US4230820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of organopolysiloxane foams
Assignee: Wacker Chemie AG
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Filing: 1979-03-02
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Granted: 1980-10-28
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Expires: 1999-03-02
Abstract
Abstract Organopolysiloxane foams are prepared by heating a mixture containing (A) a diorganopolysiloxane, (B) silicon dioxide having a surface area of at least 50 m 2 /g, (C) a peroxide compound, (D) at least one organosilicon compound containing at least 2 weight percent of Si-bonded hydroxyl groups and (E) at least one organopolysiloxane having Si-bonded hydrogen, to a temperature between 280° and 320° C. at a pressure which does not exceed the pressure of the surrounding atmosphere.
Inventors
- 👤 Adolph Maschberger
- 👤 Peter August
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:38
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/02; C08L; C08L83/00; C08L83/04; C08G; C08G77/00; C08G77/04; C08G77/12; C08G77/14; C08G77/16; C08J2383/00; C08J2383/04; Y; Y10; Y10S; Y10S528/00; Y10S528/901
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
129 words
A process for the preparation of organopolysiloxane foams which comprises rapidly heating a mixture consisting essentially of (A) a diorganopolysiloxane having terminal groups selected from the group consisting of hydroxyl groups, hydrocarbonoxy groups and mixtures thereof and having a viscosity of at least 500,000 mPa.s at 25° C., (B) a pyrogenically produced silicon dioxide having a surface area of at least 50 m 2 /g, (C) a peroxide compound, (D) 2 to 20 parts by weight per 100 parts of diorganopolysiloxane (A) of an organopolysiloxane containing at least 2 and up to 9.2 weight percent of Si-bonded hydroxyl groups and (E) at least one organopolysiloxane containing Si-bonded hydrogen, to a temperature of from 280° to 320° C. at a pressure which does not exceed that of the surrounding atmosphere.
Claim 2
Dependent Claim
129 words
A process for the preparation of organopolysiloxane foams which comprises rapidly heating a mixture consisting essentially of (A) a diorganopolysiloxane having terminal groups selected from the group consisting of hydroxyl groups, hydrocarbonoxy groups and mixtures thereof and having a viscosity of at least 500,000 mPa.s at 25° C., (B) a pyrogenically produced silicon dioxide having a surface area of at least 50 m 2 /g, (C) a peroxide compound, (D) 2 to 20 parts by weight per 100 parts of diorganopolysiloxane (A) of an organopolysiloxane containing at least 2 and up to 9.2 weight percent of Si-bonded hydroxyl groups and (E) at least one organopolysiloxane containing Si-bonded hydrogen, to a temperature of from 280° to 320° C. at a pressure which does not exceed that of the surrounding atmosphere.
Claim 3
Dependent Claim
36 words
The process of claim 1, wherein the organopolysiloxane (E) contains at least 0.01 percent by weight of Si-bonded hydrogen and is present in an amount of from 0.5 to 50 parts by weight of diorganopolysiloxane (A).
Claim 4
Dependent Claim
20 words
The process of claim 1, wherein the organopolysiloxane (E) contains from 0.01 to 1.67 percent by weight of Si-bonded hydrogen.
Claim 5
Dependent Claim
74 words
The process of claim 1, wherein the diorganopolysiloxane (A) is represented by the formula A.sub.n SiR.sub.3-n O(SiR.sub.2 O).sub.x SiR.sub.3-n Z.sub.n 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 hydroxyl groups, hydrocarbonoxy groups and mixtures thereof, n is 1 and x has a value which corresponds to a viscosity of at least 500,000 mPa·s at 25° C.
Claim 6
Dependent Claim
20 words
The process of claim 1, wherein the mixture is heated to at least 280° C. within 1 to 5 minutes.
References Cited (Backward Citations)
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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) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |