WO2010126141A1

WO2010126141A1 - Optical glass, optical element, and preform for precision press molding

Info

Publication number: WO2010126141A1
Application number: PCT/JP2010/057705
Authority: WO
Inventors: 菜那土淵; 道子荻野
Original assignee: 株式会社オハラ
Priority date: 2009-04-30
Filing date: 2010-04-30
Publication date: 2010-11-04
Also published as: CN107082562B; KR20120004538A; CN102159512A; KR101657245B1; CN107082562A

Abstract

Disclosed is optical glass which has a low Abbe number (ν_d) even though the refractive index (n_d) thereof is within a desired range, and which is highly transparent to visible light. Also disclosed are an optical element and a preform for precision press molding. The optical glass contains, in mass% relative to the total mass of the glass in terms of oxides, 5.0-40.0% of a P₂O₅ component and 10.0%-60.0% of an Nb₂O₅ component. The optical element and the preform for precision press molding are composed of the optical glass.

Description

Optical glass, optical element and precision press molding preform

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

In recent years, the digitization and high definition of devices that use optical systems have been rapidly progressing, and the precision of optical elements such as lenses used in various optical devices, including photography devices such as digital cameras and video cameras, The demand for light weight and downsizing is increasing.

Among optical glasses for producing optical elements, in particular, it has a high refractive index (n _d ) of 1.70 or more and 2.20 or less, which can reduce the weight and size of the optical element, and is 10 or more and 25 or less. The demand for glass having a high Abbe number (ν _d ) and high refractive index and high dispersion is greatly increasing. As such a high refractive index and high dispersion glass, for example, a glass represented by Patent Document 1 is known as an optical glass having a refractive index (n _d ) of 1.91 or more and an Abbe number of 21 or less. It has been. Further, as an optical glass having a refractive index (n _d ) of 1.65 or more and an Abbe number of 17.2 or more and 33.1 or less, a glass represented by Patent Document 2 is known.

JP 2005-206433 A Japanese Patent Application Laid-Open No. 06-345481

When 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 press-molding (reheat press molding), a gob or A method in which a preform material that has been cut and ground by grinding a glass block, or a preform material that has been molded by known flotation molding, is heat-softened and press-molded with a mold having a high-precision molding surface (precision press) Molding) is used.

However, the glass disclosed in Patent Document 1 has lower transparency to visible light as the Abbe number (ν _d ) is lower (λ ₇₀ is larger), and the glass having a lower Abbe number (ν _d ) is yellow or orange. Is colored. Therefore, even if the glass disclosed in Patent Document 1 has a desired high dispersion, it is not suitable for applications that transmit light in the visible region.

Further, the glasses disclosed in Patent Documents 1 and 2 have a problem that devitrification is likely to occur when the glass is produced. Furthermore, the glass that is free from devitrification when the glass is produced tends to become cloudy when the glass press-molded by reheat press is polished or when the preform is produced by polishing the glass. There was a problem. It has been difficult to produce an optical element that can control light in the visible region from glass once devitrified or cloudy.

In addition, many of the glasses disclosed in Patent Documents 1 and 2 are difficult to perform polishing or press molding. Specifically, when polishing was performed on a glass molded product after press molding to obtain an optical element, or when polishing was performed on a gob or a glass block, the glass was easily damaged. Further, when glass is heated in a mold and press-molded to make the glass into the shape of an optical element or its preform, there are many cases in which dents and cracks are generated in the glass.

Moreover, many of the glasses disclosed in Patent Documents 1 and 2 have a high glass transition point (Tg), and these glasses are difficult to soften even when heated. For this reason, when a preform material is produced from the glass of Patent Document 1, and an optical element is produced by heat-softening and press-molding the preform material, it is necessary to heat-soften the preform material and increase the temperature for press-molding. For this reason, the die used for press molding and the preform material are fused, and the optical characteristics of the optical element are affected.

In addition, the glass disclosed in Patent Documents 1 and 2 can be used to clean the preform material after polishing the glass press-molded by, for example, reheat press, or after polishing the glass. There was a problem that clouding was likely to occur during fabrication. It has been difficult to produce an optical element that can control light in the visible region, especially from glass that has once fogged.

The present invention has been made in view of the above problems, and its object is to have a low Abbe number (ν _d ) while the refractive index (n _d ) is within a desired range, And it is providing the optical glass and optical element with high transparency with respect to visible light.

Further, the present invention has the above-described refractive index (n _d ), Abbe number (ν _d ), and transparency to visible light, but is less susceptible to devitrification and clouding during glass production and processing. It is another object of the present invention to provide an optical glass and an optical element that are easy to produce a preform material and an optical element.

The present invention also provides an optical glass and an optical element that are easy to perform polishing and press molding while having transparency to the refractive index (n _d ), Abbe number (ν _d ), and visible light described above. Also aimed.

Further, the present invention has a refractive index of above (n _d), Abbe number ([nu _d) and while having a transparency to visible light, easy optical glass softened at a low temperature, optics and precision press-molding flop The purpose is to provide renovation.

The present invention provides an optical glass and an optical element that are easy to clean in the production of a preform material and an optical element while having transparency to the above-described refractive index (n _d ), Abbe number (ν _d ), and visible light. It is also intended to provide.

In order to solve the above-mentioned problems, the present inventors have conducted intensive test studies, and as a result, the glass has a high refractive index by containing a predetermined amount of P ₂ O ₅ component and Nb ₂ O ₅ component. However, the present inventors have found that the dispersion is increased to obtain a low Abbe number and that the transparency of the glass with respect to visible light is enhanced, thereby completing the present invention.

In addition, the present inventors include a predetermined amount of P ₂ O ₅ component and Nb ₂ O ₅ component, so that the refractive index (n _d ), dispersion, and transparency to visible light are enhanced, but It has also been found that the liquidus temperature is lowered and the acid resistance is increased.

In addition, the present inventors contain moderate amounts of P ₂ O ₅ component and Nb ₂ O ₅ component, so that the refractive index (n _d ), dispersion, and transparency to visible light are enhanced, but moderate It has also been found that the degree of wear is brought about and the average coefficient of linear expansion (α) is reduced.

In addition, the present inventors use the P ₂ O ₅ component and the Nb ₂ O ₅ component in combination, and suppress the contents of the P ₂ O ₅ component, the Nb ₂ O ₅ component, and the TiO ₂ component within a predetermined range. It was also found that the glass transition point (Tg) is lowered while the refractive index ( _nd ), dispersion and transparency to visible light are enhanced.

In addition, the present inventors include a P ₂ O ₅ component and an Nb ₂ O ₅ component in combination, and by 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. It was also found that the glass transition point (Tg) is lowered while the refractive index ( _nd ), dispersion and transparency to visible light are enhanced.

Further, the present inventors have found that by containing a predetermined amount of P ₂ O ₅ component and Nb ₂ O ₅ component, a refractive index (n _d), while the transparency is improved for dispersion and visible light, liquid phase It has also been found that the temperature is increased and the detergent resistance of the glass is increased. Specifically, the present invention provides the following.

(1) the entire mass of the glass in terms of oxide composition, _P 2 _{O 5} ingredient 40.0% 5.0% or more of the following in mass%, _Nb 2 _{O 5} ingredient 10.0% or more 60.0% Optical glass containing below.

(2) The optical glass according to (1), wherein a wavelength (λ ₇₀ ) having a spectral transmittance of 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 according to (1), which has a degree of wear of 100 to 400.

(4) The optical glass according to (1), which has a detergent resistance (PR) of 1 to 3 according to ISO test method.

(5) The optical glass according to (1), which contains 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 has a glass transition point (Tg) of 700 ° C. or lower.

(6) as oxide entire mass of the glass composition, the content of TiO ₂ component is less than 30.0% by mass% (1) to (5) any description of the optical glass.

(7) the entire mass of the glass in terms of oxide composition, the content of TiO ₂ component in terms of mass% is not more than 12.0 percent (6), wherein the optical glass.

(8) the entire mass of the glass in terms of oxide composition, the content of TiO ₂ component in terms of mass% is less than 10.0% (6), wherein the optical glass.

(9) The content of TiO ₂ component is less than 10.0% by mass% with respect to the total glass mass of the oxide equivalent composition, and has a glass transition point (Tg) of 700 ° C. or less. Optical glass.

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

(11) WO ₃ component 0 to 20.0% and / or BaO component 0 to 30.0% and / or SiO ₂ component 0 to 10.0% by mass% with respect to the total glass mass of the oxide equivalent composition
The optical glass according to any one of (1) to (10), further containing each component of

(12) With respect to the total glass mass of the oxide-converted composition, the composition further contains, in mass%, each of WO ₃ components greater than 0% and 20.0% or less, and BaO components greater than 0% and 30.0% or less. (11) The optical glass as described.

(13) The optical glass according to (11) or (12), wherein the content of the BaO component is 13.0% or less by mass with respect to the total mass of the glass having an oxide equivalent composition.

(14) The optical glass according to (11) or (12), wherein the content of the BaO component is less than 7.0% by mass with respect to the total mass of the glass having an oxide equivalent composition.

(15) The optical glass according to (11) or (12), wherein the BaO component content is 4.5% or less by mass with respect to the total mass of the glass having an oxide equivalent composition.

(16) The optical glass according to (11) or (12), wherein the content of the BaO component is 1.0% or more and less than 17.0% by mass% with respect to the total glass mass of the oxide equivalent composition.

(17) The optical glass according to (11) or (12), wherein the content of the BaO component is 2.0% or more and 15.0% or less with respect to the total mass of the glass having an oxide equivalent composition.

(18) The optical glass according to (11) or (12), wherein the BaO component content is greater than 7.0% and less than or equal to 30.0% by mass% relative to the total mass of the glass with an oxide equivalent composition.

(19) The optical glass according to any one of (11) to (18), wherein the content of the SiO ₂ component is 2.0% or less by mass with respect to the total mass of the glass having an oxide equivalent composition.

(20) The optical glass according to any one of (11) to (18), which contains more than 2.0% of SiO ₂ component by mass% with respect to the total glass mass of the oxide equivalent composition.

(21) The optical glass according to any one of (11) to (20), wherein the content of the WO ₃ component is 10.0% or less by mass% with respect to the total glass mass of the oxide equivalent composition.

(22) Li ₂ O component 0 to 20.0% and / or Na ₂ O component 0 to 35.0% and / or K ₂ O component 0 to 0% by mass with respect to the total glass mass of the oxide equivalent composition 20.0%
The optical glass according to any one of (1) to (21), further containing each component of

(23) 0 to 10.0% Li ₂ O component and / or 0 to 15.0% Na ₂ O component and / or K ₂ O component 0 to 0% by mass with respect to the total glass mass of the oxide equivalent composition The optical glass according to (22), further containing less than 10.0% of each component.

(24) The optical glass according to (22) or (23), which contains a Li ₂ O component as an essential component.

(25) The optical glass according to any one of (22) to (24), wherein the content of the K ₂ O component is 0.1% or more by mass% with respect to the total glass mass of the oxide equivalent composition.

(26) The optical glass according to any one of (22) to (25), wherein the mass sum Li ₂ O + Na ₂ O + K ₂ O with respect to the total glass mass of the oxide equivalent composition is 35.0% or less.

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

(28) The optical glass according to any one of (22) to (27), wherein the total mass Li ₂ O + Na ₂ O + K ₂ O with respect to the total glass mass of the oxide-converted composition is more than 7.0% and 35.0% or less.

(29) The optical glass according to any one of (22) to (28), wherein the mass sum Li ₂ O + Na ₂ O + K ₂ O with respect to the total glass mass of the oxide equivalent composition is more than 8.0%.

(30) The optical glass according to any one of (22) to (29), wherein the mass sum Li ₂ O + Na ₂ O + K ₂ O with respect to the total glass mass of the oxide equivalent composition is more than 10.0%.

(31) The optical glass according to any one of (22) to (30), wherein the mass sum Li ₂ O + Na ₂ O + K ₂ O with respect to the total glass mass of the oxide-converted composition is 15.0% or less.

(32) 15.0% or more of BaO component is contained in mass% with respect to the total glass mass of the oxide equivalent composition, and the mass sum Li ₂ O + Na ₂ O + K ₂ O is more than 10.0% from (22) ( 31) The optical glass described in any one of 31).

(33) The optical glass according to (22) to (32), which contains two or more kinds of components among Li ₂ O component, Na ₂ O component, and K ₂ O component.

(34) 0 to 5.0% of MgO component and / or 0 to 10.0% of CaO component and / or 0 to 10.0% of SrO component in mass% with respect to the total glass mass of the oxide equivalent composition
The optical glass according to any one of (1) to (33), further comprising:

(35) The optical glass according to (34), wherein the mass sum MgO + CaO + SrO + BaO is 30.0% or less with respect to the total mass of the glass having an oxide equivalent composition.

(36) 0 to 10.0% of Y ₂ O ₃ component and / or La ₂ O ₃ component 0 to 10.0% and / or Gd ₂ O _{3 in} mass% with respect to the total glass mass of the oxide equivalent composition Ingredient 0 ~ 10.0%
The optical glass according to any one of (1) to (35), further comprising:

(37) The optical glass according to (36), wherein the mass sum Y ₂ O ₃ + La ₂ O ₃ + Gd ₂ O ₃ with respect to the total glass mass of the oxide equivalent composition is 20.0% or less.

(38) B ₂ O ₃ component 0 to 10.0% and / or GeO ₂ component 0 to 10.0% and / or Bi ₂ O ₃ component 0% by mass with respect to the total glass mass of the oxide equivalent composition ˜20.0% and / or ZrO ₂ component 0 to 10.0% and / or ZnO component 0 to 10.0% and / or Al ₂ O ₃ component 0 to 10.0% and / or Ta ₂ O ₅ component 0 to 10.0% and / or Sb ₂ O ₃ component 0 to 1.0%
The optical glass according to any one of (1) to (37), further comprising:

(39) The optical glass according to any one of (1) to (38), having a refractive index (nd) of 1.70 to 2.20 and an Abbe number (νd) of 10 to 25.

(40) The optical glass according to any one of (1) to (39), wherein chemical durability (acid resistance) by a powder method is class 1 to 5.

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

(42) The optical glass according to any one of (1) to (41), wherein the average linear expansion coefficient (α) at −30 to + 70 ° C. is 150 × 10 ⁻⁷ K ⁻¹ or less.

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

(44) A precision press-molding preform made of the optical glass according to any one of (1) to (42).

(45) An optical element obtained by precision press molding the preform for precision press molding described in (44).

According to the present invention, the dispersion of the glass is enhanced and the transparency of the glass with respect to visible light is enhanced while the refractive index of the glass is increased. Therefore, it is possible to provide an optical glass and an optical element having a low Abbe number (ν _d ) while having a refractive index (n _d ) within a desired range and having high transparency to visible light.

In particular, according to the present invention, by containing a predetermined amount of _P 2 _{O 5} component and _Nb 2 _{O 5} component, desired refractive index _(n d), the transparency to the Abbe number ([nu _d) and visible light While having the glass, it is possible to provide an optical glass and an optical element that are less likely to be devitrified and cloudy during the production and processing of the glass and that are easy to produce a preform material and an optical element by polishing.

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

Further, according to the present _invention, by a combination of P 2 _{O 5} component and _Nb 2 _{O 5} _component, suppresses P 2 _{O 5} component, the content of _Nb 2 _{O 5} component and TiO ₂ component within a predetermined range An optical glass that has transparency to a desired refractive index (n _d ), Abbe number (ν _d ), and visible light but is easily softened at a low temperature, an optical element using the optical glass, and a precision press molding process Renovation can be provided.

Further, according to the present _invention, while a combination of P 2 _{O 5} component and _Nb 2 _{O 5} component, Li ₂ O component, Na ₂ O component, by containing as an essential ingredient at least one of _{K 2} O component An optical glass that has transparency to a desired refractive index (n _d ), Abbe number (ν _d ), and visible light but is easily softened at a low temperature, an optical element using the optical glass, and a precision press molding process Renovation can be provided.

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

In the optical glass of the present invention, the P ₂ O ₅ component is 5.0% or more and 40.0% or less, and the Nb ₂ O ₅ component is 10.0% or more by mass% with respect to the total glass mass of the oxide equivalent composition. Contains 60.0% or less. While the P ₂ O ₅ component and the Nb ₂ O ₅ component are used in combination, and the content ratio of the P ₂ O ₅ component and the Nb ₂ O ₅ component is kept within a predetermined range, the glass has a high refractive index. Dispersion is enhanced and the transparency of glass to visible light is enhanced. Therefore, it is possible to provide an optical glass and an optical element that have a low Abbe number (ν _d ) while having a refractive index (n _d ) within a desired range and that are highly transparent to visible light.

Of these, the first optical glass of the present invention, in terms of oxide entire mass of the glass composition, _P 2 _{O 5} ingredient 40.0% 5.0% or more of the following in weight%, _Nb 2 _{O 5} component The wavelength (λ ₇₀ ) in which the spectral transmittance is 70% is 500 nm or less and the liquidus temperature is 500 ° C. or more and 1200 ° C. or less. While the P ₂ O ₅ component and the Nb ₂ O ₅ component are used in combination, and the content ratio of the P ₂ O ₅ component and the Nb ₂ O ₅ component is kept within a predetermined range, the glass has a high refractive index. Dispersion is enhanced, the transparency of the glass to visible light is increased, the liquidus temperature of the glass is lowered, and the acid resistance of the glass is enhanced so that the glass does not corrode even if it comes into contact with the polishing liquid or cleaning liquid. It becomes difficult to be done. For this reason, the refractive index (n _d ) is within the desired range, but has a low Abbe number (ν _d ), high transparency to visible light, and devitrification and cloudiness during glass production and processing. It is possible to provide an optical glass and an optical element that are less likely to be produced and that facilitate the production of a preform material and an optical element by polishing.

The second optical glass of the present invention, the entire mass of the glass in terms of oxide composition, _P 2 _{O 5} ingredient 40.0% 5.0% or more of the following in weight%, the _Nb 2 _{O 5} component It contains 10.0% or more and 60.0% or less, and has a wear degree of 100 or more and 400 or less. While the P ₂ O ₅ component and the Nb ₂ O ₅ component are used in combination, and the content ratio of the P ₂ O ₅ component and the Nb ₂ O ₅ component is kept within a predetermined range, the glass has a high refractive index. The dispersion is increased to obtain a low Abbe number, the transparency of the glass to visible light is increased, a moderate degree of wear is brought about, and the average coefficient of linear expansion (α) is reduced. For this reason, the refractive index (n _d ) is within a desired range but has high dispersion (low Abbe number), high transparency to visible light, easy polishing, and press molding to the lens. An optical glass and an optical element with reduced depressions and cracks can be provided.

The third optical glass of the present invention, the entire mass of the glass in terms of oxide composition, _P 2 _{O 5} ingredient 40.0% 5.0% or more of the following in weight%, the _Nb 2 _{O 5} component It contains 10.0% or more and 60.0% or less, the content of the TiO ₂ component is less than 10.0%, and has a glass transition point (Tg) of 700 ° C. or less. By using the P ₂ O ₅ component and the Nb ₂ O ₅ component together, and suppressing the contents of the P ₂ O ₅ component, the Nb ₂ O ₅ component, and the TiO ₂ component within a predetermined range, it is possible to increase the refractive index of the glass. Although being achieved, the dispersion is increased to obtain a low Abbe number, the transparency of the glass to visible light is increased, and the glass transition point (Tg) is lowered. Therefore, an optical element having a low Abbe number (ν _d ) while having a refractive index (n _d ) within a desired range, high transparency to visible light, and being easy to soften and press-mold at a low temperature. Glass, an optical element using the glass, and a precision press-molding preform can be provided.

The fourth optical glass of the present invention, the entire mass of the glass in terms of oxide composition, _P 2 _{O 5} ingredient 40.0% 5.0% or more of the following in weight%, the _Nb 2 _{O 5} component The content is 10.0% or more and 60.0% or less, and the detergent resistance (PR) according to the ISO test method is a grade 1 to 3. While the P ₂ O ₅ component and the Nb ₂ O ₅ component are used in combination, and the content ratio of the P ₂ O ₅ component and the Nb ₂ O ₅ component is kept within a predetermined range, the glass has a high refractive index. Dispersion is enhanced, transparency of the glass with respect to visible light is enhanced, and detergent resistance of the glass is enhanced so that the glass is less likely to be corroded even if the glass comes into contact with the polishing liquid or the cleaning liquid. For this reason, the refractive index (n _d ) is in the desired range, but has a low Abbe number (ν _d ), high transparency to visible light, and hardly fogging during cleaning after glass polishing. It is possible to provide an optical glass and an optical element that can be easily cleaned in the production of a preform material and an optical element.

The fifth optical glass of the present invention, the entire mass of the glass in terms of oxide composition, _P 2 _{O 5} ingredient 40.0% 5.0% or more of the following in weight%, the _Nb 2 _{O 5} component It contains 10.0% or more and 60.0% or less, and a TiO ₂ component of 10.0% or more and 30.0% or less, and has a glass transition point (Tg) of 700 ° C. or less. P ₂ O ₅ component, a combination of _Nb 2 _{O 5} component and TiO ₂ _component, by reducing P 2 _{O 5} component, the content of _Nb 2 _{O 5} component and TiO ₂ component within a predetermined range, the glass high Although the refractive index is increased, the dispersion is increased to obtain a low Abbe number, the transparency of the glass to visible light is increased, and the glass transition point (Tg) is lowered. Therefore, an optical element having a low Abbe number (ν _d ) while having a refractive index (n _d ) within a desired range, high transparency to visible light, and being easy to soften and press-mold at a low temperature. Glass, an optical element using the glass, and a precision press-molding preform can be provided.

In addition, the sixth optical glass of the present invention contains 5.0% or more and 40.0% or less of the P ₂ O ₅ component and Nb ₂ O ₅ component in mass% with respect to the total glass mass of the oxide equivalent composition. 10.0% or more and 60.0% or less, containing at least one of Li ₂ O component, Na ₂ O component, and K ₂ O component as an essential component, and having a glass transition point (Tg) of 700 ° C. or less . By using at least one of the Li ₂ O component, the Na ₂ O component, and the K ₂ O component as an essential component while using the P ₂ O ₅ component and the Nb ₂ O ₅ component together, the refractive index of the glass can be increased. Although being achieved, the dispersion is increased to obtain a low Abbe number, the transparency of the glass to visible light is increased, and the glass transition point (Tg) is lowered. Therefore, an optical element having a low Abbe number (ν _d ) while having a refractive index (n _d ) within a desired range, high transparency to visible light, and being easy to soften and press-mold at a low temperature. Glass, an optical element using the glass, and a precision press-molding preform can be provided.

Hereinafter, embodiments of the optical glass of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. be able to. In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the meaning of invention is not limited.

[Glass component]
The composition range of each component constituting the optical glass of the present invention is described below. In the present specification, unless otherwise specified, the content of each component is expressed in mass% with respect to the total mass of the glass in terms of oxide. Here, the “oxide equivalent composition” means that the oxide, composite salt, metal fluoride, etc. used as the raw material of the glass component of the present invention are all decomposed and changed into oxides when melted. It is the composition which described each component contained in glass by making the total mass of the said production | generation oxide into 100 mass%.

<About essential and optional components>
The P ₂ O ₅ component is a glass forming component and is a component that lowers the melting temperature of glass. In particular, by making the content ratio of the P ₂ O ₅ component 5.0% or more, it is difficult to increase the degree of wear of the glass to a predetermined level or more while increasing the transmittance in the visible region of the glass. The occurrence of scratches can be reduced. On the other hand, by making the content ratio of the P ₂ O ₅ component 40.0% or less, while obtaining the desired high refractive index, it is difficult to reduce the abrasion degree of the glass beyond a predetermined level, thereby improving the processing efficiency of the polishing process. Can be increased. Therefore, the content of the P ₂ O ₅ component with respect to the total glass mass of the oxide conversion composition is preferably 5.0%, more preferably 8.0%, and most preferably 10.0%, and preferably 40%. The upper limit is 0.0%, more preferably 35.0%, still more preferably 33.0%, and most preferably 30.0%. The P ₂ O ₅ component can be contained in the glass using, for example, Al (PO ₃ ) ₃ , Ca (PO ₃ ) ₂ , Ba (PO ₃ ) ₂ , BPO ₄ , H ₃ PO ₄ or the like as a raw material.

Nb ₂ O ₅ component is a component for increasing the refractive index and dispersion of the glass. In particular, the desired high refractive index and high dispersion can be obtained by setting the content of the Nb ₂ O ₅ component to 10.0% or more. On the other hand, when the content of the Nb ₂ O ₅ component is 60.0% or less, the stability of the glass is increased by suppressing the increase in the liquidus temperature of the glass, and thus the devitrification resistance of the glass is increased. be able to. Therefore, the content of the Nb ₂ O ₅ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 20.0%, and most preferably 30.0%, and preferably 60%. The upper limit is 0.0%, more preferably 58.0%, still more preferably 57.0%, still more preferably 56.0%, and most preferably 55.0%. Particularly in the sixth optical glass, the content of the Nb ₂ O ₅ component is preferably 60.0%, more preferably 50.0%, and most preferably 45.0%. The Nb ₂ O ₅ component can be contained in the glass using, for example, Nb ₂ O ₅ as a raw material.

The TiO ₂ component is a component that increases the refractive index and dispersion of the glass, and is a component that increases the chemical durability of the glass, particularly the detergent resistance and acid resistance, and is an optional component in the optical glass of the present invention. . In particular, by setting the content of the TiO ₂ component to 30.0% or less, the stability of the glass is enhanced by suppressing an increase in the liquidus temperature of the glass while obtaining a high refractive index and dispersion. The devitrification resistance of the glass can be increased. Accordingly, the content of the TiO ₂ component with respect to the total glass mass of the oxide conversion composition is preferably 30.0%, more preferably 28.0%, most preferably 25.0%, and most preferably 20.0%. The upper limit. Here, in the first and second optical glasses, by making the content of the TiO ₂ component 12.0% or less, transparency of the glass with respect to visible light is particularly improved while obtaining a high refractive index and dispersion. Can do. In this case, the content of the TiO ₂ component is preferably 12.0%, more preferably 11.0%, and most preferably less than 10.0%. In the third optical glass, by the content of TiO ₂ component to less than 10.0%, while obtaining a high refractive index and dispersion, it is possible to enhance the transparency to visible light of the glass. In this case, the content of the TiO ₂ component is preferably less than 10.0%, more preferably 9.8%, and most preferably 9.5%. In the optical glass of the present invention, the content of the TiO ₂ component may be less than 5.0% in order to obtain a highly transparent glass particularly for visible light. On the other hand, in the fifth optical glass, the dispersion of the glass can be further increased by setting the content of the TiO ₂ component to 10.0% or more. Therefore, when the glass is further highly dispersed, the content of the TiO ₂ component is preferably 10.0%, more preferably 12.0%, still more preferably 13.0%, and most preferably 14%. 0.0% is the lower limit.

Although TiO ₂ component can be obtained an optical glass having desired properties without containing, by containing a TiO ₂ component than 0.1%, the acid resistance of the glass is increased, the glass Discoloration during processing can be reduced. Therefore, in this case, the content of the TiO ₂ component with respect to the total amount of glass in the oxide-converted composition is preferably 0.1%, more preferably 1.0%, and most preferably 2.0%. Here, when aiming at higher acid resistance, the content of the above-mentioned TiO ₂ component is preferably 5.0%, more preferably 11.0%, and most preferably 12.0%. The TiO ₂ component can be contained in the glass using, for example, TiO ₂ as a raw material.

The BaO component is a component that increases the refractive index of glass and is a component that increases devitrification resistance by lowering the liquidus temperature of the glass, and is an optional component in the optical glass of the present invention. Here, by making the content of the BaO component 30.0% or less, it is easy to obtain a desired high refractive index, and while suppressing deterioration in devitrification resistance, chemical durability including acid resistance Can be suppressed. In particular, the increase in the average linear expansion coefficient (α) of the glass can be suppressed by setting the content of the BaO component to 20.0% or less. Therefore, the content of the BaO component with respect to the total glass mass of the oxide conversion composition is preferably 30.0%, more preferably 28.0%, further preferably 25.0%, and most preferably 20.0%. And Of these, in the first and second optical glasses, the content of the BaO component is preferably 20.0%, more preferably 18.0%, and most preferably 15.0%. In the third optical glass, the content of the BaO component is preferably 20.0%, more preferably 19.0%, and most preferably 18.0%.

Here, in terms of obtaining a glass having particularly large dispersion (small Abbe number), the content of the BaO component with respect to the total glass mass of the oxide conversion composition is preferably less than 17.0%, more preferably 13. The upper limit is 0%, and most preferably the upper limit is 4.5%. Of these, in the first and second optical glasses, the content of the BaO component is preferably 13.0% as an upper limit, more preferably less than 10.0%, and most preferably 4.5%. The upper limit. In the third optical glass, the content of the BaO component is preferably less than 17.0%, more preferably less than 15.0%, and most preferably less than 13.0%. In the fifth optical glass, the content of the BaO component is preferably 15.0%, more preferably 13.0%, and most preferably less than 10,000%. In the sixth optical glass, the content of the BaO component is preferably less than 7.0%, more preferably less than 5.0%, and most preferably less than 4,0%.

Although it is possible to obtain an optical glass having a desired high dispersion and high transmittance without containing a BaO component, the liquidus temperature of the glass is lowered by containing more than 0% of the BaO component. Therefore, a glass having high devitrification resistance and easy to produce stably can be obtained. Therefore, when obtaining a glass with high devitrification resistance, the content of the BaO component with respect to the total glass mass of the oxide conversion composition is preferably more than 0%, more preferably 1.0%, most preferably 3. 0.0% is the lower limit. Among these, in the third optical glass, the content of the BaO component is preferably 1.0%, more preferably 3.0%, and most preferably 4.5%. In the fifth optical glass, the content of the BaO component is preferably more than 0%, more preferably 1.0%, and most preferably 2.0%. In the sixth optical glass, the content of the BaO component is preferably 0.1%, more preferably 0.5%, and most preferably 1.0%. On the other hand, by containing more than 7.0% of BaO component, it is possible to increase the detergent resistance of the glass while lowering the liquidus temperature of the glass. Therefore, the content of the BaO component in the case of obtaining a glass having high detergent resistance is preferably 7.0%, more preferably 10.0%, and most preferably 15.0%. The BaO component can be contained in the glass using, for example, BaCO ₃ , Ba (NO ₃ ) ₂ , BaF ₂ or the like as a raw material.

The SiO ₂ component is a component that reduces coloring and increases the transmittance for short-wavelength visible light, and promotes stable glass formation to increase the devitrification resistance of the glass, and is an optional component in the optical glass of the present invention. It is. In particular, by setting the content of the SiO ₂ component to 10.0% or less, a decrease in the refractive index due to the SiO ₂ component can be suppressed, so that a desired high refractive index can be easily obtained. Accordingly, the content of the SiO ₂ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, still more preferably 6.0%, and most preferably 5.0%. The upper limit. Here, the content of the above-mentioned SiO ₂ component is preferably 2.0%, more preferably 1.5%, and most preferably in that it is easy to obtain a glass having a particularly large dispersion (small Abbe number). The upper limit is 1.0%.

Thus, to reduce the content of SiO ₂ component, or even without containing SiO ₂ component, it is possible to obtain an optical glass having a desired high dispersion and high transmittance. On the other hand, particularly in the second optical glass, since the wear level of the glass is increased by containing more than 2.0% of the SiO ₂ component, it is possible to obtain a glass that can be easily molded by polishing. Accordingly, in this case, the content of the SiO ₂ component with respect to the total glass mass of the oxide conversion composition is preferably more than 2.0%, more preferably 3.0%, and most preferably 4.0%. And SiO ₂ component as a raw material such as _{_{_{_{SiO 2, K 2 SiF 6,}}}} Na 2 SiF 6 and the like can contain in the glass by using.

The WO ₃ component is a component that increases the dispersion of the glass while increasing the refractive index of the glass, and is an optional component in the optical glass of the present invention. In particular, by making the content of the WO ₃ component 20.0% or less, the glass transition point (Tg) can be lowered while improving the devitrification resistance of the glass, and the transmittance of the glass with respect to short-wavelength visible light. Can be suppressed. Therefore, the content of the WO ₃ component with respect to the total glass mass of the oxide conversion composition is preferably 20.0%, more preferably 17.0%, still more preferably 15.0%, and most preferably 10.0%. The upper limit. In particular, the content of the WO ₃ component is preferably 10.0% or less from the viewpoint that a glass having a desired high dispersion and a low glass transition point (Tg) can be easily obtained. Therefore, in this case, the content of the above-mentioned WO ₃ component is preferably 10.0%, more preferably 8.0%, still more preferably 7.0%, and most preferably 5.0%. .

Although WO ₃ ingredient is possible to obtain an optical glass having a desired high dispersion and high transmittance even without containing a WO ₃ components that contain more than 0%, the dispersion of the glass is enhanced Therefore, it is possible to easily achieve both high dispersion of glass and transparency to visible light. Accordingly, the content of the WO ₃ component with respect to the total glass mass of the oxide-converted composition in this case is preferably more than 0%, more preferably 1.0%, even more preferably 3.0%, and most preferably 4. 0.0% is the lower limit. The WO ₃ component can be contained in the glass using, for example, WO ₃ as a raw material.

The Li ₂ O component is a component that lowers the melting temperature and glass transition point (Tg) of glass, and is a component that increases devitrification resistance during glass formation, and is an optional component in the optical glass of the present invention. Here, by making the content rate of the Li ₂ O component 20.0% or less, it is possible to easily obtain a desired high refractive index, and the stability of the glass is reduced by lowering the liquidus temperature of the glass. Since it raises, generation | occurrence | production of the devitrification etc. to glass can be reduced. In particular, the increase in the average linear expansion coefficient (α) of the glass can be suppressed by setting the content of the Li ₂ O component to 10.0% or less. Therefore, the content of the Li ₂ O component with respect to the total glass mass of the oxide-converted composition is preferably 20.0%, more preferably 10.0%, and most preferably 5.0%. In particular, in the first and second optical glasses, the content of the above-described Li ₂ O component is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. In the third and fourth optical glasses, the content of the above Li ₂ O component is preferably 20.0%, more preferably 15.0%, and most preferably 10.0%. In the fifth and sixth optical glasses, the content of the Li ₂ O component is preferably 20.0%, more preferably 18.0%, still more preferably 15.0%, and most preferably 10%. 0.0% is the upper limit.

Although Li 2 _O component is possible to obtain an optical glass having a desired high dispersion and high transmittance even without containing the Li 2 _O component that contains more than 0%, the glass transition point ( Since Tg) becomes low, it is possible to obtain a glass that has a high dispersion and is easily softened at a low temperature. Accordingly, the content of the Li ₂ O component with respect to the total glass mass of the oxide-converted composition in this case is preferably more than 0%, more preferably more than 0.3%, and most preferably 0.5%. 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 glass, and is a component that increases devitrification resistance during glass formation, and is an optional component in the optical glass of the present invention. In particular, by setting the content of the Na ₂ O component to 35.0% or less, it is possible to easily obtain a desired high refractive index, and the stability of the glass is enhanced by lowering the liquidus temperature of the glass. Therefore, generation | occurrence | production of devitrification etc. to glass can be reduced. Therefore, the content of the Na ₂ O component with respect to the total glass mass of the oxide conversion composition is preferably 35.0%, more preferably 25.0%, and most preferably 15.0%. In particular, in the first optical glass, the content of Na ₂ O component described above, preferably 15.0% is more preferably 12.0%, most preferably up to 10.0%. In the second optical glass, the content of the Na ₂ O component is preferably 15.0%, more preferably 13.0%, and most preferably 12.0%. In the third and fourth optical glasses, the content of the Na ₂ O component is preferably 35.0%, more preferably 30.0%, further preferably 25.0%, and most preferably 15%. 0.0% is the upper limit. In the fifth and sixth optical glasses, the content of the Na ₂ O component is preferably 35.0%, more preferably 30.0%, still more preferably 25.0%, and most preferably 20. 0.0% is the upper limit.

Incidentally, Na 2 _O but component it is possible to obtain an optical glass having desired properties without containing, by containing a Na 2 _O component 0.1%, the liquidus temperature of the glass is increased Further, the devitrification resistance of the glass can be further increased. Therefore, in this case, the content of the Na ₂ O component with respect to the total amount of glass in the oxide conversion composition is preferably 0.1%, more preferably 0.5%, still more preferably 1.0%, most preferably 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 as a raw material.

The K ₂ O component is a component that lowers the melting temperature and glass transition point (Tg) of the glass, and is a component that increases devitrification resistance during glass formation, and is an optional component in the optical glass of the present invention. In particular, by setting the content of the K ₂ O component to 20.0% or less, it is possible to easily obtain a desired high refractive index, and the stability of the glass is enhanced by lowering the liquidus temperature of the glass. Therefore, generation | occurrence | production of the devitrification etc. to glass can be reduced. Accordingly, the content of the K ₂ O component with respect to the total glass mass of the oxide conversion composition is preferably 20.0%, more preferably 15.0%, and most preferably less than 10.0%. In particular, in the first and second optical glasses, the content of the above K ₂ O component is preferably less than 10.0%, more preferably 8.0%, even more preferably 6.0%, and most preferably. The upper limit is 5.0%. In the third and fourth optical glasses, the content of the K ₂ O component is preferably 20.0%, more preferably 15.0%, still more preferably 12.0%, and most preferably 10%. 0.0% is the upper limit. In the fifth and sixth optical glasses, the K ₂ O component content is preferably 20.0%, more preferably 15.0%, and most preferably 10.0%.

Although K 2 _O component may be obtained an optical glass having desired properties without containing, by containing K 2 _O ingredient 0.1%, the liquidus temperature of the glass is increased Further, the devitrification resistance of the glass can be further increased. Accordingly, in this case, the content of the K ₂ O component with respect to the total amount of glass in the oxide conversion composition is preferably 0.1%, more preferably 0.15%, still more preferably 0.2%, and even more preferably. The lower limit is 0.5%, most preferably 1.0%. The K ₂ O component can be contained in the glass using, for example, K ₂ CO ₃ , KNO ₃ , KF, KHF ₂ , K ₂ SiF ₆ or the like as a raw material.

Here, the optical glass of the sixth preferably contains as essential components at least one of Li ₂ O component, Na ₂ O component, and _{K 2} O component. Thereby, since the glass transition point (Tg) of optical glass becomes low, the shaping | molding temperature in press molding can be lowered | hung, and the unevenness | corrugation and cloudiness of the surface after performing press molding can be reduced further. Moreover, since the devitrification resistance of the optical glass is enhanced, an optical glass having desired optical characteristics can be more stably produced.

In the optical glass of the present invention, the mass sum of the contents of the Rn ₂ O component (wherein Rn is one or more selected from the group consisting of Li, Na, and K) is 35.0% or less. preferable. Thereby, since the fall of the refractive index of glass is suppressed, it can make it easy to obtain a desired high refractive index. Moreover, since stability of glass is improved because the liquidus temperature of glass becomes low, devitrification resistance of glass can be improved. Therefore, the mass sum of the content ratio of the Rn ₂ O component with respect to the total glass mass of the oxide conversion composition is preferably 35.0%, more preferably 25.0%, and most preferably 15.0%. In particular, in the first and second optical glasses, the above-mentioned mass sum is preferably 15.0%, more preferably 13.0%, and most preferably 12.0%. Of these, in the third optical glass, the upper limit of this mass sum is preferably 35.0%, more preferably 32.0%, and most preferably 30.0%. In the fourth optical glass, the upper limit of this mass sum is preferably 35.0%, more preferably 25.0%, and most preferably 20.0%. In the fifth and sixth optical glasses, this mass sum is preferably 35.0%, more preferably 30.0%, and most preferably 25.0%.

An optical glass having desired characteristics can be obtained without containing any Rn ₂ O component. However, by containing at least one of the Rn ₂ O components in an amount of 0.1% or more, a glass liquid can be obtained. Since the phase temperature is increased, the devitrification resistance of the glass can be further increased. Therefore, in this case, the mass sum of the content ratio of the Rn ₂ O component with respect to the total amount of glass in the oxide conversion composition is preferably 0.1%, more preferably 1.0%, still more preferably 2.0%, Most preferably, the lower limit is 3.0%.

Further, when the mass sum of the content of the Rn ₂ O component is 5.0% or more, the glass transition point (Tg) can be lowered while achieving high dispersion of the glass, and the water resistance of the glass is increased. And the detergent resistance can be increased. Therefore, the mass sum of the content ratio of the Rn ₂ O component with respect to the total glass mass of the oxide conversion composition is preferably 5.0%, more preferably 8.0%, and most preferably 10.0%. Of these, in the third optical glass, this mass sum is preferably more than 7.0%, more preferably 9.0%, and most preferably 10.0%. In the fourth optical glass, this mass sum is preferably more than 8.0%, more preferably more than 9.0%, and most preferably more than 10.0%. In the fifth optical glass, this mass sum is preferably 5.0%, more preferably 6.0%, and most preferably 7.0%. In the sixth optical glass, this mass sum is preferably 5.0%, more preferably 8.0%, and most preferably 10.0%.

In particular, in the fourth optical glass of the present invention, the BaO component is contained at 15.0% or more by mass% with respect to the total glass mass of the oxide conversion composition, and the Rn ₂ O component is 10.0% in total. It is particularly preferable to contain more. As a result, the detergent resistance of the glass is particularly enhanced, so that the occurrence of fogging on the glass can be reduced even when the glass is in contact with the polishing liquid or cleaning liquid.

In the optical glass of the present invention preferably contains two or more components of the Li ₂ O component, Na ₂ O component, and _{K 2} O component. Thereby, the glass transition point (Tg) of the optical glass is lowered, the molding temperature in press molding is lowered, and surface irregularities and fogging after the press molding can be further reduced. Moreover, since the devitrification resistance of the optical glass is enhanced, an optical glass having desired optical characteristics can be more stably produced.

The MgO component is a component that lowers the liquidus temperature of the glass and increases the devitrification resistance of the glass, and is an optional component in the optical glass of the present invention. In particular, when the content of the MgO component is 5.0% or less, a desired high refractive index and high dispersion can be easily obtained. Therefore, the content of the MgO component with respect to the total glass mass of the oxide-converted composition is preferably 5.0%, more preferably 4.0%, and most preferably 3.0%. The MgO component can be contained in the glass using, for example, MgCO ₃ or MgF ₂ as a raw material.

The CaO component is a component that lowers the liquidus temperature of the glass and increases the devitrification resistance of the glass, and is an optional component in the optical glass of the present invention. In particular, by setting the content of the CaO component to 10.0% or less, it is possible to easily obtain a desired high refractive index and high dispersion, and it is possible to suppress a decrease in devitrification resistance and chemical durability. Therefore, the upper limit of the CaO component content with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, still more preferably 6.0%, and most preferably 5.0%. And The CaO component can be contained in the glass using, for example, CaCO ₃ , CaF ₂ or the like as a raw material.

The SrO component is a component that lowers the liquidus temperature of the glass and increases the devitrification resistance of the glass, and is an optional component in the glass. In particular, by setting the content of the SrO component to 10.0% or less, it is possible to easily obtain a desired high refractive index and high dispersion, and it is possible to suppress a decrease in devitrification resistance and chemical durability. Therefore, the content of the SrO component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The SrO component can be contained in the glass using, for example, Sr (NO ₃ ) ₂ , SrF ₂ or the like as a raw material.

In the optical glass of the present invention, the mass sum of the content ratio of the RO component (wherein R is one or more selected from the group consisting of Mg, Ca, Sr, and Ba) is 30.0% or less. preferable. Thereby, since the fall of the refractive index and dispersion | distribution by RO component is suppressed, it can make it easy to obtain desired high refractive index and high dispersion | distribution. Therefore, the upper limit of the mass sum of the content rate of the RO component with respect to the total glass mass of the oxide conversion composition is preferably 30.0%, more preferably 20.0%, and most preferably 10.0%. In particular, in the first and second optical glasses, this mass sum is preferably 20.0%, more preferably 17.0%, more preferably 15.0%, and most preferably 10.0%. To do. In the third and fourth optical glasses, this mass sum is preferably 30.0%, more preferably 28.0%, still more preferably 27.0%, and most preferably 25.0%. To do. In the fifth and sixth optical glasses, the upper limit of this mass sum is preferably 30.0%, more preferably 25.0%, and most preferably 20.0%.

An optical glass having desired characteristics can be obtained without containing any RO component, but the liquid phase temperature of the glass is increased by containing at least one of the RO components by 0.1% or more. Therefore, the devitrification resistance of the glass can be further increased. Therefore, in this case, the mass sum of the content ratio of the RO component with respect to the total glass substance amount of the oxide conversion composition is preferably 0.1%, more preferably 0.5%, still more preferably 1.0%, and most preferably. Has a lower limit of 3.0%.

The Y ₂ O ₃ component is a component that 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 the Y ₂ O ₃ component 10.0% or less, desired high dispersion can be easily obtained, and the devitrification resistance of the glass can be improved. Therefore, the content of the Y ₂ O ₃ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The Y ₂ O ₃ component can be contained in the glass using, for example, Y ₂ O ₃ , YF ₃ or the like as a raw material.

The La ₂ O ₃ component is a component that 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 the La ₂ O ₃ component 10.0% or less, desired high dispersion can be easily obtained, and the devitrification resistance of the glass can be improved. Therefore, the content of the La ₂ O ₃ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. 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.

The Gd ₂ O ₃ component is a component that 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, when the content of the Gd 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. Therefore, the content of the Gd ₂ O ₃ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The Gd ₂ O ₃ component can be contained in the glass using, for example, Gd ₂ O ₃ , GdF ₃ or the like as a raw material.

In the optical glass of the present invention, the mass sum of the contents of the Ln ₂ O ₃ component (wherein Ln is one or more selected from the group consisting of Y, La, and Gd) is 20.0% or less. Is preferred. By making this mass sum 20.0% or less, an increase in the Abbe number due to the Ln ₂ O ₃ component can be suppressed, so that desired high dispersion can be easily obtained. Therefore, the mass sum of the content ratio of the Ln ₂ O ₃ component with respect to the total glass mass of the oxide conversion composition is preferably 20.0%, more preferably 18.0%, and most preferably 15.0%. .

The B ₂ O ₃ component is a component that promotes formation of a stable glass and increases devitrification resistance, and is an optional component in the optical glass of the present invention. In particular, by setting the content of the B ₂ O ₃ component to 10.0% or less, a decrease in the refractive index due to the B ₂ O ₃ component can be suppressed, so that a desired high refractive index can be easily obtained. Thereby, the increase in the average linear expansion coefficient (α) of the glass can be suppressed. Therefore, the content ratio of the B ₂ O ₃ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, still more preferably 6.0%, and most preferably 5.0. % Is the upper limit. Although B ₂ O ₃ component can be obtained an optical glass having desired properties without containing, by containing B ₂ O ₃ component of 0.1% or more, the liquidus temperature of the glass is increased Therefore, the devitrification resistance of the glass can be further increased. Therefore, in this case, the content of the B ₂ O ₃ component with respect to the total amount of glass in the oxide-converted composition is preferably 0.1%, more preferably 0.2%, still more preferably 0.3%, and most preferably Has a lower limit of 0.5%. The B ₂ O ₃ component can be contained in the glass using, for example, H ₃ BO ₃ , Na ₂ B ₄ O ₇ , Na ₂ B ₄ O ₇ · 10H ₂ O, BPO ₄ or the like as a raw material.

The GeO ₂ component is a component that increases the refractive index of the glass and promotes stable glass formation to increase the devitrification resistance of the glass, and is an optional component in the optical glass of the present invention. In particular, by setting the content of the GeO ₂ component is 10.0% or less, can reduce material costs of the glass. Therefore, the content of the GeO ₂ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The GeO ₂ component can be contained in the glass using, for example, GeO ₂ as a raw material.

Bi ₂ O ₃ component, increasing the refractive index of the glass, or to enhance the dispersion of the glass, an optional component of the optical glass of the present invention. In particular, by making the content of the Bi ₂ O ₃ component 20.0% or less, it is possible to increase the stability of the glass and suppress a decrease in devitrification resistance, and to suppress a decrease in the transmittance of the glass. it can. Therefore, the content of the Bi ₂ O ₃ component with respect to the total glass mass of the oxide-converted composition is preferably 20.0%, more preferably 15.0%, and even more preferably less than 10.0%. Preferably it is less than 5.0%.

The ZrO ₂ component is a component that reduces coloration and increases the transmittance for visible light with a short wavelength, and promotes stable glass formation to increase the devitrification resistance of the glass. The optional component in the optical glass of the present invention It is. In particular, by making the content of the ZrO ₂ component 10.0% or less, a decrease in the refractive index due to the ZrO ₂ component can be suppressed, so that a desired high refractive index can be easily obtained. Therefore, the content of the ZrO ₂ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The ZrO ₂ component can be contained in the glass using, for example, ZrO ₂ , ZrF ₄ or the like as a raw material.

The ZnO component is a component that lowers the liquidus temperature of the glass and increases the devitrification resistance of the glass, and is an optional component in the optical glass of the present invention. In particular, the desired high refractive index and high dispersion can be easily obtained by setting the content of the ZnO component to 10.0% or less. Therefore, the content of the ZnO component with respect to the total glass mass of the oxide-converted composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The ZnO component can be contained in the glass using, for example, ZnO, ZnF ₂ or the like as a raw material.

The Al ₂ O ₃ component is a component that improves the chemical durability of the glass and increases the viscosity when the glass is melted, and is an optional component in the optical glass of the present invention. In particular, by making the content of the Al ₂ O ₃ component 10.0% or less, it is possible to weaken the devitrification tendency of the glass while improving the meltability of the glass. In addition, an increase in the average linear expansion coefficient (α) can be suppressed. Therefore, the content of the Al ₂ O ₃ component with respect to the total glass mass of the oxide-converted composition is preferably 10.0%, more preferably 8.0%, and most preferably 5.0%. The Al ₂ O ₃ component can be contained in the glass using, for example, Al ₂ O ₃ , Al (OH) ₃ , AlF ₃ or the like as a raw material.

Ta ₂ O ₅ component is a component that raises the refractive index of the glass, an optional component of the optical glass of the present invention. In particular, by making the content of the Ta ₂ O ₅ component 10.0% or less, the glass can be made hard to devitrify. Therefore, the content of the Ta ₂ O ₅ component with respect to the total glass mass of the oxide conversion composition is preferably 10.0%, more preferably 8.0%, and most preferably 4.0%. The Ta ₂ O ₅ component can be contained in the glass using, for example, Ta ₂ O ₅ as a raw material.

The Sb ₂ O ₃ component is a component that increases the transmittance of the glass with respect to visible light having a short wavelength and has a defoaming effect when the glass is melted. In particular, by making the content of the Sb ₂ O ₃ component 1.0% or less, it becomes difficult for the Sb ₂ O ₃ component to be alloyed with the melting equipment (especially noble metals such as Pt), and the impurities attached to the mold are reduced. Therefore, the formation of irregularities and cloudiness on the surface of the glass molded body can be reduced. Therefore, the upper limit of the content of the Sb ₂ O ₃ component with respect to the total mass of the oxide is preferably 1.0%, more preferably 0.8%, and most preferably 0.5%. The Sb ₂ O ₃ component can be contained in the glass using, for example, Sb ₂ O ₃ , Sb ₂ O ₅ , Na ₂ H ₂ Sb ₂ O ₇ · 5H ₂ O, or the like as a raw material.

Incidentally, components defoamed fining glass is not limited to the above Sb ₂ O ₃ component, a known refining agents in the field of glass production, it is possible to use a defoamer or a combination thereof.

<About ingredients that should not be included>
Next, components that should not be contained in the optical glass of the present invention and components that are not preferably contained will be described.

Other components can be added to the optical glass of the present invention as necessary within a range not impairing the properties of the glass of the present 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 independent of each other. Or, even when it is contained in a small amount in combination, the glass is colored and has the property of causing absorption at a specific wavelength in the visible range. .

Furthermore, lead compounds such as PbO and components of Th, Cd, Tl, Os, Be, and Se tend to refrain from being used as harmful chemical substances in recent years. In addition, measures for environmental measures are required until disposal after commercialization. Therefore, when importance is placed on the environmental impact, it is preferable not to substantially contain them except for inevitable mixing. As a result, the optical glass is substantially free of substances that pollute the environment. Therefore, the optical glass can be manufactured, processed, and discarded without taking special environmental measures.

The glass composition of the present invention cannot be expressed directly in the description of mol% because the composition is expressed by mass% with respect to the total mass of the glass of oxide conversion composition, but various properties required in the present invention. The composition expressed by mol% of each component present in the glass composition satisfying the above conditions generally takes the following values in terms of oxide conversion.
P ₂ O ₅ component 5.0-40.0 mol% and Nb ₂ O ₅ component 5.0-30.0 mol%,
And TiO ₂ component 0 to 40.0 mol% and / or BaO component 0 to 30.0 mol% and / or Li ₂ O component 0 to 50.0 mol% and / or Na ₂ O component 0 to 50.0 mol% and / or K ₂ O component 0-30.0 mol% and / or WO ₃ component 0-15.0 mol% and / or MgO component 0-20.0 mol% and / or CaO component 0-25.0 mol% and / or SrO component 0 ˜15.0 mol% and / or Y ₂ O ₃ component 0 to 4.0 mol% and / or La ₂ O ₃ component 0 to 3.0 mol% and / or Gd ₂ O ₃ component 0 to 3.0 mol% and / or B ₂ O ₃ component 0 ~ 20.0 mol% and / or SiO ₂ component 0 ~ 20.0 mol% and / or GeO ₂ component 0 ~ 15.0 mol% and / or _Bi 2 _{O 3} component 0 4.0 mol% and / or ZrO ₂ component 0 ~ 13.0 mol% and / or ZnO component 0 ~ 20.0 mol% and / or _Al 2 _{O 3} component 0 ~ 15.0 mol% and / or _Ta 2 _{O 5} component 0 To 3.0 mol% and / or Sb ₂ O ₃ component 0 to 0.3 mol%

Among these, in the 1st and 2nd optical glass, the composition by mol% display of each component takes the following values in an oxide conversion composition in general.
P ₂ O ₅ component 5.0-40.0 mol% and Nb ₂ O ₅ component 5.0-30.0 mol%,
And TiO ₂ component 0-40.0 mol% and / or BaO component 0-20.0 mol% and / or SiO ₂ component 0-20.0 mol% and / or Li ₂ O component 0-30.0 mol% and / or Na ₂ O component 0 to 30.0 mol% and / or K ₂ O component 0 to 15.0 mol% and / or MgO component 0 to 20.0 mol% and / or CaO component 0 to 25.0 mol% and / or SrO component 0 ˜15.0 mol% and / or Y ₂ O ₃ component 0 to 4.0 mol% and / or La ₂ O ₃ component 0 to 3.0 mol% and / or Gd ₂ O ₃ component 0 to 3.0 mol% and / or B ₂ O ₃ component 0 ~ 20.0 mol% and / or GeO ₂ component 0 ~ 15.0 mol% and / or _Bi 2 _{O 3} component 0 ~ 4.0 mol% and / or ZrO ₂ component 0 13.0 mol% and / or ZnO component 0 ~ 20.0 mol% and / or _Al 2 _{O 3} component 0 ~ 15.0 mol% and / or _Ta 2 _{O 5} component 0 ~ 3.0 mol% and / or WO ₃ ingredient 0 To 15.0 mol% and / or Sb ₂ O ₃ component 0 to 0.3 mol%

In the third optical glass, the composition expressed by mol% of each component generally takes the following values in terms of oxide composition.
P ₂ O ₅ component 5.0-40.0 mol% and Nb ₂ O ₅ component 5.0-30.0 mol%,
And TiO ₂ component 0 to 15.0 mol% and / or BaO component 0 to 30.0 mol% and / or Li ₂ O component 0 to 50.0 mol% and / or Na ₂ O component 0 to 50.0 mol% and / or K ₂ O component 0-30.0 mol% and / or WO ₃ component 0-15.0 mol% and / or MgO component 0-20.0 mol% and / or CaO component 0-25.0 mol% and / or SrO component 0 ˜15.0 mol% and / or Y ₂ O ₃ component 0 to 4.0 mol% and / or La ₂ O ₃ component 0 to 3.0 mol% and / or Gd ₂ O ₃ component 0 to 3.0 mol% and / or B ₂ O ₃ component 0 ~ 20.0 mol% and / or SiO ₂ component 0 ~ 20.0 mol% and / or GeO ₂ component 0 ~ 15.0 mol% and / or _Bi 2 _{O 3} component 0 4.0 mol% and / or ZrO ₂ component 0 ~ 13.0 mol% and / or ZnO component 0 ~ 20.0 mol% and / or _Al 2 _{O 3} component 0 ~ 15.0 mol% and / or _Ta 2 _{O 5} component 0 To 3.0 mol% and / or Sb ₂ O ₃ component 0 to 0.3 mol%

Moreover, in the 4th optical glass, the composition by mol% display of each component takes the following values in an oxide conversion composition in general.
P ₂ O ₅ component 5.0-40.0 mol%,
Nb ₂ O ₅ component 5.0 to 30.0 mol%, and BaO component 7.0 to 30.0 mol% / or Li ₂ O component 0 to 50.0 mol% and / or Na ₂ O component 0 to 50.0 mol % And / or K ₂ O component 0-30.0 mol% and / or MgO component 0-20.0 mol% and / or CaO component 0-25.0 mol% and / or SrO component 0-15.0 mol% and / or Y ₂ O ₃ component 0 to 4.0 mol% and / or La ₂ O ₃ component 0 to 3.0 mol% and / or Gd ₂ O ₃ component 0 to 3.0 mol% and / or B ₂ O ₃ component 0 to 20 0.0 mol% and / or SiO ₂ component 0 to 20.0 mol% and / or GeO ₂ component 0 to 15.0 mol% and / or Bi ₂ O ₃ component 0 to 4.0 mol% and / or ZrO ₂ component 0 to 13.0 mol% and / or ZnO component 0 to 20.0 mol% and / or Al ₂ O ₃ component 0 to 15.0 mol% and / or TiO ₂ component 0 to 40.0 mol% and / or Ta ₂ O ₅ Component 0 to 3.0 mol% and / or WO ₃ component 0 to 15.0 mol% and / or Sb ₂ O ₃ component 0 to 0.3 mol%

In the fifth optical glass, the composition expressed by mol% of each component generally takes the following values in terms of oxide equivalent composition.
P ₂ O ₅ component 5.0-40.0 mol%,
Nb ₂ O ₅ component 5.0 to 30.0 mol%, and TiO ₂ component 13.0 to 40.0 mol%
And WO ₃ component 0 to 15.0 mol% and / or BaO component 0 to 30.0 mol% and / or Li ₂ O component 0 to 50.0 mol% and / or Na ₂ O component 0 to 50.0 mol% and / or K ₂ O component 0-30.0 mol% and / or MgO component 0-20.0 mol% and / or CaO component 0-25.0 mol% and / or SrO component 0-15.0 mol% and / or Y ₂ O ₃ Component 0 to 4.0 mol% and / or La ₂ O ₃ component 0 to 3.0 mol% and / or Gd ₂ O ₃ component 0 to 3.0 mol% and / or B ₂ O ₃ component 0 to 20.0 mol% and / or SiO ₂ component 0 to 20.0 mol% and / or GeO ₂ component 0 to 15.0 mol% and / or _Bi 2 _{O 3} component 0 to 4.0 mol% and / or ZrO ₂ component 0 ~ 3.0 mol% and / or ZnO component 0 ~ 20.0 mol% and / or _Al 2 _{O 3} component 0 ~ 15.0 mol% and / or _Ta 2 _{O 5} component 0 ~ 3.0 mol% and / or _Sb 2 _{O 3} Ingredient 0 ~ 0.3mol%

In the sixth optical glass, the composition expressed by mol% of each component generally takes the following values in terms of oxide.
P ₂ O ₅ component 5.0-40.0 mol% and Nb ₂ O ₅ component 5.0-30.0 mol%,
And Li ₂ O component 0 to 50.0 mol% and / or Na ₂ O component 0 to 50.0 mol% and / or K ₂ O component 0 to 30.0 mol% and / or BaO component 0 to 20.0 mol% and / or Or WO ₃ component 0 to 15.0 mol% and / or MgO component 0 to 20.0 mol% and / or CaO component 0 to 25.0 mol% and / or SrO component 0 to 15.0 mol% and / or Y ₂ O ₃ Component 0 to 4.0 mol% and / or La ₂ O ₃ component 0 to 3.0 mol% and / or Gd ₂ O ₃ component 0 to 3.0 mol% and / or B ₂ O ₃ component 0 to 20.0 mol% and / or SiO ₂ component 0 ~ 20.0 mol% and / or GeO ₂ component 0 ~ 15.0 mol% and / or TiO ₂ component 0 ~ 40.0mol% and / or _Bi 2 _{O 3} component 0 4.0 mol% and / or ZrO ₂ component 0 ~ 13.0 mol% and / or ZnO component 0 ~ 20.0 mol% and / or _Al 2 _{O 3} component 0 ~ 15.0 mol% and / or _Ta 2 _{O 5} component 0 To 3.0 mol% and / or Sb ₂ O ₃ component 0 to 0.3 mol%

[Production method]
The optical glass of the present invention is produced, for example, as follows. That is, the above raw materials are uniformly mixed so that each component is within a predetermined content range, and the prepared mixture is put into a quartz crucible or an alumina crucible and roughly melted, and then a platinum crucible, a platinum alloy crucible or iridium Put in a crucible and melt in the temperature range of 1000 to 1300 ° C for 2 to 10 hours, stir and homogenize to eliminate bubbles, etc., then lower the temperature to 1250 ° C or less and then stir to finish to remove striae It is produced by casting into a mold and slow cooling.

[Physical properties]
The optical glass of the present invention needs to have a high refractive index (n _d ) and a high dispersion. 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, and preferably 2.90. 20, more preferably 2.15, and most preferably 2.10. In addition, the upper limit of the Abbe number (ν _d ) of the optical glass of the present invention is preferably 25, more preferably 22, more preferably 20, and most preferably 19. As a result, the degree of freedom in optical design is increased, and a large amount of light refraction can be obtained even if the device is made thinner. The lower limit of the Abbe number (ν _d ) of the optical glass of the present invention is not particularly limited, but the Abbe number (ν _d ) of the glass obtained by the present invention is generally 10 or more, specifically 12 or more, more specifically. In many cases, it is 15 or more.

Moreover, it is preferable that the optical glass of this invention has little coloring. In particular, when the optical glass of the present invention is represented by the transmittance of the glass, the wavelength (λ ₇₀ ) showing 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, and still more preferably. Is 460 nm or less, most preferably 450 nm or less. Thereby, the absorption edge of the glass is positioned in the vicinity of the ultraviolet region, and the transparency of the glass in the visible region is enhanced. Therefore, this optical glass can be used as a material for an optical element such as a lens.

In particular, the first optical glass of the present invention preferably has high 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 upper limit of the liquidus temperature of the optical glass of the present invention is preferably 1200 ° C, more preferably 1150 ° C, and most preferably 1100 ° C. As a result, even if the molten glass flows out at a lower temperature, crystallization of the produced glass is reduced, so that the devitrification resistance when the glass is formed from the molten state can be increased. The influence on the optical characteristics of the optical element 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 obtained by the present invention is approximately 500 ° C. or higher, specifically 550 ° C. or higher, more specifically 600. Often above ℃. As used herein, “liquid phase temperature” refers to a glass sample pulverized to a particle size of about 2 mm on a platinum plate and held in a furnace with a temperature gradient from 800 ° C. to 1220 ° C. for 30 minutes. It is the lowest temperature at which no crystal is observed in the glass and devitrification does not occur, which is measured by observing the presence or absence of crystals in the glass with a microscope with a magnification of 80 after cooling.

The first optical glass of the present invention preferably has high acid resistance. In particular, the chemical durability (acid resistance) of the glass powder method according to JOGIS06-1999 is preferably class 1 to 5, more preferably class 1 to 4, and most preferably class 1 to 3. Thereby, when the optical glass is polished, the fogging of the glass due to the acidic polishing liquid or the cleaning liquid is reduced, so that the polishing process can be more easily performed. Here, “acid resistance” refers to durability against erosion of glass by acid, and this acid resistance is measured according to the Japan Optical Glass Industry Association Standard “Measurement Method of Chemical Durability of Optical Glass” JOGIS06-1999. Can do. “The chemical durability (acid resistance) by the powder method is class 1 to 5” means that the chemical durability (acid resistance) performed according to JOGIS06-1999 is the mass of the sample before and after the measurement. It means a weight loss rate of less than 2.20% by mass. In addition, “Class 1” of chemical durability (acid resistance) has a weight loss rate of the sample before and after the measurement of less than 0.20% by mass, and “Class 2” indicates the weight loss of the sample before and after the measurement. The rate is 0.20% by mass or more and less than 0.35% by mass, and “Class 3” indicates that the weight reduction rate of the sample before and after the measurement is 0.35% by mass or more and less than 0.65% by mass. “4” indicates that the weight loss rate of the sample before and after the measurement is 0.65 mass% or more and less than 1.20 mass%, and “Class 5” indicates that the weight loss rate of the sample before and after the measurement is 1.20 mass%. The amount is less than 2.20% by mass, and “Class 6” has a mass reduction rate of the sample before and after the measurement of 2.20% by mass or more.

On the other hand, the second optical glass of the present invention has a predetermined degree of wear. In particular, the abrasion degree in the measuring method according to “JOGIS10-1994 Optical Glass Abrasion Measuring Method” of optical glass is preferably 100, more preferably 150, most preferably 200 as the lower limit, preferably 400, more The upper limit is preferably 350, and most preferably 300. By setting the degree of wear 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, by setting the degree of wear to 400 or less, unnecessary wear and scratches of the optical glass are reduced, so that the optical glass can be easily handled in the polishing process, and the polishing process can be easily performed.

Moreover, it is preferable that the 2nd optical glass of this invention has a small average coefficient of linear expansion ((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, and most preferably 100 × 10 ⁻⁷ K ⁻¹ or less. It is preferable to have a temperature. Thereby, when press molding optical glass using a metal mold | die, the expansion | swelling and shrinkage | contraction by the temperature change of the lens or preform after shaping | molding are reduced. Therefore, in particular, when cooling is performed after molding, it is possible to reduce depressions (sinks) and cracks that occur when a temperature gradient is generated from the inside of the lens to the outside.

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. Thereby, since glass softens at lower temperature, glass can be press-molded at lower temperature. In addition, it is possible to extend the life of the mold by reducing oxidation of the mold used for precision press molding. Therefore, the upper limit of the glass transition point (Tg) of the optical glass of the present invention is preferably 700 ° C., more preferably 680 ° C., 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 obtained by the present invention is generally 100 ° C. or higher, specifically 150 ° C. or higher. More specifically, it is often 200 ° C. or higher.

On the other hand, the fourth optical glass of the present invention preferably has high detergent resistance. In particular, the detergent resistance (PR) carried out in accordance with 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. Thereby, when the optical glass is cleaned after polishing, the fogging of the glass due to the aqueous cleaning liquid is reduced, so that the optical glass can be more easily cleaned. Here, “detergent resistance” means that when a lens preform material is washed before molding, or when a molded lens is washed, it is exposed to chemicals used for washing for a certain period of time. Indicates the superiority or inferiority of the discoloration. This detergent resistance can be measured by the ISO test method detergent resistance (ISO 9689: 1990 (E)). Further, “detergent resistance (PR) is grade 1 to 3” means that the detergent resistance (PR) determined according to the ISO test method detergent resistance (ISO9689: 1990 (E)) is 0.00. It means that the time required to erode the 1 μm glass layer is longer than 15 minutes.

[Preforms and optical elements]
The optical glass of the present invention is useful for various optical elements and optical designs. Among them, in particular, a lens, a prism, a mirror, and the like using a means for press molding (such as precision press molding) from the optical glass of the present invention. It is preferable to prepare the optical element. As a result, when used in optical devices that transmit visible light to optical elements such as cameras and projectors, the optical system in these optical devices can be miniaturized while realizing high-definition and high-precision imaging characteristics. Can be planned. Here, in order to produce an optical element made of the optical glass of the present invention, it is possible to omit cutting and polishing, so that glass in a molten state is dropped from an outlet of an outflow pipe of platinum or the like to form a spherical shape. It is preferable to prepare a precision press-molding preform such as, and perform precision press-molding on the precision press-molding preform.

Wavelength at which the composition, refractive index (n _d ), Abbe 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%. Table 1 shows (λ ₇₀ ), liquid phase temperature, and chemical durability (acid resistance) by the powder method. In addition, the composition, refractive index (n _d ), Abbe 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%. Table 2 shows the wavelength (λ ₇₀ ), the degree of wear, and the average linear expansion coefficient. Further, the composition, refractive index (n _d ), Abbe 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%. Table 3 shows the wavelength (λ ₇₀ ) and the glass transition point (Tg). Further, the composition, refractive index (n _d ), Abbe number (ν _d ), and spectral transmittance of the glass of Examples (No. D1 to No. D5) and Comparative Example (No. D1) of the present invention are 70%. Table 4 shows the wavelength (λ ₇₀ ) shown and the detergent resistance (PR) by the ISO test method. Wavelength at which the composition, refractive index (n _d ), Abbe 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%. Tables 5 to 7 show (λ ₇₀ ) and glass transition point (Tg). Further, the composition, refractive index (n _d ), Abbe number (ν _d ), and spectral transmittance of the glass of Examples (No. F1 to No. F5) and Comparative Example (No. F1) of the present invention are 70%. Table 8 shows the wavelength (λ ₇₀ ) and the glass transition point (Tg). The following examples are merely for illustrative purposes, and are not limited to these examples.

Examples of the present invention (No. A1 to No. A7, No. B1 to No. B5, No. C1 to No. C5, No. D1 to No. D5, No. E1 to No. E14, No. F1 to No. F5) optical glass and comparative examples (No. A1, No. B1, No. C1, No. D1, No. E1, No. F1) are all oxidized corresponding to the raw materials of the respective components. Selected from high-purity raw materials used in ordinary optical glass such as oxides, hydroxides, carbonates, nitrates, fluorides, hydroxides, metaphosphate compounds, etc. After weighing and mixing uniformly so as to have the composition ratio of the comparative example, it is put into a platinum crucible and melted in an electric furnace at a temperature range of 1000 to 1300 ° C. for 2 to 10 hours depending on the difficulty of melting the glass composition. 1250 ° C after stirring and homogenizing to remove bubbles Cast into a mold and stirring homogenized by lowering the temperature down to prepare a glass was gradually cooled.

Here, the refractive index (n _d ) and the Abbe number (ν _d ) of the optical glass of the example and the glass of the comparative example were measured based on Japan Optical Glass Industry Association Standard JOGIS01-2003. The glass used in this measurement was annealed under a slow cooling furnace at a slow cooling rate of −25 ° C./hr.

Moreover, the transmittance | permeability of the optical glass of an Example and the glass of a comparative example was measured according to Japan Optical Glass Industry Association standard JOGIS02. In the present invention, the presence / absence and degree of coloration of the glass were determined by measuring the transmittance of the glass. Specifically, a face parallel polished product having a thickness of 10 ± 0.1 mm was measured for a spectral transmittance of 200 to 800 nm in accordance with JISZ8722, and λ ₇₀ (wavelength when the transmittance was 70%) was obtained.

Among these, the liquid phase temperature of the optical glass of Example (No. A1 to No. A7) and the glass of Comparative Example (No. A1), which corresponds to the first optical glass, was measured at intervals of 10 mm. Place it on a platinum plate, hold it in a furnace with a temperature gradient of 800 ° C to 1200 ° C for 30 minutes, take it out, and after cooling, observe the presence or absence of crystals in the glass sample with a microscope with a magnification of 80 times. Measured with At this time, the optical glass as a sample was pulverized into particles having a diameter of about 2 mm.

In addition, the acid resistance of the optical glass of the examples (No. A1 to No. A7) and the glass of the comparative example (No. A1) was determined by the Japan Optical Glass Industry Standard “Method for Measuring Chemical Durability of Optical Glass” JOGIS06. -Measured according to 1999. That is, a glass sample crushed to a particle size of 425 to 600 μm was placed in a specific gravity bottle and placed in a platinum basket. The platinum basket was placed in a quartz glass round bottom flask containing a 0.01N nitric acid aqueous solution and treated in a boiling water bath for 60 minutes. Calculate the weight loss rate (mass%) of the treated glass sample, class 1 if this weight loss rate (mass%) is less than 0.20, class if the weight loss rate is less than 0.20 to 0.35 2. When the weight loss rate is 0.35 to less than 0.65, class 3, when the weight loss rate is less than 0.65 to 1.20, class 4, and when the weight loss rate is less than 1.20 to 2.20 Class 5 and the weight loss rate of 2.20 or higher were classified as Class 6. At this time, it means that the acid resistance of glass is excellent, so that the number of classes is small.

On the other hand, the degree of wear of the optical glass of the examples (No. B1 to No. B5) and the glass of the comparative example (No. B1), which corresponds to the second optical glass, is “the degree of wear of the JOGIS 10-1994 optical glass”. Measured according to “Measurement method”. That is, a sample of a glass square plate having a size of 30 × 30 × 10 mm is placed on a fixed position of 80 mm from the center of a flat plate made of cast iron (250 mmφ) horizontally rotating 60 times per minute, and a load of 9.8 N (1 kgf) is applied. While applying vertically, a polishing solution obtained by adding 10 g of lapping material (alumina A abrasive grains) of # 800 (average particle size 20 μm) to 20 mL of water is uniformly fed for 5 minutes to cause friction, and the sample mass before and after the lapping is measured. Then, the wear mass was obtained. Similarly, the wear mass of the standard sample specified by the Japan Optical Glass Industry Association is obtained,
Abrasion degree = {(wear mass / specific gravity of sample) / (wear mass / specific gravity of standard sample)} × 100
Calculated by

In addition, the average linear expansion coefficient (α) of the optical glass of the examples (No. B1 to No. B5) and the glass of the comparative example (No. B1) was determined by the Japan Optical Glass Industry Association Standard JOGIS08-2003 “Heat of optical glass”. According to “Method of measuring expansion”, an average linear expansion coefficient at −30 to + 70 ° C. was determined.

On the other hand, optical glasses of Examples (No. C1 to No. C5, No. E1 to No. E14, No. F1 to No. F5) corresponding to the third, fifth and sixth optical glasses and comparative examples The glass transition point (Tg) of the glass of (No. C1, No. E1, No. F1) was obtained by performing measurement using a horizontal expansion measuring instrument. Here, the sample used for the measurement was φ4.5 mm and a length of 5 mm, and the heating rate was 4 ° C./min.

On the other hand, the detergent resistance (PR) of the optical glasses of the examples (No. D1 to No. D5) and the glasses of the comparative examples (No. D1) corresponding to the fourth optical glass is the ISO test method detergent resistance. (ISO 9689: 1990 (E)). That is, a 30 mm × 30 mm × 2 mm glass sample having 6 surfaces polished as a test piece was suspended using a platinum wire in a purified sodium tripolyphosphate aqueous solution having a concentration of 0.01 mol / L heated to 50 ° C. Immersion treatment was performed for a given time (15 minutes, 1 hour, 4 hours, 16 hours). After the immersion treatment, the weight loss of the sample was weighed, and the time required to erode a 0.1 μm thick glass layer was calculated by the following formula. However, this calculation used the value obtained by the minimum test time in which the mass reduction per sample was 1 mg or more. And when the time required to erode the 0.1 μm glass layer is longer than 240 minutes, it is class 1, when it is longer than 60 minutes and 240 minutes or less, it is class 2, and when it is 15 minutes or more and 60 minutes or less The case of less than 3 and 15 minutes was set to grade 4. At this time, the smaller the class number, the better the detergent resistance of the glass.
t0.1 = te · d · S / ((m1-m2) · 100)
t0.1: Time (minutes) required to erode the 0.1 μm glass layer
te: Processing time (minutes)
d: Specific gravity S: Surface area of the sample (cm2)
m1-m2: Sample mass loss (mg)

As shown in Table 1, the optical glasses of the examples of the present invention all have a liquidus temperature of 1200 ° C. or lower, more specifically less than 1120 ° C., and the liquidus temperature is 500 ° C. or higher. It was. On the other hand, the glass of the comparative example (No. A1) had a liquidus temperature of 1120 ° C. For this reason, it became clear that the optical glass of Examples (No. A1 to No. A7) of the present invention has a lower liquidus temperature and is less devitrified than the glass of Comparative Example (No. A1).

Further, as shown in Table 2, the optical glasses of Examples (No. B1 to No. B5) of the present invention all have a wear degree of 400 or less, more specifically less than 300. The degree was 100 or more, more specifically 200 or more. On the other hand, the glass of the comparative example (No. B1) had an abrasion degree of 300. For this reason, it has been clarified that the optical glass of the examples (No. B1 to No. B5) of the present invention has a lower degree of wear than the glass of the comparative example (No. B1).

Further, as shown in Table 3 and Tables 5 to 8, optical glass of Examples (No. C1 to No. C5, No. E1 to No. E14, No. F1 to No. F5) of the present invention. Each had a glass transition point (Tg) of 700 ° C. or lower, more specifically 670 ° C. or lower.

In particular, all of the optical glasses of Examples (No. C1 to No. C5, No. F1 to No. F5) of the present invention had a glass transition point (Tg) of 650 ° C. or lower. On the other hand, the glass of the comparative example (No. C1, No. F1) had a glass transition point (Tg) higher than 650 ° C. For this reason, the optical glass of the examples (No. C1 to No. C5, No. F1 to No. F5) of the present invention has a lower glass transition point than the glass of the comparative examples (No. C1, No. F1). It has become clear that it has a (Tg) and is easily softened at a low heating temperature.

Further, as shown in Table 4, the optical glasses of the examples (No. D1 to No. D5) of the present invention all have a detergent resistance (PR) according to the ISO test method of grades 1 to 3, more details. Was grade 1. On the other hand, the glass of the comparative example (No. D1) had a class 3 detergent resistance (PR) according to the ISO test method. For this reason, it was clarified that the optical glass of Examples (No. D1 to No. D5) of the present invention is superior in detergent resistance as compared with the glass of Comparative Example (No. D1).

In addition, in each of the optical glasses of the examples of the present invention, λ ₇₀ (wavelength at 70% transmittance) was 500 nm or less, more specifically, 492 nm or less, and was in a desired range.

In particular, the optical glasses of Examples (No. A1 to No. A7) of the present invention all had λ ₇₀ of 450 nm or less. On the other hand, in the glass of the comparative example (No. A1), λ ₇₀ was larger than 450 nm. For this reason, it became clear that the optical glass of the examples (No. A1 to No. A7) of the present invention is less colored than the glass of the comparative example (No. A1).

The optical glasses of Examples (No. B1 to No. B5) of the present invention all had a λ ₇₀ (wavelength at 70% transmittance) of 480 nm or less. On the other hand, in the glass of the comparative example (No. B1), λ ₇₀ was larger than 480 nm. For this reason, it became clear that the optical glass of the examples (No. B1 to No. B5) of the present invention is less likely to be colored than the glass of the comparative example (No. B1).

Further, the optical glasses of the examples of the present invention (No. C1 to No. C5, No. D1 to No. D5) all had a λ ₇₀ (wavelength at a transmittance of 70%) of 450 nm or less. On the other hand, the glass of the comparative example (No. D1) had a λ ₇₀ of 500 nm. For this reason, it became clear that the optical glass of the examples (No. D1 to No. D5) of the present invention is less colored than the glass of the comparative example (No. D1).

The optical glasses of Examples (No. F1 to No. F5) all had a λ ₇₀ (wavelength at 70% transmittance) of 470 nm or less. On the other hand, in the glass of the comparative example (No. F1), λ ₇₀ was larger than 470 nm. For this reason, it became clear that the optical glass of Examples (No. F1 to No. F5) of the present invention is less likely to be colored than the glass of Comparative Example (No. F1).

The optical glasses of the examples of the present invention all have a refractive index (n _d ) of 1.70 or more, more specifically 1.80 or more, and this refractive index (n _d ) of 2.20 or less. More specifically, it was 2.10 or less, and was within the desired range. In particular, the optical glass of Examples (No. C1 to No. C5) had a refractive index (n _d ) of 1.86 or more. Further, the optical glasses of the examples (No. D1 to No. D5) had a refractive index (n _d ) of 1.84 or more. In addition, the optical glasses of the examples (No. E1 to No. E14) had a refractive index (n _d ) of 1.90 or more. In addition, the optical glasses of the examples (No. F1 to No. F5) had a refractive index (n _d ) of 1.92 or more. On the other hand, the optical of Examples (No. B1 to No. B5, No. C1 to No. C5, No. D1 to No. D5, No. E1 to No. E14, No. F1 to No. F5) of the present invention. All the glasses had a refractive index (n _d ) of 2.00 or less.

The optical glasses of the examples of the present invention all have an Abbe number (ν _d ) of 10 or more, more specifically 15 or more, and this Abbe number (ν _d ) is 25 or less, and a desired range. It was in. In particular, the optical glasses of Examples (No. B1 to No. B5) of the present invention all had an Abbe number (ν _d ) of 17 or more. On the other hand, all of the optical glasses of Examples (No. B1 to No. B5, No. D1 to No. D5) of the present invention had an Abbe number (ν _d ) of 23 or less. Further, the optical glass of Examples (No. C1 to No. C5) had an Abbe number (ν _d ) of 24 or less.

In particular, the optical glass of Examples (No. E1 to No. E14, No. F1 to No. F5) had an Abbe number (ν _d ) of 20 or less. On the other hand, the glass of the comparative examples (No. E1, No. F1) had an Abbe number (ν _d ) greater than 20. For this reason, the optical glasses of the examples (No. E1 to No. E14, No. F1 to No. F5) of the present invention are highly dispersed compared to the glasses of the comparative examples (No. E1, No. F1). The Abbe number (ν _d ) was found to be low.

In addition, the optical glasses of Examples (No. A1 to No. A7) of the present invention all have chemical durability (acid resistance) by the powder method of class 1 to 5, more specifically, class 1 to 2. It was. On the other hand, the glass of the comparative example (No. A1) had class 4 chemical durability (acid resistance) by the powder method. For this reason, it was revealed that the optical glasses of the examples (No. A1 to No. A7) of the present invention are superior in acid resistance compared to the glass of the comparative example (No. A1).

Further, the optical glasses of Examples (No. B1 to No. B5) of the present invention all have an average linear expansion coefficient (α) of 150 × 10 ⁻⁷ K ⁻¹ or less, more specifically 100 × 10 ^−7. K- ¹ or less. On the other hand, the glass of the comparative example (No. B1) had an average linear expansion coefficient (α) larger than 100 × 10 ⁻⁷ K ⁻¹ or less. For this reason, it has been clarified that the optical glass of Examples (No. B1 to No. B5) of the present invention has a smaller average linear expansion coefficient (α) than the glass of Comparative Example (No. B1).

Further, the optical glass of Examples (No. A1 to No. A7) of the present invention is cut and polished to form a preform, and this preform is put into a mold and heated and softened to perform press molding, When the obtained molded body was polished, the optical glass could be stably processed into various lens shapes.

Also, the optical glass of Examples (No. B1 to No. B5) of the present invention is put into a mold, press molding is performed while the optical glass is heated and softened, and the obtained molded body is polished. As a result, it was possible to stably process the optical glass into various lens shapes.

In addition, a precision press molding preform was formed using the optical glass of the examples of the present invention (No. C1 to No. C5, No. E1 to No. E14, No. F1 to No. F5). When the preform for molding was precision press-molded, it could be stably processed into various lens shapes.

Further, the optical glass of Examples (No. D1 to No. D5) of the present invention was cut and polished to form a preform, and this preform was put into a mold and heated and softened to perform press molding, When the obtained molded product was polished and the glass after polishing was washed, the optical glass could be stably processed into various lens shapes.

Therefore, the optical glass of the embodiment of the present invention has high dispersion (low Abbe number ν _d ) while its refractive index (n _d ) is within a desired range, and is transparent to light having a wavelength in the visible region. It became clear that the nature was high.

In particular, the optical glass of Examples (No. A1 to No. A7) of the present invention has high devitrification resistance when forming glass, and it is difficult for the glass to be fogged when an abrasive ball is produced from the glass. Became clear.

Also, it has been clarified that the optical glass of Examples (No. B1 to No. B5) of the present invention is easily polished and hardly expands or contracts even when the glass changes in temperature.

Also, it was revealed that the optical glasses of the examples of the present invention (No. C1 to No. C5, No. E1 to No. E14, No. F1 to No. F5) are easily softened at a low temperature.

In addition, it has been clarified that the optical glass of Examples (No. D1 to No. D5) of the present invention can be easily cleaned in the production of preform materials and optical elements.

Although the present invention has been described in detail for the purpose of illustration, this embodiment is only for the purpose of illustration, and many modifications can be made by those skilled in the art without departing from the spirit and scope of the present invention. Will be understood.

Claims

The entire mass of the glass in terms of oxide composition, P 2 O 5 ingredient 40.0% 5.0% or more of the following in weight%, containing Nb 2 O 5 ingredient 10.0% or more 60.0% or less Optical glass.
The optical glass according to claim 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.
The optical glass according to claim 1, which has a degree of wear of 100 to 400.
The optical glass according to claim 1, which has a detergent resistance (PR) of 1 to 3 according to ISO test method.
Li 2 O component, Na 2 O component contains as essential components at least one of K 2 O component, the optical glass of claim 1 having a 700 ° C. or less of the glass transition point (Tg).
The optical glass according to any one of claims 1 to 5, wherein the content of the TiO 2 component is 30.0% or less in terms of% by mass relative to the total mass of the glass having an oxide equivalent composition.
2. The optical glass according to claim 1, wherein the content of the TiO 2 component is less than 10.0% by mass% and has a glass transition point (Tg) of 700 ° C. or less with respect to the total mass of the glass having an oxide equivalent composition.
The optical component according to claim 1, wherein the TiO 2 component is contained at 10.0% to 30.0% by mass% and has a glass transition point (Tg) of 700 ° C. or less with respect to the total glass mass of the oxide equivalent composition. Glass.
WO 3 component 0 to 20.0% and / or BaO component 0 to 30.0% and / or SiO 2 component 0 to 10.0% by mass% with respect to the total mass of the glass of oxide conversion composition
The optical glass according to claim 1, further comprising:
Li 2 O component 0 to 20.0% and / or Na 2 O component 0 to 35.0% and / or K 2 O component 0 to 20.0% by mass with respect to the total glass mass of oxide conversion composition %
The optical glass according to claim 1, further comprising:
11. The optical glass according to claim 10, wherein the total mass of Li 2 O + Na 2 O + K 2 O with respect to the total mass of the glass in terms of oxide is 35.0% or less.
The optical glass according to claim 10 or 11, comprising two or more components of Li 2 O component, Na 2 O component, and K 2 O component.
MgO component 0 to 5.0% and / or CaO component 0 to 10.0% and / or SrO component 0 to 10.0% by mass% with respect to the total mass of the glass in oxide conversion composition
The optical glass according to claim 1, further comprising:
The optical glass according to claim 13, wherein the mass sum MgO + CaO + SrO + BaO is 30.0% or less with respect to the total glass mass of the oxide equivalent composition.
Y 2 O 3 component 0 to 10.0% and / or La 2 O 3 component 0 to 10.0% and / or Gd 2 O 3 component 0 to 0% by mass with respect to the total glass mass of oxide conversion composition 10.0%
The optical glass according to claim 1, further comprising:
The optical glass according to claim 15, wherein the mass sum Y 2 O 3 + La 2 O 3 + Gd 2 O 3 with respect to the total glass mass of the oxide equivalent composition is 20.0% or less.
B 2 O 3 component 0 to 10.0% and / or GeO 2 component 0 to 10.0% and / or Bi 2 O 3 component 0 to 20% by mass with respect to the total mass of the glass having an oxide equivalent composition. 0% and / or ZrO 2 component 0 to 10.0% and / or ZnO component 0 to 10.0% and / or Al 2 O 3 component 0 to 10.0% and / or Ta 2 O 5 component 0 to 10 0.0% and / or Sb 2 O 3 component 0-1.0%
The optical glass according to claim 1, further comprising:
The optical glass according to claim 1, having a refractive index (nd) of 1.70 or more and 2.20 or less and an Abbe number (νd) of 10 or more and 25 or less.
The optical glass according to any one of claims 1 to 18, wherein the wavelength (λ 70 ) at which the spectral transmittance shows 70% is 500 nm or less.
An optical element made of the optical glass according to any one of claims 1 to 19.
A precision press-molding preform made of the optical glass according to any one of claims 1 to 19.