Audio-visual EMI shielding composition and method for preparing the same

Abstract

An audio-visual shielding composition (10) for electromagnetically shielding audio-visual equipment (12). The composition comprising a nanoparticle mixture and a suspension matrix for suspending the nanoparticle mixture and being configured to be applied to exposed component parts (14) of the audio-visual equipment (12).

Description

AUDIO-VISUAL EMI SHIELDING COMPOS ITION AND METHOD FOR PREPARING THE SAMEIntroduction

[0001] The present application relates to an Audiovisual (AV) electromagnetic interference (EMI ) shielding composition . The invention further relates to a method of preparing an AV EMI Shielding composition . The composition is used for providing improved EMI shielding for AV applications such as audio , visual or combined audio and visual electronics . The present disclosure is also relevant to audio , visual or combined audio and visual electronics comprising components coated in the composition .Background

[0002] The proli feration of electronic equipment has dramatically increased over the last 50 years , introducing an enormous amount of man-made Electromagnetic Waves (EMW) into the surroundings . In many situations , these are deliberately generated; cellular, WiFi , Bluetooth and Radio communications all involve generated EMWs . However, EMWs are also generated to various extents when electronic components conduct current . As such, EMWs from adj acent electronic components and associated connections can interact with one another generating interference . That is , as one electronic component generates EMWs , these may induct current signals or introduce harmonic distortions and increase noise floor level s in conductive paths of other components surrounding it . In many instances , this interference is inconsequential as it is relatively low level and does not af fect the operation of thosecomponents . However, in some scenarios where the interference is high ( e . g . , due to high current / voltage ) or where critical or sensitive components are present that may otherwise be af fected by interference , electromagnetic interference (EMI ) shielding becomes important . As one example , it is common for advanced driver assistance system controllers in vehicles to be housed within a special EMI shielded housing to prevent EMWs from disrupting safety critical operations .

[0003] Due to the increased amount of EMW generally, electromagnetic interference (EMI ) is also starting to emerge as a phenomenon in other applications . For example , in AV applications , some HiFi enthusiasts have started looking at improving EMI shielding in cabling between HiFi separates to mitigate perceived noise generated from EMW present in the environment . For example , in higher end audio systems , more expensive cable connectors between the speaker and ampli fier may be used, with these premium connectors typically having more expensive shielding and higher-grade conductive pathways . Equally, ferrite beads may be fitted to supress inducted noise in power cabling delivering power to the ampli fier .

[0004] The above solutions to EMI potentially of fer benefits but are limited in terms of their application . For instance , improved cabling and ferrite beads can be used to improve external cabling in separates systems , but these solutions are not applicable to all types of audio and / or visual devices . Equally, entirely enclosing larger electronic units within an EMI shielding housing is not practical for AV applications .

[0005] Accordingly, there is a need to address the above problems with an EMI shielding that is both cost-ef fective and can be applied to a variety of di f ferent AV electronic devices and / or components .Summary

[0006] In light of the above , the present invention seeks to provide an improved EMI shielding composition that is simple to produce , can be produced at a much lower cost when compared with conventional methods of EMI shielding, and is appropriate for application to a variety of AV devices and electronic components within these systems .

[0007] According to a first aspect of the invention, there is provided an audio-visual shielding composition for electromagnetically shielding audio-visual equipment , the composition comprising : a nanoparticle mixture ; and a suspension matrix for suspending the nanoparticle mixture and being configured to be applied to exposed component parts of the audio-visual equipment .

[0008] In this way, an audio-visual shielding composition for electromagnetically shielding audio-visual equipment is provided that dissipates EMI at di f ferent wavelengths by utilising a suspension matrix with di f ferent nanoparticles . The suspension matrix and nanoparticles are selected from common and af fordable materials , such that the audio-visual shielding composition can be readily produced and at a low cost . The combination of the nanoparticles suspended in the matrix provides conductive pathways embedded in ferromagnetic and dielectric materials , which act toattenuate a broad-spectrum of EMI . As a result , lower noise floor levels and a higher signal to noise ratio may be achieved in AV applications . Advantageously, the audiovisual shielding composition can be applied to various exposed surfaces in a variety of AV electronic components , allowing for easy application over existing AV component designs and for compatibility with a broad range of AV devices .

[0009] In embodiments , the composition further comprises a solvent . In this way, the audio-visual shielding composition can be applied evenly to exposed component parts of the audio-visual equipment . The amount of solvent in the audio-visual shielding composition can be varied to change the viscosity of the resulting audio-visual shielding composition, such that a particular viscosity can be achieved for a particular application . Advantageously, as the solvent evaporates , the audio-visual shielding composition cures to form a solid coating on the exposed component parts of the audio-visual equipment .

[0010] In embodiments , the composition is configured to form a viscous liquid mixture for selective application onto exposed component parts and is curable to form a solid coating once applied . In this way, Advantageously, the audio-visual shielding composition can be applied easily to an electronic device and / or an electronic component within an AV device and can cure without any additional equipment and / or chemicals through action of the solvent evaporating .

[0011] In embodiments , the suspension matrix comprises a thermoplastic resin . In this way, the audio-visualshielding composition can be produced using an af fordable and easily obtainable material . Thermoplastic resins exhibit a high strength and toughness which makes them highly durable . In addition, thermoplastics are corrosion resistant and are resistant to a range of chemicals . This results in added protection of the exposed components parts of the audio-visual equipment .

[0012] In embodiments , the suspension matrix comprises one of a Polyurethane ( PU) Film, PU resin, and a PU based glue .

[0013] In embodiments , the thermoplastic resin is selected from a group consisting of a polyethylene terephthalate resin, polyurethane resin, polypropylene resin, polyethylene resin, polyvinyl chloride resin, acrylonitrile butadiene styrene resin, and a polystyrene resin . In this way, the thermoplastic resin can be selected from accessible and low cost material s which results in lower processing and manufacturing costs .

[0014] In embodiments , the suspension matrix comprises a thermoset resin . In this way, it can be produced using an af fordable and easily obtainable material . As thermoset resins have a high heat resistance , the resultant audiovisual shielding composition can be used on high-heat component parts of AV equipment . In addition, thermoset resins of fer improved electrical insulation such that the audio-visual shielding composition can be used on a variety of exposed component parts of AV equipment .

[0015] In embodiments , the suspension matrix comprises a Magnetic Ferrofluid . Such suspension may be particularlysuitable for use when the composition is applied to the voicemail of speakers, thereby providing an improvement to the overall sound quality.

[0016] In embodiments, the thermoset resin is selected from a group consisting of an acrylic resin, a polyurethane resin, a room-temperature-vulcanizing silicone, and a UV resin. In this way, the thermoset resin can be selected from accessible and low cost materials which results in lower processing and manufacturing costs.

[0017] In embodiments, the nanoparticle mixture comprises a first nanoparticle, a second nanoparticle, and a third nanoparticle. In this way, a variety of nanoparticles with various properties are used to provide improved EMI shielding. This allows for fine-tuning of the EMI shielding performance to meet specific requirements for different applications .

[0018] It will be understood that various combinations of nanoparticles are possible. For example, one mixture can comprise one nanoparticle element from each category of nanoparticles, or an alternative mixture may contain all 3 nanoparticles elements from a one category. For example, a compound may comprise the combination of rGO, SWCNT, MWCNT and MXENE . In other mixtures, more than one nanoparticle element from each category may be provided (e.g., three particles from each category, resulting in a nine particle mixture) . In another specific example, a compound may be provided as a mixture of Copper, Aluminium, Silver and Gold nanoparticles, as an individual compound or a base layer compound, where other compounds are then applied as asecond layer on top of the first. Different combinations and layering patterns may be used when applying the materials to influence the performance and desired results.

[0019] Combinations of Dielectric, semi / super conductive, Dielectric and ferromagnetic materials and layering and combinations may be used to achieve enhanced results in specific applications. As such, the layering of compounds may be used to achieve the desired EMI dissipation.

[0020] In embodiments, the first nanoparticle is selected from a list comprising reduced graphene oxide, a singlewalled carbon nanotube, a multi-walled carbon nanotube, a carbon nanotube, a MXene nanoparticle, a pyrolitic carbon, a carbon black (Acetylene Black) , Bismuth Nano Particles / Fine Ground, Titanium Aluminium Carbide (T13ALC2 MAX Phase) , and Magnetite Nano Particle (Fe304) . In this way, the resultant audio-visual shielding composition can effectively reflect or absorb electromagnetic waves due to the inclusion of carbon nanoparticles, which have a high electrical conductivity.

[0021] In embodiments, the second nanoparticle is selected from a list comprising copper, aluminium, silver, copper-silver alloy nanoparticle, titanium nanoparticle, and gold nanoparticle. In this way, the second nanoparticle can be selected from easily accessible and low cost metals which results in lower processing and manufacturing costs.

[0022] In embodiments, the third nanoparticle is selected from a list comprising Zinc Oxide Nano Particle,zinc peroxide, zirconium dioxide, titanium dioxide, silicon dioxide, silicon carbide, and aluminium oxide. In this way, the resultant audio-visual shielding composition can effectively reflect or absorb electromagnetic waves due to the inclusion of oxide nanoparticles. Oxide nanoparticles are readily synthesised and processed, which reduces the cost of producing the composition.

[0023] In embodiments, the nanoparticle mixture is 0.1- 10% by weight of the suspension matrix. In this way, the resultant audio-visual shielding composition can effectively reflect or absorb electromagnetic waves due to the inclusion of the various nanoparticles in the nanoparticle mixture.

[0024] According to a second aspect of the invention, there is provided an audio-visual device comprising: at least one audio-visual component; and an audio-visual shielding composition for electromagnetically shielding the audiovisual device, the composition comprising: a nanoparticle mixture; and a suspension matrix for suspending the nanoparticle mixture and being configured to be applied to exposed component parts of the audio-visual device, wherein the audio-visual shielding composition is applied to the at least one audio-visual component.

[0025] In this way, an audio-visual device is provided that dissipates EMI at different wavelengths by utilising a suspension matrix with different nanoparticles. The suspension matrix and nanoparticles are selected from common and affordable materials, such that the audio-visual shielding composition can be readily produced and at a lowcost . The combination of the nanoparticles suspended in the matrix provides conductive pathways embedded in ferromagnetic and dielectric materials , which act to attenuate a broad-spectrum of EMI . As a result , once applied over the AV device , for example as a layer to form a coating or to otherwise encapsulate the device or part ( s ) of the device , the amplitude of the audio frequency response may be made more consistent over the frequency spectrum in AV applications . This , resulting in a response performance that is lower in noise floor fluctuations and improves the signal to noise ratio .

[0026] According to a third aspect of the invention, there is provided a method of preparing an audio-visual shielding composition for electromagnetically shielding audio-visual equipment , the method comprising : combining a suspension matrix with a nanoparticle mixture ; mixing the suspension matrix and the nanoparticle mixture . In this way, the audio-visual shielding composition can be produced easily and a low cost .

[0027] According to a fourth aspect of the invention, there is provided a process of applying an audio-visual shielding composition for electromagnetically shielding audio-visual equipment , the process comprising : providing an audiovisual shielding composition comprising a suspension matrix and a nanoparticle mixture ; applying the audio-visual shielding composition to the exposed component parts / face of the audio-visual equipment . In this way, the audiovisual shielding composition can be applied to a variety of exposed component parts of audio-visual equipment .Brief Description of Drawings

[0028] I llustrative embodiments of the present invention will now be described with reference to the accompanying drawings in which :Figure 1 shows a cross-section of an AV electronic device with a composition for electromagnetic shielding applied according to a first illustrative embodiment ; andFigure 2 illustrates a cross-section of a second AV electronic device with a composition for electromagnetic shielding applied .Detailed Description

[0029] Embodiments of the present invention provide an audio-visual (AV) shielding composition for electromagnetically shielding audio-visual equipment . Figure 1 shows an audio-visual shielding composition 10 according to a f irst illustrative embodiment applied to an AV electronic device 12 . The AV electronic device 12 is a processing unit or system-on-a-chip ( SoC ) which would typically be provided as a component within an AV electronic device . For example , a speaker or headphone unit would typically comprise a circuit board supporting a number of such components within its plastic housing . As shown, the AV electronic device 12 comprises metallic contacts 14 which connect to the circuit board 16 . The composition 10 is applied as a resin to the exposed contacts and cured to form a solid encasing for absorbing EMW . The present inventors have found that , whilst small , EMI would otherwise be inducted in these contacts 14 . As such, the aggregate ef fect of EMI shielding the contacts 14of the electronic components 12 within an AV device improves the overall performance of the analog audio or visual output .

[0030] The composition 10 comprises a suspension matrix and a nanoparticle mixture suspended therein . Preferably, the suspending matrix is a resin, which acts as a binder for suspending the nanoparticle mixture to form a composite substance that can be applied to AV electronic devices and components . Advantageously, the present inventors have discovered that the described audio-visual shielding composition 10 provides electromagnetic interference shielding for audio-visual equipment which has pronounced ef fects on mitigating interference , lowering the noise floor and improving the signal to noise ratio of audio and / or visual signals .

[0031] A further example application o f the composition 10 is shown in Figure 2 . In this respect , it is known to use conformal coatings 10 over circuit boards 2 in electronic devices to provide moisture and environmental protection . Adding a conformal coating 10 increases the longevity and performance of these electronic components in more demanding environments . Advantageously, the composition 10 according to embodiments of the present invention may be applied to existing conformal coatings . This results in a highly functional and ef ficient EMI shield when compared to other forms of traditional protection, which do not attenuate EMI at the AV bandwidths .

[0032] The composition 10 may be applied to other parts of electronic components but are especially ef fective whereparts are paths within or adjacent the electrical signal transmission chain. For example, open solder contacts, magnetic components, transformers, capacitors, resistors, transistors, power distribution topographies, and I / O connections may all be coated in the composition. This acts to mitigate EMI noise being inducted into these components.

[0033] The resin according to this illustrative embodiment of the present invention comprises a thermoplastic resin. A wide variety of thermoplastic resins can be used in the present invention depending on the specific application. Exemplary suitable thermoplastic resins include a polyethylene terephthalate (PT) resin, polyurethane (PU) resin, polypropylene (PP) resin, polyethylene (PE) resin, polyvinyl chloride (PVC) resin, acrylonitrile butadiene styrene (ABS) resin, a polystyrene (PS) resin, and mixtures thereof.

[0034] The resin according to some embodiments of the present invention comprises a thermoset resin. A wide variety of thermoset resins can be used. Exemplary suitable thermoset resins include an acrylic resin, a polyurethane resin, and mixtures thereof. In preferred embodiments, a photopolymer, or UV, resin is used as the suspension matrix. Once applied the composition can then be cured with light to harden the matrix. The resultant cross-linking of polymer chains within the composition thereby produces a toughened EMI shielding coating. Preferably, 405nm UV light may be used for curing. It has been found that the process of photopolymerization forms unique one-dimensional (ID) and two-dimensional (2D) structures within the composition providing exotic shielding and energy transfer properties.

[0035] In other embodiments, the suspension matrix is a room-temperature-vulcanizing silicone. This material is silicone rubber that cures at room temperature, which thereby allows the composition 10 to be applied to an AV electronic device and / or component and cured without any additional equipment and / or chemicals.

[0036] In embodiments, the suspension matrix can also comprise a solvent such that the resultant composition 10 is a lacquer. For example, a glue or silicone-based sealants may be used. In one example, the suspension matrix is an acrylic based conformal coating may be form. Advantageously, the lacquer can be applied easily to the electronic device and / or an electronic component within the device and can cure without any additional equipment and / or chemicals through action of the solvent evaporating. In embodiments, the suspension matrix is an acrylic based paint. Such paints, suspending the specified mixture, provides extremely effective wide EMI shielding. In embodiments, the suspension matrix is an oil. For example, oils such as coconut oil, olive oil, saffron oil and musk oil, may be used to polish wood or MDF board housings forming audio / visual enclosures to provide an EMI shielding veneer .

[0037] The nanoparticle mixture according to embodiments of the present invention comprises a mixture of at least one carbon or ceramic based nanoparticle, at least one metallic nanoparticle, and at least one oxide nanoparticle. A wide variety of suitable nanoparticles can be used in the present invention that can have a diameter between 1 and 100 nanometres.

[0038] Exemplary suitable carbon based nanoparticles include a graphene oxide, a single-walled carbon nanotube, a multi-walled carbon nanotube, and a carbon nanotube. In addition, exemplary suitable ceramic based nanoparticles include a MXene nanoparticle.

[0039] Exemplary suitable metallic nanoparticles include copper, aluminium, silver, and copper-silver alloy nanoparticles .

[0040] Exemplary suitable oxide nanoparticles include Zinc Oxide Nano Particle, zinc peroxide, zirconium dioxide, titanium dioxide, silicon dioxide, and aluminium oxide nanoparticles .

[0041] The mixture may further comprise at least one of silicon carbide, Bismuth, Pyrolytic Carbon, Carbon Black, Phosphorus, and Strontium Aluminate powder.

[0042] In particular, it has been found that the addition of Phosphorus and / or Strontium Aluminate powder are especially effective at further reducing the noise floor, pronouncing the EMI reducing effects. One theory is that the Carbon and MXENE based particles act as catalyst or accelerator that enhances the innate properties of the individual elements, and also amplifies the combinations of exotic properties that are observed.

[0043] Where the composition 10 comprises a nanoparticle mixture of 0.1% by weight of suspension matrix, a detectable audible effect is provided when the composition has been applied to an audio electronic component. For example, when 10g of a suspension matrix is used, thecomposition 10 contains at least 0 . 05g of the nanoparticle mixture . In one illustrative example , a 1 % concentration of the nanoparticle mixture is provided according to initial mass of the suspension matrix such that the total mass of composition 10 is 10 . 1g .

[0044] Conversely, it has been found that when the composition 10 contains a nanoparticle mixture of more than 10% by weight o f the suspension matrix, the audio signal becomes too sterile , and the suspension matrix becomes oversaturated with nanoparticles .

[0045] Although the audio output by the electronic device becomes less pleasant once the concentration of nanoparticles exceeds 10% by weight of the suspension matrix higher concentration ratios may be useful in applications such as for hearing aid devices , communications and equipment where microphone signal sensitivity and clarity of the transmitted voice is crucial .

[0046] Preferably, the composition 10 comprises a nanoparticle mixture between 0 . 1 % to 9% by weight of the suspension matrix .

[0047] The composition 10 for EMI shielding according to embodiments of the present invention may be prepared by adding a powder of nanoparticles to a suspension matrix . As mentioned above , preferably, the suspension matrix is a photopolymer, or UV, resin or lacquer where the composition 10 further comprises a solvent . Once the suspens ion matrix and the nanoparticle mixture have been combined, the composition 10 is mixed until an even distribution andpercolation threshold is achieved . Once the desired distribution and percolation has been achieved the composition 10 is applied to the target area . For example , the composition 10 is applied to open solder contacts of an electronic device , or to electronic components within an electronic device with speci fic layering depending on the desired function and shielding .

[0048] Di f ferent combinations of layers are possible . For example :Dialectric / Conduct ive / Dialectric ; orDialectric / Conduct ive / Dielectric / Conduct ive / Dielectric ; orDielectric / Ferromagnetic / Conduct ive / Dielectric / Ferroma gnetic / Conduct ive / Dielectric

[0049] A compound within one layer may also contain a mixture of dielectric, conductive and ferromagnetic elements . As such, it will be understood that the use of speci fic compound will depend on its application . For example , the combination of a dielectric, conductive and ferromagnetic elements work particularly well when applied as a coating on a speaker magnet due to the inherent magnetism of the component . The combination of elements in the compound may be speci fically selected to mitigate the EMF ef fecting the component the composition is to be applied to the most . For example , in a preferred composition for coating open solder contacts , a combination of dielectric, conductive , dielectric may be used . Preferably, each layer may be l-5mm in thickness .

[0050] As shown in Figure 1 and 2, the composition 10 can be applied to any electronic device and / or electronic component 12 within an electronic device. The composition 10 can be applied to the metallic contacts 14 of the electronic component 12. In one example, the metallic contacts 14 are completely covered by the composition 10. However, the composition 10 can be applied to parts of the metallic contacts 14.

[0051] In addition, the composition 10 can be applied directly on to an electronic component 12, such as a resistors, capacitor, and an integrated circuit (IC) chip. In this way, a top surface of the electronic component 12 is coated in the composition 10 for EMI shielding. Additionally, or alternatively, the composition 10 can be applied to the underside of a printed circuit board (PCB) 16 on which the electronic component 12 is coupled. The full surface area of the PCB can be covered with the composition 10, but only certain parts can be covered in the composition 10 depending on the electronic device and the desired EMI shielding.

[0052] In one example, the composition 10 can be applied to electric components within a headphone which leads to observable differences in the performance of the headphone output. The application of the composition 10 to various components within headphones resulted in a reduction of the noise floor level, a reduction in the Signal to Noise Ratio (SNR) , and a reduction in the Total Harmonic Distortion (THD) parameters of the headphones.

[0053] As an illustrative example, the composition may beapplied to headphones . The resultant headphones , once the composition has been applied, may be 1 . 1 dB louder and have a more linear frequency response across the spectrum, especially at 7- 13 kHz range . As such, in audio devices a signi ficant improvement in the THD and Noise Floor Levels may be achieved . In AV applications , this may therefore allow a more consistent amplitude across the frequency spectrum to be provided, for a more consistent response with less fluctuations .

[0054] Accordingly, the composition 10 for EMI shielding according to embodiments of the present invention utilises the doping of various nanoparticles , metal oxides and minerals into acrylic conformal coatings and UV resins to dissipate EMI at their various wavelengths . The suspension matrix and nanoparticles may be chosen such that they are readily available at an af fordable price and are already commonly used in the manufacturing of many electronic devices . It is believed that the combination of the nanoparticles suspended in the matrix provides for conductive paths imbedded within ferromagnetic and dielectric materials , which act to attenuate a broadspectrum of EMI with signi ficant Shielding Ef ficiency ( SE ) .

[0055] The composition 10 for EMI shielding according to embodiments of the present invention can be used in a wide variety of AV applications . For example , the composition 10 can be applied to various exposed surfaces in AV devices , allowing for easy application over existing AV component designs . This thereby may provide for improved performance compared to untreated devices without the need to redesign these devices . Similarly, the composition 1 may, forexample, also be applied on the open solder contact connecting the speaker and amplifier board, the open solder contact on the amplifier board connecting the speaker and the power input cable. The composition 1 may form a coating on the contact responsible for power distribution and the localised area where the power input is.

[0056] It will be understood that the illustrated embodiments show applications only for the purposes of explanation. In practice, the invention may be applied to many different configurations, where the embodiment is straightforward for those skilled in the art to implement. For example, the embodiments may be used in a variety of applications, such as motherboard construction, graphics cards, digital to analogue converters and vice versa, sleeve / cases or enclosures for mobile phone, laptop and tablet devices, insulation / shielding for magnets cable insulation, shielding / insulation of IC chips, essential chips such as DAC, Graphics card, OP-AMPs, Capacitors, and Transformer Shielding. The composition may also be applied to connector enclosures for, for instance, HDMI, CAT, RJ45, JST, Audio Connectors, as well as speaker, amplifier, DAC, and computer enclosures. It will also be understood that the composition may be applied to devices other than AV device such as in wire insulation and shielding, moulded enclosures, vinyl films, and stickers. In other arrangements, the composition may be applied to compounds forming speaker feet and stands, for example as pads or a formation for separating the speaker from the surface it is put on.

[0057] For example, the description herein refers to embodiments with particular combinations of steps or features, however, it is envisaged that further combinations and cross-combinations of compatible steps or features between embodiments will be possible. Indeed, isolated features may function independently as an invention from other features and not necessarily require implementation as a complete combination.

[0058] In one specific example, the composition comprises 0.1g of powders mixed into 10g of the suspension matrix, resulting in a total mass of 10.1g. The powders comprise a mixture of:Powder 'A' C / MX based particle, weight 0.033 gPowder 'B' Metal based particle, weight 0.033 gPowder 'C' Oxide based particle, weight 0.033 g

[0059] Each powder is mixed until all three have been combined. The mixed powders are then mixed into the suspension matrix, where it is mixed until the particles are evenly distributed. This is identified by a colour change in the composition mixture, indicating the suspension matrix has been fully doped with the particles.

[0060] Finally, it would be understood that the claimed composition may be applied to other applications outside of audio / visual applications, such as lighting. For example, efficiency may be increased when the composition is applied to a light generating source. In this respect, standard lightbulbs of all kinds have a transmission line where the diode and cables are connected through a solder joint andthe application of the claimed compounds may have the ef fect of lowering noise . The same is true with electromagnetic pollution in the spectrum of light at di f ferent wavelengths . As Phonons and Photons are deeply interwoven, one and the same force , yet represented as a force of its own; Photons and Phonons have a relationship whereby the ef fects measured and observed in photon spin and dynamics , are influenced first , by the vibration caused by quantum particle of sound, a phonon . The vibrations that slows down to what we call visible light is the same as the audible spectrum of sound . In one application, where the suspension matrix is UV curable , they may be cured using a 405nm UV light treated with claimed compounds on the diode or cable . This may ef fect the sound quality transmission / EMI of the resultant composition compared to curing without the modi fied light source .

Claims

CLAIMS1 . An audio-visual shielding composition for electromagnetically shielding audio-visual equipment , the composition comprising : a nanoparticle mixture ; and a suspension matrix for suspending the nanoparticle mixture and being configured to be applied to exposed component parts of the audio-visual equipment .2 . The audio-visual shielding composition according to claim 1 , wherein the composition further comprises a solvent .3 . The audio-visual shielding composition according to claim 1 or 2 , wherein the composition is configured to form an viscous liquid mixture for selective application onto exposed component parts and is curable to form a solid coating once applied .4 . The audio-visual shielding composition according to any preceding claim, wherein the suspension matrix comprises a thermoplastic resin .5 . The audio-visual shielding composition according to claim 4 , wherein the thermoplastic resin is selected from a group consisting of a polyethylene terephthalate resin, polyurethane resin, polypropylene resin, polyethylene resin, polyvinyl chloride resin, acrylonitrile butadiene styrene resin, and a polystyrene resin .6 . The audio-visual shielding composition according to any one of claims 1-3 , wherein the suspension matrix comprises at least one of a thermoset resin a polyurethane ( PU) Film, a PU resin, and PU based glue .7 . The audio-visual shielding composition according to claim 6 , wherein the thermoset resin is selected from a group consisting of an acrylic resin, a polyurethane resin, a room-temperature-vulcani zing silicone , and a UV resin .8 . The audio-visual shielding composition according to any preceding claim, wherein the nanoparticle mixture comprises a first nanoparticle , a second nanoparticle , and a third nanoparticle .9 . The audio-visual shielding composition according to claim 8 , wherein the first nanoparticle is selected from a list comprising reduced graphene oxide , a single-walled carbon nanotube , a multi-walled carbon nanotube , a carbon nanotube , a MXene nanoparticle a pyrolitic carbon, a carbon black, Bismuth Nano Particles / Fine Ground, Titanium Aluminium Carbide , and Magnetite Nano Particle .10 . The audio-visual shielding composition according to claims 8 or 9 , wherein the second nanoparticle is selected from a list comprising copper, aluminium, silver, coppersilver alloy nanoparticle , titanium nanoparticle , and gold nanoparticle .11 . The audio-visual shielding composition according to any one of claims 8 to 10 , wherein the third nanoparticleis selected from a list comprising Zinc Oxide Nano Particle , zinc peroxide , zirconium dioxide , titanium dioxide , silicon dioxide , aluminium oxide , and silicon carbide , Bismuth, Pyrolytic Carbon and Carbon Black .12 . The audio-visual shielding composition according to any preceding claims , wherein the nanoparticle mixture is 0 . 1- 10% by weight of the suspension matrix .13 . A audio-visual device comprising : at least one audio-visual component ; and an audio-visual shielding composition for electromagnetically shielding the audio-visual device , the composition comprising : a nanoparticle mixture ; and a suspension matrix for suspending the nanoparticle mixture and being configured to be applied to exposed component parts of the audio-visual device , wherein the audio-visual shielding composition is applied to the at least one audio-visual component .14 . A method of preparing an audio-visual shielding composition for electromagnetically shielding audio-visual equipment according to any of the preceding claims 1 to 11 , the method comprising : combining a suspension matrix with a nanoparticle mixture ; mixing the suspension matrix and the nanoparticle mixture .15 . A process of applying an audio-visual shielding composition for electromagnetically shielding audio-visual equipment according to any of claims 1 to 11 , the process comprising : providing an audio-visual shielding composition comprising a suspension matrix and a nanoparticle mixture ; applying the audio-visual shielding composition to exposed component parts of the audio-visual equipment .

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