Molding material
CA 2019212 C · Owner: Nippon Zeon Co. Ltd. · Inventors: Nishi, Yoshikatsu; Natsuume, Tadao; Oshima, Masayoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A molding material suitable as an optical material and an optical recording medium formed of the molding material are disclosed. The molding material comprises a hydrogenated product of a polymer formed by ring-opening polymerization of a norbornene-type monomer the, hydrogenated product having a number average molecular weight (Mn) of 20,000 to 50,000, a weight average molecular weight (Mw) of 40,000 to 80,000 and an Mw/Mn ratio of not more than 2.5, and having a volatile content of not more than 0.3% by weight.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 18, 1990 and granted August 3, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 18, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 18, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.