Production of plastics material incorporating starch
CA 2066437 A1 · Owner: Griffin, Gerald J. L. · Inventors: Griffin, Gerald J. L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A filler for plastics material comprises natural starch which before admixture with synthetic resin, is treated in a solution of calcium hydroxide or other alkali-earth metal hydroxide or of a metal hydroxide coordination complex having an alkaline character and is subsequently washed and dried before mixing with the molten resin. In a method utilising the invention the resin comprises a polymer or copolymer which affords carboxylic acid groups. A strong bonding of the resin with the starch particles results which improves the strength of the filled plastics as compared with, the corresponding plastics having an untreated starch filler.
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 11, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 11, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 11, 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.