1839results about "Electrically-conductive paints" patented technology

The invention provides a wear early-warning intelligent material based on conductive core-shell micro-nano particles and a preparation method of the wear early-warning intelligent material, and belongs to the technical field of sensing materials. Conductive core-shell micro-nano particles are used as basic sensing function units to be doped into a polymer matrix to form a sensing layer, a three-layer structure material of a bottom residual life layer, a middle sensing layer and a surface self-lubricating wear-resistant layer is designed, and the material is prepared on a metal auxiliary surface. The surface self-lubricating wear-resistant layer is consumed in the wear process, so that the wear reaches the middle sensing layer, and the resistance of the middle sensing layer is obviously changed due to the damage of the conductive micro-nano particles as an early warning signal, so that the early warning information that the surface self-lubricating wear-resistant layer is worn out and friction pair parts need to be replaced in time is realized.

The invention relates to the field of electromagnetic functional composite materials, and particularly discloses a multi-layer composite structure flexible frequency selective surface material and a preparation method thereof. The ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced band-pass frequency selection array sequentially comprises an acrylic acid polyvinylidene fluoride organic polymer coating environment-resistant layer, a metal oxide organic film isolation layer, an ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced layer, a band-pass frequency selection layer and a packaging protection layer from top to bottom, and the band-pass frequency selection layer is a hexagonal / circular ring nested band-pass frequency selection pattern array. The packaging protection layer is formed by printing a conductive coating composed of conductive filler / polymer resin matrix, and the packaging protection layer is an ink coating. The flexible frequency selective surface material has the characteristics of light weight, high strength, salt fog / rain / ultraviolet and other severe environments, frequency selective wave transmission and multiple functions, has good gas barrier property, is beneficial to maintaining the shape of an inflatable hangar made of a skin and ensuring normal operation of radar equipment, and has good practical engineering application value.

The application discloses a kind of carbon nanotube / polyaniline composite modified epoxy resin conductive paint and preparation method thereof, belong to coating technical field.The application is prepared by preliminary disentangling carbon nanotube with specific solvent, and the carbon nanotube dispersion liquid uniformly dispersed is obtained;Afterwards, polyaniline is added to carbon nanotube dispersion liquid, and carbon nanotube / polyaniline composite is prepared by solvent evaporation or purification;Finally, carbon nanotube / polyaniline composite is compounded with epoxy resin, and high-performance carbon nanotube / polyaniline composite modified epoxy resin conductive paint is obtained.The carbon nanotube / polyaniline composite modified epoxy resin conductive paint prepared by the application has more excellent mechanical properties and electrical properties than traditional conductive paint, and can be better applied in aerospace, battery, communication, new energy and other aspects.

The invention discloses an optical-grade PET release film and a preparation method and application thereof, and belongs to the technical field of PET release liners.The preparation method comprises the steps that organic silicon resin, polyacrylate and functional silicone oil serve as raw materials, hexadecafluorophthalocyanine copper serves as a catalyst, sodium hydroxide provides hydroxyl anions, and hydroxyl-containing fluorinated hydroxyaniline is obtained; amino groups on the surface of fluorinated hydroxyaniline react with carboxyl groups of graphene oxide and are grafted on the surface of graphene oxide, then hydroxyl groups in the fluorinated hydroxyaniline and carboxyl groups of acrylic acid are subjected to esterification reaction under the action of a catalyst, so that acrylic acid is grafted on fluorinated modified graphene oxide, and the fluorinated modified graphene oxide is obtained. Therefore, hydroxyl and epoxy functional groups on the surface of the graphene oxide are consumed, hindering of electron transmission is reduced, the conductivity of the release film is improved, and the antistatic requirement of the release film is met.

The invention belongs to the technical field of photovoltaic coatings, and discloses a photovoltaic coating as well as a preparation method and application thereof. The photovoltaic coating is prepared from the following raw materials: a solvent, an ultraviolet light absorber, a wetting agent, an antistatic agent, modified hydrophilic silicon dioxide, nano magnesium fluoride and nano tin dioxide, the modified hydrophilic silicon dioxide is hydrophilic silicon dioxide modified by ethylenediamine and glacial acetic acid. A coating formed by the photovoltaic coating is high in adhesive force and resistant to aging, and the light transmittance, the self-cleaning property and the antistatic property of photovoltaic glass can be obviously improved.

The invention discloses a low-melting-point glass-based inorganic anticorrosive coating with excellent conductivity and a preparation method of the low-melting-point glass-based inorganic anticorrosive coating. The inorganic anticorrosive conductive coating material comprises 80-99.5 parts of a glass base material and 0.5-20 parts of conductive phase powder dispersed in the glass base material, wherein the conductive phase powder adopts a conductive oxide; the preparation process comprises the following steps: 1) mixing glass base materials; 2) melting into molten glass; 3) crushing and introducing a conductive phase; 4) sintering into blocks; 5) crushing and screening the sample; (6) preparing slurry; (7) paint spraying; and 8) sintering and cooling to obtain the paint. The method is simple in process, low in cost, corrosion-resistant, high-temperature-resistant and good in conductivity; after the conductive phase is added, the surface resistivity of the coating is reduced to 102-109 ohms, and the minimum value of the surface resistivity is far higher than that of an existing system.

The present application relates to a kind of high weather resistance and coating adhesion sunscreen coating and its preparation method, belong to sunscreen coating technical field;The present application uses the modifier with disulfide bond and polymerizable double bond to modify polyacrylate emulsion, significantly improve the flexibility of polyacrylate molecular chain after modification, reduce solidification shrinkage stress and internal stress, improve the coating adhesion of sunscreen coating of hard filler to matrix resin, it can also form stable chemical bonding between polyacrylate resin and titanium dioxide, provide stable stress transfer path, reduce the cracking and warping of coating, in addition, the modifier of the present application has good heat resistance aromatic ring structure, using the modifier of the present application can improve the heat resistance of sunscreen coating without introducing additional modifier.

An electronic component device, includes: a redistribution layer, an electronic circuit chip and an optical circuit chip disposed on the redistribution layer, and a first sealing layer sealing the electronic circuit chip and the optical circuit chip, wherein the first sealing layer has an opening on an opposite side from a side of the redistribution layer, and a position of the opening at least partially overlaps with a position of the optical circuit chip.

The invention relates to the technical field of protective film preparation, and particularly discloses an antistatic silica gel protective film and a preparation method thereof.The protective film comprises a base material layer and an antistatic coating coated on the surface of the base material layer; the base material layer is prepared from methyl vinyl silicone rubber, modified fumed silica, a compound antistatic agent A and a vulcanizing agent, and the antistatic coating is prepared from a compound antistatic agent B and water-based acrylic resin. The preparation method comprises the following steps: banburying, calendering and vulcanizing a compound antistatic agent A, methyl vinyl silicone rubber and modified fumed silica to form the base material layer; and finally, mixing the compound antistatic agent B with water-based acrylic resin to prepare an antistatic coating solution, coating the surface of the base material layer with the antistatic coating solution, and drying and curing to obtain a finished product. The silica gel protective film prepared by the invention has excellent antistatic property, mechanical property, adhesive force and high light transmittance, and is suitable for the fields of electronic equipment screens, optical lenses and the like.

The invention discloses a UV-curable conductive polyurethane acrylate coating and a preparation method thereof, and relates to the technical field of photocureable coatings. The invention relates to a UV curing conductive polyurethane acrylate coating, which comprises a light-cured resin, a polyaniline coated carbon nanotube, a reactive diluent, a photoinitiator, an organosilicon leveling agent and a defoaming agent, the light-cured resin is prepared by mixing a polyurethane prepolymer, an epoxy acrylate resin and dihydroxy acrylate, and the polyurethane prepolymer is prepared by mixing the polyurethane prepolymer, the epoxy acrylate resin and the dihydroxy acrylate. The polyaniline coated carbon nano tube is formed by coating and modifying a carbon nano tube by aniline and a doping agent. By adopting the scheme, not only can the conductivity of the coating be improved through the polyaniline coated carbon nanotubes, but also the light-cured resin and the polyaniline coated carbon nanotubes can form a three-dimensional network structure of a conductive filler / resin base material, so that the mechanical property of the coating can be improved; further, the preparation of the UV curing conductive coating with high conductivity and mechanical property is facilitated.

The invention discloses a modified thermoplastic solid-solution anticorrosive coating, a preparation method thereof and application of the modified thermoplastic solid-solution anticorrosive coating on the surface of a pneumatic actuator, and belongs to the field of industrial equipment surface protection materials. Two novel modifiers are designed to construct a multi-protection system. Wherein the layered double hydroxide-silane covalent grafting modifier takes magnesium-aluminum layered double hydroxide as a matrix, and after covalent modification by a silane coupling agent, the matrix is compounded with a quinoline derivative in an intercalation manner, so that the interface bonding and barrier properties are improved; according to the polyaniline-graphene covalent grafting modifier, few layers of graphene and polyaniline are copolymerized and then grafted with a polyurethane prepolymer, so that the toughness and the conductive corrosion resistance of a coating are enhanced. The coating is prepared by taking polyethersulfone as a matrix, compounding the modifier, nano silicon dioxide and other components, mixing, dissolving, dispersing at a high speed and ultrasonically defoaming. The coating has the advantages of high interface adhesion, strong corrosion resistance, dynamic fatigue resistance, environmental protection, no solvent and the like, and is suitable for surface protection of key components such as a pneumatic actuator shell.

The invention discloses a PVDC (polyvinyl dichloride) coating high-brightness BOPP (biaxially-oriented polypropylene) cigarette film and a preparation method thereof, and belongs to the technical field of packaging materials. The smoke film comprises a BOPP (biaxially-oriented polypropylene) base material layer and three layers of gradient PVDC (polyvinyl dichloride) coatings coated on the surface of the BOPP base material layer, wherein the three layers of gradient PVDC coatings sequentially comprise a bottom adhesive layer, a middle barrier layer and a surface functional layer from bottom to top. The bottom adhesive layer adopts PVDC emulsion and an organic silane coupling agent KH-560, so that the binding force with a base material is enhanced; the middle barrier layer adopts high-molecular-weight PVDC and nano silicon dioxide to form a maze effect to provide main barrier performance; and the surface functional layer adopts PVDC, an acrylate copolymer and an antistatic agent, so that the glossiness and the processability are improved. The preparation method adopts an ultrasonic-assisted coating technology, an electrostatic field-assisted leveling technology, a four-stage drying technology and a dynamic tension compensation technology. The prepared product coating is uniform, compact and free of defects, the oxygen permeability is as low as 4.8-9.2 cubic centimeters per square meter per 24 hours per standard atmospheric pressure, the glossiness reaches 86-95 GU, a traditional double-layer packaging structure can be directly replaced, and the cost is reduced by 20% or above.

The invention relates to the technical field of coatings, in particular to an antistatic film material and a preparation method thereof.The antistatic film material comprises a film base material layer and a photocuring antistatic coating coated on the film base material layer, and the film base material layer is a polyethylene glycol terephthalate film; the light-cured antistatic coating is prepared from the following raw materials: water-soluble polyurethane acrylic resin, water-soluble acrylic resin, modified polyhedral oligomeric silsesquioxane, a composite conductive material, a photoinitiator, a flatting agent, a defoaming agent and water; the modified polyhedral oligomeric silsesquioxane and the composite conductive material are added into the coating base material to modify the coating base material, the coating has excellent antistatic performance and good mechanical property after being cured by ultraviolet light, and the special structure of the composite conductive filler and the compounding of the composite conductive filler and the modified polyhedral oligomeric silsesquioxane have excellent antistatic performance and good mechanical property. The anti-static performance reduction caused by low humidity and organic matter migration is avoided.

Disclosed herein is a gold powder comprises gold particles, and sulfur present on a surface of at least a part of the gold particles. A sulfur amount of the sulfur present on the surface per unit surface area is 220 μg / m2 or more and 1500 μg / m2 or less. The sulfur amount is obtained by dividing a surface sulfur amount per unit mass by specific surface area of the gold particles. The surface sulfur amount is obtained by a quantitatively analysis of a treated liquid obtained by nitric acid extraction of the gold particles.

The invention relates to the technical field of polyester powder coatings, in particular to a preparation method of a polyester type antistatic powder coating. The method comprises the following steps: firstly, determining a flow inertia factor according to the viscosity of a pre-molten material and the heating condition among different sections; determining a thermal inertia factor according to the heat-conducting property of the pre-molten material, the influence of heated melting of the feeding particle size of the feeding in the melting section and the expected arrival time of the pre-molten material; matching the flow inertia factor sequence and the thermal inertia factor sequence to obtain a delay time difference; determining a state change factor of the pre-molten material according to the delay time difference, the viscosity of the pre-molten material and the propelling speed; according to the heat conduction performance and the state change factor of the pre-melted material, total energy fluctuation of the material in the time sequence due to unstable heat absorption is determined; and the optimal feeding speed is determined according to the change of the total energy fluctuation in the material propelling length. The material agglomeration probability can be reduced through the regulation and control strategy.

The invention discloses a static conductive polysiloxane coating and a preparation method and a static conductive coating thereof.The static conductive polysiloxane coating comprises a component A and a component B. The mass ratio of the component A to the component B is 9: 1-5: 1, and the component A comprises, by mass, 45-60 parts of epoxy polysiloxane resin, 0.5-5 parts of epoxy silane modified carbon nanotubes, 1.5-4 parts of auxiliaries, 20-35 parts of filler and 10-18 parts of solvent; and the component B is an amino silane coupling agent. According to the static conductive polysiloxane coating disclosed by the invention, the carbon nano tube is modified, so that the carbon nano tube is chemically grafted with epoxy silane to form a chemical bonding network, the dispersion stability of an inorganic filler is improved, the interface bonding force between the filler and resin is also enhanced, and a conductive network which is uniformly distributed can be formed; therefore, the antistatic capability and the protection performance of the coating are improved.

The invention belongs to the field of batteries, and particularly relates to a solid-state polymer electrolyte composite membrane, a preparation method thereof and a solid-state battery. The solid polymer electrolyte composite membrane comprises an MOF functional layer, an anti-reduction coating and an anti-oxidation coating, wherein the anti-reduction coating and the anti-oxidation coating are arranged on the two sides of the MOF functional layer respectively; the MOF functional layer comprises an intermediate layer base material formed by an organic polymer, and an inorganic solid electrolyte and an MOF-based ionic conductor MOF-ILE which are dispersed in the intermediate layer base material; the MOF-based ionic conductor MOF-ILE comprises an MOF material, an ionic liquid and a lithium salt. The electrolyte membrane can meet the multifunctional requirements of all-solid-state batteries, including high ionic conductivity of the electrolyte membrane, good electrode-solid electrolyte membrane interface compatibility, high electrochemical window, excellent mechanical strength and electrochemical stability, so that the electrical performance of the all-solid-state batteries is remarkably improved.

The invention discloses a high-performance film for an automobile touch screen and a preparation method of the high-performance film, and relates to the technical field of touch screen films. According to the preparation method, 3-chloropropyltriethoxysilane reacts with N, N-dimethylethanolamine, quaternary ammonium salt groups are introduced to nano silicon dioxide particles, the nano silicon dioxide particles are endowed with antistatic and antibacterial activity, then through polycondensation and hydrolysis reaction of vinyltriethoxysilane, the dispersity and compatibility of the nano silicon dioxide particles in a polymer are improved, the mechanical strength of a coating is enhanced, agglomeration is avoided, and the anti-static and antibacterial properties of the coating are improved. Meanwhile, constructing a photo-crosslinking network by using polyethylene glycol diacrylate; the copolymer contains fluorine, hindered amine and other groups, and forms another network through the cross-linking agent to provide an anchoring frame for functional groups, so that the coating realizes long-acting synergy of antistatic, anti-ultraviolet, anti-fingerprint and other functions in an automobile environment.

The invention discloses a protective film for preventing precipitation of small molecules and a preparation method thereof, and relates to the technical field of protective films. The protective film comprises a base material layer, a functional layer stacked on one side of the base material layer and a protective layer stacked on the functional layer; wherein the functional layer comprises barrier S O2 with a fluorine-containing aluminate inorganic interface layer and a polyether amine organic interface layer; the protective layer comprises wear-resistant S C of which the surface is grafted with amino methyl ester groups; the double-layer interface of the functional layer can enhance the barrier effect and is beneficial to preventing precipitation of small molecules; a perfluoro chain segment in the protective layer can enhance hydrophobicity, a good waterproof effect is achieved, and the influence of the external environment on the base material is further avoided; and the carbamate group on the surface of the wear-resistant S C and the benzoxazine ring of the barrier S O2 are subjected to ring-opening copolymerization at a high temperature to form a covalent cross-linking interface, so that the bonding strength can be enhanced, the tensile property can be improved, and the service life of the protective film can be prolonged.

The present invention discloses a modified polyurea-based conductive anticorrosive coating, its preparation method and application, belonging to the technical field of polymer materials. The modified polyurea-based conductive anticorrosive coating prepared by the present invention uses carbon black as the main conductive filler, polyaniline and AZO as auxiliary conductive fillers, and utilizes the amino groups carried by polyaniline and the amino functional groups introduced by modified AZO, which can be chemically grafted onto the polyurea main chain during the curing process, enabling the coating to have better conductive performance and adhesion, thereby improving the corrosion resistance of the coating.

The invention discloses an adhesive tape with high stripping stability and a preparation process thereof. The adhesive tape comprises a PET (Polyethylene Terephthalate) base material subjected to corona treatment, an acrylic acid pressure-sensitive adhesive layer, a release layer and an antistatic liquid coating. The acrylic pressure-sensitive adhesive layer is composed of acrylate monomers, saturated polyester resin, bisphenol F, bisphenol A epoxy resin and amino resin. The preparation process comprises the steps of corona pretreatment of the polyethylene glycol terephthalate base material, coating of the antistatic liquid, coating of the pressure-sensitive adhesive, compounding of the release layer and curing treatment. The stripping force change rate of the adhesive tape after damp-heat aging and low-temperature aging is smaller than 5% and is far lower than the industrial standard, and the adhesive tape has excellent stripping stability, antistatic property and weather resistance and is suitable for the fields of electronic product protection, automobile paint spraying shielding and the like.

The invention discloses a battery, a positive pole piece, slurry, a dispersing agent, a preparation method and electric equipment. The battery comprises a positive electrode plate, the positive electrode plate comprises a current collector and a positive electrode material layer arranged on at least one side of the current collector, the positive electrode material layer comprises a positive electrode active material and a dispersant, the dispersant comprises a polyester compound, the polyester compound comprises a structural unit A and / or a structural unit B, the chemical formula of the structural unit A is shown in the specification, and the chemical formula of the structural unit B is shown in the specification. R1 and R2 are respectively selected from at least one of C0, a C1-C18 alkyl group and a C6-C18 aryl group; and R3 and R4 are respectively selected from at least one of H, C1-C18 alkyl groups, C6-C18 aryl groups and ester groups. The dispersing agent can improve the dispersibility of the positive electrode slurry and improve the uniformity and flexibility of the positive electrode plate, so that the battery has relatively high capacity and stability.

Concentrated dispersions of silver nanowires are used to prepare qualitatively distinct silver structures with a range of properties. The concentrated dispersions can have a high weight percent of silver nanowires and can be formulated to be flowable liquids or non-flowing pastes. The concentrated dispersions can be stable with no visible settling over the course of a week, can have non-Newtonian rheology, and can be diluted to a desired weight percent of silver nanowires without detrimental effects on the uniformity of the dispersions. The concentrated dispersions can be formulated with or without polymers or pre-polymer components. The concentrated dispersions can be formulated with silver salts to adjust dispersion of the silver nanowires and to improve electrical conductivity of cured silver structures formed from the dispersions. Methods for forming the concentrated dispersions are described as are methods to form silver structures from the dispersions.

The invention discloses a high-barrier BOPET (Biaxially Oriented Polyethylene Terephthalate) film and a preparation method thereof. Comprising the following steps: carrying out melt extrusion on dried polyester chips, cooling cast sheets, and then carrying out longitudinal stretching; after corona treatment, double surfaces are coated with a coating liquid, and the thickness of the coating is controlled to be 0.5-1 [mu] m; then transversely stretching and shaping at high temperature, so that the coating is fully crosslinked and cured; and finally, carrying out sectional cooling and rolling to obtain the BOPET film. The preparation method has the beneficial effects that the modified monomer with a quaternary ammonium salt structure is chemically synthesized and is applied to a coating liquid system of the BOPET film, so that the comprehensive performance of the film is remarkably improved.

The invention discloses superfine copper powder and a preparation method and application thereof, and belongs to the technical field of copper powder.The preparation method of the superfine copper powder comprises the following steps that a micro-channel reactor is provided, and the micro-channel reactor comprises a micro-mixer and a micro-reactor which are connected with each other; a copper salt solution, a reducing agent solution and a sodium hydroxide solution are injected into a micro-channel reactor to be evenly mixed, a mixed solution is obtained and then enters the micro-channel reactor to be subjected to a reaction, discharging is conducted, and the superfine copper powder is obtained. The injection flow rate ratio of the sodium hydroxide solution to the copper salt solution to the reducing agent solution is (0.5-2): (0.8-1.2): (0.8-1.2). According to the method, the uniformity and the preparation efficiency of the superfine copper powder are remarkably improved, meanwhile, the reaction time is greatly shortened, the yield and the purity of the superfine copper powder are remarkably improved, continuous and efficient preparation of the superfine copper powder is achieved, and the method has wide application prospects.

A readily adhesive white polyester film comprising a polyester film substrate and a coating layer on at least one surface of the polyester film substrate,the coating layer comprising a cationic antistatic agent containing nitrogen, a polyester resin, and a polyurethane resin,the proportion A (at %) of nitrogen derived from the antistatic agent and the proportion B (at %) of nitrogen derived from the polyurethane resin based on surface element distribution measurement by X-ray photoelectron spectroscopy in the coating layer satisfying the following formulas (i) and (ii), anda surface of the coating layer having a contact angle with respect to water of 50° to 70°:A (at %)>0.4  (i)2.0≤B / A≤5.0.  (ii)

The invention discloses a printing antistatic polyester release film and a preparation method thereof, the release film is composed of a PET base film and a release agent layer firmly combined with the PET base film, the PET base film is formed by blending, melting, extruding and stretching PET particles added with a composite additive, and the release agent layer is formed by curing a release agent; wherein the composite additive is prepared from polyvinylpyrrolidone, graphene oxide, 3-aminopropyl triethoxy silane and polyvinyl butyral. The release agent is prepared from a polydimethylsiloxane-amino siloxane copolymer, fluorosiloxane resin, a quaternary ammonium salt type antistatic agent, isocyanate silane and a mixture of butyl acetate and methylbenzene. The composite additive provided by the invention not only can provide stable antistatic performance when being added, but also can further enhance the printing performance and the surface activity of the PET base film in the subsequent plasma treatment process, so that the composite additive is suitable for applications such as electronic product packaging, labels and the like which have high requirements on static electricity and printing performance.

The embodiment of the invention provides antistatic coating slurry, a preparation method of the antistatic coating slurry and a preparation method of an antistatic coating. The antistatic coating slurry is prepared from the following components in parts by mass: 100 parts of resin matrix dispersion liquid, 1-15 parts of a macromolecular antistatic agent and 0.1-0.5 part of a cross-linking agent, wherein 100 parts of the resin matrix dispersion liquid comprises the following components in parts by mass: 95-99.5 parts of a resin matrix and 0.5-5 parts of a physical antistatic agent. The basic antistatic performance is provided through the macromolecular antistatic agent, the addition amount of the physical antistatic agent is reduced, it is ensured that the coating keeps high transparency and light-color appearance, the physical antistatic agent constructs an efficient conductive network under the low addition amount, and resistivity fluctuation caused by temperature and humidity changes is inhibited; the cross-linking agent improves the hardness, the wear resistance and the bending resistance of the formed antistatic coating and maintains the continuity of a conductive path; and the coating can meet the protection requirements in the aspects of light transmission, radiation protection, static electricity resistance, mechanical durability and the like.

The invention provides a secondary battery, a power utilization device and a binder, the secondary battery comprises a positive pole piece, a negative pole piece and an isolating membrane, the negative pole piece comprises a negative current collector and a negative membrane layer arranged on at least one surface of the negative current collector; the negative electrode film layer comprises a negative electrode active material and a first binder; the mass ratio of the negative electrode active material in the negative electrode film layer is 96%-98.4%; the mass ratio of the first binder in the negative electrode film layer is 0.5%-3%; the first binder includes a polymer including-COOM,-CONH2,-CN, and-COOR, where M includes an alkali metal, and R includes a substituted or unsubstituted C1-C20 alkyl group. The secondary battery in the present application has improved energy density and does not deteriorate processability.

This invention discloses a thermally conductive and electromagnetically shielding multilayer composite film, its preparation method, and its applications. The thermally conductive and electromagnetically shielding multilayer composite film of this invention comprises an insulating and thermally conductive layer, a magnetic shielding layer, a conductive shielding layer, and an insulating and thermally conductive layer stacked sequentially. The insulating and thermally conductive layer is a cellulose film containing thermally conductive fillers; the magnetic shielding layer is a cellulose film containing magnetic fillers and expanded microspheres; and the conductive shielding layer is a cellulose film containing conductive fillers and expanded microspheres. The thermally conductive and electromagnetically shielding multilayer composite film of this invention has advantages such as excellent in-plane thermal conductivity, excellent electromagnetic shielding performance, high mechanical strength, and small thickness. Furthermore, its preparation process is simple and environmentally friendly, and it has broad application prospects in fields such as 5G communication, consumer electronics, new energy batteries, and national defense.