Ultra-high-index glass microspheres and products made therefrom
Patent 4192576 Issued on March 11, 1980. Estimated Expiration Date: 
November 20, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 20, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesInventorsAssigneeApplicationNo. 05/962324 filed on 11/20/1978US Classes:359/541, With single transparent coating between spheres and atmosphere501/34, Reflective501/39, Pore-forming501/901Having R.I. at least 1.8ExaminersPrimary: McCarthy, Helen M.Attorney, Agent or FirmInternational ClassesC03C 12/02 (20060101)C03C 12/00 (20060101) C03C 3/12 (20060101) C08L 33/12 (20060101) C08K 7/00 (20060101) C08K 7/20 (20060101) C08L 27/00 (20060101) C08L 33/00 (20060101) C08L 27/16 (20060101) AbstractGlass microspheres having an index of refraction of 2.7 or higher are prepared by (1) forming the microspheres from compositions based principally on 65-85 weight-percent Bi2 O3 and 5-35 weight-percent TiO2, and (2) rapidly heating the microspheres after they have been initially formed to cause an internal structural rearrangement that raises their index. Such microspheres are useful to form retroreflective products having superior properties and a more simplified construction. | |
