US4212925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat insulating articles
Assignee: Wacker Chemie AG
•
Filing: 1978-12-01
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Granted: 1980-07-15
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Expires: 1998-12-01
Abstract
Abstract This invention relates to a process for improving heat insulating articles containing silicon dioxide having a surface area of at least 50 m 2 /g, opacifiers and, if desired, inorganic fibers which comprises treating the surface of the insulating articles with at least one organosilicon compound containing from 1 to 4 silicon atoms to render the same hydrophobic.
Inventors
- 👤 Gunter Kratel
- 👤 Gunter Stohr
- 👤 Hans Katzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:04
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/46; C04B41/49; C04B41/4905; C04B41/4922; C04B41/495; C04B41/4961; C04B41/80; C04B41/81; C04B41/82; C04B41/84; Y; Y10; Y10S; Y10S428/00; Y10S428/92; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
174 words
A process for improving heat insulating elements which are prepared via a dry process from silicon dioxide having a surface area of at least 50 m 2 /g and opacifiers which comprises treating the surface of the heat insulating elements with at least 1 organosilicon compound containing from 1 to 4 silicon atoms selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and silicon compounds of the formulas (R.sub.3 Si).sub.a Z and R.sub.a SiZ'.sub.4-a' in which R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, Z is selected from the group consisting of hydrogen, halogen, OH, --OR', --NR'X, --ONR' 2 , --SR', --OOCR', --O--, --NX and --S--, Z' is selected from the group consisting of hydrogen, halogen, --OH, --OR', --NR'X, --ONR' 2 , --SR' and --OOCR', R' is a radical having from 1 to 4 carbon atoms, X is selected from the groups consisting of hydrogen and R' and a is 1 or 2, and thereafter removing the excess organosilicon compound employed in the treatment of the elements.
Claim 2
Dependent Claim
174 words
A process for improving heat insulating elements which are prepared via a dry process from silicon dioxide having a surface area of at least 50 m 2 /g and opacifiers which comprises treating the surface of the heat insulating elements with at least 1 organosilicon compound containing from 1 to 4 silicon atoms selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and silicon compounds of the formulas (R.sub.3 Si).sub.a Z and R.sub.a SiZ'.sub.4-a' in which R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, Z is selected from the group consisting of hydrogen, halogen, OH, --OR', --NR'X, --ONR' 2 , --SR', --OOCR', --O--, --NX and --S--, Z' is selected from the group consisting of hydrogen, halogen, --OH, --OR', --NR'X, --ONR' 2 , --SR' and --OOCR', R' is a radical having from 1 to 4 carbon atoms, X is selected from the groups consisting of hydrogen and R' and a is 1 or 2, and thereafter removing the excess organosilicon compound employed in the treatment of the elements.
Claim 3
Dependent Claim
12 words
The process of claim 1, wherein the insulating elements contain organic fibers.
Claim 4
Dependent Claim
29 words
The process of claims 1 or 2, wherein the organosilicon compound is a mixture of at least two compounds selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and hexamethyldisilazane.
Claim 5
Dependent Claim
29 words
The process of claims 1 or 2, wherein a catalyst is used which accelerates the reaction of the organosilicon compound with the Si-bonded hydroxyl groups on the silicon dioxide.
Claim 6
Dependent Claim
15 words
The heat insulating elements prepared in accordance with the process of claims 1 or 2.
References Cited (Backward Citations)
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Cited
US3318844A
Cited
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Cited
GB1302462A
Cited
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Cited
US4112179A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-15 | 1984-01-14 | 1984-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-15 | 1988-01-14 | 1988-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-15 | 1992-01-14 | 1992-07-15 | $7700.00 | Window Closed / Lapsed |