Method for producing spun-bonded materials with improved tensile strength
CA 2248451 C · Owner: Montell North America Inc. · Inventors: Yoo, Hee Ju
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A spunbonded material having improved tensile strength is made by (1) continuously extruding a propylene homopolymer or random propylene/ethylene copolymer having a melt flow rate of about 3 to about 30 g/10 min at a temperature above 500°F through a spinneret to form discrete filaments (2) drawing the filaments to, molecularly orient the polymer filaments and (3) depositing the filaments in a, substantially random manner onto a carrier belt to form a web. The propylene polymer contains an additives package that includes an organic phosphite a hindered phenol, compound, calcium stearate and, optionally, a hydrotalcite compound.
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 September 22, 1998 and granted March 11, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 22, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 22, 2020.
- 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.