Molded parts with reduced microwave reflection and transmission

Abstract

This document discloses a multilayer component comprising: a first layer comprising a first polymer composition comprising a first polymer and about 0.1 wt.% to about 30 wt.% of a first conductive carbon-based filler; a second layer disposed adjacent to the surface of the first layer, wherein the second layer comprises a second polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler; wherein when the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, the multilayer component exhibits a reflected power percentage of less than 15% as measured in transmission mode when observed according to the free-space method at frequencies from about 75 GHz to 110 GHz.

Description

Technical Field

[0001] This disclosure relates to radar-absorbing materials, and in particular to layered materials configured to absorb microwave radiation. Background Technology

[0002] Radar absorbing materials (RAMs) are widely used to shield radar wave transmission and attenuate side waves that can cause ghosting (reflection) images, thus triggering erroneous actions or alarms. Therefore, the low reflectivity of RAM materials is beneficial because lower reflectivity increases sensor accuracy. Higher absorption may be needed to ensure effective signal attenuation and shield reflections from chassis parts that could generate ghosting images. Absorption occurs when electromagnetic fields / photons interact and transfer energy to the material they strike rather than transmitting through or reflecting it. Ferromagnetic and carbon-based fillers are commonly used to design electromagnetic absorbing compounds, and many RAM materials today are based on carbon-based compounds. For carbon-based compounds, a well-permeable carbon network providing high conductivity offers good shielding performance. Furthermore, higher conductivity results in better attenuation of electromagnetic waves and lower transmission of the RAM. However, for reflection, the opposite occurs at lower conductivity—leading to lower radar wave reflection. Therefore, most conventional RAMs either support transmission or reflection. The aspects of this disclosure address these and other needs. Summary of the Invention

[0003] The above and other deficiencies in the art are satisfied by the following: a multilayer part comprising a first layer, wherein the first layer comprises a first polymer composition comprising a first polymer and about 0.1 wt.% to about 20 wt.% of a first conductive carbon-based filler; a second layer disposed adjacent to the surface of the first layer, wherein the second layer comprises a second polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler; wherein when the multilayer part is oriented such that microwave radiation is incident on the second layer of the multilayer part, when observed according to the free-space method at frequencies from about 75 MHz to 110 GHz, the multilayer part exhibits a percentage reflected power of less than 15% as measured in transmission mode, and wherein the combined weight percentage value of all components does not exceed 100 wt.%, and all weight percentage values ​​are based on the total weight of the first polymer composition or the second polymer composition. The above and other features are illustrated by the following detailed description, examples, and claims. Attached Figure Description

[0004] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several aspects and, together with the specification, serve to explain the principles of this disclosure.

[0005] Figure 1 A diagram of the transmission mode for the free-space method used to determine the scattering parameters is presented, with the dielectric constant ε'(Dk) and dissipation loss ε"(Df) calculated from these scattering parameters.

[0006] Figure 2A This is a diagram of a multilayer component that directs incident microwave radiation to the second layer (layer C). Figure 2B This is a diagram of a multilayer component in which the middle third layer (layer B) is oriented to direct incident microwave radiation to the second layer (layer C).

[0007] Figure 3A Table 3A is presented, showing the configuration of the fabricated multilayer components F, G, and H. Figure 3B Table 3B is presented, showing the formulations for the configurations of multilayer components F, G, and H.

[0008] Figure 4 It is a graphical representation of the reflection, transmission, and absorption of components F, G, and H, depending on which layer is oriented toward the incident microwave radiation.

[0009] Figure 5 It is a description of calculations used to determine the propagation of electromagnetic waves in ADAS sensors.

[0010] Figure 6 Table 5 presents the theoretical calculations and measured radar absorption data for a single material.

[0011] Figure 7 Table 6 presents the theoretical calculations and measured radar absorption data for the three-layer components.

[0012] Figure 8 Table 7 presents the radar characteristics of the dual-layer component calculated at 77 GHz.

[0013] Figure 9 It is a graphical representation of the reflection and transmission of a 1mm thick double-layer system (layer 1 (ε'=15.6538, ε”=12.2659); layer 2 (ε'=2.9, ε”=0.01)) as a function of the thickness of one layer in mm.

[0014] Figure 10 Table 8 is presented, showing the multi-layer calculations for different combinations of the first and second / third layers.

[0015] Figure 11A and Figure 11BIt is a graphical representation of the transmission of a bilayer system as a function of ε” of the first layer of the bilayer system, where the thickness of the first layer is 1.6 mm and the thickness of the second layer is 0.4 mm, and Dk and Df of the first and second layers are variable.

[0016] Figures 12A-12F Transmission and reflection are functions of the top layer thickness and the bottom layer ε (top layer Dk is 2, Df is 0.001, bottom layer Dk is 6).

[0017] Figure 13A and Figure 13B It is a graphical representation of reflection as a function of the dielectric constant of the 0.4mm second (top) layer and the 1.6mm first layer of the multilayer component, where the first layer of the multilayer component has Dk = 6 / Df = 0.4 and Dk = 10 / Df = 0.5 respectively. Detailed Implementation

[0018] Radar absorbing materials (RAM) ideally possess low reflectivity (to increase sensor accuracy) and high absorption (to effectively attenuate signals and shield reflections from chassis components that may produce ghosting). Conventional RAM materials are carbon-based compounds, but these materials tend to favor either higher absorption or lower reflection. Therefore, radar material manufacturers either accept the limitations of current materials or components or attempt to mitigate the negative impact by using software or materials with lower conductivity. Using materials with lower conductivity can reduce reflection by 10-20%, but sufficient shielding can only be achieved in molded components with a thickness of at least 3 millimeters (mm).

[0019] Therefore, it is desirable to obtain a single product characterized by conflicting properties such as absorption and reflectivity. Various aspects of this disclosure provide compositions for molded parts that combine low reflectivity and high absorption characteristics for microwaves. Such materials can be used in external or internal radar absorbing component applications. This disclosure may combine a first layer material having a high Dk and dissipation factor DF with a second layer material having a low Dk value. The disclosed molded parts may be characterized by a combination of two materials, each with specific conductivity properties, thereby reconciling these conflicting requirements into a single product.

[0020] This disclosure defines material properties and thicknesses to provide molded parts that outperform molded parts formed from conventional disposable materials in terms of reflective and / or absorption or shielding properties. According to various aspects, the molded part may be described as a multilayer part. A multilayer part formed from the disclosed compositions may include one or more conductive carbon-based fillers. The multilayer part may include multiple discrete layers, such as a first layer and a second layer, each layer comprising a corresponding polymer composition described herein. For example, the multilayer part may include: a first layer comprising a first composition; and a second layer comprising a second composition. The first layer may have a thickness greater than 0.8 mm, while the second layer may have a thickness of about 0.2 mm to about 0.7 mm. When measured along an orientation such that the second layer is oriented toward the incident microwave radiation, the multilayer part may have a reflectivity of less than 15% and a transmittance of less than 3%.

[0021] Before disclosing and describing the present compounds, compositions, articles, systems, devices, and / or methods, it should be understood that they are not limited to specific synthetic methods (unless otherwise specified) or specific reagents (unless otherwise specified), as these can certainly be varied. It should also be understood that the terminology used herein is for descriptive purposes only and is not intended to be limiting. This disclosure covers various combinations of elements of this disclosure, such as combinations of elements of dependent claims derived from the same independent claim.

[0022] Furthermore, it should be understood that, unless expressly stated otherwise, no method presented herein is intended to be construed as requiring its steps to be performed in a particular order. Therefore, unless a method claim actually defines the order in which its steps are to be followed, or unless the claims or specification otherwise explicitly state that the steps are limited to a particular order, no order is intended to be inferred in any way. This applies to any possible non-explicit basis of interpretation, including: logical questions concerning the arrangement of steps or the flow of operations; general meanings derived from grammatical organization or punctuation; and the number or type of embodiments described in the specification.

[0023] Multi-layer components

[0024] Multilayer components formed from the disclosed compositions may include one or more conductive carbon-based fillers. The multilayer component may include multiple discrete layers, such as a first layer and a second layer, each layer comprising a corresponding polymer composition described herein. For example, the multilayer component may include: a first layer comprising a first composition; and a second layer comprising a second composition. Aspects of this disclosure relate to multilayer components configured to improve microwave radiation absorption. It is well known that reflectivity is determined by several factors, but primarily by the material's Dk(ε'), and materials with lower Dk generally have lower reflectivity. To reduce transmission, materials with higher conductivity are generally preferred. Therefore, combining a low-conductivity material as a first layer with a high-conductivity material as a back layer or second layer may be the optimal approach to achieving both low reflectivity and high absorption (low transmission).

[0025] A multilayer component may include at least a first layer and a second layer. When the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, when observed in free space at frequencies of approximately 77 GHz to 81 GHz, the multilayer component may exhibit a reflected power percentage of less than 15% and a transmission percentage of less than 6% as measured in transmission mode.

[0026] In some aspects, the first and second layers may be joined by an intermediate third layer comprising an adhesive, such that the adhesive is disposed between the first and second layers. The adhesive may comprise an acrylate. The intermediate third layer may have a thickness of about 10 micrometers to about 100 micrometers. Each layer of the multilayer component may have a specific thickness, and the thickness of each layer may be relative to each other. The first layer may have a thickness greater than 0.8 mm. The second layer may have a thickness of about 0.2 mm to about 0.7 mm. In some instances, the thickness ratio of the first layer to the second layer may be about 1:2 to 1:5 (or a thickness ratio of about 0.5 to 1.5, about 0.6 to 1.2, about 0.6 to 1.5, about 0.4 to 1.5, or about 0.4 to 1.2).

[0027] Each layer of a multilayer component can exhibit specific dielectric properties. For example, each layer can exhibit a specific dielectric constant. Depending on various aspects, when measured using a split post dielectric resonator (SPDR) and a network analyzer at a fixed frequency (approximately 77 GHz to 81 GHz) or at 77 GHz, the dielectric constant (Dk) of the second layer can be approximately 2 to 5. In a further aspect, the discrete layers of the multilayer component can exhibit certain dielectric properties that are related to each other. As an example, when molded samples of a first polymer of the first layer and a second polymer of the second layer are tested separately at a fixed frequency using a split post dielectric resonator (SPDR) and a network analyzer, the ratio of the Dk of the second layer to the Dk of the first layer (Dk) is... 第二层 / Dk第一层 ) can be 0.2 to 0.6, or about 0.1 to 1, or about 0.2 to 1, or about 0.1 to 6. In a specific instance, Dk 第二层 / Dk 第一层 The dissipation factor is approximately 0.2 to 0.6. Depending on the specifics, when measured using a split-pillar dielectric resonator (SPDR) and network analyzer at a fixed frequency (approximately 77 GHz to 81 GHz) or at 77 GHz, the corresponding layer can exhibit a sufficiently low dissipation factor Df. For each layer of a multilayer component with less than 15% reflection and less than 6% transmission, the dissipation factor can be less than 0.1.

[0028] polymer composition

[0029] In one aspect, the first layer comprises a first polymer composition comprising a first polymer and about 0.1 wt.% to about 20 wt.% of a first conductive carbon-based filler. The second layer may comprise a second polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler. In some instances, the first polymer and the second polymer are the same polymer. In a further aspect, the first polymer and the second polymer may comprise different polymers. The first polymer or the second polymer may comprise polyester, polycarbonate, polyamide, polyphenylene ether, or combinations thereof.

[0030] In a further aspect, the first or second polymer may comprise polycarbonate. As used herein, “polycarbonate” refers to an oligomer or polymer comprising residues of one or more dihydroxy compounds (e.g., dihydroxy aromatic compounds) linked by carbonate bonds; it also includes homopolymers, copolymers, and (co)polyesters. The terms “residue” and “structural unit” used to refer to components of the polymer are synonymous throughout the specification. In various aspects, polycarbonate may comprise bisphenol A-based polycarbonate.

[0031] The interchangeable terms "BisA", "BPA", or "bisphenol A" refer to compounds having a structure represented by the following formula:

[0032]

[0033] BisA can also be mentioned by the names 4,4'-(propane-2,2-diyl)diol; p,p'-isopropylidene bisphenol; or 2,2-bis(4-hydroxyphenyl)propane. BisA has CAS #80-05-7.

[0034] In some aspects, the polycarbonate polymer is bisphenol A polycarbonate, high molecular weight (Mw) high flowability / ductility (HFD) polycarbonate (PC), low Mw HFD polycarbonate, or combinations thereof. For example, a high flowability / ductility polycarbonate can be a polycarbonate that provides very high flowability (e.g., about 40% higher than conventional polycarbonates) while maintaining the typical flowability, toughness, and ductility of conventional polycarbonates. Examples of high flowability / ductility polycarbonates suitable for various aspects of this disclosure include LEXAN, available from SABIC. TM HFD polycarbonate series. For a given melt flow, LEXAN TM HFD polymers have a stretch / brittle transition temperature that is approximately 10-15°C lower than that of conventional PC. Furthermore, LEXAN... TM HFD polymers exhibit high ductility at temperatures as low as approximately -40°F (-40°C) and can be processed at temperatures approximately 20°F (20°C) lower than conventional PC with the same ductility.

[0035] Examples of bisphenol A polycarbonates applicable to all aspects of this disclosure include, but are not limited to, PC copolymers (of various grades available from SABIC) comprising repeating units derived from BPA and repeating units derived from sebacic acid. In a further aspect, the polycarbonate polymer may be a bisphenol A polycarbonate homopolymer, or a blend of a PC copolymer and a bisphenol A polycarbonate homopolymer.

[0036] More specifically, suitable polycarbonate copolymers may include repeating units derived from sebacic acid and BPA. Useful polycarbonate copolymers are commercially available, and include, but are not limited to, those available from SABIC. TM Obtained under the product name LEXAN TM EXL and LEXAN TM The HFD polymers sold there. The mechanism of the sebacic acid group can be described as follows.

[0037]

[0038] Sebacic acid-based PC provides improved flowability and ductility as well as shorter processing times, while BPA provides the desired thermal properties and modulus, thus providing a copolymer of sebacic acid and BPA. Examples of sebacic acid-based PC may include LEXAN, which is available from SABIC. TM HFD resins. Therefore, the polymer component may include poly(aliphatic ester)-polycarbonate copolymers comprising soft block aliphatic dicarboxylic acid ester units.

[0039] As used herein, “high molecular weight” means a molecular weight (Mw) of about 58,000 to about 75,000 g / mol. As used herein, “low molecular weight” means a Mw of about 15,000 to about 58,000 g / mol – measured by gel permeation chromatography using BPA polycarbonate standards.

[0040] In one aspect of this disclosure, the thermally conductive composition comprises about 20 wt.% to about 80 wt.% of a polycarbonate polymer. In a specific aspect, the thermally conductive composition comprises about 25 wt.% to about 70 wt.% of a polycarbonate polymer, and in a further aspect, the thermally conductive composition comprises about 35 wt.% to about 65 wt.% of a polycarbonate polymer, or even about 35 wt.% to about 50 wt.% of a polycarbonate polymer.

[0041] In various further aspects, as used herein, "polycarbonate" and "polycarbonate resin" further include homopolymers, polycarbonates containing different R... 1 Copolymers (also referred to herein as “copolycarbonates”), copolymers comprising carbonate units and other types of polymer units (such as ester units, polysiloxane units), and combinations comprising at least one homopolymer and a copolycarbonate. As used herein, “combination” includes blends, mixtures, alloys, reaction products, etc.

[0042] Non-limiting examples of polysiloxane-polycarbonate copolymers may include various copolymers available from SABIC. In one aspect, the polysiloxane-polycarbonate copolymer may contain 6% by weight of polysiloxane based on the total weight of the polysiloxane-polycarbonate copolymer. In various aspects, the weight-average molecular weight (Mw) of the 6% by weight polysiloxane block copolymer may be about 23,000 to 24,000 Daltons, determined by gel permeation chromatography using the absolute molecular weight standard of bisphenol A polycarbonate. In some aspects, the melt volumetric flow rate (MVR) of the 6% by weight siloxane polysiloxane-polycarbonate copolymer at 300°C / 1.2 kg / kg may be about 10 cm³ / 10 min (cm³). 3 / 10min) (See C9030T, a copolymer with 6% by weight polysiloxane content, available from SABIC as a “transparent” EXL C9030T resin polymer). In another example, the polysiloxane-polycarbonate block may comprise 20% by weight of polysiloxane based on the total weight of the polysiloxane-polycarbonate block copolymer. For example, a suitable polysiloxane-polycarbonate copolymer may be a bisphenol A polysiloxane-polycarbonate copolymer end-capped with p-cumylphenol (PCP) and having a 20% polysiloxane content (see C9030P, commercially available from SABIC as an “opaque” EXL C9030P). In various aspects, when tested using gel permeation chromatography (GPC) on a cross-linked styrene-divinylbenzene column according to polycarbonate standards and calibrated relative to a polycarbonate reference (using a UV-VIS detector set at 264 nm, eluting at a flow rate of approximately 1 mg / mL), the weight-average molecular weight of the 20% polysiloxane block copolymer can be from approximately 29,900 Daltons to approximately 31,000 Daltons. Furthermore, the melt volume ratio (MVR) of the 20% polysiloxane block copolymer at 300 °C / 1.2 kg can be 7 cm⁻¹. 3 / 10min, and can exhibit siloxane domains with sizes ranging from about 5 micrometers to about 20 micrometers (μm).

[0043] As provided herein, thermoplastic compositions may include blends of polycarbonate and polyester polymers or polycarbonate-polyester copolymers.

[0044] In a further aspect, the first or second polymer may include a polyester. For example, the thermoplastic composition may include polyalkylene esters (polyesters), such as polyalkylene terephthalate polymers.

[0045] Polyesters have repeating units of the following formula (A):

[0046]

[0047] Wherein, T is a residue derived from terephthalic acid or its chemical equivalent, and D is a residue derived from the polymerization of ethylene glycol, butanediol, specifically 1,4-butanediol or its chemical equivalent. Chemical equivalents of diacids include dialkyl esters, such as dimethyl esters, diaryl esters, acid anhydrides, salts, acid chlorides, acid bromides, etc. Chemical equivalents of ethylene glycol and butanediol include esters, such as dialkyl esters, diaryl esters, etc. In addition to units derived from terephthalic acid or its chemical equivalents and ethylene glycol or butanediol (specifically 1,4-butanediol) or their chemical equivalents, other T and / or D units may be present in the polyester, provided that the type or number of such units does not significantly adversely affect the desired properties of the thermoplastic composition. Poly(alkylaryl esters) may have a polyester structure according to formula (A), wherein T includes groups derived from aromatic dicarboxylic esters, alicyclic dicarboxylic acids, or derivatives thereof.

[0048] Examples of particularly useful T groups include, but are not limited to, 1,2-, 1,3-, and 1,4-phenylene; 1,4-, and 1,5-naphthylene; cis- or trans-1,4-cyclohexylene; and so on. Specifically, when T is 1,4-phenylene, the poly(alkylene aryl ester) is a poly(alkylene terephthalate). Furthermore, with respect to poly(alkylene aryl esters), particularly useful alkylene groups D include, for example, ethylene, 1,4-butylene, and bis-(alkylene-disubstituted cyclohexane), including cis- and / or trans-1,4-(cyclohexylene)dimethylene.

[0049] Examples of polyalkylene terephthalates include polyethylene terephthalate (PET), poly(1,4-butanediol terephthalate) (PBT), and poly(propylene terephthalate) (PPT). Poly(alkylene naphthate), such as polyethylene naphthate (PEN) and polybutylene naphthate (PBN), are also useful. A useful poly(cycloalkylene diester) is poly(cyclohexanedimethyl terephthalate) (PCT). Combinations comprising at least one of the aforementioned polyesters may also be used.

[0050] Copolymers including repeating alkylene terephthalate ester units and other ester groups can also be useful. Useful ester units may include different alkylene terephthalate units, which may exist as individual units or as blocks of poly(alkylene terephthalate) in the polymer chain. Specific examples of such copolymers include poly(cyclohexyl terephthalate)-co-poly(ethylene terephthalate), abbreviated PETG, wherein the polymer comprises greater than or equal to 50 mol% poly(ethylene terephthalate), and abbreviated PCTG, wherein the polymer comprises greater than 50 mol% poly(1,4-cyclohexyl terephthalate). Poly(cycloalkylene diesters) may also include poly(cyclohexanedicarboxylic acid alkylene esters). A specific example is poly(1,4-cyclohexane-dimethyl-1,4-cyclohexanedicarboxylic acid ester) (PCCD), having repeating units of formula (B):

[0051]

[0052] Wherein, as described by equation (A), R 2 It is a 1,4-cyclohexanedimethyl group derived from 1,4-cyclohexanediethanol, and T is a cyclohexane ring derived from cyclohexane dicarboxylic acid ester or its chemical equivalent, and may include cis isomers, trans isomers or combinations including at least one of the aforementioned isomers.

[0053] In another aspect, the composition may further comprise poly(1,4-butanediol terephthalate) or "PBT" resin. PBT can be obtained by polymerizing the following: a glycol component, wherein at least 70 mol%, preferably at least 80 mol%, consists of tetramethylethylene glycol; and an acid or ester component, wherein at least 70 mol%, preferably at least 80 mol%, consists of terephthalic acid and / or its derivatives forming polyesters. Commercial examples of PBT include those from SABIC. TM Manufactured under the trade name VALOX TM 315, VALOX TM 195 and VALOX TM Those obtained in 176 have an intrinsic viscosity of 0.1 dL / g to about 2.0 dL / g (or 0.1 dL / g to 2 dL / g) when measured in a 60:40 phenol / tetrachloroethane mixture or similar solvent at 23°C to 30°C. On the other hand, PBT resin has an intrinsic viscosity of 0.1 dL / g to 1.4 dL / g (or about 0.1 dL / g to about 1.4 dL / g), specifically 0.4 dL / g to 1.4 dL / g (or about 0.4 dL / g to about 1.4 dL / g).

[0054] Certain aspects of the composition include about 50 wt.% to about 99 wt.% of a thermoplastic resin, or about 40 wt.% to about 97 wt.% of a polymeric base resin, or about 55 wt.% to about 97 wt.% of a polymeric base resin, or about 60 wt.% to about 97 wt.% of a polymeric base resin, or about 70 wt.% to about 97 wt.% of a polymeric base resin, or about 40 wt.% to about 95 wt.% of a polymeric base resin, or about 55 wt.% to about 95 wt.% of a polymeric base resin, or about 60 wt.% to about 95 wt.% of a polymeric base resin, or about 75 wt.% to about 97 wt.% of a polymeric base resin.

[0055] Conductive carbon filler

[0056] The compositions disclosed herein may include conductive fillers. Suitable conductive fillers may include carbon-based or non-carbon-based fillers, such as particulate interstitial carbides and metal nanoparticles (e.g., gold, silver, copper, Fe2O3). In various aspects, the compositions include conductive carbon-based fillers, such as conductive carbon black. Generally, carbon-based fillers may include carbon fibers, carbon powder, graphite, graphene, carbon platelets, or carbon nanotubes. In various aspects, the compositions include conductive carbon black or carbon nanotubes and carbon-based fillers.

[0057] Carbon black can refer to amorphous carbon with a high surface area-to-volume ratio. Furthermore, depending on the manufacturing conditions, carbon black may also include, to varying degrees, chemisorbed oxygen complexes (such as carboxyl, quinonic, lactone, and phenolic groups) on its surface. The properties of carbon black, such as particle size, structure, and purity, can vary depending on the type of carbon black selected. On the one hand, carbon black can be well dispersed in polymer phases, maintaining the integrity of its structure or network and exhibiting a consistent particle size. However, according to certain aspects of this disclosure, conductive carbon black does not refer to carbon black used for colorant purposes.

[0058] In one example, conductive carbon black is electrically conductive carbon black. Conductive carbon black can be furnace black, acetylene black, or additional conductive carbon blacks. Conductive carbon blacks such as furnace black or acetylene black can have a content such as 1 to 10. -2 The high conductivity is demonstrated by a volume resistivity in the ohmic-cm (Ω-cm) range (0.01 to 1 Ω-cm, which can be considered as low volume resistivity). The useful conductive carbon black of this disclosure exhibits a conductivity of approximately at least 50 m² / g (m³ / g). 2 / g) to approximately 1500m 2 / g BET (Brunauer, Emmett, and Teller) specific surface area. In another aspect, the conductive carbon black powder may exhibit an oil absorption number (OAN) of at least about 100 ml / 100 g or at least 150 ml / 100 g. In a further aspect, the carbon-based filler (such as carbon black) may have a specific conductivity. For example, the conductivity of the carbon-based filler may be at least [value missing].

[0059] In specific aspects, conductive carbon black includes ENSACO TM 250g of carbon powder, available from Imerys Graphite & Carbon Switzerland. In some aspects, the thermoplastic composition may include conductive carbon black having at least one size of a specific dimensions. The conductive carbon black may include powder having a specific particle size distribution. For example, carbon-based fillers may have at least one size less than 100 nm. However, these particles may aggregate, thus having a certain structure and increased aggregate size—which may be on the micrometer scale.

[0060] In some respects, conductive carbon black may have a specific diameter. For example, conductive carbon black may have a primary particle size of 10 nanometers to 50 nanometers. In another respect, conductive carbon black may have a DBP absorption of about 80 ml / 100g to about 500 ml / 100g.

[0061] In some aspects, the composition may include about 0.5 wt.% to about 30 wt.% of conductive carbon black based on the total weight of the thermoplastic composition. The ratio of the polymer component to the conductive carbon black may be about 32:1 to about 6:1 or about 24:1 to about 6:1. In a further aspect, the composition may include about 0.1 wt.% to about 30 wt.%, or 0.1 wt.% to about 25 wt.%, 0.5 wt.% to about 25 wt.%, or about 0.5 wt.% to about 20 wt.%, or about 1 wt.% to about 20 wt.%, or about 3 wt.% to about 30 wt.%, or about 2 wt.% to about 25 wt.% of conductive carbon black, or about 10 wt.% to about 25 wt.% of conductive carbon black, or about 8 wt.% to about 25 wt.% of conductive carbon black.

[0062] Multilayer components formed from the disclosed compositions may include one or more conductive carbon-based fillers. The multilayer component may include multiple discrete layers, such as a first layer and a second layer, each layer comprising a corresponding polymer composition as described herein. For example, the multilayer component may include: a first layer comprising a first composition; and a second layer comprising a second composition. In one example, the multilayer component may include: a first polymer composition comprising a first conductive carbon-based filler; and a second polymer composition comprising a second conductive carbon-based filler. The first and second conductive carbon-based fillers may be in different layers of the multilayer component prepared according to various aspects of this disclosure. For example, the first layer of the multilayer component may include the first conductive carbon-based filler, while the second layer of the multilayer component may include the second conductive carbon-based filler, and so on.

[0063] The first conductive carbon-based filler and the second conductive carbon-based filler may be present in specific amounts. For example, the first conductive carbon-based filler may be present in the following amounts based on the total weight of the composition: about 0.1 wt.% to about 30 wt.%, or 0.5 wt.% to about 25 wt.%, or about 0.5 wt.% to about 20 wt.%, or about 1 wt.% to about 20 wt.%, or about 3 wt.% to about 30 wt.%, or about 2 wt.% to about 25 wt.%, or about 0.1 wt.% to about 12 wt.%, or about 0.1 wt.% to about 15 wt.%, or about 1 wt.% to about 12 wt.%, or about 1 wt.% to about 12 wt.%, or about 0.1 wt.% to about 8 wt.%, or about 0.1 wt.% to about 5 wt.%, or about 0.01 wt.% to about 8 wt.%, or about 0.01 wt.% to about 5 wt.%, or about 0.01 wt.% to about 3 wt.%. The second conductive carbon-based filler may be present in the following amounts: from about 0.1 wt.% to about 20 wt.% based on the total weight of the composition, or from 0.01 wt.% to about 10 wt.%, or from about 0.5 wt.% to about 15 wt.%, or from about 1 wt.% to about 12 wt.%, or from about 3 wt.% to about 12 wt.%, or from about 2 wt.% to about 15 wt.%, or from about 0.1 wt.% to about 12 wt.%, or from about 1 wt.% to about 12 wt.%, or from about 1 wt.% to about 12 wt.%, or from about 0.1 wt.% to about 8 wt.%, or from about 0.1 wt.% to about 5 wt.%, or from about 0.01 wt.% to about 5 wt.%, or from about 0.01 wt.% to about 3 wt.%.

[0064] Other additives

[0065] In some aspects, additives are conventionally used to manufacture molded thermoplastic parts, provided that optional additives do not adversely affect the desired properties of the resulting composition. Mixtures of optional additives may also be used. Such additives can be mixed at appropriate times during the mixing of the components used to form the composition mixture. Exemplary additives may include UV agents, UV stabilizers, heat stabilizers, antistatic agents, impact modifiers, antimicrobial agents, anti-drip agents, radiation stabilizers, pigments, dyes, fibers, fillers, plasticizers, fibers, flame retardants, antioxidants, lubricants, wood, glass, and metals, and combinations thereof. According to some aspects, even with the use of high levels of fillers (e.g., more than 30 wt.% filler based on the total weight of the polymer composition), the polymer composition can maintain its mechanical and dielectric properties.

[0066] The compositions disclosed herein may include one or more additional fillers. Fillers may be selected to impart additional impact strength and / or provide additional properties based on the final selection of the polymer composition. In some aspects, the filler (one or more) may include inorganic materials, which may include clay, titanium dioxide, asbestos fibers, silicate and silica powders, boron powder, calcium carbonate, talc, kaolin, sulfides, barium compounds, metals and metal oxides, wollastonite, glass beads, glass fibers, sheet fillers, fiber fillers, natural fillers and reinforcing agents, and reinforced organic fiber fillers. In some aspects, the composition may include glass fiber fillers. For example, the composition may include about 0.01 wt.% to about 25 wt.%, about 10 wt.% to about 25 wt.%, or about 15 wt.% to about 25 wt.% of the total weight of the composition as glass fiber filler. In yet another aspect, the composition may be free of or substantially free of glass fillers.

[0067] In some aspects, the thermoplastic composition may include a synergist. In various examples, fillers may act as flame-retardant synergists. When added to a flame-retardant composition, the synergist promotes improved flame-retardant properties, superior to a comparative composition containing equal amounts of all the same components except the synergist. Examples of mineral fillers that may act as synergists are mica, talc, calcium carbonate, dolomite, wollastonite, barium sulfate, silica, kaolin, feldspar, barite, etc., or combinations comprising at least one of the aforementioned mineral fillers. Metallic synergists (e.g., antimony oxide) may also be used with the flame retardant. In one example, the synergist may include magnesium hydroxide and phosphoric acid. The mineral filler may have an average particle size of about 0.1 to about 20 micrometers, specifically about 0.5 to about 10 micrometers, and more specifically about 1 to about 3 micrometers.

[0068] Thermoplastic compositions may include antioxidants. Antioxidants may include primary or secondary antioxidants. For example, antioxidants may include organic phosphites such as tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearate pentaerythritol diphosphite, etc.; alkylated monophenols or polyphenols; alkylation products of polyphenols and dienes, such as tetra[methylene(3,5-di-tert-butyl-4-hydroxycinnamic acid)]methane, etc.; butylation products of p-cresol or dicyclopentadiene; alkylated hydroquinone; hydroxylated thiodiphenyl ethers; alkylene bisphenols; benzyl compounds; β-(3,5-di-tert-butyl- Esters of 4-hydroxyphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of thioalkyl or thioaryl compounds such as distearate thiodipropionate, dodecyl thiodipropionate, tridecyl thiodipropionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, etc.; amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid, etc., or combinations comprising at least one of the aforementioned antioxidants. Based on 100 parts by weight of the total composition excluding any fillers, the antioxidant may typically be used in an amount of 0.01 to 0.5 parts by weight.

[0069] In various aspects, the thermoplastic composition may include a release agent. Exemplary release agents may include, for example, metal stearates, stearyl stearate, pentaerythritol tetrastearate, beeswax, lignite wax, paraffin wax, etc., or combinations including at least one of the foregoing release agents. Based on 100 parts by weight of the total composition excluding any fillers, the release agent is typically used in an amount of about 0.1 to about 1.0 parts by weight.

[0070] In one aspect, the thermoplastic composition may include a heat stabilizer. As examples, the heat stabilizer may include, for instance, organic phosphites such as triphenyl phosphite, tri-(2,6-dimethyl)phosphite, tri-(a mixture of monononylphenyl and dinonylphenyl)phosphite, etc.; phosphonates such as dimethylphenylphosphonate, phosphate esters such as trimethyl phosphate, etc., or combinations including at least one of the aforementioned heat stabilizers. Based on 100 parts by weight of the total composition excluding any fillers, the heat stabilizer may typically be used in an amount of 0.01 to 0.5 parts by weight.

[0071] In a further aspect, a light stabilizer may be present in the thermoplastic composition. Exemplary light stabilizers may include, for example, benzotriazoles, such as 2-(2-hydroxy-5-tolyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-benzotriazole, and 2-hydroxy-4-n-octoxybenzophenone, or combinations comprising at least one of the foregoing light stabilizers. Based on 100 parts by weight of the total composition excluding any fillers, the light stabilizer is typically used in an amount from about 0.1 to about 1.0 parts by weight. The thermoplastic composition may also include a plasticizer. For example, the plasticizer may include phthalates, such as dioctyl-4,5-epoxy-hexahydrophthalate, tri-(octyloxycarbonylethyl)isocyanurate, glyceryl tristearate, epoxidized soybean oil, or combinations comprising at least one of the foregoing plasticizers. Based on 100 parts by weight of the total composition excluding any fillers, the plasticizer is typically used in an amount from about 0.5 to about 3.0 parts by weight.

[0072] Ultraviolet (UV) absorbers may also be present in the disclosed thermoplastic compositions. Exemplary UV absorbers may include, for example, hydroxybenzophenone; hydroxybenzotriazole; hydroxybenzotriazine; cyanoacrylate; oxaloaniline; benzo[…] Azinone; 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-phenol (CYASORB) TM 5411); 2-Hydroxy-4-n-Octyloxybenzophenone (CYASORB) TM 531); 2-[4,6-bis(2,4-dimethylyl)-1,3,5-triazin-2-yl]-5-(octyloxy)-phenol (CYASORB) TM 1164); 2,2'-(1,4-phenylene)bis(4H-3,1-benzo[] (CYASORB) TM UV-3638); 1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane (UVINUL) TM 3030); 2,2'-(1,4-phenylene)bis(4H-3,1-benzo[3]) The UV absorber may include: 1,3-bis[(2-cyano-3,3-diphenylacryloyl)oxy]-2,2-bis[[(2-cyano-3,3-diphenylacryloyl)oxy]methyl]propane; nanoscale inorganic materials, such as titanium oxide, cerium oxide, and zinc oxide, all having a particle size of less than 100 nanometers; etc., or combinations comprising at least one of the aforementioned UV absorbers. Based on 100 parts by weight of the total composition excluding any fillers, the UV absorber is typically used in an amount of 0.01 to 3.0 parts by weight.

[0073] The thermoplastic composition may further include a lubricant. As examples, the lubricant may include, for instance, fatty acid esters, such as alkyl stearates, such as methyl stearate; mixtures of methyl stearate with hydrophilic and hydrophobic surfactants, including polyethylene glycol polymers, polypropylene glycol polymers, and copolymers thereof, such as methyl stearate and polyethylene glycol-polypropylene glycol copolymers in a suitable solvent; or combinations comprising at least one of the aforementioned lubricants. Based on 100 parts by weight of the total composition excluding any fillers, the lubricant may typically be used in an amount from about 0.1 to about 5 parts by weight.

[0074] Anti-drip agents can also be used in compositions, such as fibril-forming or non-fibril-forming fluoropolymers, like polytetrafluoroethylene (PTFE). Anti-drip agents can be encapsulated from rigid copolymers, such as styrene-acrylonitrile copolymer (SAN). PTFE encapsulated in SAN is referred to as TSAN. In one example, based on the total weight of the encapsulated fluoropolymer, TSAN may comprise 50 wt.% PTFE and 50 wt.% SAN. Based on the total weight of the copolymer, SAN may comprise, for example, 75 wt.% styrene and 25 wt.% acrylonitrile. Based on 100 parts by weight of the total composition excluding any fillers, an anti-drip agent such as TSAN can be used in amounts from 0.1 to 10 parts by weight.

[0075] As an example, the disclosed compositions may include impact modifiers. Impact modifiers may be chemically reactive impact modifiers. By definition, a chemically reactive impact modifier may have at least one reactive group such that when the impact modifier is added to the polymer composition, the impact properties of the composition (expressed as Izod impact value) are improved. In some examples, the chemically reactive impact modifier may be an ethylene copolymer having reactive functional groups selected from, but not limited to, acid anhydrides, carboxyl groups, hydroxyl groups, and epoxy groups.

[0076] In a further aspect of this disclosure, the composition may include a rubbery impact modifier. The rubbery impact modifier may be a polymeric material capable of substantially recovering its shape and size at room temperature after the force is removed. However, the rubbery impact modifier should generally have a glass transition temperature below 0°C. In some aspects, the glass transition temperature (T0) is... g Temperatures can be below -5℃, -10℃, or -15℃, with T below -30℃. gGenerally, it provides better performance. Representative rubbery impact modifiers may include, for example, functionalized polyolefin ethylene-acrylate terpolymers, such as ethylene-acrylate-maleic anhydride (MAH) or glycidyl methacrylate (GMA). The functionalized rubbery polymer may optionally include repeating units in its backbone derived from monomers containing anhydride groups, such as maleic anhydride. In another case, the functionalized rubbery polymer may include an anhydride moiety grafted onto the polymer in a post-polymerization step.

[0077] Properties and products

[0078] The multilayer components of this disclosure achieve low reflection (less than 25%) and low transmission (less than 6% or less than 3%). In various aspects, microwave reflection and absorption can depend on both the conductivity of the microwave and the frequency. The multilayer components of this disclosure achieve low reflection (less than 25% or less than 15%) and low transmission (less than 6% or less than 3%) at frequencies from about 77 GHz to 81 GHz.

[0079] The first layer of the multilayer component may have a thickness greater than 0.8 mm, while the second layer may have a thickness of about 0.2 mm to about 0.7 mm. When measured along a direction that causes the second layer to align with the incident microwave radiation, the multilayer component may have a reflectivity of less than 15%, specifically less than 10%, or less than 8%, or less than 6%, and a transmittance of less than 3%, or less than 2%, or less than 1%. In view of the foregoing properties, the molded component formed according to this disclosure can be used as an external or internal radar-absorbing component. Radar is widely used in advanced driver assistance systems (ADAS) because it provides blind spot detection, collision avoidance, automatic braking, traffic alerts, and other functions, and can operate in low-visibility conditions (such as rain and fog) that can impair the functioning of LiDAR and cameras. In a specific example, the molded component of this disclosure may be a component of an ADAS.

[0080] In various aspects, this disclosure relates to articles, including the compositions described herein. The compositions can be molded into useful shaped articles by various means, such as injection molding, extrusion, rotational molding, blow molding, and thermoforming. The compositions can be used to manufacture articles requiring materials with good flowability, good impact strength, and good dielectric properties. In various aspects, the compositions can be used for conductive purposes. The advantageous properties of the molded parts disclosed herein make them suitable for a range of applications, including, for example, radar materials and ADAS.

[0081] Preparation method of composition and multilayer component

[0082] Various aspects of this disclosure also relate to methods for preparing compositions comprising thermoplastic polymer components. In several aspects, the compositions can be prepared according to a variety of methods. The compositions of this disclosure can be blended, compounded, or otherwise combined with the foregoing components by various methods involving the close blending of the material with any other desired additives in the formulation. Melt processing methods can be used due to the availability of melt blending equipment in commercial polymer processing facilities. In various further aspects, the equipment used in such melt processing methods may include, but is not limited to, co-rotating and counter-rotating extruders, single-screw extruders, co-kneaders, disc-pack processors, and various other types of extrusion equipment. In a further aspect, the extruder is a twin-screw extruder. In various further aspects, the compositions can be processed in the extruder at a temperature of about 180°C to about 350°C, particularly 250°C to 300°C.

[0083] The method may further include processing the composition to provide a sheet of desired thickness. The sheet may be extruded, injection molded, extruded, or injection-extrusion molded, and may have a thickness between about 0.2 mm and 6 mm. Other methods may also be applied to thermoplastic films, including but not limited to lamination, co-extrusion, thermoforming, or hot pressing. In such aspects, additional layers of other materials (e.g., other thermoplastic polymer layers, metal layers, etc.) may be combined with the composition.

[0084] In a specific example, multi-layered components can be formed using a 2K injection molding process. In one possible embodiment of the method according to the invention, a variation of the conventional injection molding process, two-component injection molding, is referred to simply as the 2K process. 2K molding is a technique for producing articles having multiple layers (e.g., two or three layers of two different materials) of two or more different materials. Therefore, 2K molding can produce articles with layers possessing different properties.

[0085] The advantage of 2K molding is that it maintains the desired physical properties of different layers in the same steps as article molding. 2K molding is particularly suitable for articles that require painting on more than one side. In the case of a conductive layer within the article, all sides can be electrostatically painted without repeated application of the conductive layer. 2K molding can be referred to as multi-component injection molding, with two-component injection molding being particularly preferred. In the extrusion molding process according to this disclosure, the continuous production of plastic semi-finished products—specifically films, sheets, tubes, or profiles—is understood. During extrusion, a so-called extruder, consisting of a screw and a barrel, continuously extrudes a plastic compound under pressure through a forming tool. In practice, single-screw, twin-screw extruders, or special types of extruders can be used.

[0086] This disclosure covers various combinations of elements of this disclosure, such as combinations of elements of dependent claims that are subordinate to the same independent claim.

[0087] definition

[0088] It should also be understood that the terminology used herein is for descriptive purposes only and is not intended to be limiting. As used in the specification and claims, the term "comprising" may include embodiments that are "composed of" and "mainly composed 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 pertains. Reference will be made to numerous terms that should be defined herein in this specification and the appended claims.

[0089] As used in the specification and appended claims, the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly indicates otherwise. Thus, for example, a reference to “thermoplastic polymer component” includes a mixture of two or more thermoplastic polymer components. As used herein, the term “composite” includes blends, mixtures, alloys, reaction products, and the like.

[0090] A range may be expressed herein as a range from one value (the first value) to another value (the second value). When such a range is expressed, the range includes one or both of the first and second values ​​in some respects. Similarly, when a value is expressed as an approximation using the antecedent 'about', it should be understood that the particular value forms the other side. It should be further understood that the endpoints of each range are meaningful both in relation to and independent of the other endpoint. It should also be understood that multiple values ​​are disclosed herein, and each value is also disclosed herein as 'about' the particular value other than the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It should also be understood that each unit between two particular units is also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0091] As used herein, the terms “about” and “equal to or about” mean that the quantity or value discussed may be a specific value, an approximate specific value, or about the same as the specific value. Generally, it should be understood that, as used herein, nominal values ​​indicate a variation of ±10%, unless otherwise indicated or inferred. This term is intended to convey that similar values ​​promote the equivalent results or effects described in the claims. That is, it should be understood that quantities, sizes, formulations, parameters, and other quantities and characteristics are not and need not be precise, but may be approximate and / or larger or smaller as needed, reflecting tolerances, conversion factors, rounding, measurement errors, and other factors known to those skilled in the art. Generally, quantities, sizes, formulations, parameters, or other quantities or characteristics are “about” or “approximate,” whether explicitly stated or not. It should be understood that when “about” is used before a quantitative value, unless otherwise specifically stated, the parameter also includes the specific quantitative value itself.

[0092] As used herein, the terms “optional” or “optionally” mean that an event or situation subsequently described may or may not occur, and the description includes both the occurrence and non-occurrence of said event or situation. For example, the phrase “optional additional process” means that the additional process may or may not be included, and the methods included in the description include and exclude the additional process.

[0093] The components used to prepare the compositions disclosed herein, as well as the compositions themselves used in the methods disclosed herein, are 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, although specific references to various individual and collective combinations and arrangements of these compounds are not explicitly disclosed, each is specifically considered and described herein. For example, if a particular compound is disclosed and discussed, and various modifications that may be made to multiple molecules including the compound are discussed, each combination and arrangement of the compound and possible modifications are specifically considered 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, and examples of the combination molecule AD are disclosed, even though each is not described separately, they are considered individually and collectively, thereby implying that combinations AE, AF, BD, BE, BF, CD, CE, and CF are disclosed. Similarly, any subsets or combinations of these are also disclosed. Thus, for example, the subgroups AE, BF, and CE would be considered disclosed. This concept applies to all aspects of this application, including but not limited to the steps in methods for preparing and using the compositions disclosed herein. Therefore, if various additional steps are available, it should be understood that each of these additional steps may be performed in any specific aspect or combination thereof of the methods disclosed herein.

[0094] References to the weight parts of a specific element or component in the composition or article in the specification and concluding claims indicate the weight relationship between the element or component and any other element or component, expressed as 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 2:5 weight ratio, and are present in such a ratio regardless of whether the compound contains other components. Unless specifically stated to the contrary, the weight percentages of components are based on the total weight of the formulation or composition comprising that component.

[0095] Throughout the specification, the terms “residue” and “structural unit” are used synonymously when referring to the components of the polymer.

[0096] Unless otherwise specified, the terms “weight percentage,” “wt%,” and “wt.%” as used herein are used interchangeably to indicate the weight percentage of a given component based on the total weight of the composition. That is, unless otherwise specified, all wt% values ​​are based on the total weight of the composition. It should be understood that the sum of the wt% values ​​of all components in the disclosed compositions or formulations is 100.

[0097] Unless otherwise stated herein, all testing standards were up-to-date and valid at the time of filing this application. Each of the materials disclosed herein is commercially available and / or its production methods are known to those skilled in the art.

[0098] It should be understood that the compositions disclosed herein have certain functions. This document discloses certain structural requirements for performing the disclosed functions, and it should be understood that various structures exist that can perform the same functions associated with the disclosed structures, and these structures generally achieve the same results.

[0099] All aspects of this disclosure

[0100] This disclosure relates to and includes at least the following aspects.

[0101] Aspect 1A. A multilayer component comprising: a first layer comprising a first polymer composition comprising a first polymer and about 0.1 wt.% to about 30 wt.% of a first conductive carbon-based filler; a second layer disposed adjacent to the surface of the first layer, wherein the second layer comprises a second polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler, wherein when the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, when observed in free space at frequencies of about 77 GHz to 81 GHz, the multilayer component exhibits a reflected power percentage of less than 15% and a transmitted power percentage of less than 6% as measured in transmission mode, and wherein the combined weight percentage value of all components does not exceed 100 wt.%, and all weight percentage values ​​are based on the total weight of the first polymer composition or the second polymer composition.

[0102] Aspect 1B. A multilayer component comprising primarily the following: a first layer comprising a first polymer composition comprising a first polymer and about 0.1 wt.% to about 30 wt.% of a first conductive carbon-based filler; a second layer disposed adjacent to the surface of the first layer, wherein the second layer comprises a second polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler, wherein when the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, when observed according to the free-space method at frequencies of about 77 GHz to 81 GHz, the multilayer component exhibits a reflected power percentage of less than 15% and a transmitted power percentage of less than 6% as measured in transmission mode, and wherein the combined weight percentage value of all components does not exceed 100 wt.%, and all weight percentage values ​​are based on the total weight of the first polymer composition or the second polymer composition.

[0103] Aspect 1C. A multilayer component comprising: a first layer comprising a first polymer composition comprising a first polymer and about 0.1 wt.% to about 30 wt.% of a first conductive carbon-based filler; and a second layer disposed adjacent to the surface of the first layer, wherein the second layer comprises a second polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler, wherein when the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, when observed according to the free-space method at frequencies of about 77 GHz to 81 GHz, the multilayer component exhibits a reflected power percentage of less than 15% and a transmitted power percentage of less than 6% as measured in transmission mode, and wherein the combined weight percentage value of all components does not exceed 100 wt.%, and all weight percentage values ​​are based on the total weight of the first polymer composition or the second polymer composition.

[0104] Aspect 2. A multilayer component according to any one of aspects 1A-2, wherein the first layer and the second layer are connected by an intermediate third layer comprising an adhesive such that the adhesive is disposed between the first layer and the second layer.

[0105] Aspect 3. The multilayer component according to aspect 2, wherein the adhesive comprises acrylate.

[0106] Aspect 4. The multilayer component according to aspect 2, wherein the thickness of the intermediate third layer is about 10 micrometers to about 100 micrometers.

[0107] Aspect 5. A multilayer component according to any one of Aspects 1-5, wherein the thickness of the second layer is less than 0.8 mm.

[0108] Aspect 6. A multilayer component according to any one of Aspects 1-4, wherein the thickness of the second layer is about 0.2 mm to about 0.7 mm.

[0109] Aspect 7. A multilayer component according to any one of Aspects 1-4, wherein the thickness of the first layer is greater than 0.8 mm.

[0110] Aspect 8. A multi-layered component according to any one of Aspects 1-7, wherein the total thickness of the multi-layered component is less than 3.5 mm.

[0111] Aspect 9. A multilayer component according to any one of Aspects 1-8, wherein the thickness ratio of the first layer to the second layer is approximately 1:1 to 20:1.

[0112] Aspect 10. According to any one of Aspects 1-9, when molded samples of Material 1 and Material 2 are tested at a fixed frequency using a split-pillar dielectric resonator (SPDR) and a network analyzer, the dielectric constant (Dk) of the second layer is 2 to 5, and the ratio of Dk of the second layer to Dk of the first layer (Dk...第二层 / Dk 第一层 The value ranges from 0.2 to 0.6.

[0113] Aspect 11. A multilayer component according to any one of Aspects 1-10, wherein the first polymer or the second polymer comprises polyester, polycarbonate, polyamide, polyphenylene ether, polypropylene or a combination thereof.

[0114] Aspect 12. The multilayer component according to aspect 11, wherein the first polymer or the second polymer comprises polyester.

[0115] Aspect 13. A multilayer component according to any one of Aspects 1-12, wherein the first polymer and the second polymer comprise the same polymer.

[0116] Aspect 14. A multilayer component according to any one of Aspects 1-13, wherein the amount of the first conductive carbon-based filler in the first layer is greater than the amount of the second conductive carbon-based filler in the second layer.

[0117] Aspect 15. A multilayer component according to any one of Aspects 1-14, wherein the first conductive carbon-based filler and the second conductive carbon-based filler comprise carbon fibers, carbon powder, graphite, graphene, carbon sheets, carbon nanotubes, or combinations thereof.

[0118] Aspect 16. A multilayer component according to any one of Aspects 1-15, wherein the conductive carbon-based filler has a conductivity of at least 1 Siemens / cm.

[0119] Aspect 17. A multilayer component according to any one of Aspects 1-16, wherein the conductive carbon-based filler comprises conductive carbon black.

[0120] Aspect 18. A multilayer component according to any one of Aspects 1-16, wherein the conductive carbon-based filler comprises conductive carbon nanotubes.

[0121] Aspect 19. A multilayer component according to any one of Aspects 1-18, wherein one or more of the first polymer composition or the second polymer composition further comprises reinforcing filler.

[0122] Aspect 20. A multi-layered component according to any one of Aspects 1-19, wherein the multi-layered component is formed by a 2K injection molding process.

[0123] Aspect 21. An autoradar sensor comprising a multilayer component, the multilayer component comprising: a first layer comprising a first polymer composition comprising about 0.1 wt.% to about 20 wt.% of a first conductive carbon-based filler; and a second layer disposed adjacent to the surface of the first layer, wherein the second layer comprises a polymer composition comprising a second polymer and about 0.01 wt.% to about 10 wt.% of a second conductive carbon-based filler, wherein when the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, when observed according to the free-space method at frequencies of about 77 GHz to 81 GHz, the multilayer component exhibits a reflected power percentage of less than 15% and a transmitted power percentage of less than 6% as measured in transmission mode, and wherein the combined weight percentage value of all components does not exceed 100 wt.%, and all weight percentage values ​​are based on the total weight of the first polymer composition or the second polymer composition.

[0124] Aspect 22. A multilayer component according to any one of Aspects 1-20, wherein when molded samples of a first polymer of the first layer and a second polymer of the second layer are tested at 77 GHz using a split-pillar dielectric resonator (SPDR) and a network analyzer, the ratio of Dk of the second layer to Dk of the first layer (Dk... 第二层 / Dk 第一层 The value ranges from 0.2 to 0.6.

[0125] Example

[0126] The following examples are provided to provide a complete disclosure and description to those skilled in the art on how to prepare and evaluate the compounds, compositions, articles, apparatus, and / or methods claimed herein, and are intended purely as examples and not to limit the scope of this disclosure. Efforts have been made to ensure accuracy regarding figures (e.g., amounts, temperatures, etc.), but some errors and deviations should be accounted for. Unless otherwise indicated, parts are parts by weight, temperatures are in °C or at ambient temperature, and pressures are equal to or close to atmospheric pressure. Unless otherwise indicated, percentages of compositions refer to wt%.

[0127] There are various variations and combinations of mixing conditions, such as component concentration, extruder design, feed rate, screw speed, temperature, pressure, and other mixing ranges and conditions that can be used to optimize the purity and yield of the product obtained from the described process. Such process conditions can be optimized with only reasonable and routine experiments.

[0128] Scattering parameters were measured in transmission mode using a split-pillar dielectric resonator (SPDR) and a vector network analyzer according to the free-space method. This vector network analyzer was connected to two antennas to focus microwave energy onto or through a material slab at frequencies of 60-90 GHz. Reflection and transmission were directly calculated from the S11 and S21 scattering parameters. Absorption is directly related to reflection and transmission and is calculated as follows:

[0129] Absorption% = 100 - Reflection% - Transmission%

[0130] Transmission ray theory is used to calculate the dielectric constant of a monolayer material from measured scattering parameters. For example... Figure 1 As shown, the sample is evaluated in transmission mode. Figure 2A This is a diagram of a multilayer component in which the second layer (C) is oriented toward the incident microwave radiation. Figure 2B This is a diagram of a multilayer component in which the middle third layer B is oriented such that the third layer (B) or the second layer (C) is oriented toward the incident microwave radiation, unless otherwise stated.

[0131] Various compositions were prepared by varying the carbon black (CB) loading in PBT. The formulations are shown in Table 1.

[0132]

[0133] Table 2 shows the effect of carbon black (CB) loaded PBT (formulations shown in Table 1) on reflection, transmission, and absorption at 77 GHz for a 3.2 mm thick plate. It can be inferred that increasing the CB loading increases both Dk and Df. With increasing Dk and Df, the amount of transmitted signal decreases, but the amount of reflection increases simultaneously. Industrial requirements generally favor materials with reflections less than 25%, preferably less than 15%, and transmission values ​​less than 6.5%, preferably less than 3%, to provide sufficient shielding performance. At 4 wt.% CB, a 3.2 mm CB-loaded PBT will meet the minimum requirements, but theoretical calculations using a model based on the principles disclosed herein establish that at smaller wall thicknesses (less than 3.2 mm), transmission decreases and does not meet industrial requirements. Therefore, conventional single-material or monolayer materials do not achieve the desired performance balance.

[0134] Table 2. Dielectric properties of 3.2mm CB-PBT boards at 77GHz

[0135]

[0136] The composition prepared in this embodiment combines low-conductivity and high-conductivity materials to overcome these drawbacks and provides a product with low reflectance (specifically, less than 25%), high absorption (specifically, greater than 68.5% (absorption% = 100 - reflectance% - transmittance%, minimum absorption corresponds to 100 - 25 - 6.5 = 68.5%), and low transmittance (specifically, less than 6.5%). As a first proof-of-concept, two injection-molded layers A and C were joined together using an acrylate film (layer B) to prepare the following molded parts (F, G, and H) (Tables 3A and 3B, respectively). Figure 3A and Figure 3B middle).

[0137] Table 4 shows the properties ε', ε”, and tan d of the materials used. These properties were measured on the component or in the case of the acrylate film in the datasheet. The Dk / Df of layer C is much lower than that of layer A.

[0138] Table 4. Material properties used to fabricate multilayer components.

[0139]

[0140]

[0141] *No assumptions were made regarding Pyralux TM Same available data for membranes

[0142] Figure 4 The results show that when layer C with (lower) Dk and Df values ​​faces the radar wave transmitter (samples F(C), G(C), and H(C)), the fabricated components of this invention exhibit both low reflectance and low transmittance values. It also shows that when layer A with (higher) Dk and Df values ​​faces the radar wave transmitter (samples F(A), G(A), and H(A)), the reflectance is significantly higher, well above 15%. The transmittance of these materials is practically zero.

[0143] Modeling was used to further study and optimize sample thickness. Using transmission line theory, the following formulas were derived for single-layer and multi-layer models. Based on these formulas, an Excel program was developed for calculation, allowing for the calculation of the thickness of single-layer, double-layer, and triple-layer materials. Electromagnetic wave propagation in Advanced Driver Assistance Systems (ADAS) was used in the model. Microwave propagation in materials is critical for radar radome design and absorber design in ADAS sensors. Calculations are shown below. Figure 5 middle.

[0144] From Table 5 ( Figure 6 ) and Table 6 ( Figure 7It can be inferred that there is good alignment between the experimentally obtained data and the calculated data for both single-layer materials (Table 5) and three-layer stacked materials (Table 6), indicating that the model can be used for predictive calculations. Subsequently, a two-layer model is used to define a combination that will provide less than 15% reflectivity and less than 6% (preferably less than 3%) transmittance.

[0145] Table 7 (shown in) Figure 8 The image shows the radar characteristics of a dual-layer system at 77 GHz with different second-layer thicknesses and different total thicknesses. The second layer is a typical unreinforced PBT / PC material, while the first layer (Layer A) is a 10% CCB-filled PBT material. It can be inferred that a 0.3 mm to 0.7 mm thick PBT / PC material second layer (Layer C) combined with a 2 mm and 3 mm thick 10% CCB / PBT first layer (Layer A) provides reflectivity as low as 15%, while transmittance is less than 6%, even less than 3%. Clearly, reducing the thickness increases transmittance. This reduces the possible combinations at a thickness of 1.5 mm to a second layer (Layer C) between 0.4 mm and 0.6 mm to meet the desired performance, while no solution was found at a total thickness of 1 mm.

[0146] Increasing ε' and ε” to higher values, the first layer (layer A) now appears to offer a solution where a 0.4mm PBT / PC resin second layer (layer C) is combined with a 0.6mm 14.5wt.% CCB / PBT first layer (ε' = 15.6538, ε” = 12.2659) (layer A). Figure 9 Theoretical calculations were performed to find a combination that provides less than 15% reflectivity and less than 6% transmittance. Since most injection-molded products have wall thicknesses of 1.5 mm to 4 mm, and most applications have wall thicknesses between 2 mm and 3 mm, the main calculations for varying ε' and ε” between the top and bottom layers were performed at a total thickness of 2 mm, representing a worst-case scenario that satisfies the transmittance requirements. Typically, reflection appears to vary with the Dk of the second layer (layer C) material, and for materials with Dk greater than 5, a reflection below 15% seems impossible. Therefore, only materials with Dk less than or equal to 5 are considered for the second layer (layer C). This is combined with materials with higher conductivity and a preferred Df loss factor (first layer / layer A), for which materials with Dk greater than or equal to 6 are considered.

[0147] Analysis of Dk and Df data for pure resin and CB-filled resin shows that for materials with Dk values ​​of 2 to 3.5, Df varies between 0.001 and 0.02. For materials with Dk values ​​of 3.5 to 4.5, Df varies between 0.015 and 0.1. For materials with Dk values ​​of 4.5 to 5, Df varies between 0.015 and 0.25, while for materials with Dk values ​​of 6 to 10, Df varies from 0.08 to 0.4. For materials with Dk values ​​greater than 10, Df varies from 0.25 to above 1. Using these Dk and Df boundaries, and in some cases intermediate Df values, for the top layer (layer C) with Dk values ​​ranging from 2 to 5... Figure 2A The material and Dk are between 6 and 15 for the bottom layer (layer A). Figure 2A The material combinations were calculated (Table 8). Theoretical calculations were performed on a 2mm thick double-layer component. The Dk of the first or top layer (layer C) was 2-5, while the Dk of the second or bottom layer (layer A) was 6-15. The thickness of the top layer varied from 0.1mm to 1mm in discrete steps of 0.1mm. Table 8 ( Figure 10 The results of these calculations are shown for a component with a total thickness of 2 mm, where the thickness of the first layer varies between 0.1 mm and 1 mm with a discrete step size of 0.1 mm. For a system with a total thickness of 2 mm (having a first layer of 1.6 mm thickness and a second layer of 0.4 mm thickness), the ε" vs. total transmittance plot for the first layer of the double-layer system is shown. "N" indicates that no solution meeting the requirements could be found. If a solution with less than 15% reflection and less than 6% transmittance can be found for a certain combination of Dk / Df materials, the entry is indicated as "Y".

[0148] Generally, a reflectance of less than 15% is relatively easy to achieve, especially when the thickness of the second layer (layer C) is between 0.3 mm and 0.7 mm. Achieving a transmittance of less than 6% with a total wall thickness of 2 mm is more difficult. A transmittance of less than 6% is only acceptable when the underlying material has a high ε” or loss factor. Figure 11A and Figure 11B Transmission is shown as a function of ε”; only solutions with ε” greater than 2.4 are obvious. Figure 11B (Characteristically, this is characterized by an enlarged Y-axis). Therefore, using a substrate with a higher ε” will reduce transmission.

[0149] Generally, as wall thickness decreases, a higher ε” is required, but as wall thickness increases, a first layer (layer A) with a lower ε” can also provide a solution. This is in Figures 12A-12FA molded part with a second layer (layer C) having a Dk of 2 and a Df of 0.001 and a first layer (layer A) having a Dk of 6 and a varying ε” has been demonstrated. It can be inferred that at 2 mm (and disregarding the thickness of the second layer), no combination exhibits less than 15% reflection and less than 6% transmission. Increasing the total thickness to 3 mm provides a solution if the ε” of the first layer (layer A) is 2.0 or higher. Further increasing the total thickness to 4 mm shows that even with an ε” of 1.5 for the first layer (layer A), the requirements for low reflection and low transmission are met.

[0150] Initial analysis of the performed calculations indicates that reflection is primarily determined by the Dk of the second layer of C material. For example... Figure 13A and Figure 13B As shown, the Df of the second layer material has little or no effect on reflectivity. Furthermore, the data also indicate that a mismatch between the Dk of the second layer (layer C) and the first layer (layer A) significantly affects reflection. For multilayer components providing less than 15% reflectivity, a Dk of approximately 0.2 to 0.6 is required. 第二层 / Dk 第一层 The ratio provides the best results.

[0151] Based on the observed results, reflection is primarily controlled by the Dk of the top layer material. The lowest reflectance values ​​were obtained using a second layer of C with a thickness of 0.3 mm to 0.7 mm, where Dk... 第二层 / Dk 第一层 The ratio is between 0.2 and 0.6. Transmission is mainly determined by the ε” of the underlying material and the total thickness. For a total thickness of 4 mm, the first layer (layer A) material with ε” greater than 1 performs best; for a total thickness of 3 mm, the first layer (layer A) material with ε” greater than 1.5 performs best; and for a total thickness of 2 mm, the first layer (layer A) material with ε” greater than 2.4 performs best.

[0152] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. After reviewing the above description, those skilled in the art may use other embodiments. An abstract is provided to allow the reader to quickly determine the nature of this disclosure. The abstract is provided on the premise that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, in the above detailed description, various features may be grouped together to simplify the disclosure. This should not be construed as meaning that any unclaimed disclosed features are necessary for any claim. Rather, the subject matter of the invention may lie in fewer features than all of the particular disclosed embodiments. Therefore, the appended claims are hereby incorporated as examples or embodiments into the detailed description, wherein each claim exists independently as a separate embodiment, and such embodiments are contemplated to be combined with each other in various combinations or arrangements. The scope of this disclosure should be determined by reference to the appended claims and the full scope of their equivalents.

[0153] It will be apparent to those skilled in the art that various modifications and variations may be made to this disclosure without departing from its scope or spirit. Other embodiments of this disclosure will become apparent to those skilled in the art upon consideration of this specification and practice with respect to the disclosure herein. The specification and examples are intended to be regarded as exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0154] The scope of patentability of this disclosure is defined by the claims and may include other instances that may occur to those skilled in the art. Such other instances are intended to fall within the scope of the claims if they have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims.

Claims

1. A double-layer component, comprising: The first layer comprises a first polymer composition comprising a first polymer and 0.1 wt.% to 30 wt.% of a first conductive carbon-based filler; A second layer is disposed adjacent to the surface of the first layer, wherein the second layer comprises a second polymer composition comprising a second polymer and 0.01 wt.% to 10 wt.% of a second conductive carbon-based filler. When the bilayer component is oriented such that microwave radiation is incident on the second layer of the bilayer component, when observed according to the free-space method at frequencies from 77 GHz to 81 GHz, the bilayer component exhibits a reflected power percentage of less than 15% and a transmitted power percentage of less than 6% as measured in transmission mode. when tested using a split post dielectric resonator (SPDR) and network analyzer on a molded sample of the first polymer of the first layer and the second polymer of the second layer separately at a fixed frequency, wherein the dielectric constant (Dk) of the second layer is 2 to 5, and wherein the ratio of the Dk of the second layer to the Dk of the first layer (Dk 第二层 / Dk 第一层 ) is 0.2 to 0.6, The thickness ratio of the first layer to the second layer is between 1:1 and 20:1, and The combined weight percentage of all components does not exceed 100 wt.%, and all weight percentages are based on the total weight of the first polymer composition or the second polymer composition.

2. The double-layer component according to claim 1, wherein the thickness of the second layer is less than 0.8 mm.

3. The double-layer component according to claim 1, wherein the thickness of the second layer is 0.2 mm to 0.7 mm.

4. The double-layer component according to claim 1, wherein the thickness of the first layer is greater than 0.8 mm.

5. The double-layer component according to claim 1, wherein the total thickness of the double-layer component is less than 3.5 mm.

6. The double-layer component according to any one of claims 1-5, wherein the first polymer or the second polymer comprises polyester, polycarbonate, polyamide, polyphenylene ether, polypropylene, or a combination thereof.

7. The double-layer component of claim 5, wherein the first polymer or the second polymer comprises polyester.

8. The double-layer component according to any one of claims 1-5, wherein the amount of the first conductive carbon-based filler in the first layer is greater than the amount of the second conductive carbon-based filler in the second layer.

9. The double-layer component according to any one of claims 1-5, wherein the first conductive carbon-based filler and the second conductive carbon-based filler comprise carbon fiber, carbon powder, graphite, graphene, carbon sheet, carbon nanotube or a combination thereof.

10. The double-layer component according to any one of claims 1-5, wherein the double-layer component is formed by a 2K injection molding process.

11. The bilayer component according to any one of claims 1-5, wherein when molded samples of the first polymer of the first layer and the second polymer of the second layer are tested at a frequency of 77 GHz using a split-pillar dielectric resonator (SPDR) and a network analyzer, the ratio of Dk of the second layer to Dk of the first layer (Dk...) is... 第二层 / Dk 第一层 The value ranges from 0.2 to 0.

6.

12. Multi-layered components, which consist of the following composition: The first layer, wherein the first layer comprises a first polymer composition, the first polymer composition comprising a first polymer and 0.1 wt.% to 30 wt.% of a first conductive carbon-based filler; A second layer is disposed adjacent to the surface of the first layer, wherein the second layer is composed of a second polymer composition comprising a second polymer and 0.01 wt.% to 10 wt.% of a second conductive carbon-based filler; and Optionally, an intermediate third layer connects the first and second layers, wherein the intermediate third layer is composed of an adhesive such that the adhesive is disposed between the first and second layers. When the multilayer component is oriented such that microwave radiation is incident on the second layer of the multilayer component, when observed according to the free-space method at frequencies from 77 GHz to 81 GHz, the multilayer component exhibits a reflected power percentage of less than 15% and a transmitted power percentage of less than 6% as measured in transmission mode. When molded samples of the first polymer in the first layer and the second polymer in the second layer are tested at a fixed frequency using a split-pillar dielectric resonator (SPDR) and a network analyzer, the dielectric constant (Dk) of the second layer is between 2 and 5, and the ratio of Dk of the second layer to Dk of the first layer (Dk... 第二层 / Dk 第一层 The value ranges from 0.2 to 0.

6. The thickness ratio of the first layer to the second layer is between 1:1 and 20:1, and The combined weight percentage of all components does not exceed 100 wt.%, and all weight percentages are based on the total weight of the first polymer composition or the second polymer composition.

13. The multilayer component of claim 12, wherein the multilayer component includes the intermediate third layer, and wherein the adhesive is composed of acrylate.

14. The multilayer component of claim 12, wherein the multilayer component includes the intermediate third layer, and wherein the thickness of the intermediate third layer is from 10 micrometers to 100 micrometers.

15. The multilayer component according to any one of claims 12-14, wherein when molded samples of the first polymer of the first layer and the second polymer of the second layer are tested at a frequency of 77 GHz using a split-pillar dielectric resonator (SPDR) and a network analyzer, the ratio of Dk of the second layer to Dk of the first layer (Dk...) is... 第二层 / Dk 第一层 The value ranges from 0.2 to 0.6.

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