Method for producing polyamide resin
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsTakafumi Oda, Nobuhide Tsunaka, Jun Mitadera, Tomonori Kato
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Abstract
A polyamide resin is produced by polycondensing a polyamide oligomer having a relative viscosity of from 1.1 to 1.3 and a water content of 3% by weight or less by melt-kneading using an intermeshed co-rotation twin screw extruder having at least one or more open vents OV1 and OV2 and at least one or more vacuum vents VV1 and VV2. A pressure-decreasing element Y for increasing the resin filling rate is provided at a position nearer to the supply section side than positions at which the vacuum vents VV1 and VV2 are provided, and an area of 30% or less of the total screw length is a vacuum area having a pressure of 300 Torr or less.
Claims9
A polyamide resin production method for producing a polyamide resin through polycondensation of a polyamide oligomer, the polyamide oligomer comprising a diamine unit containing 70 mol % or more of a diamine unit selected from an aromatic diamine unit represented by the following general formula (I-1) and an alicyclic diamine unit represented by the following general formula (I-2);
- and a dicarboxylic acid unit containing 50 mol % or more of a dicarboxylic acid unit selected from a linear aliphatic dicarboxylic acid unit represented by the following general formula (II-1) and an aromatic dicarboxylic acid unit represented by the following general formula (II-2), wherein
- in the production method, the polyamide oligomer having a relative viscosity of from 1.1 to 1.3 and a water content of 3% by mass or less is melt-kneaded to produce the polyamide resin through polycondensation, using an intermeshed co-rotation twin screw extruder having at least one open vent and at least one vacuum vent, and
- a pressure-decreasing element is provided at a position nearer to the supply section side than a position at which the vacuum vent is provided, and an area of 30% or less of the total screw length is a vacuum area having a pressure of 300 Torr or less in the extruder:
- wherein, in the general formula (II-1) n indicates an integer of from 2 to 18, and in the general formula (II-2) Ar represents an arylene group.
Dependencies are inferred from the claim text.