Compound useful for preparing a self-flame retardant aliphatic polyamide

Abstract

Compound useful for preparing a self-flame retardant aliphatic polyamide The present invention relates to a compound of the following formula (I): its preparation process, and its use for the preparation of aliphatic polyamide incorporating a repeating unit derived from said compound within its polymer chain, which gives it self-flame retardant properties. The invention also relates to said aliphatic polyamide, an article comprising it and its preparation process. Figure for abstract: None

Description

Title of the invention: Compound useful for preparing a self-flame retardant aliphatic polyamide

[0001] The present invention relates to a compound comprising phosphorus atoms, its preparation process, and its use for the preparation of aliphatic polyamide incorporating a repeating unit derived from said compound within its polymer chain, which gives it self-flame retardant properties.

[0002] Polyamides, for example polyamide 11, known worldwide under its trademark Rilsan®, have exceptional performance in many applications such as transport, energy, consumer goods such as

[0003] sporting goods and consumer electronics, anti-corrosion protective coatings and objects obtained by 3D printing.

[0004] Polyamides in general, and PA11 in particular, certainly have a very high level of performance. However, they are not naturally fire resistant: they burn easily, giving off flaming drops that can spread fires. However, many applications in the electrical, electrotechnical, electronic fields, but also in transport (air, rail, electric vehicles, etc.) require flame retardant performance.

[0005] Many solutions have been developed by adding, by melt mixing, initially halogenated additives, now halogen-free, based on phosphorus, nitrogen or hydrated fillers. These additives are not integrated into the polymer chain of polyamides. For example, melamine cyanurate, melamine polyphosphate, red phosphorus and metal dialkylphosphinates are used as flame retardant additives. Some 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivatives are also used as additives in polymers. However, flame retardancy performance is often achieved at the expense of other material properties such as ductility, dielectric properties, thermo-oxidation resistance, dimensional stability, water uptake and rheology.

[0006] Some attempts to incorporate flame retardant repeating units have been reported, particularly with acid-derived units 3-[10-(9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide-10-y 1)] itaconic acid (DOPO-ITA). However, as detailed in the article Negrell et al. Polymer De-gradation and Stability 134 (2016) 10-18 (paragraph 3.3 and figure 12), this DOPO-ITA based on 4-carbon diacids plays a role as a chain limiter in poly- amidation and therefore cannot allow the synthesis of PAs with high molar masses.

[0007] Another diacid monomer has been reported in WO 17 / 021355, namely 3-(hydroxy(phenyl)phosphoryl)propanoic acid. This monomer having a carboxylic acid end and a phosphonic acid end also acts as a chain limiter and also does not allow the synthesis of high molecular weight polyamides.

[0008] An aim of the invention is to provide a compound which is easy to prepare and usable as a monomer for the preparation of an aliphatic polyamide, and capable of conferring self-flame retardant properties to said aliphatic polyamide.

[0009] An aim of the invention is also to provide an aliphatic polyamide having good flame retardant properties while retaining its other properties, in particular those listed above.

[0010] An object of the invention is also to provide an aliphatic polyamide having good flame retardant properties and which can have a high molar mass.

[0011] For this purpose, the invention relates to a compound of the following formula (I):

[0012] [Chem.l]

[0013] in which:

[0014] - R1 represents H, a linear, branched or cyclic alkyl group comprising from 1 to 12 carbon atoms, or a cation,

[0015] - n represents an integer from 5 to 11,

[0016] - R2 and R3 independently represent a hydrogen, a hydroxyl, an alkoxyl comprising from 1 to 2 carbon atoms, a group -Ph, -Ph-Ph or -O-Ph, where Ph is a phenyl optionally substituted by a hydroxyl,

[0017] it being understood that, when R2 and R3 each represent a group -Ph or -O-Ph, R2 and R3 can be joined together to form a biphenyl group,

[0018] - m represents an integer from 0 to 4,

[0019] - each R4 is independently selected from hydroxyl, alkyl comprising 1 to 4 carbon atoms and an alkoxyl comprising 1 to 4 carbon atoms,

[0020] - L is a single bond or a phenylene optionally substituted by one or several substituents chosen from a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms,

[0021] - R5 is chosen from a hydrogen, a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms and a group of formula (I'):

[0022] [Chem.2] NH "coor 1

[0023] in which n, R1, R2 and R3 are as defined above.

[0024] The compound of formula (I) comprises at least one phosphorus atom, which makes it capable of imparting flame retardant properties to an aliphatic polyamide prepared using the compound of formula (I) as a monomer.

[0025] According to advantageous aspects of the invention, the compound of formula (I) comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0026] - n represents 5, 10 or 11, preferably n represents 10,

[0027] - R5 represents a group of formula (!) as defined above, the compound having thus the following formula (II'):

[0028] [Chem.3]

[0029] in which R1, R2, R3, R4, m, n and L are as above,

[0030] or R5 is chosen from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms, alkoxyl comprising from 1 to 4 carbon atoms,

[0031] - R2 is -Ph, R3 is -O-Ph and R2 and R3 together form a biphenyl, the group -(P=O)R2R3 thus having the formula (III):

[0032] [Chem. 4]

[0033]

[0034] or R2 is -Ph-Ph-OH and R3 is a hydroxyl, the group -(P=O)R2R3 thus having the formula (IV): [Chem. 5]

[0035]

[0036]

[0037]

[0038]

[0039] The invention also relates to the process for preparing this compound, comprising the reaction: - of a compound A of formula (Xla) or (Xlb): [Chem. 6] in which RI and n are as defined above, [Chem. 7]

[0040]

[0041] œc r nh3 in which n is as defined above, [Chem. 8] ■ / ---MH O'

[0042]

[0043] in which n is as defined above, - with a compound B of formula (XII):

[0044] [Chem.9]

[0045]

[0046]

[0047]

[0048]

[0049] in which: - m, L and R4 are as defined above, and - R7 is chosen from a group -(C=0)H, a hydrogen, a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms, - and a compound C of formula (XIII): [Chem. 10]

[0050]

[0051]

[0052]

[0053]

[0054] R (XIH) wherein R2 and R3 are as defined above and R6 represents H or OH. According to advantageous aspects of the invention, the process for preparing the compound comprises one or more of the following characteristics, taken individually or in all technically possible combinations: - compound A has the formula (Xla) or (Xlb) as defined above in which n represents 5 or 10, or compound A is laurolactam, - compound B is chosen from benzaldehyde, vanillin and ethylvanillin, or compound B has the formula (XII'): H (Xf) in which L, R4 and m are as defined above, compound B being preferably chosen from terephthalaldehyde and divanillin, - compound C is chosen from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, hypophosphorous acid, phenyl phosphorous acid, phosphoric acid, dimethyl phosphite, diethyl phosphite, diphenyl phosphine oxide and diphenyl- phosphite, preferably compound C is the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0055] The invention also relates to the use of the compound of formula (I) as a flame retardant.

[0056] The invention also relates to the use of the compound of formula (I) as monomer or as comonomer, typically for the preparation of a (co)polymer, in particular an aliphatic polyamide.

[0057] The invention also relates to the use of the compound of formula (I) for improving the flame retardant properties of a (co)polymer, in particular of an aliphatic polyamide.

[0058] The invention also relates to a process for preparing an aliphatic polyamide comprising the polycondensation of a compound of formula (I), optionally in the presence of one or more other comonomers, typically chosen from aliphatic amino acids, aliphatic lactams, mixtures of aliphatic diamines and aliphatic dicarboxylic acids, and mixtures thereof.

[0059] The invention also relates to an aliphatic polyamide obtained by polycondensation of the compound according to the invention, optionally in the presence of one or more other comonomers, typically chosen from an aliphatic amino acid, an aliphatic lactam, or a mixture of at least one aliphatic diamine and at least one aliphatic dicarboxylic acid.

[0060] The aliphatic polyamide comprises a repeating unit derived from the compound of formula (I). The aliphatic polyamide is therefore rich in phosphorus atoms. The compound of formula (I) is used as a flame retardant and is incorporated as a unit within the polymer chain of the aliphatic polyamide. The flame retardant is thus integrated reactively and not additively. Advantageously, the aliphatic polyamides according to the invention are classified V0 in the UL94-vertical buming test, in particular for tests with a sample of aliphatic polyamide 1.6 mm thick. The invention is also based on the discovery that such aliphatic polyamides not only have good flame retardant properties, but also that they retain the intrinsic performance of the aliphatic polyamide from which they are derived (aliphatic polyamides free from a repeating unit derived from the compound of formula (I), but whose other repeating units are identical.For example, an aliphatic copolyamide PA11 whose polymer chain includes repeating units derived from the compound of formula (I) has good flame retardant properties, but retains the properties of PAU. Finally, it is possible to prepare aliphatic polyamides with high molar masses.

[0061] According to advantageous aspects of the invention, the aliphatic polyamide comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0062] - the aliphatic polyamide is obtained by polycondensation of a compound of formula (II') with an aliphatic diamine of formula H2N-L2-NH2 in which L2 is a divalent aliphatic group comprising from 4 to 36 carbon atoms, said aliphatic polyamide comprising a repeating unit of formula (XXI'):

[0063] [Chem. 12]

[0064] in which m, n, L, R2, R3 and R4 are as defined above.

[0065] - the aliphatic polyamide is obtained by polycondensation of a compound of formula (I) in which R5 is chosen from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms, the aliphatic polyamide comprising a repeating unit of formula (XXII):

[0066] [Chem. 13] (XXII)

[0067] in which m, n, R2, R3 and R4 are as defined above and R5 is chosen from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms,

[0068] - the aliphatic polyamide further comprises one or more other unit(s), ty pickling chosen from a unit obtained from at least one aliphatic amino acid, a unit obtained from at least one aliphatic lactam, a unit obtained from the polycondensation of at least one aliphatic diamine and at least one aliphatic dicarboxylic acid,

[0069] - the aliphatic polyamide further comprises a repeating unit of formula (XXIII):

[0070] [Chem. 14] O (21st century)

[0071] in which q represents an integer from 5 to 11,

[0072] - the aliphatic polyamide has a mass proportion of atomic phosphorus of at less than 0.1%,

[0073] - the aliphatic polyamide comprises fillers, reinforcing fibers, in particular glass, additives, in particular chosen from flame retardants, antioxidants, plasticizers and mixtures thereof, or a mixture of these.

[0074] The invention also relates to the use of the aliphatic polyamide defined above as a flame retardant additive in thermoplastic polymer matrices, in particular polyamide, polyolefin, polyester, PMMA or mixtures thereof.

[0075] The invention also relates to an article comprising the aliphatic polyamide defined above.

[0076] The invention also relates to a method for preparing an article comprising a step of extruding, molding or overmolding this aliphatic polyamide, whereby an article is obtained.

[0077] Definitions

[0078] An amorphous polyamide, within the meaning of the application, designates a transparent amorphous polyamide having only a glass transition temperature (no melting temperature (Tf)), or a very slightly crystalline polyamide having a glass transition temperature and a melting point such that the enthalpy of crystallization during the cooling step at a rate of 20K / min in differential scanning calorimetry (DSC) measured according to the ISO 11357-3:2013 standard is less than 30 J / g, in particular less than 20 J / g, preferably less than 15 J / g. The glass transition temperature (Tg) measured by DSC at a heating rate of 20K / min according to ISO 11357-1:2009 and ISO 11357-2:2013 for these polyamides is greater than 75°C, in particular greater than or equal to 100°C, in particular greater than or equal to 12°C, preferably greater than or equal to 140°C.

[0079] A semi-crystalline polyamide (PA), within the meaning of the application, designates a polyamide which has a melting temperature (Tf) in DSC according to the ISO 11357-3:2013 standard, and an enthalpy of crystallization during the cooling step at a rate of 20K / min in DSC measured according to the ISO 11357-3 of 2013 standard greater than 30 J / g, preferably greater than 40 J / g.

[0080] The nomenclature used to define polyamides is described in the ISO standard 16396- l:2022 "Plastics — Polyamide (PA) materials for molding and extrusion — Part 1: Designation" and is well known to those skilled in the art.

[0081] The term "polyamide" used in the present description covers both homopolyamides and copolyamides.

[0082] In the PA XY notation, X represents the number of carbon atoms from the diamine residues, and Y represents the number of carbon atoms from the diacid residues, conventionally.

[0083] In the PA X notation, X represents the number of carbon atoms derived from the amino acid or lactam residues.

[0084] The notations PA X / Y, PA X / Y / Z, etc. refer to copolyamides in which X, Y, Z, etc. represent homopolyamide units.

[0085] The polydispersity index IP is equal to the ratio of the molar mass by weight to the molar mass by number (Mw / Mn).

[0086] The number-average molar masses Mn and weight-average molar masses Mw are measured by size exclusion chromatography (or gel permeation chromatography) according to ISO 16014-1:2019. Typically, the polyamide is solubilized in hexafluoroisoproponol stabilized with 0.05 M potassium trifluoroacetate for 24 h at room temperature (20°C) at a concentration of 1 g / L. The solution obtained is then filtered through a PTFE membrane with a porosity of 0.2 pm, then injected at a flow rate of 1 mL / min into a liquid chromatography system equipped with a set of PFG columns from Polymer Standards Service consisting of a pre-column with dimensions of 50 x 8 mm, a 1000 Å column with dimensions of 300 x 8 mm and particle size of 7 pm, and a 100 Å column with dimensions of 300 x 8 mm and particle size of 7 pm. The molar masses are measured by the refractive index and are expressed in PMMA equivalents, used as a calibration standard, then converted to g / mol.

[0087] Total acidity and total basicity are measured by potentiometry.

[0088] The acidity is measured according to the following method. A sample of polyamide is dissolved in benzyl alcohol. Then, this sample is dosed potentiometrically with a 0.02N tetrabutylammonium hydroxide solution.

[0089] The basicity is measured according to the following method. A sample of polyamide is dissolved in metacresol. Then, this sample is dosed potentiometrically with a 0.02N perchloric acid solution.

[0090] The inherent viscosity is measured at a polyamide concentration of 0.5% by weight in solution in metacresol on the total weight of the solution, at 20°C, using a viscometer equipped with a Micro-Ubbelohde viscometer tube.

[0091] The crystallinity rate is calculated according to the following formula:

[0092] [Math.l] x-^ xl0 ° in which:

[0093] x denotes the crystallinity rate,

[0094] AHf * denotes the enthalpy of fusion of the polyamide

[0095] AHf denotes the enthalpy of fusion of 100% crystalline polyamide. This value can be a theoretical value obtained by mathematical models, or if the sample is available, it is the value measured on this sample.

[0096] By "linear, branched or cyclic alkyl" is meant a linear or branched saturated hydrocarbon aliphatic group or a cyclic alkyl group. The linear or branched alkyl comprises from 1 to 12, in particular from 1 to 8, preferably from 1 to 6, in particular from 1 to 4 carbon atoms. Examples of linear or branched alkyl include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl or pentyl groups. The cyclic alkyl comprises from 3 to 12, in particular from 3 to 8, preferably from 3 to 6, in particular from 3 to 4 carbon atoms. Examples of cyclic alkyl include cyclopropyl, methylcyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl groups.

[0097] An alkoxyl group is an -O-alkyl radical where the alkyl group is as previously defined. Examples of alkoxyl include methoxyl, ethoxyl, or propoxyl groups.

[0098] According to a first subject, the invention relates to a compound of the following formula (I):

[0099] [Chem. 15]

[0100] in which:

[0101] - R1 represents H, a linear, branched or cyclic alkyl group comprising from 1 to 12 carbon atoms, or a cation,

[0102] - n represents an integer from 5 to 11,

[0103] - R2 and R3 independently represent a hydrogen, a hydroxyl, an alkoxyl comprising from 1 to 2 carbon atoms, a group -Ph, -Ph-Ph or -O-Ph, where Ph is a phenyl optionally substituted by a hydroxyl,

[0104] it being understood that, when R2 and R3 each represent a -Ph group or -O-Ph, R2 and R3 can be joined together to form a biphenyl group,

[0105] - m represents an integer from 0 to 4,

[0106] - each R4 is independently selected from hydroxyl, alkyl comprising 1 to 4 carbon atoms and an alkoxyl comprising from 1 to 4 carbon atoms,

[0107] - L is a single bond or a phenylene optionally substituted by one or several substituents chosen from a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms,

[0108] - R5 is chosen from a hydrogen, a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms and a group of formula (T):

[0109] [Chem. 16] P=O ^COOR1 {H.

[0110] in which n, R1, R2 and R3 are as defined above.

[0111] Preferably, in formula (I), n represents 5, 10 or 11, particularly preferably, n represents 10. These compounds are in fact particularly suitable for being incorporated into PA6, PA11 and PA12 respectively. For example, when n is 10, the group -NH(CH2)i0-COOR1 is then derived from amino-11-undecanoic acid, and the compound of formula (!') is particularly suitable for being incorporated into a PAU.

[0112] In formula (I), R1 represents H, a linear, branched or cyclic alkyl group comprising from 1 to 12 carbon atoms, or a cation. The cation is preferably an alkaline earth or alkali cation. Preferably, R1 represents H or a cation.

[0113] In formula (I), each R4 is independently selected from hydroxyl, alkyl comprising from 1 to 4 carbon atoms, preferably from 1 to 3 carbon atoms, and alkoxyl comprising from 1 to 4 carbon atoms, preferably from 1 to 3 carbon atoms. Preferably, R4 represents OH, Me or OMe.

[0114] In formula (I), m represents an integer from 0 to 4, preferably 0 or 1. When m is 0, the compound is free of R4 group.

[0115] In formula (I), L is a single bond or a phenylene optionally substituted by one or more substituents chosen from a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, preferably from 1 to 3 carbon atoms, and an alkoxyl comprising from 1 to 4 carbon atoms, preferably from 1 to 3 carbon atoms. Preferably, L represents a single bond or a divalent phenylene of formula (L'):

[0116] [Chem. 17]

[0117] in which m and R4 are as defined above.

[0118] Two alternatives can be distinguished for the R5 group of formula (I).

[0119] According to a first alternative, in formula (I), R5 represents a group of formula (!) as defined above, and the compound thus has the following formula (II'):

[0120] [Chem. 18]

[0121] in which R1, R2, R3, R4, m, n and L are as above. Such a compound advantageously carries two -COOR1 functions which can serve as reactive groups to incorporate the compound of formula (II') within the polymer chain of aliphatic polyamides.

[0122] In a first embodiment of this first alternative, L represents a single bond. The compound then has the following formula (II'a):

[0123] [Chem. 19] R'OOC (will go)

[0124] wherein R1, R2, R3, R4, n and m are as defined above.

[0125] In a second embodiment of this first alternative, L represents the divalent phenylene of formula (L') defined above. The compound then has the following formula (II'b):

[0126] [Chem.20] (Il'b)

[0127] wherein R1, R2, R3, R4, n and m are as defined above. The two phenyl groups of the compound of formula (II'b) may be attached to any position of each phenyl. Preferably, the compound of formula (II'b) is symmetrical.

[0128] According to a second alternative, in formula (I), R5 is chosen from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms. The secondary amine function and the -COOR1 group of the -NH(CH2)n-COOR1 group can then serve as reactive groups to incorporate the compound of formula (I) within the polymer chain of aliphatic polyamides. The secondary amine function is less reactive than a -COOR1 function. Thus, the compound according to this second alternative is generally less reactive than that of formula (II') according to the first alternative above, which carries two -COOR1 functions.

[0129] Furthermore, two alternatives can be distinguished for the groups R2 and R3 of formula (I).

[0130] According to a first alternative, in formula (I), R2 is -Ph, R3 is -O-Ph and R2 and R3 together form a biphenyl, the group -(P=O)R2R3 thus having the formula (III):

[0131] [Chem.21]

[0132] The compound then has the following formula (V):

[0133] [Chem.22]

[0134] in which R1, R4, R5, L, n and m are as defined above.

[0135] According to a second alternative, in formula (I), R2 is -Ph-Ph-OH and R3 is a hydroxyl, the group -(P=O)R2R3 thus having the formula (IV):

[0136] [Chem.23]

[0137] The compound then has the following formula (VI):

[0138] [Chem.24]

[0139] in which R1, R4, R5, L, n and m are as defined above.

[0140] The compound of formula (VI) corresponds to the open form of the compound of formula (V). In practice, the two compounds can coexist. The invention therefore also relates to a mixture of the compounds of formula (V) and (VI).

[0141] According to a second object, the invention relates to a process for preparing the compound of formula (I), comprising the reaction:

[0142] - of a compound A of formula (Xla) or (Xlb):

[0143] [Chem.25] (Xla)

[0144] in which R1 and n are as defined above,

[0145] [Chem.26] (Xlb)

[0146] in which n is as defined above,

[0147] [Chem.27] (XIc)

[0148] in which n is as defined above,

[0149] - with a compound B of formula (XII):

[0150] [Chem.28]

[0151] in which:

[0152] - m, L and R4 are as defined above, and

[0153] - R7 is chosen from a group -(C=O)H, a hydrogen, a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms,

[0154] - and a compound C of formula (XIII):

[0155] [Chem.29] K* (XI N)

[0156] in which R2 and R3 are as defined above and R6 represents H or OH.

[0157] The method according to the invention is illustrated in diagram 1 which follows:

[0158] [Chem.30] (XJa) (X:c;

[0159] Scheme 1: Reaction scheme of the process for preparing the compound of formula (I)

[0160] When compound A has the formula (XIc), the reaction is preferably carried out works in the presence of an acid. This allows the opening of the lactam of formula (XIc), whereby the compound of formula (XIc) is transformed into a compound of formula (Xla) and / or (Xlb).

[0161] According to a first preferred embodiment for compound A, compound A has the formula (Xla) or (Xlb), in which n represents 5 or 10. This embodiment makes it possible to prepare compounds of formula (I) in which n represents 5 or 10, which are particularly suitable for being incorporated respectively within the polymer chain of PA6 or PAU. Typically, compound A is amino-6-hexanoic acid, amino-11-undecanoic acid, or a salt thereof.

[0162] According to a second preferred embodiment for compound A, compound A is laurolactam. Laurolactam is a compound of formula (XIc) in which n represents 11. This embodiment makes it possible to prepare a compound of formula (I) in which n represents 11, which is particularly suitable for incorporation into the polymer chain of PA 12.

[0163] According to a first preferred embodiment for compound B, compound B is chosen from benzaldehyde, vanillin and ethyl vanillin.

[0164] According to a second preferred embodiment for compound B, compound B has the formula (XII'):

[0165] [Chem.31]

[0166] in which L, R4 and m are as defined above. The compound prepared by the process then has the formula (II') defined above. Preferably, compound B is chosen from terephthalaldehyde and divanillin.

[0167] According to a preferred embodiment for compound C, compound C is selected from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, hypophosphorous acid, phenyl phosphorous acid, phosphoric acid, dimethylphosphite, diethylphosphite and diphenylphosphite, preferably compound C is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. The compound prepared then has the formula (I) in which the group -(P=O)R2R3 has the formula (III) or (IV) as defined above.

[0168] Advantageously, the starting products, namely compound A (of formulas (Xla), (Xlb), (XIc)), compound B (of formula (XII)) and compound C (of formula (XIII)) are commercially available.

[0169] Preferably, 1.0 to 2.5 equivalents of compound A are used relative to compound B.

[0170] Preferably, 1.0 to 2.5 equivalents of compound C are used relative to compound B.

[0171] Furthermore, the method according to the invention is simple. It is sufficient to mix three compounds.

[0172] The reaction is generally carried out in a solvent, preferably in a polar solvent, for example chosen from methanol, ethanol, isopropanol, dimethylsulfoxide.

[0173] The mass concentration of compound A + B + C in the solvent is 20 g / L to 250 g / L.

[0174] The reaction is typically carried out at a temperature of 50 to 100°C, and / or at atmospheric pressure.

[0175] Typically, the reaction is carried out in two stages, a first stage where compounds A and B and a solvent are added to a reactor, generally equipped with a condenser. The reaction medium is heated to solvent reflux and left stirring until the end of the first synthesis stage, then for the second stage, the reaction medium is cooled, for example to 60°C, and compound C is added. The reaction is continued with stirring until the end of the second synthesis stage. At the end of the reaction, the reaction medium is cooled to room temperature (20°C) until a white precipitate appears.

[0176] The subsequent treatment (work-up in English) to recover the compound of formula (I) is also simple. After reaction, the reaction medium is filtered and rinsed with the solvent. The solid obtained is dried under vacuum to remove the excess solvent. In particular, the compound of formula (I) is obtained directly in neutral form, and it is therefore not necessary to acidify and / or base the reaction medium. The process is therefore preferably free from an acidification or basification step.

[0177] According to a third subject, the invention relates to the use of the compound of formula (I) as defined above as a flame retardant.

[0178] According to a fourth subject, the invention relates to the use of the compound of formula (I) for improving the flame retardant properties of a (co)polymer, in particular of an aliphatic polyamide.

[0179] According to a fifth subject, the invention relates to the use of the compound of formula (I) as a monomer or as a comonomer, typically for the preparation of a (co)polymer, in particular an aliphatic polyamide. The invention relates to a process for the preparation of a (co)polymer comprising the polycondensation of a compound of formula (I), optionally in the presence of one or more other comonomers. The invention relates in particular to a process for the preparation of an aliphatic polyamide comprising the polycondensation of a compound of formula (I), optionally in the presence of one or more other aliphatic comonomers, typically chosen from an aliphatic amino acid, an aliphatic lactam, or a mixture of at least one aliphatic diamine and at least one aliphatic dicarboxylic acid. Advantageously, the compound of formula (I) does not act as a chain limiter, and it is possible to prepare aliphatic polyamides having a high molar mass.

[0180] According to a sixth subject, the invention relates to an aliphatic polyamide obtained by polycondensation of the compound according to the invention, optionally in the presence of one or more other comonomers, typically chosen from an aliphatic amino acid, an aliphatic lactam, or a mixture of at least one aliphatic diamine and at least one aliphatic dicarboxylic acid.

[0181] The embodiments described above for the compound of formula (I) are of course applicable for the repeating unit derived from the compound of formula (I), and for the aliphatic polyamide comprising it.

[0182] Two preferred alternatives of the aliphatic polyamide can be distinguished, depending on the alternative considered for the R5 group of the compound of formula (I).

[0183] According to a first alternative, the aliphatic polyamide is obtained by polycondensation of a compound of formula (II') as defined above with an aliphatic diamine of formula H2N-L2-NH2 in which L2 is a divalent aliphatic group comprising from 4 to 36 carbon atoms, said aliphatic polyamide then comprising a repeating unit of formula (XXI'):

[0184] [Chem.32]

[0185] in which m, n, L, R2, R3 and R4 are as defined above.

[0186] Preferably, L2 represents a group -(CH2)P- in which p represents an integer from 4 to 36, in particular from 4 to 24, preferably from 5 to 12, the particularly preferred p being 4, 5, 6, 10 and 12. The group -NH-L2-NH- is then derived from a linear and aliphatic diamine.

[0187] According to a second alternative for the aliphatic polyamide, the aliphatic polyamide is obtained by polycondensation of a compound of formula (I) in which R5 is chosen from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms, the aliphatic polyamide comprising a repeating unit of formula (XXII):

[0188] [Chem.33]

[0189] in which m, n, R2, R3 and R4 are as defined above and R5 is selected from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms.

[0190] Whatever the alternative considered, the aliphatic polyamide generally comprises, in addition to the repeating unit derived from the compound of formula (I) (typically in addition to the repeating unit of formula (XXI') or (XXII)), one or more other aliphatic unit(s). In addition to the repeating unit derived from the compound of formula (I) (typically in addition to the units of formula (XXI') or (XXII)), the aliphatic polyamide generally comprises one or more other unit(s), typically chosen from a unit obtained from at least one aliphatic amino acid, a unit obtained from at least one aliphatic lactam, a unit obtained from the polycondensation of at least at least one aliphatic diamine and at least one aliphatic dicarboxylic acid. If the aliphatic polyamide contains a unit obtained from the polycondensation of at least one aliphatic diamine and at least one aliphatic dicarboxylic acid, the diamine is preferably a primary diamine (two NH2 groups). In particular, the aliphatic polyamide may further comprise a repeating unit of formula (XXIII):

[0191] [Chem.34] o (XXI H)

[0192] in which q represents an integer from 5 to 11, preferably 5, 10 or 11. In a particularly preferred manner, q is equal to n as defined above, so that the group -CO-(CH2)q-NH of the repeating unit of formula (XXIII) is identical to the group(s) -CO-(CH2)n-NH of the repeating unit of formula (XXI') or (XXII).

[0193] As an example of an aliphatic amino acid, it is possible to cite alpha-omega amino acids preferably comprising from 6 to 12 carbon atoms, such as aminocaproic, amino-7-heptanoic, amino-11-undecanoic, n-heptyl-11-aminoundecanoic and amino-12-dodecanoic acids.

[0194] Examples of aliphatic lactams include those preferably comprising between 3 and 12 carbon atoms on the main ring and which may be substituted. Examples of lactams include P,[3-dimethylpropriolactam, α,α-dimethylpropriolactam, amylolactam, ca-prolactam, capryllactam, oenantholactam, 2-pyrrolidone and lauryllactam, the lactam preferably being caprolactam, oenantholactam and lauryllactam.

[0195] The aliphatic diamine has in particular from 2 to 20, in particular from 5 to 14, preferably from 6 to 12 carbon atoms. The aliphatic group can be linear, branched and / or cyclic. As examples of aliphatic diamine, it is possible to cite 1,4-diaminobutane, 1,5-diaminopentane, hexamethylenediamine, 1,10-decamethylenediamine, tetramethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, 1,5 diaminohexane, 2,2,4-trimethyl-1,6-diaminohexane, diamine polyols, methyl-pentamethylenediamine (MPMD), and trimethylhexamethylenediamine.

[0196] The dicarboxylic acid has in particular from 4 to 36 carbon atoms, preferably those having from 6 to 18 carbon atoms. As examples of aliphatic dicarboxylic acid, it is possible to cite succinic acid (4), pentanedioic acid (5), adipic acid (6), heptanedioic acid (7), octanedioic acid (8), azelaic acid (9), sebacic acid (10), undecanedioic acid (11), dodecanedioic acid (12), brassylic acid (13), tetradecanedioic acid (14), hexadecanedioic acid (15), hexadecanedioic acid (16), hexadecanedioic acid (17), hexadecanedioic acid (18), hexadecanedioic acid (19), hexadecanedioic acid (20), hexadecanedioic acid (21), hexadecanedioic acid (22), hexadecanedioic acid (23), hexadecanedioic acid (24), hexadecanedioic acid (25), hexadecanedioic acid (26), hexadecanedioic acid (27), hexadecanedioic acid (28), hexadecanedioic acid (29), hexadecanedioic acid (30), hexadecanedioic acid (31), hexadecanedioic acid (32), hexadecanedioic acid (33), hexadecanedioic acid (34), hexadecanedioic acid (35), hexadecanedioic acid (36), hexadecanedioic acid (37), hexadecanedioic acid (38), hexadecanedioic acid (39), hexadecanedioic acid (40), hexadecanedioic acid (41), hexadecanedioic acid (42), hexadecanedioic acid (43), hexadecanedioic acid (4 canedioic acid (16), octadecanoic acid (18), octadecenedioic acid (18), eicosanedioic acid (20), docosanedioic acid (22) and dimerized fatty acids, especially those containing 36 carbons. These dimerized fatty acids preferably have a dimer content of at least 98%; preferably they are hydrogenated; these are, for example, the products marketed under the brand name "PRIPOL" by the company "Cargill", or under the brand name EMPOL by the company BASF, or under the brand name Radiacid by the company OLEON, and polyoxyalkylene a,co-diacids. Fatty acid dimers are typically dimerized fatty acids obtained by oligomerization or polymerization of long-chain unsaturated monobasic hydrocarbon fatty acids (such as linoleic acid and oleic acid), as described in particular in EP0 471 566.

[0197] When the dicarboxylic acid is cycloaliphatic, it may have the following carbon skeletons: norbornyl methane, cyclohexane, cyclohexylmethane, dicyclohexylmethane, dicyclohexylpropane, di(methylcyclohexyl) or di(methylcyclohexyl)propane. 1,4-Cyclohexyldicarboxylic acid is an example of a cycloaliphatic dicarboxylic acid.

[0198] Preferably, the aliphatic polyamide comprises, in addition to the repeating units derived from the compound of formula (I), repeating units chosen from the repeating units of PA 4.12, 4.14, 4.18, 6, 6.6, 6.10, 6.12, 6.13, 6.14, 6.18, 9.12, 10.10, 10.11, 10.12, 10.14, 10.18, 11, 12, 6 / 12, 6 / 66, 6 / 12 / 66, 6 / 69 / 11 / 12, 6 / 66 / 11 / 12, 69 / 12 and mixtures thereof, preferably repeating units chosen from the repeating units of PA 6, PA 11, PA 12, PA 6.10, AP 10.10, AP 10.12, AP 6 / 12, AP 11 / 12.

[0199] Preferably, the aliphatic polyamide has a mass proportion of atomic phosphorus of at least 0.1%, in particular at least 0.2%, preferably at least 0.3% and / or at most 10.0%. The mass proportion of atomic phosphorus can be determined by X-ray fluorescence.

[0200] Advantageously, the aliphatic polyamide is classified V0 in the UL94-vertical burning test, in particular for a test with a sample of aliphatic polyamide 1.6 mm thick.

[0201] The number-average molar mass Mn of the aliphatic polyamide is preferably from 5,000 to 50,000 g / mol, more preferably from 10,000 to 35,000 g / mol, even more preferably from 15,000 to 30,000 g / mol. The aliphatic polyamide can therefore advantageously have a high molar mass.

[0202] The weight-average molar mass Mw of the aliphatic polyamide is preferably from 10,000 to 300,000 g / mol, more preferably from 20,000 to 250,000 g / mol, even more preferably from 30,000 to 200,000 g / mol.

[0203] The polydispersity index IP of the aliphatic polyamide is generally less than or equal to 15.0, in particular less than or equal to 10.0, preferably less than or equal to 9.0, for example less than or equal to 7.0.

[0204] The polydispersity index IP of the aliphatic polyamide is generally greater than or equal to 1.0, in particular greater than or equal to 2.0.

[0205] The absolute value of the difference between the total acidity and the total basicity of the aliphatic polyamide is preferably between 0 and 200 peq / g.

[0206] Preferably, the aliphatic polyamide has an inherent viscosity of between 0.40 and 1.70, advantageously of between 0.70 and 1.50.

[0207] Preferably, the aliphatic polyamide has a crystallinity rate of between 20 and 40%, in particular between 20 and 30%, measured by DSC (differential scanning calorimetry measurement) according to standard 11357-3, 1999 (2nd DSC heating at 20°C / min according to standard ISO 11357).

[0208] The aliphatic polyamide can be amorphous or semi-crystalline.

[0209] The aliphatic polyamide may further comprise fillers, reinforcing fibers, in particular glass fibers, additives, in particular chosen from flame retardants, antioxidants, plasticizers and mixtures thereof, or a mixture of these.

[0210] Among the reinforcing fibers, mention may be made of carbon or glass fibers, natural fibers or a mixture thereof.

[0211] Among the additives, mention may be made of flame retardants, chain limiting agents, impact modifiers, pigments, dyes, light (UV) and / or heat stabilizers, plasticizers, surfactants, optical brighteners, antioxidants, natural waxes, mold release agents, or mixtures thereof.

[0212] The flame retardants are in particular chosen from DOPO and its derivatives, melamine cyanurate, melamine polyphosphate, red phosphorus, metallic dialkylphosphinates and mixtures thereof.

[0213] To the extent that the aliphatic polyamides according to the invention are self-flame retardant, they may be free of flame retardant agent (used as an additive).

[0214] Typically, a chain-limiting agent comprises at least one, preferably at least two functions, each independently chosen from carboxylic acids and amines. This chain-limiting agent may be a dicarboxylic acid, a diamine or an amino acid. It makes it possible to react with the amide, amine or carboxylic acid functions of the aliphatic polyamide.

[0215] In order to ensure good properties (flexibility, burst strength, tear strength, rheology, alloy morphology, compatibilization, homogeneity, consistency, adhesion) and, in particular, good impact resistance and impact properties after aging (in particular oxidative aging at high temperature), the aliphatic polyamide may comprise an impact modifier, in particular of an elastomeric nature and preferentially functionalized by maleic anhydride.

[0216] The fillers envisaged include mineral fillers, such as those chosen from the group, given without limitation, comprising talc, kaolin, magnesia, slag, silica, carbon black, carbon nanotubes, expanded or non-expanded graphite, titanium oxide.

[0217] The reinforcing fibers are chosen from fibers, in particular short fibers. The fibers may be of synthetic origin, in particular glass or carbon fibers, or natural, typically of plant origin such as flax, reed, bamboo or hemp fibers. Preferably, the reinforcing fibers are glass fibers.

[0218] The usual stabilizers used are phenols, phosphites, UV absorbers, stabilizers of the HALS (Hindered Amine Light Stabilizer) type, metal iodides or thioethers. Mention may be made of Irganox 1010, 245, 1098, Irgafos 168, 126, Tinuvin 312, 770, Iodide P201 from the company Ciba, Nylostab S-EED from the company Clariant, AO 412S from the company Adeka Palmarole.

[0219] The mass proportion of the fillers is in particular from 0.5 to 50.0% relative to the weight of the aliphatic polyamide.

[0220] The mass proportion of the reinforcing fibers is in particular 5 to 75% relative to the weight of the aliphatic polyamide.

[0221] The mass proportion of the additives is in particular 0.05 to 3.00% relative to the weight of the aliphatic polyamide.

[0222] The cumulative mass proportion of the fillers, reinforcing fibers, and additives is in particular 0.1 to 80% relative to the weight of the aliphatic polyamide.

[0223] According to a seventh object, the invention relates to the use of the aliphatic polyamide defined above as a flame retardant additive in thermoplastic polymer matrices, in particular polyamide, polyolefin, polyester, PMMA or mixtures thereof.

[0224] According to an eighth object, the invention relates to a method for preparing an article comprising a step of extrusion, molding or overmolding of the aliphatic polyamide defined above, whereby an article is obtained.

[0225] The article is preferably a shaped article, such as fiber, fabric, film, sheet, rod, tube, extruded part, injected part, comprising the composition as defined above. Thus, the aliphatic polyamide according to the present invention is advantageous for the manufacture of articles, in particular articles or elements of sporting articles, which must in particular have both good impact resistance and good endurance to mechanical, chemical, UV and thermal aggression. Among these sporting articles, mention may be made of elements of sports shoes, sports utensils such as ice skates or other winter sports and mountaineering articles, ski bindings, snowshoes, sports bats, boards, horseshoes, fins, golf balls, leisure vehicles, in particular those intended for activities by cold weather. We can also mention, in general, leisure and DIY items, tools and road equipment subject to climatic and mechanical aggression, protective items, such as helmet visors, glasses, as well as glasses arms. We can also cite, by way of non-limiting examples, car components, such as headlight protectors, rearview mirrors, small parts of off-road vehicles, tanks, in particular, of mopeds, motorcycles, scooters, subject to mechanical and chemical aggression, screws, cosmetic items subject to mechanical and chemical aggression, lipsticks, pressure gauges, aesthetic protection elements such as gas bottles. We can also mention objects or parts of objects for electronics requiring compliance with dimensions, for example parts of mobile phones, computers, tablets, etc.

[0226] According to a ninth object, the invention relates to the article comprising the aliphatic polyamide as defined above, or capable of being obtained by this process.

[0227] The invention is illustrated with the following examples, which are provided without limitation. Example 1: Preparation of compound of formula (I)

[0228] 2.0 equivalents of amino-ll-undecanoic acid and 1.0 equivalent of terephtha- laldehyde are added to a glass reactor equipped with mechanical stirring and a condenser. Absolute ethanol is added to the reactor so as to have a concentration of 25 g / L of terephthaldehyde in ethanol. The reaction medium is heated to 90°C, i.e. reflux of ethanol, and left stirring for 1 h. The reaction medium is then cooled to 60°C and 2.0 equivalents of DOPO are added. The reaction is continued with stirring for 8 h. At the end of the reaction, the reaction medium is cooled to room temperature (20°C) until a white precipitate appears. The reaction medium is filtered and the solid is rinsed with ethanol and then dried under vacuum at 60°C.

[0229]

[0230] A compound of the following formula was thus prepared: [Chem. 35]

[0231] Example 2: preparation of aliphatic polyamide by polycondensation of a compound of formula 1 and properties of the aliphatic polyamide obtained

[0232] The polyamide denoted A is a PAU. This polyamide is prepared according to the following process. After loading the components of Table 1, the autoclave reactor is placed under an inert atmosphere. The reaction medium is then raised in temperature to 260 degrees centigrade, while maintaining stirring. The reaction medium is maintained at 260 degrees centigrade, under a pressure of 20 bars for 1 hour 30 minutes. Then, the pressure is lowered to 12 bars, while maintaining the temperature at 260 degrees centigrade. The material is then transferred into a polymerizer, under nitrogen flushing at 260 degrees centigrade. The polymerizer is placed under a vacuum of 50 mbar for 30 minutes and maintained for 1 hour 00 minutes. The material is then extruded, in the form of granules. This process is used for all the polyamides exemplified.

[0233] The resins were injected in the form of a 1000x1000x1mm plate at an injection temperature of 290°C and a mold temperature of 40°C. The transparency of the plates was determined according to ISO 13468-2:2006, the percentage of light transmitted at the wavelength of 560 nm (transmittance Tr in %).

[0234] [Tables 1] % by mass of atomic phosphorus % by mass of 11-aminoundecanoic acid % by mass of diaminodecane % by mass of diacid prepared in Example 1 PAU A (comp) 0 100 0 0 PAU B (inv) 1.0 64.34 5.56 30.10

[0235] Table 1: Natures and proportions of monomers for the preparation of polyamides

[0236] The different polyamides were characterized according to the UL94 standard in vertical combustion on injected specimens having a thickness of 1.6 mm, and their combustion times were determined. The combustion times are provided in Table 2.

[0237] [Tables2] Burning time after 1st flame application (s) Burning time after 2nd flame application (s) PAU A (comp) 2.1 >30 sample burns to the support PAU B (inv) 6.4 4.1

[0238] Table 2: fire properties of polyamides

Claims

1. Claims Compound of the following formula (I): in which: - R1 represents H, a linear, branched or cyclic alkyl group comprising from 1 to 12 carbon atoms, or a cation, - n represents an integer from 5 to 11, - R2 and R3 independently represent a hydrogen, a hydroxyl, an alkoxyl comprising from 1 to 2 carbon atoms, a group -Ph, -Ph-Ph or -O-Ph, where Ph is a phenyl optionally substituted by a hydroxyl, provided that, when R2 and R3 each represent a -Ph group Or -O-Ph, R2 and R3 can be joined together to form a biphenyl group, - m represents an integer from 0 to 4, - each R4 is independently selected from hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms, - L is a single bond or a phenylene optionally substituted by one or more substituents chosen from a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms and an alkoxyl comprising from 1 to 4 carbon atoms, - R5 is chosen from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms, alkoxyl comprising from 1 to 4 carbon atoms and a group of formula (!): [Chem.37]

2.

3.

4. in which n, R1, R2 and R3 are as defined above. A compound according to claim 1, wherein n represents 5, 10 or 11. A compound according to claim 2, wherein n represents 10. A compound according to any one of claims 1 to 3, wherein R 5 represents a group of formula (!') as defined in claim 1, the compound thus having the following formula (II'): [Chem. 3 8]

5.

6. wherein R1, R2, R3, R4, m, n and L are as defined in claim 1. A compound according to any one of claims 1 to 3, wherein R 5 is selected from hydrogen, hydroxyl, alkyl comprising from 1 to 4 carbon atoms and alkoxyl comprising from 1 to 4 carbon atoms. A compound according to any one of claims 1 to 5, wherein R 2 is -Ph, R3 is -O-Ph and R2 and R3 together form a biphenyl, the group -(P=O)R2R3 thus having the formula (III): or in which R2 is -Ph-Ph-OH and R3 is hydroxyl, the group -(P=O)R2R3 thus having the formula (IV): [Chem. 40]

7. (IV) A process for preparing a compound according to any one of claims 1 to 6, comprising the reaction: - of a compound A of formula (Xla) or (Xlb): [Chem.41] (Xla) wherein R1 and n are as defined in claim 1, [Chem. 42] (Xlb) in which n is as defined in claim 1, [Chem. 43] (XIc) in which n is as defined in claim 1, - with a compound B of formula (XII): in which: - m, L and R4 are as defined in claim 1, and - R7 is chosen from a group -(C=O)H, a hydrogen, a hydroxyl, an alkyl comprising from 1 to 4 carbon atoms, an alkoxyl comprising from 1 to 4 carbon atoms, and a compound C of formula (XIII):

8.

9.

10.

11. R' (XIII) wherein R2 and R3 are as defined in claim 1 and R6 represents H or OH. A method according to claim 7, wherein compound A has the formula (Xla) or (Xlb), wherein n represents 5 or 10. The method of claim 7, wherein compound A is laurolactam. A method according to any one of claims 7 to 9, wherein compound B is selected from benzaldehyde, vanillin and ethylvanillin. A process according to any one of claims 7 to 9 for preparing a compound according to claim 4, wherein compound B has the formula (XII'):

12.

13.

14.

15. wherein L, R4 and m are as defined in claim 1. The method of claim 11, wherein compound B is selected from terephthalaldehyde and divanillin. A method according to any one of claims 7 to 12, wherein compound C is selected from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, hypophosphorous acid, phenyl phosphorous acid, phosphoric acid, dimethylphosphite, diethylphosphite and diphenylphosphite. A process according to claim 13 for preparing the compound according to claim 6, wherein compound C is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Aliphatic polyamide obtained by polycondensation of a compound according to any one of claims 1 to 6.

16. Aliphatic polyamide according to claim 15, obtained by polycondensation of a compound according to claim 5, and comprising a repeating unit of formula (XXII):

17. O (XXII) wherein m, n, R2, R3 and R4 are as defined in claim 1 and R5 is as defined in claim 5. Aliphatic polyamide according to claim 15, obtained by polycondensation of a compound of formula (II') as defined in claim 4 with an aliphatic diamine of formula H2N-L2-NH2 in which L2 is a divalent aliphatic group comprising from 4 to 36 carbon atoms, said aliphatic polyamide comprising a repeating unit of formula (XXI'):

18.

19. wherein m, n, L, R2, R3 and R4 are as defined in claim 1. Aliphatic polyamide according to any one of claims 15 to 17, further comprising one or more other unit(s) chosen from a unit obtained from at least one aliphatic amino acid, a unit obtained from at least one aliphatic lactam, a unit obtained from the polycondensation of at least one aliphatic diamine and at least one aliphatic dicarboxylic acid. An aliphatic polyamide according to claim 18, further comprising a repeating unit of formula (XXIII): in which q represents an integer from 5 to 11.

20. Aliphatic polyamide according to any one of claims 15 to 19, having a mass proportion of atomic phosphorus of at least 0.1%.

21. Aliphatic polyamide according to any one of claims 15 to 20, comprising fillers, reinforcing fibers, in particular glass fibers, additives, in particular chosen from flame retardants, antioxidants, plasticizers and mixtures thereof, or a mixture of these.

22. Use of an aliphatic polyamide according to any one of claims 15 to 21 as a flame retardant additive in thermoplastic polymer matrices, in particular polyamide, polyolefin, polyester, PMMA or mixtures thereof.

23. A process for preparing an aliphatic polyamide according to any one of claims 15 to 21 comprising the polycondensation of a compound of formula (I) as defined in claim 1, with at least one other monomer chosen from aliphatic amino acids, aliphatic lactams, mixtures of aliphatic diamines and aliphatic dicarboxylic acids, and mixtures thereof.

24. An article comprising an aliphatic polyamide according to any one of claims 15 to 21.

25. A method of preparing an article comprising a step of extruding, molding or overmolding the aliphatic polyamide according to any one of claims 15 to 21, whereby an article is obtained.