Patent US3716527A successfully refreshed from Google Patents.
US3716527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing formaldehyde-treated starch free of unreacted or free formaldehyde
Assignee: Standard Brands Inc
•
Filing: 1971-10-22
•
Granted: 1973-02-13
•
Expires: 1991-10-22
Abstract
Abstract The invention is directed to a process for producing a formaldehyde-treated starch. A material which provides ammonium or amine groups is provided in a slurry of formaldehyde-treated starch containing free or unreacted formaldehyde at a pH of above about 6.5. The material combines with the free or unreacted formaldehyde and thus reduces vaporization of the formaldehyde.
Inventors
- 👤 E Speakman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:49
CPC Classifications
C; C08; C08B; C08B31/00; C08B31/003
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
87 words
A process for producing a formaldehyde-treated starch comprising reacting starch and formaldehyde in an aqueous slurry under conditions whereby unreacted or free formaldehyde is present in the slurry, adjusting the pH of the slurry from above about 6.5 to below a level where gelatinization of the starch occurs and providing in the slurry a sufficient amount of a material which solubilizes to yield ammonium or amine groups which react at a pH of above 6.5 with the unreacted or free formaldehyde to substantially reduce the vaporization thereof.
Claim 2
Dependent Claim
87 words
A process for producing a formaldehyde-treated starch comprising reacting starch and formaldehyde in an aqueous slurry under conditions whereby unreacted or free formaldehyde is present in the slurry, adjusting the pH of the slurry from above about 6.5 to below a level where gelatinization of the starch occurs and providing in the slurry a sufficient amount of a material which solubilizes to yield ammonium or amine groups which react at a pH of above 6.5 with the unreacted or free formaldehyde to substantially reduce the vaporization thereof.
Claim 3
Dependent Claim
47 words
A process for producing a formaldehyde-treated starch as defined in claim 1, wherein the pH of the slurry is maintained in the range of from above about 7 to below about 11.5 during the reaction of the ammonium or amine groups with the unreacted or free formaldehyde.
Claim 4
Dependent Claim
45 words
A process for producing a formaldehyde-treated starch as defined in claim 2, wherein the pH of the slurry is maintained in the range of from about 7.5 to about 9.5 during the reaction of the ammonium or amine groups with the unreacted or free formaldehyde.
Claim 5
Dependent Claim
23 words
A process for producing a formaldehyde-treated starch as defined in claim 2, wherein the material provided in the aqueous slurry is ammonium hydroxide.
Claim 6
Dependent Claim
23 words
A process for producing a formaldehyde-treated starch as defined in claim 3, wherein the material provided in the aqueous slurry is ammonium hydroxide.
Claim 7
Dependent Claim
39 words
A process for producing a formaldehyde-treated starch as defined in claim 4, wherein after the ammonium groups have reacted with the formaldehyde the pH of the slurry is lowered to the range of from about 3.5 to about 8.
Claim 8
Dependent Claim
50 words
A process for producing a formaldehyde-treated starch as defined in claim 6, wherein the starch and formaldehyde are reacted at a pH within the range of from about 1.7 to about 2.5 and the pH of the slurry is adjusted to above about 7 by the addition of sodium carbonate.
Claim 9
Dependent Claim
24 words
A process for producing a formaldehyde-treated starch as defined in claim 2, wherein the material provided in the aqueous slurry is an ammonium salt.
References Cited (Backward Citations)
US3549618A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |