908 F.Supp. 172 (1995)
LENZING AKTIENGESELLSCHAFT, Plaintiff,
v.
COURTAULDS FIBERS, INC. and Courtaulds PLC, Defendants.
No. 93 Civ. 1588 (LLS).
United States District Court, S.D. New York.
November 28, 1995.
173*173 Brumbaugh, Graves, Donohue & Raymond, New York City (John D. Murnane, Arthur S. Tenser, of counsel), for plaintiff.
Cravath, Swaine & Moore, New York City (Alan J. Hruska, of counsel), for defendants.
MEMORANDUM AND ORDER
STANTON, District Judge.
Lenzing Aktiengesellschaft ("Lenzing"), an Austrian corporation, sues Courtaulds Fibers, Inc., a Delaware corporation, and Courtaulds PLC, a British corporation with a controlling interest in Courtaulds Fibers, Inc. (collectively "Courtaulds"), alleging infringement of U.S. Patent No. 5,094,690 ("the '690 patent" or "Zikeli's patent"), which Lenzing owns.
Courtaulds moves for summary judgment that the '690 patent is invalid and unenforceable.
BACKGROUND
Zikeli's patent concerns a process patented in 1969 by Dee Lynn Johnson.
[1]Johnson discovered that a natural polymer such as cellulose—
e.g., wood pulp—could be dissolved in a solution of water and a chemical called a "tertiary amine oxide." Fibers for making nylon, polyester, and such materials may be spun from the resulting solution—a solution of cellulose in an "aqueous tertiary amine oxide."
In 1980, Neal Franks and Julianna Varga patented a particular method for dissolving the cellulose in the tertiary amine oxide solution.
[2] The "Franks and Varga method" involves using a tertiary amine oxide called N-methylmorpholine N-oxide, or "NMMO." In that method cellulose, aqueous NMMO, and water are combined to make an undissolved mixture, or "suspension." Excess water in the suspension prevents the cellulose from dissolving into the aqueous NMMO. When the suspension is exposed to heat and reduced pressure, the excess water evaporates,
174*174 allowing the cellulose to dissolve into the aqueous NMMO.
On August 16, 1988, Stefan Zikeli, an employee of Lenzing, filed an application in the Austrian Patent Office for a patent on a process disclosing steps for carrying out the Franks and Varga method. He filed a corresponding application in the United States Patent and Trademark Office on August 4, 1989, claiming priority based on the filing in Austria, and was granted the '690 patent.
The scope of Zikeli's patented invention is limited by one independent claim and eight dependent claims. Claim 1, the independent claim upon which all the dependent claims directly or indirectly depend, claims: