JP2003192384A - Methods for producing glass material for press molding, glass press molded article and optical device - Google Patents
Methods for producing glass material for press molding, glass press molded article and optical deviceInfo
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- JP2003192384A JP2003192384A JP2002280358A JP2002280358A JP2003192384A JP 2003192384 A JP2003192384 A JP 2003192384A JP 2002280358 A JP2002280358 A JP 2002280358A JP 2002280358 A JP2002280358 A JP 2002280358A JP 2003192384 A JP2003192384 A JP 2003192384A
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- glass
- temperature
- press
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はプレス成形品を作る
ためのガラス素材を溶融ガラスから作製し、この素材を
用いて光学素子ブランクなどのガラスプレス成形品を製
造する方法、ならびにガラスプレス成形品からレンズな
どの光学素子を製造する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a glass material for producing a press-formed product from molten glass and using the material to produce a glass press-formed product such as an optical element blank, and a glass press-formed product. The present invention relates to a method of manufacturing an optical element such as a lens.
【０００２】[0002]
【従来の技術】溶融ガラスを鋳型に流し込むなどしてガ
ラス板を成形し、ガラス板をアニールした後、賽の目状
に切断してカットピースを作り、これらにバレル研磨を
施してプレス成形用素材を作製する方法がある。上記素
材は再加熱、軟化された状態で成形型を使用していわゆ
るリヒートプレスを施され、レンズブランクなどの成形
品となる。そしてさらに、レンズブランクに研削、研磨
加工を施してレンズを作製することができる。2. Description of the Related Art A glass plate is formed by pouring molten glass into a mold, the glass plate is annealed, and then cut into cut pieces to make cut pieces, which are barrel-polished to form a press-forming material. There is a method of making. The above-mentioned material is subjected to so-called reheat pressing using a molding die in a state of being reheated and softened to be a molded article such as a lens blank. Then, the lens blank can be further ground and polished to produce a lens.
【０００３】[0003]
【発明が解決しようとする課題】レンズなどの材料とな
る光学ガラスのうち、ほとんどのガラスでは、上記リヒ
ートプレス成形により、品質のよい光学素子ブランクが
得られる。しかし、ガラスの種類によっては、透明なプ
レス成形用素材を使用しても、成形されたブランクが失
透し、研削、研磨を施しても到底、光学素子としては使
用できないケースがある。しかるに従来、透明なプレス
成形用素材が成形により失透するという現象が何故起こ
るのか分かっておらず、このような場合、対処のしよう
がなかったのが現状である。Among most optical glasses used as materials for lenses and the like, a good quality optical element blank can be obtained by the above-mentioned reheat press molding. However, depending on the type of glass, even if a transparent press-molding material is used, the molded blank is devitrified, and even if it is ground or polished, it cannot be used as an optical element at all. However, in the past, it was not known why the phenomenon of devitrification of a transparent press-molding material due to molding occurred, and in such a case, it was impossible to deal with it.
【０００４】そこで本発明の目的は、リヒートプレス成
形で失透しやすいガラスでも、透明な高品質のプレス成
形品を製造できる、ガラス素材の製造方法、及びプレス
成形品の製造方法を提供することにある。さらに本発明
は、ガラス素材が、リヒートプレス成形する際に失透し
やすいガラスか否かを判定し、失透しやすいガラス素材
の場合、失透が生じにくいガラス素材とし得る、ガラス
素材の製造方法及びプレス成形品の製造方法を提供する
ことにある。Therefore, an object of the present invention is to provide a method for producing a glass material and a method for producing a press-molded product, which are capable of producing a transparent high-quality press-molded product even if the glass is easily devitrified by reheat press molding. It is in. Furthermore, the present invention determines whether the glass material is a glass that is easily devitrified during reheat press molding, and in the case of a glass material that is easily devitrified, a glass material that does not easily cause devitrification can be produced. It is to provide a method and a method for manufacturing a press-formed product.
【０００５】[0005]
【課題を解決するための手段】上記課題を解決する本発
明は以下のとおりである。
（請求項１）ガラス原料を溶解する工程、得られた溶融
ガラスを成形する工程、及び成形されたガラスをアニー
ルする工程を含むプレス成形用ガラス素材の製造方法で
あって、前記溶融ガラスは、(1)室温まで急冷すると波
長４００〜２５００ｎｍにおける散乱係数が０．００５
ｃｍ-1未満であるか、または体積分率で１０-6未満の結
晶を含むガラスとなり、かつ(2)ガラス転移温度より１
０℃高い温度に３時間保持し、１０4.5 〜１０3.5 ｄＰ
ａ・ｓの粘度を示す温度に１０分間保持した後に室温ま
で急冷すると、波長４００〜２５００ｎｍの少なくとも
１波長における散乱係数が０．０１ｃｍ-1以上である
か、または体積分率で１０-5より多い結晶を含むガラス
となる組成を有すること、及び前記成形されたガラスの
アニールをガラス転移温度未満の温度で行うことを特徴
とするプレス成形用ガラス素材の製造方法（本発明の第
１の方法）。
(請求項２)ガラス原料を溶解する工程、得られた溶融ガ
ラスを成形する工程、及び成形されたガラスをアニール
する工程を含むプレス成形用ガラス素材の製造方法であ
って、前記製造方法に先立って、前記溶融ガラスが、
(1)室温まで急冷すると波長４００〜２５００ｎｍにお
ける散乱係数が０．００５ｃｍ-1未満であるか、または
体積分率で１０-6未満の結晶を含むガラスとなり、かつ
(2)ガラス転移温度より１０℃高い温度に３時間保持
し、１０4.5 〜１０3.5 ｄＰａ・ｓの粘度を示す温度に
１０分間保持した後に室温まで急冷すると、波長４００
〜２５００ｎｍの少なくとも１波長における散乱係数が
０．０１ｃｍ-1以上であるか、または体積分率で１０-5
より多い結晶を含むガラスとなる性質を有するか否かを
判定すること、及び前記溶融ガラスが前記(1)及び(2)の
ガラスとなる性質を有する場合、成形されたガラスのア
ニールをガラス転移温度未満の温度で行うことを特徴と
するプレス成形用ガラス素材の製造方法（本発明の第２
の方法）。
(請求項３)前記ガラス素材がＳｉＯ2、ＴｉＯ2及びＮｂ
2Ｏ5を含むガラスからなることを特徴とする請求項１ま
たは２に記載のプレス成形用ガラス素材の製造方法。
(請求項４)前記ガラス素材がＳｉＯ2、ＴｉＯ2及びＮｂ
2Ｏ5を含み、かつＴｉＯ2とＮｂ2Ｏ5の合量が３５重量
％以上であるガラスからなることを特徴とする請求項１
〜３のいずれかに記載のプレス成形用ガラス素材の製造
方法。
(請求項５)請求項１〜４のいずれかに記載のプレス成形
用ガラス素材を加熱、軟化してプレス成形することを特
徴とするガラスプレス成形品の製造方法。
(請求項６)請求項５に記載の方法により、光学素子ブラ
ンクを成形し、前記ブランクを研削、研磨して光学素子
を作製する光学素子の製造方法。
(請求項７)加熱軟化してプレス成形するためのプレス成
形用ガラス素材において、ガラス転移温度より１０℃高
い温度に３時間保持し、１０4.5〜１０3.5ｄＰａ・ｓの
粘度を示す温度に１０分間保持した後に室温まで急冷し
た場合には、波長４００〜２５００ｎｍの少なくとも１
波長における散乱係数が０．０１ｃｍ-1以上であるか、
または体積分率で１０-5より多い結晶を含むガラスから
なり、１０4.5〜１０3.5ｄＰａ・ｓの粘度を示す温度に
１０分間保持した後に室温まで急冷すると、波長４００
〜２５００ｎｍにおけるガラス内部の散乱係数が０．０
０５ｃｍ-1未満であるか、または内部に含有する結晶の
体積分率が１０-6未満であることを特徴とするプレス成
形用ガラス素材。Means for Solving the Problems The present invention for solving the above problems is as follows. (Claim 1) A method for producing a glass material for press molding, comprising the steps of melting a glass raw material, molding the obtained molten glass, and annealing the molded glass, wherein the molten glass comprises: (1) When rapidly cooled to room temperature, the scattering coefficient at wavelengths of 400 to 2500 nm is 0.005.
It is a glass containing crystals of less than cm -1 or less than 10 -6 in volume fraction, and (2) 1 from the glass transition temperature.
Hold at a high temperature of 0 ℃ for 3 hours, and 10 4.5 to 10 3.5 dP
When it is rapidly cooled to room temperature after being held at a temperature showing a viscosity of a · s for 10 minutes, the scattering coefficient is at least 0.01 cm −1 or more at at least one wavelength of 400 to 2500 nm, or the volume fraction is 10 −5 A method for producing a glass material for press molding, which has a composition that results in a glass containing a large number of crystals, and anneals the molded glass at a temperature lower than the glass transition temperature (the first method of the present invention. ). (Claim 2) A method of manufacturing a glass material for press molding, comprising the steps of melting a glass raw material, molding the obtained molten glass, and annealing the molded glass, which is prior to the manufacturing method. Then, the molten glass is
(1) When rapidly cooled to room temperature, the glass has a scattering coefficient at a wavelength of 400 to 2500 nm of less than 0.005 cm −1 or a crystal containing less than 10 −6 in volume fraction, and
(2) A temperature of 400 ° C. higher than the glass transition temperature is maintained for 3 hours, a temperature showing a viscosity of 10 4.5 to 10 3.5 dPa · s is maintained for 10 minutes, and then rapidly cooled to room temperature.
Scattering coefficient is at least 0.01 cm −1 or at least one wavelength of ˜2500 nm, or is 10 −5 in volume fraction.
Determining whether or not it has the property of becoming a glass containing more crystals, and if the molten glass has the property of becoming the glass of (1) and (2) above, annealing the formed glass is performed to a glass transition. A method for producing a glass material for press molding, which is characterized in that the step is performed at a temperature lower than the temperature (the second aspect of the present invention.
the method of). (Claim 3) The glass material is SiO 2 , TiO 2 or Nb.
The method for producing a glass material for press molding according to claim 1 or 2, wherein the glass material contains 2 O 5 . (Claim 4) The glass material is SiO 2 , TiO 2 or Nb.
2. A glass containing 2 O 5 and having a total amount of TiO 2 and Nb 2 O 5 of 35% by weight or more.
4. The method for producing a glass material for press molding according to any one of 3 to 3. (Claim 5) A method for producing a glass press-molded article, which comprises heating and softening the glass material for press-molding according to any one of claims 1 to 4 and press-molding. (Claim 6) A method for manufacturing an optical element, comprising forming an optical element blank by the method according to claim 5 and grinding and polishing the blank to produce an optical element. (Claim 7) In a glass material for press molding for softening by heating and press molding, the glass material is held at a temperature 10 ° C higher than the glass transition temperature for 3 hours, and at a temperature showing a viscosity of 10 4.5 to 10 3.5 dPa · s. In the case of quenching to room temperature after holding for at least 1 minute, at least 1 of wavelength 400-2500 nm
Whether the scattering coefficient at the wavelength is 0.01 cm -1 or more,
Alternatively, when a glass containing glass having a volume fraction of more than 10 −5 is contained and a temperature showing a viscosity of 10 4.5 to 10 3.5 dPa · s is maintained for 10 minutes and then rapidly cooled to room temperature, a wavelength of
The scattering coefficient inside the glass at ~ 2500 nm is 0.0
A glass material for press molding, which is less than 05 cm −1 or has a volume fraction of crystals contained therein of less than 10 −6 .
【０００６】[0006]
【発明の実施の形態】本発明は、次のような知見に基づ
きなされた。通常のガラスは、ガラス転移温度（Ｔ
ｇ）、核形成温度、結晶成長温度、溶融温度の関係は図
１のようになっている。これに対し、上記問題を起こす
ガラスでは、図２のようになっているものと考えられ
る。従来のガラス素材の製造方法においては、溶融ガラ
スから得られる成形ガラスは、Ｔｇよりやや高い温度域
でアニールされる。この場合、図１に示すガラス転移温
度（Ｔｇ）及び核形成温度の関係を有するガラスでは、
アニール時に核形成はほとんど生じない。しかし、図２
に示すガラス転移温度（Ｔｇ）及び核形成温度の関係を
有するガラスでは、Ｔｇよりやや高い温度域でアニール
すると、アニール温度が核形成温度域に入ってしまう。
そのため、アニール中に核形成が起こる。しかし、核は
微小であることからガラス自体は透明である。そして、
アニールされたガラスは、冷間加工されるか、そのまま
プレス成形用ガラス素材になる。BEST MODE FOR CARRYING OUT THE INVENTION The present invention was made based on the following findings. Normal glass has a glass transition temperature (T
The relationship among g), the nucleation temperature, the crystal growth temperature and the melting temperature is as shown in FIG. On the other hand, it is considered that the glass that causes the above problem is as shown in FIG. In the conventional glass material manufacturing method, the molded glass obtained from the molten glass is annealed in a temperature range slightly higher than Tg. In this case, the glass having the relationship between the glass transition temperature (Tg) and the nucleation temperature shown in FIG.
Almost no nucleation occurs during annealing. However, FIG.
In the glass having the relationship between the glass transition temperature (Tg) and the nucleation temperature shown in (3), the annealing temperature falls within the nucleation temperature range when annealed in a temperature range slightly higher than Tg.
Therefore, nucleation occurs during annealing. However, the glass itself is transparent because the nuclei are minute. And
The annealed glass is cold-worked or is directly used as a glass material for press molding.
【０００７】その後、上記ガラスは、リヒートプレスに
供させる際に結晶成長温度領域まで加熱される。核形成
が生じない図１に示すガラス転移温度（Ｔｇ）及び核形
成温度の関係を有するガラスでは、リヒートプレスのた
めの加熱によっても結晶成長は起こらず、内部が透明な
プレス成形品が得られる。しかし、図２に示すガラス転
移温度（Ｔｇ）及び核形成温度の関係を有するガラスで
は、上述のようにアニール時に核形成が起こるため、リ
ヒートプレスのための再加熱によってガラスの結晶化が
進み、失透してしまう。After that, the glass is heated to the crystal growth temperature range when it is subjected to reheat pressing. In the glass having the relationship between the glass transition temperature (Tg) and the nucleation temperature shown in FIG. 1 in which nucleation does not occur, crystal growth does not occur even by heating for reheat pressing, and a press-molded product having a transparent inside is obtained. . However, in the glass having the relationship between the glass transition temperature (Tg) and the nucleation temperature shown in FIG. 2, since nucleation occurs during annealing as described above, recrystallization for reheat pressing promotes crystallization of the glass, Devitrification.
【０００８】そこで本発明の第１の方法では、ガラス素
材としようとしているガラスが、図２の性質を示すガラ
スである場合、アニール温度をガラス転移温度(Ｔｇ)未
満に抑えることで、上記問題を解決した。また、本発明
の第２の方法では、ガラス素材としようとしているガラ
スが、図２の性質を示すガラスであるかどうかを予め判
定し、図２の性質を示すガラスである場合には、アニー
ル温度をガラス転移温度(Ｔｇ)未満に抑えることで、上
記問題を解決した。Therefore, in the first method of the present invention, when the glass to be used as the glass material is a glass having the properties shown in FIG. 2, the annealing temperature is kept below the glass transition temperature (Tg), which causes the above problem. Solved. In the second method of the present invention, it is preliminarily determined whether or not the glass to be used as the glass material has the properties shown in FIG. 2, and if the glass has the properties shown in FIG. The above problem was solved by keeping the temperature below the glass transition temperature (Tg).
【０００９】ガラス転移温度ではガラスの粘性はおおむ
ね２ｘ１０13ｄＰａ・ｓである事が知られている。
（「ガラス光学ハンドブック（朝倉書店、１９９９年）
／ｐ．３５６」）除歪のためのアニール処理は、ガラス
が自重で変形するよりも高い粘性を持ち、かつ除歪が実
用的に短時間で終了する温度で施されるのが通常であ
る。粘度が４ｘ１０14ｄＰａ・ｓになる温度（ひずみ
点）以下の温度では、ガラスの粘性流動はおこらず、ど
んなに長く保持しても除歪は不可能になってしまう。除
歪アニール温度のひとつの目安として、徐冷点と呼ばれ
る温度がある。この温度でのガラスの粘度は１ｘ１０13
ｄＰａ・ｓである。この温度に１５分間保持すると内部
歪が除去されるとされている。この温度はガラス組成に
依存するが、Ｔｇより高い温度、例えばＴｇ＋１０〜５
０℃である。このような事情から、これまで、除歪のた
めのアニールは徐冷点を目安にＴｇ以上の温度で施され
るのが通常であった。At the glass transition temperature, it is known that the viscosity of glass is approximately 2 × 10 13 dPa · s.
("Glass Optics Handbook (Asakura Shoten, 1999)
/ P. (356)) The annealing treatment for removing strain is usually performed at a temperature at which the glass has a higher viscosity than that when it is deformed by its own weight and the removing strain is practically completed in a short time. At a temperature below the temperature (strain point) at which the viscosity becomes 4 × 10 14 dPa · s, viscous flow of the glass does not occur, and no matter how long the glass is held, strain removal becomes impossible. A temperature called a slow cooling point is one measure of the de straining annealing temperature. The viscosity of the glass at this temperature is 1x10 13
dPa · s. It is said that the internal strain is removed by keeping this temperature for 15 minutes. This temperature depends on the glass composition, but is higher than Tg, for example, Tg + 10-5.
It is 0 ° C. Under these circumstances, it has been customary so far that annealing for strain relief is performed at a temperature of Tg or higher with an annealing point as a guide.
【００１０】それに対して、本発明の方法では、対象と
なるガラスが上記のような特殊な性質を有していること
から、アニール温度をガラス転移温度未満にする。アニ
ール温度をガラス転移温度未満のどの温度にするかは、
各ガラスのガラス転移温度（Ｔｇ）及び核形成温度の関
係を考慮して適宜決定することができる。例えば、アニ
ール温度は、Ｔｇ−１０℃以下とすることが好ましく、
より好ましくはＴｇ−１５℃以下である。アニール温度
が低ければそれだけ、アニールによる結晶の核形成を防
止できるが、低くなりすぎると歪みが残留してしまうお
それがある。そのため、アニール時の最高温度をＴｇ−
３５℃〜Ｔｇ−１５℃の範囲にすることが特に好まし
い。On the other hand, in the method of the present invention, since the target glass has the above-mentioned special properties, the annealing temperature is set to be lower than the glass transition temperature. Which temperature below the glass transition temperature should be used as the annealing temperature?
It can be appropriately determined in consideration of the relationship between the glass transition temperature (Tg) and the nucleation temperature of each glass. For example, the annealing temperature is preferably Tg-10 ° C or lower,
It is more preferably Tg-15 ° C or lower. If the annealing temperature is low, the nucleation of crystals due to annealing can be prevented, but if it is too low, strain may remain. Therefore, the maximum temperature during annealing is Tg-
It is particularly preferable to set the temperature in the range of 35 ° C to Tg-15 ° C.
【００１１】本発明の製造方法において、ガラス素材と
するガラスは、(1)室温まで急冷すると波長４００〜２
５００ｎｍにおける散乱係数が０．００５ｃｍ-1未満で
あるか、または体積分率で１０-6未満の結晶を含むガラ
スとなり、かつ(2)ガラス転移温度より１０℃高い温度
に３時間保持し、１０4.5 〜１０3.5 ｄＰａ・ｓの粘度
を示す温度に１０分間保持した後に室温まで急冷する
と、波長４００〜２５００ｎｍの少なくとも１波長にお
ける散乱係数が０．０１ｃｍ-1以上であるか、または体
積分率で１０-5より多い結晶を含むガラスとなる組成を
有するガラスである。尚、上記(2)における散乱係数及
び体積分率は、ガラス内部の散乱係数及び体積分率を用
いることが好ましい。In the manufacturing method of the present invention, the glass used as the glass material has (1) a wavelength of 400 to 2 when rapidly cooled to room temperature.
A glass containing crystals with a scattering coefficient at 500 nm of less than 0.005 cm −1 or less than 10 −6 in volume fraction, and (2) holding at a temperature 10 ° C. higher than the glass transition temperature for 3 hours, When it is held at a temperature showing a viscosity of 4.5 to 10 3.5 dPa · s for 10 minutes and then rapidly cooled to room temperature, the scattering coefficient at least at one wavelength of 400 to 2500 nm is 0.01 cm −1 or more, or at a volume fraction. A glass having a composition that results in a glass containing more than 10 −5 crystals. As the scattering coefficient and volume fraction in (2) above, it is preferable to use the scattering coefficient and volume fraction inside the glass.
【００１２】(1)の性質を示すガラスとは、実質的に結
晶を含まないガラスであり、この性質は、実用に供され
る光学ガラス材料として必要不可欠なものである。室温
まで急冷すると波長４００〜２５００ｎｍにおける散乱
係数が０．００５ｃｍ-1以上であるか、または体積分率
で１０-6以上の結晶を含むガラスでは、光学ガラスとは
なり得ない。なお、ここで急冷とは、溶融状態から（ガ
ラス転移温度−１００℃）までの１０度／分（ｄｅｇｒ
ｅｅ／分）以上の速度での冷却をいう。さらに（２）の
性質を示すガラスは、条件次第では、光学ガラスとはな
り得るが、前記図２に示す関係を有するガラスである。The glass exhibiting the property (1) is a glass containing substantially no crystal, and this property is indispensable as an optical glass material put to practical use. When rapidly cooled to room temperature, a glass having a scattering coefficient at a wavelength of 400 to 2500 nm of 0.005 cm -1 or more, or a crystal containing a volume fraction of 10 -6 or more cannot be an optical glass. In addition, here, quenching means 10 degrees / minute (degr) from a molten state to (glass transition temperature-100 degreeC).
ee / min) or higher. Further, the glass exhibiting the property of (2) can be an optical glass depending on the conditions, but is a glass having the relationship shown in FIG.
【００１３】ガラス素材とするガラスが前記図２に示す
関係を有するガラスかどうかの判断法は、実質的に結晶
を含まないガラスを、
・ガラス転移温度より１０℃高い温度に３時間保持し、
・さらに、このガラスが粘度１０4.5 〜１０3.5ｄＰａ
・ｓ（ポアズ）となる温度に１分から３０分の選択され
た時間保持後急冷し、
・光学ガラスとして使用される波長域（４００〜２５０
０ｎｍ）の少なくとも１波長における散乱係数が０．０
１ｃｍ-1以上になるガラス、あるいは体積分率で１０-5
より多い結晶を含むガラスであるかを観察することによ
り行う。なお、ガラスが粘度１０4.5 〜１０3.5ｄＰａ
・ｓとなる温度に保持する時間は、その後のリヒートプ
レス成型での熱負荷を考慮し、ガラスの耐結晶化特性を
判断するのに必要で充分な時間を選定してやればよい
が、１０分程度を目安にすればよい。また、急冷とは、
溶融状態から（ガラス転移温度−１００℃）までの１０
度／分（ｄｅｇｒｅｅ／分）以上の速度での冷却をい
う。The method for judging whether or not the glass as the glass material has the relationship shown in FIG. 2 is as follows. The glass which does not substantially contain crystals is held at a temperature higher than the glass transition temperature by 10 ° C. for 3 hours. Furthermore, this glass has a viscosity of 10 4.5 to 10 3.5 dPa.
Hold at a temperature of s (poise) for a selected time of 1 minute to 30 minutes and then rapidly cool, and a wavelength range (400 to 250) used as optical glass.
0 nm) has a scattering coefficient of 0.0 at least at one wavelength.
Glass of 1 cm -1 or more, or 10 -5 in volume fraction
This is done by observing whether the glass contains more crystals. The glass has a viscosity of 10 4.5 to 10 3.5 dPa.
-For the time to be kept at the temperature of s, considering the heat load in the subsequent reheat press molding, it is sufficient to select the time necessary and sufficient to judge the crystallization resistance of the glass, but it is about 10 minutes. Should be used as a guide. What is quenching?
10 from molten state to (glass transition temperature-100 ° C)
Cooling at a rate of not less than degree / minute (degree / minute).
【００１４】この熱処理により、散乱係数が０．０１ｃ
ｍ-1以上になる、あるいは体積分率で１０-5より多い結
晶を含むガラスであれば、図２に示す関係を有するガラ
スであり、除歪のためのアニールを上記条件で行う。こ
のようなガラスを従来のように、プレス成形前のアニー
ル時に、ガラス転移温度より高温に曝すと結晶の核形成
がおこり、プレス成形時の加熱によってプレス成形品が
失透してしまう。By this heat treatment, the scattering coefficient is 0.01c.
If the glass contains m −1 or more, or contains crystals with a volume fraction of more than 10 −5 , it is a glass having the relationship shown in FIG. 2, and annealing for strain relief is performed under the above conditions. When such a glass is exposed to a temperature higher than the glass transition temperature during annealing before press molding as in the conventional case, crystal nucleation occurs, and heating during press molding devitrifies the press molded product.
【００１５】なお、散乱損失係数は以下の方法で求め
る。あらかじめ熱処理前のガラス（厚さをｄ〔ｃｍ〕と
する）の表面反射を除いた内部透過率 Ｉｉ を求めてお
く。次に 熱処理後のガラス（厚さ ｄ〔ｃｍ〕）の表面
反射を除いた内部透過率 Ｉsを求める。次式によって、
単位厚さあたりの散乱損失係数（単位：ｃｍ-1）を算出
する。The scattering loss coefficient is obtained by the following method. The internal transmittance Ii of the glass before heat treatment (thickness is assumed to be d [cm]) excluding the surface reflection is obtained in advance. Next, the internal transmittance Is of the glass (thickness d [cm]) after heat treatment excluding the surface reflection is determined. By the formula
The scattering loss coefficient per unit thickness (unit: cm -1 ) is calculated.
【００１６】[0016]
【数１】 [Equation 1]
【００１７】測定装置は市販の２光束型紫外可視分光光
度計を利用することができる。ただし、上記方法は、散
乱による内部透過率の変化から単位厚さあたりの散乱損
失係数を求める方法であるので、この要素を満たすもの
であれば、必ずしもこの手法に限定されない。As the measuring device, a commercially available two-beam type UV-visible spectrophotometer can be used. However, the above method is a method of obtaining the scattering loss coefficient per unit thickness from the change of the internal transmittance due to scattering, so that the method is not necessarily limited to this method as long as this factor is satisfied.
【００１８】図２に示す関係を有するガラスとしては、
例えば、ＳｉＯ2、ＴｉＯ2、Ｎｂ2Ｏ5の３成分を含むガ
ラスなどを例示できる。これらの成分が過剰に含有され
るガラスの場合、特定の組成領域で上記成分が核形成材
として作用するものと考えられる。特に、ＴｉＯ2およ
びＮｂ2Ｏ5の合量が３５重量％以上のガラスにこの現象
は顕著である。他の成分の含有量にもよるが、これら合
量の上限は５０重量％と考えられる。したがって、Ｓｉ
Ｏ2、ＴｉＯ2、Ｎｂ2Ｏ5の３成分を含むガラス、特に、
ＴｉＯ2およびＮｂ2Ｏ5の合量が３５重量％以上、５０
重量％以下のガラスからプレス成形用ガラス素材を製造
するには、本発明の方法は好適である。The glass having the relationship shown in FIG.
For example, glass containing three components of SiO 2 , TiO 2 , and Nb 2 O 5 can be exemplified. In the case of a glass containing these components in excess, it is considered that the above components act as a nucleating agent in a specific composition region. In particular, this phenomenon is remarkable in the glass in which the total amount of TiO 2 and Nb 2 O 5 is 35% by weight or more. Although it depends on the contents of other components, the upper limit of the total amount of these components is considered to be 50% by weight. Therefore, Si
A glass containing three components of O 2 , TiO 2 and Nb 2 O 5 , especially,
The total amount of TiO 2 and Nb 2 O 5 is 35% by weight or more, 50
The method of the present invention is suitable for producing a glass material for press molding from glass in an amount of not more than wt%.
【００１９】図２示す関係を有するガラスであっても、
本発明の製造方法により得られたガラスは、リヒートプ
レス成形しても、得られた成形品は透明であり、光学素
子あるいは光学素子を作製するためのブランクとして好
適である。本発明の製造方法において、ガラス原料を溶
解する工程、得られた溶融ガラスを成形する工程、及び
成形されたガラスをアニールする工程の条件や方法は、
公知の条件及び方法をそのまま採用することができる。
例えば、プレス成形用ガラス素材の製法例としては、溶
融ガラスをノズルから受け型凹部に流下させて、ガラス
ゴブに成形する方法、さらにガラスゴブに粗面研磨加工
を施す方法、溶融ガラスを鋳型に鋳込み板状に成形した
後、必要形状に切断して、角やエッジを丸める加工を施
す方法などを利用することができる。Even if the glass has the relationship shown in FIG.
The glass obtained by the production method of the present invention is transparent even after reheat press molding, and is suitable as an optical element or a blank for producing an optical element. In the manufacturing method of the present invention, the conditions and methods of the step of melting the glass raw material, the step of forming the obtained molten glass, and the step of annealing the formed glass are
Known conditions and methods can be adopted as they are.
For example, as an example of a method for producing a glass material for press molding, a method of forming a glass gob by flowing molten glass from a nozzle to a receiving concave portion, a method of subjecting the glass gob to rough surface polishing, a molten glass cast into a mold plate It is possible to use, for example, a method in which after being formed into a shape, it is cut into a required shape and the corners and edges are rounded.
【００２０】本発明は、上記製造方法により製造され
る、加熱軟化してプレス成形するためのプレス成形用ガ
ラス素材を包含する。このプレス成形用ガラス素材は、
ガラス転移温度より１０℃高い温度に３時間保持し、１
０4.5〜１０3.5ｄＰａ・ｓの粘度を示す温度に１０分間
保持した後に室温まで急冷した場合には、波長４００〜
２５００ｎｍの少なくとも１波長における散乱係数が
０．０１ｃｍ-1以上であるか、または体積分率で１０-5
より多い結晶を含むガラスからなり、１０4.5〜１０3.5
ｄＰａ・ｓの粘度を示す温度に１０分間保持した後に室
温まで急冷すると、波長４００〜２５００ｎｍにおける
ガラス内部の散乱係数が０．００５ｃｍ-1未満である
か、または内部に含有する結晶の体積分率が１０-6未満
であることを特徴とする。The present invention includes a glass material for press molding which is manufactured by the above-mentioned manufacturing method and is softened by heating and press-molded. This glass material for press molding is
Hold at a temperature 10 ° C higher than the glass transition temperature for 3 hours, and
When the temperature showing a viscosity of 0 4.5 to 10 3.5 dPa · s is maintained for 10 minutes and then rapidly cooled to room temperature, the wavelength of 400 to
Scattering coefficient of at least one wavelength of 2500 nm is 0.01 cm -1 or more, or volume fraction of 10 -5
Consists of glass with more crystals, 10 4.5 -10 3.5
When it is rapidly cooled to room temperature after being kept at a temperature showing a viscosity of dPa · s for 10 minutes, the scattering coefficient inside the glass at a wavelength of 400 to 2500 nm is less than 0.005 cm −1 , or the volume fraction of the crystal contained therein. Is less than 10 −6 .
【００２１】ここで、ガラス内部の散乱係数とは、ガラ
スあるいはガラス素材の表面層を除いた内部の散乱係数
を意味する。上記表面層は、次のいずれかによって定義
することができる。
ガラス素材を加熱軟化してプレス成形し、最終ガラス
製品（例えば光学素子）のブランク（中間製品）を作製
し、前記ブランクを研削、研磨して最終ガラス製品を作
製する際、前記研削、研磨によって除去される表面層と
同等の深さを有する表面近傍の領域。
ガラスまたはガラス素材の表面から２mm以内の深さに
ある領域。
ガラスまたはガラス素材の中心部。Here, the scattering coefficient inside the glass means the scattering coefficient inside the glass or the glass material excluding the surface layer. The surface layer can be defined by any of the following. When the glass material is softened by heating and press-molded, a blank (intermediate product) of the final glass product (for example, an optical element) is manufactured, and when the final glass product is manufactured by grinding and polishing the blank, the grinding and polishing are performed. A region near the surface that has the same depth as the surface layer to be removed. A region within 2mm from the surface of glass or glass material. The center of glass or glass material.
【００２２】本発明において、光の散乱を増加させる原
因となる結晶とは、ガラス内部に析出するものである。
ガラス素材のプレス成形時にガラス表面に結合した水酸
基や他の付着物質によると考えられる結晶化層が表面か
ら数μm〜２mmまでの領域に発生することがある。しか
し、この結晶化層はガラス内部における結晶化とは異な
り、プレス成形品の表面に施される前記研削、研磨によ
って完全に除去されるため、使用上問題となることはな
い。したがって、ガラス素材が光学素子などの最終ガラ
ス製品を構成する素材として好適なものかどうかは、ガ
ラス内部の散乱係数を評価するだけで十分である。結晶
の体積分率についても同様であり、ガラス素材の上記表
面層を除いた内部に含有する結晶の体積分率を考えれ
ば、ガラス素材が光学素子などの最終ガラス製品を構成
する素材として好適なものかどうか評価することができ
る。In the present invention, the crystal that increases the scattering of light is a crystal that is deposited inside the glass.
A crystallized layer, which is considered to be caused by hydroxyl groups or other attached substances bonded to the glass surface during press molding of the glass material, may occur in a region of several μm to 2 mm from the surface. However, unlike the crystallization inside the glass, this crystallized layer is completely removed by the above-mentioned grinding and polishing performed on the surface of the press-formed product, so that there is no problem in use. Therefore, it is sufficient to evaluate the scattering coefficient inside the glass to determine whether the glass material is suitable as a material forming the final glass product such as an optical element. The same applies to the volume fraction of crystals, and considering the volume fraction of crystals contained inside the glass material excluding the above surface layer, the glass material is suitable as a material constituting the final glass product such as an optical element. You can evaluate whether it is a thing.
【００２３】このようにして得られたプレス成形用ガラ
ス素材は、必要時にプレス成形される。例えば、素材の
表面に粉末状の離型剤を塗布して、加熱、軟化し、これ
を上型および下型を備えたプレス成形型でプレス成形す
る。得られたプレス成形品は、アニールにより歪みが取
除かれる。このときのアニール温度は、通常のアニール
温度すなわちＴｇ以上の適当な温度で差し支えない。レ
ンズや光学基板などのブランクが得られるプレス成形型
を用いて、ガラス素材を成形し、アニール後に研削、研
磨加工を施して目的とするレンズや光学基板、その他の
光学素子を作ることができる。このようにして透明な光
学素子を作製することができる。The glass material for press molding thus obtained is press molded when necessary. For example, a powdery mold release agent is applied to the surface of the raw material, heated and softened, and this is press-molded with a press mold having an upper mold and a lower mold. The strain is removed from the obtained press-formed product by annealing. The annealing temperature at this time may be a normal annealing temperature, that is, an appropriate temperature of Tg or higher. A glass material can be molded using a press molding die that can obtain a blank such as a lens or an optical substrate, and can be subjected to grinding and polishing after annealing to produce a desired lens, optical substrate, or other optical element. In this way, a transparent optical element can be manufactured.
【００２４】[0024]
【実施例】以下に、本発明を実施例に基づいてさらに詳
細に説明する。
（ガラスの溶解）表1に示した組成のガラスを作成し
た。出発原料には、SiO2、Na2CO3、CaCO3、BaCO3、Ti
O2、Nb2O5、ZrO2を用いた。所定量比に秤量され充分に
混合された原料は白金製るつぼに投入され、予め１３５
０℃に保持された電気炉内で２時間溶融、清澄、均質化
された。EXAMPLES The present invention will be described below in more detail based on examples. (Melting of glass) A glass having the composition shown in Table 1 was prepared. Starting materials include SiO 2 , Na 2 CO 3 , CaCO 3 , BaCO 3 , and Ti.
O 2 , Nb 2 O 5 , and ZrO 2 were used. The raw materials, which are weighed in a predetermined ratio and mixed well, are put into a platinum crucible,
It was melted, clarified and homogenized for 2 hours in an electric furnace maintained at 0 ° C.
【００２５】[0025]
【表１】 [Table 1]
【００２６】５５０℃にあらかじめ加熱したグラファイ
ト製の鋳型にガラス融液を流し込み急冷固化することで
均質なガラスを得た。ガラスはすぐさま５５０℃に保持
された炉内に投入され後の冷間加工に充分な程度の除歪
のためにこの炉内にて徐冷された。このガラスの状態を
状態Ａとする。A glass melt was poured into a graphite mold preheated to 550 ° C. and rapidly cooled and solidified to obtain a homogeneous glass. The glass was immediately placed in a furnace kept at 550 ° C. and gradually cooled in this furnace for sufficient strain relief for subsequent cold working. The state of this glass is called state A.
【００２７】（ガラス転移温度、散乱係数、結晶の体積
分率の測定）上記状態Ａの素材ガラスのガラス転移温度
を測定した。測定は日本光学硝子工業会規格「光学ガラ
スの熱膨張の測定方法」（JOGIS０８−1975）を参考と
して実施した。用いた試料形状は長さ２０．０ｍｍ−直
径５ｍｍである。この測定により得たガラスのガラス転
移温度は６１０℃であった。(Measurement of Glass Transition Temperature, Scattering Coefficient, and Crystal Volume Fraction) The glass transition temperature of the material glass in the above state A was measured. Measurements were carried out Japan Optical Glass Industry Association standard "method of measuring the thermal expansion of optical glass" the (JOGIS08- 1975) as a reference. The sample used has a length of 20.0 mm and a diameter of 5 mm. The glass transition temperature of the glass obtained by this measurement was 610 ° C.
【００２８】ガラスを切り出し、平行研磨を実施して内
部透過率測定を行った。可視域波長のほぼ中央に相当す
る波長５８８ｎｍにおける１０ｍｍ厚換算での内部透過
率は９９．５％以上あり、散乱係数は０．００２ｃｍ-1
以下であり、波長４００〜２５００ｎｍにおいて散乱係
数は０．００５ｃｍ-1未満であった。一般には、４００
〜２５００ｎｍの広範囲な波長域にわたり内部透過率を
測定し、散乱係数に換算するよりも、ガラス中に含まれ
る結晶の体積分率を測定するほうが容易であるので、こ
こでは、ガラス中の結晶の体積分率も測定した。内部観
察によれば結晶は見当たらず、結晶の体積分率は、１０
-6よりはるかに小さく、紫外〜赤外透過限界波長におい
て散乱損失が実質的に存在しないことが確認された。The glass was cut out and subjected to parallel polishing to measure the internal transmittance. The internal transmittance in terms of 10 mm thickness at a wavelength of 588 nm, which corresponds to approximately the center of the visible wavelength, is 99.5% or more, and the scattering coefficient is 0.002 cm −1.
And the scattering coefficient was less than 0.005 cm −1 at a wavelength of 400 to 2500 nm. Generally 400
Since it is easier to measure the internal transmittance over a wide wavelength range of up to 2500 nm and convert it to a scattering coefficient, it is easier to measure the volume fraction of the crystals contained in the glass. Volume fraction was also measured. According to internal observation, no crystal was found, and the volume fraction of the crystal was 10
It is much smaller than -6 , and it was confirmed that there is substantially no scattering loss in the ultraviolet to infrared transmission limit wavelength.
【００２９】（熱処理、熱処理後の散乱係数、結晶の体
積分率の測定）このガラスを分割し、上記ガラス転移温
度より１０℃高い６２０℃に加熱し、この温度で３時間
保持した。さらに、このガラスが粘度１０4.5〜１０3.5
ｄＰａ・ｓを示す９００℃において、１０分間の加熱処
理を施した後、室温まで急冷した。このガラスの内部透
過率を上記の方法で測定した。内部透過率は９５％であ
り散乱係数は０．０５２ｃｍ-1であることがわかった。
また、このガラスの内部を顕微鏡で観察したところ、お
よそφ２０μｍ−長さ２００μｍ（体積はおよそ６．３
ｘ１０-8ｍｌ）の結晶が１ｍｌあたり２００個以上析出
し、このときの結晶体積分率は１ｘ１０-5以上であるこ
とが確認された。すなわち、このガラスはガラス転移温
度Ｔｇ以上の温度でアニールを施すと耐結晶化安定性が
著しく損なわれるガラスであることがわかった。(Heat Treatment, Measurement of Scattering Coefficient after Heat Treatment, Volume Fraction of Crystal) This glass was divided, heated to 620 ° C., which is 10 ° C. higher than the glass transition temperature, and kept at this temperature for 3 hours. Furthermore, this glass has a viscosity of 10 4.5 to 10 3.5.
After performing a heat treatment for 10 minutes at 900 ° C. showing dPa · s, it was rapidly cooled to room temperature. The internal transmittance of this glass was measured by the above method. It was found that the internal transmittance was 95% and the scattering coefficient was 0.052 cm -1 .
Also, when the inside of this glass was observed with a microscope, it was approximately φ20 μm-length 200 μm (volume was approximately 6.3).
It was confirmed that 200 or more crystals of 1 × 10 −8 ml) were precipitated per 1 ml, and the crystal volume fraction at this time was 1 × 10 −5 or more. That is, it was found that this glass is a glass whose crystallization resistance is significantly impaired when it is annealed at a temperature not lower than the glass transition temperature Tg.
【００３０】（ガラスの成形とアニール）上記ガラス融
液を鋳型に流し込み、一定の厚みと幅を有するガラス板
を成形し、ガラスの歪みを充分に除くため、以下のアニ
ールを行った。Ｔｇ温度より低い５８５℃で３時間保持
後、４８５℃まで毎時３０度で降温し、以降は５０〜１
００度/時（ｄｅｇｒｅｅ／時）の速度で室温まで冷却
した。その後、ガラス板をおよそ２０ｘ３０ｘ３０ｍｍ
に賽の目状に切断し、カットピースと呼ばれるガラス片
に加工した。上記アニールにより、ガラスの歪は充分取
り除かれ、切断にあたってカケやワレの問題はなかっ
た。これらのカットピースにバレル研磨を施し、プレス
成形用ガラス素材に仕上げた。(Molding and Annealing of Glass) The above glass melt was poured into a mold to form a glass plate having a certain thickness and width, and the following annealing was performed in order to sufficiently remove the distortion of the glass. After holding at 585 ° C, which is lower than the Tg temperature, for 3 hours, the temperature is lowered to 485 ° C at 30 degrees per hour, and thereafter 50 to 1
It was cooled to room temperature at a rate of 00 degrees / hour (degree / hour). Then, the glass plate is about 20x30x30mm
It was cut into a square shape and processed into glass pieces called cut pieces. By the above-mentioned annealing, the distortion of the glass was sufficiently removed, and there was no problem of chipping or cracking when cutting. These cut pieces were barrel-polished to obtain a glass material for press molding.
【００３１】次に、同じガラス融液を流出パイプから連
続して流出するとともに、流出パイプの下方に次々と運
ばれる成形型の凹部で一定量のガラス融液を受けて、マ
ーブル状のガラスゴブを成形し、上記と同様の条件でア
ニールを行った。アニール後、バレル研磨を施し、プレ
ス成形用ガラス素材に仕上げた。この方法でも、ガラス
の歪は充分取り除かれ、バレル研磨にあたってカケやワ
レの問題はなかった。Next, the same glass melt is continuously discharged from the outflow pipe, and a certain amount of the glass melt is received by the recesses of the molding die which are successively carried below the outflow pipe to form a marble gob. It was molded and annealed under the same conditions as above. After annealing, barrel polishing was applied to finish the glass material for press molding. Even with this method, the distortion of the glass was sufficiently removed, and there was no problem of cracks or cracks in barrel polishing.
【００３２】このようにしてガラス融液からガラス成形
体を成形し、アニールを行った後、機械加工（例えば、
上記のような切断、バレル研磨などの加工）が施された
プレス成形用素材を１０4.5〜１０3.5ｄＰａ・ｓの粘度
を示す温度に１０分間保持した後に室温まで急冷し、波
長４００〜２５００ｎｍにおける散乱係数と素材中の結
晶の体積分率を測定したところ、波長４００〜２５００
ｎｍにおけるガラス内部の散乱係数は０．００５ｃｍ-1
未満であり、素材内部には結晶が認められなかった。プ
レス成形用素材は、目的とするプレス成形品の重量と等
しい重量を有し、形状はプレス成形に適するよう整えら
れている。例えば、マーブル状、球状、回転楕円体など
の回転対称軸を有するものなどを例示することができ
る。In this way, a glass molded body is molded from the glass melt, annealed, and then machined (for example,
The material for press molding which has been subjected to the above-mentioned cutting, processing such as barrel polishing) is held at a temperature showing a viscosity of 10 4.5 to 10 3.5 dPa · s for 10 minutes and then rapidly cooled to room temperature at a wavelength of 400 to 2500 nm. When the scattering coefficient and the volume fraction of crystals in the material were measured, the wavelength was 400 to 2500.
The scattering coefficient inside the glass at nm is 0.005 cm -1
It was less than 1, and no crystals were observed inside the material. The press-molding material has a weight equal to the weight of the target press-molded product, and the shape is adjusted to be suitable for press-molding. For example, those having a rotational symmetry axis such as a marble, a sphere, and a spheroid can be exemplified.
【００３３】次に、このようにして得られたプレス成形
用ガラス素材を用い、図３に示す加熱スケジュールでリ
ヒートプレスを施した。但し、室温から５７５℃までは
約１時間で昇温し、５７５℃以降の昇温をこの加熱スケ
ジュールに従った。リヒートプレス成形で作製したレン
ズブランクをアニールした後、内部観察を行ったところ
結晶の析出は見られなかった。この成型されたガラスを
研削、研磨加工して透明なレンズを作製した。Next, the glass material for press molding thus obtained was subjected to reheat pressing according to the heating schedule shown in FIG. However, the temperature was raised from room temperature to 575 ° C. in about 1 hour, and the heating after 575 ° C. was in accordance with this heating schedule. After annealing the lens blank produced by reheat press molding, internal observation revealed that no crystal precipitation was observed. The molded glass was ground and polished to produce a transparent lens.
【００３４】（比較例）実施例と同様にガラス融液を溶
解・急冷固化後、引き続きこのガラスのＴｇよりわずか
に高い６１５℃で徐歪のためにアニールを施した（６１
５℃にて３時間保持後、500℃まで３０度/時（ｄｅｇｒ
ｅｅ／時）で降温。以降は５０〜１００度/時（ｄｅｇ
ｒｅｅ／時）の速度で室温まで冷却）。このガラスをお
よそ２０ｘ３０ｘ３０ｍｍに切り出し、実施例と同様に
リヒートプレスを施した。(Comparative Example) The glass melt was melted and rapidly solidified in the same manner as in the example, and subsequently annealed at 615 ° C. slightly higher than the Tg of this glass for gradual strain (61).
After holding at 5 ℃ for 3 hours, up to 500 ℃ at 30 ℃ / hour (degr
ee / hour). After that, 50 to 100 degrees / hour (deg
cooling to room temperature at a rate of ree / hour). This glass was cut into pieces of about 20 × 30 × 30 mm and subjected to reheat pressing as in the examples.
【００３５】リヒートプレス成形で作製したガラス内部
には多量の結晶が確認された。およそφ２０μｍ−長さ
１００μｍ（体積はおよそ３．２ｘ１０-8ｃｃ）の結晶
が１ｃｃあたり２００個以上析出し光学素子としての使
用にかなうものではなかった。A large amount of crystals were confirmed inside the glass produced by the reheat press molding. About 200 or more crystals having a diameter of about 20 μm and a length of 100 μm (volume of about 3.2 × 10 −8 cc) were deposited per cc, which was not suitable for use as an optical element.
【００３６】[0036]
【発明の効果】本発明によれば、失透しやすいガラスで
も高品質なリヒートプレス成形品を成形できるプレス成
形用ガラス素材、そしてこのガラス素材を用いたプレス
成形品、ならびにこのようなプレス成形品を用いた光学
素子を製造することができる。EFFECTS OF THE INVENTION According to the present invention, a glass material for press molding capable of molding a high-quality reheat press-molded product even with glass that is easily devitrified, a press-molded product using this glass material, and such press-molding. An optical element using the product can be manufactured.
【図１】通常のガラスのガラス転移温度（Ｔｇ）、核形
成温度、結晶成長温度、溶融温度の関係を示す。FIG. 1 shows the relationship among glass transition temperature (Tg), nucleation temperature, crystal growth temperature, and melting temperature of ordinary glass.
【図２】問題を起こすと考えられるガラスのガラス転移
温度（Ｔｇ）、核形成温度、結晶成長温度、溶融温度の
関係を示す。FIG. 2 shows the relationship among glass transition temperature (Tg), nucleation temperature, crystal growth temperature, and melting temperature of glass which is considered to cause a problem.
【図３】実施例におけるリヒートプレスで採用した加熱
スケジュールを示す。但し、室温から５７５℃までは約
１時間で昇温し、５７５℃以降の昇温をこの加熱スケジ
ュールに従った。FIG. 3 shows a heating schedule adopted in the reheat press in the example. However, the temperature was raised from room temperature to 575 ° C. in about 1 hour, and the heating after 575 ° C. was in accordance with this heating schedule.
フロントページの続き Ｆターム(参考） 4G062 AA04 AA11 BB01 BB20 DA04 DA05 DA06 DB01 DC01 DD01 DE01 DF01 EA01 EB01 EB02 EB03 EB04 EC01 ED01 EE01 EE02 EF01 EG01 EG02 EG03 EG04 FA01 FB01 FB02 FB03 FB04 FB05 FC01 FC02 FC03 FD01 FE01 FF01 FG01 FG02 FG03 FG04 FG05 FH01 FJ01 FK01 FL01 GA01 GA10 GB01 GC01 GD01 GE01 HH01 HH03 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM02 NN01 NN33 Continued front page F-term (reference) 4G062 AA04 AA11 BB01 BB20 DA04 DA05 DA06 DB01 DC01 DD01 DE01 DF01 EA01 EB01 EB02 EB03 EB04 EC01 ED01 EE01 EE02 EF01 EG01 EG02 EG03 EG04 FA01 FB01 FB02 FB03 FB04 FB05 FC01 FC02 FC03 FD01 FE01 FF01 FG01 FG02 FG03 FG04 FG05 FH01 FJ01 FK01 FL01 GA01 GA10 GB01 GC01 GD01 GE01 HH01 HH03 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM02 NN01 NN33
Claims (7)
融ガラスを成形する工程、及び成形されたガラスをアニ
ールする工程を含むプレス成形用ガラス素材の製造方法
であって、前記溶融ガラスは、(1)室温まで急冷すると
波長４００〜２５００ｎｍにおける散乱係数が０．００
５ｃｍ-1未満であるか、または体積分率で１０-6未満の
結晶を含むガラスとなり、かつ(2)ガラス転移温度より
１０℃高い温度に３時間保持し、１０4.5 〜１０3.5 ｄ
Ｐａ・ｓの粘度を示す温度に１０分間保持した後に室温
まで急冷すると、波長４００〜２５００ｎｍの少なくと
も１波長における散乱係数が０．０１ｃｍ-1以上である
か、または体積分率で１０-5より多い結晶を含むガラス
となる組成を有すること、及び前記成形されたガラスの
アニールをガラス転移温度未満の温度で行うことを特徴
とするプレス成形用ガラス素材の製造方法。1. A method of manufacturing a glass material for press molding, comprising the steps of melting a glass raw material, molding the obtained molten glass, and annealing the molded glass, wherein the molten glass comprises: (1) When rapidly cooled to room temperature, the scattering coefficient at wavelengths of 400 to 2500 nm is 0.00
A glass containing crystals of less than 5 cm −1 or less than 10 −6 in volume fraction, and (2) holding at a temperature 10 ° C. higher than the glass transition temperature for 3 hours, 10 4.5 to 10 3.5 d
When it is rapidly cooled to room temperature after being kept at a temperature showing a viscosity of Pa · s for 10 minutes, the scattering coefficient is at least 0.01 cm −1 or more at a wavelength of 400 to 2500 nm, or the volume fraction is 10 −5 or more. A method for producing a glass material for press molding, comprising: having a composition of a glass containing a large number of crystals; and annealing the molded glass at a temperature lower than a glass transition temperature.
融ガラスを成形する工程、及び成形されたガラスをアニ
ールする工程を含むプレス成形用ガラス素材の製造方法
であって、前記製造方法に先立って、前記溶融ガラス
が、(1)室温まで急冷すると波長４００〜２５００ｎｍ
における散乱係数が０．００５ｃｍ-1未満であるか、ま
たは体積分率で１０-6未満の結晶を含むガラスとなり、
かつ(2)ガラス転移温度より１０℃高い温度に３時間保
持し、１０4.5 〜１０3.5 ｄＰａ・ｓの粘度を示す温度
に１０分間保持した後に室温まで急冷すると、波長４０
０〜２５００ｎｍの少なくとも１波長における散乱係数
が０．０１ｃｍ-1以上であるか、または体積分率で１０
-5より多い結晶を含むガラスとなる性質を有するか否か
を判定すること、及び前記溶融ガラスが前記(1)及び(2)
のガラスとなる性質を有する場合、成形されたガラスの
アニールをガラス転移温度未満の温度で行うことを特徴
とするプレス成形用ガラス素材の製造方法。2. A method of manufacturing a glass material for press molding, comprising the steps of melting a glass raw material, molding the obtained molten glass, and annealing the molded glass, which is prior to the manufacturing method. Then, when the molten glass is (1) rapidly cooled to room temperature, the wavelength is 400 to 2500 nm.
Has a scattering coefficient of less than 0.005 cm −1 or has a volume fraction of less than 10 −6 crystals,
And (2) if the temperature is higher than the glass transition temperature by 10 ° C. for 3 hours, the temperature showing the viscosity of 10 4.5 to 10 3.5 dPa · s is maintained for 10 minutes, and then rapidly cooled to room temperature, the wavelength of 40
The scattering coefficient at least at one wavelength of 0 to 2500 nm is 0.01 cm -1 or more, or the volume fraction is 10
-5 to determine whether or not it has a property of becoming a glass containing more than 5 crystals, and the molten glass (1) and (2)
The method for producing a glass material for press molding, which comprises annealing the formed glass at a temperature lower than the glass transition temperature when the glass has the property of becoming glass.
Ｎｂ2Ｏ5を含むガラスからなることを特徴とする請求項
１または２に記載のプレス成形用ガラス素材の製造方
法。3. The method for producing a glass material for press molding according to claim 1, wherein the glass material is a glass containing SiO 2 , TiO 2 and Nb 2 O 5 .
Ｎｂ2Ｏ5を含み、かつＴｉＯ2とＮｂ2Ｏ5の合量が３５
重量％以上であるガラスからなることを特徴とする請求
項１〜３のいずれかに記載のプレス成形用ガラス素材の
製造方法。4. The glass material contains SiO 2 , TiO 2 and Nb 2 O 5 , and the total amount of TiO 2 and Nb 2 O 5 is 35.
The method for producing a glass material for press molding according to any one of claims 1 to 3, which is made of glass in an amount of at least wt%.
成形用ガラス素材を加熱、軟化してプレス成形すること
を特徴とするガラスプレス成形品の製造方法。5. A method for producing a glass press-formed product, which comprises heating and softening the glass material for press-molding according to any one of claims 1 to 4 and press-molding the glass material.
ブランクを成形し、前記ブランクを研削、研磨して光学
素子を作製する光学素子の製造方法。6. A method of manufacturing an optical element, which comprises molding an optical element blank by the method according to claim 5 and grinding and polishing the blank to fabricate an optical element.
ス成形用ガラス素材において、 ガラス転移温度より１０℃高い温度に３時間保持し、１
０4.5〜１０3.5ｄＰａ・ｓの粘度を示す温度に１０分間
保持した後に室温まで急冷した場合には、波長４００〜
２５００ｎｍの少なくとも１波長における散乱係数が
０．０１ｃｍ-1以上であるか、または体積分率で１０-5
より多い結晶を含むガラスからなり、 １０4.5〜１０3.5ｄＰａ・ｓの粘度を示す温度に１０分
間保持した後に室温まで急冷すると、波長４００〜２５
００ｎｍにおけるガラス内部の散乱係数が０．００５ｃ
ｍ-1未満であるか、または内部に含有する結晶の体積分
率が１０-6未満であることを特徴とするプレス成形用ガ
ラス素材。7. A press-molding glass material for softening by heating and press-molding, which is held at a temperature 10 ° C. higher than the glass transition temperature for 3 hours.
When the temperature showing a viscosity of 0 4.5 to 10 3.5 dPa · s is maintained for 10 minutes and then rapidly cooled to room temperature, the wavelength of 400 to
Scattering coefficient of at least one wavelength of 2500 nm is 0.01 cm -1 or more, or volume fraction of 10 -5
When it is made of glass containing more crystals, and is rapidly cooled to room temperature after being kept at a temperature showing a viscosity of 10 4.5 to 10 3.5 dPa · s for 10 minutes, a wavelength of 400 to 25
The scattering coefficient inside the glass at 00 nm is 0.005c
A glass material for press molding, which is less than m −1 or has a volume fraction of crystals contained therein of less than 10 −6 .
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002280358A JP4113753B2 (en) | 2001-10-15 | 2002-09-26 | Manufacturing method of glass material for press molding, manufacturing method of glass press molded product, manufacturing method of optical element |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001-316630 | 2001-10-15 | ||
| JP2001316630 | 2001-10-15 | ||
| JP2002280358A JP4113753B2 (en) | 2001-10-15 | 2002-09-26 | Manufacturing method of glass material for press molding, manufacturing method of glass press molded product, manufacturing method of optical element |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008010836A Division JP4990805B2 (en) | 2001-10-15 | 2008-01-21 | Method for producing glass material for press molding, method for producing glass press-molded product, and method for producing optical element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003192384A true JP2003192384A (en) | 2003-07-09 |
| JP4113753B2 JP4113753B2 (en) | 2008-07-09 |
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ID=27615426
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|---|---|---|---|
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| JP (1) | JP4113753B2 (en) |
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|---|---|---|---|---|
| JP2008266028A (en) * | 2007-04-16 | 2008-11-06 | Ohara Inc | Optical glass |
| JP2009527442A (en) * | 2006-08-31 | 2009-07-30 | シーディージーエム グラス コーポレーション リミテッド | High refractive index, high dispersibility environmental countermeasure heavy flint optical glass and manufacturing method and equipment |
| WO2018008358A1 (en) * | 2016-07-04 | 2018-01-11 | 日本電気硝子株式会社 | Disk-shaped glass and method for manufacturing same |
| WO2019155755A1 (en) * | 2018-02-08 | 2019-08-15 | 株式会社 オハラ | Optical glass, preform, and optical element |
| CN115175881A (en) * | 2020-02-28 | 2022-10-11 | 豪雅株式会社 | Glass material for molding |
-
2002
- 2002-09-26 JP JP2002280358A patent/JP4113753B2/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009527442A (en) * | 2006-08-31 | 2009-07-30 | シーディージーエム グラス コーポレーション リミテッド | High refractive index, high dispersibility environmental countermeasure heavy flint optical glass and manufacturing method and equipment |
| JP2008266028A (en) * | 2007-04-16 | 2008-11-06 | Ohara Inc | Optical glass |
| WO2018008358A1 (en) * | 2016-07-04 | 2018-01-11 | 日本電気硝子株式会社 | Disk-shaped glass and method for manufacturing same |
| JPWO2018008358A1 (en) * | 2016-07-04 | 2019-04-18 | 日本電気硝子株式会社 | Disc-like glass and method for producing the same |
| WO2019155755A1 (en) * | 2018-02-08 | 2019-08-15 | 株式会社 オハラ | Optical glass, preform, and optical element |
| JP2019137571A (en) * | 2018-02-08 | 2019-08-22 | 株式会社オハラ | Optical glass, preform, and optical element |
| JP6991667B2 (en) | 2018-02-08 | 2022-02-03 | 株式会社オハラ | Optical glass, preforms and optics |
| CN115175881A (en) * | 2020-02-28 | 2022-10-11 | 豪雅株式会社 | Glass material for molding |
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| Publication number | Publication date |
|---|---|
| JP4113753B2 (en) | 2008-07-09 |
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