JPH0686308B2 - Optical glass - Google Patents
Optical glassInfo
- Publication number
- JPH0686308B2 JPH0686308B2 JP60263311A JP26331185A JPH0686308B2 JP H0686308 B2 JPH0686308 B2 JP H0686308B2 JP 60263311 A JP60263311 A JP 60263311A JP 26331185 A JP26331185 A JP 26331185A JP H0686308 B2 JPH0686308 B2 JP H0686308B2
- Authority
- JP
- Japan
- Prior art keywords
- glass
- temperature
- optical glass
- optical
- refractive index
- 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
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- Glass Compositions (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、比較的低温にてプレス成形でき、プレス成形
後研削または研摩を必要としない精密プレスレンズ用の
光学ガラスに関する。Description: TECHNICAL FIELD The present invention relates to an optical glass for precision press lenses which can be press-formed at a relatively low temperature and does not require grinding or polishing after press-forming.
従来の技術 従来同じような光学恒数を持つものとして、SKタイプ、
及びSSKタイプの光学ガラスが存在する。またプレス成
形用のガラスとして、リン酸塩系ガラス（特開昭55−15
4343、特開昭58−79839、特開昭60−122749参照）フル
オロリン酸塩系ガラス（特開昭56−59641、特開昭56−1
49343、特開昭58−217451参照）、フツホウ酸塩系ガラ
ス（特開昭59−146952参照）が知られている。Conventional technology The SK type, which has the same optical constant as before,
And SSK type optical glasses exist. Further, as a glass for press molding, a phosphate glass (see JP-A-55-15
4343, JP-A-58-79839, JP-A-60-122749) Fluorophosphate glass (JP-A-56-59641, JP-A-56-1)
49343, see JP-A-58-217451), and fluoroborate-based glasses (see JP-A-59-146952).
発明が解決しようとする問題点 従来よりあるSKタイプ、及びSSKタイプの光学ガラス
は、屈伏温度（At）が630℃もしくはそれ以上のものし
か存在せず、そのプレス温度は700℃を超える高い温度
でなければ成形することが出来なかった。第１表にSKタ
イプ、及びSSKタイプの例（屈折率（nd）、アッベ数
（νｄ）、屈伏温度（At）、並びに比重）を示す。Problems to be Solved by the Invention Conventional SK-type and SSK-type optical glasses have a deformation temperature (At) of only 630 ° C or higher, and the pressing temperature is a high temperature exceeding 700 ° C. Otherwise, it could not be molded. Table 1 shows examples of SK type and SSK type (refractive index (nd), Abbe number (νd), deformation temperature (At), and specific gravity).
プレス成形後、研削または研摩を必要としない精密プレ
ス加工の型材その他について特許等で発表されている
が、プレス成形温度が高温になると型材の酸化等の問題
が起り、面精度の保持が難しく量産には適さない。その
ためプレスされるガラスは、可能な限り低い温度で成形
されるのが望ましい。上記特許はそのためにガラス成形
酸化物として、リン酸及びホウ酸を選んでいる。しかし
リン酸及びホウ酸は、低温化には有利ではあるが、ガラ
スの化学的耐久性及び耐候性に問題が生じやすい。また
フッ素の導入は、低温化及び低分散化に有利であるが、
ガラス溶融時における安定性、プレス温度におけるフッ
素の揮発による型材、環境等に問題が生じやすい。鉛を
含んでいるガラスも上記特許に見られるが、鉛を含むと
フッ素同様鉛の揮発物が型材に付着し面精度の保持等に
問題が生じやすい。 Precision press mold materials that do not require grinding or polishing after press molding have been announced in patents, etc., but when the press molding temperature becomes high, problems such as oxidation of mold materials occur, making it difficult to maintain surface accuracy and mass production. Not suitable for. Therefore, it is desirable that the pressed glass be formed at the lowest possible temperature. For that purpose, the above-mentioned patent selects phosphoric acid and boric acid as glass forming oxides. However, although phosphoric acid and boric acid are advantageous for lowering the temperature, problems tend to occur in the chemical durability and weather resistance of the glass. Further, the introduction of fluorine is advantageous for lowering the temperature and lowering the dispersion,
Problems are likely to occur in stability during melting of glass, mold material, environment, etc. due to volatilization of fluorine at the pressing temperature. Glass containing lead is also found in the above patent, but when lead is contained, volatile substances of lead, like fluorine, adhere to the mold material, and problems such as maintaining surface accuracy tend to occur.
発明の目的 従って、本発明の第一の目的は比較的低い温度で精密プ
レスができ、プレス成形後研削または研摩を必要としな
い精密プレスレンズ用光学ガラスを提供することにあ
る。OBJECTS OF THE INVENTION Therefore, a first object of the present invention is to provide an optical glass for precision press lenses, which can perform precision press at a relatively low temperature and does not require grinding or polishing after press molding.
また、本発明の第二の目的は屈折率（nd）が1.595−1.6
35、アッベ数（νｄ）が50以上という中屈折率低分散の
光学ガラスを提供することにある。A second object of the present invention is that the refractive index (nd) is 1.595-1.6.
35, to provide an optical glass having a low medium-refractive-index dispersion having an Abbe number (νd) of 50 or more.
問題点を解決するための手段 本発明者等は以上のような従来の光学ガラス及びプレス
成形用光学ガラスの諸欠点をかんがみて、種々考察研究
した結果、SiO2、B2O3、Li2O、BaO、La2O3を必須とする
ガラス組成の光学ガラスは、SKタイプ、及びSSKタイプ
の光学ガラスとほぼ同等の光学恒数を有し、かつこれよ
りも低い温度においてプレス成形でき、型材への影響を
殆どないこと、及び更に上記特許のプレス成形用光学ガ
ラスよりも、安定性、化学的耐久性、耐候性、溶融性に
すぐれ、従来の光学ガラスと同様に扱え、かつ屈伏温度
（At）が低いため、プレス成形後研削または研摩を必要
としない精密プレスレンズ用光学ガラスとして最適であ
るところのガラス組成物を見出し、本発明に到達したも
のである。Means for Solving the Problems In view of various drawbacks of the conventional optical glass and the optical glass for press molding as described above, as a result of various studies, SiO2, B2O3, Li2O, BaO, La2O3 was selected. Optical glass of the essential glass composition, SK type, and has an optical constant almost equal to SSK type optical glass, and can be press-molded at a temperature lower than this, there is almost no effect on the mold material, And further, it is superior in stability, chemical durability, weather resistance, and meltability to the optical glass for press molding of the above patent, can be handled like conventional optical glass, and has a low yield temperature (At), so press molding The present invention has been accomplished by finding a glass composition that is most suitable as an optical glass for precision press lenses that does not require post-grinding or polishing.
すなわち、本発明を重量％で示すと SiO2 20−40％ B2O3 10〜20％ Li2O ３−９％ Na2O ０−10％ K2O ０−７％ ただし Li2O、Na2O、K2Oの二種以上 ９−18％ SrO ０−11％ BaO 13−45％ ZnO ０−５％ La2O3 ５−18％ Gd2O3 ０−５％ Yd2O3 ０−５％ からなる組成を有している。That is, when the present invention is expressed by weight%, SiO2 20-40% B2O3 10-20% Li2O 3-9% Na2O 0-10% K2O 0-7% However, two or more kinds of Li2O, Na2O and K2O 9-18% SrO It has a composition of 0-11% BaO 13-45% ZnO 0-5% La2O3 5-18% Gd2O3 0-5% Yd2O3 0-5%.
本発明に係る光学ガラスの各成分範囲を上記のように限
定した理由は次のとおりである。The reasons for limiting the respective component ranges of the optical glass according to the present invention as described above are as follows.
SiO2はガラスの網目を構成する主成分であるが、40％を
超えると、溶融時の粘性が大きくなり屈伏温度（At）の
上昇をまねき、20％より少ないと失透傾向が大きくな
る。SiO2 is the main constituent of the glass network, but when it exceeds 40%, the viscosity during melting increases and the yield temperature (At) rises, and when it is less than 20%, the devitrification tendency increases.
B2O3は、SiO2と同様ガラスの網目を構成し、ガラスの安
定化に有効な成分である。またガラスの均質化に有効で
あり、さらに適量含有させることにより屈伏温度（At）
を下げる。しかし10％より少ないと上記の効果が少な
く、20％より多くなると化学的耐久性が悪くなる。B2O3 forms a glass network like SiO2 and is an effective component for stabilizing glass. It is also effective for homogenizing glass, and the yielding temperature (At) can be improved by adding an appropriate amount.
Lower. However, if it is less than 10%, the above effect is small, and if it is more than 20%, the chemical durability is deteriorated.
Li2Oは、本発明において重要な意味を持つ成分であり、
Li2Oを必須配合成分として適量加えることにより、ガラ
スの安定性を損なうことなく、著しくプレス成形時の温
度を下げる効果を持つ。Li2Oが３％少ないと上記効果が
少なく、９％より多いと失透傾向の増大をまねく。Li2O is a component having an important meaning in the present invention,
By adding an appropriate amount of Li2O as an essential component, it has the effect of significantly lowering the temperature during press molding without impairing the stability of the glass. If the amount of Li2O is 3% less, the above effect is less, and if it is more than 9%, the devitrification tendency increases.
Na2O、K2Oもそれぞれプレス成形時の温度降下に寄与す
るが、Na2Oが10％、K2Oが７％より多いと失透傾向が増
大するばかりでなく、化学的耐久性も悪くなる。Na2O and K2O also contribute to the temperature drop during press molding, but when Na2O is more than 10% and K2O is more than 7%, not only the devitrification tendency increases but also the chemical durability deteriorates.
Li2O、Na2O及びK2Oの二種以上の合量が９％より少ない
と、プレス成形時の温度上昇となり、18％より多いと、
化学的耐久性が悪くなるとともに失透傾向も増大する。If the total amount of two or more of Li2O, Na2O and K2O is less than 9%, the temperature rises during press molding, and if it is more than 18%,
The chemical durability deteriorates and the devitrification tendency increases.
SrOは任意配合成分であり、BaOと組み合せることによ
り、BaOを単体で使用するよりも屈伏温度（At）を下げ
るが、SrOを11％より多くすると失透傾向の増大、及び
所定の光学性能が得られないのでこれ以下とする。SrO is an optional compounding ingredient, and when combined with BaO, it lowers the yield temperature (At) compared to using BaO alone, but when SrO is more than 11%, the devitrification tendency increases and the specified optical performance Since it can not be obtained, it will be less than this.
BaOは必須配合成分であり、屈折率を高めることに有効
であるが、13％より少ないと効果が少なく、45％より多
いと失透傾向が増大する。BaO is an essential compounding ingredient and is effective in increasing the refractive index, but if it is less than 13%, the effect is small, and if it is more than 45%, the devitrification tendency increases.
ZnOは任意配合成分であり、化学的耐久性が増すが、５
％より多いと失透傾向が増大する。ZnO is an optional compounding ingredient, increasing its chemical durability, but
%, The devitrification tendency increases.
La2O3は必須配合成分であり、BaOと同様に屈折率を高
め、化学的耐久性を良くする。５％より少ないと前記効
果が少なく、18％より多いと屈伏温度（At）の上昇、失
透傾向の増大となる。La2O3 is an essential compounding ingredient, and like BaO, it raises the refractive index and improves the chemical durability. If it is less than 5%, the above effect is small, and if it is more than 18%, the yield temperature (At) increases and the devitrification tendency increases.
Yd2O3及びGd2O3はそれぞれ任意配合成分であり、La2O3
と合せて光学性能の調整に使用するが、その量はそれぞ
れ５％以下で充分であり、これを超えると屈服温度（A
t）の上昇をもたらす。Yd2O3 and Gd2O3 are optional compounding ingredients, La2O3
5% or less is sufficient for adjusting the optical performance, and if the amount exceeds 5%, the yielding temperature (A
t) rise.
本発明の光学ガラスには、上記成分の他に光学性能の調
整、溶融性の改善、ガラス化範囲の拡大等のために、本
発明の目的から外れない限り、GeO2、ZrO2、TiO2、Nb2O
5、Ta2O5、Y2O3、In2O3、Ga2O3、Al2O3、WO3、MgO、Ca
O、PbOなどを含有させることができる。In the optical glass of the present invention, in addition to the above components, adjustment of optical performance, improvement of meltability, expansion of vitrification range, etc., unless deviated from the object of the present invention, GeO2, ZrO2, TiO2, Nb2O.
5, Ta2O5, Y2O3, In2O3, Ga2O3, Al2O3, WO3, MgO, Ca
O, PbO, etc. can be contained.
実施例 次に本発明に係る実施例の組成（数値は重量％、屈折率
（nd）、アッベ数（νｄ）、屈伏温度（At）、並びに比
重を示す）を第２表に示す。Example Next, Table 2 shows the composition (numerical values are weight%, refractive index (nd), Abbe number (νd), deformation temperature (At), and specific gravity) of an example according to the present invention.
本発明の光学ガラスは各成分の原料として、各々相当す
る酸化物、水酸化物、炭酸塩、硝酸塩等を使用し、所定
の割合で秤量し充分混合してガラス調合原料として、白
金製ルツボに投入して電気炉で1000−1200℃で溶融し、
白金製攪拌棒にて攪拌して、清澄、均質化してから適当
な温度に予熱した金型内に鋳込んだ後、除冷して作る。
なおガラスの着色を防ぎ、脱泡のために少量のAs2O3を
加えること、又は工業上良く知られている脱泡成分の少
量添加は、本発明の効果に影響を与えない。The optical glass of the present invention uses, as raw materials for each component, corresponding oxides, hydroxides, carbonates, nitrates, etc., weighed and mixed sufficiently at a predetermined ratio and used as a glass preparation raw material in a platinum crucible. Charge and melt in an electric furnace at 1000-1200 ℃,
Stir with a platinum stir bar to clarify and homogenize, then cast in a mold preheated to an appropriate temperature and then cool.
It should be noted that addition of a small amount of As2O3 for preventing decoloration of glass and defoaming, or addition of a small amount of defoaming component well known in industry does not affect the effect of the present invention.
発明の効果 本発明によれば、屈伏温度（At）が550℃以下で、屈折
率（nd）が1.595−1.635、アッベ数（νｄ）が50以上の
光学恒数を有し、失透に対して安定で、比較的低い温度
で精密プレスができ、プレス成形後研削または研摩を必
要としないプレスレンズ用光学ガラスが得られる。 EFFECTS OF THE INVENTION According to the present invention, an optical constant having a yield temperature (At) of 550 ° C. or lower, a refractive index (nd) of 1.595-1.635, and an Abbe number (νd) of 50 or more is used. The optical glass for press lenses is stable and stable, can be precision pressed at a relatively low temperature, and does not require grinding or polishing after press molding.
Claims (1)
d）が1.595〜1.635であり、アッベ数（νｄ）が50以上
の比較的低軟化点を有し中屈折率低分散の特性を有する
精密プレスレンズ用光学ガラス1. SiO 2 20-40 wt% B 2 O 3 10-20 wt% Li 2 O 3-9 wt% Na 2 O 0-10 wt% K 2 O 0-7 wt% Li 2 O, Two or more of Na 2 O and K 2 O 9-18 wt% SrO 0-11 wt% BaO 13-45 wt% ZnO 0-5 wt% La 2 O 3 5-18 wt% Gd 2 O 3 0-5 % Yb 2 O 3 0-5% by weight or more The bending temperature (At) is 550 ° C or less, and the refractive index (n
d) is 1.595 to 1.635, Abbe's number (νd) is 50 or more, has a relatively low softening point, and has a medium refractive index and low dispersion optical glass for precision press lenses
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60263311A JPH0686308B2 (en) | 1985-11-22 | 1985-11-22 | Optical glass |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60263311A JPH0686308B2 (en) | 1985-11-22 | 1985-11-22 | Optical glass |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62123040A JPS62123040A (en) | 1987-06-04 |
| JPH0686308B2 true JPH0686308B2 (en) | 1994-11-02 |
Family
ID=17387713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60263311A Expired - Fee Related JPH0686308B2 (en) | 1985-11-22 | 1985-11-22 | Optical glass |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0686308B2 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2616958B2 (en) * | 1988-05-10 | 1997-06-04 | 株式会社住田光学ガラス | Optical glass for precision press molding |
| JPH0743791Y2 (en) * | 1989-02-07 | 1995-10-09 | タナシン電機株式会社 | Tape recorder device |
| JP2535407B2 (en) * | 1989-05-31 | 1996-09-18 | ホーヤ株式会社 | Optical glass |
| JP2726310B2 (en) * | 1989-07-04 | 1998-03-11 | 株式会社住田光学ガラス | Optical glass for precision press molding |
| JP4923366B2 (en) * | 2001-09-13 | 2012-04-25 | 日本電気硝子株式会社 | Optical glass for mold press molding |
| JP3555681B2 (en) * | 2001-10-29 | 2004-08-18 | 日本電気硝子株式会社 | Glass for mold press molding |
| JP4453328B2 (en) * | 2003-10-09 | 2010-04-21 | 日本電気硝子株式会社 | Mold press molding glass and method for producing the same |
| JP2009073674A (en) * | 2006-09-04 | 2009-04-09 | Nippon Electric Glass Co Ltd | Method for producing glass |
| JP6163620B1 (en) * | 2017-04-05 | 2017-07-12 | 株式会社住田光学ガラス | Optical glass and optical element |
| JP7089870B2 (en) * | 2017-12-28 | 2022-06-23 | 株式会社オハラ | Optical glass, optics and preforms |
| CN111204969A (en) * | 2020-03-06 | 2020-05-29 | 成都光明光电股份有限公司 | Optical glass, glass preform, optical element and optical instrument |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57179047A (en) * | 1981-04-24 | 1982-11-04 | Fuji Photo Film Co Ltd | Optical glass |
| JPS58194755A (en) * | 1982-05-07 | 1983-11-12 | Ohara Inc | Optical glass |
| DE3331106C2 (en) * | 1983-08-30 | 1985-09-19 | Schott Glaswerke, 6500 Mainz | Optical glass with a Brecht value ≥ 1.60 and an Abbe number ≥ 58, with high chemical stability and resistance to segregation and crystallization in the system SiO 2 -B 2 O 3 -SrO-La 2 O 3 -Al? 2? O? 3? -BaO-alkali oxide-F |
-
1985
- 1985-11-22 JP JP60263311A patent/JPH0686308B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62123040A (en) | 1987-06-04 |
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|---|---|---|---|
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Free format text: JAPANESE INTERMEDIATE CODE: R250 |
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