58 results about "Diphenylmethane" patented technology

The invention discloses a single-component high-heat-resistance type epoxy adhesive and a preparation method of the single-component high-heat-resistance type epoxy adhesive. The adhesive is prepared from the following components in parts by weight: 30 to 40 parts of N, N-4, 4 '-diphenylmethane bismaleimide; 50 parts of bisphenol F epoxy resin; 36.47 parts of 4, 4 '-diaminodiphenyl sulfone; 20 to 40 phr of phenyl glycidyl ether; 1 to 2 phr of two terminal type epoxy silicone oil; 4 to 6 phr of hydroxyl-terminated polyether sulfone; 10 to 20 phr of boron nitride, the surface of which is modified by gamma-glycidyl ether oxypropyl trimethoxy silane; and 1 to 3 phr of an adhesion promoter. According to the adhesive disclosed by the invention, the heat resistance, the mechanical property, the dimensional stability, the process adaptability and the like are synergistically improved, the use requirements of an aviation structural part on long-term service at 150-180 DEG C and an electronic packaging device on the condition of short-time reflow soldering at about 200 DEG C can be met, and the reliability of the adhesive in a high-temperature environment is remarkably improved.

The present application relates to the technical field of rubber, in particular to a kind of giant engineering machinery tire anti-split body rubber composition and preparation method thereof. With 100 parts by weight of natural rubber component as benchmark, further comprising the following components: natural rubber 100 parts, carbon black 40-50 parts, zinc oxide 6-8 parts, cobalt salt 0.2-0.4 parts, antioxidant 2246 0.5-1 part, antioxidant S-TMQ 0.2-1.0 parts, N,N'-4,4'-diphenyl methane bismaleimide 0.5-1.5 parts, insoluble sulfur 8-12 parts, accelerator 0.3-0.7 parts, anti-scorching agent 0.05-0.15 parts. The present application solves the shortcomings of lower adhesive property of body rubber and insufficient anti-splitting ability of existing technology under harsh road conditions and hot and humid, steam, salt water environment, greatly reduces the occurrence probability of body delamination and bead bulging under hot and humid environment in Southeast Asia, improves the anti-splitting ability of body rubber, and ensures the service life of giant tire under high load operation.

The application belongs to the technical field of spraying materials, and particularly discloses a kind of corrosion-resistant spraying materials applied to railway freight cars and a preparation method thereof.The corrosion-resistant spraying material applied to railway freight cars provided by the application comprises component A and component B, component A comprises terminal isocyanate-based polyether type prepolymer and diphenylmethane-4,4'-diisocyanate;the terminal isocyanate-based polyether type prepolymer is prepared by reacting polyol compound and diphenylmethane-4,4'-diisocyanate;the polyol compound comprises polypropylene glycol, glycerol type polyether polyol and polyether polyol with a functionality of greater than or equal to 4.5.Component B comprises polyoxypropylene polyether polyol and diethyl toluene diamine.The application provides a corrosion-resistant, impact-resistant and strongly adhesive corrosion-resistant spraying material applied to railway freight cars by reasonably designing material components, which can effectively block corrosive media and protect the car body, and is suitable for complex railway freight transport scenarios.

To provide an injection chemical composition that can achieve both curability in water and foaming and curability in non-water environments, even after being exposed to high temperature and high humidity environments. [Solution] An injection solution composition comprising a first agent (A) and a second agent (B), wherein the first agent (A) comprises an aqueous solution of sodium silicate (A-1), an organic polyol (A-2), and a tertiary amine catalyst (A-3), and the second agent (B) comprises an organic polyisocyanate containing a mixture of diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate having 3 or more isocyanate functional groups (B-1), or a reaction product (B-1') of an active hydrogen group-containing compound and a mixture (B-1), at least one acid component (B-2) selected from the group consisting of phosphate monoesters and phosphate diesters, and at least one hydrolyzable component (B-3) selected from the group consisting of orthoester compounds and acetal compounds.

The application belongs to the technical field of diamine and polyamine of diphenylmethane series, and particularly relates to a preparation method of diamine and polyamine (DAM) of diphenylmethane series, that is, before a condensation reaction, a mixing characteristic parameter 1.0<=M<=1.5 of a pre-reaction liquid for the condensation reaction is controlled; the pre-reaction liquid is a mixed liquid formed after a mixture of a formaldehyde solution and aniline hydrochloride or a mixture of the formaldehyde solution and aniline hydrochloride / condensation reaction liquid is pre-mixed. In the method, the mixing characteristic parameter M is controlled in a suitable range, so that the content of N-methyl impurities and the content of macromolecular polymers in the DAM product can be maximally reduced, and the running stability of a production device and the quality of downstream products can be improved.

To provide a thermosetting coating composition capable of forming a cured coating film excellent in extensibility, toughness and shielding properties.SOLUTION: The thermosetting coating composition according to the present invention comprises a polycarbonate polyol (A) and / or a polyether polyol (B), a carbodiimide-modified diphenylmethane diisocyanate (C), at least one selected from the group consisting of a trimethylolpropane adduct isocyanate (D), a biuret isocyanate (E), and an allophanate isocyanate (F), and a color pigment (G).SELECTED DRAWING: Figure 1

The application relates to the cable field and discloses a novel high-heat-dissipation energy storage device cable and a preparation method thereof. The novel high-heat-dissipation energy storage device cable comprises, from inside to outside, a core, a cross-linked polyethylene insulation layer, a shielding layer, a filling layer, an inner protective layer, an armored layer and an outer protective layer. The filling layer is filled with a composite phase change material. The composite phase change material comprises binary eutectic material, cross-linked polyurethane, graphene powder and modified spherical alumina. The cross-linked polyurethane is prepared by using PEG6000, diphenyl methane diisocyanate and boric acid as raw materials. The modified spherical alumina is prepared by grafting a modified silane coupling agent on the surface of spherical alumina through a thiol-alkene click reaction between triallyl isocyanurate and 3-mercapto propyl triethoxysilane. The filling layer filled with the composite phase change material has the characteristics of good heat conductivity, high phase change latent heat, wide phase change temperature range, good thermal cycle stability and good flame retardance.

The invention relates to a composite material for a cushion pad between battery cells of a new energy battery and a preparation method of the composite material, and belongs to the technical field of cushion pads between battery cells. The chain extender is self-made, the chain extender, the hydroxyl-terminated silicone oil and the diphenylmethane-4, 4 '-diisocyanate are subjected to vulcanization forming to obtain the composite material of the cushion pad between the battery cells of the new energy battery, the chain extender contains multiple amino groups and has large steric hindrance, and after the chain extender reacts with isocyanate, the chain extender can be used for preparing the cushion pad between the battery cells of the new energy battery, so that the service life of the cushion pad between the battery cells of the new energy battery is prolonged, and the service life of the cushion pad between the battery cells of the new energy battery is prolonged. A stable three-dimensional network structure with a firm phase interface is formed, chain segment movement is greatly limited, phase separation is inhibited, the modulus and rebound resilience of the composite material cushion pad are improved, the cushion pad has excellent mechanical integrity, long-term stability and compression permanent deformation resistance, and meanwhile, due to the fact that the chain segment movement is limited, the service life of the cushion pad is prolonged. And the material can still keep good dimensional stability at high temperature.

The utility model relates to a kind of high-purity high-efficiency diphenylmethane reaction liquid distillation device, more than one regular metal packing section is arranged in upper portion of evaporation tank, evaporation tank top is connected with benzene recovery storage tank by gas phase extraction pipeline with first, second heat exchanger in proper order, heat absorption heat course import of first heat exchanger is connected with reaction liquid inlet pipe, heat absorption heat course export is connected with reboiler bottom feed, reboiler top is connected with evaporation tank middle portion, the gas phase extraction pipeline after second heat exchanger is divided into reflux pipeline, reflux pipeline is connected with evaporation tank upper portion by reflux control valve;Evaporation tank bottom or lower portion is connected with two routes, one is connected with reboiler bottom feed by circulating pipeline with circulation control valve in proper order, another is connected with diphenylmethane storage tank by liquid phase extraction pipeline with extraction control valve, extraction pump in proper order.The device structure is simple, can effectively improve diphenylmethane, benzene distillation separation purity and efficiency, meet the requirement of energy saving and consumption reduction of industrial production simultaneously.

The application belongs to the technical field of materials, and provides a bio-based bismaleimide resin and a preparation method and application thereof, the resin being prepared by copolymerization of curcumin allyl ether and N,N'-4,4'-diphenylmethane bismaleimide. The curcumin allyl ether has a beta-diketone conjugated system, and is prepared by nucleophilic substitution reaction of curcumin and allyl bromide in a potassium carbonate acetone system; when prepared, the two are cured in stages at 150-240 DEG C to form a high crosslinking network, and a vacuum degassing and curing process is combined. The bio-based bismaleimide resin provided in the application has a curing peak temperature that is 20-30 DEG C lower than that of a traditional BD resin, a Tg that is nearly 90 DEG C higher than that of the BD resin, a carbon residue rate at 800 DEG C that is greater than or equal to 42%, an LOI that is greater than or equal to 37%, reaches a UL-94 V-0 level, a THR that is as low as 12.4 kJ / g, less flammable volatile matter at high temperatures, and a high degree of carbonization of residual carbon.

The application discloses a shape-selective catalyst for preparing 4,4'-disubstituted diphenylmethane by alkylation and a preparation method and application thereof. The catalyst is composed of a molecular sieve and an oxide for modifying the molecular sieve. The oxide is an oxide corresponding to the highest valence of a modified element. The modified element includes phosphorus, titanium, zirconium, gallium, indium, germanium, molybdenum, tungsten, rhenium or copper. The mass content of the oxide in the catalyst is 0.01-20% in the catalyst with a mass of 100%. The catalyst has good thermal stability and chemical stability, can be repeatedly used, has a simple regeneration method and a high activity recovery rate.

The invention belongs to the technical field of organic fine chemical synthesis, and particularly relates to a method for green synthesis of 4, 4 '-difluorobenzophenone. According to the method for synthesizing 4, 4 '-difluorobenzophenone provided by the invention, diphenylmethane is taken as a raw material, the modified zeolite catalyst is adopted for reaction, and high conversion rate of the raw material and high selectivity of a target intermediate product can be obtained. A specific catalyst system, a reaction reagent and a reaction medium are introduced into each step, so that the yield of each step is superior to that of an existing traditional process; meanwhile, the initial raw material cost is low, the process cost is reduced, the process is safer, the selectivity is higher, and the environmental influence is smaller.

The application relates to the technical field of preparation of diamines and polyamines in a diphenylmethane series, and provides a preparation method of diamines and polyamines in a diphenylmethane series with improved 2,4-MDA selectivity; through the preparation method, the selectivity of 2,4-MDA can be improved. In the preparation method, formaldehyde and aniline are contacted and reacted in the presence of an acid catalyst to prepare the diamines and polyamines in the diphenylmethane series, and the acid catalyst is added into a reaction system in multiple steps based on the total amount of the acid catalyst.

The application discloses a green preparation method of 4,4'-difluorobenzophenone. The method uses 4,4'-difluorobenzene as raw material, potassium bromide as catalyst, acetic acid as solvent, and oxygen as oxidant, and 4,4'-difluorobenzophenone is generated in high selectivity through one-step oxidation under mild conditions. The application surprisingly finds that in the presence of potassium bromide, a new non-metallic catalytic oxidation system of potassium bromide / acetic acid / oxygen is used to realize high-efficiency and high-selectivity conversion of the C-H bond at the benzyl position. Compared with the traditional method, the application does not need to use a transition metal catalyst, does not need to use carbon tetrachloride and other materials damaging the ozone layer, and does not need to involve a dangerous intermediate such as a diazonium salt, the process route is short, the atomic economy is high, the product yield is high, the product purity is high, the catalyst is cheap and easy to obtain, and the application has excellent industrial application prospect and green chemistry characteristics.

This invention discloses a colored TPU elastic fiber material and its preparation method. The method includes the following steps: Step 1: Under a protective atmosphere, polytetramethylene ether glycol and diphenylmethane-4,4'-diisocyanate are mixed, the temperature is raised to 80°C, and the reaction is carried out for 2-3 hours. Then, the mixture is cooled to 30°C, N,N-dimethylacetamide is added, followed by the dropwise addition of ethylenediamine solution. Stirring continues for 2-3 hours to obtain a spinning solution. Step 2: A modifier is added to N,N-dimethylacetamide and stirred until homogeneous to obtain a modifier solution. The modifier solution is mixed with the spinning solution, stirred continuously, and after vacuum degassing, spun to obtain the TPU elastic fiber material. This invention significantly improves the dyeing performance and flame retardancy of TPU fibers by adding a modifier solution, solving the problems of difficult dyeing and flammability of traditional materials.

The application discloses a method for preparing fluorine-containing diphenylmethane compounds by using sulfur hexafluoride as a fluorination reagent, and belongs to the technical field of organic chemical synthesis. The preparation method comprises the following steps: (1) mixing a photocatalyst, a solvent and a reducing agent, and performing ultrasonic treatment to obtain solution A; mixing a reaction substrate and the solvent to obtain solution B; the photocatalyst is one or more of 4CzIPN, Ir[dF(CF3)ppy]2(dtbpy))PF6, 9-thioxanthone and 10-phenylphenothiazine; the reaction substrate is a compound with a structural formula of R1 and R2 are both H, alkoxy or halogen; (2) mixing the obtained solution A and solution B in a sulfur hexafluoride gas atmosphere, and performing reaction under blue light illumination, and the fluorine-containing diphenylmethane compounds are obtained. The method has the beneficial effects that the fluorine-containing diphenylmethane compounds are efficiently prepared by using sulfur hexafluoride as the fluorination reagent, and by selecting raw materials and catalysts with certain proportions; the reaction raw materials are cheap; the preparation process is safe, mild, has good substrate compatibility and high preparation efficiency.

The application relates to a preparation method of a diisocyanate and a polyisocyanate in a diphenylmethane series, which comprises the following steps: S1: performing a phosgenation reaction on a diphenylmethane series diamine and a polyamine with phosgene in a solvent to obtain a first mixed solution; S2: performing a phosgene removal treatment on the first mixed solution to obtain a second mixed solution; S3: performing a stripping treatment on the second mixed solution with HCl gas to obtain a third mixed solution; and S4: performing a solvent removal treatment on the third mixed solution to obtain a diphenylmethane series diisocyanate and polyisocyanate crude product. The preparation method of the diisocyanate and the polyisocyanate in the diphenylmethane series in one embodiment of the application can prepare a diphenylmethane series diisocyanate and polyisocyanate product with light color by optimizing process parameters of the stripping treatment step.

The application discloses a kind of high IPT cold-heat cycle resistant polyphenylene sulfide composite material and preparation method and application.The composite material includes the following components by mass percentage:PPS resin 44.1~60.5%,N,N-4,4-diphenylmethane bismaleimide 6~10%,compatibility agent 3~5%,glass fiber 30~40%,antioxidant 0.3~0.5%,lubricant 0.2~0.4%.The composite material has excellent bevel electric leakage tracking resistance,can reach 1KV by IPT test,has good cold-heat cycle resistance,at low temperature-40 DEG C,2 hours and high temperature 150 DEG C,2 hours;High-low temperature switching time is 3 minutes,crack and no crack are generated after 300 cycles,which can be used for preparing busbar and module cover plate products in new energy materials.

The application discloses a long-acting toughened polylactic acid composite material and a preparation method thereof, and belongs to the field of high polymer materials. A flexible macromolecular coupling agent is provided, and a general structure formula is as follows: n is 13-45, R1 is selected from one of a hydrocarbon group containing 3-10 carbon atoms, m-xylylene, p-xylylene, a monosubstituted benzene ring or diphenylmethane, R2 is selected from one of iminopropyl or 3-thiopropyl, and R3 is selected from methyl or ethyl. The long-acting toughened polylactic acid composite material of the flexible macromolecular coupling agent has excellent rigid and tough balanced performance and excellent anti-hygrothermal aging performance, and can be applied to polylactic acid products for long-term use.

The present invention relates to a process for preparing a polyisocyanate composition comprising at least one polyisocyanates of the diphenylmethane series comprising providing a mixture (M1) comprising a polyamine composition (PA1) comprising di- and polyamines of the diphenylmethane series with a 2-ring content (2RC-1) and a mixture (M2) comprising a polyamine composition (PA2) comprising di- and polyamines of the diphenylmethane series with a 2-ring content (2RC-2); preparing a mixture (M3) from mixture (M1) and mixture (M2); and conversion of mixture (M3) to obtain mixture (M4) comprising a polyisocyanate composition; wherein the difference in the 2-ring content (2RC-1) of polyamine composition (PA1) and the 2-ring content (2RC-2) of polyamine composition (PA2) is more than 10 %. The present invention furthermore is directed to the isocyanate composition obtained or obtainable according to said process and the use thereof for the preparation of polyurethanes or polyisocyanurates.

The invention discloses a graphite ore flotation reagent system for removing foaming agent components. The graphite ore flotation reagent system comprises 15-25 parts of biphenyl formyl, 30-60 parts of alkylbenzene, 10-30 parts of diphenylmethane and 15-25 parts of neutral oil. The invention discloses a preparation method of a graphite ore flotation reagent system for removing a foaming agent component, which comprises the following steps: step 1, adding biphenyl formyl in a formula amount into neutral oil in a formula amount, and heating and stirring to obtain a neutral oil solution of the biphenyl formyl; 2, cooling to room temperature, and adding alkylbenzene and diphenylmethane according to a formula ratio to obtain a mixed solution; 3, stirring the mixed solution at a high speed; and fourthly, the mixed solution stands for at least 24 h, if layering does not occur, a graphite ore flotation reagent system with the foaming agent component removed is obtained, and otherwise, the third step is executed. The graphite ore flotation reagent system has the advantages of being high in flotation rate, good in product fluidity and high in enrichment ratio. The preparation method disclosed by the invention has the advantages of simplicity in operation and low production cost.

The application provides a preparation method of 4,4'-difluorobenzyl and application thereof. The preparation method of 4,4'-difluorobenzyl comprises the following steps: A) pyridine hydrofluoric acid salt solution and 4,4'-diaminodiphenyl methane are subjected to a salification reaction to obtain a salification product; B) the salification product is subjected to a diazotization reaction with nitrite to obtain a diazonium salt; and C) the diazonium salt is subjected to a thermal decomposition reaction to obtain 4,4'-difluorobenzyl. In the preparation method, pyridine hydrofluoric acid solution is used to replace hydrogen fluoride, the raw material used is safer, almost no hydrogen fluoride is overflowed under heating conditions, the corrosion of the equipment is smaller, the stability of the diazonium salt obtained by reaction is excellent, the diazonium salt is not easy to decompose at room temperature, and the decomposition at high temperature basically does not release a large amount of heat, so that the explosion risk is greatly reduced.

The application discloses an anti-impact and anti-scratching automobile hub cover and a preparation method thereof, and relates to the technical field of high polymer materials.The automobile hub cover comprises at least: 100 parts of nylon 6 resin; 5-15 parts of bismaleimide resin prepolymer; 10-15 parts of hydrogenated styrene-butadiene block copolymer grafted maleic anhydride; 10-20 parts of modified basalt fiber; 5-15 parts of modified polyarylate fiber; 0.2-0.5 parts of antioxidant; 0.3-0.8 parts of light stabilizer; 2-4 parts of color master batch; 0.3-0.8 parts of lubricant; the bismaleimide resin prepolymer is prepared by mixing 4,4'-diphenylmethane bismaleimide and 2,2'-diallyl bisphenol A; the modified basalt fiber is co-precipitated and modified by polydopamine, polyethyleneimine and octaamino cage-shaped polyhedral oligomeric silsesquioxane functionalized graphene oxide; and the modified polyarylate fiber is co-precipitated and modified by polydopamine and polyethyleneimine.The automobile hub cover prepared by the application has low moisture absorption, high impact resistance and excellent scratch resistance.

The present invention provides a spray-applied polyurethane insulation material for tunnels in cold regions, its application, and its construction method. The spray-applied polyurethane insulation material for tunnels in cold regions is composed of raw materials with a mass ratio of 0.8-1.2 of material A and material B. By mass parts, material A includes 90-100 parts of polyether polyol, 90-100 parts of polyester polyol, 5-10 parts of chain extender, 1-4 parts of catalyst, 10-20 parts of flame retardant, 0.5-3 parts of water, and 1-3 parts of surfactant. The B component is diphenylmethane diisocyanate. The flame retardant is composed of flame retardant A and flame retardant B in a mass ratio of 10:1-2.5. The spray-applied polyurethane insulation material of the present invention is used to construct tunnel structures in cold regions, providing good flame retardant and insulation effects.

The utility model relates to the technical field of diaminodiphenylmethane production, in particular to a 4, 4 '-diphenylmethane production device. The feeding mechanism for 4, 4 '-diaminodiphenyl methane production comprises a reaction kettle and a feeding mechanism, the feeding mechanism comprises a feeding pipe, a liquid conveying pipe, a connecting assembly, a water pump, a storage box, a mounting base, a rotating roller, a baffle and a fixing assembly, the feeding pipe is fixedly connected and communicated with the upper portion of the reaction kettle, and the feeding pipe is detachably connected with one end of the liquid conveying pipe through the connecting assembly; the storage box is fixedly connected and communicated with the other end of the liquid conveying pipe, the water pump is arranged on the liquid conveying pipe, the mounting base is fixedly connected with the feeding pipe, the rotating roller is rotationally connected with the mounting base and the feeding pipe and extends into the feeding pipe, the baffle is fixedly connected with the rotating roller, and the fixing assembly is arranged on the mounting base. The speed of the phenol solution entering the reaction kettle can be changed according to the reaction condition through the feeding mechanism, so that the condensation reaction effect is improved.

The invention belongs to the field of functional macromolecules, and particularly relates to a detachable and repairable epoxy vitrimer based on a dynamic carbon-sulfur bond and a preparation method of the detachable and repairable epoxy vitrimer based on the dynamic carbon-sulfur bond, and the detachable and repairable epoxy vitrimer is prepared by taking diphenylmethane bismaleimide, trimethylolpropane triglycidyl ether, dimercaptodiphenyl sulfide or octyldithiol and triethylamine as raw materials, and carrying out curing reaction at 50-150 DEG C for more than 4 hours. After complete curing, the epoxy vitrimer has good solvent resistance, can be completely disassembled in a specific sulfydryl solvent at the same time, and in addition, can realize hot-pressing recovery and remolding at a high temperature.

The invention discloses a method for preparing 4, 4 '-dihydroxybenzaldehyde through alkylation The invention discloses a shape-selective catalyst based on 4, 4 '-disubstituted diphenylmethane and a preparation method and application thereof, the catalyst is composed of a molecular sieve and an oxide for modifying the molecular sieve, the oxide is an oxide corresponding to the highest valence of a modification element, and the modification element comprises phosphorus, titanium, zirconium, gallium, indium, germanium, molybdenum, tungsten, rhenium or copper; the mass of the catalyst is 100%, the oxide accounts for 0.01-20% of the mass of the catalyst, and the balance is the molecular sieve. The catalyst has the advantages of good thermal stability, good chemical stability, reusability, simple regeneration method and high activity recovery rate.

The invention discloses a preparation method of a Taniaphos supported catalyst by a solvent weaving method, and belongs to the technical field of organic chemistry. The method comprises the following steps: adding a Taniaphos ligand and a metal salt into a reaction container at room temperature, adding a solvent in an inert gas atmosphere, stirring at room temperature until the Taniaphos ligand and the metal salt are completely dissolved, and then adding an aryl-containing comonomer to obtain a reaction solution; adding Lewis acid or Bronsted acid, and carrying out Friedel-Crafts alkylation reaction to obtain a supported Taniaphos catalyst; wherein the aryl-containing comonomer comprises at least one of biphenyl, triphenylbenzene, diphenylmethane, triphenylmethane, furan, thiophene and pyrrole. The method is simple and efficient, the supported Taniaphos catalyst shows excellent catalytic activity and good stability in an asymmetric allyl alkylation reaction of a cinnamyl bromide substrate, and the product can be obtained only through solvent extraction and distillation without column chromatography. The activity of the catalyst remains unchanged after the catalyst is recycled for five times.

Mask for lightening keratinous materials. The present invention relates to a mask for lightening keratinous materials, comprising: A) a mask fabric, and B) a composition, comprising: a) at least one synthetic mica and / or fluorophlogopite; b) alginic acid and / or alginates; and c) at least one compound selected from xanthan gum, sclerotium gum, and hydroxylated derivatives of diphenylmethane. The present invention also relates to a non-therapeutic method for lightening keratinous materials with said mask. Figure for the abstract: none.

The application provides a preparation method of diphenylmethane series diamines and polyamines. In the preparation method of the diphenylmethane series diamines and polyamines, a solid acid catalyst with an acid amount greater than 1.3 mmol / g is used as a catalyst for an aminal transposition rearrangement reaction, the selectivity of the solid acid catalyst in the aminal transposition rearrangement reaction can be significantly improved, the content of tricyclic untransposed substances in the diphenylmethane series diamines and polyamines is reduced, and then high-quality diphenylmethane diisocyanate is obtained.