Antioxidant hindered phenolaldehydes
CA 1048529 A · Owner: Ciba-Geigy Ag · Inventors: Schmidt, Andreas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
New p-hydroxyphenyl aldehydes of the formula in which R1 and R5 are each hydrogen or methyl and R2, R4, R6 and R7 each, represent a variety of organic substituents and n is 0 or 1 are used as, stabilizers for polymeric substrates. They are manufactured by reducing the corresponding p-hydroxyphenylacetic acid chloride with hydrogen or by reacting a p-nydroxybenzyl halido with an aldehyde in the presence of a base or by reucting a dithiocarbamic acid p-hydroxybenzyl ester with an aldehyde in the presence of a base.
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 February 13, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 13, 1996.
- 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.