Polyamide based on 4,4'-diaminodicyclohexylmethane and 4,4'-methylene-bis-cyclohexylamine

Abstract

The present invention relates to a filament made of or comprising a polymer composition (P) which comprises at least 50.0 wt. % (based on the total weight of the polymer composition (P)) of at least one polyamide (PA) comprising the recurring units (RPA) and (R*PA): (I) where n is 7 or 8; and wherein at least 30.0 mol.% of the moieties derived from 4,4'- diaminodicyclohexylmethane are in a trans / trans configuration, this proportion being based on the total number of moles of the moieties derived from 4,4'-diaminodicyclohexylmethane in the polyamide (PA).

Description

Polyamide based on 4,4’-diaminodicyclohexylmethane and 4,4'-methylene-bis-cycIohexylamine

[0001] The present invention relates to a polyamide (PA) based on 4,4’- diaminodicyclohexylmethane (PACM) and 4,4'-methylene-bis-cyclohexylamine (MACM), to a filament made of this polyamide (PA), as well as to a process for manufacturing a three-dimensional (3D) article, part or composite material, from such filament.Technical Field

[0002] Many objects, from household items to motor parts, are produced either from a single mass of material or they are milled or carved from a larger block of material. An alternative approach to manufacture objects is to deposit a layer of material, and then add another layer on top, followed by another and another, and so on. This process of adding gave rise to the name additive manufacturing (AM), more commonly known as 3D printing. The range of specially designed 3D-printed products on the market is now considerable - from motor parts to dental implants. They can be notably manufactured using plastics. It is expected that additive manufacturing will disrupt established practices and overturn conventional assumptions about mass production in distant factories. Local fabrication in small volumes, or even of single items, close to the end user will become viable.

[0003] In an extrusion-based AM system, a 3D part is printed from a digital representation of the 3D part in a layer-by-layer manner by extruding and adjoining strips of a part material. The part material is extruded through an extrusion tip carried by a print head of the system, and is deposited as a sequence of roads on a platen in an x-y plane. The extruded part material fuses to previously deposited part material, and solidifies upon a drop in temperature. The position of the print head relative to the substrate is then incremented along a z-axis (perpendicular to the x-y plane), and the process is then repeated to form a 3D part resembling the digital representation. An example of extrusion-based AM system starting from filaments is called Fused Filament Fabrication (FFF), also known as Fused Deposition Modelling (FDM).

[0004] One of the fundamental limitations associated with known extrusion-based AM methods using polymeric part material in the form of filaments is based on the lack of identification of polymeric material presenting the right set of properties, in order to print articles, parts or composite materials with acceptable properties, notably thermal and mechanical properties.

[0005] Certain polyamides are used for manufacturing articles by extrusion-based 3D printing. Mention can for example be made of polyamide 12 (PA12) and polyamide 6 (PA6). These polyamides advantageously have a melting point (Tm) (or melting temperature) lower than 280°C, and therefore have a much broader temperature window for their synthesis and processing in the melt, which first offers more flexibility in synthesis and processing, but also leads to printed parts with less colouring due to degradation. These polyamides however usually exhibit a low glass transition temperature (Tg), e.g. below 50°C, which make them unsuitable to prepare articles used in applications requiring a high temperature resistance as their mechanical properties, such as modulus or strength, fall significantly above this temperature. For example, PA12 has a Tg of 40°C and PA6 has a Tg of 50°C. Moreover, PA 6 absorbs so much moisture when exposed to ambient environment or when it is soaked in water (around 9 wt.%) that its Tg decreases dramatically and parts made with PA 6 have lower modulus when exposed at temperatures above room temperature. In addition, these polyamides and their filaments require a drying step before being used.Technical problem

[0006] Some applications sometimes require the preparation of transparent or translucent 3D objects prepared by FFF and exhibiting a combination of mechanical properties (e.g. modulus and strength), even at high temperatures. For instance, articles to be used in applications like automotive interior and exterior need to withstand temperatures as high as 80°C. These properties should also not be affected by the humidity present in the environment.

[0007] The polyamide and filament used in the FFF should also be easily processable with the available 3D printers.

[0008] The material of the 3D object should also exhibit UV and chemical resistance. UV resistance is for instance needed when the 3D object is to be left outdoors or under sunlight.

[0009] Finally, customers are more and more sensitive to using materials prepared from biobased components.

[0010] The filament and the polyamide of the invention address this technical problem.Background Art

[0011] US 5,360,891 (Huels) relates to a colourless and transparent, amorphous processable polyamide comprising the reaction product of I. a linear aliphatic dicarboxylic acid; II. a) 35-60 mol % of trans, trans-bis(4-aminocyclohexyl)-methane; and II. b) 65-40 mol % of other aliphatic, cycloaliphatic, araliphatic or aromatic diamines as starting components.

[0012] US 2003 / 0235666 discloses a transparent polyamide moulding material having a melting enthalpy between 0 and 12 J / g and comprising: A. 100 mole-% of a diamine mixture having approximately 10 to about 70 mole-% of PACM with less than 50 wt. -% of trans, trans-isomer and approximately 90 to about 30 mole-% of MACM [bis- (4-amino-3-methy[-cyc[ohexy[)-methane], and B. 100 mole-% of long-chain aliphatic dicarboxylic acids having 8 to 14 C atoms or mixtures of these dicarboxylicacids.

[0013] EP 4067409 (EMS) discloses a polyamide comprising biobased diamine monomer of the structurewith a biobased content higher than 85%. It also more specifically discloses a polyamide based on MACM.12 / PACM.12 with a molar ratio between 5:95 and 95:5. There are no examples based on the use of sebacic acid.

[0014] US 2015 / 0099847 (Evonik) relates to a composition, comprising a blend of two polyamides wherein one of them is a polyamide having as copolymerized units bis(4- aminocyclohexyljmethane (PACM) and a linear dicarboxylic acid having from 8 to 18 C atoms.

[0015] US 8,399,557 (Arkema) relates to a transparent blend or alloy comprising from 1 to 99 wt.% of a copolymer comprising two types of units: (Al) amide units, including at least one cycloaliphatic unit and (A2) flexible ether units, wherein the cycloaliphatic diamine or diamines can be chosen from bis(3-methyl-4-aminocyclohexyl) methane(BMACM), para-aminodicyclohexylmethane (PACM), isophoronediamine (IPD), bis(4-aminocyclohexyl) methane (BACM), 2,2-bis(3-methyl-4-aminocyclohexyl) propane (BMACP) or 2,6-bis(aminomethyl)norbornane (BAMN).

[0016] WO 2019 / 170463 discloses filaments for 3D printing comprising a core material coated with a layer of shell material, wherein the core material comprises at least one thermoplastic polymer.

[0017] WO 2021 / 160959 discloses polyamide in the powder form for 3D printing.

[0018] US 2021 / 0040318 discloses a blend comprising an amorphous polyamide and a crystalline polyamide for 3D printing. The crystalline polyamide may be PACM 12.

[0019] GB 1 150860 discloses a crystalline oriented filament of a high molecular weight polymer PACM.X where X is a C9-C14 aliphatic diacid.

[0020] US 3,393,210 (Dupont, 1968) describe a fiber-forming polycarbonamide (including copolycarbonamide) presenting the following recurring unit:

[0021] None of these documents describes the claimed subject-matters.Brief disclosure of the invention

[0022] The invention is set out in the appended set of claims.

[0023] The present invention relates to a polyamide as defined in any one of claims 1-20.

[0024] The present invention also relates to a polymer composition as defined in any one of claims 21-31.

[0025] The present invention relates to a filament as defined in any one of claims 32-37 spool of filament as defined in claim 38.

[0026] The present invention also relates to a method for manufacturing a 3D object as defined in any one of claims 39-41.

[0027] The invention also relates to the use as defined in claim 42 or 43

[0028] More details and precisions for all these subject-matters are given below.General definitions

[0029] These definitions apply to the present disclosure.

[0030] wt.% is a percentage by weight. Mol.% is a percentage by mole.

[0031] Unless otherwise stated, the proportions of recurring units in the polyamide are given in mol% and relative to the total proportion of recurring units in the polyamide.

[0032] When numerical ranges are indicated herein, the end-points of the ranges (even of open-ended ranges such as those comprising "at least" or "at most") are included.

[0033] In the present application, unless otherwise indicated, any specific embodiment or technical feature relating to one of the subject-matters of the invention is applicable to and interchangeable with another embodiment or technical feature relating also to said subject matter and disclosed elsewhere in the application.Disclosure of the invention

[0034] About the polyamide (PA) of the invention

[0035] The polyamide (PA) of the invention comprises the recurring units (RPA) and (R*PA):where n is 7 or 8, and wherein at least 30.0 mol.% of the moieties derived from 4,4’- diaminodicyclohexylmethane are in a trans / trans configuration, this proportion being based on the total number of moles of the moieties derived from 4,4’- diaminodicyclohexylmethane in the polyamide (PA).

[0036] n may be 7. n is preferably 8.

[0037] In polyamide (PA), the proportion of units (RPA) where the moieties derived from 4,4’ - diaminodicyclohexylmethane (PACM) are in a trans / trans configuration is at least 30 mol%. This proportion is based on (or relative) to the total number of moles of the moieties derived from 4,4’-diaminodicyclohexylmethane (PACM) in the polyamide (PA). A proportion of trans / trans higher than 30.0 mol.% makes it possible to have a semi-crystalline polyamide (PA) exhibiting suitable thermal properties, in particular a high glass transition temperature (Tg) and a low melting point (Tm) which ensures a good processing of the polyamide, notably during printing. The polyamide thusadvantageously differences from most of the commercially available polyamides, such as PA 12 (Tg<50°C) and PA6 (Tg<60°C, hydrophilic). The polyamide of the invention also advantageously presents a combination of optical, mechanical and chemical properties.

[0038] This proportion is preferably at least 40.0 mol.%, more preferably at least 45.0 mol%, more preferably at least 46.0 mol.%.

[0039] This proportion may be at most 70.0 mol.%, preferably at most 60.0 mol.%, even more preferably at most 55.0 mol% or at most 51.0 mol%.

[0040] This proportion may be between 30.0 mol.% and 100.0 mol.% or between 30.0 and 55.0 mol%.

[0041] This proportion of moieties derived from 4,4’ -diaminodicyclohexylmethane which are in a trans / trans configuration is controlled by the proportion of trans / trans in the monomer 4,4’-diaminodicyclohexylmethane (PACM). The molecule of PACM can indeed exist as trans / trans (TT) (CAS N°6693-29-4), cis / trans (CT) (CAS N°6693- 30-7) and cis / cis (CC) (CAS N° 6693-31-8).

[0042] The proportion of trans / trans isomer in PACM monomer is at least 30.0 mol%, this proportion being calculated as TT / [TT+CT+CC] x 100. All ranges provided for the proportion of trans / trans in polyamide (PA) apply identically for the proportion of trans / trans in PACM monomer. This proportion may thus be between 30.0 mol.% and 100.0 mol.% or between 30.0 and 55.0 mol%.

[0043] Polyamide (PA) preferably does not comprise recurring units derived from a lactam of from an aminoacid or from dodecanedioic acid or from 1,6-hexamethylenediamine.

[0044] Molar ratio R= (RPA) / (R*PA)

[0045] The molar ratio R = (RPA) / (R*PA) is preferably between 75 / 25 and 99 / 1.

[0046] R may be more particularly between 75 / 25 and 95 / 5.

[0047] R is preferably greater than or equal to (>) 78 / 22, preferably > 80 / 20.

[0048] R may be lower than and equal to (<) 92 / 8.

[0049] R may thus be between 78 / 22 and 95 / 5, preferably between 80 / 20 and 95 / 5.

[0050] Total proportion T of recurring units (RPA) and

[0051] The total proportion T of recurring units (RPA) and (R*PA) is preferably at least 98.0 mol%, this proportion T being based on the total amount of recurring units in the polyamide (PA).

[0052] T is preferably at least 99.0 mol%, preferably at least 99.5 mol%. The recurring units of polyamide (PA) consist essentially of recurring units (RPA) and (R*PA).

[0053] The polyamide (PA) is preferably free of recurring units comprising an aromatic ring, such as a phenyl ring. Such recurring units are obtained through the use of monomers comprising an aromatic ring, such as terephthalic acid or isophthalic acid. In this context, "free of recurring units comprising an aromatic ring " refers to a polyamide (PA) containing a total proportion of recurring units comprising an aromatic ring that is less than 1.0 mol%, preferably less than 0.5 mol%, even preferably less than 0.2 mol%, this proportion being relative to the total amount of recurring units in the polyamide (PA). This ensures that the polyamide (PA) exhibits better UV resistance.

[0054] According to a preferred embodiment, T = 100%. According to this embodiment, the recurring units of polyamide (PA) consist of recurring units (RPA) and (RPA*).

[0055] The polyamide (PA) is micro-crystalline. The term "micro-crystalline" refers to a semi-crystalline polymer, the structure of which comprising spherulites having a size small enough not to diffract light and thus allowing good transparency.

[0056] The polyamide (PA) is such that at least 30.0 mol.% of the moieties derived from 4,4’ - diaminodicyclohexylmethane are in a trans / trans configuration, this proportion being based on the total number of moles of the moieties derived from 4,4’- diaminodicyclohexylmethane in the PA. A proportion lower than 30.0 mol.% may results in a copolyamide that does not exhibit good properties.

[0057] End- groups of the polyamide (PA)

[0058] The end-groups of the polyamide (PA) are selected in the group of -NH2, -COOH and amide end-groups. Indeed, the end-groups in the polyamide (PA) may be -NH? or - COOH. Yet, when the polycondensation involves the addition of an end-capping agent, these end-groups may be converted, partially or totally, into amide end-groups.

[0059] The amide end groups are of formula -NH-C(=O)-R where R is an an alkyl group, an aryl group or a cycloalkyl group and / or of formula -C(=O)-NH-R' where R' is an alkyl group or a cycloalkyl group. R is more particularly a linear or branched C2-C18 alkyl group or a C5-C10 cycloalkyl group. R’ is more particularly a linear or branched C2- Ci8 alkyl group.

[0060] The amide end groups of formula -NH-C(=O)-R result from the reaction of the end- groups -NH2 with a monocarboxylic acid (end-capping agent) of formula R-COOH.

[0061] The monocarboxylic acid (end-capping agent) may advantageously be selected in the group consisting of benzoic acid; cyclohexanoic acid; R-COOH where R is a linear or branched Ci-Cis alkyl group and combination of two or more of these acids. R is the radical derived from the acid of formula R-COOH.

[0062] The monocarboxylic acid (end-capping agent) may more particularly be selected in the group consisting of acetic acid, propanoic acid, butyric acid, valeric acid, caproic acid, lauric acid, stearic acid, 2-ethylhexanoic acid, cyclohexanoic acid, benzoic acid and combination of two or more of these acids.

[0063] The monocarboxylic acid (end-capping agent) is more particularly of formula CH3- (CH2)m-C00H where m is an integer between 0 and 16. The amide end groups are then of formula -NH-C(=O)-(CH2)m-CH3.

[0064] The amide end groups of formula -C(=O)-NH-R' result from the reaction of the end- groups -COOH with a primary amine (end-capping agent) of formula R'-NH2.

[0065] The primary amine (end-capping agent) may advantageously be selected in the group consisting of the amines of formula R'-NH2where R' is a linear or branched C2-Cis alkyl group. R' is the radical derived from the amine of formula R'-NH2.

[0066] The primary amine (end-capping agent) is more particularly of formula CH3-(CH2)m - NH2where m' is an integer between 2 and 18. The amide end groups are then of formula -C(=O)-NH-(CH2)m’-CH3.

[0067] The primary amine (end capping agent) may more particularly be selected in the group consisting of propyl amine, butylamine, pentylamine, hexylamine, 2- ethylhexylamine, n-octylamine, n-dodecylamine, n-tetradecylamine, n- hexadecylamine, stearylamine, cyclohexylamine and combination of two or more of these amines.

[0068] The proportion of the end groups can be quantified by1H NMR or by potentiomtric techniques.

[0069] Properties of the polyamide (PA)

[0070] The polyamide (PA) preferably exhibits a heat of fusion Hm of at least 10 J / g, preferably at least 15.0 J / g. Hm is determined on the 2ndheat scan in differential scanning calorimeter (DSC) according to ISO11357, using a heating and cooling rate of 20°C / min. Hm may more particularly be determined according to the method disclosed in the experimental section.

[0071] Hm is preferably at least 18.0 J / g. Hm is generally at most 25.0 J / g.

[0072] Hm is generally between 10.0 and 25.0 J / g or between 15.0 and 25.0 J / g.

[0073] The polyamide (PA) exhibits a melting point (Tm) of at least 250°C. Tm is determined on the 2ndheat scan in differential scanning calorimeter (DSC) according to ISO 11357, using a heating and a cooling rate of 20°C / min. The conditions of the protocol provided in the experimental section may preferably be followed to determine Tm.

[0074] Tm is preferably at least 255°C, preferably at least 260°C. Tm is generally at most 280°C.

[0075] Tm is generally between 250°C and 280°C.

[0076] The polyamide (PA) exhibits a glass transition temperature (Tg) which is at least 130°C. Tg is determined on the 2ndheat scan in differential scanning calorimeter (DSC) according to ISO11357, using heating and cooling rates of 20°C / min. The conditions of the protocol provided in the experimental section may preferably be followed to determine Tg.

[0077] Tg is preferably at least 140°C, preferably at least 142°C, preferably at least 145°C. Tg is generally at most 160°C.

[0078] Tg may be between 130°C and 160°C.

[0079] The polyamide (PA) may have a number average molecular weight Mn ranging from 5,000 g / mol to 40,000 g / mol, for example from 7,000 g / mol to 35,000 g / mol or from 9,000 to 30,000 g / mol.

[0080] Mn can be determined using the following equation (1): Mn = 2,000,000 / [EG] (1) wherein [EG] is the proportion of end-groups in the PA expressed in mmol / kg. more precisely known methods to measure amine end-groups concentration and acid end groups-concentrations. The end-groups in the polyamide (PA) are generally amine and / or acid moieties. Yet, when the polycondensation involves the addition of an endcapping agent, the amine end-groups are converted, partially or totally, into modified end-group(s). For instance, when the end-capping is an acid such as benzoic acid or acetic acid, the remaining amine groups may be totally or partially converted into benzamide or acetamide end groups.

[0081] The concentration of the end-groups is determined according to techniques well- known to the skilled person. The amine and acid groups are usually determined by potentiometric titration.1H NMR may also be conveniently used.

[0082] The polyamide (PA) has preferably a water uptake at saturation, by immersion in water at 23 °C, of less than 6.0 wt.%.

[0083] The water uptake at 23°C is determined by (i) providing a specimen shaped in the form of a ISO527 type IA tensile bar in its dry state (moisture content of less than 0.2 wt.%), (ii) immersing the same in deionized water at 23°C, until reaching a constant weight, (iii) calculating the water uptake with the formula:Wate r u pta kwherein Wbefore is the weight of the shaped specimen in its original dry state and Wafter is the weight of the shaped specimen after water uptake.

[0084] Optical properties

[0085] The polyamide (PA) also exhibits interesting optical properties. The polyamide (PA) preferably exhibits a transparency of at least 90.0%, preferably at least 92.0%, when measured in accordance with ASTM D1003 on an injection moulded specimen of 2.5 mm thickness. The polyamide (PA) preferably exhibits a haze of at most 10.0%, preferably at most 8.0%, when measured in accordance with ASTM D1003 on an injection moulded specimen of 2.5 mm thickness.

[0086] It is noted that the optical properties are not fully translated on the 3D objects prepared by 3D printing due to the weld lines. The 3D objects are more translucent than transparent.

[0087] Bio-based content

[0088] The polyamide (PA) may preferably exhibit a biobased content of at least 40.0 %, the biobased content being expressed as the % of organic carbon of renewable origin in the polyamide (PA) and measured according to ASTM D6866-22.

[0089] This biobased content can be reached through the use of biobased sebacic acid (generally obtained industrially from castor oil) or azelaic acid (see Polymers (Basel), 2021, 13(23), p. 4091 doi: 10.3390 / polyml3234091).

[0090] The biobased content is defined as the % of organic carbon of renewable origin. It corresponds to the amount of C calculated from measured14C percent in the sample and corrected for isotopic fraction. A polymer having a biobased content of 100% has all its carbon atoms of a renewable origin.

[0091] According to an embodiment, biobased MACM and PACM may be used in the preparation of the polyamide (PA). Biobased MACM and PACM may be prepared from biobased toluene and aniline by hydrogenation of the corresponding aromatic diamines according to EP 0618188. Biobased aromatics (BTX) can be prepared according to ACS Sustainable Chem. Eng. 2018, 6, 3472-3480 from black liquors which are formed in the paper production by the digestion of pulpwood. The general scheeme of preparation of biobased MACM and PACM can thus be following: black liquor => biobased toluene => biobased aniline => product of formula:group, R1 and R2 are -NH2, A is -CH2-, x is an integer between 0 and 3 and y is 1 => catalytic hydrogenation to MACM and PACM.

[0092] With the use of a biobased MACM and PACM and biobased biobased sebacic acid and / or azelaic acid, the biobased content of the polyamide (PA) may be at least 80.0 %, preferably at least 85.0 %, preferably at least 90.0 %, preferably at least 95.0 %, preferably at least 99.5 %.

[0093] Through the use of biobased monomers and if the polyamide comprise amide end- groups, biobased amide end-groups, the biobased content of the polyamide (PA) can also be 100 %. The biobased content may thus be between 40 and 100 % or between 80.0 and 100.0 %.

[0094] Preparation of the polyamide (PA)

[0095] The polyamide (PA) comprises the recurring units (RPA) and (R*PA) formed from the polycondensation of a reaction mixture (RM) comprising the following monomers: 1) PACM or 4,4 ’-diaminodicyclohexylmethane (aka 4,4’-methylene-bis- cyclohexylamine or bis(4-aminocyclohexyl)methane) of formula:2) MACM or 4,4’-methylene-bis(2-methylcyclohexylamine) of formula:3) sebacic acid of formula HOOC-(CH2)s-COOH and / or azelaic acid of formula HOOC-(CH2)7-COOH.

[0096] Recurring units (RPA) result from the condensation of PACM and the diacid(s). Recurring units (R*PA) result from the condensation of MACM and the diacid(s).

[0097] If the reaction mixture (RM) comprises a combination of sebacic and azelaic acid, both recurring units (RPA) and (R*PA) have both -(CH2)s- and -(CH2)?- moieties.

[0098] The proportions of these monomers in the reaction mixture (RM) make it possible to control the relative proportions of the recurring units in the polyamide (PA).

[0099] The proportion of trcms / trcms isomer in PACM monomer is at least 30.0 mol%, this proportion being calculated as TT / [TT+CT+CC] x 100 where TT, CT and CC designate respectively the isomers of PACM in the trans / trans (TT), cis / trans (CT) and cis / cis (CC) configurations.

[0100] The proportion of trans / trans isomer in monomer PACM may be easily determined by chromatography (e.g. gas chromatography such as GC-FID (flame ionization detector)). Depolymerization of the polyamide (PA) in acidic or basic conditions and analysis of the monomers make it possible to determine the proportion of trans / trans moieties in the polyamide (PA).

[0101] The polyamide (PA) is prepared with the use of a reaction mixture (RM) comprising the monomers. The reaction mixture (RM) also generally further comprises a catalyst. The catalyst is generally selected in the group of phosphorous-containing inorganic acids and salts thereof. The catalyst may be selected in the group consisting of phosphorous acid, ortho-phosphoric acid, meta-phosphoric acid, alkali-metal hypophosphite such as sodium hypophosphite and phenylphosphinic acid. A convenient catalyst used is sodium hypophosphite.

[0102] The reaction mixture (RM) may also comprise at least one end-capping agent.

[0103] The temperature at which the reaction mixture is heated must be high enough to induce the reaction between the amine groups and the carboxylic groups and to decrease the viscosity of the mixture. The polycondensation results in the formation of the amide bonds and the release of water as a by-product.

[0104] The reaction mixture (RM) is preferably heated at a temperature of at least Tm+10°C, Tm being the melting temperature of the polyamide (PA). The temperature at which the reaction mixture is heated is generally at least 250°C.

[0105] The polycondensation is advantageously performed in the melt, notably in the absence of a solvent.

[0106] The polycondensation is advantageously performed in a well stirred vessel such as a stirred reactor. The vessel is also advantageously equipped with means to remove the volatile products of reaction.

[0107] The conditions disclosed in the experimental section may be followed, and if needs be adapted, for the preparation of the polyamide (PA).

[0108] About the polymer composition (P)

[0109] The invention also relates to a polymer composition (P) comprising at least one polyamide (PA) as disclosed herein.

[0110] The proportion of polyamide(s) (PA) in the polymer composition (P) is typically at least 10.0 wt.%. This proportion may be at least 40.0 wt%, preferably at least 50.0 wt%, preferably at least 60.0 wt.%, preferably at least 70.0 wt.%, preferably at least 80.0 wt.%. This proportion may be between 10.0 wt.% and 100.0 wt.% or between 50.0 wt.% and 100.0 wt.%.

[0111] The polymer composition (P) may comprise one or more polyamide (PA) as described herein. It may comprise more than one polyamide (PA). In this case, the polyamide(s) (PA) are blended together.

[0112] Preferably, the polymer composition (P) is free of an aromatic polyamide. Preferably, the polymer composition (P) is free of an amorphous polyamide. An aromatic polyamide is a polyamide comprising recurring units having an aromatic moiety. An amorphous polyamide is a polyamide having a heat of fusion Hm lower than 4.0 J / g. The expression "free ofX" means that the polymer composition (P) does not comprise X or if it comprises X, the proportion of X in the composition (P) is less than 1.0 wt%, preferably less than 0.5 wt%, preferably less than 0.1 wt%.

[0113] Preferably, the polymer composition (P) is free of a polyamide other than the polyamide(s) (PA). Preferably, the polymer composition (P) does not comprise a polyamide other than the polyamide(s) (PA).

[0114] Additives

[0115] The polymer composition (P) may also comprise at least one additive selected from the group consisting of fillers, colorants, dyes, pigments, lubricants, plasticizers, flame retardants, tougheners, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electromagnetic absorbers and combination thereof.

[0116] The filler may be more particularly selected in the group consisting of continuous or chopped carbon fibers, continuous or chopped glass fibers, milled carbon fibers, milled glass fibers, glass beads, glass microspheres, wollastonite, silica beads, talc, calcium carbonates, biobased fibers, polymeric fibers and combination thereof.[001 17] The synthetic polymeric fibers are for instance aramid fibers, rock wool fibers, natural fibers (e.g. linen, hemp, cellulose, or nanocellulose), and any combination of two or more thereof.

[0118] The filler is more particularly a carbon fiber, notably selected in the group consisting of continuous carbon fibers, chopped carbon fibers and milled carbon fibers.

[0119] The flame retardant may be an halogen-based flame retardant or a phosphorous-based flame retardant. The phosphorous-based flame retardant may be selected in the group consisting of metal alkyl phosphinates. An example of metal alkyl phosphinate is aluminum diethyl phosphinate, for instance the one known under the trade name Exolit® from Clariant. Another example of phosphorous-based flame retardant which makes it possible to have 3D objects of good quality while ensuring a good level of flame retardancy is disclosed below:

[0120] The heat stabilizer may be more particularly selected in the group consisting of mono- or divalent coppers, stabilizers based on secondary aromatic amines, stabilizers based on sterically hindered phenols, phosphites, phosphonites, metal salts, metal oxides and combination thereof.

[0121] According to an embodiment, the polymer composition (P) comprises at least one additive selected from the group consisting of fillers that are not fibrous fillers, colorants, dyes, pigments, lubricants, plasticizers, flame retardants, tougheners,nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electromagnetic absorbers and combination thereof.

[0122] According to another embodiment, the polymer composition (P) comprises at least one additive selected from the group consisting of colorants, dyes, pigments, lubricants, plasticizers, flame retardants, tougheners, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electromagnetic absorbers and combination thereof.

[0123] The polymer composition (P) may more particularly comprise or consist of:- at least one polyamide (PA) as defined herein;- optionally at least one filler as defined herein; and- optionally at least one additive other than a filler as defined herein.

[0124] The additive(s) (e.g. filler(s) and / or additive(s) other than a filler) are generally blended with the polyamide(s) (PA) of the polymer composition (P).

[0125] The proportion of the additive(s) (e.g. filler(s) and / or are additive(s) other than a filler) in the polymer composition (P) is generally lower than 50.0 wt%, even lower than 40.0 wt% or lower than 30.0 wt.%. The proportion of the additive(s) in the polymer composition (P) is generally between 0.01 and 50.0 wt%, even between 0.10 and 40.0 wt% or between 0.50 and 40.0 wt.%.

[0126] More particularly, the invention also relates to a polymer composition (P) which comprises at least one polyamide (PA) as defined herein, at least one filler and optionally at least one additive other than a filler. The total proportion of filler(s) and the optional additive(s) is generally lower than 50.0 wt%, even lower than 40.0 wt% or lower than 30.0 wt.%. The proportion of the optional additive(s) is usually between 0.01 wt.% and 20.0 wt.%, preferably between 0.1 wt.% and 10.0 wt.%. The filler may be one of the fillers disclosed above.

[0127] According to a specific embodiment (E), the filament of the invention is made of a polymer composition (P) consisting of:- at least one polyamide (PA) as defined herein;- optionally at least one filler as defined herein; and- optionally at least one additive other than a filler as defined herein.

[0128] The components of the polymer composition (P) are preferably blended.

[0129] The polymer composition (P) is typically prepared by mixing the components of the polymer composition (P), the polymeric component(s) being in the molten form.Suitable melt-mixing apparatus for the mixing are, for example, kneaders, Banbury mixers, single-screw extruders, and twin-screw extruders. Preferably, use is made of an extruder fitted with means for dosing all the desired components to the extruder, either to the extruder’s throat or to the melt.

[0130] The mixing of the components of the polymer composition (P) is performed until the polymer composition (P) is homogeneous.

[0131] Filament of the invention

[0132] The filament of the invention is made of or comprises the polymer composition (P) as defined herein.

[0133] The filament has a cylindrical or substantially cylindrical geometry.

[0134] The filament may have a cylindrical or substantially cylindrical geometry with a diameter d between 0.5 mm and 5.0 mm. d may vary between 0.8 and 4.0 mm or between 1.0 mm and 3.5 mm.

[0135] d can be chosen to feed a specific FFF 3D printer. An example of diameter used extensively in FFF process has a diameter d of 1.75 mm or 2.85 mm.

[0136] Preferentially, the filament has a round cross-section.

[0137] The expression "filament” refers to a thread-like object or fiber or strand formed.

[0138] Preferably, the filament is a full filament. The term "full" is used in comparison to a hollow geometry and denotes a filament which is not hollow.

[0139] According to a preferred embodiment, the filament does not present a core / shell geometry with another polymeric composition. The "core / shell geometry " refers to a filament having an elongated core radially surrounded by an outer shell. The core and the shell are generally made of two different polymer compositions or of two polymers of the same composition but with distinct physico-chemical properties.

[0140] The core / shell geometry requires the use of a more complex coextrusion system than a simple extrusion system. Moreover, during the 3D printing process, the material(s) of the shell are mixed with the material(s) of the core and this results in several anticipated technical difficulties (inhomogeneity of the composition of the 3D object, contamination with the material(s) of the shell, etc).

[0141] To avoid the inhomogeneity described above, the components of the composition (P) are preferably blended together. The term "blend" is intended to denote a homogeneous (or uniform) physical mixture. The term "blended" is intended to meanthat the components, notably of the polymer composition (P), form an homogeneous (or uniform) physical mixture.

[0142] Preferably, the composition of the filament consists of the polymer composition (P).

[0143] The length L of the filament is generally at least 200 mm.

[0144] The filament may be in the form of a spool. The invention thus also relates to a spool of the filament of the invention. The spool is made of or comprises the polymer composition (P).

[0145] The filament of the present invention is prepared by extruding the polymer composition (P). The method of preparation disclosed in the experimental section may be followed for the preparation of a filament according to the invention.

[0146] The extruder that is used for the preparation of the filament is fed with the polymer composition (P) or polyamide (PA) in the form of a powder or in the form of pellets. The invention thus also relates to the polymer composition (P) or the polyamide (PA) in the form of a powder or in the form of pellets.

[0147] The diameter of the filament can be modified by adapting the size of the die or nozzle of the extruder and / or adjusting the draw ratio of filament after exit from the die.

[0148] According to an embodiment, the method of preparation of the filament is an integrated process in which the polymer composition (P) and the filaments are prepared in a one-step process.

[0149] The conditions given in the examples may be followed to prepare the filament according to the invention.

[0010] The present invention additionally relates to the use of a polyamide (PA) as described herein or the polymer composition (P) as described for the manufacture of a filament for use in the manufacture of three-dimensional objects.

[0151] Method for manufacturing a 3D object

[0152] The present invention also relates to the use of polyamide (PA) as described herein or the polymer compostion (P) as described herein or the filament as described herein, for the manufacture of a 3D object using additive manufacturing, preferably FFF or FDM.

[0153] The present invention also relates to a method for manufacturing a 3D object using an additive manufacturing (AM) system where the polyamide (PA) as deiscosed herein or the polymer composition (P) as disclosed herein is used as the feedstock of the 3Dprinter. The AM system may for instance be an extrusion-based additive manufacturing system (for example FFF or FDM).

[0154] The 3D object or article obtainable by such method of manufacture can be used in a variety of final applications. Mention can be made in particular of implantable devices, medical devices, dental prostheses, brackets and complex shaped parts in the aerospace industry and under-the-hood parts in the automotive industry which require a high resistance temperature.

[0155] The method more particularly comprises the following steps:- advancing the filament of the invention to a print head;- heating the filament in the print head to a molten state (preferably the filament is heated at a temperature which is at least Tm + 10°C);- extruding the material in the molten state from a nozzle in the print head;- ensuring relative movement in X- and Y- directions of the print head to form the cross sectional shape of the 3D object; and / or- ensuring relative movement in the Z-direction of the print head to form the 3D object in elevation.

[0156] According to an embodiment, the method for manufacturing a 3D object with an AM system comprises a step consisting in extruding the composition (P) into a filament. This step may, for example, occur when printing or depositing strips or layers of filament. The method for manufacturing 3D objects with an extrusion-based AM system is also known as Fused Filament Fabrication technique (FFF) or Fused Deposition Modeling (FDM).

[0157] FFF / FDM 3D printers are, for example, commercially available from Apium, from Roboze, from Hyrel or from Stratasys, Inc. (under the trade name Fortus®).

[0158] The present invention relates also to an AM method for manufacturing a three- dimensional (3D) article, part or composite material, comprising extruding the filament described above.

[0159] The AM method of the present invention is preferably a Fused Filament Fabrication (FFF) method, also known as Fused Deposition Modelling (FDM).

[0160] In some embodiments, the method further comprises at least one of the following steps, in connection with the 3D printer:- feeding the filament to a discharge head member having a throughbore ending with a discharge tip and a circumferential heater to melt the filament in the throughbore;- heating the filament to a temperature of at least Tm+10°C, prior to extrusion;- compressing the filament with a piston, for example with the unmelted filament acting as a piston, in the throughbore;- ensuring relative movement in X- and Y- directions of the discharge tip and of a receiving platform while discharging the filament on the receiving platform to form the cross sectional shape; and / or- ensuring relative movement in the Z-direction of the discharge tip and the receiving platform while discharging the filament on the receiving platform to form the 3D object or part in elevation.

[0161] The 3D object may be built on substrate, for example a horizontal substrate and / or on a planar substrate. The substrate may be moveable in all directions, for example in the horizontal or vertical direction. During the 3D printing process, the substrate can, for example, be lowered, in order for the successive layer of polymeric material to be deposited on top of the former layer of polymeric material.

[0162] In some embodiments, the AM method for making a 3D object further comprises a step consisting in producing a support structure, using a support material. According to such embodiments, the 3D object is built upon the support structure and both the support structure and the 3D object are produced using the same AM method.

[0163] The 3D printer may comprise a chamber in order to maintain the filament at determined at a specific temperature. This temperature may be at approximately the Tg of the polyamide (PA), e.g. Tg ± 10°C.

[0164] While not strictly necessary, the 3D object may also be subjected to heat-treatment after manufacture (also called annealing or tempering). In this case, the 3D object is placed in an oven set up at a temperature ranging from 80 to 200°C, preferably from 100 to 180°C, for a period of time of ranging from about 30 minutes to 24 hours, preferably from 1 hour to 8 hours.

[0165] The conditions of the 3D printing method provided in the experimental section may be followed.

[0166] 3D objects / other articles

[0167] The filament of the invention makes it possible to prepare a 3D object comprising the polyamide (PA) as described herein.

[0168] Other articles: the polymer composition (P) or the polyamide (PA) may also be used for the preparation of various articles, notably decorative articles (in particular in theautomobile interior); sport articles (in particular ski boots, midsoles for sport shoes); toys; household articles (in particular containers, dishes, bowls, tins, beakers, baby bottles, drinking bottles, components of kitchen appliances); components of spectacles (in particular spectacle frames or spectacle sidepieces, safety gogles); medical objects (in particular containers, syringes); parts of smart phones (in particular protective covers). These articles can be prepared by injection molding.Experimental section

[0169] Raw materials used00170] DSC

[0171] DSC analyses were carried out according to ISO11357 and data were collected through a two heat, one cool method.

[0172] The DSC used was DSC 8000 (Perkin Elmer).1001731 Water uptake

[0174] The polyamides were shaped according to ISO527 in their dry state (moisture content of less than 0.2 wt.%), and then immersed in deionized water at 23°C, until reaching a constant weight.

[0175] Tensile properties

[0176] Tensile modulus, tensile strength and tensile elongation at break were measured according to ISO 527-2.

[0177] The polyamides were prepared by melt polycondensation by using the appropriate amounts of the monomers. The conditions given below for two copolyamides can be followed for the preparation of the other polyamides.

[0178] Example 1 - preparation of PACM.10 / MACM.10 with R = 80 / 20

[0179] 0.88 g (4.183 mmol) of PACM50, 0.25 g of MACM (1.045 mmol) and 1.06 g of (5.2 mmol) of sebacic acid were introduced in a glass tube. The glass tube is place under a nitrogen stream, inserted into a metallic heating block and the temperature was gradually raised up to 320°C over 60 min. Upon reaching 320°C, the reaction mixture is kept for an additional 30 min at 320°C, then the glass tube is removed from the heating block and allowed to cool down to about 20°C.

[0180] Example 2 - preparation of PACM.10 / MACM.10 with R = 85 / 15

[0181] 1192 g of PACM50, 234.8 g of MACM, 1327.8 g of CIO diacid, and 25.65 g of an aqueous solution of sodium hypophosphite monohydrate (5 wt%, 2 mmol) and 450 g of water were introduced in a stainless-steel reactor equipped with a mechanical stirrer. The reactor was purged with nitrogen, closed and the temperature in the reactor was gradually increased up to 280°C. The reaction proceeded under pressure at 11 bars. Condensation water as well as water added and from the catalyst solution were distilled off through a controlled valve. The reaction mixture was kept at 280°C and the reactor pressure was gradually decreased to 0.5 bar over 60 min, and maintained 15 min at 0.5 bar. The resulting polymer was then discharged as a strand and pelletized.

[0182] Determination of the Mn by the end-group analysis

[0183] The end groups, amine end groups (-NH2) and carboxylic acid end groups (-COOH), of the polyamides are determined by potentiometric titration and expressed in mmol / kg. Mn (g / mol) is then determined by equation (1).Table 1Table 2

[0184] Other resultsTable 3Table 4Table 5IPA: isopropyl alcohol; Wex-cide® and Vesphene® are traditional disinfectants commercialized in the USA

[0185] As can be seen, the mechanical properties of the copolyamide of the invention remain quite unaffected after exposure to some aggressive chemical compounds.

[0186] Filament preparation and characterization

[0187] Feed stocks for filament production consisted of neat polymer (PA) pellets. Filament of diameter 1.75 mm was prepared for each composition using a Brabender® Intelli- Torque Plasti-Corder® Torque Rheometer extruder equipped with a 0.75" (1.905 cm) 32 L / D general purpose single screw, a heated capillary die attachment, a 3 / 32” diameter nozzle with land of length 1 .5”, and downstream, custom-designed filament conveying apparatus. Other downstream equipment included a belt puller and a Dual Station Coder, both manufactured by ESI-Extrusion Services. A Beta LaserMike® 5012 with DataPro 1000 data controller was used to monitor filament dimensions. The melt strand was cooled with air. The Brabender® zone set point temperatures were 250-280°C in the barrel zone and just above the melt temperature with the die at 270°C. The Brabender® speed ranged from 25 to 60 rpm and the puller speed from 20 to 70 feet per minute (6.093 to 21.336 m / min).

[0188] 3D printing

[0189] Filaments described above were printed on an Argo 500 extrusion-based additive manufacturing system commercially available from Roboze Inc., (Houston, Texas, USA, or Bara, Italy). Nylon build sheets were employed as the printed object substrate. During the printing trials, the extruder temperature was set between 300 and 390°C, and the heated chamber was set at approximately the Tg of the material e.g. at130-150°C. A 0.6 mm Roboze Argo Tip3-HSA tip was used for the model material, with a 0.1 to 0.3mm layer thickness. The material was extruded as a series of roads in a layer-by-layer fashion to print structures in the heated chamber. ASTM Type I, IV and V tensile bars were printed for each formulation, using 100% infill and either 45° / -45° alternating rasters or 0790° alternating rasters, and objects were promptly removed from the heated chamber and build sheet after printing. We observed that the PA filament of the invention has a good printing ability and exhibits high thermomechanical properties.Table 6

[0190] As can be seen in Table 6, the 3D object prepared with the copolyamide of the invention retains good mechanical properties. Moreover, the 3D object so prepared is translucent. The copolyamide of the invention can thus be used for the preparation of 3D objects by 3D printing (FFF) when visual effects are required.

Claims

ClaimsClaim 1. Polyamide (PA) comprising the recurring units (RPA) and (R*PA):wherein:• n is 7 or 8; preferably n is 8;• molar ratio R = (RPA) I (R*PA) is between 75 / 25 and 99 / 1;• the total proportion T of recurring units (RPA) and (R*PA) is at least 98.0 mol%, this proportion T being based on the total amount of recurring units in the polyamide (PA); and• at least 30.0 mol.% of the moieties derived from 4,4’- diaminodicyclohexylmethane are in a trans / trans configuration, this proportion being based on the total number of moles of the moieties derived from 4,4’-diaminodicyclohexylmethane in the polyamide (PA).Claim 2. Polyamide (PA) according to claim 1, wherein the molar ratio R = (RPA) / (R*PA) is between 75 / 25 and 99 / 1, preferably between 78 / 22 and 95 / 5, preferably between 80 / 20 and 95 / 5.Claim 3. Polyamide (PA) according to claim 1 or 2, wherein R is lower than and equal to 92 / 8.Claim 4. Polyamide (PA) according to any one of the preceding claims, wherein the total proportion T of recurring units (RPA) and (R*PA) is 99.0 mol%, preferably at least 99.5 mol%.Claim 5. Polyamide (PA) according to any one of the preceding claims, wherein the recurring units of polyamide (PA) consist essentially of or consist of recurring units (RPA) and (RPA*).Claim 6. Polyamide (PA) according to any one of the preceding claims, wherein the proportion of 4,4’ -diaminodicyclohexylmethane moieties in a trans / trans configuration is:- at least 40.0 mol.%, preferably at least 45.0 mol%, preferably at least 46.0 mol%; and / or- at most 70.0 mol.%, preferably at most 60.0 mol.%, even more preferably at most 55.0 mol% or at most 51.0 mol%.Claim 7. Polyamide (PA) according to any one of the preceding claims, wherein the proportion of 4,4 ’-diaminodicyclohexylmethane moieties in a trans / trans configuration is between 30.0 mol.% and 55.0 mol.%.Claim 8. Polyamide (PA) according to any one of the preceding claims, wherein the polyamide (PA) is free of recurring units comprising an aromatic ring such as a phenyl ring.Claim 9. Polyamide (PA) according to any one of the preceding claims, wherein the polyamide (PA) is micro-crystalline.Claim 10. Polyamide (PA) according to any one of the preceding claims, wherein the end- groups of the polyamide (PA) are selected in the group of -NH2, -COOH and amide end- groups.Claim 11. Polyamide (PA) according to claim 10, wherein the amide end groups of the polyamide (PA) are of formula -NH-C(=O)-R where R is an an alkyl group, an aryl group or a cycloalkyl group and / or of formula -C(=O)-NH-R' where R' is an alkyl group or a cycloalkyl group.Claim 12. Polyamide (PA) according to any one of the preceding claims, exhibiting a melting point (Tm) between 250°C and 280°C, Tm being determined by DSC on the 2ndheat scan according to ISO11357.Claim 13. Polyamide (PA) according to any one of the preceding claims, exhibiting a glass transition temperature (Tg) between 130°C and 160 °C, Tg being determined on the 2ndheatscan in differential scanning calorimeter (DSC) according to ISO11357, using heating and cooling rates of 20°C / min.Claim 14. Polyamide (PA) according to any one of the preceding claims, exhibiting a heat of fusion (Hm) of at least 10.0 J / g, preferably at least 15.0 J / g, Hm being determined on the 2ndheat scan in differential scanning calorimeter (DSC) according to ISO11357, using a heating and cooling rate of 20°C / min.Claim 15. Polyamide (PA) according to any one of the preceding claims, having a number average molecular weight Mn ranging from 5,000 g / mol to 40,000 g / mol.Claim 16. Polyamide (PA) according to any one of the preceding claims, having a water uptake at saturation, by immersion in water at 23°C, of less than 6.0 wt.%, the water uptake being determined according to the method provided in the description.Claim 17. Polyamide (PA) according to any one of the preceding claims, exhibiting a transparency of at least 90.0%, preferably at least 92.0%, when measured in accordance with ASTM D1003 on an injection moulded specimen of 2.5 mm thickness.Claim 18. Polyamide (PA) according to any one of the preceding claims, exhibiting a haze of at most 10.0%, preferably at most 8.0%, when measured in accordance with ASTM D1003 on an injection moulded specimen of 2.5 mm thickness.Claim 19. Polyamide (PA) according to any one of the preceding claims, wherein the polyamide (PA) exhibits a biobased content of at least 40.0 %, preferably at least 80.0 %, preferably at least 85.0 %, preferably at least 90.0 %, preferably at least 95.0 %, preferably at least 99.5 %, the biobased content being expressed as the % of organic carbon of renewable origin in the polyamide (PA) and measured according to ASTM D6866-22.Claim 20. Polyamide (PA) according to any one of the preceding claims, prepared by polycondensing a reaction mixture (RM) comprising the following monomers:1) PACM or 4,4’ -diaminodicyclohexylmethane of formula:3) sebacic acid of formula H00C-(CH2)s-C00H and / or azelaic acid of formula HOOC-(CH2)7-COOH; wherein the proportion of trans / trans isomer in PACM monomer is at least 30.0 mol%, this proportion being calculated as TT / [TT+CT+CC] x 100 where TT, CT and CC designate respectively the isomers of PACM in the trans / trans (TT), cis / trans ( CT) and cis / cis (CC) configurations.Claim 21. Polymer composition (P) comprising or consisting of:- at least one polyamide (PA) as disclosed in any one of the preceding claims;- optionally at least one filler; and- optionally at least one additive other than a filler, notably selected in the group consisting of colorants, dyes, pigments, lubricants, plasticizers, flame retardants, tougheners, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electromagnetic absorbers and combination thereof.Claim 22. Polymer composition (P) according to claim 21 wherein the polymer composition (P) comprises or consist of at least one polyamide (PA) and as additives: i) at least one filler and ii) optionally at least one additive other than a filler, notably selected in the group consisting of colorants, dyes, pigments, lubricants, plasticizers, flame retardants, tougheners, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electromagnetic absorbers and combination thereof.Claim 23. Polymer composition (P) according to claim 21 or 22, wherein the proportion of polyamide(s) (PA) in the polymer composition (P) is:- at least 10.0 wt%; or- at least 40.0 wt%; or- at least 50.0 wt%: or- at least 60.0 wt%; or- at least 70.0 wt.%; or- at least 80.0 wt.%; this proportion being based on the total weight of the polymer composition (P).Claim 24. Polymer composition (P) according to any one of claims 21-23, wherein the polymer composition (P) comprises at least one additive selected from the group consisting of colorants, dyes, pigments, lubricants, plasticizers, flame retardants, tougheners, nucleating agents, heat stabilizers, light stabilizers, antioxidants, processing aids, fusing agents, electromagnetic absorbers and combination thereof.Claim 25. Polymer composition (P) according to any one of claims 21-24, wherein the polymer composition (P) comprises at least one filler selected in the group consisting of continuous or chopped carbon fibers, continuous or chopped glass fibers, milled carbon fibers, milled glass fibers, glass beads, glass microspheres, wollastonite, silica beads, talc, calcium carbonates, biobased fibers, polymeric fibers and combination thereof.Claim 26. Polymer composition (P) according to any one of claims 21-25, wherein the proportion of the filler(s) and / or additive(s) other than a filler in the polymer composition (P) is lower than 50.0 wt%.Claim 27. Polymer composition (P) according to any one of claims 21-26, wherein the proportion of the additive(s) in the polymer composition (P) is between 0.01 and 50.0 wt%, even between 0.10 and 40.0 wt% or between 0.50 and 40.0 wt.%.Claim 28. Polymer composition (P) according to any one of claims 21-27, wherein the filler(s) and / or additive(s) other than a filler are blended with the polyamide(s) (PA).Claim 29. Polymer composition (P) according to any one of claims 21-28, wherein the polymer composition (P) comprises only one polyamide (PA).Claim 30. Polymer composition (P) according to any one of claims 21-29, wherein the polymer composition (P) does not comprise a polyamide other than polyamide(s) (PA).Claim 31. Polymer composition (P) according to any one of claims 21-30, in the form of a powder or in the form of pellets.Claim 32. Filament made of or comprising a polyamide (PA) as disclosed in any one of claims 1-20 or a polymer composition (P) as disclosed in any one of claims 21-31 and having a cylindrical or substantially cylindrical geometry and a diameter d between 0.5 mm and 5.0 mm.Claim 33. Filament according to claim 32, wherein the components of the composition (P) are blended together.Claim 34. Filament according to claim 32 or 33, wherein the composition of the filament consists of the polymer composition (P).Claim 35. Filament according to any one of claims 32-34, wherein the filament is full.Claim 36. Filament according to any one of claims 32-35, wherein the filament does not present a core / shell geometry.Claim 37. Filament according to any one of claims 32-36, having a length L of at least 200 mm.Claim 38. A spool of filament according to any one of the claims 32-37.Claim 39. Method for manufacturing a 3D object using an additive manufacturing system and a filament according to any one of claims 32-37.Claim 40. Method of claim 39, wherein the method comprises a step consisting in extruding the composition (P) into a filament.Claim 41. Method of claim 39 or 40, comprising the following steps:- advancing the filament to a print head;- heating the filament in the print head to a molten state, the filament being preferably heated at a temperature which is at least Tm + 10°C where Tm is the melting point of polyamide (PA);- extruding the material in the molten state from a nozzle in the print head;- ensuring relative movement in X- and Y- directions of the print head to form the cross sectional shape of the 3D object; and / or- ensuring relative movement in the Z-direction of the print head to form the 3D object in elevation.Claim 42. Use of the filament according to any one of claims 32-37 in 3D printing.Claim 43. Use of the polyamide (PA) as defined in any one of claims 1-20 or of a polymer composition as defined in any one of claims 21-31, for the preparation of an article by injection moulding.

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