311 results about "Pyromellitic acid dianhydride" patented technology

The invention provides a polyimide film manufactured from a polyamic acid prepared from pyromellitic dianhydride in combination with 10 to 60 mol % of phenylenediamine and 40 to 90 mol % of 3,4′-oxydianiline, based on the overall diamine. The polyimide film, when used as a metal interconnect board substrate in flexible circuits, chip scale packages (CSP), ball grid arrays (BGA) or tape-automated bonding (TAB) tape by providing metal interconnects on the surface thereof, achieves a good balance between a high elastic modulus, a low thermal expansion coefficient, alkali etchability and film formability.

The invention relates to a biaxially oriented polyimide film for flexible printed circuit board base material and a preparation method of the biaxially oriented polyimide film. The method is characterized by mainly comprising the following steps of: (1) polymerizing: preparing a basic solution of polyimide acid according to the following proportions: 1-5% of p-phenylenediamine, 2-8% of biphenyltetracarboxylic dianhydride, 5-10% of diaminodiphenyl ether, 8-15% of pyromellitic dianhydride and 62-84% of dimethylacetylamide; (2) salivating the solution into a film; (3) longitudinally stretching the film according to the stretching ratio of 1:1.02-1.15; (4) transversely stretching the film according to the stretching ratio of 1:1.05-1.2 and carrying out imidization; (5) cutting the edge and rolling up the film; (6) postprocessing the film; and (7) cutting and packaging the film. The special biaxially oriented polyimide film material conforming to the flexible printed circuit board base material can be obtained by using the preparation method provided by the invention.

The invention discloses a dimension stable polyimide film, which contains the following components: component A: copolymer of biphenyl tetracarboxylic acid dianhydride, pyromellitic dianhydride and p-phenylenediamine in dimethyl acetamide solvent; component B: copolymer of pyromellitic dianhydride and p-phenylenediamine in dimethyl acetamide solvent; copolymer of pyromellitic dianhydride and p-phenylenediamine, 4, 4'-diaminodiphenyl ether in dimethyl acetamide solvent; wherein, the weight percent of the component A is 20 to 50 percent; the weight percent of the component B is 5 to 20 percent; the weight percent of the component C is 30 to 60 percent; the invention also discloses a preparation method of the dimension stable polyimide film. The dimension stable polyimide film of the invention has high tensile elastic modulus, low thermal expansion coefficient, low shrinkage rate and good dimensional stability, and is mainly used as a substrate of flexible circuit FPC and achieves high performance of FPC.

The invention discloses a catalyst for catalyzing in preparation of pyromellitic acid dianhydride from durene. In the catalyst, V2O5-TiO2-P2O5-Sb2O3-MoO3 is taken as a composition system; a major catalyst consists of V2O5 and TiO2 in the ratio of (0.18-0.20):(0.82-0.80); a catalyst accelerator consists of P2O5, Sb2O3 and MoO3; and when the weight of the major catalyst is set as 1, P2O5 accounts for 0.017-0.019, Sb2O3 accounts for 0.036-0.038, and MoO3 accounts for 0.002-0.004. The invention further discloses a preparation method of the catalyst. The catalyst has the characteristics of high selectivity and high yield, and is suitable to be applied to gas-phase oxidation of durene.

The invention discloses a preparation method for a graphene-polyimide composite film. The preparation method comprises the following steps: adopting graphene and polyamide acid prepared through enabling 4, 4-diaminodiphenyl ether and pyromellitic acid dianhydride to be subjected to polycondensation in a solvent; adding dispersed graphene suspension liquid into the polyamide acid prepared through polycondensation reaction, dispersing circularly for 10-16 hours, adjusting the molar ratio of amine to anhydride in the polyamide acid to (1:0.98)-(1:0.995), and enabling the viscosity to reach 60000 CP-90000 CP, wherein the graphene is 1-15% of the solid content of the polyamide acid; then, defoaming and casting for forming the film; finally, performing imidization, rolling and slitting. According to the graphene-polyimide composite film prepared by the preparation method, the tensile strength is not less than 100 Mpa, the heat-conducting property is not less than 5w/m.k, and the elongation at break is not less than 15%.

The invention discloses a superhydrophobic nanofiber membrane and a preparation method thereof. The superhydrophobic nanofiber membrane comprise the steps of dissolving monomer biphenyl tetracarboxylic dianhydride and p-phenylenediamine in N, N-dimethylformamide, reacting at low temperature to synthesize PAA, preparing a PAA nanofiber membrane from PAA through electrostatic spinning, and then imidizing to obtain a PI membrane; and carrying out layer-by-layer self-assembly by using ferric chloride and phytic acid and carrying out dip-coating modification by using a PDMS solution to obtain the superhydrophobic nanofiber membrane. According to the invention, a layer-by-layer self-assembly structure is utilized, a silane coupling agent is introduced on the basis, and the layer-by-layer self-assembly structure and the silane coupling agent are combined to obtain an oil-water separation membrane with super-hydrophobic and super-oleophilic wettability. A nano structure with a rough surface has improved oil-water separation performance, the separation efficiency of the membrane can reach 99% or above, and by verification, the membrane can be recycled.

The invention discloses a preparation method and an application of a pyromellitic dianhydride modified banana peel adsorbent, and is characterized in that the preparation method comprises the steps: washing cleanly banana peels, drying, then smashing, and thus obtaining preprocessed banana peels; then, according to the mass percentage concentration, adding 78-92% of N,N-dimethylformamide and 1.0-5% of pyromellitic dianhydride into a reactor, completely dissolving, and then adding 5-18% of the alkalized banana peels, wherein the sum of the percentages of the components is 100%; and at the constant temperature of 70+/-3 DEG C, carrying out a reflux reaction for 3-6 h, carrying out suction filtration, washing to be neutral, drying, and thus obtaining the pyromellitic dianhydride modified banana peel adsorbent. The adsorbent can directly adsorb lead ions in a water body, is high in adsorption efficiency, has good physicochemical and mechanical stability, can be used in a relatively wide pH range, and can be renewable and be used repeatedly; the banana peels are natural biomacromolecules, are biodegradable, belong to agricultural waste reuse, and is easy to obtain and cheap; and the adsorbent is a natural green adsorbent.

The invention relates to a device and method for recovering sulfuric acid in waste sulfuric acid generated in the process of producing a perylene-3,4,9,10-tetracarboxylic dianhydride pigment, mainly solving the problem that the waste sulfuric acid generated when perylene series pigments are produced can not be recovered. The device comprises a concentrating pan, a fractionating tower, a dilute sulfuric acid preheater, a concentrated sulfuric acid cooler, a concentrated sulfuric acid buffer tank, a concentrated sulfuric acid head tank, a waste sulfuric acid head tank, a medicament head tank and the like. The method is characterized in that concentrated sulfuric acid in the concentrated sulfuric acid buffer tank is circularly preheated in the concentrated sulfuric acid head tank, the preheater, the fractionating tower, the concentrating pan and the concentrated sulfuric acid cooler; the sulfuric acid enters the fractionating tower after being evaporated, and the waste sulfuric acid in the concentrating pan is sent to the waste sulfuric acid head tank and then enters the preheater; the waste sulfuric acid enters the fractionating tower; the waste sulfuric acid enters the concentrating pan after being concentrated, and a medicament is added to the concentrating pan; and the hot sulfuric acid enters the cooler after being cooled and then enters the concentrated sulfuric acid buffer tank, and part of the sulfuric acid is sent to the head tanks and part of the sulfuric acid is sent to a product storage tank by a pump. The device and the method have the advantage that the sulfuric acid in the waste sulfuric acid can be effectively recovered.

The invention provides a method for preparing nano-silica-containing polyimide hybrid material. The preparation method comprises the following steps: ultrasonically mixing nano-silica, coupling agents and toluene in a reaction kettle filled with nitrogen; stirring the mixture at a certain temperature to cool the mixture to room temperature; adding paraformaldehyde and the phenol to the sol so as to obtain transparent modified silica sol; adding diamine monomer PAPB and ODA to N,N-dimethylacetamide under nitrogen protection and stirring to completely dissolve the obtained product; adding an equimolar amount of pyromellitic dianhydride equally divided to the solution in two steps so as to obtain polyamide acid solution; adding the obtained modified silica sol to the obtained polyamide acid solution so as to obtain mixed glue solution; and placing the obtained glue solution at a certain temperature for vacuum drying so as to obtain the nano-silica-containing polyimide hybrid material. Compared with non-hybrid polyimide, the composite material synthesized by the method has better mechanical properties, thermal stability and lower coefficient of thermal expansion.

The invention provides a process for stably producing a corona-resistant polyimide film in the actual environment, comprising the following steps: preparing a component A and a component B, wherein the component A is a stable and uniform corona-resistant slurry, and the component B is a polyamic acid solution with low molecular weight; adding the component A into the component B; stirring mechanically at strong force so that nano fillings in a mixing system are distributed uniformly and stable; adding pyromellitic dianhydrider by adopting the in situ polymerization process for continuous reaction to prepare a corona-resistant polyimide solution with high molecular weight; preparing the corona-resistant polyimide solution with high molecular weight into a film at 130-175 DEG C by adopting the corresponding sobbering process according to the characteristics of the corona-resistant polyimide solution with high molecular weight; and preparing the film into the corona-resistant polyimide film at 380-450 DEG C by adopting the imidization process.

The invention discloses a corona-resistance polyimide film, which comprises emulsion, amine solution and pyromellitic dianhydride, wherein the emulsion comprises 7 to 14 mass percent of nano metal oxide and nano metal nitride, 0.3 to 0.6 mass percent of dispersant, 0.3 to 0.5 mass percent of emulsifier and the balance of pyrrolidone; the amine solution comprises 20 to 25 mass percent of 4,4'-diamino-diphenyl ether and 75 to 80 mass percent of dimethylacetylamide, and the mass ratio of the emulsion to the amine solution is 1:(1.1-1.3); and the mass ratio of the pyromellitic dianhydride to the 4,4'-diamino-diphenyl ether is 1:(1.09). The invention also discloses the manufacturing method of the corona-resistance polyimide film. In the invention, the nano metal oxide and nitride are fully dispersed in polyamic acid resin by adding the emulsifier and dispersant and by a high-pressure emulsification technique, and the content of the nano metal oxide and nitride in the polyamic acid resin is high. Therefore, the produced film has high corona resistance and small astigmatic aberration, and at the same time, the film has high mechanical performance, electrical performance and the like.

The invention discloses a fiber composite material for robotic electronic skin and a preparation method thereof. The fiber composite material is prepared according to the following steps: a, adding pyromellitic dianhydride and 4,4'-diphenyl ether diamine into N-methylpyrrolidone, performing a polycondensation reaction, and then performing wet spinning and hot stretching to obtain hollow polyimidefiber; b, filling the hollow polyimide fiber with tin-gallium liquid metal; c, curing the tin-gallium liquid metal in a room-temperature environment to obtain the fiber composite material for the electronic skin. The preparation method has the beneficial effects as follows: the hollow fiber material is used and filled with the liquid metal, and the tin-gallium liquid metal has excellent electricalconductivity as well as good stretchability in a solid state, the obtained fiber composite material has high stretchability and high electrical conductivity and has a broad application prospect in the fields of flexible wearable devices, the flexible electronic skin, intelligent robots and the like.

The present invention discloses a polyimide resin synthesis method. The polyimide resin comprises a thermally conductive nanometer powder mixture and a resin solid, wherein the resin solid is polyamic acid, and the thermally conductive nanometer powder mixture is a mixture of three thermally conductive nanometer powders such as Al2O3, NB and AlN, and is 10-30% of the total amount of the resin solid. During synthesis, pyromellitic dianhydride reacts with 4,4'-diaminodiphenyl ether to obtain polyamic acid, the grinded thermally conductive nanometer powder mixture is added to the polyamic acid according to a certain proportion, then pyromellitic dianhydride is added to control a viscosity of the final reaction product to reach 85000-95000 CP, and deaeration slobbering film formation is performed to obtain the finished product. According to the polyimide resin synthesized by the method, a thermal conductivity coefficient can be more than three times the thermal conductivity coefficient of the ordinary polyimide film, excellent electrical property, excellent thermal property and excellent mechanical property are provided, and a storage life of the electronic component can be substantially improved.

The invention discloses a dimensionally stable oxazolyl polyimide film and a preparation method thereof. The dimensionally stable oxazolyl polyimide film is prepared by the steps of carrying out polymerization reaction on aromatic diamine and aromatic dianhydride in a polar aprotic solvent, and carrying out salivation and thermal imidization on an obtained polyamide acid resin solution, wherein aromatic diamine contains the following components in percentage by weight: 10%-30% of p-phenylenediamine, 5%-40% of 2-(4-aminophenyl)-5-amino benzoxazole and the balance of 4,4',-diaminodiphenyl ether,and aromatic dianhydride contains the following components in percentage by weight: 3,3',4,4'-biphenyl tetracarboxylic dianhydride and the balance of pyromellitic acid dianhydride. The dimensionallystable oxazolyl polyimide film prepared from the raw material in parts by weight has excellent dimensional stability, and meanwhile, the water absorption rate of the film is less than 2%.

The invention discloses a preparation method of a phosphotungstic acid-polyimide composite proton exchange membrane. Diphenyl ether diamine and benzenetetracarboxylic anhydride with equal molar weight are added in dimethyl sulfoxide solvent to synthesize polyamide acid solution, deionized water, sodium tungstate and concentrated phosphoric acid are then added for heating and stirring to form a solution, the solution is poured on a glass plate, the glass plate is flatly placed in an oven in a stepped temperature rise mode for imidization, and the phosphotungstic acid-polyimide composite proton exchange membrane is obtained. The preparation method is simple in method, the cost of prepared membrane is low, and the membrane is even in distribution, and conductivity and alcohol blocking performance are obviously improved. Compared with a Nafion membrane, the phosphotungstic acid-polyimide composite proton exchange membrane prepared by the method obviously improves proton conduction performance at high temperature (lower than 100 DEG C), carbinol permeability is reduced, swelling degree is reduced, cost is lowered, and the preparation method brings convenience to mass production.

The invention discloses a heat conduction graphite flake, and a manufacturing process thereof. The heat conduction graphite flake comprises a polyimide film, a first coating layer and a second coating layer, wherein the first coating layer and the second coating layer are respectively arranged on the upper surface and the lower surface of the polyimide film; the first coating layer and the second coating layer are formed by sintering a graphite modifier; the graphite modifier comprises the following components in parts by weight: 20-25 parts of benzophenonetetracarboxylic dianhydride, 14-16 parts of pyromellitic dianhydride, 22-26 parts of diaminodiphenyl methane, 25-35 parts of dimethylformamide, 1.8-2.5 parts of ethylene glycol, and 2.5-3 parts of polydimethylsiloxane. According to the heat conduction graphite flake, the heat conduction performance can be improved in the vertical direction and the horizontal direction, local overheat is avoided, the uniform heat conduction performance is achieved, and the stability and reliability of radiation performance of products are improved.

The invention belongs to the technical field of resin production, and particularly relates to a polyester resin for an anti-yellowing HAA (N,N,N',N'-tetra(Beta-hydroxyethyl)adipamide) system and further relates to a preparation method and application of the polyester resin. The anti-yellowing HAA system provided by the invention is polymerized by using pyromellitic dianhydride, 1,6-hexanediamine,isophthalic acid, phloroglucinol formic acid, ethanetricarboxylic acid monoester, 2,5-dihydroxy hexane, neopentyl glycol and 2,2'-diphenic acid. Because a polyimide chain is carried in the molecular chain of the polyester resin obtained by the materials and a specific process, the high temperature-resistant and anti-yellowing properties are excellent; moreover, because the materials containing phenolic hydroxyl groups, such as phloroglucinol formic acid and ethanetricarboxylic acid monoester, are used for participating in reaction and the phenolic functional group with high anti-yellowing capability is contained in the polyester chain, the polyester product has excellent high temperature-resistant and anti-yellowing properties, and is ultimately used in the powder paint of the HAA system,so that a coated panel with excellent anti-yellowing property can be obtained.

Provided is a polyimide film having a non-thermoplastic polyimide layer, wherein: the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer preferably contains at least one ofa biphenyl-tetracarboxylic dianhydride (BPDA) residue derived from 3,3',4,4'-BPDA and a phenylenebis(trimellitic monoester) dianhydride (TAHQ) residue derived from 1,4-TAHQ, as well as at least one of a pyromellitic dianhydride (PMDA) residue derived from PMDA and a napthalenetetracarboxylic dianhydride (NTCDA) residue derived from 2,3,6,7-NTCDA, the total amount of these residues being at least80 mol parts with respect to 100 mol parts of a tetracarboxylic acid residue; and the dielectric loss tangent (Df) is preferably 0.004 or less.

The invention discloses a corona-resistant PI (polyimide) film, which comprises the following components in parts by weight: 13-20 parts of 4,4'-diaminodiphenyl ether, 9-12 parts of pyromellitic dianhydride, 8-14 parts of biphenylether dianhydride; 2-5 parts of a nano filler; 160-190 parts of N, N-dimethylacetamide and 0.5-2 parts of a lubricant. The polyimide film prepared by the method has the advantages of strength, rigidity and dimensional stability; the film is produced through a casting nozzle and a casting machine has good uniformity, and the surface is clean and flat; by a biaxial stretching and heat treatment process, the longitudinal modulus and the transverse modulus of the polyimide film can be further improved, and thermal expansion coefficient and thermal shrinkage can be reduced.

A polyamide acid which contains at least one diamine compound selected from among diamine compounds represented by general formula (8) within the range of 3-60 parts by mole in total per 100 parts by mole of all diamine components, while containing a biphenyl tetracarboxylic acid dianhydride within the range of 40-100 parts by mole and a pyromellitic acid dianhydride within the range of 0-60 parts by mole per 100 parts by mole of all acid anhydride components; and a thermoplastic polyimide which is obtained curing this polyamide acid.

(In formula (8), linking group X represents a single bond or a divalent group selected from among —CONH—; each Y independently represents a hydrogen atom, a monovalent hydrocarbon group having 1-3 carbon atoms or an alkoxy group; n represents an integer of 0-2; and each of p and q independently represents an integer of 0-4.)

The invention discloses a preparation method of a lanthanide ion loaded metal-organic framework material capable of realizing lighting adjustability and sensing property. The preparation method comprises the following steps: with Zn(NO3)2.6H2O, (NH4)6Mo7O24.4H2O and pyromellitic dianhydride as raw materials, complexing all the raw materials to obtain a complex; soaking the complex into an EuCl3 or Tb(ClO4)3 solution to respectively obtain a lanthanide doped complex; and soaking the doped complex into an MClx solution to respectively obtain complexes M-Eu@[NH4]2[ZnL].6H2O and M-Tb@[NH4]2[ZnL].6H2O. According to the invention, a novel lanthanide MOFs molecule with lighting adjustability and sensing property can be obtained through simple soaking; and the lanthanide doping operation is convenient, stable, efficient, strong in repeatability and favorable in control effect on the lighting adjustability and sensing property of MOFs.