| 摘要 |
774,248. Glass. SOC. ANON. DES MANUFACTURES DES GLACES ET PRODUITS CHIMIQUES DE ST.-GOBAIN, CHAUNY & CIREY. June 13, 1955 [June 11, 1954; May 11, 1955], No. 17010/55. Class 56 Alkaline-phosphoric glass comprises 50- 66 weight per cent P 2 O 5 or a mixture of P 2 O 5 with Al 2 O 3 and / or B 2 O 3 (the P 2 O 3 + B 2 O 3 being at least half the weight of the glass, and the major part being P 2 O 5 ); 9-13 weight per cent PbO + BaO; and an alkaline oxide or mixture of alkaline oxides X 2 O corresponding in molecular proportions to 24-35 weight per cent of Na 2 O, the ratio of the X 2 O to PbO + BaO lying the range 2 to 3.5 to 1. |
