公开(公告)号：JPS55115840A

公开(公告)日：1980-09-06

申请号：JP2424979

申请日：1979-03-01

Applicant: TORAY INDUSTRIES

Inventor： KONDOU RIYOUZOU ,  YOKOYAMA TSUKASA ,  IKENO SHIGEO

IPC: C07C47/058 ,  C07C45/00 ,  C07C67/00

Abstract: PURPOSE:To bring a gas containing formaldehyde (K), stripped in a stripping step between dissolving and regeneration steps, into contact with a hydrous DMSO solution for recovering excess K used in the regeneration of cellulose. CONSTITUTION:Cellulose (C), a low-polymerization degree polyoxymethylene (F), and DMSO (D) are fed to the dissolving step A to give a formaldehyde adduct solution in D. The solution is then fed to the stripping step E, and heated with the carrier gas G to change excess F into the mixed gas Fg, which is fed to the gas- liquid contact step H. K in the mixed gas Fg is collected by the hydrous DMSO solution filled into the step H and external circulation system, and converted into F to give a slurry of F. F obtained by separation of the slurry or the slurry is directly fed to the step A.