High strength and toughness thin spray material

Abstract

The present invention discloses a high-strength and toughness thin-sprayed material, relating to the technical field of coal mine tunnel reinforcement. The high-strength and toughness thin-sprayed material comprises the following raw materials in percentage by weight: 20-30 parts by weight of cement, 30-50 parts by weight of filler, 10-30 parts by weight of polymer emulsion, and 0.5-2 parts by weight of an additive. The polymer emulsion is prepared by the following steps: S1: reacting cellulose, glacial acetic acid, and acetic anhydride to obtain pretreated cellulose; S2: reacting the pretreated cellulose, n-butyric acid, and acetic anhydride to obtain modified cellulose; and S3: preparing a core-shell emulsion polymer and adding the pretreated cellulose to obtain the polymer emulsion. The thin-sprayed material prepared in this application has high strength, toughness, and high viscosity.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine tunnel reinforcement, in particular to a high-strength and toughness thin spraying material. Background Art

[0002] The weathering of exposed coal and rock masses is primarily influenced by wind and water, disrupting the inherent moisture balance within the exposed surrounding rock. When the underground air is humid and contains high amounts of water, the surrounding rock absorbs this moisture, causing water absorption and softening, leading to rock mass disintegration and subsequent strength reduction. When the underground air is relatively dry, the flowing wind removes the inherent moisture from the rock mass, causing weathering and cracking, which also reduces its strength. Therefore, while ensuring isolation and sealing properties, the selected materials must also consider reinforcement and protective properties with high compressive and flexural strength. Currently, domestic coal mines generally use shotcrete or mortar to seal the surface of the roadway. However, with the development of intensive coal mining technology, the shortcomings of this method are becoming increasingly apparent. Due to the heavy workload, difficulty in auxiliary transportation, and high cost of underground material handling, traditional dry shotcreting technology reduces the workload and cost of material transportation. Thin-layer spraying for mining is a new support concept. Spraying materials are usually composed of cement, polymers, and reactive or non-reactive multi-component materials. They are mostly applied to the surrounding rock surface to seal the tunnel surface and protect the anchor mesh support system. Considering the support effect of the spray layer under stress-controlled and structural-controlled geological conditions, the support mechanism of the thin-layer spray layer can be simply expressed as the bearing layer effect, the bonding effect, and the wedge effect. The bearing layer effect is mainly reflected in the spray layer being subjected to force as an independent support structure. It bears external forces through its own compressive and bending strength; the bonding effect includes the bonding effect between the spray layer and the base rock surface and the bonding effect of the spray layer penetrating into the cracks of the surrounding rock. When the spray layer material penetrates into the cracks, the wedge effect is reflected in the increase in the compressive stiffness of the filled joints.

[0003] Compared with the spraying layer of traditional shotcrete, thin-layer spraying technology has the advantages of fast construction speed, strong adhesion, low cost, energy saving and environmental protection. The thin-layer spraying material for mining is a polymer-modified cement-based material, which is mainly divided into two types: reactive and non-reactive. The reactive type is mainly a polyurethane / polyurea two-component system. Its advantages are good film-forming and curing properties and high compressive strength. Its disadvantages are the exothermic phenomenon during the curing process and high requirements for spraying equipment. The non-reactive type is mainly based on cement-based materials, which are generally modified by adding polymer additives to cement paste. Its advantages are low price, but low support strength and poor bonding ability. Based on the above ideas and combined with the special characteristics of underground, the best choice for solving the problem at present is to use high-strength thin-layer spraying materials that have fast spraying and fast hardening, high adhesion to surrounding rocks and support materials, high density of closed isolation, and high compressive and flexural strength. This is the best way to solve the problem. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength and high-toughness thin-film spraying material to solve the following technical problems:

[0005] The existing non-reactive thin-shot spraying materials for mining have low support strength and poor bonding ability.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] High-strength and toughness thin-film spraying material includes the following raw materials in the following weight percentages:

[0008] 20-30 parts by weight of cement, 30-50 parts by weight of filler, 10-30 parts by weight of polymer emulsion, and 0.5-2 parts by weight of additive.

[0009] As a further solution of the present invention: the cement comprises one or more of silicate cement and sulphoaluminate cement mixed in any ratio.

[0010] As a further solution of the present invention: the silicate cement is any one of PO42.5, PO52.5 and PO62.5 ordinary silicate cement.

[0011] As a further embodiment of the present invention: the sulphoaluminate cement is SAC72.5.

[0012] As a further solution of the present invention: the filler includes at least one of talc powder, light calcium carbonate, silicon dioxide powder, mica powder, and silica fume powder.

[0013] As a further embodiment of the present invention, the auxiliary agent comprises a defoamer, a film-forming agent, and a water-reducing agent mixed in a mass ratio of (0.06-0.2):(0.15-0.2):(0.08-0.25). As a further embodiment of the present invention, the defoamer is tributyl phosphate.

[0014] As a further embodiment of the present invention: the film-forming agent is sodium dihydrogen phosphate.

[0015] As a further embodiment of the present invention, the water reducer is any one of a polycarboxylic acid water reducer, a naphthalene water reducer, and an aliphatic water reducer.

[0016] As a further embodiment of the present invention: the preparation method of the polymer emulsion comprises the following steps:

[0017] S1: Add cellulose, glacial acetic acid, and acetic anhydride into a reaction flask, raise the temperature to 30-50°C, and keep the temperature for 1-2 hours to obtain pretreated fiber;

[0018] S2: Add pretreated cellulose, n-butyric acid, and acetic anhydride to a reaction flask, stir evenly, heat to 70-80°C, add concentrated sulfuric acid, keep warm for 1-3 hours, add water, heat to 80-90°C, keep warm for 1-3 hours, wash with water, filter, and dry to obtain modified cellulose;

[0019] S3: Add NaHCO3, potassium persulfate, disodium dodecyl diphenyl ether sulfonate, and deionized water into the reactor, add the core monomer mixture, mix evenly, heat to 80°C, keep warm for 3-6 hours, continue to add the shell monomer mixture and modified cellulose, keep warm for 3-6 hours to obtain a polymer emulsion.

[0020] As a further embodiment of the present invention, the mass ratio of cellulose, glacial acetic acid and acetic anhydride in S1 is 10:(1-3):(1-3).

[0021] As a further embodiment of the present invention, the addition ratio of cellulose, n-butyric acid, acetic anhydride, concentrated sulfuric acid and water in S2 is 10 g: (1-3 g): (1-5 g): (0.2-0.5 mL): (100-200 mL).

[0022] As a further embodiment of the present invention: the core monomer mixture in S3 is obtained by mixing methyl methacrylate, butyl acrylate, methacrylic acid, hydroxyethyl acrylate and hydroxypropyl acrylate in a mass ratio of (80-100):(80-100):(2-10):(2-10):(1-5).

[0023] As a further embodiment of the present invention: the shell monomer mixture in S3 is obtained by mixing methyl methacrylate, butyl acrylate, methacrylic acid, hydroxyethyl acrylate and hydroxypropyl acrylate in a mass ratio of (120-180):(10-50):(10-30):(1-5):(1-5):(30-60).

[0024] As a further embodiment of the present invention, the mass ratios of NaHCO3, potassium persulfate, disodium dodecyl diphenyl ether sulfonate, deionized water, core monomer mixture, shell monomer mixture, and modified cellulose in S3 are (0.3-0.5): (0.5-1): (1-1.5): (500-900): (30-40): (60-70): (50-100). Beneficial effects of the present invention:

[0025] (1) The thin-sprayed material prepared in this application is specifically a material that seals, isolates, reinforces, and has a short solidification time, and is used to quickly seal the surface of coal walls, metals, and other materials. The material prepared in this application combines the tensile strength of cellulose with the high toughness and density of polymers. At the same time, considering the need for rapid support and protection, fillers are added to cement to achieve new high density, high flexural strength, high compressive strength, and rapid strength growth. The thin-sprayed material prepared in this application achieves rapid spraying and rapid hardening, high adhesion to the surrounding rock, high compressive strength and flexural strength; the spraying thickness of 20mm can replace the metal anchor mesh; it can be used to seal the surrounding rock and also anchor on it; the high density of the thin-sprayed material effectively isolates toxic and harmful gases and moisture in the tunnel; prevents rusting of various metal support materials such as anchor rods, anchor cables, steel belts, and trays; and effectively prevents the coal and rock mass on the surface of the exposed tunnel from weathering under the action of water and toxic and harmful gases, thereby affecting the deep coal and rock mass; and prevents the ignition of coal seams prone to spontaneous combustion. The spray layer of the thin spray material prepared in this application has strong adhesion to the coal rock mass, metal mesh, anchor rod, tray and anchor cable head, and is permanently bonded and does not fall off; it has better support synergy.

[0026] (2) The thin-film spraying material of the present application uses cement as the main agent, and polymer emulsion is added to the cement-based material, which has outstanding bonding strength, can improve the flexibility of the cement-based material, and significantly improve the adhesion, flexural resistance, waterproofness and crack resistance of the cement-based material. Modified cellulose is added during the emulsion preparation process to effectively improve the storage stability and flexural resistance of the thin-film spraying material, improve bonding force, increase cohesion, enhance flexural strength, improve impact resistance, improve wear resistance, enhance durability and improve water retention. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] The preparation method of the polymer emulsion comprises the following steps:

[0029] S1: Add 200 g of cellulose, 20 g of glacial acetic acid, and 20 g of acetic anhydride into a reaction flask, heat to 30°C, and keep warm for 1 hour to obtain pretreated fiber;

[0030] S2: Add 200 g of pretreated cellulose, 20 g of n-butyric acid, and 20 g of acetic anhydride to a reaction flask, stir evenly, heat to 70°C, add 4 mL of concentrated sulfuric acid, keep warm for 1 hour, add 2000 mL of water, heat to 80°C, keep warm for 1 hour, wash with water, filter, and dry to obtain modified cellulose;

[0031] S3: 80 g of methyl methacrylate, 80 g of butyl acrylate, 2 g of methacrylic acid, 2 g of hydroxyethyl acrylate, and 1 g of hydroxypropyl acrylate were mixed to obtain a core monomer mixture;

[0032] S4: 120 g of methyl methacrylate, 10 g of butyl acrylate, 10 g of methacrylic acid, 1 g of hydroxyethyl acrylate, and 1 g of hydroxypropyl acrylate were mixed to obtain a shell monomer mixture;

[0033] S5: Add 0.6 g NaHCO3, 1 g potassium persulfate, 1 g disodium dodecyl diphenyl ether sulfonate, and 1000 mL deionized water into a reactor, add 60 g core monomer mixture and 100 g modified cellulose, mix well, heat to 80°C, keep warm for 3 h, continue to add 120 g shell monomer mixture, keep warm for 3 h to obtain a polymer emulsion.

[0034] Example 2

[0035] The preparation method of the polymer emulsion comprises the following steps:

[0036] S1: 200 g of cellulose, 40 g of glacial acetic acid, and 40 g of acetic anhydride were added to a reaction flask, heated to 40°C, and kept warm for 1.5 h to obtain pretreated fiber;

[0037] S2: Add 200 g of pretreated cellulose, 40 g of n-butyric acid, and 80 g of acetic anhydride to a reaction flask, stir evenly, heat to 75°C, add 8 mL of concentrated sulfuric acid, keep warm for 2 h, add 3000 mL of water, heat to 85°C, keep warm for 1-3 h, wash with water, filter, and dry to obtain modified cellulose;

[0038] S3: 90 g of methyl methacrylate, 90 g of butyl acrylate, 8 g of methacrylic acid, 8 g of hydroxyethyl acrylate, and 3 g of hydroxypropyl acrylate were mixed to obtain a core monomer mixture;

[0039] S4: 150 g of methyl methacrylate, 30 g of butyl acrylate, 20 g of methacrylic acid, 3 g of hydroxyethyl acrylate, and 3 g of hydroxypropyl acrylate were mixed to obtain a shell monomer mixture;

[0040] S5: 0.8 g NaHCO3, 1.5 g potassium persulfate, 2 g disodium dodecyl diphenyl ether sulfonate, and 1500 mL deionized water were added to a reactor, 70 g core monomer mixture and 150 g modified cellulose were added, mixed evenly, heated to 80°C, and kept warm for 5 h. 130 g shell monomer mixture was added and the mixture was kept warm for 3 h to obtain a polymer emulsion.

[0041] Example 3

[0042] The preparation method of the polymer emulsion comprises the following steps:

[0043] S1: 200 g of cellulose, 60 g of glacial acetic acid, and 60 g of acetic anhydride were added to a reaction flask, heated to 50°C, and kept warm for 2 h to obtain pretreated fiber;

[0044] S2: Add 200 g of pretreated cellulose, 60 g of n-butyric acid, and 100 g of acetic anhydride to a reaction flask, stir evenly, heat to 80°C, add 10 mL of concentrated sulfuric acid, keep warm for 3 h, add 4000 mL of water, heat to 90°C, keep warm for 3 h, wash with water, filter, and dry to obtain modified cellulose;

[0045] S3: 100 g of methyl methacrylate, 100 g of butyl acrylate, 10 g of methacrylic acid, 10 g of hydroxyethyl acrylate, and 5 g of hydroxypropyl acrylate were mixed to obtain a core monomer mixture;

[0046] S4: 180 g of methyl methacrylate, 50 g of butyl acrylate, 30 g of methacrylic acid, 5 g of hydroxyethyl acrylate, and 5 g of hydroxypropyl acrylate were mixed to obtain a shell monomer mixture;

[0047] S5: Add 1 g of NaHCO3, 2 g of potassium persulfate, 3 g of disodium dodecyl diphenyl ether sulfonate, and 1800 mL of deionized water into a reactor, add 80 g of the core monomer mixture and 200 g of modified cellulose, mix well, heat to 80°C, keep warm for 6 h, continue to add 140 g of the shell monomer mixture, and keep warm for 6 h to obtain a polymer emulsion.

[0048] Example 4

[0049] The preparation method of high-strength and toughness thin-film spraying material comprises the following steps:

[0050] A1: 30 parts by weight of PO42.5 Portland cement, 30 parts by weight of light calcium carbonate (fineness: 80 mesh), 30 parts by weight of the polymer emulsion prepared in Example 1, 0.4 parts by weight of tributyl phosphate, 0.4 parts by weight of sodium dihydrogen phosphate, and 0.2 parts by weight of JM-PCA (I) type polycarboxylate superplasticizer (Subot New Materials Co., Ltd.) were mixed;

[0051] A2: Mix the polymer emulsion and tributyl phosphate, stir until uniform, add sodium dihydrogen phosphate, and stir until uniform to obtain a liquid phase component;

[0052] A3: Combine PO42.5 silicate cement and light calcium carbonate to obtain a solid phase component;

[0053] A4: Pour the solid phase material into the liquid phase material, stir evenly, add water reducer, stir evenly to obtain high strength and toughness spray material.

[0054] Example 5

[0055] The preparation method of high-strength and toughness thin-film spraying material comprises the following steps:

[0056] A1: 30 parts by weight of PO42.5 Portland cement, 30 parts by weight of light calcium carbonate (fineness: 80 mesh), 30 parts by weight of the polymer emulsion prepared in Example 2, 0.4 parts by weight of tributyl phosphate, 0.4 parts by weight of sodium dihydrogen phosphate, and 0.2 parts by weight of JM-PCA (I) type polycarboxylate superplasticizer (Subot New Materials Co., Ltd.) were mixed;

[0057] A2: Mix the polymer emulsion and tributyl phosphate, stir until uniform, add sodium dihydrogen phosphate, and stir until uniform to obtain a liquid phase component;

[0058] A3: Combine PO42.5 silicate cement and light calcium carbonate to obtain a solid phase component;

[0059] A4: Pour the solid phase material into the liquid phase material, stir evenly, add water reducer, stir evenly to obtain high strength and toughness spray material.

[0060] Example 6

[0061] The preparation method of high-strength and toughness thin-film spraying material comprises the following steps:

[0062] A1: 30 parts by weight of PO42.5 Portland cement, 30 parts by weight of light calcium carbonate (fineness: 80 mesh), 30 parts by weight of the polymer emulsion prepared in Example 3, 0.4 parts by weight of tributyl phosphate, 0.4 parts by weight of sodium dihydrogen phosphate, and 0.2 parts by weight of JM-PCA (I) type polycarboxylate superplasticizer (Subot New Materials Co., Ltd.) were mixed;

[0063] A2: Mix the polymer emulsion and tributyl phosphate, stir until uniform, add sodium dihydrogen phosphate, and stir until uniform to obtain a liquid phase component;

[0064] A3: Combine PO42.5 silicate cement and light calcium carbonate to obtain a solid phase component;

[0065] A4: Pour the solid phase material into the liquid phase material, stir evenly, add water reducer, stir evenly to obtain high strength and toughness spray material.

[0066] Comparative Example 1

[0067] The preparation method of the polymer emulsion comprises the following steps:

[0068] S1: 120 g of methyl methacrylate, 10 g of butyl acrylate, 10 g of methacrylic acid, 1 g of hydroxyethyl acrylate, 1 g of hydroxypropyl acrylate, and 30 g of modified sodium cellulose were mixed to obtain a shell monomer mixture;

[0069] S2: Add 0.6 g NaHCO3, 1 g potassium persulfate, 1 g disodium dodecyl diphenyl ether sulfonate, and 1000 mL deionized water into a reactor, add 60 g core monomer mixture and 100 g cellulose, mix well, heat to 80°C, keep warm for 3 h, continue to add 120 g shell monomer mixture, keep warm and react for 3 h to obtain a polymer emulsion.

[0070] Comparative Example 2

[0071] The preparation method of the polymer emulsion comprises the following steps:

[0072] S1: Add 200 g of cellulose, 20 g of glacial acetic acid, and 20 g of acetic anhydride into a reaction flask, heat to 30°C, and keep warm for 1 hour to obtain pretreated fiber;

[0073] S2: Add 200 g of pretreated cellulose, 20 g of n-butyric acid, and 20 g of acetic anhydride to a reaction flask, stir evenly, heat to 70°C, add 4 mL of concentrated sulfuric acid, keep warm for 1 hour, add 2000 mL of water, heat to 80°C, keep warm for 1 hour, wash with water, filter, and dry to obtain modified cellulose;

[0074] S3: 80 g of methyl methacrylate, 80 g of butyl acrylate, 2 g of methacrylic acid, 2 g of hydroxyethyl acrylate, and 1 g of hydroxypropyl acrylate were mixed to obtain a monomer mixture;

[0075] S4: Add 0.6 g NaHCO3, 1 g potassium persulfate, 1 g disodium dodecyl diphenyl ether sulfonate, and 1000 mL deionized water into a reactor, add 60 g monomer mixture and 100 g modified cellulose, mix well, heat to 80°C, keep warm for 3 h, and react for 3 h to obtain a polymer emulsion.

[0076] Comparative Example 3

[0077] The preparation method of the polymer emulsion comprises the following steps:

[0078] S1: Add 200 g of cellulose, 20 g of glacial acetic acid, and 20 g of acetic anhydride into a reaction flask, heat to 30°C, and keep warm for 1 hour to obtain pretreated fiber;

[0079] S2: Add 200 g of pretreated cellulose, 20 g of n-butyric acid, and 20 g of acetic anhydride to a reaction flask, stir evenly, heat to 70°C, add 4 mL of concentrated sulfuric acid, keep warm for 1 hour, add 2000 mL of water, heat to 80°C, keep warm for 1 hour, wash with water, filter, and dry to obtain modified cellulose;

[0080] S3: 120 g of methyl methacrylate, 10 g of butyl acrylate, 10 g of methacrylic acid, 1 g of hydroxyethyl acrylate, 1 g of hydroxypropyl acrylate, and 30 g of modified sodium cellulose were mixed to obtain a monomer mixture;

[0081] S4: Add 0.6 g NaHCO3, 1 g potassium persulfate, 1 g disodium dodecyl diphenyl ether sulfonate, and 1000 mL deionized water into a reactor, mix well, heat to 80°C, keep warm for 3 h, continue to add 120 g monomer mixture, keep warm and react for 3 h to obtain a polymer emulsion.

[0082] Comparative Example 4

[0083] Compared with Example 4, only the polymer emulsion prepared in Example 1 added in Example 4 was replaced by the polymer emulsion prepared in Comparative Example 1 in equal amount, and the remaining components and steps were completely consistent with Example 4.

[0084] Comparative Example 5

[0085] Compared with Example 4, only the polymer emulsion prepared in Example 1 added in Example 4 was replaced by the polymer emulsion prepared in Comparative Example 2 in equal amount, and the remaining components and steps were completely consistent with Example 4.

[0086] Comparative Example 6

[0087] Compared with Example 4, only the polymer emulsion prepared in Example 1 added in Example 4 was replaced by the polymer emulsion prepared in Comparative Example 3 in equal amount, and the remaining components and steps were completely consistent with Example 4.

[0088] Performance testing

[0089] Spraying solution

[0090] (1) Determination of spraying thickness

[0091] a. For tunnels covered only with metal support materials such as anchor nets, anchor cables, anchor rods, steel belts, trays, and not sprayed, no primer is required and the average spraying thickness is 10-15mm;

[0092] b. For tunnels under excavation, anchor mesh support is first carried out, and then spray materials are used to fully cover the surface of exposed coal and rock mass and metal support materials for protection, with an average spray thickness of 20mm;

[0093] c. For the re-spraying of old tunnels that have been sprayed, only surface sealing and protection treatment is performed to delay the corrosion and weathering of the sprayed surface, with an average thickness of 10mm.

[0094] (2) Determination of the amount of spraying material used

[0095] The usage of high-strength thin-film spraying materials is calculated based on a cross-section of 13m2 as follows:

[0096] a. Thickness 10mm, use 21kg per square meter. 1 ton can spray 3.66 linear meters;

[0097] b. Thickness 15mm, use 30kg per square meter. 1 ton can spray 2.56 linear meters;

[0098] c. Thickness 20mm, use 42kg per square meter. 1 ton can spray at least 1.83 linear meters.

[0099] For every 10mm increase in the thickness of the primer material, about 10-20kg is used per square meter. The specific spraying thickness is determined on site based on the tunnel forming and crushing conditions.

[0100] (3) Construction method

[0101] First, the tunnel is leveled with primer materials; then, high-strength thin-film spraying materials are used to seal and protect the metal support materials or the coal and rock surfaces;

[0102] (4) Technical indicators and parameters

[0103] a. When spraying newly excavated tunnels, the coating must be dense and continuous, without interruption or leakage. In the protruding positions of metal support materials (anchor rods, anchor cables, anchor nets, steel belts, trays, etc.), or when re-spraying old tunnels and encountering slurry peeling or cracking sections, the spray material must be used to cover them densely to meet the requirements of protective sealing;

[0104] b. The power parameters of the spraying device are shown in Table 1;

[0105] Table 1: Pneumatic spray pump performance parameter statistics

[0106] Numerical Power Source 0.4-0.6 (high wind pressure) MPa Output pressure 1MPa Pumping distance Horizontal 50m, lift 15m Spray material flow 2-3m / h Gas consumption ≤11 Sound power level ≤110 Pump size 1600mm×800mm×700mm(L×W×H) Pump weight 520kg

[0107] Performance testing

[0108] (1) Tensile bond strength: measured according to the national standard GB / T25181-2010 "Premixed Mortar". The test results are shown in Table 1.

[0109] (2) Setting time: The setting time of the slurry was tested according to GB / T1346-2011 “Test methods for water consumption, setting time and soundness of cement of standard consistency”. The test results are shown in Table 1.

[0110] (3) Flexural and compressive strength: According to GB / T17671-2021 “Test method for strength of cement mortar (ISO method)”, 40 mm × 40 mm × 160 mm prism specimens were prepared for flexural and compressive strength tests. The test results are shown in Table 1.

[0111] Table 1: Statistical table of material performance test data of Examples 4-6 and Comparative Examples 4-6

[0112]

[0113]

[0114] As can be seen from Table 1, the thin spray material prepared in this application has the advantages of strong bonding strength, rapid curing, excellent mechanical properties, etc., excellent gap filling ability and good ductility, and can play a supporting and sealing role when the spray thickness is very thin.

[0115] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0116] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. High strength and toughness thin spray material, characterized by: The raw materials include the following weight percentages: 20-30 parts by weight of cement, 30-50 parts by weight of filler, 10-30 parts by weight of polymer emulsion, 0.5-2 parts by weight of additives; The preparation method of the polymer emulsion comprises the following steps: S1: Add cellulose, glacial acetic acid, and acetic anhydride into a reaction flask, heat to 30-50°C, and keep warm for 1-2 hours to obtain pretreated cellulose; S2: Add pretreated cellulose, n-butyric acid, and acetic anhydride to a reaction flask, stir evenly, heat to 70-80°C, add concentrated sulfuric acid, keep warm for 1-3 hours, add water, heat to 80-90°C, keep warm for 1-3 hours, wash with water, filter, and dry to obtain modified cellulose; S3: NaHCO3, potassium persulfate, disodium dodecyl diphenyl ether sulfonate, and deionized water are added to a reaction kettle, and the core monomer mixture is added and mixed evenly. The mixture is heated to 80°C and kept warm for 3-6 hours. The shell monomer mixture and modified cellulose are then added and kept warm for 3-6 hours to obtain a polymer emulsion. The core monomer mixture in S3 is obtained by mixing methyl methacrylate, butyl acrylate, methacrylic acid, hydroxyethyl acrylate, and hydroxypropyl acrylate in a mass ratio of (80-100):(80-100):(2-10):(2-10):(1-5); The S3 shell monomer mixture is obtained by mixing methyl methacrylate, butyl acrylate, methacrylic acid, hydroxyethyl acrylate and hydroxypropyl acrylate in a mass ratio of (120-180):(10-50):(10-30):(1-5):(1-5).

2. The high-strength and toughness sprayed material according to claim 1, characterized in that: The cement includes one or more of silicate cement and sulphoaluminate cement mixed in any ratio.

3. The high-strength and toughness sprayed material according to claim 1, characterized in that: The filler includes at least one of talc powder, light calcium carbonate, silicon dioxide powder and mica powder.

4. The high-strength and toughness sprayed material according to claim 1, characterized in that: The auxiliary agent is obtained by mixing a defoamer, a film-forming agent and a water-reducing agent in a mass ratio of (0.06-0.2):(0.15-0.2):(0.08-0.25).

5. The high-strength and toughness sprayed material according to claim 1, characterized in that: The mass ratio of cellulose, glacial acetic acid and acetic anhydride in S1 is 10:(1-3):(1-3).

6. The high-strength and toughness thin-sprayed material according to claim 1, characterized in that: The addition ratio of cellulose, n-butyric acid, acetic anhydride, concentrated sulfuric acid, and water in S2 is 10 g: (1-3 g): (1-5 g): (0.2-0.5 mL): (100-200 mL).

7. The high-strength and toughness thin-sprayed material according to claim 1, characterized in that: The mass ratios of NaHCO3, potassium persulfate, disodium dodecyl diphenyl ether sulfonate, deionized water, core monomer mixture, shell monomer mixture, and modified cellulose in S3 are (0.3-0.5):(0.5-1):(1-1.5):(500-900):(30-40):(60-70):(50-100).

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