Collateral for a security interest recorded Mar 12, 2021 (HSBC Bank USA, National Association).
Term ended Aug 24, 2026 · High confidence
20-year base term ended Aug 24, 2026
Held by Tronox LLC
Filed Jul 14, 2009 as application 12/502,678 · Granted Dec 13, 2011
Base term, 20 years from filing
Today
Term ended Aug 24, 2026
2006
2026
Clock starts
Aug 24, 2006
Aug 24, 2006
Term ended
Aug 24, 2026
Aug 24, 2026
Granted
Dec 13, 2011
Dec 13, 2011
base term
after the term ends
fee events
Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
None
Term adjustment
No prosecution delay on this record.
None
Terminal disclaimer
No disclaimer on this record.
3 of 3
Maintenance fees paid
Three maintenance fees fall due, at 3.5, 7.5 and 11.5 years from grant. This counts the ones the record shows paid.
4
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.
This patent's term is its 20-year base term, with no adjustment for prosecution delay. All three maintenance fees were paid, so no fee lapse ended it. Confidence: High. from the record
How we calculated this date
One row per rule, each showing its own input and what it did to the date. A step we could not verify says so instead of resolving itself.
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Aug 24, 2006, when application 11/509,339, the earliest non-provisional in its chain, was filed (this one was filed Jul 14, 2009) | Aug 24, 2026 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | None on file | no change | High confidence |
| Terminal disclaimer cap | None on record | no cap applied | High confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 3 of 3 maintenance fees paid | term ended | High confidence |
| Computed term end | The steps above, in order | Aug 24, 2026 | High confidence |
This family
| US 7,820,583 | In force Mar 2028 | Mar 2028 |
| US 8,075,859 | this patent Aug 2026 | Aug 2026 |
| US 7,842,641 | Term ended Aug 2026 | Aug 2026 |
| US 8,501,132 | Term ended Aug 2026 | Aug 2026 |
The applications whose file history this site holds. The family may have others.
Assignments
Assignment documents as recorded at the USPTO, oldest first, with the reel and frame each was recorded at. A recorded assignment is a filed document, not a statement of current ownership, and the absence of a later one is not evidence that the last one still stands.
| Recorded | Assignor | Assignee | Conveyance |
|---|---|---|---|
| Aug 9, 2013 Reel 30982, frame 732 | Millennium Inorganic Chemicals, Inc. | Cristal USA Inc. | Change of Name |
| May 10, 2019 Reel 49148, frame 729 | Cristal USA Inc. | Tronox LLC | Assignment of Assignor's Interest |
| May 1, 2020 Reel 52554, frame 529 | Tronox LLC | Wilmington Trust, National Association, as Collateral Agent | Security Interest |
| May 29, 2020 Reel 52784, frame 278 | Fu, Guoyi; Augustine, Steven M. | Millennium Inorganic Chemicals, Inc. | Assignment of Assignor's Interest |
| Mar 12, 2021 Reel 55579, frame 619 | Tronox LLC | HSBC Bank USA, National Association, as Collateral Agent | Security Interest |
| Apr 7, 2022 Reel 59629, frame 581 | Wilmington Trust, National Association | Tronox LLC | Release of Security Interest |
| Sep 26, 2025 Reel 72942, frame 255 | Tronox LLC | Wilmington Trust, National Association, as Collateral Agent | Security Interest |
Sources
Google Patents · The patent document at USPTO · Assignment records at USPTO
USPTO account required: This application in Patent Center · USPTO's maintenance fee lookup
Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.
Free plan: 3 watched companies. Pro: unlimited.
Alerts on its grants, lapses and transfers.
Citations
7
later US patents cite this one
That is below the median of utility patents granted in 2011 in our data, the only group it is compared against.
How we rank
Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.