JPH0764573B2 - Mold for optical element - Google Patents
Mold for optical elementInfo
- Publication number
- JPH0764573B2 JPH0764573B2 JP63116341A JP11634188A JPH0764573B2 JP H0764573 B2 JPH0764573 B2 JP H0764573B2 JP 63116341 A JP63116341 A JP 63116341A JP 11634188 A JP11634188 A JP 11634188A JP H0764573 B2 JPH0764573 B2 JP H0764573B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- molding
- optical element
- hardness
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
- C03B11/06—Construction of plunger or mould
- C03B11/08—Construction of plunger or mould for making solid articles, e.g. lenses
- C03B11/084—Construction of plunger or mould for making solid articles, e.g. lenses material composition or material properties of press dies therefor
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2215/00—Press-moulding glass
- C03B2215/02—Press-mould materials
- C03B2215/05—Press-mould die materials
- C03B2215/07—Ceramic or cermets
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Ceramic Products (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、光学素子の成形型に関する。The present invention relates to a mold for an optical element.
近年、レンズ，プリズム，フィルタ等の光学素子の製造
方法として、研削，研磨等を行わずに、高い面精度の一
対の成形型間に加熱軟化した光学素子のガラス素材を挿
入配置し、これを加圧するだけで光学素子を得る押圧成
形が行われている。In recent years, as a method of manufacturing optical elements such as lenses, prisms, and filters, a glass material of an optical element that has been softened by heating is inserted and arranged between a pair of molding dies with high surface accuracy without grinding or polishing. Press molding is performed in which an optical element is obtained only by applying pressure.
従来、かかる製造方法において用いられる成形型は、例
えば特開昭59−123631号公報に開示されるように、WC
（炭化タングステン）およびCo（コバルト）を主成分と
する材料により形成されていた。Conventionally, the molding die used in such a manufacturing method is WC as disclosed in, for example, JP-A-59-123631.
(Tungsten carbide) and Co (cobalt) as the main components.
しかし、上記従来のWC−Co系合金からなる成形型は、第
１図および第２図に示すように、約500℃以上の温度領
域で曲げ強度および硬度が急激に低下してしまった。第
１図は、横軸に温度をとり、縦軸に曲げ強度をとったも
ので、第１図において実線１が上記従来の成形型の特性
を示す。また、第２図は、横軸に温度をとり、縦軸に硬
度をとったもので、第２図において実線２が上記従来の
成形型の特性を示す。However, as shown in FIG. 1 and FIG. 2, the bending mold and the hardness of the conventional mold made of the above WC-Co alloy drastically decreased in the temperature range of about 500 ° C. or higher. FIG. 1 shows temperature on the horizontal axis and bending strength on the vertical axis. In FIG. 1, the solid line 1 shows the characteristics of the conventional molding die. Further, in FIG. 2, the horizontal axis represents temperature and the vertical axis represents hardness, and the solid line 2 in FIG. 2 shows the characteristics of the conventional molding die.
このように、WC−Co系合金からなる成形型が、曲げ強度
および硬度の低下を生じるのは、バインダーとして用い
られるCoの表面析出および酸化が原因であり、またWC粒
子のＷの解離および酸化が原因である。曲げ強度および
硬度の低下は、ガラスレンズ等の成形に際して、成形面
の表面劣化や形状変化（型変化）等の現象となって現
れ、レンズ精度を低下せしめ、さらには型表面に設けた
コーティング層の剥離等を惹起し、成形型の耐久性を著
しく低下させてしまう。As described above, the reason why the mold made of the WC-Co alloy causes a decrease in bending strength and hardness is due to the surface precipitation and oxidation of Co used as a binder, and the dissociation and oxidation of W in WC particles. Is the cause. The decrease in bending strength and hardness manifests itself as a phenomenon such as surface deterioration of the molding surface and shape change (mold change) during the molding of glass lenses, etc., which lowers the lens accuracy and further a coating layer provided on the mold surface. Peeling off of the mold and the durability of the molding die are significantly reduced.
本発明は、かかる従来の問題点に鑑みてなされたもの
で、型寿命が長く、低コストにして高品質の光学素子を
得ることができる光学素子の成形型を提供することを目
的とする。。The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a mold for an optical element, which has a long mold life, can be manufactured at low cost, and can obtain a high quality optical element. .
上記目的を達成するために、本発明は、光学素子の成形
型において、少なくとも型基材がWCおよびCr3C2（炭酸
クロム）を75〜97重量％含有し、かつCo（コバルト）を
含有しないように構成した。WCおよびCr3C2が75重量％
未満であると、十分な硬度が得られないとともに、結晶
粒が大きくなり易くなってしまう。一方、WCおよびCr3C
2が97重量％を越えると、脆性が増加してしまう。In order to achieve the above object, the present invention relates to a mold for an optical element, in which at least the mold base contains WC and Cr 3 C 2 (chromium carbonate) in an amount of 75 to 97% by weight and contains Co (cobalt). Configured not to. 75% by weight of WC and Cr 3 C 2
If it is less than this, sufficient hardness cannot be obtained, and the crystal grains tend to become large. On the other hand, WC and Cr 3 C
When 2 exceeds 97% by weight, brittleness increases.
本発明において、WCとCr3C2との割合は、重量比で0.5≧
Cr3C2／（Cr3C2＋WC）≧0.05が特に好ましい。Cr3C2／
（Cr3C2＋WC）が0.5より大きくなると、熱膨張係数が大
きくなり過ぎてしまうとともに、研削の際のみがき粗さ
が悪くなってしまう。一方、Cr3C2／（Cr3C2＋WC）が0.
05より小さくなると、熱膨張係数が小さくなり過ぎてし
まうとともに、耐高温酸化性が低下してしまう。In the present invention, the weight ratio of WC and Cr 3 C 2 is 0.5 ≧.
Cr 3 C 2 / (Cr 3 C 2 + WC) ≧ 0.05 is particularly preferable. Cr 3 C 2 /
If (Cr 3 C 2 + WC) is larger than 0.5, the coefficient of thermal expansion will be too large, and the roughness will be poor only during grinding. On the other hand, Cr 3 C 2 / (Cr 3 C 2 + WC) is 0.
If it is less than 05, the thermal expansion coefficient will be too small and the high temperature oxidation resistance will decrease.
また、本発明においては、NiとCrをバインダーとして用
いてもよい。さらに、成形型の型基材だけでなく、成形
型全体をWCおよびCr3C2を75〜97重量％含有する合金か
ら形成してもよい。型基材をWCおよびCr3C2で成形した
ときには、成形面に対し、窒化物，炭化物，硼化物等の
セラミックス層や高融点合金層を被覆するとよい。Further, in the present invention, Ni and Cr may be used as binders. Furthermore, not only the mold bases of the mold, the entire mold WC and Cr 3 C 2 may be formed from 75 to 97 wt% containing alloys. When the mold base material is molded with WC and Cr 3 C 2 , the molding surface is preferably covered with a ceramic layer of a nitride, a carbide, a boride or the like or a high melting point alloy layer.
なお、本発明の成形型は、所定量の合金粉末を粉末焼結
により焼結して概略形状に作成と、これを研削，研磨し
て最終形状に加工する。The forming die of the present invention sinters a predetermined amount of alloy powder by powder sintering to form a rough shape, and then grinds and polishes this to form a final shape.
本発明の成形型によれば、Coを含有していないので、曲
げ強度および硬度が高温領域においても優れており、ま
た高温耐食性に優れ、熱膨張係数も光学ガラスに極めて
近似しており、精密成形を行うことができ、高品質の光
学素子を得ることができる。また、型基材の成形面にコ
ーティング層を形成した場合、型基材とコーティング層
との密着性は、極めて良好となる。According to the mold of the present invention, since it does not contain Co, the bending strength and hardness are excellent even in the high temperature region, the high temperature corrosion resistance is excellent, and the coefficient of thermal expansion is extremely close to that of optical glass. Molding can be performed and a high quality optical element can be obtained. Further, when the coating layer is formed on the molding surface of the mold base material, the adhesion between the mold base material and the coating layer becomes extremely good.
（第１実施例） 粒径３μｍ以下のWC、粒径５μｍ以下のCr3C2および微
粒粉末のNiを所定量混合し、これを通常の条件で仮焼結
した後、機械研削を施し、本焼結を行って、WC78重量
％、Cr3C2５重量％およびNi17重量％からなる型基材を
得た。そして、この型基材の成形面にCrN−BN層を0.5μ
ｍの厚さで形成した。(First Example) A predetermined amount of WC having a particle size of 3 μm or less, Cr 3 C 2 having a particle size of 5 μm or less, and Ni of a fine powder were mixed, pre-sintered under normal conditions, and then mechanically ground, The main sintering was performed to obtain a mold base material composed of 78% by weight of WC, 5% by weight of Cr 3 C 2 and 17% by weight of Ni. Then, a CrN-BN layer of 0.5μ is formed on the molding surface of this mold base material.
It was formed with a thickness of m.
（第２実施例） 第１実施例と同様にして、WC−７Cr3C2−13Ni−2Crから
なる型基材を作成し、この成形面にCrN−BN層0.5μｍの
厚さで形成した。(Second Embodiment) In the same manner as in the first embodiment, to create a mold substrate comprising a WC-7Cr 3 C 2 -13Ni- 2Cr, was formed to a thickness of CrN-BN layer 0.5μm on the molding surface .
（第３実施例） 第１実施例と同様にして、WC−30Cr3C2−18Niからなる
型基材を作成し、この成形面にCrN−BN層を0.5μｍの厚
さで形成した。(Third Embodiment) In the same manner as in the first embodiment, to create a mold substrate comprising a WC-30Cr 3 C 2 -18Ni, to form a CrN-BN layer on the molding surface at a thickness of 0.5 [mu] m.
（第４実施例） 第１実施例と同様にして、WC−30Cr3C2−15Ni−2Moから
なる成形型を得た。本実施例では、コーティング層を設
けていない。(Fourth Embodiment) In the same manner as in the first embodiment, to obtain a mold made of WC-30Cr 3 C 2 -15Ni- 2Mo. In this embodiment, no coating layer is provided.
各実施例で得た成形型を用いて、SiO2−PbO−BaO系光学
ガラスの一種であるBaSF08を約550℃の型表面温度で500
ショットの連続成形を行い、その後の成形型の変化を評
価した。その結果を次表に示した。Using the molds obtained in the respective examples, BaSF08, which is a type of SiO 2 —PbO—BaO optical glass, was applied at a mold surface temperature of about 550 ° C.
Continuous molding of shots was performed, and changes in the molding die after that were evaluated. The results are shown in the table below.
上記表から判るように、各実施例の成形型は、多少の変
色は生じるものの、500ショット後においても何らの形
状変化がなく、いずれも継続使用が可能な状態であり、
実用に適することができる。ただ、コーティング層を設
けていない第４実施例の形成型よりもコーティング層を
設けた第１〜第３実施例の成形型の方が、成形レンズ面
の粗さが細かく、耐久性も優れていた。また、各実施例
の成形型の熱膨張係数は、従来例の成形型の熱膨張係数
よりも大きく、6.5×10-6〜８×10-6の値を示し、光学
ガラスの熱膨張係数と近似しており、精密成形に最適で
ある。さらに、セラミックス、超合金等の耐温耐久性材
料の中でも中間の熱膨張係数であるため、使い易いもの
である。 As can be seen from the above table, the molding die of each example, although some discoloration occurs, there is no shape change after 500 shots, both are in a state in which continuous use is possible,
Can be suitable for practical use. However, the molding dies of the first to third embodiments provided with the coating layer have finer surface roughness of the molded lens and are superior in durability than the molding dies of the fourth embodiment not provided with the coating layer. It was Further, the coefficient of thermal expansion of the molding die of each example is larger than that of the molding die of the conventional example, and shows a value of 6.5 × 10 −6 to 8 × 10 −6 , which is equal to that of the optical glass. It is similar and is most suitable for precision molding. Furthermore, it has an intermediate coefficient of thermal expansion among temperature resistant and durable materials such as ceramics and superalloys, and is therefore easy to use.
なお、第２実施例の成形型について、曲げ強度および硬
度を測定し、その結果を第１図および第２図に示した。
第１図において、実線３が第２実施例の成形型の特性を
示し、第２図において実線４が第２実施例の成形型の特
性を示す。第１図および第２図から判るように、第２実
施例の成形型は、従来例の成形型に比して、高温領域で
の曲げ強度および硬度が優れている。The bending strength and hardness of the mold of Example 2 were measured, and the results are shown in FIGS. 1 and 2.
In FIG. 1, solid line 3 shows the characteristics of the molding die of the second embodiment, and in FIG. 2, solid line 4 shows the characteristics of the molding die of the second embodiment. As can be seen from FIGS. 1 and 2, the forming die of the second embodiment is superior in bending strength and hardness in the high temperature region to the forming die of the conventional example.
以上のように、本発明の光学素子の成形型によれば、少
なくとも型基材がWCおよびCr3C2を75〜97重量％含有か
つCoを含有しないようになっているので、高温領域にお
いて曲げ強度および硬度が優れ、また高温耐食性に優れ
るとともに、熱膨張係数も光学ガラスに極めて近似して
いるので、精密成形に最適であり、コーティング層の剥
離を生じることもなく、型寿命が長くなって、低コスト
にして高品質の光学素子を得ることができる。As described above, according to the mold for the optical element of the present invention, at least the mold base material contains 75 to 97% by weight of WC and Cr 3 C 2 and does not contain Co, so that in a high temperature region. It has excellent bending strength and hardness, high-temperature corrosion resistance, and a coefficient of thermal expansion that is very close to that of optical glass, making it ideal for precision molding, with no peeling of the coating layer and longer mold life. Thus, it is possible to obtain a high quality optical element at low cost.
第１図は成形型の曲げ強度を示す特性図、第２図は成形
型の硬度を示す特性図である。FIG. 1 is a characteristic diagram showing the bending strength of the forming die, and FIG. 2 is a characteristic diagram showing the hardness of the forming die.
Claims (1)
び炭化クロムを75〜97重量％含有し、かつコバルトを含
有しないことを特徴とする光学素子の成形型。1. A mold for an optical element, characterized in that at least a mold base material contains 75 to 97% by weight of tungsten carbide and chromium carbide and does not contain cobalt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63116341A JPH0764573B2 (en) | 1988-05-13 | 1988-05-13 | Mold for optical element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63116341A JPH0764573B2 (en) | 1988-05-13 | 1988-05-13 | Mold for optical element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01286964A JPH01286964A (en) | 1989-11-17 |
| JPH0764573B2 true JPH0764573B2 (en) | 1995-07-12 |
Family
ID=14684548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63116341A Expired - Fee Related JPH0764573B2 (en) | 1988-05-13 | 1988-05-13 | Mold for optical element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0764573B2 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60127246A (en) * | 1983-12-09 | 1985-07-06 | Matsushita Electric Ind Co Ltd | Direct press mold for optical glass lenses |
-
1988
- 1988-05-13 JP JP63116341A patent/JPH0764573B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01286964A (en) | 1989-11-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |