131 results about "Polyimide membrane" patented technology

The invention discloses a high-temperature-resistant, bending-resistant and high-flexibility polyimide film for flexible display and a preparation method of the high-temperature-resistant, bending-resistant and high-flexibility polyimide film. According to the polyimide film, by introducing the nano silicon dioxide particles and constructing the porous structure design, the problems that a traditional polyimide film is insufficient in stability in a high-temperature environment, cracks are likely to be generated after bending, and the flexibility is poor are effectively solved. The polyimide film disclosed by the invention is prepared by adopting a diamine monomer and a dianhydride monomer as main raw materials, adding nano silicon dioxide particles, and carrying out solution polymerization, gelation, pore regulation and control and thermal imidization processes. The obtained polyimide film has a micron-sized porous structure, keeps stable at a high temperature of 400 DEG C, does not generate cracks after being bent for 100,000 times, has tensile strength of more than or equal to 150MPa, elongation at break of more than or equal to 25% and light transmittance of more than or equal to 85%, and is suitable for a substrate material of a flexible display device.

The disclosure describes a device, method, and transfer apparatus for stamping thermoplastic composite blanks. The blanks may consist of laminated fibrous plies which may comprise continuous fibers in a thermoplastic polymer matrix. Supporting unidirectional fibers or holding tapes, pre-impregnated with polymer and extending beyond a shaping area's edges may be clamped in jaws, allowing the blank to be suspended and heated without sagging. The transfer system moves the blank between a heating station and a stamping station, where a punch and die may shape it while maintaining calibrated tension to reduce defects such as creasing or delamination. Advanced jaw mechanisms, including pivoting jaws with multiple clamping slots, enable differential tensioning of plies for precise forming of complex geometries. After stamping, excess fiber extensions may be trimmed and may be recycled. This approach eliminates the need for nonrecyclable polyimide films and improves process reliability for thick or heavy blanks.

The disclosure describes a device, method, and transfer apparatus for stamping thermoplastic composite blanks. The blanks may consist of laminated fibrous plies which may comprise continuous fibers in a thermoplastic polymer matrix. Supporting unidirectional fibers or holding tapes, pre-impregnated with polymer and extending beyond a shaping area's edges may be clamped in jaws, allowing the blank to be suspended and heated without sagging. The transfer system moves the blank between a heating station and a stamping station, where a punch and die may shape it while maintaining calibrated tension to reduce defects such as creasing or delamination. Advanced jaw mechanisms, including pivoting jaws with multiple clamping slots, enable differential tensioning of plies for precise forming of complex geometries. After stamping, excess fiber extensions may be trimmed and may be recycled. This approach eliminates the need for nonrecyclable polyimide films and improves process reliability for thick or heavy blanks.

The application discloses a super-thin polyimide film preparation process and a super-thin polyimide film current collector, relates to the field of polyimide film post-processing, and discloses the super-thin polyimide film preparation process, wherein a polyimide film with a thickness of 8-12 mu m is thinned to a polyimide film with a thickness of 3-6 mu m through alkali immersion; the polyimide film uniformly passes through an alkali tank; the moving speed of the polyimide film is 0.01-1 m / min; the alkali is NaOH solution and KOH solution; the mass concentration of the alkali is 3-10%; and the temperature of the alkali is 25-50 DEG C. The polyimide film with a thickness of 3-6 mu m is formed after acid pickling, water washing and drying; the acid pickling adopts hydrochloric acid with a concentration of 1-4%; and the alkali with a certain concentration can uniformly etch the surface of the polyimide film, so that the thickness of the polyimide film is thinned from 8-12 mu m to 3-6 mu m, the super-thin polyimide film is prepared, the super-thin polyimide film is used as a carrier of the super-thin current collector for preparing new energy batteries, and the super-thin current collector has high strength and stability.

The present invention provides a polyimide film and a manufacturing method therefor, wherein in the dimension change measurement by a thermomechanical analyzer (TMA) that performs a temperature rise procedure from 25° C. to 400° C. after storage for 48 hours at a humidity of 50% RH, the temperature-rise thermal expansion coefficient (50 to 200° C.) in the TD direction is −1.5 ppm / ° C. to 6 ppm / ° C., the temperature-rise thermal expansion coefficient (50 to 200° C.) being the slope of a straight line connecting a dimensional measurement value in the TD direction of the polyimide film as measured at 200° C. in the first run during the temperature rise procedure and a dimensional measurement value in the TD direction of the polyimide film as measured at 50° C. in the first run during the temperature rise procedure, and the dimensional measurement values in the TD direction correspond to dimensional change values calculated by converting, into 1 m, the length of a sample of the polyimide film used in the measurement by the thermomechanical analyzer.

The utility model discloses a flexible circuit board adopting aluminum as a conducting circuit, and relates to the technical field of flexible circuit boards. Comprising an aluminum foil layer which forms a conduction circuit through an etching process and plays a role in electrical conduction; the bottom polyimide film is located at the bottom layer of the flexible circuit board and plays a role in insulation and welding resistance; the bottom layer epoxy resin glue covers the bottom layer polyimide film and is used for bonding the bottom layer polyimide film and the aluminum foil layer; the top polyimide film is located on the top layer of the flexible circuit board and plays a role in insulation and welding resistance; and the top epoxy resin adhesive covers the lower surface of the top polyimide film and is used for bonding the top polyimide film and the aluminum foil layer. On the basis of a conventional flexible circuit board processing technology, aluminum is used for replacing copper to serve as a conducting circuit. According to the circuit board, the cost and the weight are remarkably reduced while the good conductive performance is guaranteed, and the circuit board has good corrosion resistance and is suitable for various severe environments.

The present application relates to a kind of preparation methods of peelable polyimide laminated film, which is made of multiple polyimide composite films by hot pressing forming, wherein the polyimide composite film is composed of polyimide film and adhesive, by controlling the thickness of adhesive layer, forming temperature, forming pressure and holding time, the peel strength of laminated film is controlled, and the peel strength controllable polyimide laminated film is obtained.Compared with the prior art, the present application effectively controls the peel strength of laminated film, and obtains a peelable polyimide laminated film with controllable peel strength.The method can control the peel strength of laminated film according to the use requirement, is easy to process and use, has low requirement for equipment, is easy to implement, and can be used for preparing peelable gasket.

The application provides a conical double-clad fiber probe integrated with photoacoustic excitation and detection, which integrates pump light excitation and detection light sensing through a conical double-clad fiber, integrates functions such as photoacoustic excitation, gas-light interaction and interference detection in a micro probe, effectively simplifies the device structure, reduces the volume, and significantly improves the integration and compactness. At the same time, the conical part of the conical double-clad fiber can realize lateral diffusion of pump light, so that it can fully act on the measured gas in the closed gas chamber without additional configuration of optical components such as mirrors, and the problem of weak photoacoustic signal in a small space is improved. In addition, the application uses a fiber Fabry-Perot interference structure to complete vibration detection with a polyimide diaphragm, replacing the traditional electronic detector, having excellent anti-electromagnetic interference capability, and can accurately identify weak vibration signals, effectively improving the sensitivity and operation stability of gas detection.

The objective of the present invention is to lower a coefficient of thermal expansion of a polyimide film having a relatively high coefficient of thermal expansion. The film according to the present invention contains a polyimide and an oxide containing a boron element. The oxide containing the boron element is preferably obtained from a boric acid and alumina sol. Furthermore, the film preferably has a coefficient of thermal expansion of 50 ppm / °C or less. Furthermore, the film preferably exhibits a light transmittance of 74 % or more at wavelengths of 420nm. In addition, the film preferably exhibits a yellowness index (YI) of 6.0 or less. Furthermore, the film preferably exhibits a thermal conductivity in the range 0.231 W / mK or more and 0.275 W / mK or less.

The invention relates to the technical field of precision printing, and discloses a composite screen printing plate based on a double-layer polyimide film, which comprises a precision printing layer, a printing layer, a printing layer and a printing layer, the supporting ink penetrating layer is composed of a second polyimide film and is compounded with the precise printing layer through a middle bonding layer; and the composite reinforced substrate layer is polymer screen cloth and is fixedly connected with the back surface of the supporting ink-permeable layer through a hot melt adhesive layer. According to the invention, the expensive stainless steel wire mesh or steel sheet is replaced by the cheap polyester mesh and the high-molecular adhesive; the material cost is reduced, the preparation process is simplified, and the manufacturing cost and the energy consumption are further reduced; the whole screen functional structure is composed of the polyimide film and the polymer glue layer, and the thermal expansion coefficients of all layers of materials are similar, so that the inherent thermal mismatch problem of a traditional metal-PI composite structure is solved; under the environment of temperature change, all the layers cooperatively deform, and pattern micro-deformation and alignment deviation caused by internal stress are effectively eliminated.

The application discloses a preparation method of a crosslinked sulfonated polyimide film, and comprises the following steps: synthesizing 3,5-bis(4-aminophenoxy)benzoic acid through nucleophilic substitution and reduction reaction; synthesizing 4,4'-(1,1'-bis(4-aminophenoxy))octafluorobiphenyl through nucleophilic substitution and reduction reaction; taking 3,5-bis(4-aminophenoxy)benzoic acid and 4,4'-(1,1'-bis(4-aminophenoxy))octafluorobiphenyl as raw materials, and preparing a sulfonated polyimide polymer containing carboxyl groups through high-temperature polycondensation reaction; dissolving the sulfonated polyimide polymer containing carboxyl groups in an organic solvent, and adding polyvinyl alcohol and 4-dimethylaminopyridine to react; after the reaction is completed, casting into a film, and after washing and acidification, the crosslinked sulfonated polyimide film is obtained. The crosslinked sulfonated polyimide film prepared by the method has good performance, and has a good application prospect in a vanadium redox flow battery.

The invention relates to a polyimide-polyoxyethylene blended hollow fiber membrane and a preparation method thereof, and belongs to the technical field of separation membranes, the polyimide-polyoxyethylene blended hollow fiber membrane is prepared by blending polyimide and polyoxyethylene, and the mass ratio of polyimide to polyoxyethylene is 80: 20-90: 10; the membrane material is applied to flue gas decarburization and can stably run for a long time under the flue gas working condition, the CO2 permeability is improved by 30% or above compared with a pure polyimide membrane, the CO2 / N2 selectivity is maintained to be 50 or above, polyimide and polyoxyethylene are subjected to blending modification, and the prepared hollow fiber membrane has high selectivity, high breathability and good stability.

The application discloses a preparation method of super-high thermal conductive graphite film, which comprises the following steps: S1, polyimide film is placed in a high-temperature furnace for pre-carbonization to obtain a carbonized film; S2, the pre-carbonized film is subjected to temperature rising and falling cycle treatment under inert gas protection, and then is subjected to carbonization treatment, and is naturally cooled to room temperature to obtain a carbonized film; S3, graphene oxide nanosheet and hexagonal boron nitride nanosheet dispersion liquid are sprayed on the surface of the carbonized film, and the carbonized film is dried to obtain a carbonized film sprayed with graphene oxide nanosheet and hexagonal boron nitride nanosheet; S4, the carbonized film sprayed with graphene oxide nanosheet and hexagonal boron nitride nanosheet is subjected to gradient temperature rising graphitization treatment under inert gas protection, and is cooled to obtain a carbon foam film; and S5, the carbon foam film is subjected to calendering by a calendering machine to obtain the super-high thermal conductive graphite film. The whole process scheme improves the thermophysical properties of the graphite film, is suitable for continuous industrial production, and improves the product stability and reliability.

The invention discloses a humidity-driven soft actuator and a preparation method thereof, the actuator takes a patterned black polyimide (PI) film as a substrate, and the substrate is compounded with two-dimensional transition metal carbide Ti3C2Tx (MXene) / amylopectin amp; a functional layer is formed by Amylose / carbon nanotubes (CNTs), when the functional layer absorbs moisture and expands, the actuator is bent towards the PI side, and when the functional layer is dehumidified and contracts, the actuator is bent reversely; the bending response direction is defined through the substrate gap direction of nanosecond laser machining, and the initial curvature and the bending degree are regulated and controlled through vacuum hot pressing treatment. The components cooperate to endow the actuator with rapid humidity response capability and excellent mechanical stability. The technical problems that an existing humidity driving actuator is poor in programmability and an interface is prone to stripping are solved, an external driving source is not needed, the technology is simple, convenient and controllable, and the potential application value in the fields of soft robots, flexible intelligent equipment and the like is shown.

The invention relates to the technical field of organic solvent nanofiltration, in particular to a preparation method of a polyimide organic solvent nanofiltration membrane. The preparation method comprises the following steps: preparing polyamide acid resin slurry as a membrane casting solution, and curing the membrane casting solution on a non-woven fabric to form a membrane; immersing the obtained membrane in deionized water; immersing the obtained membrane in an imidization reagent for reaction to generate polyimide, immersing the obtained membrane in deionized water, and immersing the polyimide membrane in a solution containing a cross-linking agent; and washing to obtain the polyimide organic solvent nanofiltration membrane. The organic solvent nanofiltration membrane has high flux and interception performance in a polar organic solvent, not only has long-term stability in common organic solvents such as alcohols, ketones, esters, hydrocarbons and the like, but also has long-term stability in strong polar aprotic solvents such as DMF (Dimethyl Formamide), DMAc (Dimethyl Acrylate), NMP (N-Methyl Pyrrolidone), DMSO (Dimethyl Sulfoxide) and the like; the film has potential application value in the fields of chemical industry, pharmacy, food and the like.

A method of making a polyimide membrane includes mixing dianhydride and phenylenediamine monomers in a first solvent to form a mixture; heating the mixture thereby polymerizing to form a polyimide polymer in a crude mixture; precipitating and separating the polyimide polymer from the crude mixture; mixing and dissolving the polyimide polymer in a second solvent to form a polyimide solution; applying the polyimide solution onto a surface of a substrate to form a polyimide liquid layer on the substrate; immersing the substrate after the applying in at least one liquid medium selected from the group consisting of water and alcohol, thereby precipitating the polyimide polymer from the polyimide solution to form the polyimide membrane disposed on the surface of the substrate. A desalination system containing the polyimide membrane, and a desalination process.

The invention discloses infrared physiotherapy composite glass and a preparation method thereof. The infrared physiotherapy composite glass comprises a rigid glass substrate, a far infrared functional layer, an interface buffer layer and a protective layer which are sequentially stacked from bottom to top, the far infrared functional layer is prepared from the following raw materials in percentage by mass: 55%-65% of Cr2O3, 35%-45% of Fe3O4 and 0.5%-2% of Y2O3; a patterned electrode layer is arranged between the far infrared functional layer and the rigid glass substrate / interface buffer layer; the interface buffer layer comprises a bonding layer and an inorganic transition layer which are sequentially arranged from top to bottom; the protective layer comprises a polyimide film base material, an infrared antireflection film arranged on the upper surface of the polyimide film base material, and an antibacterial coating arranged on the lower surface of the polyimide film base material. The far infrared functional layer ensures that the high proportion of 4-14 [mu] m wave band is larger than or equal to 75% and the high emissivity is larger than or equal to 0.85, the design of the interface buffer layer solves the problem of mismatching of thermal expansion between layers, and the design of the protective layer can resist bacteria and meet the safety standard of direct contact with skin.

The application provides a light-shielding flexible copper-clad plate, a preparation method and application thereof. The light-shielding flexible copper-clad plate comprises a copper foil layer and a polyimide film layer, and further comprises a light-shielding adhesive layer arranged between the copper foil layer and the polyimide film layer. The light-shielding adhesive layer comprises a composite light-shielding filler, the composite light-shielding filler comprises modified flaky light-shielding pigment, carbon black and auxiliary filler, and the weight ratio of the modified flaky light-shielding pigment, the carbon black and the auxiliary filler is (3-6):(2-5):(1-3). The modified flaky light-shielding pigment comprises flaky light-shielding pigment and an inorganic oxide layer coated on the surface of the flaky light-shielding pigment. Based on a ternary composite light-shielding system, the combination of black pigment with a flaky structure and nanoscale carbon black is adopted, and the auxiliary filler is supplemented, so that a multi-dimensional light-shielding network is constructed, thereby realizing high optical density under a lower filler content and ensuring excellent light-shielding effect.

The present application provides a kind of polyimide precursor, polyimide, its preparation method and application.The polyimide precursor has the repeat unit structure shown in formula I, the polyimide has the repeat unit structure shown in formula II:Wherein, R a It represents the residue of tetracarboxylic dianhydride component, and the residue of tetracarboxylic dianhydride component includes the residue of 9,9-bis(3,4-dicarboxyphenyl) fluorene dianhydride component;R b It represents the residue of aromatic diamine. The polyimide formed by the polyimide precursor, or the polyimide having the repeat unit shown in formula II has good solubility in various solvents, thereby giving it good processability; and the polyimide film provided by the present application has higher light transmittance, lower yellowness index, excellent thermal stability, higher glass transition temperature and good mechanical properties.

The invention relates to the technical field of electronic special gas purification, in particular to a separation device and method for removing carbon dioxide and hydrogen sulfide in silicon tetrafluoride mixed gas through a two-stage membrane. The two-stage membrane of the separation membrane element of the CHA molecular membrane and the polyimide membrane is adopted, and the rectifying tower is coupled, so that the use of chemical substances such as sulfuric acid and an adsorbent can be avoided on the basis of obtaining the high-purity silicon tetrafluoride product gas, and the production cost and the post-treatment cost are reduced.

This invention discloses a polyimide precursor, its synthesis method, and a photosensitive resin composition containing the polyimide precursor. The synthesis method involves reacting dianhydride, an alcohol with unsaturated double bonds exhibiting free radical polymerization, and a side-chain modifier in a solvent under the catalysis of an alkaline catalyst; adding a dehydrating condensing agent and stirring; adding a diamine and reacting; finally, adding a capping agent to quench the reaction and filtering; adding the filtrate to a poor solvent within 0-2 hours to precipitate solid polyimide precursor resin, which is then refrigerated. The side-chain modifier is selected from any one or more of alcohol-based, ether-alcohol-based, and amine-based side-chain modifiers; the capping agent is selected from any one or more of alcohol-based, ether-alcohol-based, and amine-based capping agents. This invention improves the solubility of the functional resin and controls its dissolution rate without altering the main structure of the polyimide precursor, thus ensuring the performance of the final polyimide film after heat curing.

Polymeric membranes that incorporate an imidazole moiety that can be used in sour natural gas separation and purification applications.

The application provides a preparation method of a nanofiltration membrane, and belongs to the technical field of membrane separation. The method comprises the following steps: immersing a polyimide membrane into a crosslinking solution to obtain a support layer; immersing the support layer into a mixed solution of 1,3,5-tris(tris(2-hydroxyethyl)ammonium methyl)benzene and an amino alcohol, and then air-drying to obtain an intermediate; pouring a polyacyl chloride solution onto the surface of the intermediate, and then drying to obtain the nanofiltration membrane. The 1,3,5-tris(tris(2-hydroxyethyl)ammonium methyl)benzene and the small-molecule amino alcohol with strong hydrophilicity are mixed, and then subjected to an interfacial reaction with the polyacyl chloride solution to construct a separation layer of the nanofiltration membrane. The nanofiltration membrane has a regular pore structure, can realize size screening on dye molecules, and the negative charge on the surface of the nanofiltration membrane can produce electrostatic repulsion on anionic dyes, so that the rejection performance of the nanofiltration membrane on the anionic dyes is improved and the flux is maintained.

The invention discloses a sulfonated fluorine-containing polyimide-metal organic framework composite membrane as well as a preparation method and application thereof, and belongs to the technical field of all-vanadium redox flow battery diaphragms. The method comprises the following steps: synthesizing sulfonated fluorine-containing polyimide FSPI by using a high-temperature one-step method; preparing a metal organic framework MIL-101 (Cr) by adopting a hydrothermal method; the preparation method comprises the following steps: preparing a metal organic framework alpha-Fe2O3 / MIL-101 (Cr) by adopting a hydrothermal method; and preparing the sulfonated fluorine-containing polyimide-metal organic framework composite membrane FSPI / alpha-Fe2O3 / MIL-101 (Cr) by adopting a tape casting method. An ion transmission channel is regulated and controlled by introducing a metal organic framework alpha-Fe2O3 / MIL-101 (Cr) into sulfonated fluorine-containing polyimide. And the regulated ion transmission channel is larger than hydrated protons (lt, 0.24 nm) and smaller than hydrated vanadium ions (gt, 0.6 nm), so that the ion selectivity of the sulfonated fluorine-containing polyimide diaphragm is improved. The composite membrane prepared by the invention has high proton conductivity, good vanadium resistance and excellent ion selectivity. When the prepared composite membrane is used in the all-vanadium redox flow battery, the cycling stability of the battery is improved.

The present application discloses a black matting polyimide film, which comprises a polyimide accounting for 71-89 wt% of the film, the polyimide being obtained by chemical cyclization after polymerization of diamine and dianhydride to form polyamic acid; a carbon black accounting for 2-9 wt% of the film, wherein the median particle size (D50) is less than 1 μm; and a polyimide matting agent, wherein the median particle size (D50) is 0.3-4 μm, and the weight percentage of the polyimide matting agent in the film is 9-20 wt%, so that the film has a breaking elongation greater than 15%, a peak height (Spk) less than 300 nm, a 60-degree glossiness less than 30 GU, and a transmittance less than 1%.

The application discloses a polyimide film with epoxy cross-linking and a preparation method thereof. The preparation method comprises the following steps: step one, preparation of a polyamide acid solution; step two, preparation of a polyimide solution; and step three, preparation of a polyimide film. The polyimide film disclosed by the application forms a network microporous structure between polymer molecular chains by introducing a large-volume flexible cross-linking agent, increases gas permeability and gas selectivity, and thus improves the comprehensive gas separation performance of the polymer film material.

The utility model discloses a full-carbon-fiber microsatellite solar wing substrate. The solar wing substrate is composed of an upper-layer carbon fiber grid panel, a lower-layer carbon fiber grid panel, a carbon fiber honeycomb and a metal embedded part. A polyimide film is attached to the surface of the upper-layer carbon fiber grid plate, the carbon fiber honeycomb is arranged between the upper-layer carbon fiber grid plate and the lower-layer carbon fiber grid plate, the metal embedded part is embedded in the carbon fiber honeycomb, and all the components are fixed through glue joint. The all-carbon fiber microsatellite solar wing substrate provided by the utility model has the characteristics of light weight, high rigidity, short processing period, low manufacturing cost and the like.

The invention relates to the technical field of copper-clad plates, and discloses a high-frequency fluorine-based flexible copper-clad plate which sequentially comprises a high-frequency low-roughness copper foil A, a PFA film A, a dielectric layer, a PFA film B and a high-frequency low-roughness copper foil B from outside to inside, and the materials of all the layers are subjected to accurate model selection so as to adapt to roll-to-roll production and high-frequency use requirements. The thickness control range is strictly controlled within + / -1 [mu] m, and the overall flatness and dimensional stability of the stack-up structure are ensured; the thickness of the PFA film is controlled within + / -1 [mu] m, the glass transition temperature (TG) is 90-140 DEG C, the elastic modulus is 270 MPa or above, and the melting point is 300 DEG C; and carrying out surface modification treatment. According to the invention, by optimizing the stacking structure of the copper-clad plate and the type selection of each layer of material and adopting the cooperation of the PFA film and the low-roughness copper foil, the stable dielectric property and low signal loss under high frequency are ensured, the problems of easy deformation and poor adhesion of the traditional PFA film are solved, and the peel strength and the structural stability of the copper-clad plate are improved.

This invention provides a polyamic acid solution, polyimide, a polyimide film, its preparation method, and its applications. The polyimide film is obtained by blending a low-crosslinking, high-molecular-weight polyamic acid solution with a high-rigidity, low-molecular-weight, crosslinkable polyamic acid solution, followed by solution molding and imidization. This invention utilizes a crosslinked sacrificial network structure to dissipate energy during material stretching, while avoiding material uniformity problems caused by introducing other incompatible systems. The performance advantages of the constructed interpenetrating network structure effectively improve the overall mechanical properties of the polyimide film. The resulting polyimide film exhibits excellent mechanical properties and can be used as a flexible display substrate, etc.