Dust-proof film
CA 1330860 C · Owner: Matsumoto, Muneyuki · Inventors: Nakagawa, Hiroaki; Matsumoto, Muneyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A dust-proof film is made from a material which contains a cellulose ester and whose transmittances of light having a wavelength of 365 nm and a wavelength of 436 are 98% or more, or the dust-proof film is formed of cellulose propionate whose weight average molecular weight using polystyrene as a reference is 60,000 - 400,000. The dust-proof film has a long life and excels in light resisting properties with respect to the i-line. In addition, the dust-proof film is useful as a long-life pellicle for a broad line and exhibits high light transmittance properties with respect to both the i-line and the g-line.
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
- Granted July 26, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 26, 2011.
- 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.