PRODUCTION OF OXYMETHYLENE POLYMER

摘要

PURPOSE:To enable continuous production of the titled polymer in high conversion and efficiency, by polymerizing trioxane under a specific condition using a reactor having a cross-section consisting of a pair of mutually overlapped eccentric circles having the same diameter and containing a pair of stirring shafts and elliptical paddles fixed to the shafts. CONSTITUTION:A heating or cooling jacket 4 is attached to the outer wall of a barrel 5 of a reactor having a cross-section consisting of a pair of mutually overlapped eccentric circles having the same diameter. A raw material feeding port 1 and a product delivery port 2 are attached to both ends of the barrel. A pair of horizontal stirring shafts 3 are inserted in the barrel and paddles 6 having elliptical cross-sections are fixed to the shafts.One of the paddles is placed opposite to one of the other row of paddles and is shaped to be rotatable keeping a small clearance between the tip end of the paddle and the inner wall of the barrel and the opposite paddle. The longitudinal arrangement of the paddles on the stirring shaft is selected to give >=10% filling ratio of retaining polymer when a liquid mixture containing <=50mol% trioxane is continuously supplied through the raw material feeding port 1 and (co)polymerizied. Trioxane is polymerized in the above reactor.