Low-density polyether block amide and hollow glass reinforcement composition and its uses

Abstract

The present invention relates to a molding composition comprising, by weight: (A) 65% to 98%, in particular 65% to 95%, of at least one copolyamide having amide units (Ba1) and polyether units (Ba2), (B) 2% to 30%, in particular 5% to 30%, of hollow glass reinforcements, (C) 0 to 5%, preferably 0.1% to 2%, of at least one additive, the sum of the proportions of the components (A) + (B) + (C) of the composition being equal to 100%.

Description

Technical Field

[0001] The present invention relates to a composition comprising at least one polyether block amide (PEBA) and at least one hollow glass reinforcement having a low density, and to its use for the preparation of articles, in particular by injection, especially articles for electronics, sports, motor vehicles or industry. Background Art

[0002] Articles for electronic, sports, motor vehicle or industrial applications must all become lighter in order to consume less energy or minimize the energy consumed, especially when used in a sports context. They must also allow athletes to obtain the sensations necessary for controlling movements and for the rapid transmission of muscle impulses.

[0003] PEBA or PEBA-based compositions are generally used in these applications, where the activity, brightness and ductility of articles containing these compositions are very important, especially at ambient temperature to very low temperatures (e.g. -30 °C).

[0004] The density of PEBA measured according to ISO 1183-3:1999 is generally greater than or equal to 1. However, this density may be too high for certain applications such as those mentioned above and especially for sports.

[0005] In addition, the combination of polyamides and hollow glass beads has also been described in the literature.

[0006] Thus, international application WO 2007 / 058812 describes a composition comprising a thermoplastic resin and beads having a D50 of less than or equal to 25 μm. The composition does not contain PEBA.

[0007] Patent US9321906 describes a composition comprising a host resin selected from polyamides and propylene resins and hollow glass microspheres. The composition does not contain PEBA.

[0008] Application US20170058123 describes a molding composition having a density of less than 0.97 g / cm 3 , which comprises an amorphous polyamide, a microcrystalline or partially semi-crystalline polyamide, hollow glass beads and an impact modifier. The composition does not contain PEBA.

[0009] Application US 2006 / 189784 describes a composition comprising a polyether amide and glass particles, the polyether amide comprising a carboxylic polyamide and a polyether amine.

[0010] In addition, the composition for the above applications must be capable of being easily injected and allow the obtaining of parts having an attractive appearance and the ability to be dyed in various colors.

[0011] Accordingly, the present invention relates to a molding composition which, by weight, comprises:

[0012] (A) 65% to 98%, especially 65% to 95%, of at least one copolyamide having amide units (Ba1) and having polyether units (Ba2),

[0013] (B) 2% to 30%, especially 5% to 30%, of hollow glass reinforcements,

[0014] (C) 0% to 5%, preferably 0.1% to 2%, of at least one additive,

[0015] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0016] Surprisingly, the inventors have found that adding hollow glass beads in a specific proportion range to PEBA enables the obtaining of a composition with low density without loss of rigidity by an injection molding method, while still maintaining good impact strength, good elongation, and good injectability.

[0017] Regarding PEBA (A)

[0018] Polyether block amide (PEBA) is a copolymer having amide units (Ba1) and polyether units (Ba2), the amide units (Ba1) corresponding to aliphatic repeating units selected from: units obtained from at least one amino acid or units obtained from at least one lactam, or units X.Y obtained by polycondensation of:

[0019] - at least one diamine, which is preferably selected from linear or branched aliphatic diamines or mixtures thereof, and

[0020] - at least one carboxylic diacid, which is preferably selected from:

[0021] linear or branched aliphatic diacids or mixtures thereof,

[0022] the diamine and the diacid contain 4 to 36 carbon atoms, advantageously 6 to 18 carbon atoms;

[0023] the polyether units (Ba2) are especially derived from at least one polyalkylene ether polyol, especially polyalkylene ether diol,

[0024] PEBA is produced in particular by the co-condensation of polyamide sequences with reactive ends and polyether sequences with reactive ends, for example, in particular:

[0025] 1) Polyamide sequences with diamine chain ends and polyoxyalkylene sequences with dicarboxylic acid chain ends.

[0026] 2) Polyamide sequences with dicarboxylic acid chain ends and polyoxyalkylene sequences with diamine chain ends (obtained by the cyanoethylation and hydrogenation of α,ω-dihydroxylated aliphatic polyoxyalkylene sequences known as polyalkylene ether diols (polyether diols)).

[0027] 3) Polyamide sequences with dicarboxylic acid chain ends and polyether diols. In this particular case, the product obtained is a polyether ester amide. The copolymers of the present invention are advantageously of this type.

[0028] Polyamide sequences with dicarboxylic acid chain ends, for example, come from the condensation of polyamide precursors in the presence of chain-limiting carboxylic diacids.

[0029] Polyamide sequences with diamine chain ends, for example, come from the condensation of polyamide precursors in the presence of chain-limiting diamines.

[0030] Polyamide and polyether block polymers may also contain randomly distributed units. These polymers can be prepared by the simultaneous reaction of polyether and polyamide block precursors.

[0031] For example, polyether diols, polyamide precursors, and chain-limiting diacids can be reacted. The result is a polymer that essentially has polyether blocks, polyamide blocks of highly variable length, and various reagents that have reacted randomly (statistically) along the polymer chain.

[0032] Alternatively, polyether diamines, polyamide precursors, and chain-limiting diacids can be reacted. The result is a polymer that essentially has polyether blocks, polyamide blocks of highly variable length, and various reagents that have reacted randomly (statistically) along the polymer chain.

[0033] Amide unit (Ba1):

[0034] The amide unit (Ba1) corresponds to the aliphatic repeating unit as defined above.

[0035] Advantageously, the amide unit (Ba1) is selected from polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, especially polyamide 11.

[0036] More advantageously, the amide unit (Ba1) is selected from polyamide 11 and polyamide 12, especially polyamide 11.

[0037] Polyether unit (Ba2):

[0038] The polyether unit is particularly derived from at least one polyalkylene ether polyol, in particular they are derived from at least one polyalkylene ether polyol. In other words, the polyether unit consists of at least one polyalkylene ether polyol. In this embodiment, the expression "at least one polyalkylene ether polyol" means that the polyether unit consists only of the alcohol chain ends and thus cannot be a polyether diamine triblock type compound.

[0039] Therefore, the composition of the present invention does not contain polyether diamine triblocks.

[0040] Advantageously, the polyether unit (Ba2) is selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene glycol (PO3G), polytetramethylene glycol (PTMG) and mixtures or copolymers thereof, in particular PTMG.

[0041] The number average molecular weight (Mn) of the polyether block is advantageously from 200 to 4000 g / mol, preferably from 250 to 2500 g / mol, in particular from 300 to 1100 g / mol.

[0042] The PEBA can be prepared by the following method, wherein:

[0043] - In a first step, the polyamide block (Ba1) is prepared by polycondensation of the following substances in the presence of a chain limiter selected from carboxylic diacids

[0044] lactam, or

[0045] amino acid, or

[0046] diamine and carboxylic diacid; and if desired, comonomers selected from lactam and α-ω amino carboxylic acid;

[0047] Then

[0048] - In a second step, the obtained polyamide block (Ba1) is reacted with the polyether block (Ba2) in the presence of a catalyst.

[0049] The general method for the two-step preparation of the copolymer of the present invention is known and described, for example, in French patent FR2 846 332 and European patent EP 1 482 011.

[0050] The reaction for forming the block (Ba1) is usually carried out at 180 to 300 °C, preferably 200 to 290 °C, the pressure in the reactor is 5 to 30 bar and maintained for about 2 to 3 hours. The pressure is slowly reduced by bringing the reactor to atmospheric pressure, and then the excess water is distilled off, for example for 1 or 2 hours.

[0051] Once a polyamide with carboxylic acid end groups has been prepared, a polyether and a catalyst are added. The polyether can be added in one or more stages, and the catalyst can also be added in one or more stages. In a preferred embodiment, the polyether is added first, and the reaction between the OH end groups of the polyether and the COOH end groups of the polyamide begins with the formation of ester bonds and the removal of water. As much water as possible is removed from the reaction medium by distillation, and then the catalyst is introduced to complete the bonding of the polyamide block and the polyether block. The second step is carried out with stirring, preferably under a vacuum of at least 15 mmHg (2000 Pa), at a temperature such that the reagents and the copolymer obtained are in a molten state. By way of example, the temperature can be from 100 to 400 °C and most commonly from 200 to 300 °C. The reaction is monitored by measuring the torque exerted by the molten polymer on the stirrer or by measuring the electrical power consumed by the stirrer. The end point of the reaction is determined by the target torque or power value.

[0052] One or more molecules used as antioxidants can also be added at the moment considered most appropriate during the synthesis, such as 1010 or 245.

[0053] A PEBA preparation method can also be considered such that all the monomers are added in a single step at the start for the polycondensation of the following substances:

[0054] lactam, or

[0055] amino acid, or

[0056] diamine and dicarboxylic acid; and optionally, other polyamide comonomers;

[0057] - in the presence of a chain limiter selected from dicarboxylic acids;

[0058] - in the presence of block (Ba2) (polyether);

[0059] - in the presence of a catalyst for the reaction between the soft block (Ba2) and the block (Ba1).

[0060] Advantageously, the dicarboxylic acid is used as a chain limiter and is introduced in a stoichiometric excess relative to the diamine.

[0061] Advantageously, a strong acid such as phosphoric acid, hypophosphorous acid or boric acid or a derivative of a metal selected from titanium, zirconium and hafnium is used as a catalyst.

[0062] The polycondensation can be carried out at a temperature of 240 to 280 °C.

[0063] Generally, known copolymers with ether and amide units consist of linear and semi-crystalline aliphatic polyamide sequences (e.g. "Pebax" from Arkema).

[0064] In one embodiment, the copolyamide having an amide unit (Ba1) and a polyether unit (Ba2) has a density of greater than or equal to 1, particularly greater than or equal to 1.01, especially greater than or equal to 1.02, as determined according to ISO 1183-3:1999.

[0065] In one embodiment, polyetheramines are excluded from the polyether unit (Ba2).

[0066] Regarding the hollow glass reinforcement (B)

[0067] The hollow glass reinforcement corresponds to a glass reinforcement material having a hollow (as opposed to solid) structure, and it can have any shape as long as it is hollow.

[0068] The hollow glass reinforcement can in particular be hollow glass fibers or hollow glass beads. In particular, the hollow glass reinforcement is selected from hollow glass beads.

[0069] Before using the composition, the short hollow glass fibers preferably have a length of 2 to 13 mm, preferably 3 to 8 mm.

[0070] Hollow glass fibers refer to glass fibers in which the hollow (or pore or window or void) inside the fiber is not necessarily concentric with the outer diameter of the fiber.

[0071] The hollow glass fibers can be:

[0072] - having a circular cross-section with an outer diameter of 7 μm to 75 μm, preferably 9 μm to 25 μm, more preferably 10 μm to 12 μm.

[0073] Obviously, the diameter of the hollow (the term "hollow" can also be referred to as a pore or window or void) is not equal to the outer diameter of the hollow glass fiber.

[0074] Advantageously, the diameter of the hollow (or pore or window) is 10% to 80%, particularly 60% to 80%, of the outer diameter of the hollow fiber.

[0075] - or having a non-circular cross-section with an L / D ratio (where L represents the maximum dimension of the cross-section of the fiber and D represents the minimum dimension of the cross-section of the fiber) of 2 to 8, particularly 2 to 4. L and D can be measured by scanning electron microscopy (SEM).

[0076] Advantageously, the content of the hollow glass reinforcement is 5 to 25% by weight, preferably 7 to 25% by weight, especially 10 to 25% by weight.

[0077] In one embodiment, the hollow glass reinforcement is hollow glass beads.

[0078] The hollow glass beads are present in the composition in an amount of 2 to 30% by weight, especially 5 to 30% by weight.

[0079] In another embodiment, they are present in an amount of 5 to 25% by weight, especially 7 to 25% by weight, particularly 10 to 25% by weight.

[0080] The hollow glass beads have a compressive strength of at least 50 MPa, and particularly preferably at least 100 MPa, measured in glycerol according to ASTM D 3102-72 (1982).

[0081] Advantageously, the hollow glass beads have a volume average diameter d of 10 to 80 μm, preferably 13 to 50 μm, measured by laser diffraction according to standard ASTM B 822-17. 50 。

[0082] The hollow glass beads can be surface-treated, for example, using systems based on: aminosilanes, epoxysilanes, polyamides (especially water-soluble polyamides), fatty acids, waxes, silanes, titanates, urethanes, polyhydroxyethers, epoxides, nickel, or mixtures thereof, which are suitable for this purpose. The hollow glass beads are preferably surface-treated with aminosilanes, epoxysilanes, polyamides, or mixtures thereof.

[0083] The hollow glass beads can be formed from borosilicate glass, preferably from calcium-borosilicate sodium-oxide carbonate glass.

[0084] The hollow glass beads preferably have a true density of 0.10 to 0.65 g / cm3, preferably 0.20 to 0.60 g / cm3, particularly preferably 0.30 to 0.50 g / cm3, measured according to ASTM standard D 2840-69 (1976) using a gas pycnometer and helium as the measuring gas.

[0085] Advantageously, the hollow glass beads have a compressive strength of at least 50 MPa, especially at least 100 MPa, measured in glycerol according to ASTM D 3102-72 (1982).

[0086] Regarding the composition

[0087] In the first variant, the molding composition comprises, by weight:

[0088] (A) 65 to 98%, especially 65 to 95%, of at least one copolyamide having amide units (Ba1) and having polyether units (Ba2).

[0089] (B) 2 to 30%, especially 5 to 30%, of hollow glass reinforcements.

[0090] (C) 0 to 5%, preferably 0.1 to 2% of at least one additive,

[0091] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0092] In one embodiment of the first variant, the molding composition consists of the following (by weight):

[0093] (A) 65 to 98%, especially 65 to 95% of at least one copolyamide having an amide unit (Ba1) and a polyether unit (Ba2),

[0094] (B) 2 to 30%, especially 5 to 30% of hollow glass reinforcement,

[0095] (C) 0 to 5% of at least one additive,

[0096] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0097] In another embodiment of the first variant, the molding composition consists of the following (by weight):

[0098] (A) 68 to 97.9%, especially 68 to 94.9% of at least one copolyamide having an amide unit (Ba1) and a polyether unit (Ba2),

[0099] (B) 2 to 30%, especially 5 to 30% of hollow glass reinforcement,

[0100] (C) 0.1 to 2% of at least one additive,

[0101] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0102] In the second variant, the composition comprises by weight:

[0103] (A) 70 to 95%, especially 70 to 93%, particularly 70 to 90% of at least one copolyamide having an amide unit (Ba1) and a polyether unit (Ba2),

[0104] (B) 5 to 25%, especially 7 to 25%, particularly 10 to 25% of hollow glass reinforcement,

[0105] (C) 0 to 5%, preferably 0.1 to 2% of at least one additive,

[0106] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0107] In one embodiment of the second variant, the molding composition consists of the following (by weight):

[0108] (A) 70 to 95%, especially 70 to 93%, particularly 70 to 90% of at least one copolyamide having an amide unit (Ba1) and having a polyether unit (Ba2),

[0109] (B) 5 to 25%, especially 7 to 25%, particularly 10 to 25% of hollow glass reinforcement,

[0110] (C) 0 to 5% of at least one additive,

[0111] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0112] In another embodiment of the second variant, the molding composition consists of the following (by weight):

[0113] (A) 73 to 94.9%, especially 73 to 92.9%, particularly 73 to 89.9% of at least one copolyamide having an amide unit (Ba1) and having a polyether unit (Ba2),

[0114] (B) 5 to 25%, especially 7 to 25%, particularly 10 to 25% of hollow glass reinforcement,

[0115] (C) 0.1 to 2% of at least one additive,

[0116] The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

[0117] Advantageously, the molding composition according to the invention has a density of less than 1, more preferably less than 0.98, as determined according to ISO 1183-3:1999.

[0118] More advantageously, the molding composition according to the invention has a density of less than 0.97, even more preferably less than 0.96, as determined according to ISO 1183-3:1999.

[0119] Advantageously, the amide unit (Ba1) corresponds to the aliphatic repeating unit as defined above.

[0120] Advantageously, the amide units (Ba1) of the copolyamide of the composition of the present invention are selected from polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, especially polyamide 11.

[0121] More advantageously, the amide units (Ba1) of the copolyamide of the composition of the present invention are selected from polyamide 11 and polyamide 12, especially polyamide 11.

[0122] Regarding additive (C)

[0123] The additive is optional and accounts for 0 to 5% by weight, especially 0.1 to 2% by weight.

[0124] The additive is selected from fillers, dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, lubricants, flame retardants, natural waxes, impact modifiers, laser marking additives and mixtures thereof.

[0125] As an example, the stabilizer can be a UV stabilizer, an organic stabilizer or more generally a combination of organic stabilizers, such as phenolic antioxidants (e.g., Irganox 245 or type 1098 or 1010 from Ciba - BASF), phosphite antioxidants (e.g., 126 from Ciba - BASF) and even optionally other stabilizers such as HALS (which means hindered amine light stabilizer (e.g., Tinuvin 770 from Ciba - BASF)), anti - UV agents (e.g., Tinuvin 312 from Ciba), phosphorus - based stabilizers. Amine antioxidants such as Naugard 445 from Crompton or even multifunctional stabilizers such as Nylostab S - EED from Clariant can also be used.

[0126] The stabilizer can also be an inorganic stabilizer, such as a copper - based stabilizer. As examples of such inorganic stabilizers, halides and copper acetate can be mentioned. Secondly, other metals such as silver can optionally be considered, but these are known to be less effective. These copper - based compounds are usually related to alkali metal (especially potassium) halides.

[0127] For example, the plasticizer is selected from benzenesulfonamide derivatives, such as n - butylbenzenesulfonamide (BBSA); ethyltoluenesulfonamide or N - cyclohexyltoluenesulfonamide; hydroxybenzoates, such as 2 - ethylhexyl p - hydroxybenzoate and 2 - decylhexyl p - hydroxybenzoate; esters or ethers of tetrahydrofurfuryl alcohol, such as oligoethyleneoxy tetrahydrofurfuryl alcohol; and esters of citric acid or hydroxy - malonic acid, such as oligoethyleneoxy malonate.

[0128] The use of a mixture of plasticizers is not outside the scope of the present invention.

[0129] For example, the filler may be selected from silica, graphite, expanded graphite, carbon black, kaolin, magnesium oxide, slag, talc, wollastonite, mica, nano-fillers (carbon nanotubes), pigments, metal oxides (titanium oxide), metals, advantageously wollastonite and talc, preferably talc.

[0130] For example, the impact modifier is a polyolefin having a modulus of <200 MPa, in particular <100 MPa, measured at 23 °C according to ISO standard 178:2010.

[0131] In one embodiment, the impact modifier is selected from functionalized or non-functionalized polyolefins having a modulus of <200 MPa, in particular <100 MPa, and mixtures thereof.

[0132] Advantageously, the functionalized polyolefin has a functional group selected from maleic anhydride, carboxylic acid, carboxylic anhydride and epoxide functional groups, and is particularly selected from ethylene / octene copolymers, ethylene / butene copolymers, ethylene / propylene (EPR) elastomers, elastomeric ethylene-propylene-diene copolymers (EPDM) and ethylene / (meth)acrylic acid alkyl ester copolymers.

[0133] For example, the laser marking additive is: from MERCK 8850 and from Ampacet Corporation's Laser 1001074-E / Laser 1001088-E.

[0134] According to another aspect, the present invention relates to the use of the composition as defined above for the preparation of articles, in particular for articles for electronics, sports, motor vehicles or industry.

[0135] All the technical features defined above for the composition are also valid for its use.

[0136] In one embodiment, the article is prepared by injection molding.

[0137] According to yet another aspect, the present invention relates to an article obtained by injection molding with the composition as described above.

[0138] All the technical features detailed above for the composition are valid for the article.

[0139] According to another aspect, the present invention relates to the use of a hollow glass reinforcement of 2 to 30% by weight and at least one PEBA, optionally comprising at least one additive for a composition, said PEBA being present in an amount of 65 to 98% by weight, and said additive accounting for 0 to 5% by weight, the density of the composition being lower than the density of the PEBA used alone, optionally accompanied by at least one additive, and the density of the composition being lower than 1.

[0140] All the technical features defined above for the composition are valid for its use. Examples

[0141] Preparation and mechanical properties of the compositions of the present invention:

[0142] The compositions of Tables I and II were prepared by melt blending PEBA pellets with hollow glass beads and optionally additives. The mixture was prepared by compounding on a co-rotating twin-screw extruder with a 26 mm diameter (with a flat temperature profile (T°) at 250 °C). The screw speed was 250 rpm and the flow rate was 15 kg / h.

[0143] The introduction of the hollow glass beads was carried out using a side feeder.

[0144] One or more PEBA and the additives were added in the main hopper during the compounding process.

[0145] The composition was then molded on an injection molding machine (Engel) into dumbbells (see Tables 3 and 4) or rods at a set point temperature of 220 °C and a molding temperature of 50 °C in order to study the properties of the composition according to the following criteria.

[0146] The tensile modulus was measured at 23 °C according to ISO standard 527-1:2012 on 1A dumbbells.

[0147] The machine used was of the INSTRON 5966 type. For modulus measurements, the crosshead speed was 1 mm / min. The test conditions were 23 °C + / - 2 °C, on dry samples.

[0148] The impact strength was determined according to ISO 179-1:2010 / 1eU (Charpy impact) on non-notched rods with dimensions of 80 mm × 10 mm × 4 mm at a temperature of 23 °C + / - 2 °C and a relative humidity of 50% + / - 10%, or on dry samples at -30 °C + / - 2 °C and a relative humidity of 50% + / - 10%.

[0149] The density of the injected composition was measured on a bar measuring 80 mm × 10 mm × 4 mm at a temperature of 23 °C in accordance with ISO standard 1183-3:1999.

[0150] [Table 1]

[0151]

[0152]

[0153] NB: No damage

[0154] [Table 2]

[0155]

[0156] NB: No damage

[0157] Adding hollow glass beads to the PEBA makes it possible to significantly reduce the density of the composition relative to the PEBA alone, and thus obtain a composition that is lighter in weight than the PEBA alone without loss of rigidity and at the same time has very good impact strength and good processability (see Tables 3 and 4).

[0158] 1A dumbbells were obtained by injection on an Engel-type injection molding machine:

[0159] [Table 3]

[0160]

[0161] [Table 4]

[0162]

[0163]

Claims

1. A composition comprising, by weight: (A) 65% to 98% of at least one copolyamide having amide units (Ba1) and having polyether units (Ba2), wherein said amide units (Ba1) correspond to repeating units selected from units obtained from at least one amino acid or units obtained from at least one lactam, or units X.Y obtained from the polycondensation of at least one diamine and at least one dicarboxylic acid, (B) 5% to 30% of hollow glass reinforcements, (C) 0% to 5% of at least one additive, The sum of the proportions of the components (A) + (B) + (C) of the composition is equal to 100%.

2. The composition according to claim 1, wherein The composition comprises, by weight: (A) 65% to 95% of at least one copolyamide having amide units (Ba1) and having polyether units (Ba2).

3. The composition according to claim 1, characterized in that The composition comprises, by weight: (C) 0.1% to 2% of at least one additive.

4. The composition according to any one of claims 1 to 3, characterized in that The polyether units (Ba2) are selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene glycol (PO3G), polytetramethylene glycol (PTMG), and mixtures or copolymers thereof.

5. The composition according to claim 4, characterized in that The polyether units (Ba2) are selected from polytetramethylene glycol (PTMG).

6. The composition according to any one of claims 1 to 3, characterized in that The copolyamide having amide units (Ba1) and having polyether units (Ba2) has a density greater than or equal to 1 as determined according to ISO 1183-3:1999.

7. The composition according to claim 6, wherein The copolyamide having amide units (Ba1) and having polyether units (Ba2) has a density greater than or equal to 1.01 as determined according to ISO 1183-3:1999.

8. The composition according to claim 7, characterized in that The copolyamide having amide units (Ba1) and having polyether units (Ba2) has a density greater than or equal to 1.02 as determined according to ISO 1183-3:1999.

9. The composition according to any one of claims 1 to 3, characterized in that The composition has a density less than 1 as determined according to ISO 1183-3:1999.

10. The composition according to claim 9, wherein The composition has a density less than 0.98 as determined according to ISO 1183-3:1999.

11. The composition according to any one of claims 1 to 3, characterized in that The content of the hollow glass reinforcements is 5 to 25% by weight.

12. The composition according to claim 11, characterized in that The content of the hollow glass reinforcements is 7 to 25% by weight.

13. The composition according to claim 12, wherein The content of the hollow glass reinforcements is 10 to 25% by weight.

14. The composition according to any one of claims 1 to 3, characterized in that The hollow glass reinforcements are hollow glass beads.

15. The composition according to claim 14, wherein The hollow glass beads have a volume average diameter d of 10 to 80 μm measured by laser diffraction in accordance with ASTM standard B 822-17 50 .

16. The composition according to claim 15, wherein The hollow glass beads have a volume average diameter d of 13 to 50 μm measured by laser diffraction in accordance with ASTM standard B 822-17 50 .

17. The composition according to claim 14, characterized in that The hollow glass beads have a true density of 0.10 to 0.65 g / cm measured according to ASTM D2840-69(1976) using a gas pycnometer and helium as the measuring gas. 3 ​ 18. The composition according to claim 17, characterized in that The hollow glass beads have a true density of 0.20 to 0.60 g / cm measured according to ASTM D2840-69(1976) using a gas pycnometer and helium as the measuring gas. 3 ​ 19. The composition according to claim 18, characterized in that The hollow glass beads have a true density of 0.30 to 0.50 g / cm measured according to ASTM D2840-69(1976) using a gas pycnometer and helium as the measuring gas. 3 ​ 20. The composition according to claim 14, wherein The hollow glass beads have a compressive strength of at least 50 MPa as measured in glycerol according to ASTM D3102-72(1982).

21. The composition according to claim 20, wherein The hollow glass beads have a compressive strength of at least 100 MPa as measured in glycerol according to ASTM D3102-72(1982).

22. The composition according to any one of claims 1 to 3, characterized in that The amide units (Ba1) are selected from polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012.

23. The composition according to claim 22, characterized in that The amide units (Ba1) are selected from polyamide 11.

24. The composition according to any one of claims 1 to 3, characterized in that The amide units (Ba1) are selected from polyamide 11 and polyamide 12.

25. The composition according to claim 24, characterized in that The amide units (Ba1) are selected from polyamide 11.

26. The composition according to any one of claims 1 to 3, characterized in that The at least one additive is selected from fillers, dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, optical brighteners, antioxidants, lubricants, flame retardants, natural waxes, impact modifiers and mixtures thereof.

27. Use of a composition as defined in any one of claims 1 to 26 for the preparation of an article.

28. The use according to claim 27, wherein The article is selected from articles for electronics, sports, motor vehicles or industry.

29. Use according to claim 27 or 28, characterized in that The article is prepared by injection molding.

30. An article obtained by injection molding with a composition as defined in any one of claims 1 to 26.

31. Use of a hollow glass reinforcement of 2 to 30% by weight as defined in any one of claims 1 to 26 and at least one copolyamide having amide units (Ba1) and having polyether units (Ba2), optionally comprising at least one additive as defined in any one of claims 1 to 26, for forming a composition as defined in any one of claims 1 to 26, the copolyamide having amide units (Ba1) and having polyether units (Ba2) being present in an amount of 65 to 98% by weight, and the additive being present in an amount of 0 to 5% by weight, the density of the composition being lower than the density of the copolyamide having amide units (Ba1) and having polyether units (Ba2) used alone, optionally in the presence of at least one additive, and the density of the composition being lower than 1.

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