Summary of the invention
Purpose of the present invention is exactly the opticglass that is provided for making the optical spectacle glass of higher dioptry, littler proportion and/or is used for digital product lens technologies field at above-mentioned weak point, has specific refractory power (n
d) between 1.87~1.93, Abbe number (υ
d) in 29~32.5, and do not contain harmful component PbO and As
2O
3And heavy metal oxide B component aO, WO
3, do not contain expensive GeO
2High refractive index optical spectacle glass.
For achieving the above object, eliminate the defective of known class like refractive index glass, the present invention is through research repeatedly, and finds in the result of test, do not containing expensive GeO
2Component and BaO, WO
3On the basis etc. component, can adopt the specific composition scope to be solved.
Technical solution of the present invention is: a kind of high refractive index optical phosphate glass is characterized in that: its compositional range contains in oxide compound by weight percentage:
SiO
2 2~10%;
B
2O
3 10~24%;
Nb
2O
5 13~27%;
Ta
2O
5 0~5%;
TiO
2 5~15%;
La
2O
3 15~30%;
Y
2O
3 0~10%;
Gd
2O
3 0~10%;
∑(La
2O
3、Y
2O
3、Gd
2O
3) 16%<X<40%;
ZrO
2 2~9%;
CaO 5~15%;
MgO 0~5%;
SrO 0~7%;
ZnO 0~5%;
∑(MgO、SrO、ZnO) X≤10%;
Li
2O 0~4%;
Na
2O 0~3%;
K
2O 0~3%;
∑(Li
2O、Na
2O、K
2O) X≤6%。
Preferred technical solution of the present invention is: described compositional range in oxide compound is by weight percentage:
SiO
2 2~8%;
B
2O
3 12~22%;
Nb
2O
5 15~25%;
Ta
2O
5 0~4%;
TiO
2 6~13%;
La
2O
3 15~28%;
Y
2O
3 0~9%;
Gd
2O
3 0~9%;
∑(La
2O
3、Y
2O
3、Gd
2O
3) 16%<X<35%;
ZrO
2 3~8%;
CaO 6~14%;
MgO 0~5%;
SrO 0~6%;
ZnO 0~4%;
∑(MgO、SrO、ZnO) X≤8%;
Li
2O 0~4%;
Na
2O 0~2%;
K
2O 0~2%;
∑(Li
2O、Na
2O、K
2O) X≤4%。
∑ (Li described in the technology of the present invention solution
2O, Na
2O, K
2O) lower value is greater than 1%.
The lower value of the ∑ described in the technology of the present invention solution (MgO, SrO, ZnO) is greater than 2%.
Compositional range described in the technology of the present invention solution also comprises finings Sb in oxide compound by weight percentage
2O
3, the higher limit of its add-on is 0.5%.
The essential component of the present invention contains: SiO
2, B
2O
3, Nb
2O
5, La
2O
3, TiO
2, CaO, ZrO
2Deng, also further contain Ta
2O
5, Y
2O
3, MgO, ZnO, Li
25 kinds of O etc. and more than, do not contain PbO, As
2O
3Etc. harmful oxide compound and BaO, WO
3Deng heavy metal oxide, though the optical characteristics that has is same with the known optical glassy phase, but their difference is to have demonstrated better water tolerance, wear resistance and transmitance, more low-gravity characteristics are arranged, more can demonstrate low production cost and good environmental compatibility owing to the reduction of raw material and technology cost simultaneously.
Opticglass of the present invention can satisfy fusing and the brilliant tendency of resistive connection simultaneously, has specific refractory power (n
d) between 1.87~1.93, Abbe number (υ
d) in 29~32.5, preferred version has specific refractory power (n
d) between 1.88~1.92, Abbe number (υ
d) in 29.5~32, this class opticglass is more suitable for being used for the making of ophthalmic lens and the lens of digital product use the field.
Opticglass of the present invention stems from the environment friendly heavy-lanthanide flint category of glass, and contains a small amount of but the present invention is main and is necessary Ta
2O
5, MgO and/or R
2Components such as O.Such parent glass belongs to the borate glass system.
For obtaining required specific refractory power and Abbe number, B in the glass of the present invention
2O
3Content preferably at least 12%, more preferably at least 17%.The high-content of glass of the present invention is 22%.
Glass of the present invention comprises SiO
2Content at least 2%, preferably at least 3%, especially preferably at least 4%, the highlyest be preferably 8%.A small amount of SiO
2Introducing can obtain good wear resistance and change stability.Yet must restriction SiO
2The highest introducing amount, otherwise will reduce La
2O
3Meltbility in substrate glass, and then also will weaken the brilliant tendency of resistive connection.
The most important essential component Nb of glass of the present invention
2O
5, be the oxide compound that obtains desirable specific refractory power and Abbe number.In addition, Nb
2O
5Another effect be the matrix of stable borates glass.The content at least 13% of this component in glass, more preferably 15%, preferred especially 20%, the highest by preferred 24%.
Another important essential component TiO in the glass of the present invention
2Content is at least 5%, and more preferably 7%, preferred especially 10%, the highest by preferred 13%.When this composition introducing amount surpasses 13%, glass crystallization tendency will be tending towards strong, and glass coloring also will be deepened, and the while has also been reduced the Abbe number of glass, promptly causes the raising of dispersion values.On the contrary, this component is lower than 5%, can not obtain required specific refractory power and low-gravity.
An important essential component La again in the glass of the present invention
2O
3(comprise Gd
2O
3, Y
2O
3) be the oxide compound that improves specific refractory power, increases Abbe number.Found La
2O
3/ B
2O
3Can form stable glass than≤3.So La
2O
3, Y
2O
3, Gd
2O
3Three kinds of component total contents are preferred at most 40%, and more preferably 35% or lower.When the total content of these components surpasses 40%, be difficult to obtain required specific refractory power, also will increase the crystallization tendency and the specific gravity of glass of glass simultaneously.
Essential component ZrO in the glass of the present invention
2Content mostly is 9% most, and when content surpasses 10%, the glass melting difficulty that becomes also is difficult to obtain more high refractive index.Therefore be the The above results that more is easy to get, this component introducing amount is preferred 8%, and more preferably 7% or lower.On the contrary, this component preferred minimum to 3% or more than.Otherwise, will increase glass crystallization tendency.
Another kind of important component CaO in the glass of the present invention reduces the crystallization tendency, reduces proportion and alleviates the essential component of glass coloring.This component concentration is preferred 15%, and more preferably 12%, preferred especially 10%, when content surpasses 15%, not only reduce specific refractory power, glass produces phase-splitting and changes the stability variation simultaneously.
Glass of the present invention also comprises preferred MgO, SrO, three kinds of components of ZnO.This component is favourable to alleviating crystallization tendency and proportion.Three's total content preferably mostly is most 10%, and more preferably 8% or lower.
Glass of the present invention also comprises optional Ta
2O
5Component.This component has obvious effects to reducing liquidus temperature, and improves specific refractory power.But excessive introducing will increase specific gravity of glass, rare above-mentioned effect.Therefore, this component preferably mostly is most 5%, and more preferably 4%.
Glass of the present invention also can add alkalimetal oxide Li
2O, Na
2O, K
2The O component.The a small amount of introducing of this component helps improving meltbility and viscosity, will cause specific refractory power to reduce yet increase the introducing amount, simultaneously also will making stability variation.Therefore, alternative adds in right amount, introduces total amount and preferably mostly is most 4%, more preferably 3% or lower.
The preferred Sb of glass of the present invention
2O
3As finings, its introducing amount is no more than 0.5%.
The present invention has specific refractory power (n
d) between 1.87~1.93, Abbe number (υ
d) in 29~32.5, the transmitance in the visible range is 85%, proportion (ρ) is lower than 4.1, does not contain PbO and As
2O
3Etc. harmful oxide compound and BaO, WO
3Deng the characteristic of heavy metal oxide, and be suitable for the opticglass of the usefulness of once shaped and secondary press.The present invention stems from environment friendly heavy-lanthanide flint glass category, and it is specially adapted to the opticglass of glasses, also applicable to the lens of making digital product.
Embodiment
To opticglass of the present invention exemplarily be described with embodiment below.
Table 1 is included in 5 embodiment in the preferred compositing range, and these are comparative embodiment, compare with these different physicochemical characteristics with described opticglass of the present invention, comprise that simultaneously 2 typical comparative examples compare with it.
Opticglass of the present invention removes and does not contain PbO and As
2O
3Outside objectionable constituent, also do not contain BaO, WO
3And expensive GeO
2Deng composition.
The invention still further relates to a kind of melting method for preparing opticglass of the present invention.This method is that the component with known formation glass is mixed with compound with oxide compound, nitrate and carbonate and is heated to the formation molten mass.The main ingredient of this molten mass contains SiO
2, B
2O
3, Nb
2O
5, TiO
2, ZrO
2, oxide compound such as CaO, wherein contain Y
2O
3, Gd
2O
3Also add Ta by the present invention as other component
2O
5, MgO, SrO, ZnO and alkalimetal oxide Li
2O, Na
2O, K
2The finings of O and trace.
The preparation method of opticglass of the present invention: take by weighing various oxide compounds, raw materials such as preferably nitrate, carbonate add micro-finings Sb
2O
3, its thorough mixing is even, and in 1300 ℃ of down fusings, stirring, clarification and homogenizing being suitable for carrying out under the temperature of moulding die mould and/or secondary hot pressing, can obtain opticglass of the present invention to this compound thus in a kind of continuous smelting process unit.
Table 1:ZDW glass embodiment and comparative example (amount is represented with weight percent)
Compare with typical comparative example a, comparative example b from the embodiment 1 to embodiment 5 of table 1, glass of the present invention not only has specific refractory power and the Abbe number in the required scope, also has more good transmitance and lower proportion.Be particularly suitable for the glasses optical field and use, be suitable for the lens technologies field of digital product too.ρ represents specific gravity of glass; L
TThe expression liquidus temperature.
Brilliant tendency of good resistive connection and processing performance more can be suitable for once shaped and/or secondary mould pressing and make different size ophthalmic lens and optical element.
Specific gravity of glass described in the technology of the present invention solution is less than 4.1 or lower.
Glass of the present invention must have the characteristics of low thermoforming viscosity and low hot pressing temperature, is suitable in low-temperature condition compacted under and hot pressing, does not use under the condition of high temperature and oxidized with the protection mould, to reach the purpose that reduces production costs.
In addition, by the melting technology technology, low crystallization tendency can be suitable for the formation that do not produce nucleus in once shaped and/or the secondary hot pressing process.Also must reach simultaneously have lower proportion, high transmitance and excellent water tolerance and wear resistance.