US4333847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixation by anion exchange of toxic materials in a glass matrix
Assignee: Individual
•
Filing: 1979-08-10
•
Granted: 1982-06-08
•
Expires: 1999-08-10
Abstract
Abstract This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal. Thereafter, the resulting glass now characterized by a distribution of internally bonded or immobilized, toxic, radioactive anions can be packaged in suitable containers, and disposed of as by burial, and/or they can be sintered to collapse the pores thereof prior to disposal or for producing useful radiation sources. The porous glass or a porous silica gel having said silicon-bonded organofunctionalsiloxy groups and/or said hydrous polyvalent metal oxy groups, the pores of said glass or silica gel remaining open and uncollapsed, can be used advantageously as a backfill for an underground radioactive waste burial site and as overpack in the waste disposal container. Also included is a novel method for bonding the polyvalent metal to the porous silica glass or gel by substituting the protons of the silicon-bonded hydroxyl groups thereof with an alkali metal or ammonium cation followed by displacement of said cation with the non-radioactive polyvalent metal cation.
Inventors
- 👤 Danh C. Tran
- 👤 Pedro B. Macedo
- 👤 Joseph H. Simmons
- 👤 Catherine J. Simmons
- 👤 Nicholas Lagakos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:05
CPC Classifications
C; C03; C03C; C03C1/00; C03C1/002; C03C1/02; C03C1/026; C03C11/00; C03C11/005; C03C21/00; C03C21/001; C03C23/00; C03C23/0095; C03C3/00; C03C3/04; C03C3/06; C03C3/061; C03C3/076; C03C3/089; G; G21; G21F; G21F9/00; G21F9/02; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/305; G21F9/34; G21F9/36; C03C2201/00; C03C2201/06; C03C2201/08; C03C2201/10; C03C2201/20; C03C2201/23; C03C2201/30; C03C2201/34; C03C2201/3411; C03C2201/3423; C03C2201/3429; C03C2201/40; C03C2201/42; C03C2201/50; C03C2201/54
Claims Analysis
Total Claims: 71
Claim 1
Independent Claim
190 words
A process for separating and immobilizing radioactive anions and/or radioactive cations from a liquid containing same comprising contacting said liquid with a porous silica glass or gel comprising at least 82 mol percent silica having interconnected pores and (a) non-radioactive cationic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic organosiloxy groups and displaceable by said radioactive anions; and/or (b) non-radioactive anionic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive cations ionically bonded to said anionic organosiloxy groups and displaceable by said radioactive cations; and/or (c) non-radioactive cationic polyvalent metals bonded to silicon of the glass or gel through divalent oxygen linkages on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic metals and displaceable by said radioactive anions, to provide a distribution of radioactive anions and/or cations internally bonded within the pores of said glass or gel and heating the porous silicate glass or gel to collapse said pores containing said internally bonded radioactive anions and/or cations.
Claim 2
Dependent Claim
190 words
A process for separating and immobilizing radioactive anions and/or radioactive cations from a liquid containing same comprising contacting said liquid with a porous silica glass or gel comprising at least 82 mol percent silica having interconnected pores and (a) non-radioactive cationic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic organosiloxy groups and displaceable by said radioactive anions; and/or (b) non-radioactive anionic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive cations ionically bonded to said anionic organosiloxy groups and displaceable by said radioactive cations; and/or (c) non-radioactive cationic polyvalent metals bonded to silicon of the glass or gel through divalent oxygen linkages on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic metals and displaceable by said radioactive anions, to provide a distribution of radioactive anions and/or cations internally bonded within the pores of said glass or gel and heating the porous silicate glass or gel to collapse said pores containing said internally bonded radioactive anions and/or cations.
Claim 3
Dependent Claim
69 words
Process as claimed in claim 1 wherein a porous silica glass is used and (a) said non-radioactive organosiloxy groups are ammonium organosiloxy groups; (b) said non-radioactive anionic organosiloxy groups are oxycarbonylorganosiloxy groups; (c) said non-radioactive cationic polyvalent metal is selected from the group consisting of --Zr 3+ , --Pb + , --Th 3+ and --Ti 3+ ; said non-radioactive anions are hydroxyl anions; and said non-radioactive cations are protons.
Claim 4
Dependent Claim
105 words
Process as claimed in claim 3 wherein said ammonium organosiloxy groups are represented by the formula: ##STR11## said oxycarbonylorganosiloxy groups are represented by the formula ##STR12## wherein in said formulas n is an integer of 1 to 18 and the unfilled valances of silicon in each formula is connected through oxygen to silicon of the glass, and/or are connected to a monovalent hydrocarbon group, and/or is connected through silicon by carbon linkages to additional --C n H 2n NH 3 + , --C n H 2n NHC n H 2n NH 3 + or --C n H 2n NHC n H 2n COO - groups.
Claim 5
Dependent Claim
17 words
Process as claimed in claim 3 wherein said ammonium organosiloxy groups are represented by the formula: ##STR13##
Claim 6
Dependent Claim
17 words
Process as claimed in claim 3 wherein said ammonium organosiloxy groups are represented by the formula: ##STR14##
Claim 7
Dependent Claim
16 words
Process as claimed in claim 3 wherein said oxycarbonylorganosiloxy groups are represented by the formula: ##STR15##
Claim 8
Dependent Claim
62 words
Process as claimed in claim 2 wherein the porous silica glass is represented by the formula: ##STR16## wherein M is a tetravalent metal in which the two unfilled valences of M are bonded ionically to additional OH - anions, are bonded through divalent oxygen linkage to another silicon of the glass and/or are bonded through divalent oxygen linkage to other M atoms.
Claim 9
Dependent Claim
35 words
Process as claimed in claim 1 wherein porous silica glass containing integral boron is used and some of said groups (a), (b) and (c) are bonded through oxy linkages to boron of said porous glass.
Claim 10
Dependent Claim
15 words
A process as claimed in claim 1 wherein the resulting glass is buried at sea.
Claim 11
Dependent Claim
20 words
A process as claimed in claim 1 wherein the resulting glass product is stored beneath the surface of the earth.
Claim 12
Dependent Claim
22 words
A process as claimed in claim 1 further comprising incorporating the resulting glass product into an instrument as a source of radioactivity.
Claim 13
Dependent Claim
14 words
A process as claimed in claim 11 further comprising destroying microorganisms employing said device.
Claim 14
Dependent Claim
15 words
A process as claimed in claim 11 further comprising sterilizing sewage sludge employing said device.
Claim 15
Dependent Claim
29 words
A sintered silicon dioxide-containing matrix containing radioactive anions internally bonded to internal silicon atoms of said matrix through polyvalent metal oxy groups selected from the group consisting of ##STR17##
Claim 16
Dependent Claim
29 words
A sintered silicon dioxide-containing matrix containing radioactive anions internally bonded to internal silicon atoms of said matrix through polyvalent metal oxy groups selected from the group consisting of ##STR17##
Claim 17
Dependent Claim
26 words
A matrix as claimed in claim 14 wherein said matrix is sintered porous silicate glass having a SiO 2 content of at least 82 mol percent.
Claim 18
Dependent Claim
20 words
A matrix as claimed in claim 14 containing at least 1 ppb radioactive material encapsulated and immobilized in said matrix.
Claim 19
Dependent Claim
20 words
A matrix as claimed in claim 14 containing at least 10 ppb radioactive material encapsulated and immobilized in said matrix.
Claim 20
Dependent Claim
17 words
A matrix as claimed in claim 14 wherein said radioactive anions are chromate, Tc - and/or molybdate.
Claim 21
Dependent Claim
23 words
A matrix as claimed in claim 14 characterized by a radiation activity of at least one microcurie per cubic centimeter of said matrix.
Claim 22
Dependent Claim
17 words
A matrix as claimed in claim 14 wherein said radioactive anions are derived from radioactive nuclear waste.
Claim 23
Independent Claim
86 words
A method for the prevention of the dissemination of radioactive materials into the environment comprising surrounding radwaste containing radioactive cations and/or radioactive anions in a silica gel or silica glass substrate with an ion exchange backfill comprising a porous silicate glass or silica gel having interconnected pores and non-radioactive cationic and/or anionic groups bonded to silicon of the glass or gel on the internal surfaces of the pores thereof, said non-radioactive cationic and/or anionic groups being capable of being displaced by said radioactive cations and/or anions.
Claim 24
Independent Claim
86 words
A method for the prevention of the dissemination of radioactive materials into the environment comprising surrounding radwaste containing radioactive cations and/or radioactive anions in a silica gel or silica glass substrate with an ion exchange backfill comprising a porous silicate glass or silica gel having interconnected pores and non-radioactive cationic and/or anionic groups bonded to silicon of the glass or gel on the internal surfaces of the pores thereof, said non-radioactive cationic and/or anionic groups being capable of being displaced by said radioactive cations and/or anions.
Claim 25
Dependent Claim
16 words
A method according to claim 21 wherein said ion exchange backfill is an anion exchange medium.
Claim 26
Dependent Claim
16 words
A method according to claim 21 wherein said ion exchange backfill is a cation exchange medium.
Claim 27
Dependent Claim
21 words
A method according to claim 21 wherein said ion exchange backfill is an anion exchange medium and a cation exchange medium.
Claim 28
Dependent Claim
22 words
A method as claimed in claim 21 wherein said radwaste is disposed in an underground site and said backfill surrounds said radwaste.
Claim 29
Dependent Claim
58 words
A method according to claim 21 wherein said ion exchange backfill comprises a porous silicate glass having interconnected pores and cationic ammonium organosiloxy groups bonded to silicon of the glass and/or anionic organosiloxy groups bonded to silicon of the glass and/or hydrous polyvalent metals bonded to silicon through divalent oxygen linkages on the internal surfaces of said pores.
Claim 30
Dependent Claim
23 words
A method according to claim 26 wherein said hydrous polyvalent metal is selected from the group consisting of Zr, Pb, Th, and Ti.
Claim 31
Dependent Claim
62 words
Method as claimed in claim 26 wherein (a) said non-radioactive organosiloxy groups are ammonium organosiloxy groups; (b) said non-radioactive anionic organosiloxy groups are oxycarbonylorganosiloxy groups; (c) said non-radioactive cationic polyvalent metal is selected from the group consisting of --Zr 3+ , --Pb + , --Th 3+ and --Ti 3+ ; said non-radioactive anions are hydroxyl anions; and said non-radioactive cations are protons.
Claim 32
Dependent Claim
105 words
Method as claimed in claim 28 wherein said ammonium organosiloxy groups are represented by the formula: ##STR18## said oxycarbonylorganosiloxy groups are represented by the formula: ##STR19## wherein in said formulas n is an integer of 1 to 18 and the unfilled valences of silicon in each formula are connected through oxygen to silicon of the glass, and/or is connected to a monovalent hydrocarbon group, and/or is connected through silicon to carbon linkages to additional --C n H 2n NH 3 + , --C n H 2n NHC n H 2n NH 3 + or --C n H 2n NHC n H 2n COO - groups.
Claim 33
Dependent Claim
19 words
Method as claimed in claim 29 wherein said ammonium organosiloxy groups are represented by the formula: --OSiC.sub.3 H.sub.6 NH.sub.3.sup.+.
Claim 34
Dependent Claim
17 words
Method as claimed in claim 29 wherein said ammonium organosiloxy groups are represented by the formula: ##STR20##
Claim 35
Dependent Claim
16 words
Method as claimed in claim 29 wherein said oxycarbonylorganosiloxy groups are represented by the formula: ##STR21##
Claim 36
Dependent Claim
62 words
Method as claimed in claim 28 wherein the porous silica glass is represented by the formula: ##STR22## wherein M is a tetravalent metal in which the two unfilled valences of M are bonded ionically to additional OH - anions, are bonded through divalent oxygen linkage to another silicon of the glass and/or are bonded through divalent oxygen linkage to other M atoms.
Claim 37
Dependent Claim
13 words
A method according to claim 26 wherein said hydrous polyvalent metal is Zr.
Claim 38
Dependent Claim
81 words
A method according to claim 21 wherein said ion exchange backfill includes a porous silicate glass having interconnected pores and non-radioactive cations selected from the group consisting of alkali metal cations, Group Ib metal cations and/or ammonium cations bonded to silicon through divalent oxygen linkages on the internal surfaces of said pores, said nonradioactive cations being capable of being displaced by said radioactive cations to provide a distribution of internal silicon-bonded radioactive cation oxy groups within the pores of said glass.
Claim 39
Dependent Claim
98 words
A process for containing a radioactive material which comprises impregnating a porous silicage glass having interconnected pores and non-radioactive organofunctionalsiloxy groups bonded to silicon of the glass and/or having non-radioactive hydrous polyvalent metal oxides bonded to silicon of the glass through divalent oxygen linkages on the internal surfaces of said pores, said a liquid solution containing radioactive anions to dispose said solution within the pores of said glass to provide a distribution of internally bonded radioactive anions within the pores of said glass, and heating the porous glass to collapse said pores containing said internally bonded radioactive anions.
Claim 40
Dependent Claim
98 words
A process for containing a radioactive material which comprises impregnating a porous silicage glass having interconnected pores and non-radioactive organofunctionalsiloxy groups bonded to silicon of the glass and/or having non-radioactive hydrous polyvalent metal oxides bonded to silicon of the glass through divalent oxygen linkages on the internal surfaces of said pores, said a liquid solution containing radioactive anions to dispose said solution within the pores of said glass to provide a distribution of internally bonded radioactive anions within the pores of said glass, and heating the porous glass to collapse said pores containing said internally bonded radioactive anions.
Claim 41
Independent Claim
103 words
A method for preparing an anion exchange medium for the removal of radioactive anions from a liquid stream comprising bonding anion exchange groups to silicon-bonded oxygen of a porous silicate glass or porous silica-gel having interconnected pores, said anion exchange groups being polyvalent hydrous metal oxide groups exhibiting anion exchange properties involving surface hydroxyl groups, the hydrous metal oxide groups being bonded to silicon via divalent oxygen linkages by converting silicon-bonded hydroxyl groups of said porous glass or silica gel to alkali metal oxy groups, displacing the alkali metal ions with polyvalent metal nitrate groups, and replacing the nitrate groups with hydroxyl groups.
Claim 42
Independent Claim
103 words
A method for preparing an anion exchange medium for the removal of radioactive anions from a liquid stream comprising bonding anion exchange groups to silicon-bonded oxygen of a porous silicate glass or porous silica-gel having interconnected pores, said anion exchange groups being polyvalent hydrous metal oxide groups exhibiting anion exchange properties involving surface hydroxyl groups, the hydrous metal oxide groups being bonded to silicon via divalent oxygen linkages by converting silicon-bonded hydroxyl groups of said porous glass or silica gel to alkali metal oxy groups, displacing the alkali metal ions with polyvalent metal nitrate groups, and replacing the nitrate groups with hydroxyl groups.
Claim 43
Dependent Claim
31 words
A method as claimed in claim 37 wherein the polyvalent metal nitrate group are selected from the group consisting of --Zr(NO 3 ), --PbNO, --Ti(NO 3 ), and --Th(NO 3 ).
Claim 44
Dependent Claim
48 words
A method as claimed in claim 38 wherein the silicon-bonded hydroxyl groups are converted to sodium oxy groups in an NH 4 OH medium, the sodium atoms are displaced in a slightly acidic medium, and the nitrate groups are replaced by treatment with an NH 4 OH solution.
Claim 45
Dependent Claim
30 words
A method in accordance with claim 39 wherein the nitrate groups are replaced with hydroxyl groups by heating to decompose the metal nitrate to the oxide and hydrating the oxide.
Claim 46
Dependent Claim
85 words
An underground reservoir for storing radioactive ionic wastes which are contained in a silica gel or silica glass substrate comprising a container containing said wastes disposed within an underground cavity and a backfill surrounding said container, said backfill comprising particles of silica glass or gel having interconnected pores and nonradioactive ions ionically bonded to ionic groups or atoms bonded to silicon of said glass or gel on the internal surfaces of said pores, said non-radioactive ions being displaceable bu said radioactive ions of said waste.
Claim 47
Dependent Claim
85 words
An underground reservoir for storing radioactive ionic wastes which are contained in a silica gel or silica glass substrate comprising a container containing said wastes disposed within an underground cavity and a backfill surrounding said container, said backfill comprising particles of silica glass or gel having interconnected pores and nonradioactive ions ionically bonded to ionic groups or atoms bonded to silicon of said glass or gel on the internal surfaces of said pores, said non-radioactive ions being displaceable bu said radioactive ions of said waste.
Claim 48
Dependent Claim
78 words
A package for storing radioactive ionic wastes which are contained in a silica gel or silica-glass substrate comprising a container containing said wastes and an overpack surrounding said wastes, said overpack comprising particles of silica glass or gel having interconnected pores and non-radioactive ions ionically bonded to ionic groups or atoms bonded to silicon of said glass or gel on the internal surfaces of said pores, said non-radioactive ions being displaceable by said radioactive ions of said waste.
Claim 49
Dependent Claim
78 words
A package for storing radioactive ionic wastes which are contained in a silica gel or silica-glass substrate comprising a container containing said wastes and an overpack surrounding said wastes, said overpack comprising particles of silica glass or gel having interconnected pores and non-radioactive ions ionically bonded to ionic groups or atoms bonded to silicon of said glass or gel on the internal surfaces of said pores, said non-radioactive ions being displaceable by said radioactive ions of said waste.
Claim 50
Dependent Claim
32 words
Package as claimed in claim 42 wherein said radwaste is contained in a first container, said overpack surrounds said first container and a second container contains said first container and said overpack.
Claim 51
Dependent Claim
130 words
A process for separating and immobilizing radioactive anions and/or radioactive cations from a liquid containing same comprising contacting said liquid with a porous silica glass or gel comprising at least 82 mol percent silica having interconnected pores and (a) non-radioactive cationic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic organosiloxy groups and displaceable by said radioactive anions; and/or (b) non-radioactive anionic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive cations ionically bonded to said anionic organosiloxy groups and displaceable by said radioactive cations to provide a distribution of radioactive anions and/or cations internally bonded within the pores of said glass or gel.
Claim 52
Dependent Claim
130 words
A process for separating and immobilizing radioactive anions and/or radioactive cations from a liquid containing same comprising contacting said liquid with a porous silica glass or gel comprising at least 82 mol percent silica having interconnected pores and (a) non-radioactive cationic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic organosiloxy groups and displaceable by said radioactive anions; and/or (b) non-radioactive anionic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive cations ionically bonded to said anionic organosiloxy groups and displaceable by said radioactive cations to provide a distribution of radioactive anions and/or cations internally bonded within the pores of said glass or gel.
Claim 53
Dependent Claim
44 words
Process as claimed in claim 44 wherein a porous glass is used and (a) a non-radioactive organosiloxy groups are ammonium organosiloxy groups; and (b) said non-radioactive anionic organosiloxy groups are oxycarbonylorganosiloxy groups; said non-radioactive anions are hydroxyl anions, and said non-radioactive cations are protons.
Claim 54
Dependent Claim
104 words
Process as claimed in claim 45 wherein said ammonium organosiloxy groups are represented by the formula: ##STR23## said oxycarbonylorganosiloxy groups are represented by the formula: ##STR24## wherein in said formulas n is an integer of 1 to 18 and the unfilled valences of silicon in each formula is connected through oxygen to silicon of the glass, and/or are connected to a monovalent hydrocarbon group, and/or is connected through silicon by carbon linkages to additional --C n H 2n NH 3 +, --C n H 2n NHC n H 2n NH 3 + or --C n H 2n NHC n H 2n COO - groups.
Claim 55
Dependent Claim
17 words
Process as claimed in claim 46 wherein said ammonium organosiloxy groups are represented by the formula: ##STR25##
Claim 56
Dependent Claim
17 words
Process as claimed in claim 46 wherein said ammonium organosiloxy groups are represented by the formula: ##STR26##
Claim 57
Dependent Claim
16 words
Process as claimed in claim 46 wherein said oxycarbonylorganosiloxy groups are represented by the formula: ##STR27##
Claim 58
Dependent Claim
34 words
Process as claimed in claim 44 wherein porous silica glass containing integral boron is used and some of said groups (a) and (b) are bonded through oxy linkages to boron of said porous glass.
Claim 59
Independent Claim
113 words
A method for the preparation of the dissemination of radioactive materials into the environment comprising surrounding radwaste containing radioactive cations and/or radio-active anions with an ion exchange backfill comprising a porous silicate glass or silica gel having interconnected pores and (a) non-radioactive cationic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic organosiloxy groups and displaceable by said radioactive anions; and/or (b) non-radioactive anionic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive cations ionically bonded to said anionic organosiloxy groups and displaceable by said radioactive cations.
Claim 60
Independent Claim
113 words
A method for the preparation of the dissemination of radioactive materials into the environment comprising surrounding radwaste containing radioactive cations and/or radio-active anions with an ion exchange backfill comprising a porous silicate glass or silica gel having interconnected pores and (a) non-radioactive cationic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic organosiloxy groups and displaceable by said radioactive anions; and/or (b) non-radioactive anionic organosiloxy groups bonded to silicon of the glass or gel on the internal surfaces of said pores and non-radioactive cations ionically bonded to said anionic organosiloxy groups and displaceable by said radioactive cations.
Claim 61
Dependent Claim
16 words
A method according to claim 51 wherein said ion exchange backfill is an anion exchange medium.
Claim 62
Dependent Claim
16 words
A method according to claim 51 wherein said ion exchange backfill is a cation exchange medium.
Claim 63
Dependent Claim
21 words
A method according to claim 51 wherein said ion exchange backfill is an anion exchange medium and a cation exchange medium.
Claim 64
Dependent Claim
22 words
A method as claimed in claim 51 wherein said radwaste is disposed in an underground site and said backfill surrounds said radwaste.
Claim 65
Dependent Claim
47 words
A method according to claim 51 wherein said ion exchange backfill comprises a porous silicate glass having interconnected pores and cationic ammonium organosiloxy groups bonded to silicon of the glass and/or anionic organosiloxy groups bonded to silicon of the glass on the internal surfaces of said pores.
Claim 66
Dependent Claim
38 words
Method as claimed in claim 56 wherein (a) said nonradioactive organosiloxy groups are ammonium organosiloxy groups; and (b) said non-radioactive anionic organosiloxy groups are oxycarbonylorganosiloxy groups; said non-radioactive anions are hydroxyl anions; and said non-radioactive cations are protons.
Claim 67
Dependent Claim
105 words
Method as claimed in claim 56 wherein said ammonium organosiloxy groups are represented by the formula: ##STR28## said oxycarbonylorganosiloxy groups are represented by the formula: ##STR29## wherein in said formulas n is an integer of 1 to 18 and the unfilled valences of silicon in each formula are connected through oxygen to silicon of the glass, and/or is connected to a monovalent hydrocarbon group, and/or is connected through silicon to carbon linkages to additional --C n H 2n NH 3 + , --C n H 2n NHC n H 2n NH 3 + or --C n H 2n NHC n H 2n COO - groups.
Claim 68
Dependent Claim
19 words
Method as claimed in claim 58 wherein said ammonium organosiloxy groups are represented by the formula: --OSiC.sub.3 H.sub.6 NH.sub.3.sup.+.
Claim 69
Dependent Claim
17 words
Method as claimed in claim 58 wherein said ammonium organosiloxy groups are represented by the formula: ##STR30##
Claim 70
Dependent Claim
16 words
Method as claimed in claim 58 wherein said oxycarbonylorganosiloxy groups are represented by the formula: ##STR31##
Claim 71
Dependent Claim
81 words
A method according to claim 51 wherein said ion exchange backfill includes a porous silicate glass having interconnected pores and non-radioactive cations selected from the group consisting of alkali metal cations, Group Ib metal cations and/or ammonium cations bonded to silicon through divalent oxygen linkages on the internal surfaces of said pores, said nonradioactive cations being capable of being displaced by said radioactive cations to provide a distribution of internal silicon-bonded radioactive cation oxy groups within the pores of said glass.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |