JP5824261B2 - Method for assembling mold for manufacturing quartz glass molded body - Google Patents

Description

  The present invention relates to a method for assembling a mold material used for producing a quartz glass molded body for obtaining a ring-shaped or disk-shaped quartz glass product.

  In recent years, glass products, in particular quartz glass products made of quartz glass, are not limited to optical devices such as optical lenses, but take advantage of their durability and chemical stability to manufacture jigs for semiconductor manufacturing and liquid crystal display panels. Widely used in photomasks for optical systems or precision parts for optical communications. As a manufacturing process of such a quartz glass product, a process that mainly uses a removal step of removing an unnecessary region from a workpiece, such as etching or grinding, has been adopted.

  However, the manufacturing process by etching is limited to relatively fine processing of the surface of the workpiece, and there is a problem in that the glass product to be obtained is limited. In addition, since the manufacturing process by grinding is performed to grind the work object little by little and process it into a desired shape, it takes a long time to process and removes unnecessary parts from the work object by grinding. Compared to the weight of the processed quartz glass product, a larger weight of the quartz glass material is required, resulting in problems in manufacturing efficiency and manufacturing cost.

  In order to solve these problems, there is a method for producing a glass product by manufacturing a quartz glass molded body by melt-molding a rough shape of a glass product using a mold material, and subjecting the quartz glass molded body to mechanical processing such as grinding. Are known.

  Hereinafter, a conventional method for producing a rough shape of a glass product using a mold material by melt molding will be briefly described.

  As shown in FIG. 1, a mold material 10 used for melt molding is a cylinder divided into two or more having a desired inner diameter, and is installed on an upper surface 12 a of a bottom plate 12. A quartz glass base material 16 to be melt-molded is placed inside the mold 10 and heated at a heating temperature of 1500 ° C. to 2000 ° C. in an inert gas atmosphere such as nitrogen gas by a heating device such as an electric furnace. To do. Thereby, the quartz glass base material 16 is heated and melted and manufactured as a cylindrical quartz glass molded body 16a having the same dimensions as the inner diameter of the mold material.

  However, the cylindrical mold 10 is difficult to manufacture, requires a large apparatus for processing, takes time to manufacture, and costs the manufacturing cost. In addition, since the molds divided into two or more parts are combined into a cylindrical shape, even if one of the divided molds breaks, it will not function as a mold material. There was also the problem of having to leave.

  In order to solve such a problem, in order to be able to use a common member that can be easily manufactured, as shown in FIG. 2, a regular polygonal columnar mold 10 configured by combining plate members 14 of the same size is used. The inventor has proposed to use (Japanese Patent Application No. 2010-26808)

  Also in this case, similarly to the above, the quartz glass base material 16 is placed in the regular polygonal columnar mold 10 made of the plate material 14, and is heated at 1500 ° C. to 2000 ° C. with a heating device in an inert gas atmosphere such as nitrogen gas. A polygonal columnar quartz glass molded body 16a partitioned by the inner surface 14a of the plate member 14 is manufactured by heating and melting. A quartz glass product having a desired shape can be obtained by machining such as cutting the quartz glass molded body 16a.

Japanese Patent No. 4054977

  By using a regular polygonal columnar cylinder assembled with plate material as a mold material, stock of spare parts prepared in the event of breakage becomes unnecessary, processing time spent for manufacturing the mold material can be omitted, and regular polygons can be created by assembling the plate material. Since the columnar mold was completed, the cost could be reduced.

  However, in the case of using a mold material obtained by assembling plate materials into a regular polygonal columnar body, it is necessary to prepare a plurality of plate materials having a width corresponding to the outer diameter in order to obtain a quartz glass molded body having a desired outer diameter. If the dimensional accuracy of the plate material is increased and it is not assembled correctly, it becomes a distorted regular polygonal column, and a quartz glass molded body with a desired outer diameter may not be obtained. Assembling a regular polygonal columnar mold using a plate material Took a lot of effort and time.

  In addition, since the regular polygonal columnar bodies are assembled by using the same size plate material as a set, in order to cope with the diversification of the size or shape of quartz glass products that are increasing in recent years However, it is necessary to prepare a set of plates corresponding to these sizes in advance. However, it is practical to prepare a size that is not used frequently, because it is a problem of the storage location and the management becomes complicated. is not.

  The present invention provides a method for assembling a mold material that can easily and accurately assemble a regular polygonal column-shaped mold material and can easily cope with diversification of the size or shape of a quartz glass product. Is.

  The present invention relates to a method for assembling a regular polygonal column-shaped member, and more specifically, a regular polygonal column-shaped assembly jig having a guide surface on its side surface is placed on a bottom plate, and quartz is further melt-molded thereon. After placing the glass base material, a plate material with a width larger than the length of one side of the regular polygonal column assembly jig is brought into close contact with the guide surface of the assembly jig, and the other end of the plate material exceeds the corner of the assembly jig. Then, one end surface of the next plate material is brought into contact with the side surface portion of the adjacent plate material, and is closely adhered to the guide surface of the assembly jig, and this operation is performed on all sides to make the internal shape of the plate material a polygonal columnar body. This is an assembly method.

  By assembling a regular polygonal column-shaped mold material made of plate material, which is a component of the mold material used in the production of a quartz glass molded body, by using a polygonal columnar assembly jig having a guide surface, Since not only the assembly is simplified, but the accuracy can be improved, the distortion of the regular polygonal cylinder inner diameter is eliminated, and a quartz glass molded body having a desired outer diameter is obtained, so that the yield is improved.

The perspective view, upper surface top view, and manufacturing process figure of the mold material for quartz glass molded object manufacture which used the conventional cylindrical member as the mold material. The perspective view, upper surface top view, and manufacturing process figure of the mold material for quartz glass molded object manufacture which used the regular polygonal columnar body as a mold material. Explanatory drawing and the manufacturing process figure of the assembly method of the mold material which uses the assembly jig of this invention.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 3, the assembly jig 18 is a regular polygonal columnar body (in the example shown, a regular octagonal columnar body), and the length of one side is the length of the side of the mold 10 of the regular polygonal columnar body to be manufactured. It is matched with the size.

  Since the outer diameter of the quartz glass molded body to be obtained is determined by the size of the regular polygon of the assembly jig 18, in order to obtain the quartz glass molded body having various outer diameters, the size corresponding to the target diameter is used. An assembly jig 18 needs to be prepared.

  The height of the assembly jig 18 is preferably 1 cm to 5 cm, although it depends on the desired size of the regular polygonal columnar mold. If the height of the assembly jig 18 is lower than 1 cm, the area of the guide surface that is in contact with the plate material 14 is small, so that the assembly work of the plate material 14 is not performed smoothly, and the plate material 14 does not become vertical. Since it will incline and the precision of the regular polygonal column type | mold inner surface falls, it is unpreferable. That is, when the plate member 14 is inclined, the inner diameter of the regular polygonal column mold member is reduced, and there is a possibility that a quartz glass molded body having a desired diameter cannot be obtained.

  Further, when the height of the assembly jig 18 is 5 cm or more, the area of the guide surface that is in contact with the plate member 14 increases, so that not only the accuracy of the inner surface of the regular polygonal column mold material is improved, but also for installation. However, the weight of the assembling jig is increased and handling becomes difficult, and the amount of heat when the quartz glass base material 16 is melted is consumed for heating the assembling jig 18, which is inefficient. It will be a thing.

  In an actual manufacturing site, in view of the above points, the size and height of the assembly jig 18 are a balance between the height and diameter of the regular polygonal columnar mold material, the work space, the desired size of the quartz glass molded body, and the like. To decide.

  When one end of the plate is aligned with the apex of the assembly jig 18, even when the assembly jig 18 of various sizes is used to change the outer diameter of the quartz glass molded body, The same plate material 14 can be used.

  The thickness of the plate member 14 is not particularly limited as long as it has sufficient strength at the time of melt molding, and the required strength can be obtained in the range of 0.5 cm to 5.0 cm. Further, it is desirably 1.0 cm to 3.0 cm. When the thickness of the plate material 14 is less than 1.0 cm, although depending on the method of manufacturing the plate material 14, there is a high possibility that the mechanical strength is reduced and a problem is caused in durability.

  If the thickness of the plate material 14 is greater than 3.0 cm, problems such as an increase in the amount of heat for heating the plate material 14 and an accompanying increase in cooling time and a decrease in workability due to an increase in the weight of the plate material 14 occur. .

  The material of the mold for producing the quartz glass molded body is not particularly limited as long as it does not react at all under the melting condition of the quartz glass, but is easy to process, physical / chemical stability, high temperature It is desirable to use carbon from the viewpoint of the degree of expansion, the low content of impurities, and the material price.

In order to prevent the reaction between carbon and fused silica glass on the surface of the carbon plate material 14 in contact with the fused quartz glass, carbon felt is interposed, alumina (A1 ₂ O ₃ ), silicon nitride (Si ₃ N). ₄ ) Or even if a protective film made of silicon carbide (SiC) is coated, there is no problem. These protective films can be produced by a wet method or a dry method. For example, the wet method can be prepared by adding water to each powder to form a slurry, and then coating with a spray, or applying a slurry with a brush or the like and then drying. Further, the dry method can be manufactured by a sputtering method using an alumina target or the like, a reactive ion plating method using a silicon target, or the like.

  In the assembly procedure of the present invention, the bottom plate 12 is placed at a place where the mold material 10 is to be installed, and the assembly jig 18 and the quartz glass base material 16 are sequentially placed at the center thereof. Subsequently, a plate material 14-1 having a width larger than the length of the side of the assembly jig 18 is brought into close contact with the guide surface 19 on the side surface of the assembly jig 18 corresponding to each side of the regular octagonal prism of the assembly jig 18. Install. One end of the plate material 14-1 is installed so as to match the corner 18-1 of the assembly jig 18, and the other end is passed over the adjacent corner 18-2 of the assembly jig 18. Next, one end portion of the second plate material 14-2 is brought into contact with the side surface of the plate material 14-1, and the side surface of the plate material 14-2 is brought into close contact with the guide surface 19 of the assembly jig 18. By performing this for each side, the regular octagonal columnar mold 10 is assembled.

  The plate material assembled into a regular octagonal column shape is fixed using appropriate means, for example, a fixing jig made of the same material as the plate material 14.

  In particular, when trying to obtain a cylindrical quartz glass molded body, it is smaller than the desired inner diameter of the quartz glass molded body on the lower surface and / or upper surface of the quartz glass base material in order to improve the yield. It is desirable to install a cylindrical jig having an outer diameter.

  The quartz glass molded body whose outer peripheral shape is a regular octagon is obtained by moving the mold 10 for producing a quartz glass molded body 10 in which the quartz glass base material 16 is installed in this way to a heating furnace or the like and performing melt molding. Is obtained.

  The quartz glass base material is melt-formed by heating to 1500 ° C. to 2000 ° C., but a more preferable heating temperature is 1700 ° C. to 1900 ° C. This is because if the temperature is lower than 1700 ° C., the melt viscosity of quartz glass is large, so that it takes a long time for melt molding. If the temperature exceeds 1900 ° C., the reaction between quartz glass and carbon tends to occur.

  Table 1 shows the material and size of the assembly jig 18 used for constructing the regular hexagonal, regular octagonal, and regular dodecagonal polygonal mold 10 and the time required for the construction. In addition, the result of melt-molding a cylindrical quartz glass base material using this mold material is also shown. Further, Table 1 shows a case in which no assembly jig is used as a comparative example.

  As can be seen from Table 1, by using the assembly jig 18, the time required for constructing the regular polygonal column-shaped mold material was greatly reduced, and the shape of the resulting quartz glass molded body 16a was also stable.

DESCRIPTION OF SYMBOLS 10 Mold material 12 Bottom plate 12a Bottom plate upper surface 14 Plate material 14a Plate material inner peripheral surface 16 Quartz glass base material 16a Quartz glass molded body 18 Assembly jig 19 Guide surface

Claims (2)

A method for assembling a regular polygonal column-shaped mold material for forming a quartz glass material in which a quartz glass base material is placed in a mold material, heated and melted in a heating and melting furnace, and the fused quartz glass is matched with the shape of the mold material. After installing a regular polygonal column-shaped assembly jig having a guide surface on its side surface and placing a quartz glass base material on the bottom plate, one end of a plate material whose one side is larger than the length of the side of the assembly jig Place the other end of the plate material over the corner of the assembly jig in close contact with the corner of the assembly jig, and then adjoin one end of the second plate at the corner of the assembly jig. A method of assembling the mold material in which the inner surface shape is a regular polygonal columnar body by contacting the side surface of the plate material to be repeated and repeating this. The method for assembling a mold according to claim 1, wherein the material of the plate member and the assembly jig is carbon.