Method for continuously producing polyamide oligomers and producing semicrystalline or amorphous polyamides that can be thermoplastically processed

Patent metadata

Field	Value
Publication number	US-10676569-B2
Application number	US-201414896780-A
Country	US
Kind code	B2
Filing date	Jun 11, 2014
Priority date	Jun 12, 2013
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

The invention relates to a process for continuously preparing polyamide oligomers. This comprises continuous conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, heating of the aqueous solution beyond a dissolution or storage temperature, the residence time of the monomer solution in the oligomerization reactor being limited and the pressure or the partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and/or the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and continuous discharge of the polyamide oligomers from the oligomerization reactor. A polyamide oligomer preparable by this process can be provided continuously in a mixture with water in a process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide and then postcondensed to give a polyamide. This polyamide can be used for production of moldings by means of injection molding, multicomponent injection molding, injection molding/welding, extrusion, coextrusion, blow molding or thermoforming.

First claim

The invention claimed is:

1. A process for continuously preparing polyamide oligomers, comprising
continuously conveying an aqueous solution of water and polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, wherein the aqueous solution has a water content in a range from 5 wt. % to 95 wt. % based on the water and the polyamide-forming monomers combined,
heating the aqueous solution beyond a dissolution or storage temperature, a residence time of the monomer solution in the oligomerization reactor being limited and a pressure or partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and
continuously discharging an aqueous solution of the polyamide oligomers from the oligomerization reactor;
wherein:
during a first mean residence time t1 of the aqueous solution in the oligomerization reactor the temperature of the reaction mixture approaches and/or attains a first oligomerization temperature OT1 and the pressure or the partial steam pressure in the oligomerization reactor approaches or is a first pressure p1,
during a second mean residence time t2 thereafter the temperature of the aqueous solution approaches or attains a second oligomerization temperature OT2 and the pressure or the partial steam pressure in the oligomerization reactor approaches or is a second pressure p2,
the first mean residence time t1 is greater than or equal to the second mean residence time t2 and the first oligomerization temperature OT1 is less than the second oligomerization temperature OT2,
the first oligomerization temperature OT1 is within a range from 225° C. to 255° C., and
the second mean residence time t2 is at least 10 minutes.

2. The process according to claim 1 , wherein polyamides in the case of exclusive hydrolytic cleavage of the amide groups provides a composition of the following formula (I)
A1 a1 |B1 b1 |A2 a2 |B2 b2 |B3 b3 |AX ax |BY by |AB ab |A2B a2b |AXBY axby   (I)

in which
A1 denotes units which derive from an unsubstituted or substituted monocarboxylic acid or derivative thereof,
A2 denotes units which derive from an unsubstituted or substituted dicarboxylic acid or derivative thereof,
AX denotes units which derive from a compound having a carboxyl functionality greater than two,
B1 denotes units which derive from a monofunctional amine,
B2 denotes units which derive from a diamine,
B3 denotes units which derive from a triamine,
BY denotes units which derive from a compound having an amino functionality greater than three,
AB denotes units which derive from an aminocarboxylic acid,
A2B denotes units which derive from an aminodicarboxylic acid,
AXBY denotes units which derive from a compound having amino and carboxyl groups where the functionalities X+Y are greater than 2,
with the proviso that the sum of all indices a1+b1+a2+b2+b3+ax+by+ab+a2b+axby adds up to 100 mol %.

3. The process according to claim 1 , wherein the polyamide-forming monomers are selected from the group consisting of
A) unsubstituted or substituted aromatic dicarboxylic acids and derivatives of unsubstituted or substituted aromatic dicarboxylic acids,
B) unsubstituted or substituted aromatic diamines,
C) aliphatic or cycloaliphatic dicarboxylic acids,
D) aliphatic or cycloaliphatic diamines,
E) monocarboxylic acids,
F) monoamines,
G) at least trifunctional amines,
H) lactams,
I) ω-amino acids, and
K) compounds which are different than A) to I) and are cocondensable therewith, and mixtures thereof.

4. The process according to claim 3 , wherein at least one of components A) and B) is present for provision of the aqueous composition in step a).

5. The process according to claim 3 , wherein the aromatic dicarboxylic acid A) is terephthalic acid, isophthalic acid, or a mixture of terephthalic acid and isophthalic acid.

6. The process according to claim 1 , wherein the polyamide is selected from the group consisting of PA 6.T, PA 9.T, PA8.T, PA 10.T, PA 12.T, PA 6.I, PA 8.I, PA 9.I, PA 10.I, PA 12.I, PA 6.T/6, PA 6.T/10, PA 6.T/12, PA 6.T/6.I, PA6.T/8.T, PA 6.T/9.T, PA 6.T/10T, PA 6.T/12.T, PA 12.T/6.T, PA 6.T/6.I/6, PA 6.T/6.I/12, PA 6.T/6.I/6.10, PA 6.T/6.I/6.12, PA 6.T/6.6, PA 6.T/6.10, PA 6.T/6.12, PA 10.T/6, PA 10.T/11, PA 10.T/12, PA 8.T/6.T, PA 8.T/66, PA 8.T/8.I, PA 8.T/8.6, PA 8.T/6.I, PA 10.T/6.T, PA 10.T/6.6, PA 10.T/10.I, PA 10T/10.I/6.T, PA 10.T/6.I, PA 4.T/4.I/46, PA 4.T/4.I/6.6, PA 5.T/5.I, PA 5.T/5.I/5.6, PA 5.T/5.I/6.6, PA 6.T/6.I/6.6, PA MXDA.6, PA IPDA.I, PA IPDA.T, PA MACM.I, PA MACM.T, PA PACM.I, PA PACM.T, PA MXDA.I, PA MXDA.T, PA 6.T/IPDA.T, PA 6.T/MACM.T, PA 6.T/PACM.T, PA 6.T/MXDA.T, PA 6.T/6.I/8.T/8.I, PA 6.T/6.I/10.T/10.I, PA 6.T/6.I/IPDA.T/IPDA.I, PA 6.T/6.I/MXDA.T/MXDA.I, PA 6.T/6.I/MACM.T/MACM.I, PA 6.T/6.I/PACM.T/PACM.I, PA 6.T/10.T/IPDA.T, PA 6.T/12.T/IPDA.T, PA 6.T/10.T/PACM.T, PA 6.T/12.T/PACM.T,PA 10.T/IPDA.T, PA 12.T/IPDA.T and copolymers and mixtures thereof.

7. The process according to claim 1 , wherein the first pressure p1 corresponds to the saturation vapor pressure of water at the first oligomerization temperature OT1 and the second pressure p2 is below the saturation vapor pressure of water at the second oligomerization temperature OT2.

8. The process according to claim 1 , wherein the first mean residence time t1 is 0 min to 240 min.

9. The process according to claim 1 , wherein the first pressure p1 is 1.5 MPa to 5.0 MPa.

10. The process according to claim 1 , wherein the second oligomerization temperature OT2 is 240° C. to 300° C.

11. The process according to claim 1 , wherein the second mean residence time t2 is 20 minutes to 50 minutes.

12. The process according to claim 1 , wherein the pressure p2 is 1.9 MPa to 5.0 MPa.

13. A polyamide oligomer prepared by the process according to claim 1 .

14. A process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide, comprising
continuously providing a mixture comprising water and a polyamide oligomer according to claim 13 , and
postcondensing the polyamide oligomer to give a polyamide.

15. A polyamide prepared by the process according to claim 14 .

16. A method for the production of films, monofilaments, fibers, yarns or textile fabrics comprising the use of an aliphatic polyamide according to claim 15 .

17. A method for the production of electrical and electronic components and for high-temperature automotive applications comprising use of a semiaromatic polyamide according to claim 15 .

18. The method according to claim 17 for use in soldering operations under lead-free conditions and, for production of plug connectors, microswitches, microbuttons, semiconductor components, and reflector housings of light-emitting diodes.

19. The process according to claim 1 , further comprising, prior to continuously conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor:
combining at least one dicarboxylic acid, at least one diamine, and water to form the aqueous solution of polyamide-forming monomers.

20. The process according to claim 1 , wherein the second mean residence time t2 is at least 20 minutes.

21. The process according to claim 1 , wherein the second mean residence time t2 is 20 minutes to 60 minutes.

22. The process according to claim 1 , wherein conversion of mono

Assignees

• Basf Se

Inventors

• Clauss Joachim
• Schwiegk Stefan
• Kory Gad
• Schmidt Christian
• Wilms Axel
• Richter Florian
• Zhu Ning
• Biedasek Silke
• Queiroz Da Fonseca Isa Alexandra
• Sack Heinrich
• Schneller Arnold
• Stammer Achim
• Rauschenberger Volker

Classifications

• C08G69/28 Primary

  Preparatory processes · CPC title

• C08G69/30 Primary

  Solid state polycondensation · CPC title