Water-based adhesive and preparation method thereof

Abstract

The invention discloses a water-based adhesive and a preparation method thereof, and relates to the technical field of chemical engineering. The preparation method comprises the following steps: putting polybutylene adipate polyester polyol and homemade polyol into a reaction kettle 1, vacuumizing, cooling, adding a catalyst, adding isophorone diisocyanate, heating, carrying out heat preservation treatment, adding a modifier and a hydrophilic chain extender, carrying out a stirring reaction, adding 1, 4-butanediol, continuously carrying out a reaction while adding acetone to reduce viscosity, and cooling to obtain a polyurethane prepolymer; adding triethylamine into the prepolymer for salinization, dispersing deionized water into the prepolymer under high-speed stirring, stirring to obtain an acetone-containing water-based emulsion, continuously dropwise adding ethanediamine for chain extension reaction, and finally performing reduced-pressure extraction to remove acetone to obtain the water-based polyurethane adhesive. The polyurethane adhesive prepared by the preparation method disclosed by the invention has excellent mechanical property and flame retardant property.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical industry, and in particular to a water-based adhesive and a preparation method thereof. Background Art

[0002] Waterborne polyurethane (WPU) has water as its dispersion medium, which overcomes the shortcomings of solvent-based polyurethane, such as flammability, odor, toxicity, and air pollution. Therefore, it has attracted people's attention and is widely used in elastomers, foaming materials, coatings, adhesives, etc., most of which involve flammable materials. If these materials are not flame-retardant when used, there is a safety hazard of causing fire. Therefore, the flame retardant property of WPU will be one of the important directions of its functionalization.

[0003] In the reactive flame-retardant waterborne polyurethane system, the flame retardant participates in the synthesis reaction of the waterborne polyurethane. It has the advantages of good durability and no precipitation of the flame retardant during use. It is a hot topic in the research of waterborne polyurethane flame retardancy. Summary of the invention

[0004] The object of the present invention is to provide a water-based adhesive and a preparation method thereof to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A water-based adhesive and a preparation method thereof, comprising the following preparation steps:

[0007] (1) by weight, 40-60 parts of polybutylene adipate polyester polyol, 20-30 parts of self-made polyol, 0.03-0.05 parts of catalyst, 50-70 parts of isophorone diisocyanate, 3-5 parts of modifier, 2-3 parts of hydrophilic chain extender, 1-2 parts of 1,4-butanediol, 10-20 parts of acetone, 10-20 parts of triethylamine, 3-5 parts of ethylenediamine, and 60-80 parts of deionized water;

[0008] (2) placing polybutylene adipate polyester polyol and self-made polyol in a reaction kettle 1, vacuuming for 1-2 hours at a temperature of 110-120°C and a rotation speed of 600-700 r / min, cooling to 60-70°C, then adding a catalyst, then adding isophorone diisocyanate, heating to 80-85°C, and keeping the temperature for 2-3 hours in a nitrogen atmosphere, then adding a modifier and a hydrophilic chain extender, and rotating at a temperature of 80-90°C. The reaction was stirred at a speed of 600-700r / min for 1-2h, and then 1,4-butanediol was added to continue the reaction. During this period, acetone was added to reduce the viscosity. The temperature was then lowered to 50-55°C, and triethylamine was added to the prepolymer for salification for 0.5-1h. Deionized water was dispersed in the prepolymer under high-speed stirring. After stirring for 0.5h, an acetone-containing aqueous emulsion was obtained. Ethylenediamine was continued to be added dropwise for chain extension reaction for 9h. Finally, the acetone was removed under reduced pressure to obtain a water-based polyurethane adhesive.

[0009] Preferably, the preparation method of the self-made polyol in step (1) is as follows: by weight, 20-30 parts of rice husk powder, 60-80 parts of polyethylene glycol-400, 20-30 parts of castor oil, and 0.3-0.5 parts of p-toluenesulfonic acid are taken, and the rice husk powder, polyethylene glycol-400 and castor oil are placed in a reaction kettle 2, and then p-toluenesulfonic acid is added, and the reaction is stirred for 2-3 hours at a temperature of 155-165° C. and a rotation speed of 400-600 r / min to obtain a reaction product, and the reaction product is mixed with anhydrous ethanol in a mass ratio of 1:10-1:20, and the mixture is stirred for 120 minutes under magnetic stirring, and then vacuum filtered, and the filter residue is washed with anhydrous ethanol for multiple times until the filtrate is colorless, and the filtrate is placed in a rotary evaporator to remove anhydrous ethanol and water, and vacuum dried to remove residual moisture to obtain a liquefied product, i.e., the self-made polyol.

[0010] Preferably, the preparation process of the modifier in step (1) is as follows: 30-50 parts of ethylene glycol, 10-20 parts of phosphorus oxychloride and 10-20 parts of dichloromethane are taken by weight, and ethylene glycol, phosphorus oxychloride and dichloromethane are placed in a reaction kettle 3, and stirred for reaction for 4-6 hours under a nitrogen atmosphere, a temperature of 30-35° C., and a rotation speed of 300-400 r / min. A wet pH test paper is used to detect the outlet of hydrochloric acid gas. When the color of the test paper no longer turns red, the reaction is continued for 1-2 hours, and then the temperature is increased to perform reduced pressure distillation. When the temperature rises to 150-160° C. and no liquid slips out, the reaction is stopped to obtain a light yellow transparent viscous liquid, that is, the modifier.

[0011] Preferably, the catalyst in step (1) is dibutyltin dilaurate.

[0012] Preferably, the hydrophilic chain extender in step (1) is dimethylolpropionic acid.

[0013] In summary, due to the adoption of the above technology, the beneficial effects of the present invention are:

[0014] The invention adds a modifier and a self-made adhesive so that the prepared polyurethane adhesive has excellent mechanical properties and flame retardant properties. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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 work belong to the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0016] Example 1

[0017] A water-based adhesive and a preparation method thereof, comprising the following preparation steps:

[0018] (1) By weight, 40 parts of polybutylene adipate polyester polyol, 20 parts of homemade polyol, 0.05 parts of catalyst, 50 parts of isophorone diisocyanate, 5 parts of modifier, 2 parts of hydrophilic chain extender, 2 parts of 1,4-butanediol, 10 parts of acetone, 20 parts of triethylamine, 3 parts of ethylenediamine, and 80 parts of deionized water were taken;

[0019] (2) Polybutylene adipate polyester polyol and self-made polyol are placed in a reactor 1, and vacuum treated for 2 hours at a temperature of 120°C and a rotation speed of 600 r / min. The temperature is then reduced to 60°C, and a catalyst is then added. Then isophorone diisocyanate is added, and the temperature is raised to 85°C. In a nitrogen atmosphere, the temperature is kept for 3 hours. Then a modifier and a hydrophilic chain extender are added. The temperature is stirred at 80°C and a rotation speed of 700 r / min for 2 hours. Then 1,4-butanediol is added to continue the reaction. During this period, acetone is added to reduce the viscosity. The temperature is then reduced to 55°C. Triethylamine is added to the prepolymer for salting for 1 hour. Deionized water is dispersed in the prepolymer under high-speed stirring. After stirring for 0.5 hour, an aqueous emulsion containing acetone is obtained. Ethylene diamine is continuously added dropwise for chain extension reaction for 9 hours. Finally, the acetone is removed under reduced pressure to obtain a water-based polyurethane adhesive.

[0020] The preparation method of the self-made polyol in step (1) is as follows: 30 parts of rice husk powder, 60 parts of polyethylene glycol-400, 30 parts of castor oil, and 0.5 parts of p-toluenesulfonic acid are taken by weight, and the rice husk powder, polyethylene glycol-400 and castor oil are placed in a reaction kettle 2, and then p-toluenesulfonic acid is added, and the reaction is stirred for 3 hours at a temperature of 165° C. and a rotation speed of 400 r / min to obtain a reaction product, and the reaction product is mixed with anhydrous ethanol in a mass ratio of 1:10, and the mixture is stirred for 120 minutes under magnetic stirring, and then vacuum filtered, and the filter residue is washed with anhydrous ethanol for multiple times until the filtrate is colorless, and the filtrate is placed in a rotary evaporator to remove anhydrous ethanol and water, and vacuum dried to remove residual moisture to obtain a liquefied product, i.e., the self-made polyol.

[0021] The preparation process of the modifier in step (1) is as follows: 30 parts of ethylene glycol, 20 parts of phosphorus oxychloride and 10 parts of dichloromethane are taken by weight, and ethylene glycol, phosphorus oxychloride and dichloromethane are placed in a reactor 3, and stirred for reaction for 4 hours under a nitrogen atmosphere, a temperature of 35° C. and a rotation speed of 400 r / min. A wet pH test paper is used to detect the outlet of hydrochloric acid gas. When the color of the test paper no longer turns red, the reaction is continued for another 2 hours, and then the temperature is increased to perform reduced pressure distillation. When the temperature rises to 150° C. and no liquid slips out, the reaction is stopped to obtain a light yellow transparent viscous liquid, that is, the modifier.

[0022] The catalyst in step (1) is dibutyltin dilaurate.

[0023] The hydrophilic chain extender in step (1) is dimethylol propionic acid.

[0024] Example 2

[0025] A water-based adhesive and a preparation method thereof, comprising the following preparation steps:

[0026] (1) By weight, 50 parts of polybutylene adipate polyester polyol, 30 parts of homemade polyol, 0.05 parts of catalyst, 60 parts of isophorone diisocyanate, 5 parts of modifier, 2 parts of hydrophilic chain extender, 2 parts of 1,4-butanediol, 10 parts of acetone, 20 parts of triethylamine, 3 parts of ethylenediamine, and 70 parts of deionized water;

[0027] (2) Polybutylene adipate polyester polyol and self-made polyol are placed in a reactor 1, and vacuum treated for 1-2 hours at a temperature of 110°C and a rotation speed of 600-700 r / min. The temperature is then reduced to 60°C, and a catalyst is then added. Then, isophorone diisocyanate is added, and the temperature is raised to 80°C. In a nitrogen atmosphere, the temperature is kept for 2 hours. Then, a modifier and a hydrophilic chain extender are added. The temperature is stirred at 90°C and a rotation speed of 700 r / min for 2 hours. Then, 1,4-butanediol is added to continue the reaction. During this period, acetone is added to reduce the viscosity. The temperature is then reduced to 55°C. Triethylamine is added to the prepolymer for salting for 1 hour. Deionized water is dispersed in the prepolymer under high-speed stirring. After stirring for 0.5 hour, an aqueous emulsion containing acetone is obtained. Ethylenediamine is continuously added dropwise for chain extension reaction for 9 hours. Finally, the acetone is removed under reduced pressure to obtain a water-based polyurethane adhesive.

[0028] The preparation method of the self-made polyol in step (1) is as follows: 20-30 parts of rice husk powder, 80 parts of polyethylene glycol-400, 30 parts of castor oil, and 0.5 parts of p-toluenesulfonic acid are taken by weight, the rice husk powder, polyethylene glycol-400 and castor oil are placed in a reaction kettle 2, and then p-toluenesulfonic acid is added, and the reaction is stirred for 2 hours at a temperature of 155° C. and a rotation speed of 500 r / min to obtain a reaction product, the reaction product is mixed with anhydrous ethanol in a mass ratio of -1:20, and the mixture is stirred for 120 minutes under magnetic stirring, and then vacuum filtered, the filter residue is washed with anhydrous ethanol for multiple times until the filtrate is colorless, the filtrate is placed in a rotary evaporator to remove anhydrous ethanol and water, and the residual water is removed by vacuum drying to obtain a liquefied product, i.e., the self-made polyol.

[0029] The preparation process of the modifier in step (1) is as follows: 50 parts of ethylene glycol, 10 parts of phosphorus oxychloride and 20 parts of dichloromethane are taken by weight, and ethylene glycol, phosphorus oxychloride and dichloromethane are placed in a reactor 3, and stirred for reaction for 6 hours under a nitrogen atmosphere, a temperature of 35° C. and a rotation speed of 300 r / min. A wet pH test paper is used to detect the outlet of hydrochloric acid gas. When the color of the test paper no longer turns red, the reaction is continued for another 2 hours, and then the temperature is increased to perform reduced pressure distillation. When the temperature rises to 150° C. and no liquid slips out, the reaction is stopped to obtain a light yellow transparent viscous liquid, that is, the modifier.

[0030] The catalyst in step (1) is dibutyltin dilaurate.

[0031] The hydrophilic chain extender in step (1) is dimethylol propionic acid.

[0032] Example 3

[0033] A water-based adhesive and a preparation method thereof, comprising the following preparation steps:

[0034] (1) By weight, 60 parts of polybutylene adipate polyester polyol, 20 parts of homemade polyol, 0.05 parts of catalyst, 70 parts of isophorone diisocyanate, 3 parts of modifier, 2-3 parts of hydrophilic chain extender, 2 parts of 1,4-butanediol, 10 parts of acetone, 20 parts of triethylamine, 3 parts of ethylenediamine, and 80 parts of deionized water;

[0035] (2) Polybutylene adipate polyester polyol and self-made polyol are placed in a reactor 1, and vacuum treated for 2 h at a temperature of 120°C and a rotation speed of 700 r / min. The temperature is then reduced to 60°C, and a catalyst is then added. Then isophorone diisocyanate is added, and the temperature is raised to 85°C. In a nitrogen atmosphere, the temperature is kept for 2 h. Then a modifier and a hydrophilic chain extender are added. The temperature is stirred at 85°C and a rotation speed of 700 r / min for 2 h. Then 1,4-butanediol is added to continue the reaction. During this period, acetone is added to reduce the viscosity. The temperature is then reduced to 55°C. Triethylamine is added to the prepolymer for salification for 0.5 h. Deionized water is dispersed in the prepolymer under high-speed stirring. After stirring for 0.5 h, an aqueous emulsion containing acetone is obtained. Ethylene diamine is continuously added dropwise for chain extension reaction for 9 h. Finally, the acetone is removed under reduced pressure to obtain a water-based polyurethane adhesive.

[0036] The preparation method of the self-made polyol in step (1) is as follows: 30 parts of rice husk powder, 70 parts of polyethylene glycol-400, 30 parts of castor oil, and 0.3 parts of p-toluenesulfonic acid are taken by weight, and the rice husk powder, polyethylene glycol-400 and castor oil are placed in a reaction kettle 2, and then p-toluenesulfonic acid is added, and the reaction is stirred for 2 hours at a temperature of 165° C. and a rotation speed of 500 r / min to obtain a reaction product, and the reaction product is mixed with anhydrous ethanol in a mass ratio of 1:20, and the mixture is stirred for 120 minutes under magnetic stirring, and then vacuum filtered, and the filter residue is washed with anhydrous ethanol for multiple times until the filtrate is colorless, and the filtrate is placed in a rotary evaporator to remove anhydrous ethanol and water, and vacuum dried to remove residual moisture to obtain a liquefied product, i.e., the self-made polyol.

[0037] The preparation process of the modifier in step (1) is as follows: 50 parts of ethylene glycol, 10 parts of phosphorus oxychloride and 20 parts of dichloromethane are taken by weight, and ethylene glycol, phosphorus oxychloride and dichloromethane are placed in a reactor 3, and stirred for reaction for 4 hours under a nitrogen atmosphere, a temperature of 35° C. and a rotation speed of 400 r / min. A wet pH test paper is used to detect the outlet of hydrochloric acid gas. When the color of the test paper no longer turns red, the reaction is continued for another 2 hours, and then the temperature is increased to perform reduced pressure distillation. When the temperature rises to 160° C. and no liquid slips out, the reaction is stopped to obtain a light yellow transparent viscous liquid, that is, the modifier.

[0038] The catalyst in step (1) is dibutyltin dilaurate.

[0039] The hydrophilic chain extender in step (1) is dimethylol propionic acid.

[0040] Comparative Example 1

[0041] A water-based adhesive and a preparation method thereof, comprising the following preparation steps:

[0042] (1) By weight, 60 parts of polybutylene adipate polyester polyol, 0.05 parts of catalyst, 70 parts of isophorone diisocyanate, 3 parts of modifier, 2-3 parts of hydrophilic chain extender, 2 parts of 1,4-butanediol, 10 parts of acetone, 20 parts of triethylamine, 3 parts of ethylenediamine, and 80 parts of deionized water were taken;

[0043] (2) Polybutylene adipate polyester polyol is placed in a reactor 1, and vacuumed for 2 h at a temperature of 120°C and a rotation speed of 700 r / min. The temperature is then lowered to 60°C, and a catalyst is then added. Then isophorone diisocyanate is added, and the temperature is raised to 85°C. In a nitrogen atmosphere, the temperature is kept for 2 h. Then a modifier and a hydrophilic chain extender are added. The temperature is stirred for 2 h at a temperature of 85°C and a rotation speed of 700 r / min. Then 1,4-butanediol is added to continue the reaction. During this period, acetone is added to reduce the viscosity. The temperature is then lowered to 55°C. Triethylamine is added to the prepolymer for salification for 0.5 h. Deionized water is dispersed in the prepolymer under high-speed stirring. After stirring for 0.5 h, an aqueous emulsion containing acetone is obtained. Ethylenediamine is continuously added dropwise for chain extension reaction for 9 h. Finally, the acetone is removed under reduced pressure to obtain a waterborne polyurethane adhesive.

[0044] The preparation process of the modifier in step (1) is as follows: 50 parts of ethylene glycol, 10 parts of phosphorus oxychloride and 20 parts of dichloromethane are taken by weight, and ethylene glycol, phosphorus oxychloride and dichloromethane are placed in a reactor 3, and stirred for reaction for 4 hours under a nitrogen atmosphere, a temperature of 35° C. and a rotation speed of 400 r / min. A wet pH test paper is used to detect the outlet of hydrochloric acid gas. When the color of the test paper no longer turns red, the reaction is continued for another 2 hours, and then the temperature is increased to perform reduced pressure distillation. When the temperature rises to 160° C. and no liquid slips out, the reaction is stopped to obtain a light yellow transparent viscous liquid, that is, the modifier.

[0045] The catalyst in step (1) is dibutyltin dilaurate.

[0046] The hydrophilic chain extender in step (1) is dimethylol propionic acid.

[0047] Comparative Example 2

[0048] A water-based adhesive and a preparation method thereof, comprising the following preparation steps:

[0049] (1) By weight, 60 parts of polybutylene adipate polyester polyol, 20 parts of homemade polyol, 0.05 parts of catalyst, 70 parts of isophorone diisocyanate, 2-3 parts of hydrophilic chain extender, 2 parts of 1,4-butanediol, 10 parts of acetone, 20 parts of triethylamine, 3 parts of ethylenediamine, and 80 parts of deionized water;

[0050] (2) Polybutylene adipate polyester polyol and self-made polyol are placed in a reactor 1, and vacuum treated for 2 h at a temperature of 120°C and a rotation speed of 700 r / min. The temperature is then reduced to 60°C, and a catalyst is then added. Then isophorone diisocyanate is added, and the temperature is raised to 85°C. In a nitrogen atmosphere, the temperature is kept for 2 h. Then a hydrophilic chain extender is added. The temperature is stirred at 85°C and a rotation speed of 700 r / min for 2 h. Then 1,4-butanediol is added to continue the reaction. During this period, acetone is added to reduce the viscosity. The temperature is then reduced to 55°C. Triethylamine is then added to the prepolymer for salification for 0.5 h. Deionized water is dispersed in the prepolymer under high-speed stirring. After stirring for 0.5 h, an aqueous emulsion containing acetone is obtained. Ethylene diamine is continuously added dropwise for chain extension reaction for 9 h. Finally, the acetone is removed under reduced pressure to obtain a water-based polyurethane adhesive.

[0051] The preparation method of the self-made polyol in step (1) is as follows: 30 parts of rice husk powder, 70 parts of polyethylene glycol-400, 30 parts of castor oil, and 0.3 parts of p-toluenesulfonic acid are taken by weight, and the rice husk powder, polyethylene glycol-400 and castor oil are placed in a reaction kettle 2, and then p-toluenesulfonic acid is added, and the reaction is stirred for 2 hours at a temperature of 165° C. and a rotation speed of 500 r / min to obtain a reaction product, and the reaction product is mixed with anhydrous ethanol in a mass ratio of 1:20, and the mixture is stirred for 120 minutes under magnetic stirring, and then vacuum filtered, and the filter residue is washed with anhydrous ethanol for multiple times until the filtrate is colorless, and the filtrate is placed in a rotary evaporator to remove anhydrous ethanol and water, and vacuum dried to remove residual moisture to obtain a liquefied product, i.e., the self-made polyol.

[0052] The catalyst in step (1) is dibutyltin dilaurate.

[0053] The hydrophilic chain extender in step (1) is dimethylol propionic acid.

[0054] Testing method: Pour the adhesives of Examples 1-3 and Comparative Examples 1-2 onto a framed glass template for leveling, and cure at room temperature for one week before peeling off the film and drying it for later use;

[0055] 1. Determination of initial adhesion, tensile strength and elongation at break

[0056] According to the method specified in the national standard GB9286-88, take PVC (2.5cm×25cm) and a 0.5cm thick wood board, apply glue, heat in a 60℃ oven for 5 minutes, press with a 10kg weight for 1 minute after bonding, and measure the initial adhesion, tensile strength and elongation at break with a universal tensile machine within 10 minutes;

[0057] 2. Limiting oxygen index (LOI) test

[0058] According to ASTM D2863 standard, the film was made into 100mm×6.5mm×3mm for testing;

[0059] Table 1

[0060]

[0061]

[0062] From the comparison of the data in Examples 1-3 and Comparative Examples 1-2 in Table 1, it can be seen that the polyurethane adhesive prepared by the present invention has excellent mechanical properties and flame retardant properties.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0064] It should be noted that, in this article, relational terms such as first and second, etc. are only used 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 "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Claims

1. A water-based adhesive and a preparation method thereof, characterized in that: The method comprises the following preparation steps: (1) by weight, 40-60 parts of polybutylene adipate polyester polyol, 20-30 parts of self-made polyol, 0.03-0.05 parts of catalyst, 50-70 parts of isophorone diisocyanate, 3-5 parts of modifier, 2-3 parts of hydrophilic chain extender, 1-2 parts of 1,4-butanediol, 10-20 parts of acetone, 10-20 parts of triethylamine, 3-5 parts of ethylenediamine, and 60-80 parts of deionized water; (2) placing polybutylene adipate polyester polyol and self-made polyol in a reaction kettle 1, vacuuming for 1-2 hours at a temperature of 110-120°C and a rotation speed of 600-700 r / min, cooling to 60-70°C, then adding a catalyst, then adding isophorone diisocyanate, heating to 80-85°C, and keeping the temperature for 2-3 hours in a nitrogen atmosphere, then adding a modifier and a hydrophilic chain extender, and rotating at a temperature of 80-90°C. The reaction was stirred at a speed of 600-700r / min for 1-2h, and then 1,4-butanediol was added to continue the reaction. During this period, acetone was added to reduce the viscosity. The temperature was then lowered to 50-55°C, and triethylamine was added to the prepolymer for salification for 0.5-1h. Deionized water was dispersed in the prepolymer under high-speed stirring. After stirring for 0.5h, an acetone-containing aqueous emulsion was obtained. Ethylenediamine was continued to be added dropwise for chain extension reaction for 9h. Finally, the acetone was removed under reduced pressure to obtain a water-based polyurethane adhesive.

2. A water-based adhesive and a preparation method thereof according to claim 1, characterized in that: The preparation method of the self-made polyol in step (1) is as follows: by weight, 20-30 parts of rice husk powder, 60-80 parts of polyethylene glycol-400, 20-30 parts of castor oil, and 0.3-0.5 parts of p-toluenesulfonic acid are taken, and the rice husk powder, polyethylene glycol-400 and castor oil are placed in a reaction kettle 2, and then p-toluenesulfonic acid is added, and the reaction is stirred for 2-3 hours at a temperature of 155-165° C. and a rotation speed of 400-600 r / min to obtain a reaction product, and the reaction product is mixed with anhydrous ethanol in a mass ratio of 1:10-1:20, and the mixture is stirred for 120 minutes under magnetic stirring, and then vacuum filtered, and the filter residue is washed with anhydrous ethanol for multiple times until the filtrate is colorless, and the filtrate is placed in a rotary evaporator to remove anhydrous ethanol and water, and vacuum dried to remove residual moisture to obtain a liquefied product, i.e., the self-made polyol.

3. The water-based adhesive and preparation method thereof according to claim 1, characterized in that: The preparation process of the modifier in step (1) is as follows: 30-50 parts of ethylene glycol, 10-20 parts of phosphorus oxychloride and 10-20 parts of dichloromethane are taken by weight, and ethylene glycol, phosphorus oxychloride and dichloromethane are placed in a reaction kettle 3, and stirred for reaction for 4-6 hours under a nitrogen atmosphere, a temperature of 30-35° C., and a rotation speed of 300-400 r / min. A wet pH test paper is used to detect the outlet of hydrochloric acid gas. When the color of the test paper no longer turns red, the reaction is continued for 1-2 hours, and then the temperature is increased to perform reduced pressure distillation. When the temperature rises to 150-160° C. and no liquid slips out, the reaction is stopped to obtain a light yellow transparent viscous liquid, that is, the modifier.

4. The water-based adhesive and preparation method thereof according to claim 1, characterized in that: The catalyst in step (1) is dibutyltin dilaurate.

5. The water-based adhesive and preparation method thereof according to claim 1, characterized in that: The hydrophilic chain extender described in step (1) is dimethylolpropionic acid.

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