WO2020008134A1

WO2020008134A1 - Use of peba foams for vibration filtering

Info

Publication number: WO2020008134A1
Application number: PCT/FR2019/051626
Authority: WO
Inventors: Clio COCQUET
Original assignee: Arkema France
Priority date: 2018-07-03
Filing date: 2019-07-02
Publication date: 2020-01-09
Also published as: TW202006020A; FR3083540B1; FR3083540A1; CN112368319B; EP3818096A1; CN112368319A; TWI808212B

Abstract

The invention concerns the use of a copolymer foam with polyamide blocks and polyether blocks for vibration filtering. The invention can be applied to the manufacture of vibration filtering parts such as feet for food processors of the blender or mixer type, parts for motor vehicles or any vehicle, in particular suspension devices for motor vehicle gearboxes, or suspension devices for helicopter gearboxes.

Description

USE OF PEBA FOAMS FOR THE FILTERING OF

VIBRATIONS

FIELD OF THE INVENTION

The present invention relates to the use of a polyamide block and polyether block copolymer foam for filtering vibrations. TECHNICAL BACKGROUND

In many applications, for example in the field of small household appliances or the automobile, it may be desirable to incorporate into the devices used a means of filtering the vibrations emitted by the device. Certain polymeric foams have shown promise in the implementation of such means.

The document FR 3047245 describes PEBA foams having a high capacity to restore elastic energy during stresses under low stress, a low remanent deformation in compression and a high resistance to fatigue in compression. These foams also have interesting anti-shock, anti-vibration and anti-noise properties. However, no vibration filtering properties are mentioned.

There is therefore a real need to provide a material capable of effectively filtering vibrations. SUMMARY OF THE INVENTION

The invention relates first of all to the use of a polyamide block and polyether block copolymer foam for filtering vibrations.

In embodiments, the foam is non-crosslinked.

In embodiments, the polyamide blocks are blocks of polyamide 6, polyamide 11, polyamide 12, polyamide 5.4, polyamide 5.9, polyamide 5.10, polyamide 5.12, polyamide 5.13, polyamide 5.14, polyamide 5.16, polyamide 5.18, polyamide 5.36, polyamide 6.4, polyamide 6.9, polyamide 6.10, polyamide 6.12, polyamide 6.13, polyamide 6.14, polyamide 6.16, polyamide 6.18, polyamide 6.36, polyamide 10.4, polyamide 10.9, polyamide 10.10, polyamide 10.12 , polyamide 10.13, polyamide 10.14, polyamide 10.16, polyamide 10.18, polyamide 10.36, polyamide 10.T, polyamide 12.4, polyamide 12.9, polyamide 12.10, polyamide 12.12, polyamide 12.13, polyamide 12.14 , polyamide 12.16, polyamide 12.18, polyamide 12.36, polyamide 12.T or mixtures, or copolymers, of these, preferably polyamide 1 1, polyamide 12, polyamide 6, or polyamide 6.10 .

In embodiments, the polyether blocks are blocks of polyethylene glycol, propylene glycol, polytrimethylene glycol, polytetrahydrofuran, or mixtures, or copolymers, of these, preferably polyethylene glycol or polytetrahydrofuran.

In embodiments:

- The polyamide blocks of the copolymer have a number-average molar mass of 100 to 20,000 g / mol, preferably from 200 to 10,000 g / mol, even more preferably from 200 to 1,500 g / mol; and or

- The polyether blocks of the copolymer have a number-average molar mass of 100 to 6000 g / mol, preferably from 200 to 3000 g / mol, even more preferably from 800 to 2500 g / mol.

In embodiments, the mass ratio of the polyamide blocks relative to the polyether blocks of the copolymer is from 0.1 to 10, preferably from 0.3 to 3, even more preferably from 0.3 to 0.9.

In embodiments, the foam has a density less than or equal to 800 kg / m ³ , preferably less than or equal to 600 kg / m ³ , more preferably less than or equal to 400 kg / m ³ , more particularly preferably less than or equal to 300 kg / m ³ .

In embodiments, the foam also contains one or more additives, preferably chosen from copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylate, and copolymers of ethylene and of alkyl ( meth) acrylate.

The invention also relates to a vibration filtering piece made of a polyamide block and polyether block copolymer foam as defined above. The invention also relates to a vibration filtering part comprising at least one element made of a polyamide block and polyether block copolymer foam as defined above.

In embodiments, the vibration filtering part is chosen from among household robot feet, such as mixers and mixers, automotive parts or any vehicle, such as the suspension devices of motor vehicle gearboxes. , or the suspension devices of helicopter gearboxes.

The present invention makes it possible to meet the need expressed above. More particularly, it provides a polymer foam, light and recyclable, making it possible to effectively filter vibrations.

This is accomplished through the use of a polyamide block and polyether block copolymer.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 represents the curve obtained by dynamic mechanical analysis during the measurement of the delta tangents of the foamed PEBA B (gray dotted curve) and of the non-foamed PEBA B (black curve in solid line) described in Example 2. The temperature ( in ° C) on the abscissa and the tangent delta on the ordinate.

FIG. 2 represents the curve obtained by dynamic mechanical analysis during the measurement of the delta tangents of the foamed PEBA A-2 described in example 3. The frequency (in Hz) is shown on the abscissa and the delta tangent is shown on the ordinate.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention is now described in more detail and without limitation in the description which follows.

The invention relates to the use of a polyamide block and polyether block (PEBA) copolymer foam for filtering vibrations.

Filtering vibrations consists in cutting off high frequencies, that is to say frequencies higher than the product of the natural frequency of the object made of filter material multiplied by 1.4.

It is a separate application of vibration absorption as mentioned for example in document FR 3047245.

PEBAs result from the polycondensation of polyamide blocks with reactive ends with polyether blocks with reactive ends, such as, inter alia polycondensation: 1) polyamide blocks with diamine chain ends with polyoxyalkylene blocks with dicarboxylic chain ends;

2) polyamide blocks with ends of dicarboxylic chains with polyoxyalkylene blocks with ends of diamine chains, obtained for example by cyanoethylation and hydrogenation of polyoxyalkylene blocks a, w- aliphatic dihydroxylates called polyetherdiols;

3) polyamide blocks at the ends of dicarboxylic chains with polyetherdiols, the products obtained being, in this particular case, polyetheresteramides.

Polyamide blocks with dicarboxylic chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-limiting dicarboxylic acid. Polyamide blocks with diamine chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain limiting diamine.

Three types of polyamide blocks can advantageously be used.

According to a first type, the polyamide blocks come from the condensation of a dicarboxylic acid, in particular those having from 4 to 20 carbon atoms, preferably those having from 6 to 18 carbon atoms, and from an aliphatic or aromatic diamine , in particular those having from 2 to 20 carbon atoms, preferably those having from 6 to 14 carbon atoms.

As examples of dicarboxylic acids, mention may be made of 1,4-cyclohexyldicarboxylic acid, butanedioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic, octadecanedicarboxylic acids and terephthalic and isophthalic acids, but also dimerized fatty acids .

As examples of diamines, mention may be made of tetramethylene diamine, hexamethylenediamine, 1, 10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylene diamine, isomers of bis- (4-aminocyclohexyl) -methane (BACM), bis - (3-methyl-4-aminocyclohexyl) methane (BMACM), and 2-2-bis- (3-methyl-4-aminocyclohexyl) -propane (BMACP), para-amino-di-cyclo-hexyl-methane ( PACM), isophoronediamine (IPDA), 2,6-bis- (aminomethyl) -norbornane (BAMN) and piperazine (Pip).

Advantageously, polyamide blocks PA 4.12, PA 4.14, PA 4.18, PA 6.10, PA 6.12, PA 6.14, PA 6.18, PA 9.12, PA 10.10, PA 10.12, PA 10.14 and PA 10.18 are used. In the PA XY notation, X represents the number of carbon atoms derived from diamine residues, and Y represents the number of carbon atoms derived from diacid residues, in a conventional manner. According to a second type, the polyamide blocks result from the condensation of one or more α, w-aminocarboxylic acids and / or from one or more lactams having from 6 to 12 carbon atoms in the presence of a dicarboxylic acid having from 4 to 12 carbon atoms or a diamine. Examples of lactams include caprolactam, enantholactam and lauryllactam. As examples of α, w-amino carboxylic acid, mention may be made of aminocaproic, amino-7-heptanoic, amino-11-undecanoic and amino-12-dodecanoic acids.

Advantageously, the polyamide blocks of the second type are blocks of PA 1 1 (polyundecanamide), of PA 12 (polydodecanamide) or of PA 6 (polycaprolactam). In the PA X notation, X represents the number of carbon atoms derived from the amino acid residues.

According to a third type, the polyamide blocks result from the condensation of at least one α, w-aminocarboxylic acid (or a lactam), at least one diamine and at least one dicarboxylic acid.

In this case, the polyamide PA blocks are prepared by polycondensation:

- linear or aromatic aliphatic diamine (s) having X carbon atoms;

- Carboxylic acid (s) having Y carbon atoms; and

- the comonomer (s) {Z}, chosen from lactams and a, w-aminocarboxylic acids having Z carbon atoms and equimolar mixtures of at least one diamine having X1 carbon atoms and at least one dicarboxylic acid having Y1 carbon atoms, (X1, Y1) being different from (X, Y),

- Said comonomer (s) {Z} being introduced in a proportion by weight ranging advantageously up to 50%, preferably up to 20%, even more advantageously up to 10% relative to all of the polyamide precursor monomers;

- in the presence of a chain limiter chosen from dicarboxylic acids.

Advantageously, the dicarboxylic acid having Y carbon atoms, which is introduced in excess relative to the stoichiometry of the diamine or diamines, is used as chain limiter.

According to a variant of this third type, the polyamide blocks result from the condensation of at least two α, w-aminocarboxylic acids or of at least two lactams having from 6 to 12 carbon atoms or from a lactam and a aminocarboxylic acid not having the same number of atoms carbon in the possible presence of a chain limiter. As examples of aliphatic α, w-aminocarboxylic acid, mention may be made of aminocaproic, amino-7-heptanoic, amino-11-undecanoic and amino-12-dodecanoic acids. As examples of lactams, mention may be made of caprolactam, oenantholactam and lauryllactam. As examples of aliphatic diamines, mention may be made of hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylene diamine. As examples of cycloaliphatic diacids, mention may be made of 1,4-cyclohexyldicarboxylic acid. Mention may be made, as examples of aliphatic diacids, of butane-dioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic acids and dimerized fatty acids. These dimerized fatty acids preferably have a dimer content of at least 98%; preferably they are hydrogenated; these are for example the products marketed under the brand name "PRIPOL" by the company "CRODA", or under the brand EMPOL by the company BASF, or under the brand Radiacid by the company OLEON, and polyoxyalkylenes a, w-diacids . Mention may be made, as examples of aromatic diacids, of terephthalic (T) and isophthalic (I) acids. As examples of cycloaliphatic diamines, mention may be made of the isomers of bis- (4-aminocyclohexyl) -methane (BACM), bis- (3-methyl-4-aminocyclohexyl) methane (BMACM) and 2-2-bis- (3-methyl-4-aminocyclohexyl) - propane (BMACP), and para-amino-di-cyclo-hexyl-methane (PACM). Other commonly used diamines can be isophoronediamine (IPDA), 2,6-bis- (aminomethyl) -norbornane (BAMN) and piperazine.

As examples of polyamide blocks of the third type, the following may be cited:

- PA 6.6 / 6, where 6.6 denotes hexamethylenediamine units condensed with adipic acid and 6 denotes units resulting from the condensation of caprolactam;

- PA 6.6 / 6.10 / 1 1/12, where 6.6 denotes hexamethylenediamine condensed with adipic acid, 6.10 denotes hexamethylenediamine condensed with sebacic acid, 1 1 denotes units resulting from the condensation of acid aminoundecanoic and 12 designates motifs resulting from the condensation of lauryllactam.

PA X / Y, PA X / Y / Z, etc. relate to copolyamides in which X, Y, Z, etc. represent homopolyamide units as described above. Advantageously, the polyamide blocks of the copolymer used in the invention comprise polyamide blocks PA 6, PA 11, PA 12, PA 5.4, PA 5.9, PA 5.10, PA 5.12, PA 5.13, PA 5.14, PA 5.16, PA 5.18, PA 5.36, PA 6.4, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA 6.14, PA 6.16, PA 6.18, PA 6.36, PA 10.4, PA 10.9, PA 10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16 , PA 10.18, PA 10.36, PA 10.T, PA 12.4, PA 12.9, PA 12.10, PA 12.12, PA 12.13, PA 12.14, PA 12.16, PA 12.18, PA 12.36, PA 12.T, or mixtures or copolymers of these; and preferably comprise blocks of polyamide PA 6, PA 11, PA 12, PA 6.10, PA 10.10, PA 10.12, or mixtures or copolymers thereof.

Polyether blocks are made up of alkylene oxide units.

The polyether blocks may in particular be PEG blocks (polyethylene glycol), that is to say made up of ethylene oxide units, and / or PPG blocks (propylene glycol), that is to say made up of propylene oxide units, and / or P03G blocks (polytrimethylene glycol), that is to say made up of polytrimethylene glycol ether units, and / or PTMG blocks, that is to say made up of tetramethylene glycol units also called polytetrahydrofuran. PEBA copolymers can comprise in their chain several types of polyethers, the copolyethers possibly being block or random.

It is also possible to use blocks obtained by oxyethylation of bisphenols, such as for example bisphenol A. These latter products are described in particular in document EP 613919.

The polyether blocks can also consist of ethoxylated primary amines. By way of example of ethoxylated primary amines, mention may be made of the products of formula:

H - (OCH ₂ CH ₂ ) _m —N - (CH ₂ CH ₂ 0) _n - H

(CH,),

CH ₃

in which m and n are integers between 1 and 20 and x an integer between 8 and 18. These products are for example commercially available under the brand NORAMOX® from the company CECA and under the brand GENAMIN® from the company Clariant.

The flexible polyether blocks can comprise polyoxyalkylene blocks with ends of Nhh chains, such blocks being obtainable by cyanoacetylation of polyoxyalkylene a, w-dihydroxylated aliphatic blocks called polyetherdiols. More particularly, the commercial products Jeffamine or Elastamine can be used (for example Jeffamine® D400, D2000, ED 2003, XTJ 542, commercial products of the company Huntsman, also described in documents JP 2004346274, JP 2004352794 and EP 148201 1).

The polyetherdiol blocks are either used as such and copolycondensed with polyamide blocks with carboxylic ends, or aminated to be transformed into polyether diamines and condensed with polyamide blocks with carboxylic ends. The general method for the preparation in two stages of the PEBA copolymers having ester bonds between the PA blocks and the PE blocks is known and is described, for example, in document FR 2846332. The general method of preparing the PEBA copolymers of the invention having amide bonds between the PA blocks and the PE blocks is known and described, for example in document EP 148201 1. The polyether blocks can also be mixed with polyamide precursors and a diacid chain limiter to prepare polymers with polyamide blocks and polyether blocks having units distributed in a statistical manner (one-step process).

Of course, the designation PEBA in the present description of the invention relates as well to PEBAX® marketed by Arkema, to Vestamid® marketed by Evonik®, to Grilamid® marketed by EMS, as to Pelestat® type PEBA marketed by Sanyo or any other PEBA from other suppliers.

If the block copolymers described above generally comprise at least one polyamide block and at least one polyether block, the present invention also covers all the alloys of copolymers comprising two, three, four (or even more) different blocks chosen from those described in the present description, since these blocks comprise at least polyamide and polyether blocks.

For example, the copolymer alloy according to the invention can comprise a segmented block copolymer comprising three different types of blocks (or "triblock"), which results from the condensation of several of the blocks described above. Said triblock is preferably chosen from copolyetheresteramides and copolyetheramideurethanes.

PEBA copolymers which are particularly preferred in the context of the invention are copolymers comprising blocks:

- PA 1 1 and PEG; - PA 1 1 and PTM G;

- PA 12 and PEG;

- PA 12 and PTMG;

- PA 6.10 and PEG;

- PA 6.10 and PTMG;

- PA 6 and PEG;

- PA 6 and PTMG.

The foam according to the invention comprises a PEBA copolymer as described above: preferably only one such copolymer is used. However, it is possible to use a mixture of two or more of two PEBA copolymers as described above.

The number-average molar mass of the polyamide blocks in the PEBA copolymer is preferably from 100 to 20,000 g / mol, more preferably from 200 to 10,000 g / mol, even more preferably from 200 to 1,500 g / mol. In embodiments, the number-average molar mass of the polyamide blocks in the PEBA copolymer is from 100 to 200 g / mol, or from 200 to 500 g / mol, or from 500 to 1000 g / mol, or from 1000 to 1500 g / mol, or from 1500 to 2000 g / mol, or from 2000 to 2500 g / mol, or from 2500 to 3000 g / mol, or from 3000 to 3500 g / mol, or from 3500 to 4000 g / mol, or from 4000 to 5000 g / mol, or from 5000 to 6000 g / mol, or from 6000 to 7000 g / mol, or from 7000 to 8000 g / mol, or from 8000 to 9000 g / mol, or from 9000 to 10000 g / mol, or from 10000 to 1100 g / mol, or from 1000 to 12000 g / mol, or from 12000 to 13000 g / mol, or from 13000 to 14000 g / mol, or from 14000 to 15000 g / mol , or from 15,000 to 16,000 g / mol, or from 16,000 to 17,000 g / mol, or from 17,000 to 18,000 g / mol, or from 18,000 to 19,000 g / mol, or from 19,000 to 20,000 g / mol.

The number-average molar mass of the polyether blocks is preferably from 100 to 6000 g / mol, more preferably from 200 to 3000 g / mol, even more preferably from 800 to 2500 g / mol. In embodiments, the number-average molar mass of the polyether blocks is from 100 to 200 g / mol, or from 200 to 500 g / mol, or from 500 to 800 g / mol, or from 800 to 1000 g / mol , or from 1000 to 1500 g / mol, or from 1500 to 2000 g / mol, or from 2000 to 2500 g / mol, or from 2500 to 3000 g / mol, or from 3000 to 3500 g / mol, or from 3500 to 4000 g / mol, or from 4000 to 4500 g / mol, or from 4500 to 5000 g / mol, or from 5000 to 5500 g / mol, or from 5500 to 6000 g / mol.

The number-average molar mass is fixed by the content of chain limiter. It can be calculated according to the relation:

M _n = n monomer X MW repetition motif / chain niimator MW Chain limiter In this formula, n _monomer is the number of moles of monomer or _im chain itor represents the number of moles limiter (e.g., diacid) excess repetition MWmotif represents the molar mass of the repeating unit, and chain MWiimiteur represents the molar mass of the limiter (for example diacid) in excess.

The number-average molar mass of the polyamide blocks and of the polyether blocks can be measured before the copolymerization of the blocks by chromatography on permeable gel (GPC).

Advantageously, the mass ratio of the polyamide blocks relative to the polyether blocks of the copolymer is from 0.1 to 10, preferably from 0.3 to 3, even more preferably from 0.3 to 0.9. In particular, the mass ratio of the polyamide blocks relative to the polyether blocks of the copolymer can be from 0.1 to 0.2, or from 0.2 to 0.3, or from 0.3 to 0.4, or from 0 , 4 to 0.5, or 0.5 to 0.6, or 0.6 to 0.7, or 0.7 to 0.8, or 0.8 to 0.9, or 0 , 9 to 1, or 1 to 1, 5, or 1, 5 to 2, or 2 to 2.5, or 2.5 to 3, or 3 to 3.5, or 3.5 to 4, or from 4 to 4.5, or from 4.5 to 5, or from 5 to 5.5, or from 5.5 to 6, or from 6 to 6.5, or from 6.5 to 7 , or from 7 to 7.5, or from 7.5 to 8, or from 8 to 8.5, or from 8.5 to 9, or from 9 to 9.5, or from 9.5 to 10.

Preferably, the copolymer used in the invention has an instantaneous hardness less than or equal to 40 Shore D, more preferably less than or equal to 35 Shore D. The hardness measurements can be carried out according to ISO standard 868.

The polyamide block and polyether block copolymer is used to form a foam, preferably without a crosslinking step. The foam is formed by mixing the copolymer in the molten state with a blowing agent and then performing a foaming step.

According to one embodiment, the foam thus formed essentially consists, or even consists, of the copolymer described above (or the copolymers, if a mixture of copolymers is used) and optionally the blowing agent, if the latter remains present in the pores of the foam, especially if it is a closed pore foam.

The polyamide block and polyether block copolymer can be combined with various additives, for example copolymers of ethylene and vinyl acetate or EVA (for example those marketed under the name of Evatane® by Arkema), or copolymers of ethylene and acrylate, or copolymers of ethylene and alkyl (meth) acrylate, for example those sold under the name Lotryl® by Arkema. These additives can be used to adjust the hardness of the foamed part, its appearance and its comfort. The additives can be added in a content of 0 to 50% by mass, preferably from 5 to 30% by mass, relative to the copolymer with polyamide blocks and with polyether blocks.

The blowing agent can be a chemical or physical agent. Preferably, it is a physical agent, such as, for example, dinitrogen or carbon dioxide, or a hydrocarbon, chlorofluorocarbon, hydrochlorocarbon, hydrofluorocarbon or hydrochlorofluorocarbon (saturated or unsaturated). For example, butane or pentane can be used.

A physical blowing agent is mixed with the copolymer in liquid or supercritical form, then converted to the gas phase during the foaming step.

According to preferred embodiments, the mixture of the copolymer and the blowing agent is injected into a mold, and the foaming is produced by the opening of the mold. This technique makes it possible to directly produce three-dimensional foamed objects with complex geometries.

It is also a relatively simple technique to implement, in particular with respect to certain processes for melting foamed particles as described in the prior art: in fact, filling the mold with foamed polymer granules then melting the particles to ensure mechanical strength of the parts without destroying the structure of the foam are complex operations.

Other foaming techniques that can be used include batch foaming and extrusion foaming.

The foam according to the invention preferably has a density less than or equal to 800 kg / m ³ , more preferably less than or equal to 600 kg / m ³ , more particularly preferably less than or equal to 400 kg / m ³ , or even less or equal to 300 kg / m ³ . It can for example have a density of 50 to 800 kg / m ³ , and more particularly preferably from 100 to 600 kg / m ³ . Density control can be achieved by adapting the parameters of the manufacturing process.

Preferably, this foam has a rebound resilience, according to ISO 8307, greater than or equal to 55%.

Preferably, this foam has a residual compression deformation, according to ISO 7214, less than or equal to 10%, and more particularly preferably less than or equal to 8%.

Preferably, this foam also has excellent fatigue resistance and damping properties. The foam according to the invention can be used to manufacture vibration filtering parts. For example, it can be the feet of household robots, such as blenders and kitchen mixers. It can also be auto parts or parts of any vehicle, such as air or water vehicles, for example helicopters, airplanes, boats. Examples of such filtration parts are: suspension devices for motor vehicle gearboxes, suspension devices for helicopter transmission boxes.

An advantage of the foam objects according to the invention is that they can be easily recycled, for example by melting them in an extruder equipped with a degassing outlet (optionally after cutting them into pieces).

EXAMPLES

The following examples illustrate the invention without limiting it.

In the examples below, the tangent delta (tan delta) of the PEBA (foamed or not) is calculated by the ratio of the dissipative module (or "loss module", E ") on the elastic module (or" storage modulus ", E '). The dissipative module E "and the elastic module E" are measured by dynamic mechanical analysis (DMA).

Example 1

A foam is formed from a PEBA A (called "PEBA A-1 foamed"). Foamed PEBA A-1 has a density of 0.65 g / cm ³ .

PEBA A is a block copolymer of PA1 1 and of PTMG blocks of density 1.02 g / cm ³ , having a melting temperature of 135 ° C and a hardness of 32 Shore D 15s.

Foamed PEBA A-1 is compared to non-foamed PEBA A.

The delta tangent of PEBA A-1 foamed and PEBA A unfoamed is measured as indicated above. The operating conditions for the measurement of the dissipative module E "and of the elastic module E" by DMA are as follows:

- Device used: DMA Q800 2;

- Geometry (tools): Tension / Dual Cantilever;

- Test: Temperature sweep with ramp of 2 ° C / min;

Frequency: 1 Hz;

- Amplitude: 20 pm.

The results are summarized in the table above.

Foamed PEBA A-1 has a delta tangent lower than that of non-foamed PEBA A, therefore it has a better vibration filtering property at the temperatures tested.

Example 2

A foam is formed from a PEBA B (called "foamed PEBA B"). Foamed PEBA B has a density of 0.1 g / cm ³ .

PEBA B is a PA12 block and PTMG block copolymer with a density of 1.01 g / cm ³ , having a melting temperature of 159 ° C. and a hardness of 50 Shore D 15 s.

Foamed PEBA B is compared to unfoamed PEBA B.

The delta tangent of the foamed PEBA B and the non-foamed PEBA B is measured as indicated above. The operating conditions for the measurement of the dissipative module E "and of the elastic module E" by DMA are identical to those of example 1.

The results are summarized in Figure 1.

Foamed PEBA B has a lower delta tangent than unfoamed PEBA B, therefore it has a better vibration filtering property at the temperatures tested.

Example 3

A foam is formed from PEBA A (called "PEBA A-2 foamed"). Foamed PEBA A-2 has a density of 0.2 g / cm ³ . The tangent delta of the foamed PEBA A-2 is measured as indicated above. The operating conditions for the measurement of the dissipative module E ”and of the elastic module E 'by DMA are as follows:

Device used: Q800;

- Tools: Compression on a 12 mm diameter pad cut from the foam;

- Test: Frequency sweep from 10 Hz to 100 Hz;

Temperature: 20 ° C;

Applied deformation: 0.1%;

Static force: 5 N.

The results are summarized in Figure 2.

PEBA A-2 foam has a very low tangent delta over a wide frequency range at 20 ° C.

Claims

1. Use of a polyamide block and polyether block copolymer foam for filtering vibrations.

2. Use according to claim 1, wherein the foam is non-crosslinked.

3. Use according to claim 1 or 2, in which the polyamide blocks are blocks of polyamide 6, polyamide 11, polyamide 12, polyamide 5.4, polyamide 5.9, polyamide 5.10, polyamide 5.12, polyamide 5.13, polyamide 5.14, polyamide 5.16, polyamide 5.18, polyamide 5.36, polyamide 6.4, polyamide 6.9, polyamide 6.10, polyamide 6.12, polyamide 6.13, polyamide 6.14, polyamide 6.16, polyamide 6.18, polyamide 6.36, polyamide 10.4, polyamide 10.9, polyamide 10.10, polyamide 10.12, polyamide 10.13, polyamide 10.14, polyamide 10.16, polyamide 10.18, polyamide 10.36, polyamide 10.T, polyamide 12.4, polyamide 12.9, polyamide 12.10, polyamide 12.12, polyamide 12.13, polyamide 12.14, polyamide 12.16, polyamide 12.18, polyamide 12.36, polyamide 12.T or mixtures, or copolymers, of these, preferably polyamide 11, polyamide 12, polyamide 6, or polyamide 6.10.

4. Use according to one of claims 1 to 3, in which the polyether blocks are blocks of polyethylene glycol, propylene glycol, polytrimethylene glycol, polytetrahydrofuran, or mixtures, or copolymers, of these, of preferably polyethylene glycol or polytetrahydrofuran.

5. Use according to one of claims 1 to 4, wherein

the polyamide blocks of the copolymer have a number-average molar mass of 100 to 20,000 g / mol, preferably from 200 to 10,000 g / mol, even more preferably from 200 to 1500 g / mol; and or

6. Use according to one of claims 1 to 5, in which the mass ratio of the polyamide blocks relative to the polyether blocks of the copolymer is from 0.1 to 10, preferably from 0.3 to 3, even more preferably from 0 , 3 to 0.9.

7. Use according to one of claims 1 to 6, wherein the foam has a density less than or equal to 800 kg / m ³ , preferably less than or equal to 600 kg / m ³ , more preferably less than or equal to 400 kg / m ³ , more particularly preferably less than or equal to 300 kg / m ³ .

8. Use according to one of claims 1 to 7, in which the foam also contains one or more additives, preferably chosen from copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylate, and ethylene and alkyl (meth) acrylate copolymers.

9. Vibration filtering piece made of a polyamide block and polyether block copolymer foam as defined in one of claims 1 to 8.

10. A vibration filtering piece comprising at least one element consisting of a polyamide block and polyether block copolymer foam as defined in one of claims 1 to 8.

11. Vibration filtering part according to claim 9 or 10 chosen from household robot feet, such as mixers and mixers, automobile parts or any vehicle, such as the suspension devices of motor vehicle gearboxes. , or the suspension devices of helicopter gearboxes.