Process for the preparation of halogenated (meth)acrylic esters and poly (meth) arcylates obtained with said (meth)acrylic esters
申请人:Akzo Nobel N.V.
公开号:EP0824096A2
公开(公告)日:1998-02-18
The present invention is directed to a process for the preparation of (meth)acrylates of halogenated alcohols by direct esterification of said alcohols with (meth)acrylic acid (chloride) wherein at least 2,6-substituted pyridine derivative is used as a polymerization inhibitor at room temperature or lower. Suitable at least 2,6-substituted pyridine derivatives are 2,6-lutidine, 2,4,6-collidine or 2,6-di-tert.butyl-4-methyl pyridine.
With the halogenated (meth)acrylate esters prepared with the process according to the invention, very pure homo- and copolymers can be prepared, resulting in polymers having a low optical loss of 0.1 dB/cm or lower at 1300 nm and lower than 0.4 dB/cm at 1550 nm.
The oxidation of halogen anions by dimethyldioxirane (DMD) produced reactive species which led, in acidic media, to the halogenation of activatedaromatic rings. The reaction can be efficiently controlled to obtain selective and mixed halogenated species.