Protective glue and stone-like coating containing same

Abstract

The invention discloses a protective adhesive and a stone-like coating containing the same. The stone-like coating comprises the following components in parts by weight: 15-20 parts of the protective glue, 50-60 parts of base paint and 10-15 parts of a continuous phase, wherein the protective glue comprises the following components in parts by weight: 50-100 parts of composite protective glue powder and 800-900 parts of deionized water; wherein the composite protective rubber powder comprises magnesium lithium silicate and modified bentonite in a mass ratio of 2: 1. The preparation method has the beneficial effects that in the preparation process of the protective glue, the bentonite is subjected to intercalation modification, so that the bentonite and the magnesium lithium silicate are cooperated through the effects of static electricity, hydrogen bonds and the like, and the comprehensive performance of the stone-like coating is effectively improved.

Description

[0001] 1. A protective adhesive, characterized in that it comprises 50-100 parts by weight of composite protective adhesive powder and 800-900 parts by weight of deionized water; wherein the composite protective adhesive powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 2:1.

[0002] 2. The protective adhesive according to claim 1, characterized in that the preparation process of the modified bentonite is as follows:

[0003] S1: Add alkali lignin and ammonium peroxide to sodium hydroxide solution, stir and activate at room temperature, then raise the temperature to 70-80℃, add 3-chloro-2-hydroxypropyltrimethylammonium chloride, react for 4-5 hours, after the reaction is completed, adjust the pH to neutral, centrifuge, dialysis purification, and finally freeze-dry to obtain modified lignin.

[0004] S2: Add sodium-based bentonite to deionized water, raise the temperature to 60-70℃, sonicate for 20-30 minutes, then add modified lignin, react for 4-5 hours, centrifuge, and dry to obtain modified bentonite.

[0005] 3. The protective adhesive according to claim 1, characterized in that the modified lignin raw material comprises the following components: by weight, 10-12 parts alkali lignin, 4-5 parts ammonium persulfate, 60-70 parts sodium hydroxide solution, and 16-18 parts 3-chloro-2-hydroxypropyltrimethylammonium chloride.

[0006] 4. The protective adhesive according to claim 1, characterized in that the modified bentonite raw material comprises the following components: by weight, 10-12 parts sodium bentonite, 3-4 parts modified lignin, and 80-100 parts deionized water.

[0007] 5. A stone-like coating with a protective colloid according to any one of claims 1-4, characterized in that it comprises 15-20 parts by weight of the protective colloid, 50-60 parts by weight of the base paint, and 10-15 parts by weight of the continuous phase.

[0008] 6. The stone-like coating according to claim 5, characterized in that the base paint comprises the following components: by weight, 200-300 parts deionized water, 5-10 parts hydroxyethyl cellulose, 1-3 parts bactericide, 1-2 parts dispersant, 1-2 parts defoamer, 3-5 parts colorant, 10-25 parts film-forming aid, and 150-300 parts base paint emulsion.

[0009] 7. The stone-like coating according to claim 6, wherein the base paint emulsion comprises one or more of silicone-acrylic emulsion and pure acrylic emulsion.

[0010] 8. The stone-like coating according to claim 5, characterized in that the continuous phase comprises the following components: by weight, 100-120 parts deionized water, 80-100 parts continuous phase emulsion, 1-2 parts preservative, 2-3 parts antifreeze, and 3-4 parts film-forming aid.

[0011] 9. The stone-like coating according to claim 8, wherein the continuous phase emulsion comprises one or more of silicone-acrylic emulsion, pure acrylic emulsion, and waterborne polyurethane emulsion.

[0012] A protective adhesive and a stone-like coating containing the same. Technical Field

[0013] This invention belongs to the field of coating technology, specifically relating to a protective adhesive and a stone-like coating containing the same. Background Technology

[0014] In the field of coating technology, the performance defects of traditional protective colloids and stone-like coatings have long constrained the industry's development. In existing technologies, protective colloid systems mostly use bentonite or lithium magnesium silicate as a single base material, failing to form a synergistic modification system. For example, while traditional sodium-based bentonite possesses expansibility, its interlayer ion exchange capacity is limited. Without modification, it is prone to collapse due to water molecule intrusion, leading to a sharp drop in the viscosity of the protective colloid. During storage, it often exhibits instability phenomena such as stratification and flocculation. While lithium magnesium silicate, when used alone, provides a certain thickening effect with its rigid layered structure, it lacks flexible support, resulting in insufficient toughness in the protective colloid system. Under shear force or temperature fluctuations, it is prone to irreversible viscosity decay, severely affecting the coating's application performance.

[0015] In the application of stone-like coatings, the water resistance defects of existing technologies are particularly prominent. Traditional protective colloids cannot construct an effective anti-permeability network, allowing water molecules to rapidly penetrate through the interlayer channels of unmodified bentonite or the interlayer gaps of lithium magnesium silicate sheets. This leads to problems such as swelling and decreased adhesion of the coating film in humid environments. Furthermore, existing modification technologies have significant limitations. Traditional bentonite modification often employs simple inorganic salt intercalation or low-molecular-weight surfactant treatment, making it difficult to achieve deep control of the interlayer structure. Consequently, the improvement in salt spray resistance and weather resistance of the modified material is limited.

[0016] Therefore, in order to solve the above problems, the present invention provides a protective adhesive and a stone-like coating containing the same. Summary of the Invention

[0017] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a protective adhesive and a stone-like coating containing the same.

[0018] The objective of this invention can be achieved through the following technical solutions:

[0019] A protective adhesive comprises 50-100 parts by weight of composite protective adhesive powder and 800-900 parts by weight of deionized water; wherein the composite protective adhesive powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 2:1.

[0020] In the scheme, lithium magnesium silicate and modified bentonite are compounded in a 2:1 ratio in the composite protective adhesive powder. The modified bentonite fills the pores of the rigid framework of lithium magnesium silicate after intercalation, expansion and exfoliation, forming a rigid-flexible three-dimensional network. Its quaternary ammonium salt cation and lithium magnesium silicate lithium ion have the best charge matching and strong bridging effect. The two layers are interlaced to form tortuous channels to block water. If the ratio is unbalanced, it will destroy the structural complementarity, electrostatic synergy and water blocking mechanism, resulting in a decrease in performance.

[0021] In a more optimized manner, the preparation process of the modified bentonite is as follows:

[0022] S1: Add alkali lignin and ammonium peroxide to sodium hydroxide solution, stir and activate at room temperature, then raise the temperature to 70-80℃, add 3-chloro-2-hydroxypropyltrimethylammonium chloride, react for 4-5 hours, after the reaction is completed, adjust the pH to neutral, centrifuge, dialysis purification, and finally freeze-dry to obtain modified lignin.

[0023] S2: Add sodium-based bentonite to deionized water, raise the temperature to 60-70℃, sonicate for 20-30 minutes, then add modified lignin, react for 4-5 hours, centrifuge, and dry to obtain modified bentonite.

[0024] The specific synthesis process of the modified lignin in the scheme is as follows:

[0025]

[0026] More preferably, the modified lignin raw material comprises the following components: by weight, 10-12 parts alkali lignin, 4-5 parts ammonium persulfate, 60-70 parts sodium hydroxide solution, and 16-18 parts 3-chloro-2-hydroxypropyltrimethylammonium chloride.

[0027] In a more optimized manner, the modified bentonite raw material comprises the following components: by weight, 10-12 parts sodium-based bentonite, 3-4 parts modified lignin, and 80-100 parts deionized water.

[0028] More optimally, a stone-like coating containing a protective colloid comprises 15-20 parts by weight of the protective colloid, 50-60 parts by weight of a base paint, and 10-15 parts by weight of a continuous phase.

[0029] More preferably, the base paint comprises the following components by weight: 200-300 parts deionized water, 5-10 parts hydroxyethyl cellulose, 1-3 parts bactericide, 1-2 parts dispersant, 1-2 parts defoamer, 3-5 parts colorant, 10-25 parts film-forming aid, and 150-300 parts base paint emulsion.

[0030] Ideally, the base paint emulsion includes one or more of silicone-acrylic emulsion and pure acrylic emulsion.

[0031] More preferably, the continuous phase comprises the following components: by weight, 100-120 parts deionized water, 80-100 parts continuous phase emulsion, 1-2 parts preservative, 2-3 parts antifreeze, and 3-4 parts film-forming aid.

[0032] More preferably, the continuous phase emulsion includes one or more of silicone-acrylic emulsion, pure acrylic emulsion, and aqueous polyurethane emulsion.

[0033] The advantages of this invention compared to existing technologies are as follows:

[0034] In the preparation process of the protective colloid, the present invention modifies the bentonite by intercalation, so that it can synergize with lithium magnesium silicate through electrostatic and hydrogen bonding, thereby effectively improving the overall performance of the stone-like coating.

[0035] Firstly, modified bentonite undergoes interlayer expansion and exfoliation under the influence of lignin intercalation, forming a more porous layered structure. The quaternary ammonium cations introduced onto its surface and the lithium ions between the magnesium silicate layers generate a cation bridging effect through electrostatic attraction, promoting the cross-connection of the lamellar structures of the two materials. The excellent expansibility of modified bentonite (manifested as significant volume expansion after water absorption) complements the inherent rigid cardboard framework of magnesium silicate, creating a synergistic effect: on the one hand, the expanding structure of bentonite effectively fills the network pores of magnesium silicate; on the other hand, the rigid framework of magnesium silicate provides strong support for the layered structure of bentonite. This unique interaction ultimately constructs a three-dimensional network structure that combines rigidity and flexibility, thereby significantly improving the viscosity stability of the protective adhesive system.

[0036] Secondly, the aromatic ring structure of the lignin groups in modified bentonite can form hydrophobic microdomains with the emulsion polymer chains, reducing the diffusion coefficient of water molecules. Furthermore, the three-dimensional network formed by the compound system exhibits a tortuous channel effect: when water molecules penetrate the coating, they must bypass the interlaced lamellar structure of modified bentonite and lithium magnesium silicate, increasing the path length by 3-5 times, thereby slowing down the penetration rate. Simultaneously, the quaternary ammonium salt groups between the bentonite layers form weak bonds with water molecules, further hindering water migration. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1:

[0039] A stone-like coating containing a protective colloid comprises, by weight, 15 parts of the protective colloid, 50 parts of a base paint, and 10 parts of a continuous phase;

[0040] The base paint includes the following components by weight: 200 parts deionized water, 5 parts hydroxyethyl cellulose, 1 part bactericide, 1 part dispersant, 1 part defoamer, 3 parts colorant, 10 parts film-forming aid, and 150 parts silicone-acrylic emulsion.

[0041] The continuous phase comprises the following components by weight: 100 parts deionized water, 80 parts silicone-acrylic emulsion, 1 part preservative, 2 parts antifreeze, and 3 parts film-forming aid.

[0042] The protective colloid comprises the following components: 50 parts of composite protective colloid powder and 800 parts of deionized water; wherein the composite protective colloid powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 2:1.

[0043] The preparation process of modified bentonite is as follows:

[0044] S1: Add 10 parts of alkali lignin and 4 parts of ammonium peroxide to 60 parts of sodium hydroxide solution, stir and activate at room temperature, then raise the temperature to 70℃, add 16 parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride, react for 4 hours, after the reaction is completed, adjust the pH to neutral, centrifuge, dialysis and purify, and finally freeze dry to obtain modified lignin.

[0045] S2: Add 10 parts of sodium-based bentonite to 80 parts of deionized water, raise the temperature to 60℃, sonicate for 20 min, then add 3 parts of modified lignin, react for 4 h, centrifuge, and dry to obtain modified bentonite.

[0046] Example 2:

[0047] A stone-like coating containing a protective colloid comprises, by weight, 20 parts of the protective colloid, 60 parts of a base paint, and 15 parts of a continuous phase;

[0048] The base paint includes the following components by weight: 300 parts deionized water, 10 parts hydroxyethyl cellulose, 3 parts bactericide, 2 parts dispersant, 2 parts defoamer, 5 parts colorant, 25 parts film-forming aid, and 300 parts silicone-acrylic emulsion.

[0049] The continuous phase comprises the following components by weight: 120 parts deionized water, 100 parts silicone-acrylic emulsion, 2 parts preservative, 3 parts antifreeze, and 4 parts film-forming aid.

[0050] The protective colloid comprises the following components: 100 parts of composite protective colloid powder and 900 parts of deionized water; wherein the composite protective colloid powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 2:1.

[0051] The preparation process of modified bentonite is as follows:

[0052] S1: Add 12 parts of alkali lignin and 5 parts of ammonium peroxide to 70 parts of sodium hydroxide solution, stir and activate at room temperature, then raise the temperature to 80℃, add 18 parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride, react for 5 hours, after the reaction is completed, adjust the pH to neutral, centrifuge, dialysis and purify, and finally freeze dry to obtain modified lignin.

[0053] S2: Add 12 parts of sodium-based bentonite to 100 parts of deionized water, raise the temperature to 70℃, sonicate for 30 min, then add 4 parts of modified lignin, react for 5 h, centrifuge, and dry to obtain modified bentonite.

[0054] Example 3

[0055] A stone-like coating containing a protective colloid comprises 17.5 parts by weight of the protective colloid, 55 parts by weight of a base paint, and 12.5 parts by weight of a continuous phase;

[0056] The base paint includes the following components by weight: 250 parts deionized water, 7.5 parts hydroxyethyl cellulose, 2 parts bactericide, 1.5 parts dispersant, 1.5 parts defoamer, 4 parts colorant, 17.5 parts film-forming aid, and 225 parts silicone-acrylic emulsion.

[0057] The continuous phase comprises the following components by weight: 110 parts deionized water, 90 parts silicone-acrylic emulsion, 1.5 parts preservative, 2.5 parts antifreeze, and 3.5 parts film-forming aid.

[0058] The protective colloid comprises the following components: 75 parts of composite protective colloid powder and 850 parts of deionized water; wherein the composite protective colloid powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 2:1.

[0059] The preparation process of modified bentonite is as follows:

[0060] S1: 11 parts of alkali lignin and 4.5 parts of ammonium peroxide were added to 65 parts of sodium hydroxide solution and stirred at room temperature for activation. Then the temperature was raised to 75°C and 17 parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride were added. The reaction was carried out for 4.5 hours. After the reaction was completed, the pH was adjusted to neutral. After centrifugation, the mixture was purified by dialysis and finally freeze-dried to obtain modified lignin.

[0061] S2: Add 11 parts of sodium-based bentonite to 90 parts of deionized water, raise the temperature to 65℃, sonicate for 25 min, then add 3.5 parts of modified lignin, react for 4.5 h, centrifuge, and dry to obtain modified bentonite.

[0062] Comparative Example 1

[0063] No modification was made to the bentonite; otherwise, it was the same as in Example 3, as follows:

[0064] A stone-like coating containing a protective colloid comprises 17.5 parts by weight of the protective colloid, 55 parts by weight of a base paint, and 12.5 parts by weight of a continuous phase;

[0065] The base paint includes the following components by weight: 250 parts deionized water, 7.5 parts hydroxyethyl cellulose, 2 parts bactericide, 1.5 parts dispersant, 1.5 parts defoamer, 4 parts colorant, 17.5 parts film-forming aid, and 225 parts silicone-acrylic emulsion.

[0066] The continuous phase comprises the following components by weight: 110 parts deionized water, 90 parts silicone-acrylic emulsion, 1.5 parts preservative, 2.5 parts antifreeze, and 3.5 parts film-forming aid.

[0067] The protective colloid comprises the following components: 75 parts of composite protective colloid powder and 850 parts of deionized water; wherein the composite protective colloid powder comprises lithium magnesium silicate and bentonite in a mass ratio of 2:1.

[0068] Comparative Example 2

[0069] The protective colloid uses only lithium magnesium silicate, and the rest is the same as in Example 3, as detailed below:

[0070] A stone-like coating containing a protective colloid comprises 17.5 parts by weight of the protective colloid, 55 parts by weight of a base paint, and 12.5 parts by weight of a continuous phase;

[0071] The base paint includes the following components by weight: 250 parts deionized water, 7.5 parts hydroxyethyl cellulose, 2 parts bactericide, 1.5 parts dispersant, 1.5 parts defoamer, 4 parts colorant, 17.5 parts film-forming aid, and 225 parts silicone-acrylic emulsion.

[0072] The continuous phase comprises the following components by weight: 110 parts deionized water, 90 parts silicone-acrylic emulsion, 1.5 parts preservative, 2.5 parts antifreeze, and 3.5 parts film-forming aid.

[0073] The protective colloid comprises the following components: 75 parts lithium magnesium silicate and 850 parts deionized water.

[0074] Comparative Example 3

[0075] The composite protective powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 5:1, and the rest is the same as in Example 3, as detailed below:

[0076] A stone-like coating containing a protective colloid comprises 17.5 parts by weight of the protective colloid, 55 parts by weight of a base paint, and 12.5 parts by weight of a continuous phase;

[0077] The base paint includes the following components by weight: 250 parts deionized water, 7.5 parts hydroxyethyl cellulose, 2 parts bactericide, 1.5 parts dispersant, 1.5 parts defoamer, 4 parts colorant, 17.5 parts film-forming aid, and 225 parts silicone-acrylic emulsion.

[0078] The continuous phase comprises the following components by weight: 110 parts deionized water, 90 parts silicone-acrylic emulsion, 1.5 parts preservative, 2.5 parts antifreeze, and 3.5 parts film-forming aid.

[0079] The protective colloid comprises the following components: 75 parts of composite protective colloid powder and 850 parts of deionized water; wherein the composite protective colloid powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 5:1.

[0080] The preparation process of modified bentonite is as follows:

[0081] S1: 11 parts of alkali lignin and 4.5 parts of ammonium peroxide were added to 65 parts of sodium hydroxide solution and stirred at room temperature for activation. Then the temperature was raised to 75°C and 17 parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride were added. The reaction was carried out for 4.5 hours. After the reaction was completed, the pH was adjusted to neutral. After centrifugation, the mixture was purified by dialysis and finally freeze-dried to obtain modified lignin.

[0082] S2: Add 11 parts of sodium-based bentonite to 90 parts of deionized water, raise the temperature to 65℃, sonicate for 25 min, then add 3.5 parts of modified lignin, react for 4.5 h, centrifuge, and dry to obtain modified bentonite.

[0083] Comparative Example 4

[0084] The composite protective powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 1:5, and the rest is the same as in Example 3, as detailed below:

[0085] A stone-like coating containing a protective colloid comprises 17.5 parts by weight of the protective colloid, 55 parts by weight of a base paint, and 12.5 parts by weight of a continuous phase;

[0086] The base paint includes the following components by weight: 250 parts deionized water, 7.5 parts hydroxyethyl cellulose, 2 parts bactericide, 1.5 parts dispersant, 1.5 parts defoamer, 4 parts colorant, 17.5 parts film-forming aid, and 225 parts silicone-acrylic emulsion.

[0087] The continuous phase comprises the following components by weight: 110 parts deionized water, 90 parts silicone-acrylic emulsion, 1.5 parts preservative, 2.5 parts antifreeze, and 3.5 parts film-forming aid.

[0088] The protective colloid comprises the following components: 75 parts of composite protective colloid powder and 850 parts of deionized water; wherein the composite protective colloid powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 1:5.

[0089] The preparation process of modified bentonite is as follows:

[0090] S1: 11 parts of alkali lignin and 4.5 parts of ammonium peroxide were added to 65 parts of sodium hydroxide solution and stirred at room temperature for activation. Then the temperature was raised to 75°C and 17 parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride were added. The reaction was carried out for 4.5 hours. After the reaction was completed, the pH was adjusted to neutral. After centrifugation, the mixture was purified by dialysis and finally freeze-dried to obtain modified lignin.

[0091] S2: Add 11 parts of sodium-based bentonite to 90 parts of deionized water, raise the temperature to 65℃, sonicate for 25 min, then add 3.5 parts of modified lignin, react for 4.5 h, centrifuge, and dry to obtain modified bentonite.

[0092] Weigh each component according to the weight proportions of the examples and comparative examples, and then physically blend them separately to form a protective colloid, a base paint, and a continuous phase. Before use, blend the protective colloid, base paint, and continuous phase again according to the above weight proportions to obtain the final coating.

[0093] Testing experiment:

[0094] The coatings obtained from the examples and comparative examples were subjected to relevant tests, and the data are shown in the table below:

[0095]

[0096] Conclusion: This invention significantly improves the overall performance of stone-like coatings by intercalating and modifying bentonite and compounding it with lithium magnesium silicate at a 2:1 mass ratio. Experimental data show that Examples 1 to 3 exhibited no stratification or turbidity in the 60-day storage stability test, showed no abnormalities in water resistance for 96 hours, and showed no cracks or significant deformation in the impact resistance test.

[0097] In Comparative Example 1, the unmodified bentonite system exhibited slight stratification and turbidity during storage, slight swelling in water resistance after 96 hours, and slight localized deformation in impact resistance. This indicates that unmodified bentonite cannot form an effective synergistic water-blocking structure and rigid-flexible support system with lithium magnesium silicate. In Comparative Example 2, when lithium magnesium silicate was used alone, slight stratification and turbidity were also observed during storage, swelling was observed in water resistance after 96 hours, and localized deformation was more pronounced in impact resistance due to the lack of flexible support, demonstrating that a single material is insufficient to construct a stable three-dimensional network.

[0098] Comparative Examples 3 and 4, due to deviations in the mixing ratio of lithium magnesium silicate to modified bentonite from 2:1 (5:1 and 1:5 respectively), exhibited slight stratification with a tendency to flocculate during storage stability. In the water resistance test, Comparative Example 3 showed edge swelling after 96 hours, while Comparative Example 4 showed abnormalities starting after 88 hours. The impact resistance and local deformation were more significant than in the examples. Specifically, when the mass ratio of lithium magnesium silicate to modified bentonite was 5:1, the rigid skeleton was too dense, and the modified bentonite could not fully fill the pores, resulting in insufficient network flexibility. When the mass ratio of lithium magnesium silicate to modified bentonite was 1:5, the skeleton support was insufficient, and the modified bentonite expansion structure expanded disorderly.

[0099] In summary, the synergistic effect of modified bentonite and lithium magnesium silicate and the key role of the 2:1 compounding ratio in this invention are evident. This design effectively improves the storage stability, water resistance and impact resistance of the coating by constructing a rigid-flexible three-dimensional network and tortuous water-blocking channels, and its performance is superior to that of traditional single-material or unbalanced systems.

[0100] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0101] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A protective adhesive, characterized in that, It comprises 50-100 parts by weight of composite protective powder and 800-900 parts by weight of deionized water; wherein the composite protective powder comprises lithium magnesium silicate and modified bentonite in a mass ratio of 2:

1.

2. The protective adhesive according to claim 1, characterized in that, The preparation process of the modified bentonite is as follows: S1: Add alkali lignin and ammonium peroxide to sodium hydroxide solution, stir and activate at room temperature, then raise the temperature to 70-80℃, add 3-chloro-2-hydroxypropyltrimethylammonium chloride, react for 4-5 hours, after the reaction is completed, adjust the pH to neutral, centrifuge, dialysis purification, and finally freeze-dry to obtain modified lignin. S2: Add sodium-based bentonite to deionized water, raise the temperature to 60-70℃, sonicate for 20-30 minutes, then add modified lignin, react for 4-5 hours, centrifuge, and dry to obtain modified bentonite.

3. The protective adhesive according to claim 1, characterized in that, The modified lignin raw material comprises the following components: by weight, 10-12 parts alkali lignin, 4-5 parts ammonium persulfate, 60-70 parts sodium hydroxide solution, and 16-18 parts 3-chloro-2-hydroxypropyltrimethylammonium chloride.

4. The protective adhesive according to claim 1, characterized in that, The modified bentonite raw material includes the following components: by weight, 10-12 parts sodium-based bentonite, 3-4 parts modified lignin, and 80-100 parts deionized water.

5. A stone-like coating with a protective adhesive according to any one of claims 1-4, characterized in that, It comprises 15-20 parts by weight of the protective colloid, 50-60 parts of the base paint, and 10-15 parts of the continuous phase.

6. The stone-like coating according to claim 5, characterized in that, The base paint comprises the following components by weight: 200-300 parts deionized water, 5-10 parts hydroxyethyl cellulose, 1-3 parts bactericide, 1-2 parts dispersant, 1-2 parts defoamer, 3-5 parts colorant, 10-25 parts film-forming aid, and 150-300 parts base paint emulsion.

7. The stone-like coating according to claim 6, characterized in that, The base paint emulsion includes one or more of silicone-acrylic emulsion and pure acrylic emulsion.

8. The stone-like coating according to claim 5, characterized in that, The continuous phase comprises the following components by weight: 100-120 parts deionized water, 80-100 parts continuous phase emulsion, 1-2 parts preservative, 2-3 parts antifreeze, and 3-4 parts film-forming aid.

9. The stone-like coating according to claim 8, characterized in that, The continuous phase emulsion includes one or more of silicone-acrylic emulsion, pure acrylic emulsion, and waterborne polyurethane emulsion.

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