Multilayer conductor, method for its manufacture and assembly comprising the multilayer conductor

Abstract

A multilayer conductor comprises a conductor layer and a dielectric layer on the conductor layer. The dielectric layer comprises a polymer composition with a loss factor (Df) of less than 0.001 and includes a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof. The materials described here can advantageously provide improved adhesion between the conductor and the dielectric layer. Methods for fabricating the multilayer conductor are also described. The multilayer conductor can be useful in the fabrication of magnetic self-resonance structures.

Description

REFERENCE TO RELATED REGISTRATION

[0001] This application claims priority over the preliminary US patent application No. 63 / 461,399, filed on April 24, 2023, the contents of which are hereby incorporated in full by reference. BACKGROUND

[0002] Inductive wireless power transfer offers a method for powering and charging mobile electronic devices, such as smartphones. Ideally, this technology should be highly efficient and easy to manufacture, for example, using a cost-effective method for large-scale production. Such a technology could enable the powering and charging of high-performance equipment, including electric passenger cars, forklifts, material handling equipment, buses, and autonomous transport vehicles.

[0003] Existing methods for inductive wireless power transmission can utilize a magnetic self-resonance structure. These structures can comprise a multitude of structured and interconnected conductors, maintaining the same distance to the z-axis between each set of conductors. Previously, materials used to fabricate such structures were limited by the material requirements (e.g., electrical performance and dielectric strength) for specific applications.

[0004] Therefore, it would be desirable to expand the range of materials suitable for this application. A further advantage would be the improved adhesion between the conductor metal and the dielectric layer. Such structures could be particularly well-suited as magnetic self-resonance structures for inductive wireless power transmission applications. SUMMARY

[0005] A multilayer conductor comprises a conductor layer and a dielectric layer on the conductor layer, wherein the dielectric layer comprises a polymer composition having a loss factor (Df) of less than 0.001 and includes a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof; and wherein an interface between the conductor layer and the dielectric layer has a peel strength of at least 5 pound-force per linear inch (PLI) (0.88 kilonewtons per meter).

[0006] A method for producing the multilayer conductor, comprising: applying a coating composition, comprising a polymer composition having a loss factor (Df) of less than 0.001 and comprising a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof, and a solvent, to the first layer; removing the solvent to provide a coated conductor with a surface coated with the polymer composition; contacting the coated conductor with the dielectric layer to provide a composite comprising the conductor layer and the dielectric layer, wherein a coated surface of the coated conductor is in direct contact with the dielectric layer; wherein the dielectric layer comprises the same polymer composition as the coating composition.

[0007] Another aspect of the present disclosure is an assembly comprising the multilayer conductor, wherein the assembly is preferably a magnetic self-resonance structure.

[0008] The features described above and others are illustrated by the figures below and the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following figures represent exemplary embodiments. Fig. Figure 1 shows a top view of a magnetic self-resonance structure (MSRS) coil with a structured conductor connected to a dielectric material. Fig. Figure 2 shows a cross-section of an MSRS coil with multiple layers of structured conductor structures connected to a dielectric material. Fig.Figure 3 shows a coated conductor in contact with a dielectric layer to provide a composite according to one aspect of the present disclosure. Fig. Figure 4 shows a first and a second multilayer conductor structure which can be laminated to provide a final multilayer conductor structure according to one aspect of the disclosure. DETAILED DESCRIPTION

[0010] A key challenge in providing bonded conductor-dielectric structures is bonding the resin to the conductor. The inventors unexpectedly discovered that certain materials can be used as dielectric layers in a multilayer conductor when prepared according to the present disclosure. In particular, the inventors advantageously developed a method for producing a multilayer conductor wherein the conductor is pre-coated with a specific thin film layer. The thin film layer can act as an adhesive and improve the bond between the conductor and the dielectric layer. Furthermore, the advantage is that, due to the range of dielectric constants of the dielectric materials found to be useful here, the number of layers required to achieve the electrical resonance of the target operating frequency can be modified.The present disclosure therefore represents a significant improvement.

[0011] Accordingly, one aspect of the present disclosure is a multilayer conductor. The multilayer conductor comprises a conductor layer and a dielectric layer on the conductor layer. If multiple conductor layers or dielectric layers are present, they are arranged alternately. In one aspect, the multilayer conductor comprises two conductor layers and a dielectric layer placed between them. In another aspect, the multilayer conductor comprises multiple conductors and multiple dielectric layers, with the conductor layers and the dielectric layers arranged alternately.

[0012] The dielectric layer of the multilayer conductor comprises a polymer composition. This polymer composition has a loss factor of less than 0.001. The polymer composition includes a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof.

[0013] In some aspects, the polymer composition may optionally include a reinforcing filler. The reinforcing filler may generally comprise any suitable material. In one aspect, the reinforcing filler may have a high aspect ratio (e.g., an aspect ratio greater than 1:1, 5:1, 10:1, 20:1, or 40:1). For example, the reinforcing filler may comprise nanofibers or nanoplates. Preferred reinforcing materials are non-electrically conductive. Non-conductive particles are defined as those with a resistivity greater than 1 × 10⁻⁶. 8 Ohm. In one aspect, an electrically conductive filler can be excluded from the core layer.

[0014] Examples of reinforcing fillers include mica, quartz, glass, calcium silicate, aluminum silicate, zirconium silicate, aluminum silicates, titanium dioxide, barium titanate, calcium carbonate, calcium sulfate, iron oxide, lithium aluminum silicate, silicon carbide, magnesium silicate, zirconium oxide, or a combination thereof. The reinforcing fillers can optionally be treated on the surface to improve adhesion and dispersion with the core layer.

[0015] In one aspect, the reinforcing filler may preferably be a fibrous reinforcing filler, for example, glass fibers. Glass fibers may include E-, A-, C-, ECR-, R-, S-, D-, or non-ferrous glass, or the like. The reinforcing fillers may be provided in the form of monofilament or multifilament fibers and may be used individually or in combination with other fiber types, for example, by co-weaving or core / sheath, side-by-side, orange-type, or matrix and fibril constructions, or by other methods known to a person skilled in the art of fiber production. Fibrous fillers may be formed, for example, in the form of rovings, woven fiber reinforcements such as 0-90 degree fabrics or the like, non-woven fiber reinforcements such as continuous strand mats, cut strand mats, woven fabrics, papers, and felts, or the like. In one aspect, the reinforcing filler, if present, may include glass fibers.

[0016] If present, reinforcing fillers may be included in the polymer composition in such an amount as, for example, more than 0 to 30 percent by weight, or 1 to 30 percent by weight, or 5 to 25 percent by weight, or 10 to 20 percent by weight, in each case based on the total weight of the polymer composition of the dielectric layer.

[0017] In one specific aspect, the dielectric layer comprises a cyclic olefin copolymer. Cyclic olefin copolymers generally consist of repeating monomer units derived from cyclic and acyclic olefins, or ring-opening polymers based on cyclic olefins. Examples of cyclic olefins include, but are not limited to, norbornene-based olefins, tetracyclododecene-based olefins, dicyclopentadiene-based olefins, and derivatives thereof. Derivatives include alkyl (preferably C1-20 alkyl, more preferably C1-10 alkyl), alkylidenes (preferably C1-20 alkylidenes, more preferably C1-10 alkylidenes), aralkyl (preferably C6-30 aralkyl, more preferably C6-18 aralkyl), cycloalkyl (preferably C3-30 cycloalkyls, more preferably C3-18 cycloalkyls), ether-, acetyl-, aromatic-, ester-, hydroxy-, alkoxy-, cyano-, amide-, imide- and silyl-substituted derivatives.

[0018] In one aspect, the cyclic olefin copolymer can exhibit a melt volume flow rate of 1 to 50 cm³ per 10 minutes. In another aspect, the cyclic olefin copolymer can exhibit a glass transition temperature greater than 125 °C. In another aspect, the cyclic olefin copolymer can exhibit a relative permittivity greater than 2 at 1 to 10 kilohertz (kHz). In another aspect, the cyclic olefin copolymer can exhibit a loss factor of less than 0.001 at 1 gigahertz (GHz).

[0019] In one specific aspect, the cyclic olefin copolymer can be an ethylene / norbornene cyclic olefin copolymer. In another aspect, the cyclic olefin copolymer can have a melt flow rate of 40 to 50 grams per 10 minutes (g / 10 minutes) at 260 °C under a load of 2.16 kilograms and a glass transition temperature of 270 to 275 °C, determined according to ISO 11357-1. In yet another aspect, the cyclic olefin copolymer can have a melt volume rate of 1 to 10 cubic centimeters per 10 minutes (cm³ / 10 minutes) at 260 °C under a load of 2.16 kilograms according to ISO 1133 and a glass transition temperature of 150 to 165 °C, determined according to ISO 11357-1.

[0020] In one aspect, the dielectric layer can comprise a combination of two or more cyclic olefin copolymers. For example, in one aspect, the dielectric layer can comprise a first cyclic olefin copolymer and a second cyclic olefin copolymer. The first and second cyclic olefin copolymers can differ in their chemical composition, molecular weight, or a combination thereof. In a specific aspect, the first cyclic olefin copolymer and the second cyclic olefin copolymer can be present in a weight ratio of 1:99 to 99:1, or 5:95 to 95:5, or 5:95 to 50:50, or 5:95 to 20:80, or 5:95 to 15:85.

[0021] In one specific aspect, the dielectric layer can comprise a first cyclic olefin copolymer with a melt volume rate of 5 to 15 cm³ / 10 minutes at 260 °C under a load of 2.16 kilograms according to ISO 1133 and a glass transition temperature of 135 to 150 °C, determined according to ISO 11357-1; and a second cyclic olefin copolymer with a melt volume rate of 5 to 15 cm³ / 10 minutes. 3 / 10 minutes at 260 °C under a load of 2.16 kilograms according to ISO 1133 and a melting temperature of 80 to 900 °C, determined according to ISO 11357. In one embodiment, the first cyclic olefin copolymer can comprise an ethylene-norbornene copolymer. In one embodiment, the second cyclic olefin copolymer can be a cyclic olefin copolymer elastomer. In one embodiment, the second cyclic olefin copolymer can comprise an ethylene-norbornene copolymer.

[0022] In one embodiment, the dielectric layer may comprise a cyclic olefin copolymer in combination with a polymer other than the cyclic olefin copolymer. If present, the polymer other than the cyclic olefin copolymer has a loss factor (Df) of less than 0.001 and preferably comprises a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof. In a specific aspect, the polymer other than the cyclic olefin copolymer comprises a transoctenamer rubber, as further explained below. When present in combination, the cyclic olefin copolymer and the polymer different from the cyclic olefin polymer can be present in the dielectric layer in a weight ratio of 10:90 to 90:10 or 50:50 to 90:10 or 60:40 to 80:20 or 65:35 to 75:25.

[0023] Examples of cyclic olefin copolymers are commercially available, such as TOPAS 5013S-04, TOPAS 5013S-04, TOPAS 6013M-07 and TOPAS ELASTOMER E-140 from TOPAS Advance Polymers, those under the trade name APEL from Mitsui Chemical Co., those under the trade name ZEONEX from ZEON Corp., those under the trade name ZEONOR from ZEON Corp. and those under the trade name ARTON from JSR Corp.

[0024] In one embodiment, the dielectric layer can comprise a transoctenamer rubber. As used here, transoctenamer rubber refers to a resin produced by the polymerization of cyclooctene, wherein a double bond exists between two units of eight repeating methylene groups. The term "trans" refers to the trans-cis ratio of the resin's double bonds. As used here, a transoctenamer rubber has a high trans content, for example, a trans-cis ratio of at least 50:50, or at least 60:40, or at least 70:30, or at least 75:25, or 70:30 to 90:10, or 75:25 to 90:10, or 75:25 to 85:15. As is known to those skilled in the art, the trans-cis ratio of the double bonds influences the crystallinity of the polyoctenamer. In general, increasing trans content results in greater crystallinity and consequently a higher melting temperature.In one embodiment, the transoctenamer rubber can have a crystallinity of at least 10%, or at least 20%, or at least 25%, or 20 to 40%, or 25 to 40%. The transoctenamer rubber can have a melting point of more than 40°C, or more than 50°C, or 50 to 100°C, or 50 to 80°C, or 50 to 60°C.

[0025] Methods for producing a polyoctenamer resin are disclosed, for example, in US Patent No. 3,798,185, US Patent No. 3,849,509, US Patent No. 4,095,033, US Patent No. 3,804,804 and US Patent No. 3,836,593, the contents of which are hereby incorporated in full by reference for all purposes.

[0026] In a specific aspect, transoctenamer rubber can have a trans content of 70 to 90% or 75 to 85%, a molecular weight of 75,000 to 125,000 grams per mole (g / mol) or 90,000 to 110,000 g / mol and a melting temperature of 50 to 60 °C.

[0027] Transoctenamer rubbers suitable for use in the dielectric layer according to the present disclosure are commercially available, for example under the trade name VESTENAMER from Evonik.

[0028] In one aspect, the dielectric layer can comprise the transoctenamer rubber in combination with a polymer other than the transoctenamer rubber. If present, the polymer other than the transoctenamer rubber has a loss factor (Df) of less than 0.001 and preferably comprises a cyclic olefin copolymer, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof. For example, the dielectric layer can comprise the cyclic olefin copolymer and the transoctenamer rubber. When present in combination, the cyclic olefin copolymer and the transoctenamer rubber in the dielectric layer can be in a weight ratio of cyclic olefin copolymer:transoctenamer rubber of 10:90 to 90:10 or 50:50 to 90:10 or 60:40 to 80:20 or 65:35 to 75:25.

[0029] In one embodiment, the dielectric layer can comprise the syndiotactic polystyrene. The syndiotactic polystyrene can be a syndiotactic polystyrene homopolymer or copolymer. As used herein, the term "syndiotactic" refers to polymers exhibiting a stereoregular structure of a racemic triad greater than or equal to 80% syndiotactic, preferably greater than or equal to 90% syndiotactic, or greater than or equal to 95% syndiotactic, or 80 to 100% syndiotactic, or 90 to 100% syndiotactic, or 95 to 100% syndiotactic, for example, as determined by 13 C-13 nuclear magnetic resonance spectroscopy (NMR). Typical polymerization processes for the production of syndiotactic polystyrene are well known in the industry and are described, for example, in US patents Nos. 4,680,353, 5,066,741, 5,206,197 and 5,294,685, the contents of which are hereby incorporated by reference.

[0030] Suitable syndiotactic polystyrene is commercially available, for example under the trade name XAREC from Idemitsu.

[0031] In one specific aspect, the dielectric layer can comprise the syndiotactic polystyrene and a reinforcing filler, preferably glass fibers. If present, the reinforcing filler can be in an amount greater than 0 to 30% by weight, or 1 to 30% by weight, or 5 to 25% by weight, or 10 to 20% by weight, respectively, based on the total weight of the syndiotactic polystyrene and the reinforcing filler.

[0032] In one embodiment, the dielectric layer can comprise a polymethylpentene olefin copolymer. The polymethylpentene olefin copolymer comprises a 4-methyl-1-pentene homopolymer or a 4-methyl-1-pentene / α-olefin statistical copolymer containing 80 to 99.9 wt., preferably 90 to 99.9 wt., repeating units derived from 4-methyl-1-pentene and 0.1 to 20 wt., preferably 0.1 to 10 wt., an α-olefin having 2 to 20, preferably 6 to 20, carbon atoms. The polymethylpentene olefin copolymer described herein is unmodified. The term "unmodified" means that the polymer does not contain any grafting agents acting upon it to modify its polymer matrix.

[0033] In the case of the statistical copolymer of 4-methyl-1-pentene / α-olefin, the α-olefin copolymerized with 4-methyl-1-pentene can be an α-olefin with 2 to 20, preferably 6 to 20, carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, or 1-eicosene. For copolymerization with 4-methyl-1-pentene, these α-olefins can be used individually or in combination of two or more types.

[0034] In one embodiment, the polymethylpentene olefin polymer can have a melt flow rate (MFR: ASTM D1238, 260 °C, 5.0 kilogram (kg) load) of 0.1 to 200 grams per 10 minutes (g / 10 min), preferably 1 to 150 g / 10 min. In one aspect, the polymethylpentene olefin polymer can have a dielectric constant greater than 1 at 1 megahertz (MHz), preferably greater than or equal to 2 at 1 MHz. In another aspect, the polymethylpentene olefin polymer can have a loss factor of less than 0.001 at 1 GHz or less than 0.0005 at 1 kHz.

[0035] In one specific aspect, the polymethylpentene olefin copolymer can be a statistical 4-methyl-1-pentene / α-olefin copolymer containing 90 to 95% by weight, based on the total weight of the copolymer, repeating units derived from 4-methyl-1-pentene and 5 to 10% by weight of repeating units derived from C 16-18 -olefins are derived from it. The polymethylpentene olefin copolymer can exhibit a melt flow rate of 20 to 25 grams per 10 minutes, determined at 260 °C under a load of 5 kilograms.

[0036] Exemplary polymethylpentene olefin copolymers suitable for use in the present disclosure include those available from Mitsui Chemicals, Inc. as TPXMX001, MX002, MX004, MX021, MX321, RT18 and DX845.

[0037] In one embodiment, the dielectric layer can minimize or exclude polymers other than the cyclic olefin copolymer, transoctenamer rubber, syndiotactic polystyrene, and polymethylpentene olefin copolymer. For example, any suitable polymer other than the cyclic olefin copolymer, transoctenamer rubber, syndiotactic polystyrene, and polymethylpentene olefin copolymer can be present in the dielectric layer in an amount of 5% or less by weight, 1% or less by weight, or 0.1% or less by weight, in each case based on the total weight of the dielectric layer. In another embodiment, polymers other than the cyclic olefin copolymer, transoctenamer rubber, syndiotactic polystyrene, and polymethylpentene olefin copolymer can be excluded from the dielectric layer.

[0038] In one embodiment, the dielectric layer can include a cross-linked section at an interface between the dielectric layer and the conductor layer. For example, the cross-linked section can extend up to 25 micrometers into the dielectric layer from the interface. In another embodiment, the cross-linked section, if present, can extend 5 to 25 micrometers into the dielectric layer from the interface.

[0039] Advantageously, the interface between the conductor layer and the dielectric layer can exhibit significantly improved adhesion strength. For example, the interface between the conductor layer and the dielectric layer can have a peel strength of at least 5 pounds of force per linear inch (PLI) (876 newtons per meter).

[0040] The multilayer conductors described here can generally have any suitable shape, including, for example, rectangular, tubular, cylindrical, C-shaped, or spirally wound. In one embodiment, the multilayer conductor can, for example, be wound in a spiral shape for use in an induction coil or a transformer.

[0041] Fig. Figure 1 shows a top view of a multilayer conductor (100) wound in a spiral shape or coil, wherein the dielectric material (102) is arranged alternately with structured conductor (101). Fig. Figure 2 shows a cross-sectional view of a multilayer conductor, including alternating layers of structured conductor (201) and dielectric material (202). While in Fig.Since two four layers of each material are shown, it is understood that the number of layers can be selected based on the identity of each layer and the corresponding material properties, the thickness of each layer, and the end application. A suitable number of layers can be determined by a person skilled in the art taking into account the present disclosure.

[0042] A method for manufacturing the multilayer conductor represents a further aspect of the present disclosure. The method described here can advantageously enable an improved connection between a conductor layer and a dielectric layer of a multilayer conductor, particularly between materials that typically do not adhere well with previously known methods.

[0043] The process according to the present disclosure can be described as in Fig.Figure 3 is shown. The process involves applying a coating composition to a conductive layer. The coating composition comprises a polymer composition and a solvent. The polymer composition has a loss factor (D). f ) of less than 0.001 and comprises a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer, or a combination thereof. All previously discussed variations in polymer composition for the dielectric layer also apply to the polymer composition of the present coating composition.

[0044] The solvent comprises an organic solvent capable of dissolving the polymer composition. Suitable solvents can be selected by a person skilled in the art based on the chemical composition of the polymer composition and taking into account the present disclosure. Exemplary solvents for providing the coating composition may include, among others, aromatic hydrocarbon solvents such as toluene, xylene, and the like. In one aspect, the solvent is toluene.

[0045] The coating composition may comprise the polymer composition in an amount of 1 to 50% by weight, or 5 to 40% by weight, or 5 to 30% by weight, or 5 to 20% by weight, or 5 to 15% by weight, based on the total weight of the coating composition. Conversely, the solvent may be present in the coating composition in an amount of 50 to 99% by weight, or 60 to 95% by weight, or 70 to 95% by weight, or 80 to 95% by weight, or 85 to 95% by weight, in each case based on the total weight of the coating composition.

[0046] The coating composition may optionally include one or more additives, such as a reactive monomer, a source of free radicals, or both. A reactive monomer and a source of free radicals may be included if crosslinking is desired after the coating composition is applied to the conductor.

[0047] The coating composition can be applied to the conductor layer using any suitable coating process, such as dip coating, spin coating, drop coating, doctor blade coating, slot die coating, and the like. Specifically, slot die coating can be used for this purpose.

[0048] The conductor can be any suitable conductive material and may preferably comprise copper or aluminum. In one aspect, the conductor comprises copper.

[0049] Following the application of the coating composition to the conductor (301), the process includes removing the solvent to provide a coated conductor. As described in Fig. As shown in Figure 3, the coated conductor (304) comprises the conductor (301) having a surface that is at least partially coated with the polymer composition (305) (which is present as a thin layer after removal of the solvent). In one embodiment, the coated conductor can comprise the polymer composition arranged thereon with a thickness of 5 to 25 micrometers, for example 6 to 25 micrometers.

[0050] As in Fig.As shown in Figure 3, the coated conductor (304) is in contact with a dielectric layer (302) to form a multilayer conductor (300) comprising the conductor layer (301) and the dielectric layer (302) (which is known to comprise a combination of the polymer composition coating (305) and the dielectric layer (303)), wherein the coated surface of the coated conductor is in direct contact with the dielectric layer. In one embodiment, a coated conductor can be in contact with each side of a dielectric layer (i.e., two coated conductors are in contact with a dielectric layer to form a sandwich structure). The coated surface of each coated conductor is in direct contact with the dielectric layer.

[0051] Preferably, the dielectric layer comprises the same polymer composition as the coating composition. Without being bound to any particular theory, it is assumed that the pre-coating step with the coating composition enables the improved adhesion of the special dielectric layers described herein. For example, the interface between the conductor layer and the dielectric layer can exhibit a peel strength of at least 5 pounds per linear inch (PLI).

[0052] Bonding the coated conductor to the dielectric layer can, in one aspect, involve laminating the coated conductor onto the dielectric layer. Lamination can be performed under heat and / or pressure for a duration sufficient to bond the coated conductor to the dielectric layer. For example, laminating the coated conductor onto the first dielectric layer can be carried out at a pressure of 50 to 200 pounds per square inch (PSI; 0.34 to 1.38 megapascals (MPa)), or 50 to 150 PSI (0.34 to 1.03 MPa), or 75 to 125 PSI (0.52 to 0.86 MPa), or 100 to 110 PSI (0.69 to 0.76 MPa). a temperature of 100 to 500 °F (37.8 to 260 °C) or 200 to 400 °F (93.3 to 204.4 °C) or 300 to 400 °F (148.9 to 204.4 °C) or 350 to 375 °F (176.7 to 190.6 °C), and for a duration of 1 to 60 minutes or 10 to 45 minutes or 15 to 45 minutes or 20 to 40 minutes or 25 to 35 minutes.

[0053] The process may involve repeating the steps of depositing and contacting to provide a multilayer conductor with a predetermined number of layers, with the conductor and dielectric layers arranged alternately.

[0054] In a further advantageous feature, the multilayer conductor does not include any material with a dielectric strength lower than that of the polymer composition (e.g., the dielectric layer). For example, the multilayer conductor preferably has no air gaps between the conductor and the dielectric layer that could lead to reduced performance.

[0055] With reference to Fig.4. The method described here can be used in one aspect to provide a first multilayer conductor (400) comprising a first dielectric layer (402) with a coated conductor (401, 501) arranged on each side of the first dielectric layer (i.e., forming a sandwich-like multilayer structure where the layers are arranged in the following order: conductor (401) - first dielectric layer (402) - conductor (501)). A second multilayer conductor (500) can be provided comprising a second dielectric layer (502) with a coated conductor (601, 701) arranged on each side of the second dielectric layer (i.e., forming a sandwich-like multilayer structure where the layers are arranged in the following order: conductor (601) - second dielectric layer (502) - conductor (701)).

[0056] The first dielectric layer and the second dielectric layer can be the same or different. The first multilayer conductor and the second multilayer conductor can be positioned on either side of an adhesive layer (403) and stacked together to form a multilayer stack (600) with layers in the following order: conductor - first dielectric layer - conductor - adhesive - conductor - second dielectric layer - conductor. It is understood that any suitable number of multilayer conductors can be laminated together to form a multilayer stack with a desired number of layers.

[0057] As in Fig. As shown in Figure 4, the conductors can optionally be structured conductors, with a variety of features (404) on an outer surface of each conductor.

[0058] In one embodiment, a multilayer conductor can be produced by laminating the first and second multilayer conductors (i.e., from Fig. 4) are formed. Laminating the first and second multilayer conductors can be accomplished by laminating the adjacent conductor layers (e.g., 501 and 601) using an additional dielectric material or an adhesive (403). Preferably, the spacing between the conductor layers is maintained (i.e., in one aspect, the thickness of the adhesive (403) can be within 10% of the thickness of the dielectric layers (402, 502)).

[0059] The multilayer conductor of the present disclosure can be particularly useful in magnetic self-resonance systems (MSRS). Accordingly, an assembly comprising the multilayer conductor represents a further aspect of the present disclosure. Preferably, the assembly is an MSRS device.

[0060] In one aspect, the multilayer conductor may be contained in an assembly that includes a magnetic core adjacent to at least a portion of the multilayer conductor. The magnetic core may contribute to confining the magnetic field. In another aspect, a cylindrical magnetic core may be arranged at the center of a multilayer conductor wound into a spiral or coil. In yet another aspect, the multilayer conductor comprises a plurality of conductor layers and dielectric layers arranged concentrically around a common axis, with the conductor layers and dielectric layers alternating. The magnetic core may further include a central post, and the common axis forms a loop around the central post and around a central axis of the multilayer conductor. In some aspects, the multilayer conductor may have a toroidal or cylindrical shape.The assembly can further include an AC power source that is electrically coupled to at least one of the conductor layers of the multilayer conductor. Such assemblies can be particularly useful in wireless power transmission applications.

[0061] This revelation is further illustrated by the following examples, which are not limiting. EXAMPLES Examples 1-19: Dielectric characterization of polymer compositions

[0062] The materials used in the examples below are described in Table 1. Table 1 component Chemical description Suppliers COC1 Cyclic olefin copolymer, available as TOPAS 5013S-04 TOPAS Advance Polymers COC2 Cyclic olefin copolymer, available as TOPAS 6015S-04 TOPAS Advance Polymers COC3 Cyclic olefin copolymer, available as TOPAS 6013M-07 TOPAS Advance Polymers COC4 Cyclic olefin copolymer, available as TOPASELASTOMER E-140 TOPAS Advance Polymers GOAL Transoctenamer rubber, available as VESTENAMER8012 Evonik PS-GF Syndiotactic polystyrene with 15 wt% glass fiber filling, available as XAREC SP140 Idemitsu PMP Polymethylpentene olefin copolymer, available as TPXMX002 Mitsui PPS Polyphenylene sulfide, available as Ryton QA-200P Solvay PP-GF Homopolypropylene with 40 wt% long glass fibers, available as THERMYLENE P6-40FG-0100 Asahi PP Polypropylene, available as Pinnacle Polymers 2180H PinnaclePolymers, LLC PPE Polyphenylene ether resin, available as TEMPPECLEAR The Resin Enterprise, Inc. PEEK Polyetheretherketone, available as Ketaspire KT-880P Solvay PPE / HIPS-GF Polyphenylene ether / high-impact polystyrene blend with 15% glass fibers, available as NORYL NHP9023 SABIC PSU Polysulfone, available as UDEL P1700 Solvay PEI-Si Polyetherimide siloxane copolymer, available as SILTEMST TM1500 SABIC PEI Polyetherimide, available as ULTEM 1000 SABIC ABS Acrylonitrile butadiene styrene, available as TERLURAN GP22 INEOSStyrolution Group GmbH TPI Thermoplastic polyimide, available as EXTEM XH1015 SABIC PBT Polybutylene terephthalate, available as VALOX 325 SABIC LCP Liquid crystal polymer with a melting point of 330 °C, available as L600BB Seyang Polymer

[0063] The electrical properties of the materials listed in Table 1 were tested and are shown in Table 2. The electrical tests were performed at 1 MHz. The dielectric strength for each material is also given in Table 2. Table 2 Example 1 component Thickness for D K (in) D K ,1MHz D F ,1 MHz Tg(°C) Thickness for DS (mil) Total voltage (kV) Dielectric breakdown (V / mil) 1 COC1 0,0615 2,33 0,0003 130 17,8 21,63 1215 2 COC2 0,0664 2,34 0,0003 150 17 23,45 1379 3 COC3 / COC4 (90:10) 0,0575 2,32 0,0003 17,6 21,64 1230 4 COC4 / TOR(70:30) 0,0594 2,30 0,0005 6 / -90 17,9 19,05 1064 5 PS-GF 0,062 3,00 0,0007 95 17,3 17,2 996 6 PMP 0,0595 2,14 0,0009 93 18 23,17 1287 7* PPS 0,123 3,25 0,0010 90 15,4 17,75 1153 8* PP-GF 0,0641 2,80 0,0011 -20 20,9 11,45 548 9* PP 0,0554 2,22 0,0011 -5 16,7 20,01 1198 10* PPE 160- 0,0642 2.59 0,0012 180 25,7 22,83 888 11* PEEK 0,0572 3,21 0,0029 57,2 22,95 401 12* PPE / HIPS-GF 0,0616 2,70 0,0035 61,6 19,87 323 13* PSU 0,0633 3,05 0,0045 63,3 24,33 384 14* PEI-Si 0,1328 2,96 0,0057 N / A 15* PEI 0,123 3,14 0,0066 N / A 16* ABS 0,0635 2,79 0,0088 104 63,5 26,49 417 17* TPI 0,1311 3,52 0,0127 N / A 18* PBT 0,0555 3,12 0,0177 55,5 22,09 398 19* LCP 0,0564 3,24 0,0401 56,4 24,52 435 * indicates a comparative example

[0064] As can be seen from Table 2, the compositions according to examples 1 to 6 each exhibited a D f from less than 0.001 at 1 MHz. These materials are useful as dielectric materials, especially for magnetic self-resonance structure (MSRS) devices operating at low frequencies. Examples 20-21: Methods for joining dielectric layers to a conductor

[0065] The COC1 material was used to further demonstrate a method for improving the adhesion of the polymer material to a conductor (e.g., copper). Standard copper foil alone cannot be directly bonded to COC1. Adhesion was achieved with these materials using two methods. Example 20

[0066] In an initial bonding process, the copper foil was first coated with a dilute solution of COC1 in toluene with a solids content of 10 wt% using a roller slitting blade process to obtain an 8-micrometer-thick layer of COC1 on the surface of the copper foil. The COC1-coated copper was then bonded to a 20-micrometer-thick (0.5 mm) layer of COC1 by lamination at 100 PSI (0.69 MPa) and a temperature of 360 °F (182 °C) for 30 minutes. The resulting bond exhibited an adhesion strength of 8.2 PLI (1.4 kilonewtons per meter) when determined using a 90-degree peel tester. Example 21

[0067] In a second bonding process, the copper foil was coated with a dilute solution of a formulated composition in toluene containing 10% by weight of solids using a roller slitting blade coating process to obtain an 8-micrometer-thick film of the formulated composition on the surface of the copper foil. The formulated composition comprises COC1; A reactive monomer that can be crosslinked by radicals (e.g., a bismaleimide, styrene-butadiene deblock or triblock copolymer, zinc dimethacrylate, thioene combinations such as 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO) or pentaerythritol tetra(3-mercaptopropionate (PETMP))) and an initiator as a source of free radicals (e.g., a peroxide such as 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3 (DYBP)) in the ratio 8:2:0.1. A co-agent may also be present, for example, triallyl isocyanurate (TAIC).The formulated composition was applied to a 20-thousandth of an inch (0.5 millimeters) thick COC1 layer by laminating it for 30 minutes at 100 PSI (0.69 MPa) and a temperature of 360 °F (182 °C). The resulting composite exhibited an adhesion strength of 10.8 PLI ​​(1.9 kilonewtons per meter) as measured by a 90-degree peel tester.

[0068] These methods were used to produce composites that were tested for their adhesion strength. If a pre-coating step is omitted, a testable sample cannot be produced because the adhesion between the copper and the COC1 is insufficient (i.e., the copper does not adhere to the COC1).

[0069] The present revelation also includes the following aspects.

[0070] Aspect 1: A multilayer conductor comprising a conductor layer and a dielectric layer on the conductor layer, wherein the dielectric layer has a polymer composition with a loss factor (D f ) of less than 0.001 and comprises a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer or a combination thereof; and wherein an interface between the conductor layer and the dielectric layer has a peel strength of at least 5 pound-force per linear inch (PLI) (0.88 kilonewtons per meter).

[0071] Aspect 2: The multilayer conductor according to Aspect 1, comprising at least two conductor layers and a dielectric layer, wherein the conductor layers and the dielectric layer are arranged alternately.

[0072] Aspect 3: The multilayer conductor according to aspect 1 or 2, wherein the dielectric layer further comprises a reinforcing means, preferably wherein the reinforcing means comprises a reinforcing filler, woven glass fiber or non-woven glass fiber.

[0073] Aspect 4: The multilayer conductor according to one of aspects 1 to 3, wherein the dielectric layer comprises a cross-linked section at an interface between the dielectric layer and the conductor layer.

[0074] Aspect 5: The multilayer conductor according to aspect 4, wherein the cross-linked section extends from the interface up to 25 micrometers into the dielectric layer.

[0075] Aspect 6: The multilayer conductor according to one of aspects 1 to 5, wherein the dielectric layer comprises the cyclic olefin copolymer.

[0076] Aspect 7: The multilayer conductor from one of aspects 1 to 6, wherein the dielectric layer comprises a first cyclic olefin copolymer and a second cyclic olefin copolymer, wherein preferably the first cyclic olefin copolymer and the second cyclic olefin copolymer are present in a weight ratio of 1:99 to 99:1 or 5:95 to 95:5.

[0077] Aspect 8: The multilayer conductor according to one of aspects 1 to 7, wherein the dielectric layer comprises the transoctenamer rubber.

[0078] Aspect 9: The multilayer conductor according to one of aspects 1 to 8, wherein the dielectric layer comprises the cyclic olefin copolymer and the transoctenamer rubber, preferably in a weight ratio of cyclic olefin copolymer to transoctenamer rubber of 10:90 to 90:10 or 50:50 to 90:10 or 60:40 to 80:20 or 65:35 to 75:25.

[0079] Aspect 10: The multilayer conductor according to one of aspects 1 to 9, wherein the dielectric layer comprises the syndiotactic polystyrene.

[0080] Aspect 11: The multilayer conductor according to aspect 10, wherein the dielectric layer further comprises a reinforcing filler comprising glass fibers, wherein the reinforcing filler is preferably present in an amount of 1 to 30 percent by weight or 5 to 25 percent by weight or 10 to 20 percent by weight, based on the total weight of the dielectric layer.

[0081] Aspect 12: The multilayer conductor according to one of aspects 1 to 11, wherein the dielectric layer comprises the polymethylpentene olefin copolymer.

[0082] Aspect 13: Method for producing the multilayer conductor according to any one of Aspects 1 to 12, wherein the method comprises: applying a coating composition comprising the polymer composition and a solvent to the conductor layer; removing the solvent to provide a coated conductor with a surface coated with the polymer composition; contacting the coated conductor with the dielectric layer; wherein the dielectric layer comprises the same polymer composition as the coating composition.

[0083] Aspect 14: Method according to aspect 13, further comprising repeating the application and contacting to obtain a multilayer conductor with a predetermined number of layers, wherein the conductor and dielectric layers are arranged alternately.

[0084] Aspect 15: Methods according to aspects 13 or 14, comprising the application of the coating composition to the conductor layer by slot nozzle coating.

[0085] Aspect 16: Method according to any of aspects 13 to 15, wherein contacting the polymer composition-coated surface of the conductor layer with the dielectric layer comprises laminating the conductor layer onto the dielectric layer.

[0086] Aspect 17: Method according to any of Aspects 13 to 16, wherein the coating composition further comprises a reactive monomer, a source of free radicals or both.

[0087] Aspect 18: Method according to any of aspects 13 to 17, wherein the conductor comprises copper or aluminium.

[0088] Aspect 19: Method according to one of aspects 13 to 18, wherein the conductor layer comprises the polymer composition in a thickness of 6 to 25 micrometers.

[0089] Aspect 20: Method according to one of aspects 13 to 19, wherein the multilayer conductor has no gap between the conductor and the dielectric layer.

[0090] Aspect 21: Method according to any of aspects 13 to 20, wherein the dielectric layer comprises a cross-linked section at an interface between the dielectric layer and the conductor layer, the cross-linked section extending from the interface up to 25 micrometers into the dielectric layer.

[0091] Aspect 22: Method according to any of Aspects 13 to 21, wherein an interface between the conductor layer and the dielectric layer has a peel strength of at least 5 pound-force per linear inch (PLI) (0.88 kilonewtons per meter).

[0092] Aspect 23: An assembly comprising: the multilayer conductor according to one of Aspects 1 to 12; and a magnetic core adjacent to at least part of the multilayer conductor.

[0093] Aspect 24: The assembly according to aspect 23, wherein the multilayer conductor comprises a plurality of conductor layers and dielectric layers arranged concentrically around a common axis, the conductor layers and dielectric layers being arranged alternately.

[0094] Aspect 25: The assembly according to aspect 24, wherein the magnetic core includes a central post and the common axis forms a loop around the central post and around a central axis of the multilayer conductor.

[0095] Aspect 26: The assembly according to one of aspects 23 to 25, wherein the multilayer conductor has a ring-shaped form.

[0096] Aspect 27: The assembly consisting of one of aspects 23 to 25, wherein the multilayer conductor has a cylindrical shape.

[0097] Aspect 28: The assembly consisting of one of aspects 23 to 27, which further comprises an alternating current source that is electrically coupled to at least one of the conductor layers of the multilayer conductor.

[0098] Aspect 29: The arrangement of one of aspects 23 to 28, wherein the arrangement is a magnetic self-resonance structure.

[0099] The compositions, processes, and articles may alternatively comprise, consist of, or substantially consist of any suitable materials, steps, or components disclosed herein. The compositions, processes, and articles may additionally or alternatively be formulated to be free of, or substantially free of, any materials (or species), steps, or components that are not otherwise necessary to achieve the function or objectives of the compositions, processes, and articles.

[0100] All areas disclosed herein include the endpoints, and the endpoints are independently combinable with one another. “Combinations” include mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like do not denote any order, quantity, or significance, but are used to distinguish one element from another. The terms “a,” “an,” and “the” do not denote any quantitative restriction and are to be understood as including both the singular and plural forms unless otherwise stated herein or clearly contradicted by the context. “Or” means “and / or” unless clearly stated otherwise. Reference to “an aspect” throughout the description means that a particular element described in connection with the aspect is contained in at least one aspect described herein and may or may not be present in other aspects.The term "combination thereof," as used here, encompasses one or more of the listed elements and is open-ended, allowing for the presence of one or more unmentioned similar elements. Furthermore, it should be understood that the described elements can be combined in any suitable way in the various aspects.

[0101] It is understood that when an element is described as being "on" another element or "in contact" with another element, it may be located directly on top of the other element or there may be intervening elements, unless explicitly stated otherwise. Conversely, when an element is described as being "directly on" or "directly in contact with" another element, there are no intervening elements.

[0102] Exemplary embodiments are described here with reference to cross-sectional diagrams, which are schematic representations of idealized embodiments. Therefore, deviations from the shapes shown in the diagrams, for example due to manufacturing techniques and / or tolerances, are to be expected. Consequently, the embodiments described here should not be interpreted as being limited to the specific shapes of areas shown, but should also include deviations in shape that result, for example, from manufacturing. For instance, an area shown or described as flat may typically exhibit rough and / or nonlinear features. Furthermore, sharp angles shown may be rounded.Therefore, the areas shown in the figures are schematic in nature and their shapes are not intended to illustrate the exact shape of an area or to limit the scope of the present claims.

[0103] Unless otherwise stated herein, all testing standards are the latest standards in force at the date of filing of this application or, if priority is claimed in accordance with the claim, at the date of filing of the earliest priority application in which the testing standard appears.

[0104] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as they are generally understood by a person skilled in the art in the field to which this application belongs. All cited patents, patent applications, and other references are hereby incorporated in their entirety by reference. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term in the present application shall prevail over the conflicting term in the incorporated reference.

[0105] Compounds are described using standard nomenclature. For example, any position not substituted by a specified group is assumed to be valence-balanced by a specified bond or hydrogen atom. A hyphen (“-”) not placed between two letters or symbols is used to indicate a bonding site for a substituent. For example, -CHO is bonded via the carbon atom of the carbonyl group.

[0106] Although certain embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents may occur to the applicants or a person skilled in the art that are not currently foreseeable or likely to be foreseeable. Accordingly, the claims as filed and as amended are intended to encompass all such alternatives, modifications, variations, improvements, and substantial equivalents. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 461,399

[0001] US 3,798,185

[0025] US 3,849,509

[0025] US 4,095,033

[0025] US 3,804,804

[0025] US 3,836,593

[0025] US 4,680,353

[0029] US 5,066,741

[0029] US 5,206,197

[0029] Cited non-patent literature

[0000] ISO 11357-1

[0019] ISO 11357

[0021]

Claims

[1] Multilayer conductor comprising a conductor layer and a dielectric layer on the conductor layer, wherein the dielectric layer comprises a polymer composition with a loss factor (Df) of less than 0.001 and includes a cyclic olefin copolymer, a transoctenamer rubber, syndiotactic polystyrene, a polymethylpentene olefin copolymer or a combination thereof; and wherein an interface between the conductor layer and the dielectric layer is provided with a peel strength of at least 5 pound-force per linear inch (PLI) (0.88 kilonewtons per meter). [2] Multilayer conductor according to claim 1, comprising at least two conductor layers, wherein the conductor layers and the dielectric layer are arranged alternately. [3] Multilayer conductor according to claim 1 or 2, wherein the dielectric layer further comprises a reinforcing means. [4] Multilayer conductor according to any one of claims 1 to 3, wherein the dielectric layer comprises a cross-linked section at an interface between the dielectric layer and the conductor layer. [5] Multilayer conductor according to claim 4, wherein the cross-linked section extends from the interface up to 25 micrometers into the dielectric layer. [6] Multilayer conductor according to any one of claims 1 to 5, wherein the dielectric layer comprises the cyclic olefin copolymer. [7] Multilayer conductor according to any one of claims 1 to 6, wherein the dielectric layer comprises a first cyclic olefin copolymer and a second cyclic olefin copolymer. [8] Multilayer conductor according to any one of claims 1 to 7, wherein the dielectric layer comprises the transoctenamer rubber. [9] Multilayer conductor according to any one of claims 1 to 8, wherein the dielectric layer comprises the cyclic olefin copolymer and the transoctenamer rubber. [10] Multilayer conductor according to any one of claims 1 to 9, wherein the dielectric layer comprises syndiotactic polystyrene. [11] Multilayer conductor according to claim 10, wherein the dielectric layer further comprises a reinforcing filler comprising glass fibers. [12] Multilayer conductor according to any one of claims 1 to 11, wherein the dielectric layer comprises the polymethylpentene olefin copolymer. [13] Method for manufacturing the multilayer conductor according to any one of claims 1 to 12, wherein the method comprises: Applying a coating composition that the polymer composition and a solvent contains, on the conductor layer; Removal of the solvent to obtain a surface of the conductor layer coated with the polymer composition; and Contacting the surface of the conductor layer coated with the polymer composition with the dielectric layer; wherein the dielectric layer comprises the same polymer composition as the coating composition. [14] Method according to claim 13, further comprising repeating the application and contacting to provide a multilayer conductor with a predetermined number of layers, wherein the conductor and dielectric layers are arranged alternately. [15] Method according to claim 13 or 14, comprising applying the coating composition to the conductor layer by slot nozzle coating. [16] Method according to any one of claims 13 to 15, wherein contacting the polymer composition-coated surface of the conductor layer with the dielectric layer comprises laminating the conductor layer onto the dielectric layer. [17] Method according to any one of claims 13 to 16, wherein the coating composition further comprises a reactive monomer, a source of free radicals or both. [18] Method according to any one of claims 13 to 17, wherein the conductor comprises copper or aluminium. [19] Method according to any one of claims 13 to 18, wherein the conductor layer comprises the polymer composition in a thickness of 6 to 25 micrometers. [20] Method according to any one of claims 13 to 19, wherein the multilayer conductor has no gap between the conductor and the dielectric layer. [21] Method according to any one of claims 13 to 20, wherein the dielectric layer comprises a cross-linked section at an interface between the dielectric layer and the conductor layer, wherein the cross-linked section extends from the interface up to 25 micrometers into the dielectric layer. [22] Method according to any one of claims 13 to 21, wherein an interface between the conductor layer and the dielectric layer has a peel strength of at least 5 pound-force per linear inch (PLI) (0.88 kilonewtons per meter). [23] Assembly comprising the following: the multi-layer conductor according to any one of claims 1 to 12; and a magnetic core that borders at least part of the multilayer conductor. [24] Assembly according to claim 23, wherein the multilayer conductor comprises a plurality of conductor layers and dielectric layers arranged concentrically around a common axis, the conductor layers and dielectric layers being arranged alternately. [25] Assembly according to claim 24, wherein the magnetic core comprises a central post and the common axis forms a loop around the central post and around a central axis of the multilayer conductor. [26] Assembly according to one of claims 23 to 25, wherein the multilayer conductor has a ring-shaped form. [27] Assembly according to one of claims 23 to 25, wherein the multilayer conductor has a cylindrical shape. [28] Assembly according to one of claims 23 to 27, further comprising an alternating current source which is electrically connected to a conductor layer of the multilayer conductor. [29] Assembly according to any one of claims 23 to 28, wherein the assembly is a magnetic self-resonant structure.

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