| 摘要 |
PCT No. PCT/DE79/00149 Sec. 371 Date Aug. 20, 1980 Sec. 102(e) Date Aug. 18, 1980 PCT Filed Dec. 19, 1979 PCT Pub. No. WO80/01274 PCT Pub. Date Jun. 26, 1980.Fluorophosphate glass free of beryllium with a refractive index ne between 1.40 and 1.46, an Abbe value ve between 85 and 94 and a high positive anomalous partial dispersion value + DELTA ve between 19 and 28 is described. The glass is melted from a mixture containing as groups of components metaphosphate, fluorides and an alkali fluoroborate in certain proportions expressed in % by weight, in the following manner: the intermixed mixtue is heated to a temperature between 800 DEG and 800 DEG C., the melt refined at a temperature between 900 DEG and 1000 DEG C. for a period of 8 and 25 minutes, homogenized at a temperature between 900 DEG and 1000 DEG C. within a period of time of 5 to 15 minutes, the temperature reduced to a pouring temperature between 575 DEG and 650 DEG C. and the melt poured into casting molds preheated to approximately 320 DEG C., in particular aluminum molds.
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