A solid cationic etherifying agent and preparation method thereof

Abstract

The present invention relates to the technical field of etherifying agents, and discloses a solid cationic etherifying agent and a preparation method thereof. The present invention is carried out by adding organosilicon-modified gemini quaternary ammonium salt, pyridine-modified epoxy resin-modified quaternary ammonium salt, and 3-chloro-2-hydroxypropyltrimethylammonium chloride into a reactor for reaction, and vacuum drying is performed after the reaction is completed to obtain a solid cationic etherifying agent. In organosilicon-modified gemini quaternary ammonium salt, imidazole group inhibits the synthesis of ergosterol in fungal cell membrane, causing fungal death, and playing an antibacterial role; gemini quaternary ammonium salt has a better bactericidal effect than single-chain quaternary ammonium salt; in pyridine-modified epoxy resin-modified quaternary ammonium salt, pyridine group can interact with bacterial cell membrane, affect bacterial metabolism and cell structure, and play an antibacterial role; sulfur element can bind to protein and DNA in bacteria, inhibit enzyme activity and protein synthesis, and play a bactericidal role; sulfur element can also damage bacterial cell wall and cell membrane, accelerating cell death.

Description

Technical Field

[0001] The invention relates to the technical field of etherifying agents, in particular to a solid cationic etherifying agent and a preparation method thereof. Background Art

[0002] Solid cationic etherifying agent is a solid etherifying agent with a quaternary ammonium salt structure, which can react with starch, cellulose, etc. to produce cationic biodegradable macromolecular compounds such as starch and cellulose, and is widely used in the fields of salt-free printing and dyeing, papermaking auxiliaries, cotton fiber textiles, oil extraction, daily chemical industry, etc. However, most solid cationic etherifying agents have poor antibacterial effects, which limits their further application and development. For example, patent CN108102000A discloses a fast-reacting solid etherifying agent, which shortens the reaction time of preparing the etherifying agent, has better environmental protection and high production efficiency, but its antibacterial effect needs to be improved. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the deficiencies of the prior art, the present invention provides a solid cationic etherifying agent and a preparation method thereof, which have good antibacterial effect.

[0005] (II) Technical solution

[0006] To achieve the above object, the present invention provides the following technical scheme: a solid cationic etherifying agent, comprising the following weight components: 15-20 weight parts of organosilicon-modified gemini quaternary ammonium salt, 16-18 weight parts of pyridine-modified epoxy resin-modified quaternary ammonium salt, and 5-7 weight parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride.

[0007] Preferably, the method for preparing the organosilicon-modified gemini quaternary ammonium salt comprises the following steps:

[0008] (1) Add methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide catalyst to tetrahydrofuran solvent, stir and mix, react at 35-45° C. for 3-5 hours, and after the reaction is completed, filter, wash and dry to obtain intermediate 1;

[0009] (2) Under a nitrogen atmosphere, N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate catalyst were added to N,N-dimethylformamide solvent, and the reaction was carried out at 75-90°C for 5-8 hours. After the reaction, the reaction was distilled under reduced pressure, washed and dried to obtain intermediate 2;

[0010] (3) Add intermediate 1, intermediate 2 and acetic acid into a three-necked flask, then add isopropanol of the same solute volume, and stir and heat to 78-82°C under nitrogen replacement conditions, reflux for 6-8 hours. After the reaction is completed, let it stand and cool, and rotary evaporate to obtain organosilicon-modified gemini quaternary ammonium salt.

[0011] Preferably, in step (1), the mass ratio of methyl glycidol, dichloromethyltriethoxysilane and potassium hydroxide is 1:0.4-0.6:0.04-0.05.

[0012] Preferably, in step (2), the mass ratio of N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate is 1:1.2-1.4:0.04-0.08.

[0013] Preferably, in step (3), the mass ratio of intermediate 1, intermediate 2 and acetic acid is 1:1.8-2:1.5-1.7.

[0014] Preferably, the preparation method of the pyridine-modified epoxy resin-modified quaternary ammonium salt comprises the following steps:

[0015] S1. Add 3-5 parts by weight of bisphenol A epoxy resin to a thermostatic reactor, stir and heat the system to control the temperature at 45-55 ° C, 7-11 parts by weight of 2,3-pyridinedicarboxylic acid and 0.2-0.5 parts by weight of triethylamine catalyst are fully mixed and added to the thermostatic reactor, and the temperature is raised to the reaction temperature at 300-500rmp and the temperature is controlled for 3-4h. After the reaction is completed, filter and distill under reduced pressure to obtain a pyridine-modified epoxy resin;

[0016] S2. Add 4-((ethylaniline)methyl)benzenesulfonic acid and pyridine-modified epoxy resin to acetonitrile solvent, stir and mix, react at 30-40° C. for 1.5-2 h, and after the reaction, wash and dry to obtain intermediate 3;

[0017] S3. Add 10-12 parts by weight of epichlorohydrin to a reactor under an ice-water bath, stir for 20-30 minutes, add 5-8 parts by weight of intermediate 3 dropwise thereto, react at 25-28°C for 3-4.5 hours, filter, wash and vacuum dry after the reaction to obtain a pyridine-modified epoxy resin modified quaternary ammonium salt.

[0018] Preferably, the temperature of the temperature-controlled reaction in S1 is 90-95°C.

[0019] Preferably, the mass ratio of 4-((ethylaniline)methyl)benzenesulfonic acid to pyridine-modified epoxy resin in S2 is 1:0.75-0.8.

[0020] Preferably, the dropping time in S3 is 1.5-2h.

[0021] Preferably, the preparation method of the solid cationic etherifying agent is: adding organosilicon-modified gemini quaternary ammonium salt, pyridine-modified epoxy resin-modified quaternary ammonium salt, and 3-chloro-2-hydroxypropyltrimethylammonium chloride into a reactor, reacting at a speed of 800-1000 rpm for 5-10 minutes, and vacuum drying after the reaction to obtain a solid cationic etherifying agent.

[0022] 3. Beneficial technical effects

[0023] The invention prepares a solid cationic etherifying agent by adding organosilicon-modified gemini quaternary ammonium salt, pyridine-modified epoxy resin-modified quaternary ammonium salt and 3-chloro-2-hydroxypropyltrimethylammonium chloride into a reactor for reaction, and vacuum drying after the reaction is completed.

[0024] The hydroxyl group in methyl glycidol reacts with the chlorine in dichloromethyltriethoxysilane to introduce a silicon-oxygen bond and a diepoxy group to obtain intermediate 1. The bromine in 4-bromo-N,N-dimethylaniline reacts with the imidazole group in N-methylimidazole to introduce an imidazole group to obtain intermediate 2. The tertiary amine in intermediate 2 reacts with acetic acid to obtain a quaternary ammonium salt. The quaternary ammonium salt attacks the diepoxy group in intermediate 1 to undergo a ring-opening reaction to obtain an organosilicon-modified gemini quaternary ammonium salt. The epoxy group in bisphenol A epoxy resin undergoes a ring-opening esterification reaction with 2,3-pyridinedicarboxylic acid to introduce a pyridine group to obtain a pyridine-modified epoxy resin. The hydroxyl group in the pyridine-modified epoxy resin reacts with the sulfonic acid group in 4-((ethylaniline)methyl)benzenesulfonic acid to introduce a tertiary amine to obtain intermediate 3. The tertiary amine in intermediate 3 undergoes a quaternization reaction with epichlorohydrin to obtain a quaternary ammonium salt modified by pyridine-modified epoxy resin.

[0025] In silicone-modified gemini quaternary ammonium salts, the imidazole group inhibits the biosynthesis of ergosterol in the fungal cell membrane, resulting in changes in cell membrane permeability, causing the loss of important intracellular substances and leading to fungal death, thereby playing an antibacterial role; compared with traditional single-chain quaternary ammonium salts, the structure of gemini quaternary ammonium salts has a stronger positive charge and better bactericidal effect; in pyridine-modified epoxy resin-modified quaternary ammonium salts, the pyridine group contains a nitrogen heterocyclic structure with a high electron density and anti-nucleophilicity, which makes the pyridine derivative have certain lipophilicity and electrophilicity, and can interact with biological molecules such as bacterial cell membranes and enzymes, thereby affecting the physiological metabolic process and cell structure of bacteria and playing an antibacterial role; sulfur can combine with proteins and DNA in bacteria, interfere with bacterial metabolic activities, inhibit enzyme activity and protein synthesis in bacterial cells, and achieve a bactericidal effect. Sulfur can also damage bacterial cell walls and cell membranes and accelerate cell death. DETAILED DESCRIPTION Example 1

[0026] (1) Add methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide catalyst to tetrahydrofuran solvent, stir and mix, wherein the mass ratio of methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide is 1:0.4:0.04, react at 35° C. for 3 h, and after the reaction is completed, filter, wash and dry to obtain intermediate 1;

[0027] (2) Under a nitrogen atmosphere, N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate catalyst were added to N,N-dimethylformamide solvent, wherein the mass ratio of N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate was 1:1.2:0.04, and the reaction was carried out at 75°C for 5 hours. After the reaction, the reaction was carried out under reduced pressure distillation, washed and dried to obtain intermediate 2;

[0028] (3) Add intermediate 1, intermediate 2 and acetic acid into a three-necked flask, wherein the mass ratio of intermediate 1, intermediate 2 and acetic acid is 1:1.8:1.5, and then add isopropanol of the same solute volume, and stir and heat to 78°C under nitrogen replacement conditions, reflux for 6 hours, and after the reaction is completed, let it stand and cool, and rotary evaporate to obtain organosilicon-modified gemini quaternary ammonium salt;

[0029] (4) Add 3 parts by weight of bisphenol A epoxy resin to a thermostatic reactor, stir and heat until the system temperature is controlled at 45°C, fully mix 7 parts by weight of 2,3-pyridinedicarboxylic acid and 0.2 parts by weight of triethylamine catalyst, add them to the thermostatic reactor, heat to the reaction temperature at 300 rpm and control the temperature for 3 hours, wherein the temperature of the temperature control reaction is 90°C. After the reaction is completed, filter and distill under reduced pressure to obtain pyridine modified epoxy resin;

[0030] (5) Add 4-((ethylaniline)methyl)benzenesulfonic acid and pyridine-modified epoxy resin to acetonitrile solvent, wherein the mass ratio of 4-((ethylaniline)methyl)benzenesulfonic acid to pyridine-modified epoxy resin is 1:0.75, stir and mix, react at 30°C for 1.5h, and after the reaction is completed, wash and dry to obtain intermediate 3;

[0031] (6) Add 10 parts by weight of epichlorohydrin to a reactor under an ice-water bath, stir for 20 minutes, and then dropwise add 5 parts by weight of intermediate 3 for 1.5 hours. After the dropwise addition is completed, react at 25° C. for 3 hours. After the reaction is completed, filter, wash and vacuum dry to obtain a pyridine-modified epoxy resin modified quaternary ammonium salt;

[0032] (7) 15 parts by weight of organosilicon-modified gemini quaternary ammonium salt, 16 parts by weight of pyridine-modified epoxy resin-modified quaternary ammonium salt, and 5 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride are added to a reactor, and the mixture is reacted at a speed of 800 rpm for 5 minutes. After the reaction is completed, the mixture is vacuum dried to obtain a solid cationic etherifying agent. Example 2

[0033] (1) Add methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide catalyst to tetrahydrofuran solvent, stir and mix, wherein the mass ratio of methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide is 1:0.6:0.05, react at 45° C. for 5 h, and after the reaction is completed, filter, wash and dry to obtain intermediate 1;

[0034] (2) Under a nitrogen atmosphere, N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate catalyst were added to N,N-dimethylformamide solvent, wherein the mass ratio of N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate was 1:1.4:0.08, and the reaction was carried out at 90°C for 8 hours. After the reaction, the reaction was carried out under reduced pressure distillation, washed and dried to obtain intermediate 2;

[0035] (3) Add intermediate 1, intermediate 2 and acetic acid into a three-necked flask, wherein the mass ratio of intermediate 1, intermediate 2 and acetic acid is 1:2:1.7, and then add isopropanol of the same solute volume, and stir and heat to 82°C under nitrogen replacement conditions, reflux for 8 hours, and after the reaction is completed, let it stand and cool, and rotary evaporate to obtain organosilicon-modified gemini quaternary ammonium salt;

[0036] (4) Add 5 parts by weight of bisphenol A epoxy resin to a thermostatic reactor, stir and heat until the system temperature is controlled at 55°C, fully mix 11 parts by weight of 2,3-pyridinedicarboxylic acid and 0.5 parts by weight of triethylamine catalyst, add them to the thermostatic reactor, heat to the reaction temperature at 500 rpm and control the temperature for 4 hours, wherein the temperature of the temperature control reaction is 95°C. After the reaction is completed, filter and distill under reduced pressure to obtain pyridine modified epoxy resin;

[0037] (5) Add 4-((ethylaniline)methyl)benzenesulfonic acid and pyridine-modified epoxy resin to acetonitrile solvent, wherein the mass ratio of 4-((ethylaniline)methyl)benzenesulfonic acid to pyridine-modified epoxy resin is 1:0.8, stir and mix, react at 40°C for 2h, and after the reaction is completed, wash and dry to obtain intermediate 3;

[0038] (6) Add 12 parts by weight of epichlorohydrin to a reactor under an ice-water bath, stir for 30 minutes, and then dropwise add 8 parts by weight of intermediate 3 for 2 hours. After the dropwise addition is completed, react at 28° C. for 4.5 hours. After the reaction is completed, filter, wash and vacuum dry to obtain a pyridine-modified epoxy resin modified quaternary ammonium salt;

[0039] (7) 20 parts by weight of organosilicon-modified gemini quaternary ammonium salt, 18 parts by weight of pyridine-modified epoxy resin-modified quaternary ammonium salt, and 7 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride are added to a reactor, and the mixture is reacted at a speed of 1000 rpm for 10 minutes. After the reaction is completed, the mixture is vacuum dried to obtain a solid cationic etherifying agent. Example 3

[0040] (1) Add methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide catalyst to tetrahydrofuran solvent, stir and mix, wherein the mass ratio of methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide is 1:0.5:0.045, react at 40° C. for 4 hours, and after the reaction is completed, filter, wash and dry to obtain intermediate 1;

[0041] (2) Under a nitrogen atmosphere, N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate catalyst were added to N,N-dimethylformamide solvent, wherein the mass ratio of N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate was 1:1.3:0.06, and the reaction was carried out at 82°C for 6.5 hours. After the reaction, the reaction was carried out under reduced pressure distillation, washed and dried to obtain intermediate 2;

[0042] (3) Add intermediate 1, intermediate 2 and acetic acid into a three-necked flask, wherein the mass ratio of intermediate 1, intermediate 2 and acetic acid is 1:1.9:1.6, and then add isopropanol of the same solute volume, and stir and heat to 80°C under nitrogen replacement conditions, reflux for 7 hours, and after the reaction is completed, let it stand and cool, and rotary evaporate to obtain organosilicon-modified gemini quaternary ammonium salt;

[0043] (4) Add 4 parts by weight of bisphenol A epoxy resin to a thermostatic reactor, stir and heat until the system temperature is controlled at 50°C, fully mix 9 parts by weight of 2,3-pyridinedicarboxylic acid and 0.3 parts by weight of triethylamine catalyst, add them to the thermostatic reactor, heat to the reaction temperature at 400 rpm and control the reaction for 3.5 hours, wherein the temperature of the temperature control reaction is 90-95°C. After the reaction is completed, filter and distill under reduced pressure to obtain pyridine modified epoxy resin;

[0044] (5) Add 4-((ethylaniline)methyl)benzenesulfonic acid and pyridine-modified epoxy resin to acetonitrile solvent, wherein the mass ratio of 4-((ethylaniline)methyl)benzenesulfonic acid to pyridine-modified epoxy resin is 1:0.78, stir and mix, react at 35°C for 1.8h, and after the reaction is completed, wash and dry to obtain intermediate 3;

[0045] (6) Add 11 parts by weight of epichlorohydrin to a reactor under an ice-water bath, stir for 25 minutes, and then dropwise add 6 parts by weight of intermediate 3 for 1.8 hours. After the dropwise addition is completed, react at 26° C. for 3.5 hours. After the reaction is completed, filter, wash and vacuum dry to obtain a pyridine-modified epoxy resin modified quaternary ammonium salt;

[0046] (7) 18 parts by weight of organosilicon-modified gemini quaternary ammonium salt, 17 parts by weight of pyridine-modified epoxy resin-modified quaternary ammonium salt, and 6 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride were added to a reactor, and the mixture was reacted at a speed of 900 rpm for 8 minutes. After the reaction was completed, the mixture was vacuum dried to obtain a solid cationic etherifying agent. Example 4

[0047] (1) Add methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide catalyst to tetrahydrofuran solvent, stir and mix, wherein the mass ratio of methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide is 1:0.4:0.04, react at 35° C. for 3 h, and after the reaction is completed, filter, wash and dry to obtain intermediate 1;

[0048] (2) Under a nitrogen atmosphere, N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate catalyst were added to N,N-dimethylformamide solvent, wherein the mass ratio of N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate was 1:1.2:0.04, and the reaction was carried out at 75°C for 5 hours. After the reaction, the reaction was carried out under reduced pressure distillation, washed and dried to obtain intermediate 2;

[0049] (3) Add intermediate 1, intermediate 2 and acetic acid into a three-necked flask, wherein the mass ratio of intermediate 1, intermediate 2 and acetic acid is 1:2:1.7, and then add isopropanol of the same solute volume, and stir and heat to 82°C under nitrogen replacement conditions, reflux for 8 hours, and after the reaction is completed, let it stand and cool, and rotary evaporate to obtain organosilicon-modified gemini quaternary ammonium salt;

[0050] (4) Add 5 parts by weight of bisphenol A epoxy resin to a thermostatic reactor, stir and heat until the system temperature is controlled at 55°C, fully mix 11 parts by weight of 2,3-pyridinedicarboxylic acid and 0.5 parts by weight of triethylamine catalyst, add them to the thermostatic reactor, heat to the reaction temperature at 500 rpm and control the temperature for 4 hours, wherein the temperature of the temperature control reaction is 95°C. After the reaction is completed, filter and distill under reduced pressure to obtain pyridine modified epoxy resin;

[0051] (5) Add 4-((ethylaniline)methyl)benzenesulfonic acid and pyridine-modified epoxy resin to acetonitrile solvent, wherein the mass ratio of 4-((ethylaniline)methyl)benzenesulfonic acid to pyridine-modified epoxy resin is 1:0.78, stir and mix, react at 35°C for 1.8h, and after the reaction is completed, wash and dry to obtain intermediate 3;

[0052] (6) Add 11 parts by weight of epichlorohydrin to a reactor under an ice-water bath, stir for 25 minutes, and then dropwise add 6 parts by weight of intermediate 3 for 1.8 hours. After the dropwise addition is completed, react at 26° C. for 3.5 hours. After the reaction is completed, filter, wash and vacuum dry to obtain a pyridine-modified epoxy resin modified quaternary ammonium salt;

[0053] (7) 18 parts by weight of organosilicon-modified gemini quaternary ammonium salt, 17 parts by weight of pyridine-modified epoxy resin-modified quaternary ammonium salt, and 6 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride were added to a reactor, and the mixture was reacted at a speed of 900 rpm for 8 minutes. After the reaction was completed, the mixture was vacuum dried to obtain a solid cationic etherifying agent.

[0054] Comparative Example 1

[0055] Compared with Example 4, this comparative example is different in that no organosilicon-modified gemini quaternary ammonium salt is added.

[0056] Comparative Example 2

[0057] Compared with Example 4, this comparative example is different in that no pyridine-modified epoxy resin-modified quaternary ammonium salt is added.

[0058] Using Staphylococcus aureus, Escherichia coli and Candida krusei as test strains, 1.5 mL of bacterial suspension of the test strains (concentration of 1×105 CFU / mL) was added to a sterile culture dish containing MH broth medium, and then the solid cationic etherifying agent sample was attached to the surface of the culture medium and cultured in a constant temperature incubator at 40°C for 14 hours. After culture, the diameter of the inhibition zone was measured.

[0059] Table 1: Antimicrobial testing.

[0060]

[0061] It can be seen from Table 1 that Examples 1-4 of the present invention have better antibacterial effects than Comparative Examples 1-2.

[0062] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A solid cationic etherifying agent, characterized in that: The invention comprises the following components by weight: 15-20 parts by weight of organosilicon-modified gemini quaternary ammonium salt, 16-18 parts by weight of pyridine-modified epoxy resin-modified quaternary ammonium salt, and 5-7 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride; The preparation method of the organosilicon-modified gemini quaternary ammonium salt comprises the following steps: (1) Add methyl glycidol, dichloromethyl triethoxysilane and potassium hydroxide catalyst to tetrahydrofuran solvent, stir and mix, react at 35-45° C. for 3-5 hours, and after the reaction is completed, filter, wash and dry to obtain intermediate 1; (2) Under a nitrogen atmosphere, N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate catalyst were added to N,N-dimethylformamide solvent, and the reaction was carried out at 75-90°C for 5-8 hours. After the reaction, the reaction was distilled under reduced pressure, washed and dried to obtain intermediate 2; (3) Add intermediate 1, intermediate 2, and acetic acid into a three-necked flask, then add isopropanol of the same solute volume, stir and heat to 78-82°C under nitrogen replacement conditions, reflux for 6-8h, and after the reaction is completed, let stand and cool, and rotary evaporate to obtain organosilicon-modified gemini quaternary ammonium salt; In the step (1), the mass ratio of methyl glycidol, dichloromethyltriethoxysilane and potassium hydroxide is 1:0.4-0.6:0.04-0.05; In the step (2), the mass ratio of N-methylimidazole, 4-bromo-N,N-dimethylaniline and potassium carbonate is 1:1.2-1.4:0.04-0.08; In step (3), the mass ratio of intermediate 1, intermediate 2 and acetic acid is 1:1.8-2:1.5-1.7; The preparation method of the pyridine-modified epoxy resin modified quaternary ammonium salt comprises the following steps: S1. Add 3-5 parts by weight of bisphenol A epoxy resin to a thermostatic reactor, stir and heat the system to control the temperature at 45-55 ° C, 7-11 parts by weight of 2,3-pyridinedicarboxylic acid and 0.2-0.5 parts by weight of triethylamine catalyst are fully mixed and added to the thermostatic reactor, and the temperature is raised to the reaction temperature at 300-500rmp and the temperature is controlled for 3-4h. After the reaction is completed, filter and distill under reduced pressure to obtain a pyridine-modified epoxy resin; S2. Add 4-((ethylaniline)methyl)benzenesulfonic acid and pyridine-modified epoxy resin to acetonitrile solvent, stir and mix, react at 30-40° C. for 1.5-2 h, and after the reaction, wash and dry to obtain intermediate 3; S3. 10-12 parts by weight of epichlorohydrin was added to the reactor under an ice-water bath, stirred for 20-30 min, 5-8 parts by weight of intermediate 3 was added dropwise thereto, and after completion of the addition, the reaction was carried out at 25-28 ° C for 3-4.5 h. After completion of the reaction, the reaction was filtered, washed and dried in vacuo to obtain a quaternary ammonium salt of pyridine-modified epoxy resin; The mass ratio of 4-((ethylaniline)methyl)benzenesulfonic acid to pyridine-modified epoxy resin in S2 is 1:0.75-0.

8.

2. The solid cationic etherifying agent according to claim 1, characterized in that The temperature of the temperature-controlled reaction in S1 is 90-95°C.

3. The solid cationic etherifying agent according to claim 1, characterized in that The dropping time in S3 is 1.5-2h.

4. A method for preparing a solid cationic etherifying agent as claimed in any one of claims 1 to 3, characterized in that: The preparation method of the solid cationic etherifying agent comprises: adding organosilicon-modified gemini quaternary ammonium salt, pyridine-modified epoxy resin-modified quaternary ammonium salt and 3-chloro-2-hydroxypropyltrimethylammonium chloride into a reactor, reacting at a speed of 800-1000 rpm for 5-10 minutes, and vacuum drying after the reaction to obtain the solid cationic etherifying agent.

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