Waterproof flame-retardant adhesive and preparation method thereof

Abstract

The invention relates to the field of adhesives, in particular to a waterproof flame-retardant adhesive and a preparation method thereof.The waterproof flame-retardant adhesive is prepared from, by weight, 40-60 parts of epoxy resin, 20-30 parts of acrylic ester, 10-15 parts of organic silicon modifier, 15-25 parts of flame retardant, 2-5 parts of coupling agent, 5-10 parts of plasticizer, 8-12 parts of filler, 0.5-1.5 parts of initiator and 30-50 parts of solvent. The adhesive has the beneficial effects that by adding the organic silicon modifier, a layer of compact organic silicon film can be formed on the surface of the adhesive, so that the invasion of moisture is effectively blocked; meanwhile, a copolymer network structure formed by the epoxy resin and the acrylate also has certain hydrophobicity, and through the synergistic effect of the epoxy resin and the acrylate, the adhesive has good waterproof performance and can keep a stable bonding effect in a humid environment.

Description

Technical Field

[0001] The present invention relates to the field of adhesives, in particular to a waterproof and flame-retardant adhesive and a preparation method thereof. Background Art

[0002] Adhesives are widely used in a wide range of fields, including construction, electronics, and packaging. However, in some specialized environments, such as humid construction environments and electronic equipment assembly with stringent fire protection requirements, conventional adhesives struggle to meet these requirements. Conventional adhesives tend to lose their tack in humid environments, resulting in reduced bonding effectiveness. Furthermore, they are prone to burning when exposed to open flames or high temperatures, posing a significant safety hazard.

[0003] Although some existing adhesives have certain waterproof or flame retardant properties, it is often difficult to take into account both waterproof and flame retardant properties at the same time, and there may be problems such as complex process and high cost during the preparation process, which limits their large-scale application. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings, the present invention provides a technical solution that can solve the above-mentioned problems.

[0005] A waterproof flame-retardant adhesive comprises the following raw materials in parts by weight: 40-60 parts of epoxy resin, 20-30 parts of acrylate, 10-15 parts of organosilicon modifier, 15-25 parts of flame retardant, 2-5 parts of coupling agent, 5-10 parts of plasticizer, 8-12 parts of filler, 0.5-1.5 parts of initiator and 30-50 parts of solvent.

[0006] As a further solution of the present invention: the epoxy resin is a low-viscosity bisphenol A epoxy resin; the acrylate is a copolymer of methyl methacrylate and butyl acrylate; and the organosilicon modifier is hydroxyl-terminated polydimethylsiloxane.

[0007] As a further embodiment of the present invention, the flame retardant is a mixture of melamine cyanurate, ammonium polyphosphate and aluminum hydroxide in a mass ratio of 2:3:1; the coupling agent is silane coupling agent KH-550; the plasticizer is dioctyl phthalate; the filler is nano-calcium carbonate; the initiator is benzoyl peroxide; and the solvent is acetone.

[0008] A method for preparing a waterproof flame-retardant adhesive comprises the following steps:

[0009] (1) Weigh each raw material by weight;

[0010] (2) adding epoxy resin, acrylate and organosilicon modifier into a reaction kettle, stirring and mixing at 60-80° C. to obtain a mixed resin;

[0011] (3) Add flame retardant, coupling agent, plasticizer and filler to the mixed resin and continue stirring for 30 to 60 minutes to fully disperse the components;

[0012] (4) adding a solvent to the above mixture, stirring evenly, and heating to 80-90°C;

[0013] (5) adding an initiator to the reaction system and reacting at 80-90° C. for 2-4 hours;

[0014] (6) After the reaction is completed, the mixture is cooled to room temperature to obtain the waterproof and flame-retardant adhesive.

[0015] As a further solution of the present invention: a high-precision electronic balance is used when weighing the raw materials, and the weighing error is controlled within ±0.1%.

[0016] As a further solution of the present invention: the stirring speed during the preparation of the mixed resin is 150 to 200 rpm, and the temperature is controlled by a circulating heating system in the reactor jacket, and the temperature fluctuation does not exceed ±2°C.

[0017] As a further solution of the present invention: when dispersing the components, the order of adding is solid first and then liquid, the stirring speed is 250-300 rpm, and the dispersion state of the materials is observed every 15 minutes.

[0018] As a further solution of the present invention: the solvent addition rate is 5 to 10 ml / min, and the heating rate is 2 to 3° C. / min.

[0019] As a further solution of the present invention: the initiator is added through a metering pump, the addition time is controlled within 5 to 10 minutes, and the viscosity change of the reaction system is detected every 30 minutes during the reaction.

[0020] As a further solution of the present invention: after the reaction is completed, the cooling rate is 5-8°C / min, and stirring is continued during the cooling process.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) By adding an organosilicon modifier, a dense organosilicon film can be formed on the surface of the adhesive, effectively blocking the intrusion of moisture; at the same time, the copolymer network structure formed by epoxy resin and acrylate also has a certain hydrophobicity. The synergistic effect of the two makes the adhesive have good waterproof performance and can maintain a stable bonding effect in a humid environment;

[0023] (2) By using a composite flame retardant composed of melamine cyanurate, ammonium polyphosphate and aluminum hydroxide, melamine cyanurate will decompose and produce non-flammable gas during the combustion process, diluting the oxygen concentration and inhibiting combustion; ammonium polyphosphate will form polymetaphosphoric acid when heated, which has a dehydration and carbonization effect, forming a carbon layer to block heat and oxygen; aluminum hydroxide decomposes and absorbs heat, lowering the system temperature, and the aluminum oxide generated at the same time can enhance the stability of the carbon layer; the three flame retardants cooperate with each other to exert a synergistic flame retardant effect, significantly improving the flame retardant properties of the adhesive.

[0024] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships as shown, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0028] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0029] Example 1

[0030] Raw material ratio (by weight): epoxy resin (low viscosity bisphenol A type) 40 parts; acrylate (copolymer of methyl methacrylate and butyl acrylate) 20 parts; organosilicon modifier (hydroxyl-terminated polydimethylsiloxane) 10 parts; flame retardant (melamine cyanurate, ammonium polyphosphate and aluminum hydroxide compounded in a mass ratio of 2:3:1) 15 parts; coupling agent (silane coupling agent KH-550) 2 parts; plasticizer (dioctyl phthalate) 5 parts; filler (nano-calcium carbonate) 8 parts; initiator (benzoyl peroxide) 0.5 parts; solvent (acetone) 30 parts;

[0031] The following steps are involved:

[0032] (1) Use an electronic balance with an accuracy of 0.01g for weighing. Calibrate and zero the balance before weighing. Use clean weighing paper or weighing vessels for different raw materials to avoid cross contamination.

[0033] (2) After cleaning and drying the reactor, add epoxy resin, turn on the heating device of the reactor, and raise the temperature to 60°C at a heating rate of 5°C / min. After the epoxy resin is completely melted, start the stirrer and set the stirring speed to 120r / min; slowly add acrylate and silicone modifier in sequence, and continue stirring for 30 minutes to fully mix the components to form a mixed resin;

[0034] (3) After ammonium polyphosphate, melamine cyanurate, and aluminum hydroxide are mixed in proportion, put into a high-speed grinder and crushed to 200 mesh, and sieved for later use; while stirring, the crushed flame retardant, coupling agent, plasticizer, and filler are added to the reactor in sequence, the stirring speed is increased to 150r / min, and the mixture is dispersed for 40 minutes; during this period, the stirring is paused every 10 minutes to clean the materials attached to the inner wall of the reactor to ensure uniform dispersion;

[0035] (4) Slowly add the solvent to the reactor at a rate of 5 to 10 ml / min. Use a rotational viscometer to monitor the viscosity of the system in real time. Adjust the amount of solvent added to keep the viscosity within a suitable range. Heat the mixture in a water bath at a rate of 2°C / min to 80°C. Stir continuously to ensure uniform heating of the system.

[0036] (5) When the system temperature stabilizes at 80°C and is maintained for 5 minutes, grind the initiator into fine powder and slowly add it to the reactor. Immediately increase the stirring speed to 200 r / min. During the reaction, record the system temperature and viscosity data every 30 minutes. Adjust the reactor temperature with jacket cooling water to prevent overheating and causing implosion.

[0037] (6) After the reaction is completed for 3 hours, the heating device is turned off and the reaction system is allowed to cool naturally to room temperature; during the cooling process, stirring is continued at a low speed to prevent the system from stratification; after cooling is completed, the adhesive is filtered using a 200-mesh filter to remove possible lumps, impurities, etc.; the filtered adhesive is transferred to a clean sealed container and labeled with information such as the product name and preparation date to obtain a waterproof and flame-retardant adhesive.

[0038] Example 2

[0039] Raw material ratio (by weight): epoxy resin (low viscosity bisphenol A type) 60 parts; acrylate (copolymer of methyl methacrylate and butyl acrylate) 30 parts; organosilicon modifier (hydroxyl-terminated polydimethylsiloxane) 15 parts; flame retardant (melamine cyanurate, ammonium polyphosphate and aluminum hydroxide compounded in a mass ratio of 2:3:1) 25 parts; coupling agent (silane coupling agent KH-550) 5 parts; plasticizer (dioctyl phthalate) 10 parts; filler (nano-calcium carbonate) 12 parts; initiator (benzoyl peroxide) 1.5 parts; solvent (acetone) 50 parts;

[0040] (1) Use an electronic balance with an accuracy of 0.01g for weighing. Calibrate and zero the balance before weighing. Use clean weighing paper or weighing vessels for different raw materials to avoid cross contamination.

[0041] (2) After cleaning and drying the reactor, add epoxy resin, turn on the heating device of the reactor, and raise the temperature to 80°C at a heating rate of 6°C / min. After the epoxy resin is completely melted, start the stirrer and set the stirring speed to 150r / min; slowly add acrylate and silicone modifier in sequence, and continue stirring for 30 minutes to fully mix the components to form a mixed resin;

[0042] (3) After ammonium polyphosphate, melamine cyanurate, and aluminum hydroxide are mixed in proportion, put into a high-speed grinder and crushed to 200 mesh, and sieved for later use; while stirring, the crushed flame retardant, coupling agent, plasticizer, and filler are added to the reactor in sequence, the stirring speed is increased to 200 r / min, and the mixture is dispersed for 60 minutes; during this period, the stirring is paused every 15 minutes to clean the materials attached to the inner wall of the reactor to ensure uniform dispersion;

[0043] (4) Slowly add the solvent to the reactor at a rate of 8 to 10 ml / min. Use a rotational viscometer to monitor the viscosity of the system in real time. Adjust the amount of solvent added to keep the viscosity within a suitable range. Heat the mixture in a water bath at a rate of 3°C / min to 90°C, stirring continuously to ensure uniform heating of the system.

[0044] (5) When the system temperature stabilizes at 90°C and is maintained for 10 minutes, grind the initiator into fine powder and slowly add it to the reactor. Immediately increase the stirring speed to 250 r / min. During the reaction, record the system temperature and viscosity data every 30 minutes. Adjust the reactor temperature with jacket cooling water to strictly control the reaction temperature within the range of 90 ± 2°C.

[0045] (6) After the reaction is completed for 4 hours, the heating device is turned off, the cooling system is turned on, and the mixture is cooled to room temperature at a rate of 5°C / min; during the cooling process, stirring is continued at a low speed to prevent the system from stratification; after the cooling is completed, vacuum degassing is performed, the vacuum degree is controlled at -0.09 MPa, and the degassing time is 15 minutes; finally, the adhesive is filtered using a 200-mesh filter to remove impurities, and the filtered adhesive is transferred to a clean sealed container and labeled with product information to obtain a waterproof and flame-retardant adhesive.

[0046] Example 3

[0047] Raw material ratio (by weight): epoxy resin (low viscosity bisphenol A type) 50 parts; acrylate (copolymer of methyl methacrylate and butyl acrylate) 25 parts; organosilicon modifier (hydroxyl-terminated polydimethylsiloxane) 12 parts; flame retardant (melamine cyanurate, ammonium polyphosphate and aluminum hydroxide compounded in a mass ratio of 2:3:1) 20 parts; coupling agent (silane coupling agent KH-550) 3 parts; plasticizer (dioctyl phthalate) 7 parts; filler (nano-calcium carbonate) 10 parts; initiator (benzoyl peroxide) 1 part; solvent (acetone) 40 parts;

[0048] The following steps are involved:

[0049] (1) Use an electronic balance with an accuracy of 0.01g for weighing. Calibrate and zero the balance before weighing. Use clean weighing paper or weighing vessels for different raw materials to avoid cross contamination.

[0050] (2) After cleaning and drying the reactor, add epoxy resin, turn on the heating device of the reactor, and raise the temperature to 70°C at a heating rate of 5°C / min. After the epoxy resin is completely melted, start the stirrer and set the stirring speed to 130r / min; slowly add acrylate and silicone modifier in sequence, and continue stirring for 30 minutes to fully mix the components to form a mixed resin;

[0051] (3) After ammonium polyphosphate, melamine cyanurate, and aluminum hydroxide are mixed in proportion, put into a high-speed grinder and crushed to 200 mesh, and sieved for later use; while stirring, the crushed flame retardant, coupling agent, plasticizer, and filler are added to the reactor in sequence, the stirring speed is increased to 180r / min, and the mixture is dispersed for 30 minutes; during this period, the stirring is paused every 10 minutes to clean the materials attached to the inner wall of the reactor to ensure uniform dispersion;

[0052] (4) Slowly add the solvent to the reactor at a rate of 6 to 8 ml / min. Use a rotational viscometer to monitor the viscosity of the system in real time. Adjust the amount of solvent added to keep the viscosity within a suitable range. Heat the mixture in a water bath at a rate of 2.5°C / min to 85°C. Stir continuously to ensure uniform heating of the system.

[0053] (5) When the system temperature stabilizes at 85°C and is maintained for 8 minutes, grind the initiator into fine powder and slowly add it to the reactor. Immediately increase the stirring speed to 220 r / min. During the reaction, record the system temperature and viscosity data every 30 minutes. Adjust the reactor temperature with jacket cooling water to strictly control the reaction temperature within the range of 85±2°C.

[0054] (6) After the reaction is completed for 3 hours, the heating device is turned off and the reaction system is allowed to cool naturally to room temperature; during the cooling process, stirring is continued at a low speed to prevent the system from stratification; after cooling is completed, the adhesive is filtered using a 200-mesh filter to remove possible lumps, impurities, etc.; the filtered adhesive is transferred to a clean sealed container and labeled with information such as the product name and preparation date to obtain a waterproof and flame-retardant adhesive.

[0055] Comparative Example 1

[0056] Raw material ratio (by weight): epoxy resin (low viscosity bisphenol A type) 40 parts; acrylate (copolymer of methyl methacrylate and butyl acrylate) 20 parts; coupling agent (silane coupling agent KH-550) 2 parts; plasticizer (dioctyl phthalate) 5 parts; filler (nano-calcium carbonate) 8 parts; initiator (benzoyl peroxide) 0.5 parts; solvent (acetone) 30 parts; no organic silicon modifier and flame retardant are added;

[0057] The following steps are involved:

[0058] (1) Use an electronic balance with an accuracy of 0.01g for weighing. Calibrate and zero the balance before weighing. Use clean weighing paper or weighing vessels for different raw materials to avoid cross contamination.

[0059] (2) After cleaning and drying the reactor, add epoxy resin, turn on the heating device of the reactor, and raise the temperature to 60°C at a heating rate of 5°C / min. After the epoxy resin is completely melted, start the stirrer and set the stirring speed to 120 r / min; slowly add acrylate and continue stirring for 30 minutes to fully mix the components to form a mixed resin;

[0060] (3) While stirring, add the coupling agent, plasticizer, and filler to the reactor in sequence, increase the stirring speed to 150 r / min, and disperse for 30 minutes; during this period, pause stirring every 10 minutes to clean the materials attached to the inner wall of the reactor to ensure uniform dispersion;

[0061] (4) Slowly add the solvent to the reactor at a rate of 5 to 10 ml / min. Use a rotational viscometer to monitor the viscosity of the system in real time. Adjust the amount of solvent added to keep the viscosity within a suitable range. Heat the mixture in a water bath at a rate of 2°C / min to 80°C. Stir continuously to ensure uniform heating of the system.

[0062] (5) When the system temperature stabilizes at 80°C and is maintained for 5 minutes, grind the initiator into fine powder and slowly add it to the reactor. Immediately increase the stirring speed to 200 r / min. During the reaction, record the system temperature and viscosity data every 30 minutes. Adjust the reactor temperature with jacket cooling water to prevent overheating and causing implosion.

[0063] (6) After the reaction is completed for 3 hours, the heating device is turned off and the reaction system is allowed to cool naturally to room temperature; during the cooling process, stirring is continued at a low speed to prevent the system from stratification; after cooling is completed, the adhesive is filtered using a 200-mesh filter to remove possible lumps, impurities, etc.; the filtered adhesive is transferred to a clean sealed container and labeled with information such as the product name and preparation date to obtain a waterproof and flame-retardant adhesive.

[0064] Comparative Example 2

[0065] Raw material ratio (by weight): epoxy resin (low viscosity bisphenol A type) 60 parts; acrylate (copolymer of methyl methacrylate and butyl acrylate) 30 parts; organosilicon modifier (hydroxyl-terminated polydimethylsiloxane) 15 parts; coupling agent (silane coupling agent KH-550) 5 parts; plasticizer (dioctyl phthalate) 10 parts; filler (nano-calcium carbonate) 12 parts; initiator (benzoyl peroxide) 1.5 parts; solvent (acetone) 50 parts; no flame retardant added;

[0066] The following steps are involved:

[0067] (1) Use an electronic balance with an accuracy of 0.01g for weighing. Calibrate and zero the balance before weighing. Use clean weighing paper or weighing vessels for different raw materials to avoid cross contamination.

[0068] (2) After cleaning and drying the reactor, add epoxy resin, turn on the heating device of the reactor, and raise the temperature to 80°C at a heating rate of 6°C / min. After the epoxy resin is completely melted, start the stirrer and set the stirring speed to 150r / min; slowly add acrylate and silicone modifier in sequence, and continue stirring for 30 minutes to fully mix the components to form a mixed resin;

[0069] (3) While stirring, add the coupling agent, plasticizer, and filler to the reactor in sequence, increase the stirring speed to 200 r / min, and disperse for 40 minutes; during this period, pause stirring every 10 minutes to clean the materials attached to the inner wall of the reactor to ensure uniform dispersion;

[0070] (4) Slowly add the solvent to the reactor at a rate of 8 to 10 ml / min. Use a rotational viscometer to monitor the viscosity of the system in real time. Adjust the amount of solvent added to keep the viscosity within a suitable range. Heat the mixture in a water bath at a rate of 3°C / min to 90°C, stirring continuously to ensure uniform heating of the system.

[0071] (5) When the system temperature stabilizes at 90°C and is maintained for 5 minutes, grind the initiator into fine powder and slowly add it to the reactor. Immediately increase the stirring speed to 250 r / min. During the reaction, record the system temperature and viscosity data every 30 minutes. Adjust the reactor temperature with jacket cooling water to strictly control the reaction temperature within the range of 90±2°C.

[0072] (6) After the reaction is completed for 4 hours, the heating device is turned off, the cooling system is turned on, and the mixture is cooled to room temperature at a rate of 5°C / min; during the cooling process, stirring is continued at a low speed to prevent the system from stratification; after the cooling is completed, vacuum degassing is performed, the vacuum degree is controlled at -0.09 MPa, and the degassing time is 15 minutes; finally, the adhesive is filtered through a 200-mesh filter to remove impurities, and the filtered adhesive is transferred to a clean sealed container and labeled with product information to obtain a waterproof and flame-retardant adhesive.

[0073]

[0074] By comparing the examples and the comparative examples, it can be clearly seen that the waterproof and flame-retardant adhesive prepared by the present invention has significantly improved waterproofness and flame retardancy, while maintaining good bonding strength, after the organic silicon modifier and the composite flame retardant are added simultaneously.

[0075] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0076] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A waterproof flame retardant adhesive, characterized in that: The raw materials include, by weight, 40 to 60 parts of epoxy resin, 20 to 30 parts of acrylate, 10 to 15 parts of silicone modifier, 15 to 25 parts of flame retardant, 2 to 5 parts of coupling agent, 5 to 10 parts of plasticizer, 8 to 12 parts of filler, 0.5 to 1.5 parts of initiator, and 30 to 50 parts of solvent.

2. The waterproof and flame-retardant adhesive according to claim 1, characterized in that: The epoxy resin is a low-viscosity bisphenol A epoxy resin; the acrylate is a copolymer of methyl methacrylate and butyl acrylate; and the organosilicon modifier is a hydroxyl-terminated polydimethylsiloxane.

3. The waterproof and flame-retardant adhesive according to claim 1, characterized in that: The flame retardant is a mixture of melamine cyanurate, ammonium polyphosphate and aluminum hydroxide in a mass ratio of 2:3:1; the coupling agent is silane coupling agent KH-550; the plasticizer is dioctyl phthalate; the filler is nano-calcium carbonate; the initiator is benzoyl peroxide; and the solvent is acetone.

4. A method for preparing the waterproof flame retardant adhesive according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Weigh each raw material by weight; (2) adding epoxy resin, acrylate and organosilicon modifier into a reaction kettle, stirring and mixing at 60-80° C. to obtain a mixed resin; (3) Add flame retardant, coupling agent, plasticizer and filler to the mixed resin and continue stirring for 30 to 60 minutes to fully disperse the components; (4) adding a solvent to the above mixture, stirring evenly, and heating to 80-90°C; (5) adding an initiator to the reaction system and reacting at 80-90° C. for 2-4 hours; (6) After the reaction is completed, the mixture is cooled to room temperature to obtain the waterproof and flame-retardant adhesive.

5. The preparation method according to claim 4, characterized in that: A high-precision electronic balance is used when weighing raw materials, and the weighing error is controlled within ±0.1%.

6. The preparation method according to claim 4, characterized in that: The stirring speed during the preparation of the mixed resin is 150 to 200 rpm, and the temperature is controlled by a circulating heating system in the reactor jacket, with the temperature fluctuation not exceeding ±2°C.

7. The preparation method according to claim 4, characterized in that: When dispersing the components, add the solid first and then the liquid, stir at a speed of 250-300 rpm, and observe the dispersion state of the materials every 15 minutes.

8. The preparation method according to claim 4, characterized in that: The solvent addition rate is 5-10 ml / min, and the heating rate is 2-3°C / min.

9. The preparation method according to claim 4, characterized in that: The initiator is added through a metering pump, and the addition time is controlled within 5 to 10 minutes. During the reaction process, the viscosity change of the reaction system is detected every 30 minutes.

10. The preparation method according to claim 4, characterized in that: After the reaction is completed, the cooling rate is 5-8°C / min, and stirring is continued during the cooling process.

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