Process for producing crosslinked urea-formaldehyde polymer particles
CA 1192339 A · Owner: Mitsui Chemicals Inc. · Inventors: Seita, Kenzo; Usami, Kaoru; Ifuku, Naoyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Title of the Invention Process for Producing Crosslinked, Urea-Formaldehyde Polymer Particles Abstract, Disclosed is a process for producing fine particles of crosslinked urea-formaldehyde polymer which comprises the steps of synthesizing a precondensate of urea and formaldehyde, allowing the precondensate to react by the addition of an aqueous solution of an acid catalyst and then neutralizing the reaction mixture characterized, in that the filtrate obtained in the filtration step for separating the polymer particles is recycled to the reaction system at the step of synthesizing a precondensate - 2 -, of urea and formaldehyde and/or the step of allowing the precondensate to react by the …
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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 August 20, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 20, 2002.
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Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.