# US 2020/0399426 A1 · Process for synthesizing polyamide pa 6-6

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- Number: US 2020/0399426 A1
- Document ID: US20200399426A1
- Status: Published application
- Kind: A1
- Application number: 16/319,101
- Filed: 2017-07-25
- Published: 2020-12-24
- Earliest claimed: 2016-07-25
- Assignees: Arkema France
- Applicants: Arkema France
- Inventors: Jean-Luc DUBOIS
- Web page: https://patentgrep.com/patent/US20200399426A1

## CPC

- C08G 69/28: Preparatory processes
- B60C 9/0007: {Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal}
- C08G 69/265: {from at least two different diamines or at least two different dicarboxylic acids}
- D01F 6/90: of polyamides
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS

## Abstract

A process for synthesizing polyamide PA 6-6, including a first step of reacting, in the presence of water, a compound of R0COO—(CH2)4—COOR′0 in which R0 and R′0, which may be identical or different, represent H or a linear or branched alkyl radical comprising from 1 to 4 carbon atoms, with hexamethylenediamine (HMDA), at a temperature of less than or equal to 160° C., to form a reaction medium, and then a second step of heating the reaction medium to a temperature of greater than or equal to 200° C.; the reaction medium also including a compound of R1—COO—(CH2)n—CH═CH—(CH2)n—COO—R2 and/or a compound of R3—(CH2)m—CH═CH—(CH2)n—COO—R4.

## Claims

### Claim 1

A process for synthesizing polyamide PA 6-6, comprising:
a first step of reacting, in the presence of water, a compound of formula (I):
R0—OOC—(CH2)4—COO—R′0 (I)
in which R0 and R′0, which may be identical or different, represent H or a linear or branched alkyl radical comprising from 1 to 4 carbon atoms,
with hexamethylenediamine (HMDA), to form a reaction medium, and then
a second step of heating the reaction medium to a temperature of greater than or equal to 200° C.;
the reaction medium also comprising:
a compound of formula (A):
R1—OOC—(CH2)n—CH═CH—(CH2)n—COO—R2 (A)
and/or a compound of formula (B):
R3—(CH2)m—CH═CH—(CH2)n—COO—R4 (B)
in which:
R1, R2 and R4, which may be identical or different, represent H or a linear or branched alkyl radical comprising from 1 to 4 carbon atoms,
R3 represents —CN or —COO—R5, R5 representing H or a linear or branched alkyl radical comprising from 1 to 4 carbon atoms,
m represents 0, 1 or 2 and n is an integer between 7 and 13, limits inclusive.

### Claim 2 (depends on 1)

The process as claimed in claim 1, in which R0, R′0, R1, R2 and R4, which may be identical or different, represent H or a —CH3 group and R3 represents —CN.

### Claim 3 (depends on 1)

The process as claimed in claim 1, in which m=0 and n=7.

### Claim 4 (depends on 1)

The process as claimed in claim 1, in which the compound of formula (A) and the compound of formula (B) are added to the reaction medium in the form of a mixture of the compound of formula (A) and of the compound of formula (B) and the mixture of the compound of formula (A) and of the compound of formula (B) comprises from 95 mol % to 99.9 mol % of the compound of formula (A) and from 0.1% to 5% of the compound of formula (B).

### Claim 5 (depends on 1)

The process as claimed in claim 1, in which the sum of the amounts of the compound of formula (A) and of the compound of formula (B) in the reaction medium represents from 0.1 mol % to 20 mol % of the sum of the amounts of HMDA and of the compound of formula (I).

### Claim 6 (depends on 1)

The process as claimed in claim 1, in which the first step is performed in the presence of an amount of water such that the mole ratio of the amount of water/sum of the amounts of compound of formula (I), of HMDA, of compound of formula (A) and of compound of formula (B) is between 1/15 and 15/1.

### Claim 7 (depends on 1)

The process as claimed in claim 1, in which the first step is performed at a temperature of between 80 and 160° C.

### Claim 8 (depends on 1)

The process as claimed in claim 1, in which the second step is performed at a temperature of between 200 and 300° C.

### Claim 9 (depends on 1)

A polyamide PA 6-6 that may be obtained by performing the process as defined in claim 1.

### Claim 10

A polyamide PA 6-6 comprising at least one residue chosen from the group constituted by the residues of formulae (A′) and (B′):
—[CO—(CH2)n—CH═CH—(CH2)n,—CO]— (A′),
—[CO—(CH2)m—CH═CH—(CH2)n—CO]— (B′),
in which m represents 0, 1 or 2 and n is an integer between 7 and 13, limits inclusive.

### Claim 11 (depends on 10)

The polyamide PA 6-6 as claimed in claim 10, comprising two or three different residues chosen from the group constituted by the residues of formulae (A′) and (B′).

### Claim 12 (depends on 10)

The polyamide PA 6-6 as claimed in claim 10, comprising several residues of formulae —[CO—(CH2)n—CH═CH—(CH2)n—CO]— (A′) and/or —[CO—(CH2)m—CH═CH—(CH2)n,—CO]— (B′).

### Claim 13 (depends on 10)

The polyamide PA 6-6 as claimed in claim 10, in which m=0 and n=7.

### Claim 14 (depends on 10)

The polyamide PA 6-6 as claimed in claim 10, in which the molar percentage of the amount of residues (A′) and (B′) relative to the amount of adipic acid and hexamethylenediamine residues is from 0.1 mol % to 20 mol %.

### Claim 15 (depends on 9)

Use of a polyamide PA 6-6 as defined in claim 9, for the production of textile fibers, for the production of carpet fibers, for the production of tire cords or for the production of molded parts, such as tubes.

### Claim 16 (depends on 1)

The process as claimed in claim 1, wherein the first step of reacting is at a temperature of less than or equal to 160° C.