Method for the production of transparent polyamides

Patent metadata

Field	Value
Publication number	US-12384883-B2
Application number	US-201917282067-A
Country	US
Kind code	B2
Filing date	Oct 2, 2019
Priority date	Oct 3, 2018
Publication date	Aug 12, 2025
Grant date	Aug 12, 2025

Abstract

A process for manufacturing a transparent polyamide including a step of polycondensation of a mixture of monomers including at least one dicarboxylic acid and at least one cycloaliphatic diamine, in which the cycloaliphatic diamine includes two rings linked by an alkylene group including 1 to 6 carbon atoms, each ring being substituted by an amine group and at least one alkyl group, which may be identical or different, including 1 to 6 carbon atoms, wherein the diamine decomposes into six isomer fractions when it is subjected to analysis by gas chromatography on a nonpolar column and, when the isomer fractions are named isomer fractions I to VI in their order of elution, the mass content F I of fraction I of the cycloaliphatic diamine does not exceed 35%. A transparent polyamide capable of being obtained by the process, and to articles obtained from such a polyamide or from such a formulation.

First claim

The invention claimed is:

1. A process for manufacturing a transparent polyamide comprising a step of polycondensation of a mixture of monomers comprising at least one dicarboxylic acid and at least one cycloaliphatic diamine,
in which the cycloaliphatic diamine comprises two rings linked by an alkylene group comprising 1 to 6 carbon atoms, each ring being substituted by an amine group and at least one alkyl group, which may be identical or different, comprising 1 to 6 carbon atoms,
wherein the diamine decomposes into six isomer fractions when it is subjected to analysis by gas chromatography on a nonpolar column and wherein, when said isomer fractions are named isomer fractions I to VI in their order of elution, the mass content F I of fraction I of said cycloaliphatic diamine does not exceed 33%,
wherein the dicarboxylic acid is a mixture of terephthalic acid and isophthalic acid comprising at least 50 mol % of terephthalic acid,
wherein the cycloaliphatic diamine is bis(3-methyl-4-aminocyclohexyl)methane and the polycondensation is carried out in the presence of lauryllactam or aminoundecanoic acid.

2. The process as claimed in claim 1 , in which at least one cycloaliphatic diamine is characterized by a mass content of isomer fraction F II which is greater than its mass content of isomer fraction F I .

3. The process as claimed in claim 1 , in which the at least one cycloaliphatic diamine is characterized by a difference ΔF II/I between the mass content of isomer fraction II and isomer fraction I which is greater than 0%.

4. The process as claimed in claim 1 , in which the dicarboxylic acid is a mixture of terephthalic acid and isophthalic acid comprising at least 60 mol % of terephthalic acid.

5. The process as claimed in claim 1 , in which the polycondensation is carried out in the presence of aminoundecanoic acid.

6. The process as claimed in claim 1 , in which the polycondensation is carried out in the presence of lauryllactam.

7. A transparent polyamide obtained by the process as claimed in claim 1 .

8. A formulation obtained from a transparent polyamide as claimed in claim 7 via mixing with one or more other polymers, additives, fillers and/or modifiers.

9. Articles obtained from a transparent polyamide as claimed in claim 7 .

10. The process as claimed in claim 1 , in which the dicarboxylic acid is a mixture of terephthalic acid and isophthalic acid comprising at least 75 mol % of terephthalic acid.

11. The process as claimed in claim 1 , in which the mass content F I of fraction I of said cycloaliphatic diamine does not exceed 30%.

Assignees

• Arkema France

Inventors

• Briffaud Thierry
• Saillard Benjamin
• Cassiano Gaspar Stefânia
• Verger Joël
• Olivier-Chanu Fabienne

Classifications

• C08G69/36 Primary

  derived from amino acids, polyamines and polycarboxylic acids · CPC title

• C08G69/265 Primary

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