Thermoplastic compositions with ultra-high dielectric constant for nanomolding technology (NMT) applications

Abstract

The thermoplastic composition comprises: from about 30 wt% to about 80 wt% of a polymer base resin component; from about 3 wt% to about 20 wt% of a polycarbonate component; from about 2 wt% to about 15 wt% of an impact modifier component; from about 10 wt% to about 50 wt% of a glass fiber component; and from about 0.5 wt% to about 8 wt% of a carbon additive comprising carbon fibers. The composition has a dielectric constant (Dk) of at least 5 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method.

Description

Technical Field

[0001] The present disclosure relates to thermoplastic compositions with high dielectric constants suitable for use in nanomolding technology (NMT) applications. Background Art

[0002] Nanomolding technology (NMT) is an innovative technology that integrates plastic resins with metals through a convenient injection molding process. NMT materials are widely used in consumer electronics due to their excellent characteristics, such as good metal-bonding reliability, high productivity, and good cost-effectiveness. In particular, these materials are suitable for antenna split applications in mobile devices (such as mobile phones and tablets) to achieve better waterproof performance and antenna efficiency.

[0003] 5G is becoming a major telecommunications network worldwide. The high operating frequency of 5G networks places new and different demands on materials. To achieve good antenna performance, different strategies can be applied to the antenna splitter design of 5G mobile devices. Low dielectric constant (Dk) and low dissipation factor (Df) materials can have a minimal impact on the device's radio frequency (RF) performance, thereby improving antenna efficiency. Therefore, one strategy is to use low Dk / Df NMT materials in antenna splitter applications. Increasing the number of antennas in 5G mobile devices can also improve overall antenna efficiency. However, the space available for adding additional antennas in the device is limited. One solution to increasing the number of antennas is to reduce the size of each individual antenna. Typically, the length of a patch antenna is determined by the Dk of the substrate. The higher the Dk of the substrate, the shorter the antenna length. Therefore, a second strategy for improving antenna efficiency is to use high-Dk NMT materials as the antenna substrate. In this case, due to the reduced antenna size, more antennas can be positioned in a limited space.

[0004] Technologies for low Dk NMT solutions have been reported. For example, PCT Application Publication No. WO2019130269 describes a thermoplastic resin composition including a polymer resin, a dielectric glass fiber component, hollow glass fibers, and an impact modifier.

[0005] Furthermore, CN107365480A describes a high-heat-resistant, low-k NMT material and its preparation method. The NMT material includes 50-80 parts of PCT resin (e.g., poly (1,4-CHDM terephthalate), 20-50 parts of glass fiber, 3-15 parts of a toughening agent, 0.08-1.5 parts of an antioxidant, and 0.05-3.0 parts of a lubricant. The NMT material has high heat resistance and a relatively low dielectric constant (2.9 at 100 MHz).

[0006] However, compositions for high Dk NMT regimens, particularly for regimens with a Dk of 4.5 or greater, are currently unknown.

[0007] Aspects of the present disclosure address these and other shortcomings. Summary of the Invention

[0008] Aspects of the present disclosure relate to thermoplastic compositions comprising: from about 30 wt% to about 80 wt% of a polymer base resin component; from about 3 wt% to about 20 wt% of a polycarbonate component; from about 2 wt% to about 15 wt% of an impact modifier component; from about 10 wt% to about 50 wt% of a glass fiber component; and from about 0.5 wt% to about 8 wt% of a carbon additive comprising carbon fibers. The composition has a dielectric constant (Dk) of at least 5 at frequencies of 1 GHz to 30 GHz as tested according to a coaxial method. DETAILED DESCRIPTION

[0009] The present disclosure relates to NMT compositions having very high dielectric constants (Dk), high metal bonding strengths, and good mechanical properties. Carbon fibers and graphite may be included in the compositions to increase the Dk of the compositions. The compositions described herein have very high Dk properties, good TRI bonding strengths, high adhesion to glass, and good mechanical / processing properties. The very high Dk properties of the compositions make them good candidates for antenna substrate materials in 5G mobile device technology.

[0010] In certain aspects, the present disclosure relates to a thermoplastic composition comprising: a polymer base resin component; a polycarbonate component; an impact modifier component; a glass fiber component; and from about 0.5 wt % to about 8 wt % of a carbon additive comprising carbon fibers. The composition has a dielectric constant (Dk) of at least 5 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method. The combined weight percentage values ​​of all components do not exceed 100 wt %, and all weight percentage values ​​are based on the total weight of the composition.

[0011] Before the compounds, compositions, articles, systems, devices and / or methods of the present invention are disclosed and described, it should be understood that they are not limited to specific synthetic methods unless otherwise specified, or that they are not limited to specific reagents unless otherwise specified, as this can, of course, vary. It should also be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0012] The present disclosure includes various combinations of elements of the present disclosure, for example, combinations of elements from dependent claims that depend upon the same independent claim.

[0013] Furthermore, it should be understood that, unless expressly stated otherwise, it is not intended that any method described herein be construed as requiring that its steps be performed in a specific order. Thus, if a method claim does not actually state the order in which its steps are to be followed, or if it is not otherwise expressly stated in the claims or specification that the steps are to be restricted to a specific order, no order is to be inferred in any respect. This applies to any possible non-express basis for interpretation, including: matters of logic regarding the arrangement of steps or operational flow; ordinary meaning derived from grammatical organization or punctuation; and the number or type of aspects described in the specification.

[0014] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited.

[0015] definition

[0016] It should also be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. As used in the specification and claims, the term "comprising" may include aspects of "consisting of" and "consisting essentially of." Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Throughout this specification and the appended claims, reference will be made to a number of terms that will be defined herein.

[0017] As used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to "a polymeric base resin" includes a mixture of two or more polymeric base resins.

[0018] As used herein, the term "combination" is inclusive of blends, mixtures, alloys, reaction products, and the like.

[0019] Ranges can be expressed herein as from a value (first value) to another value (second value). When expressing such a range, the range includes one or both of the first value and the second value in some aspects. Similarly, when a value is expressed as an approximation by using the antecedent 'about', it will be understood that a specific value forms another aspect. It will be further understood that the endpoints of each range are significant relative to the other endpoint and are independent of the other endpoint. It will also be understood that many values ​​are disclosed herein, and each value is also disclosed herein as "about" this specific value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It will also be understood that each unit between two specific units is also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0020] As used herein, the terms "about" and "equal to or approximately" mean that the amount or value in question can be the specified value, approximate the specified value, or be approximately the same as the specified value. It is generally understood that, as used herein, unless otherwise stated or inferred, it is a variation of ±10% of the nominal value. The term is intended to convey that similar values ​​promote equivalent results or effects as described in the claims. That is, it should be understood that amounts, dimensions, formulas, parameters, and other quantities and characteristics are not and do not need to be exact, but can be approximate and / or larger or smaller as needed, reflecting tolerances, conversion factors, rounding, measurement errors, etc. and other factors known to those skilled in the art. Generally, amounts, dimensions, formulas, parameters, or other quantities or characteristics are "about" or "approximately", whether or not explicitly stated to be so. It should be understood that if "about" is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless otherwise specifically stated.

[0021] Disclosed are components used to prepare the compositions of the present disclosure, as well as the compositions themselves used in the methods disclosed herein. These and other materials are disclosed herein, and it should be understood that when combinations, subsets, interactions, groups, etc. of these materials are disclosed, while specific reference to each different individual and collective combination and arrangement of these compounds cannot be explicitly disclosed, each is specifically contemplated and described herein. For example, if a specific compound is disclosed and discussed, and multiple modifications that can be made to a number of molecules comprising these compounds are discussed, each and every combination and arrangement of the compound, as well as possible modifications, is specifically contemplated, unless specifically indicated to the contrary. Thus, if a class of molecules A, B, and C and a class of molecules D, E, and F are disclosed, as well as an example of a combination of molecules AD, then even if each is not listed individually, each is considered a combination individually and collectively, and AE, AF, BD, BE, BF, CD, CE, and CF are also considered disclosed. Similarly, any subset or combination of these is also disclosed. Thus, for example, a subset of AE, BF, and CE would be considered disclosed. This concept applies to all aspects of this application, including but not limited to steps in methods of making and using the compositions of the present disclosure. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific aspect or combination of aspects of the methods of the present disclosure.

[0022] References in the specification and concluding claims to parts by weight of a particular element or component in a composition or article denote the weight relationship of that element or component to any other elements or components in the composition or article expressed in parts by weight. Thus, in a compound containing 2 parts by weight of component X and 5 parts by weight of component Y, X and Y are present in a weight ratio of 2:5, and this ratio remains true regardless of whether the compound contains additional components.

[0023] Unless specifically stated to the contrary, weight percentages of a component are based on the total weight of the formulation or composition in which the component is included.

[0024] The terms "BisA," "BPA," or "bisphenol A" may be used interchangeably, and as used herein, refer to a compound having a structure represented by the following formula:

[0025]

[0026] BisA may also be referred to as 4,4'-(propane-2,2-diyl)diphenol; p,p'-isopropylidenediphenol; or 2,2-bis(4-hydroxyphenyl)propane. BisA has CAS# 80-05-7.

[0027] As used herein, "polycarbonate" refers to an oligomer or polymer comprising the residues of one or more dihydroxy compounds (eg, dihydroxy aromatic compounds) connected by carbonate linkages; it also includes homopolycarbonates, copolycarbonates, and (co)polyester carbonates.

[0028] The terms "residue" and "structural unit" used to refer to components of a polymer are synonymous throughout this specification.

[0029] As used herein, the terms "weight percent," "wt%," and "wt.%" are used interchangeably to represent the weight percentage of a given component based on the total weight of the composition, unless otherwise specified. That is, all wt% values ​​are based on the total weight of the composition, unless otherwise specified. It should be understood that the sum of the wt% values ​​of all components in a disclosed composition or formulation equals 100.

[0030] Unless otherwise specified herein, all test standards are the most current standards in effect at the time this application is submitted.

[0031] Each of the materials disclosed herein is commercially available and / or its production methods are known to those skilled in the art.

[0032] It should be understood that the compositions disclosed herein have certain functions. Certain structural requirements are disclosed herein for performing the disclosed functions, and it should be understood that there are multiple structures that can perform the same functions related to the disclosed structures, and these structures will generally achieve the same results.

[0033] Thermoplastic composition

[0034] Aspects of the present disclosure relate to thermoplastic compositions comprising: a polymer base resin component; a polycarbonate component; an impact modifier component; a glass fiber component; and from about 0.5 wt % to about 8 wt % of a carbon additive comprising carbon fibers. The composition has a dielectric constant (Dk) of at least 5 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method. The combined weight percentage values ​​of all components do not exceed 100 wt %, and all weight percentage values ​​are based on the total weight of the composition.

[0035] In certain aspects, the composition includes from about 30 wt % to about 80 wt % of a polymer base resin component; from about 3 wt % to about 20 wt % of a polycarbonate component; from about 2 wt % to about 15 wt % of an impact modifier component; from about 10 wt % to about 50 wt % of a glass fiber component; and from about 0.5 wt % to about 8 wt % of a carbon additive comprising carbon fibers.

[0036] In some aspects, the polymer base resin component comprises polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyamide (PA), or a combination thereof. In a specific aspect, the polymer base resin component comprises PBT.

[0037] In certain aspects, the polycarbonate component comprises a polycarbonate (PC) homopolymer, a PC copolymer, or a combination thereof. In a particular aspect, the polycarbonate component comprises a PC copolymer, and the PC copolymer comprises PC monomers and isophthalic acid, terephthalic acid, and resorcinol (ITR) monomers. The PC monomers can be bisphenol-A (BPA) in a further aspect. An exemplary PC copolymer is LEXAN available from SABIC. TM SLX resin, which is an ITR-BPA copolymer. In some aspects, the composition can include from about 3 wt% to about 20 wt%, or from about 5 wt% to 20 wt%, or from about 5 wt% to 10 wt% of the polycarbonate component.

[0038] Impact modifiers may include, but are not limited to, ethylene-acrylate-glycidyl methacrylate terpolymers, ethylene-glycidyl methacrylate copolymers, polyolefin copolymers, ethylene acrylate copolymers, or combinations thereof. In some aspects, the polyolefin copolymers include styrene-ethylene-butylene-styrene (SEBS), styrene-ethylene-propylene-styrene (SEPS), styrene-butadiene-styrene (SBS), or combinations thereof. In particular aspects, the impact modifier component includes ethylene-acrylate-glycidyl methacrylate terpolymers. An exemplary impact modifier is LOTADER® from Arkema. TM AX8900, which includes glycidyl methacrylate units, is available from Arkema under the trade name LOTADER TMThe impact modifier can be present in the composition in an amount from about 2 wt% to about 15 wt%, or from about 2 wt% to about 10 wt%, or from about 2 wt% to about 8 wt%, or from about 2 wt% to about 6 wt%.

[0039] In some aspects, the glass fiber component comprises round glass fibers, flat glass fibers, or a combination thereof. In a particular aspect, the glass fiber component comprises flat glass fibers. In some aspects, the composition can comprise from about 10 wt % to about 50 wt % of the glass fiber component.

[0040] In certain aspects, the carbon additive comprises chopped carbon fibers having a length of less than 25 millimeters (mm) and a diameter of at least 5 micrometers. Exemplary carbon fibers suitable for use in aspects of the present disclosure are available from Teijin Carbon fiber HT C483.

[0041] The carbon additive may further include, but is not limited to, graphite, carbon powder, carbon nanotubes, or a combination thereof.

[0042] The composition can further include at least one other additive. At least one other additive can include, but is not limited to, nucleating agent, stabilizer, other impact modifier, acid scavenger, anti-drip agent, antioxidant, antistatic agent, chain extender, coloring agent, release agent, flow promoter, lubricant, mold release agent (mold release agent), plasticizer, quencher, flame retardant, UV stabilizer or its combination. At least one other additive can be included in the thermoplastic composition with any amount that can not significantly adversely affect the desired properties of the composition. In particular aspects, the composition includes at least one other additive of about 0.1wt% to about 2wt%.

[0043] The compositions according to aspects of the present disclosure have a dielectric constant (Dk) of at least 5 at a frequency of 1 GHz to 30 GHz. In a further aspect, the composition has a Dk of at least 6, at least 7, or 5-15 at a frequency of 1 GHz to 30 GHz. In a specific aspect, the composition has a Dk of at least 5, or at least 6, or at least 7, or 5-15 at a frequency of 1 GHz. In a further aspect, the composition has a Dk of at least 7 or 7-15 at a frequency of 3 GHz or at a frequency of 30 GHz. Dk can be measured according to a coaxial method comprising measuring these values ​​using a coaxial probe and a network analyzer. The sample size is 40-200 millimeters (mm); the sample thickness is 0.1-10 mm thick (preferably 2-3 mm); and the test is performed in a clean room with constant temperature and humidity using a 100 mm × 45 mm × 3.0 mm sample block.

[0044] In some aspects, the carbon additive comprises carbon fibers, and the composition has a Dk of at least 7 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method.

[0045] In particular aspects, the composition has a TRI bond strength of at least 20 MPa as measured according to ISO 19095. In further aspects, the composition has a TRI bond strength of at least 25 MPa, or at least 30 MPa, or at least 35 MPa, or at least 40 MPa as measured according to ISO 19095.

[0046] Manufacturing method

[0047] One or any of the aforementioned components as described herein can first be dry blended with each other, or dry blended with any combination of the aforementioned components, and then fed into an extruder from one or more feeders, or fed into an extruder separately from one or more feeders. The filler used in this disclosure can also first be processed into a masterbatch and then fed into an extruder. The components can be fed into an extruder from a throat hopper or any side feeder.

[0048] The extruders used in the present disclosure can have a single screw, multiple screws, intermeshing co-rotating or counter-rotating screws, non-intermeshing co-rotating or counter-rotating screws, reciprocating screws, screws with pins, screws with screens, pinned barrels, rollers, plungers, helical rotors, co-kneaders, disc pack processors, various other types of extrusion equipment, or a combination comprising at least one of the foregoing.

[0049] The components can also be mixed together and then melt blended to form the thermoplastic composition. Melt blending of the components involves the use of shear forces, extensional forces, compressive forces, ultrasonic energy, electromagnetic energy, thermal energy, or a combination comprising at least one of the foregoing forces or energy forms.

[0050] If the resin is a semi-crystalline organic polymer, the barrel temperature on the extruder during compounding can be set to a temperature where at least a portion of the polymer reaches a temperature greater than or equal to about the melt temperature, or to the flow point (e.g., glass transition temperature) if the resin is an amorphous resin.

[0051] If desired, the mixture comprising the above components can undergo multiple blending and forming steps. For example, the thermoplastic composition can first be extruded and formed into pellets. The pellets can then be fed into a molding machine where they can be formed into any desired shape or product. Alternatively, the thermoplastic composition emitted from a single melt mixer can be formed into a sheet or strand and subjected to post-extrusion processes such as annealing, uniaxial or biaxial orientation.

[0052] In some aspects, the melt temperature in this process can be kept as low as possible to avoid excessive thermal degradation of the components. In some aspects, the melt temperature is maintained between about 230°C and about 350°C, although higher temperatures can be used provided that the residence time of the resin in the processing equipment is relatively short. In some aspects, the melt-processed composition exits the processing equipment, such as an extruder, through a small exit hole in the die. The resulting strands of molten resin can be cooled by passing the strands through a water bath. The cooled strands can be chopped into pellets for packaging and further processing.

[0053] Manufactured products

[0054] In certain aspects, the present disclosure relates to formed, shaped, or molded articles comprising thermoplastic compositions. Thermoplastic compositions can be formed into useful shaped articles by various means such as injection molding, extrusion, rotational molding, blow molding, and thermoforming to form, for example, articles and structural components for personal or commercial electronic devices, including, but not limited to, mobile phones, tablet computers, personal computers, notebook computers, and laptops, as well as other such devices, medical applications, RFID applications, automotive applications, and the like. In further aspects, the articles are extrusion molded. In still further aspects, the articles are injection molded. In particular aspects, the articles are antenna shunts for mobile devices.

[0055] The present disclosure includes various combinations of elements of the present disclosure, for example, combinations of elements from dependent claims that depend upon the same independent claim.

[0056] Aspects of the Disclosure

[0057] In various aspects, the present disclosure relates to and includes at least the following aspects.

[0058] Aspect 1. A thermoplastic composition comprising:

[0059] about 30 wt % to about 80 wt % of a polymeric base resin component;

[0060] about 3 wt % to about 20 wt % of a polycarbonate component;

[0061] from about 2 wt % to about 15 wt % of an impact modifier component;

[0062] about 10 wt % to about 50 wt % of a glass fiber component; and about 0.5 wt % to about 8 wt % of a carbon additive comprising carbon fibers,

[0063] wherein the composition has a dielectric constant (Dk) of at least 5 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method, and

[0064] The combined weight percentage values ​​of all components do not exceed 100 wt %, and all weight percentage values ​​are based on the total weight of the composition.

[0065] Aspect 2. The thermoplastic composition according to aspect 1, wherein the polymer base resin component comprises polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyamide (PA), or a combination thereof.

[0066] Aspect 3. The thermoplastic composition according to aspect 1 or 2, wherein the polymer base resin component comprises PBT.

[0067] Aspect 4. The thermoplastic composition according to any one of aspects 1 to 3, wherein the polycarbonate component comprises a polycarbonate (PC) homopolymer, a PC copolymer, or a combination thereof.

[0068] Aspect 5. The thermoplastic composition of aspect 4, wherein the polycarbonate component comprises the PC copolymer, and the PC copolymer comprises PC monomers and isophthalic acid, terephthalic acid, and resorcinol (ITR) monomers.

[0069] Aspect 6. The thermoplastic composition of any one of aspects 1 to 5, wherein the impact modifier component comprises an ethylene-acrylate-glycidyl methacrylate terpolymer, an ethylene-glycidyl methacrylate copolymer, a polyolefin copolymer, an ethylene acrylate copolymer, or a combination thereof.

[0070] Aspect 7. The thermoplastic composition of any one of aspects 1 to 6, wherein the impact modifier component comprises an ethylene-acrylate-glycidyl methacrylate terpolymer.

[0071] Aspect 8. The thermoplastic composition of any one of aspects 1 to 7, wherein the glass fiber component comprises round glass fibers, flat glass fibers, or a combination thereof.

[0072] Aspect 9. The thermoplastic composition of aspect 8, wherein the glass fiber component comprises flat glass fibers.

[0073] Aspect 10. The thermoplastic composition of any one of aspects 1 to 9, wherein the carbon additive further comprises graphite, carbon powder, carbon nanotubes, or a combination thereof.

[0074] Aspect 11. The thermoplastic composition of any of aspects 1-10, wherein the composition further comprises at least one additional additive.

[0075] Aspect 12. The thermoplastic composition according to aspect 11, wherein the at least one additional additive comprises a nucleating agent, a stabilizer, an additional impact modifier, an acid scavenger, an anti-drip agent, an antioxidant, an antistatic agent, a chain extender, a colorant, a mold release agent, a flow promoter, a lubricant, a release agent, a plasticizer, a quencher, a flame retardant, a UV stabilizer, or a combination thereof.

[0076] Aspect 13. The thermoplastic composition of aspect 11 or 12, wherein the composition comprises from about 0.1 wt% to about 2 wt% of the at least one additional additive.

[0077] Aspect 14. The thermoplastic composition of any one of aspects 1 to 13, wherein the carbon fibers comprise chopped carbon fibers having a length of less than 25 millimeters (mm) and a diameter of at least 5 micrometers.

[0078] Aspect 15. The thermoplastic composition of any one of aspects 1 to 14, wherein the carbon additive comprises carbon fibers and the composition has a dielectric constant (Dk) of at least 7 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method.

[0079] Aspect 16. The thermoplastic composition of any one of aspects 1 to 15, wherein the composition has a TRI bond strength of at least 35 MPa as measured according to ISO 19095.

[0080] Aspect 17. An article comprising the thermoplastic composition according to any one of aspects 1 to 16.

[0081] Aspect 18. The article of manufacture of aspect 17, wherein the article of manufacture is an antenna shunt for a mobile device.

[0082] Example

[0083] The following examples are presented to provide a person of ordinary skill in the art with a complete disclosure and description of how to prepare and evaluate the compounds, compositions, articles, devices and / or methods claimed herein, and these examples are intended to be purely exemplary and not intended to limit the present disclosure. Efforts have been made to ensure the accuracy of numbers (e.g., amounts, temperatures, etc.), but some errors and deviations should be taken into account. Unless otherwise stated, parts are parts by weight, temperatures are in ° C or are ambient temperature, and pressures are at or near atmospheric pressure. Unless otherwise stated, percentages relating to compositions are expressed in wt%.

[0084] There are many variations and combinations of reaction conditions, such as component concentrations, desired solvents, solvent mixtures, temperature, pressure, and other reaction ranges and conditions, which can be used to optimize the product purity and yield obtained from the process. Only reasonable routine experimentation is required to optimize such process conditions.

[0085] Comparative compositions and example compositions corresponding to the present disclosure were formed and tested. The extrusion and molding profiles of the compositions are provided in Tables 1 and 2, respectively:

[0086] Table 1 - Extrusion profiles of comparative and example compositions

[0087] parameter unit condition Barrel size mm 1500 mold mm 4 Zone 1 temperature ℃ 100 Zone 2 temperature ℃ 200 Zone 3 temperature ℃ 250 Zone 4 temperature ℃ 250 Zone 5 temperature ℃ 250 6-zone temperature ℃ 260 7-zone temperature ℃ 260 8-zone temperature ℃ 260 9 zone temperature ℃ 260 10 zone temperature ℃ 260 Zone 11 Temperature ℃ 260 mold temperature ℃ 260 Screw speed rpm 200 Throughput kg / hr 50 Torque ％ 70-80 Vacuum 1 -bar -0.08 Side feeder 1 speed rpm 250 Melt temperature ℃ 265-275

[0088] Table 2 - Molding profile of comparative and example compositions

[0089]

[0090] As shown in Table 3, PBT-based NMT compositions were prepared; the properties of these compositions are shown in Table 4.

[0091] Table 3 - Comparative and Example Compositions

[0092]

[0093] Table 4 - Properties of the compositions of Table 3

[0094]

[0095]

[0096] The "coaxial method" for determining Dk involves measuring these values ​​using a coaxial probe and a network analyzer. Sample size is 40-200 millimeters (mm); sample thickness is 0.1-10 mm thick (preferably 2-3 mm); and the test is conducted in a clean room with constant temperature and humidity using a 100 mm x 45 mm x 3.0 mm coupon.

[0097] As shown in Table 3, PBT is the base resin, polycarbonate is included as a bond strength enhancer, AX8900 (ethylene acrylate-glycidyl methacrylate (GMA) copolymer) is the impact modifier, and flat glass fiber is the inorganic filler. Graphite is also added to increase the Dk of the composition. As shown, the graphite loading increases from 3 wt% to 6 wt% to 8 wt% from E1.1 to E1.3, respectively. Composition C1 is a control sample and does not include graphite in the formulation.

[0098] As shown in Table 4, when 3 wt% graphite is added, the Dk of the composition increases to 5.15 (E1.1) at 1 GHz, which is much higher than the comparative composition C1 (Dk 3.74). Example composition E1.1 also shows good performance, such as TRI bond strength >31 megapascals (MPa) and impact strength (NII) 127 joules / meter (J / m). When the graphite content is increased to 6 wt%, the Dk of the composition further increases to 7.84 (E1.2) at 1 GHz, but has much lower TRI bond strength (23.7 MPa) and flowability (MVR drops significantly). When 8 wt% graphite is used, the Dk of the composition is 9.78 (E1.3) at 1 GHz. However, the TRI bond strength of the composition further decreases to 20.8 MPa, with a much lower NII of 113 J / m.

[0099] Based on this data, we observed that graphite can be an effective additive for increasing the dielectric constant (Dk) of NMT compositions. When the graphite loading was not high (i.e., ≤6 wt%), the high-Dk NMT formulation exhibited good TRI bond strength and mechanical properties. However, at higher graphite loadings (>6 wt%), the metal bond strength, impact strength, and flow properties of the composition decreased significantly.

[0100] Additional example compositions were prepared and tested as shown in Tables 5 and 6, respectively.

[0101] Table 5 - Example compositions

[0102]

[0103]

[0104] Table 6 - Properties of the compositions of Table 5

[0105]

[0106] The compositions of Table 5 have even higher Dk properties for NMT compositions. Carbon fiber was used as an additive to increase the Dk of the composition. From E2.1 to E2.4, the carbon fiber loading decreased from 6 wt%, 4 wt%, 3 wt%, and 2.5 wt%, respectively. In E2.5, a polycarbonate copolymer (SLX20 / 80) was included as a bond strength enhancer. SLX20 / 80 has the following chemical structure:

[0107]

[0108] In this general structure, x and y can vary from 10 to 90. SLX20 / 80 identifies a copolymer having x = 20 (isophthalic acid, terephthalic acid, and resorcinol (ITR) blocks) and y = 80 (polycarbonate (PC) blocks).

[0109] As shown in Table 6, when 6 wt% carbon fiber is added, the Dk of the composition is as high as 13.85 (E2.1) at 1 GHz, which is much higher than the corresponding composition including graphite in E1.2. From these results, it can be observed that carbon fiber is much more effective than graphite in increasing the Dk of the composition. At a test frequency of 30 GHz, the Dk of the E2.1 composition is still at a high level of 12.6. Furthermore, the E2.1 composition also has very good overall performance. The TRI bond strength of the composition is 41.5 MPa, similar to the control sample in C1 with a TRI bond strength of 40.1 MPa. The mechanical properties of the composition are also very good, with an NII of 138 J / m and a flexural modulus of 14 GPa.

[0110] As shown in E2.2 to E2.4, when the carbon fiber content is reduced to 4wt%, 3wt%, and 2.5wt%, respectively, the Dk of the composition at 1 GHz decreases to 10.25, 8.9, and 7.91. These are still very high levels for high-Dk NMT compositions. Similar Dk performance is observed at higher frequencies. The TRI bond strength of these compositions is very good, with values ​​greater than 40 MPa. When the carbon fiber content is reduced from 6% to 2.5%, the NII of the composition increases from 138 to 161 J / m (E2.1 to E2.4).

[0111] As shown in Example composition E2.5, PC copolymers (e.g., ITR-PC copolymers) can be used as bond strength enhancers. This composition exhibits good overall performance. Compared to the composition containing PC homopolymer E2.3, this composition exhibits a slightly lower Dk, at 8.54 at 1 GHz. Other properties, including metal bond strength and mechanical properties, are comparable to those of PC homopolymers.

[0112] Thus, it can be observed from Tables 5 and 6 that carbon fiber is a very effective additive for increasing the dielectric constant Dk of the composition. The composition comprising carbon fiber as a high Dk filler, PBT as a base resin, PC homopolymer or PC copolymer as a bond strength promoter, glass fiber as a filler, and an impact modifier exhibits very high Dk, high bond strength (>40 MPa), and very good mechanical properties.

[0113] The above description is intended to be illustrative, not restrictive. For example, the above embodiments (or one or more aspects thereof) may be used in combination with each other. Other aspects may be used, such as by a person of ordinary skill in the art after reading the above description. The abstract is provided to comply with 37 CFR § 1.72 (b) to enable the reader to quickly determine the nature of the disclosure of this technology. It is submitted with the understanding that this abstract is not used to interpret or limit the scope or meaning of the claims. Moreover, in the above detailed description, various features may be combined together to simplify the disclosure. This should not be interpreted as intending to make unclaimed disclosed features essential to any claim. On the contrary, the subject matter of the present invention may not lie in all features of a particular disclosed aspect. Therefore, the following claims are incorporated into the detailed description as embodiments or aspects, each claim independently as a separate aspect, and it is conceivable that these aspects can be combined with each other in various combinations or arrangements. The scope of the present disclosure should be determined with reference to the appended claims and all equivalent scopes to which these claims are entitled.

Claims

1. A thermoplastic composition comprising: 30 wt% to 80 wt% of a polymer base resin component; 3 wt % to 10 wt % of a polycarbonate component; 2 wt % to 15 wt % of an impact modifier component; 10 wt % to 50 wt % of a glass fiber component; and 0.5wt% to 8wt% of a carbon additive comprising carbon fibers, wherein the composition has a dielectric constant (Dk) of at least 5 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method, and The combined weight percentage values ​​of all components do not exceed 100 wt %, and all weight percentage values ​​are based on the total weight of the composition.

2. The thermoplastic composition according to claim 1, wherein the polymer base resin component comprises polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyamide (PA), or a combination thereof.

3. The thermoplastic composition of claim 1, wherein the polymer base resin component comprises PBT.

4. The thermoplastic composition of claim 1, wherein the polycarbonate component comprises a polycarbonate (PC) homopolymer, a PC copolymer, or a combination thereof.

5. The thermoplastic composition of claim 4, wherein the polycarbonate component comprises the PC copolymer, and the PC copolymer comprises PC monomers and isophthalic acid, terephthalic acid, and resorcinol (ITR) monomers.

6. The thermoplastic composition of claim 1, wherein the impact modifier component comprises ethylene-acrylate-glycidyl methacrylate terpolymer, ethylene-glycidyl methacrylate copolymer, a polyolefin copolymer, an ethylene acrylate copolymer, or a combination thereof.

7. The thermoplastic composition of claim 1, wherein the impact modifier component comprises an ethylene-acrylate-glycidyl methacrylate terpolymer.

8. The thermoplastic composition of claim 1, wherein the glass fiber component comprises round glass fibers, flat glass fibers, or a combination thereof.

9. The thermoplastic composition of claim 1, wherein the carbon additive further comprises graphite, carbon powder, carbon nanotubes, or a combination thereof.

10. The thermoplastic composition of claim 1, wherein the carbon fibers comprise chopped carbon fibers having a length of less than 25 millimeters (mm) and a diameter of at least 5 micrometers.

11. The thermoplastic composition of claim 1 , wherein the composition further comprises at least one additional additive comprising a nucleating agent, a stabilizer, an additional impact modifier, an acid scavenger, an anti-drip agent, an antioxidant, an antistatic agent, a chain extender, a colorant, a mold release agent, a flow promoter, a lubricant, a release agent, a plasticizer, a quencher, a flame retardant, or a combination thereof.

12. The thermoplastic composition of any one of claims 1 to 11, wherein the carbon additive comprises carbon fibers and the composition has a dielectric constant (Dk) of at least 7 at a frequency of 1 GHz to 30 GHz as tested according to a coaxial method.

13. The thermoplastic composition of any one of claims 1 to 11, wherein the composition has a TRI bond strength of at least 35 MPa as measured according to ISO 19095.

14. An article comprising the thermoplastic composition according to any one of claims 1 to 11.

15. The article of claim 14, wherein the article is an antenna shunt for a mobile device.

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