Cellulosic web with a permeant barrier or contaminant trap
CA 2336795 C · Owner: Wood, Willard E. · Inventors: Beaverson, Neil J.; Wood, Willard E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Nonwoven cellulosic fiber webs including paperboards and corrugated , paperboard etc. are described containing a barrier layer (250) that can act both as a barrier to the passage of a permeant and as a trap for contaminant materials that can arise in new materials or from the recycle of fiber in the manufacture of paperboard. The effective material which acts as a trap or barrier is a cyclodextrin compound, substantially free of an inclusion complex compound. The cyclodextrin barrier layer (250) can be corrugated or sheet laminated with or on the cellulosic web (240). Alternatively the cyclodextrin , material can be included in a coating composition that is coated (210) on the …
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 April 13, 1999 and granted September 23, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 13, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 13, 2021.
- 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.