Thermoplastic polymer composition, its preparation process and vibration damping device incorporating it.

Abstract

The invention relates to a thermoplastic polymer composition based on at least one propylene polymer, and a device for a motor vehicle, particularly an electric one, capable of damping vibrations at frequencies of 1-3000 Hz and at average temperatures of 10-50°C. The composition (I1, I2) comprises, by mass fractions: 50-70% of a non-elastomeric polymer matrix, the matrix being based on at least one propylene polymer selected from among propylene homopolymers and copolymers; 20-45% of a reinforcing filler comprising a fibrous filler; and 2-18% of a plasticizing system comprising at least one aliphatic, alicyclic, or aromatic hydrocarbon resin having a glass transition temperature (Tg) equal to or greater than 20°C. Fig. 3

Description

Title of the invention: Thermoplastic polymeric composition, its preparation process and vibration damping device incorporating it. technical field

[0001] The invention relates to a thermoplastic polymer composition based on at least one propylene polymer, and a device for a motor vehicle, in particular an electric vehicle, capable of damping vibrations at frequencies of 1-3000 Hz and at average temperatures of 10-50° C. The invention applies in particular to any structural part transmitting vibrations and to any anti-vibration support of an electric motor vehicle (e.g. calipers, engine mounts and air conditioning compressor mounts, by way of non-limitation), and also of any other vehicle, for example aircraft or spacecraft, in all or part of the aforementioned frequency and average temperature ranges. Previous technique

[0002] As is known, brake caliper bodies and engine support arms for motor vehicles are made of a metallic material, for example, aluminum or magnesium-based. These metallic structural parts generally exhibit satisfactory mechanical properties, but have the disadvantage of being relatively heavy and providing poor vibration damping during driving, particularly at frequencies ranging from 1 to 3000 Hz and at temperatures below or equal to 90°C.

[0003] EP 3 831 885 Al in the name of the Applicant relates to a thermoplastic polymer composition comprising polyamides, including an aliphatic polyamide (PA), a polyphthalamide (PPA), and a reinforcing filler comprising glass fibers. The composition exhibits, after wet conditioning "RH50", maximum tan delta values ​​according to ISO 6721-5 between 60-90°C and 1-3000 Hz.

[0004] One disadvantage of currently available thermoplastic polymer compositions based on glass fiber-reinforced polyamides is that they do not exhibit satisfactory damping characteristics between 1 and 3000 Hz at temperatures below 50°C, conditions which characterize structural parts transmitting vibrations and anti-vibration mounts in electric motor vehicles.

[0005] US 2022 / 195250 A1 relates to a damping material and a damping sheet made from it, for example in the automotive or electrical appliance industry. The damping material comprises by weight: 10-50% of a block copolymer elastomer, such as a styrene block elastomer, 5-40% of a specific length fiber, for example glass or carbon, 5-45% of a non-elastomeric thermoplastic polymer, such as PE, PS or PLA, 5-50% of a tackifying agent, such as a C5, C9 or terpene cutting resin, 0-50% of an inorganic filler, such as mica or talc, and 0-30% of a flame retardant.

[0006] A major drawback of the thermoplastic polymer composition presented in US 2022 / 195250 Al lies in the use in its polymer matrix of a high amount of styrene block thermoplastic elastomer in addition to the non-elastomer thermoplastic polymer, because this thermoplastic elastomer has a very low glass transition temperature Tg, generating problems of use at room temperature and is also likely to generate mixing problems with an olefinic thermoplastic polymer. Description of the invention

[0007] An object of the invention is to propose a high mechanical and anti-vibration thermoplastic polymer composition which remedies in particular the aforementioned disadvantages by presenting satisfactory mechanical properties and improved damping at the frequencies and temperatures characterizing the stresses applied to a structural part transmitting vibrations or to an anti-vibration support in an electric motor vehicle, in particular.

[0008] This goal is achieved in that the Applicant has just discovered unexpectedly during its research that, if a non-elastomeric polymeric matrix comprising a propylene polymer and a hydrocarbon plasticizing resin with a Tg of 20°C or greater is combined with a fibrous reinforcing filler, then, compared to a control composition consisting of an aliphatic polyamide (e.g. PA 6) reinforced with glass fibers, damping quantified by a loss factor (measured by dynamic mechanical analysis both dry and after conditioning in a humid atmosphere of type RH50) can be obtained which is significantly improved at frequencies of 1-3000 Hz and at average temperatures of 10-50°C, and static mechanical properties (measured both at 23°C and at 60°C) which are generally preserved.

[0009] Thus, a thermoplastic polymeric composition according to the invention is suitable for damping vibrations at frequencies of 1-3000 Hz and average temperatures of 10-50°C, and it comprises, in mass fractions: 50-70% of a non-elastomeric polymeric matrix, the matrix being based on at least one propylene polymer chosen from among propylene homopolymers and copolymers, 20-45% of a reinforcing filler comprising a fibrous filler, and 2-18% of a plasticizing system comprising at least one aliphatic, alicyclic or aromatic hydrocarbon resin having a glass transition temperature Tg equal to or greater than 20°C.

[0010] It should be noted that a composition thus defined can be used to form all or part of a vibration damping device for an electric motor vehicle, such as a structural part transmitting vibrations or an anti-vibration support damping vibrations between two rigid elements and supporting a load (e.g., a connecting support linking the motor to the vehicle body), as a partial or total replacement of the metal parts conventionally used for such a device which have a high weight and insufficient vibration damping at the aforementioned frequencies and temperatures. Detailed description Non-elastomeric polymer matrix

[0011] In the present description, the expression "based on" means that the matrix comprises predominantly by weight the constituent concerned, i.e. by a mass fraction greater than 50%, preferably equal to or greater than 75% and which may go up to 100%.

[0012] By "non-elastomeric polymer matrix," it is understood here that a composition according to the invention is completely devoid of elastomer, i.e., is free of any thermoplastic elastomer and any rubber. Thus, the polymer matrix of a composition according to the invention may consist of one or more non-elastomeric thermoplastic polymers.

[0013] According to another general feature of the invention, said at least one propylene polymer may be included in said matrix in a mass fraction of 75-100% in the matrix and may be: - a virgin homopolymer of propylene selected from isotactic polypropylenes, - a virgin interpolymer of propylene and an alpha-olefin other than propylene (e.g., butylene or hexene), for example, a polypropylene copolymer (PPC), or - a recycled homopolymer or copolymer of propylene derived from a post-industrial (PIR) or post-consumer (PCR) type recycled polyolefin material.

[0014] According to a first embodiment of the invention which can complement the previous feature, said matrix is ​​made up of said at least one polymer of propylene, preferably being made up of said virgin homopolymer of propylene or of said recycled homopolymer or copolymer of propylene.

[0015] According to a second embodiment of the invention as a variant of said first embodiment, said matrix comprises at least one other non-propylene thermoplastic polymer in a mass fraction in the matrix of 5-40% (preferably 10-25%), which is selected from: - vinyl acetate (EVA) polymers optionally coupled with a compatibilizing agent, - poly(butylene terephthalate) (PBT) coupled with a compatibilizing agent, and - Aliphatic polyamides, in particular selected from PA 6, PA 11 and PA 12 and coupled with a compatibilizing agent, the compatibilizing agent, of polymeric type, comprising for example a maleic anhydride grafted polypropylene.

[0016] According to another general feature of the invention, said matrix of the composition is devoid of polyphthalamide (PPA). Reinforcing load

[0017] By "reinforcing filler" in the present description means one or more individual filler(s) of reinforcing grade for said polymeric matrix, which is / are dispersed homogeneously in the composition.

[0018] The reinforcing load according to the invention comprises: - a fibrous (i.e., fibrillar) filler, which may include organic or mineral fibers, continuous or discontinuous, for example selected from discontinuous carbon, glass, aramid fibers and mixtures thereof, and - optionally in addition non-fibrous fillers, preferably inorganic fillers such as lamellar or non-lamellar fillers.

[0019] Preferably, the fibrous filler consists entirely or partly of discontinuous glass fibers.

[0020] In the present description, "glass fibers" means short glass fibers of length and diameter of 1-8 mm and 5-15 pm respectively (preferably 2-6 mm in length and 8-12 pm in diameter), which are provided with a sizing suitable for at least one propylene polymer.

[0021] In the present description, "non-fibrous inorganic fillers of lamellar type" means a mineral filler having a lamellar structure, as opposed to non-lamellar inorganic fillers such as silicas and chalks, for example.

[0022] More particularly, this refers to an inorganic filler with lamellae having an aspect ratio greater than 10, preferably greater than 20, it being specified that the "aspect ratio" refers, in a known manner, to the ratio of the largest average dimension (usually width or length) to the smallest average dimension (usually thickness) characterizing lamellae of the lamellar inorganic load. This average ratio can be measured by scanning electron microscopy (SEM).

[0023] Advantageously, the lamellar inorganic filler can be chosen from phyllosilicates and talcs.

[0024] The term "phyllosilicate" is understood to mean, in a known manner, a subgroup of the silicate group, phyllosilicates being constructed by stacking tetrahedral layers ("T") where the tetrahedra share three out of four vertices (the "basal" oxygens), the fourth vertex (the "apical" oxygen) being connected to an octahedral layer ("O") occupied by different cations. Examples of suitable phyllosilicates include smectites, kaolinite and kaolins, micas, vermiculites, and montmorillonites.

[0025] Also known is: - by "kaolinite", a phyllosilicate mineral species composed of hydrated aluminum silicate, with the formula Al2Si2O5(OH)4; - by "mica", a mineral group within phyllosilicates primarily based on aluminum and potassium silicate; and - by "talc", a mineral species essentially composed of doubly hydroxylated magnesium silicate with the formula Mg3Si4Oi0(OH)2.

[0026] According to another general feature of the invention, the reinforcing filler may comprise, in mass fractions in the composition: 20-40% of said fibrous filler, preferably discontinuous glass fibers, 0-13% of a non-fibrous inorganic filler of lamellar type, for example selected from phyllosilicates and talcs, and 0-12% of a non-fibrous and non-lamellar inorganic filler, for example chosen from calcium carbonates.

[0027] According to a preferred embodiment of the invention, the reinforcing filler consists, in mass fractions in the composition: of 25-35% of said glass fibers, and of 0-15% of talc and / or chalk. Plasticizing system

[0028] According to another general feature of the invention, the plasticizing system preferably comprises, as a mass fraction in the composition: 5-15% of said at least one hydrocarbon resin which is specifically aliphatic or alicyclic and has a glass transition temperature (Tg) inclusively between 25 and 50°C, said at least one hydrocarbon resin being for example an alicyclic hydrogenated resin with a glass transition temperature Tg of 30-45° C and a number-average molecular mass Mn of 480-600 g / mol.

[0029] According to another general feature of the invention which may complement the previous one and which defines a first embodiment of the invention, the plasticizing system may further comprise, in mass fraction in the composition: 3-13% (for example 5-10%) of at least one other aliphatic or alicyclic hydrocarbon resin having a glass transition temperature Tg less than or equal to 0°C, preferably comprising at least one amorphous aliphatic or alicyclic polyolefin having a glass transition temperature Tg inclusively between -45 and -10°C and a Brookfield viscosity in the melt state at 190°C inclusively between 1.0 and 4.0 Pa.s, measured according to ASTM D 3236, said at least one other hydrocarbon resin being, for example, an amorphous homopolymer of propylene or an amorphous ethylene-propylene copolymer, or an amorphous mixture of aliphatic polyolefins, for example, of an amorphous homopolymer of propylene and an amorphous ethylene-propylene copolymer. .

[0030] In variant of said first mode of the invention, according to another general characteristic defining a second mode of the invention, the plasticizing system may further comprise, in mass fraction in the composition: 3-13% (for example 5-10%) of at least one other specifically aromatic hydrocarbon resin having a glass transition temperature Tg inclusive between 30 and 45°C, preferably an aromatic polyolefin selected from the homopolymers and copolymers of styrene.

[0031] The glass transition temperatures Tg of the hydrocarbon resins of the plasticizing system are measured, for example, by the technique of differential scanning calorimetry (“DSC” for “Differential Scanning Calorimetry” in English).

[0032] According to another general feature of the invention which may complement any one of the aforementioned features, the composition preferably comprises, in mass fractions: 55-65% of said matrix, which comprises said at least one propylene polymer in a mass fraction in said matrix of 75-100%, and 25-40% of said reinforcing filler, which comprises said fibrous filler in a mass fraction in the reinforcing filler of 75-100%. 5-15% of said plasticizing system, which comprises said at least one aliphatic, alicyclic or aromatic hydrocarbon resin in a mass fraction in the plasticizing system of 40-100% (for example 60-90%).

[0033] Properties, preparation and applications of compositions according to the invention

[0034] According to another general feature of the invention which may complement any one of the aforementioned features, said composition may exhibit, after conditioning in air at 50% relative humidity (RH50), tan delta values, measured by dynamic mechanical analysis (“DMA”) according to ISO 6721-5 on rectangular specimens 34.81 mm long, 4 mm wide and 2 mm thick, by sweeps at frequencies ranging from 0.1 Hz to 20 Hz and with a strain amplitude of 2.5 pm, in 5°C increments over a temperature range from Tg - 60°C to Tg + 60°C, these tan delta values, obtained by the time-temperature superposition principle, being maximum at a temperature between 20°C and 50°C in a frequency range from 1 Hz to 3000 Hz, and satisfying one of the less the following conditions (i), (ii), (iii), for at least one frequency inclusively between 1 Hz and 3000 Hz: (i) at 20° C: tan delta > 2.50%, advantageously tan delta > 4.00%, (ii) at 30° C: tan delta > 4.00%, advantageously tan delta > 5.00%, (iii) at 40° C: tan delta > 4.50%, advantageously tan delta > 6.00%.

[0035] According to another general feature of the invention which may complement any of the aforementioned features, the composition may exhibit, at 60°C after humid conditioning in air at 50% relative humidity, a Young's modulus measured according to ISO 527 which is advantageously greater than 2.5 GPa and preferably greater than 3.5 GPa.

[0036] A composition according to the invention may comprise the product of a melt mixture of said matrix, said reinforcing filler and said plasticizing system, preferably by extrusion.

[0037] A dynamic function device according to the invention is adapted to equip a motor vehicle, aircraft or space vehicle, the device being capable of damping vibrations in a frequency range of 1 to 3000 Hz and average temperatures of 10 to 50° C seen by the device within the vehicle, the device comprising a composition as defined above which is injection molded and is optionally attached to a metallic insert, for example threaded (the possible metallic insert being a minority by mass in the device compared to the molded composition whose mass fraction in the device can thus vary from 80% to 100%, for example).

[0038] Advantageously, said device may be suitable for equipping an electric motor vehicle, and this device may be selected from structural parts that transmit vibrations (e.g., parts adapted to be connected to the vehicle's wheels so as to receive the vibrations) and anti-vibration mounts that combine first and second rigid elements by damping vibrations between each other and in supporting a load, the anti-vibration support is preferably a linking support connecting the engine to an element of the vehicle structure, such as a side member of its body.

[0039] This device according to the invention is advantageously chosen, for example, from among calipers, engine mounts and air conditioning compressor mounts for an electric motor vehicle.

[0040] As indicated above, a device according to the invention could be used in any other motor vehicle, for example, an aircraft or spacecraft. Measurement methods

[0041] As indicated in general terms above and in relation to the embodiment examples presented below, the polymeric compositions obtained (both the non-conforming compositions of the invention and the compositions according to the invention), after conditioning in air at 50% relative humidity (RH50), were characterized by tan delta values ​​measured by dynamic mechanical analysis (“DMA” for “Dynamic Mechanical Analysis”).

[0042] The air conditioning at 50% relative humidity (RH50 conditioning), which was used prior to characterizing the compositions by "DMA", followed a protocol derived from ISO 1110 and defined by the Applicant by implementing the following four steps, for H2 test specimens: - weighing of H2 test specimens after their injection molding (mass in the dry state); - partial saturation of H2 test tubes in a climatic chamber for 72 hours at 50°C and 95% humidity, then weighing; - storage of the H2 test tubes at 23°C and RH50, and weighing every 24 hours until their mass stabilizes (mass variation less than 0.1% from one day to the next); then - calculation of the percentage of water reabsorption by comparing the mass of each H2 stabilized test specimen to the mass of each dry test specimen.

[0043] The compositions obtained by "DMA" were also characterized in the dry state, it being specified that the Applicant carried out the dry conditioning of the H2 test tubes by implementing the following three steps: - weighing of H2 test specimens after their injection molding (mass in the dry state), - vacuum heat sealing of H2 test specimens to prevent their reabsorption of water, and - weighing of H2 test specimens before the "DMA" analysis, to ensure that they have not reabsorbed water.

[0044] The “DMA” measurement protocol followed in this description to obtain the tan delta (i.e., tangent θ) values ​​used a “3-point fixed support” (“Dual Cantilever” in English) mounting according to ISO 6721-5:1996, revised in 2019 (bending vibrations – non-resonant method), based on the general principles set out in ISO 6721-1. This measurement protocol implements frequency sweeps with the strain amplitude on said rectangular specimens (34.81 mm long, 4 mm wide and 2 mm thick) over said temperature range relative to the glass transition temperature Tg of each composition obtained. The Tg of each composition obtained by this same "DMA" technique with "3-point embedding" was measured using said rectangular specimens by temperature sweeps at 2.5 pm of deformation, at a frequency f of 1 Hz and following a ramp of 3° C per minute. The time-temperature superposition (TTS) principle was then used to construct master curves covering the frequency range of interest from 1 to 3000 Hz at the desired temperatures. A brief description of the diagrams follows.

[0045] Other features, advantages and details of the present invention will become apparent from the following description of several exemplary embodiments of the invention, given by way of illustration and not limitation in relation to the accompanying drawings, among which: Fig. 1

[0046] [Fig.1] represents two photographs, the photograph on the left showing a TA Instruments “DMA Q800” device used for dynamic mechanical analysis (“DMA”) according to the invention in order to obtain the damping values ​​(tan delta) as a function of frequency, and the photograph on the right showing a “three-point fixed mount” type setup used for this dynamic mechanical analysis (“DMA”) in relation to this device. Fig. 2

[0047] [Fig.2] is a graph showing the damping properties (average tan delta between 1 and 3000 Hz) obtained as a function of temperature (°C) with the apparatus and the assembly of [Fig.1], for three compositions not in accordance with the invention Cl, C2, C3. Fig. 3

[0048] [Fig.3] is a graph showing the damping properties (average tan delta between 1 and 3000 Hz) obtained as a function of temperature (°C) with the apparatus and the assembly of [Fig.1], for two other compositions not in accordance with the invention C4, C5 and for two compositions according to the invention II, 12. Fig. 4

[0049] [Fig.4] is a graph showing the damping properties (average tan delta between 1 and 3000 Hz) obtained as a function of temperature (°C) with the device and the assembly of [Fig.1], for two other compositions not in accordance with the invention C6, C7 in comparison with the two compositions according to the invention II, 12 as characterized in [Fig.3]. Fig. 5

[0050] [Fig.5] is a graph showing the damping properties (average tan delta) between 1 and 3000 Hz) obtained as a function of temperature (°C) with the apparatus and the assembly of [Fig.1], for two other compositions according to the invention 13,14. Fig. 6

[0051] [Fig.6] is a graph showing the damping properties (average tan delta) between 1 and 3000 Hz) obtained as a function of temperature (°C) with the apparatus and the setup of [Fig. 1], for two other compositions according to the invention 15, 16. Examples of embodiments of the invention

[0052] In all the following examples, the compositions not conforming to the invention C1-C7, as well as the compositions according to the invention 11-16, were prepared by melting, by extrusion in a Leistritz ZSE40MAXX twin-screw extruder (length ratio L / diameter D = 40), and then the compositions obtained were injection molded via an Engel 400t vertical press.

[0053] Formulation of compositions Cl-C7 and 11-16 and ingredients used

[0054] Table 1 below indicates the formulations (mass fractions of ingredients in each composition in %), extrusion parameters, injection and the properties of the C1-C3 compositions. [Tables 1] Ingredients Cl C2 C3 Virgin Polypropylene PPH 3060 (Total) 70 65 60 EVA Copolymer Vinavil 5603P 0 5 10 Glass Fibers DS 2200-10P 30 30 30 Extrusion Parameters Cl C2 C3 Outlet Material Temperature (°C) 194 196 194 Power (%) 71 60 55 Screw Speed ​​(rpm) 150 150 150 Total Throughput (kg / h) 15 15 15 Number of Die Holes 2 2 2 Outlet Pressure (105 Pa) 52 47 43 Injection Parameters Cl C2 C3 Mold temperature (°C) 60 60 60 Switching injection pressure (10⁵ Pa) 1048 1014 987 Holding pressure (10⁵ Pa) 500 500 500 Holding time (s) 7 7 7 Cooling time (s) 15 15 15 Properties Cl C2 C3 Tg (DMA) (°C) 21 22 22 Tan delta at 30°C and 1 Hz 0.036 0.046 0.052 Young's modulus at 23°C (GPa) 6494 5135 4816 Standard deviation 272 177 195 Young's modulus at 60°C (GPa) 4135 3271 3033 Standard deviation 382 252 124

[0055] As can be seen in the graph of [Fig.2], the addition, in the glass fiber reinforced polymer matrix, of 5% and 10% by weight of an ethylene-vinyl acetate copolymer (EVA of Tg = -3° C) to polypropylene, gives compositions C2 and C3 a significant improvement in damping in the temperature range 20-50° C compared to composition Cl, but these compositions C2-C3 exhibit very insufficient mechanical properties.

[0056] Table 2 below indicates the formulations (mass fractions of ingredients in each composition in %), extrusion parameters, injection and the properties of compositions C4, C5 and II, 12. [Tables 2] Ingredients C4 C5 II 12 Virgin Polypropylene PPH 3060 (Total) 65 60 65 60 Amphora Polypropylene Plasticizer (Tg < 0°C) Regalflex P1023 5 10 0 0 Alicyclic Plasticizer (Tg > 20°C) Regalite R1090 0 0 5 10 Glass Fibers DS 2200-10P 30 30 30 30 Extrusion Parameters C4 C5 II 12 Outlet Material Temperature (°C) 193 188 203 190 Power (%) 65->70 59->65 71 63 Screw speed (rpm) 150 150 150 150 Total throughput (kg / h) 15 15 15 15 Number of die holes 3 3 3 3 Outlet pressure (10⁵ Pa) 50 46->50 53 49 Injection parameters C4 C5 II 12 Mold temperature (°C) 30 30 30 30 Switching injection pressure (10⁵ Pa) 863 833 912.5 939 Holding pressure (10⁵ Pa) 700 610 700 700 Holding time (s) 10 10 10 10 Cooling time (s) 20 20 20 20 Properties C4 C5 II 12 Tg (DMA) (°C) 14 14 80 62 Tan delta at 30°C and at 1 Hz 0.039 0.038 0.047 0.065 Young's modulus at 23°C (GPa) 5259 5346 6069 5655 Standard deviation 275 325 370 284 Young's modulus at 60°C (GPa) 3603 3293 3696 3303 Standard deviation 286 241 323 216

[0057] As seen in [Fig.3], the addition, to the glass fiber reinforced polypropylene matrix, of 5% and 10% by weight of a plasticizer according to the invention (Regalite R1090 alicyclic resin with a Tg of approximately 36°C) gives compositions II and 12 a significant improvement in damping in the 20-50°C range, as well as improved mechanical properties, compared to compositions C4-C5 whose sole plasticizer is not according to the invention (Regalflex aliphatic resin: amorphous propylene homopolymer with a Tg of approximately -10°C and a Brookfield viscosity at 190°C of 2.3 Pa.s).

[0058] Table 3 below indicates the formulations (mass fractions of ingredients in each composition in %), extrusion parameters, injection and the properties of compositions II, 12 and C6, C7. [Tables 3] Ingredients II 12 C6 C7 Virgin Polypropylene PPH 3060 (Total) 65 60 95 90 Alicyclic Plasticizer Regalite R1090 5 10 5 10 (Tg > 20°C) DS 2200-10P Glass Fibers Extrusion Parameters II 12 C6 C7 Outlet Material Temperature (°C) 203 190 189 200 Power (%) 71 63 70 62 Screw Speed ​​(rpm) 150 150 150 150 Total Throughput (kg / h) 15 15 15 15 Number of Die Holes 3 3 3 3 Outlet Pressure (10⁵ Pa) 53 49 44 42 Injection Parameters II 12 C6 C7 Mold Temperature (°C) 30 30 30 30 Switching Injection Pressure (10⁵ Pa) 912.5 939 749 739 Holding Pressure (10⁵ Pa) 700 700 450 450 Holding time (s) 10 10 10 10 Cooling time (s) 20 20 20 20 Properties II 12 C6 C7 Tg (DMA) (°C) 80 62 82 62 Tan delta at 30°C and 1 Hz 0.047 0.065 0.088 0.111 Young's modulus at 23°C (GPa) 6069 5655 1312 1065 Standard deviation 370 284 70 40 Young's modulus at 60°C (GPa) 3696 3303 495 434 Standard deviation 323 216 138 39

[0059] As can be seen in Table 3 and [Fig.4], the reinforcement by a fibrous filler (e.g. glass fibers) of the polypropylene matrix with added 5% and 10% by weight of a plasticizer according to the invention (Regalite R1090 alicyclic resin), even if it reduces the damping of compositions II, 12 in the 20-50°C range compared to compositions C6, C7 without fibrous filler, gives these compositions II, 12 satisfactory mechanical strength (in particular in terms of Young's modulus, both at 23°C and at 60°C at RH50) compared to compositions C6, C7 whose mechanical strength is prohibitive.

[0060] Table 4 below indicates the formulations (mass fractions of ingredients in each composition in %), extrusion parameters, injection and the properties of compositions 13 and 14. [Tables 4] Ingredients 13 14 Virgin Polypropylene PPH 3060 (Total) 60 0 Recycled Polypropylene (PCR 70%) rPP 1002 (Ineos) 0 60 Alicyclic Plasticizer (Tg > 20°C) Regalite R1090 10 10 Glass Fibers DS 2200-10P 30 30 Extrusion Parameters 13 14 Outlet Material Temperature (°C) 195 193 Power (%) 56 51 Screw Speed ​​(rpm) 150 150 Total Throughput (kg / h) 15 15 Number of Die Holes 2 2 Outlet Pressure (10⁵ Pa) 45 41 Injection Parameters 13 14 Mold Temperature (°C) 30 30 Injection Switching Pressure (10⁵ Pa) 886 785 Pressure Holding pressure (105 Pa) 500 500 Holding time (s) 10 10 Cooling time (s) 20 20 Properties 13 14 Tg (DMA) (°C) 63 68 Tan delta at 30°C and 1 Hz 0.050 0.049 Young's modulus at 23°C (GPa) 5399 5686 Standard deviation 353 254 Young's modulus at 60°C (GPa) 2327 2508 Standard deviation 34 119

[0061] As seen in [Fig.5], the use, in the matrix reinforced by a fibrous filler and supplemented with a plasticizer according to the invention (Regalite R1090 alicyclic resin), of virgin polypropylene (PP) and recycled polypropylene (rPP) confers overall the same advantageous damping properties in the 20-50°C range and a mechanical strength similar to compositions 13 and 14 (the measured Young's moduli of composition 14 based on rPP are however higher than those of composition 13 based on PP).

[0062] Table 5 below indicates the formulations (mass fractions of ingredients in each composition in %), extrusion parameters, injection and the properties of compositions 15 and 16. [Tables 5] Ingredients 15 16 Virgin Polypropylene PPH 3060 (Total) 60 55 Alicyclic Plasticizer (Tg > 20°C) Regalite R1090 10 10 Omya Chalk BSH 0 5 Glass Fibers DS 2200-10P 30 30 Extrusion Parameters 15 16 Outlet Material Temperature (°C) 194 194 Power (%) 54 53 Screw Speed ​​(rpm) 150 150 Total Throughput (kg / h) 15 15 Number of Die Holes 2 2 Outlet Pressure (10⁵ Pa) 42 43 Injection Parameters 15 16 Mold Temperature (°C) 60 60 Switching Injection Pressure (10⁵ Pa) 863 900 Holding Pressure (10⁵ Pa) 500 500 Time Maintenance (s) 7 7 Cooling time (s) 15 15 Properties 15 16 Tg (DMA) (°C) 73 73 Tan delta at 30°C and 1 Hz: 0.049, 0.055; Young's modulus at 23°C (GPa): 5866, 5435; Standard deviation: 123, 300; Young's modulus at 60°C (GPa): 3263, 3044; Standard deviation: 349, 219

[0063] As seen in [Fig.6], the use, in the polypropylene matrix reinforced by a fibrous filler and supplemented with a plasticizer according to the invention (Regalite R1090 alicyclic resin), of 5% by weight of a non-fibrous filler of the lamellar inorganic type (e.g. chalk), gives composition 16 improved damping properties above 20°C and an overall preserved mechanical strength, compared to composition 15 reinforced only by this fibrous filler.

Claims

Demands

1. Thermoplastic polymeric composition (11-16) suitable for damping vibrations at frequencies from 1 to 3000 Hz and at average temperatures from 10 to 50°C, wherein the composition comprises, by mass fractions: 50-70% of a non-elastomeric polymeric matrix, the matrix being based on at least one propylene polymer selected from propylene homopolymers and copolymers, 20-45% of a reinforcing filler comprising a fibrous filler, and 2-18% of a plasticizing system comprising at least one aliphatic, alicyclic or aromatic hydrocarbon resin having a glass transition temperature Tg equal to or greater than 20°C.

2. Thermoplastic polymeric composition (11-16) according to claim 1, wherein the plasticizing system comprises, by mass fraction in the composition: 5-15% of said at least one hydrocarbon resin which is aliphatic or alicyclic and has a glass transition temperature Tg inclusive between 25 and 50°C, preferably an alicyclic hydrogenated resin with a glass transition temperature Tg of 30-45°C and a number-average molecular weight Mn of 480-600 g / mol.

3. Thermoplastic polymeric composition according to claim 2, wherein the plasticizing system further comprises, by mass fraction in the composition: 3-13% of at least one other aliphatic or alicyclic hydrocarbon resin having a glass transition temperature Tg less than or equal to 0°C, preferably comprising at least one amorphous aliphatic or alicyclic polyolefin having a glass transition temperature Tg inclusively between -45 and -10°C and a Brookfield melt viscosity at 190°C inclusively between 1.0 and 4.0 Pa·s, measured according to ASTM D 3236, said at least one other hydrocarbon resin being, for example, an amorphous homopolymer of propylene or an amorphous ethylene-propylene copolymer, or an amorphous mixture of aliphatic polyolefins, for example of an amorphous homopolymer of propylene and an amorphous ethylene-propylene copolymer.

4. Thermoplastic polymeric composition according to claim 2, wherein the plasticizing system further comprises, by mass fraction in the composition: 3-13% of at least one other aromatic hydrocarbon resin having a glass transition temperature Tg inclusive between 30 and 45°C, preferably an aromatic polyolefin selected from styrene homopolymers and copolymers.

5. Thermoplastic polymeric composition (11-16) according to any one of the preceding claims, wherein the reinforcing filler comprises, in mass fractions in the composition: 20-40% of said fibrous filler, preferably selected from discontinuous glass fibers, 0-13% of a non-fibrous inorganic filler of lamellar type, for example selected from phyllosilicates and talcs, and 0-12% of a non-fibrous, non-lamellar inorganic filler, for example selected from calcium carbonates.

6. Thermoplastic polymeric composition (11-16) according to claim 5, wherein the reinforcing filler consists, in mass fractions in the composition: of 25-35% glass fibers, and of 0-15% talc and / or chalk.

7. Thermoplastic polymeric composition (11-16) according to any one of the preceding claims, wherein the composition comprises, in mass fractions: 55-65% of said matrix, which comprises said at least one propylene polymer in a mass fraction in the matrix of 75-100%, 25-40% of said reinforcing filler, which comprises said fibrous filler in a mass fraction in the reinforcing filler of 75-100%, and 5-15% of said plasticizing system, which comprises said at least one aliphatic, alicyclic or aromatic hydrocarbon resin in a mass fraction in the plasticizing system of 40-100%.

8. Thermoplastic polymeric composition (11-16) according to any one of the preceding claims, wherein the composition has, at 60°C after humid conditioning in air at 50% relative humidity, a Young's modulus measured according to ISO 527 that is greater than 2.5 GPa and preferably greater than 3.5 GPa.

9. Thermoplastic polymeric composition (11-16) according to any one of the preceding claims, wherein said at least one propylene polymer is included in said matrix in a mass fraction in the matrix of 75-100%, and is: - a virgin propylene homopolymer selected from isotactic polypropylenes, - a virgin propylene interpolymer and an alpha-olefin other than propylene, or - a recycled propylene homopolymer or copolymer derived from a post-industrial (PIR) or post-consumer (PCR) type recycled polyolefin material.

10. Thermoplastic polymeric composition (11-16) according to claim 9, wherein said matrix is ​​made up of said at least one polymer of propylene, preferably being made up of said virgin homopolymer of propylene or of said recycled homopolymer or copolymer of propylene.

11. Thermoplastic polymer composition according to claim 9, wherein said matrix comprises at least one other non-propylene thermoplastic polymer in a mass fraction in the matrix of 5-40%, which is selected from: - vinyl acetate polymers optionally coupled to a compatibilizing agent, - poly(butylene terephthalate) coupled to a compatibilizing agent, and - aliphatic polyamides, preferably selected from PA 6, PA 11 and PA 12, coupled to a compatibilizing agent, the compatibilizing agent comprising, for example, maleic anhydride grafted polypropylene.

12. Thermoplastic polymeric composition according to claim 11, wherein said matrix is ​​devoid of polyphthalamide.

13. A dynamic function device for a motor vehicle, aircraft, or spacecraft, the device being capable of damping vibrations in a frequency range of 1 to 3000 Hz and at average temperatures of 10 to 50°C as seen by the device within the vehicle, wherein the device comprises a composition (11-16) according to a of the preceding claims which is injection molded and which is optionally integral with a metallic insert, for example threaded.

14. Device according to claim 13, said motor vehicle being an electric motor vehicle, wherein the device is selected from: structural parts transmitting vibrations, for example parts adapted to be connected to the wheels of the vehicle so as to receive the vibrations, and anti-vibration mounts joining first and second rigid elements by damping vibrations between them and supporting a load, the anti-vibration mount preferably being a connecting support linking the electric motor to an element of the structure of the motor vehicle, such as a side member of the vehicle body.

15. Device according to claim 14, wherein the device is selected from brackets, engine mounts and air conditioning compressor mounts for the electric motor vehicle.

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