US4190710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blowing agents based on urea dicarboxylic acid anhydride
Assignee: Bayer AG
•
Filing: 1978-03-22
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Granted: 1980-02-26
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Expires: 1998-03-22
Abstract
Abstract Blowing agents comprising urea dicarboxylic acid anhydride do not give rise to discoloring decomposition residues nor form acid or alkaline by-products. These blowing agents may be used for expanding thermoplastic resins.
Inventors
- 👤 Kurt Ley
- 👤 Hermann Hagemann
- 👤 Helmut Hurnik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:43
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S521/00; Y10S521/909; Y10S521/91
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
41 words
A process for the production of a foamed thermoplastic mass comprising mixing a thermoplastic with a blowing agent comprising urea dicarboxylic acid anhydride, and heating the resulting mixture to a temperature from about 150° to 350° C. thereby to effect foaming.
Claim 2
Dependent Claim
41 words
A process for the production of a foamed thermoplastic mass comprising mixing a thermoplastic with a blowing agent comprising urea dicarboxylic acid anhydride, and heating the resulting mixture to a temperature from about 150° to 350° C. thereby to effect foaming.
Claim 3
Dependent Claim
21 words
A process as claimed in claim 1, wherein the mixture is heated to a temperature from about 160° to 300° C.
Claim 4
Dependent Claim
46 words
A process as claimed in claim 1, wherein the blowing agent comprises 10 to 100% by weight of urea dicarboxylic acid anhydride, 0 to 90% by weight of at least one water-eliminating compound and 0 to 90% by weight of at least one known blowing agent.
Claim 5
Dependent Claim
37 words
A process as claimed in claim 1, wherein the blowing agent consists essentially of 35 to 80% by weight of urea one water-eliminating compound and 0 to 45% by weight of at least one known blowing agent.
References Cited (Backward Citations)
US4104195A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-25 | 1983-08-27 | 1984-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-25 | 1987-08-27 | 1988-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-25 | 1991-08-27 | 1992-02-26 | $7700.00 | Window Closed / Lapsed |