Granted Patent
Utility
US 4,784,772 · App. 07/062,675
Method for the production and use of ultrapure water and apparatus therefor
Inventors:
Yoshihisa Gotoh, Toshihiko Tutumi, Toshiaki Takahashi, Katsuhiko Ito
Patented Case
View Patent ↗
Granted: Nov 15, 1988
Filed: Jun 16, 1987
Inventors
Yoshihisa Gotoh
Toshihiko Tutumi
Toshiaki Takahashi
Katsuhiko Ito
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
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.