Environmentally friendly water-based adhesive and preparation method thereof

Abstract

The present invention relates to an environmentally friendly water-based adhesive and a preparation method thereof, and belongs to the technical field of polymer materials. The environmentally friendly water-based adhesive with excellent anti-yellowing performance includes, by weight: 80-120 parts of modified water-based acrylic emulsion, 10-15 parts of diluent, 5-10 parts of anti-yellowing agent, 2-15 parts of toughening agent, 50-80 parts of rosin resin, and 10-50 parts of hydroxyl-terminated polymethyl silicone oil; the phosphite structure in the anti-yellowing agent effectively decomposes the hydroperoxide in the acrylic adhesive, inhibits high-temperature yellowing, the sulfone group enhances the molecular thermal stability, and the isocyanurate ring and the maleimide group cooperate to reduce yellowing; the coupling agent in the modified water-based acrylic emulsion connects shell powder and resin to purify formaldehyde, and the silicon oxygen bond cooperates with the shell powder to give the adhesive excellent water resistance; the environmentally friendly water-based adhesive prepared by the present invention not only has excellent anti-yellowing effect, but also has good stickiness and water resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to an environmentally friendly water-based adhesive and a preparation method thereof. Background Art

[0002] Adhesive, also known as bonding agent, is a non-metallic medium material that can tightly connect objects. It forms a thin layer between the surfaces of the adherends, but can make the bonded parts meet actual requirements in terms of mechanical properties and physical and chemical properties.

[0003] With the increasingly stringent environmental regulations and the continuous enhancement of people's environmental awareness, traditional adhesives release harmful substances during curing, which not only endangers human health but also pollutes the environment, and there are safety risks during storage and preparation. Therefore, the use of low-volatile materials has become an effective means to protect human and environmental health; acrylic adhesives are popular because of their wide source of raw materials, simple preparation process, rapid drying and molding, high transparency, convenient use and good durability. Among them, water-based acrylic adhesives have the advantages of environmental protection, non-flammability, a wide range of solid content, and adjustable penetration. However, water-based acrylic adhesives are easy to react with oxygen in the air at high temperatures to form peroxides with high activity, generating dark yellow products, causing the adhesive to turn yellow and have poor water resistance; therefore, the research and development of an environmentally friendly water-based adhesive has important practical significance and application value. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an environmentally friendly water-based adhesive and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An environmentally friendly water-based adhesive comprises the following raw materials in parts by weight: 80-120 parts of modified water-based acrylic emulsion, 10-15 parts of diluent, 5-10 parts of anti-yellowing agent, 2-15 parts of toughening agent, 50-80 parts of rosin resin, and 10-50 parts of hydroxyl-terminated polymethyl silicone oil;

[0007] The toughening agent is 2-chloro-1,3-butadiene;

[0008] The diluent is ethyl acetate.

[0009] The anti-yellowing agent is prepared by the following method:

[0010] Step A1: p-Aminophenol, maleic anhydride and tetrahydrofuran were mixed, stirred in an ice-water bath for 5 min, filtered, washed, and then the temperature was adjusted to 25°C, triethylamine, toluene and diphenylphosphine chloride were added dropwise, and after the addition, the temperature was slowly raised to 90°C, and the reaction was kept at this temperature for 3 h, cooled, and dried to obtain compound 1;

[0011] Further, the usage ratio of p-aminophenol, maleic anhydride, tetrahydrofuran, triethylamine, toluene, and diphenylphosphine chloride is 6.04-6.54 g: 5.1-5.3 g: 8-10 mL: 7.5 g: 80 g: 14-16 g;

[0012] Firstly, the amino group of p-aminophenol reacts with maleic anhydride, and then the hydroxyl group of p-aminophenol reacts with the chlorine atom of diphenylphosphine chloride to synthesize the phosphite-containing compound 1;

[0013] Step A2: 1-oxiranylmethyl-3,5-diallyl isocyanurate, 4-hydroxyphenyl sulfone and formic acid were mixed evenly, reacted at 40° C. for 1 h, cooled and dried to obtain compound 2;

[0014] Further, the usage ratio of 1-oxiranylmethyl-3,5-diallyl isocyanurate, 4-hydroxyphenyl sulfone, and formic acid is 5.1-5.3 g: 2-2.4 g: 5-10 mL;

[0015] Secondly, compound 2 was synthesized by reacting the epoxy group of 1-oxiranylmethyl-3,5-diallyl isocyanurate with the hydroxyl group of 4-hydroxyphenyl sulfone;

[0016] Step A3: Disperse compound 1 and benzoyl peroxide in xylene, add compound 2 and stir evenly, heat to 90° C. under nitrogen protection for 4.5 hours, distill under reduced pressure, cool, wash, filter, and vacuum dry to obtain an anti-yellowing agent;

[0017] Furthermore, the usage ratio of compound 1, benzoyl peroxide, xylene and compound 2 is 3-5 g: 0.15 g: 50-70 mL: 6-8 g.

[0018] Finally, the anti-yellowing agent was synthesized by copolymerizing the carbon-carbon double bonds of compound 1 and compound 2.

[0019] The modified aqueous acrylic emulsion is prepared by the following method:

[0020] Step B1: Mix shell powder and ethanol, stir magnetically and heat in a water bath to 50-80°C, then add vinyl trimethoxysilane, ethyl orthosilicate, anhydrous ethanol and deionized water, react at 50°C for 4h, keep constant temperature and continue stirring for 2h, filter, and vacuum dry at 45°C for 24h to obtain modified shell powder;

[0021] Further, the usage ratio of shell powder, ethanol, vinyl trimethoxysilane, ethyl orthosilicate, anhydrous ethanol, and deionized water is 0.15-0.25 g: 10-20 mL: 0.3-0.75 g: 0.3-0.7 g: 1-2 g: 1-5 mL;

[0022] Firstly, the silicon-oxygen bonds of vinyl trimethoxysilane and ethyl orthosilicate are hydrolyzed and condensed to form polysiloxane, and the hydrolyzed silanol groups at the ends of polysiloxane react with the hydroxyl groups on the surface of shell powder to synthesize modified shell powder;

[0023] Step B2: Disperse the modified shell powder in isopropanol, then add methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, acrylic acid and azobisisobutyronitrile, mix, stir and heat in a water bath to reflux to 85°C, react for 3 hours, then add ammonia water for neutralization, continue stirring for 20 minutes, and obtain a modified waterborne acrylic emulsion;

[0024] Furthermore, the dosage ratio of modified shell powder, isopropyl alcohol, methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, acrylic acid, azobisisobutyronitrile and ammonia water is 7-9g:40-60mL:19.5g:15g:4-5g:4.5g:0.44g:10-40mL.

[0025] The modified shell powder, methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate and the carbon-carbon double bond of acrylic acid are copolymerized by using azobisisobutyronitrile as an initiator to synthesize a modified waterborne acrylic emulsion.

[0026] A method for preparing an environmentally friendly water-based adhesive comprises the following steps:

[0027] S1. The modified water-based acrylic emulsion, the toughening agent and the diluent are uniformly mixed, stirred at a speed of 800-1000 r / min for 20-30 min, an anti-yellowing agent is added, and stirring is continued for 1-1.5 h to obtain a mixture;

[0028] S2. After mixing rosin resin and hydroxyl-terminated polymethyl silicone oil evenly, add them into the mixture and stir at 80-85° C. for 1 hour to obtain an environmentally friendly water-based adhesive.

[0029] Beneficial effects of the present invention:

[0030] The environmentally friendly water-based adhesive of the present invention uses a modified water-based acrylic emulsion as a matrix, which gives the adhesive excellent adhesion and water resistance, and also adds a macromolecular polymer anti-yellowing agent to reduce yellowing of the adhesive caused by high temperature, thereby extending the service life of the material.

[0031] The phosphite structure in the anti-yellowing agent prepared by the present invention can not only effectively decompose the hydroperoxide in the acrylic adhesive, prevent free radical oxidation reaction, and improve the stability of the adhesive, but also inhibit yellowing at high temperature by virtue of strong redox effect, and maintain the good appearance of the adhesive; at the same time, the sulfone group, as a strong electron-withdrawing group, can reduce the electron cloud density of the connected carbon atoms, enhance the molecular thermal stability, and restrict the movement of the molecular chain through chain extension, thereby further improving the heat resistance; in addition, 1-oxiranylmethyl-3,5-diallyl isocyanurate has no active hydrogen in the six-membered ring structure, thus giving the adhesive good thermal stability and hydrolysis stability, and cooperates with the maleimide group formed by maleic anhydride and amino group, thereby enhancing the intermolecular force, improving the heat resistance of the material, and reducing the yellowing caused by high-temperature thermal aging; in addition, the anti-yellowing agent has high compatibility with acrylic acid, thereby preventing the migration of the anti-yellowing agent.

[0032] The silane coupling agent in the modified water-based acrylic emulsion prepared by the invention reacts with the hydroxyl groups on the surface of the shell powder after being hydrolyzed, thereby reducing the hydrophilicity of the shell powder, enhancing the lipophilicity and improving the dispersibility in the acrylic resin. Meanwhile, the silane coupling agent has high compatibility with acrylic acid and can be used as a bridge to connect the shell powder and the resin, thereby introducing the formaldehyde purification function of the shell powder itself into the modified water-based acrylic emulsion, thereby improving the safety of the adhesive. In addition, through thermal decomposition, azobisisobutyronitrile forms primary free radicals, which triggers polymerization of unsaturated double bonds on the modified shell powder, butyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate and acrylic acid, thereby forming a modified water-based acrylic emulsion containing siloxane bonds. Since the siloxane bonds have large bond angles and high bond energy, they can be used in conjunction with the shell powder to give the adhesive excellent water resistance. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1: A method for preparing an environmentally friendly water-based adhesive, comprising the following steps:

[0035] S1. Weigh the raw materials by weight: 80 parts of modified water-based acrylic emulsion (prepared in this embodiment), 10 parts of diluent, 5 parts of anti-yellowing agent (prepared in this embodiment), 2 parts of toughening agent, 50 parts of rosin resin, and 10 parts of hydroxyl-terminated polymethyl silicone oil; uniformly mix the modified water-based acrylic emulsion, 2-chloro-1,3-butadiene and ethyl acetate, stir for 20 minutes at a speed of 800 r / min, add the anti-yellowing agent, and continue stirring for 1 hour to obtain a mixture;

[0036] S2, after mixing rosin resin and hydroxyl-terminated polymethyl silicone oil evenly, adding the mixture, stirring at 80° C. for 1 h, to prepare an environmentally friendly water-based adhesive;

[0037] The anti-yellowing agent is prepared by the following method:

[0038] Step A1: 6.04 g of p-aminophenol, 5.1 g of maleic anhydride and 8 mL of tetrahydrofuran were mixed, stirred in an ice-water bath for 5 min, filtered, washed, and then adjusted to 25°C, 7.5 g of triethylamine, 80 g of toluene and 14 g of diphenylphosphine chloride were added dropwise, and after the addition was complete, the temperature was slowly raised to 90°C, and the reaction was kept at this temperature for 3 h, cooled, and dried to obtain compound 1;

[0039] Step A2: 5.1 g of 1-oxiranylmethyl-3,5-diallyl isocyanurate, 2 g of 4-hydroxyphenyl sulfone and 5 mL of formic acid were mixed evenly, reacted at 40° C. for 1 h, cooled and dried to obtain compound 2;

[0040] Step A3: Disperse 3 g of compound 1 and 0.15 g of benzoyl peroxide in 50 mL of xylene, add 6 g of compound 2 and stir evenly, heat to 90° C. under nitrogen protection for 4.5 h, distill under reduced pressure, cool, wash, filter, and vacuum dry to obtain an anti-yellowing agent;

[0041] The modified aqueous acrylic emulsion is prepared by the following method:

[0042] Step B1: 0.15 g of shell powder and 10 mL of ethanol were mixed, magnetically stirred and heated in a water bath to 50° C., and then 0.3 g of vinyl trimethoxysilane, 0.3 g of ethyl orthosilicate, 1 g of anhydrous ethanol and 1 mL of deionized water were added, reacted at 50° C. for 4 h, kept at a constant temperature and continued to stir for 2 h, filtered, and vacuum dried at 45° C. for 24 h to obtain modified shell powder;

[0043] Step B2: Disperse 7 g of modified shell powder in 40 mL of isopropanol, add 19.5 g of methyl methacrylate, 15 g of butyl acrylate, 4 g of 2-hydroxyethyl acrylate, 4.5 g of acrylic acid and 0.44 g of azobisisobutyronitrile, mix, stir and heat in a water bath to reflux to 85°C, react for 3 hours, then add 10 mL of ammonia water for neutralization, continue stirring for 20 minutes to obtain a modified water-based acrylic emulsion.

[0044] Embodiment 2: A method for preparing an environmentally friendly water-based adhesive, comprising the following steps:

[0045] S1. Weigh the raw materials by weight: 100 parts of modified water-based acrylic emulsion (prepared in this embodiment), 12 parts of diluent, 7 parts of anti-yellowing agent (prepared in this embodiment), 8 parts of toughening agent, 65 parts of rosin resin, and 30 parts of hydroxyl-terminated polymethyl silicone oil; uniformly mix the modified water-based acrylic emulsion, 2-chloro-1,3-butadiene and ethyl acetate, stir for 25 minutes at a speed of 900 r / min, add the anti-yellowing agent, and continue stirring for 1.2 hours to obtain a mixture;

[0046] S2, after mixing rosin resin and hydroxyl-terminated polymethyl silicone oil evenly, adding the mixture, stirring at 82° C. for 1 h, to prepare an environmentally friendly water-based adhesive;

[0047] The anti-yellowing agent is prepared by the following method:

[0048] Step A1: 6.29 g of p-aminophenol, 5.2 g of maleic anhydride and 9 mL of tetrahydrofuran were mixed, stirred in an ice-water bath for 5 min, filtered, washed, and then the temperature was adjusted to 25°C, 7.5 g of triethylamine, 80 g of toluene and 15 g of diphenylphosphine chloride were added dropwise, and after the addition, the temperature was slowly raised to 90°C, and the reaction was kept at this temperature for 3 h, cooled, and dried to obtain compound 1;

[0049] Step A2: 5.2 g of 1-oxiranylmethyl-3,5-diallyl isocyanurate, 2.2 g of 4-hydroxyphenyl sulfone and 7 mL of formic acid were mixed evenly, reacted at 40° C. for 1 h, cooled and dried to obtain compound 2;

[0050] Step A3: Disperse 4 g of compound 1 and 0.15 g of benzoyl peroxide in 60 mL of xylene, add 7 g of compound 2 and stir evenly, heat to 90° C. under nitrogen protection for 4.5 h, distill under reduced pressure, cool, wash, filter, and vacuum dry to obtain an anti-yellowing agent;

[0051] The modified aqueous acrylic emulsion is prepared by the following method:

[0052] Step B1: 0.2 g of shell powder and 15 mL of ethanol were mixed, magnetically stirred and heated in a water bath to 65° C., and then 0.52 g of vinyl trimethoxysilane, 0.5 g of ethyl orthosilicate, 1.5 g of anhydrous ethanol and 3 mL of deionized water were added, reacted at 50° C. for 4 h, kept at a constant temperature and continued to stir for 2 h, filtered, and vacuum dried at 45° C. for 24 h to obtain modified shell powder;

[0053] Step B2: Disperse 8 g of modified shell powder in 50 mL of isopropanol, add 19.5 g of methyl methacrylate, 15 g of butyl acrylate, 4.5 g of 2-hydroxyethyl acrylate, 4.5 g of acrylic acid and 0.44 g of azobisisobutyronitrile, mix, stir and heat in a water bath to reflux to 85°C, react for 3 hours, then add 25 mL of ammonia water for neutralization, continue stirring for 20 minutes to obtain a modified water-based acrylic emulsion.

[0054] Embodiment 3: A method for preparing an environmentally friendly water-based adhesive, comprising the following steps:

[0055] S1. Weigh the raw materials by weight: 120 parts of modified water-based acrylic emulsion (prepared in this embodiment), 15 parts of diluent, 10 parts of anti-yellowing agent (prepared in this embodiment), 15 parts of toughening agent, 80 parts of rosin resin, and 50 parts of hydroxyl-terminated polymethyl silicone oil; uniformly mix the modified water-based acrylic emulsion, 2-chloro-1,3-butadiene and ethyl acetate, stir for 30 minutes at a speed of 1000 r / min, add the anti-yellowing agent, and continue stirring for 1.5 hours to obtain a mixture;

[0056] S2, after mixing rosin resin and hydroxyl-terminated polymethyl silicone oil evenly, adding the mixture, stirring at 85° C. for 1 h, to prepare an environmentally friendly water-based adhesive;

[0057] The anti-yellowing agent is prepared by the following method:

[0058] Step A1: 6.54 g of p-aminophenol, 5.3 g of maleic anhydride and 10 mL of tetrahydrofuran were mixed, stirred in an ice-water bath for 5 min, filtered, washed, and then the temperature was adjusted to 25°C, 7.5 g of triethylamine, 80 g of toluene and 16 g of diphenylphosphine chloride were added dropwise, and after the addition, the temperature was slowly raised to 90°C, and the reaction was kept at this temperature for 3 h, cooled, and dried to obtain compound 1;

[0059] Step A2: 5.3 g of 1-oxiranylmethyl-3,5-diallyl isocyanurate, 2.4 g of 4-hydroxyphenyl sulfone and 10 mL of formic acid were mixed evenly, reacted at 40° C. for 1 h, cooled and dried to obtain compound 2;

[0060] Step A3: Disperse 5 g of compound 1 and 0.15 g of benzoyl peroxide in 70 mL of xylene, add 8 g of compound 2 and stir evenly, heat to 90° C. under nitrogen protection for 4.5 h, distill under reduced pressure, cool, wash, filter, and vacuum dry to obtain an anti-yellowing agent;

[0061] The modified aqueous acrylic emulsion is prepared by the following method:

[0062] Step B1: 0.25 g of shell powder and 20 mL of ethanol were mixed, magnetically stirred and heated in a water bath to 80° C., and then 0.75 g of vinyl trimethoxysilane, 0.7 g of ethyl orthosilicate, 2 g of anhydrous ethanol and 5 mL of deionized water were added, reacted at 50° C. for 4 h, kept at a constant temperature and continued to stir for 2 h, filtered, and vacuum dried at 45° C. for 24 h to obtain modified shell powder;

[0063] Step B2: Disperse 9 g of modified shell powder in 60 mL of isopropanol, add 19.5 g of methyl methacrylate, 15 g of butyl acrylate, 5 g of 2-hydroxyethyl acrylate, 4.5 g of acrylic acid and 0.44 g of azobisisobutyronitrile, mix, stir and heat in a water bath to reflux to 85°C, react for 3 h, then add 40 mL of ammonia water for neutralization, continue stirring for 20 min, and obtain a modified water-based acrylic emulsion.

[0064] Comparative Example 1: This comparative example is an environmentally friendly water-based adhesive. The difference from Example 3 is that an equal amount of 1,6-hexamethylene-bis(N,N-dimethylaminourea) is used to replace the anti-yellowing agent prepared in Example 3, and the rest are the same.

[0065] Comparative Example 2: This comparative example is an environmentally friendly water-based adhesive. The difference from Example 3 is that an equal amount of acrylic acid is used to replace the modified water-based acrylic emulsion prepared in Example 3, and the rest is the same.

[0066] Performance test: The environmentally friendly water-based adhesives prepared in Examples 1-3 and the comparative example were applied to the surface of the substrate, with standard test size, and the peeling force was tested according to the standard GBT 2792-2014, and the holding force was tested according to the standard GB4851-1998; the samples were placed in a UV aging box, the conditions were 60°C, 0.86w / cm2, and placed for 500h to test the yellow index; the environmentally friendly water-based adhesive was applied between two wooden boards with a specification of 50mm×120mm×0.3, and after curing, the wooden boards were placed in distilled water and immersed for 60, 90, and 120 days respectively to test the water resistance; the test results are shown in the following table:

[0067] Table 1

[0068]

[0069] It can be seen from the test data in Table 1 that the environmentally friendly water-based adhesive prepared by the present invention has an excellent anti-yellowing effect. It can also be seen from the above table that the environmentally friendly water-based adhesive prepared by the present invention has good sustained adhesion and water resistance.

[0070] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing an environmentally friendly water-based adhesive, characterized in that: The specific steps include: S1. Weigh the raw materials by weight: 80-120 parts of modified water-based acrylic emulsion, 10-15 parts of diluent, 5-10 parts of anti-yellowing agent, 2-15 parts of toughening agent, 50-80 parts of rosin resin, and 10-50 parts of hydroxyl-terminated polymethyl silicone oil; uniformly mix the modified water-based acrylic emulsion, toughening agent and diluent, stir for 20-30 minutes at a speed of 800-1000 r / min, add the anti-yellowing agent, and continue stirring for 1-1.5 hours to obtain a mixture; S2, after mixing rosin resin and hydroxyl-terminated polymethyl silicone oil evenly, adding the mixture, stirring at 80-85° C. for 1 hour, to prepare an environmentally friendly water-based adhesive; The anti-yellowing agent is prepared by the following method: Step A1: p-Aminophenol, maleic anhydride and tetrahydrofuran were mixed, stirred in an ice-water bath for 5 min, filtered, washed, and then the temperature was adjusted to 25°C, triethylamine, toluene and diphenylphosphine chloride were added dropwise, and after the addition, the temperature was slowly raised to 90°C, and the reaction was kept at this temperature for 3 h, cooled, and dried to obtain compound 1; Step A2: 1-oxiranylmethyl-3,5-diallyl isocyanurate, 4-hydroxyphenyl sulfone and formic acid were mixed evenly, reacted at 40° C. for 1 h, cooled and dried to obtain compound 2; Step A3: Disperse compound 1 and benzoyl peroxide in xylene, add compound 2 and stir evenly, heat to 90° C. under nitrogen protection for 4.5 hours, distill under reduced pressure, cool, wash, filter, and vacuum dry to obtain an anti-yellowing agent; The modified aqueous acrylic emulsion is prepared by the following method: Step B1: Mix shell powder and ethanol, stir magnetically and heat in a water bath to 50-80°C, then add vinyl trimethoxysilane, ethyl orthosilicate, anhydrous ethanol and deionized water, react at 50°C for 4h, keep constant temperature and continue stirring for 2h, filter, and vacuum dry at 45°C for 24h to obtain modified shell powder; Step B2: Disperse the modified shell powder in isopropanol, then add methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, acrylic acid and azobisisobutyronitrile, mix, stir and heat in a water bath to reflux to 85°C, react for 3 hours, then add ammonia water for neutralization, continue stirring for 20 minutes, and obtain a modified water-based acrylic emulsion.

2. The method for preparing an environmentally friendly water-based adhesive according to claim 1, characterized in that: In step A1, the usage ratio of p-aminophenol, maleic anhydride, tetrahydrofuran, triethylamine, toluene and diphenylphosphine chloride is 6.04-6.54 g: 5.1-5.3 g: 8-10 mL: 7.5 g: 80 g: 14-16 g.

3. The method for preparing an environmentally friendly water-based adhesive according to claim 1, characterized in that: In step A2, the usage ratio of 1-oxiranylmethyl-3,5-diallyl isocyanurate, 4-hydroxyphenyl sulfone and formic acid is 5.1-5.3 g: 2-2.4 g: 5-10 mL.

4. The method for preparing an environmentally friendly water-based adhesive according to claim 1, characterized in that: In step A3, the usage ratio of compound 1, benzoyl peroxide, xylene and compound 2 is 3-5 g: 0.15 g: 50-70 mL: 6-8 g.

5. The method for preparing an environmentally friendly water-based adhesive according to claim 1, characterized in that: In step B1, the usage ratio of shell powder, ethanol, vinyl trimethoxysilane, ethyl orthosilicate, anhydrous ethanol and deionized water is 0.15-0.25 g: 10-20 mL: 0.3-0.75 g: 0.3-0.7 g: 1-2 g: 1-5 mL.

6. The method for preparing an environmentally friendly water-based adhesive according to claim 1, characterized in that: In step B2, the dosage ratio of modified shell powder, isopropanol, methyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, acrylic acid, azobisisobutyronitrile and ammonia water is 7-9g:40-60mL:19.5g:15g:4-5g:4.5g:0.44g:10-40mL.

7. The method for preparing an environmentally friendly water-based adhesive according to claim 1, characterized in that: The toughening agent is 2-chloro-1,3-butadiene, and the diluent is ethyl acetate.

8. An environmentally friendly water-based adhesive, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 7.

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