Production method of aromatic polycarbonate
View Patent ↗The object of the present invention is to provide a production method for an aromatic polycarbonate, in which eye boogers at the time of extrusion molding are reduced, and a continuous operation for a long period of time is possible. The present invention relates to a method when an extrusion molding is produced using an extruder in which a tapered part 1 has a half apex angle of from 4 to 20° formed at the outlet part of a die hole 9 , and outlet parts of plural die holes 9 are arranged in a staggered state at the resin discharge surface side of a die plate 10 , the shear rate γ at the extruder outlet is from 100 to 500 sec −1 , and the shear stress τ is from 50 to 200 kPa.
1. A production method of an aromatic polycarbonate, comprising extrusion molding an aromatic polycarbonate with an extruder and pelletizing the same wherein
a shear rate (γ) at an outlet of the extruder is in a range of from 100 to 500 sec −1 , and a shear stress (τ) at the outlet of the extruder is in a range of from 50 to 200 kPa,
wherein a viscosity average molecular weight (Mv) is 13,000 or more, the proportion of hydroxyl group (OH) in the whole terminal groups is from 5 to 50 mol %, and a ratio of the total mole number of branched structural units to one mole of a structural unit represented by the following formula (a) is from 0.1 to 0.8 mol %:
wherein X represents a single bond, an alkylene group having from 1 to 8 carbon atoms, an alkylidene group having from 2 to 8 carbon atoms, a cycloalkylene group having from 5 to 15 carbon atoms, a cycloalkylidene group having from 5 to 15 carbon atoms, or a divalent group selected from the group consisting of —O—, —S—, —CO—, —SO— and —SO 2 —.
2. The production method of an aromatic polycarbonate as claimed in claim 1 , wherein a die for extruder having a taper having a half apex angle of from 4 to 20° formed on the outlet part of the die for extruder is used.
3. The production method of an aromatic polycarbonate as claimed in claim 1 , wherein die holes formed on a die plate are arranged in a staggered state.
4. The production method of an aromatic polycarbonate as claimed in claim 1 , wherein the aromatic polycarbonate is obtained by a reaction between an aromatic dihydroxy compound and a carbonic diester.
5. The production method of an aromatic polycarbonate as claimed in claim 2 , wherein die holes formed on a die plate are arranged in a staggered state.
6. The production method of an aromatic polycarbonate as claimed in claim 2 , wherein the aromatic polycarbonate is obtained by a reaction between an aromatic dihydroxy compound and a carbonic diester.
7. The production method of an aromatic polycarbonate as claimed in claim 3 , wherein the aromatic polycarbonate is obtained by a reaction between an aromatic dihydroxy compound and a carbonic diester.
8. The production method of an aromatic polycarbonate as claimed in claim 5 , wherein the aromatic polycarbonate is obtained by a reaction between an aromatic dihydroxy compound and a carbonic diester.