Patent US4751202A successfully refreshed from Google Patents.
US4751202A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacturing vitreous beads
Assignee: AGC Glass Europe SA
•
Filing: 1986-06-20
•
Granted: 1988-06-14
•
Expires: 2006-06-20
Abstract
Abstract A process of manufacturing vitreous beads is disclosed in which feedstock particles of a glass-former composition containing chemically bound water, are fed through a heating zone in which the particles are vitrified and spherulized and the resulting vitreous beads are cooled. The size of the feedstock particles and their content of substance which becomes gaseous during the passage of the particles through said heating zone are such that a least 20% by weight of the formed beads have a relative density greater than I.O. The vitrifiable oxide forming elements of said glass-former composition may be chemically interlinked, and the feedstock may be prepared as a silica-based gel or precipitate having a composition suitable for vitrification into a glass of any desired composition for example one which by virtue of its low alkali content is resistant to hydrolytic attack. By control of the cellulating agent content (bound water and optionally a gas evolving salt radical such as nitrate or sulphate) of the feedstock, and its granulometry, the relative proportions of solid and hollow beads which will be produced in a given spherulizing run can be controlled.
Inventors
- 👤 Francois Toussaint
- 👤 Pierre Goelff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:17
CPC Classifications
C; C03; C03C; C03C12/00; C03C1/00; C03C1/006; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2996
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
138 words
In a process for manufacturing vitreous beads, including the steps of: feeding a glass-forming composition in particulate form through a heating zone of a spherulizing furnace where the glass-forming composition is heated to a temperature effective to vitrify and spherulize the particles thereof to produce vitreous beads; and cooling the vitreous beads, the improvement comprising: providing a glass-forming composition in particulate form containing chemically bound water and having a particle size range effective to form both hollow vitreous beads and solid vitreous beads and having a content of at least one substance which becomes gaseous during feeding of the particles through the heating zone effective to obtain up to 80% hollow vitreous beads having a relative density of less than 1.0 and at least 20% by weight of solid vitreous beads having a relative density greater than 1.0.
Claim 2
Dependent Claim
138 words
In a process for manufacturing vitreous beads, including the steps of: feeding a glass-forming composition in particulate form through a heating zone of a spherulizing furnace where the glass-forming composition is heated to a temperature effective to vitrify and spherulize the particles thereof to produce vitreous beads; and cooling the vitreous beads, the improvement comprising: providing a glass-forming composition in particulate form containing chemically bound water and having a particle size range effective to form both hollow vitreous beads and solid vitreous beads and having a content of at least one substance which becomes gaseous during feeding of the particles through the heating zone effective to obtain up to 80% hollow vitreous beads having a relative density of less than 1.0 and at least 20% by weight of solid vitreous beads having a relative density greater than 1.0.
Claim 3
Dependent Claim
24 words
The process according to claim 1, wherein at least 30% by weight of the vitreous beads produced have a relative density greater than 1.0.
Claim 4
Dependent Claim
30 words
The process according to claim 1, wherein the glass-forming composition further comprises less than 15% by dry weight of sodium and potassium calculated as the total of their respective oxides.
Claim 5
Dependent Claim
30 words
The process according to claim 1, wherein the glass-forming composition further comprises less than 10% by dry weight of sodium and potassium calculated as the total of their respective oxides.
Claim 6
Dependent Claim
15 words
The process according to claim 1, wherein the glass-forming composition is substantially insoluble in water.
Claim 7
Dependent Claim
25 words
The process according to claim 1, wherein the glass-forming composition further comprises at least one vitrifiable, oxide-forming substance which is chemically bonded within the composition.
Claim 8
Dependent Claim
19 words
The process according to claim 6, including the further step of preparing, as the glass-forming composition, a silica-based gel.
Claim 9
Dependent Claim
19 words
The process according to claim 6, including the further step of preparing, as the glass-forming composition, a silica-based precipitate.
Claim 10
Dependent Claim
28 words
The process according to claim 1, wherein the glass-forming composition in particulate form has a particle size range which includes particles ranging from 20 μm to 250 μm.
Claim 11
Dependent Claim
27 words
The process according to claim 1, wherein the glass-forming composition further comprises ions which function as devitrification nucleating agents and the vitreous beads produced are vitro-ceramic beads.
Claim 12
Dependent Claim
25 words
The process according to claim 10, wherein the ions which functon as devitrification nucleating agents comprise at least one of titanium ions and zirconium ions.
Claim 13
Dependent Claim
25 words
The process according to claim 10, including the further step of subjecting the vitreous beads to a devitrifying treatment to convert them into vitro-ceramic beads.
Claim 14
Dependent Claim
33 words
The process according to claim 1, wherein the glass-forming composition further comprises at least one of boron and aluminium in an amount of at least 10% by dry weight calculated as the oxide.
Claim 15
Dependent Claim
34 words
The process according to claim 1, wherein the glass forming composition further comprises at least one of boron and aluminum in an amount of at least 15% by dry weight calculated as the oxide.
Claim 16
Dependent Claim
38 words
The process according to claim 1, wherein the glass-forming composition further comprises glass-forming components which are vitrifiable to form a special glass selected from the group consisting of an alumino-silicate glass, a boro-silicate glass, and an alumino-boro-silicate glass.
Claim 17
Dependent Claim
17 words
The process according to claim 1, wherein the glass-forming composition further comprises at least one gas-evolving salt.
Claim 18
Dependent Claim
32 words
The process according to claim 1, wherein the glass-forming composition further comprises at least one gas-evolving salt which is at least one salt selected from the group consisting of nitrates and sulfates.
Claim 19
Dependent Claim
133 words
Vitreous beads produced by a process comprising: providing a glass-forming composition in particulate form containing chemically bound water; feeding the glass-forming composition in particulate form through a heating zone of a spherulizing furnace where the glass-forming composition is heated to a temperature effective to vitrify and spherulize the particles thereof to produce vitreous beads; and cooling the vitreous beads, wherein the glass-forming composition has a particle size range effective to form both hollow vitreous beads and solid vitreous beads and a content of at least one substance which becomes gaseous during feeding of the composition through the heating zone effective to obtain up to 80% hollow vitreous beads having a relative density of less than 1.0 and at least 20% by weight of solid vitreous beads having a relative density greater than 1.0.
Claim 20
Dependent Claim
133 words
Vitreous beads produced by a process comprising: providing a glass-forming composition in particulate form containing chemically bound water; feeding the glass-forming composition in particulate form through a heating zone of a spherulizing furnace where the glass-forming composition is heated to a temperature effective to vitrify and spherulize the particles thereof to produce vitreous beads; and cooling the vitreous beads, wherein the glass-forming composition has a particle size range effective to form both hollow vitreous beads and solid vitreous beads and a content of at least one substance which becomes gaseous during feeding of the composition through the heating zone effective to obtain up to 80% hollow vitreous beads having a relative density of less than 1.0 and at least 20% by weight of solid vitreous beads having a relative density greater than 1.0.
References Cited (Backward Citations)
US3030215A
Cited
US3242032A
Cited
GB1011596A
Cited
US3365315A
Cited
US3838998A
Cited
US4113915A
Cited
US4002482A
Cited
US4059423A
Cited
US4063916A
Cited
US4133854A
Cited
US4367919A
Cited
FR2463108A2
Cited
US4340642A
Cited
US4336338A
Cited
GB2151610A
Cited
US4391646A
Cited
US4448599A
Cited
US4472185A
Cited
US4564556A
Cited
US4640905A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |