US4070346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of polyurethane powder
Assignee: Bayer AG
•
Filing: 1977-03-23
•
Granted: 1978-01-24
•
Expires: 1997-03-23
Abstract
Abstract The instant invention is directed to the production of polyurethane or polyurea powder. The process broadly comprises atomizing an isocyanate, polyisocyanate or isocyanate pre-polymer in the liquid state and bringing the atomized particles into contact with a gaseous diamine or polyamine until they are converted to the solid state.
Inventors
- 👤 Hildegard Schnoring
- 👤 Bernd Klinksiek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:54
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/32; C08G18/3225; C08G18/3228; C08G18/08; C08G18/0895; C08G18/10; Y; Y10; Y10S; Y10S528/00; Y10S528/902
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
68 words
An interface polyaddition process for producing polyurethane polyurea in the form of powder, the particles of which may contain other substances enclosed in them, comprising converting a polyisocyanate into small particles in the liquid state, bringing the particles into contact with a gaseous diamine or polyamine until they have been converted into the solid state by polyisocyanate-polyaddition, and separating the said product from the gaseous diamine or polyamine.
Claim 2
Dependent Claim
68 words
An interface polyaddition process for producing polyurethane polyurea in the form of powder, the particles of which may contain other substances enclosed in them, comprising converting a polyisocyanate into small particles in the liquid state, bringing the particles into contact with a gaseous diamine or polyamine until they have been converted into the solid state by polyisocyanate-polyaddition, and separating the said product from the gaseous diamine or polyamine.
Claim 3
Dependent Claim
23 words
An interface polyaddition process according to claim 1 wherein a mixture of an inert carrier gas and gaseous diamine or polyamine is used.
Claim 4
Dependent Claim
20 words
The process of claim 2, wherein said polyisocyanate is supplied at a temperature below the dew point of said mixture.
Claim 5
Dependent Claim
20 words
The process of claim 2, wherein said polyisocyanate is supplied at a temperature above the dew point of said mixture.
Claim 6
Dependent Claim
26 words
The process of claim 1, wherein the contact with gaseous diamine or polyamine is stopped as soon as the polyisocyanate particles have formed a solid covering.
Claim 7
Dependent Claim
17 words
The process of claim 1, wherein an inert solid or liquid substance is added to the polyisocyanate.
Claim 8
Dependent Claim
47 words
The process of claim 1, wherein slowly reacting chain-lengthening agents are added to the polyisocyanate before the conversion into small particles in the liquid state and the said polyisocyanate is brought into contact with only sufficient diamine or polyamine to enable a solid covering to be formed.
Claim 9
Dependent Claim
11 words
The process of claim 1, wherein said polyisocyanate is a diisocyanate.
Claim 10
Dependent Claim
12 words
The process of claim 1, wherein said polyisocyanate is an isocyanate prepolymer.
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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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |