CN115090125A - Method, device and product for preparing polyamide thin-layer composite film by transfer printing - Google Patents

Abstract

The invention discloses a method, a device and a product for preparing a polyamide thin-layer composite film by transfer printing. The method comprises: uniformly coating a polyamine solution on the surface of a conveying mechanism through a coating mechanism to form a polyamine liquid film; The conveying mechanism with the liquid film is immersed in the polybasic acid chloride solution, and the polyamine and the polybasic acid chloride undergo a polymerization reaction at the interface to form a polyamide nano-film; the porous base film of the compounding mechanism is compounded with it from the upper side of the polyamide nano-film to obtain a polyamide Thin-layer composite film; applying pressure and temperature through a hot pressing mechanism to enhance the composite strength of the porous base film and the polyamide nano-film; the polyamide thin-layer composite film is dried and rolled after the separation mechanism. The preparation method of the invention is easy to operate, and the polyamide nano-film synthesized at the free interface can be composited with various porous base films continuously and on a large scale.

Description

Method, device and product for preparing polyamide thin-layer composite film by transfer printing

technical field

The invention relates to the technical field of membrane separation, in particular to a method, a device and a product for preparing a polyamide thin-layer composite membrane by transfer printing.

Background technique

Polyamide thin-layer composite membranes are widely used in separation and purification and other fields because of their wide selection of porous base membranes and selective separation layers, and easy and precise control of the surface properties of selective separation layers. and other important applications. The interfacial polymerization method has become the main method for preparing polyamide thin-layer composite films due to its mild operating conditions, simple process, high synthesis efficiency and low preparation cost. However, due to the excessively fast rate of interfacial polymerization, it is more difficult to control the interfacial polymerization, which makes the improvement of the performance of composite membranes a challenge and a difficult problem. Therefore, increasing the controllability of the interfacial polymerization process is a sufficient condition for the preparation of structurally controllable high-performance composite membranes.

For example, the Chinese patent document with publication number CN111420566B discloses a preparation method of a polyamide solvent-resistant nanofiltration membrane containing fluorinated organic nanoparticles. Fluorinated organic nanoparticles were formed by Michael addition and Schiff base reaction, and then a polyamide film containing fluorinated organic nanoparticles was formed on the surface of the porous support film through interfacial polymerization with polybasic acid chloride. Using the low surface energy characteristics of fluorinated organic nanoparticles, the interfacial polymerization process is regulated, and the chemical composition, microstructure, and hydrophilicity and hydrophobicity of the polyamide separation layer are optimized to obtain a polyamide solvent-resistant nanofiltration membrane with a unique pore structure. The prepared membrane It has high separation selectivity and solvent permeation flux, and the membrane preparation method is simple and easy to control, and has a good industrial application prospect. However, this method cannot avoid the influence of the properties of the porous base film on the interfacial polymerization process.

The Chinese patent document whose publication number is CN112755813B discloses a method for preparing a thin-film composite film containing an intermediate layer, wherein metal ions and organic phosphoric acid are complexed on the surface of the supporting layer to obtain several complex intermediate layers, and then the complex intermediate layers are prepared. After in-situ polymerization and curing on the surface of the intermediate layer, a polymer selection layer is formed, and a thin film composite film can be obtained. In this invention, a material with complexation effect is selected as the intermediate layer, and a hollow fiber membrane composite membrane containing the intermediate layer is prepared. The introduction of the intermediate layer by a simple soaking method avoids the influence of the porous base membrane structure on the interfacial polymerization reaction, optimizes the uniformity of the selected layer structure, and improves the dehydration performance of the organic solvent (ethanol) in the polyamide hollow fiber membrane composite membrane. Compared with the polyamide thin film composite membrane without the intermediate layer, the separation factor of the polyamide thin film composite membrane with the intermediate layer is greatly improved. However, the introduction of the intermediate layer leads to complicated preparation steps of the composite membrane, and also weakens the bonding force between the selective separation layer and the porous base membrane.

The Chinese patent document with publication number CN112657352B discloses a method for preparing a polyamide thin film composite reverse osmosis membrane. First, an ultra-thin metal-organic framework CuBDC nanosheet with amphiphilic properties is prepared and placed in a water/oil two-phase On the interface, the water phase is an aqueous solution of m-phenylenediamine, and the oil phase is n-hexane. After the n-hexane is completely volatilized, a n-hexane solution containing trimesoyl chloride is slowly added to the interface to react to form a modified polyamide. nanofilm. The membrane was carefully placed on the ultrafiltration membrane substrate to obtain a polyamide thin-layer composite reverse osmosis membrane. The intrinsic thickness of the polyamide film formed on the CuBDC-assisted free interface is about 5 nm. The ultra-thin metal organic framework nanosheets provide directionality for the thermal diffusion of the interfacial polymerization reaction, enhance the intensity of the interfacial polymerization reaction, and improve the transfer of m-phenylenediamine to oil. The rate of diffusion in the phase direction increases the surface area and cross-linking degree of the ultra-thin polyamide film while forming the ultra-thin polyamide film, and greatly improves the flux and salt rejection rate of the membrane. Free interfacial polymerization can effectively avoid the influence of the properties of the porous base film on the reaction and improve the controllability of the reaction. However, this method is complicated to operate, and it is easy to introduce defects during the transfer of polyamide films, making it difficult to achieve large-area preparation.

Transfer printing is a printing method in which disperse dyes or coatings are printed on paper according to the pattern to make transfer paper, and then the dyes or coatings on the transfer paper are transferred to textiles under certain conditions.

SUMMARY OF THE INVENTION

The invention provides a method and a device for preparing a polyamide thin-layer composite film by transfer printing, the purpose of which is to transfer the polyamide nano-film generated by interfacial polymerization to the surface of a porous base film and realize the efficient and stable composite of the two. The polyamide thin-layer composite film was obtained. The preparation method is simple to operate, suitable for a wide variety of porous base films, and can also improve the force and composite strength between the polyamide nano-film and the porous base film through a hot pressing process and regulating the surface properties of the porous base film. The upper side of the amide nano-film is compounded with it to avoid the problem that the high-viscosity amine solution is not easy to remove, and can realize the continuous preparation of a large-area structure-controllable high-performance polyamide thin-layer composite film.

The technical scheme of the present invention is as follows:

A device for preparing a polyamide thin-layer composite film by transfer printing, comprising a conveying mechanism, a coating mechanism, a reaction mechanism, a compounding mechanism, a hot pressing mechanism, a separation mechanism, a drying mechanism and a winding mechanism;

The coating mechanism is arranged above the conveying mechanism, and is used for coating the first reaction monomer solution on the surface of the conveying mechanism to form the first reaction monomer liquid film;

The reaction mechanism is arranged downstream of the coating mechanism and upstream of the compounding mechanism, and is used to provide the solution of the second monomer and the liquid film of the first monomer to form a stable liquid-liquid interface, carrying the transmission of the liquid film of the first reaction monomer. When the mechanism passes through the reaction mechanism, the first reaction monomer and the second reaction monomer undergo a polymerization reaction at the interface to form a polyamide nano-film;

The compounding mechanism is arranged downstream of the reaction mechanism, and is used to complete the compounding of the porous base film and the polyamide nano-film to prepare the polyamide thin-layer compound film;

The hot-pressing mechanism is arranged downstream of the compounding mechanism and upstream of the disengaging mechanism, and is used to enhance the compounding strength of the polyamide nano-film and the porous base film;

The disengagement mechanism is arranged downstream of the hot pressing mechanism, and is used for separating the polyamide thin-layer composite film from the conveying mechanism;

The drying mechanism and the winding mechanism are sequentially arranged downstream of the separation mechanism, and are used for drying and winding the polyamide thin-layer composite film.

Preferably, the porous base film is compounded with the polyamide nanofilm on the upper side of the polyamide nanofilm.

Preferably, the conveying mechanism is a roller or a conveying belt.

Preferably, the material of the conveying mechanism is aluminum film, steel belt, nylon film, polyurethane or polyester film; the width of the conveying mechanism is 0.01-20 meters.

Preferably, the distance between the blade of the coating mechanism and the conveying mechanism is adjustable.

Preferably, the compounding mechanism is composed of rotating rollers.

The hot pressing mechanism applies pressure and temperature to the polyamide composite membrane to enhance the composite strength of the polyamide nano-film and the porous base membrane.

The invention also provides a method for preparing the polyamide thin-layer composite film by transfer printing, comprising the following steps:

(1) the solution of the first reaction monomer polyamine is evenly coated on the surface of the conveying mechanism through the coating mechanism to form a polyamine solution liquid film;

(2) immersing the conveying mechanism with the liquid film of the polyamine solution on the surface into the solution of the second reaction monomer polybasic acid chloride, and the polyamine and the polybasic acid chloride undergo a polymerization reaction at the interface to generate a polyamide nano-film;

(3) compounding the porous base film from the upper side of the polyamide nano-film with the compounding mechanism to obtain a polyamide thin-layer composite film;

(4) Apply a certain pressure and temperature through the hot pressing mechanism to enhance the composite strength of the porous base film and the polyamide nanofilm;

(5) The conveying mechanism with the polyamide thin-layer composite film attached thereto is immersed in a release mechanism containing constant temperature water, and the polyamide thin-layer composite film is released from the conveying mechanism, followed by drying and winding.

In the method of the present invention, the polyamide nano-film prepared by forming a free interface on the dense substrate for polymerization is compounded with the porous base film by means of transfer printing, which not only ensures that the interfacial polymerization process is not affected by the porous base film, but also widens the It can increase the bonding force between the porous base membrane and the selective separation layer through hot pressing operation or optimize the properties of the porous base membrane, and maintain the separation performance of the polyamide thin-layer composite membrane during long-term use.

In step (1):

Preferably, the polyamine solution is an aqueous polyamine glycerol solution.

Further preferably, the viscosity range of the polyamine glycerol aqueous solution is 10-300 mPa·s.

The polyamine solution in this viscosity range can be stably dispersed on the surface of the conveyor belt. If the solution viscosity is too low, it is not conducive to the formation of a stable and uniform liquid film; if the solution viscosity is too high, the amount of amine monomers participating in the reaction is reduced, which is not conducive to the preparation of polyamide films with high cross-linking degree.

The thickness of the polyamine liquid film can be controlled by adjusting the distance between the doctor blade of the coating mechanism and the conveying mechanism.

Preferably, the thickness of the polyamine liquid film is 1-500 μm.

When the polyamine liquid film is too thin, the total amount of polyamine monomers is insufficient, which will easily cause damage and defects of the polyamide nanofilm; when the polyamine liquid film is too thick, the liquid film is prone to flow during the transfer process, resulting in interfacial disturbances and defects. Inhomogeneity of the interface.

Further preferably, the thickness of the polyamine liquid film is 20-300 μm.

The polyamine is at least one selected from 1,3-cyclohexanedimethylamine, diethylenetriamine, p-phenylenediamine, piperazine, o-phenylenediamine and m-phenylenediamine; the concentration of the polyamine solution is 0.01～100g/L.

Monomer concentration is one of the key factors affecting polymerization kinetics. When the monomer concentration is low, the prepared polyamide film is loose and prone to defects; when the monomer concentration is moderate, the monomer diffusion ability matches the reaction ability, and the prepared polyamide film has high permeability selectivity When the monomer concentration is too high, the monomer diffuses too fast, and the prepared polyamide film is thicker, resulting in lower permeability.

Further preferably, the polyamine is m-phenylenediamine; the concentration of the m-phenylenediamine solution is 1-50 g/L.

In step (2):

The polybasic acid chloride is at least one of phthaloyl chloride, trimesoyl chloride, terephthaloyl chloride and isophthaloyl chloride; the solvent of the polybasic acid chloride solution is heptane, n-hexane, cyclohexane, At least one of trifluorotrichloroethane and isoparaffin; the monomer concentration of the polybasic acid chloride solution is 0.1-10 g/L.

Further preferably, the polybasic acid chloride is trimesic acid chloride; the solvent is isoparaffin; the monomer concentration of the polybasic acid chloride solution is 0.3-5 g/L.

The monomer concentration of the polybasic acid chloride solution is also one of the key factors affecting the polymerization kinetics. Both too high and too low concentrations of acid chloride monomers cannot form polyamide films with high permeation selectivity.

Preferably, the time of the interfacial polymerization reaction is 5-900 s.

Shorter reaction times fail to form dense polyamide films; too long results in reduced efficiency and reduced permeability.

Further preferably, the interfacial polymerization reaction time is 30-450s.

In step (3):

The polyamide nanofilm on the surface of the conveying mechanism is compounded with various porous base films.

Preferably, the porous base film is a polypropylene film, a polyethylene film, a nylon film, a polyvinylidene chloride film, a polyacrylonitrile film, or a single-sided mussel biomimetic modification of various film materials with different surface properties. Asymmetric membrane.

In step (4):

The composite strength of the porous base film and the polyamide nano film is enhanced by the hot pressing mechanism.

Preferably, the temperature of the hot pressing is 50-100°C; the hot pressing pressure is 10-100000Pa.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention has developed a method and device for preparing polyamide thin-layer composite film by transfer printing, which can be prepared in a large scale and continuously;

(2) The porous base film is composited with the nano film on the upper side of the polyamide nano film, that is, the second monomer solution side. The low polarity of the solvent of the second monomer solution can infiltrate the porous base film with solvent resistance and low surface energy. , which is conducive to the bonding of this type of porous base film and nano-film, thus expanding the types of porous base films;

(3) The first monomer solution with high viscosity is located on the outer surface of the nano-film, which is easier to be cleaned and removed;

(4) The composite strength of the polyamide nano-film and the porous base film can be effectively enhanced by adjusting the pressure and temperature of the hot-pressing roller;

(5) The bonding force between the selective separation layer and the base membrane can be enhanced by optimizing the properties of the porous base membrane, thereby ensuring the long-term usability of the polyamide thin-layer composite membrane;

(6) The method has universal applicability to various polyamide films and various porous base films, and the prepared polyamide thin-layer composite membrane can be applied to fields such as organic nanofiltration, organic reverse osmosis, and gas separation.

We can transfer the polyamide nanofilm to the surface of the porous base film in a complete and large area by the transfer printing method, and expand the method of preparing the polyamide composite film.

Description of drawings

Figure 1 is a schematic structural diagram of an apparatus for preparing a polyamide thin-layer composite film by transfer printing.

Detailed ways

The polyamide thin-layer composite organic nanofiltration membrane can be prepared using the structural device shown in FIG. 1 .

First, the solution containing polyamine is coated with a certain thickness of polyamine glycerin aqueous solution on the surface of the conveyor belt through a scraper, and is immersed in the solution containing polybasic acid chloride under the driving of a motor, and reacts for a certain period of time. The polyamide nano-film generated at the free interface is then compounded with the polypropylene film, and then immersed in the detachment tank. The polyamide thin-layer composite film automatically floats on the water surface, enters the drying device, and is collected by the winding mechanism. layer composite film. The conveyor belt is then cycled and reused.

In the examples, rejection rate and permeation flux are two important parameters for evaluating organic nanofiltration membranes. where the retention rate is defined as:

Among them, C _f represents the concentration of the solute in the feed solution before treatment; C _p represents the concentration of the solute in the filtrate after the treatment.

The permeation flux is defined as: under certain operating pressure conditions, the volume of organic solvent permeating unit membrane area per unit pressure and unit time, its unit is L/m ² h bar, and the formula is:

Among them, V represents the volume of the filtrate passing through the organic nanofiltration membrane, in L; A represents the effective membrane area, in m ² ; t represents time, in h; P represents the pressure used in the test, in bar.

The present invention is described in more detail by the following examples, but the examples do not constitute a limitation of the present invention.

Example 1

m-phenylenediamine is selected as the polyamine monomer, m-phenylenediamine is dissolved in an aqueous solution of glycerin, the concentration of m-phenylenediamine is 30 g/L, and the viscosity of the amine monomer solution is controlled at 200-250 mPa·s. Select trimesic acid chloride as polybasic acid chloride monomer, dissolve trimesic acid chloride in hexane, and the concentration of trimesic acid chloride is 1.5g/L.

The container containing the m-phenylenediamine solution was coated with a 200-μm-thick m-phenylenediamine solution liquid film on the surface of the conveyor belt with a width of 3 meters and a smooth material made of aluminum through a scraper. Then enter the reaction mechanism, the liquid film of m-phenylenediamine solution contacts with the solution of trimesoyl chloride to trigger interfacial polymerization, and after 300s of reaction, then through the compounding mechanism, the resulting polyamide nano-film is compounded with the polypropylene film. When the temperature of the hot pressing mechanism is 60°C and the pressure is 100Pa, the composite strength of the polyamide nanofilm and the porous base film is enhanced. Then the composite film and the conveyor belt enter the release tank together, and the polyamide thin-layer composite film that falls off automatically is dried at 60° C., heat-treated for 5 minutes, and wound to obtain the polyamide thin-layer composite film. The organic nanofiltration test results are shown in Table 1.

Examples 2 to 6

The viscosity of the polyamine solution is adjusted to be 10-50 mPa·s, 50-100 mPa·s, 100-150 mPa·s, 150-200 mPa·s, and 250-300 mPa·s, respectively, and other conditions are the same as those in Example 1.

Test Example 1

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 1-6 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 1.

Table 1 Retention rate and permeation flux of polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 1-6

Examples 7-10

The thickness of the polyamine solution liquid film uniformly coated on the conveyor belt was adjusted to be 20 μm, 50 μm, 100 μm, and 300 μm, respectively, and other conditions were the same as in Example 1.

Test case 2

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 7-10 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 2.

Table 2 Retention rate and permeation flux of polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 7-10

Examples 11 to 14

The materials of the adjustment conveyor belt are steel, polyurethane, nylon, and polyester film respectively, and other conditions are the same as those in Example 1.

Test case 3

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 11-14 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 3.

Table 3 Retention rate and permeation flux of polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 11-14

Examples 15 to 18

Adjust the width of the conveyor belt to be 0.2 m, 1 m, 5 m, and 10 m respectively, and the remaining conditions are the same as in Example 1.

Test Example 4

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 15-18 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 4.

Table 4 Retention rate and permeation flux of polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 15-18

Examples 19 to 22

The concentration of the m-phenylenediamine solution was adjusted to be 5g/L, 10g/L, 20g/L and 50g/L respectively, and the remaining conditions were the same as those in Example 1.

Test Example 5

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 19-22 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 5.

Table 5 Rejection rate and permeation flux of polyamide thin-layer composite membranes prepared in Examples 19-22

Examples 23 to 26

The interfacial polymerization reaction times were adjusted to be 30s, 120s, 240s, and 450s, respectively, and the remaining conditions were the same as those in Example 1.

Test Example 6

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 23-26 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 6.

Table 6 Removal rate and permeation flux of polyamide thin-layer composite membranes prepared in Examples 23-26

Examples 27 to 33

The porous base membranes were adjusted to polyethylene, nylon, polyvinylidene chloride, polysulfone, polyacrylonitrile, asymmetric membranes with different surface properties prepared by biomimetic modification of single-sided mussels of polypropylene membranes, and single-sided mussels of polyethylene membranes. The surface properties of the asymmetric membranes prepared by biomimetic modification are very different, and other conditions are the same as those in Example 1.

Test Example 7

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 27-33 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 7.

Table 7 Rejection rate and permeation flux of the polyamide thin-layer composite membranes prepared in Examples 27-33

Examples 34 to 37

The temperature of the hot-pressing mechanism was adjusted to be 70°C, 80°C, 90°C, and 100°C, respectively, and the remaining conditions were the same as those in Example 1.

Test Example 8

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 34-37 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 8.

Table 8 Removal rate and permeation flux of polyamide thin-layer composite membranes prepared in Examples 34-37

Examples 38 to 41

Adjust the pressure of the hot pressing mechanism to be 500Pa, 3000Pa, 6000Pa, and 10000Pa respectively, and the remaining conditions are the same as those in Example 1.

Test Example 9

The polyamide thin-layer composite organic nanofiltration membranes prepared in Examples 38-41 were tested for rejection rate and ethanol flux. The test method is: place the prepared organic nanofiltration membrane in a standard organic nanofiltration test device, and test the rejection rate and ethanol flux of the organic nanofiltration membrane to 50ppm Rhodamine B ethanol solution at 25°C and a pressure of 6 bar. . The results are shown in Table 9.

Table 9 Removal rate and permeation flux of polyamide thin-layer composite membranes prepared in Examples 38-41

The above-mentioned embodiments describe the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned embodiments are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions and equivalent replacements made should be included within the protection scope of the present invention.

Claims (10)

1. a device for preparing polyamide thin-layer composite film by transfer printing, is characterized in that, comprises transmission mechanism, coating mechanism, reaction mechanism, compound mechanism, hot pressing mechanism, detachment mechanism, drying mechanism and winding mechanism; The coating mechanism is arranged above the conveying mechanism, and is used for coating the first reaction monomer solution on the surface of the conveying mechanism to form the first reaction monomer liquid film; The reaction mechanism is arranged downstream of the coating mechanism and upstream of the compounding mechanism, and is used to provide the solution of the second monomer and the liquid film of the first monomer to form a stable liquid-liquid interface, carrying the transmission of the liquid film of the first reaction monomer. When the mechanism passes through the reaction mechanism, the first reaction monomer and the second reaction monomer undergo a polymerization reaction at the interface to form a polyamide nano-film; The compounding mechanism is arranged downstream of the reaction mechanism, and is used to complete the compounding of the porous base film and the polyamide nano-film to prepare the polyamide thin-layer compound film; The hot-pressing mechanism is arranged downstream of the compounding mechanism and upstream of the disengaging mechanism, and is used to enhance the compounding strength of the polyamide nano-film and the porous base film; The disengagement mechanism is arranged downstream of the hot pressing mechanism, and is used for separating the polyamide thin-layer composite film from the conveying mechanism; The drying mechanism and the winding mechanism are sequentially arranged downstream of the separation mechanism, and are used for drying and winding the polyamide thin-layer composite film. 2 . The device for preparing a polyamide thin-layer composite membrane by transfer printing according to claim 1 , wherein the porous base membrane is composited with the polyamide nano-membrane on the upper side of the polyamide nano-membrane. 3 . 3. The device for preparing polyamide thin-layer composite film by transfer printing according to claim 1, wherein the hot pressing mechanism applies pressure and temperature to the polyamide composite film to strengthen the polyamide nano-film and porous Composite strength of base film. 4. a method for preparing polyamide thin-layer composite film by transfer printing, is characterized in that, comprises the following steps: (1) the solution of the first reaction monomer polyamine is evenly coated on the surface of the conveying mechanism through the coating mechanism to form a polyamine solution liquid film; (2) immersing the conveying mechanism with the liquid film of the polyamine solution on the surface into the solution of the second reaction monomer polybasic acid chloride, and the polyamine and the polybasic acid chloride undergo a polymerization reaction at the interface to generate a polyamide nano-film; (3) compounding the porous base film from the upper side of the polyamide nano-film with the compounding mechanism to obtain a polyamide thin-layer composite film; (4) applying pressure and temperature through a hot-pressing mechanism to enhance the composite strength of the porous base film and the polyamide nanofilm; (5) The conveying mechanism with the polyamide thin-layer composite film attached thereto is immersed in a release mechanism containing constant temperature water, and the polyamide thin-layer composite film is released from the conveying mechanism, followed by drying and winding. 5. The method for preparing a polyamide thin-layer composite film by transfer printing according to claim 4, wherein the polyamine solution is a polyamine glycerin aqueous solution; the viscosity range of the polyamine glycerin aqueous solution is 10～10～ 300mPa·s. 6 . The method for preparing a polyamide thin-layer composite film by transfer printing according to claim 4 , wherein the thickness of the polyamine liquid film is 1-500 μm. 7 . 7. the method for preparing polyamide thin-layer composite film by transfer printing according to claim 4, is characterized in that, described polyamine is 1,3-cyclohexanedimethylamine, diethylenetriamine, p-phenylenediamine , at least one of piperazine, o-phenylenediamine and m-phenylenediamine; the concentration of the polyamine solution is 0.01-100 g/L. 8. the method for preparing polyamide thin-layer composite film by transfer printing according to claim 4, is characterized in that, described polybasic acid chloride is phthaloyl chloride, trimesoyl chloride, terephthaloyl chloride, m-benzene At least one of the diformyl chlorides; the solvent of the polybasic acid chloride solution is at least one of heptane, n-hexane, cyclohexane, trifluorotrichloroethane, and isoparaffin; the monomer concentration of the polybasic acid chloride solution is 0.1 ~10g/L. 9 . The method for preparing a polyamide thin-layer composite film by transfer printing according to claim 4 , wherein the hot-pressing temperature is 50-100° C. and the hot-pressing pressure is 10-100,000 Pa. 10 . 10 . A polyamide thin-layer composite film prepared by transfer printing, characterized in that, it is prepared by the preparation method according to any one of claims 4 to 9 .

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