Method for producing polyamide resin

Patent metadata

Field	Value
Publication number	US-2016376407-A1
Application number	US-201414903247-A
Country	US
Kind code	A1
Filing date	Jul 2, 2014
Priority date	Jul 10, 2013
Publication date	Dec 29, 2016
Grant date	—

Abstract

A polyamide resin is produced through polycondensation by melt-kneading a polyamide oligomer having a relative viscosity of from 1.1 to 1.3 and a water content of 3% by mass or less in a cylinder (S) of an extruder. The extruder includes open vents (OV 1 ) and (OV 2 ) and vacuum vents (V 1 ) and (V 2 ). The open vent (OV 1 ) is arranged near a supply port (A 3 ), e.g., above the supply port (A 3 ), and a pressure-decreasing element (Y) is arranged on an upstream side with respect to positions of the vacuum vents (V 1 ) and (V 2 ). In addition, the open vent (OV 2 ) is arranged in a preceding area (OA) and is brought into a pressurized state.

First claim

1 . A polyamide resin production method for producing a polyamide resin through polycondensation of a polyamide oligomer using an extruder including an intermeshed co-rotation twin screw within a cylinder, the polyamide oligomer comprising: a diamine unit comprising 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 comprising 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),
the production method comprising supplying the polyamide oligomer having a relative viscosity of from 1.1 to 1.3 and a water content of 3% by mass or less from a supply port into the cylinder and melt-kneading the polyamide oligomer in the cylinder to produce the polyamide resin through polycondensation, the extruder comprising an open vent ( 1 ), an open vent ( 2 ), and a vacuum vent, the open vent ( 1 ) being arranged at at least one of a position above the supply port or a position on an upstream end side with respect to a position of the supply port in the cylinder, the extruder further comprising a pressure-decreasing element arranged on an upstream side with respect to a position of the vacuum vent, the open vent ( 2 ) being arranged on a side downstream with respect to the position of the supply port in the cylinder and upstream with respect to a position of the pressure-decreasing element, the open vent ( 2 ) being brought into a pressurized state, an area of 50% or less of a total screw length of the extruder comprising a vacuum area at 300 torr or less:

wherein, in the general formula (II-1), n represents an integer of from 2 to 18, and in the general formula (II-2), Ar represents an arylene group.

2 . The polyamide resin production method according to claim 1 , wherein the extruder comprises only one open vent ( 2 ).

3 . The polyamide resin production method according to claim 1 , wherein a relative viscosity of the polyamide resin is from 1.8 to 4.0.

4 . The polyamide resin production method according to claim 1 , wherein the polyamide oligomer has blended therein a phosphorus compound at a phosphorus atom concentration of from 10 ppm to 500 ppm.

5 . The polyamide resin production method according to claim 1 , wherein a kneading section for kneading the polyamide oligomer is arranged both in the vacuum area and at a position on an upstream side with respect to the vacuum area.

6 . The polyamide resin production method according to claim 1 , wherein at least one vacuum vent is arranged in an area of 25% or less of the total screw length from an end on a die side of the extruder.

7 . The polyamide resin production method according to claim 1 , wherein a kneading section comprising a kneading element having strong distributive mixing performance is arranged in an area of 25% or less of the total screw length from an end on a die side of the extruder.

8 . The polyamide resin production method according to claim 1 , wherein a kneading section for kneading the polyamide oligomer is arranged at a position on an upstream side with respect to the vacuum area and the kneading section comprises a kneading element having strong dispersive mixing performance.

9 . (canceled)

10 . A polyamide resin production method for producing a polyamide resin through polycondensation of a polyamide oligomer using an extruder including an intermeshed co-rotation twin screw within a cylinder, the polyamide oligomer comprising: a diamine unit comprising 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 comprising 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),
the production method comprising supplying the polyamide oligomer having a water content of 3% by mass or less from a supply port into the cylinder and melt-kneading the polyamide oligomer in the cylinder to produce the polyamide resin through polycondensation, the extruder comprising, in the cylinder, a vacuum vent, a pressure-decreasing element arranged on an upstream side with respect to a position of the vacuum vent, and an open vent ( 1 A) arranged on a side downstream with respect to the supply port and upstream with respect to the pressure-decreasing element, an area of 50% or less of a total screw length of the extruder comprising a vacuum area at 300 torr or less, a difference between a relative viscosity of a polyamide resin located below the open vent ( 1 A) and a relative viscosity of a polyamide resin extruded from the extruder being 0.9 or less:

wherein, in the general formula (II-1), n represents an integer of from 2 to 18, and in the general formula (II-2), Ar represents an arylene group.

11 . The polyamide resin production method according to claim 10 , wherein the relative viscosity of the polyamide resin located below the open vent ( 1 A) is 1.6 or more.

12 . The polyamide resin production method according to claim 10 , wherein the extruder further comprises a preceding open vent at at least one of a position above the supply port or a position on an upstream end side with respect to the open vent ( 1 A) in the cylinder.

13 . The polyamide resin production method according to claim 10 , wherein a relative viscosity of the polyamide oligomer is from 1.1 to 1.3.

14 . The polyamide resin production method according to claim 10 , wherein the open vent ( 1 A) is in a pressurized state.

15 . The polyamide resin production method according to claim 10 , wherein a relative viscosity of the polyamide resin is from 1.8 to 4.0.

16 . The polyamide resin production method according to claim 10 , wherein a molecular weight distribution (Mw/Mn) of the polyamide resin is from 1.8 to 2.5.

17 . The polyamide resin production method according to claim 10 , wherein the polyamide oligomer has blended therein a phosphorus compound at a phosphorus atom concentration of from 10 ppm to 500 ppm.

18 . The polyamide resin production method according to claim 10 , wherein a kneading section for kneading the polyamide oligomer is arranged both in the vacuum area and at a position on an upstream side with respect to the vacuum area.

19 . The polyamide resin production method according to claim 10 , wherein at least one vacuum vent is arranged in an area of 25% or less of the total screw length from an end on a die side of the extruder.

20 . The polyamide resin production method according to claim 10 , wherein a kneading section comprising a kneading element having strong distributive mixing performance is arranged in an area of 25% or less of the total screw length from an end on a die side of the extruder.

21 . The polyamide resin production method according to claim 10 , wherein a kneading section for kneading t

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• Tsunaka Nobuhide
• Oda Takafumi
• Mitadera Jun
• Kato Tomonori

Classifications

• B29C48/40

  using two or more parallel screws {or at least two parallel non-intermeshing screws}, e.g. twin screw extruders · CPC title

• B29C48/405

  Intermeshing co-rotating screws · CPC title

• B29C48/022

  characterised by the choice of material · CPC title

• B29C48/57

  provided with kneading disc-like elements, e.g. with oval-shaped elements · CPC title

• C08L77/06

  Polyamides derived from polyamines and polycarboxylic acids (C08L77/10 takes precedence) · CPC title