| PATENT ASSIGNEE'S COUNTRY | Japan |
| UPDATE | 03.99 |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT CLAIMS |
Alkali-free glass consisting of - Silica (60 - 68 %) - Alumina (10 - 16 %) - Boria (10 - 12 %) - Magnesia (< 5 %) - CaO (< 5 %) - SrO (3 - 5 %) - BaO (3 - 5 %) - SrO+BaO (6 - 8 %) Compn has strain point > 650C & av. thermal expansion coe fficient < 0.0000040/C within 50 - 300C, & of which the wt loss per unit area after immersion at 25C for 20 min in liquid prepd by mixing a 40 % ammonium fluoride aq soln & 50% HF aq soln in vol. ratio of 9:1 is < 0.56 mg/square.cm, the wt. loss per unit area after immersion at 95C for 20 hours & 0.1 N HCl is < 0.2 mg/square.cm & liquidus T < T at which viscosity is 10000 poise |
| PATENT PHOTOCOPY | Available on request |
|
Want more information ? Interested in the hidden information ? Click here and do your request. |