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  Optical glass, precision press-molding preform, process for producing the preform, optical element and process for producing the elementUSPTO Application #: 20060105900Title: Optical glass, precision press-molding preform, process for producing the preform, optical element and process for producing the element Abstract: An optical glass having high refractivity and a low sag temperature and having a low-temperature softening property that enables precision press-molding is provided, and the optical glass contains, by mol %, 5 to 50% of B2O3, 3 to 50% of SiO2, 5 to 40% of TiO2, 1 to 40% of ZnO, 5 to 20% of La2O3, 0 to 10% of Gd2O3, 0 to 15% of Nb2O5, 0 to 10% of ZrO2, 0 to 5% of Ta2O5, 0 to 10% of Bi2O3, 0 to 10% of MgO, 0 to 8% of CaO, 0 to 10% of SrO, 0 to 10% of BaO, provided that the total content of MgO, CaO, SrO and BaO is 15% or less, 0 to 20% of Li2O, and 0 to 5% of Na2O, optionally containing Sb2O3 as a refining agent, and having a refractive index (nd) of 1.8 or more and an Abbe's number (vd) of 35 or less. (end of abstract) Agent: Nixon & Vanderhye, PC - Arlington, VA, US Inventors: Yoshiko Kasuga, Xuelu Zou USPTO Applicaton #: 20060105900 - Class: 501078000 (USPTO) Related Patent Categories: Compositions: Ceramic, Ceramic Compositions, Glass Compositions, Compositions Containing Glass Other Than Those Wherein Glass Is A Bonding Agent, Or Glass Batch Forming Compositions, Silica Containing, Less Than 40 Percent By Weight Silica, And Boron, And Rare Earth (i.e., Elements With Atomic Number 39 Or 57-71) The Patent Description & Claims data below is from USPTO Patent Application 20060105900. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to an optical glass, a precision press-molding preform formed of the above optical glass, a process for producing the preform, an optical element formed of the above optical glass and a process for producing the element. TECHNICAL BACKGROUND [0002] A high-refractivity low-dispersion glass is briskly in high demand as a material for optical elements such as various lenses. As a glass having such optical properties, there are known a heavy tantalum flint glass TaSF17, and the like, which are described in "Glass Composition Handbook" written by Hiroshi OGAWA and Shinei OGAWA and issued by Japan Glass Product Society, 1991, page 106. DISCLOSURE OF THE INVENTION [0003] In recent years, with rapid widespread use of digital cameras, video cameras and the like, glass lenses as parts therefor are much in demand. On the other hand, with an increase in the pixels of the cameras, optical elements such as glass lenses are required to have high performances, and it is required to produce optical elements formed of a glass having high form accuracy highly productively. [0004] A precision press-molding method is known as a method for highly productively producing optical elements formed of a glass having high form accuracy. Any one of conventional glasses such as TaSF17 has a high glass transition temperature, and they are hence not suitable for precision press-molding. [0005] Overcoming the problems of the above conventional glasses, the first object of the present invention is to provide an optical glass that has a high refractive index and that has a low sag temperature and a low-temperature softening property enabling precision press-molding. [0006] Further, the second and third objects of the present invention are to provide a precision press-molding formed of the optical glass that achieves the above object and to provide a process for producing such a precision press-molding preform. [0007] Furthermore, the fourth and fifth objects of the present invention are to provide an optical element formed of the optical glass that achieves the above object and a process for producing such an optical element. [0008] The present inventors have made diligent studies and as a result have found that the above objects can be achieved by an optical glass comprising B.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZnO and La.sub.2O.sub.3 which are co-present as essential components and having contents of these essential components and other optional components in predetermined ranges, and the present invention has been accordingly completed. [0009] That is, the present invention provides [0010] (1) an optical glass comprising, by mol %, [0011] 5 to 50% of B.sub.2O.sub.3, [0012] 3 to 50% of SiO.sub.2, [0013] 5 to 40% of TiO.sub.2, [0014] 1 to 40% of ZnO, [0015] 5 to 20% of La.sub.2O.sub.3, [0016] 0 to 10% of Gd.sub.2O.sub.3, [0017] 0 to 15% of Nb.sub.2O.sub.5, [0018] 0 to 10% of ZrO.sub.2, [0019] 0 to 5% of Ta.sub.2O.sub.5, [0020] 0 to 10% of Bi.sub.2O.sub.3, [0021] 0 to 10% of MgO, Continue reading... Full patent description for Optical glass, precision press-molding preform, process for producing the preform, optical element and process for producing the element Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Optical glass, precision press-molding preform, process for producing the preform, optical element and process for producing the element patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Optical glass, precision press-molding preform, process for producing the preform, optical element and process for producing the element or other areas of interest. ### Previous Patent Application: Furnace with series-arranged baths for producing glass compounds having a low degree of unmelted material Next Patent Application: Slag conditioner composition, process for manufacture and method of use in steel production Industry Class: Compositions: ceramic ### FreshPatents.com Support Thank you for viewing the Optical glass, precision press-molding preform, process for producing the preform, optical element and process for producing the element patent info. IP-related news and info Results in 0.43898 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m |
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