Multi-layer structure polymer and resin composition
CA 2010257 C · Owner: Nishihara, Hajime · Inventors: Seki, Junji; Nishihara, Hajime; Maeda, Katsuaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multi-layer structure polymer (A) comprising (i) 2 to 30% by weight of an alkyl methacrylate unit (ii), 50 to 80% by weight of an alkyl acrylate unit (iii) 5 to, 20% by weight of an unsaturated nitrile unit and (iv) 5 to 40% by weight of an aromatic vinyl unit wherein:, (a) the multi-layer structure polymer consists essentially of an inner layer and an outer layer in a ring form, the portion of the inner layer (.beta. layer) within the ring has an average diameter of 2,000 to 6,500 .ANG. (b) the outer layer (.alpha. layer) portion surrounding the inner layer in the ring form has an average thickness of 200 to 500 .ANG. (c) the inner layer portion has a plurality of small particles …
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 February 16, 1990 and granted June 17, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 16, 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.