Thermoplastic composition with optimal balance of properties

Abstract

The present invention relates to a thermoplastic composition comprising (A) an aromatic polycarbonate, (B) a polyethylene terephthalate, (C) a polybutylene terephthalate, (D) an impact modifier, preferably (E) a styrene acrylonitrile copolymer, and optionally (F) an additive. The thermoplastic composition according to the invention has an improved balance between impact properties, flowability and stiffness. The invention also relates to an article comprising the thermoplastic composition of the invention.

Description

[0001] The present invention relates to a thermoplastic composition comprising (A) an aromatic polycarbonate, (B) polyethylene terephthalate, (C) polybutylene terephthalate, (D) an impact modifier, preferably (E) a styrene acrylonitrile copolymer and optionally (F) an additive. The thermoplastic composition according to the present invention has an improved balance between impact properties, fluidity and stiffness. The present invention also relates to an article comprising the thermoplastic composition.

[0002] Polycarbonate-based thermoplastic compositions are known in the art, for example:

[0003] WO 2017 / 093232 discloses a thermoplastic composition comprising 0 to 50 weight percent of polycarbonate, 10 to 50 weight percent of polyester carbonate copolymer, 5 to 20 weight percent of polyethylene terephthalate, 20 to 50 weight percent of polybutylene terephthalate, and optionally 5 to 30 weight percent of an impact modifier, wherein the weight percents are based on the combined amount of polycarbonate, polyester carbonate copolymer, polyethylene terephthalate, polybutylene terephthalate, and the optional impact modifier.

[0004] US2008 / 0269399 discloses a composition comprising a polyester-polycarbonate polymer containing isophthalate-terephthalate-resorcinol ester units and carbonate units, a first polyester selected from polyethylene terephthalate, polyethylene isophthalate or a combination thereof, and a second polyester containing butylene terephthalate units, cyclohexane dimethyl terephthalate units or a combination of cyclohexane dimethyl terephthalate units and ethylene terephthalate units. The polyester-polycarbonate polymer in this reference is made using an interfacial process.

[0005] However, for demanding applications, such as automotive exterior parts, there remains a need for thermoplastic compositions having an improved balance between impact properties, flow and stiffness. Improved low temperature impact is particularly desirable.

[0006] It has been found that this need is at least partially met according to the present invention, which is directed to a thermoplastic composition comprising:

[0007] (A) 30 to 59 weight percent of an aromatic polycarbonate, wherein the aromatic polycarbonate has a weight average molecular weight in the range of 14.0 to 45.6 kg / mol as measured by gel permeation chromatography (GPC) using polystyrene standards;

[0008] (B) 20 to 40 weight percent of polyethylene terephthalate, wherein the polyethylene terephthalate has an intrinsic viscosity in the range of 0.50 to 1.21 dl / g as measured according to ASTM D2857-95 (2007);

[0009] (C) 2 to 25 weight percent of polybutylene terephthalate, wherein the polybutylene terephthalate has a weight average molecular weight in the range of 45.0 to 150.0 kg / mol as measured by gel permeation chromatography (GPC) using polystyrene standards;

[0010] (D) 10 to 20 weight percent of an impact modifier having a fraction in the range, wherein the impact modifier is selected from acrylonitrile styrene butadiene copolymers, ethylene acrylate copolymers, ethylene glycidyl acrylate copolymers, and mixtures thereof;

[0011] The weight % are based on the total weight of the thermoplastic composition.

[0012] The thermoplastic composition was found to exhibit an improvement in impact properties without much loss in flow and stiffness. In the context of the present invention, impact properties are quantified by notched Izod measurements (at 23, 0 and -10°C, ISO 180 / 1A); flowability is quantified by spiral flow measurements (ASTM D-3123 09 (2017), at 3 mm thickness), and stiffness is quantified by tensile modulus (ISO 527).

[0013] (A) Aromatic polycarbonate

[0014] Aromatic polycarbonates are generally manufactured using two different technologies. In the first technology, which is called the interfacial technology or interfacial process, phosgene is reacted with a bisphenol, usually bisphenol A (BPA), in the liquid phase. Another well-known technology is the so-called melt technology, sometimes also called melt transesterification or melt polycondensation technology. In the melt technology or melt process, a bisphenol, usually BPA, is reacted with a carbonate, usually diphenyl carbonate (DPC), in the melt phase. Aromatic polycarbonates obtained by the melt transesterification process are known to be structurally different from aromatic polycarbonates obtained by the interfacial process. In this regard, it should be particularly noted that the so-called "melt polycarbonates" generally have the least amount of Fries branches, which are generally absent in "interfacial polycarbonates". In addition, melt polycarbonates generally have a greater number of phenolic hydroxyl end groups, while polycarbonates obtained by the interfacial process are generally end-capped and have phenolic hydroxyl end groups of up to 150 ppm, preferably up to 50 ppm, and more preferably up to 10 ppm.

[0015] According to the present invention, it is preferred that the aromatic polycarbonate comprises or consists of a bisphenol A polycarbonate homopolymer (also referred to herein as bisphenol A polycarbonate). Preferably, the aromatic polycarbonate of the present invention disclosed herein comprises at least 75% by weight, preferably at least 95% by weight, of bisphenol A polycarbonate based on the total amount of aromatic polycarbonate. More preferably, the aromatic polycarbonate in the composition consists essentially of or consists of bisphenol A polycarbonate. The aromatic polycarbonate according to the present invention has a weight average molecular weight (Mw) in the range of 14.0 to 45.6 kg / mol, preferably in the range of 17.7 to 38.9 kg / mol, more preferably in the range of 20.0 to 36.1 kg / mol, measured using gel permeation chromatography (GPC) using polystyrene standards. The aromatic polycarbonate preferably has a melt volume rate of 4-30 cc / 10 min measured according to ASTM D1238 (300° C., 1.2 kg).

[0016] In one aspect, the polycarbonate is an interfacial polycarbonate. In another aspect, the polycarbonate is a molten polycarbonate. In yet another aspect, the polycarbonate is a mixture of 20-80 wt % or 40-60 wt % interfacial polycarbonate and 80-20 wt % or 60-40 wt % molten polycarbonate based on the weight of the aromatic polycarbonate.

[0017] The aromatic polycarbonate according to the present invention preferably comprises two or more aromatic polycarbonates having different weight average molecular weights. Preferably, the aromatic polycarbonate according to the present invention comprises two aromatic polycarbonates PC1 and PC2, wherein PC1 has a weight average molecular weight in the range of 14.2 to 26.1 kg / mol, preferably in the range of 18.3 to 23.8 kg / mol, more preferably in the range of 19.8 to 22.1 kg / mol, determined using GPC using polystyrene standards, wherein PC2 has a weight average molecular weight in the range of 26.2 to 45.0 kg / mol, preferably in the range of 28.3 to 39.8 kg / mol, more preferably in the range of 29.8 to 34.1 kg / mol, determined using GPC using polystyrene standards. The ratio of the amount between PC1 and PC2 is preferably in the range of 0.5:1 to 7.5:1, preferably in the range of 0.5:1 to 6:1.

[0018] In embodiments where the aromatic polycarbonate comprises two aromatic polycarbonates PC1 and PC2, the weight average molecular weight of the aromatic polycarbonate may be calculated using the following equation:

[0019]

[0020] Among them, M W(PC) is the weight average molecular weight of the aromatic polycarbonate; M W(PC1) is the weight average molecular weight of PC1; MW(PC2) is the weight average molecular weight of PC2; is the weight fraction of PC1 based on the total weight of the thermoplastic composition; is the weight fraction of PC2 based on the total weight of the thermoplastic composition.

[0021] The same calculation applies for embodiments where the aromatic polycarbonate comprises more than two aromatic polycarbonates.

[0022] In another aspect the aromatic polycarbonate comprises a polycarbonate copolymer comprising structural units of bisphenol A and structural units from another bisphenol.

[0023] (B) Polyethylene terephthalate

[0024] Polyethylene terephthalate (PET) is a well-known polyester and is readily available. The polyethylene terephthalate may be a mixture of two or more different polyethylene terephthalates, for example a mixture of polyethylene terephthalates having mutually different molecular weights.

[0025] The polyethylene terephthalate may be, for example, a polyethylene terephthalate comprising polymerized units derived from ethylene glycol and terephthalic acid or an ester thereof, such as dimethyl terephthalate. Preferably, the polyethylene terephthalate comprises polymerized units derived from ethylene glycol and terephthalic acid or an ester thereof, such as dimethyl terephthalate.

[0026] The polyethylene terephthalate has an intrinsic viscosity in the range of 0.50 to 1.21 dl / g, preferably in the range of 0.71 to 1.08 dl / g, more preferably in the range of 0.75 to 0.96 dl / g, measured according to ASTM D2857-95 (2007).

[0027] Polyethylene terephthalate according to the present invention can be obtained by interfacial polymerization or melt condensation, by solution phase condensation or by transesterification polymerization, wherein in transesterification polymerization, for example, dialkyl esters such as dimethyl terephthalate can be transesterified with ethylene glycol using acid catalysis, to produce polyethylene terephthalate. Alternatively, polyethylene terephthalate according to the present invention can be obtained by purchasing commercially available polyethylene terephthalate. In another embodiment, polyethylene terephthalate is a recycled material.

[0028] (C) Polybutylene terephthalate

[0029] The polybutylene terephthalate (PBT) according to the present invention may be, for example, a polymer comprising polymerization units derived from terephthalic acid or a diester thereof, such as dimethyl terephthalate, and polymerization units derived from butanediol, such as 1,4-butanediol.

[0030] PBT may also contain polymerized units derived from other monomers, such as, in particular, isophthalic acid. For example, PBT may contain up to 10.0 wt. %, based on the weight of PBT, of polymerized units derived from isophthalic acid. Preferably, PBT contains up to 5.0 wt. %, such as 1.0-4.0 wt. %, of units derived from isophthalic acid. Alternatively, PBT may be free of monomeric units other than units derived from butanediol and terephthalic acid or its diesters. In other words, PBT may be free of isophthalic acid.

[0031] The PBT may be a single polymer or may be a combination of 2 or more, preferably 2, PBTs having mutually different properties. For example, the PBT may comprise a first PBT and a second PBT, each having a different weight average molecular weight. The PBT in the composition of the present invention may accordingly be a blend of such a first and a second (or additional) PBT.

[0032] In embodiments where the PBT comprises two PBTs: PBT1 and PBT2, the weight average molecular weight of the PBT can be calculated using the following equation:

[0033]

[0034] Among them, M W(PBT) is the weight average molecular weight of the aromatic polycarbonate; M W(PBT1) is the weight average molecular weight of PBT1; M W(PBT2) is the weight average molecular weight of PBT2; is the weight fraction of PBT1 based on the total weight of the thermoplastic composition; is the weight fraction of PBT2 based on the total weight of the thermoplastic composition.

[0035] The same calculation applies for embodiments where the PBT comprises more than two PBTs.

[0036] The PBT according to the present invention has a weight average molecular weight within the range of 45.0 to 150.0 kg / mol, preferably within the range of 58.1 to 135.2 kg / mol, more preferably within the range of 64.2 to 125.3 kg / mol, as measured by GPC using polystyrene standards.

[0037] The PBT may have a carboxyl end group content of 10-80 mmol / kg, preferably 20-60 mmol / kg, more preferably 20-40 mmol / kg, as determined according to ASTM D7409-15.

[0038] (D) Impact modifier

[0039] The thermoplastic composition of the present invention comprises an impact modifier. The impact modifier is selected from acrylonitrile styrene butadiene copolymer, ethylene acrylate copolymer, ethylene glycidyl acrylate copolymer and a mixture thereof.

[0040] Preferably, the impact modifier has an average particle size in the range of 152 to 627 nm, preferably in the range of 226 to 445 nm, more preferably in the range of 256 to 397 nm, more preferably in the range of 272 to 335 nm, wherein the average particle size is calculated by the particle size of 10,000 particles obtained by TEM.

[0041] Preferably, the impact modifier is acrylonitrile-styrene-butadiene (ABS) copolymer.It has been found that thermoplastic compositions comprising ABS exhibit improved flow and impact properties over other commonly used impact modifiers, such as methyl methacrylate butadiene styrene core-shell impact modifiers (MBS).

[0042] Preferably, the acrylonitrile-styrene-butadiene has an acrylonitrile content in the range of 8.3 to 19.8 wt. %, preferably in the range of 10.2 to 14.7 wt. %, a butadiene content in the range of 27.5 to 73.2 wt. %, preferably in the range of 38.2 to 61.7 wt. %, more preferably in the range of 44.2 to 54.6 wt. % and a styrene content in the range of 23.4 to 46.8 wt. %, preferably in the range of 32.1 to 42.0 wt. %, based on the total weight of the acrylonitrile-butadiene-styrene copolymer. It was found that the butadiene content in the preferred range leads to the best balance between impact properties and stiffness.

[0043] (E) Styrene acrylonitrile copolymer (SAN)

[0044] Preferably, the thermoplastic composition according to the invention comprises a styrene acrylonitrile copolymer.

[0045] The SAN according to the present invention preferably has an acrylonitrile level in the range of 12 to 56 wt%, preferably in the range of 18 to 31 wt%, more preferably in the range of 19 to 29 wt%, based on the total weight of the styrene acrylonitrile copolymer. It was found that the acrylonitrile level in the preferred range leads to improved compatibility between SAN and PC.

[0046] Preferably, the SAN according to the present invention has an MFR in the range of 8 to 30 g / 10 min, preferably in the range of 9 to 23 g / 10 min, more preferably in the range of 10 to 18 g / 10 min, measured at 230°C / 1.2 kg according to ASTM D1238. It was found that thermoplastic compositions comprising SAN in the preferred MFI range exhibit the best balance of flow / impact properties.

[0047] (F) Optional Additives

[0048] Optionally, the thermoplastic composition according to the present invention comprises additives. Common additives include, but are not limited to, fillers, reinforcing agents (e.g., glass fibers or glass sheets), antioxidants, heat stabilizers, light stabilizers, UV light stabilizers and / or UV absorbing additives, plasticizers, lubricants, release agents, specifically glyceryl monostearate, pentaerythritol tetrastearate, tristearate, octadecyl stearate, antistatic agents, defogging agents, antimicrobial agents, colorants (e.g., dyes or pigments), etc. (A) aromatic polycarbonate, (B) polyethylene terephthalate, (C) polybutylene terephthalate, (D) impact modifiers, and (E) styrene acrylonitrile copolymers are not additives.

[0049] Thermoplastic composition

[0050] The thermoplastic composition comprises:

[0051] (A) 30 to 59 wt %, preferably 30 to 56 wt %, more preferably 33 to 52 wt % of an aromatic polycarbonate;

[0052] (B) 20 to 40% by weight, preferably 25 to 35% by weight, of polyethylene terephthalate;

[0053] (C) 2 to 25 wt%, preferably 8 to 16 wt% of polybutylene terephthalate; and

[0054] (D) 10 to 20 wt %, preferably 12 to 16 wt % of an impact modifier.

[0055] The weight % are based on the total weight of the thermoplastic composition.

[0056] Thermoplastic compositions comprising preferred amounts of (A), (B), (C) and (D) were found to have an improved flow / impact balance.

[0057] Preferably, the thermoplastic composition according to the present invention comprises 0 to 5 wt% of (E) styrene acrylonitrile copolymer (SAN) as a flow modifier to improve the flow properties of the thermoplastic composition. Preferably, the thermoplastic composition comprises 1.7 to 5.0 wt%, preferably 2.1 to 4.9 wt% SAN. It was found that the thermoplastic composition comprising SAN within the preferred amount range exhibited the best balance of flow / impact properties.

[0058] Optionally, the thermoplastic composition according to the invention comprises 0 to 3% by weight, preferably 0 to 1.5% by weight, of (F) additives.

[0059] Preferably, the thermoplastic composition according to any one of the preceding claims, wherein the following inequality is satisfied:

[0060]

[0061] More preferably,

[0062] Among them, M W(PC) is the weight average molecular weight of the aromatic polycarbonate, M W(聚对苯二甲酸丁二酯) is the weight average molecular weight of the polyester polybutylene terephthalate, is the weight fraction of polybutylene terephthalate based on the total weight of the thermoplastic composition, wherein the weight average molecular weight is measured by GPC using polystyrene standards. Thermoplastic compositions satisfying the inequality are found to have improved impact properties.

[0063] In embodiments where the aromatic polycarbonate comprises two or more aromatic polycarbonates, for example two aromatic polycarbonates PC1 and PC2, the weight average molecular weight of the aromatic polycarbonate can be calculated using the following equation:

[0064]

[0065] Among them, M W(PC) is the weight average molecular weight of the aromatic polycarbonate; M W(PC1) is the weight average molecular weight of PC1; M W(PC2) is the weight average molecular weight of PC2; is the weight fraction of PC1 based on the total weight of the thermoplastic composition; is the weight fraction of PC2 based on the total weight of the thermoplastic composition. The same calculation applies to embodiments where the PBT comprises two or more PBTs.

[0066] Preferably, the thermoplastic composition according to the present invention has one or more or is selected to have one or more of the following properties:

[0067] - A spiral flow of at least 44.0 cm, preferably at least 45.0 cm, measured according to ASTM D-3123 09 (2017) using a 3 mm thickness;

[0068] a notched Izod impact strength at 0°C of at least 30 kJ / m2, preferably at least 50 kJ / m2, measured according to ISO 180 / 1A;

[0069] Notched Izod impact strength at -10°C of at least 24 kJ / m2, preferably at least 30 kJ / m2, measured according to ISO 180 / 1A;

[0070] A tensile modulus of at least 1900 MPa, preferably at least 1950 MPa, more preferably at least 2000 MPa, measured according to ISO 527 at a temperature of 23°C.

[0071] Preferably, the total amount of (A) aromatic polycarbonate, (B) polyethylene terephthalate, (C) polybutylene terephthalate, (D) impact modifier and (E) styrene acrylonitrile copolymer is at least 98 wt % and no more than 100 wt %, based on the total weight of the thermoplastic composition.

[0072] (A) aromatic polycarbonate, (B) polyethylene terephthalate, (C) polybutylene terephthalate, (D) impact modifier, (E) styrene acrylonitrile copolymer and (F) additives may be referred to as components of the thermoplastic composition according to the present invention.

[0073] Thermoplastic compositions can be manufactured by various methods known in the art. For example, first (A) aromatic polycarbonate, (B) polyethylene terephthalate, (C) polybutylene terephthalate, (D) impact modifier and (E) styrene acrylonitrile copolymer are optionally blended with any (F) additives in a high-speed mixer or by manual stirring. The blend is then fed into the throat of a twin-screw extruder via a hopper. The thermoplastic composition described herein is typically extruded on a WP 25 millimeter (mm) co-rotating intermeshing twin-screw extruder with an L / D of 41. Alternatively, at least one component can be directly fed to the extruder at the throat and / or downstream through a side feed port, or by compounding it to a masterbatch with the desired polymer and feeding it to the extruder, at least one component is incorporated into the composition. The extruder is generally operated at a temperature higher than the temperature required to cause the thermoplastic composition to flow, and in a typical experiment, the barrel temperature of the extruder is set to 150°C to 260°C. The material is run at 55-60% torque during compounding, and a vacuum of 100 mbar to 800 mbar is applied to the melt. The extrudate can be immediately cooled in a water bath and pelletized. The pellets so prepared can be one quarter inch long or shorter as desired. Such pellets can be used for subsequent molding, shaping or forming.

[0074] The present invention also relates to an article comprising the thermoplastic composition according to the present invention, wherein the article is preferably an automotive exterior, more preferably a heavy truck exterior, such as a wheel cover, a side panel, an air deflector, a front grille and a lower grille, a center and corner bumper, a step / pedal, a fender, a cladding, a side skirt, a battery cover. Preferably, the article comprises at least 90% by weight, preferably at least 95% by weight, more preferably at least 98% by weight, and most preferably 100% by weight of the thermoplastic composition. The article can be prepared, for example, by injection molding, extrusion, blow molding and thermoforming.

[0075] In the context of the present invention the terms "amount" and "weight" have the same meaning, both referring to the amount by mass of a component in the thermoplastic composition.

[0076] experiment

[0077] Material

[0078]

[0079] Example Preparation, Measurement Methods and Eq1

[0080] All examples were obtained by compounding process on a 25 mm co-rotating intermeshing twin screw extruder with L / D of 41. The ingredients of each example were added at the feed throat of the extruder. The barrel temperature of the extruder was set at 150°C to 260°C. The material was run to maintain 55-60% torque during compounding, and a vacuum of 100 millibar (mbar)-800 mbar was applied to the melt. The examples were molded on an Engel 75T molding machine for further testing. Ex. refers to examples according to the present invention and CE. refers to comparative examples.

[0081]

[0082] result

[0083] The compositions of the examples as well as their properties are shown in the table below.

[0084] Table 1. Composition and properties of Examples 1 to 8

[0085] CE.1 Ex.2 Ex.3 CE.4 CE.5 CE.6 CE.7 Ex.8 PC 1 ％ 39.25 39.25 39.25 39.25 39.25 57.39 67.39 57.39 PET ％ 40 30 20 10 - 30 20 20 PBT 1 ％ - 10 20 30 40 - - 10 ABS ％ 20 20 20 20 20 12 12 12 additive ％ 0.75 0.75 0.75 0.75 0.75 0.61 0.61 0.61 Results of Eq. 1 kg / mol 154.4 148.0 145.9 144.8 154.4 Spiral Flow cm 58.8 52.8 48.8 46.2 45.4 47.0 45.0 44.7 INI at 23°C kJ / m2 21.8 55.6 56.0 54.1 56.5 61.0 59.0 61.0 INI at 0℃ kJ / m2 17.1 38.2 41.5 35.8 41.4 38.0 53.0 56.0 INI at -10℃ kJ / m2 17.1 35.1 29.2 25.3 24.9 32.4 37.5 53.1 Ten.Mod.* GPa 1886 1944 1986 1999 1990 2080 2080 2120

[0086] *Ten.Mod.=tensile modulus

[0087] Examples 1 to 5 are comparable to each other, and among these examples, only Ex. 2, 3 (containing both PBT and PET in amounts according to the invention) show the best balance between spiral flow, INI and tensile modulus. By comparison between Examples 6 to 8, it is clear that only Ex. 8 containing both PBT and PET shows a better INI at -10°C.

[0088] Table 2. Composition and properties of Examples 9 to 12

[0089] Ex.9 Ex.10 Ex.11 CE.12 PC 1 ％ 47.25 43.25 39.25 35.25 PET ％ 30 30 30 30 PBT 1 ％ 10 10 10 10 ABS ％ 12 16 20 24 additive ％ 0.75 0.75 0.75 0.75 Results of Eq. 1 kg / mol 154.4 154.4 154.4 154.4 Spiral Flow cm 50.4 51.3 52.8 54.2 INI at 23°C kJ / m2 55.0 56.3 55.6 55.9 INI at 0℃ kJ / m2 35.6 38.6 38.2 40.4 INI at -10℃ kJ / m2 24.5 33.0 35.1 27.8 Tensile modulus GPa 2111 2036 1944 1842

[0090] According to Table 2, too high an amount of ABS leads to unsatisfactory tensile modulus.

[0091] Table 3. Composition and properties of Examples 13 to 16

[0092] CE.15 CE.16 CE.13 CE.14 PC 1 ％ 49.25 45.25 61.39 57.39 PET ％ 30 30 30 30 PBT 1 ％ 10 10 - - MBS ％ 10 14 8 8 SAN ％ 4 additive ％ 0.75 0.75 0.61 0.61 Spiral Flow cm 49.4 51.2 36.2 40.0 INI at 23°C kJ / m2 41.1 41.5 57.1 61.6 INI at 0℃ kJ / m2 35.7 36.8 51.2 45.1 INI at -10℃ kJ / m2 24.8 33.4 40.0 26.9 Tensile modulus GPa 2106 1998 2080 2110

[0093] According to Table 3, MBS is not as effective as ABS as an impact modifier because MBS causes poorer spiral flow (CE.13, 14) or poorer INI at 23°C (CE.15, 16).

[0094] Table 4. Composition and properties of Examples 17 to 25

[0095]

[0096] *Ten.Mod.=tensile modulus

[0097] According to Table 4, the result of Eq1 related to the molecular weight of PC and PBT needs to be at least 101.5 kg / mol to achieve improved INI at -10°C (at least 30.0 kJ / m2).

[0098] Table 5. Composition and properties of Examples 26 to 28

[0099] Ex.26 Ex.27 Ex.28 PC 1 ％ 31.25 18.125 5 PC 2 ％ 5 18.125 28.25 PET ％ 30 30 30 PBT 1 ％ 10 10 10 ABS ％ 20 20 20 SAN ％ 3 3 6 additive ％ 0.75 0.75 0.75 Results of Eq. 1 kg / mol 155.6 158.8 161.8 Spiral Flow cm 57.4 58.1 60.1 INI at 23°C kJ / m2 56.6 58.0 53.0 INI at 0℃ kJ / m2 36.7 51.0 29.9 INI at -10℃ kJ / m2 27.1 29.4 23.6 Tensile modulus GPa 1990 1994 2044

[0100] According to Table 5, using SAN as a flow modifier can produce better spiral flow properties, but too high an amount of SAN leads to too low an INI at -10 °C.

Claims

1. A thermoplastic composition comprising: (A) 30 to 59 weight percent of an aromatic polycarbonate, wherein the aromatic polycarbonate has a weight average molecular weight in the range of 14.0 to 45.6 kg / mol as measured by gel permeation chromatography (GPC) using polystyrene standards; (B) 20 to 40 weight percent of polyethylene terephthalate, wherein the polyethylene terephthalate has an intrinsic viscosity in the range of 0.50 to 1.21 dl / g as measured according to ASTM D2857-95 (2007); (C) 2 to 25 weight percent polybutylene terephthalate, wherein the polybutylene terephthalate has a weight average molecular weight in the range of 45.0 to 150.0 kg / mol as measured by gel permeation chromatography (GPC) using polystyrene standards; (D) 10 to 20 weight percent of an impact modifier having a fraction in the range , wherein the impact modifier is selected from acrylonitrile styrene butadiene copolymers, ethylene acrylate copolymers, ethylene glycidyl acrylate copolymers, and mixtures thereof; The weight % is based on the total weight of the thermoplastic composition.

2. The thermoplastic composition according to claim 1, wherein the thermoplastic composition comprises (E) 0 to 5 weight percent of a styrene acrylonitrile copolymer.

3. The thermoplastic composition according to claim 2, wherein (E) the styrene acrylonitrile copolymer has an acrylonitrile level in the range of 12 to 56 wt%, preferably in the range of 18 to 31 wt%, more preferably in the range of 19 to 29 wt%, based on the total weight of the styrene acrylonitrile copolymer.

4. Thermoplastic composition according to claim 2 or 3, wherein the thermoplastic composition comprises 1.7 to 5.0 wt%, preferably 2.1 to 4.9 wt% of (E) styrene acrylonitrile copolymer.

5. The thermoplastic composition according to any one of claims 2 to 4, wherein (E) the styrene acrylonitrile copolymer has an MFR in the range of 8 to 30 g / 10 min, preferably in the range of 9 to 23 g / 10 min, more preferably in the range of 10 to 18 g / 10 min, measured at 230°C / 1.2 kg according to ASTM D1238.

6. The thermoplastic composition according to any one of the preceding claims, wherein the following inequality is satisfied: Among them, M W(PC) is the weight average molecular weight of the aromatic polycarbonate, M W(聚对苯二甲酸丁二酯) is the weight average molecular weight of polyester polybutylene terephthalate, is the weight fraction of polybutylene terephthalate based on the total weight of the thermoplastic composition, wherein the weight average molecular weight is measured by GPC using polystyrene standards.

7. Thermoplastic composition according to any one of the preceding claims, wherein the (D) impact modifier has an average particle size in the range of 152 to 627 nm, preferably in the range of 226 to 445 nm, more preferably in the range of 256 to 397 nm, more preferably in the range of 272 to 335 nm.

8. The thermoplastic composition according to any one of the preceding claims, wherein (D) the impact modifier is acrylonitrile butadiene styrene copolymer.

9. The thermoplastic composition according to claim 8, wherein the acrylonitrile butadiene styrene copolymer has an acrylonitrile content in the range of 8.3 to 19.8 wt. %, a butadiene content in the range of 27.5 to 73.2 wt. %, preferably 38.2 to 61.7 wt. %, and a styrene content of 23.4 to 46.8 wt. %, based on the total weight of the acrylonitrile butadiene styrene copolymer.

10. The thermoplastic composition according to any one of the preceding claims, wherein (A) the aromatic polycarbonate comprises two or more aromatic polycarbonates having different weight average molecular weights.

11. Thermoplastic composition according to any one of the preceding claims, wherein (B) polyethylene terephthalate has an intrinsic viscosity in the range of 0.71 to 1.08 dl / g, preferably in the range of 0.75 to 0.96 dl / g.

12. Thermoplastic composition according to any one of the preceding claims, wherein the thermoplastic composition comprises 30 to 56 wt%, preferably 33 to 52 wt%, of (A) aromatic polycarbonate.

13. The thermoplastic composition according to any one of the preceding claims, selected to have one or more of the following: A spiral flow of at least 44.0 cm, preferably at least 45.0 cm, measured according to ASTM D-3123 09 (2017) using a 3 mm thickness; a notched Izod impact strength at 0°C of at least 30 kJ / m2, preferably at least 50 kJ / m2, measured according to ISO 180 / 1A; Notched Izod impact strength at -10°C of at least 24 kJ / m2, preferably at least 30 kJ / m2, measured according to ISO 180 / 1A; A tensile modulus of at least 1900 MPa, preferably at least 1950 MPa, more preferably at least 2000 MPa, measured according to ISO 527 at a temperature of 23°C.

14. The thermoplastic composition of any of the preceding claims, wherein the total amount of (A) aromatic polycarbonate, (B) polyethylene terephthalate, (C) polybutylene terephthalate, (D) impact modifier, and (E) styrene acrylonitrile copolymer is at least 98 weight percent and no more than 100 weight percent, based on the total weight of the thermoplastic composition.

15. An article comprising the thermoplastic composition according to any one of the preceding claims, wherein the article is preferably an automotive exterior part.

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