Electrical device comprising an electrical insulation

Abstract

The invention relates to the use of a polymer composition (PC) comprising at least one semi¬ aromatic polyamide (PA) for the preparation of an electrical insulation polymeric article, wherein polyamide (PA) is a semi-aromatic copolyamide (PA) exhibiting a melting temperature (Tm) between 250°C and 295°C, this latter value being excluded (< 295°C), a glass transition temperature (Tg) of at least 135.0°C, preferably at least 140°C, and comprising at least 90.0 mol%, preferably at least 95.0 mol%, preferably at least 99.0 mol% of recurring units (RPA) formed from the polycondensation of a diamine component (A) and a dicarboxylic acid component (B) wherein: a) the diamine component (A) consists of: between 15.0 and 54.0 mol% of 1,6-diaminohexane; - between 15.0 and 40.0 mol% of a diamine (DI) selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines; - between 15.0 and 64.0 mol% of a diamine (D2) selected in the group consisting of 1,3-bis(aminomethyl)cyclohexane, 1,4- bis(aminomethyl)cyclohexane and a combination of said two diamines; b) the dicarboxylic acid component (B) consists of: - between 90.0 mol% and 100 mol% of terephthalic acid; - between 0 and 10.0 mol% of another dicarboxylic acid (DI) selected in the group consisting of isophthalic acid, dicarboxylic acids of formula HOOC-(CH2)X-COOH where x is an integer from (5) to (16) and combination thereof; these proportions in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

Description

ELECTRICAL DEVICE COMPRISING AN ELECTRICAL INSULATIONThis application claims priority of US provisional application N° 63 / 656,507 filed on 5 June 2024 and European patent application N° 24183279.9 filed on 20 June 2024, the content of which being entirely incorporated herein by reference for all purposes. In case of any incoherency between this application and one of the priority applications that would affect the clarity of a term or expression, it should be made reference to this application only.[FIELD OF THE INVENTION]

[0001] The invention relates to the use of a composition (PC) comprising a semi-aromatic polyamide (PA) for the preparation of an electrical insulation polymeric article, notably in the form of a film (F) or a layer (L). The invention also relates to a method for preparing an electrical insulation polymeric article. The invention also relates to an electrical device comprising an electrical insulation polymeric article comprising polyamide (PA).[BACKGROUND OF THE INVENTION]

[0002] Plastics have inherent electrical insulating properties to prevent the flow of electrical current and are used in a variety of applications.

[0003] Electric machines such as motors and generators are widely known and used in a wide range of applications and require insulation layers.

[0004] Most slot liner films in the market today are aramid papers (such as Nomex® 410) or laminates which offer low elongation at break and require thicknesses of -250 micron to insulate voltages used in electric motors. These papers and laminates also have a tendency to rip when the end windings are bent in an electric motor, requiring designers to extend the end windings several mm beyond the slot opening.

[0005] WO 2021 / 224456 (DI) discloses an electrical or electronic article comprising a semiaromatic polyamide. Polyamide (PA) of claim 1 differs from the polyamide of DI in that it is derived from hexamethylene diamine and 1,9-diaminononane or 1,10- diaminodecane whereas in DI only one C4 to CIO aliphatic diamine is used. DI does not disclose nor suggest the composition of polyamide (PA).

[0006] EP 4276136 (or WO 2021 / 037850) (D2) discloses an electrical or electronic article comprising a polymer composition (PC) comprising (see D2, claim 1): a polyamide (PA) and a glass fibre. D2 discloses polyamide of example E5 with a Tm of 315°Cand formed from 57 mol% 1,6-hexamethylenediamine (HMD A), 35 mol% 1,10- diaminododecane (DMDA), 8 mol% l,3-bis(aminomethyl)cyclohexane (1,3-BAC) and 100 mol% TA (see DI, Table 1, example E5).

[0007] WO 2024 / 115690 (D3) was published on 6 June 2024 and discloses a 6T / 10T / BACT or 6T / 9T / BACT copolyamides but does not disclose the use of said polyamide for the preparation of an electrical insulation polymeric article.

[0008] WO 2024 / 061681 discloses the use of a polyamide-based composition, and an insulation film prepared by said polyamide-based composition.

[0009] There is the need of polymeric material that can be easily transformed into a film or a layer to be used as electrical insulation article, notably having a thickness lower than 300 pm.

[0010] In the context of the invention, thickness is measured according to available standards. Thickness can be measured according to ASTM D6988 - 21 or ASTM D8136-24. Thickness can also be measured following the method disclosed in ASTM E252-24 (this method involves the measurement of the weight of a square of a material having a measured length and width and calculation of the thickness by formula: thickness = weight / [length x width x density],

[0011] The polymeric material should exhibit a high elongation at break and a high CTI (Comparative Tracking Index). This ensures for instance that the film does not rip as easily as the aramid paper or laminate and can withstand the stresses from the end windings. The film should enable a low creepage distance and minimization of the end windings in the electrical machines.

[0012] Moreover, in some cases, the temperature in the electrical machine may be quite high, so that the polymeric material should exhibit thermal resistance to maintain its integrity and also its insulation properties.

[0013] Finally, there is a need of a material with improved dielectric strength both when dried and after exposure to humidity (hence, a low variation of those properties when exposed to humidity).

[0014] The invention aims at solving this technical problem.

[0001] These definitions apply to the present disclosure.

[0002] wt.% is a percentage by weight. Mol.% is a percentage by mole.

[0003] 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.

[0004] When numerical ranges are given herein, unless otherwise expressly indicated, the end-points of the ranges (even in the open-ended ranges such as those comprising "at least", "at most", "lower than", "up to", etc or in ranges comprising “between’") are included. The expression "at least" therefore corresponds to the mathematical symbol > in the context of the present invention. The expression "at most" therefore corresponds to the mathematical symbol < in the context of the present invention. For clarity then, the ranges comprising the expression “between X and Y” are thus equivalent to “from X to Y”.

[0005] 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. Likewise, unless otherwise indicated, any specific embodiment or technical feature relating to one of the subject-matters of the invention (e.g. use) is applicable to or interchangeable with another embodiment or technical feature (i) relating to another subject-matter (e.g. electrical article) of the invention and (ii) disclosed elsewhere in the application.

[0006] In the set of claims, the method or the electrical device is defined with features relating to polyamide (PA) (e.g. claim 31 refers to polyamide (PA) as defined in claims 5-31 or any one of claims 5-31) or polymer composition (PC) (e.g. claim 32 refers to polymer composition as defined in claims 22-26 or any one of claims 22-26) as defined in previous claims. For clarity, this means that the features can be taken from a combination of those claims or from a claim alone.

[0007] The proportions of diamines in the diamine component (A) are based on the total amount of diamines in the diamine component (A). The proportions of carboxylic diacids in the dicarboxylic acid component (B) are based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

[0008] The proportions of recurring units in polyamide (PA) are expressed in mol% and are based on the total amount of recurring units in the polyamide (PA).

[0009] An electrical insulation polymeric article is an article made of or comprising a polymeric composition which is used to isolate an electrical conductor from another conductor or from any other conductive material or grounded surface.

[0010] An electrical device is a machine (or a part of a machine) or a device (or part of a device) containing one or more electrical conductor.

[0011] The recurring units of polyamide (PA) are linked to one another by amide bonds.

[0012] The proportions of the monomers of polyamide (PA) are, as is usually done, given by reference to their proportions in the diamine component (A) and in the dicarboxylic acid component (B). Those proportions can be translated into and correspond to the proportions of monomers present in the polyamide (PA) in polymerized form after polycondensation. In other words, these proportions of monomers in the polyamide (PA) correspond to the proportions of the said monomers in the polymerized form.

[0013] When a norm (e.g. ASTM) is used in the present invention, unless otherwise explicitly indicated, it is referred to the lattest version of this norm available at the priority date of the present application.

[0001] The invention is set out in the appended set of claims.

[0002] The invention relates to the use as disclosed in any one of claims 1-23.

[0003] The invention also relates to the method as disclosed in any one of claims 24-26.

[0004] The invention also relates to an electrical device as disclosed in any one of claims 27- 30

[0005] More precisions and details about the invention and the claimed subject-matters are now provided below.

[0001] Figure 1 represents a stator (1) comprising slots (2), each slot comprising a slot liner (3).

[0002] Figure 2 represents a stator (1) comprising slots (2), each slot being closed by a slot wedge (4).

[0003] As is visible, both components - represented in darker color - are disposed in different places of the slots of the stator.

[0015] Electrical insulation polymeric articles

[0016] As a first aspect, the invention relates to the use of the polymer composition (PC) as defined herein comprising at least one semi-aromatic polyamide (PA) as defined herein for the preparation of an electrical insulation polymeric article.

[0017] As a second aspect, the invention relates to a method for preparing an electrical insulation polymeric article by injection molding the polymer composition (PC) as defined herein or by extruding the polymer composition (PC) as defined herein in the form of a film (F). For the preparation of a film, the polymer composition (PC) as defined herein is heated and melt-extruded through a slit die to form an extruded layer, and the extruded layer is cooled.

[0018] According to an embodiment, the electrical insulation polymeric article is in the form of a film (F) or in the form of a layer (L) in an electrical device which comprises or is made of the polymer composition (PC) as defined herein.

[0019] Electrical insulation film (F)

[0020] Film (F) comprises one or more layers made of or comprising a polymer composition (PC) as defined herein.

[0021] According to an embodiment, the film (F) is a monolayer film. According to another embodiment, the film (F) is a multilayer film and comprises at least one layer comprising or made of polymer composition (C) and at least one additional layer, notably made of or comprising a polymer which is not a polyamide (PA) as defined herein.

[0022] Film (F) is prepared by extrusion or coextrusion. Conditions of preparation of a film (F) by extrusion are provided in the Experimental Section and may be followed.

[0023] The thickness of film (F) is typically lower than or equal to 750 pm. The thickness is more particularly between 20 and 500 pm, more particularly between 20 and 200 pm.

[0024] Slot liner

[0025] According to an embodiment, the electrical insulation polymeric article is a slot liner.

[0026] Electric motors convert electrical energy into mechanical energy in the form of motion. Electric generators convert mechanical energy into electrical energy. Although the two machines have different functions, they both comprise a stator which is the stationary part of the machine and which comprises conductors, usually in the form of copper wire coils, inserted in slots. In the case of a motor, the stator produces a magnetic field to interact magnetically with a rotor or other moving element. Although the stator in an electric motor is stationary, it provides the driving forces that rotate the rotor. Stator configurations may vary for different motorapplications and generally have a "core" formed from laminations of steel or other magnetic material. This core provides the path for magnetic flux threading through the stator. The slots are formed in this core to provide locations for coils of electrical conductors. Alternating current passing through the conductive coils creates the rotating magnetic field used for the operation of the motor. To avoid damages and to improve the performance of the electric machine, an electrical insulation film between the windings and the stator needs to be present in the slots of the stator. Two components are generally inserted into the slots for this: a slot liner and a slot wedge.

[0027] A slot liner is a component in an electrical machine such as a motor or generator which provides a mechanical protective barrier and an electrical insulation barrier between the windings and the stator. The component is cut and shaped from a film to fit within the slots of the motor or generator.

[0028] A slot liner is typically shaped into different configurations and sizes. For instance, the slot liner may be as depicted on Fig. 7 of US 4,151,436; Fig. 7 of US 4,247,978; Fig. 1 of US 3,943,392; Fig. 3 of US 5,306,976; Fig. 6 of US 2010 / 0141079 Al or Fig. 2 of US 2011 / 0095641 Al or Fig. 1 of US 2016 / 0065025.

[0029] Typically, the slot liner is substantially U-shaped.

[0030] Typically, the slot liner is designed, e.g. to be folded on itself, to facilitate the axial insertion in or along the slot but radial insertion is also used in the industry.

[0031] The slot liner exhibits typically a thickness lower than 750 pm. The thickness is more particularly between 20 and 500 pm, more particularly between 20 and 200 pm.

[0032] Slot wedge

[0033] According to an embodiment, the electrical insulation polymeric article is a slot wedge. A slot wedge is a slot closure to hold the stator windings in the slots.

[0034] The slot wedge exhibits typically a thickness lower than 750 pm. The thickness is more particularly between 20 and 500 pm, more particularly between 20 and 200 pm.

[0035] The slot wedge may be prepared with the conventional techniques of transformation of the polymeric materials such as extrusion or injection molding.

[0036] A slot liner or a slot wedge is typically prepared by conventional techniques. For instance, a convenient method of preparation of a slot liner consists in extruding the polymer composition (PC) into a film, generally at the desired thickness of the slot liner or slot wedge. Then the slot liner or slot wedge is formed from a section that is cut from the film and contoured so as to fit into the space within the slot.

[0037] Other applications

[0038] According to an embodiment, the electrical insulation polymeric article is an electrically-insulating film of a power electronic system, such as an inverter, a converter or an on-board charger. This film may be used as a single layer or may be used in combination with an applied adhesive to electrically isolate conductive elements inside the power electronics system.

[0039] Electrical insulation layer (L)

[0040] According to an embodiment, the electrical insulation polymeric article is an electrical insulation layer (L) in an electric conductor. The invention thus relates also to a conductor comprising an electrical conductor and at least one layer around the conductor made of or comprising the polymer composition (PC) as defined herein.

[0041] The conductor may for instance be a magnet wire.

[0042] According to an embodiment, the electrical insulation polymeric article is a coated busbar comprising a metal conductor which transmits currents from one point to another coated with an electrical insulation layer (L) to isolate the busbar from surrounding conductive surfaces.

[0043] According to an embodiment, the electrical insulation polymeric article is an electrically-insulating component of a transformer, notably a high-voltage or low- voltage transformer. Similar to electric motors and generators, transformers typically contain coils of insulated wires wrapped around ferromagnetic cores. There are various insulating components similar to slot liners in these transformers which are intended to electrically isolate coils from one another and from the cores.

[0044] According to an embodiment, the electrical insulation polymeric article is a coating on a cooling plate. Such cooling plates are used, for example, in battery management systems, heat sinks in power modules, etc., and are often composed of metal for better heat conduction. In many cases, these metal cooling plates must be electrically isolated from surrounding conductive components by cooling plate insulation.

[0045] Electrical device

[0046] As a third aspect, the invention also relates to an electrical device comprising at least one electrical insulation polymeric article made of or comprising the polymer composition (PC) as defined herein.

[0047] Some examples of electrical devices comprising one or more the electrical insulation polymeric articles are provided in the table below:

[0048] All details and embodiments disclosed herein for polyamide (PA) or for polymer composition (PC) are applicable to the electrical device.

[0049] Polymer composition (PC)

[0050] Details about the polymer composition (PC) which is defined and used herein are now provided. All proportions of the components of the polymer composition (PC) are given by weight and relative to the total weight of the polymer composition (PC).

[0051] Polymer composition (PC) comprises at least one polyamide (PA) as disclosed herein. The proportion of polyamide(s)(PA) is typically at least 30.0 wt%.

[0052] According to an embodiment, polymer composition (PC) which is defined and used herein comprises, consists essentially of or consists of:- at least 30.0 wt% of at least one polyamide (PA) as disclosed herein;- a component (c) blended with polyamide(s) (PA) and selected in the group consisting of fillers (Fi), plastic additives (Add), polyamides (PA*) and combinations of two or more of said components, where polyamide (PA*) is polyamide having a composition of monomers distinct from the composition of polyamide (PA).

[0053] According to another embodiment, polymer composition (PC) which is defined and used herein comprises, consists essentially of or consists of:- at least 30.0 wt% of at least one polyamide (PA) as disclosed herein;- at least one filler (Fi);- optionally at least one additive (Add); where polyamide (PA), the particulate filler (Fi) and optional additive (Add) form a blend.

[0054] According to an embodiment, the proportion of polyamide(s) (PA) in polymer composition (PC) is between 30.0 wt% and 100.0 wt%. This proportion may be at least 50.0 wt% or at least 75.0 wt%.

[0055] The proportion of component (c) or the total proportion (Fi)+(Add) in polymer composition (PC) is typically at most 70.0 wt%.

[0056] Filler(s) (Fi)

[0057] According to an embodiment, polymer composition (PC) comprises at least one filler (Fi).

[0058] The filler (Fi) may be selected from talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate, silica, alumina, glass fibers, carbon fibers, synthetic polymeric fibers, aramid fibers, aluminum fibers, titanium fibers, magnesium fibers, boron carbide fibers, rock wool fibers, steel fibers, wollastonite and combination thereof.

[0059] According to an embodiment, the filler (Fi) is glass fibers or carbon fibers. Glass fibers include chopped strand A-, E-, C-, D-, S- and R-glass fibers, as described in chapter 5.2.3, p. 43-48 of Additives for Plastics Handbook, 2ndedition, John Murphy.

[0060] Plastic additive(s) (Add)

[0061] According to an embodiment, polymer composition (PC) comprises at least one plastic additive (Add). A plastic additive (Add) is not a reinforcing filler (Fi).

[0062] The plastic additive (Add) is typically selected from conventional additives for plastic, notably in the group consisting of antioxidants, tougheners, impact modifiers, plasticizers, colorants, pigments, antistatic agents, dyes, lubricants, thermal stabilizers, light stabilizers, flame retardants, nucleating agents, antioxidants, UV absorbers, acid scavengers and combinations thereof.

[0063] According to an embodiment, the proportion of plastic additive(s) (Add) is between 0.01 and 60.0 wt%.

[0064] Polyamide(s) (PA*)

[0065] Component (c) may be at least one polyamide (PA*) having a composition of monomers distinct from polyamide (PA).

[0066] Polyamide (PA*) is typically selected in the group of aliphatic polyamides and semiaromatic polyamides.

[0067] Polymer composition (PC) is prepared by a method comprising a step in which the components of the polymer composition (PC) are introduced into a mixer to form a blend, the polymeric component of the polymer composition (PC) being in the molten form. The shear forces generated in the mixer are typically high enough to mix the components and obtain an homogenous blend.

[0068] The mixer is notably a single screw extruder, a twin screw extruder, an agitator, an internal mixer that comprises two rotors enclosed in a mixing chamber (e.g. a Banbury mixer). The mixer is conveniently an extruder, preferably a twin screw extruder. An example of twin screw extruder that can be used for the preparation of polymer composition (PC) is ZSK 26 Me18of Coperion.

[0069] Polyamide (PA)

[0070] Details are now given about polyamide (PA). Each feature and embodiment relating polyamide (PA) disclosed herein, notably in the claims, are applicable to all subjectmatters of the invention.

[0071] Polyamide (PA) is a semi-aromatic copolyamide (PA) exhibiting a melting temperature (Tm) between 250°C and 295°C, this latter value being excluded (< 295°C), a glass transition temperature (Tg) of at least 135.0°C, preferably at least 140°C, and comprising at least 90.0 mol%, preferably at least 95.0 mol% of recurring units (RPA) formed from the polycondensation of a diamine component (A) and a dicarboxylic acid component (B) wherein: a) the diamine component (A) consists of: between 15.0 and 54.0 mol% of 1,6-diaminohexane;- between 15.0 and 40.0 mol% of a diamine (DI) selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;- between 15.0 and 64.0 mol% of a diamine (D2) selected in the group consisting of l,3-bis(aminomethyl)cyclohexane, 1,4- bis(aminomethyl)cyclohexane and a combination of said two diamines; b) the dicarboxylic acid component (B) consists of:- between 90.0 mol% and 100 mol% of terephthalic acid;- between 0 and 10.0 mol% of at least one dicarboxylic acid (DI) selected in the group consisting of isophthalic acid, dicarboxylic acids of formula HOOC-(CH2)X-COOH where x is an integer from 5 to 16 and combination thereof; these proportions in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

[0072] Polyamide (PA) thus comprises in reacted form the diamines of the diamine component (A) and the dicarboxylic acids of the dicarboxylic acid component (B) with the proportions indicated herein.

[0073] Polyamide (PA) is formed from the polycondensation of the diamine component (A) and the dicarboxylic acid component (B). All diamines and all dicarboxylic acids as monomers of PA are present respectively in the diamine component (A) and in the dicarboxylic acid component (B). Therefore, the proportion of -NH2 from the diamine component (A) and the proportion of -COOH from the di carboxylic acid component (B) are substantially equimolar. The molar ratio -NH2 from the diamine component(A) / COOH from the dicarboxylic acid component (B) is preferably comprised between 0.9 to 1.1, preferentially 0.95 to 1.05, even more preferentially between 0.98 to 1.02.

[0074] The proportion of recurring units (RPA) is at least 90.0 mol%, preferably at least 95.0 mol% of recurring units (RPA), preferably at least 99.0 mol% of recurring units (RPA).

[0075] Polyamide (PA) may comprise recurring units (RPA*) other than recurring units (RPA), the proportion of which being at most 10.0 mol%. Units (RPA*) are selected in the group of units derived from the condensation of a diamine and dicarboxylic acid, units derived from a lactam and units derived from an aminoacid. Said recurring units (RPA*) are preferably not derived from a lactam or from an aminoacid.

[0076] According to an embodiment of the present disclosure, polyamide (PA) is free of recurring units derived from a lactam and / or from an aminoacid. The expression "free of recurring unit derived from a monomer X" means that the proportion of said recurring units is lower than or equal to 1.5 mol%, preferably lower than or equal to 1.0 mol%, preferably lower than or equal to 0.5 mol%, preferably lower than or equal to 0.25 mol% or that polyamide (PA) does not comprise said recurring units.

[0077] According to an embodiment, the recurring units of polyamide (PA) consist of recurring units (RPA).

[0078] According to an embodiment, polyamide (PA) is a 6T / 10T / BACT copolyamide where BAC designates 1,3-BAC and / or 1,4-BAC with the proportions of monomers indicated herein, in particular in the claims. All details and embodiments disclosed herein apply to this embodiment.

[0079] More details about the diamine component (A) and the dicarboxylic acid component(B) are now provided below.

[0080] About the diamine component (A)

[0081] The diamine component (A) is based on the following diamines: 1,6-diaminohexane (of formula NH2-(CH2)e-NH2); a diamine (DI) selected in the group consisting of 1,9- diaminononane (of formula NH2-(CH2)9-NH2), 1,10-diaminodecane (of formula NH2-(CH2)IO-NH2) and a combination of said two diamines; and a bis(aminomethyl)cyclohexane (D2).

[0082] The diamine component (A) comprises 1,6-diaminohexane. The proportion of 1,6- diaminohexane is between 15.0 and 54.0 mol%.

[0083] The diamine component (A) comprises also another diamine (DI) selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines. This diamine (DI) may be more particularly 1,9-diaminononane.This diamine (DI) may also be more particularly 1,10-diaminodecane. The proportion of said other diamine(s) (DI) is between 15.0 and 40.0 mol%.

[0084] The diamine component (A) comprises also a bis(aminomethyl)cyclohexane (D2) selected in the group consisting of l,3-bis(aminomethyl)cyclohexane, 1,4- bis(aminomethyl)cyclohexane and a combination of said two diamines. 1,3-bis(aminomethyl)cyclohexane (1,3-BAC) is the diamine of formula: l,4-bis(aminomethyl)cyclohexane (1,4-BAC) is the diamine of formula:This diamine (D2) may be more particularly 1,3- bis(aminomethyl)cyclohexane. This diamine (D2) may be more particularly 1,4- bis(aminomethyl)cyclohexane. The proportion of said other diamine(s) (D2) is between 15.0 and 64.0 mol%.

[0085] In the following table, several embodiments disclosing several ranges of proportions (in mol%) for each of the three components of the diamine component (A) are provided, each range being defined by a lower end-point and an upper end-point:

[0086] All details and embodiments disclosed in the present disclosure are applicable to any one of embodiments (Emb l)-(Emb 11).

[0087] About the dicarboxylic acid component (B)

[0088] The dicarboxylic acid component (B) is based on terephthalic acid as the major component of the dicarboxylic acid component (B). It may also comprise at least one dicarboxylic acid (DI) selected in the group consisting of isophthalic acid, dicarboxylic acids of formula HOOC-(CH2)X-COOH where x is an integer from 5 to 16 and combination thereof, x may more particularly be from 6 to 10.

[0089] The proportion of the dicarboxylic acid(s) (DI) in the dicarboxylic acid component (B) is between 0 and 10.0 mol%. According to an embodiment, this proportion may be between 0 and 5.0 mol%.

[0090] According to another embodiment, the dicarboxylic acid component (B) consists of terephthalic acid or of terephthalic acid and isophthalic acid.

[0091] The diacid (DI) other than terephthalic acid may be more particularly isophthalic acid.

[0092] Recurring units

[0093] The skilled person understands that polyamide (PA) can be described as comprising the following recurring units (RPAI) + (RPA?) + [(RpA3a) and / or (RpA3b)] :(RPA2); and(RpA3b) or the following recurring units (RPAI), (RPA?) and (RpA3a):(RpA3a) where Ri is hexamethylene -(CH2)e- and R2 is the divalent radical of a diamine selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines. For clarity, the divalent radical of 1,9-diaminononane is -(CH2)9- and the divalent radical of 1, 10-diaminodecane is -(CH2)IO-

[0094] The skilled person understands that RPAI corresponds to the recurring unit obtained from the reaction of terephthalic acid with 1,6-diaminohexane and RPA2 corresponds to the recurring unit obtained from the reaction of terephthalic acid with the other diamine(s) in C9 and / or CIO. Likewise, RpA3a corresponds to the recurring unit obtained from the reaction of terephthalic acid with the 1,3- bis(aminomethyl)cyclohexane. RpA3b corresponds to the recurring unit obtained from the reaction of terephthalic acid with the l,4-bis(aminomethyl)cyclohexane.

[0095] (RPAI) is formed from the condensation of terephthalic acid and 1,6-diaminohexane. (RPA?) is formed from the condensation of terephthalic acid and diamine(s) (DI). (RpA3a) is formed from the condensation of terephthalic acid and 1,3-BAC. (RpA3b) is formed from the condensation of terephthalic acid and 1,4-BAC.

[0096] If present, the at least one dicarboxylic acid (DI) leads also other recurring units present in polyamide (PA).

[0097] Embodiment (E): according to a preferred embodiment (E), the dicarboxylic acid component (B) consists essentially of or consists of terephthalic acid.

[0098] The expression "consist essentially" means in the context of the invention in relation to the dicarboxylic acid component (B) that the dicarboxylic acid component (B) consists of terephthalic acid and up to 2.0 mol%, preferably up to 1.0 mol%, even more preferably up to 0.5 mol%, of at least one additional dicarboxylic acid other than terephthalic acid, this proportion in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).

[0099] All details and embodiments disclosed in the present disclosure are applicable to embodiment (E). In particular, embodiments (Emb l)-(Emb 11) are applicable to embodiment (E).

[0100] According to this embodiment, the recurring units of polyamide (PA) consist essentially of (RPAI) + (RPA2) + [(RpA3a) and / or (RpA3b)].

[0101] According to an embodiment, the recurring units of polyamide (PA) consist of (RPAI) + (RPA2) + [(RpA3a) and / Or (RpA3b)] .

[0102] All the proportions and embodiments provided herein for diamines 1,6- diaminohexane, DI and D2 in the diamine component (A) can be translated into and correspond to respectively proportions of (RPAI), (RPA2) and (RpA3a) and / or (RpA3b). Inparticular, the following Table provides the ranges of proportions of each recurring units with lower end-points and upper end-points for each range:

[0103] The polyamide (PA) of the invention preferably has a number average molecular weight ("Mn") ranging from 8,000 g / mol to 40,000 g / mol, more particularly from 10,000 and 20,000 g / mol, more particularly between 13,000 and 16,000 g / mol. It was indeed been observed that this range of Mn is optimized for the preparation of a film or a layer.

[0104] Mn is determined by size exclusion chromatography (SEC) with polystyrene standards or by using the following equation (1): Mn = 2,000,000 / [EG] (1) wherein [EG] is the proportion of end-groups in the polyamide (PA) expressed in mmol / kg. The end-groups in the polyamide (PA) are generally amine and / or acid moi eties. Yet, when the polycondensation involves the addition of an end-capping 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.

[0105] The end-groups in polyamide (PA) are selected in the group of -NEh, -COOH and amide end-groups. Indeed, the end-groups in the polyamide (PA) may be -NH2 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.

[0106] The amide end groups are of formula -NH-C(=O)-R where R is 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 C1-C17 alkyl group or a C5-C10 cycloalkyl group. R' is more particularly a linear or branched C2- Cis alkyl group.

[0107] 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.

[0108] 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 C1-C17 alkyl group and combination of two or more of these acids. R is the radical derived from the acid of formula R-COOH.

[0109] 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.

[0110] The monocarboxylic acid (end-capping agent) is more particularly of formula CH3- (CH2)n-COOH where n is an integer between 0 and 16. The amide end groups are then of formula -NH-C(=O)-(CH2)n-CH3.

[0111] 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.

[0112] The primary amine (end-capping agent) may advantageously be selected in the group consisting of the amines of formula R-NH2 where R' is a linear or branched C2-C18 alkyl group. R' is the radical derived from the amine of formula R-NH2.

[0113] The primary amine (end-capping agent) is more particularly of formula CH3-(CH2)n- NH2 where n' is an integer between 2 and 18. The amide end groups are then of formula -C(=O)-NH-(CH2)n'-CH3.

[0114] 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.

[0115] The composition of polyamide (PA) is determined with well-known analytical techniques. The composition of polyamide (PA), the proportions of recurring units and end-groups in the polyamide (PA) can be determined by1H NMR spectroscopy.They can also be determined after digestion (hydrolysis) of the polyamide (PA) and analysis of the mixture resulting from said digestion. The analysis is performed by the usual analytical techniques available to the skilled person. Gas chromatography (GC) and / or liquid chromatography (LC) can conveniently be used for this analysis. High- performance liquid chromatography (HPLC) is a convenient analytical technique for this analysis. See ACS Sustainable Chem. Eng. 2020, 8, 31, 11818-11826. The hydrolysis of the polyamide is preferably performed in acidic conditions: the sample of polyamide is mixed with a strong acid and the mixture is heated at a temperature higher than 150°C until digestion is complete. The resulting mixture is then cooled to room temperature, diluted with a solvent and the obtained mixture is analyzed by at least one analytical method. As an example of conditions of digestion, the following conditions are given: mix the weighed sample of polyamide (40-50 mg) with a strong acid (0.5 mL of HBr, 48 wt% in water) in an hydrolysis tube and after purging O2 with vacuum and adding N2 (cycle vacuum / N2: 3 times) heat the mixture at a temperature higher than 150°C (160°C) until digestion is complete (generally, a duration of at least 4 hours is needed). Then cool to room temperature. The mixture is diluted with a solvent (mixture acetonitrile / water with vol. ratio 2 / 1) and the obtained mixture is analyzed by LC-MS (Liquid Chromatography coupled with Mass Spectroscopy).

[0116] The proportion of the end groups in polyamide (PA) can be quantified by 'H NMR or by potentiometric techniques.

[0117] The polyamide (PA) preferably exhibits an inherent viscosity ("IV") measured according to ASTM D5336 between 0.80 and 1.50 dL / g, more particularly between 0.85 and 1.30 dL / g, more particularly between 0.90 and 1.20 dL / g. The IV can be measured conveniently in a 60 wt% / 40 wt% phenol / tetrachloroethane mixture.

[0118] Moisture absorption

[0119] The polyamide (PA) advantageously exhibits a water uptake at 23°C lower than 5.0 wt%.

[0120] The water uptake at 23°C is determined by (i) providing a specimen shaped according to ISO527 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:Water uptakewherein Wbefore is the weight of the shaped specimen in its original dry state and Waiter is the weight of the shaped specimen after water uptake.

[0121] Biocontent

[0122] Sustainable resins are more and more sought after. This is why polyamide (PA) preferably exhibits a bio content of at least 10.0%, preferably at least 15.0%, the biocontent being expressed as the % of organic carbon of renewable origin determined according to ASTM D6866-22. The bio content of the polyamide (PA) may be at least 20.0%.

[0123] The biocontent may be between 10.0 and 21.0%.

[0124] The bio 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.

[0125] Both the C9 and CIO diamines that are used for the preparation of the polyamide (PA) can be biobased or issued from petroleum or natural gas:

[0126] The polyamide (PA) disclosed herein is therefore preferably prepared from biobasec1,9-nonanediamine (C9) and / or 1,10-decanediamine (CIO). This makes it possible to obtain a polyamide (PA) with a high bio content. The high bio content of the PA comes primarily from the C9 and / or CIO diamine.

[0127] According to an embodiment, the polyamide (PA) disclosed herein is prepared from biobased 1,9-nonanediamine (C9) and / or 1,10-decanediamine (CIO) exhibiting a bio content of at least 99.0%, preferably at least 99.5%, preferably at least 99.9%, the biocontent being expressed as the % of organic carbon of renewable origin measured according to ASTM D6866-22.

[0128] However, it is also possible to increase the bio content with the use of a biobased terephthalic acid. A bio based terephthalic acid may for instance be prepared from a biobased furfural as disclosed in Tachibana, Y., Kimura, S. & Kasuya, K.-i. “Synthesis and Verification of Biobased Terephthalic Acid from Furfural” Sci. Rep. 5, 8249; DOE10.1038 / srep08249 (2015). The bio content of polyamide (PA) as defined above may then be at least 50.0% or at least 65.0%.

[0129] Thermal properties of polyamide (PA)

[0130] 1) Melting point (Tm)

[0131] The polyamide (PA) exhibits a Tm between 250.0°C and 295.0°C, this value of 295.0 being excluded (< 295.0°C).

[0132] Tm is preferably at most 275°C or at most 270°C.

[0133] While still being high, such a Tm is beneficial for the processability, notably by extrusion, of the polyamide (PA) or the polymer composition (PC) specifically extrusion

[0134] Tm can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.

[0135] Tm can more particularly be measured according to the method described in the Experimental Section.

[0136] Tm can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418 using a heating and cooling rate of 20°C / min. Three scans were used for each DSC test: a first heat up to 350°C, followed by a first cool down to 0°C,followed by a second heat up to 360°C. The Tm was determined from the second heat up.

[0137] 2) Glass transition temperature (Tg)

[0138] The polyamide (PA) exhibits a Tg of at least 135.0°C, preferably at least 140°C, preferably at least 145°C.

[0139] The polyamide (PA) generally exhibits a Tg of at most 200°C or at most 180°C or at most 160°C.

[0140] The Tg may more particularly be from 135.0°C to 180°C or between 145°C and 180°C or between 145°C and 160°C.

[0141] Tg can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.

[0142] Tg can more particularly be measured according to the method described in the Experimental Section.

[0143] Tg can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418 using a heating and cooling rate of 20°C / min. Three scans were used for each DSC test: a first heat up to 350°C, followed by a first cool down to 0°C, followed by a second heat up to 360°C. The Tg was determined from the second heat up.

[0144] According to a preferred embodiment, the polyamide (PA) exhibits a difference (Tm - Tg) lower than 130°C, preferably lower than 125°C.

[0145] 3) Crystallization temperature (Tc)

[0146] Polyamide (PA) exhibits a Tc lower than or equal to 225 °C, preferably lower than or equal to 220°C.

[0147] Tc is generally at least 170°C or at least 190°C.

[0148] Tc may be between 170°C and 225°C.

[0149] Tc is measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.

[0150] Tc can more particularly be measured according to the method described in the Experimental Section.

[0151] Tc can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418 using a heating and cooling rate of 20°C / min. Three scans are used for each DSC test: a first heat up to 350°C, followed by a first cool down to 0°C, followed by a second heat up to 360°C. Tc is determined from the first cool down.

[0152] The polyamide (PA) of the invention preferably exhibits a difference (Tm - Tc) of at least 50.0°C, preferably of at least 55.0°C, preferably at least 60.0°C. (Tm - Tc) may be between 50.0 and 85.0°C.

[0153] 4) Heat of fusion (Hm)

[0154] The polyamide (PA) is semi-crystalline.

[0155] The polyamide (PA) exhibits a Hm of at least 15.0 J / g, preferably at least 20.0 J / g, preferably at least 25.0 J / g, preferably at least 27.0 J / g.

[0156] Hm may be at most 40.0 J / g or at most 39.0 J / g.

[0157] Hm is preferably between 15.0 and 40.0 J / g, preferably between 15.0 and 40.0 J / g (this latter value being excluded).

[0158] Hm can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.

[0159] Hm can more particularly be measured the method described in the Experimental Section.

[0160] Hm can be measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418 using a heating and cooling rate of 20°C / min. Three scans were used for each DSC test: a first heat up to 350°C, followed by a first cool down to 0°C, followed by a second heat up to 360°C.

[0161] Process of preparation of polyamide (PA)

[0162] The polyamide (PA) described herein is prepared by polycondensation, notably by heating a reaction mixture (RM) comprising all the monomers that constitute the polyamide (PA) [e.g. 1,6-hexanediamine, DI and D2, terephthalic acid and optionally DI], preferably in the presence of less than 60 wt.% of water, preferentially less than 30 wt.%, less than 20 wt.%, less than 10 wt.%, preferentially with no added water. This proportion is given based on the total weight of the reaction mixture (RM).

[0163] The temperature at which the reaction mixture (RM) 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 reaction mixture. This temperature is generally at least 200°C. The reaction mixture (RM) is preferably heated at a temperature > Tm + 25°C. The polycondensation results in the formation of the amide bonds and the release of water as a by-product.

[0164] The reaction mixture (RM) comprises all the diamines of the diamine component (A) and all the dicarboxylic acid(s) of the dicarboxylic acid component (B). As detailed above, the proportions of the two components is such that the reaction mixturecomprises the monomers in a quantity such that the proportion of -COOH groups from the monomers and the proportion of -NH2 groups from the monomers are substantially equimolar. The molar ratio -NH2 from the monomers / -COOH from the monomers is preferably between 0.9 and 1.1, preferentially between 0.95 and 1.05, even more preferentially between 0.98 and 1.02.

[0165] The reaction mixture (RM) preferably further comprises a catalyst. The catalyst may be selected in the group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, phenylphosphonic acid, phenylphosphinic acid, salts of said acids with mono- to trivalent cations and esters of said acids. The cations may for example be Na, K, Mg, Ca, Zn or Al. Examples of esters are triphenyl phosphate, triphenyl phosphite and tris(nonylphenyl) phosphite. A convenient catalyst used is phosphorous acid.

[0166] The proportion of the catalyst in the reaction mixture (RM) is preferably between 0.005 and 2.5 wt% based on the weight of the monomers in the reaction mixture.

[0167] According to an embodiment of the present disclosure, the reaction mixture (RM) comprises or consists of:- the monomers that constitute the polyamide (PA), as disclosed herein;- optionally a catalyst, notably selected in the group consisting of phosphorous acid, ortho-phosphoric acid, meta-phosphoric acid, alkali-metal hypophosphite, such as sodium hypophosphite and phenylphosphinic acid, and combination thereof;- optionally at least one end-capping agent selected in the group of monocarboxylic acids, primary amines and combination thereof;- water, the proportion of which is less than 60 wt.% of water, preferably less than 30 wt.%, preferably less than 20 wt.%, preferably less than 10 wt.%, this proportion is given based on the total weight of the reaction mixture (RM). According to an embodiment, there is no added water at the beginning of the polycondensation.

[0168] For control of the molar mass, it is possible to use at least one chain transfer agent, preferably selected from Ci-Cis monocarboxylic acids and C3-C18 monoamines. The chain transfer 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, butylamine, pentylamine, hexylamine, 2-ethylhexylamine, n-octylamine, n-dodecylamine, n- tetradecylamine, n-hexadecylamine, stearylamine, cyclohexylamine and mixtures thereof.

[0169] The polycondensation is advantageously performed in a well-stirred vessel equipped with means to remove the volatile products of the reaction. As the viscosity of the reaction mixture increases over time, the stirrer is adapted to provide sufficient stirring to the reaction mixture (RM) at the beginning of the polymerization and when the conversion of the polycondensation is nearly complete.

[0170] The conditions disclosed in the experimental section may conveniently be used for the preparation of the polyamide (PA) which is defined herein.[EXPERIMENTAL SECTION]

[0171] Raw materials used for the preparation of the polyamides

[0172] The following raw materials were used to prepare the polymer samples:Table I

[0173] Thermal properties

[0174] Tg, Tm and Hm were measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418 using a heating and cooling rate of 20°C / min. Three scans were used for each DSC test: a first heat up to 350°C, followed by a first cool down to 0°C, followed by a second heat up to 360 °C. The Tg, Tm and Hm were determined from the second heat up. The Tc was determined from the cool down.

[0175] Inherent viscosity (IV)

[0176] The inherent viscosity (IV) is measured according to ASTM D5336 in a mixture 60 wt% phenol - 40 wt% tetrachloroethane.

[0177] Biocontent

[0178] Determined according to ASTM D6866-22.

[0179] Preparation of the conolvamides

[0180] All of the copolyamides disclosed in Table II were prepared in an autoclave reactor equipped with a distillate line fitted with a pressure control valve.

[0181] All copolyamides were prepared by charging into the reactor the monomers with the proportions targeted, water and phosphorous acid and by following the procedure given below in Example 1.

[0182] Example 1 (El): the polyamide El was prepared by charging into the reactor 1.77 g of 1,6-diaminohexane, 2.05 g of 1,10-diaminodecane, 0.96 g of 1,3-cyclohexane- bis(methylamine), 5.32 g of terephthalic acid, 4.98 g of deionized water, and 0.0033 g of phosphorous acid. The reactor was sealed, purged with N2 gas three times. The reactor was heated to 177 °C and held for 30 min, followed by heating to 232 °C and holding for 30 min, followed by heating to 288 °C and holding for 30 min, followed by heating to 343 °C and holding for 35 min. The steam generated was slowly released to keep the internal pressure under 200 psig. Once the temperature was at 343 °C for 35 min, the reactor pressure was slowly reduced to atmospheric pressure over 25 min. After finishing the depressurization, N2 gas was used to continuously purge the reactor over 25 min. Afterwards, the reactor was cooled to room temperature and the polymer was retrieved from the reactor.

[0183] Preparation of a film of polyamide (El)

[0184] Pellets of the different materials were processed into films with a thickness of -200 pm and a width of 4 inches using a single screw OCS extruder (Optical Control System, GmbH). The extruder employed a single-stage, non-vented screw with a diameter of 20 mm and an L / D ratio of 30. The extruder barrel comprised four heated sections, which were sequentially operated from rear to front at temperature settings (Zl / Z2 / Z3 / Adapter) of 300 / 310 / 312 / 315°C for PA9T and 323 / 326 / 326 / 340°C for El. Simultaneously, the film die maintained a temperature of 330°C for PA9T and 350°C for El. The film was drawn and formed on two chill rolls, set at 125°C for PA9T and 130°C for El on the 1stchiller, and at 110°C for PA9T and 125°C for PPA on the 2ndchiller. The chiller rolls were used to control the rate of crystallization. The throughput rate of the film and compound was determined by a take-up rate of -1.5 m / min, while the extruder operated at a screw speed of -30 rpm based on the film thickness.

[0185] As can be seen with the results of Table II, the specific proportions of the monomers makes it possible to have a balance of properties, notably a high Tg and a Tm < 295°C.

[0186] Moreover, the polyamide of the invention exhibits significantly high elongation at break and notched impact. It also exhibits improved notched impact.Table IICE9 corresponds to E5 in EP 4276136 (D2); CE10 corresponds to El in EP 4276136 (D2)

[0187] Melt stability: this test determines the change in viscosity of a plastic as a function of time (Txstands for the viscosity at x min). Testing was performed in accordance with ASTM D3855 on polyamide having been dried. Apparatus used: Dynisco LCR 7000 Capillary Rheometer.Table III: melt stability measurement at Tm+20°CTable IV: melt stability measurement at 350°C

[0188] As can be seen, the polyamide used for the invention makes it possible to have better melt stability which is needed for extrusion and for the preparation of a film.

[0189] Improved melt flow: this test was performed in accordance with ASTM D1238 method A with a load of 2.16 kg. Apparatus used: Zwick / Roell Mflow 738827.Table V: melt flow

[0190] As can be seen, the polyamide used for the invention is characterized by a better flowability than the other polyamide (for substantially the same IV) which is needed for the extrusion and preparation of a film.

[0191] Dielectric properties: this test was performed at room temperature, with AC voltage.It was performed in oil with a 1" cylindrical flat face electrode, accordance with ASTM D149.Table VI: dielectric properties for dried filmsTable VII: dielectric properties for films after humidity exposure [films were conditions in a Memmert humidity chamber at 85°C, 85% relative humidity for 340 hours]

[0192] As can be seen, the polyamide used for the invention is characterized by a better dielectric strength than the other polyamide and by a better stability of the dielectric strength in humid conditions.

[0193] As a summary, the polyamide of the invention and a composition comprising it are well suited to be well extruded in the form of a thin material having a combination of properties (thermal resistance, dielectric strength even after exposure to humidity).

Claims

CLAIMSClaim 1. Use of a polymer composition (PC) comprising at least one semi -aromatic polyamide (PA), the proportion of polyamide(s) (PA) being notably at least 30.0 wt%, for the preparation of an electrical insulation polymeric article, wherein polyamide (PA) is a semi-aromatic copolyamide (PA) exhibiting:- a melting temperature (Tm) between 250°C and 295°C, this latter value being excluded (< 295°C);- a glass transition temperature (Tg) of at least 135.0°C, preferably at least 140°C;Tm and Tg being measured by DSC according to ASTM D3418; and comprising at least 90.0 mol%, preferably at least 95.0 mol%, preferably at least 99.0 mol% of recurring units (RPA) formed from the polycondensation of a diamine component (A) and a dicarboxylic acid component (B) wherein: a) the diamine component (A) consists of: between 15.0 and 54.0 mol% of 1,6-diaminohexane;- between 15.0 and 40.0 mol% of a diamine (DI) selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;- between 15.0 and 64.0 mol% of a diamine (D2) selected in the group consisting of l,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,4- bis(aminomethyl)cyclohexane (1,4-BAC) and a combination of said two diamines; b) the dicarboxylic acid component (B) consists of:- between 90.0 mol% and 100 mol% of terephthalic acid;- between 0 and 10.0 mol% of at least one dicarboxylic acid (DI) selected in the group consisting of isophthalic acid, dicarboxylic acids of formula HOOC-(CH2)X-COOH where x is an integer from 5 to 16 and combination thereof; these proportions in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B).Claim 2. Use according to claim 1, wherein the article is in the form of a film (F) or in the form of a layer (1) in an electrical device, the thickness of the film (F) or layer (1) being notably lower than or equal to 750 pm or between 20 and 500 pm.Claim 3. Use according to claim 1 or 2, wherein film (F) is (i) a monolayer film or (ii) a multilayer film comprising at least one layer comprising or made of polymer composition (C) and at least one additional layer, notably made of or comprising a polymer which is not a polyamide (PA).Claim 4. Use according to any one of the preceding claims, wherein the electrical insulation polymeric article is:- a slot liner; or- a slot wedge; or- an electrically-insulating film of a power electronic system, such as an inverter, a converter or an on-board charger; or- an electrically-insulating component of a transformer.Claim 5. Use according to any one of the preceding claims, wherein the recurring units of polyamide (PA) consist of recurring units (RPA) or the proportion of recurring units (RPA) is at least 99.0 mol%.Claim 6. Use according to any one of the preceding claims, wherein polyamide (PA) is a 6T / 10T / BACT or 6T / 9T / BACT, where BAC designates 1,3-BAC and / or 1,4-BAC, preferably 1,3-BAC.Claim 7. Use according to any one of the preceding claims, wherein the ranges of the proportions of the components of the diamine component (a) are provided in any one of the embodiment (Emb l)-(Emb 11) described below:Claim 8. Use according to any one of the preceding claims, wherein the proportion of dicarboxylic acid(s) (DI) in dicarboxylic acid component (B) is between 0 and 5.0 mol% and / or wherein the dicarboxylic acid component (B) consists of terephthalic acid or of terephthalic acid and isophthalic acid.Claim 9. Use according to any one of the preceding claims, wherein the recurring units of polyamide (PA) consist essentially or consist of recurring units (RPA).Claim 10. Use according to any one of the preceding claims, wherein the polyamide (PA) is free of free of recurring units derived from a lactam and / or from an aminoacid.Claim 11. Use according to any one of the preceding claims, wherein polyamide (PA) comprises the following recurring units (RPAI) + (RPA?) + [(RpA3a) and / or (RpA3b)] :(RPA2); and(RpA3b) or the following recurring units (RPAI), (RPA?) and (RpA3a):(RpA3a) where Ri is hexamethylene -(CH2)e- and R2 is the divalent radical of a diamine selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines. For clarity, the divalent radical of 1,9-diaminononane is -(CH2)9- and the divalent radical of 1,10-diaminodecane is -(CH2)IO-.Claim 12. Use according to claim 11, wherein the recurring units of polyamide (PA) consist essentially or consist of recurring units (RPAI) + (RPA?) + [(RpA3a) and / or (RpA3b)].Claim 13. Use according to claim 11 or 12, wherein the proportions of recurring units are the following: from 15.0 to 54.0 mol% for RPAI; from 15.0 to 40.0 mol% for RPA2; from 15.0 to 64.0 mol% for RpA3a and / or RpA3b. or are provided in the following table:Claim 14. Use according to any one of the preceding claims, wherein the number average molecular weight ("Mn") ranges from 8,000 g / mol to 40,000 g / mol, more particularly from 10,000 and 20,000 g / mol, more particularly between 13,000 and 16,000 g / mol, Mn being determined by size exclusion chromatography (SEC) with polystyrene standards or by using the following equation (1): Mn = 2,000,000 / [EG] (1) wherein [EG] is the proportion of end- groups in the polyamide (PA) expressed in mmol / kg.Claim 15. Use according to any one of the preceding claims, wherein polyamide (PA) exhibits an inherent viscosity ("IV") measured according to ASTM D5336 between 0.80 and 1.50 dL / g, more particularly between 0.85 and 1.30 dL / g, more particularly between 0.90 and 1.20 dL / g, IV being measured conveniently in a 60 wt% / 40 wt% phenol / tetrachloroethane mixture.Claim 16. Use according to any one of the preceding claims, wherein the end-groups in polyamide (PA) are selected in the group of-NEh, -COOH and amide end-groups.Claim 17. Use according to any one of the preceding claims, wherein polyamide (PA) exhibits a water uptake at 23°C lower than 5.0 wt%, water uptake at 23°C being determined by (i) providing a specimen shaped according to ISO527 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 k 100whereinWbefore is the weight of the shaped specimen in its original dry state and Waiter is the weight of the shaped specimen after water uptake.Claim 18. Use according to any one of the preceding claims, wherein polyamide (PA) exhibits a bio content of at least 10.0%, preferably at least 15.0%, the biocontent being expressed as the % of organic carbon of renewable origin determined according to ASTM D6866-22.Claim 19. Use according to any one of the preceding claims, wherein polyamide (PA) exhibits a crystallization temperature (Tc) lower than or equal to 225 °C, preferably lower than or equal to 220°C, Tc being notably measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.Claim 20. Use according to any one of the preceding claims, wherein polyamide (PA) exhibits a difference (Tm - Tc) of at least 50.0°C, preferably of at least 55.0°C, preferably at least 60.0°C., Tm and Tc being notably measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.Claim 21. Use according to any one of the preceding claims, wherein polyamide (PA) exhibits a heat of fusion Hm of at least 15.0 J / g, preferably at least 20.0 J / g, preferably at least 25.0 J / g, preferably at least 27.0 J / g, Hm being notably measured by Differential Scanning Calorimetry (“DSC”) according to ASTM D3418, notably using a heating and cooling rate of 20°C / min.Claim 22. Use according to any one of the preceding claims, wherein polymer composition (PC) comprises or consists of:- at least 30.0 wt% of at least one polyamide (PA);- a component (c) blended with polyamide(s) (PA) and selected in the group consisting of fillers (Fi), plastic additives (Add), polyamides (PA*) and combinations of two or more of said components, where polyamide (PA*) is a polyamide having a composition of monomers distinct from the composition of polyamide (PA).Claim 23. Use according to any one of the preceding claims, wherein polymer composition (PC) comprises or consists of:- at least 30.0 wt% of at least one polyamide (PA);- at least one filler (Fi);- optionally at least one additive (Add); where polyamide (PA), the particulate filler (Fi) and optional additive (Add) form a blend.Claim 24. Use according to any one of claims 1-23, wherein:- the proportion of polyamide(s) (PA) in polymer composition (PC) is at least 50.0 wt% or at least 75.0 wt%; and / or- the proportion of component (c) or the total proportion (Fi)+(Add) in polymer composition (PC) is typically at most 70.0 wt%.Claim 25. Use according to any one of claims 22-24, wherein filler (Fi) is selected from talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium carbonate, silica, alumina, glass fibers, carbon fibers, synthetic polymeric fibers, aramid fibers, aluminum fibers, titanium fibers, magnesium fibers, boron carbide fibers, rock wool fibers, steel fibers, wollastonite and combination thereof or filler (Fi) is glass fibers and / or carbon fibers.Claim 26. Use according to any one of claims 22-25, wherein the proportion of plastic additive(s) (Add) is between 0.01 and 60.0 wt%.Claim 27. Method for preparing an electrical insulation polymeric article (i) by injection molding a polymer composition (PC) or (ii) by extruding polymer composition (PC) in the form of a film (F), the polymer composition (PC) comprising at least one semi-aromatic polyamide (PA), the proportion of polyamide(s) (PA) being notably at least 30.0 wt%, whereinpolyamide (PA) is a semi-aromatic copolyamide (PA) exhibiting a melting temperature (Tm) between 250°C and 295°C, this latter value being excluded (< 295°C), a glass transition temperature (Tg) of at least 135.0°C, preferably at least 140°C, Tm and Tg being measured by DSC according to ASTM D3418, and comprising at least 90.0 mol%, preferably at least 95.0 mol%, preferably at least 99.0 mol% of recurring units (RPA) formed from the polycondensation of a diamine component (A) and a dicarboxylic acid component (B) wherein: a) the diamine component (A) consists of: between 15.0 and 54.0 mol% of 1,6-diaminohexane;- between 15.0 and 40.0 mol% of a diamine (DI) selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;- between 15.0 and 64.0 mol% of a diamine (D2) selected in the group consisting of l,3-bis(aminomethyl)cyclohexane, 1,4- bis(aminomethyl)cyclohexane and a combination of said two diamines; b) the dicarboxylic acid component (B) consists of:- between 90.0 mol% and 100 mol% of terephthalic acid;- between 0 and 10.0 mol% of another dicarboxylic acid (DI) selected in the group consisting of isophthalic acid, dicarboxylic acids of formula HOOC-(CH2)X-COOH where x is an integer from 5 to 16 and combination thereof; these proportions in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B); the electrical insulation polymeric article having notably a thickness lower than or equal to 750 pm or between 20 and 500 pm.Claim 28. Method according to claim 27, where polyamide (PA) is as defined claims 5-21 or any one of claims 5-21.Claim 29. Method according to claim 27 or 28, wherein:- the article is as defined in claims 2-4 or any one of claims 2-4; and / or- the polymer composition is as defined in claims 22-26 or any one of claims 22-26.Claim 30. Electrical device comprising at least one electrical insulation polymeric article made of or comprising a polymer composition (PC) which comprises at least one semi-aromatic polyamide (PA), the proportion of polyamide(s) (PA) being notably at least 30.0 wt%, wherein polyamide (PA) is a semi-aromatic copolyamide (PA) exhibiting a melting temperature (Tm) between 250°C and 295°C, this latter value being excluded (< 295°C), a glass transition temperature (Tg) of at least 135.0°C, preferably at least 140°C, Tm and Tg being measured by DSC according to ASTM D3418, and comprising at least 90.0 mol%, preferably at least 95.0 mol%, preferably at least 99.0 mol% of recurring units (RPA) formed from the polycondensation of a diamine component (A) and a dicarboxylic acid component (B) wherein: a) the diamine component (A) consists of: between 15.0 and 54.0 mol% of 1,6-diaminohexane;- between 15.0 and 40.0 mol% of a diamine (DI) selected in the group consisting of 1,9-diaminononane, 1,10-diaminodecane and a combination of said two diamines;- between 15.0 and 64.0 mol% of a diamine (D2) selected in the group consisting of l,3-bis(aminomethyl)cyclohexane, 1,4- bis(aminomethyl)cyclohexane and a combination of said two diamines; b) the dicarboxylic acid component (B) consists of:- between 90.0 mol% and 100 mol% of terephthalic acid;- between 0 and 10.0 mol% of another dicarboxylic acid (DI) selected in the group consisting of isophthalic acid, dicarboxylic acids of formula HOOC-(CH2)X-COOH where x is an integer from 5 to 16 and combination thereof; these proportions in mol% being based on the total amount of dicarboxylic acids in the dicarboxylic acid component (B); the electrical insulation polymeric article having notably a thickness lower than or equal to 750 pm or between 20 and 500 pm.Claim 31. Electrical device according to claim 30, wherein polyamide (PA) is as defined in claims 5-21 or any one of claims 5-21.Claim 32. Electrical device according to claim 30 or 31, wherein the polymer composition is as defined in claims 22-26 or any one of claims 22-26.Claim 33. Electrical device according to any one of claims 30-32, where the electrical device is: a stator of a motor or of a generator comprising at least one slot liner comprising or made of the polymer composition (PC), notably as defined in claims 22-26 or any one of claims 22-26; or a stator of a motor or of a generator comprising at least one slot wedge comprising or made of the polymer composition (PC), notably as defined in claims 22-26 or any one of claims 22-26; or a conductor comprising an electrical conductor and at least one layer around the conductor comprising or made of the polymer composition (PC), notably as defined in claims 22-26 or any one of claims 22-26; or a busbar comprising at least one layer comprising or made of the polymer composition (PC), notably as defined in claims 22-26 or any one of claims 22-26, the function of the layer being to isolate the busbar from surrounding conductive surfaces; or a transformer comprising one or more electrically-insulating component made of or comprising the polymer composition (PC), notably as defined in claims 22-26 or any one of claims 22-26; or a cooling plate comprising one or more electrically-insulating coating made of or comprising the polymer composition (PC), notably as defined in claims 22-26 or any one of claims 22-26.

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