Lightweight paper and process for producing same
CA 1279159 C · Owner: Nagata, Youzi · Inventors: Kurokawa, Akio; Ifuku, Naoyuki; Seita, Kenzo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A lightweight paper having a superior opacity and printing opacity is provided, which lightweight paper comprises dry pulp, 0.015 to 1.2% by weight based on the pulp of an alumina polymer and 0.5 to 30X by weight based on the pulp of a coaggregate formed from agglomeratd particles of urea-formaldehyde polymer (A) and agglomerated particles of hydrated silicic acid (B) in a ratio of (A):(B) of 5:95 to 95:5.
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 January 22, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 22, 2008.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.