Electrostatically paintable molded articles and method for the manufacture thereof

Abstract

To provide an improved poly(phenylene ether) / polyester composition which exhibits superior mechanical strength, low moisture uptake, superior dimensional stability, and superior conductivity.SOLUTION: An article is molded from a thermoplastic composition including particular amounts of a poly(phenylene ether), a poly(butylene terephthalate), an impact modifier, a reactive compatibilizer, and a conductive filler including carbon nanotubes. The article is an electrostatically paintable automotive component, and exhibits a desirable combination of good conductivity and thermal stability. Methods of making the molded article are also disclosed.SELECTED DRAWING: None

Description

Technical Field

[0001] Disclosed herein are electrostatically paintable molded articles comprising a thermoplastic composition comprising poly(phenylene ether) and polyester, which exhibit enhanced properties such as improved impact strength, low moisture absorption, and high heat resistance.

Background Art

[0002] Poly(phenylene ether) is a commercially attractive material because of its unique combination of properties, including, for example, high temperature resistance, dimensional and hydrolytic stability, and electrical properties. Compatibilized poly(phenylene ether) / polyester blends by combining poly(phenylene ether) with polyester have sought to obtain a desirable balance of properties such as dimensional stability and impact strength. Current poly(phenylene ether) / polyester compositions do not provide a sufficient balance of properties for specific applications, including, for example, automotive parts that can be painted online and in-line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] Accordingly, in order to address the above technical limitations, there is a continuing need for improved poly(phenylene ether) / polyester compositions. In particular, it would be advantageous to provide a composition that exhibits good mechanical strength, low moisture absorption, good dimensional stability, and good electrical conductivity.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a molded article comprising a thermoplastic composition, the thermoplastic composition comprising 18 to 30 weight percent poly(phenylene ether), 50 to 80 weight percent poly(butylene terephthalate), 5 to 15 weight percent impact modifier, 0.1 to 1.4 weight percent reactive compatibilizer, and 0.2 to 10 weight percent conductive filler comprising carbon nanotubes, wherein the weight percents are based on the total weight of the thermoplastic composition, the molded article is an electrostatically paintable automotive part, and the molded article exhibits a volume resistivity of less than 0.5 kiloohm centimeter (kOhm·cm) and a Vicat softening temperature of greater than 165° C. as determined in accordance with ISO 306.

[0006] Another aspect is a molded article comprising a thermoplastic composition, the thermoplastic composition comprising a poly(phenylene ether) comprising poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity, measured at 25 °C in chloroform using an Ubbelohde viscometer, of greater than 0.25 deciliter / gram, a first poly(butylene terephthalate) having an intrinsic viscosity, measured in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane at 30 °C, of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, a poly(butylene terephthalate) comprising a second poly(butylene terephthalate) having an intrinsic viscosity, measured in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane at 30 °C, of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, an impact modifier comprising a hydrogenated block copolymer, a polymer compatibilizer having an average of 10 or more pendant epoxy groups per molecule, and a conductive filler comprising carbon nanotubes, the molded article being an electrostatically paintable automotive part, the molded article having a volume resistivity of less than 0.5 kOhm·cm, a Vicat softening temperature of greater than 165 °C as determined according to ISO 306, a notched Izod impact strength of 8 kJ / m 2 or more, preferably from 8 to 12 kJ / m 2 as measured according to ISO 180 / 1A, and a melt volume flow rate of less than 12 cm 3 / 10 min as determined according to ISO 1133, and exhibiting a moisture absorption of 0.3 weight percent or less based on the weight of the molded article.

[0007] Another aspect of the present disclosure is a method for manufacturing a moldable article that can be electrostatically coated. The method includes a step of melt-mixing 18 to 30 weight percent of poly(phenylene ether), 50 to 80 weight percent of poly(butylene terephthalate), 5 to 15 weight percent of an impact modifier, 0.1 to 1.4 weight percent of a reactive compatibilizer, and 0.2 to 10 weight percent of a conductive filler including carbon nanotubes to provide a thermoplastic composition, where the weight percents are based on the total weight of the thermoplastic composition, and a step of molding the thermoplastic composition to provide a moldable article that can be electrostatically coated. The moldable article that can be electrostatically coated exhibits a volume resistivity of less than 0.5 kOhm·cm and a Vicat softening temperature exceeding 165°C as determined in accordance with ISO 306.

[0008] The above and other features are illustrated by the following figures and detailed description.

Brief Description of the Drawings

[0009] The following figures are exemplary embodiments.

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] It is desirable that automotive-related articles match the color of other parts of the vehicle, providing a desirable aesthetic appearance to the vehicle. Certain automotive articles made from thermoplastic compositions are typically difficult to paint online with the rest of the vehicle or inline where lower temperatures can be used because at least a part of them uses high temperatures. Thus, in both cases, materials having particularly high dimensional stability, especially materials with electrostatically applied paints, are required. To address this problem, such parts have been painted "offline" using specially formulated paints in separate operations. In the "offline" application of the finish color coat, sufficient color matching is not always obtained. In addition, the parts of the vehicle to be painted are first primed with a base coat before the application of the finish color coat. Then the entire vehicle is painted. Under such circumstances, if the color of the article does not exactly match the color of the primer, the painted article may appear different from the primed parts of the vehicle. Electrostatic painting can also offer high paint transfer efficiency, cost reduction, and improved environmental performance. Therefore, it has been desirable to provide improved compositions that are particularly well-suited for use in the preparation of electrostatically paintable molded articles, especially for automotive applications.

[0012] The inventors have unexpectedly discovered that a thermoplastic composition comprising a specific amount of poly(phenylene ether), poly(butylene terephthalate), an impact modifier, a reactive compatibilizer, and a conductive filler can provide a desirable combination of properties including, for example, good mechanical strength, low moisture absorption, good dimensional stability, lower warpage, and good electrical conductivity. Thus, the compositions described herein may be particularly well-suited for providing molded articles for automotive applications, such as thermally stable automotive parts suitable for online or inline electrostatic painting. Therefore, significant improvements are provided by the present disclosure.

[0013] Accordingly, one aspect of the present disclosure is a molded article comprising a thermoplastic composition. The thermoplastic composition comprises a poly(phenylene ether), a poly(butylene terephthalate), an impact modifier, a reactive compatibilizer, and a conductive filler.

[0014] As used herein, the poly(phenylene ether) comprises repeating structural units according to formula (1),

Chemical formula

[0015] In one aspect, the poly(phenylene ether) block comprises 2,6-dimethyl-1,4-phenylene ether repeating units, i.e., repeating units of formula (2) [Chemical formula] (2), 2,3,6-trimethyl-1,4-phenylene ether repeating units, or combinations thereof.

[0016] Poly(phenylene ether) can typically include molecules having aminoalkyl-containing end group(s) (plural possible) disposed ortho to the hydroxy group. Also typically present are tetramethyldiphenoquinone (TMDQ) end groups obtained from a reaction mixture containing 2,6-dimethylphenol where tetramethyldiphenoquinone by-products are present. Poly(phenylene ether) can be in the form of a homopolymer, copolymer, graft copolymer, ionomer, or block copolymer, as well as combinations thereof.

[0017] Poly(phenylene ether) can be prepared by an oxidative polymerization method. In such a method, poly(phenylene ether) is the product of oxidative polymerization of a monomer mixture containing a monohydric phenol (which can be as described above).

[0018] In one aspect, poly(phenylene ether) includes a poly(phenylene ether)-polysiloxane block copolymer. As used herein, the term “poly(phenylene ether)-polysiloxane block copolymer” refers to a block copolymer containing at least one poly(phenylene ether) block and at least one polysiloxane block.

[0019] In one aspect, the poly(phenylene ether)-polysiloxane block copolymer is prepared by an oxidative copolymerization method. In this method, the poly(phenylene ether)-polysiloxane block copolymer is the product of a process that includes the step of oxidatively copolymerizing a monomer mixture containing a monohydric phenol and a hydroxyaryl-terminated polysiloxane. In one aspect, the monomer mixture includes 70 to 99 parts by weight of the monohydric phenol and 1 to 30 parts by weight of the hydroxyaryl-terminated polysiloxane, based on the total weight of the monohydric phenol and the hydroxyaryl-terminated polysiloxane. The hydroxyaryl di-terminated polysiloxane can include a plurality of repeating units having the structure of formula (3),

Chemical formula

Chemical formula

[0020] In one embodiment, the monohydric phenol includes 2,6-dimethylphenol, and the hydroxyaryl-terminated polysiloxane has the structure of formula (5),

Chemical formula

[0021] The acid-catalyzed copolymerization process produces a poly(phenylene ether)-polysiloxane block copolymer as the desired product and poly(phenylene ether) (without incorporated polysiloxane blocks) as a byproduct. It is not necessary to separate the poly(phenylene ether) from the poly(phenylene ether)-polysiloxane block copolymer. Thus, the poly(phenylene ether)-polysiloxane block copolymer can be utilized as a “reaction product” that contains both poly(phenylene ether) and the poly(phenylene ether)-polysiloxane block copolymer. Certain isolation procedures, such as precipitation from isopropanol, can ensure that the reaction product is essentially free of residual hydroxyaryl-terminated polysiloxane starting material. In other words, these isolation procedures ensure that essentially all of the polysiloxane content of the reaction product is in the form of poly(phenylene ether)-polysiloxane block copolymer. Detailed methods for forming the poly(phenylene ether)-polysiloxane block copolymer are described in U.S. Pat. Nos. 8,017,697 and 8,669,332 to Carrillo, the contents of which are hereby incorporated by reference in their entirety.

[0022] In one embodiment, the poly(phenylene ether) can have an intrinsic viscosity of from 0.03 to 2 deciliters per gram (dl / g). In one embodiment, the poly(phenylene ether) has an intrinsic viscosity of greater than 0.25 dl / g, such as from 0.25 to 1.7 dl / g, specifically from 0.25 to 0.7 dl / g, more specifically from 0.35 to 0.55 dl / g, even more specifically from 0.35 to 0.50 dl / g, or from 0.4 to 0.6 dl / g, as measured at 25° C. in chloroform using an Ubbelohde viscometer.

[0023] In one aspect, the poly(phenylene ether) comprises a homopolymer or copolymer of monomers selected from the group consisting of 2,6-dimethylphenol, 2,3,6-trimethylphenol, and combinations thereof. In one aspect, the poly(phenylene ether) comprises a poly(phenylene ether)-polysiloxane block copolymer. In one aspect, the poly(phenylene ether)-polysiloxane block copolymer can provide, for example, from 0.05 to 2 weight percent, specifically from 0.1 to 1 weight percent, more specifically from 0.2 to 0.8 weight percent of siloxane groups to the composition as a whole.

[0024] The poly(phenylene ether) is present in the composition in an amount of 18 to 30 weight percent, based on the total weight of the thermoplastic composition. Within this range, the poly(phenylene ether) can be present in an amount of 20 to 30 weight percent, or 21 to 30 weight percent, or 20 to 28 weight percent, or 21 to 28 weight percent, or 21 to 27 weight percent, or 18 to 26 weight percent, or 19 to 26 weight percent, each based on the total weight of the thermoplastic composition.

[0025] In addition to the poly(phenylene ether), the thermoplastic composition comprises poly(butylene terephthalate). In one aspect, the poly(butylene terephthalate) can have an intrinsic viscosity of from 0.2 to 1.5 dl / g as measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane. In one aspect, at least some of the poly(butylene terephthalate) contains nucleophilic groups such as carboxylic acid groups. Optionally, it is desirable to reduce the number of carboxyl end groups to less than 20 microequivalents / gram (meq / g) of the poly(butylene terephthalate), typically by use of acid-reactive species. In other cases, it is desirable for the poly(butylene terephthalate) to have a fairly high carboxyl end group concentration in the range of 20 to 250 meq / g of the poly(butylene terephthalate), more specifically 30 to 100 meq / g per gram of the poly(butylene terephthalate).

[0026] In one aspect, at least a combination of poly(butylene terephthalate) can be included in the thermoplastic composition. In one aspect, the thermoplastic composition can include a first poly(butylene terephthalate) and a second poly(butylene terephthalate). The first poly(butylene terephthalate) can have an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, as measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane. The second poly(butylene terephthalate) can have an intrinsic viscosity of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, as measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane. In one aspect, the first poly(butylene terephthalate) can have an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, and a carboxyl end group concentration of less than 20 meq / g of poly(butylene terephthalate), more specifically, from 10 to less than 20 meq / g of poly(butylene terephthalate), as measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane. In one aspect, the second poly(butylene terephthalate) can have an intrinsic viscosity of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, and a carboxyl end group concentration of greater than 20 meq / g of poly(butylene terephthalate), more specifically, from 25 to 50 meq / g of poly(butylene terephthalate), as measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane.

[0027] Poly(butylene terephthalate) is present in the thermoplastic composition in an amount of 50 to 80 weight percent, based on the total weight of the thermoplastic composition. Within this range, poly(butylene terephthalate) can be present in an amount of 50 to 75 weight percent, or 55 to 80 weight percent, or 55 to 75 weight percent, or 57 to 80 weight percent, or 57 to 75 weight percent, or 57 to 72 weight percent, or 51 to 65 weight percent, or 51 to 60 weight percent, each based on the total weight of the thermoplastic composition.

[0028] In addition to poly(phenylene ether) and poly(butylene terephthalate), the thermoplastic composition includes an impact modifier. Examples of suitable impact modifiers include block copolymers, elastomers such as polybutadiene, random copolymers such as ethylene vinyl acetate (EVA), and combinations including two or more of the foregoing impact modifiers.

[0029] In one aspect, the impact modifier comprises a hydrogenated block copolymer of an alkenyl aromatic and a conjugated diene. For simplicity, this component is referred to as a "hydrogenated block copolymer". The hydrogenated block copolymer can include from 10 to 90 weight percent poly(alkenyl aromatic) content and from 90 to 10 weight percent hydrogenated poly(conjugated diene) content, based on the weight of the hydrogenated block copolymer. In one aspect, the hydrogenated block copolymer is a low poly(alkenyl aromatic content) hydrogenated block copolymer, in which case the poly(alkenyl aromatic) content is less than 10 to 40 weight percent, or 20 to 35 weight percent, or 25 to 35 weight percent, or 30 to 35 weight percent, based on the weight of all low poly(alkenyl aromatic content) hydrogenated block copolymers. In one aspect, the hydrogenated block copolymer is a high poly(alkenyl aromatic) content hydrogenated block copolymer, in which case the poly(alkenyl aromatic) content is from 40 to 90 weight percent, or 50 to 80 weight percent, or 60 to 70 weight percent, based on the weight of all high poly(alkenyl aromatic content) hydrogenated block copolymers.

[0030] In one aspect, the hydrogenated block copolymer has a weight average molecular weight of from 40,000 to 400,000 grams per mole (g / mol). The number average molecular weight and the weight average molecular weight can be determined by gel permeation chromatography based on comparison with polystyrene standards. In one aspect, the hydrogenated block copolymer has a weight average molecular weight of from 200,000 to 400,000 g / mol, or from 220,000 to 350,000 g / mol. In one aspect, the hydrogenated block copolymer has a weight average molecular weight of from 40,000 to 200,000 g / mol, or from 40,000 to 180,000 g / mol, or from 40,000 to 150,000 g / mol.

[0031] The alkenyl aromatic monomer used to prepare the hydrogenated block copolymer can have a structure according to formula (6),

Chemical formula

[0032] The conjugated diene used to prepare the hydrogenated block copolymer can be a C 4-20 conjugated diene. Suitable conjugated dienes include, for example, 1,3-butadiene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, etc., and combinations thereof. In one embodiment, the conjugated diene is 1,3-butadiene, 2-methyl-1,3-butadiene, or a combination thereof. In one embodiment, the conjugated diene is 1,3-butadiene.

[0033] A hydrogenated block copolymer is a copolymer comprising (A) at least one block derived from an alkenyl aromatic compound and (B) at least one block derived from a conjugated diene, wherein the aliphatic unsaturation content in block (B) is at least partially reduced by hydrogenation. In one embodiment, the aliphatic unsaturation in block (B) is reduced by at least 50 percent, or at least 70 percent. The sequences of blocks (A) and (B) include a linear structure, a graft structure, and a radial teleblock structure with or without branched chains. Linear block copolymers include a tapered linear structure and a non-tapered linear structure. In one embodiment, the hydrogenated block copolymer has a tapered linear structure. In one embodiment, the hydrogenated block copolymer has a non-tapered linear structure. In one embodiment, the hydrogenated block copolymer comprises a (B) block incorporating alkenyl aromatic monomers randomly. The linear block copolymer structure includes a diblock (A-B block), triblock (A-B-A block or B-A-B block), tetrablock (A-B-A-B block), and pentablock (A-B-A-B-A block or B-A-B-A-B block) structures, as well as a linear structure containing six or more blocks in total of (A) and (B), and the molecular weight of each (A) block can be the same as or different from that of other (A) blocks, and the molecular weight of each (B) block can be the same as or different from that of other (B) blocks. In one embodiment, the hydrogenated block copolymer is a diblock copolymer, a triblock copolymer, or a combination thereof.

[0034] In one aspect, the hydrogenated block copolymer excludes monomer residues other than alkenyl aromatic compounds and conjugated dienes. In one aspect, the hydrogenated block copolymer is composed of blocks derived from alkenyl aromatic compounds and conjugated dienes. It does not contain grafts formed from these or any other monomers. It is also composed of carbon and hydrogen atoms, thus excluding heteroatoms. In one aspect, the hydrogenated block copolymer contains residues of one or more acid functionalizing agents such as maleic anhydride. In one aspect, the hydrogenated block copolymer includes a polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymer.

[0035] In one aspect, the hydrogenated block copolymer is a polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymer having a polystyrene content of 10 to 50 weight percent, or 20 to 40 weight percent, or 20 to 35 weight percent, or 25 to 35 weight percent, based on the weight of the polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymer. In these aspects, the polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymer can optionally have a weight average molecular weight of 200,000 to 400,000 g / mol, or 250,000 to 350,000 g / mol as determined by size exclusion chromatography using polystyrene standards.

[0036] Methods for preparing hydrogenated block copolymers are known in the art, and many hydrogenated block copolymers are commercially available. Exemplary commercially available hydrogenated block copolymers include the following: polystyrene-poly(ethylene-propylene) diblock copolymers available from Kraton Performance Polymers Inc. as KRATON™ G1701 (having 37 weight percent polystyrene) and G1702 (having 28 weight percent polystyrene), polystyrene-poly(ethylene-butylene)-polystyrene triblock copolymers available from Kraton Performance Polymers Inc. as KRATON™ G1641 (having 33 weight percent polystyrene), G1650 (having 30 weight percent polystyrene), G1651 (having 33 weight percent polystyrene), and G1654 (having 31 weight percent polystyrene), and polystyrene-poly(ethylene-ethylene / propylene)-polystyrene triblock copolymers available from Kuraray as SEPTON™ S4044, S4055, S4077, and S4099.Examples of additional commercially available hydrogenated block copolymers include: from Dynasol, CALPRENE™ H6140 (having 31 weight percent polystyrene), H6170 (having 33 weight percent polystyrene), H6171 (having 33 weight percent polystyrene), and H6174 (having 33 weight percent polystyrene); and polystyrene - poly(ethylene - butylene) - polystyrene (SEBS) triblock copolymers available from Kuraray as SEPTON™ 8006 (having 33 weight percent polystyrene) and 8007 (having 30 weight percent polystyrene); polystyrene - poly(ethylene - propylene) - polystyrene (SEPS) copolymers available from Kuraray as SEPTON™ 2006 (having 35 weight percent polystyrene) and 2007 (having 30 weight percent polystyrene); and from Kraton Performance Polymers Inc., KRATON™ G4609 (containing 45% mineral oil and SEBS having 33 weight percent polystyrene) and G4610 (containing 31% mineral oil and SEBS having 33 weight percent polystyrene); and oil - extended compounds of these hydrogenated block copolymers available from Asahi as TUFTEC™ H1272 (containing 36% oil and SEBS having 35 weight percent polystyrene). Mixtures of two or more hydrogenated block copolymers can be used. In one embodiment, the hydrogenated block copolymer comprises a polystyrene - poly(ethylene - butylene) - polystyrene triblock copolymer having a weight - average molecular weight of at least 100,000 g / mol, or from 200,000 to 400,000 g / mol.

[0037] The composition comprises an impact modifier in an amount of 5 to 15 weight percent, based on the total weight of the thermoplastic composition. Within this range, the amount of the impact modifier can be, respectively, 8 to 15 weight percent, or 10 to 15 weight percent, or 11 to 14 weight percent, based on the total weight of the thermoplastic composition.

[0038] The thermoplastic composition further comprises a reactive compatibilizer. In one aspect, the reactive compatibilizer is preferably a polymeric compatibilizer. As used herein and throughout, a reactive compatibilizer or polymeric compatibilizer refers to a poly(phenylene ether), poly(butylene terephthalate), or a polymeric polyfunctional compound that interacts with both. This interaction may be chemical (e.g., grafting) and / or physical (e.g., affecting the surface properties of the dispersed phase). When the interaction is chemical, the compatibilizer may be partially or fully reacted with the poly(phenylene ether), poly(butylene terephthalate), or both, such that the composition comprises a reaction product. For example, the epoxy groups of the compatibilizer may react with the acid groups present on the poly(butylene terephthalate) in the melt blend. The use of a polymeric compatibilizer can improve the compatibility between the poly(phenylene ether) and the poly(butylene terephthalate), which can be evidenced by enhanced impact strength, mold knit line strength, elongation, and / or the formation of a unique two-phase morphology. Such a morphology is evidenced by the occurrence of two distinct phases within the molded part, a continuous phase comprising the polyester and a dispersed phase comprising the poly(phenylene ether). The dispersed phase particles can have an average particle diameter of from 0.2 to 5 micrometers (μm), more specifically from 0.5 to 4 μm, and even more specifically from 0.5 to 3 μm. The average particle diameter is the average circular diameter of at least 100 particles and can be determined by scanning electron microscopy or transmission electron microscopy. In the case of elliptical particles, the "circular diameter" is the average of the major and minor axes of each particle. In other words, the diameters of the circumscribed and inscribed circles are averaged for each elliptical particle.

[0039] Exemplary examples of suitable compatibilizers include, but are not limited to: copolymers of glycidyl methacrylate (GMA) with alkenes, copolymers of GMA with alkenes and acrylic esters, copolymers of GMA with alkenes and vinyl acetate, copolymers of GMA and styrene. Suitable alkenes include ethylene, propylene, and mixtures of two or more of the foregoing. Suitable acrylic esters include alkyl acrylate monomers, such as, but not limited to, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and combinations of the foregoing alkyl acrylate monomers. When present, the acrylic ester can be used in an amount of 15 to 35 weight percent based on the total amount of monomers used in the copolymer. When present, vinyl acetate can be used in an amount of 4 to 10 weight percent based on the total amount of monomers used in the copolymer. Exemplary examples of suitable compatibilizers include ethylene-glycidyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-alkyl acrylate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, ethylene-glycidyl methacrylate-ethyl acrylate copolymer, and ethylene-glycidyl methacrylate-butyl acrylate copolymer.

[0040] The use of glycidyl methacrylate copolymers as polymer compatibilizers is known in the art as exemplified by U.S. Pat. Nos. 5,698,632 and 5,719,236, the contents of which are hereby incorporated by reference. However, contrary to the prior art that teaches that the compatibilizer can be a compound having two pendant epoxy groups per molecule and some monofunctional species, it has been discovered that the polymer compatibilizer must have, per molecule, an average of 3 or more pendant epoxy groups, more specifically, an average of 8 or more pendant epoxy groups, more specifically, an average of 11 or more pendant epoxy groups, more specifically, an average of 15 or more pendant epoxy groups, more specifically, an average of 17 or more pendant epoxy groups. The diglycidyl compounds do not exhibit the reactivity required to form a composition having a stable phase morphology.

[0041] In one aspect, the reactive compatibilizer is preferably a polymer compatibilizer having, per molecule, an average of 3 or more pendant epoxy groups, or an average of 5 or more pendant epoxy groups, or an average of 8 or more pendant epoxy groups, or an average of 10 or more pendant epoxy groups.

[0042] The reactive compatibilizer is present in the thermoplastic composition in an amount of 0.1 to 1.4 weight percent, based on the total weight of the thermoplastic composition. Within this range, the reactive compatibilizer can be present in an amount of 0.2 to 1.4 weight percent, or 0.5 to 1.4 weight percent, or 0.8 to 1.4 weight percent, or 0.1 to 1.2 weight percent, or 0.2 to 1.2 weight percent, or 0.5 to 1.2 weight percent, or 0.8 to 1.2 weight percent, or 0.9 to 1.1 weight percent, or 0.95 to 1.05 weight percent, each based on the total weight of the composition.

[0043] The thermoplastic composition further comprises a conductive filler (e.g., an electric conduction filler) including carbon nanotubes. The carbon nanotubes can be single-layer or multi-layer. In one aspect, the carbon nanotubes can be multi-layer. In one aspect, the carbon nanotubes can have an average diameter of 2 to 100 nanometers (nm), or 2 to 50 nm, or 2 to 20 nm, or 2 to 12 nm, or 5 to 12 nm, or 8 to 11 nm, or 8.5 to 10.5 nm. In one aspect, the carbon nanotubes can have an average length of 0.1 to 10 μm, or 0.1 to 5 μm, or 0.1 to 2.5 μm, or 0.5 to 2.5 μm. In a particular aspect, the carbon nanotubes can have an average length of 0.5 to 2.5 μm and an average diameter of 8.5 to 10.5 nm.

[0044] The conductive filler including carbon nanotubes is present in an amount of 0.2 to 10 weight percent based on the total weight of the thermoplastic composition in the thermoplastic composition. Within this range, the conductive filler including carbon nanotubes can be, respectively, in an amount of 0.2 to 8 weight percent, or 0.2 to 5 weight percent, or 0.2 to 2 weight percent, or 0.2 to 1.5 weight percent, or 0.2 to 1 weight percent, or less than 0.2 to 1 weight percent, or 0.2 to 0.95 weight percent, or 0.2 to 0.75 weight percent, or 0.2 to 0.65 weight percent, or 0.25 to 0.65 weight percent based on the total weight of the thermoplastic composition.

[0045] In one aspect, conductive fillers other than carbon nanotubes can be excluded from the thermoplastic composition. For example, conductive fillers such as conductive carbon black or inorganic fillers (e.g., metal fibers, metal disks, metal particles, metal-coated disk-shaped fillers, etc.) can be excluded from the thermoplastic composition.

[0046] The thermoplastic composition can optionally further comprise an additive composition. The additive composition comprises one or more additives. The additives can be, for example, stabilizers, release agents, lubricants, processing aids, drip retardants, nucleating agents, UV blockers, dyes, pigments, antioxidants, antistatic agents, foaming agents, mineral oils, metal deactivators, antiblocking agents, or combinations thereof. In one aspect, the additive composition can comprise a stabilizer, an antioxidant, or a combination thereof. When present, such additives are typically used in a total amount of from 0.1 to 10 weight percent, based on the total weight of the composition. In certain aspects, the additive composition can comprise a stabilizer, an antioxidant, or a combination thereof and be present in an amount of from 0.1 to 5 weight percent, based on the total weight of the thermoplastic composition.

[0047] The composition can optionally minimize or exclude additional components not specifically described herein. For example, the composition can comprise less than 5 weight percent, or less than 2 weight percent, or less than 1 weight percent or less than 0.1 weight percent of poly(phenylene ether), poly(butylene terephthalate), and any thermoplastic polymer other than the polymeric reactive compatibilizers described above. In one aspect, the composition can exclude polyamide. In one aspect, the composition can exclude polyesters other than poly(butylene terephthalate). In one aspect, the composition can minimize or exclude glass fibers. In one aspect, impact modifiers other than hydrogenated block copolymers can be minimized (i.e., present in an amount less than 1 weight percent) or excluded from the thermoplastic composition. In one aspect, the composition can minimize or exclude homopolystyrene or rubber-modified polystyrene. In one aspect, the composition can minimize or exclude flame retardants, such as organic phosphorus flame retardants.

[0048] It will be understood that the total amount of the components of the thermoplastic composition is 100 weight percent in total.

[0049] In certain embodiments, the thermoplastic composition comprises from 20 to 28 weight percent, preferably from 21 to 27 weight percent, of poly(phenylene ether); from 51 to 65 weight percent, preferably from 51 to 60 weight percent, of poly(butylene terephthalate); from 10 to 15 weight percent, preferably from 11 to 14 weight percent, of an impact modifier; from 0.8 to 1.2 weight percent of a reactive compatibilizer; and from 0.2 to less than 1 weight percent, preferably from 0.25 to 0.65 weight percent, of a conductive filler comprising carbon nanotubes, wherein the weight percents are based on the total weight of the thermoplastic composition. The poly(phenylene ether) can include poly(2,6-dimethyl-1,4-phenylene ether), and preferably, the poly(phenylene ether) has an intrinsic viscosity greater than 0.25 deciliter / gram as measured using an Ubbelohde viscometer in chloroform at 25°C. The poly(butylene terephthalate) can have an intrinsic viscosity of from 0.2 to 1.5 dl / g as measured at 30°C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane. The poly(butylene terephthalate) can include a first poly(butylene terephthalate) having an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, as measured at 30°C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane, and a second poly(butylene terephthalate) having an intrinsic viscosity of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, as measured at 30°C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane. The impact modifier can include a hydrogenated block copolymer comprising polystyrene-poly(ethylene-butylene)-polystyrene. The reactive compatibilizer can include a polymeric compatibilizer having an average of 10 or more pendant epoxy groups per molecule. The carbon nanotubes can have an average length of from 0.5 to 2.5 micrometers and an average diameter of from 8.5 to 10.5 nanometers.

[0050] The compositions of the present disclosure can be produced, for example, by melt blending the components of the composition. The components of the composition can be mixed or blended using ordinary equipment such as ribbon blenders, HENSCHEL™ mixers, BANBURY™ mixers, drum tumblers, etc., and the blended composition can then be melt blended or melt kneaded. Melt blending or melt kneading can be carried out using ordinary equipment such as single-screw extruders, twin-screw extruders, multi-screw extruders, co-kneaders, etc. For example, the present composition can be prepared by melt blending the components in a twin-screw extruder at a temperature of 270 to 310 °C, or 280 to 300 °C. The extrudate can be quenched immediately in a water bath and pelletized. The pellets so prepared can be made to be 1 / 4 inch or less in length as desired. Such pellets can be used for subsequent molding, shaping, or forming.

[0051] The thermoplastic compositions according to the present disclosure can exhibit a desirable combination of properties. In particular, molded articles containing the composition have a volume resistivity of less than 0.5 kOhm·cm and a Vicat softening temperature of greater than 165 °C, or greater than 170 °C, or greater than 175 °C, or greater than 180 °C, as determined according to ISO 306. Molded articles containing the composition can also exhibit one or more of a notched Izod impact strength of 8 kilojoules per square meter (kJ / m 2 ) or more, preferably 8 to 12 kJ / m 2 , a melt volume flow rate of less than 12 cubic centimeters per 10 minutes (cm 3 / 10 min) according to ISO 1133, or a moisture absorption of 0.3 weight percent or less based on the weight of the molded article.

[0052] The combination of properties exhibited by the molded article comprising the composition according to the present disclosure is particularly useful for electrostatically paintable molded articles, such as electrostatically paintable automotive parts. As such, the molded article according to the present disclosure can be configured to withstand an electrostatic painting process. In other words, the molded article can be subjected to the high temperatures associated with automotive painting without unintended degradation or deformation. Thus, advantageously, the molded automotive parts comprising the compositions described herein can be painted in-line with the rest of the outside of the vehicle. Exemplary electrostatically paintable automotive parts include, but are not limited to, fuel tank flaps, service flaps, windshield washer flaps, fenders, side body moldings, door trims, door handle covers, mirror skull covers, body panels, or roof rack covers.

[0053] A method for manufacturing an electrostatically paintable molded article represents another aspect of the present disclosure. The method includes the step of melt mixing 18 to 30 weight percent of poly(phenylene ether), 50 to 80 weight percent of poly(butylene terephthalate), 5 to 15 weight percent of an impact modifier, 0.1 to 1.4 weight percent of a reactive compatibilizer, and 0.2 to 10 weight percent of a conductive filler comprising carbon nanotubes, to provide a molten thermoplastic composition, wherein the weight percent of each component is based on the total weight of the molten thermoplastic composition. The method further includes the step of molding the thermoplastic composition to provide an electrostatically paintable molded article. The molding of the molten thermoplastic composition can be by, for example, injection molding, extrusion, rotational molding, blow molding, and thermoforming. In one aspect, the molding of the molten thermoplastic composition includes extrusion molding.

[0054] In connection with the molded article and the thermoplastic composition, all of the variations described above are equally applicable to the method for manufacturing an electrostatically paintable molded article.

[0055] Inexpensively, the electrostatically coatable molded article exhibits a volume resistivity of less than 0.5 kOhm·cm and a Vicat softening temperature exceeding 165°C, determined in accordance with ISO 306. Therefore, significant improvements are provided by the present disclosure.

[0056] This disclosure is further illustrated by the following non-limiting examples.

Examples

[0057] The materials used in the following examples are shown in Table 1.

[0058]

Table 1

[0059] The compositions of the following examples were prepared by extrusion on a 28 mm pin-type co-rotating twin-screw extruder. The extruder barrel temperature was set from 150°C to 300°C. Typically, the feed rate was 15 to 20 kg / h, the screw rotated at 300 - 500 rpm, and the torque was between 60 and 90%. All examples were processed on a 3-lobe extruder. The samples were injection molded using a molding machine set at 40 - 300°C and a mold set at 120°C to 80°C.

[0060] The composition was evaluated for its physical properties according to the following test standards and procedures. The notched Izod impact strength (INI) was determined according to ISO 180 / 1A. The volume resistivity (SVR) was determined as follows. Tensile bars were molded according to ISO 3167. Sharp and shallow cuts were made near each end of the narrow central part of the bar. The bar was brittle fractured at each cut, separating the narrow central part, and now had fracture ends with dimensions of 10×4 millimeters. If necessary to obtain brittle fracture, the tensile bar was first cooled, for example, in dry ice or liquid nitrogen in a -40 °C freezer. The length of the bar between the fracture ends was measured. The fracture ends of the sample were painted with conductive silver paint and the paint was dried. Using a multimeter in resistance mode, electrodes were attached to each of the painted surfaces and the resistance was measured with an applied voltage of 500 - 1000 millivolts. The value of the volume resistivity was obtained by multiplying the measured resistance by the fracture area on one side of the bar and dividing by the length, according to the formula ρ = R×A / L, where ρ is the volume resistivity expressed in ohm·cm, R is the measured resistance expressed in ohm, A is the fracture area expressed in cm 2 and L is the sample length expressed in cm. Thus, the volume resistivity value has the unit of ohm·cm and is expressed as kiloohm·cm (kohm·cm). The heat resistance (Vicat B) was measured according to ISO 306 (in units of °C). The melt volume rate (MVR) was determined according to ISO 1133 under a load of 5 kg at 260 °C using a holding time of 300 seconds.

[0061] The composition and properties are shown in Table 2.

[0062]

Table 2

[0063]

Table 3

[0064] As shown in Table 2, the compositions according to Examples 1, 3, and 5 indicate that an increase in the amount of PPE can provide a higher Vicat temperature. Generally, a Vicat temperature exceeding 165°C is desirable for certain applications including in-line coating. Materials having a Vicat temperature below 165°C may be prone to deformation at the temperatures required for in-line coating. Examples 1 - 6 also show the effect of partial replacement of PBT-1 with a higher molecular weight PBT (PBT-2). Inclusion of PBT-2 was observed to enhance the impact properties of the composition and to provide a slight improvement in thermal performance.

[0065] Examples 4 and 7 in Table 2 show that even a slight increase in the amount of impact modifier can provide a 10% increase in impact performance, however, a slight reduction in MVR, conductivity, and thermal performance was observed.

[0066] Examples 8 - 14 in Table 2 show how the CNT loading can affect the conductivity performance of the composition. An increase in CNT shows an increase in conductivity for the composition (see Examples 8 - 12). When only PBT-1 was used in the composition, a large change was observed between 0.37 and 0.45 weight percent loading of CNT. However, when a combination of PBT-1 and PBT-2 was used, a significantly larger increase in conductivity was observed when the CNT loading was increased from 0.45 to 0.6 weight percent compared to when only PBT-1 was used (see Examples 8 - 12 vs 13 - 14).

[0067] Examples 15 - 17 in Table 2 illustrate the effect of PPE and impact modifier loading on the thermal and mechanical properties, fluidity, and conductivity of the composition. For example, increasing the impact modifier up to 14% resulted in lower heat resistance.

[0068] Comparative Examples 1 to 3 illustrate the effect of compatibilizer loading on the composition. Figure 1 shows scanning electron micrographs (SEM) of the composition, in which the morphology of the dispersed phase (PPE) in the continuous phase (PBT) with different ratios of compatibilizer and without any compatibilizer can be visualized. As shown in Figure 1, CE2 with a 1% compatibilizer loading gives good dispersion of PPE in the continuous phase, is uniformly distributed, and is very homogeneous. However, the composition of CE1 with half the amount of compatibilizer provided a less homogeneous dispersed phase with a random distribution. The lack of compatibilizer as seen in CE3 hinders the formation of a proper continuous phase.

[0069] Comparative Examples 4 and 5 utilized conductive carbon black as the conductive filler instead of carbon nanotubes. As shown in Table 2, a higher loading of CCB was required to achieve a conductivity comparable to that of the composition containing CNT instead.

[0070] The one-sided moisture absorption experiment was carried out by directly contacting a square plaque with a wet cotton. The plaque has dimensions of 17.5×17.5×3 millimeters. The plaque was formulated from the composition according to Example 13 and the composition according to Comparative Example 6 (CE6), and a reference material based on polyphenylene ether and polyamide. The compositions of Example 13 and Comparative Example 6 are shown in Table 3.

[0071]

Table 4

[0072] After contact with moist cotton for a defined time (e.g., 24 hours, 5 days or 14 days), a 3D image of the plaque was created and the deformation of the material was evaluated. After 5 days of contact with moist cotton, the composition according to Example 13 did not show significant warping across the plaque (e.g., ±0.75 mm). In contrast, the composition according to CE6 showed significant warping. Specifically, the center of the plaque of CE6 typically showed a warp of more than 1 mm, e.g., 1 to 3 mm, while the outer edge of the plaque showed a warp of more than 1 mm, e.g., 1 to 3 mm, in the opposite direction to the center of the plaque. Thus, an improvement in dimensional stability compared to current materials on the market was observed for the compositions according to the present disclosure.

[0073] Moisture absorption was measured after specific conditions in an artificial climate chamber set at a temperature of 23 °C and a relative humidity of 50%. The moisture absorption of the PBT-PPE material according to Example 13 under these conditions was significantly lower than that of CE6 based on polyamide, as shown in Figure 2. Such behavior can have a significant impact on the dimensional stability of the material and, as described above, the warping is significantly reduced compared to the reference.

[0074] This disclosure further encompasses the following aspects.

[0075] Aspect 1: A molded article comprising a thermoplastic composition, the thermoplastic composition comprising 18 to 30 weight percent of poly(phenylene ether), 50 to 80 weight percent of poly(butylene terephthalate), 5 to 15 weight percent of an impact modifier, 0.1 to 1.4 weight percent of a reactive compatibilizer, and 0.2 to 10 weight percent of a conductive filler comprising carbon nanotubes, wherein the weight percents are based on the total weight of the thermoplastic composition, the molded article is an electrostatically paintable automotive part, and the molded article exhibits a volume resistivity of less than 0.5 kOhm·cm and a Vicat softening temperature of more than 165 °C as determined according to ISO 306.

[0076] Aspect 2: The molded article has an Izod impact strength of 8 kJ / m as measured according to ISO 180 / 1A 2 above, preferably 8 to 12 kJ / m2 The notched Izod impact strength and a melt volume flow rate of less than 12 cm 3 / 10 min according to ISO 1133, of the molded article of Aspect 1.

[0077] Aspect 3: The molded article is a molded article of Aspect 1 or 2, showing moisture absorption of 0.3 weight percent or less based on the weight of the molded article.

[0078] Aspect 4: The poly(phenylene ether) contains poly(2,6-dimethyl-1,4-phenylene ether), and preferably, the poly(phenylene ether) has an intrinsic viscosity exceeding 0.25 deciliter / gram, measured at 25 °C in chloroform using an Ubbelohde viscometer, of the molded article of any one of Aspects 1 to 3.

[0079] Aspect 5: The poly(butylene terephthalate) has an intrinsic viscosity of 0.2 to 1.5 dl / g when measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane, of the molded article of any one of Aspects 1 to 4.

[0080] Aspect 6: The poly(butylene terephthalate) contains at least a combination of two poly(butylene terephthalates), and preferably, the poly(butylene terephthalate) has an intrinsic viscosity of less than 1 dl / g, preferably 0.5 to 0.9 dl / g when measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane, of the first poly(butylene terephthalate), and a poly(butylene terephthalate) having an intrinsic viscosity exceeding 1 dl / g, preferably 1.05 to 1.5 dl / g when measured at 30 °C in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane, of the molded article of any one of Aspects 1 to 5.

[0081] Aspect 7: The impact modifier contains a hydrogenated block copolymer containing polystyrene-poly(ethylene-butylene)-polystyrene, of the molded article of any one of Aspects 1 to 6.

[0082] Aspect 8: A molded article according to any one of Aspects 1 to 7, wherein the reactive compatibilizer comprises a polymeric compatibilizer having an average of 10 or more pendant epoxy groups per molecule.

[0083] Aspect 9: A molded article according to any one of Aspects 1 to 8, wherein the carbon nanotubes have an average length of 0.5 to 2.5 micrometers and an average diameter of 8.5 to 10.5 nanometers.

[0084] Aspect 10: A molded article according to any one of Aspects 1 to 9, further comprising an additive composition, preferably the additive composition comprises a stabilizer, an antioxidant, or a combination thereof, more preferably the additive composition is present in an amount of 0.1 to 5 weight percent based on the total weight of the thermoplastic composition.

[0085] Aspect 11: A molded article according to Aspect 1, wherein the thermoplastic composition comprises 20 to 28 weight percent, preferably 21 to 27 weight percent, of poly(phenylene ether), 51 to 65 weight percent, preferably 51 to 60 weight percent, of poly(butylene terephthalate), 10 to 15 weight percent, preferably 11 to 14 weight percent, of an impact modifier, 0.8 to 1.2 weight percent of a reactive compatibilizer, and 0.2 to less than 1 weight percent, preferably 0.25 to 0.65 weight percent, of a conductive filler comprising carbon nanotubes, and the weight percents are based on the total weight of the thermoplastic composition.

[0086] Aspect 12: The poly(phenylene ether) includes poly(2,6-dimethyl-1,4-phenylene ether), and preferably, the poly(phenylene ether) has an intrinsic viscosity exceeding 0.25 deciliter / gram, measured at 25 °C in chloroform using an Ubbelohde viscometer. The poly(butylene terephthalate) has an intrinsic viscosity of 0.2 to 1.5 dl / g when measured at 30 °C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane. Optionally, the poly(butylene terephthalate) has an intrinsic viscosity of less than 1 dl / g, preferably 0.5 to 0.9 dl / g, when measured at 30 °C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane (first poly(butylene terephthalate)), and has an intrinsic viscosity exceeding 1 dl / g, preferably 1.05 to 1.5 dl / g, when measured at 30 °C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane (second poly(butylene terephthalate)). The impact modifier includes a hydrogenated block copolymer containing polystyrene-poly(ethylene-butylene)-polystyrene. The reactive compatibilizer includes a polymeric compatibilizer having an average of 10 or more pendant epoxy groups per molecule. Also, the carbon nanotubes have an average length of 0.5 to 2.5 micrometers and an average diameter of 8.5 to 10.5 nanometers. The molded article has a notched Izod impact strength of 8 kJ / m 2 or more, preferably 8 to 12 kJ / m 2 as per ISO 180 / 1A, a melt volume flow rate of less than 12 cm 3 / 10 min as per ISO 1133, a volume resistivity of less than 0.5 kOhm·cm, and a Vicat softening temperature exceeding 165 °C as determined according to ISO 306, of the molded article of Aspect 11.

[0087] Aspect 13: The automotive part is electrostatically paintable, and preferably, the automotive part is a molded article of any one of Aspects 1 to 12, which is a vehicle tank flap, a service flap, a wiper fluid flap, a fender, a side body molding, a door trim, a door handle cover, a mirror skull cover, a body panel, or a roof rack cover.

[0088] Aspect 14: A method for manufacturing an electrostatically paintable molded article, the method comprising the steps of melt-mixing 18 to 30 weight percent of poly(phenylene ether), 50 to 80 weight percent of poly(butylene terephthalate), 5 to 15 weight percent of an impact modifier, 0.1 to 1.4 weight percent of a reactive compatibilizer, and 0.2 to 10 weight percent of a conductive filler containing carbon nanotubes, to provide a melt thermoplastic composition, wherein the weight percents are based on the total weight of the thermoplastic composition, and molding the melt thermoplastic composition to provide an electrostatically paintable molded article, the electrostatically paintable molded article exhibiting a volume resistivity of less than 0.5 kOhm·cm and a Vicat softening temperature exceeding 165°C as determined according to ISO 306.

[0089] Aspect 15: The method of Aspect 14, wherein the molding of the thermoplastic composition comprises extrusion molding.

[0090] Aspect 16: A molded article comprising a thermoplastic composition, the thermoplastic composition comprising a poly(phenylene ether) containing poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity exceeding 0.25 deciliter / gram as measured at 25 °C in chloroform using an Ubbelohde viscometer, a first poly(butylene terephthalate) having an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, as measured at 30 °C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane, a poly(butylene terephthalate) comprising a second poly(butylene terephthalate) having an intrinsic viscosity of more than 1 dl / g, preferably from 1.05 to 1.5 dl / g, as measured at 30 °C in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane, an impact modifier comprising a hydrogenated block copolymer, a polymer compatibilizer having an average of 10 or more pendant epoxy groups per molecule, and a conductive filler comprising carbon nanotubes, the molded article being an electrostatically paintable automotive part, and the molded article having a volume resistivity of less than 0.5 kOhm·cm, a Vicat softening temperature exceeding 165 °C as determined according to ISO 306, a notched Izod impact strength of 8 kJ / m 2 or more, preferably from 8 to 12 kJ / m 2 as measured according to ISO 180 / 1A, and a melt volume flow rate of less than 12 cm 3 / 10 min as determined according to ISO 1133, and exhibiting a moisture absorption of 0.3 weight percent or less based on the weight of the molded article.

[0091] Compositions, methods, and articles can optionally include, consist of, or consist essentially of any suitable materials, steps, or components disclosed herein. Compositions, methods, and articles can also, alternatively, be formulated to lack, or be substantially free of, any materials (or species), steps, or components not otherwise necessary to achieve the functions or objectives of the compositions, methods, and articles.

[0092] All ranges disclosed in this specification include endpoints, and the endpoints are independent and combinable with each other. "Combination" includes blends, mixtures, alloys, reaction products, etc. Terms such as "first", "second", etc. do not indicate order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a", "an", or "the" do not indicate a limitation of quantity and should be construed to include both the singular and plural forms unless otherwise specified herein or clearly negated by the context. "Or" means "and / or" unless otherwise explicitly specified. Throughout the specification, references to "one aspect" mean that the particular elements described in connection with the aspect are included in at least one aspect described herein and may or may not be present in other aspects. The term "combinations thereof" as used herein includes one or more of the recited elements, is not limited, and allows for the presence of one or more similar elements not named. Additionally, it should be understood that the described elements can be combined in any suitable manner in various aspects.

[0093] Unless otherwise specified herein, all test standards are the latest standards in force at the filing date of this application, or, if priority is claimed, at the filing date of the earliest priority application in which the test standard appears.

[0094] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All patents, patent applications, and other references cited are hereby incorporated by reference in their entirety. However, if the terms in this application conflict or are contrary to the terms in the incorporated references, the terms of this application shall prevail over the conflicting terms of the incorporated references.

[0095] Compounds are described using standard nomenclature. For example, any position not substituted by any of the indicated groups is understood to have the indicated bond or its valence filled by a hydrogen atom. A dash ("-") not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -CHO is attached via the carbon of the carbonyl group.

[0096] As used herein, the term "hydrocarbyl," whether used alone or as a prefix, suffix, or fragment of another term, refers to a residue containing only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight-chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when a hydrocarbyl residue is described as substituted, it may optionally contain heteroatoms in addition to the carbon and hydrogen members of the substituted residue. Thus, when specifically described as substituted, a hydrocarbyl residue can also contain one or more carbonyl groups, amino groups, hydroxyl groups, etc., or can contain heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" refers to a branched or straight-chain, saturated aliphatic hydrocarbon group, e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, and n- and s-hexyl. "Alkenyl" refers to a straight-chain or branched-chain, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HC=CH2)). "Alkoxy" refers to an alkyl group linked through oxygen (i.e., alkyl-O-), e.g., methoxy, ethoxy, and sec-butyloxy groups. "Alkylene" refers to a straight-chain or branched-chain, saturated, divalent aliphatic hydrocarbon group (e.g., methylene (-CH2-) or propylene (-(CH2)3-)). "Cycloalkylene" refers to a divalent cyclic alkylene group, -C n H 2n-xmeans that in the formula, x is the number of hydrogens replaced for cyclization (plural possible). "Cycloalkenyl" means a monovalent group having one or more rings and one or more carbon-carbon double bonds within the ring, and all ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing a specific number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. "Arylene" means a divalent aryl group. "Alkylarylene" means an arylene group substituted with an alkyl group. "Arylalkylene" means an alkylene group substituted with an aryl group (e.g., benzyl). The prefix "halo" means a group or compound containing one or more fluoro, chloro, bromo, or iodo substituents. Combinations of different halo atoms (e.g., bromo and fluoro), or only chloro atoms can be present. The prefix "hetero" means that a compound or group contains at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatoms), and the heteroatom(s) is / are each independently N, O, S, Si, or P. "Substituted" means that a compound or group is, instead of hydrogen, each independently, C 1-9 alkoxy, C 1-9 haloalkoxy, nitro (-NO2), cyano (-CN), C 1-6 alkylsulfonyl (-S(=O)2-alkyl), C 6-12 arylsulfonyl (-S(=O)2-aryl), thiol (-SH), thiocyano (-SCN), tosyl (CH3C6H4SO2-), C 3-12 cycloalkyl, C 2-12 alkenyl, C 5-12 cycloalkenyl, C 6-12 aryl, C 7-13 arylalkylene, C 4-12 heterocycloalkyl, and C 3-12 heteroaryl and can be substituted with at least one (e.g., 1, 2, 3, or 4) substituent, provided that the standard atomic valence of the substituted atom is not exceeded. The number of carbon atoms indicated within the group excludes any substituents. For example, the -CH2CH2CN group is a C2 alkyl group substituted with nitrile.

[0097] Although specific embodiments have been described, applicants or those skilled in the art may come up with alternatives, modifications, changes, improvements, and substantial equivalents that are not currently expected or cannot be expected. Accordingly, the appended claims, as filed and subject to amendment, are intended to cover all such alternatives, modifications, changes, improvements, and substantial equivalents.

Claims

1. A molded article comprising a thermoplastic composition, the thermoplastic composition comprising: 18 to 30 weight percent poly(phenylene ether); 50 to 80 weight percent poly(butylene terephthalate); 5 to 15 weight percent of an impact modifier; 0.1 to 1.4 weight percent of a reactive compatibilizer; 0.2 to 10 weight percent of a conductive filler comprising carbon nanotubes; Including, The weight percentages are based on the total weight of the thermoplastic composition, The molded article is an electrostatically paintable automotive part, and The molded article is A volume resistivity of less than 0.5 kOhm cm; and a Vicat softening temperature greater than 165° C., determined according to ISO 306; Showing, Molded Article.

2. The molded article is 8 kJ / m, measured according to ISO 180 / 1A ２ or more, preferably 8 to 12 kJ / m ２ Notched Izod impact strength, and According to ISO 1133, 12 cm ３ / Melt volume flow rate of less than 10 minutes, The molded article according to claim 1 .

3. 3. The molded article of claim 1 or 2, wherein the molded article exhibits a moisture absorption of 0.3 weight percent or less, based on the weight of the molded article.

4. 4. The molded article of any one of claims 1 to 3, wherein the poly(phenylene ether) comprises poly(2,6-dimethyl-1,4-phenylene ether), and preferably the poly(phenylene ether) has an intrinsic viscosity greater than 0.25 deciliters per gram measured using an Ubbelohde viscometer in chloroform at 25°C.

5. 5. The molded article of claim 1, wherein the poly(butylene terephthalate) has an intrinsic viscosity of 0.2 to 1.5 dl / g, measured in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane at 30° C.

6. The poly(butylene terephthalate) comprises a combination of at least two poly(butylene terephthalates), preferably the poly(butylene terephthalate) is a first poly(butylene terephthalate) having an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, measured at 30° C. in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane; a second poly(butylene terephthalate) having an intrinsic viscosity of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, measured at 30° C. in a 1:1 (w / w) mixture of phenol and 1,1,2,2-tetrachloroethane; The molded article according to any one of claims 1 to 5, comprising:

7. The molded article of any one of claims 1 to 6, wherein the impact modifier comprises a hydrogenated block copolymer comprising polystyrene-poly(ethylene-butylene)-polystyrene.

8. 8. The molded article of claim 1, wherein the reactive compatibilizer comprises a polymeric compatibilizer having an average of 10 or more pendant epoxy groups per molecule.

9. The carbon nanotubes are an average length of 0.5 to 2.5 micrometers; and an average diameter of 8.5 to 10.5 nanometers; The molded article according to any one of claims 1 to 8, having

10. 10. The molded article of any one of claims 1 to 9, further comprising an additive composition, preferably the additive composition comprises a stabilizer, an antioxidant, or a combination thereof, more preferably the additive composition is present in an amount of 0.1 to 5 weight percent based on the total weight of the thermoplastic composition.

11. The thermoplastic composition comprises from 20 to 28 weight percent, preferably from 21 to 27 weight percent, of said poly(phenylene ether); 51 to 65 weight percent, preferably 51 to 60 weight percent, of said poly(butylene terephthalate); 10 to 15 weight percent, preferably 11 to 14 weight percent, of said impact modifier; 0.8 to 1.2 weight percent of said reactive compatibilizer; 0.2 to less than 1 weight percent, preferably 0.25 to 0.65 weight percent, of the conductive filler comprising the carbon nanotubes; Including, 10. The molded article of claim 1, wherein the weight percentage is based on the total weight of the thermoplastic composition.

12. the poly(phenylene ether) comprises poly(2,6-dimethyl-1,4-phenylene ether), preferably the poly(phenylene ether) has an intrinsic viscosity, measured using an Ubbelohde viscometer in chloroform at 25° C., of greater than 0.25 deciliters per gram; the poly(butylene terephthalate) has an intrinsic viscosity of 0.2 to 1.5 dl / g, measured at 30° C. in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane; and optionally the poly(butylene terephthalate) is a first poly(butylene terephthalate) having an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, measured at 30° C. in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane; a second poly(butylene terephthalate) having an intrinsic viscosity of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, measured at 30° C. in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane; Including, the impact modifier comprises a hydrogenated block copolymer comprising polystyrene-poly(ethylene-butylene)-polystyrene; The reactive compatibilizer comprises a polymeric compatibilizer having an average of 10 or more pendant epoxy groups per molecule; and the carbon nanotubes have an average length of 0.5 to 2.5 micrometers and an average diameter of 8.5 to 10.5 nanometers; The molded article is 8 kJ / m, measured according to ISO 180 / 1A ２ or more, preferably 8 to 12 kJ / m ２ Notched Izod impact strength, According to ISO 1133, 12 cm ３ / Melt volume flow rate of less than 10 minutes, A volume resistivity of less than 0.5 kOhm cm; and Vicat softening temperature greater than 165°C, determined according to ISO 306 The molded article according to claim 11 .

13. The automotive part is electrostatically paintable; 13. The molded article according to any one of claims 1 to 12, wherein the automotive part is a car tank flap, a service flap, a wiper fluid flap, a fender, a side body molding, a door trim, a door handle cover, a mirror skull cover, a body panel, or a roof rack cover.

14. 1. A method for producing an electrostatically paintable molded article, the method comprising the steps of: 18 to 30 weight percent poly(phenylene ether); 50 to 80 weight percent poly(butylene terephthalate); 5 to 15 weight percent of an impact modifier; 0.1 to 1.4 weight percent of a reactive compatibilizer; 0.2 to 10 weight percent of a conductive filler comprising carbon nanotubes; to provide a molten thermoplastic composition, the weight percentage being based on the total weight of the thermoplastic composition; and shaping said molten thermoplastic composition to provide said electrostatically paintable shaped article; Including, Preferably, the shaping of the thermoplastic composition comprises extrusion, The electrostatically paintable molded article is A volume resistivity of less than 0.5 kOhm cm; and a Vicat softening temperature greater than 165° C., determined according to ISO 306; Showing, a method.

15. A molded article comprising a thermoplastic composition, the thermoplastic composition comprising: a poly(phenylene ether) comprising poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity greater than 0.25 deciliters per gram as measured using an Ubbelohde viscometer in chloroform at 25° C.; a first poly(butylene terephthalate) having an intrinsic viscosity of less than 1 dl / g, preferably from 0.5 to 0.9 dl / g, measured at 30° C. in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane; a second poly(butylene terephthalate) having an intrinsic viscosity of greater than 1 dl / g, preferably from 1.05 to 1.5 dl / g, measured at 30° C. in a 1:1 weight-to-weight mixture of phenol:1,1,2,2-tetrachloroethane; and a poly(butylene terephthalate) comprising an impact modifier comprising a hydrogenated block copolymer; a polymeric compatibilizer having an average of 10 or more pendant epoxy groups per molecule; A conductive filler including carbon nanotubes; Including, The molded article is an electrostatically paintable automotive part, and The molded article is A volume resistivity of less than 0.5 kOhm cm; a Vicat softening temperature greater than 165° C., determined according to ISO 306; 8 kJ / m, measured according to ISO 180 / 1A ２ or more, preferably 8 to 12 kJ / m ２ Notched Izod impact strength, and According to ISO 1133, 12 cm ３ / A melt volume flow rate of less than 10 minutes, and Moisture absorption of 0.3 weight percent or less, based on the weight of said molded article; Showing, Molded Article.

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