Self-flame retardant copolyesteramide

Abstract

The present invention relates to self-flame retardant copolyesteramides, characterized in that they are obtained by polycondensation of at least one polyamide monomer with at least one phosphorus-containing diol. The present invention also relates to the use of the copolyesteramides according to the invention for the manufacture of electrical and / or electrotechnical articles, tubes, cables, electrical safety articles, molded articles and / or articles obtained by 3D printing.

Description

[Technical Field]

[0001] The present invention relates to halogen-free flame retardant polyamide-based thermoplastic elastomeric polymers (hereinafter TPE-A), more particularly to copolymers comprising at least one polyamide monomer, a process for their production by copolymerization, and their use as flame retardant materials in all types of articles where fire resistance is desired, for example in the electrical, household appliance and electrical engineering sectors.

[0002] The copolymers of interest in the present invention are produced in particular from polyamide monomers containing at least 8 carbon atoms, preferably at least 10 carbon atoms, in contrast to the monomers containing less than 8 carbon atoms used in so-called "general purpose" polyamides, such as PA6 and PA66, which have much higher sales volumes (volumes) and much lower costs compared to technical or specialty polyamides. [Background technology]

[0003] The use of non-halogenated flame retardants is needed to replace halogenated flame retardants, which have the drawback of producing toxic and corrosive vapors upon ignition.

[0004] Patent documents WO2010 / 047469, JP2009215347, WO2006 / 121549 and EP2571939 describe, inter alia, TPE (thermoplastic elastomeric polymer) compositions which are both halogen-free flame retardant and have good mechanical properties.

[0005] The UL94 test (NF T 51-072 standard) provides a means of classifying materials according to their fire behavior. Materials are given a rating ranging from V0, which represents a material with very good flame spread resistance properties, to No Classification (NC), which represents a material with no fire resistance. The criteria for this classification are summarized in Table 1 in the Examples below.

[0006] A flame retardant that is effective in one type of polymer is not necessarily effective as a flame retardant in another type of polymer with the same classification in the UL94 test. This is particularly true for melamine cyanurate, which is effective in polyamides but not in TPEs, such as copolymers with polyamide and polyether blocks. Polyamide and polyether blocks do not resist first ignition in the UL94 test, as shown in Table 2 of EP 2571939. The same problem arises with phosphine metal salts, which were recently developed for effective flame retardancy in polyamides and later classified as V0. When the same phosphine metal salts are incorporated into a TPE matrix, the TPE is found to fail to achieve a good classification in the UL94 test. The TPE creeps in the flame, causing flaming drips from the first ignition, making it impossible to perform the second ignition of the UL94 test. Materials of this type that creep (or flow) when a flame is applied cannot be used in the electrical and electrical engineering sectors, and even more so in the field of electrical safety.

[0007] To avoid these problems of creep and the formation of flame-burning drips, it is known practice to incorporate "anti-drip" additives into the material, such as PTFE, talc, organophilic modified clay-type mineral nanofillers, or silicone agents. In the case of TPEs, not only are these anti-drip additives insufficient to move from a V2 classification to a V1 or V0 classification in the UL94 test, but they also have the drawback of making the material stiffer and reducing the elongation at break, thus altering the characteristic mechanical properties of the thermoplastic elastomer.

[0008] Polyamide-based TPE structures (TPE-A) are obviously more difficult to flame retardant than "long-chain" polyamides, which themselves are more difficult to flame retardant than "short-chain" polyamides or nylons. This difficulty leads to the use of higher amounts of additives (20% to 30% by weight based on the total weight of the PA-based composition). The additives, which are almost always phosphorus-containing, are expensive, and reduce other "performance" aspects of the TPE, particularly with regard to ductility, flow, elasticity, surface quality of extruded parts, moisture absorption, electrical insulation, and the variable cost of the formulation. Summary of the Invention

[0009] It is therefore an object of the present invention to provide a flame-retardant polyamide-based thermoplastic elastomeric polymer (abbreviated as "TPE-A") that requires little or no flame-retardant additives (10 wt. % or less, based on the total weight of the polymer composition), which are likely to degrade the mechanical properties of parts made from said TPE-A.

[0010] The object of the present invention is in particular to achieve at least the following three criteria: - Free of halogenated flame retardants, - Classification of V0 or V1 in UL94 test without creep or drip; and preferably has a Shore hardness, measured according to the ISO 868 standard, ranging from 50 Shore A to 80 Shore D, preferably from 60 Shore A to 72 Shore D. The object of the present invention is to provide a thermoplastic polymer composition which satisfies the above requirements.

[0011] The applicant has now found polyamide-based copolyesteramides that meet the above three criteria without the aforementioned drawbacks by incorporating a phosphorus-containing diol by copolymerization with said polyamide, which is rendered flame retardant.

[0012] The present invention therefore relates to self-flame retardant copolyesteramides, characterized in that they are obtained by polycondensation of at least one polyamide monomer with at least one phosphorus-containing diol, advantageously chosen from phosphine oxides, phosphinates, phosphonates, phosphates, phosphines, phosphites, phosphonites, phosphorites, phosphoranes and / or derivatives thereof.

[0013] The phosphorus-containing diol preferably has the following formula: TIFF0007753103000001.tif86170[In the formula, R1 represents a methyl, ethyl, propyl, butyl or isobutyl group, or a -[-O-R4] group, where R4 represents a methyl, ethyl, propyl or butyl group; R2 and R3 are identical or different, preferably identical, and represent a methylene, ethylene or propylene group; x and y are the same or different, preferably the same, and each represents a number from 1 to 10.] is selected from one of the compounds

[0014] In certain embodiments of the present invention, the phosphorus-containing diol has the formula: TIFF0007753103000002.tif28170[In the formula, R1 represents a methyl, ethyl or propyl group; R2 and R3 may be the same or different and represent a methylene, ethylene, or propylene group, and x and y each represent a number from 1.2 to 1.9. The oligomeric phosphonate diols are selected from the following:

[0015] In this case, it is preferable that R1 represents a methyl group, and x and y each represent a number from 1.5 to 1.7.

[0016] In another particularly advantageous embodiment of the present invention, the phosphorus-containing diol is a bis(hydroxyalkyl)phosphine oxide, such as isobutylbis(hydroxymethyl)phosphine oxide, isobutylbis(hydroxyethyl)phosphine oxide, or a bis(hydroxyalkyl)phosphine oxide of the formula: isobutylbis(hydroxypropyl)phosphine oxide (IHPO) of TIFF0007753103000003.tif28170.

[0017] In the copolyesteramides of the invention, the polyamide monomers are advantageously chosen from 12, 11, 10, 10, 6, 59, 510, 512, 513, 514, 516, 518, 536, 69, 610, 612, 613, 614, 616, 618, 636, 109, 1010, 1012, 1013, 1014, 1016, 1018, 1036, 10T, 129, 1210, 1212, 1213, 1214, 1216, 1218, 1236, 9T, 10T, 11T, 12T and mixtures thereof.

[0018] The weight percentage of phosphorus atoms in the copolymer is advantageously in the range of 0.1% to 10%, preferably 0.2% to 5%, preferably between 0.5% and 3%, preferably between 0.5% and 2%, based on the total weight of the copolyesteramide, which amounts to 100%.

[0019] The copolyesteramide of the present invention further comprises at least one other constituent monomer of the polymer, advantageously in the form of another difunctional polymer block having a terminal alcohol or amine functionality, said polymer being preferably chosen from polyethers, polyesters, polysiloxanes, such as polydimethylsiloxanes, polyolefins, polycarbonates, and mixtures thereof.

[0020] The copolyesteramide preferably comprises a polyether diol selected from poly(ethylene) glycol (PEG), poly(1,2-propylene glycol) (PPG), polytetramethylene glycol (PTMG), polyhexamethylene glycol, poly(1,3-propylene glycol) (PO3G), poly(3-alkyltetrahydrofuran), in particular poly(3-methyltetrahydrofuran (poly(3MeTHF)), and mixtures thereof, preferably comprising PTMG.

[0021] When the copolyesteramide of the invention comprises, besides the polyamide block and the phosphorus-containing diol monomer, at least one other difunctional block, the weight percentage of phosphorus atoms in the copolyesteramide is advantageously between 1% and 3%, preferably between 1% and 2%, based on the total weight of the copolyesteramide, which amounts to 100%.

[0022] The present invention also relates to a process for synthesizing the inventive copolyesteramides defined above, comprising the polycondensation of at least one polyamide precursor monomer with at least one phosphorus-containing diol and, optionally, at least one other difunctional polymer block as defined above, bearing terminal alcohol or amine functionality.

[0023] The present invention further relates to a non-halogenated flame retardant composition, characterized in that it comprises at least one copolyesteramide of the invention diluted in a thermoplastic polymer matrix, the polymer matrix advantageously comprising at least one homopolymer or copolymer thermoplastic polymer chosen from polyolefins, polyamides, fluoropolymers, saturated polyesters, polycarbonates, styrene resins, PMMA, thermoplastic polyurethanes (TPU), ethylene-vinyl acetate (EVA) copolymers, copolymers having polyamide blocks and polyether blocks, copolymers having polyester blocks and polyether blocks, copolymers having polyamide blocks, polyether blocks and polyester blocks, copolymers of ethylene and alkyl (meth)acrylates, copolymers of ethylene and vinyl alcohol (EVOH), ABS, SAN, ASA, polyacetals, polyketones, and mixtures thereof.

[0024] The composition advantageously comprises from 1% to 99% by weight of the copolyesteramide of the invention and from 1% to 99% by weight of the polymer matrix, the total weight of the composition being 100%.

[0025] The compositions of the present invention advantageously contain no flame retardant additives, with the only flame retardant effect being provided by the copolyesteramide itself.

[0026] Alternatively, the composition of the present invention further comprises at least one flame retardant additive, preferably in an amount of less than 10%, preferably in an amount of less than 5%, added by physical mixing, preferably by compounding, the flame retardant additive being selected from hydrated fillers of the aluminum trihydroxide and / or magnesium dihydroxide type, melamine derivatives, phosphorus-containing flame retardants, in particular metal salts of phosphinic acids, metal salts of diphosphinic acids, and mixtures thereof.

[0027] The present invention also relates to the use of the copolyesteramides or the compositions of the invention for the manufacture of electrical and / or electrotechnical articles, tubes, cables, electrical safety articles, molded articles and / or articles obtained by 3D printing.

[0028] The present invention further relates to articles obtained from at least one copolyesteramide or from the composition of the present invention by injection molding, extrusion, coextrusion, hot compression molding, multi-shot injection molding or 3D printing. DETAILED DESCRIPTION OF THE INVENTION

[0029] It should be noted that in this description, when ranges are referred to, expressions of the type "within the range of" or "including" include the limits of that range. Conversely, expressions of the type "between... and..." do not include a range limit.

[0030] Unless otherwise stated, percentages expressed are percentages by weight. Unless otherwise stated, the parameters referred to are those measured at atmospheric pressure and ambient temperature (20-25°C, typically 23°C).

[0031] The present invention will now be described in detail, but the following description is given in a non-limiting sense.

[0032] The polymers of the present invention are "inherently flame retardant" due to the internal phosphorus content in the polymer chain. The copolyesteramides result from the direct reaction by polycondensation of at least one polyamide monomer with at least one phosphorus-containing diol, and not from compounding (physical mixing) a polyamide with any flame retardant additive.

[0033] The compositions have been observed in the context of the present invention to have not only good flame retardant properties but also good mechanical properties, such as good ductility and good rebound resilience.

[0034] The phosphorus-containing diols are advantageously selected from phosphine oxides, phosphinates, phosphonates, phosphates, phosphines, phosphites, phosphonites, phosphorites, phosphoranes and / or derivatives thereof.

[0035] The phosphorus-containing diol preferably has the following formula: TIFF0007753103000004.tif84170[In the formula, R1 represents a methyl, ethyl, propyl, butyl or isobutyl group, or a -[-O-R4] group, where R4 represents a methyl, ethyl, propyl or butyl group; R2 and R3 are the same or different and represent a methylene, ethylene, or propylene group; x and y may be the same or different and each represent a number from 1 to 10. is selected from one of the compounds

[0036] In certain embodiments of the present invention, the phosphorus-containing diol has the formula: TIFF0007753103000005.tif27170[In the formula, R1 represents a methyl, ethyl or propyl group; R2 and R3 are the same or different and represent a methylene, ethylene, or propylene group; x and y each represent a number between 1.2 and 1.9. The oligomeric phosphonate diols are selected from the following:

[0037] In this case, it is preferable that R1 represents a methyl group and x represents a number from 1.5 to 1.7.

[0038] In another particularly advantageous embodiment of the present invention, the phosphorus-containing diol is a bis(hydroxyalkyl)phosphine oxide, such as isobutylbis(hydroxymethyl)phosphine oxide, isobutylbis(hydroxyethyl)phosphine oxide, or a bis(hydroxyalkyl)phosphine oxide of the formula: isobutylbis(hydroxypropyl)phosphine oxide (IHPO) of TIFF0007753103000006.tif28170.

[0039] Three types of polyamide monomers can be used to advantage.

[0040] Three types of polyamides may be used in the composition of the PA precursor.

[0041] In the first type, the polyamide monomer is at least one dicarboxylic acid X (aliphatic, cycloaliphatic or aromatic), chosen in particular from dicarboxylic acids having from 4 to 36 carbon atoms, preferably from dicarboxylic acids having from 6 to 18 carbon atoms, at least one diamine Y (aliphatic, cycloaliphatic or aromatic), chosen in particular from diamines having from 2 to 36 carbon atoms, preferably from diamines having from 6 to 12 carbon atoms; It consists of:

[0042] Examples of aliphatic diacids are butanedioic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, myristic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, octadecanedicarboxylic acid, and dimerized fatty acids.

[0043] An example of a cycloaliphatic diacid that may be mentioned is 1,4-cyclohexanedicarboxylic acid.

[0044] Examples of aromatic diacids that may be mentioned are the sodium, potassium or lithium salts of terephthalic acid (T), isophthalic acid (I), and 5-sulfoisophthalic acid.

[0045] Examples of aliphatic diamines that may be mentioned are tetramethylenediamine, hexamethylenediamine, decamethylene-1,10-diamine, dodecamethylenediamine, trimethylhexamethylenediamine.

[0046] Alicyclic diamines that are sometimes mentioned are bis(4-aminocyclohexyl)methane (BACM or PACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM or MACM), and 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and isomers of piperazine (Pip).

[0047] The copolyesteramides of the present invention advantageously comprise at least one XY type monomer selected from 59, 510, 512, 513, 514, 516, 518, 536, 69, 610, 612, 613, 614, 616, 618, 636, 109, 1010, 1012, 1013, 1014, 1016, 1018, 1036, 10T, 129, 1210, 1212, 1213, 1214, 1216, 1218, 1236, 9T, 10T, 11T, 12T, and mixtures thereof.

[0048] In the second type, the polyamide monomer comprises one or more α,ω-aminocarboxylic acids and / or one or more lactams Z having 6 to 12 carbon atoms in the presence of a dicarboxylic acid having 4 to 36 carbon atoms.

[0049] Examples of lactams that may be mentioned are caprolactam, enantholactam, and laurolactam.

[0050] Examples of α,ω-aminocarboxylic acids that may be mentioned are aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0051] The second type of polyamide monomer advantageously consists of amino 11, 12 or 6.

[0052] In a third type, the polyamide monomers consist of at least one monomer of a first type XY and at least one monomer of a second type Z. In other words, the polyamide monomer results from the polycondensation of at least one α,ω-aminocarboxylic acid (or lactam) with at least one diamine and dicarboxylic acid.

[0053] In this case, the mixture forms monomers XY, - one or more aliphatic, cycloaliphatic or aromatic diamines having X carbon atoms, - one or more dicarboxylic acids containing carbon atoms of Y and - one or more comonomers Z chosen from lactams and α,ω-aminocarboxylic acids having carbon atoms of Z It consists of in the presence of a chain limiter selected from dicarboxylic acids or diamines, or in the presence of an excess of diacids or diamines used as structural units.

[0054] As chain limiter it is advantageous to use a dicarboxylic acid having Y carbon atoms, the chain limiter being introduced in excess with respect to the stoichiometry of the diamine.

[0055] In another variant, the polyamide monomer comprises at least two different α,ω-aminocarboxylic acids or at least two different lactams having 6 to 12 carbon atoms, or a lactam and an aminocarboxylic acid having different numbers of carbon atoms, optionally in the presence of a chain limiter.

[0056] The NF EN ISO 1874-1:2011 standard defines the nomenclature for polyamides. In the present description, the term "monomer" should be interpreted as meaning "repeating unit." A special case occurs when the repeating unit of a polyamide consists of a combination of a diacid and a diamine. In this specification, this repeating unit is considered to correspond to a monomer, i.e., a "diamine-diacid" or "XY" pair, which is a combination of equimolar amounts of a diamine and a diacid. The rationale for this is that the diacid or diamine is merely an individual structural unit that cannot polymerize by itself.

[0057] Examples of polyamides are those formed by the following monomer mixtures: Formula 6 / 12, in which 6 represents caprolactam and 12 represents laurolactam. - 11 / 12 [wherein 11 represents 11-aminoundecanoic acid and 12 represents laurolactam] - 6 / 11 [wherein 6 represents caprolactam and 11 represents 11-aminoundecanoic acid.] - 6 / 66 [wherein 6 represents caprolactam and 66 represents the monomer resulting from the condensation of hexamethylenediamine with adipic acid]

[0058] Further examples that may be mentioned are the mixtures 1010 / 11, 610 / 11, 1012 / 11, 1010 / 11 / 12, 610 / 1010 / 11, 610 / 612 / 11, 610 / 612 / 1010, 11 / 636, 11 / 1036, and 1010 / 1036.

[0059] In the copolyesteramide of the invention, said at least one polyamide monomer is advantageously chosen from 12, 11, 10, 10, 6, 59, 510, 512, 513, 514, 516, 518, 536, 69, 610, 612, 613, 614, 616, 618, 636, 109, 1010, 1012, 1013, 1014, 1016, 1018, 1036, 10T, 129, 1210, 1212, 1213, 1214, 1216, 1218, 1236, 9T, 10T, 11T, 12T, and mixtures thereof.

[0060] In a particular embodiment of the present invention, the copolyesteramide further comprises, in addition to the polyamide monomer and the phosphorus-containing diol, at least one other oligomer, generally having terminal alcohol (diol) or optionally amine (diamine) functionality, preferably a polymeric diol, in particular in the form of a diol polymer block.

[0061] In particular in this case, the copolyesteramide of the present invention then forms a polyamide-based thermoplastic elastomer (abbreviated as TPE-A) comprising a diol polymer. The latter generally forms flexible or soft blocks in the copolyesteramide of the present invention. Said blocks are said to be "flexible" because they have a low glass transition temperature (Tg). A low glass transition temperature is understood to mean a glass transition temperature Tg of less than 15°C, preferably less than 0°C, advantageously -15°C, even more advantageously -30°C, and optionally less than -50°C.

[0062] The number-average molar mass Mn of the diol polymer according to the invention, optionally in the form of a flexible block, is in the range from 250 to 5000 g / mol, preferably from 250 to 3000 g / mol, more preferably from 500 to 2000 g / mol.

[0063] Said difunctional polymers, preferably diol polymers, according to the invention are chosen in particular from polyethers, polyesters, polysiloxanes, such as blocks of polydimethylsiloxane or PDMS, polyolefins, polycarbonates, and mixtures thereof.

[0064] For the purposes of the present invention, polyether (hereinafter abbreviated as PE) is understood to mean polyoxyalkylenes, such as polyalkylene ether polyols, especially polyalkylene ether diols. The PE block in the copolymer of the present invention comprises at least one molecule selected from poly(ethylene glycol) (PEG), poly(1,2-propylene glycol) (PPG), polytetramethylene glycol (PTMG), polyhexamethylene glycol, poly(1,3-propylene glycol) (PO3G), poly(3-alkyltetrahydrofuran), especially poly(3-methyltetrahydrofuran (poly(3MeTHF)), and mixtures thereof. This can also be considered as an alternating, statistical, or block "copolyether" type PE, which contains at least two sequences of the aforementioned PE types.

[0065] The polyethers may also include PE obtained by oxyethylation of bisphenols, such as bisphenol A. These latter products are described in patent EP 613919.

[0066] The polyether may comprise an ethoxylated primary amine. An example of an ethoxylated primary amine is represented by the formula: TIFF0007753103000007.tif38170 [wherein m and n are between 1 and 20, and x is between 8 and 18.] These products are commercially available from CECA under the Noramox® brand and from Clariant under the Genamin® brand.

[0067] Therefore, the chain ends of the PE blocks can be di-OH, di-NH2, diisocyanate or diacid according to their synthesis process. In the case of the present invention, the PE used is advantageously di-OH.

[0068] The PE in the copolyesteramide of the invention is advantageously a soft block (SB) comprising tetramethylene glycol units, the SB block being preferably a PTMG block.

[0069] The SB blocks can also be considered as polyether blocks of a copolymer in which the majority monomer is ethylene oxide, where the ethylene oxide preferably accounts for more than 50% by weight, based on the total weight of the copolymer.

[0070] For the purposes of this invention, polyester (hereinafter abbreviated as PES) is understood to mean a polyester conventionally prepared by polycondensation between a dicarboxylic acid and a diol. Suitable carboxylic acids include those previously mentioned for forming polyamide blocks, with the exception of aromatic acids such as terephthalic acid and isophthalic acid. Suitable diols include linear aliphatic diols such as ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, and 1,6-hexylene glycol; branched diols such as neopentyl glycol, 3-methylpentane glycol, and 1,2-propylene glycol; and cyclic diols such as 1,4-bis(hydroxymethyl)cyclohexane and 1,4-cyclohexanedimethanol.

[0071] The term "polyester" is also understood to mean poly(caprolactone) and PES based on fatty acid dimers, in particular the Priplast® range of products from Croda.

[0072] This can also be considered as an alternating, statistical or block "copolyether" type PES, which contains at least two sequences of the aforementioned PES types.

[0073] The term polysiloxane (hereinafter abbreviated as PSi) is understood for the purposes of the present invention to mean any linear or cyclic organosilicon polymer or oligomer with a branched or crosslinked structure. Polysiloxanes are obtained by polymerization of functionalized silanes and essentially consist of repeating main units in which silicon atoms are interconnected via oxygen atoms (siloxane chains -Si-O-Si- chains), with hydrocarbon radicals attached directly to said silicon atoms via carbon atoms and optionally substituted. The most common hydrocarbon radicals are alkyl radicals, especially C1-C10 radicals, in particular methyl, fluoroalkyl radicals, aryl radicals, in particular phenyl, and alkenyl radicals, in particular vinyl; other types of radicals which can be attached to the siloxane chain directly or via a hydrocarbon radical are, in particular, hydrogen, halogens, in particular chlorine, bromine or fluorine, thiols, alkoxy radicals, polyoxyethylene (or polyether) radicals, in particular polyoxyethylene and / or polyoxypropylene, hydroxy or hydroxyalkyl radicals, substituted or unsubstituted amine groups, amide groups, acyloxy or acyloxyalkyl radicals, hydroxyalkylamino or aminoalkyl radicals, quaternary ammonium groups, amphoteric or betaine groups, anionic groups such as carboxylates, thioglycolates, sulfosuccinates, thiosulfates, phosphates, sulfates and mixtures thereof, this list being, of course, by no means exhaustive ("organo-modified" silicones).

[0074] The polysiloxane preferably includes polydimethylsiloxane (hereinafter abbreviated as PDMS block), polymethylphenylsiloxane and / or polyvinylsiloxane.

[0075] The term polyolefin (hereinafter abbreviated as PO block) is understood for the purposes of the present invention to mean any polymer comprising an α-olefin as a monomer, i.e. an olefin homopolymer or a copolymer of at least one α-olefin with at least one other copolymerizable monomer, advantageously an α-olefin containing from 2 to 30 carbon atoms.

[0076] Examples of α-olefins that may be mentioned are ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 1-docosene, 1-tetracosene, 1-hexacosene, 1-octacosene, and 1-triacontene. These α-olefins may be used alone or as a mixture of two or more α-olefins.

[0077] Examples that are sometimes mentioned include: - ethylene homopolymers and copolymers, in particular low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE) and polyethylene obtained by metallocene catalysis; - propylene homopolymers and copolymers, essentially amorphous or atactic poly-α-olefins (APAOs); ethylene / α-olefin copolymers, such as ethylene / propylene, EPR (ethylene-propylene rubber) and EPDM (ethylene-propylene-diene) elastomers, and mixtures of polyethylene with EPR or EPDM; - styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), and styrene / ethylene-propylene / styrene (SEPS) block copolymers; - copolymers of ethylene with at least one product chosen from salts or esters of unsaturated carboxylic acids, such as alkyl (meth)acrylates (alkyl optionally containing up to 24 carbon atoms), vinyl esters of saturated carboxylic acids, such as vinyl acetate or propionate, and dienes, such as 1,4-hexadiene or polybutadiene.

[0078] In an advantageous embodiment of the invention, the polyolefin comprises polyisobutylene and / or polybutadiene.

[0079] In a particularly advantageous embodiment, the copolyesteramide of the present invention comprises at least one flexible polyolefin block (PO block) and at least one hydrophilic hard block (hereinafter abbreviated as hHB) comprising both a polyamide and a polyether, such as a polyetheramide block, a polyetheresteramide block, and / or a polyetheramideimide block, etc. The PO block preferably comprises a polyolefin containing terminal acid, alcohol, or amine groups, preferably terminal alcohol (diol) groups.

[0080] The term polycarbonate (hereinafter abbreviated as PC block) is understood for the purposes of the present invention to mean more particularly any aliphatic polycarbonate. Aliphatic polycarbonates are described, for example, in documents DE2546534 and JP1009225. Such homopolymer or copolymer polycarbonates are also described in US471203. Patent applications WO92 / 22600 and WO95 / 12629 also describe copolymers containing polycarbonate blocks and methods for their synthesis. The blocks (and their synthesis) described in these documents are entirely feasible for the synthesis of the PC block copolyesteramides according to the present invention. The polycarbonate blocks in the copolyesteramides of the present invention are preferably of the formula: TIFF0007753103000008.tif31170 [wherein a is an integer of 2 to 300; R 1 and R2 are the same or different and represent a linear or branched aliphatic or alicyclic chain having 2 to 18 carbon atoms, or represent a polyoxyalkylene group, or represent a polyester group. It has.

[0081] R 1 and R 2 is selected from hexylene, decylene, dodecylene, 1,4-cyclohexylene, 2,2-dimethyl-1,3-propylene, 2,5-dimethyl-2,5-hexene or polyoxyethylene.

[0082] When a copolyesteramide comprises at least one polyamide (optionally in the form of a rigid polyamide block), at least one phosphorus-containing diol, and optionally at least one other polymer (especially in the form of a flexible block), it is self-evident that the present invention encompasses virtually all copolyesteramides comprising two, three, four (or more) different blocks selected from the blocks described herein, as long as at least one of these blocks is a polyamide block and has reacted with a phosphorus-containing diol to form an ester linkage.

[0083] A copolyesteramide, for purposes of this invention, is a polymer that includes at least one polyamide precursor monomer and a phosphorus-containing diol.

[0084] The weight percentage of phosphorus atoms in the copolymer is advantageously in the range of 0.1% to 10%, preferably 0.2% to 5%, preferably between 0.5% and 3%, preferably between 0.5% and 2%, based on the total weight of the copolyesteramide, which is 100%, thereby optimizing the UL94 test results obtained with the inventive inherently flame-retardant copolyesteramides.

[0085] The copolyesteramide of the present invention may further comprise another polymer (for example, PE).When the copolyesteramide of the present invention comprises at least one other bifunctional block other than polyamide precursor monomer, the weight percentage of phosphorus atoms in the copolyesteramide is between 1% and 3%, preferably between 1% and 2%, based on the total weight of the copolyesteramide, which is 100%.This allows the self-flammable copolyesteramide of the present invention to obtain the best results in the UL94 test.

[0086] The present invention also provides a method for synthesizing the inventive copolyesteramides defined above, comprising the polycondensation of at least one polyamide monomer with at least one phosphorus-containing diol and, optionally, at least one other difunctional polymer block, as defined above, having terminal alcohol or amine functionality.

[0087] The method for synthesizing the copolyesteramides of the present invention utilizes any means that allows copolymerization of polyamide monomers with phosphorus-containing diols and, optionally, the soft blocks. Numerous means can be considered, including in solution, in bulk, or via interfacial techniques, as well as the combination of several of these methods, as described in Chapter 9 of Handbook of Condensation Thermoplastic Elastomers (Stojko Fakirox, ed., Wiley-VCH, Weinheim, 2005).

[0088] Copolyesteramides result from the polycondensation of polyamide monomers with phosphorus-containing diols and with soft blocks SB of polymers (eg polyethers) having alcohol chain ends.

[0089] In practice, the process of copolymerization of polyamide monomers with SB and phosphorus-containing diols is carried out in two main steps or in a single main step.

[0090] In both the first and second steps, it is advantageous to carry out the operation in the presence of a catalyst. The term "catalyst" is understood to mean any product that makes it possible to accelerate the formation of ester bonds. The esterification catalyst is advantageously a derivative of a metal selected from the group consisting of titanium, zirconium, and hafnium, or else formed with strong acids, such as phosphoric acid or boric acid. The catalysts described in the following patents can be used: US 4,331,786, US 4,115,475, US 4,195,015, US 4,839,441, US 4,864,014, US 4,230,838 et US 4,332,920, WO 04,037,898, EP 1,262,527, EP 1,270,211, EP 1,136,512, EP 1,046,675, EP 1,057,870, EP 1,155,065, EP 506,495, and EP 504,058.

[0091] In a first embodiment, the method of the invention comprises two main steps: in a first step (I), the polyamide monomers only undergo polymerization, and in a second step (II), said at least one PA is reacted, preferably in the presence of a catalyst and under reduced pressure, with at least one phosphorus-containing diol, and optionally also with a diol polymer (SB block).

[0092] The step (I) may involve any means known to those skilled in the art for producing polyamides, such as by polycondensation reaction between a polyamide precursor and a dicarboxylic acid or diamine as a chain regulator. In this case, step I is divided into the following substeps: (I-1) charging a mixture comprising at least one PA precursor and at least one chain regulator, such as a diacid, into a reactor (e.g., an autoclave). The chain regulator is preferably selected from adipic acid, sebacic acid, terephthalic acid, isophthalic acid, and mixtures thereof. (I-2) Heating the mixture to a temperature in the range of 180 to 350°C, preferably 200 to 300°C, preferably 230 to 290°C. Water may optionally be added to the mixture to improve heat transfer and / or to obtain sufficient pressure, particularly for ring opening of, for example, lactam 12. (I-3) A hot isothermal stage in which the temperature of the mixture is kept constant for a time sufficient to bring all the materials introduced in I-1 into a fluid state, i.e., a state of sufficiently low viscosity for a homogeneous mixture to exist, the temperature being in the range of 180 to 350° C., preferably 200 to 300° C., preferably 230 to 290° C. The duration of the hot isothermal stage is generally in the range of 15 minutes to 5 hours, preferably 30 minutes to 4 hours, preferably 30 minutes to 3 hours.

[0093] During this hot isothermal stage, a pressure of, for example, between 1 bar and 40 bar is generated in the reactor, which preferably does not exceed 30 bar, although this maximum pressure is in fact reactor-dependent and depends on the manner in which the reactor is installed. (1-4) A step of removing water by expanding (reducing the pressure) the mixture to return it to atmospheric pressure and / or by distillation. This water is the water optionally added in steps I-1, I-2 and / or I-3 or the water formed in these steps. (I-5) Purging with inert gas until complete polymerization of the mixture in the form of polyamide blocks.

[0094] The purging time may be within a range of several minutes to several hours, preferably 5 minutes to 5 hours, preferably 30 minutes to 3 hours, preferably 1 hour to 2 hours.

[0095] Step I may further comprise one or more of the following substeps: (I-6) If necessary, an optional step of holding under reduced pressure, for example less than 500 mbar, preferably less than 100 mbar, in order to increase the polymerization yield. - (I-7) An optional step of recovering PA.

[0096] All starting materials required for the formation of the PA may be charged to the reactor at the beginning in any order that the skilled person considers appropriate, as is the case, for example, in step I-1 of the process described above, although it is of course possible to consider the introduction of one or more starting materials in any of the substeps I-1 to I-7.

[0097] The temperature in this main step I is within the range of 180 to 350°C, preferably 200 to 300°C, and more preferably 230 to 290°C.

[0098] The PA may be extruded for later use, stored in the reactor, or transferred to another reactor for carrying out Step II, described below.

[0099] Step (II) comprises the following substeps: (II-1) contacting in a reactor at least a portion of the amount of at least one phosphorus-containing diol and optionally at least one soft block SB with the PA formed in step I and adjusting the temperature of the resulting mixture so that the temperature is in the range of 180 to 350°C, preferably 200 to 300°C, preferably 200 to 260°C; (II-2) an optional step of purging with nitrogen (or another inert gas) and / or under slightly reduced pressure, for example below 500 mbar, preferably below 100 mbar, to remove the water formed in the reactor during the copolymerization, (II-3) an optional step of introducing the remainder of said at least one block SB, if necessary.

[0100] The temperature and duration of each step can be easily adjusted by one skilled in the art to optimize the reactivity of the polycondensation while minimizing side reactions. The temperature in this main step II is similarly in the range of 180 to 350°C, preferably 200 to 300°C, and more preferably 200 to 260°C.

[0101] In a second embodiment, the process of the present invention comprises a single main step, characterized in that the at least one phosphorus-containing diol and, optionally, the "other polymer" (soft block), as well as the starting materials necessary for the formation of the PA, are introduced directly in main step I, i.e., in any of intermediate steps I-1 to I-7. In this embodiment, main steps I and II are practically carried out simultaneously, thus saving time, whereas in the two main step embodiment, steps I and II are carried out sequentially.

[0102] Regardless of its embodiment (in one step or two steps), the process of the invention comprises a final step III of finishing and recovering the copolyesteramide, which step III comprises at least two of the following substeps: (III-1) Adjusting the viscosity of the resulting copolyesteramide. The pressure in the reactor is reduced under high vacuum until the desired viscosity, i.e., the desired molar mass of the copolymer, is obtained. "Desired molar mass" is understood to mean a number-average molar mass in the range of 5,000 to 100,000 g / mol, preferably in the range of 15,000 to 50,000 g / mol, and preferably in the range of 10,000 to 40,000 g / mol. The pressure during this substep is preferably less than 100 mbar, preferably less than 50 mbar, preferably less than 10 mbar, more preferably less than 1 mbar.

[0103] The increase in the molar mass of the copolymer, and therefore the increase in the viscosity of the medium, is determined, for example, by measuring the change in the value of the torque exerted on the stirrer by the molten polymer or by measuring the power consumed by the stirrer for a given stirring measure. (III-2) extruding and recovering said copolyesteramide, for example in the form of pellets or in any other form.

[0104] (III-3) An optional step of baking the pellets to reduce the residual moisture content to less than 0.1% by weight.

[0105] The stirring rate at each step is optimized according to the rheology of the medium and the nature of the stirrer.

[0106] The reduction in pressure may occur gradually or in steps, the maximum reduction in pressure depending on the nature of the species present, their hydrophilic or hydrophobic nature, and their reactivity.

[0107] The catalyst may be added in one of steps I and / or II, preferably in one of substeps II, if it is a hydrolysis sensitive catalyst.

[0108] The present invention further provides a non-halogenated flame retardant composition, characterized in that it comprises at least one copolyesteramide of the invention diluted in a thermoplastic polymer matrix, the polymer matrix advantageously comprising at least one homopolymer or copolymer thermoplastic polymer chosen from polyolefins, polyamides, fluoropolymers, saturated polyesters, polycarbonates, styrene resins, PMMA, thermoplastic polyurethanes (TPU), ethylene-vinyl acetate (EVA) copolymers, copolymers having polyamide blocks and polyether blocks, copolymers having polyester blocks and polyether blocks, copolymers having polyamide blocks, polyether blocks and polyester blocks, copolymers of ethylene and alkyl (meth)acrylates, copolymers of ethylene and vinyl alcohol (EVOH), ABS, SAN, ASA, polyacetals, polyketones, and mixtures thereof.

[0109] The composition advantageously comprises from 1% to 99% by weight of the copolyesteramide of the invention and from 1% to 99% by weight of the polymer matrix, the total weight of the composition being 100%.

[0110] The compositions of the present invention advantageously contain no flame retardant additives, with the only flame retardant effect being provided by the copolyesteramide itself.

[0111] Alternatively, the composition of the present invention further comprises at least one flame retardant additive, preferably in an amount of less than 10%, preferably in an amount of less than 5%, added by physical mixing, preferably by compounding, the flame retardant additive being selected from hydrated fillers of the aluminum trihydroxide and / or magnesium dihydroxide type, melamine derivatives, phosphorus-containing flame retardants, in particular metal salts of phosphinic acids, metal salts of diphosphinic acids, and mixtures thereof.

[0112] The present invention also relates to the use of the copolyesteramides or the compositions of the invention for the manufacture of electrical and / or electrotechnical articles, tubes, cables, electrical safety articles, molded articles and / or articles obtained by 3D printing.

[0113] The present invention further relates to articles obtained from at least one copolyesteramide or from the composition of the present invention by injection molding, extrusion, coextrusion, hot compression molding, multi-shot injection molding or 3D printing. [Example]

[0114] Products used in the test: Phosphorus-containing monomers: RF1: Isobutylbis(hydroxypropyl)phosphine oxide (IHPO) RF2:Formula: Oligomeric phosphonate polyol (OP560) from TIFF0007753103000009.tif22170

[0115] Polyamide Monomer: A11 is 11-aminoundecanoic acid to produce a prepolymer of Mn: 1000 g / mol. DC6 is adipic acid used as a chain limiter.

[0116] For tests on flexible blocks: PTMG 1000: Polytetramethylene glycol (Mn: 1000g / mol)

[0117] Preparation of flame retardant material: A glass reactor was charged with 11-aminoundecanoic acid, adipic acid, polytetramethylene glycol (optional), and a phosphorus-containing compound in the proportions listed in Table 2. The mixture was inertized by purging with nitrogen and heated with stirring to a material temperature of 235 °C. Polymerization took place under nitrogen purging, and an increase in the stirring torque was observed. If a polyether was present, it was necessary to work under reduced pressure and add a catalyst (zirconium butoxide type).

[0118] UL94 test: This standardized test is carried out on a set of five identical test specimens (127 mm x 12.7 mm x 1.6 mm). The specimens are suspended from a support. They are ignited from below with a 20 mm high blue flame from a Bunsen burner. The flame is applied for 10 seconds and then removed. The time interval T1 during which combustion (flaming combustion, then red-hot combustion) persists is recorded. The flame is then applied again for 10 seconds and then removed. The time interval T2 during which combustion persists is also recorded. The phenomenon of afterglow is taken into account due to the possibility of flaming drips and the tendency for fire to spread if dropped onto cotton placed directly below the test specimen. TIFF0007753103000010.tif58170

[0119] In Table 2 below, "NC" stands for no classification for materials that do not have fire resistance.

[0120] DSC conditions: Equipment: DSC TA Q2000 with Intracooler cooling module Ramp up to 240°C at 20°C / min Decrease to -80°C at a rate of 20°C / min Ramp up to 240°C at 20°C / min

[0121] viscosity: The viscosity of the solution is measured in meta-cresol according to standard ISO 394.

[0122] Test results: TIFF0007753103000011.tif123153

[0123] No flexible block The best results of the UL94 test are obtained for the intrinsically flame-retardant copolyesteramides of the present invention in Examples 3 and 4, which use the phosphorus-containing monomer RF2, where the weight percentage of phosphorus atoms (%P) in the copolymer is between 0.5% and 2% (0.79% in Example 3 and 1.58% in Example 4), based on the total weight of the copolyesteramide, which is 100%.

[0124] With flexible block The best results in the UL94 test are obtained for the inherently flame-retardant copolyesteramide in Example 11 of the present invention using the phosphorus-containing monomer RF2, where the weight percentage of phosphorus atoms (%P) in the copolymer is between 1% and 2% (1.58% in Example 11), based on the total weight of the copolymer, which is taken to be 100%.

[0125] In summary, the polymers of the present invention allow for cost savings in the production of flame retardant materials, since flame retardant additives are used in smaller amounts or not at all, thus eliminating the step of compounding the polymer with such additives. TIFF0007753103000012.tif79170

[0126] Charpy impact tests were carried out on the copolyesteramide of Example 3 (Ex3) and the PA12-PTMG copolymer (CP3), which have similar hardness (about 70 shD).

[0127] Testing was performed on dry samples (drying protocol: 60°C overnight) according to the ISO 179 1eA standard at 23°C. Test specimens (80mm x 10mm x 4mm) were injection molded in an Xplore IM12 press paired with an Xplore MC 15 twin-screw mini-extruder. The self-flame retardant copolyesteramide from Example 3 of the present invention, which uses the phosphorus-containing monomer RF2 and has a weight percentage of phosphorus atoms in the copolymer of 0.79%, based on the total weight of the copolyesteramide, exhibits better recovery in impact tests than the non-flame retardant copolyesteramide CP3 and shows the best results in UL94.

[0128] The product was melted and homogenized in an Xplore Micro 5C mini-extruder and molded in a twin mini-injector.

Claims

1. 1. An inherently flame-retardant copolyesteramide, characterized in that it is obtained by polycondensation of at least one polyamide monomer with at least one phosphorus-containing diol, The phosphorus-containing diol has the following formula: [In the formula, R １ is a methyl, ethyl, propyl, butyl or isobutyl group, or a group —[—O—R ４ ] (wherein, R ４ represents a methyl, ethyl, propyl or butyl group; R ２ and R ３ are the same or different and represent a methylene, ethylene or propylene group; x and y are the same or different and each represents a number from 1 to 10.

1. The self-flame retardant copolyesteramide, wherein the self-flame retardant copolyesteramide is selected from one of the compounds

2. The phosphorus-containing diol has the formula: [In the formula, R １ represents a methyl, ethyl or propyl group, R ２ and R ３ are the same or different and represent a methylene, ethylene or propylene group; x and y each represent a number from 1.2 to 1.9.] 2. The copolyesteramide of claim 1, wherein the oligomeric phosphonate diol is selected from the group consisting of:

3. R １ 3. Copolyesteramide according to claim 2, characterized in that x represents a methyl group and x and y each represent a number between 1.5 and 1.

7.

4. 4. The copolyesteramide of any one of claims 1 to 3, wherein the at least one polyamide monomer is selected from the following polyamide monomers: 12, 11, 6, 59, 510, 512, 513, 514, 516, 518, 536, 69, 610, 612, 613, 614, 616, 618, 636, 109, 1010, 1012, 1013, 1014, 1016, 1018, 1036, 10T, 129, 1210, 1212, 1213, 1214, 1216, 1218, 1236, 9T, 10T, 11T, 12T, and mixtures thereof.

5. 5. Copolyesteramide according to claim 1, characterized in that the weight percentage of phosphorus atoms in the copolymer is in the range of 0.1% to 10%, based on the total weight of the copolyesteramide, which amounts to 100%.

6. 6. Copolyesteramide according to claim 1, characterized in that it further comprises at least one other difunctional polymer block having a terminal alcohol or amine function.

7. 7. The copolyesteramide of claim 6, wherein the polymer is selected from polyethers; polyesters; polysiloxanes; polyolefins; polycarbonates; and mixtures thereof.

8. 8. The copolyesteramide of claim 6 or 7, comprising a polyether diol selected from poly(ethylene) glycol (PEG), poly(1,2-propylene glycol) (PPG), polytetramethylene glycol (PTMG), polyhexamethylene glycol, poly(1,3-propylene glycol) (PO3G), poly(3-alkyltetrahydrofuran), poly(3-methyltetrahydrofuran (poly(3MeTHF)), and mixtures thereof.

9. 9. Copolyesteramide according to any one of claims 6 to 8, characterized in that the weight percentage of phosphorus atoms in the copolymer is between 1 and 3%, based on the total weight of the copolyesteramide, which amounts to 100%.

10. 10. A method for synthesizing the copolyesteramide of any one of claims 1 to 9, comprising the polycondensation of at least one polyamide monomer with at least one phosphorus-containing diol and, optionally, at least one other difunctional polymer block having terminal alcohol or amine functionality.

11. A non-halogenated flame retardant composition, characterized in that it comprises at least one copolyesteramide according to any one of claims 1 to 9 diluted in a thermoplastic polymer matrix.

12. 12. The composition of claim 11, wherein the thermoplastic polymer matrix comprises at least one homopolymer or copolymer thermoplastic polymer selected from polyolefins, polyamides, fluoropolymers, saturated polyesters, polycarbonates, styrene resins, PMMA, thermoplastic polyurethanes (TPU), ethylene-vinyl acetate (EVA) copolymers, copolymers having polyamide blocks and polyether blocks, copolymers having polyester blocks and polyether blocks, copolymers having polyamide blocks, polyether blocks and polyester blocks, copolymers of ethylene and alkyl (meth)acrylates, copolymers of ethylene and vinyl alcohol (EVOH), ABS, SAN, ASA, polyacetals, polyketones, and mixtures thereof.

13. 13. The composition of claim 11 or 12, comprising 1% to 99% by weight of said copolyesteramide and 1% to 99% by weight of said thermoplastic polymer matrix, the total weight of the composition being 100%.

14. 14. The composition according to any one of claims 11 to 13, characterized in that it does not contain any flame retardant additives and the only flame retardant effect is provided by the copolyesteramide itself.

15. 14. The composition according to any one of claims 11 to 13, characterized in that it further comprises at least one flame retardant additive added by physical mixing and chosen from hydrated fillers of the aluminum trihydroxide and / or magnesium dihydroxide type, melamine derivatives, phosphorus-containing flame retardants, metal salts of phosphinic acids, metal salts of diphosphinic acids, and mixtures thereof.

16. 16. Use of the copolyesteramides according to any one of claims 1 to 9 or the compositions according to any one of claims 11 to 15 for the manufacture of electrical articles, electrotechnical articles, tubes, cables, electrical safety articles, moulded articles or articles obtained by 3D printing.

17. 16. An article obtained from at least one copolyesteramide according to any one of claims 1 to 9 or from a composition according to any one of claims 11 to 15 by injection molding, extrusion, coextrusion, hot compression molding, multi-shot injection molding or 3D printing.

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