Patent US3895826A successfully refreshed from Google Patents.
US3895826A
Expired / Lapsed
US
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Process of making dispersion of urea-formaldehyde resins
Assignee: Dulux Australia Ltd
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Filing: 1974-09-24
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Granted: 1975-07-22
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Expires: 1994-09-24
Abstract
Abstract A process of preparing beads of urea-formaldehyde resin in which disperse particles of an aqueous urea-formaldehyde syrup are converted to hard polymer and azeotropically dehydrated. The aqueous syrup must have a solids content of at least 65% by weight and the mol ratio of formaldehyde to urea must be within the range of 1.9 - 2.3 to 1.
Inventors
- 👤 Raymond Harry Gunning
- 👤 Frederick John Lubbock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:00
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/02; C08J3/09; C08J3/16; C08J3/24; C08L; C08L101/00; C08J2361/00; C08J2361/20; C08J2361/22; C08J2361/24
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
117 words
A PROCESS OF PREPARING BEADS OF UREA-FORMALDEHYDE RESIN IN WHICH AN AQUEOUS UREA-FORMALDEHYDE CONVERTIBLE SYRUP WHICH HAS A SOLIDS CONTENT OF AT LEAST 65% BY WEIGHT AND A MOL RATIO OF FORMALDEHYDE OT UREA OF 1.9-2.3 TO 1 IS DISPERSED IN THE FORM OF GLOBULES IN A HYDROCARBON LIQUID IN THEPRESENCE OF A STABILIZER FOR THE DISPRSION AND FROM 0 TO 15% BY WEIGHT OF THE CONTINUOUS PHASE OF A POLYMERIC THICKENER THEREFOR, CONVERTING THE DISPERSE SYRUP GLOBULES TO HARD POLYMER BY ADDING A CATALYST FOR THE CURING REACTION AND THEN AZEOTROPICALLY STRIPPING WATER FROM THE SYSTEM TO GIVE AN ANHYDROUS SLURRY OF SOLID POLYMER BEADS WITH DIAMETERS WITHIN THE RANGE OF 1-100 MICRONS IN HYDROCARBON LIQUID.
Claim 2
Dependent Claim
117 words
A PROCESS OF PREPARING BEADS OF UREA-FORMALDEHYDE RESIN IN WHICH AN AQUEOUS UREA-FORMALDEHYDE CONVERTIBLE SYRUP WHICH HAS A SOLIDS CONTENT OF AT LEAST 65% BY WEIGHT AND A MOL RATIO OF FORMALDEHYDE OT UREA OF 1.9-2.3 TO 1 IS DISPERSED IN THE FORM OF GLOBULES IN A HYDROCARBON LIQUID IN THEPRESENCE OF A STABILIZER FOR THE DISPRSION AND FROM 0 TO 15% BY WEIGHT OF THE CONTINUOUS PHASE OF A POLYMERIC THICKENER THEREFOR, CONVERTING THE DISPERSE SYRUP GLOBULES TO HARD POLYMER BY ADDING A CATALYST FOR THE CURING REACTION AND THEN AZEOTROPICALLY STRIPPING WATER FROM THE SYSTEM TO GIVE AN ANHYDROUS SLURRY OF SOLID POLYMER BEADS WITH DIAMETERS WITHIN THE RANGE OF 1-100 MICRONS IN HYDROCARBON LIQUID.
Claim 3
Dependent Claim
16 words
A process according to claim 1 wherein the catalyst for the curing reaction is sulphuric acid.
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) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |