Polyamide composition

Abstract

The present invention relates to polyamides, compositions containing the polyamides, their uses, molded articles derived therefrom, and methods for their production. The polyamides are the product of polycondensation between an acid component and an amine component, where the acid component contains, per mole of the acid component, 25-50 mol% of at least one fatty acid dimer, 46-70 mol% of at least one aliphatic diacid, and 0-11 mol% of at least one chain terminator; and the amine component contains, per mole of the amine component, 13-29 mol% of at least one aliphatic diamine and 66-82 mol% of at least one alicyclic diamine. The polyamides are particularly suitable for use as hot melt adhesives for low-pressure, low-temperature overmolding of heat-sensitive batteries, such as lithium polymer batteries.

Description

[Technical Field]

[0001] The present invention relates to polyamides, compositions containing same, their uses, molded articles derived therefrom, and methods for producing same. The polyamides are particularly suitable as hot melt adhesives for low pressure, low temperature overmolding of heat sensitive batteries, such as lithium polymer batteries. [Background technology]

[0002] Many portable electronic devices are equipped with batteries, allowing them to be used without the need to connect to a power supply network. To give them sufficient strength, protect them from environmental conditions, and prevent improper handling by users, batteries are usually packaged in protective casings. Battery casings are usually made from low-pressure injected plastics, for example by overmolding starting from polyamide.

[0003] Although batteries that exhibit satisfactory performance, e.g., lithium-ion batteries, are already available, new technological (e.g., battery life, performance, weight), industrial (e.g., starting materials), and / or regulatory (e.g., interoperability, recyclability) constraints necessitate the development of alternative technologies, e.g., lithium-polymer batteries.

[0004] Lithium polymer batteries (or lithium ion polymer batteries), also referred to as LiPo, LIP, Li-poly, or lithium-poly, are rechargeable batteries that use a polymer electrolyte instead of a liquid electrolyte. These batteries are advantageous in that they can be replaced without destroying or damaging the electronic device containing the battery. This allows for an increase in the lifespan of the electronic device. Furthermore, this allows for the battery to be recycled if the electronic device containing the battery is broken. Finally, these batteries exhibit sufficient performance. However, they have the disadvantage of being sensitive to temperature and pressure. For example, conventional methods for low-pressure overmolding used for lithium ion batteries are unsuitable in that they use plastics, such as polyamide, that need to be injected at high temperatures, usually above 200°C.

[0005] Overmolding methods and / or various types of polyamides are well known.

[0006] For example, application EP 1533331 A1 describes, in particular, at least one dimerized unsaturated C 12 ~C 24 Fatty acids and at least one aliphatic C6-C 18 an acid component containing a dicarboxylic acid; at least one C2-C8 alkylenediamine; at least one C 24 ~C 48 The present invention relates to polyamides that are the polycondensation product of an amide dimer and an amine component that includes at least one polyoxyalkylene diamine.

[0007] Patent EP2094802B1 relates in particular to a molding element for bonding to a substrate of metal or synthetic material as a fastening device, comprising a hot melt adhesive, and also to the use of a polyamide-based hot melt adhesive for the production of the molding element, in which the polyamide is a polyamide containing 20 to 50 mol % of a dimer fatty acid and / or C4 to C 18 Dicarboxylic acids, 0-5 mol% C 12 ~C 22The hot melt adhesive comprises a fatty acid monomer, 5 to 50 mol% of an aliphatic polyamide, 0 to 40 mol% of an alicyclic diamine, and 0 to 35 mol% of a polyether diamine, and has a softening temperature of between 150°C and 250°C and a tensile strength of 1 to 35 MPa.

[0008] Patent EP 2298830 B1 describes, in particular, a method for producing molded parts in a low-pressure injection molding process, comprising the steps of: at least one dimer fatty acid, at least one aliphatic C6-C 24 The present invention relates to the use of polyamides based on the reaction product of dicarboxylic acids and aliphatic diamines, alicyclic diamines, and / or polyether diamines, in which the amount of amine component is selected so that the amine groups are mainly contained in terminal positions, and which have an amine value of 2 to 20 mg KOH / g.

[0009] Application CN108148198A specifically describes a hot melt polyamide adhesive that can be low pressure injection molded, containing 80-100 mol% of at least one C 14 ~C 18 dicarboxylic acids, 10 to 90 mol % of at least one C2-C 20 The present invention relates to a hot-melt polyamide adhesive containing a polyamide obtained by reacting an aliphatic amine, 10 to 80 mol% of an alicyclic amine, and 0 to 80 mol% of at least one polyetheramine, wherein the polyamide does not contain a fatty acid dimer, and the total amount of diamines is 100 mol%.

[0010] Application CN109705797A particularly relates to a polyamide-type injection molding material for packaging batteries, comprising 50 mol% of component A and 50 mol% of component B; component A comprising 80-95 mol% of an aliphatic fatty acid dimer and 5-20% of an aliphatic dicarboxylic acid; component B comprising 70-90 mol% of a diamine and 10-30% of a polyetheramine; and 5-20% by weight of a rosin-type resin.

[0011] Application WO2017 / 007648A1 describes a dimer of hydrogenated fatty acid, saturated linear C6-C 14It relates to a transparent polyamide that is the reaction product of a carboxylic acid, an aliphatic C4-C8 diamine, and dipiperidine.

[0012] Patent EP 2311118 B1 relates in particular to a method for manufacturing a battery, by which the cell package consisting of at least one individual cell in a cell casing, and the electronic component consisting essentially of a coated hardened plastic part integrated so that the electronic safety circuit and the external contact surfaces of the battery are components of one and the same electronic component, can be loaded and positioned in an injection mould during the one-stage manufacture of the battery, and the remaining free space can be filled with a mass of liquid plastic which is subsequently hardened.

[0013] However, there is a real need to provide polyamides that can be used in hot melt adhesives and that are suitable for low-pressure, low-temperature injection molding processes. In particular, there is a need to provide polyamides that are suitable for overmolding heat-sensitive elements, especially lithium polymer batteries. In particular, there is a need to provide polyamides that can be injection molded at lower temperatures than conventional overmolding processes while retaining sufficient mechanical and thermal properties. There is also a need to provide polyamides that can be easily recycled after being injection molded onto heat-sensitive devices. Summary of the Invention

[0014] The present invention first provides a polyamide that is a product of polycondensation of an acid component and an amine component, The acid component is: - 25 to 50 mol %, preferentially 30 to 50 mol %, very preferentially 35 to 50 mol % of at least one fatty acid dimer; - 46 to 70 mol %, preferentially 49 to 70 mol %, very preferentially 52 to 70 mol % of at least one aliphatic dibasic acid; - 0 to 11 mol %, preferentially 0 to 10 mol %, very preferentially 2 to 5 mol % of at least one chain limiter; Contains The amine component is, per mole of amine component: - 13 to 29 mol %, preferentially 16 to 26 mol %, very preferentially 19 to 23 mol % of at least one aliphatic diamine; - 66 to 82 mol %, preferentially 69 to 79 mol %, very preferentially 72 to 76 mol % of at least one cycloaliphatic diamine; and - 0 to 15 mol %, preferentially 0 to 10 mol %, very preferentially 3 to 5 mol % of at least one polyetheramine; Contains The polyamide comprises a molar ratio of -COOH / (-NH and / or -NH2) between 1.00 and 1.20, preferentially between 1.04 and 1.15, very preferentially between 1.07 and 1.11.

[0015] In an embodiment, the fatty acid dimer is the product of a coupling reaction of an unsaturated monocarboxylic acid; preferentially selected from unsaturated monocarboxylic acids containing from 10 to 22 carbon atoms; very preferentially selected from unsaturated monocarboxylic acids containing from 12 to 18 carbon atoms; and even more preferentially selected from unsaturated monocarboxylic acids containing from 16 to 18 carbon atoms.

[0016] In an embodiment, the aliphatic dibasic acid is selected from saturated aliphatic dicarboxylic acids; preferentially linear or branched saturated aliphatic dicarboxylic acids; very preferentially linear saturated dicarboxylic acids having 4 to 22 carbon atoms; more preferentially succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, thapsic acid, and mixtures thereof; and even more preferentially azelaic acid, sebacic acid, dodecanedioic acid, and mixtures thereof.

[0017] In an embodiment, the chain limiter is selected from a monocarboxylic acid, an anhydride, a monohalogenated acid, a monoester or a monoisocyanate; preferentially, the chain limiter is a monocarboxylic acid; very preferentially, the chain limiter is selected from an aliphatic monocarboxylic acid, an alicyclic acid, an aromatic monocarboxylic acid, and mixtures thereof; even more preferentially, the chain limiter is an aliphatic monocarboxylic acid.

[0018] In an embodiment, the aliphatic diamine is a linear or branched saturated aliphatic diamine; preferentially of the formula H2N-(CH2) n saturated linear aliphatic diamines of the formula -NH2 (n is between 2 and 12); very preferentially selected from ethylenediamine, propanediamine, butanediamine, pentanediamine, hexanediamine, decanediamine, and mixtures thereof; more preferentially, the aliphatic diamine is ethylenediamine.

[0019] In embodiments, the alicyclic diamine is selected from the group consisting of bis(3,5-dialkyl-4-aminocyclohexyl)methane, bis(3,5-dialkyl-4-aminocyclohexyl)ethane, bis(3,5-dialkyl-4-aminocyclohexyl)propane, bis(3,5-dialkyl-4-aminocyclohexyl)butane, bis(3-methyl-4-aminocyclohexyl)methane (BMACM or MACM), bis(p-aminocyclohexyl)methane (PACM), isopropylidenedi(cyclohexyl)methane (PACM), and bis(3,5-dialkyl-4-aminocyclohexyl)methane (BMACM). cyclohexanediamine), cycloaliphatic diamines having a carbon-based skeleton (e.g., norbornylmethane, cyclohexylmethane, dicyclohexylpropane, di(methylcyclohexyl), di(methylcyclohexyl)propane), and mixtures thereof; preferentially, the cycloaliphatic diamine is piperazine.

[0020] In some embodiments, the polyetheramine is selected from polyoxyalkylenediamines having a number average molecular weight (Mn) ranging from 200 to 4000 g / mol; preferentially, the polyetheramine is selected from polyoxypropylenediamine, polyoxybutylenediamine, bis(diaminopropyl)polytetrahydrofuran, and mixtures thereof; very preferentially, the polyetheramine is polyoxypropylenediamine.

[0021] In embodiments, the polyamide is a polycondensation product of an acid component and an amine component; The acid component is: 35-50 mole % of at least one fatty acid dimer; 52-70 mole % of at least one aliphatic dibasic acid; 2-5 mol % of at least one chain limiter; Contains The amine component is, per mole of amine component: 19-23 mole % of at least one aliphatic diamine which is ethylenediamine; 72 to 76 mole % of at least one alicyclic diamine that is piperazine; and 3 to 5 mole percent of at least one polyetheramine that is a polyoxypropylene diamine; Contains The polyamide comprises a molar ratio of —COOH / (—NH and / or —NH 2 ) of 1.07 to 1.11.

[0022] The present invention secondly relates to a composition containing the polyamide defined above.

[0023] In an embodiment, the composition contains at least one additive; preferentially at least one additive selected from fillers, antioxidants or stabilizers, mold release agents, adhesion promoters, pigments, and mixtures thereof.

[0024] In an embodiment, the polyamide has a viscosity at a temperature of 150° C. of less than or equal to 10,000 mPa.s; preferentially between 3,000 and 6,000 mPa.s.

[0025] In an embodiment, the polyamide composition has a softening point of 150°C or less; preferentially between 100 and 145°C; very preferentially between 115°C and 140°C.

[0026] The invention thirdly relates to a molded article comprising an insert, preferentially a lithium polymer battery, and a polyamide composition as defined above, the insert being at least partly overmolded with the polyamide composition.

[0027] Fourthly, the present invention provides a method for producing a molded article, comprising: - providing the mold; - Inserting an insert, preferentially a lithium polymer battery, into the mould; - heating the polyamide composition to a temperature of not more than 150°C, preferentially between 120°C and 150°C, to obtain a molten polyamide composition; - 0.5×10 5 ~50×10 5 Pa, preferentially 2 × 10 5 ~40×10 5 injecting the molten polyamide composition at a pressure of 100 Pa; - cooling the injected polyamide composition; - optionally removing the resulting molded article from the mold.

[0028] The present invention relates in a fifth aspect to the use of the polyamide defined above or a composition containing it as a hot melt adhesive for low pressure overmolding of heat sensitive batteries.

[0029] The present invention makes it possible to meet the above-mentioned needs.

[0030] Surprisingly, the inventors have demonstrated that the polyamides of the present invention are particularly suitable for producing casings for batteries, especially lithium polymer batteries. This is because the polyamides, or compositions containing them, can be injected at low pressure and low temperature, especially at temperatures below 150°C, making them particularly suitable for overmolding heat-sensitive elements, especially heat-sensitive batteries. Furthermore, although the viscosity and softening point of the polyamides are lower than those of known polyamides used in battery overmolding methods, the casings obtained by overmolding exhibit sufficient mechanical and thermal properties, especially sufficient impact strength, even under high temperature gradients during use (e.g., depending on the season and heating of electronic devices). Finally, the adhesion of injection-molded polyamides to various types of substrates (e.g., acrylonitrile-butadiene-styrene or ABS substrates) is sufficient. DETAILED DESCRIPTION OF THE INVENTION

[0031] The invention will now be described in more detail and in a non-limiting manner in the following description.

[0032] For the purposes of the present invention, the term "hot melt" is intended to mean the ability of the polyamide to melt under the influence of heat.

[0033] In this specification, unless otherwise indicated, all percentages given are mole percentages.

[0034] For the purposes of the present invention, the expressions "between" or "to" are intended to mean that the limits are included in the stated range.

[0035] polyamide In a first aspect, the present invention provides a polyamide that is the product of the polycondensation of an acid component and an amine component, comprising: The acid component is: - 25 to 50 mol %, preferentially 30 to 50 mol %, very preferentially 35 to 50 mol % of at least one fatty acid dimer; - 46 to 70 mol %, preferentially 49 to 70 mol %, very preferentially 52 to 70 mol % of at least one aliphatic dibasic acid; - 0 to 11 mol %, preferentially 0 to 10 mol %, very preferentially 2 to 5 mol % of at least one chain limiter; Contains The amine component is, per mole of amine component: - 13 to 29 mol %, preferentially 16 to 26 mol %, very preferentially 19 to 23 mol % of at least one aliphatic diamine; - 66 to 82 mol %, preferentially 69 to 79 mol %, very preferentially 72 to 76 mol % of at least one cycloaliphatic diamine; and - 0 to 15 mol %, preferentially 0 to 10 mol %, very preferentially 3 to 5 mol % of at least one polyetheramine; Contains The polyamide comprises a molar ratio of -COOH / (-NH and / or -NH2) between 1.00 and 1.20, preferentially between 1.04 and 1.15, very preferentially between 1.07 and 1.11.

[0036] The molar ratio -COOH / (-NH and / or -NH2) between the carboxylic acid functions and the primary and / or secondary amine functions, the content of which is expressed in mg KOH / g, is determined potentiometrically.

[0037] The polyamides can be obtained by polycondensation of acid and amine components according to conventional methods. Depending on the method used, the polyamides can be random or block polymers, preferentially random polymers.

[0038] Fatty Acid Dimers Fatty acid dimers are polymerized fatty acids that refer to compounds produced from the coupling reaction of unsaturated fatty acids, resulting in a mixture of products bearing two acid functional groups. Fatty acid dimers can be obtained by the dimerization reaction of unsaturated monocarboxylic acids. Thus, fatty acid dimers are reaction products of the coupling of unsaturated monocarboxylic acids. Unsaturated monocarboxylic acids are those with 10 to 22 carbon atoms (C 10 ~C 22 ), unsaturated monocarboxylic acids containing preferentially 12 to 18 carbon atoms (C 12 ~C 18 ), unsaturated monocarboxylic acids containing very preferentially 16 to 18 carbon atoms (C 16 ~C 18 The unsaturated monocarboxylic acid may be selected from the group consisting of carboxylic acids.

[0039] The fatty acid dimers can be obtained from unsaturated monocarboxylic acids by well-known methods, for example as described in patent applications US 2793219 and US 2955121. The unsaturated monocarboxylic acids can be chosen from oleic acid, linoleic acid, linolenic acid, and mixtures thereof.

[0040] Depending on whether they are crude or distilled, fatty acid dimers exhibit dimer contents ranging from 75% to over 98% depending on the commercial grade, as a mixture of monomers, trimers, and more or less of the higher homologues.

[0041] Fatty acid dimers are commercially available from Oleon under the name Radiacid®, from Croda under the name Pripol® or from Kraton under the name Unydime®.

[0042] Aliphatic dibasic acids Throughout this specification, the expressions "diacid," "carboxylic diacid," and "dicarboxylic acid" refer to the same product.

[0043] Aliphatic dibasic acids are saturated aliphatic dicarboxylic acids; preferentially linear or branched saturated aliphatic dicarboxylic acids; very preferentially dicarboxylic acids having from 4 to 22 carbon atoms (C4-C 22 ) saturated aliphatic dicarboxylic acids; more preferentially succinic acid (butanedioic acid) (C4), glutaric acid (pentanedioic acid) (C5), adipic acid (hexanedioic acid) (C6), pimelic acid (heptanedioic acid) (C7), suberic acid (octanedioic acid) (C8), azelaic acid (nonanedioic acid) (C9), sebacic acid (decanedioic acid) (C 10 ), undecanedioic acid (C 11 ), dodecanedioic acid (C 12 ), brassylic acid (tridecanedioic acid) (C 13 ), tetradecanedioic acid (C 14 ), pentadecanedioic acid (C 15 ), thapsic acid (hexadecanedioic acid) (C 16 ), and mixtures thereof; even more preferentially azelaic acid (C9), sebacic acid (C 10 ), dodecanedioic acid (C 12 ), and mixtures thereof.

[0044] Chain limiting agent The polyamides of the present invention are synthesized by conventional methods, optionally in the presence of at least one chain limiting agent.

[0045] The chain limiter may be selected from monocarboxylic acids, anhydrides (e.g. phthalic anhydride), monohalogenated acids, monoesters or monoisocyanates; preferentially, the chain limiter is a monocarboxylic acid; very preferentially, the chain limiter is selected from aliphatic monocarboxylic acids, cycloaliphatic acids, aromatic monocarboxylic acids, and mixtures thereof; even more preferentially, the chain limiter is an aliphatic monocarboxylic acid.

[0046] The monocarboxylic acid may be an aliphatic monocarboxylic acid selected from acetic acid, propionic acid, lactic acid, valeric acid, caproic acid, capric acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, isobutyric acid, or a mixture thereof. The alicyclic acid may be cyclohexanecarboxylic acid. The aromatic monocarboxylic acid may be selected from benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid, and a mixture thereof.

[0047] Chain limiters are commercially available from Oleon under the name Radiacid®.

[0048] Aliphatic diamines Aliphatic diamines are linear or branched saturated aliphatic diamines; preferentially of the formula H2N-(CH2) n -NH2 (n is between 2 and 12) saturated linear aliphatic diamines; very preferentially they can be selected from ethylenediamine, propanediamine, butanediamine, pentanediamine, hexanediamine, decanediamine, and mixtures thereof; more preferentially, the aliphatic diamine is ethylenediamine. Advantageous branched aliphatic diamines include 2-methylpentamethylenediamine, 1,3-pentanediamine, methylpentanediamine, and trimethylhexamethylenediamine.

[0049] Alicyclic diamine Alicyclic diamines include bis(3,5-dialkyl-4-aminocyclohexyl)methane, bis(3,5-dialkyl-4-aminocyclohexyl)ethane, bis(3,5-dialkyl-4-aminocyclohexyl)propane, bis(3,5-dialkyl-4-aminocyclohexyl)butane, bis(3-methyl-4-aminocyclohexyl)methane (BMACM or MACM), bis(p-aminocyclohexyl)methane (PACM), isopropylidenedi(cyclohexyl)a The diamine may be selected from polyaminoethylamine (PACP), isophoronediamine, piperazine, aminoethylpiperazine, dimethylpiperazine, 4,4'-trimethylenedipiperidine, 1,4-cyclohexanediamine, cycloaliphatic diamines having a carbon-based skeleton (e.g., norbornylmethane, cyclohexylmethane, dicyclohexylpropane, di(methylcyclohexyl), di(methylcyclohexyl)propane), and mixtures thereof; preferentially, the cycloaliphatic diamine is piperazine.

[0050] A non-exhaustive list of these cycloaliphatic diamines is given in the publication "Cycloaliphatic Amines" (Encyclopedia of Chemical Technology, Kirk-Othmer, 4th edition (1992), pp. 386-405).

[0051] Polyetheramine The polyetheramine can be selected from polyoxyalkylene diamines having a number average molecular weight (Mn) ranging from 200 to 4000 g / mol. Preferably, the polyetheramine comprises a polyoxyalkylene chain carrying an amine group at the chain end. The polyetheramine can be selected from polyoxypropylene diamines, polyoxybutylene diamines, bis(diaminopropyl)polytetrahydrofurans, and mixtures thereof; very preferably, the polyetheramine is polyoxypropylene diamine.

[0052] Polyetheramines are commercially available from Huntsman under the name Jeffamine® and from BASF under the name Baxxodur®.

[0053] In one particular embodiment, the polyamide is the product of polycondensation of an acid component and an amine component; The acid component is: - 35-50% of at least one fatty acid dimer; - 52-70% of at least one aliphatic dibasic acid; - 2-5% of at least one chain limiter; Contains The amine component is, per mole of amine component: - 19-23% of at least one aliphatic diamine, which is ethylenediamine (C2); - 72 to 76% of at least one cycloaliphatic diamine that is piperazine; and - 3-5% of at least one polyetheramine, which is a polyoxypropylenediamine; Contains The polyamide comprises a molar ratio of -COOH / (-NH+-NH2) of 1.07 to 1.11.

[0054] Polyamides can be prepared according to conventional methods. For example, all the reagents are placed in a suitable reactor equipped with a mixer and then heated under nitrogen at a temperature between 190 and 250 °C for 20 to 500 minutes (until the volume of the distillate no longer increases under nitrogen flush). The reactor is then filled with 5 × 10 5 From 500 x 10 5 The mixture is placed under vacuum at a pressure between 5 and 500 mPa (5 to 500 mbar) and maintained under these conditions until the desired viscosity is obtained.

[0055] composition In a second aspect, the present invention relates to a composition containing a polyamide as defined above.

[0056] The polyamide composition may contain at least one additive in addition to the polyamide obtained by polycondensation of the acid component and the amine component.

[0057] The additives may be selected from fillers, antioxidants or stabilizers, mold release agents, adhesion promoters, pigments, and mixtures thereof.

[0058] The adhesive composition may contain 0 to 5%, preferentially 0.5 to 5%, of additives relative to the weight of the polyamide.

[0059] In one embodiment, the polyamide composition does not contain a tackifying resin.

[0060] The polyamide composition may have a viscosity of less than or equal to 10,000 mPa.s, preferentially between 3,000 and 6,000 mPa.s, at a temperature of 150° C. The viscosity is measured in accordance with the ASTM D3236 standard using a Brookfield apparatus and an SC4-A27 spindle.

[0061] The polyamide composition may have a softening point (softening temperature) of not more than 150° C., preferentially between 100 and 145° C., and very preferentially between 115 and 140° C. The softening point may be measured in accordance with the ASTM D3461 standard using a “cup and ball” apparatus and a temperature gradient of 2° C. / min.

[0062] The polyamide composition may also have a tensile strength of 1.5 to 3.1 MPa. The tensile strength can be measured in accordance with ISO 527 standard by preparing type 1A test specimens and applying tension to these test specimens using a dynamometer at a rate of 50 mm / min.

[0063] The polyamide composition may also have an elongation at break of 70 to 170%. The elongation at break may be measured in accordance with ISO 527 standard by preparing type 1A test specimens and applying tension to these specimens using a dynamometer at a rate of 50 mm / min.

[0064] The polyamide composition may also have a Shore A hardness of 60 to 80. The Shore A hardness may be measured in accordance with the ISO 868 standard using a hardness tester and recording the values ​​immediately and after 15 seconds.

[0065] The polyamide composition may also have a Shore D hardness of 15 to 30%, which may be measured in accordance with ISO 868 standard by using a hardness tester to record the values ​​immediately and after 15 seconds.

[0066] Molded product In a third aspect, the present invention relates to a molded article comprising an insert and a polyamide composition as described above, the insert being at least partially overmolded with the polyamide composition. The insert can be a battery, preferentially a heat-sensitive battery, very preferentially a lithium polymer battery.

[0067] The molded article may further comprise a substrate. The substrate may be made of a material selected from plastic, metal, glass, ceramic or any other suitable substance, preferably plastic; very preferably, the plastic is a thermoplastic polymer. For example, the thermoplastic polymer may be acrylonitrile-butadiene-styrene (ABS).

[0068] In one embodiment, the polyamide composition can be injected between the insert and the substrate to ensure adhesion of the two parts together. In this configuration, the substrate forms the outer casing of the molded article. In another embodiment, the polyamide composition can be injected around the insert and, if present, the substrate. In this configuration, the overmolded polyamide composition forms the outer casing of the molded article. Any other configurations are possible.

[0069] The insert around which the polyamide composition is overmolded can be any suitable insert, particularly a battery, especially a rechargeable battery, such as those used in electronic devices such as phones and laptops, hi one preferred embodiment, the insert is a polymer lithium battery.

[0070] The molded article can be obtained by any suitable molding method, such as extrusion, cast molding, injection molding, compression molding, or transfer molding. In one preferred embodiment, the molded article is obtained by a method based on low temperature and low pressure injection, as described below.

[0071] Method for manufacturing molded articles In a third aspect, the present invention relates to a method for producing a molded article.

[0072] The low-temperature, low-pressure injection method is - providing the mold; - inserting the part to be adhesively bonded (insert), preferentially a lithium polymer battery, into the mould; - heating the polyamide composition to a temperature of not more than 150°C, preferentially between 120°C and 150°C, to obtain a molten polyamide composition; - 0.5×10 5 ~50×10 5 Pa, preferentially 2 × 10 5 ~40×10 5 injecting the molten polyamide composition at a pressure of 100 Pa; - cooling the injected polyamide composition; - optionally removing the resulting molded article from the mold.

[0073] Depending on the construction, the mold may form an integral part of the molded article (for example, if the polyamide composition is injected between the insert and the substrate) or may be removed after overmolding of the polyamide composition.

[0074] The use of the polyamide composition to obtain a molded article is particularly advantageous in that the polyamide composition can be molded at low pressure, that the polyamide composition exhibits sufficient flow properties at molding temperatures of 150° C. or less, and that the polyamide composition exhibits sufficient temperature strength in a molded state. These properties make the polyamide composition suitable for molding electronic devices that are sensitive to high temperatures and generate heat, particularly lithium polymer batteries.

[0075] use In a fourth aspect, the present invention relates to the use of a polyamide as defined above or a polyamide composition containing it as a hot melt adhesive for the low pressure overmolding of heat sensitive batteries, preferentially lithium polymer batteries, and optionally their substrates. [Example]

[0076] The following examples illustrate the present invention but do not limit it.

[0077] Materials used Fatty acid dimer: Radiacid 0970® from Oleon (fatty acid dimer, refined, high purity); Aliphatic monobasic acid: Radiacid 0944® (aliphatic monobasic acid) from Oleon; Aliphatic dibasic acids 1: Sebacic acid; Aliphatic dibasic acids 2: dodecanedioic acid; Aliphatic dibasic acids 3: azelaic acid; Aliphatic diamines: ethylenediamine; Cyclic diamines: piperazine; Polyetheramine: Jeffamine D2000® (polyoxypropylene diamine) from Huntsman; Fillers: liquid dyes based on carbon black (2.5-10%); Release agent: ethylene bis-stearamide.

[0078] Method for preparing polyamides All reactants were charged into a suitable reactor equipped with a mixer and then heated under nitrogen for 4 hours 30 minutes to a temperature of 225° C. The reactor was subsequently held at this temperature for 2 hours 30 minutes and then placed under vacuum at a pressure between 1000 and 5000 Pa for 1 hour.

[0079] polyamide TIFF0007811581000001.tif84170

[0080] Polyamide composition TIFF0007811581000002.tif51170

[0081] The weight percentages of fillers and molding agents are expressed relative to the weight of polyamide.

[0082] result TIFF0007811581000003.tif50170

[0083] Compositions 1 to 4, which contain polyamides P1 to P4, respectively, have viscosities and softening points that are particularly suitable for their use as hot-melt adhesives in methods for overmolding heat-sensitive inserts, in particular lithium polymer batteries, and make it possible to obtain molded articles with sufficient mechanical and thermal properties.

Claims

1. A polyamide that is the product of the polycondensation of an acid component and an amine component, The acid component is, per mole of the acid component: 25 to 50 mole % of at least one fatty acid dimer; 46 to 70 mole % of at least one aliphatic diacid; 0 to 11 mole % of at least one chain limiter; Including, The amine component has, per mole of the amine component: 13 to 29 mole % of at least one aliphatic diamine; 66 to 82 mole % of at least one cycloaliphatic diamine; and 0 to 15 mole % of at least one polyetheramine; Including, The polyamide has a -COOH / (-NH and / or -NH ２ ) molar ratio of the polyamide.

2. 2. The polyamide of claim 1, wherein the fatty acid dimer is the product of a coupling reaction of unsaturated monocarboxylic acids.

3. 3. Polyamide according to claim 1, wherein the aliphatic dibasic acid is chosen from saturated aliphatic dicarboxylic acids.

4. 4. Polyamide according to any one of claims 1 to 3, wherein the chain limiter is selected from monocarboxylic acids, anhydrides, monohalogenated acids, monoesters or monoisocyanates.

5. 5. Polyamide according to any one of claims 1 to 4, wherein the aliphatic diamine is chosen from linear or branched saturated aliphatic diamines.

6. Alicyclic diamines include bis(3,5-dialkyl-4-aminocyclohexyl)methane, bis(3,5-dialkyl-4-aminocyclohexyl)ethane, bis(3,5-dialkyl-4-aminocyclohexyl)propane, bis(3,5-dialkyl-4-aminocyclohexyl)butane, bis(3-methyl-4-aminocyclohexyl)methane (BMACM or MACM), bis(p-aminocyclohexyl)methane (PACM), isopropylidenedi(cyclohexylamine) (PACP), isophoronediamine, pipette, 6. The polyamide of claim 1, wherein the alkyl esters of the alkyl esters are selected from the group consisting of piperazine, aminoethylpiperazine, norbornylmethane, cyclohexylmethane, dicyclohexylpropane, di(methylcyclohexyl), di(methylcyclohexyl)propane, 1,4-cyclohexanediamine, 4,4'-diamino-dicyclohexylmethane, piperazine, cyclohexane-bis-(methylamine), isophoronediamine (IPDA), dimethylpiperazine, dipiperidylpropane, norbornanediamine, and mixtures thereof.

7. 7. Polyamide according to any one of claims 1 to 6, wherein the polyetheramine is chosen from polyoxyalkylenediamines having a number average molecular weight (Mn) in the range of 200 to 4000 g / mol.

8. the polyamide is a polycondensation product of an acid component and an amine component; The acid component is, per mole of the acid component: 35 to 50 mole % of at least one fatty acid dimer; 52 to 70 mole % of at least one aliphatic diacid; 2-5 mol % of at least one chain limiter; Including, The amine component has, per mole of the amine component: 19 to 23 mole % of at least one aliphatic diamine which is ethylenediamine; 72 to 76 mole % of at least one cycloaliphatic diamine which is piperazine; and 3 to 5 mole % of at least one polyetheramine which is a polyoxypropylene diamine; Including, The polyamide has a -COOH / (-NH and / or -NH ２ 8. The polyamide according to claim 1, comprising a molar ratio of:

9. A composition comprising the polyamide of any one of claims 1 to 8.

10. 10. The composition of claim 9, comprising at least one additive.

11. 11. The composition of any one of claims 9 to 10, wherein the polyamide composition has a viscosity of 10,000 mPa s or less at a temperature of 150°C.

12. 12. The composition of any one of claims 9 to 11, wherein the polyamide composition has a softening point of 150°C or less.

13. 13. A molded article comprising an insert and the polyamide composition of any one of claims 9 to 12, wherein the insert is at least partially overmolded with the polyamide composition.

14. 1. A method for producing a molded article, comprising: providing a mold; Inserting an insert into the mold; a step of heating the polyamide composition according to any one of claims 9 to 12 to a temperature of 150°C or less to obtain a molten polyamide composition; 0.5 x 10 ５ ~50 x 10 ５ injecting the molten polyamide composition at a pressure of 100 Pa; cooling the injected polyamide composition; Optionally removing the resulting molded article from the mold.

15. Use of a polyamide according to any one of claims 1 to 12 or a composition comprising the same as a hot melt adhesive for low pressure overmolding of batteries.

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