Patent US3816376A successfully refreshed from Google Patents.
US3816376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous manufacture of amino resin solutions
Assignee: BASF SE
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Filing: 1972-06-19
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Granted: 1974-06-11
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Expires: 1992-06-19
Abstract
Abstract Continuous process for the manufacture of amino resin solutions, especially solutions of urea/formaldehyde resins, by contacting the reactants in a cascade of at least three stirred vessels with back-mixing of the solution whilst maintaining specific molar ratios of amino resin forming material to formaldehyde and specific pH ranges in the individual stirred vessels.
Inventors
- 👤 F Brunnmueller
- 👤 H Schatz
- 👤 J Mayer
- 👤 O Grabowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:34
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/04; C08G12/10; C08G12/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
34 words
A process as claimed in claim 1 wherein the molar ratio of formaldehyde to amino resin forming material in the subsequent stirred vessel or vessels is in the range of from 1.8 to 2.1.
Claim 2
Dependent Claim
20 words
A process as claimed in claim 1, wherein the reaction is carried out in four or five cascade-connected stirred vessels.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 1, wherein the amino resin forming material is urea.
Claim 4
Dependent Claim
46 words
A process as claimed in claim 1, wherein the catalyst mixture is a solution containing ammonia or amines and acids or acid salts thereof having a pK value of less than 4.0, the molar retio of ammonia or amine to acid being from 10 to 150.
Claim 5
Dependent Claim
39 words
A process as claimed in claim 1, wherein, in place of pure formaldehyde solution, a solution of a precondensate of formaldehyde and urea having a molar ratio of formaldehyde to urea of at least 1:3.5 is reacted with urea.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |