SEMI-AROMATIC POLYAMIDES WITH A LOW MELTING TEMPERATURE

1 . A polyamide (PA) exhibiting a melting temperature Tm lower than 300° C. (<300° 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 38.0 and 54.0 mol % of 1,6-diaminohexane;

between 15.0 and 40.0 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 15.0 and 40.0 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);

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 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 diacids in the dicarboxylic acid component (B);

Tm being measured by 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 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); or

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

6 . The Polyamide (PA), according to claim 1 , comprising the 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 38.0 and 54.0 mol %;

R PA2 : between 15.0 and 40.0 mol %;

R PA3 : between 15.0 and 40.0 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 %.

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 38.0 and 52.0 mol %; or

between 38.0 and 47.0 mol %; or

between 42.0 and 47.0 mol %; or

between 48.0 and 52.0 mol %; or

between 38.0 and 42.0 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 33.0 mol %; or

between 18.0 and 40.0 mol %; or

between 33.0 and 37.0 mol %; or

between 18.0 and 22.0 mol %; or

between 23.0 and 27.0 mol %; or

between 28.0 and 32.0 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 18.0 and 40.0 mol %; or

between 18.0 and 22.0 mol %; or

between 28.0 and 32.0 mol %; or

between 33.0 and 37.0 mol %.

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

between 42.0 and 47.0 mol % of 1,6-diaminohexane;

between 33.0 and 37.0 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 18.0 and 22.0 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 48.0 and 52.0 mol % of 1,6-diaminohexane;

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 28.0 and 32.0 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 38.0 and 42.0 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 33.0 and 37.0 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 48.0 and 52.0 mol % of 1,6-diaminohexane;

between 28.0 and 32.0 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 18.0 and 22.0 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 48.0 and 52.0 mol % of 1,6-diaminohexane;

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 28.0 and 32.0 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 43.0 and 47.0 mol % of 1,6-diaminohexane;

between 33.0 and 37.0 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 18.0 and 22.0 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 42.0 and 47.0 mol % of R PA1 ;

between 33.0 and 37.0 mol % of R PA2 ;

between 18.0 and 22.0 mol % of R PA3 .

or the following ones:

between 48.0 and 52.0 mol % of R PA1 ;

between 18.0 and 22.0 mol % of R PA2 ;

between 28.0 and 32.0 mol % of R PA3 ;

or the following ones:

between 38.0 and 42.0 mol % of R PA1 ;

between 23.0 and 27.0 mol % of R PA2 ;

between 33.0 and 37.0 mol % of R PA3 ;

or the following ones:

between 48.0 and 52.0 mol % of R PA1 ;

between 28.0 and 32.0 mol % of R PA2 ;

between 18.0 and 22.0 mol % of R PA3 ;

or the following ones:

between 48.0 and 52.0 mol % of R PA1 ;

between 18.0 and 22.0 mol % of R PA2 ;

between 28.0 and 32.0 mol % of R PA3 ;

or the following ones:

between 43.0 and 47.0 mol % of R PA1 ;

between 33.0 and 37.0 mol % of R PA2 ;

between 18.0 and 22.0 mol % of R PA3 ;

these proportions being given relative to the total proportions of recurring units in the polyamide (PA).

14 . (canceled)

15 . (canceled)

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

lower than or equal to 280° C.; and/or

at least 250° C.;

Tm being measured by 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 140° C.; and/or

at most 200° C.;

Tg being measured by 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., the melting temperature Tm and the glass transition temperature Tg being measured by DSC according to ASTM D3418, using a heating and cooling rate of 20° C./min; 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 DSC according to ASTM D3418, using a heating and cooling rate of 20° C./min.

19 . (canceled)

20 . The Polyamide (PA) according to claim 1 , exhibiting a heat of fusion Hm:

of at least 15.0 J/g; and/or

between 15.0 and 40.0 J/g;

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

21 . 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.

22 . (canceled)

23 . 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, the bio content being defined as the % of organic carbon of renewable origin and corresponding to the amount of C calculated from measured 14 C percent and corrected for isotopic fraction.

24 . (canceled)

25 . 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 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).

26 . 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 an external lubricants, flame retardants, smoke-suppressing agents, anti-static agents, anti-blocking agents and any combination thereof; and

fibers.

27 . A method of preparing a thermoplastic composite, the method comprising using the polyamide (PA) according to claim 1 .