Collateral for a security interest recorded Mar 12, 2021 (HSBC Bank USA, National Association).
Term ends Aug 1, 2029 · High confidence
20-year base term ends Feb 16, 2029
Held by Tronox LLC
Filed Feb 16, 2009 as application 12/371,760 · Granted Feb 1, 2011
Base term plus 166 days of patent term adjustment (USPTO delay)
Today
2009
2029
Clock starts
Feb 16, 2009
Feb 16, 2009
Term ends
Aug 1, 2029
Aug 1, 2029
Granted
Feb 1, 2011
Feb 1, 2011
base term
patent term adjustment
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
166
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
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.
3
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 runs 166 days past its 20-year base term on prosecution delay. All three maintenance fees are recorded paid; no more fees are due. 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 Feb 16, 2009, when this application, 12/371,760, was filed | Feb 16, 2029 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +166 days, USPTO patent term adjustment record | Aug 1, 2029 | 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 | In force | High confidence |
| Computed term end | The steps above, in order | Aug 1, 2029 | High confidence |
This family
| US 7,879,759 | this patent Aug 2029 | Aug 2029 |
| US 8,148,295 | In force Apr 2029 | Apr 2029 |
| US 8,465,714 | In force Feb 2029 | Feb 2029 |
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 |
|---|---|---|---|
| Feb 18, 2010 Reel 23956, frame 105 | Augustine, Steve M.; Fu, Guoyi; Watson, Mark | Millennium Inorganic Chemicals, Inc. | Assignment of Assignor's Interest |
| 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 |
| 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.
What's changing
Aug 2029
Term ends Aug 1, 2029. No further fees fall due before then
Note
The 166 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
14
later US patents cite this one
That is above 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.
In force means the term is running and no lapse is on record. It is not a finding that the patent is valid.