US4778502A
Expired / Lapsed
US
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Production of glass microspheres
Assignee: Saint Gobain Vitrage SA
•
Filing: 1987-03-02
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Granted: 1988-10-18
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Expires: 2007-03-02
Abstract
Abstract Processes and apparatus for the production of hollow microspheres by thermal expansion of glass particles including the thermal treatment of extremely small glass particles whose dimensions are less than 50 micrometers and, preferably, less than 35 micrometers or even 20 micrometers, which include a fluidizing agent. This technique makes possible the production of extremely small glass microspheres under satisfactory yield conditions. Also, the hollow microsphere products produced by these processes and apparatus.
Inventors
- 👤 Patrick Garnier
- 👤 Daniel Abriou
- 👤 Jean-Jacques Gaudiot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:28
CPC Classifications
C; C03; C03C; C03C11/00; C03C11/002; C03B; C03B19/00; C03B19/10; C03B19/107; C03B19/1075; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
118 words
In a process for forming hollow microspheres from glass particles whose dimensions are less than 50 micrometers by grinding the glass particles, suspending these particles in a gas current, passing said suspended particles through burner means and recovering the formed micropheres, the improvement which comprises mixing a fluidizing agent with the glass particles prior to passing said particles through the burner means, said fluidizing comprising an organic compound having a first part which exhibits an affinity for glass and a second part which promotes the independence of the particles, said organic compound added in an amount sufficient to reduce the forces of attraction of the particles but less than that which would reduce the fluidity of the mixture.
Claim 2
Dependent Claim
118 words
In a process for forming hollow microspheres from glass particles whose dimensions are less than 50 micrometers by grinding the glass particles, suspending these particles in a gas current, passing said suspended particles through burner means and recovering the formed micropheres, the improvement which comprises mixing a fluidizing agent with the glass particles prior to passing said particles through the burner means, said fluidizing comprising an organic compound having a first part which exhibits an affinity for glass and a second part which promotes the independence of the particles, said organic compound added in an amount sufficient to reduce the forces of attraction of the particles but less than that which would reduce the fluidity of the mixture.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the fluidizing agent organic compound comprises a polar part exhibiting an affinity for glass and nonpolar part.
Claim 4
Dependent Claim
14 words
The process of claim 2, wherein the polar part comprises amino and/or hydroxyl groups.
Claim 5
Dependent Claim
15 words
The process of claim 3, wherein the fluidizing agent is an alkanolamine or alkylene glycol.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein the fluidizing agent is mixed with glass particles in proportions not exceeding 0.5% by weight.
Claim 7
Dependent Claim
25 words
The process of claim 1, wherein at least 90% by weight of the treated glass particles have a granulometry of less than about 35 micrometers.
Claim 8
Dependent Claim
23 words
The process of claim 6, wherein at least 90% by weight of the particles have a granulometry of less than about 20 micrometers.
Claim 9
Dependent Claim
18 words
The process of claim 1, wherein the fluidizing agent is introduced during the grinding of the glass particles.
Claim 10
Dependent Claim
111 words
ln a process for forming hollow microspheres from glass particles whose dimensions are less than 50 micrometers by grinding the glass particles, suspending these particles in a gas current, passing said suspended particles through burner means and recovering the formed microspheres, the improvement which comprises mixing a fluidizing agent of an organic compound with the glass particles prior to passing said particles through the burner means, said fluidizing agent organic compound comprising a polar part exhibiting an affinity for glass and a nonpolar part and added in an amount sufficient to reduce the forces of attraction of the particles but less than that which would reduce the fluidity of the mixture.
Claim 11
Dependent Claim
111 words
ln a process for forming hollow microspheres from glass particles whose dimensions are less than 50 micrometers by grinding the glass particles, suspending these particles in a gas current, passing said suspended particles through burner means and recovering the formed microspheres, the improvement which comprises mixing a fluidizing agent of an organic compound with the glass particles prior to passing said particles through the burner means, said fluidizing agent organic compound comprising a polar part exhibiting an affinity for glass and a nonpolar part and added in an amount sufficient to reduce the forces of attraction of the particles but less than that which would reduce the fluidity of the mixture.
Claim 12
Dependent Claim
14 words
The process of claim 9, wherein the polar part comprises amino and/or hydroxyl groups.
Claim 13
Dependent Claim
15 words
The process of claim 9, wherein the fluidizing agent is an alkanolamine or alkylene glycol.
Claim 14
Dependent Claim
20 words
The process of claim 9, wherein fluidizing agent is mixed with glass particles in proportions not exceeding 0.5% by weight.
Claim 15
Dependent Claim
25 words
The process of claim 9, wherein at least 90% by weight of the treated glass particles have a granulometry of less than about 35 micrometers.
Claim 16
Dependent Claim
23 words
The process of claim 9, wherein at least 90% by weight of the particles have a granulometry of less than about 20 micrometers.
Claim 17
Dependent Claim
18 words
The process of claim 9, wherein the fluidizing agent is introduced during the grinding of the glass particles.
Claim 18
Dependent Claim
119 words
In a process for forming hollow microspheres from glass particles whose dimensions are less than 50 micrometers by grinding the glass particles, suspending these particles in gas current, passing said suspended particles through burner means and recovering the formed microspheres, the improvement which comprises mixing a fluidizing agent with the glass particles prior to passing said particles through the burner means, said fluidizing agent comprising an organic compound having a polar part exhibiting an affinity for glass and a nonpolar part, wherein the polar part comprises amino and/or hydroxyl groups, said organic compound added in an amount sufficient to reduce the forces of attraction of the particles but less than that which would reduce the fluidity of the mixture.
Claim 19
Dependent Claim
119 words
In a process for forming hollow microspheres from glass particles whose dimensions are less than 50 micrometers by grinding the glass particles, suspending these particles in gas current, passing said suspended particles through burner means and recovering the formed microspheres, the improvement which comprises mixing a fluidizing agent with the glass particles prior to passing said particles through the burner means, said fluidizing agent comprising an organic compound having a polar part exhibiting an affinity for glass and a nonpolar part, wherein the polar part comprises amino and/or hydroxyl groups, said organic compound added in an amount sufficient to reduce the forces of attraction of the particles but less than that which would reduce the fluidity of the mixture.
Claim 20
Dependent Claim
15 words
The process of claim 16 wherein the fluidizing agent is an alkanolamine or alkylene glycol.
Claim 21
Dependent Claim
20 words
The process of claim 17, wherein fluidizing agent is mixed with glass particles in proportions not exceeding 0.5% by weight.
Claim 22
Dependent Claim
25 words
The proeess of claim 18, wherein at least 90% by weight of the treated glass particles have a granulometry of less than about 35 micrometers.
Claim 23
Dependent Claim
23 words
The process of claim 19, wherein at least 90% by weight of the particles have a granulometry of less than about 20 micrometers.
Claim 24
Dependent Claim
18 words
The process of claim 20, wherein the fluidizing agent is introduced during the grinding of the glass particles.
Claim 25
Dependent Claim
25 words
The process of claim 1 wherein said hollow microspheres are formed with a distribution average corresponding to dimensions that are not greater than 20 micrometers.
Claim 26
Dependent Claim
24 words
The process of claim 1 wherein said hollow microspheres are formed with distribution average corresponding to dimensions that are not greater than 10 micrometers.
Claim 27
Dependent Claim
20 words
The process of claim 1 wherein said hollow microspheres are formed with a real density of greater than 0.4 g/cc.
Claim 28
Dependent Claim
19 words
The process of claim 1 wherein said hollow microspheres are formed with a density of less than 2.2 g/cc.
Claim 29
Dependent Claim
19 words
The process of claim 1 wherein said hollow microspheres are formed with a density of less than 1.2 g/cc.
Claim 30
Dependent Claim
25 words
The process of claim 9 wherein said hollow microspheres are formed with a distribution average corresponding to dimensions that are not greater than 20 micrometers.
Claim 31
Dependent Claim
25 words
The process of claim 9 wherein said hollow microspheres are formed with a distribution average corresponding to dimensions that are not greater than 10 micrometers.
Claim 32
Dependent Claim
20 words
The process of claim 9 wherein said hollow microspheres are formed with a real density of greater than 0.4 g/cc.
Claim 33
Dependent Claim
19 words
The process of claim 9 wherein said hollow microspheres are formed with a density of less than 2.2 g/cc.
Claim 34
Dependent Claim
19 words
The process of claim 9 wherein said hollow microspheres are formed with a density of less than 1.2 g/cc.
Claim 35
Dependent Claim
25 words
The process of claim 16 wherein said hollow microspheres are formed with a distribution average corresponding to dimensions that are not greater than 20 micrometers.
Claim 36
Dependent Claim
25 words
The process of claim 16 wherein said hollow microspheres are formed with a distribution average corresponding to dimensions that are not greater than 10 micrometers.
Claim 37
Dependent Claim
20 words
The process of claim 16 wherein said hollow microspheres are formed with a real density of greater than 0.4 g/cc.
Claim 38
Dependent Claim
19 words
The process of claim 16 wherein said hollow microspheres are formed with a density of less than 2.2 g/cc.
Claim 39
Dependent Claim
19 words
The process of claim 16 wherein said hollow microspheres are formed with a density of less than 1.2 g/cc.
References Cited (Backward Citations)
US2911669A
Cited
GB960902A
Cited
US3365315A
Cited
US3838998A
Cited
FR2249585A5
Cited
US4017290A
Cited
FR2318123A1
Cited
US4059423A
Cited
US4475936A
Cited
US4391646A
Cited
FR2524610A1
Cited
FR2529879A1
Cited
US4459145A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-18 | 1992-04-18 | 1992-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-18 | 1996-04-18 | 1996-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-18 | 2000-04-18 | 2000-10-18 | $7700.00 | Window Closed / Lapsed |