SEMI-AROMATIC POLYAMIDES WITH A LOW MELTING TEMPERATURE

1 . A polyamide (PA) exhibiting a melting temperature Tm-strictly lower than 290° C. and comprising recurring units formed from the polycondensation of a diamine component (A) and a dicarboxylic acid component (B) wherein:

a) the diamine component (A) comprises:

between 15.0 and 25.0 mol % of 1,6-hexanediamine;

between 18.0 and 30.0 mol % of a diamine (D1) selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;

between 50.0 and 64.0 mol % of a diamine (D2) selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane and a combination of said two diamines;

these proportions in mol % being based on the total amount of diamines in the diamine component (A); and

b) the dicarboxylic acid component (B) comprises:

between 95.0 and 100.0 mol % of terephthalic acid;

between 0 and 5.0 mol % of another diacid (DI) selected from the group consisting of isophthalic acid, adipic acid and a combination of the two said diacids;

these proportions in mol % being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B);

Tm being measured by Differential Scanning calorimetry (“DSC”) according to ASTM D3418, using a heating and cooling rate of 20° C./min.

2 . The Polyamide (PA) according to claim 1 , wherein the diamine component (A) consists essentially of 1,6-diaminohexane; a diamine (D1) selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines and a diamine (D2) selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane and a combination of said two diamines, the expression “consist essentially of” meaning that the diamine component (A) consist of 1,6-diaminohexane, of D1 and of D2 and up to 2.0 mol % of at least one additional diamine other than 1,6-diaminohexane, of D1 and of D2, this proportion in mol % being based on the total amount of diamines in the diamine component (A), and/or wherein the dicarboxylic acid component (B) consists essentially of terephthalic acid and the other diacid(s) (DI), the expression “consist essentially” meaning that the dicarboxylic acid component (B) consists of terephthalic acid, of diacid (DI) and up to 2.0 mol % of at least one additional diacid other than terephthalic acid and diacid(s) (DI), this proportion in mol % being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

3 . (canceled)

4 . The Polyamide according to claim 1 , wherein the dicarboxylic acid component (B) consists essentially of or consists of terephthalic acid, the expression “consist essentially” meaning that the dicarboxylic acid component (B) consists of terephthalic acid and up to 2.0 mol % of at least one additional diacid other than terephthalic acid, this proportion in mol % being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

5 . The Polyamide (PA) according to claim 1 , wherein the proportions in the dicarboxylic acid component (B) are the following ones:

between 95.0 and 99.9 mol % of terephthalic acid and between 0.1 and 5.0 mol % of the other diacid(s) (DI); or

between 98.0 and 99.9 mol % of terephthalic acid and between 0.1 and 2.0 mol % of the other diacid(s) (DI).

6 . The Polyamide (PA) according to claim 1 comprising recurring units (R PA1 ), (R PA2 ) and (R PA3 ):

or the following ones:

where R 1 is —(CH 2 ) 6 — and R 2 is the divalent radical of a diamine selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;

the proportions in said recurring units being the following:

R PA1 : between 15.0 and 25.0 mol %;

R PA2 : between 18.0 and 30.0 mol %;

R PA3 : between 50.0 and 64.0 mol %;

these proportions in mol % being relative to the total amount of recurring units in the polyamide (PA);

wherein the total proportion of recurring units (R PA1 ), (R PA2 ) and (R PA3 ) is at least 95.0 mol %, more particularly at least 99.0 mol %; or

wherein the recurring units of the polyamide (PA) consists essentially of the recurring units (R PA1 ), (R PA2 ) and (R PA3 ), the expression “consist essentially” in relation to the recurring units of polyamide (PA) meaning that the recurring units of the polyamide consist of (R PA1 ), (R PA2 ) and (R PA3 ) and up to 2.0 mol % of recurring units other than recurring units (R PA1 ), (R PA2 ) and (R PA3 ).

7 . (canceled)

8 . (canceled)

9 . The Polyamide (PA) according to claim 1 , wherein the proportion of 1,6-hexanediamine in the diamine component (A) or the proportion of R PA1 in the polyamide (PA) is;

between 18.0 and 22.0 mol %; or

between 15.0 and 22.0 mol %; or

between 18.0 and 22.0 mol %.

10 . The Polyamide (PA) according to claim 1 , wherein the proportion in the diamine component (A) of the other diamine (D1) selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines or the proportion of R PA2 in the polyamide (PA) is:

between 18.0 and 27.0 mol %; or

between 23.0 and 27.0 mol %;

between 18.0 and 22.0 mol %.

11 . The Polyamide (PA) according to claim 1 , wherein the proportion in the diamine component (A) of the other diamine (D2) selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane and a combination of said two diamines or the proportion of R PA3 in the polyamide (PA) is:

between 50.0 and 62.0 mol %; or

between 53.0 and 62.0 mol %; or

between 53.0 and 57.0 mol %; or

between 58.0 and 62.0 wt %; or

between 61.0 and 64.0 mol %.

12 . The Polyamide (PA) according to claim 1 , wherein the proportions in the diamine component (A) are the following ones:

between 18.0 and 22.0 mol % of 1,6-diaminohexane;

between 23.0 and 27.0 mol % of a diamine (D1) selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;

between 53.0 and 57.0 mol % of a diamine (D2) selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane and a combination of said two diamines;

or the following ones:

between 18.0 and 22.0 mol % of 1,6-hexanediamine;

between 18.0 and 22.0 mol % of a diamine (D1) selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;

between 58.0 and 62.0 mol % of a diamine (D2) selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane and a combination of said two diamines;

or the following ones:

between 15.0 and 20.0 mol % of 1,6-hexanediamine;

between 18.0 and 22.0 mol % of a diamine (D1) selected from the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;

between 61.0 and 64.0 mol % of a diamine (D2) selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane and a combination of said two diamines;

13 . The Polyamide (PA) according to claim 6 , wherein the proportions are the following ones:

between 18.0 and 22.0 mol % of R PA1 ;

between 23.0 and 27.0 mol % of R PA2 ;

between 53.0 and 57.0 mol % of R PA3 ,

or the following ones:

between 18.0 and 22.0 mol % of R PA1 ;

between 18.0 and 22.0 mol % of R PA2 ;

between 58.0 and 62.0 mol % of R PA3 ;

or the following ones:

between 15.0 and 20.0 mol % of R PA1 ;

between 18.0 and 22.0 mol % of R PA2 ;

between 61.0 and 64.0 mol % of R PA3 .

14 . (canceled)

15 . (canceled)

16 . The Polyamide (PA) according to claim 1 , wherein the melting temperature Tm of the polyamide (PA) is:

lower than 285° C.; and/or

at least 250° C.;

Tm being measured by Differential Scanning calorimetry (“DSC”) according to ASTM D3418, using a heating and cooling rate of 20° C./min.

17 . The Polyamide (PA) according to claim 1 , wherein the glass transition temperature Tg of the polyamide (PA) is:

at least 155° C.; and/or

at most 200° C.;

Tg being measured by Differential Scanning calorimetry (“DSC”) according to ASTM D3418, using a heating and cooling rate of 20° C./min.

18 . The Polyamide (PA) according to claim 1 , exhibiting a difference (Tm-Tg) lower than 130° C.; and/or exhibiting a difference (Tm-Tc) of at least 50.0° C., the melting temperature Tm and the crystallization temperature Tc being measured by Differential Scanning calorimetry (“DSC”) according to ASTM D3418, using a heating and cooling rate of 20° C./min.

19 . (canceled)

20 . (canceled)

21 . The Polyamide (PA) according to claim 1 , exhibiting a heat of fusion Hm of at least 15.0 J/g, Hm being measured by Differential Scanning calorimetry (“DSC”) according to ASTM D3418 using a heating and cooling rate of 20° C./min; and/or exhibiting a heat of fusion Hm between 15.0 and 40.0 J/g, Hm being measured by Differential Scanning calorimetry (“DSC”) according to ASTM D3418, using a heating and cooling rate of 20° C./min.

22 . (canceled)

23 . The Polyamide (PA) according to claim 1 , exhibiting an inherent viscosity (“IV”) measured according to ASTM D5336 is:

between 0.5 and 1.5 dL/g; or

between 0.7 and 1.3 dL/g; or

between 0.75 and 1.20 dL/g; or

between 0.80 and 1.00 dL/g; or

between 0.90 and 1.20 dL/g; or

between 0.95 and 1.20 dL/g.

24 . (canceled)

25 . The Polyamide (PA) according to claim 1 , exhibiting a bio content of at least 10.0%, the biocontent being expressed as the % of organic carbon of renewable origin determined according to ASTM D6866-22.

26 . (canceled)

27 . (canceled)

28 . (canceled)

29 . The Polyamide (PA) according to claim 1 , prepared by polycondensation by heating a reaction mixture (RM) comprising all the monomers, the reaction mixture (RM) comprising:

the monomers that constitute the polyamide (PA);

optionally a catalyst, selected from the group consisting of phosphorous acid, ortho-phosphoric acid, meta-phosphoric acid, alkali-metal hypophosphite, and combination thereof;

optionally at least one end-capping agent selected from the group consisting of monocarboxylic acids, primary amines and combination thereof;

water, the proportion of which is less than 60 wt. %, this proportion is given based on the total weight of the reaction mixture (RM).

30 . A Thermoplastic composite (TC) comprising:

a polymer matrix comprising the polyamide (PA) according to claim 1 , and optionally at least one plastic additive, selected from the group consisting of colorants, ultraviolet light stabilizers, heat stabilizers, antioxidants, acid scavengers, processing aids, internal lubricants and/or external lubricants, flame retardants, smoke-suppressing agents, anti-static agents, anti-blocking agents and any combination thereof; and

fibers.

31 . (canceled)