Process for the preparation of a polyamide

Patent metadata

Field	Value
Publication number	US-9850348-B2
Application number	US-201414763642-A
Country	US
Kind code	B2
Filing date	Jan 30, 2014
Priority date	Jan 30, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The invention relates to a process for preparing a semi-aromatic polyamide from diamine and dicarboxylic acid, comprising steps of •(i) dosing a liquid diamine to an agitated powder comprising an aromatic dicarboxylic acid thereby forming a powder comprising a diamine/dicarboxylic acid salt (DD-salt), and •(ii) solid-state polymerizing the DD-salt to obtain the polyamide.

First claim

The invention claimed is:

1. A process for preparing granulated particles of a semi-crystalline semi-aromatic copolyamide from diamines and a dicarboxylic acid, the process comprising the steps of:
(i) forming a powder comprising a diamine/dicarboxylic acid salt (DD-salt) by dosing a liquid diamine mixture comprising at least two aliphatic diamines selected from C2-C10 diamines to an agitated powder comprising an aromatic dicarboxylic acid selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid, biphenyl-4,4′-dicarboxylic acid and combinations thereof at a dosing rate of at most 4 mole % diamine per minute, relative to the molar amount of the dicarboxylic acid such that the dicarboxylic acid constitutes at least 50 mole %, relative to the total molar amount of dicarboxylic acid of the agitated powder, thereby forming the powder comprising the DD-salt in the absence of melting, and thereafter
(ii) subjecting the powder comprising the DD-salt without intervening melting of the powder to solid-state polymerization conditions to thereby obtain the granulated particles of semi-crystalline semi-aromatic copolyamide having a microporous structure with a BET surface value of at least 0.4 m 2 /g as measured according to ISO 9377:2010 and a particle size distribution (d50) of at least 50 μm.

2. The process according to claim 1 , which comprises subjecting the powder obtained from step (i) to a solid-state shaping process prior to conducting the solid-state polymerization according to step (ii).

3. The process according to claim 1 , wherein the agitated powder further comprises an aliphatic dicarboxylic acid selected from the group consisting of adipic acid and cyclohexane dicarboxylic acid.

4. The process according to claim 1 , wherein the at least two aliphatic diamines are selected from the group consisting of 1,4-butane diamine, 1,6-hexane diamine and 1,10-decane diamine.

5. The process according to claim 1 , wherein step (ii) comprises the sub-steps of:
(ii-a) condensing the DD-salt obtained in step (i) at a first condensation temperature (Tc1) at least 10° C. below the melting point of the DD-salt to produce a solid prepolymer; and
(ii-b) conducting further condensation of the solid prepolymer resulting from step (ii-a) at a second condensation temperature (Tc2) at least 15° C. below the melting temperature of the prepolymer and the melting temperature of the resulting copolyamide to thereby obtain the granulated particles of semi-crystalline semi-aromatic copolyamide in a solid state.

6. The process according to claim 1 wherein the granulated particles of semi-crystalline semi-aromatic copolyamide have a melting temperature of at least 280° C.

7. The process according to claim 1 wherein the DD-salt has a melting temperature of at least 240° C.

8. The process according to claim 5 , wherein the prepolymer has a viscosity number of at least 10 ml/g prior to step (ii-b).

9. The process according to claim 5 , wherein the dicarboxylic acid comprises at least 90 mole % terephthalic acid relative to the total molar amount of dicarboxylic acid, and wherein the liquid diamine mixture comprises a C2-C10 diamine, in an amount of at least 80 mole % relative to the total molar amount of diamines.

10. The process according to claim 5 , wherein step (ii-b) comprises adding supplemental diamine during the further condensation.

11. The process according to claim 1 , wherein the copolyamide has a viscosity number of at least 20 ml/g, as measured in 96% sulphuric acid (0.005 g/ml) at 25° C. according to ISO 307, fourth edition.

12. The process according to claim 11 , wherein the copolyamide has a viscosity number of at least 50 ml/g.

13. The process according to claim 1 , wherein the aromatic dicarboxylic acid constitutes at least 80 mole %, relative to the total molar amount of dicarboxylic acid of the agitated powder.

14. The process according to claim 1 , wherein the powder particles of semi-crystalline semi-aromatic copolyamide have a BET surface value of 0.6 to 1.5 m 2 /g and a particle size distribution (d50) of at least 100 μm.

15. A semi-crystalline semi-aromatic copolyamide powder, obtained by the process according to claim 1 .

Assignees

• Dsm Ip Assets Bv

Inventors

• Grolman Eric
• Rulkens Rudy
• Dullaert Konraad Albert Louise Hector
• Kierkels Renier Henricus Maria
• Vanden Poel Geert Adelina Rudolf

Classifications

• C08L77/06

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

• C08G69/265

  from at least two different diamines or at least two different dicarboxylic acids · CPC title

• C07C209/68 Primary

  from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton · CPC title

• C08G69/30

  Solid state polycondensation · CPC title

• C07C51/412

  by conversion of the acids, their salts, esters or anhydrides with the same carboxylic acid part · CPC title