非常に純粋な2,4′-メチレンジフェニルジイソシアネートの製造方法

Japanese Patent JP5199532

B2

In the production of a diphenylmethanedi-isocyanate fraction containing at least 99 wt% binuclear di-isocyanate by reaction of aniline and formaldehyde followed by phosgenation and separation, the crude product is worked up by removal of some or all of the 2,2'-MDI to give a fraction containing 0-0.4 wt% 2,2'-MDI, 1-95 wt% 4,4'MDI and 5-98.6 wt% 2,4'-MDI. A method for the production of a diphenylmethanedi-isocyanate (MDI) fraction (I) containing at least 99 wt% binuclear MDI, involves (a) acid-catalysed reaction of aniline and formaldehyde to give di- and poly-amines, (b) phosgenation (optionally in solvent) to give crude di- and poly-isocyanate, (c) separation to give a faction containing at least 95 wt% binuclear MDI with a 4,4'-MDI content of 49-95.99 wt%, a 2,4'-MDI content of 4-45 wt% and a 2,2'-MDI content of 0.01-20 wt%, (d) optional removal of 10-98 wt% of the 4,4'-MDI and (e) removal of some or all of the 2,2'-MDI to give a fraction containing 0-0.4 wt% 2,2'MDI, 1-95 wt% 4,4'-MDI and 5-98.6 wt% 2,4'-MDI. An independent claim is also included for a method for the production of polyurethanes and prepolymers by reacting (I) with polyethers or polyesters.

Hans-Georg Pilkur
Jeffrey Bolton
Walter Meckel
Ulrich Wolf
Matthias Wintermantel
Jochen Marlenholtz

JP2005029552A

May 15, 2013

February 04, 2005

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Bayer MaterialScience AG

C07C263/10; C07C263/20; C07C265/14; C08G18/10; C08G18/12; C08G18/42; C08G18/48; C08G18/76; C09J175/04

JP53009750A
JP5163231A
JP6087814A
JP2002502838A
JP49048313A
JP58090540A

社団法人 日本化学会編,新実験化学講座1 基本操作I,日本,丸善株式会社,1978年 3月20日,第3刷,p.404-425

Einzel Felix-Reinhard
Takuya Kuno

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