| 摘要 |
1,204,670. Glass composition. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 27 Dec., 1967 [29 Dec., 1966; 4 Aug., 1967], No. 58666/67. Heading C1M. A glass is composed, in mol. per cent, of: SiO 2 , 27À5-40; B 2 O 3 , 0-10; Al 2 O 3 , 10-30; CaO, 15-5; BaO, 15-30; MgO, 0-24; Na 2 O, 0-15; Li 2 O+Na 2 O, 0-17À5; CaO+BaO+ MgO+Li 2 O+Na 2 O, 42-52À5. The glass is resistant to attack by alkali metal vapour and may be used for Na-vapour-lamp envelopes. |
