CN110819220A - Graphene/silver-plated hollow glass bead electromagnetic shielding coating and preparation method thereof - Google Patents
Graphene/silver-plated hollow glass bead electromagnetic shielding coating and preparation method thereof Download PDFInfo
- Publication number
- CN110819220A CN110819220A CN201810921969.0A CN201810921969A CN110819220A CN 110819220 A CN110819220 A CN 110819220A CN 201810921969 A CN201810921969 A CN 201810921969A CN 110819220 A CN110819220 A CN 110819220A
- Authority
- CN
- China
- Prior art keywords
- parts
- silver
- graphene
- hollow glass
- electromagnetic shielding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
- C09D175/04—Polyurethanes
- C09D175/06—Polyurethanes from polyesters
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/08—Anti-corrosive paints
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/24—Electrically-conducting paints
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
- C09D7/40—Additives
- C09D7/60—Additives non-macromolecular
- C09D7/61—Additives non-macromolecular inorganic
- C09D7/62—Additives non-macromolecular inorganic modified by treatment with other compounds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
- C09D7/40—Additives
- C09D7/70—Additives characterised by shape, e.g. fibres, flakes or microspheres
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/001—Conductive additives
Abstract
The invention relates to the field of electromagnetic shielding coatings, and provides a graphene/silver-plated hollow glass bead electromagnetic shielding coating and a preparation method thereof, which solve the problems of high density, easy sedimentation of conductive filler, poor coating adhesion, attenuated conductive performance, high cost and difficult stable dispersion of graphene in the prior art, and the graphene/silver-plated hollow glass bead electromagnetic shielding coating is prepared by uniformly mixing a main paint and a curing agent, wherein the main paint is prepared from the following raw materials in parts by weight: 30-50 parts of polyester polyol; 0.1-2 parts of modified graphene; 15-25 parts of silver-plated hollow glass beads; 20-40 parts of a solvent; 1-3 parts of an auxiliary agent; 1-5 parts of pigment. The curing agent is prepared from the following raw materials in parts by weight: 3-8 parts of an isocyanate curing agent; 0.2-0.5 part of a catalyst; 5-10 parts of a solvent.
Description
Technical Field
The invention relates to application of graphene in paint, in particular to a graphene/silver-plated hollow glass bead electromagnetic shielding material and a preparation method thereof, and belongs to the technical field of electromagnetic shielding paint production.
Background
With the rapid development of science and technology, a large number of electronic and electrical devices and communication devices emit electromagnetic waves into the surrounding environment during use, and when the energy of the emitted electromagnetic waves exceeds a certain value, the health of human beings and the normal operation of the electronic devices are affected. In order to reduce the harmful effect of electromagnetic waves, electromagnetic shielding is performed by using a low-resistance conductor material, which produces a shielding effect by utilizing the reflection of electromagnetic waves on the surface of a shielding conductor and the absorption of electromagnetic waves inside the conductor and the loss during transmission. The traditional method for shielding electromagnetic waves uses metal and metal composite materials, but the metal and metal composite materials have the defects of difficult processing, heavy weight, poor environmental stability, easy corrosion by some gases and liquids in the air, difficult control of the wave band for shielding the electromagnetic waves and the like, so the application range of the metal and metal composite materials is limited. In contrast, the electromagnetic shielding coating combines the electromagnetic control technology with the coating production process, and becomes the most widely used electromagnetic shielding material at home and abroad at present by the advantages of easy processing, convenient construction, low cost and the like, and accounts for more than 70 percent of the whole shielding material.
According to the different components of the electromagnetic shielding conductive coating, the electromagnetic shielding conductive coating can be divided into an intrinsic type (also called structural type) electromagnetic shielding conductive coating and a doped type (also called composite type) electromagnetic shielding conductive coating, wherein the doped type electromagnetic shielding conductive coating is the main type currently applied. The doped electromagnetic shielding conductive coating is characterized in that conductive fillers with conductivity are doped in a coating without conductivity, conductive filler particles are mutually connected in a system to form a conductive path for conducting electricity, the commonly used conductive fillers mainly comprise various metals and metal oxide powder, various carbon-based conductive materials and various composite conductive materials, such as silver powder, copper powder, nickel powder, carbon black, graphite, carbon nano tubes, silver-coated copper powder, silver-coated nickel powder, silver-plated graphite and the like, the main components of the conductive fillers are synthetic resin, conductive fillers, solvents and some auxiliary agents, the shielding efficiency of the coating is mainly determined by the conductive fillers in the system, and the electromagnetic shielding conductive coating is roughly divided into three categories, namely a metal system, a carbon system and a composite system according to the difference of the conductive fillers.
In the metallic shielding paint, although the good conductivity makes the electric loss and skin effect of electromagnetic wave obvious and the shielding effect is good, the silver base is expensive, and is only suitable for some special occasions, and the popularization and application of the silver base are limited. For the copper-based shielding material, the copper has the problem that the copper is easy to oxidize and reduce the conductivity due to active chemical properties, so that the practical application of the copper-based shielding material is influenced.
For the electromagnetic shielding coating, practical applications such as adhesion and coatability are considered, and a number of disadvantages exist. For example, the density of the conductive filler is too high, which results in high density of the whole shielding material, and the conductive filler and resin are layered during mixing, coating, drying and the like due to large difference between the densities of the conductive filler and the resin, thereby affecting the uniformity of the whole. Therefore, it is an important direction to research and prepare electromagnetic wave shielding materials with strong conductive shielding property, light weight, good coating performance, wide applicable frequency range and low price.
Graphene is a newly discovered carbonaceous material with a two-dimensional lamellar structure and formed by close packing of single-layer carbon atoms in recent years, has extremely high mechanical properties, and is high in strength and good in conductivity, thereby being an excellent conductive filler. The carrier mobility of the graphene reaches 200000 cm2V. s) with a higher conductivity than silver or copper (10)6S/cm) and the theoretical specific surface area is as high as 2600 m2The conductive filler has more outstanding performance compared with the traditional carbon conductive filler. Chinese patent with publication number CN 101508855A discloses a water-based graphite conductive coating and a preparation method thereof, wherein the adhesive force is 2-3 grade, and the adhesive force is poor; publication No. CN 103131232A discloses a high-performance water-based graphene conductive coating and a preparation method thereof, and publication No. CN104163928A discloses a conductive and heat-conductive graphene slurry and a coating, wherein the conductive fillers in the two patents are used in large amounts, so that the color of the coating is dark, and the formed coating is not high in transparency or fullness; chinese patent publication No. CN 102254584 a discloses a general conductive paste based on graphene filler, which uses graphene and a conductive material as a conductive filler, and has good conductivity, but the conductive paste has a large amount of filler, especially graphene, and has high cost, and has the problems of difficult dispersion, poor compatibility with resin, and unsatisfactory adhesion. The technical contents listed in the prior art merely represent the techniques mastered by the inventor and are not of course considered as the prior art for evaluating the novelty and inventive step of the present invention.
Disclosure of Invention
For the conductive filler, for example, a chemical plating method is adopted, hollow glass beads are used as a matrix, a metal layer is coated outside the matrix, the beads and graphene are used as conductive fillers and are mixed with film-forming resin, and the light electromagnetic wave shielding coating with good uniformity and no delamination can be prepared.
The object of the invention can be achieved by the following measures: the graphene/silver-plated hollow glass bead electromagnetic shielding coating is characterized in that: the paint is prepared by uniformly mixing main paint and a curing agent, wherein the main paint is prepared from the following raw materials in parts by weight:
30-50 parts of polyester polyol
0.1-2 parts of modified graphene
15-25 parts of silver-plated hollow glass beads
20-40 parts of solvent
1-3 parts of assistant
1-5 parts of pigment and filler;
the curing agent is prepared from the following raw materials in parts by weight:
3-8 parts of isocyanate curing agent
0.2 to 0.5 portion of catalyst
5-10 parts of a solvent.
The modified graphene in the invention is grafted modified graphene.
The preparation method of the modified graphene subjected to grafting treatment comprises the following steps: preparing an ethanol solution of a silane coupling agent, adding graphene for ultrasonic dispersion, reacting at 50-70 ℃, washing, filtering and drying after the reaction to obtain the modified graphene subjected to grafting treatment. Wherein the silane coupling agent is one or more of KH-550, KH-560 and KH-570.
A more specific synthesis method of the modified graphene subjected to grafting treatment comprises the following steps: dropwise adding a small amount of hydrochloric acid into a certain amount of absolute ethyl alcohol solution, adjusting the pH value to 4.5-5.5, adding a certain amount of silane coupling agent to prepare a 5% mixed solution, uniformly stirring to fully hydrolyze the mixed solution, adding graphene into the solution, performing ultrasonic dispersion for 2 hours, keeping the temperature of reactants at 60 ℃, stirring for 3 hours, cooling to room temperature, washing off unreacted silane coupling agent by using acetone, filtering, and finally drying in a vacuum drying oven at 60 ℃ for 4 hours to obtain the graphene grafted with the silane coupling agent.
The preparation method of the silver-plated hollow glass bead comprises the following steps: and adding the pretreated hollow glass beads into the reducing solution, slowly dripping the silver-ammonia solution into the reducing solution, centrifuging, cleaning and drying.
A more specific preparation method of the silver-plated hollow glass microspheres comprises the following steps:
the pretreatment of the hollow glass microspheres generally comprises the following steps: coarsening, sensitizing, activating and drying. The pretreatment of the glass beads has great influence on the plating process, especially the sensitization and activation processes. The coarsening liquid consists of 10 ml/L of 40 percent hydrofluoric acid and 2 g/L of sodium fluoride. The sensitizing solution is SnCl220 g/L, HCl 40 ml/L, 0.1 g/L pure Sn particles. Composition of activating solution PdCl20.3 g/L、HCl 15 ml/L。
The silver ammonia solution comprises the following components: AgNO335 g/L and 200 ml/L, NaOH 14 g/L ammonia water. The reducing solution comprises the following components: formaldehyde 22 ml/L. During plating, the pretreated hollow glass beads are added into the reducing solution according to the amount of 32 g/L, stirred and dispersed for 10min, and then the silver-ammonia solution is slowly dripped into the reducing solution and kept stirring. After plating, the plating solution and the glass beads are separated by a centrifugal machine, washed by deionized water and dried.
The polyester polyol in the invention can adopt various polyester polyols in the prior art, and preferably adopts the polyester polyol with the hydroxyl value of 18-34 mgKOH/g.
The isocyanate-based curing agent in the present invention is preferably HDI trimer.
The preparation method of the isocyanate curing agent comprises the following steps: adding isocyanate into a reactor, adding the same amount of solvent, stirring for dissolving, adding a catalyst, heating for reacting until NCO% = 7.5-8.5%, adding a polymerization inhibitor which is equal to the catalyst, continuously stirring for 0.5 h, cooling, and discharging to obtain the isocyanate trimer.
In the preparation of the curing agent, a further technical scheme is that the isocyanate is HDI; the solvent is a mixed solvent of butyl acetate, ethyl acetate, DMF and xylene; the catalyst is one or a mixture of triethylene diamine, stannous octoate and tris- (dimethylamino methyl) phenol, the dosage of the catalyst is less than 0.5 percent of the total weight of the raw materials, and the polymerization inhibitor is one or a mixture of phosphoric acid, phthalide chloride and p-toluenesulfonic acid; the heating reaction temperature is 70-90 ℃.
The catalyst of the present invention is preferably dibutyl tin dilaurate.
The solvent in the invention can adopt one or more of dimethylbenzene, butyl acetate, cyclohexanone, ethyl acetate and PMA.
The auxiliary agent comprises a dispersing agent, an anti-settling agent and a flatting agent; wherein the anti-settling agent is: one or two of the rheological modified wax liquid, the polyamide wax powder and the organic bentonite are mixed according to the proportion of more than zero, and the mass percent of the rheological modified wax liquid, the polyamide wax powder and the organic bentonite is 0.5-1%;
wherein the dispersant is: 0.2-1% of nonionic dispersant by mass;
wherein the leveling agent is: one or two of the organic silicon flatting agent or the fluorine-containing flatting agent in a mass percentage of 0.2-1%.
The pigment and filler in the invention can adopt 796 titanium dioxide, 696 titanium dioxide, 596 titanium dioxide, precipitated barium sulfate, N234 carbon black, U carbon black and the like.
The invention further provides a preparation method of the graphene/silver-plated hollow glass bead electromagnetic shielding coating, which comprises the following steps:
(1) preparing a main paint: sequentially adding 30-50 parts of polyester polyol, 20-40 parts of solvent and 1-3 parts of auxiliary agent into a cylinder, uniformly stirring at high speed, adding 0.1-2 parts of modified graphene, 15-25 parts of silver-plated hollow glass beads and 1-5 parts of pigment and filler while stirring, uniformly stirring at high speed, grinding with a grinder until the fineness is less than or equal to 50 mu m, and filtering with a filter screen to obtain main paint;
(2) preparation of the curing agent: 3-8 parts of isocyanate curing agent, 0.2-0.5 part of catalyst and 5-10 parts of solvent are sequentially added into a cylinder, dispersed at low speed for 30 min, and then filtered by a filter screen to obtain the curing agent.
Compared with the existing electromagnetic shielding coating, the invention has the following beneficial effects:
(1) when the thickness of the coating prepared by the method is 30-60 mu m, the shielding effectiveness is more than or equal to 60 dB, and the surface resistivity is less than or equal to 0.06 omega.
(2) According to the invention, the graphene and the silver-plated hollow glass beads are cooperatively used in the coating, and compared with the method of simply using the graphene or the silver-plated hollow glass beads in the coating, the graphene sheet and the silver-plated hollow glass beads are easier to form a conductive path, so that the addition amount of the graphene sheet and the silver-plated hollow glass beads with the same conductive effect is obviously reduced, and the cost is lower; and the conductivity is more stable.
(3) The conductive filler is not easy to settle, has good weather resistance and is not easy to oxidize, so the coating has long service life and has a lasting shielding effect on electromagnetic waves.
(4) The mechanical property of the coating can be obviously enhanced by adding the graphene, and the adhesive force and the corrosion resistance of the coating are improved.
Detailed Description
The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.
Preparation of graphene grafted with silane coupling agent
Dripping 20-30 drops of hydrochloric acid into 100 mL of absolute ethyl alcohol solution, adjusting the pH value to 4.5-5.5, adding a certain amount of silane coupling agent KH-560 to prepare a 5% mixed solution, stirring uniformly by using a glass rod to fully hydrolyze the mixed solution, adding 1.5g of graphene into the solution, ultrasonically dispersing for 2 h, keeping the temperature of reactants at 60 ℃, stirring for 2-4 h, cooling to room temperature, washing off unreacted silane coupling agent by using acetone, filtering by using a filter membrane, and finally drying for 4 h in a vacuum drying oven at 60 ℃ to obtain the graphene grafted with the silane coupling agent, namely the modified graphene grafted with the silane coupling agent.
Preparation of silver-plated hollow glass microspheres
Since the electroless plating must take place on a catalytically active surface, the glass beads must be pretreated to deposit a layer of a noble metal having catalytic properties, such as palladium, silver, gold, etc., on the surface to enable the electroless plating to take place.
The pretreatment of the hollow glass microspheres generally comprises the following steps: coarsening, sensitizing, activating and drying.
The roughening solution comprises the following components: 10 ml/L of 40% hydrofluoric acid and 2 g/L of sodium fluoride. Coarsening process: adding the glass beads into the coarsening liquid, and mechanically stirring for 10 minutes; standing until the bead layer and the aqueous solution layer are separated, taking out the coarsening solution, and then washing the beads for 3 times by using deionized water.
The sensitizing solution comprises the following components: SnCl220 g/L, HCl 40 ml/L, 0.1 g/L pure Sn particles. And (3) sensitization: pouring the sensitizing solution into the roughened glass microspheres at room temperature; reacting for 15 minutes under mechanical stirring, and then standing; after the micro-bead layer and the aqueous solution layer are separated, the sensitizing solution is completely absorbed, and the cleaning solution is cleaned until no Cl & lt- & gt exists.
The activating solution comprises the following components: PdCl20.3 g/L, HCl 15 ml/L. And (3) an activation process: adding the activating solution into the sensitized glass beads; reacting for 15 minutes under mechanical stirring, and then standing; after the micro-bead layer and the aqueous solution layer are separated, the activating solution is sucked up, washed for three times and then dried at 120 ℃.
The chemical silver plating of the glass beads is to mix silver ammonia solution and reducing agent to reduce and deposit silver ions on the surfaces of the hollow glass beads, thereby preparing the light conductive filler. The hollow glass microsphere is pretreated, and a certain amount of metal palladium is deposited on the surface of the hollow glass microsphere, so that the hollow glass microsphere has surface activity, and the silver can be ensured to be deposited on the surface of the microsphere and not generated in a plating solution.
The silver ammonia solution comprises the following components: AgNO335 g/L and 200 ml/L, NaOH 14 g/L ammonia water. When in preparation, as the NaOH releases heat when dissolved, the NaOH is separately dissolved, and AgNO is added after the temperature is reduced to room temperature3And ammonia water.
The reducing solution comprises the following components: formaldehyde 22 ml/L.
During plating, the pretreated hollow glass beads are added into the reducing solution according to the amount of 32 g/L, stirred and dispersed for 10min, and then the silver-ammonia solution is slowly dripped into the reducing solution and stirred. After plating, separating the plating solution and the glass beads by a centrifugal machine, separating for 5 min at 1000 r/min, then washing for 3-4 times by deionized water, and drying.
Preparation of curing agent HDI trimer solution
Adding a certain amount of HDI into a three-neck flask provided with a reflux condenser pipe, a thermometer and a stirrer, adding xylene with the same amount, stirring and dissolving, adding a catalyst of tris- (dimethylaminomethyl) phenol, heating to 70 ℃ for reaction, adding a polymerization inhibitor phthalide chloride with the same amount as the catalyst when NCO% =8.0%, continuously stirring for 0.5 h, and diluting with xylene until the solid content is 53%, thus obtaining the HDI trimer solution.
Example 1:
preparation of graphene/silver-plated hollow glass bead electromagnetic shielding coating
(1) Preparing a main paint: adding 80 kg of polyester polyol, 36kg of dimethylbenzene serving as a solvent, 36kg of butyl acetate serving as a solvent, 1.2 kg of nonionic dispersant serving as a dispersant, 0.8kg of organic bentonite serving as an anti-settling agent and l.0 kg of organic silicon leveling agent serving as a leveling agent into a cylinder in sequence, uniformly stirring at a high speed, adding 0.8kg of modified graphene, 40 kg of silver-plated hollow glass microspheres, 3.6kg of titanium dioxide serving as a pigment and filler and 3.6kg of precipitated barium sulfate serving as a pigment and filler while stirring, grinding by using a grinder after uniformly stirring at a high speed until the fineness is less than or equal to 50 mu m, and filtering by using a filter screen to obtain the main paint;
(2) preparation of the curing agent: sequentially adding 8kg of HDI tripolymer solution, 0.2 kg of dibutyl tin dilaurate solution and 12 kg of dimethylbenzene serving as a solvent into a cylinder, dispersing at low speed for 30 min, and filtering by using a filter screen to obtain a curing agent;
(3) mixing and constructing the main paint and the curing agent to form a coating layer: the main paint and the curing agent obtained in the two steps are firstly blended and stirred uniformly according to the weight ratio of 5:1, then the diluent is added to adjust the construction viscosity, the mixture is atomized to the construction surface by common air spraying equipment, and the mixture is baked for 30 min at 70 ℃ to obtain the paint.
Example 2:
preparation of graphene/silver-plated hollow glass bead electromagnetic shielding coating
(1) Preparing a main paint: 96 kg of polyester polyol, 36kg of dimethylbenzene serving as a solvent, 36kg of PMA serving as a solvent, 6kg of cyclohexanone serving as a solvent, 1.5 kg of nonionic dispersant serving as a dispersant, 0.8kg of rheological modified wax liquid serving as an anti-settling agent and l.0 kg of organic silicon leveling agent serving as a leveling agent are sequentially added into a cylinder and uniformly stirred at a high speed, 0.5kg of modified graphene, 42 kg of silver-plated hollow glass microspheres and 5kg of titanium dioxide serving as a pigment and filler are added while stirring, the mixture is uniformly stirred at a high speed and then ground by a grinder until the fineness is less than or equal to 50 mu m, and the mixture is filtered by a filter screen to obtain main paint;
(2) preparation of the curing agent: sequentially adding 8.5 kg of HDI tripolymer solution, 0.25 kg of dibutyl tin dilaurate solution and 16 kg of butyl acetate serving as a solvent into a cylinder, dispersing at a low speed for 30 min, and filtering by using a filter screen to obtain a curing agent;
(3) mixing and constructing the main paint and the curing agent to form a coating layer: the main paint and the curing agent obtained in the two steps are firstly blended and stirred uniformly according to the weight ratio of 5:1, then the diluent is added to adjust the construction viscosity, the mixture is atomized to the construction surface by common air spraying equipment, and the mixture is baked for 30 min at 70 ℃ to obtain the paint.
Example 3:
preparation of graphene/silver-plated hollow glass bead electromagnetic shielding coating
(1) Preparing a main paint: sequentially adding 100 kg of polyester polyol, 30 kg of dimethylbenzene serving as a solvent, 36kg of PMA serving as a solvent, 1 kg of nonionic dispersant serving as a dispersant, 0.3 kg of polyamide wax powder serving as an anti-settling agent and 0.5kg of fluorine-containing leveling agent serving as a leveling agent into a cylinder, uniformly stirring at a high speed, adding 0.5kg of modified graphene, 36kg of silver-plated hollow glass beads and 3 kg of N234 carbon black serving as a pigment and filler while stirring, uniformly stirring at a high speed, grinding by using a grinder until the fineness is less than or equal to 50 mu m, and filtering by using a filter screen to obtain main paint;
(2) preparation of the curing agent: sequentially adding 7.5 kg of HDI tripolymer solution, 0.4 kg of dibutyl tin dilaurate solution and 8kg of butyl acetate serving as a solvent into a cylinder, dispersing at low speed for 30 min, and filtering by using a filter screen to obtain a curing agent;
(3) mixing and constructing the main paint and the curing agent to form a coating layer: the main paint and the curing agent obtained in the two steps are firstly blended and stirred uniformly according to the weight ratio of 5:1, then the diluent is added to adjust the construction viscosity, the mixture is atomized to the construction surface by common air spraying equipment, and the mixture is baked for 30 min at 70 ℃ to obtain the paint.
The test was performed with reference to GJB 2604-:
| performance index | GJB 2604-1996 | Example 1 | Example 2 | Example 3 |
| Shielding effectiveness dB | 60~80 | 65 | 63 | 61 |
| Surface resistivity omega | ≤0.06 | 0.054 | 0.055 | 0.059 |
| Grade of adhesion | 0~1 | 1 | 1 | 1 |
| Impact strength kgcm | 50 | 61 | 59 | 53 |
The graphene/silver-plated hollow glass bead electromagnetic shielding coating construction reference comprises the following steps:
(1) before spraying, the pretreatment procedures such as cleaning the surface of a workpiece and the like need to be done, and the workpiece needs to be kept clean and dry. The main paint and the curing agent are firstly blended and stirred uniformly according to the proportion of 5:1, then the diluent is added to adjust the construction viscosity to 18-22 s, and the paint is coated after the paint is placed for 5 min.
(2) The coating method adopts air spraying construction, and the spraying pressure is as follows: 0.4-0.6 MPa, gun distance: 0.2 to 0.4 m and a spraying thickness of 30 to 60 μm.
(3) During construction, if the paint liquid has coarse grains, the paint liquid can be filtered by 120-mesh filter cloth.
The curing temperature of the coating is 70 ℃, and the curing time is 30 min.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and although the present invention has been described in detail by referring to the preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention can be made without departing from the spirit and scope of the technical solutions, and all the modifications and equivalent substitutions should be covered by the claims of the present invention.
Claims (10)
1. The graphene/silver-plated hollow glass bead electromagnetic shielding coating is characterized in that: the paint is prepared by uniformly mixing main paint and a curing agent, wherein the main paint is prepared from the following raw materials in parts by weight:
30-50 parts of polyester polyol
0.1-2 parts of modified graphene
15-25 parts of silver-plated hollow glass beads
20-40 parts of solvent
1-3 parts of assistant
1-5 parts of pigment and filler;
the curing agent is prepared from the following raw materials in parts by weight:
3-8 parts of isocyanate curing agent
0.2 to 0.5 portion of catalyst
5-10 parts of a solvent.
2. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 1, characterized in that: the polyester polyol is a mixture of any one or more than two of conventional polyester polyol, polycaprolactone polyol and polycarbonate diol mixed in any ratio.
3. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 2, characterized in that: the graphene sheets have the diameter of 5-30 micrometers and the number of layers less than or equal to 10, and are treated by a silane coupling agent.
4. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 3, characterized in that: the silver content of the silver-plated hollow glass bead is more than or equal to 30wt% after plating.
5. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 4, characterized in that: the solvent is one or a mixture of more of dimethylbenzene, butyl acetate, cyclohexanone, ethyl acetate and PMA in any ratio.
6. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 5, characterized in that: the auxiliary agent is one or a mixture of a plurality of dispersing agents, anti-settling agents and flatting agents which are mixed in any ratio.
7. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 6, characterized in that: the pigment is one or a mixture of more of 796 titanium dioxide, 696 titanium dioxide, 596 titanium dioxide, precipitated barium sulfate, N234 carbon black, U carbon black and the like which are mixed in any ratio.
8. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 7, characterized in that: the isocyanate curing agent is HDI tripolymer solution.
9. The graphene/silver-plated hollow glass bead electromagnetic shielding paint according to claim 8, characterized in that: the catalyst is dibutyl tin dilaurate.
10. A preparation method of a graphene/silver-plated hollow glass bead electromagnetic shielding coating is characterized by comprising the following steps:
(1) preparing a main paint: sequentially adding 30-50 parts of polyester polyol, 20-40 parts of solvent and 1-3 parts of auxiliary agent into a cylinder, uniformly stirring at high speed, adding 0.1-2 parts of modified graphene, 15-25 parts of silver-plated hollow glass beads and 1-5 parts of pigment while stirring, uniformly stirring at high speed, grinding with a grinder until the fineness is less than or equal to 50 mu m, and filtering with a filter screen to obtain the main paint;
(2) preparation of the curing agent: sequentially adding 3-8 parts of isocyanate curing agent, 0.2-0.5 part of catalyst and 5-10 parts of solvent into a cylinder, dispersing at low speed for 30 min, and filtering by using a filter screen to obtain the curing agent;
(3) mixing and constructing the main paint and the curing agent to form a coating layer: the main paint and the curing agent obtained in the two steps are firstly blended and stirred uniformly according to the weight ratio of 5:1, then the diluent is added to adjust the construction viscosity, the mixture is atomized to the construction surface by common air spraying equipment, and the mixture is baked for 30 min at 70 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810921969.0A CN110819220A (en) | 2018-08-14 | 2018-08-14 | Graphene/silver-plated hollow glass bead electromagnetic shielding coating and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810921969.0A CN110819220A (en) | 2018-08-14 | 2018-08-14 | Graphene/silver-plated hollow glass bead electromagnetic shielding coating and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110819220A true CN110819220A (en) | 2020-02-21 |
Family
ID=69547166
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810921969.0A Pending CN110819220A (en) | 2018-08-14 | 2018-08-14 | Graphene/silver-plated hollow glass bead electromagnetic shielding coating and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110819220A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111524654A (en) * | 2020-04-29 | 2020-08-11 | 国网河南省电力公司内乡县供电公司 | Preparation method of enhanced cable |
| CN111584154A (en) * | 2020-05-26 | 2020-08-25 | 中国电子科技集团公司第三十八研究所 | Preparation method of hole plugging silver paste for interconnection of any layers of multifunctional board and hole plugging silver paste |
| CN113831595A (en) * | 2020-06-24 | 2021-12-24 | 合肥杰事杰新材料股份有限公司 | Modified graphene, heat-conducting PBT material and preparation method thereof |
| CN115926434A (en) * | 2023-02-03 | 2023-04-07 | 安徽工业大学 | Layered polyurethane electromagnetic shielding composite foam and preparation method thereof |
-
2018
- 2018-08-14 CN CN201810921969.0A patent/CN110819220A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111524654A (en) * | 2020-04-29 | 2020-08-11 | 国网河南省电力公司内乡县供电公司 | Preparation method of enhanced cable |
| CN111524654B (en) * | 2020-04-29 | 2022-03-01 | 国网河南省电力公司内乡县供电公司 | Preparation method of enhanced cable |
| CN111584154A (en) * | 2020-05-26 | 2020-08-25 | 中国电子科技集团公司第三十八研究所 | Preparation method of hole plugging silver paste for interconnection of any layers of multifunctional board and hole plugging silver paste |
| CN113831595A (en) * | 2020-06-24 | 2021-12-24 | 合肥杰事杰新材料股份有限公司 | Modified graphene, heat-conducting PBT material and preparation method thereof |
| CN115926434A (en) * | 2023-02-03 | 2023-04-07 | 安徽工业大学 | Layered polyurethane electromagnetic shielding composite foam and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110819220A (en) | Graphene/silver-plated hollow glass bead electromagnetic shielding coating and preparation method thereof | |
| EP3723465B1 (en) | Electromagnetic shielding filler, electromagnetic shielding coating comprising same, preparation method and application thereof | |
| CN109206961B (en) | Graphene electric-conduction heat-conduction coating and preparation method thereof | |
| CN105112894A (en) | Method for conducting surface chemical copper plating on inorganic particles through dopamine | |
| CN110846881B (en) | Co3O4Preparation method of/PANI/MXene/PI electromagnetic shielding fabric | |
| CN111205713B (en) | Graphene shielding film slurry and preparation method and application thereof | |
| CN109423636B (en) | Preparation method of secondary silver-plated high-conductivity filler | |
| CN108034313B (en) | Electromagnetic shielding coating and preparation method and application thereof | |
| KR20130104848A (en) | Metal-graphene powder and coating composition for shielding electromagnetic wave comprising the same | |
| CN112105248B (en) | Electromagnetic shielding film and preparation method thereof | |
| CN109111586A (en) | The preparation method of conductive rubber strip and its application in 5G communication | |
| CN113667399A (en) | Flexible thermal protection coating, flexible thermal protection coating for ethylene propylene rubber and preparation method of flexible thermal protection coating | |
| CN109102962A (en) | The Preparation method and use of conductive rubber strip | |
| CN108822649A (en) | A kind of doping silver nanowires and the flexible and transparent conductive coating of graphene and preparation method thereof | |
| CN113801572B (en) | Super-hydrophobic and high-stability nano ceramic coating and application method thereof | |
| CN112625441B (en) | Manganese-zinc ferrite/polyaniline/titanium carbide composite wave-absorbing material and preparation method thereof | |
| CN116875103B (en) | Nano heat conduction wave absorbing auxiliary agent, low-temperature curing thermosetting powder coating and preparation method and application thereof | |
| KR20030041645A (en) | Conductive paint composition for shielding a substrate against EMI/RFI | |
| CN1417377A (en) | Preparation of coating solution for forming transparent conducting layer | |
| KR100582659B1 (en) | Electrically conductive paint compositions and preparation method thereof | |
| CN109880459A (en) | A kind of anticorona acrylic acid conductive coating and its preparation method and application | |
| CN109608676B (en) | Flexible PC graphene coated electromagnetic shielding film material and preparation method thereof | |
| CN112538296A (en) | Graphene network conductive coating for flexible circuit and preparation method thereof | |
| CN109880499B (en) | Metallizable explosion-proof coating, preparation and application thereof, explosion-proof layer with antenna, preparation thereof, and 3D glass or ceramic cover | |
| CN111420619A (en) | Preparation method of cellulose-chitosan/PANI composite aerogel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200221 |