公开(公告)号：WO1979000220A1

公开(公告)日：1979-05-03

申请号：PCT/GB1978000026

申请日：1978-10-18

Applicant: THORN ELECTRICAL IND LTD ,  HING P ,  KHAN E

Inventor： THORN ELECTRICAL IND LTD

IPC: C04B35/50

CPC classification number: C03C3/15 ,  C03C3/19 ,  C03C8/24 ,  C04B37/005 ,  C04B37/025 ,  C04B2235/6562 ,  C04B2235/6565 ,  C04B2237/066 ,  C04B2237/343 ,  C04B2237/401 ,  C04B2237/403 ,  C04B2237/765 ,  H01J61/36

Abstract: Sealing materials for making heat-resistant seals in electrical discharge devices comprise a rare earth oxide, such as lanthanum oxide, and boric oxide, preferably together with minor amounts of phosphorus pentoxide, aluminium oxide and magnesium oxide. Preferred compositions comprise 55 to 95 percent lanthanum or other oxide, 5 to 45 percent boric oxide and 0 to 5 percent phosphorus pentoxide, 0 to 5 percent aluminium oxide and 0 to 5 percent magnesium oxide. The compositions can be made by mixing the oxides, or appropriate salts, calcining the mixture at up to 1200 C and crushing it to a powder. They may be used as frits in a slurry or formed into pressed elements such as discs or washers. Sealing can be accomplished by heating the surfaces to be joined, together with the interposed sealing composition, to a temperature between 1100 and 1650 C.