10results about How to "Lower percolation threshold" patented technology

The invention is applicable to the technical field of conductive adhesives, and provides a conductive nanoparticle-doped epoxy resin conductive adhesive which comprises the following raw materials in parts by weight: 0.05-4 parts of conductive metal nanoparticles, 0.03-6 parts of conductive polymer nanoparticles, 45-80 parts of modified flaky silver-coated copper powder, 10-50 parts of epoxy resin, 10-30 parts of a curing agent, 0.001-1 part of an accelerant and 0.2-0.6 part of a modifier. The invention further provides a preparation method of the epoxy resin conductive adhesive doped with the conductive nanoparticles. The invention also provides application of the epoxy resin conductive adhesive doped with the conductive nanoparticles in preparation of a semiconductor packaging material. The conductive metal nanoparticles and the conductive polymer nanoparticles are introduced into the formula of the conductive adhesive in a doping manner, the usage amount of the micron silver coated copper powder can be reduced on the premise of ensuring that the conductive adhesive has good conductivity, and the preparation method is convenient to operate, simple and easy to implement and low in raw material price.

The invention provides a polyvinylidene fluoride-based nanofiber yarn wave-absorbing fabric as well as a preparation method and application thereof, and belongs to the technical field of preparation of wave-absorbing composite materials. The preparation method comprises the following steps: preparing nanofiber yarns or nanofiber core-spun yarns by adopting a conjugate electrostatic spinning technology, directly adding a conductive substance into a spinning solution to form conductive nanofibers, and further coating the nanofiber yarns or the nanofiber core-spun yarns with a PDA shell layer to improve the wear resistance and reduce silver nanoparticles in situ; finally, the yarns are woven into fabric through a weaving or knitting technology, and the fabric is applied to the fields of buildings, electromagnetic protective clothing, flexible electronics and the like. Compared with an existing microwave absorbing material, the fabric-based material is light in weight and good in mechanical flexibility and processability. Fabrics formed of nanofiber yarns or nanofiber core spun yarns facilitate the induction of interfacial polarization and multiple reflections, and can deeply design material properties. The material provided by the invention has better wear resistance, wearability and microwave absorption performance, and is suitable for actual production and application.

The invention belongs to the technical field of polymer composite materials, and relates to an ionic liquid modified magnesium hydroxide flame-retardant master batch for rotational moulding and a preparation method thereof, the flame-retardant master batch comprises the following components by mass percentage: 10.0%-40.0% of polyethylene, 3.0%-10.0% of polyethylene wax, 15.0%-60.0% of functional magnesium hydroxide, 0-50.0% of magnesium hydroxide, 5.0%-10.0% of a flexibilizer, and 3.0%-10.0% of an antioxidant. The preparation method has the advantages that groups with specific functions are introduced to N at two different positions of an imidazole ring, organic and inorganic compounding is realized through the groups, the problem of thermoplasticity of Mg (OH) 2 is solved, and the prepared composite material has the characteristic of low percolation threshold value; the imidazole structure in the ionic liquid has high thermal stability and charring ability, and meanwhile, the silica structure is easy to migrate to the surface of the material during combustion to generate a barrier layer, so that the thermal insulation and flame retardant effects are achieved.

The invention provides a flexible conductive composite material and a preparation method and application thereof, and belongs to the technical field of high polymer materials, and the preparation method comprises the following steps: mixing graphene, carbon nanotubes and a polar organic solvent to obtain a nano carbon material dispersion liquid; mixing raw silicone rubber, a silane coupling agent and the nano carbon material dispersion liquid, and carrying out surface modification treatment to obtain a nano carbon modified raw rubber mixed liquid; and mixing the nanocarbon modified raw rubber mixed solution with a cross-linking agent, and carrying out a cross-linking reaction to obtain the flexible conductive composite material. The prepared flexible conductive composite material has a low seepage threshold value and high mechanical performance, and after the flexible conductive composite material serves as a sensing layer of the flexible piezoresistive sensor, the flexible piezoresistive sensor can have a large measuring range and high sensitivity and repeated loading capacity.

The invention provides a low dielectric and electromagnetic shielding LCP composite material and a preparation method thereof, belongs to the technical field of high polymer material processing, and aims to solve the technical problem of poor dielectric and electromagnetic shielding performance of an LCP material. The LCP composite material is prepared from the following raw materials: LCP resin, polytetrafluoroethylene resin, low-dielectric glass fibers, electroplated metal low-dielectric glass fibers, conductive filler and auxiliaries. According to the invention, the LCP resin is used as matrix resin to be compounded with the polytetrafluoroethylene resin, so that the obtained resin matrix not only has excellent mechanical properties, weather resistance, solvent resistance and the like, but also has excellent dielectric properties, and is very low in dielectric constant and dielectric loss; the low-dielectric glass fiber, the electroplated metal low-dielectric glass fiber and the conductive filler are compounded to serve as the filling agent, a good conductive network can be constructed in a resin matrix, the conductive seepage threshold value is reduced, the mechanical property of the resin matrix is enhanced, and meanwhile the conductivity and the heat conductivity coefficient of the resin matrix can be remarkably improved.

This application relates to the field of metal surface treatment, specifically disclosing a fingerprint-resistant galvanized sheet and its production method. The fingerprint-resistant galvanized sheet includes a substrate, a galvanized layer formed on the surface of the substrate, and an inorganic passivation layer and an organic composite coating sequentially coated on the surface of the galvanized layer. The organic composite coating includes an acrylate-polysiloxane modified resin system and a hybrid conductive network filler dispersed in the resin system. The hybrid conductive network filler is composed of two-dimensional nano-graphene and one-dimensional conductive material in a mass ratio of 5:1 to 15:1, and the surface of the hybrid conductive network filler is grafted with a silane coupling agent. The organic composite coating is distributed in a transverse gradient on the surface of the galvanized sheet, with a film weight of 0.8-1.0 g / m² in the central region and 0.6-0.8 g / m² in the edge region. The fingerprint-resistant galvanized sheet of this application exhibits excellent fingerprint resistance and corrosion resistance, while also achieving high conductivity.

The invention discloses a self-supporting electromagnetic shielding composite film and a preparation method thereof. The self-supporting electromagnetic shielding composite film is composed of three-dimensional fractal silver dendrites (AgFDs) and aramid nanofiber (ANFs). The preparation method comprises the following steps: carrying out suction filtration on AgFDs / ANFs mixed dispersion liquid by adopting a vacuum-assisted suction filtration technology to prepare a wet film, and then washing, drying and hot-pressing to prepare the composite film. Under the conditions that the mass fraction of AgFDs is 80-92 wt% and the total thickness is smaller than or equal to 20 microns, the conductivity of the composite film ranges from 1.5 * 10 < 4 > S / m to 2.0 * 10 < 6 > S / m, the electromagnetic shielding effectiveness can be adjusted within the range of 30-100 dB, the electromagnetic shielding effectiveness per unit thickness reaches up to 1500-6000 dB / mm, and the composite film is particularly suitable for electromagnetic shielding of flexible electronic components and circuits.

The invention discloses a preparation method of a flexible automatic temperature limiting conductive material, and belongs to the technical field of functional material preparation. The normal-temperature flexible thermal management material is prepared by using EVA as a supporting material, hexadecanoic acid and stearic acid as phase-change materials and graphite as a conductive filler and adjusting the use ratio of the materials, so that excellent temperature control performance and a relatively low conversion temperature point are achieved. Meanwhile, the material is combined with the interdigital electrode, so that the heat sensitivity of the device is improved, the resistance value of the composite material is reduced, and the use requirements under different powers are met by adjusting the pattern of the interdigital electrode, so that the response speed of the whole composite material to the temperature is improved; high PTC strength and good room temperature resistivity are achieved by changing the content of the conductive filler in the composite material. Under different proportions of components, the composite material has good electric heating performance, and meanwhile, under the conditions of different voltages, cyclic pressurization and further pressurization, the temperature control condition is good.

This invention discloses an enhanced antistatic polyetheretherketone (PEEK) composite material and its preparation method. The composite material is prepared from the following raw materials in parts by weight: 60-85 parts of PEEK resin, 5-15 parts of a first synergistic component, 3-10 parts of a second synergistic component, 2-8 parts of a third synergistic component, and 1-5 parts of a high-temperature processing aid. The first synergistic component is a mixture of a metal-based conductive filler and a high-temperature resistant antistatic synergist; the second synergistic component is ionic liquid-functionalized modified graphene; the third synergistic component is a composite of carbon nanotubes and conductive nanofibers; and the high-temperature processing aid includes a high-temperature lubricant and a high-temperature antioxidant. The preparation method includes steps such as preparing various premixes, melt blending, extrusion granulation, and supercritical fluid in-mold foaming. This invention constructs a stable three-dimensional conductive network through the synergistic effect of multi-scale conductive fillers, giving the composite material excellent antistatic properties.

The invention discloses printable electrode slurry for a flexible electronic device and a preparation method of the printable electrode slurry, and belongs to the technical field of electrode slurry, and the printable electrode slurry comprises flaky tungsten powder, mesoporous silica, fibrous magnesium oxide powder, a defoaming agent, a leveling agent and the balance of a waterborne polyurethane binder. According to the flaky tungsten powder, a continuous conductive network is formed through surface contact, and the seepage threshold value is reduced; the mesoporous silica is used as a flexible buffer phase and can absorb more than 90% of bending stress; the silicon dioxide-magnesium oxide composite ceramic phase is cured at 180 DEG C to form a compact framework, so that the resistance fluctuation of the slurry under the thermal cycle of-40 DEG C to 150 DEG C is less than 3%, and the resistance increase is less than 8% after the slurry is aged for 500 hours at the humidity of 85 DEG C / 85%.