindrical mold 3 is circular, the shape of the cross section perpendicular to the longitudinal direction of the container 5 is also circular, and it becomes a tightly fitted state as shown in FIG. 1 . Fig. 3 shows the cross-sectional shape when it is cut by III shown in Fig. 1, and it is a tightly fitted state. The heat from the outside is easily conducted to the material glass 1 inside by the tight fit. The internal cross-sectional shape of the container 5 is also the same as the internal cross-sectional shape of the cylindrical mold 3, which can be circular, oval, or polygonal. In order to squeeze the first mold 2 to the second mold 4, except for the ring described later, The cross-sectional shape of the inside of the container 5 is preferably substantially the same at any position (height) except for the shape of the notch 52 . The inner surface of the cylindrical mold 3 that compresses the material glass 1 is easily deteriorated by heat and pressure. Therefore, by arranging the container 5 that can be separated from the cylindrical mold 3 inside, even if it is damaged, only the container 5 can be replaced, and the inner surface can be made undeteriorated. In addition, the container 5 has a first container opening 51 , and when the manufacturing device D1 is used, the material glass 1 and the first mold 2 are inserted through the first container opening 51 (see FIG. 1 ) located inside the first opening 33 .

The manufacturing devices D1 and D2 of the present invention require the first mold 2 . The first mold 2 has a first mold glass pressing surface 21 . The shape of the first mold glass pressing surface 21 is preferably capable of being inserted into the first opening 33 and the first opening 51 of the container, and has a gap where the material glass 1 is not easily leaked when the material glass 1 is compressed. In the case where the gap is not suitable, the glass may leak from the gap between the first mold 2 and the barrel mold 3 (or container 5 ) at the time of extrusion.

In addition, the downward extrusion by the first mold 2 (in the direction of the arrow in FIG. 1 ) is usually performed by pressing the first mold 2 with an extrusion unit (not shown), but it can also be performed by fixing the first mold 2 A mold 2 that moves the cylindrical mold 3 upward to squeeze the material glass 1 inside can also be rotated 90° from the vertical direction by making the manufacturing devices D1, D2, and the first mold 2 and/or the cylindrical mold 3 moves in the lateral direction to extrude the material glass 1. Both manufacturing devices D1, D2 are capable of carrying out this extrusion method. Here, an embodiment in which pressing is performed by moving the first die 2 downward by fixing the cylindrical die 3 will be described.

The manufacturing apparatuses D1 and D2 of the present invention have the second die 4 as needed. The second mold 4 is located at the lowest part inside the barrel mold 3 and locked. In the case of the manufacturing device D1, since the container 5 exists, the second mold 4 is arranged at the lowermost part of the container 5 . The second mold 4 can be separated from the barrel mold 2 and the container 5 . The upper surface of the second mold glass pressing surface 43 of the lowermost second mold 4 located inside the cylindrical mold 3 is in contact with the glass 1 and is one of the most damaged parts due to the application of a large pressure. By being able to separate, the damaged and enlarged second mold 4 can be replaced with an undamaged mold. The second mold 4 has glass channels 41 . The glass passage 41 is a passage that communicates the inside of the container 5 (the second mold glass pressing surface 43 ) with the glass discharge passage 35 and the second opening 34 . The shape of the glass passage 41 is not particularly limited, but preferably has the same shape as the glass discharge passage 35 of the cylindrical mold 3 from the viewpoint of stably discharging the glass.

In addition, the cross-sectional shape and number of the glass channels 41 of the second mold 4 are not particularly limited. (a) of FIG. 5 is the second mold 4 used in FIG. 1, and a glass channel 41 having a circular cross section is formed in the center. In addition, five glass channels 412 are formed in the second mold 4 shown in (b) of FIG. 5 . Therefore, five columnar glasses can be produced from the second mold in (b) of FIG. 5 . In (c) of FIG. 5, the cross-section of the glass channel 413 is a triangular shape, and in (d) of FIG. 5, the cross-section of the glass channel 414 is in the shape of an elongated rectangle. By using these second molds, Triangular prism glass and plate glass can be manufactured separately. In addition, in the case of using the second mold shown in (b) to (d) of FIG. 5 , it is preferable to set the glass discharge channel 35 and the second opening 34 to have corresponding shapes. The end of the second mold glass pressing surface 43 of the second mold 4 is formed with an annular notch 42 on the outer periphery, and engages with the annular notch 52 formed on the inner periphery of the container 5 to suppress glass leakage.

The manufacturing apparatuses D1 to D5 of the present invention can stretch the discharged columnar glass 11 downward using the two guide rollers 7 as needed (see FIG. 6 ). The guide roller 7 is composed of two discs, sandwiches the columnar glass 11 between the two discs, and guides it in a predetermined direction. When the guide roller 7 is not used, since the amount of glass already discharged is small in the initial stage of discharging the columnar glass 11 , the downward pulling force is small. However, in the late stage of discharge, since the amount of discharged glass increases and its own weight increases, the force to pull it downward becomes greater, and the columnar glass 11 may elongate and become thinner. However, by using the two guide rollers 7 rotating at a constant speed, the columnar glass 11 can be stretched at a constant speed, so that the deformation of the cross-sectional shape of the columnar glass 11 can be suppressed, and the production of the columnar glass can be performed stably. . As shown in FIG. 6 , the guide roller 7 rotates the two discs so as to pull the glass downward.

Fig. 7 shows a manufacturing apparatus D3 according to another embodiment of the present invention. In D3, the cylindrical mold 3 with the upper part closed was used. Above the inside of the cylindrical mold 3 , there is a first mold 2 integrated with the cylindrical mold 3 . The lower part of the cylindrical mold 3 is open, and the second mold 4 having the through glass channel 41 can be inserted. The second mold 4 is supported by one or more telescopic parts 8 (consisting of a first telescopic part 81 and a second telescopic part 82 ) at a position that does not interfere with the exit of the glass channel 41 . As long as the expansion and contraction part 8 can raise the second mold 4 and the glass material 1 arranged above the second mold 4, it is not limited to this form, and the raising means of various mechanisms can be used.

The manufacturing device D3 is a method of fixing the cylindrical mold 3 and raising the second mold 4, but as another method, it is also possible to make the glass material 1 way of compression. Moreover, also about manufacturing apparatus D3, similarly to manufacturing apparatuses D1 and D2, it has heating means around the cylinder mold 3, and can heat the glass inside.

The manufacturing device D4 in FIG. 10 and the manufacturing device D5 in FIG. 11 are different from the manufacturing devices D1 and D2 in that the cylindrical mold discharge part 32 is not provided as a member but as a cylindrical cavity. Therefore, the opening area of the second opening 34 of the manufacturing devices D4 and D5 is large, and the opening shape of the second opening 34 of D4 does not need to be the same as the cross-sectional shape of the obtained columnar glass when it is cut perpendicular to the longitudinal direction. . The glass discharged from the glass discharge port 44 of the second mold 4 is stretched in the longitudinal direction into columnar glass, and discharged from the second opening 34 through the cylindrical mold discharge part 32 . The cross-sectional shape of the columnar glass obtained using manufacturing apparatuses D4 and D5 is the same shape as the shape of the glass discharge port 44 . In addition, the second mold modification example of (b) to (d) of FIG. 5 and the roll of FIG. 6 can also be applied to the manufacturing apparatuses D1 to D5.

[Manufacturing method] Next, the manufacturing method of the columnar glass 11 of this invention is demonstrated using FIG. 4. FIG. In the manufacturing apparatus D4 used in FIG. 4 , a block-shaped material glass 1 of a predetermined size is put in from the first opening, and pressed from above to below by the first mold 2 . The injected material glass 1 can also be loosely located inside the container 5 before extrusion. After inserting the material glass 1 of a predetermined size into the container 5 , the first mold 2 is arranged on the first opening 51 of the container from above ( FIG. 4( a )). In addition, in the manufacturing method of the present invention, since the high temperature does not reach the level of melting the material glass 1 , a release agent such as powdery boron nitride (BN) is not added. Therefore, the production method of the present invention is very suitable for glasses that are sensitive to fluctuations in glass components. In addition, although it is preferable not to use a release agent, it can be used according to circumstances as long as it does not interfere with use.

Next, the glass material 1 is heated by a heating unit (not shown). The heating unit heats from the outside of the first mold 2 and the cylindrical mold 3 by a predetermined method such as a burner. This softens the material glass 1 . By pressing the softened material glass 1 downward, the material glass 1 is deformed. Even if the glass is not in a shape that closely fits inside the cylindrical mold 2 when inserted, it can be expanded in the vertical direction (horizontal direction) relative to the longitudinal direction by pressing, and there is no gap in the lateral direction. Fill the glass ((b) of Fig. 4). At this time, the viscosity of the glass is about 1.0×10 ⁴ Pa·s to 5.0×10 ⁵ Pa·s.

When the pressing is further continued, the glass is discharged as columnar glass 11 ((c) of FIG. 4 ).

The temperature suitable for extrusion is not particularly limited as long as the glass can be deformed by extrusion, but the viscosity of the glass is preferably 1.0×10 ⁴ Pa·s to 5.0×10 ⁵ Pa The temperature of about s is 500-900 degreeC as an example of the specific temperature of the glass at this time.

The discharge speed of the discharged columnar glass 11 , that is, the extrusion speed is not particularly limited, and may be, for example, a speed of 1 to 30 mm/min, or may be, for example, a speed of 1 to 20 mm/min. If the discharge speed is faster than this range, the pressing pressure is too high, and the material glass 1 may be damaged before deformation. If the discharge speed is slower than this range, the production speed is too slow and the efficiency is low.

The pressure on the material glass 1 is preferably 1.5 to 50 MPa. In addition, it is preferable to adjust the load and pressure in accordance with the extrusion speed since the extrusion speed is preferably constant when producing such a columnar glass 11 .

Although not shown, it is preferable to arrange a heat-resistant sheet between the first mold glass pressing surface 21 of the first mold 2 and the glass material 1 . Thereby, glass can be suppressed from intruding into the gap between the container 5 and the first mold 2 . Examples of the heat-resistant sheet include carbon-containing sheets, and specifically, expanded graphite sheets and the like.

Also in production apparatuses D1, D2, and D5, columnar glass can be produced on the same conditions as D4 above.

In the manufacturing apparatus D3 shown in FIG. 7, manufacturing is performed by the following method. That is, the manufacturing method using the manufacturing device D3 includes: the step of preparing a cylindrical cylindrical mold having at least one opening; and the step of placing the glass material on the glass pressing surface of the mold having the a glass pressing surface and a glass passage penetrating the mold from the glass pressing surface; or at least one of the barrel molds is moved to squeeze the glass material with the mold; and the squeezed glass is discharged from the opening through the glass channel by squeezing to become Columnar glass steps.

A specific manufacturing method using the manufacturing apparatus D3 will be described using FIG. 7 . The glass material 1 is placed on the second mold 4 . In addition, in the second mold 4 , there are second mold glass extrusion surfaces 43 and glass channels 41 . In the state where the glass material 1 is placed, the second mold 4 and the glass material 1 on the second mold 4 are raised by extending the expansion and contraction portion 8 . The lower opening of the barrel mold 3 allows the second mold 4 to be inserted into the barrel mold 3, and the glass material 1 on the second mold 4 and the second mold 4 rises to place the second mold 4 on the second mold 4. The glass material 1 is inserted into the cylinder 33. Although not shown in the figure, the glass inside the cylindrical shape 33 is heated to a temperature capable of thermoforming by a heating unit. The telescopic part 8 is further raised until the second mold 4 and the glass material 1 placed on the second mold 4 come into contact with the first mold 2 placed in the upper part (opposite to the opening) inside the cylindrical mold 3 . When it rises further, the heated glass material 1 is deformed, and the columnar glass 11 is discharged from the glass discharge port 44 communicating with the glass channel 41 and the opening of the cylindrical mold 3 .

[columnar glass] The columnar glass 11 obtained by the manufacturing apparatus and manufacturing method of this invention is demonstrated. In one embodiment of the present invention, one or more columnar glasses 11 are obtained corresponding to one material glass 1 inserted into the manufacturing apparatus. That is, the glass volume of the material glass 1 is substantially the same as the volume of the obtained columnar glass 11 (except that a part of the material glass 1 remains in the manufacturing apparatus).

The cross-sectional shape of the columnar glass 11 depends on the shape of the opening of the second opening 34 or the glass discharge port 44 of the second mold 4 . That is, if the shape of the second opening 34 or the glass outlet 44 of the second mold 4 is circular, columnar glass 11 with a circular cross section is obtained. In addition, by changing the shape of the second opening 34 or the glass discharge port 44 of the second mold 4 , polygonal cross sections such as triangles and quadrilaterals, and elliptical cross sections can also be formed.

The columnar glass 11 obtained by the present invention is characterized in that its cross-sectional area is very small. Defined by cross-sectional area. The cross-sectional area can be, for example, 50 mm ² or less, for example, can be 40 mm ² or less, and can be 30 mm ² or less.

The columnar glass 11 has a surface that can be shipped directly from the factory without polishing. Since it is not ground, glass shavings can be suppressed. The surface of the columnar glass 11 obtained by the manufacturing method of the present invention can be shipped even in an unpolished state. For example, multiple precision extruded glass materials (sometimes called preforms) can be produced by simply dividing a column of glass. In an unpolished state, the arithmetic average roughness Ra is 0.001 to 0.20 μm, and the ten-point average roughness Rz is 0.01 to 1.2 μm. In this specification, the arithmetic average roughness Ra and the ten-point average roughness Rz are values measured with a surface roughness and profile measuring instrument (SURFCOM 2900 SD3-12, manufactured by Tokyo Seiki Co., Ltd.). In addition, the measurement of the arithmetic average roughness Ra and the ten-point average roughness Rz was performed by scanning the side surface of the columnar glass parallel to the longitudinal direction. The columnar glass 11 obtained by the production method of the present invention may have linear stripes formed in the longitudinal direction. This is due to extrusion of softened glass by pressure. Since there are linear stripes in the longitudinal direction, the anti-slip effect of the cutting blade is exhibited in the cutting for dividing the columnar glass into multiple pieces. In addition, as described above, since there is no need to use a release agent, foreign matter derived from the release agent does not appear on the surface or inside of the glass.

Furthermore, the columnar glass 11 obtained by the manufacturing method of this invention can be manufactured so that a cross-sectional shape may be uniform or substantially uniform. In one columnar glass 11 , the ratio of the cross-sectional shape with the largest area to the cross-sectional shape with the smallest area (maximum area/minimum area) is preferably 1.2 or less, more preferably 1.1 or less.

Furthermore, in the production method of the present invention, the preferable difference between the crystallization peak temperature and the temperature at logη=5.3 ((crystallization peak temperature (Tc°C)) - (temperature at logη=5.3°C)) is 200°C The following glass materials. In addition, the difference between the crystallization peak temperature and the temperature at logη=5.3 is preferably greater than 0°C, more preferably 50°C or higher, and further preferably 100°C, 150°C, and 200°C or higher in this order. In general, there is a large difference between the crystallization peak temperature and the temperature at logη=5.3, and it is difficult to devitrify during molding. From this point of view, the difference between the crystallization peak temperature and the temperature at logη=5.3 is preferably greater than 0°C as described above, more preferably 50°C or higher, and further preferably 100°C, 150°C, and 200°C or higher in this order. . On the other hand, even if the difference between the crystallization peak temperature and the temperature at logη=5.3 is 200° C. or less, the devitrification during molding according to the present invention can be suppressed. Therefore, the method of the present invention and the crystallization peak temperature A combination of glasses whose temperature difference with logη=5.3 is 200°C or less is preferable. Such glass has high stability in a viscous region, and can be suitably produced by the production method and production apparatus of the present invention. In addition, Fig. 8 shows a graph of differential calorimetry analysis of general glass, and in Fig. 8, the crystallization peak temperature is a part of Tc. For a glass with high thermal stability and difficult to crystallize when heated, no clear crystallization peak will appear in the DSC curve, or even if there is a crystallization peak, the difference between the crystallization peak temperature Tc and T (logη=5.3) is larger value. On the other hand, glass with a Tc-T (logη=5.3) of 200°C or less tends to devitrify when heated, softened, and formed, and the devitrification resistance is insufficient. However, according to the present invention, high-quality glass can be obtained without devitrification. Columnar glass, therefore, the columnar glass manufacturing method of the present invention is particularly advantageous as a method for forming glass having a Tc-T (logη=5.3) of 200°C or lower.

EXAMPLES Columnar glass was manufactured using the manufacturing apparatus D1 shown in FIG. 1 with respect to the following glass having a volume of 22 cm ³ solidified at room temperature. In D1, the cross-sections of the glass passage 41 and the glass discharge passage 35 are dimensioned to match the shape of the cross-section of the manufactured columnar glass. In addition, between the first mold glass pressing surface 21 of the first mold 2 and the material glass 1, an expanded graphite sheet having a thickness of 1.5 mm was arranged. Conditions are described below. In addition, although heating is performed in order to soften glass, the temperature at this time is adjusted suitably so that it may fall in the following viscosity range. In addition, in Table 1, regarding the crystallization peak temperature (Tc) - (temperature at logη=5.3) [°C], the crystallization peak temperature is relatively hard to crystallize and the deviation of the crystallization peak temperature is slightly larger in the glass that is easy to crystallize The glass has recorded the range of its crystallization peak temperature. Glass used: optical glass 1-4 (the shape of the obtained columnar glass is shown in Table 1 below) Speed: 10mm/min; Load: 770-12315N; Temperature: 550-860°C; Glass viscosity: 2.0×10 ⁴ Pa ·s～1.0×10 ⁵ Pa·s.

[Table 1]

(result) A columnar glass having a predetermined shape is obtained from any one of the optical glasses 1 to 4. Stripes in the longitudinal direction were observed on both sides of the columnar glass. In addition, regarding the columnar glass of Example 1, Ra was 0.025 μm, Rz was 0.845 μm, and foreign substances such as crystals of 3 μm or more were not observed. In addition, each characteristic of the optical glass 1 of Example 1 is described in Table 2, and the enlarged photograph of Example 1 is shown in FIG. 9 .

[Table 2]

1: Material glass 11: columnar glass 2: The first mold 21: The first mold glass extrusion surface 3: barrel mold 31: Side part of cylinder mold 32: Barrel mold discharge part 33: First opening 34: Second opening 35: Glass discharge channel 4: Second mold 41, 412, 413, 414: glass channel 42: Annular notch 43: Second mold glass extrusion surface 44: Glass outlet 5: container 51: The first opening of the container 52: Annular notch 7: guide roller 8: Telescopic part 81: The first telescopic part 82: The second telescopic part D1~D5: Manufacturing device

Fig. 1 shows a schematic cross-sectional view of a manufacturing device D1 of columnar glass. Fig. 2 shows a schematic cross-sectional view of a columnar glass manufacturing device D2. FIG. 3 shows a cross-sectional view taken along a line (III in FIG. 1 ) perpendicular to the longitudinal direction of the manufacturing apparatus D2. Fig. 4 shows a state in which columnar glass is produced by the columnar glass manufacturing apparatus D4. Fig. 5 shows an example of the second mold. FIG. 6 shows a state in which the discharged columnar glass is stretched by guide rollers 7 . Fig. 7 shows a schematic cross-sectional view of a columnar glass manufacturing device D3. Fig. 8 shows a graph of differential scanning calorimetry (DSC) of a general glass. Fig. 9 is a side enlarged photograph of Example 1. Fig. 10 shows a schematic cross-sectional view of a columnar glass manufacturing device D4. Fig. 11 shows a schematic cross-sectional view of a columnar glass manufacturing device D5.

2: The first mold

21: The first mold glass extrusion surface

3: barrel mold

31: Side part of cylinder mold

32: Barrel mold discharge part

34: Second opening

35: Glass discharge channel

4: Second mold

41: Glass channel

42: Annular notch

43: Second mold glass extrusion surface

5: container

51: The first opening of the container

52: Annular notch

D1: Manufacturing device

Claims (21)

A columnar glass manufacturing method, the columnar glass is manufactured from a glass material, comprising: a step of preparing a cylindrical mold having a first opening and a second opening communicating with the first opening and having an opening area smaller than that of the first opening; a step of disposing glass material in said barrel mold; a step of heating the configured glass material to soften it; inserting a first mold having a glass pressing face through the first opening so that the glass pressing face contacts the glass material; and A step of pressing the softened glass material by moving at least one of the first mold and the barrel mold to discharge the glass from the second opening to become columnar glass. The columnar glass manufacturing method as claimed in item 1, wherein, The cylindrical mold has a second mold inside, and the second mold has a glass channel through which the softened glass material is discharged from the second opening to become the columnar glass. The columnar glass manufacturing method as claimed in item 2, wherein, The second mold has one or more of the glass channels. The columnar glass manufacturing method according to any one of Claims 1 to 3, wherein, The cross-section of the columnar glass has a polygonal, circular or elliptical cross-sectional shape. A columnar glass manufacturing apparatus having: a cylindrical mold having a first opening and a second opening, the second opening communicates with the first opening and has an opening area smaller than that of the first opening; The first mold is used for extruding the glass material arranged inside the cylindrical mold, and has a glass extrusion surface capable of being inserted into the cylindrical mold through the first opening; an extruding unit for extruding the first mold toward the glass material; and A heating unit is used to soften the glass material. The columnar glass manufacturing device according to claim 5, wherein, There is a second mold inside the barrel mold, the second mold has a glass channel, the second mold is configured such that the softened glass material is discharged from the second opening through the glass channel to become the columnar glass. A columnar glass having an arithmetic average roughness Ra of 0.001 to 0.20 μm and a ten-point average roughness Rz of 0.01 to 1.2 μm on a side surface. The columnar glass as claimed in item 7, wherein, The difference between the crystallization peak temperature Tc and the temperature at logη=5.3 ((crystallization peak temperature Tc)−(temperature at logη=5.3)) is 0° C. or higher. The columnar glass as claimed in item 7 or 8, wherein, The shape of the vertical section with respect to the length direction is the same or substantially the same. A columnar glass manufacturing method, the columnar glass is manufactured from a glass material, comprising: the step of preparing a cylindrical mold having at least one opening; a step of inserting a mold having a glass pressing surface into said cylindrical mold in a state where said glass pressing surface is in contact with said glass material through said opening; the step of heating, softening the glass material; and A step of pressing the glass material by moving at least one of the mold or the cylindrical mold, and discharging it as columnar glass from a glass discharge port provided in the mold. The columnar glass manufacturing method as claimed in claim 10, wherein, The mold has a glass channel through which the pressed glass is discharged from the glass discharge port as the columnar glass. The columnar glass manufacturing method as claimed in claim 11, wherein, The mold has one or more of the glass channels. The columnar glass manufacturing method as claimed in claim 10, wherein, The cross-section of the columnar glass has a polygonal, circular or elliptical cross-sectional shape. A columnar glass manufacturing apparatus having: a cylindrical mold having at least one opening; a die for extruding a glass material to the inside of the barrel mold, insertable into the barrel mold from the opening, and having a glass discharge port that discharges the glass upon extrusion; an extruding unit for extruding the glass material by the die; and A heating unit is used to soften the glass material. A columnar glass manufacturing method, the columnar glass is manufactured from a glass material, comprising: the step of preparing a cylindrical mold having a first opening and a second opening communicating with the first opening, having a second mold inside the cylindrical mold; a step of disposing glass material in said barrel mold; a step of heating the configured glass material to soften it; inserting a first mold having a glass pressing face through the first opening so that the glass pressing face contacts the glass material; and A step of pressing the softened glass material by moving at least one of the first mold and the cylindrical mold to discharge the glass from the second opening to become columnar glass. The columnar glass manufacturing method as claimed in claim 15, wherein, The second mold has a glass channel through which softened glass is discharged from the second opening to become the columnar glass. The columnar glass manufacturing method as claimed in claim 16, wherein, The second mold has one or more of the glass channels. The columnar glass manufacturing method as claimed in claim 15, wherein, The cross-section of the columnar glass has a polygonal, circular or elliptical cross-sectional shape. A columnar glass manufacturing apparatus having: a cylindrical mold having a first opening and a second opening communicating with the first opening; The first mold is used for extruding the glass material arranged inside the cylindrical mold, and has a glass extrusion surface capable of being inserted into the cylindrical mold through the first opening; an extruding unit, configured to extrude the first mold to the glass material; a second mold configured inside the barrel mold; and A heating unit is used to soften the glass material. The columnar glass manufacturing apparatus as claimed in claim 19, wherein, The second mold has glass channels for discharging glass material. The columnar glass manufacturing apparatus as claimed in claim 20, wherein, The second mold has one or more of the glass channels.

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