CN1666967A - Optical glass - Google Patents

Abstract

Provided is a glass preform material having optical constants in a specific range, low transition temperature (Tg) and used for precision press forming by comprehensively eliminating various defects of the optical glass which are known in the conventional technique and to provide the optical glass suitable for the precision press forming. The optical glass contains, as essential components, SiO<SB>2</SB>, B<SB>2</SB>O<SB>3</SB>, La<SB>2</SB>O<SB>3</SB>, Gd<SB>2</SB>O<SB>3</SB>and Li<SB>2</SB>O wherein the total amount of SiO<SB>2</SB>, B<SB>2</SB>O<SB>3</SB>, La<SB>2</SB>O<SB>3</SB>, Gd<SB>2</SB>O<SB>3</SB>and Li<SB>2</SB>O to the total mass of the glass composition is >=91 mass% and has the optical constant of refractive index (nd) within a range from 1.65 to 1.71 and Abbe number ([nu]d) within a range from >55 to 60, the logarithm log[eta]of viscosity (dPa*s) of >=0.5 in a liquidus temperature and the glass transition temperature (Tg) within a range from 550 to 630[deg.]C.

Description

Opticglass

Technical field

The present invention relates to have low transition temperature (Tg) and low dispersed, be applicable to the glass preshaping body of precision pressure moulding and the opticglass that adapts to the precision pressure moulding.

Background technology

In recent years, small-sized, the lightweight of optical device take shape, in order to reduce the lens piece number of the optical system that constitutes optical device, use the glass non-spherical lens to increase gradually, therefore, make the pressure forming of thermoplastic glass preshaping body with the mould with high precision molding surface, the shape copying of the high precision molding surface of mould is obtained the method for glass non-spherical lens on the glass preshaping body, promptly the method for making non-spherical lens by the precision pressure moulding becomes main stream approach.

When utilizing the precision pressure moulding to make the glass ware forming product, because must under hot environment, make the pressure forming of thermoplastic glass preshaping body, so, the mould that use this moment also is under the hot environment, how the situations such as high precision molding surface that mold release film that the oxidized burn into of mould molding face is located at mould molding face surface was damaged, can not keeps mould can take place, and mould itself damages easily also.In case so, replacing, the maintenance number of times of mould will be increased, low cost, a large amount of production can not be realized.Therefore, for suppressing above-mentioned damage, keep the high precision molding surface of mould and make the precision pressure moulding under the low temperature become possibility for a long time, the glass such as glass preshaping body that use in glass that uses in the precision pressure moulding and the precision pressure moulding are hoped to have alap transition temperature (Tg).Now, because in a single day the glass transition temperature of used glass preshaping body surpasses 630 ℃ in the precision pressure moulding, just be difficult to realize the precision pressure moulding, so people need transition temperature (Tg) at the low dispersed glass below 630 ℃.In addition, even the glass preshaping body of devitrification is carried out the precision pressure moulding, can not eliminate devitrification (hereinafter referred is " devitrification ") yet, the glass ware forming product that comprise devitrification can not be used for optical elements such as lens, so, the glass of used glass preshaping body in the precision pressure moulding must be the glass of devitrification resistance excellence.

The opticglass that is used for non-spherical lens requires to have various optical constants (specific refractory power (nd) and Abbe number (ν d)), wherein, in recent years for revising the chromatic aberration of optical system, to Abbe number (ν d) big, also promptly have low dispersed lens demand arranged.Particularly in optical design, the demand of refractive index (nd) 1.65～1.71, the low dispersed opticglass of Abbe number (ν d) greater than 55 is very strong.

For this reason, all the time, in order to obtain low dispersed glass, people have proposed various schemes.For example, in patent documentation 1 (Japanese kokai publication sho 53-4023 communique), disclosed B ₂O ₃-La ₂O ₃-HfO ₂Be optical glass, but since in the document alkali composition or the fluorine content of the composition of the reduction transition temperature in the concrete disclosed glass few, so transition temperature (Tg) height, the precision pressure difficult forming.In addition, because contain high price raw material HfO ₂So, the problem that has cost to rise.

In patent documentation 2 (Japanese kokai publication sho 56-169150 communique), disclosed H ₂O ₃-La ₂O ₃-Gd ₂O ₃-RO+F is optical glass, has disclosed B in the patent documentation 3 (Japanese kokai publication hei 3-16932 communique) ₂O ₃-Li ₂O ₃-Gd ₂O ₃-LaF ₃Be optical glass, but the two fluorinated volume all in a lot, the fusing volatilization violent, be difficult to obtain uniform glass.

In patent documentation 4 (Japanese kokai publication hei 8-259257 communique), disclosed SiO ₂-B ₂O ₃-Li ₂O-ZnO-La ₂O ₃Be optical glass, but because high dispersive composition ZnO and the alkaline components content height of the concrete disclosed glass of the document so Abbe number (ν d) is low to 48～55, do not have the optical constant of above-mentioned particular range.Therefore, can not satisfy requirement in the above-mentioned in recent years optical design.

In patent documentation 5 (TOHKEMY 2003-238198 communique), disclosed B ₂O ₃-La ₂O ₃-Li ₂O-LiF-ZnO-ZnF ₂Be optical glass, but volatilization is violent in the content height of fluorine compounds, fusing, is difficult to obtain uniform glass.In addition, concrete disclosed glass in the document is because high dispersive composition TiO ₂, Ta ²O ⁵, Nb ₂O ₅, ZnO content many, so Abbe number (ν d) is low to 35～55, do not have the optical constant of above-mentioned particular range.Therefore, can not satisfy requirement in the above-mentioned in recent years optical design.

In patent documentation 6 (TOHKEMY 2002-249337 communique), disclosed B ₂O ₃-La ₂O ₃-Gd ₂O ₃-ZnO is optical glass, in patent documentation 7 (JP 2003-201143 communique), has disclosed B ₂O ₃-SiO ₂-La ₂O ₃-Gd ₂O ₃-ZnO-La ₂O ₃Be optical glass, but the content of the two high dispersive composition ZnO is all very high, so Abbe number (ν d) does not have the optical constant of above-mentioned particular range to 55.Therefore, can not satisfy requirement in the above-mentioned in recent years optical design.

In patent documentation 8 (JP 55-3329 communique), B is disclosed ₂O ₃-SiO ₂-SnO ₂-La ₂O ₃-Yb ₂O ₃Be optical glass, in patent documentation 9 (JP 54-3115 communique), disclose B ₂O ₃-SiO ₂-La ₂O ₃-ZnO-SnO ₂-bivalent metal oxide is optical glass, and the two all contains SnO ₂SnO ₂Easily with platinum reaction the becoming alloy that is used as the glass melting crucible, so on producing, should not contain.

In patent documentation 10 (examined patent publication 53-42328 communique), disclosed B ₂O ₃-SiO ₂-La ₂O ₃-ZrO ₂(or) Ta ₂O ₅Be optical glass, because high dispersive composition ZrO ₂, Ta ₂O ₅Content ZrO ₂+ Ta ₂O ₅Reach 5～25%, so do not have the optical constant of above-mentioned particular range.Therefore, can not satisfy requirement in the above-mentioned in recent years optical design.

Summary of the invention

To sum up, no matter existing low dispersed opticglass is that transition temperature (Tg) is high or transition temperature (Tg) is low, all because do not have the optical constant etc. of the above-mentioned specified range that tight demand is arranged in recent years, so can not satisfy the requirement in the above-mentioned optical design in recent years.

The objective of the invention is to, in view of above-mentioned problem, comprehensive every shortcoming of eliminating opticglass described in the prior art provides the optical constant with above-mentioned specified range and transition temperature (Tg) is low, the glass preshaping body that can be used for the precision pressure moulding and the opticglass that is suitable for the precision pressure moulding.

The inventor etc. are for addressing the above problem, and repeatedly after the further investigation, found that, will be for the SiO of glass composition gross mass ₂, B ₂O ₃, La ₂O ₃, Gd ₂O ₃With Li ₂The total amount of O is set in more than the predetermined value, with La ₂O ₃, Gd ₂O ₃, Yb ₂O ₃With Lu ₂O ₃Total mass content and the SiO of each composition ₂, B ₂O ₃The ratio of total mass content be set in the particular range, just can obtain fluorinated volume extremely hangs down even not fluorine-containing, as to have above-mentioned particular range optical constant and has the low transition temperature (Tg) of energy precision pressure moulding, the viscosity (dPas) under the liquidus temperature, the glass preshaping body that is used for the precision pressure moulding, and the optical glass of suitable precision pressure moulding, so far finish the present invention.

The inventor etc. also find: with La contained in the glass composition ₂O ₃With Gd ₂O ₃Mass ratio be set in particular range, just can be made into the optical constant transitivity with expection and the optical glass with fabulous stability, thereby finish the present invention.

More specifically, the present invention relates to following content.

(1) a kind of opticglass is characterized in that, has specific refractory power (nd) 1.65～1.71, Abbe number (ν d) greater than 55 optical constants until 60 scope, and the logarithm log η of the viscosity under the liquidus temperature (dPas) is more than or equal to 0.5.

As (1) described opticglass, it is characterized in that (2) second-order transition temperature (Tg) is smaller or equal to 630 ℃.

As (1) or (2) described opticglass, it is characterized in that (3) second-order transition temperature (Tg) is smaller or equal to 625 ℃.

As the described opticglass in (1)～(3), it is characterized in that (4) second-order transition temperature (Tg) is more than or equal to 550 ℃.

As the described opticglass in (1)～(4), it is characterized in that (5) second-order transition temperature (Tg) is more than or equal to 570 ℃.

As each described opticglass of (1)～(5), it is characterized in that (6) the logarithm log η of the viscosity under the described liquidus temperature (dPas) is 0.5～2.0.

Such as each described optical glass of (1)～(6), it is characterized in that (7) containing must composition SiO ₂, B ₂O ₃, La ₂O ₃, Gd ₂O ₃With Li ₂O, described total amount that must composition is more than or equal to 91 quality % with respect to the ratio of glass composition gross mass.

(8) such as (7) described optical glass, it is characterized in that, contain each composition that following oxide converts and forms: with quality representation, in the above-mentioned necessary composition, SiO ₂Be 1～12%, B ₂O ₃Be 20～45%, La ₂O ₃Be 14～30%, Gd ₂O ₃Be 28～40%, Li ₂O is 0.5～5% scope, in any composition, and Yb ₂O ₃Be 0～5%, Lu ₂O ₃Be 0～5%, TiO ₂Be 0～0.1%, ZrO ₂Be 0～4%, ZnO is 0～less than 3.5%, RO is below 0～4%, Sb ₂O ₃0～1% scope, wherein, RO be selected among CaO, SrO, the BaO more than a kind, the total amount of RO+ZnO is 0～4%, fluorine (F) total amount that the fluoride of above-mentioned part or all of oxide replaces forms with respect to the described oxide conversion of 100 mass parts, is the scope of 0～2 mass parts.

In addition, " oxide compound converts and forms " in this specification sheets is the oxide compound of supposition as the raw material of glass constituent of the present invention, double salt, all decompose when becoming oxide compound during fusions such as metal fluoride, quality summation with the oxide compound of this generation is 100 quality %, the composition of contained each composition in the represented glass, and the F total amount that the fluorochemical of above-mentioned part or all of oxide compound replaces, be to convert with above-mentioned oxide compound that to form 100 mass parts be benchmark, the represented amount of mass fraction when with regard to the F atom, calculating the fluorine that can exist in the glass composition of the present invention and containing rate.

(9) such as (7) described optical glass, it is characterized in that, contain each composition that following oxide converts and forms: represent with mol%, in the above-mentioned necessary composition, SiO ₂Be 1～25%, B ₂O ₃Be 40～70%, La ₂O ₃Be 3～15%, Gd ₂O ₃Be 3～20%, Li ₂O is 1～20% scope, in any composition, and Yb ₂O ₃Be 0～5%, Lu ₂O ₃Be 0～5%, TiO ₂Be 0～0.1%, ZrO ₂Be 0～5%, ZnO is 0～less than 5%, RO is 0～5%, Sb ₂O ₃0～1%, wherein, RO be selected among CaO, SrO, the BaO more than a kind, the total amount of RO+ZnO is 0～10%, the convert ratio of the total mole number that forms of the fluorine molal quantity that the fluoride of above-mentioned part or all of oxide replaces and above-mentioned oxide is 0～0.15.

In addition, in this specification sheets, when using " oxide compound converts and forms " in order to represent the component that mol% represents, all decompose when becoming oxide compound when being supposition as fusions such as the oxide compound of the raw material of glass constituent of the present invention, double salt, metal fluorides, total mole number with the oxide compound of this generation is 100mol%, the composition of contained each composition in the represented glass.

As each described opticglass of (7)～(9), it is characterized in that (10) above-mentioned opticglass is not fluorine-containing in fact.

(11) such as each described optical glass of (7)～(10), it is characterized in that La ₂O ₃, Gd ₂O ₃, Yb ₂O ₃, Lu ₂O ₃Total mass content and the SiO of each composition ₂, B ₂O ₃The ratio of total mass content in 1.0～1.5 scope.

(12) such as the described optical glass of (7)～(11) any one, it is characterized in that La ₂O ₃Mass content and Gd ₂O ₃The ratio of mass content in 0.1～1.0 scope.

(13) a kind of optical glass is characterized in that, contains each composition that following oxide converts and forms: with quality representation, and in the above-mentioned necessary composition, SiO ₂Be 1～12%, B ₂O ₃Be 20～45%, La ₂O ₃Be 14～30%, Gd ₂O ₃Be 28～40%, Li ₂O is 0.5～5% scope, in any composition, and Yb ₂O ₃Be 0～5%, Lu ₂O ₃Be 0～5%, TiO ₂Be 0～0.1%, ZrO ₂Be 0～4%, ZnO is 0～less than 3.5%, RO is below 0～4%, Sb ₂O ₃0～1% scope, wherein, RO be selected among CaO, SrO, the BaO more than a kind, the total amount of RO+ZnO is 0～4%, fluorine (F) total amount that the fluoride of above-mentioned part or all of oxide replaces forms with respect to the described oxide conversion of 100 mass parts, is the scope of 0～2 mass parts.

(14) the optical element forming preshaping body that forms by each described opticglass of (1)～(13).

(15) optical element that forms with the preshaping body moulding by (14) described optical element forming.

(16) optical element that forms by each described opticglass moulding of (1)～(13).

The invention effect

Opticglass of the present invention, have specific refractory power (nd) 1.65～1.71, Abbe number (ν d) greater than 55 optical constants until 60 scopes, second-order transition temperature (Tg) is 550～630 ℃, viscosity under the liquidus temperature (dPas) is 0.5～2.0, so, be applicable to glass preshaping body and precision pressure moulding that the precision pressure moulding is used.In addition, compare with existing optical glass, Abbe number (ν d) is big, and namely low good dispersion satisfies the requirement in the above-mentioned in recent years optical design, and is industrially very useful.

Embodiment

Below, specify the present invention.

Earlier the composition that can contain in the optical glass of the present invention is described.Below, if no special instructions, the containing ratio of each composition namely represents with quality %.

Optical glass of the present invention contains each composition that following oxide converts and forms, with quality representation, and in necessary composition, SiO ₂Be 1～12%, B ₂O ₃Be 20～45%, La ₂O ₃Be 14～30%, Gd ₂O ₃Be 28～40%, Li ₂O is the scope greater than 0.5～5%, must composition SiO ₂, B ₂O ₃, La ₂O ₃, Gd ₂O ₃, Li ₂The ratio of the total amount of O and glass composition gross mass is more than or equal to 91 quality %, and in any composition, Yb ₂O ₃0～5% and/or Lu ₂O ₃0～5% and/or TiO ₂0～0.1% and/or ZrO ₂Be 0～4% and/or ZnO be 0～less than 3.5% and/or RO is below 0～4%, Sb ₂O ₃0～1%, wherein, RO be selected among CaO, SrO, the BaO more than a kind, the total amount of RO+ZnO is 0～4%, and, the fluorine total amount that the fluoride of contained above-mentioned part or all of oxide replaces, forming with respect to the described oxide conversion of 100 mass parts, is the scope of 0～2 mass parts, La ₂O ₃, Gd ₂O ₃, Yb ₂O ₃, Lu ₂O ₃Total mass content and the SiO of each composition ₂, B ₂O ₃The ratio of total mass content in 1.0～1.5 scope, optical constant with refractive index (nd) 1.65～1.71, Abbe number (ν d) scope greater than 55～60, the logarithm log η of the viscosity under the liquidus temperature (dPas) is more than or equal to 0.5, and glass transition temperature (Tg) is smaller or equal to 630 ℃.

About necessary composition

In the glass of above-mentioned composition, SiO ₂Composition is the composition that effectively improves glass viscosity, improves devitrification resistance in optical glass of the present invention, when its content very little the time, is difficult to fully reach above-mentioned effect, and when its content was too many, then transition temperature (Tg) raise, and easily produces not fused mass.

Therefore, in order to keep devitrification resistance, to be easy to obtain low transition temperature (Tg), the lower limit that can contain is preferably 1%, more preferably 1.5%, is preferably 2% especially, and the upper limit is preferably 12%, more preferably 11%, is preferably 10% especially.

Can be with for example SiO ₂Deng being used as raw material, with SiO ₂Composition imports in the glass composition.

B ₂O ₃Composition is indispensable network former composition in optical glass of the present invention.But when it is measured when very few, devitrification resistance is just not enough, and in case too much, chemical durability will variation.Therefore, for the chemical stability that is easy to keep good, the lower limit that can contain is preferably 20%, more preferably 23%, is preferably 25% especially, and the upper limit is preferably 45%, more preferably 42%, is preferably 40% especially.

Can be with for example H ₃BO ₃Deng being used as raw material, with B ₂O ₃Composition imports in the glass composition.

As mentioned above, the inventor finds, with La ₂O ₃, Gd ₂O ₃, Yb ₂O ₃, Lu ₂O ₃Each becomes subtotaling mass content and SiO ₂, B ₂O ₃The ratio of total mass content, i.e. (La ₂O ₃+ Gd ₂O ₃+ Yb ₂O ₃+ Lu ₂O ₃)/(SiO ₂+ B ₂O ₃) value be set in particular range, can improve devitrification resistance and chemical durability, keep low transition point (Tg), and can also keep the optical constant of expecting.

For reaching above-mentioned effect, (La of the present invention ₂O ₃+ Gd ₂O ₃+ Yb ₂O ₃+ Lu ₂O ₃)/(SiO ₂+ B ₂O ₃) value be preferably 1.0～1.5, more preferably 1.0～1.45, be particularly preferably 1.0～1.4.

For the Effective Raise glass refraction, reach low decentralized, La ₂O ₃Composition is indispensable composition in the glass of the present invention.But, measure when very few when it, just be difficult to the optical constant value is remained in the above-mentioned particular range, and measure when too much when it, devitrification resistance is with regard to variation.

Therefore, for reaching above-mentioned effect, the lower limit that can contain is preferably 14%, more preferably 14.5%, is preferably 15% especially, and the upper limit is preferably 30%, more preferably 28%, is preferably 27% especially.Can be with for example La ₂O ₃, La (NO ₃) ₃XH ₂O, LaF ₃Deng being used as raw material, with La ₂O ₃Composition imports in the glass composition.

Gd ₂O ₃Composition is the Effective Raise glass refraction, reaches and hang down decentralized composition.But, measure when very few when it, just can not give full play to above-mentioned effect, in case too much, devitrification resistance on the contrary can variation.

Therefore, for keeping the optical constant of the expection in the opticglass of the present invention, and be easy to the devitrification resistance that keeps good, and the lower limit that can contain is preferably 28%, more preferably 30%, is preferably 31% especially, and the upper limit is preferably 40%, more preferably 39%, is preferably 38% especially.

Can be with for example Gd ₂O ₃, GdF ₃Deng being used as raw material, with Gd ₂O ₃Composition imports glass composition.

In more preferably mode of the present invention, the La in the glass composition ₂O ₃Quality and Gd ₂O ₃Mass ratio, i.e. (La ₂O ₃)/(Gd ₂O ₃) value is preferably and is limited to predetermined value.This value is the key factor that promotes the low decentralized of optical glass and improve devitrification resistance.The inventor finds, by this value is set in pre-determined range, can realize having simultaneously the Abbe number of expection and the opticglass of good devitrification resistance.

(La ₂O ₃)/(Gd ₂O ₃) the lower limit of value be preferably 0.1, more preferably 0.2, be particularly preferably 0.3, the upper limit is preferably 1.0, more preferably 0.9, is particularly preferably 0.8.

Li ₂The O composition plays and reduces transition temperature (Tg) significantly and promote blended frit fused effect.But when its content was very few, these effects were insufficient, and in case too much, devitrification resistance is with regard to rapid deterioration.

Therefore, for the transition temperature (Tg) or the devitrification resistance that are easy to keep good, the lower limit that can contain is preferably 0.5%, more preferably 1%, is preferably 1.5% especially, and the upper limit is preferably 5%, more preferably 4%, is preferably 3% especially.

Can be with for example Li ₂CO ₃, LiF, LiNO ₃, LiOH etc. is as raw material, with Li ₂The O composition imports in the glass composition.

In addition, be enhancement of dispersion, the raising chemical durability that suppresses glass, the necessary composition SiO in the optical glass of the present invention ₂, B ₂O ₃, La ₂O ₃, Gd ₂O ₃, Li ₂O quality sum and oxide convert the ratio of the glass gross mass that forms be preferably greater than equal 91%, more preferably more than or equal to 92%, more preferably more than or equal to 93%, be particularly preferably more than or equal to 94%.

Any composition

Yb ₂O ₃Composition is the Effective Raise glass refraction, reaches and hang down decentralized composition.But, when interpolation is excessive, can cause the devitrification resistance variation of glass.

For the optical constant that keeps the present invention to expect, and be easy to the devitrification resistance that keeps good, can contain be preferably smaller or equal to 5%, more preferably smaller or equal to 4%, be particularly preferably the Yb smaller or equal to 3% ₂O ₃Composition.

Can be with for example Yb ₂O ₃, YbF ₃Deng being used as raw material, with Yb ₂O ₃Composition imports glass composition.

Lu ₂O ₃Composition is the Effective Raise glass refraction, reaches and hang down decentralized composition.But, when addition is too much, will cause the devitrification resistance variation of glass.For keeping the optical constant of expection of the present invention, and be easy to the devitrification resistance that keeps good, its content is preferably smaller or equal to 5%, more preferably smaller or equal to 4%, be preferably smaller or equal to 3% especially.

Can be with for example Lu ₂O ₃Deng being used as raw material, with Lu ₂O ₃Composition imports in the glass composition.

TiO ₂Can cause the transmittance variation, make the glass enhancement of dispersion, but, also can add according to purpose for preventing the solarization (solarization) of glass.For keeping optical constant of the present invention, its content is preferably smaller or equal to 0.1%, more preferably below 0.05%, most preferably be and do not contain.

Can be with for example TiO ₂Deng being used as raw material, with TiO ₂Composition imports glass composition.

ZrO ₂Composition has the adjustment optical constant, improves devitrification resistance, improves the effect of chemical durability, but when interpolation is excessive, causes devitrification resistance to worsen on the contrary, and be difficult to make transition temperature (Tg) to remain on the low value of expection.

Therefore, for transition temperature (Tg), the devitrification resistance that is easy to keep good, its content is preferably smaller or equal to 4%, more preferably smaller or equal to 3.5%, be preferably smaller or equal to 3% especially.

Can be with for example ZrO ₂ZrF ₄Deng being used as raw material, with ZrO ₂Composition imports in the glass composition.

The ZnO composition is the have substantial degradation composition of effect of transition temperature (Tg) of tool, but because be the high dispersive composition, so, in case add excessively, just being difficult to have the optical constant in the above-mentioned specified range, devitrification resistance is variation also.

Therefore, for keeping good devitrification resistance, and reduce transition temperature (Tg), its content preferably is less than 3.5%, more preferably smaller or equal to 3.3%, be particularly preferably smaller or equal to 3.0%.Can be with for example ZnO, ZnF ₂Deng as raw material, the ZnO composition is imported in the glass composition.

Na ₂O and K ₂O has reduction transition temperature (Tg) and promotes blended frit fused effect, but because content is when too much, can cause devitrification resistance, the remarkable variation of chemical durability, so, be preferably with 2%, more preferably 1% to be the upper limit, to be preferably and not contain especially.

The one kind or two or more RO composition that is selected from CaO, SrO, the BaO composition can effectively be adjusted optical constant.But when the total amount of CaO, SrO, BaO composition was too much, devitrification resistance will variation.

Therefore, for the devitrification resistance that is easy to keep good especially, the total content of CaO, SrO, BaO composition is preferably smaller or equal to 4%, more preferably smaller or equal to 3.5%, be preferably smaller or equal to 3% especially.

Can be with for example CaCO ₃, CaF ₂, Ca (OH) ₂Deng as raw material, the CaO composition is imported in the glass composition.

Can be with for example Sr (NO ₃) ₂, SrF ₂, Sr (OH) ₂Deng as raw material, the SrO composition is imported in the glass composition.

Can be with for example BaCO ₃, Ba (NO ₃) ₂, BaF ₂, Ba (OH) ₂Deng as raw material, the BaO composition is imported in the glass composition.

In addition, the total amount of above-mentioned RO+ZnO is too much, also can cause the devitrification resistance variation.Therefore, the total content of CaO, SrO, BaO, ZnO be preferably smaller or equal to 4%, more preferably smaller or equal to 3.5%, be preferably smaller or equal to 3% especially.

Sb ₂O ₃Defoamer when composition can be used as glass melting adds, and its amount reaches 1% namely enough.

The F composition can effectively reduce dispersion, reduction transition temperature (Tg), the raising devitrification resistance of glass, particularly by making F composition and La ₂O ₃The composition coexistence can obtain having the optical constant in the above-mentioned particular range, and has the low dispersed optical glass of the low transition temperature (Tg) of energy precision pressure moulding.

In addition, in optical glass of the present invention, the F composition is considered to exist with the form with the fluoride of the part or all of replacement of the one kind or two or more oxide of each silicon, other metallic element.When too much with the total amount in F of the fluoride of the part or all of replacement of this oxide, the volatile quantity of fluorine composition can increase, and is difficult to obtain uniform glass.And because the volatilization of fluorine composition, be difficult to keep the optical constant of expecting.

Therefore, with respect to the glass composition that the oxide compound of 100 mass parts converts and forms, its content is preferably smaller or equal to 2 mass parts, more preferably smaller or equal to 1.9 mass parts, be preferably smaller or equal to 1.8 mass parts especially.Or do not contain in fact." not containing in fact " of the present invention is meant except that the impurity of sneaking into, and nobody is the situation that makes it to contain.

About the composition that should not contain

Below, the composition that should not contain in the opticglass of the present invention is described.

The problem that lead compound had is; easy and the melt bonded composition of mould when being the precision pressure moulding; and not only when glass is made but also until the discarded measure that all needs aspect the environment protection of glass cold working such as grinding and glass; be the big composition of carrying capacity of environment, so should not contain lead compound in the opticglass of the present invention.

As ₂O ₃, cadmium and thorium all be that environment is brought adverse effect, the very large composition of carrying capacity of environment, so, should not contain mentioned component in the optical glass of the present invention.

In case contain P in the optical glass of the present invention ₂O ₅, be easy to cause devitrification resistance to worsen, so should not contain P ₂O ₅

In the fusion tank that platinum crucible processed or the position that contacts with melten glass are formed by platinum during melten glass, tellurium and platinum form alloy, form the hear resistance variation at the position of alloy, the worry that causes the molten glass flow danger that accidents happened in this position perforate is arranged, so, should not contain TeO in the optical glass of the present invention ₂

In the opticglass of the present invention, also preferably do not contain coloring components such as V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Eu, Nd, Sm, Tb, Dy, Er.In addition, be meant that except that the impurity of sneaking into, nobody is the situation that makes it to contain " not containing " herein.

Mol% represents

Because the composition of glass composition of the present invention represents with quality %, not directly to represent with mol%, satisfy the composition that the mol% of existing each composition in the glass composition of every characteristic of the presently claimed invention represents, converting to form with oxide is roughly following value.

Contain each composition that following oxide converts and forms, wherein, must composition be: the SiO of 1～25mol% ₂, 40～70mol% B ₂O ₃, 3～15mol% La ₂O ₃, 3～20mol% Gd ₂O ₃, 1～20mol% Li ₂O in addition, contains following any composition: the Yb of 0～5mol% ₂O ₃, and/or the Lu of 0～5mol% ₂O ₃, and/or the TiO of 0～0.1mol% ₂, and/or the ZrO of 0～5mol% ₂, and/or 0～less than ZnO and/or the RO of 0～5mol% and/or the Sb of 0～1mol% of 5mol% ₂O ₃, wherein, RO is be selected from CaO, SrO, BaO one kind or two or more, the total amount of RO+ZnO is 0～10mol%, and the fluoride of above-mentioned part or all of oxide the F molal quantity that replaces and the ratio that the oxide conversion forms total mole number are 0～0.15.

SiO in the glass composition of the present invention ₂The effect of composition as mentioned above, for reaching above-mentioned effect, can contain lower limit be preferably about 1mol%, more preferably about 2mol%, be particularly preferably about 3mol%, the upper limit be preferably about 25mol%, more preferably about 23mol%, be particularly preferably about 21mol%.

B in the glass composition of the present invention ₂O ₃The effect of composition as mentioned above, for reaching above-mentioned effect, can contain lower limit be preferably about 40mol%, more preferably about 45mol%, be particularly preferably about 47mol%, the upper limit be preferably about 70mol%, more preferably about 67mol%, be particularly preferably about 68mol%.

La in the glass composition of the present invention ₂O ₃The effect of composition as mentioned above, for reaching above-mentioned effect, can contain lower limit be preferably about 3mol%, more preferably about 3.5mol%, be particularly preferably about 4mol%, the upper limit be preferably about 15mol%, more preferably about 13mol%, be particularly preferably about 11mol%.

Gd in the glass composition of the present invention ₂O ₃The effect of composition as mentioned above, for reaching above-mentioned effect, can contain lower limit be preferably about 3mol%, more preferably about 4mol%, be particularly preferably about 6mol%, the upper limit be preferably about 20mol%, more preferably about 19mol%, be particularly preferably about 17mol%.

Yb in the glass composition of the present invention ₂O ₃The effect of composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 5mol%, more preferably about 3mol%, be particularly preferably about 2mol%.

Lu in the glass composition of the present invention ₂O ₃The effect of composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 5mol%, more preferably about 3mol%, be particularly preferably about 2mol%.

TiO in the glass composition of the present invention ₂The effect of composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 0.1mol%, more preferably about 0.05mol%, be preferably and do not contain especially.

ZrO in the glass composition of the present invention ₂The effect of composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 5mol%, more preferably about 3mol%, be preferably about 2mol% especially.

The effect of the ZnO composition in the glass composition of the present invention as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 5mol%, more preferably about 4.8mol%, be preferably about 4.6mol% especially.

The effect of RO composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 5mol%, more preferably about 4.5mol%, be preferably about 4mol% especially.And the total mole number of above-mentioned RO+ZnO, can contain the upper limit be preferably about 10mol%, more preferably about 8mol%, be preferably about 6mol% especially.

Li in the glass composition of the present invention ₂The effect of O composition as mentioned above, for reaching above-mentioned effect, the content lower limit be preferably about 1mol%, more preferably about 2mol%, be preferably about 3mol% especially, the upper limit be preferably about 20mol%, more preferably about 19mol%, be preferably about 18mol% especially.

Na in the glass composition of the present invention ₂O and K ₂The effect of O composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 4mol%, more preferably about 2mol%, be particularly preferably and do not contain.

Sb in the glass composition of the present invention ₂O ₃The effect of composition as mentioned above, for reaching above-mentioned effect, can contain the upper limit be preferably about 1mol%, more preferably about 0.8mol%, be particularly preferably about 0.5mol%.

F composition in the glass composition of the present invention as mentioned above, for reaching above-mentioned effect, the mole number of the F that partly or entirely replaces with fluorochemical of above-mentioned oxide compound and oxide compound convert the ratio of the total mole number formed be preferably approximately smaller or equal to 0.15, more preferably approximately smaller or equal to 0.14, be preferably approximately smaller or equal to 0.13 especially.Or in fact do not contain." not containing in fact " of the present invention is meant except that the impurity of sneaking into, and nobody is the situation that makes it to contain.

＜rerum natura 〉

Below, the rerum natura of optical glass of the present invention is described.

Opticglass of the present invention is mainly with acting on the glass preshaping body that obtains the glass ware forming product by thermoplastic, precision pressure moulding.Therefore, for the damage that can suppress used mould this moment, keep the high-precision modeling face of mould and for can realize at low temperatures the precision pressure moulding for a long time, preferably has alap transition temperature (Tg).For this reason, by adopting the composition of above-mentioned particular range, can realize the glass transition temperature (Tg) of expection.

The lower limit of the second-order transition temperature of opticglass of the present invention (Tg) is preferably 550 ℃, more preferably 570 ℃, is preferably 575 ℃ especially, and the upper limit is preferably 630 ℃, more preferably 625 ℃, is preferably 620 ℃ especially.In the present invention, if Tg is excessively low, chemical durability variation then, devitrification resistance descends simultaneously, is difficult to carry out steady production.And if Tg is too high, moldability variation not only then, and meltbility can descend, easily produce slag.But, if the amount increase for preventing from that slag from improving melt temperature, will exist from melt container, melting out platinum, the trend of light transmission variation.

For realizing stably manufactured according to following manufacture method, it is very important that the liquidus temperature of opticglass of the present invention is controlled at below 1100 ℃.Be particularly preferably and be controlled at below 1065 ℃, but because this can widen the temperature range of steady production, and can reduce the glass melting temperature, so the energy that can suppress to consume.

In addition, " liquidus temperature " is meant the glass specimen that carrying has been pulverized on the platinum plate, keeps taking out after 30 minutes in having the stove of thermograde, examines under a microscope to have or not the crystallization of remollescent glass, the minimum temperature when being considered to not have crystallization.

As mentioned above, opticglass of the present invention can be used as pressure forming glass preshaping body, perhaps also can be directly with the melten glass pressure forming.Manufacture method and thermoforming process during as the glass preshaping body do not have special restriction, can use known manufacture method and forming method.The manufacture method of glass preshaping body both can adopt the manufacture method of the forming method of the glass cylinder that for example Japanese kokai publication hei 8-319124 communique disclosed, opticglass that Japanese kokai publication hei 8-73229 communique disclosed and manufacturing installation etc. directly to make the technical scheme of glass preshaping body by melten glass, perhaps also can make by band is carried out cold working.

In addition, use optical glass of the present invention to make melten glass from platinum or strengthen platinum to drip and when making the glass preshaping body, if the viscosity of melten glass is excessively low, in the glass preshaping body, sneak into lines easily, if viscosity is too high, then because deadweight and surface tension cause glass to be difficult to cut off.

Therefore, for realizing high-quality stably manufactured, the logarithmic value log η lower limit of the viscosity under the liquidus temperature (dPas) is preferably 0.3, more preferably 0.4, is preferably 0.5 especially, and the upper limit is preferably 2.0, more preferably 1.8, is preferably 1.5 especially.

In addition, the thermoforming process of glass preshaping body is not particularly limited, for example, can uses the method for described optical element forming method of Japanese Patent Publication 62-41180 and so on.In addition, also can make the glass preshaping body by opticglass of the present invention, the glass preshaping body is carried out press working, make optical element, perhaps also can adopt without the glass preshaping body and directly fusion, this opticglass of remollescent be carried out the direct compression method of forming that press working is made optical element.In addition, optical element can be used as for example various lens such as biconvex, concave-concave, plano-convex, plano-concave, meniscus, speculum, prism, diffraction grating etc.

Embodiment

Below, the narration embodiments of the invention, but the purpose of following embodiment only is to illustrate, and the invention is not restricted to following embodiment.

＜embodiment 1～23 〉

Table 1～table 4 has shown the composition of the embodiment No.1～No.23 of opticglass of the present invention, and the measurement result of the specific refractory power of these glass (nd), Abbe number (ν d) and transition temperature (Tg), the result of the viscosity of liquidus temperature and devitrification resistance test.Will with the common optical glass raw materials such as corresponding each oxide of the raw material of each composition, hydroxide, carbonate, nitrate, fluoride, proportion of composing weighing according to each embodiment mixes, form and cooperate raw material, it is added platinum crucible, and the meltbility that causes according to composition was 1000～1300 ℃ of lower meltings 3～5 hours, after clarifying, be stirred to evenly, injection mould etc. is cast, and Slow cooling is made optical glass of the present invention.

The composition of each composition is represented with quality % in the table.When the glass total mass of the composition that converts with oxide compound was 100 mass parts, the mass fraction when being the calculating of F atom with fluorine contained in the glass composition was represented the containing ratio of fluorine composition.

The specific refractory power (nd) and Abbe number (ν d) of gained opticglass when measuring the speed that slowly cools for-25 ℃/h.

Measure second-order transition temperature (Tg) according to the method described in Japanese optics nitre industry meeting specification JOJIS 082003 " measuring method of opticglass thermal expansion " (optics ガ ラ ス Hot Peng Zhang Measuring decides method).Wherein, the sample of long 50mm, diameter 4mm is used in test piece.

The mensuration of liquidus temperature is the glass specimen that carrying is pulverized on the platinum plate, keeps taking out after 30 minutes in the stove of band thermograde, examines under a microscope to have or not the crystallization of remollescent glass, obtains the minimum temperature of thinking when not having crystallization.

Viscosities il under the liquidus temperature (dPas) is used falling-sphere viscometer (Ball raising typeviscometer, OPT enterprise of limited commercial firm: the viscosity of mensuration liquidus temperature model BVM-13LH).Common logarithm with viscosities il when in addition, representing viscosity in table 1～5 represents.

Reference examples A～F

In addition, table 5 has shown the composition of the opticglass No.A～No.F of reference examples, and the measurement result of the viscosity under the specific refractory power of these glass (nd), Abbe number (ν d), transition temperature (Tg), liquidus temperature and the liquidus temperature.The optical glass of reference examples is the same with embodiment, will with the common optical glass raw materials such as corresponding each oxide of the raw material of each composition, hydroxide, carbonate, nitrate, fluoride, proportion of composing weighing according to each reference examples mixes, and forms to cooperate raw material, and it is added platinum crucible, the meltbility that causes according to composition, 1000～1300 ℃ of lower meltings 3～5 hours, clarify, be stirred to evenly after, inject mould etc. and cast, Slow cooling is made the optical glass of reference examples.

Table 1

Embodiment	??1	??2	????3	????4	????5	????6
							????SiO 2	??5.40	??5.40	????5.40	????6.20	????6.20	????6.40
????B 2O 3	??35.49	??34.49	????37.29	????37.49	????36.49	????34.49
							????La 2O 3	??22.72	??22.72	????22.72	????19.72	????19.72	????21.72
????Gd 2O 3	??32.07	??32.07	????32.07	????32.07	????32.07	????34.07
							????Yb 2O 3
????Lu 2O 3
							????ZrO 2				????1.00	????1.00
????ZnO	??2.00	??3.00			????1.00
							????CaO				????1.20	????1.20
????SrO
							????BaO
????Li 2O	??2.30	??2.30	????2.50	????2.30	????2.30	????3.30
							????Sb 2O 3	??0.02	??0.02	????0.02	????0.02	????0.02	????0.02
????F
							Add up to	??100.00	??100.00	????100.00	????100.00	????100.00	????100.00
????nd	??1.7023	??1.7063	????1.6940	????1.6892	????1.6937	????1.6992
							????νd	??55.7	??55.3	????56.3	????56.3	????55.9	????55.7
????Tg(℃)	??607	??603	????614	????605	????607	????595
							????SiO 2+B 2O 3+La 2O 3????+Gd 2O 3+Li 2O	??97.98	??96.98	????99.98	????97.78	????96.78	????99.98
????(La 2O 3+Gd 2O 3+Yb 2O 3+ ????Lu 2O 3)/(SiO 2+B 2O 3)	??1.34	??1.37	????1.28	????1.19	????1.219	????1.369
							????La 2O 3/Gd 2O 3	??0.71	??0.71	????0.71	????0.611	????0.611	????0.64
Liquidus temperature (℃)	??1045	??1050	????1042	????1019	????1030	????1055
							Viscosity under the liquidus temperature (log η)	??0.78	??0.75	????0.75	????0.95	????0.85	????0.70

Table 2

Embodiment	????7	????8	????9	????10	????11	????12
							????SiO 2	????8.20	????5.40	????8.20	????5.40	????6.20	????10.00
????B 2O 3	????32.49	????37.19	????31.49	????37.49	????37.49	????31.69
							????La 2O 3	????22.72	????22.72	????22.72	????20.00	????18.00	????17.04
????Gd 2O 3	????32.07	????32.07	????32.07	????32.07	????32.07	????37.75
							????Yb 2O 3
????Lu 2O 3
							????ZrO 2				????2.72	????2.72
????ZnO			????1.00
							????CaO	????1.20		????1.20		????1.20	????1.20
????SrO
							????BaO
????Li 2O	????3.30	????2.60	????3.30	????2.30	????2.30	????2.30
							????Sb 2O 3	????0.02	????0.02	????0.02	????0.02	????0.02	????0.02
????F
							Add up to	????100.00	????100.00	????100.00	????100.00	????100.00	????100.00
????nd	????1.6999	????1.6943	????1.7039	????1.6962	????1.6912	????1.6932
							????νd	????55.5	????56.2	????55.3	????55.3	????55.7	????56
????Tg(℃)	????594	????601	????588	????610	????611	????618
							????SiO 2+B 2O 3+La 2O 3????+Gd 2O 3+Li 2O	????98.78	????99.98	????97.78	????97.26	????96.06	????98.78
????(La 2O 3+Gd 2O 3+Yb 2O 3+ ????Lu 2O 3)/(SiO 2+B 2O 3)	????1.35	????1.29	????1.38	????1.21	????1.15	????1.31
							????La 2O 3/Gd 2O 3	????0.71	????0.71	????0.71	????0.62	????0.56	????0.45
Liquidus temperature (℃)	????1060	????1050	????1030	????1052	????1057	????1071
							Viscosity under the liquidus temperature (log η)	????0.65	????0.75	????0.90	????0.72	????0.70	????0.68

Table 3

Embodiment	????13	????14	????15	????16	????17	????18
							????SiO 2	????2.20	????6.20	????4.20	????4.20	????4.20	????5.40
????B 2O 3	????39.49	????35.49	????37.49	????37.49	????37.49	????34.29
							????La 2O 3	????19.72	????19.72	????16.44	????15.04	????15.04	????21.72
????Gd 2O 3	????32.07	????32.07	????35.61	????37.75	????37.75	????32.07
							????Yb 2O 3	????1.00	????1.00	????2.74
????Lu 2O 3	????1.00	????1.00		????2.00
							????ZrO 2
????ZnO						????1.00
							????CaO	????1.20	????1.20	????1.20	????1.20	????1.20	????1.00
????SrO						????1.00
							????BaO	????1.00	????1.00			????2.00	????1.00
????Li 2O	????2.30	????2.30	????2.30	????2.30	????2.30	????2.50
							????Sb 2O 3	????0.02	????0.02	????0.02	????0.02	????0.02	????0.02
????F		????1.75
							Add up to	????100.00	????101.75	????100.00	????100.00	????100.00	????100.00
????nd	????1.6945	????1.6907	????1.6932	????1.6924	????1.6914	????1.7042
							????νd	????56.5	????56.8	????56.5	????56.3	????56.7	????55.5
????Tg(℃)	????607	????605	????609	????609	????610	????600
							????SiO 2+B 2O 3+La 2O 3????+Gd 2O 3+Li 2O	????95.78	????95.78	????96.04	????96.78	????93.78	????95.98
????(La 2O 3+Gd 2O 3+Yb 2O 3+ ????Lu 2O 3)/(SiO 2+B 2O 3)	????1.29	????1.29	????1.31	????1.31	????1.19	????1.36
							????La 2O 3/Gd 2O 3	????0.62	????0.62	????0.46	????0.40	????0.32	????0.68
Liquidus temperature (℃)	????1080	????1060	????1097	????1094	????1099	????1058
							Viscosity under the liquidus temperature (log η)	????0.55	????0.70	????0.50	????0.50	????0.50	????0.70

Table 4

Embodiment	????19	????20	????21	????22	????23
						????SiO 2	????5.40	????6.20	????4.20	????7.20	????8.20
????B 2O 3	????34.29	????37.49	????37.49	????39.49	????35.49
						????La 2O 3	????21.72	????20.72	????15.54	????17.72	????18.72
????Gd 2O 3	????32.07	????32.07	????37.75	????32.07	????32.07
						????Yb 2O 3			????1.50
????Lu 2O 3
						????ZrO 2	????1.00
????ZnO					????1.00
						????CaO		????1.20	????1.20	????1.20	????1.20
????SrO	????3.00
						????BaO
????Li 2O	????2.50	????2.30	????2.30	????2.30	????3.30
						????Sb 2O 3	????0.02	????0.02	????0.02	????0.02	????0.02
????F		????1.75	????1.75
						Add up to	????100.00	????101.75	????101.75	????100.00	????100.00
????nd	????1.7054	????1.6839	????1.6902	????1.6753	????1.6847
						????νd	????55.3	????57	????56.7	????57.5	????56.6
????Tg(℃)	????602	????602	????601	????612	????590
						????SiO 2+B 2O 3La 2O ????+Gd 2O 3+Li 2O	????95.98	????98.78	????97.28	????98.78	????97.78
????(La 2O 3+Gd 2O 3+Yb 2O 3+ ????Lu 2O 3)/(SiO 2+B 2O 3)	????1.36	????1.21	????1.31	????1.07	????1.16
						????La 2O 3/Gd 2O 3	????0.68	????0.65	????0.41	????0.55	????0.58
Liquidus temperature (℃)	????1058	????1015	????1085	????1030	????1030
						Viscosity under the liquidus temperature (log η)	????0.69	????1.00	????0.57	????0.94	????0.97

Table 5

Reference examples	????A	????B	????C	????D	????E	????F
							????SiO 2	????7.00	????6.00	????6.00	????7.10		????4.98
????B 2O 3	????32.50	????29.00	????25.20	????22.90	????27.00	????24.89
							????La 2O 3	????23.00	????21.00	????29.90	????16.00	????15.00	????9.95
????Gd 2O 3	????8.00	????16.00		????24.00
							????Nb 2O 5					????3.00	????4.98
????Y 2O 3		????10.00	????4.00
							????ZnO	????12.00	????1.00	????29.00	????13.90	????40.00	????39.80
????CaO		????10.00
							????SrO	????9.30
????BaO				????10.00	????13.00
							????MgO	????4.20
????Li 2O	????2.00	????2.00	????0.70	????0.10	????2.00	????4.98
							????Na 2O	????1.00			????5.00
????K 2O		????5.00	????4.80
							????WO 3						????9.95
????As 2O 3	????1.00		????0.40
							????Sb 2O 3				????1.00		????0.50
????F					????7.21	????7.01
							Add up to	????100.00	????100.00	????100.00	????100.00	????107.21	????107.01
????nd	????1.6789	The bulk glass devitrification	????1.6966	????1.7023	The bulk glass devitrification	The bulk glass devitrification
							????νd	????54.8	????49.4	????50.3
????Tg(℃)	????542		????519	????532
							????SiO 2+B 2O 3+La 2O 3????+Gd 2O 3+Li 2O	????72.50	????74.00	????61.80	????70.10	????44.00	????45.00
????(La 2O 3+Gd 2O 3+Yb 2O 3+ ????Lu 2O 3)/(SiO 2+B 2O 3)	????0.79	????1.06	????0.96	????1.33	????0.56	????0.33
							????La 2O 3/Gd 2O 3	????2.88	????1.31	????-	????0.67	????-	????-
Liquidus temperature (℃)	????1077			????1087
							Viscosity under the liquidus temperature (log η)	????0.32			????0.41

Shown in table 1～table 4, opticglass No.1～the No.23 of the embodiment of the invention has the optical constant of above-mentioned specified range, promptly, specific refractory power (nd) 1.65～1.71, Abbe number (ν d) greater than 55 less than 60, in addition, transition temperature (Tg) is in 550～630 ℃ scope, and the viscosity under the liquidus temperature (dPas) is 0.5～2.0, so be applicable to employed preshaping body of precision pressure moulding and precision pressure moulding.

Otherwise as shown in table 5, the specific refractory power of the glass of reference examples No.A, C, D (nd) is in 1.65～1.71 scope, but Abbe number (ν d) does not have the optical constant of above-mentioned specified range below 55, can not satisfy the requirement in the optical design in recent years.

In addition, produce crystallization in the glass of reference examples No.B, E, F, very unstable, do not have the optical constant of above-mentioned specified range, can not satisfy the requirement in the optical design in recent years.

In addition, the composition ZnO of the reduction glass viscosity in the glass of reference examples No.A, D substantially exceeds the scope of the total content 0～4% of RO+ZnO, because the viscosity (dPas) of above-mentioned liquidus temperature departs from stated limit, so be difficult to realize stably manufactured.

Claims (15)

1. an opticglass is characterized in that, has specific refractory power (nd) 1.65～1.71, Abbe number (ν d) greater than 55 optical constants until 60 scope, and the logarithm log η of the viscosity under the liquidus temperature (dPas) is more than or equal to 0.5.

2. opticglass as claimed in claim 1 is characterized in that glass transition temperature Tg is smaller or equal to 630 ℃.

3. opticglass as claimed in claim 1 is characterized in that, the logarithm log η of the viscosity dPas under the described liquidus temperature is 0.5～2.0.

4. optical glass as claimed in claim 1 is characterized in that, containing must composition SiO ₂, B ₂O ₃, La ₂O ₃, Gd ₂O ₃With Li ₂O, described total amount that must composition is more than or equal to 91 quality % with respect to the ratio of glass composition gross mass.

5. opticglass as claimed in claim 4 is characterized in that, contains each composition that following oxide compound converts and forms:

With quality representation, in the described necessary composition, SiO ₂Be 1～12%, B ₂O ₃Be 20～45%, La ₂O ₃Be 14～30%, Gd ₂O ₃Be 28～40%, Li ₂O is 0.5～5% scope,

In any composition, Yb ₂O ₃Be 0～5%, Lu ₂O ₃Be 0～5%, TiO ₂Be 0～0.1%, ZrO ₂Be 0～4%, ZnO is 0～less than 3.5%, RO is below 0～4%, Sb ₂O ₃0～1% scope, wherein, RO be selected among CaO, SrO, the BaO more than a kind or a kind, the total amount of RO+ZnO is 0～4%,

The fluorine F total amount that the fluorochemical of described part or all of oxide compound replaces is formed with respect to the described oxide compound conversion of 100 mass parts, is the scope of 0～2 mass parts.

6. opticglass as claimed in claim 4 is characterized in that, contains each composition that following oxide compound converts and forms:

Represent with mol%, in the described necessary composition, SiO ₂Be 1～25%, B ₂O ₃Be 40～70%, La ₂O ₃Be 3～15%, Gd ₂O ₃Be 3～20%, Li ₂O is 1～20% scope,

In any composition, Yb ₂O ₃Be 0～5%, Lu ₂O ₃Be 0～5%, TiO ₂Be 0～0.1%, ZrO ₂Be 0～5%, ZnO is 0～less than 5%, RO is 0～5%, Sb ₂O ₃0～1% scope, wherein, RO be selected among CaO, SrO, the BaO more than a kind, the total amount of RO+ZnO is 0～10%,

The fluorine F mole number that the fluorochemical of described part or all of oxide compound replaces is 0～0.15 with the ratio of the total mole number that described oxide compound conversion is formed.

7. opticglass as claimed in claim 4 is characterized in that, described opticglass is not fluorine-containing in fact.

8. optical glass as claimed in claim 4 is characterized in that, La ₂O ₃, Gd ₂O ₃, Yb ₂O ₃, Lu ₂O ₃Total mass content and the SiO of each composition ₂, B ₂O ₃The ratio of total mass content in 1.0～1.5 scope.

9. optical glass as claimed in claim 4 is characterized in that, La ₂O ₃Mass content and Gd ₂O ₃The ratio of mass content in 0.1～1.0 scope.

10. an opticglass is characterized in that, contains each composition that following oxide compound converts and forms:

With quality representation, in the described necessary composition, SiO ₂Be 1～12%, B ₂O ₃Be 20～45%, La ₂O ₃Be 14～30%, Gd ₂O ₃Be 28～40%, Li ₂O is 0.5～5% scope,

In any composition, Yb ₂O ₃Be 0～5%, Lu ₂O ₃Be 0～5%, TiO ₂Be 0～0.1%, ZrO ₂Be 0～4%, ZnO is 0～less than 3.5%, RO is 0～4%, Sb ₂O ₃0～1% scope, wherein, RO be selected among CaO, SrO, the BaO more than a kind, the total amount of RO+ZnO is 0～4%,

The fluorine F total amount that the fluorochemical of described part or all of oxide compound replaces is formed with respect to the described oxide compound conversion of 100 mass parts, is the scope of 0～2 mass parts.

11. the optical element forming preshaping body that forms by the described opticglass of claim 1.

12. the optical element forming preshaping body that forms by the described opticglass of claim 10.

13. the optical element forming preshaping body that forms by claim 11 or 12 described opticglass.

14. the optical element that forms by the described opticglass moulding of claim 1.

15. the optical element that forms by the described opticglass moulding of claim 10.