IP Library › Granted Patent US 4,869,845
Granted Patent Utility
US 4,869,845 · App. 07/256,825

Water treatment compositions

Inventor: Fu Chen
Patented Case View Patent ↗
Granted: Sep 26, 1989 Filed: Oct 12, 1988
Inventor
Fu Chen
Assignee (at issue)
Betz Laboratories, Inc.

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.

Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 4,869,845
App. No.
07/256,825
Filed
1988-10-12
Granted
1989-09-26
Kind
A