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GB2137981A - Optical Glass - Google Patents

Optical Glass Download PDF

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Publication number
GB2137981A
GB2137981A GB08405441A GB8405441A GB2137981A GB 2137981 A GB2137981 A GB 2137981A GB 08405441 A GB08405441 A GB 08405441A GB 8405441 A GB8405441 A GB 8405441A GB 2137981 A GB2137981 A GB 2137981A
Authority
GB
United Kingdom
Prior art keywords
weight
glass
sio2
ceo2
glasses
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.)
Granted
Application number
GB08405441A
Other versions
GB8405441D0 (en
GB2137981B (en
Inventor
Danau Grabowski
Dr Ludwig Ross
Volkmar Geiler
Dr Georg Gliemeroth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carl Zeiss AG
Original Assignee
Carl Zeiss AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Carl Zeiss AG filed Critical Carl Zeiss AG
Publication of GB8405441D0 publication Critical patent/GB8405441D0/en
Publication of GB2137981A publication Critical patent/GB2137981A/en
Application granted granted Critical
Publication of GB2137981B publication Critical patent/GB2137981B/en
Expired legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/062—Glass compositions containing silica with less than 40% silica by weight
    • C03C3/064—Glass compositions containing silica with less than 40% silica by weight containing boron
    • C03C3/068—Glass compositions containing silica with less than 40% silica by weight containing boron containing rare earths

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Glass Compositions (AREA)

Abstract

Optical glass with nd>/=1 .70, vd>/=48, having good stability to devitrification and good chemical resistance, has the following composition (in wt%): <IMAGE> Wherein M=Li, Na, K:A=Mg, Ca, Sr, Ba. The glass may also comprise: <IMAGE>

Description

SPECIFICATION Optical Glass It is an object of the present invention to provide a range of compositions for an optical glass having a refractive index of greater than or equal to 1.70 and an Abbe index of greater than or equal to 48, whose stability to devitrification is such that it is possible to produce large castings in high production numbers while meeting the customary optical quality requirements.
It has been proposed to introduce fluoride ions into glass, as described in DE-OS 27 56 160.
These glasses contain, however, more than 17% (by weight) Gd203 and the stability to dev-itrification is very low in these glasses. DE-AS 26 33 946 describes glasses containing fluoride which are composed on the basis of B203-La203-Y203; these glasses, however, need to contain Ta205 which is very expensive.
The glasses described in JP-OS 78 04 023 partly overlap the position range in the nd-vddiagram of the present application but these glasses by needs contain HfO2 in amounts ranging as high as 25% by weight. Although the glasses described in DE-OS 31 380 138 contains from 1 to 4% Fions, they differ from the present application by having a content pf W03 in amounts up to 20%.
A glass satisfying all requirements mentioned (good stability to devitrification, high refractive index with dispersion being as low as possible, absence of materials causing internal stresses in the glass such as Cd, Th) can be achieved using glass compositions according to the present invention.
According to the present invention there is provided an optical glass with a refractive index of greater than or equal to 1.70 and an Abbe index greater than or equal tp 48, having the following composition (in % by weight): SiO2 0.5-10 B203 15 -35 La2O3 35 -51 ZnO 0.51.0 ZrO2 2 - 8 F- 0.5- 5 M20 0 - 2.5 AO O - 4.5 wherein M20 is an alkali metal oxide or a mixture of alkali metal oxides, said alkali metal or metals being selected from Li, Na and K; AO is an alkaline earth metal oxide or mixture of alkaline earth metal oxides, said alkaline earth metal or metals being selected from Mg, Ca, Sr and Ba; and SiO2+B203 falls in the range 20 43 weight %.
It is preferred that the optical glass of the present invention has the following composition: SiO2 1 - 8 B203 26 -35 Na2O 0.3- 1.5 K20 .0.2- 2 Li2O 0 - 1 ZnO 0.5- 6 CaO 0.5- 2 La2O3 39 -46 ZrO2 2 8 Y203 2 -12 Gd203 3 -12 F- 0.5- 5.
The M20 content may be 0.5 to 2.5 or 0.2 to 2 (in percent by weight). It is preferred that as further components the glass contains 0--1 weight % CeO2 and optionally SnO2 such that CeO2+SnO2 is 0-2 weight %. As another component, 0--3 weight % Nb205 may be included.
In the glass according to the present invention, 0.55% by weight of the oxygen ions are replaced by fluoride ions. The fluoride ions, in addition to retarding crystallization and improving the melting properties of the mixture, cause an improvement in the transmission and a shift of the absorption edge (border/boundary) toward shorter wavelengths. The fluoride ions may typically be introduced into the glass by means of LaF3, YF3, NaF or KF, for example.
The essential feature of the glasses of the present invention is that they are free from oxides of Cd and Th, which cause internal stresses and that 0.5 to 5% by weight of the amount of 02- ions have been replaced by F- ions. The glasses of the invention are characterized by good chemical stability and very good transmission in the visible region of the spectrum.
The glasses of the invention meet the requirement for good stability towards devitrification when produced according to the currently customary technical glass melting procedures and have refractive values of greater than or equal to 1.70 and Abbe indices of greater than or equal to 48, which clearly differentiates them from the alkali-free glasses described in the Japanese patent applications or patents 75 006 326; 760 175 70, 7804023, 31 830 138. The essential characteristic is that all these requirements have been met without any addition of any environmentally stressful oxides, such as CdO and ThO2. Good crystallization stability is obtained through specific quantities of SiO2, B203, ZnO, Zero2, Y203, Nb205 and Gd203, as well as balanced additions of M20-oxides, CeO2 (up to 0.5% by weight), SnO2 (up to 1.6% by weight).Additionally, it is possible to forego the utilization of very expensive raw materials such as Ta205 so that the glasses of the invention have a markedly lower cost component for raw materials than previously-known glasses (DE-OS 22 37 259 and JP--OS 50 14 712: which specify at least 2% by weight of Ta2O5).
The components used result in an excellent transmission (pure transmission at 400 nm and 25 mm layer thickness greater than or equal to 0.941 in the glasses of the present invention; which transmission cannot be obtained with known glasses containing, among other ingredients, TiO2 and/or PbO (DE-AS 2 652 747).
The Table below contains 12 examples of embodiments in the preferred composition range.
The glasses of the invention are produced as follows: The raw materials (oxides and preferably carbonates and fluorides) are weighed; a clarifying agent, such as As203, is added in quantities of 0.11% by weight, and then the mixture is mixed well.
The glass mixture is melted down in a Pt or ceramic crucible at about 1260-1 3000 C, is then purified and homogenized well by means of an agitator. At a casting temperature of 1090-1 2000 C, the glass is then processed to the desired dimensions.
Melting Example for 100 kg Calculated Glass Quantity Weighed Oxide % by weight Raw Material in (Kg) SiO2 3.90 powdered quartz 3.91 B203 34.40 H3BO3 60.94 Li20 0.40 Li2CO3 1.00 CaO 1.40 CaCO3 2.49 ZnO 5.40 ZnO 5.43 La2o3 45.80 La2O3 42.07 LaF3 4.03 ZrO2 7.00 7.02 Nb205 1.70 Nb2O5 1.70 129.49 As2O3 0.20 As203 0.20 clarifying agent mixture 129.69 The properties of this glass are listed in Example 6 in the Table below.
1 2 3 4 5 6 7 8 9 10 11 12 SiO2 4.92 1.94 7.35 2.35 2.09 3.90 4.94 3.94 0.94 3.94 3.94 2.40 B2O3 34.00 32.00 27.00 31.00 31.64 34.40 29.21 34.06 32.40 29.20 27.71 30.60 Li2O 0.50 0.40 0.30 0.75 0.30 0.30 0.30 Na2O 0.24 1.14 K2O 1.50 CaO 0.20 1.40 1.40 1.51 1.40 1.40 0.25 ZnO 1.40 5.40 2.40 2.40 0.70 5.40 5.40 5.40 8.75 5.40 5.40 2.05 La2O3 42.30 50.31 39.00 43.23 39.24 45.80 44.00 42.50 48.61 44.00 44.00 45.50 Y2O3 7.00 7.63 7.63 11.90 2.00 2.00 3.00 5.30 Gd2O3 7.58 11.30 8.00 10.92 4.00 3.48 4.00 6.00 8.10 CeO2 0.25 SnO2 0.30 0.50 1.55 ZrO2 2.50 7.15 4.75 4.00 3.11 7.00 7.05 7.05 7.15 7.05 7.05 4.30 Nb2O5 2.50 1.70 1.20 1.20 1.85 1.20 1.20 As2O3 0.30 0.20 0.30 0.20 0.20 0.10 0.30 0.10 0.10 0.10 0.10 F- 1.60 1.80 1.20 1.60 1.50 1.20 1.60 1.20 0.85 1.20 4.15 0.50 nd 1.7287 1.7652 1.7490 1.7546 1.7548 1.7455 1.7515 1.7379 1.7590 1.7600 1.7585 1.7503 vd 55.78 48.9 51.70 52.15 52.49 50.54 50.20 51.0 49.5 48.5 50.2 50.46

Claims (12)

1. An optical glass with a refractive index of greater than or equal to 1.70 and an Abbe index greater than or equal to 48, having the following composition (in % by weight): SiO2 0.5-10 B2O3 15 -35 La2o3 35 -51 ZnO 0.5-10 ZrO2 2 - 8 F- 0.5- 5 M20 0 - 2.5 AO O - 4.5 wherein M20 is an alkali metal oxide or a mixture of alkali metal oxides, said alkali metal or metals being selected from Li, Na and K; AO is an alkaline earth metal oxide or mixture of alkaline earth metal oxides, said alkaline earth metal or metals being selected from Mg, Ca, Sr and Ba; and SiO2+B203 falls in the range 20-43 weight %.
2. A glass as claimed in Claim 1 comprising (in % by weight): SiO2 1 - 8 B2O3 26 -35 Na2O 0.3- 1.5 K20 0.2- 2 Li2O 0 - 1 ZnO 0.5- 6 CaO 0.5- 2 La2O3 39 -46 ZrO2 2 - 8 Y203 2 -12 Gd203 3 -1.2 F- 0.5- 5.
wherein SiO2+B2O3 falls in the range 27-43 weight % and Na2O+K20+Li2Ofalls in the range 0.22.5 weight %.
3. A glass as claimed in claim 1 or 2; further containing 0.2 2 weight %M2O.
4. A glass as claimed in claim 1 or 2, further containing 0.5-2;5 weight % M2O.
5. A glass as claimed in any one of claims 1 to 4 containing 0-1 weight % CeO2.
6. A glass as claimed in any preceding claim further containing 0-0.5 weight % CeO2.
7. A glass as claimed in any preceding claim further containing 0-1.6 weight % SnO2.
8. A glass as claimed in any one of the preceding claims containing 0-3 weight % Nb2O5.:
9. A glass as clamied in any one of the preceding claims containing 0-2.1 weight % CeO2+SnO2.
10. A glass as claimed in any one of claims 1 to 8 containing 0-2 weight % CeO2+SnO2.
11. A glass as claimed in claim 1 substantially as hereinbefore described in any one of Examples 1 to
12.
GB08405441A 1983-03-03 1984-03-01 Optical glass Expired GB2137981B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19833307497 DE3307497C2 (en) 1983-03-03 1983-03-03 Optical glass in the system Si0? 2? - B? 2? 0? 3? - La 2 0 3 - Zr0? 2? - alkali oxide - alkaline earth oxide - Zn0 - F with refractive index? 1.70, Payoff? 48, with good devitrification stability and good chemical resistance

Publications (3)

Publication Number Publication Date
GB8405441D0 GB8405441D0 (en) 1984-04-04
GB2137981A true GB2137981A (en) 1984-10-17
GB2137981B GB2137981B (en) 1986-12-03

Family

ID=6192394

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08405441A Expired GB2137981B (en) 1983-03-03 1984-03-01 Optical glass

Country Status (4)

Country Link
JP (1) JPS59169952A (en)
DE (1) DE3307497C2 (en)
FR (1) FR2541988B1 (en)
GB (1) GB2137981B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002062712A1 (en) * 2001-02-05 2002-08-15 Koninklijke Philips Electronics N.V. Multicomponent glass, glass fiber, twister and taper
SG110058A1 (en) * 2002-06-19 2005-04-28 Zeiss Stiftung Lead-free and preferably arsenic-free lanthanum heavy flint glasses
GB2411398A (en) * 2004-02-26 2005-08-31 Schott Ag Lead- and arsenic-free optical lanthanum flint glasses
US8039408B2 (en) 2006-03-28 2011-10-18 Hoya Corporation Optical glass, preform for precision press molding, optical element and method of manufacturing thereof
CN102344248A (en) * 2010-07-26 2012-02-08 株式会社小原 Optical glass, perform, and optical element
CN111453989A (en) * 2019-01-22 2020-07-28 成都光明光电股份有限公司 Lanthanide optical glass and glass preform, element and instrument thereof

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3500578C2 (en) * 1985-01-10 1987-02-12 Schott Glaswerke, 6500 Mainz Optical glass with refractive indices from 1.73 to 1.80 and Abbe numbers ≥ 49
JP4739721B2 (en) * 2003-11-17 2011-08-03 株式会社オハラ Optical glass
JP2010083702A (en) * 2008-09-30 2010-04-15 Hoya Corp Optical glass, glass gob for press forming and optical element
KR101679443B1 (en) 2009-02-03 2016-11-24 호야 가부시키가이샤 Optical glass, preform for precision press molding, and optical element
JP6095260B2 (en) * 2010-07-26 2017-03-15 株式会社オハラ Optical glass, preform and optical element
JP6096409B2 (en) * 2010-10-29 2017-03-15 株式会社オハラ Optical glass, preform and optical element
JP6076594B2 (en) * 2010-12-13 2017-02-08 株式会社オハラ Optical glass, preform and optical element
JP5731358B2 (en) * 2011-09-01 2015-06-10 株式会社オハラ Optical glass, preform and optical element
JP5800766B2 (en) 2011-10-28 2015-10-28 株式会社オハラ Optical glass, preform and optical element
JP5705175B2 (en) * 2011-08-05 2015-04-22 株式会社オハラ Optical glass, preform and optical element
CN102311229A (en) * 2011-09-07 2012-01-11 成都光明光电股份有限公司 Optical glass and optical element
JP5727417B2 (en) * 2012-06-15 2015-06-03 Hoya株式会社 Optical glass, optical element and manufacturing method thereof
JP6049591B2 (en) * 2013-07-31 2016-12-21 株式会社オハラ Optical glass, preform material and optical element
JP6462244B2 (en) * 2014-01-07 2019-01-30 日本電気硝子株式会社 Optical glass
JP6462245B2 (en) * 2014-01-07 2019-01-30 日本電気硝子株式会社 Optical glass
CN111453988A (en) * 2019-01-22 2020-07-28 成都光明光电股份有限公司 Optical glass and glass prefabricated member, element and instrument thereof
CN109455925B (en) * 2019-01-22 2022-04-22 成都光明光电股份有限公司 Low-softening-point optical glass and glass prefabricated member, element and instrument thereof
CN109553296B (en) * 2019-01-22 2022-08-02 成都光明光电股份有限公司 Optical glass and glass prefabricated member, element and instrument thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1286749A (en) * 1969-05-01 1972-08-23 Corning Glass Works Glass having high refraction, especially for fibre optical applications
GB2024804A (en) * 1978-06-21 1980-01-16 Ohara Optical Glass Mfg Optical glass
GB1562130A (en) * 1977-12-14 1980-03-05 Ohara Optical Glass Mfg Optical glass

Family Cites Families (12)

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Publication number Priority date Publication date Assignee Title
DE2237259A1 (en) 1971-07-30 1973-02-01 Hoya Glass Works Ltd OPTICAL GLASSES
JPS582074B2 (en) 1973-05-15 1983-01-13 カブシキガイシヤ シヤケン Shashinshiyokujiki
JPS5117570A (en) 1974-08-02 1976-02-12 Meidensha Electric Mfg Co Ltd KOIRUSHIKEN SOCHI
JPS5214607A (en) * 1975-07-24 1977-02-03 Obara Optical Glass Optical glass not containing thorium
JPS5215510A (en) 1975-07-28 1977-02-05 Nippon Chemical Ind Optical glass
JPS5263211A (en) 1975-11-20 1977-05-25 Nippon Chemical Ind Optical glass
DE2756160A1 (en) * 1977-12-16 1979-06-21 Ohara Optical Glass Mfg Optical glass having high refractive and low dispersive properties - and free of poisonous thorium oxide
JPS5678447A (en) * 1979-11-29 1981-06-27 Minolta Camera Co Ltd Optical glass
JPS5734044A (en) * 1980-08-07 1982-02-24 Nippon Kogaku Kk <Nikon> Optical glass
DE3130066A1 (en) * 1981-07-30 1983-02-17 Schott Glaswerke, 6500 Mainz CdO-, ThO2- and Ta2O5-free or low Ta2O5 optical glass having a refractive index of 1.76 - 1.81 and an Abbe number of 51-44
DE3138138C2 (en) 1981-09-25 1983-10-27 Schott Glaswerke, 6500 Mainz Th0 2 - and Cd0-free optical glass with refractive indices 1.73 - 1.88 and Abbe numbers of 35 - 52
JPH0514712A (en) 1991-07-02 1993-01-22 Ricoh Co Ltd Picture reader

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1286749A (en) * 1969-05-01 1972-08-23 Corning Glass Works Glass having high refraction, especially for fibre optical applications
GB1562130A (en) * 1977-12-14 1980-03-05 Ohara Optical Glass Mfg Optical glass
GB2024804A (en) * 1978-06-21 1980-01-16 Ohara Optical Glass Mfg Optical glass

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002062712A1 (en) * 2001-02-05 2002-08-15 Koninklijke Philips Electronics N.V. Multicomponent glass, glass fiber, twister and taper
US6690869B2 (en) 2001-02-05 2004-02-10 Koninklijke Philips Electronics N.V. Multicomponent glass, glass fiber, twister and taper
SG110058A1 (en) * 2002-06-19 2005-04-28 Zeiss Stiftung Lead-free and preferably arsenic-free lanthanum heavy flint glasses
US7091145B2 (en) 2002-06-19 2006-08-15 Schott Ag Lead-free and preferably arsenic-free lanthanum heavy flint glass
GB2411398A (en) * 2004-02-26 2005-08-31 Schott Ag Lead- and arsenic-free optical lanthanum flint glasses
GB2411398B (en) * 2004-02-26 2010-12-29 Schott Ag Lead- and arsenic-free optical lanthanum flint glasses
US8039408B2 (en) 2006-03-28 2011-10-18 Hoya Corporation Optical glass, preform for precision press molding, optical element and method of manufacturing thereof
US8349749B2 (en) 2006-03-28 2013-01-08 Hoya Corporation Optical glass, preform for precision press molding, optical element and method of manufacturing thereof
US8748328B2 (en) 2006-03-28 2014-06-10 Hoya Corporation Optical glass, preform for precision press molding, optical element and method of manufacturing thereof
CN102344248A (en) * 2010-07-26 2012-02-08 株式会社小原 Optical glass, perform, and optical element
CN105948483A (en) * 2010-07-26 2016-09-21 株式会社小原 Optical glass, preform, and optical element
CN107879619A (en) * 2010-07-26 2018-04-06 株式会社小原 Optical glass, preform, optical element and optical device
CN105948483B (en) * 2010-07-26 2020-05-15 株式会社小原 Optical glass, preform and optical element
CN111453989A (en) * 2019-01-22 2020-07-28 成都光明光电股份有限公司 Lanthanide optical glass and glass preform, element and instrument thereof

Also Published As

Publication number Publication date
DE3307497C2 (en) 1985-09-12
FR2541988B1 (en) 1991-07-12
GB8405441D0 (en) 1984-04-04
DE3307497A1 (en) 1984-09-06
GB2137981B (en) 1986-12-03
JPS59169952A (en) 1984-09-26
FR2541988A1 (en) 1984-09-07

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PCNP Patent ceased through non-payment of renewal fee

Effective date: 19950301