Patent US2796489A successfully refreshed from Google Patents.
Patent US2828308A successfully refreshed from Google Patents.
US2828308A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying trichlorocyanuric acid
Assignee: Purex Corp Ltd
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Filing: 1955-09-09
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Granted: 1958-03-25
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Expires: 1975-09-09
Abstract
No abstract record available.
Inventors
- 👤 Walter K Lorenz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:07
CPC Classifications
C; C07; C07D; C07D251/00; C07D251/02; C07D251/12; C07D251/26; C07D251/30; C07D251/36
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
92 words
THE METHOD OF SEPARATING IMPURITIES INCLUDING INORGANIC SALTS FROM A COMMERCIAL GRADE CHLORINATED HETEROCYCLIC NITROGEN COMPOUND OF THE GROUP CONSISTING OF N,N'',N"-TRICHLOROMELAMINE, N,N''-DICHLOROAMMELLINE, N-CHLOROAMMELIDE, TRICHLOROISOCYANURIC ACID, 1,3-DICHLOROHYDROURACIL, DICHLOROISOCYANURIC ACID, MONOCHLOROISOCYANURIC ACID, N,N-DICHLORO-5,5-DIMETHYLHYDANTOIN, AND N,N-DICHLORO-5-METHYL-HYDANTOIN; SAID METHOD INCLUDING THE STEPS OF MIXING THE IMPURE COMPOUND WITH COLD CONCENTRATED SULFURIC ACID AND THEREBY SELECTIVELY DISSOLVING THE PURE COMPOUND IN THE ACID WHILE LEAVING UNDISSOLVED IMPURITIES, SEPARATING THE RESULTING SOLUTION FROM THE IMPURITY RESIDUE, COOLING THE SOLUTION TO PRECIPITATE SAID COMPOUND IN SUBSTANTIALLY PURE SOLID FORM, AND SEPARATING THE SOLID PRECIPITATE FROM THE RESIDUAL LIQUID.
Claim 2
Independent Claim
92 words
THE METHOD OF SEPARATING IMPURITIES INCLUDING INORGANIC SALTS FROM A COMMERCIAL GRADE CHLORINATED HETEROCYCLIC NITROGEN COMPOUND OF THE GROUP CONSISTING OF N,N'',N"-TRICHLOROMELAMINE, N,N''-DICHLOROAMMELLINE, N-CHLOROAMMELIDE, TRICHLOROISOCYANURIC ACID, 1,3-DICHLOROHYDROURACIL, DICHLOROISOCYANURIC ACID, MONOCHLOROISOCYANURIC ACID, N,N-DICHLORO-5,5-DIMETHYLHYDANTOIN, AND N,N-DICHLORO-5-METHYL-HYDANTOIN; SAID METHOD INCLUDING THE STEPS OF MIXING THE IMPURE COMPOUND WITH COLD CONCENTRATED SULFURIC ACID AND THEREBY SELECTIVELY DISSOLVING THE PURE COMPOUND IN THE ACID WHILE LEAVING UNDISSOLVED IMPURITIES, SEPARATING THE RESULTING SOLUTION FROM THE IMPURITY RESIDUE, COOLING THE SOLUTION TO PRECIPITATE SAID COMPOUND IN SUBSTANTIALLY PURE SOLID FORM, AND SEPARATING THE SOLID PRECIPITATE FROM THE RESIDUAL LIQUID.
Claim 3
Dependent Claim
14 words
THE METHOD AS DEFINED IN CLAIM 1, IN WHICH SAID COMPOUND IS TRICHLOROISOCYANURIC ACID.
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) | 1961-03-24 | 1961-09-23 | 1962-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-24 | 1965-09-23 | 1966-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-24 | 1969-09-23 | 1970-03-25 | $7700.00 | Window Closed / Lapsed |