JP2007137687A - Molding die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a glass-made molding die having high durability, by suppressing cracking or chipping at the lower end corner part of the molding die body by virtue of a metal-made protective film covering the lower end corner part of the molding die body. <P>SOLUTION: This molding die 1 is provided with a columnar glass-made molding die body 10 having a molding surface formed on the upper end face 10a, and a metal-made protective film 11 covering around the lower end corner part 10c of the molding die body 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold.

  2. Description of the Related Art Conventionally, as a method for manufacturing an optical element typified by an optical lens, a so-called precision press molding method is known in which a glass material heated using a molding die is press molded. For example, when a glass element is molded by a precision press molding method, since the glass material heated to the vicinity of the glass softening point is pressed by the mold, the mold has high heat resistance, low thermal expansion, and high hardness. It is desirable to be a thing. Commonly used mold materials include cemented carbide and cermet. However, when a cemented carbide or cermet is used as the material of the mold, there are problems that it is difficult to precisely process the mold, and that the processing time is increased and the processing cost of the mold is increased. In addition, the processing tool for processing the mold is likely to be worn and deformed, and there is a possibility that the processing shape of the mold may vary. Thus, when variation occurs in the processing shape of the mold, there is a problem that an optical element having a desired shape and dimension cannot be obtained.

  In view of such a problem, for example, Patent Document 1 proposes a glass mold.

Patent Document 2 discloses a mold comprising a glass mold body and a metal or ceramic bonded body bonded to the base surface of the mold body. Patent Document 2 describes that the durability of the mold can be improved by bonding a metal or other bonded body to the base of the glass mold main body.
JP-A 64-33022 JP-A-1-102136

  Since glass is more workable than cemented carbide, cermet, and the like, the glass mold disclosed in Patent Document 1 can be manufactured relatively easily and with high accuracy. However, glass is a brittle material. For this reason, in particular, due to contact with other members of the molding apparatus such as a press head during pressing or handling, there is a problem that the base side corner opposite to the molding surface is likely to crack or chip. There is. There is a problem that when the base side corner is cracked or chipped, the desired optical performance cannot be obtained, and in the worst case, the optical element cannot be molded.

  Further, the molding die composed of a glass molding die main body and a joined body joined to the molding die main body described in Patent Document 2 has stress applied repeatedly for each press, press head, etc. Thus, there is a problem that the joined body is separated from the mold main body by an impact load due to contact with other members of the molding apparatus. That is, there is a problem that it is difficult to achieve sufficient durability with the glass mold having the joined body described in Patent Document 2.

  The present invention has been made in view of such problems, and an object thereof is to provide a glass mold having high durability.

  The mold according to the present invention includes a columnar glass mold main body having a molding surface formed on the upper end surface, and a metal protective film that wraps around and covers the lower end corner of the mold main body.

  In the present specification, “glass” includes crystallized glass.

  According to the present invention, the metal protective film covering the lower end corner of the mold main body suppresses cracking and chipping of the lower end corner of the mold main body, thereby realizing a highly durable glass mold. be able to.

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

(Embodiment 1)
FIG. 1 is a cross-sectional view of a mold 1 according to the first embodiment.

  The mold 1 according to the first embodiment includes a mold body 10, a protective film 11, an adhesion film 12, and a release film 13.

  The mold body 10 is made of glass (amorphous glass or crystallized glass). For this reason, the shaping | molding die 1 is easy to produce and can be produced at low cost. Further, variation in the shape of the mold 1 can be reduced. The glass mold body 10 can be produced, for example, by precision press-molding a glass base material using a mother mold.

The glass type of the glass used for the mold body 10 is not particularly limited, and can be appropriately determined depending on the application of the mold 1. When the mold 1 is used for molding an element molded at a relatively high temperature such as a glass element, the mold body 10 preferably has high heat resistance and high hardness. In this case, for example, the mold body 10 is preferably made of a so-called silicate glass mainly composed of SiO ₂ (silicon dioxide). This is because silicate glass has a particularly high glass transition temperature (Tg), a low thermal expansion coefficient (α), and a high strength among glasses. Specific examples of the silicate glass include quartz glass, borosilicate glass, silica soda glass, and silica lime glass. Among these, alkali-free glass such as quartz glass having a particularly high glass transition temperature and a low thermal expansion coefficient and not containing an alkali component is particularly preferable.

  Moreover, you may produce the shaping | molding die main body 10 using the crystallized glass which crystallized the silicate type glass etc. from a viewpoint of obtaining still higher heat resistance and durability.

  The mold body 10 is columnar, preferably cylindrical, and the upper end surface 10a is formed with, for example, a concave molding surface for molding an element. On the other hand, the lower end surface 10b serving as a mounting surface for the apparatus is formed flat (preferably flat and smooth).

  A lower end corner portion 10c located at the periphery of the lower end surface 10b serving as an attachment surface is covered with a metal protective film 11 so as to go around. The mold body 10 formed of glass which is a brittle material is likely to be cracked, pitched and chipped. In particular, the lower end corner portion 10c that is in contact with the forming apparatus is particularly susceptible to cracking, and the lower end corner portion 10c, which is liable to be cracked, is covered with a metallic protective film 11 having spreadability. Can be effectively suppressed.

  In addition, the above-described joined body made of metal or the like is easily dropped from the glass mold body, whereas the metallic protective film 11 is relatively thin and highly flexible, so that it is dropped from the mold body 10. Hateful. Therefore, by providing the metallic protective film 11, it is possible to prevent the glass mold body 10 from being cracked or chipped over a long period of time. From such a viewpoint, the protective film 11 is particularly preferably made of a metal having high adhesion to glass. Examples of materials having high adhesion to glass include metals such as Ta, Ti, Ni and Cr, and alloys containing two or more metals selected from the group consisting of Ta, Ti, Ni and Cr (preferably, An alloy composed of two or more metals substantially selected from the group consisting of Ta, Ti, Ni and Cr).

  Moreover, when the shaping | molding die 1 is a thing for shape | molding the element shape | molded especially at comparatively high temperature, such as a glass element, it is preferable that the protective film 11 has high heat resistance and antioxidant property.

  In the first embodiment, the protective film 11 is formed so as to cover the lower end corner portion 10c and cover the entire lower end surface 10b. When the protective film 11 is formed so as to cover only the lower end corner portion 10c, the lower end surface 10b comes into contact with and collides with the mounting surface of the molding machine and the like, so that from the end of the protective film 11 positioned below the lower end surface 10b. Although there exists a possibility that it may peel, it can suppress effectively that the protective film 11 peels from the shaping | molding die main body 10 by forming so that the whole lower end surface 10b may be coat | covered as shown in FIG. Further, from the viewpoint of effectively suppressing peeling of the protective film 11, the protective film 11 may be provided so as to cover the entire surface of the mold body 10.

  As described above, the lower end surface 10 b of the mold body 10 is covered with the protective film 11, while the upper end surface 10 a is covered with the adhesion film 12 and the release film 13. The mold release film 13 is for improving the mold release property of the molded body with respect to the mold 1. In the present specification, the “release film” refers to a film having a higher release property with respect to the molded body than the mold body 10. In other words, it refers to a film having lower adhesion to the molded body than the mold body 10.

  By providing the release film 13 on the molding surface, the molding of the element becomes smooth, and molding defects such as cracking and chipping of the element can be reduced. Therefore, it is possible to improve element productivity and non-defective product rate.

  The release film 13 is preferably inert to the material of the element to be molded.

  For example, when the mold 1 is for molding a glass element, the release film 13 is made of noble metals such as Pt, Ir, W, Re, Ta, Rh, Ru, Os, or Pt, Ir, W, An alloy containing two or more kinds of noble metals selected from the group consisting of Re, Ta, Rh, Ru, and Os (preferably consisting essentially of Pt, Ir, W, Re, Ta, Rh, Ru, and Os An alloy composed of two or more kinds of noble metals selected from the group is preferred.

  The adhesion film 12 provided between the release film 13 and the mold body 10 improves the adhesion of the release film 13 to the mold body 10. The adhesion film 12 is more adhesive to the mold body 10 than the release film 13 and has higher adhesion to the release film 13. By providing this adhesion film 12, peeling of the release film 13 can be effectively suppressed. In particular, when the mold 1 is for molding a glass element, the adhesion of the release film 13 to the glass is low and the adhesion to the glass mold body 10 is also low. For this reason, when the adhesion film 12 is not present, the release film 13 is easily peeled off from the mold body 10. However, even in such a case, peeling of the release film 13 can be effectively suppressed by providing the adhesion film 12.

  The adhesion film 12 is made of, for example, a metal such as Ta, Ti, Ni, or Cr, or an alloy containing two or more metals selected from the group consisting of Ta, Ti, Ni, and Cr (preferably substantially Ta, And an alloy made of two or more metals selected from the group consisting of Ti, Ni and Cr. The adhesion film 12 may be formed of the same material as the protective film 11, and the adhesion film 12 and the protection film 11 may be formed from the same film in the same process.

  In the first embodiment, the adhesion film 12 and the release film 13 extend downward from the upper end surface 10a so as to cover the upper end surface 10a on which the molding surface is formed and to cover the upper end corner. That is, the end portions of the adhesion film 12 and the release film 13 are formed so as to be positioned on the peripheral surface of the mold body 10. By doing in this way, it can suppress effectively that the contact | adherence film | membrane 12 and the release film 13 peel from the shaping | molding die main body 10. FIG.

  In addition, by providing the metal adhesion film 12 and the release film 13 having conductivity on the mold body 10, the mold release property can be improved and the charging of the mold 1 can be suppressed. Therefore, it is possible to effectively suppress dust and the like in the atmosphere from adhering.

  The total film thickness of the adhesion film 12 and the release film 13 is preferably 1 μm or less. By doing so, it becomes easy to maintain the shape accuracy of the molding surface.

  The adhesion film 12 and the release film 13 can be formed by, for example, a sputtering method.

  FIG. 2 is a diagram illustrating a usage pattern of the mold 1.

  The mold 1 is disposed on a lower heating plate 5 in which a heater 4 is embedded, for example, as a lower mold. The upper mold 2 is arranged so as to face the molding surface of the mold 1. The base surface of the upper mold 2 is attached to the upper heating plate 3 in which the heater 4 is embedded. The upper heating plate 3 is connected to a pressurizer (not shown) such as a cylinder, and the glass material 6 disposed between the mold 1 and the upper mold 2 is pressed by the function of the pressurizer. The mold 1 and the upper mold 2 have the same outer diameter, and a barrel mold 7 having an inner diameter substantially equal to the outer diameter of the mold 1 is provided around the mold 1 and the upper mold 2. The mold 1 and the upper mold 2 are configured to slide in the body mold 7, and relative displacement between the mold 1 and the upper mold 2 is suppressed by the body mold 7.

  The mold 1 is fixed to the lower heating plate 5 with a certain amount of play in consideration of the amount of thermal expansion of each member. For this reason, when the element is molded, the mold 1 may be displaced to some extent and collide with the lower heating plate 5. Since the mold main body 10 is made of brittle glass, there is a possibility that cracking, pitching, chipping or the like may occur particularly in the lower end corner portion 10c due to the collision with the lower heating plate 5. However, in this Embodiment 1, since the lower end corner | angular part 10c and the lower end surface 10b are coat | covered with the metallic protective film 11 which has a malleability, generation | occurrence | production of a crack etc. is suppressed effectively. In addition, since cracks and the like are suppressed, the heat distribution of the entire mold 1 is stabilized, and stable production of elements is possible.

  In the usage example shown in FIG. 2, the mold 1 is used as the lower mold, but the mold 1 may of course be used as the upper mold.

(Modification 1: First Modification of Embodiment 1)
FIG. 3 is a cross-sectional view of a mold according to the first modification.

  In the mold according to this modification, a notch 10d having a depth t4 equal to the sum of the film thickness t2 of the adhesion film 12 and the film thickness t3 of the release film 13 circulates around the upper end corner of the mold body 10. Is formed. For this reason, the surface of the release film 13 and the peripheral surface of the mold body 10 are substantially flush.

  In the mold 1 according to the first embodiment, as shown in FIG. 1, a step is formed on the peripheral surface of the mold 1 by the release film 13. For this reason, as shown in FIG. 2, when the mold 1 slides with respect to the body mold 7, sliding resistance is generated at the step portion, which causes the release film 13 and the adhesion film 12 to form the mold. There is a risk of peeling from the main body 10.

  However, in the first modification, the surface of the release film 13 and the surface of the mold body 10 are almost flush with each other, and therefore the release film 13 and the adhesion film 12 caused by the sliding resistance with the body mold 7. Can be effectively suppressed.

(Modification 2: Second Modification of Embodiment 1)
FIG. 4 is a cross-sectional view of a mold according to the second modification.

  In the mold according to the second modification, the protective film 11 is formed so as to cover the entire surface of the mold body 10. Since the part located on the upper end surface 10a of the protective film 11 also has a function as the adhesion film 12, in other words, in the second modification, the adhesion film and the protection film are integrally formed.

  By forming the protective film 11 so as to cover the entire surface including the lower end corner portion of the mold body 10 as in the second modification, the peeling of the protective film 11 can be further effectively suppressed. In addition, as compared with the case where the protective film 11 and the adhesive film 12 are separately formed, the protective film 11 having the function as the adhesive layer can be formed with fewer steps.

  In the second modification, the portion that is provided on the upper end surface 10 a of the protective film 11 that also functions as an adhesion film and the portion of the protective film 11 that covers the upper end corner of the mold body 10 are covered. A release film 13 is formed. From the viewpoint of maintaining the shape of the molding surface, the total sum of the thickness of the protective film 11 and the thickness of the release film 13 is preferably 1 μm or less.

(Modification 3: Further Modification of Modification 2)
FIG. 5 is a cross-sectional view of a mold according to the third modification.

  In the third modification, a notch 10d having a depth t4 equal to the film thickness t2 of the release film 13 is formed around the upper end corner of the mold main body 10 so as to surround the peripheral surface of the mold main body 10. The surface of the release film 13 is substantially flush. For this reason, it is possible to effectively suppress the peeling of the release film 13 due to the sliding resistance with the body mold 7 for the same reason as described in the first modification.

  As described above, the optical element mold according to the present invention is excellent in durability. Therefore, it is useful for molding plastic optical elements, glass optical elements, and the like.

1 is a cross-sectional view of a mold 1 according to Embodiment 1. FIG. FIG. 2 is a diagram illustrating a usage pattern of the mold 1. 6 is a cross-sectional view of a mold according to Modification Example 1. FIG. 10 is a cross-sectional view of a mold according to Modification 2. FIG. 10 is a cross-sectional view of a mold according to Modification 3. FIG.

Explanation of symbols

1 Mold
2 Upper mold
3 Upper heating plate
4 Heater
5 Lower heating plate
6 Glass materials
7 Body type
10 Mold body
11 Protective film
12 Adhesive film
13 Release film

Claims (16)

A columnar glass mold body with a molding surface formed on the upper end surface;
A metal protective film that wraps around the lower end corner of the mold body; and
A mold equipped with. The mold according to claim 1, wherein
The said protective film is a shaping | molding die provided over the lower end surface whole surface from the lower end corner | angular part of the said shaping | molding die main body. The mold according to claim 1, wherein
The said protective film is a shaping | molding die provided over the whole surface including the lower end corner | angular part of the said shaping | molding die main body. In the mold according to claim 3,
A molding die in which the protective film located on the molding surface is covered with a release film. The mold according to claim 4, wherein
The mold which is extended downward so that the mold release film covers the protective film located on the upper end corner of the mold body. In the mold according to claim 5,
A mold in which a notch having a depth equal to the film thickness of the release film is formed around the upper end corner of the mold body. The mold according to claim 1, wherein
A release film formed on the adhesion film,
An adhesion film that is provided between the molding surface and the release film, and adheres the release film to the molding surface;
A mold further comprising The mold according to claim 7, wherein
The adhesive film extends downward to cover the upper end corner of the mold body, and the release film extends downward to cover the adhesive film extended downward. Mold. The mold according to claim 8, wherein
A mold in which a notch having a depth equal to the sum of the film thickness of the adhesive film and the film thickness of the release film is formed around the upper end corner of the mold body. The mold according to claim 7, wherein
The mold in which the adhesion film and the protective film are integrally formed. The mold according to claim 1, wherein
The mold body is formed of glass mainly composed of silicon dioxide. In the mold according to claim 4 or 7,
The mold is formed of a noble metal or an alloy containing a noble metal. In the mold according to claim 4 or 7,
The release film may be a metal selected from the group consisting of Pt, Ir, W, Re, Ta, Rh, Ru, and Os, or Pt, Ir, W, Re, Ta, Rh, Ru, and Os. A molding die formed of an alloy containing two or more metals selected from the group consisting of: The mold according to claim 1, wherein
The protective film is formed of a metal selected from the group consisting of Ta, Ti, Ni and Cr, or an alloy containing two or more metals selected from the group consisting of Ta, Ti, Ni and Cr. Type. The mold according to claim 4, wherein
A molding die in which the sum of the thickness of the protective film and the thickness of the release film is 1 μm or less. The mold according to claim 7, wherein
A molding die in which the total thickness of the adhesive film and the release film is 1 μm or less.

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