IP Library › Granted Patent US 4,962,241
Granted Patent Utility
US 4,962,241 · App. 07/309,671

Process for producing dihydroxynaphthalenes

Inventors: Masaaki Yasuda, Hisaya Miki
Patented Case View Patent ↗
Granted: Oct 9, 1990 Filed: Feb 3, 1989
Inventors
Masaaki Yasuda
Hisaya Miki
Assignee (at issue)
Mitsui Petrochemical Industries, Ltd.

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 4,962,241
App. No.
07/309,671
Filed
1989-02-03
Granted
1990-10-09
Kind
A