KR20120004538A - Optical glass, optical element, and preform for precision press molding - Google Patents

Abstract

Provided is an optical glass, an optical element, and a preform for precision press molding having a low Abbe's number (v _d ) having a refractive index n _d in a desired range and high transparency to visible light. Optical glass, with respect to the total mass of the glass composition in terms of oxide, and contains not more than 5.0% to 40.0% of P ₂ O ₅ component in% by weight and containing Nb ₂ O ₅ component than 60.0% over 10.0%. Moreover, the optical element and the preform for precision press molding consist of the said optical glass.

Description

OPTICAL GLASS, OPTICAL ELEMENT, AND PREFORM FOR PRECISION PRESS MOLDING}

The present invention relates to an optical glass, an optical element and a preform for precision press molding.

In recent years, the digitization and high-definition of devices that use optical systems are rapidly progressing, and high precision, light weight, and miniaturization of optical devices such as lenses used in various optical devices, as well as photographing equipment such as digital cameras and video cameras, etc. The demand is getting stronger.

Among the optical glass for manufacturing the optical element, in particular, it has a high refractive index (n _d ) of 1.70 or more and 2.20 or less, and has an Abbe number (ν _d ) of 10 or more and 25 or less, which makes it possible to reduce the weight and size of the optical element. The demand for glass having refractive index and high dispersion is very high. As such a high refractive index high-dispersion glass, optical glass which has refractive index (n _d ) is 1.91 or more and has an Abbe number of 21 or less, for example, as represented by patent document 1 (Unexamined-Japanese-Patent No. 2005-206433). Glass is known. Moreover, the glass like that represented by patent document 2 (Unexamined-Japanese-Patent No. 06-345481) is known as an optical glass whose refractive index n _d is 1.65 or more and has an Abbe number of 17.2 or more and 33.1 or less.

1. Japanese Patent Publication No. 2005-206433 2. Japanese Patent Application Publication No. 06-345481

In the case of manufacturing an optical element using such glass, a method of grinding and polishing a glass molded product (molded glass) obtained by heat-softening a glass material and pressing molding (rich press molding), or a gob or glass block Is used to heat-soften a preform material obtained by cutting and grinding, or a preform material formed by a known floating molding or the like, and press molding into a mold having a high precision molding surface (precision press molding). .

However, as the glass disclosed in Patent Literature 1, the lower the Abbe's number (v _d ), the lower the transparency to visible light (larger value of λ ₇₀ ), and the lower the Abbe's Number (v _d ) is yellow or orange (橙色) is colored. For this reason, although the glass disclosed by patent document 1 has a desired high dispersion, it is not suitable for the use which permeate | transmits the light of a visible region.

Moreover, the glass disclosed by patent documents 1 and 2 has a problem that devitrification is easy to produce when producing glass. Moreover, the glass which avoided devitrification at the time of manufacturing glass has a problem which becomes easy to become cloudy when grinding the glass press-molded by a Richt press, or when grinding a glass and manufacturing a preform material. Once devitrified or clouded, it is particularly difficult to fabricate optical elements that control light in the visible region.

Moreover, the glass disclosed by patent documents 1 and 2 also had many things which are difficult to carry out grinding | polishing process and press molding. Specifically, glass was easily scratched when the glass molded article after press molding was polished to obtain an optical element, or when the lump or glass block was polished. Moreover, when glass was heated in a metal mold | die and press-molding, and the glass was made into the shape of an optical element or its preform, the glass was often dent or cracked.

In addition, the glass disclosed by patent documents 1 and 2 has many high glass transition points (Tg), and these glass hardly softens even if it heats. For this reason, when a preform material is produced from the glass of patent document 1, and a preform material is heat-softened and press-molded and an optical element is produced, it is necessary to raise the temperature which heat-softens and preforms a preform material for press molding. The used mold and preform material may be fused or may affect the optical properties of the optical device.

In addition, when the glass disclosed by patent documents 1 and 2 wash | cleans glass after grinding-processing glass press-formed by a Richt press, or wash | cleans after grinding | polishing-processing glass, and produces a preform material, for example, There is a problem that it is easy to become cloudy. With the glass once clouded, it is particularly difficult to fabricate an optical element that controls light in the visible region.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide an optical glass having a low Abbe number ν _d while having a refractive index n _d in a desired range, and having high transparency to visible light, and an optical element. It is.

In addition, the present invention, while having transparency to the refractive index (n _d ), Abbe number (ν _d ) and visible light as described above, is difficult to devitrify or blur during glass production and processing, and produces a preform material or an optical device by polishing. Another object of the present invention is to provide an optical glass and an optical element that are easy to do.

In addition, another object of the present invention is to provide an optical glass and an optical element having the above-described refractive indices n _d , Abbe's number ν _d , and transparency to visible light, and which are easy to be polished or pressed.

Another object of the present invention is to provide an optical glass, an optical element, and a preform for precision press molding, having transparency to refractive index n _d , Abbe number ν _d , and visible light, which are easily softened at low temperature. It is done.

The present invention also provides an optical glass and an optical element having transparency to the refractive index n _d , Abbe number ν _d , and visible light, which are easy to clean in preparation of a preform material or an optical element. The purpose.

The present inventors have found that, by containing a result, a predetermined amount of P ₂ O ₅ component, and Nb ₂ O ₅ component of intensive testing and research to solve the above problems, the high and the variance as reduced high refractive index of the glass painter obtained number of low Abbe In addition, the inventors have found that the transparency of the glass to visible light increases, and have completed the present invention.

The inventors also found that by containing a predetermined amount of the P ₂ O ₅ component and the Nb ₂ O ₅ component, the transparency to refractive index (n _d ), dispersion and visible light is increased, the liquidus temperature of the glass is lowered, and acid resistance is also increased. Found.

In addition, the inventors of the present invention contain a predetermined amount of P ₂ O ₅ component and Nb ₂ O ₅ component, thereby increasing the refractive index (n _d ), transparency to visible light, bringing about appropriate wear, and also having an average linear expansion coefficient ( It was also found that α) became small.

In addition, the present inventors use the P ₂ O ₅ component and the Nb ₂ O ₅ component together, and suppress the content rate of the P ₂ O ₅ component, the Nb ₂ O ₅ component, and the TiO ₂ component within a predetermined range, whereby the refractive index (n _d ) It has also been found that the glass transition point (Tg) is lowered as the transparency to dispersion and visible light increases.

In addition, the present inventors use at least one of a Li ₂ O component, a Na ₂ O component, and a K ₂ O component as an essential component while using the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination, thereby increasing the refractive index (n _d). ), It was also found that the glass transition point (Tg) was lowered as transparency to dispersion and visible light increased.

Further, the inventors of the present invention, by containing a predetermined amount of the P ₂ O ₅ component and Nb ₂ O ₅ component, the transparency to the refractive index (n _d ), dispersion and visible light increases, the liquidus temperature is high, and the detergent resistance of the glass I found it to be high. Specifically, the present invention provides the following.

(1) in terms of oxide glass based on the total mass, in mass% P ₂ O ₅ component of 5.0% or more and 40.0% or less, Nb ₂ O ₅ optical glass containing components less than 60% more than 10% of the composition.

(2) The optical glass according to (1), wherein the wavelength λ ₇₀ at which the spectral transmittance is 70% is 500 nm or less and has a liquidus temperature of 500 ° C or more and 1200 ° C or less.

(3) The optical glass as described in (1) which has a wear degree of 100 or more and 400 or less.

(4) The optical glass as described in (1) whose detergent resistance (PR) by ISO test method is a grade 1-3.

(5) Li ₂ O component, Na ₂ O component, the optical glass according to at least contains any one, as an essential component, and having a glass transition point (Tg) of less than 700 ℃ (1) of the K ₂ O component.

6 in terms of the oxide optical glass according to any one of 30% or less (1) to (5), the content of the glass with respect to the total mass of the composition, TiO ₂ component in terms of mass%.

(7) The optical glass according to the 12% or less (6) the content of the TiO ₂ component, the weight% based on the entire mass of the glass composition in terms of oxide.

(8) The optical glass according to the 10% less than 6, the content of the TiO ₂ component, the weight% based on the entire mass of the glass composition in terms of oxide.

(9) an optical glass as described in respect to the total mass of the glass composition in terms of oxide, and the content of the TiO ₂ component in terms of percent by mass less than 10.0%, (1) having a glass transition point (Tg) of less than 700 ℃.

(10) The optical glass according to (1), which contains 10.0% or more and 30.0% or less of the TiO ₂ component by mass% with respect to the total glass mass of the oxide conversion composition, and has a glass transition point (Tg) of 700 ° C or less.

(11) By mass% with respect to the total glass mass of the oxide conversion composition

WO ₂ component 0-20.0% and / or

0-30.0% BaO component and / or

SiO ₂ Component 0 ~ 10.0%

The optical glass in any one of (1)-(10) which contains each component of further.

(12) By mass% with respect to the total glass mass of the oxide conversion composition,

More than 0% and no more than 20.0% of the WO ₃ component, and

BaO is more than 0% and less than 30.0%

The optical glass as described in (11) which contains each component of further.

(13) Optical glass as described in (11) or (12) whose content of BaO component is 13.0% or less in mass% with respect to the glass total mass of oxide conversion composition.

(14) Optical glass as described in (11) or (12) whose content of BaO component is less than 7.0% by mass% with respect to the glass total mass of oxide conversion composition.

(15) Optical glass as described in (11) or (12) whose content of BaO component is 4.5% or less in mass% with respect to the glass total mass of oxide conversion composition.

(16) Optical glass as described in (11) or (12) whose content of BaO component is 1.0% or more and less than 17.0% by mass% with respect to the glass total mass of oxide conversion composition.

(17) Optical glass as described in (11) or (12) whose content of BaO component is 2.0% or more and 15.0% or less in mass% with respect to the glass total mass of oxide conversion composition.

(18) Optical glass as described in (11) or (12) whose content of BaO component is more than 7.0% and 30.0% or less in mass% with respect to the glass total mass of oxide conversion composition.

19 in terms of an oxide optical glass according to any one of 2.0% or less (11) to (18) the content of the glass with respect to the total mass of the composition, SiO ₂ component in terms of mass%.

20 in terms of an oxide optical glass according to any one of the glass with respect to the total mass of the composition, 11% by weight containing more than 2.0% of SiO ₂ as a component to (18).

21 in terms of an oxide optical glass according to any one of 10.0% or less, 11 to 20, the content of WO ₃ ingredient with respect to total mass of the glass composition, in mass%.

(22) With respect to the total glass mass of the oxide conversion composition, in mass%

Li ₂ O component 0-20.0% and / or

Na ₂ O component 0-35.0% and / or

K ₂ O Component 0 ~ 20.0%

The optical glass in any one of (1)-(21) which contains each component of further.

(23) With respect to the total glass mass of the oxide conversion composition, in mass%

Li ₂ O component 0-10.0% and / or

0-25.0% Na ₂ O component and / or

K ₂ O Component 0 ~ 10.0% or less

The optical glass as described in (22) which contains each component of further.

24. An optical glass according to the Li ₂ O component 22 or 23, which contains as an essential component.

25 in terms of an oxide optical glass according to any one of 0.1% or more (22) to (24) the content of K ₂ O component with respect to the total mass of glass of the following composition, in mass%.

26 in terms of an oxide optical glass according to any one of the weight sum _{Li 2 O + Na 2 O +} K 2 O is 35.0% or less (22) to (25) for the entire mass of the glass composition.

(27) The optical glass according to any one of (22) to (26), wherein the sum of mass Li ₂ O + Na ₂ O + K ₂ O to the total glass mass of the oxide conversion composition is 5.0% or more and 35.0% or less.

28. An optical glass according to any one of the oxide glass composition in terms of weight the sum of the total mass of _{Li 2 O + Na 2 O +} K 2 O is 35.0% or less lots (22) to (27) than the 7.0%.

29 in terms of an oxide optical glass according to any one of the mass number of the sum (22) to _{(28) Li 2 O + Na} 2 O + K 2 O is more than 8.0% of the total mass of the glass composition.

30. An optical glass according to any one of the oxide in terms of the composition by weight the sum _{Li 2 O + Na 2 O +} K 2 O to the total mass of glass is large (22) to (29) than the 10.0% of.

31 in terms of an oxide optical glass according to any one of the weight sum _{Li 2 O + Na 2 O +} K 2 O is 15% or less 22 to 30 with respect to the total mass of the glass composition.

(32) (22) to (31) containing 15.0% or more of BaO component in mass% and a mass sum Li ₂ O + Na ₂ O + K ₂ O of 10.0% or more with respect to the total glass mass of the oxide conversion composition; The optical glass as described in any one of the above.

(33) Li ₂ O component, Na ₂ O component and the optical glass as described in (22) to (32) comprising two or more components of the K ₂ O component.

(34) With respect to the total glass mass of the oxide conversion composition, in mass%,

MgO component 0-5.0% and / or

CaO component 0-10.0% and / or

SrO component 0 ~ 10.0%

The optical glass in any one of (1)-(33) which contains each component of further.

The optical glass as described in (34) whose mass sum MgO + CaO + SrO + BaO with respect to the glass total mass of oxide conversion composition is 30.0% or less.

(36) With respect to the total glass mass of the oxide conversion composition, in mass%

Y ₂ O ₃ component 0-10.0% and / or

La ₂ O ₃ component 0-10.0% and / or

Gd ₂ O ₃ Component 0 ~ 10.0%

The optical glass in any one of (1)-(35) which contains each component of further.

37 in terms of an oxide optical glasses described glass composition by weight total _{Y 2 O 3 + La 2 O} 3 + Gd 2 O 3 is 20.0% less than 36, relative to the total mass of.

(38) With respect to the total glass mass of the oxide conversion composition, in mass%,

B ₂ O ₃ Component 0-10.0% and / or

GeO ₂ component 0-10.0% and / or

0-20.0% of Bi ₂ O ₃ component and / or

ZrO ₂ component 0-10.0% and / or

ZnO component 0-10.0% and / or

Al ₂ O ₃ component 0-10.0% and / or

Ta ₂ O ₅ component 0-10.0% and / or

Sb ₂ O ₃ Component 0 ~ 1.0%

The optical glass in any one of (1)-(37) which contains each component of further.

(39) The optical glass according to any one of (1) to (38), having a refractive index (n _d ) of 1.70 or more and 2.20 or less and having an Abbe number (ν _d ) of 10 or more and 25 or less.

The optical glass in any one of (1)-(39) whose chemical durability (acid resistance) by the powder method is class 1-5.

(41) The optical glass according to any one of (1) to (40), wherein the wavelength λ ₇₀ at which the spectral transmittance is 70% is 500 nm or less.

The optical glass in any one of (1)-(41) whose average linear expansion coefficient ((alpha)) at -30- + 70 degreeC is 150x10 <^-7> K <^-1> or less.

(43) An optical element comprising the optical glass according to any one of (1) to (42).

(44) Preform for precision press molding which consists of optical glass in any one of (1)-(42).

(45) An optical element formed by precision press molding the preform for precision press molding according to (44).

According to this invention, while the high refractive index of glass is aimed at, glass dispersion becomes high and transparency of the glass to visible light becomes high. For this reason, it is possible to provide an optical glass and an optical element having a low Abbe's number ν _d while having a refractive index n _d in a desired range and having high transparency to visible light.

In particular, according to the present invention, by containing a predetermined amount of the P ₂ O ₅ component and Nb ₂ O ₅ component, the glass is produced while having transparency to the desired refractive index (n _d ), Abbe number (ν _d ) and visible light It is possible to provide an optical glass and an optical element that are hardly devitrified or cloudy at the time of processing and processing, and are easy to produce a preform material or an optical element by polishing.

In addition, according to the present invention, by containing a predetermined amount of the P ₂ O ₅ component and Nb ₂ O ₅ component, while having a desired refractive index (n _d ), Abbe number (ν _d ) and transparency to visible light, It is possible to provide an optical glass and an optical element that are easy to press molding.

In addition, according to the present invention, by using the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination and suppressing the content rates of the P ₂ O ₅ component, the Nb ₂ O ₅ component and the TiO ₂ component within a predetermined range, a desired refractive index (n _It is possible to provide an optical glass having transparency to _d ), Abbe's number (v _d ) and visible light, and easy to soften at a low temperature, and an optical element and a preform for precision press molding using the same.

Furthermore, according to the present invention, by using at least one of a Li ₂ O component, a Na ₂ O component, and a K ₂ O component as an essential component while using the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination, a desired refractive index ( It is possible to provide an optical glass having transparency to n _d ), Abbe's number (ν _d ) and visible light, and easy to soften at a low temperature, and an optical element and a preform for precision press molding using the same.

In addition, according to the present invention, by containing a predetermined amount of P ₂ O ₅ component and Nb ₂ O ₅ component, while having a desired refractive index (n _d ), Abbe number (ν _d ) and transparency to visible light, while preform material and optical It is possible to provide an optical glass and an optical element that can be easily washed in fabrication of the device.

The optical glass of the present invention is to, by mass% P ₂ O ₅ component of 5.0% or more and 40.0% or less, Nb ₂ O ₅ component with respect to the total mass of the glass composition in terms of oxide containing at least 10% less than 60.0%. By using the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination and suppressing the content rates of the P ₂ O ₅ component and the Nb ₂ O ₅ component within a predetermined range, the high refractive index of the glass can be achieved while the dispersion is increased, thereby increasing the dispersion of the glass against visible light. Transparency can be increased. For this reason, it is possible to provide an optical glass and an optical element having a low Abbe's number ν _d while having a refractive index n _d in a desired range and having high transparency to visible light.

Among them, the first optical glass of the present invention contains an oxide equivalent with respect to the glass the total mass of the composition, in weight% P ₂ O ₅ component of 5.0% or more and 40.0% or less, 10.0% or 60.0% of Nb ₂ O ₅ component below The wavelength λ ₇₀ at which the spectral transmittance is 70% is 500 nm or less, and has a liquidus temperature of 500 ° C. or more and 1200 ° C. or less. By a combination of P ₂ O ₅ component, and Nb ₂ O ₅ component, and suppression within the P ₂ O ₅ component, and Nb ₂ O content of the predetermined range of ₅ components, increases the dispersion as reduced high refractive index of the glass painter, the visible light of the glass Transparency becomes high, the liquidus temperature of glass becomes low, and acid resistance of glass becomes high, and glass becomes difficult to invade even if glass and polishing liquid or cleaning liquid contact. For this reason, the refractive index n _d is in a desired range, has a low Abbe number ν _d , high transparency to visible light, hardly devitrifies or blurs during glass production and processing, and is a preform material by polishing. It is possible to provide an optical glass and an optical element that are easy to manufacture an optical element.

In addition, the second optical glass of the present invention, terms of oxides with respect to the glass the total mass of the composition, in weight% P ₂ O ₅ component of 5.0% or more and 40.0% or less, and the Nb ₂ O ₅ ingredient contains not less than 10.0% 60.0% It has a wear rate of 100 or more and 400 or less. By using the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination and suppressing the content rates of the P ₂ O ₅ component and the Nb ₂ O ₅ component within a predetermined range, a high refractive index of the glass is achieved while the dispersion becomes high, resulting in a low Abbe number. The transparency of the glass to visible light is increased, the appropriate degree of wear is brought about, and the average linear expansion coefficient α is small. For this reason, the refractive index n _d is within a desired range, has a high dispersion (low Abbe's number), high transparency to visible light, is easy to be polished, and also has a dent (defect) or crack of the lens by press molding. This reduced optical glass and optical element can be provided.

In addition, the third optical glass of the present invention, terms of oxides with respect to the glass the total mass of the composition, in weight% P ₂ O ₅ component of 5.0% or more and 40.0% or less, and containing less than 60% more than 10% of Nb ₂ O ₅ ingredient , TiO ₂ component is less than 10.0% and has a glass transition point (Tg) of 700 ° C. or less. By a combination of P ₂ O ₅ component, and Nb ₂ O ₅ component, and suppresses the content of P ₂ O ₅ component, Nb ₂ O ₅ component and a TiO ₂ component in a predetermined range, as reduced high refractive index of the glass artist, the higher the dispersion A low Abbe number is obtained, the transparency of the glass to visible light is increased, and the glass transition point (Tg) is lowered. For this reason, optical glass having a low Abbe number (ν _d ) having a refractive index n _d in a desired range, high transparency to visible light and easy softening at low temperatures, and easy to press molding, and an optical element using the same And a preform for precision press molding.

In addition, the fourth optical glass of the present invention, terms of oxides with respect to the glass the total mass of the composition, in weight% P ₂ O ₅ component of 5.0% or more and 40.0% or less, and the Nb ₂ O ₅ ingredient contains not less than 10.0% 60.0% In addition, the detergent resistance (PR) level is 1 ~ 3 by ISO test method. By a combination of P ₂ O ₅ component, and Nb ₂ O ₅ component, and suppression within the P ₂ O ₅ component, and Nb ₂ O content of the predetermined range of ₅ components, increases the dispersion as reduced high refractive index of the glass painter, the visible light of the glass The transparency to the glass is increased, and the detergent resistance of the glass is increased, so that the glass is difficult to invade even when the glass is in contact with the polishing liquid or the cleaning liquid. For this reason, the refractive index n _d is in a desired range, has a low Abbe number ν _d , has high transparency to visible light, and is difficult to become cloudy at the time of cleaning after polishing of the glass, and thus, for the production of a preform material or an optical element. It is possible to provide an optical glass and an optical element that can be easily cleaned.

In addition, the fifth optical glass, terms of oxides with respect to the glass the total mass of the composition, in weight% P ₂ O ₅ component of 5.0% or more and 40.0% or less, 60.0% or 10.0% of Nb ₂ O ₅ component or less and TiO of the invention _It contains 10.0% or more and 30.0% or less of _two components, and has a glass transition point (Tg) of 700 degrees C or less. By using together the P ₂ O ₅ component, the Nb ₂ O ₅ component and the TiO ₂ component, and suppressing the content rates of the P ₂ O ₅ component, the Nb ₂ O ₅ component and the TiO ₂ component within a predetermined range, the higher refractive index of the glass is achieved. The higher the dispersion, the lower the Abbe number, the higher the transparency of the glass to visible light, and the lower the glass transition point (Tg). For this reason, optical glass having a low Abbe's number (v _d ) having a refractive index n _d in a desired range, high transparency to visible light and easy softening at low temperatures, and easy to press molding, and an optical element using the same And a preform for precision press molding.

In addition, the sixth optical glass of the present invention, terms of oxides with respect to the glass the total mass of the composition, in weight% P ₂ O ₅ component of 5.0% or more and 40.0% or less, and the Nb ₂ O ₅ ingredient contains not less than 10.0% 60.0% And at least one of a Li ₂ O component, a Na ₂ O component, and a K ₂ O component as essential components, and have a glass transition point (Tg) of 700 ° C or lower. By using at least one of a Li ₂ O component, a Na ₂ O component, and a K ₂ O component as an essential component while using the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination, the dispersion becomes high while achieving high refractive index of the glass. A low Abbe number is obtained, the transparency of the glass to visible light is increased, and the glass transition point (Tg) is lowered. For this reason, optical glass having a low Abbe's number (v _d ) having a refractive index n _d in a desired range, high transparency to visible light and easy softening at low temperatures, and easy to press forming, and an optical element using the same And a preform for precision press molding.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of the optical glass of this invention is described in detail, this invention is not limited to the following embodiment, It can implement by changing suitably within the desired range of this invention. Although description may be abbreviate | omitted suitably about the part which overlaps description, it does not limit the meaning of invention.

[Glass component]

The composition range of each component which comprises the optical glass of this invention is described below. In this specification, the content rate of each component shall be represented by the mass% with respect to the glass total mass of oxide conversion composition, unless there is particular notice. Here, the "oxide conversion composition" means the total mass of the oxide produced when it is assumed that all oxides, complex salts, metal fluorides, and the like, which are used as raw materials for the glass constituents of the present invention, are decomposed into oxides during melting. It is a composition which described each component contained in glass as 100 mass%.

<Required ingredients and optional ingredients>

The P ₂ O ₅ component is a glass forming component and is a component that lowers the melting temperature of the glass. In particular, by making the content of the P ₂ O ₅ component 5.0% or more, the occurrence of scratches caused by polishing can be reduced by increasing the transmittance in the visible region of the glass and making the glass less likely to rise above a predetermined level. . On the other hand, by setting the content of the P ₂ O ₅ component to 40.0% or less, it is possible to increase the processing efficiency of polishing by making it difficult to lower the wear degree of the glass to a predetermined value or more while obtaining a desired high refractive index. Accordingly, the content of P ₂ O ₅ component to the free total mass of the oxide in terms of composition, preferably 5.0%, preferably 8.0%, and most preferably is 10.0% as the lower limit, preferably 40% more, More preferably, it is 35.0%, More preferably, it is 33.0%, Most preferably, it is 30.0%. The P ₂ O ₅ component is, for example, Al (PO ₃ ) ₃ , Ca (PO ₃ ) ₂ , Ba (PO ₃ ) ₂ , BPO ₄ , H ₃ PO ₄ as a raw material. It can contain in glass using etc.

The Nb ₂ O ₅ component is a component which raises the refractive index and dispersion of glass. In particular, when the content of the Nb ₂ O ₅ component is 10.0% or more, the desired high refractive index and high dispersion can be obtained. On the other hand, by the content of Nb ₂ O ₅ component to less than 60.0%, it is possible to suppress an increase in the liquidus temperature of the glass, whereby it is possible to increase resistance to devitrification of the glass because it can increase the stability of the glass. Therefore, the content rate of the Nb ₂ O ₅ component with respect to the total glass mass of an oxide conversion composition becomes like this. Preferably it is 10.0%, More preferably, it is 20.0%, Most preferably, it is 30.0% as a minimum, Preferably it is 60.0%, More preferably, the upper limit is 58.0%, still more preferably 57.0%, still more preferably 56.0%, and most preferably 55.0%. In particular, the optical glass of claim 6, and a is the content of the above-described Nb ₂ O ₅ component preferably 60.0%, preferably 50% more, most preferably 45.0% as an upper limit. The Nb ₂ O ₅ component is, for example, Nb ₂ O ₅ as a raw material. It can contain in glass using etc.

The TiO ₂ component is a component that increases the refractive index and dispersion of the glass, and at the same time, is a component that enhances the chemical durability of the glass, particularly the detergent resistance and the acid resistance, and is an optional component in the optical glass of the present invention. In particular, when the content ratio of the TiO ₂ component is 30.0% or less, high refractive index and dispersion are obtained, and thus the stability of the glass is increased by suppressing the increase in the liquidus temperature of the glass, so that the devitrification resistance of the glass can be improved. Therefore, the content ratio of the TiO ₂ component of the total mass of the glass composition in terms of oxide is preferably, more preferably 30%, is a 28.0%, more preferably 25.0%, most preferably from 20.0% as an upper limit. Here, in the first and second optical glass, while obtaining a high refractive index dispersion and by the content of the TiO ₂ component to less than 12% and in particular improve the transparency to the visible light of the glass. In this case, the content rate of the above-described TiO ₂ component is preferably 12.0%, more preferably 11.0% as an upper limit, and most preferably less than 10.0%. Further, the third optical glass, since the content ratio of the TiO ₂ component is less than 10.0%, while obtaining a high refractive index and dispersion can improve the transparency to the visible light of the glass. In this case, the content rate of the above-described TiO ₂ component is preferably less than 10.0%, more preferably 9.8%, and most preferably 9.5% as an upper limit. In the optical glass of the present invention, the content rate of the TiO ₂ component can be made less than 5.0%, particularly in order to obtain a glass having high transparency to visible light. On the other hand, in the fifth optical glass, since the content ratio of the TiO ₂ component in the above 10.0%, it can be more enhanced the dispersion of the glass. Therefore, in order to further achieve high dispersion of the glass, the content rate of the TiO ₂ component described above is preferably 10.0%, more preferably 12.0%, still more preferably 13.0%, and most preferably 14.0%. do.

Even if the TiO ₂ component is not contained, optical glass having desired characteristics can be obtained. However, since the acid resistance of the glass is increased by containing 0.1% or more of the TiO ₂ component, discoloration during glass processing can be reduced. Therefore, in this case in terms of the oxide content of the TiO ₂ component of the total mass of the glass composition, and the preferably 0.1%, more preferably 1.0%, most preferably from 2.0% as the lower limit. Here, in the case to achieve a higher acid resistance, the content of the above-described TiO ₂ component is preferably 5.0%, preferably 11.0%, most preferably 12% than the lower limit. The TiO ₂ component is, for example, TiO ₂ as a raw material. It can contain in glass using etc.

A BaO component is a component which raises the refractive index of glass, and is a component which raises devitrification resistance by lowering the liquidus temperature of glass, and is an arbitrary component in the optical glass of this invention. Here, by making the content rate of BaO component into 30.0% or less, desired high refractive index can be obtained easily, and the fall of chemical durability including acid resistance can be suppressed, suppressing the fall of devitrification resistance. In particular, by making the content rate of BaO component into 20.0% or less, increase of the average linear expansion coefficient ((alpha)) of glass can be suppressed. Therefore, the content rate of BaO component with respect to the total glass mass of oxide conversion composition becomes like this. Preferably it is 30.0%, More preferably, it is 28.0%, More preferably, it is 25.0%, Most preferably, it is 20.0% as an upper limit. Among these, the content rate of BaO component mentioned above in the 1st and 2nd optical glass becomes like this. Preferably it is 20.0%, More preferably, 18.0%, Most preferably, 15.0% is an upper limit. In addition, the content rate of BaO component mentioned above in 3rd optical glass becomes like this. Preferably it is 20.0%, More preferably, 19.0%, Most preferably, 18.0% is made into an upper limit.

Here, especially the content rate of BaO component with respect to the glass total mass of oxide conversion composition in the point which can obtain glass with a large dispersion (small Abbe number) becomes like this. Preferably it is less than 17.0%, More preferably, it is 13.0% The upper limit is set, most preferably 4.5%. Among these, the content rate of BaO component mentioned above in 1st and 2nd optical glass becomes like this. Preferably it is 13.0% as an upper limit, More preferably, it is less than 10.0%, Most preferably, it is 4.5%. In addition, the content rate of BaO component mentioned above in 3rd optical glass becomes like this. Preferably it is less than 17.0%, More preferably, it is less than 15.0%, Most preferably, it is less than 13.0%. Moreover, the content rate of BaO component mentioned above in 5th optical glass becomes like this. Preferably it is 15.0%, More preferably, it is 13.0% as an upper limit, Most preferably, it is less than 10,0%. In addition, the content rate of BaO component mentioned above in 6th optical glass becomes like this. Preferably it is less than 7.0%, More preferably, it is less than 5.0%, Most preferably, it is less than 4,0%.

Although it is possible to obtain an optical glass having a desired high dispersion and high transmittance even without containing BaO component, by containing more BaO component than 0%, the liquidus temperature of the glass is lowered, so that the glass having high devitrification resistance and easy to produce stably can be obtained. have. Therefore, the content rate of BaO component with respect to the glass total mass of oxide conversion composition in the case of obtaining glass with high devitrification resistance becomes like this. Preferably it is more than 0%, More preferably, it is 1,0%, Most preferably, 3.0 Let% be the lower limit. Among these, the content rate of BaO component mentioned above in 3rd optical glass becomes like this. Preferably it is 1.0%, More preferably, it is 3.0%, Most preferably, let it be a minimum of 4.5%. In addition, the content rate of BaO component mentioned above in 5th optical glass becomes like this. Preferably it is more than 0%, More preferably, it is 1.0%, Most preferably, let it be a minimum of 2.0%. In addition, the content rate of BaO component mentioned above in 6th optical glass becomes like this. Preferably it is 0.1%, More preferably, it is 0.5%, Most preferably, let 1.0% be a lower limit. On the other hand, by containing more than 7.0% of BaO component, the detergent resistance of glass can be improved, reducing the liquidus temperature of glass. Therefore, the content rate of BaO component mentioned above in the case of obtaining glass with high detergent resistance becomes like this. Preferably it is 7.0%, More preferably, it is 10.0%, Most preferably, let 15.0% be a minimum. BaO component, for example, as a raw material using a _{BaCO 3, Ba (NO 3)} 2, BaF 2 , etc. may be contained in the glass.

The SiO ₂ component is a component which reduces coloring, increases the transmittance for short wavelength visible light, promotes stable glass formation, and improves the devitrification resistance of the glass, and is an optional component in the optical glass of the present invention. In particular, the high desired it is possible to suppress a decrease in the refractive index due to the SiO ₂ component by the content of SiO ₂ component to less than 10% can be easily obtained and a refractive index. Accordingly, the content of SiO ₂ component to the entire mass of the glass composition in terms of oxide, and a preferably 10.0%, preferably 8.0%, more preferably 6.0%, most preferably from 5.0% more than the upper limit. Here, the content of the SiO ₂ component described above is preferably 2.0%, more preferably 1.5%, and most preferably 1.0%, in that the glass having a large dispersion (low Abbe number) can be easily obtained. .

In this way, the content of the SiO ₂ component is reduced, or the optical glass having the desired high dispersion and high transmittance can be obtained even without containing the SiO ₂ component. On the other hand, especially in the second optical glass, by increasing containing a SiO ₂ component than 2.0% to obtain a glass that can be due to high degree of wear of the glass, to facilitate the molding by polishing. Accordingly, the content of SiO ₂ component to the entire mass of the glass composition in terms of oxides in this case is, preferably, and more than the 2.0%, and the more preferably 3.0%, most preferably from 4.0% as the lower limit. The SiO ₂ component is, for example, SiO ₂ , K ₂ SiF ₆ , Na ₂ SiF ₆ as a raw material. It can contain in glass using etc.

WO ₃ components, a component to increase the dispersion of the glass while raising the refractive index of the glass, an optional component of the optical glass of the present invention. In particular, by setting the content of the WO ₃ component to 20.0% or less, the glass transition point (Tg) can be lowered while improving the devitrification resistance of the glass, and the decrease in the transmittance of the glass with respect to the short wavelength visible light can be suppressed. Accordingly, the content of WO ₃ components of the entire mass of the glass composition in terms of oxide, and a preferably 20.0%, more preferably 17%, more preferably 15.0%, most preferably from 10.0% as an upper limit. Here, in particular, it is preferable that the content of the WO ₃ component be 10.0% or less in that a glass having a desired high dispersion and low glass transition point (Tg) can be easily obtained. Therefore, the content rate of the above-described WO ₃ component in this case is preferably 10.0%, more preferably 8.0%, still more preferably 7.0%, and most preferably 5.0%.

Since WO ₃ ingredient can be obtained an optical glass having a dispersion and a high transmittance and a desired, even if not contained, but, by increasing containing WO ₃ ingredient than 0% becomes high, dispersion of the glass, easily transparency to high dispersion and the visible light of the glass It can be compatible. Therefore, in this case the oxide equivalent content of WO ₃ components of the glass the total mass of the composition in the can, and preferably more than the 0%, and more preferably 1.0%, more preferably 3.0%, and most preferably Let 4.0% be a lower limit. The WO ₃ component can be contained in glass, using WO ₃ etc. as a raw material.

The Li ₂ O component is a component that lowers the melting temperature of the glass and the glass transition point (Tg), and increases the devitrification resistance at the time of glass formation, and is an optional component in the optical glass of the present invention. Here, by setting the content of the Li ₂ O component to 20.0% or less, the desired high refractive index can be easily obtained and the liquidus temperature of the glass is lowered, so that the stability of the glass is increased, so that occurrence of devitrification of the glass can be reduced. In particular, by the content of Li ₂ O component to less than 10%, it is possible to suppress the increase in the average linear expansion coefficient (α) of the glass. Accordingly, the content of Li ₂ O component to the entire mass of the glass composition in terms of oxide, and a preferably 20.0%, preferably 10% more, and most preferably from 5.0% as the upper limit. In particular, the content rate of the above-described Li ₂ O component in the first and second optical glasses is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. In addition, the third and the content of the above Li ₂ O component in the fourth optical glass, and a preferably 20.0%, more preferably 15.0%, most preferably from 10.0% as an upper limit. Further, the fifth and the sixth content of the above Li ₂ O component is preferably an upper limit to 20.0%, preferably 18.0%, more preferably 15.0%, most preferably 10.0% than that of the optical glass do.

Li ₂ and without containing any O-component, but can be obtained an optical glass having a dispersion and a high permeability, by increasing containing Li ₂ O ingredient than 0%, the lowered the glass transition point (Tg), while maintaining the high dispersion It is possible to obtain glass which is easy to soften at low temperatures. Accordingly, the content of Li ₂ O component to the free total mass of the oxide in terms of the composition in this case is preferably more than the 0%, more preferably more than the 0.3%, and most preferably from 0.5% It is the lower limit. The Li ₂ O component can be contained in the glass using, for example, Li ₂ CO ₃ , LiNO ₃ , LiF, or the like as a raw material.

The Na ₂ O component is a component that lowers the melting temperature and glass transition point (Tg) of the glass, and improves the devitrification resistance at the time of glass formation, and is an optional component in the optical glass of the present invention. In particular, when the content of Na ₂ O component is 35.0% or less, the desired high refractive index can be easily obtained, and the stability of the glass is increased by lowering the liquidus temperature of the glass, so that generation of devitrification or the like of the glass can be reduced. Accordingly, the content of Na ₂ O component to the entire mass of the glass composition in terms of oxide, and a preferably 35.0%, more preferably 25.0%, most preferably 15% as an upper limit. In particular, the content rate of the Na ₂ O component described above in the first optical glass is preferably 15.0%, more preferably 12.0%, and most preferably 10.0%. Further, the content of the above Na ₂ O component in the second optical glass, and a preferably 15%, more preferably 13.0%, most preferably 12% as an upper limit. Further, the by the content of the above Na ₂ O component is preferably an upper limit to 35.0%, preferably 30.0%, more preferably 25.0%, most preferably 15% than in the third and fourth optical glass do. Further, the fifth and the sixth content of the above Na ₂ O component is preferably an upper limit to 35.0%, preferably 30.0%, more preferably 25.0%, most preferably 20.0% than that of the optical glass do.

Na ₂ O, but can obtain an optical glass having the desired properties without containing the following ingredients, by including more than 0.1% of the Na ₂ O component, it is because it can increase the liquid phase temperature of the glass, it can be more enhanced resistance to devitrification of the glass . Accordingly, the content of Na ₂ O component to the free total mass of the oxide in terms of the composition in this case is preferably 0.1%, more preferably 0.5%, more preferably 1.0%, most preferably from 2.0% Is the lower limit. The Na ₂ O component can be contained in the glass using, for example, Na ₂ CO ₃ , NaNO ₃ , NaF, Na ₂ SiF _6, or the like.

K ₂ O component is a component lowering the melting temperature and the glass transition point (Tg) of the glass and at the same time, a component improving the devitrification of the glass during forming, is any component in the optical glass of the present invention. In particular, when the content rate of the K ₂ O component is 20.0% or less, the desired high refractive index can be easily obtained, and the stability of the glass is increased by lowering the liquidus temperature of the glass, so that occurrence of devitrification of the glass can be reduced. Accordingly, the content of K ₂ O component to the entire mass of the glass composition in terms of oxide is preferably less than 20.0%, as a preferably 15% than the upper limit, and most preferably 10.0%. In particular, the first and second content of the above K ₂ O ingredient in the optical glass is preferably less than 10%, more preferably 8.0%, more preferably 6.0%, most preferably from 5.0% Is the upper limit. Further, the by the content of the above K ₂ O component is preferably an upper limit to 20.0%, preferably 15.0%, more preferably 12.0%, most preferably 10% than in the third and fourth optical glass do. Further, the fifth and the content of the above K ₂ O component in the sixth optical glass, and a preferably 20.0%, more preferably 15.0%, most preferably from 10.0% as an upper limit.

Although optical glass with desired characteristics can be obtained without containing the K ₂ O component, by containing 0.1% or more of K ₂ O component, the liquidus temperature of the glass can be increased, so that the devitrification resistance of the glass can be further improved. Accordingly, the content of K ₂ O ingredients in the glass the total mass of the oxide in terms of composition in this case is preferably 0.1%, more preferably 0.15%, more preferably 0.2%, even more preferably 0.5 %, Most preferably 1.0%. K ₂ O component is, for example, as a raw material by using a _{K 2 CO 3, KNO 3,} KF, KHF 2, K 2 SiF 6 can be contained in the glass.

Here, the sixth optical glass, Li ₂ O ingredient preferably contains at least one of Na ₂ O component and the K ₂ O ingredient as an essential ingredient. For this reason, since the glass transition point Tg of optical glass becomes low, the shaping | molding temperature in press molding can be reduced, and the unevenness | corrugation of the surface after press molding, or the phenomenon which becomes cloudy can be further reduced. Moreover, since the devitrification resistance of an optical glass becomes high, the optical glass which has a desired optical characteristic can be manufactured more stably.

In the optical glass of the present invention, Rn ₂ O component is preferably not more than 35% content by weight of the sum of (wherein, Rn is at least one element selected from the group consisting of Li, Na, K). For this reason, since the fall of the refractive index of glass can be suppressed, a desired high refractive index can be obtained easily. Moreover, since stability of glass becomes high by decreasing liquidus temperature of glass, devitrification resistance of glass can be improved. Therefore, the content ratio by mass of the sum of Rn ₂ O component to the entire mass of the glass composition in terms of oxide, and a preferably 35.0%, more preferably 25.0%, most preferably 15% as an upper limit. In particular, the above-mentioned mass sum in the first and second optical glasses is preferably 15.0%, more preferably 13.0%, and most preferably 12.0%. Among these, the mass sum in the third optical glass is preferably 35.0%, more preferably 32.0%, and most preferably 30.0%. Moreover, the said mass sum in 4th optical glass becomes like this. Preferably it is 35.0%, More preferably, it is 25.0%, Most preferably, it is 20.0%. In addition, the said mass sum in 5th and 6th optical glass becomes like this. Preferably it is 35.0%, More preferably, it is 30.0%, Most preferably, it is 25.0% as an upper limit.

Optical glass having desired characteristics can be obtained even if it does not contain any of the Rn ₂ O components. However, by containing 0.1% or more of at least one of the Rn ₂ O components, the liquidus temperature of the glass can be increased, so that the glass devitrification resistance Can be made higher. Therefore, the content ratio by weight the sum of the in this case the oxide in terms of free total mass of Rn ₂ O component for the composition according to is, preferably 0.1%, more preferably 1.0%, more preferably 2.0%, and most preferably Has a lower limit of 3.0%.

When the total mass of the content ratio of the Rn ₂ O component is 5.0% or more, the glass transition point (Tg) can be lowered while the glass is highly dispersed, and the water resistance and the detergent resistance of the glass can be improved. Therefore, the content ratio by mass of the sum of Rn ₂ O component to the entire mass of the glass composition in terms of oxide, preferably 5.0%, preferably 8.0%, and most preferably 10.0% less than the lower limit. Among these, the said mass sum in 3rd optical glass becomes like this. Preferably it is more than 7.0%, More preferably, it is 9.0%, Most preferably, let 10.0% be a minimum. In addition, the said mass sum in 4th optical glass becomes like this. Preferably it is more than 8.0%, More preferably, it is more than 9.0%, Most preferably, it is more than 10.0%. In addition, the said mass sum in 5th optical glass becomes like this. Preferably it is 5.0%, More preferably, it is 6.0%, Most preferably, let it be 7.0%. In addition, the said mass sum in 6th optical glass becomes like this. Preferably it is 5.0%, More preferably, it is 8.0%, Most preferably, let 10.0% be a minimum.

In particular, in the fourth optical glass of the present invention, it is particularly preferable to contain 15.0% or more of the BaO component in mass% and more than 10.0% of the total of the Rn ₂ O components in mass% with respect to the total glass mass of the oxide conversion composition. . For this reason, since the detergent resistance of glass becomes especially high, the phenomenon which glass becomes cloudy even if glass, a polishing liquid, or a cleaning liquid contacts is able to be reduced.

In the optical glass of the present invention, it is preferable to contain Li ₂ O component, Na ₂ O component and the K ₂ O component of two or more of the components. As a result, the glass transition point Tg of the optical glass is lowered, thereby lowering the molding temperature in press molding, and further reducing the unevenness and cloudiness of the surface after press molding. Moreover, since the devitrification resistance of an optical glass can be improved, the optical glass which has a desired optical characteristic can be manufactured more stably.

MgO component is a component which lowers the liquidus temperature of glass, and improves the devitrification resistance of glass, and is an arbitrary component in the optical glass of this invention. In particular, by making the content of the MgO component 5.0% or less, the desired high refractive index and high dispersion can be easily obtained. Therefore, the content rate of the MgO component with respect to the glass total mass of oxide conversion composition becomes like this. Preferably it is 5.0%, More preferably, it is 4.0%, Most preferably, let it be an upper limit. MgO component is, for example, as a raw material MgCO _3, MgF ₂ It can contain in glass using etc.

CaO component is a component which lowers the liquidus temperature of glass and raises the devitrification resistance of glass, and is an arbitrary component in the optical glass of this invention. In particular, when the content ratio of CaO component is 10.0% or less, desired high refractive index and high dispersion can be easily obtained, and a decrease in devitrification resistance and chemical durability can be suppressed. Therefore, the content rate of CaO component with respect to the total glass mass of oxide conversion composition becomes like this. Preferably it is 10.0%, More preferably, it is 8.0%, More preferably, it is 6.0%, Most preferably, let 5.0% be an upper limit. CaO component is, for example, as a raw material using a CaCO _3, CaF _2, etc. may be contained in the glass.

SrO component is a component which lowers the liquidus temperature of glass, raises the devitrification resistance of glass, and is an arbitrary component in glass. In particular, by setting the content of the SrO component to 10.0% or less, the desired high refractive index and high dispersion can be easily obtained, and the decrease in devitrification resistance and chemical durability can be suppressed. Therefore, the content rate of the SrO component with respect to the total glass mass of oxide conversion composition becomes like this. Preferably it is 10.0%, More preferably, it is 8.0%, Most preferably, let 5.0% be an upper limit. SrO component is, for example, as a raw material by using _{Sr (NO 3) 2, SrF} 2 , etc. may be contained in the glass.

In the optical glass of this invention, it is preferable that the mass sum of the content rate of RO component (wherein R is 1 or more types chosen from the group which consists of Mg, Ca, Sr, Ba) is 30.0% or less. For this reason, since the fall of the refractive index and dispersion | distribution by RO component can be suppressed, desired high refractive index and high dispersion can be obtained easily. Therefore, the mass sum of the content rate of RO component with respect to the glass total mass of oxide conversion composition becomes like this. Preferably it is 30.0%, More preferably, it is 20.0%, Most preferably, let 10.0% be an upper limit. In particular, the mass sum in the first and second optical glasses is preferably 20.0%, more preferably 17.0%, still more preferably 15.0%, and most preferably 10.0%. The mass sum in the third and fourth optical glasses is preferably 30.0%, more preferably 28.0%, still more preferably 27.0%, and most preferably 25.0%. The mass sum in the fifth and sixth optical glass is preferably 30.0%, more preferably 25.0%, and most preferably 20.0%.

An optical glass having desired characteristics can be obtained even if it does not contain any of the RO components. However, by containing at least one of the RO components of 0.1% or more, the liquidus temperature of the glass can be increased, thereby further improving the devitrification resistance of the glass. Can be. Therefore, the mass sum of the content rate of RO component with respect to the glass total mass of oxide conversion composition in this case becomes like this. Preferably it is 0.1%, More preferably, it is 0.5%, More preferably, it is 1.0%, Most preferably 3.0 Let% be the lower limit.

Y ₂ O ₃ component is, at the same time increase the refractive index of the glass, a component for improving the chemical durability of the glass, an optional component of the optical glass of the present invention. In particular, when the content of the Y ₂ O ₃ component is 10.0% or less, desired high dispersion can be easily obtained, and the devitrification resistance of the glass can be improved. Accordingly, the content of Y ₂ O ₃ component to the entire mass of the glass composition in terms of oxide, and a preferably 10.0%, preferably 8.0%, most preferably from 5.0% more than the upper limit. Y ₂ O ₃ component is, for example, as a raw material Y ₂ O _3, YF ₃ It can contain in glass using etc.

The La ₂ O ₃ component is a component which increases the refractive index of the glass and improves the chemical durability of the glass, and is an optional component in the optical glass of the present invention. In particular, by making the content of La ₂ O ₃ component to less than 10.0%, desired high and can easily obtain the dispersion can improve the resistance to devitrification of the glass. Therefore, the content rate of the La ₂ O ₃ component with respect to the total glass mass of oxide conversion composition becomes like this. Preferably it is 10.0%, More preferably, it is 8.0%, Most preferably, let 5.0% be an upper limit. The La ₂ O ₃ component can be contained in the glass using, for example, La ₂ O ₃ , La (NO ₃ ) ₃ .XH ₂ O (X is an arbitrary integer) or the like as a raw material.

Gd ₂ O ₃ component is a component for improving the chemical durability of the glass while improving the refractive index of the glass, an optional component of the optical glass of the present invention. In particular, by setting the content of the Gd ₂ O ₃ component to 10.0% or less, desired high dispersion can be easily obtained and the devitrification resistance of the glass can be improved. Accordingly, the content of Gd ₂ O ₃ component to the entire mass of the glass composition in terms of oxide, and a preferably 10.0%, preferably 8.0%, most preferably from 5.0% more than the upper limit. Gd ₂ O ₃ component is, for example, as a raw material by using a Gd ₂ O _3, GdF ₃ may be contained in the glass.

In the optical glass of the present invention, Ln ₂ O ₃ component is preferred that the content ratio by mass of the sum of (wherein, Ln is Y, La, at least one element selected from the group consisting of Gd), not more than 20.0%. By setting the mass sum to 20.0% or less, the increase in Abbe number due to the Ln ₂ O ₃ component can be suppressed, so that desired high dispersion can be easily obtained. Therefore, the content ratio by mass of the sum of Ln ₂ O ₃ component to the entire mass of the glass composition in terms of oxide, and a preferably 20.0%, more preferably 18.0%, most preferably 15% as an upper limit.

The B ₂ O ₃ component promotes stable glass formation, enhances devitrification resistance, and is an optional component in the optical glass of the present invention. In particular, by making the content of B ₂ O ₃ component to less than 10.0%, it is easy to obtain a desired refractive index and it is possible to suppress a decrease in the refractive index due to the B ₂ O ₃ component. In addition, the increase of the average linear expansion coefficient (alpha) of glass can be suppressed by this. Accordingly, the content of B ₂ O ₃ component of the glass the total mass of the oxide in terms of composition, and a preferably 10.0%, preferably 8.0%, more preferably 6.0%, most preferably from 5.0% more than the upper limit . Although optical glass having desired characteristics can be obtained even without containing B ₂ O ₃ 3 component, by containing 0.1% or more of B ₂ O ₃ component, the liquidus temperature of the glass can be increased, thereby improving the devitrification resistance of the glass. Can be. Accordingly, the content of B ₂ O ₃ component of the glass the total mass of the oxide in terms of the composition in this case is preferably 0.1%, more preferably 0.2%, more preferably 0.3%, most preferably from 0.5 Let% be the lower limit. The B ₂ O ₃ component is, for example, H ₃ BO ₃ , Na ₂ B ₄ O ₇ , Na ₂ B ₄ O ₇ · 10H ₂ O, BPO ₄ as a raw material. It can contain in glass using etc.

GeO ₂ component is a component improving the devitrification of the glass to promote the stable free form at the same time increase the refractive index of the glass, an optional component of the optical glass of the present invention. In particular, by the content of the GeO ₂ component to less than 10.0%, thereby reducing the material cost of the glass. Accordingly, the content of the GeO ₂ component to the entire mass of the glass composition in terms of oxide, and a preferably 10.0%, preferably 8.0%, most preferably from 5.0% more than the upper limit. The GeO ₂ component is, for example, GeO ₂ as a raw material. It can contain in glass using etc.

Bi ₂ O ₃ component, raise the refractive index of the glass, a component to increase the dispersion of the glass, an optional component of the optical glass of the present invention. In particular, by making the content ratio of Bi ₂ O ₃ component to less than 20.0%, it is possible to suppress a decrease in resistance to devitrification by increasing the stability of the glass, it is possible to suppress a decrease in the transmittance of the glass. Accordingly, the content of Bi ₂ O ₃ component of the glass the total mass of the oxide in terms of composition is preferably, more preferably 20.0%, and to 15.0% as an upper limit, and more preferably less than 10%, and most preferably Should be less than 5.0%.

ZrO ₂ component, to reduce the coloring components and to increase the resistance to devitrification of the glass at the same time increasing the transmittance of visible light of short wavelength, to promote the stable free form, is any component in the optical glass of the present invention. In particular, since the reduction of the refractive index due to the ZrO ₂ component can be suppressed by setting the content of the ZrO ₂ component to 10.0% or less, the desired high refractive index can be easily obtained. Accordingly, the content of the ZrO ₂ component of the total mass of the glass composition in terms of oxides is and the preferably 10.0%, preferably 8.0%, most preferably from 5.0% more than the upper limit. ZrO ₂ component is, for example, as a raw material by using a ZrO _2, ZrF ₄ can be contained in the glass.

A ZnO component is a component which lowers the liquidus temperature of glass and raises the devitrification resistance of glass, and is an arbitrary component in the optical glass of this invention. In particular, by setting the ZnO component content to 10.0% or less, the desired high refractive index and high dispersion can be easily obtained. Therefore, the content rate of the ZnO component with respect to the glass total mass of oxide conversion composition becomes like this. Preferably it is 10.0%, More preferably, it is 8.0%, Most preferably, let 5.0% be an upper limit. ZnO is a component, for example, as a raw material using a ZnO, ZnF _2, etc. may be contained in the glass.

The Al ₂ O ₃ component is a component which improves the chemical durability of glass and raises the viscosity at the time of glass melting, and is an arbitrary component in the optical glass of this invention. In particular, when the content rate of the Al ₂ O ₃ component is 10.0% or less, the devitrification tendency of the glass can be weakened while increasing the meltability of the glass. In addition, an increase in the average linear expansion coefficient α can be suppressed. Accordingly, the content of Al ₂ O ₃ component to the entire mass of the glass composition in terms of oxide, and a preferably 10.0%, preferably 8.0%, most preferably from 5.0% more than the upper limit.

Al ₂ O ₃ component is, for example, as a raw material by using a Al ₂ O _3, Al (OH) _3, AlF ₃ may be contained in the glass.

Ta ₂ O ₅ component is a component improving the refractive index of the glass, an optional component of the optical glass of the present invention. In particular, when the content rate of the Ta ₂ O ₅ component is 10.0% or less, the glass may be hardly devitrified. Accordingly, the content of Ta ₂ O ₅ component to the entire mass of the glass composition in terms of oxide, and a preferably 10.0%, more preferably 8.0%, most preferably from 4.0% as the upper limit. The Ta ₂ O ₅ component is, for example, Ta ₂ O ₅ as a raw material. It can contain in glass using etc.

Sb ₂ O ₃ component is a component having a degassing (脫泡) effect and at the same time increasing the transmittance of the glass to visible light of short wavelength components of, when melting the glass. In particular, when the content of the Sb ₂ O ₃ component is 1.0% or less, the Sb ₂ O ₃ component is less likely to be alloyed with a melting facility (especially precious metals such as Pt), and impurities attached to the mold are reduced. Unevenness and clouding can be reduced. Therefore, the content of Sb ₂ O ₃ component to the entire mass of the oxide basis is preferably 1.0%, more preferably 0.8%, most preferably from 0.5% as the upper limit. Sb ₂ O ₃ component is, for example, as a raw material by using a _{Sb 2 O 3, Sb 2 O} 5, Na 2 H 2 Sb 2 O 7 and 5H ₂ O may be contained in the glass.

Defoaming components to the glass fining is not limited to the above-Sb ₂ O ₃ ingredient may be used by the known clarifier of the glass manufacturing agents, defoamers, or combinations thereof.

<About ingredients which should not be contained>

Next, the component which should not be contained in the optical glass of this invention, and the component which is not preferable when contained are demonstrated.

The other component can be added to the optical glass of this invention as needed in the range which does not impair the characteristic of the glass of this invention.

In addition, each transition metal component, such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo, except Ti, Zr, Nb, W, La, Gd, Y, Yb, and Lu, is each independently Or even when it contains a small amount in combination, glass is colored and it has the property to generate absorption in the specific wavelength of a visible region, Therefore, it is preferable to contain substantially no optical glass especially using the wavelength of a visible region.

Furthermore, lead compounds such as PbO and the components of Th, Cd, Tl, Os, Be, and Se tend to refrain from being used as harmful chemicals in recent years, and not only glass manufacturing processes, but also processing and disposal after commercialization. It needs environmental measures to get to. Therefore, in the case of emphasizing the environmental impact, it is preferable not to contain these substantially except inevitable mixing. As a result, the optical glass is substantially free of substances that pollute the environment. For this reason, such optical glass can be manufactured, processed, and disposed without taking special environmental measures.

The glass composition of the present invention is not expressed directly in terms of mol% because its composition is expressed in mass% relative to the total mass of glass in terms of oxide, but satisfies various properties required in the present invention. The composition by mol% display of each component which exists in a glass composition takes the following values generally in oxide conversion composition.

5.0-40.0 mol% of P ₂ O ₅ component and

Nb ₂ O ₅ Component 5.0-30.0 mol%,

And

0-40.0 mol% and / or TiO ₂ component

BaO component 0-30.0 mol% and / or

0 to 50.0 mol% of Li ₂ O component and / or

0-50.0 mol% and / or Na ₂ O component

K ₂ O component 0-30.0 mol% and / or

0-15.0 mol% and / or WO ₃ component

0-20.0 mol% and / or MgO component

CaO component 0-25.0 mol% and / or

SrO component 0-15.0 mol% and / or

0 to 4.0 mol% and / or Y ₂ O ₃ component

0-3.0 mol% and / or La ₂ O ₃ component

0-3.0 mol% and / or Gd ₂ O ₃ component

0-20.0 mol% and / or B ₂ O ₃ component

0-20.0 mol% and / or SiO ₂ component

0-15.0 mol% and / or GeO ₂ component

0 to 4.0 mol% and / or Bi ₂ O ₃ component

ZrO ₂ component 0-13.0 mol% and / or

ZnO component 0-20.0 mol% and / or

0-25.0 mol% and / or Al ₂ O ₃ component

0-3.0 mol% and / or Ta ₂ O ₅ component

Sb ₂ O ₃ Component 0 ~ 0.3mol%

Among these, the composition by mol% display of each component in a 1st and 2nd optical glass takes the following values generally in oxide conversion composition.

5.0-40.0 mol% of P ₂ O ₅ component and

Nb ₂ O ₅ Component 5.0-30.0 mol%,

And

0-40.0 mol% and / or TiO ₂ component

BaO component 0-20.0 mol% and / or

0-20.0 mol% and / or SiO ₂ component

0 to 30.0 mol% of Li ₂ O component and / or

0-20.0 mol% and / or Na ₂ O component

K ₂ O component 0-15.0 mol% and / or

0-20.0 mol% and / or MgO component

CaO component 0-25.0 mol% and / or

SrO component 0-15.0 mol% and / or

0 to 4.0 mol% and / or Y ₂ O ₃ component

0-3.0 mol% and / or La ₂ O ₃ component

0-3.0 mol% and / or Gd ₂ O ₃ component

0-20.0 mol% and / or B ₂ O ₃ component

0-15.0 mol% and / or GeO ₂ component

0 to 4.0 mol% and / or Bi ₂ O ₃ component

ZrO ₂ component 0-13.0 mol% and / or

ZnO component 0-20.0 mol% and / or

0-25.0 mol% and / or Al ₂ O ₃ component

0-3.0 mol% and / or Ta ₂ O ₅ component

0-15.0 mol% and / or WO ₃ component

Sb ₂ O ₃ Component 0 ~ 0.3mol%

In addition, the composition by mol% display of each component in 3rd optical glass takes the following values generally in oxide conversion composition.

5.0-40.0 mol% of P ₂ O ₅ component and

Nb ₂ O ₅ Component 5.0-30.0 mol%,

And

0-15.0 mol% and / or TiO ₂ component

BaO component 0-30.0 mol% and / or

0 to 50.0 mol% of Li ₂ O component and / or

0-50.0 mol% and / or Na ₂ O component

K ₂ O component 0-30.0 mol% and / or

0-15.0 mol% and / or WO ₃ component

0-20.0 mol% and / or MgO component

CaO component 0-25.0 mol% and / or

SrO component 0-15.0 mol% and / or

0 to 4.0 mol% and / or Y ₂ O ₃ component

0-3.0 mol% and / or La ₂ O ₃ component

0-3.0 mol% and / or Gd ₂ O ₃ component

0-20.0 mol% and / or B ₂ O ₃ component

0-20.0 mol% and / or SiO ₂ component

0-15.0 mol% and / or GeO ₂ component

0 to 4.0 mol% and / or Bi ₂ O ₃ component

ZrO ₂ component 0-13.0 mol% and / or

ZnO component 0-20.0 mol% and / or

0-25.0 mol% and / or Al ₂ O ₃ component

0-3.0 mol% and / or Ta ₂ O ₅ component

Sb ₂ O ₃ Component 0 ~ 0.3mol%

In addition, the composition by mol% display of each component in 4th optical glass takes the following values generally in oxide conversion composition.

5.0-20.0 mol% of P ₂ O ₅ component,

Nb ₂ O ₅ ingredient 5.0 ~ 30.0mol%, and

BaO component 7.0 ~ 30.0mol% / or

And

0 to 50.0 mol% of Li ₂ O component and / or

0-50.0 mol% and / or Na ₂ O component

K ₂ O component 0-30.0 mol% and / or

0-20.0 mol% and / or MgO component

CaO component 0-25.0 mol% and / or

SrO component 0-15.0 mol% and / or

0 to 4.0 mol% and / or Y ₂ O ₃ component

0-3.0 mol% and / or La ₂ O ₃ component

0-3.0 mol% and / or Gd ₂ O ₃ component

0-20.0 mol% and / or B ₂ O ₃ component

0-20.0 mol% and / or SiO ₂ component

0-15.0 mol% and / or GeO ₂ component

0 to 4.0 mol% and / or Bi ₂ O ₃ component

ZrO ₂ component 0-13.0 mol% and / or

ZnO component 0-20.0 mol% and / or

0-25.0 mol% and / or Al ₂ O ₃ component

0-40.0 mol% and / or TiO ₂ component

0-3.0 mol% and / or Ta ₂ O ₅ component

0-15.0 mol% and / or WO ₃ component

Sb ₂ O ₃ Component 0 ~ 0.3mol%

In addition, the composition by mol% display of each component in 5th optical glass takes the following values generally in oxide conversion composition.

5.0-20.0 mol% of P ₂ O ₅ component,

Nb ₂ O ₅ ingredient 5.0 ~ 30.0mol%, and

TiO ₂ component 13.0 ~ 40.0mol%

And

0-15.0 mol% and / or WO ₃ component

BaO component 0-30.0 mol% and / or

0 to 50.0 mol% of Li ₂ O component and / or

0-50.0 mol% and / or Na ₂ O component

K ₂ O component 0-30.0 mol% and / or

0-20.0 mol% and / or MgO component

CaO component 0-25.0 mol% and / or

SrO component 0-15.0 mol% and / or

0 to 4.0 mol% and / or Y ₂ O ₃ component

0-3.0 mol% and / or La ₂ O ₃ component

0-3.0 mol% and / or Gd ₂ O ₃ component

0-20.0 mol% and / or B ₂ O ₃ component

0-20.0 mol% and / or SiO ₂ component

0-15.0 mol% and / or GeO ₂ component

0 to 4.0 mol% and / or Bi ₂ O ₃ component

ZrO ₂ component 0-13.0 mol% and / or

ZnO component 0-20.0 mol% and / or

0-25.0 mol% and / or Al ₂ O ₃ component

0-3.0 mol% and / or Ta ₂ O ₅ component

Sb ₂ O ₃ Component 0 ~ 0.3mol%

In addition, the composition by mol% display of each component in 6th optical glass takes the following values generally in oxide conversion composition.

5.0-40.0 mol% of P ₂ O ₅ component and

Nb ₂ O ₅ Component 5.0-30.0 mol%,

And

0 to 50.0 mol% of Li ₂ O component and / or

0-50.0 mol% and / or Na ₂ O component

K ₂ O component 0-30.0 mol% and / or

BaO component 0-20.0 mol% and / or

0-15.0 mol% and / or WO ₃ component

0-20.0 mol% and / or MgO component

CaO component 0-25.0 mol% and / or

SrO component 0-15.0 mol% and / or

0 to 4.0 mol% and / or Y ₂ O ₃ component

0-3.0 mol% and / or La ₂ O ₃ component

0-3.0 mol% and / or Gd ₂ O ₃ component

0-20.0 mol% and / or B ₂ O ₃ component

0-20.0 mol% and / or SiO ₂ component

0-15.0 mol% and / or GeO ₂ component

0-40.0 mol% and / or TiO ₂ component

0 to 4.0 mol% and / or Bi ₂ O ₃ component

ZrO ₂ component 0-13.0 mol% and / or

ZnO component 0-20.0 mol% and / or

0-25.0 mol% and / or Al ₂ O ₃ component

0-3.0 mol% and / or Ta ₂ O ₅ component

Sb ₂ O ₃ Component 0 ~ 0.3mol%

[Manufacturing method]

The optical glass of this invention is produced as follows, for example. That is, the raw materials are uniformly mixed so that each component is within a range of a predetermined content rate, and the prepared mixture is poured into a quartz crucible or an alumina crucible and coarsely melted, followed by a platinum crucible, a platinum alloy crucible or an iridium crucible. It is prepared by melting in a temperature range of 1000 ~ 1300 ℃ for 2-10 hours, homogenizing and removing the foam, lowering the temperature to 1250 ℃ or less, and then performing a final stirring to remove the striae, injecting into a mold and is produced by cooling .

[Properties]

The optical glass of the present invention needs to have high dispersion and high dispersion while having a high refractive index n _d . In particular, the refractive index (n _d ) of the optical glass of the present invention is preferably 1.70, more preferably 1.75, still more preferably 1.80, most preferably 1.90 is the lower limit, preferably 2.20, and more preferably 2.15, most preferably 2.10. In addition, the Abbe's number (v _d ) of the optical glass of the present invention is preferably 25, more preferably 22, still more preferably 20, and most preferably 19. As a result, the degree of freedom in optical design increases, and even if the device is thinned, a large amount of light refractive index can be obtained. The lower limit of the Abbe's number (ν _d ) of the optical glass of the present invention is not particularly limited, but the Abbe's number (ν _d ) of the glass obtainable by the present invention is generally 10 or more, specifically 12 or more, and more specifically, There are many more than 15.

Moreover, it is preferable that the optical glass of this invention has little coloring. Particularly, in the optical glass of the present invention, the wavelength λ ₇₀ exhibiting a spectral transmittance of 70% in a sample having a thickness of 10 mm is 500 nm or less, more preferably 480 nm or less, still more preferably 460 nm or less, in terms of a glass having a thickness of 10 mm. Most preferably, it is 450 nm or less. As a result, the absorption end of the glass is located in the vicinity of the ultraviolet region, and the transparency of the glass in the visible region is increased. Thus, such optical glass can be used as a material for optical elements such as lenses.

In particular, it is preferable that the 1st optical glass of this invention is high in devitrification resistance. In particular, the optical glass of the present invention preferably has a low liquidus temperature of 1200 ° C or lower. More specifically, the liquidus temperature of the optical glass of this invention becomes like this. Preferably it is 1200 degreeC, More preferably, it is 1150 degreeC, Most preferably, it is 1100 degreeC as an upper limit. Therefore, even if the molten glass flows out at a lower temperature, the crystallization of the produced glass is reduced, so that the devitrification resistance when the glass is formed in the molten state can be increased, and the influence on the optical characteristics of the optical element using the glass can be improved. Can be reduced. On the other hand, the lower limit of the liquidus temperature of the optical glass of the present invention is not particularly limited, but the liquidus temperature of the glass obtainable by the present invention is generally 500 ° C or more, specifically 550 ° C or more, and more specifically 600 ° C or more. There are many. "Liquid temperature" in the present specification is a glass sample pulverized in the form of particles having a diameter of about 2 mm on a platinum plate, held for 30 minutes in a furnace operated at a temperature gradient of 800 ° C to 1220 ° C, taken out, and after cooling the crystals in the glass It refers to the lowest temperature at which crystals are not confirmed and no devitrification occurs in the glass, measured by observing the presence or absence with a microscope of 80x magnification.

Moreover, it is preferable that the 1st optical glass of this invention has high acid resistance. Especially the chemical durability (acid resistance) by the powder method of glass based on JOGIS 06-1999 becomes like class 1-5, More preferably, it is class 1-4, Most preferably, it is class 1-3. Thereby, when the optical glass is polished, the phenomenon of clouding of the glass due to the acidic polishing liquid or the cleaning liquid is reduced, so that polishing can be performed more easily. Here, "acid resistance" is durability against the erosion of glass by an acid, and such acid resistance can be measured by the Japan Optical Glass Industry Standard "Measurement method of chemical durability of optical glass" JOGIS 06-1999. In addition, the meaning of "chemical durability (acid resistance) by the powder method is class 1-5" means that the chemical durability (acid resistance) performed in accordance with JOGIS 06-1999 is 2.20 mass% in the weight loss rate of the sample before and after the measurement. It means less than. Here, "Class 1" of chemical durability (acid resistance) has a weight loss rate of less than 0.20 mass% of the sample before and after the measurement, and "Class 2" has a weight loss rate of 0.20 mass% or more and 0.35 mass% of the sample before and after the measurement. "Class 3" is 0.35 mass% or more and less than 0.65 mass% of the mass of the sample before and after the measurement, and "Class 4" is 0.65 mass% or more and 1.20 mass% of the mass of the sample before and after the measurement. The "class 5" is less than 1.20 mass% or more and less than 2.20 mass% of the mass of the sample before and after measurement, and the "class 6" is 2.20 mass% or more of the mass loss of the sample before and after measurement.

On the other hand, the second optical glass of the present invention has a predetermined wear degree. Especially the wear degree in the measuring method based on "JOGIS 10-1994 optical glass wear method measuring method" of optical glass becomes like this. Preferably it is 100, More preferably, it is 150, Most preferably, it is 200 as a minimum, Preferably it is 400 More preferably, 350 is the upper limit. By setting the wear degree to 100 or more, the glass is easily polished when the polishing process is performed, so that the processing efficiency of the polishing process can be increased, and the polishing process can be easily performed. On the other hand, when the wear degree is 400 or less, wear and scratches more than necessary for the optical glass are reduced, so that handling in polishing processing on the optical glass becomes easy, so that polishing processing can be easily performed.

Moreover, it is preferable that the 2nd optical glass of this invention is small in average linear expansion coefficient ((alpha)). In particular, the optical glass of the present invention preferably has a low liquid phase of 150 × 10 ⁻⁷ K ⁻¹ or less, more preferably 120 × 10 ⁻⁷ K ⁻¹ or less, most preferably 100 × 10 ⁻⁷ K ⁻¹ or less It is desirable to have a temperature. Thereby, when press-molding optical glass using a metal mold | die, expansion and contraction by the temperature change of the lens or preform after shaping | molding are reduced. For this reason, in the case of cooling after molding, it is possible to reduce the dents and cracks of the lens, which occur when the temperature gradient from the inside of the lens to the outside occurs.

On the other hand, the third, fifth and sixth optical glasses of the present invention have a glass transition point (Tg) of 700 ° C or lower. Since glass softens at a lower temperature by this, glass can be press-molded at lower temperature. Moreover, the oxidation of the metal mold | die used for precision press molding can be reduced, and long life of a metal mold | die can also be attained. Therefore, the glass transition point (Tg) of the optical glass of the present invention is preferably 700 ° C, more preferably 680 ° C, still more preferably 670 ° C, and most preferably 650 ° C. The lower limit of the glass transition point (Tg) of the optical glass of the present invention is not particularly limited, but the glass transition point (Tg) of the glass obtainable by the present invention is generally 100 ° C or more, specifically 150 ° C or more, and more specifically. In many cases, it is 200 degreeC or more.

On the other hand, it is preferable that the 4th optical glass of this invention has high detergent resistance. In particular, the detergent resistance (PR) carried out according to the ISO test method detergent resistance (ISO 9689: 1990 (E)) is preferably Class 1 to 3, more preferably Class 1 to 2, most preferably Class 1 to be. For this reason, when the optical glass is washed after the polishing process, the swelling phenomenon of the glass by the aqueous cleaning liquid is reduced, so that the cleaning of the optical glass can be performed more easily. Here, "detergent resistant" refers to the superiority of the changed state when exposed to chemicals used for cleaning for a certain period of time when the lens preform material is washed before molding, or when the molded lens is washed. Such detergent resistance can be measured by ISO test method detergent resistance (ISO 9689: 1990 (E)). In addition, "detergent-resistance (PR) is grade 1-3" means that detergent-resistance (PR) calculated | required according to ISO test method detergent resistance (ISO 9689: 1990 (E)) erodes the 0.1 micrometer glass layer. This means that the time required to do this is longer than 15 minutes.

[Preform and Optical Device]

The optical glass of the present invention is useful for various optical devices and optical designs, and among them, in particular, optical devices such as lenses, prisms, mirrors, etc. can be used from the optical glass of the present invention by means of press molding (precision press molding, etc.). It is preferable to produce. As a result, when used in an optical device that transmits visible light to an optical element such as a camera or a projector, it is possible to miniaturize the optical system in these optical devices while realizing high-resolution imaging characteristics with high definition. Here, in order to manufacture the optical element which consists of the optical glass of this invention, cutting and grinding | polishing processes can be abbreviate | omitted. Therefore, the glass of molten state is dripped at the outflow path of the outflow pipes, such as platinum, for precision press molding, such as spherical shape. It is preferable to manufacture a preform and to perform precision press molding with respect to such a preform for precision press molding.

Example

Wavelength (λ) at which the composition, refractive index (n _d ), Abbe's number (ν _d ), and spectral transmittance of the glass of Examples (No.A1 to No.A7) and Comparative Example (No.A1) of the present invention are 70%. ₇₀ ), the liquidus temperature and the chemical durability (acid resistance) by the powder method are shown in Table 1. In addition, the wavelength of the composition, refractive index (n _d ), Abbe's number (ν _d ), and spectral transmittance of the glass of Examples (No.B1 to No.B5) and Comparative Example (No.B1) of the present invention are 70%. (λ ₇₀ ), abrasion degree and average linear expansion coefficient are shown in Table 2. In addition, the wavelength of the composition, refractive index (n _d ), Abbe's number (ν _d ), and spectral transmittance of the glass of Examples (No.C1 to No.C5) and Comparative Example (No.C1) of the present invention are 70%. (λ ₇₀ ) and the glass transition point (Tg) are shown in Table 3. Further, the wavelengths of the compositions, refractive indexes (n _d ), Abbe's numbers (ν _d ), and spectral transmittances of the glass of Examples (No.D1 to No.D5) and Comparative Examples (No.D1) of the present invention exhibit 70% ( (lambda ₇₀ ) and detergent resistance (PR) by the ISO test method are shown in Table 4. Wavelength (λ) where the composition, refractive index (n _d ), Abbe's number (ν _d ), and spectral transmittance of the glass of Examples (No.E1 to No.E14) and Comparative Example (No.E1) of the present invention are 70%. ₇₀ ) and the glass transition point (Tg) are shown in Tables 5-7. Moreover, the wavelength of the composition, refractive index (n _d ), Abbe's number ((nu) _d ), and spectral transmittance of glass of the Example (No.F1-No.F5) and the comparative example (No.F1) of this invention show 70%. (λ ₇₀ ) and the glass transition point (Tg) are shown in Table 8. The following examples are for the purpose of illustration only, and are not limited to these examples.

Embodiment of this invention (No.A1-No.A7, No.B1-No.B5, No.C1-No.C5, No.D1-No.D5, No.E1-No.E14, No.F1- The optical glass of No. F5) and the glass of Comparative Examples (No.A1, No.B1, No.C1, No.D1, No.E1, No.F1) are all raw materials of the respective components, High purity raw materials used for ordinary optical glass such as hydroxides, carbonates, nitrates, fluorides, hydroxides, and metaphosphate compounds are selected, weighed and uniformly mixed so as to have the composition ratios of the Examples and Comparative Examples shown in Tables 1 to 8 After that, the mixture was put into a platinum crucible, dissolved in an electric furnace at a temperature range of 1000 to 1300 ° C. for 2 to 10 hours in a furnace, and homogenized to remove bubbles, and then lowered to 1250 ° C. or lower to homogenize the mixture. After injecting into a mold, it was cooled and produced glass.

Here, the refractive index (n _d ) and Abbe number (ν _d ) of the optical glass of the example and the glass of the comparative example were measured based on the Japan Optical Glass Industry Association standard JOGIS 01-2003. The glass used for this measurement used what was processed by the slow cooling furnace by setting the slow cooling rate to -25 degreeC / hr on an anal condition. In addition, the optical transmittance of the Example and the glass transmittance of the comparative example were measured according to the Japan Optical Glass Industry Association standard JOGIS 02. In this invention, the presence or absence of the coloring of glass was calculated | required by measuring the transmittance | permeability of glass. Specifically, the spectral transmittance of 200-800 nm was measured for the facing parallel abrasive article with a thickness of 10 +/- 0.1 mm, and λ ₇₀ (wavelength at the time of transmittance of 70%) was obtained.

Among them, the liquidus temperature of the optical glass of the examples (No.A1 to No.A7) and the glass of the comparative example (No.A1) corresponding to the first optical glass is the pulverized glass sample on the platinum plate at 10 mm intervals. After holding for 30 minutes in a furnace operating at a temperature gradient of 800 ° C to 1200 ° C, the resultant was taken out, and after cooling, the presence or absence of crystals in the glass sample was measured by observing with a microscope of 80 times magnification. At this time, the optical glass was pulverized in the form of particles having a diameter of about 2 mm as a sample.

In addition, the acid resistance of the optical glass of the Example (No.A1-No.A7) and the glass of the comparative example (No.A1) is referred to Japanese Optical Glass Industry Standard "Measurement method of chemical durability of optical glass" JOGIS 06-1999. It measured accordingly. That is, a glass sample crushed at a particle size of 425-600 µm was taken in a pycnometer and placed in a platinum basket. The platinum basket was placed in a quartz glass round bottom flask containing 0.01 N nitric acid solution and treated for 60 minutes in boiling water. The weight loss rate (mass%) of the glass sample after the treatment is calculated, and the weight loss rate (mass%) is less than 0.20 in class 1 and the weight loss rate is less than 0.20 to 0.35 in class 2, and the reduction rate is 0.35 to 0.65. In the case of less than class 3, the loss rate was less than 0.65-1.20, the class 4 and the loss rate was less than 1.20-2.20 were classified as class 5, and the loss rate was 2.20 or more. At this time, the smaller the number of classes, the better the acid resistance of the glass.

On the other hand, the wear degree of the optical glass of the Example (No.B1-No.B5) corresponding to 2nd optical glass and the glass of the comparative example (No.B1) is a "method of measuring the wear degree of JOGIS 10-1994 optical glass." It measured according to. That is, a sample of a 30 × 30 × 10 mm glass plate is placed 80 mm from the center of a flat cast iron plate (250 mmφ) that rotates horizontally 60 minutes per minute, and a load of 9.8 N (1 kgf) is vertical. While adding to a 20 mL of water, a polishing liquid containing 10 g of a # 800 (average particle size 20 μm) wrap material (aluminum A abrasive grain) was supplied and rubbed uniformly for 5 minutes, and the friction was measured. Obtained. In the same way, the wear mass of the standard sample designated by the Japan Optical Glass Industry Association

Abrasion degree = {(wear mass / specific gravity of sample) / (wear mass / specific gravity of standard sample)} × 100.

Moreover, the average linear expansion coefficient ((alpha)) of the optical glass of Example (No.B1-No.B5) and the glass of the comparative example (No.B1) was measured by Japan Optical Glass Industry Standard JOGIS 08-2003 "The measurement of thermal expansion of optical glass." According to the method, the average linear expansion coefficient in -30- + 70 degreeC was calculated | required.

On the other hand, the optical glass and the comparative example (No.C1-No.C5, No.E1-No.E14, No.F1-No.F5) corresponding to the third, fifth and sixth optical glass The glass transition point (Tg) of the glass of .C1, No.E1, No.F1) was calculated | required by measuring using a lateral expansion measuring instrument. Here, the sample at the time of measurement used the thing of (phi) 4.5mm and length 5mm, and made it the temperature rise rate 4 degree-C / min.

On the other hand, the detergent resistance (PR) of the optical glass of the Example (No.D1-No.D5) and the glass of the comparative example (No.D1) corresponding to 4th optical glass is ISO test method detergent resistance (ISO 9689: Measurement according to 1990 (E)). That is, a 30 mm x 30 mm x 2 mm glass sample polished on six surfaces as a test piece was attached to a solution of purified sodium tripolyphosphate at a concentration of 0.01 mol / L heated at 50 ° C using a platinum wire, for a predetermined time (15 minutes, 1 hour, 4 hours, 16 hours). After the immersion treatment, the mass loss of the sample was weighed, and the time required for eroding the glass layer having a thickness of 0.1 μm was calculated by the following equation. However, this calculation used the value obtained by the minimum test time which the mass loss per sample becomes 1 mg or more. In addition, if the time required to erode a 0.1 μm glass layer is longer than 240 minutes, it is longer than class 1, 60 minutes, and if it is 240 minutes or less, it is less than class 3, 15 minutes In the case of the class 4. At this time, the smaller the number of grades, the better the detergent resistance of the glass.

t0.1 = te.dS / ((m1-m2) .100)

t0.1: The time required to erode a glass layer of 0.1 μm (minutes)

te: processing time (minutes)

d: specific gravity

S: surface area of the sample (cm2)

m1-m2: mass loss of the sample (mg)

As shown in Table 1, all of the optical glass of the embodiment of the present invention, the liquidus temperature is less than 1200 ℃, more specifically less than 1120 ℃ and at the same time the liquidus temperature was 500 ℃ or more. On the other hand, the liquidus temperature of the glass of the comparative example (No.A1) was 1120 degreeC. For this reason, it became clear that the optical glass of the Example (No.A1-No.A7) of this invention is low in liquidus temperature and hardly devitrified compared with the glass of the comparative example (No.A1).

In addition, as shown in Table 2, all of the optical glasses of Examples (No. B1 to No. B5) of the present invention have a wear degree of 400 or less, more specifically, less than 300, and such wear degree is 100 or more, More specifically, it was 200 or more. On the other hand, the glass of the comparative example (No. B1) was 300 in wear. For this reason, it became clear that the optical glass of the Example (No. B1-No. B5) of this invention has a low wear compared with the glass of a comparative example (No. B1).

In addition, as shown in Table 3 and Tables 5-8, the optical glass of the Example (No.C1-No.C5, No.E1-No.E14, No.F1-No.F5) of this invention, In all, the glass transition point (Tg) was 700 degrees C or less, More specifically, it was 670 degrees C or less.

In particular, the glass transition point (Tg) of the optical glass of the Example (No.C1-No.C5, No.F1-No.F5) of this invention was 650 degrees C or less. On the other hand, the glass transition point (Tg) of the glass of the comparative examples (No.C1, No.F1) was higher than 650 degreeC. For this reason, the optical glass of the Example (No.C1-No.C5, No.F1-No.F5) of this invention has the glass transition point (lower than the glass of the comparative example (No.C1, No.F1) ( Tg), it becomes clear that it is easy to soften at a low heating temperature.

In addition, as shown in Table 4, all of the optical glasses of Examples (No. D1 to No. D5) of the present invention have a detergent resistance (PR) grade 1 to 3 by ISO test method, more specifically, It was one. On the other hand, the glass of the comparative example (No.D1) had grade 3 detergent resistance (PR) by the ISO test method. For this reason, it became clear that the optical glass of the Example (No.D1-No.D5) of this invention is excellent in detergent resistance compared with the glass of a comparative example (No.D1).

Moreover, as for the optical glass of the Example of this invention, (lambda) ₇₀ (wavelength at the time of 70% of the transmittance | permeability) was 500 nm or less, More specifically, it was 492 nm or less, and it existed in the desired range.

In particular, (lambda) ₇₀ was 450 nm or less in the optical glass of the Example (No.A1-No.A7) of this invention. On the other hand, (lambda) ₇₀ was larger than 450 nm of the glass of the comparative example (No.A1). For this reason, it became clear that the optical glass of the Example (No.A1-No.A7) of this invention is difficult to color compared with the glass of the comparative example (No.A1).

Moreover, as for the optical glass of the Example (No.B1-No.B5) of this invention, (lambda) ₇₀ (wavelength at the time of 70% of the transmittance | permeability) was 480 nm or less in all. On the other hand, (lambda) ₇₀ of the glass of the comparative example (No.B1) was larger than 480 nm. For this reason, it became clear that the optical glass of the Example (No.B1-No.B5) of this invention is hard to be colored compared with the glass of the comparative example (No.B1).

Moreover, (lambda) ₇₀ (wavelength at the time of 70% of the transmittance | permeability) of the optical glass of the Example (No.C1-No.C5, No.D1-No.D5) of this invention was 450 nm or less. On the other hand, (lambda) ₇₀ was 500 nm in the glass of the comparative example (No.D1). For this reason, it became clear that the optical glass of the Example (No.D1-No.D5) of this invention is hard to color compared with the glass of a comparative example (No.D1).

In addition, as for the optical glass of the Example (No.F1-No.F5), (lambda) ₇₀ (wavelength at the time of 70% of the transmittance | permeability) was 470 nm or less in all. On the other hand, (lambda) ₇₀ of the glass of the comparative example (No.F1) was larger than 470 nm. For this reason, it became clear that the optical glass of the Example (No.F1-No.F5) of this invention is difficult to color compared with the glass of a comparative example (No.F1).

In addition, all of the optical glasses of the embodiment of the present invention, the refractive index (n _d ) is 1.70 or more, more specifically 1.80 or more, while the refractive index (n _d ) is 2.20 or less, more specifically 2.10 or less, the desired range Was within. In particular, the refractive index n _d of the optical glass of Examples (No.C1-No.C5) was 1.86 or more. Moreover, the refractive index n _d of the optical glass of the Example (No.D1-No.D5) was 1.84 or more. Moreover, the refractive index n _d of the optical glass of the Example (No.E1-No.E14) was 1.90 or more. Moreover, the refractive index n _d of the optical glass of the Example (No.F1-No.F5) was 1.92 or more. On the other hand, in the embodiment of the present invention (No.B1-No.B5, No.C1-No.C5, No.D1-No.D5, No.E1-No.E14, No.F1-No.F5) All of the glasses had a refractive index (n _d ) of 2.00 or less.

In addition, the embodiment has both the optical glass of the present invention at the same time as the Abbe number (ν _d) of 10 or more, more specifically 15 or more, such an Abbe number (ν _d) is 25 or less, it was within a desired range. In particular, the optical glass of the embodiment (No.B1 ~ No.B5) of the invention, were all the Abbe number (ν _d) is 17 or more. On the other hand, as for the optical glass of the Example (No.B1-No.B5, No.D1-No.D5) of this invention, Abbe's number ((nu) _d ) was 23 or less in all. Moreover, Abbe's number ((nu) _d ) was 24 or less in the optical glass of the Example (No.C1-No.C5).

In particular, in the optical glass of Examples (No.E1-No.E14, No.F1-No.F5), Abbe's number ((nu) _d ) was 20 or less. On the other hand, Abbe's number ((nu) _d ) was larger than 20 in the glass of the comparative example (No.E1, No.F1). For this reason, the optical glass of the Example (No.E1-No.E14, No.F1-No.F5) of this invention is a high dispersion | dispersion compared with the glass of the comparative example (No.E1, No.F1), and Abe It became clear that the number v _d was low.

In addition, the optical glass of the Example (No.A1-No.A7) of this invention was the chemical durability (acid resistance) by the powder method in all classes 1-5, More specifically, it was class 1-2. On the other hand, the chemical durability (acid resistance) by the powder method of the glass of the comparative example (No.A1) was class 4. For this reason, it became clear that the optical glass of the Example (No.A1-No.A7) of this invention is excellent in acid resistance compared with the glass of a comparative example (No.A1).

In addition, in the optical glass of the Example (No.B1-No.B5) of this invention, all the average linear expansion coefficients ((alpha)) are 150x10 <^-7> K <^-1> or less, More specifically, 100x10 <^-7> K <^{-> It} was ¹ or less. On the other hand, the glass of the comparative example (No. B1) was larger in average linear expansion coefficient (alpha) than 100x10 <^-7> K <^-1> . For this reason, it became clear that the optical glass of the Example (No.B1-No.B5) of this invention has a small average linear expansion coefficient (alpha) compared with the glass of the comparative example (No.B1).

Furthermore, the optical glass of the Example (No.A1-No.A7) of this invention is cut and polished, and a preform is formed, this preform is put into a metal mold | die, press-molding, heat-softening, and the obtained molded object is polished As a result, the optical glass was stably processed into various lens shapes.

In addition, the optical glass of the Examples (No. B1 to No. B5) of the present invention was put into a mold, press-molded while heat-softening the optical glass, and the obtained molded article was subjected to polishing, so that various lenses were stably obtained. Optical glass could be processed into the shape of.

Furthermore, the preform for precision press molding is formed using the optical glass of the Example (No.C1-No.C5, No.E1-No.E14, No.F1-No.F5) of this invention, and precision press molding When the preform was processed by precision press molding, it could be stably processed into various lens shapes.

Furthermore, the optical glass of the Example (No.D1-No.D5) of this invention is cut and polished, and a preform is formed, this preform is put into a metal mold | die, press-molding, heat-softening, and the obtained molded object is ground-processed The glass after polishing was washed, and optical glass could be processed stably in the shape of various lenses.

Therefore, it became clear that the optical glass of the Example of this invention has high dispersion | dispersion (low Abbe number v _d ), in the refractive index n _d in the desired range, and high transparency with respect to the light of the wavelength of a visible region.

In particular, it has become clear that the optical glass of Examples (No. A1 to No. A7) of the present invention has high devitrification resistance at the time of glass formation, and it is difficult to cause a phenomenon that becomes cloudy when glass is produced from glass. .

In addition, it became clear that the optical glass of the Example (No. B1-No. B5) of this invention is easy to grind, and it is hard to expand and contract even if glass changes temperature.

Moreover, it became clear that the optical glass of the Example (No.C1-No.C5, No.E1-No.E14, No.F1-No.F5) of this invention is easy to soften at low temperature.

Moreover, it became clear that the optical glass of the Example (No.D1-No.D5) of this invention is easy to wash | clean in manufacture of a preform material or an optical element.

Although the present invention has been described in detail for purposes of illustration, it should be understood that various changes may be made by those skilled in the art for the purpose of illustration only, without departing from the spirit and scope of the invention. Could be.

Claims (21)

In terms of oxide glass based on the total mass, in mass% P ₂ O ₅ component of 5.0% or more and 40.0% or less, Nb ₂ O ₅ optical glass containing components less than 60% more than 10% of the composition.
The method of claim 1,
The optical glass which has a liquidus temperature of 500 nm or more and 1200 degrees C of wavelength (lambda ₇₀ ) which shows a spectral transmittance 70% or less.
The method of claim 1,
Optical glass having a wear degree of 100 or more and 400 or less.
The method of claim 1,
Optical glass with grade 1-3 of detergent resistance (PR) by ISO test method.
The method of claim 1,
An optical glass containing at least one of a Li ₂ O component, a Na ₂ O component, and a K ₂ O component as an essential component, and having a glass transition point (Tg) of 700 ° C. or less.
The method according to any one of claims 1 to 5,
Terms of oxides is 30% or less the optical glass content of the TiO ₂ component, the mass% of the entire mass of the glass composition.
The method of claim 1,
And with respect to the total mass of the glass composition in terms of oxide, the content of the TiO ₂ component in terms of percent by mass less than 10.0%, 700 ℃ glass optical glass having a transition point (Tg) of less than.
The method of claim 1,
With respect to the total mass of the glass composition in terms of oxide, the optical glass having a glass transition point (Tg) not higher than the TiO ₂ component and not less than 10.0% 30.0%, 700 ℃ by mass.
The method according to any one of claims 1 to 8,
By mass% with respect to the glass total mass of oxide conversion composition
WO ₂ component 0-20.0% and / or
0-30.0% BaO component and / or
SiO ₂ Component 0 ~ 10.0%
Optical glass containing each component of the.
The method according to any one of claims 1 to 9,
By mass% with respect to the glass total mass of oxide conversion composition
Li ₂ O component 0-20.0% and / or
Na ₂ O component 0-35.0% and / or
K ₂ O Component 0 ~ 20.0%
Optical glass containing each component of the.
The method of claim 10,
Mass sum _{Li 2 O + Na 2 O +} K 2 O is less than or equal to 35.0% An optical glass for the glass composition in terms of the total mass of the oxide.
The method according to claim 10 or 11,
An optical glass including two or more components of a Li ₂ O component, a Na ₂ O component, and a K ₂ O component.
The method according to any one of claims 1 to 12,
By mass% with respect to the glass total mass of oxide conversion composition
MgO component 0-5.0% and / or
CaO component 0-10.0% and / or
SrO component 0 ~ 10.0%
Optical glass containing each component of the.
The method of claim 13,
Optical glass whose mass sum MgO + CaO + SrO + BaO is 30.0% or less with respect to the glass total mass of oxide conversion composition.
The method according to any one of claims 1 to 14,
By mass% with respect to the glass total mass of oxide conversion composition
Y ₂ O ₃ component 0-10.0% and / or
La ₂ O ₃ component 0-10.0% and / or
Gd ₂ O ₃ Component 0 ~ 10.0%
Optical glass containing each component of the.
16. The method of claim 15,
By weight of the sum total mass of the glass composition in terms of oxide _{Y 2 O 3 + La 2 O} 3 + Gd 2 O 3 is less than or equal to 20.0% optical glass.
The method according to any one of claims 1 to 16,
By mass% with respect to the glass total mass of oxide conversion composition
B ₂ O ₃ Component 0-10.0% and / or
GeO ₂ component 0-10.0% and / or
0-20.0% of Bi ₂ O ₃ component and / or
ZrO ₂ component 0-10.0% and / or
ZnO component 0-10.0% and / or
Al ₂ O ₃ component 0-10.0% and / or
Ta ₂ O ₅ component 0-10.0% and / or
Sb ₂ O ₃ Component 0 ~ 1.0%
Optical glass containing each component of the.
The method according to any one of claims 1 to 17,
An optical glass having a refractive index (n _d ) of 1.70 or more and 2.20 or less, and having an Abbe number (ν _d ) of 10 or more and 25 or less.
The method according to any one of claims 1 to 18,
The optical glass whose wavelength (lambda ₇₀ ) which shows a spectral transmittance 70% is 500 nm or less.
An optical element comprising the optical glass according to any one of claims 1 to 19.
The preform for precision press molding which consists of an optical glass of any one of Claims 1-19.