Heat-resistant heat transfer tube

Abstract

Disclosed is a thermal management system, particularly a battery thermal management system, and a flame-retardant heat transfer tube for use in said thermal management system. The flame-retardant heat transfer tube comprises a composition containing at least one polyphenylsulfide polymer, at least one polyphenylsulfone polymer, and at least one epoxy-functional thermoplastic elastomer. A method for cooling a battery and / or a method for operating a battery includes passing a heat transfer fluid, preferably a water / ethylene glycol mixture, through such a flame-retardant heat transfer tube.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 21306421.5, filed October 11, 2021, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates generally to thermal management systems, and more particularly to flame-retardant heat transfer tubes for use in thermal management systems, especially electric vehicles. [Background technology]

[0003] Rechargeable batteries are well known and are becoming increasingly widely used in many applications, including for propulsion of electric vehicles. Recently, across all industries, much of the development in the field of rechargeable batteries has focused on lithium-ion based batteries, which are based on different types of lithium salts. Naturally, new technologies outside the realm of lithium-ion based batteries are also being explored and continually developed.

[0004] In the field of electric mobility, batteries need to provide ever greater instantaneous power and have high storage capacities. Currently, batteries with operating voltages of several hundred volts are known. To achieve the desired voltage and current, it is common to connect several individual battery cells together in parallel and / or series.

[0005] While electric vehicle batteries have advanced to provide more power and require less frequent charging, one of the biggest challenges to battery safety remains the ability to design effective cooling systems.

[0006] Unlike conventional power systems, batteries, and particularly rechargeable batteries, have stringent requirements for their operating environment: Batteries tend to operate best within a relatively narrow temperature range.

[0007] Generally, low temperatures affect the chemical properties of the battery, slowing down reaction rates and therefore reducing the flow of electricity during charging or discharging. High temperatures increase reaction rates while also increasing energy dissipation, thus generating even more excess heat, potentially causing an uncontrolled increase in temperature and potentially irreversible damage to the cell. In a typical Li-ion battery, temperatures exceeding 80°C in even a portion of its structure can initiate exothermic chemical reactions that cause further temperature increases in the battery, ultimately resulting in the complete destruction of the battery and the risk of fire and explosion.

[0008] On the other hand, practical applications of batteries require them to be efficient over a much wider temperature range. For example, vehicle batteries need to function properly in any environment in which people are expected to use them, and so they need to operate over a temperature range of -20°C to +40°C or more. In addition, the charge and discharge cycles of a battery can generate heat in the battery itself, making it even more difficult to maintain the battery within an acceptable temperature range.

[0009] Typical Li-ion battery performance figures indicate that while the usable temperature range is typically between -20°C and 60°C, good power output is only achieved between 0°C and 40°C, with optimal performance occurring between 20°C and 40°C. Temperature also affects battery life; in fact, the number of charge / discharge cycles a battery can withstand before being considered depleted drops rapidly below 10°C due to anode plating and above 60°C due to electrode material degradation. The temperature range for optimal performance may vary for different battery chemistries and constructions; however, all current commercial batteries share a relatively narrow temperature range over which their performance is optimal. It is also generally important to ensure that the entire battery is maintained uniformly at the same temperature, without hot or cold regions, which can reduce its lifespan and safety.

[0010] For this reason, it is now common practice to incorporate battery thermal management systems (BTMS) into commercial battery assemblies, especially when battery safety, reliability, and lifespan are important concerns. These BTMS can be more or less complex depending on the type of battery; however, one common element is the presence of a heat transfer fluid that exchanges heat with the battery, thereby heating or cooling it.

[0011] For the thermal management of batteries, there are several heat transfer systems, such as air cooling, liquid cooling, and direct refrigerant cooling, among which liquid cooling is the most commonly used system due to its convenient design and excellent heat transfer performance.

[0012] This type of heat transfer system is already common in conventional drives, ie vehicles with internal combustion engines, so the use of water or a water / ethylene glycol mixture is widespread.

[0013] A significant safety drawback of using this water-based heat transfer medium is its electrical conductivity. If the heat transfer circuit were to leak, for example as a result of an accident, the leaked water or water / ethylene glycol mixture could cause a short circuit. This could result in a fire or other emergency, potentially causing additional, potentially serious, damage to the vehicle. To reduce this risk, thermal management system components must have high flame resistance. One conventional method for identifying the flame resistance of plastic materials is a standard test developed by Underwriters Laboratory (USA) called UL94 (Standard Number for Flammability Tests of Plastic Materials for Equipment and Appliance Parts). Preferably, thermal management system components used in electric vehicle batteries should comply with Standard V0, which identifies plastic materials that "can cease burning within 10 seconds when dropped vertically and do not ignite."

[0014] Thus, there is a continuing need in the art for thermal management systems for batteries, particularly those used in electric vehicles, that utilize optimized heat transfer tubes that have the highest flame retardancy ratings while simultaneously possessing the mechanical properties necessary to withstand the demands of vehicle use. Additionally, there remains a need for heat transfer tubes that also have high chemical resistance to heat transfer fluids commonly used in thermal management systems, such as water / ethylene glycol mixtures. Summary of the Invention

[0015] It has now been found that a specific composition comprising at least one polyphenylsulfide, at least one polyphenylsulfone and an epoxy-functional thermoplastic elastomer makes it possible to obtain a heat transfer tube that meets the most stringent requirements for use in a battery thermal management system.

[0016] Therefore, the first object of the present invention is to 45 to 75% by weight of at least one polyphenyl sulfide (PPS), 20 to 45% by weight of at least one polyphenylsulfone (PPSU), 5 to 15% by weight of at least one epoxy-functional thermoplastic elastomer (TPE); A heat transfer tube comprising a composition comprising: The weight percentages are based on the total weight of the composition.

[0017] The heat transfer tube of the present invention has a V-0 rating as determined in accordance with UL94 (Standard Number for Flammability Tests of Plastic Materials for Equipment and Appliance Parts) and is halogen-free. It has mechanical properties, such as tensile strength and tensile modulus, that meet the needs of the application. Preferably, in addition to having a flame-retardant V-0 rating, the tube exhibits a strain at break of more than 30% (measured at room temperature (23°C) according to ISO527-2).

[0018] Additionally, the heat transfer tube of the present invention is resistant to chemical aging in water / ethylene glycol mixtures.

[0019] A second object of the present invention is a thermal management system, particularly a battery thermal management system, that includes the heat transfer tube of the first object.

[0020] A further object of the present invention is a method for cooling and / or operating a battery comprising passing a heat transfer fluid, preferably a water / ethylene glycol mixture, through a heat transfer tube according to the first object. DETAILED DESCRIPTION OF THE INVENTION

[0021] The first object of the present invention is to 45 to 75% by weight of at least one polyphenylene sulfide polymer; 20 to 45% by weight of at least one polyphenylsulfone polymer; 5 to 15% by weight of at least one epoxy-functional thermoplastic elastomer; A heat transfer tube comprising a composition comprising: The weight percentages are based on the total weight of the composition.

[0022] Polyphenylene sulfide polymer (PPS) The composition contains at least one polyphenylene sulfide polymer (hereinafter "PPS").

[0023] In its broadest definition, PPS can be made from substituted and / or unsubstituted phenylene sulfide groups.

[0024] According to this specification, PPS polymers are those comprising repeating units of formula (A) (R PPS ) (mole % based on the total number of moles of repeat units in the PPS polymer): [ka] (wherein R is independently selected from the group consisting of halogen, a C1 to C12 alkyl group, a C7 to C24 alkylaryl group, a C7 to C24 aralkyl group, a C6 to C24 arylene group, a C1 to C12 alkoxy group, and a C6 to C18 aryloxy group, and i is independently 0 or an integer of 1 to 4).

[0025] According to formula (A), the repeating unit (R PPS ) may contain 1 to 4 radical groups R. When i is 0, the corresponding aromatic ring does not contain any radical groups R.

[0026] The PPS polymer preferably comprises repeating units of formula (A') (R PPS ), i.e., any polymer comprising at least 50 mole % repeat units of formula (A) where i is 0: [ka]

[0027] According to one embodiment of the present invention, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% of the repeat units in the PPS are repeat units of formula (A) or (A') (R PPS ) The mole % is based on the total moles of repeat units in the PPS polymer.

[0028] The PPS may or may not be acid washed.

[0029] In some embodiments, the PPS is acetic acid washed PPS.

[0030] According to one embodiment of the present invention, the PPS polymer has 100 mol % of repeating units of formula (A) or (A′) (R PPS According to this embodiment, the PPS polymer comprises repeating units (R PPS ) essentially consists of

[0031] Suitable PPS is commercially available under the trade name Ryton® PPS from Solvay Specialty Polymers USA, LLC. In the context of this application, Ryton® PPS products beginning with the prefix "QA," such as QA200N, refer to acid-washed PPS.

[0032] The melt flow rate of PPS (316°C, 5 kg load, ASTM D1238, Procedure B) may be 50 to 400 g / 10 min, e.g., 60 to 300 g / 10 min, or 70 to 200 g / 10 min. For example, Ryton® PPS QA220N and QA200N have melt flow rates of 160 g / 10 min and 100 g / 10 min, respectively. Ryton® PPS QC220N, QC210N, and QC200N have melt flow rates of 175 g / 10 min, 135 g / 10 min, and 100 g / 10 min, respectively.

[0033] Melt flow rate (MFR), also known as melt flow index (MFI) as used herein, is used to characterize polymer melts. It is an indirect measure of molecular weight, meaning that a high MFR corresponds to a low molecular weight. At the same time, melt flow rate is also a measure of the ability of a material melt to flow under pressure. Melt flow rate is inversely proportional to the viscosity of a polymer melt. If the MFI or MFR is low, the melt viscosity and melt flow resistance will be high.

[0034] The composition comprises at least one PPS in an amount of at least 45 wt%, at least 47 wt%, or at least 50 wt%, based on the total weight of the composition.

[0035] The composition comprises at least one PPS in an amount of less than 75 wt%, less than 70 wt%, less than 65 wt%, or less than 60 wt%, based on the total weight of the composition.

[0036] Preferably, the composition comprises at least one PPS in an amount ranging from 45 to 75 wt %, or from 50 to 65 wt %, based on the total weight of the composition.

[0037] Polyphenylsulfone polymer (PPSU) The composition includes at least one polyphenylsulfone polymer (hereinafter "PPSU").

[0038] As used herein, PPSU refers to a polymer having a repeating unit of formula (B) (R PPSU ), where mole % is based on the total number of moles of repeat units in the PPSU polymer: [ka]

[0039] According to one embodiment of the present disclosure, at least 60 mol %, at least 70 mol %, at least 80 mol %, at least 90 mol %, at least 95 mol %, or at least 99 mol %, or all, of the repeat units in the PPSU polymer (based on the total number of moles of repeat units in the PPSU polymer) are repeat units of formula (B) (R PPSU )

[0040] PPSU can be prepared by known methods and is available, among others, as RADEL® PPSU from Solvay Specialty Polymers USA, LLC. Suitable PPSU polymers can be selected from, but are not limited to, Radel® R-5500NT, R-5700NT, R-5800NT, and R-5900NT.

[0041] The melt flow rate of the PPSU (365°C, 5 kg load, according to ASTM D1238) may be 5 to 40 g / 10 min, for example, 5 to 35 g / 10 min, 10 to 40 g / 10 min, 10 to 30 g / 10 min, 12 to 40 g / 10 min, 20 to 40 g / 10 min, or 10 to 35 g / 10 min. For example, Radel® PPSUR-5500NT, R-5700NT, R-5800NT, and R-5900NT have melt flow rates of 12 to 17 g / 10 min, 34 to 40 g / 10 min, 20 to 28 g / 10 min, and 26 to 36 g / 10 min, respectively.

[0042] The composition comprises at least one PPSU in an amount of at least 22 wt%, such as at least 25 wt%, at least 27 wt%, or at least 29 wt%, based on the total weight of the composition.

[0043] The composition may comprise at least one PPSU in an amount of less than 43 wt%, such as less than 40 wt%, or less than 38 wt%, based on the total weight of the composition.

[0044] Preferably, the composition may comprise at least one PPSU in an amount ranging from 22 to 43 wt%, such as from 25 to 40 wt%, or from 29 to 38 wt%, based on the total weight of the composition.

[0045] Epoxy-functional thermoplastic elastomer (TPE) The composition comprises at least one epoxy-functional thermoplastic elastomer (hereinafter "TPE").

[0046] In the context of the present invention, an "elastomer" is defined as a polymeric material that exhibits (1) a low glass transition temperature (Tg), i.e., a glass transition temperature below 25°C, or even below 0°C, and (2) a low modulus of elasticity (Young's modulus), i.e., a modulus of elasticity below 200 MPa, or even below 100 MPa.

[0047] The polymer backbone of the TPE may be selected from elastomeric backbones comprising polyethylene and copolymers thereof, such as ethylene-butene; ethylene-octene; polypropylene and copolymers thereof; polybutene; polyisoprene; ethylene-propylene-rubber (EPR); ethylene-propylene-diene monomer rubber (EPDM); ethylene-acrylate rubber; butadiene-acrylonitrile rubber, ethylene-acrylic acid (EAA), ethylene-vinyl acetate (EVA); acrylonitrile-butadiene-styrene rubber (ABS); block copolymer styrene-ethylene butadiene styrene (SEBS); block copolymer styrene butadiene styrene (SBS); core-shell elastomers of the methacrylate-butadiene-styrene (MBS) type, or mixtures of one or more of the above.

[0048] The TPE used in the composition contains epoxy functionality. Backbone functionalization can result from copolymerization of epoxy-functional monomers or from grafting the polymer backbone with additional epoxy-functional components.

[0049] Specific examples of TPEs are, in particular, poly(ethylene-co-glycidyl methacrylate) copolymers, poly(ethylene-co-methyl(meth)acrylate-co-glycidyl acrylate) copolymers, poly(ethylene-co-n-butyl acrylate-co-glycidyl acrylate) copolymers, and copolymers of styrene and glycidyl(meth)acrylate. Notable, non-limiting examples of commercially available TPEs suitable for the heat transfer tube of the present invention include, for example, Lotader® AX8900 and Lotader® AX8840 from Arkema (Bristol, PA, USA), which are poly(ethylene-co-alkyl acrylate-co-glycidyl acrylate) terpolymers (containing structural units derived from 67% by weight of ethylene, 25% by weight of methyl acrylate, and 8% by weight of glycidyl methacrylate), and poly(ethylene-co-glycidyl methacrylate) copolymers (containing structural units derived from 92% by weight of ethylene and 8% by weight of glycidyl methacrylate), or Igetabond® BF-E from Sumitomo Chemical Co., Ltd., which is also a poly(ethylene-co-glycidyl methacrylate) copolymer (containing structural units derived from 88% by weight of ethylene and 12% by weight of glycidyl methacrylate). Another example of a suitable TPE is commercially available from Dow Inc. (Midland, MI, USA) under the trade name Paraloid™ EXL2314, which is a core-shell acrylate-based polymer composed of a core primarily composed of crosslinked poly(n-butyl acrylate) rubber and a shell primarily composed of poly(methyl methacrylate)-poly(glycidyl methacrylate) copolymer.

[0050] The composition preferably comprises a TPE having a melt flow rate (ASTM D1238, 190°C, 2.16 kg load) of less than 10 g / 10 min, e.g., less than 7 g / 10 min, less than 6 g / 10 min, less than 5 g / 10 min, or less than 4 g / 10 min.

[0051] The composition comprises at least one TPE in an amount of at least 6 wt%, or at least 7 wt%, such as at least 8 wt%, based on the total weight of the composition.

[0052] The composition may comprise at least one TPE in an amount of less than 14 wt%, such as less than 12 wt%, based on the total weight of the composition.

[0053] Preferably, the composition may comprise at least one TPE in an amount ranging from 5 to 14% by weight, such as from 6 to 12% by weight, based on the total weight of the composition.

[0054] additives In some embodiments, the composition may further comprise optional additives such as, but not limited to, antioxidants (e.g., ultraviolet light stabilizers and heat stabilizers), processing aids, nucleating agents, lubricants, flame retardants, smoke suppressants, antistatic agents, antiblocking agents, colorants, pigments, and the like.

[0055] When present, additives are typically included in the composition in an amount of not more than 10 wt.%, or even not more than 8 wt.%, or not more than 5 wt.%, relative to the total weight of the composition. The additives are usually present in an amount of at least 0.5 wt.%, for example at least 0.8 wt.%, or at least 1 wt.%, relative to the total weight of the composition.

[0056] In some embodiments, one or more pigments may be particularly desirable additives to obtain white, black, or colored tubes. The pigments may be black pigments such as carbon black, white pigments such as zinc oxide, zinc sulfide, lithopone, antimony white, titanium dioxide (rutile or anatase, preferably rutile), and / or colored pigments. The pigments are typically present in an amount of 0 to 6 wt. %, preferably 0.05 to 5 wt. %, and especially 0.1 to 3 wt. %, based on the total weight of the composition.

[0057] In some embodiments, antioxidants can be particularly desirable additives. Antioxidants can improve the thermal and light stability of the composition. For example, antioxidants that are thermal stabilizers can improve the thermal stability of the composite during manufacturing (or in high-temperature application settings), for example, by helping to prevent polymer degradation while allowing the polymer to be processable at higher temperatures.

[0058] Desirable antioxidants include, but are not limited to, copper salts (e.g., CuO and CuO), alkali metal halides (e.g., CuI, KI, and KBr, including combinations of alkali metal halides, such as, but not limited to, CuI / KI), hindered phenols, hindered amine light stabilizers (“HALS”) (e.g., tertiary amine light stabilizers), and organic or inorganic phosphorus-containing stabilizers (e.g., sodium hypophosphite or manganese hypophosphite).

[0059] In some embodiments, the additive is a halogen-free flame retardant. In some embodiments, the halogen-free flame retardant is an organophosphorus compound selected from the group consisting of phosphine salts (phosphinates), diphosphine salts (diphosphinates), and condensation products thereof. In alternative embodiments, the composition is flame retardant-free.

[0060] The composition is preferably halogen-free, meaning that no halogen-containing components are used in the composition.

[0061] The composition can exclude other polymers different from the TPE, PPS, and PPSU polymers.

[0062] The composition preferably excludes poly(etherimide) (“PEI”) polymers; the terms “poly(etherimide)” and / or “polymer (PEI)” refer to at least 50 mole % of repeat units (R 1 ) containing at least one aromatic ring, at least one imide group, by itself and / or in its amic acid form, and at least one ether group, based on the total number of moles in the polymer. PEI ) means a polymer containing repeating units (R PEI ) may optionally further comprise at least one amide group that is not included in the amic acid form of the imide group.

[0063] The heat transfer tube of the present invention comprises the composition detailed above. The heat transfer tube typically consists of the composition detailed above.

[0064] Advantageously, the heat transfer tube of the present invention has a V-0 rating as determined by the UL94 standard (Standard number for plastic material flammability test for equipment and appliance parts of Underwriters Laboratory (USA)).

[0065] The heat transfer tube can be manufactured using any suitable method known in the art. Heat transfer tubes are typically manufactured by extrusion. Suitably, the entire length of the tube is extrudable and / or extruded in a single extrusion process.

[0066] The heat transfer tube of the present invention suitably has a substantially constant cross section along its entire length. The tube preferably has a circular cross section. The tube is hollow to allow the flow of heat transfer fluid.

[0067] The hollow heat transfer tube of the present invention has an inner surface layer that is in direct contact with the heat transfer fluid, and this inner surface layer is preferably made from the composition detailed above. Preferably, the entire hollow heat transfer tube of the present invention is made from the composition detailed above.

[0068] The dimensions of the heat transfer tube are not limited and are determined by the dimensions of the thermal management system in which the tube is used. In some embodiments, the heat transfer tube may have a diameter ranging from 5 to 50 mm, or even from 5 to 30 mm. The wall thickness of the tube may typically range from 0.5 to 5.0 mm, from 0.8 to 5.0 mm, or even from 1.0 to 5.0 mm.

[0069] A second object of the present invention is a thermal management system comprising the heat transfer tube according to the first object of the present invention. The thermal management system further comprises a heat transfer fluid. The heat transfer fluid is contained within the heat transfer tube. The heat transfer fluid preferably passes (flows) through the interior of the heat transfer tube. The heat transfer fluid may be selected from the group consisting of water, a water / ethylene glycol mixture, a chlorofluorocarbon (CFC), a hydrochlorofluorocarbon (HFC), and a (per)fluoropolyether (PFPE). In a preferred embodiment of the present invention, the heat transfer fluid is selected from the group consisting of water or a water / ethylene glycol mixture. In a specific embodiment, the heat transfer fluid may be selected from the group consisting of a chlorofluorocarbon (CFC), a hydrochlorofluorocarbon (HFC), and a (per)fluoropolyether (PFPE). The thermal management system according to claim 8 further comprises a heat transfer fluid contained within the heat transfer tube.

[0070] In one embodiment of the present invention, the thermal management system is a Battery Thermal Management System (hereinafter "BTMS"), which is a thermal management system for controlling the temperature of a battery system, preferably a rechargeable battery system.

[0071] While BTMSs can be more or less complex depending on the application, they typically have at least the ability to cool the battery if its temperature is too high and heat the battery if its temperature is too low, using a heat transfer fluid flowing through cooling tubes of the present invention that exchange heat with the battery. Other common features of BTMSs are an insulation system to reduce the effect of the external environment on battery temperature and a ventilation system to help dissipate any dangerous gases that may be present within the battery pack.

[0072] Typically, the heat transfer fluid is circulated by a pump in a closed system including the heat transfer tube of the present invention in thermal contact with the battery and a second system capable of heating and / or cooling the heat transfer fluid to a desired temperature. This second system can include any combination of a cooling system and a heating system, or can combine heating and cooling functions in a heat pump. The circulating heat transfer fluid absorbs heat from or releases heat to the battery, and then it is circulated in the second system to return the heat transfer fluid to the desired temperature. More or less sophisticated control systems may exist to control the instantaneous temperature of the heat transfer fluid and the temperature of the battery to optimize the temperature of the heat transfer fluid at each instant.

[0073] Therefore, a further object of the present invention is a method for controlling the temperature in a battery, comprising the step of circulating a heat transfer fluid in a closed system comprising a heat transfer tube of the present invention, said system being in thermal contact with the battery and with a second system capable of heating and / or cooling the fluid to a desired temperature.

[0074] A further object of the invention is a method of operating a battery, comprising the step of controlling the temperature of the battery as defined above.

[0075] Batteries containing the BTMS detailed above can be used in any application where a rechargeable battery can be used, notable non-limiting examples of such applications being urban mobility vehicles such as automobiles, electric bicycles, and buses.

[0076] The above-described embodiments are intended to be illustrative and not limiting. Additional embodiments are within the concept of the present invention. In addition, while the present invention has been described with reference to specific embodiments, those skilled in the art will recognize that changes in form and detail may be made without departing from the spirit and scope of the invention. [Example]

[0077] raw materials PPS Polymer (PPS): Ryton® QA200N obtained from Solvay Specialty Polymers USA, LLC; acid washed PPS with a melt flow rate of 100 g / 10 min at 316° C. and 5 kg load (ASTM D1238).

[0078] PPSU-1 polymer: Radel® R-5500NT obtained from Solvay Specialty Polymers USA, LLC; having a melt flow rate (ASTM D1238) of 12-17 g / 10 min at 365° C. and 5 kg load.

[0079] PPSU-2 polymer: Radel® R-5800NT obtained from Solvay Specialty Polymers USA, LLC; having a melt flow rate (ASTM D1238) of 20-28 g / 10 min at 365° C. and 5 kg load.

[0080] PPSU-3 polymer: Radel® R-5900NT obtained from Solvay Specialty Polymers USA, LLC; having a melt flow rate (ASTM D1238) of 26-36 g / 10 min at 365° C. and 5 kg load.

[0081] PPSU-4 polymer: RADEL® R-5600NT obtained from Solvay Specialty Polymers USA, LLC; having a melt flow rate (ASTM D1238) of 34-40 g / 10 min at 365° C. and 5 kg load.

[0082] TPE-1: Lotader® AX8900 from Arkema, Bristol USA; having a melt flow index (ASTM D1238) of 6 g / 10 min at 190° C. and a load of 2.16 kg.

[0083] TPE-2: Igetabond® BF-E from Sumitomo Chemical Co., Ltd.; having a melt flow rate of 3 g / 10 min (JIS K7210-1, 190° C., 21.2 N) and a Tg of −26° C.

[0084] AO: Irgafos® 168 from BASF; tris(2,4-di-tert-butylphenyl) phosphite, used as an antioxidant.

[0085] Carbon black concentrate (“CBC”): 30 wt. % Arosperse 11W carbon black (Orion Engineered Carbons GmbH, Germany) in Ryton® PPS QA200N (Solvay Specialty Polymers USA, LLC).

[0086] General Procedure for Preparation of Composition The PPSU polymer was first dried in an oven at 135°C for at least 5 hours. Dry blending was then performed by mixing the polymers on a vibrating shaker for 2-3 minutes to ensure uniformity. The dry blend was then placed in a gravimetric feeder and fed into a twin-screw extruder (Clextral D32), where it was melted and extruded. The temperature during extrusion was controlled at approximately 320°C for the reference composition and 340-350°C for the compositions according to the present invention.

[0087] The melt stream was cooled and fed to a pelletizer. The pellets were collected and kept in sealed plastic buckets until use for injection molding.

[0088] test The following test methods were used to evaluate the compositions: Tensile properties - ISO 527 Type 1A bars and small flakes (1.6 mm) were produced by injection molding at Billion Injection (300-320°C for Reference Compositions 1 and 2, and 340°C for Examples 1-4). Tensile properties were determined according to ISO 527-2 at room temperature (23°C) at a rate of 1 mm / min for tensile modulus and 5 mm / min for ultimate properties (stress and strain at break).

[0089] Weld line strength measurements were performed using ISO 527.

[0090] ISO 178 was used to determine the flexural properties.

[0091] Charpy impact properties were measured at 23°C according to ISO 179-1 / 1eU (unnotched) and ISO 179-1 / 1eA (notched).

[0092] D3835: Melt viscosity evaluation of extruded pellets was performed using a Netzsch RH2000 capillary rheometer at 316°C (Reference Compositions 1 and 2) and 340°C (Example 1) for 60 s -1 The measurement was carried out by capillary rheometry.

[0093] UL94: Flame retardancy was evaluated according to the standard UL94 of Underwriters Laboratory (USA) for samples with a thickness of 1.6 mm.

[0094] Some compositions are as detailed in Table 1, in which all percentages are by weight calculated relative to the total weight of the composition.

[0095] [Table 1]

[0096] The results are summarized in Table 2 below.

[0097] [Table 2]

[0098] Relative to a reference composition containing PPS and TPE, the composition of the present invention containing PPSU-1 unexpectedly resulted in a material meeting a V0 rating according to the UL 94 flammability standard. In addition to improved flame retardancy, the composition also showed improved strain at break (greater than 30%).

[0099] Pipe Extrusion Test Using the composition of Example 1 in Table 1, tubing was made as follows: the material was dried at 90°C for 4 hours before being placed in an extruder. The barrel extruder temperature was set at 330-350°C.

[0100] The tube was extruded using a calibrated bath. The resulting tube had an excellent surface appearance and a regular shape. The tube had an outer diameter of 16 mm, a wall thickness of 1.5 mm, and a total length of 10 cm.

[0101] A simple free-fall dart test was performed to determine impact resistance on ten tubes made from the same composition as in Example 1. The free-fall dart test was performed at a temperature of -40°C using an 880g dart from a single drop height of 65cm. None of the tubes broke.

[0102] Impact of PPS Selection Additional formulations of the present invention were prepared according to the general procedure detailed above using different PPSU Radel® products in Examples 2-4; the compositions of each are shown in Table 3 (with Example 1 repeated for comparison), in which all percentages are by weight based on the total weight of each composition.

[0103] [Table 3]

[0104] The tensile properties and impact properties of Examples 1 to 4 are summarized in Table 4.

[0105] [Table 4]

[0106] All of Examples 1-4 had adequate and similar tensile modulus, tensile strength, tensile strength at break, and impact properties, regardless of the PPSU polymer used in the four formulations.

[0107] All of Examples 1-4 had strains at break greater than 30%. However, when the PPS and TPE in the compositions of Examples 1-4 were the same, it was observed that using PPSU-2, PPSU-3, and PPSU-4, which generally had MFRs in the range of 20-40 g / 10 min (ASTM D1238, 5 kg load, 365°C), improved strain at break compared to using PPSU-1, which had an MFR of 12-17 g / 10 min (ASTM D1238, 5 kg load, 365°C). While not wishing to be limited by this theory, it is believed that the less viscous PPSU (having an MFR of 20-40 g / 10 min (ASTM D1238, 5 kg load, 365°C)) improved the strain at break of the compositions.

[0108] Impact of TPE selection Additional formulations of the present invention were prepared in Examples 5-6 following the general procedure detailed above using two different TPEs; the compositions of each are shown in Table 5, where all percentages are by weight based on the total weight of each composition.

[0109] [Table 5]

[0110] The tensile and impact properties of Examples 5 and 6 are summarized in Table 6.

[0111] [Table 6]

[0112] Although both Examples 5 and 6 yielded adequate and similar tensile properties regardless of the TPE used in the formulation, the formulation of Example 6 containing TPE-2: Igetabond® FB-E yielded a material with a much better strain at break, in fact having a value twice as high (70%) as that obtained with the equivalent formulation of Example 5 containing TPE-1: Lotader® AX8900 (35%). Without wishing to be limited by this theory, it is believed that the more viscous TPE (indeed Igetabond® FB-E, which has a lower MFR than Lotader® AX8900) improved the strain at break.

[0113] Effect of PPSU content Additional formulations according to the present invention were prepared according to the general procedure detailed above using PPSU-1 (Radel® R-5500NT) in compositions ranging in content from 20 to 33% by weight in Examples 7-10; the compositions of each are shown in Table 7, where all percentages are by weight based on the total weight of each composition.

[0114] [Table 7]

[0115] The tensile properties and impact properties of Examples 7 to 10 are summarized in Table 8.

[0116] [Table 8]

[0117] All of Examples 7-10 exhibited adequate and similar tensile modulus, tensile strength, tensile strength at break, and strain at break of greater than 30%, regardless of the amount of PPSU-1 used in the four formulations.

[0118] However, it was observed that when the PPSU content was increased from 20 wt% to 33 wt%, the impact properties increased, with the materials obtained in Examples 9 and 10 having improved impact resistance compared to Examples 7 and 8.

[0119] The materials of Examples 9 and 10 were confirmed to meet the V0 rating according to the UL94 flammability standard.

[0120] chemical aging Polymer specimens were produced by injection molding according to ISO 527-2 Type 1A using the formulation of Example 1. The specimens were chemically aged in an autoclave at 135°C by direct contact with a 50:50 (v / v) blend of ethylene glycol (Frostox® HT12 from Haertol) and water for up to 1000 hours.

[0121] The tensile and flexural properties of the polymer specimens were measured before exposure to the ethylene glycol / water blend (t=0 h) and after 500 and 1000 h of exposure and then compared to the initial values.

[0122] The results are shown in Table 9, where the tensile and flexural modulus and strength are the values ​​V at time "t" (t=500h or 1000h) compared to the initial values. t The percent change (negative for a decrease, positive for an increase) of V at t = 0h i follows the formula: % change = 100*(V t -V i ) / V i .

[0123] [Table 9]

[0124] This test demonstrated the high chemical resistance of the composition of Example 1 used in tubing according to the present invention.

Claims

1. 45 to 75% by weight of at least one polyphenylene sulfide polymer; 20 to 45% by weight of at least one polyphenylsulfone polymer; 5 to 15% by weight of at least one epoxy-functional thermoplastic elastomer; A heat transfer tube comprising a composition comprising: The weight percentages are based on the total weight of the composition.

2. 2. The heat transfer tube according to claim 1, having a V-0 rating determined according to UL94 standard (Standard number for plastic material flammability test for equipment and appliance parts of Underwriters Laboratory (USA)).

3. The polyphenylsulfone polymer has a repeating unit of formula (B) (R ＰＰＳＵ ): 【Chemical 1】 3. The heat transfer tube according to claim 1, wherein the polyphenylsulfone polymer comprises at least 50 mole % of the repeating unit (R), wherein the mole % is based on the total number of moles of repeating units in the polyphenylsulfone polymer.

4. 3. The heat transfer tube according to claim 1, wherein the thermoplastic elastomer in the composition is selected from the group consisting of poly(ethylene-co-glycidyl methacrylate) copolymer, poly(ethylene-co-methyl(meth)acrylate-co-glycidyl acrylate) copolymer, poly(ethylene-co-n-butyl acrylate-co-glycidyl acrylate) copolymer, and copolymers of styrene and glycidyl (meth)acrylate.

5. 3. A heat transfer tube according to claim 1 or 2, having a substantially constant cross section, preferably a circular cross section, along its entire length.

6. 3. A heat transfer tube according to claim 1 or 2, which is hollow to allow heat transfer fluid to flow therethrough.

7. 3. The heat transfer tube according to claim 1, wherein the diameter is in the range of 5 to 50 mm and the wall thickness is in the range of 0.5 to 5.0 mm.

8. A thermal management system comprising the heat transfer tube according to claim 1 or 2.

9. The thermal management system of claim 8 further comprising a heat transfer fluid contained within the heat transfer tubes.

10. 9. The thermal management system of claim 8, wherein the heat transfer fluid is selected from the group consisting of water, a water / ethylene glycol mixture, a chlorofluorocarbon (CFC), a hydrochlorofluorocarbon (HFC), and a (per)fluoropolyether (PFPE).

11. 10. An apparatus comprising the thermal management system of claim 8, wherein the apparatus exchanges heat with the heat transfer fluid within the thermal management system.

12. 12. The device according to claim 11, which is a battery, preferably a rechargeable battery.

13. 13. A device comprising the battery of claim 12, which is an electric vehicle.

14. 10. A method for controlling temperature in a battery, comprising circulating a heat transfer fluid in a closed system including the heat transfer tube of claim 1, said system being in thermal contact with said battery and with a second system capable of heating and / or cooling said fluid to a desired temperature.

15. 15. A method of operating a battery, comprising the method of controlling the temperature within the battery of claim 14.

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