The Patent Finder
US

Process for Hydrothermal Production of Sodium Silicate Solutions and Precipitated Silicas

US 7,622,097 In force
OverviewFamilyAssignmentsSources & methods
Collateral for a security interest recorded Mar 12, 2021 (HSBC Bank USA, National Association).

Term ends Jan 22, 2028 · High confidence

Held by Tronox LLC
Filed Jul 20, 2007 as application 11/880,334 · Granted Nov 24, 2009
Base term plus 186 days of patent term adjustment (USPTO delay)
Today
20 years from filing
2007 2028
Clock starts
Jul 20, 2007
Term ends
Jan 22, 2028
Granted
Nov 24, 2009
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
186
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.
23
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 186 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.
StepInputDate after this stepConfidence
Base term, 20 years from filingClock starts Jul 20, 2007, when this application, 11/880,334, was filedJul 20, 2027High confidence
Continuity chainEvery parent in the chain resolvedno changeHigh confidence
Patent term adjustment+186 days, USPTO patent term adjustment recordJan 22, 2028High confidence
Terminal disclaimer capNone on recordno cap appliedHigh confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events3 of 3 maintenance fees paidIn forceHigh confidence
Computed term endThe steps above, in orderJan 22, 2028High confidence

This family

US 7,264,672Term ended
Oct 2026
Oct 2026
US 7,622,097this patent
Jan 2028
Jan 2028
US 9,028,913Lapsed on the fee record
May 2023
May 2023
US 7,717,999In force
Dec 2028
Dec 2028
US 8,226,911In force
Oct 2030
Oct 2030
US 8,057,770In force
Jul 2027
Jul 2027
US 8,178,065In force
Oct 2030
Oct 2030
US 7,824,322Lapsed on the fee record
Nov 2022
Nov 2022
8 of 23 applications in this family shown, earliest filings first. 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.
RecordedAssignorAssigneeConveyance
Oct 16, 2007
Reel 19972, frame 112
Trabzuni, Fadi Mohammed Saeed; El Dekki, Hassan Moenes; Gopalkrishnan, Chathangat CheroolilNational Titanium Dioxide Co., Ltd., the (Cristal)Assignment of Assignor's Interest
Jun 25, 2019
Reel 49583, frame 638
The National Titanium Dioxide Co. Ltd. (Cristal)Tronox LLCAssignment of Assignor's Interest
May 1, 2020
Reel 52554, frame 529
Tronox LLCWilmington Trust, National Association, as Collateral AgentSecurity Interest
Mar 12, 2021
Reel 55579, frame 619
Tronox LLCHSBC Bank USA, National Association, as Collateral AgentSecurity Interest
Apr 7, 2022
Reel 59629, frame 581
Wilmington Trust, National AssociationTronox LLCRelease of Security Interest
Sep 26, 2025
Reel 72942, frame 255
Tronox LLCWilmington Trust, National Association, as Collateral AgentSecurity 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.

The Patent Finder CompaniesExpirationsCalculatorWatchlistPricing MethodologyCorrectionsLegalPrivacysupport@thepatentfinder.com Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) Part of 137 Finder · © 2026 137 Finder LLC · Sources cited