Patent US3305535A successfully refreshed from Google Patents.
US3305535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polyurethane plastics
Assignee: Bayer AG
•
Filing: 1961-02-28
•
Granted: 1967-02-21
•
Expires: 1981-02-28
Abstract
No abstract record available.
Inventors
- 👤 Merten Rudolf
- 👤 Braun Gunther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:03
CPC Classifications
C; C07; C07H; C07H15/00; C07H15/02; C07H15/04; C07H15/08; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/487; C08G18/4883; C08G18/56; C08G18/67; C08G18/6795
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A PROCESS FOR PREPARING POLYURETHANE PLASTICS WHICH COMPRISES REACTING AN ORGANIC POLYISOCYANATE WITH A POLYHYDROXYL COMPOUND OBTAINED FROM THE REACTION OF A CARBOHYDRATE HAVING AT LEAST FOUR CARBON ATOMS WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALCOHOLS AND PHENOLS AND AT LEAST 0.5 MOL PER MONOSACCHARIDE UNIT OF AN OXO COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALDEHYDES AND KETONES IN THE PRESENCE OF WATER AND AN ACID CATALYST, REMOVING WATER FROM THE PRODUCT OF SAID FIRST STEP TO A RESIDUAL WATER CONTENT OF LESS THAN ONE PERCENT AND THEREAFTER REACTING THE PRODUCT WITH AN ALKYLENE OXIDE.
Claim 2
Dependent Claim
99 words
A PROCESS FOR PREPARING POLYURETHANE PLASTICS WHICH COMPRISES REACTING AN ORGANIC POLYISOCYANATE WITH A POLYHYDROXYL COMPOUND OBTAINED FROM THE REACTION OF A CARBOHYDRATE HAVING AT LEAST FOUR CARBON ATOMS WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALCOHOLS AND PHENOLS AND AT LEAST 0.5 MOL PER MONOSACCHARIDE UNIT OF AN OXO COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALDEHYDES AND KETONES IN THE PRESENCE OF WATER AND AN ACID CATALYST, REMOVING WATER FROM THE PRODUCT OF SAID FIRST STEP TO A RESIDUAL WATER CONTENT OF LESS THAN ONE PERCENT AND THEREAFTER REACTING THE PRODUCT WITH AN ALKYLENE OXIDE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-20 | 1970-08-22 | 1971-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-20 | 1974-08-22 | 1975-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-20 | 1978-08-22 | 1979-02-21 | $7700.00 | Window Closed / Lapsed |