Environment-friendly shield tail sealing grease for high water pressure shield tunnel and preparation method thereof

Abstract

The application discloses a shield tail sealing grease for high water pressure shield tunnel and a preparation method thereof. The shield tail sealing grease is prepared from the following components in parts by weight: base oil 240-305 parts, viscosity index modifier 25-140 parts, thickening agent 40-140 parts, filler 510-640 parts, reinforcing agent 30-55 parts, calcium base grease 10-35 parts, and composite modification additive 8-25 parts. The base oil is a mixture of recycled vegetable oil and C5 petroleum resin, the reinforcing agent is plant fiber, the viscosity index modifier is a mixture of polyisobutylene, polymerized rosin, succinimide and polyisoprene, the thickening agent is a mixture of polyisobutylene, alginic acid and sodium polyacrylate, the reinforcing agent is organic lubricating material and calcium filler, the calcium base grease is added, and the composite modification additive is composed of thymol, zinc borate and zinc dialkyldithiophosphate. The shield tail sealing grease for high water pressure shield tunnel is prepared by using a preparation process of drying, filtering, heat preservation, constant temperature and speed control physical kneading.

Description

Technical Field

[0001] This invention relates to shield tail sealing grease, and more particularly to an environmentally friendly shield tail sealing grease for high water pressure shield tunnels and its preparation method. Background Technology

[0002] In recent years, with the continuous development of infrastructure in my country, there have been more and more large-scale high-water-pressure, large-diameter shield tunnel projects, and the demand for the continued development and utilization of underground space has been increasing. More tunnel projects crossing rivers and seas are also being planned. The working conditions faced by shield tunneling are becoming more and more complex, thus placing higher demands on shield tunneling construction.

[0003] Tail seal failure is a common safety issue in tunnel boring machine (TBM) construction. Leaks in the tail seal system can lead to increased ground subsidence, insufficient grouting pressure, and in severe cases, tunnel collapse. Currently, tail seals primarily employ sealing grease between multiple tail brushes. The quality of this grease's sealing performance directly determines the tail seal's effectiveness and impacts the safety of TBM tunneling; therefore, the stability and reliability of the tail seal grease are crucial.

[0004] Tail sealing grease is a consumable filling material used for sealing the tail of tunnels in underground engineering using the shield tunneling method. Its main functions are sealing, waterproofing, lubrication, and corrosion prevention. Currently, there are many domestic manufacturers of tail sealing grease, but the quality varies greatly, and they generally perform poorly when encountering conditions such as high water pressure and underwater tunnels. While imported products, such as those from France or Japan, perform well in terms of quality, they are generally much more expensive than domestic products, resulting in higher costs.

[0005] In recent years, in response to the national call for green and sustainable development, the environmental friendliness of shield-tail sealing greases has received widespread attention from all sectors of society. Currently, the main raw materials for mainstream sealing greases on the market are derived from non-degradable petroleum derivatives, which are not environmentally friendly. Moreover, the small amounts of heavy metals and benzene-based organic compounds they contain can cause environmental pollution through long-term contact with surrounding soil, groundwater, and seawater.

[0006] Existing patented technologies for shield tail sealing grease have the following problems:

[0007] 1. Difficulty in handling sealing challenges under high water pressure conditions: Currently, most shield tail sealing greases can only handle relatively low construction water pressures, making it difficult to meet the construction requirements of high water pressure environments. Moreover, when traversing strata with a permeability coefficient exceeding 50 m / day, the construction water and soil pressure will increase significantly due to the high porosity and permeability of the strata. Existing shield tail sealing grease technology is insufficient to cope with this, and there is an urgent need for a shield tail sealing grease that can effectively handle high water pressure and high stratum permeability coefficient conditions.

[0008] 2. Lack of environmental performance: Most existing shield tail sealing greases use petroleum derivatives as the main raw materials, which are difficult to degrade and are not conducive to green environmental protection and energy conservation and emission reduction. The existing shield tail sealing greases usually have high contents of arsenic, cadmium, mercury heavy metal ions and toxic benzene organic compounds. When shield tunneling crosses agricultural farmland, rivers, lakes and oceans, it will pollute the surrounding environment. There is an urgent need for environmentally friendly shield tail sealing greases.

[0009] 3. Insufficient pumpability: Existing tail seal greases struggle to achieve a balance between high water pressure resistance and good pumpability. During tunnel boring machine (TBM) construction, the pumpability of the tail seal grease affects its filling quality, causing numerous inconveniences and potentially threatening project safety. Therefore, there is an urgent need for tail seal greases with excellent pumpability and high water pressure resistance.

[0010] 4. Inadequate ability to address the problem of sand inrush at the shield tail: Sand and soil inrush at the shield tail frequently occurs when traversing water-rich sandy soil layers. Existing shield tail sealing greases, after mixing with sand and soil, cannot ensure the safety and effectiveness of the shield tail seal, nor can they guarantee a strong adhesion between the grease and the shield tail brush, thus affecting the safety of the project. Therefore, there is an urgent need for a shield tail sealing grease that can effectively address the problem of sand inrush.

[0011] 5. Insufficient protection for the tail shield brush: Existing tail shield sealing greases are prone to causing corrosion of the tail shield brush during use, offering limited protection and failing to effectively extend its service life. The tail shield brush is susceptible to wear, deformation, and corrosion during shield tunneling construction. Replacing the tail shield brush is not only complex but also costly in terms of manpower and resources. Therefore, there is an urgent need for tail shield sealing greases that can effectively extend the service life of the tail shield brush.

[0012] 6. Low Cost-Effectiveness: Existing tail sealant greases are not cost-effective, especially environmentally friendly ones. Furthermore, existing tail sealant greases have poor adhesion to the tail brush, leading to high consumption during construction. For example, the consumption of tail sealant grease in shield tunneling is typically 35-45 kg / ring. Taking 1000 rings of shield tunneling as an example, the cost of using existing greases would be approximately 550,000-750,000 yuan, placing significant pressure on construction cost control. Therefore, there is an urgent need for cost-effective tail sealant greases. Summary of the Invention

[0013] To address the aforementioned problems, this invention proposes an environmentally friendly tail sealant grease suitable for high-water-pressure shield tunnels and its preparation method. By weight, its components include: 240-305 parts base oil, 25-140 parts viscosity index modifier, 40-140 parts thickener, 510-640 parts filler, 30-55 parts reinforcing agent, 10-35 parts calcium-based grease, and 8-35 parts composite modifying additives. This invention provides an environmentally friendly grease formulation for high-water-pressure shield tunneling projects. While ensuring the grease's water pressure resistance, sealing performance, and pumpability, it selects environmentally friendly and easily degradable raw materials, reducing the impact on surrounding groundwater, seawater, soil, and organisms.

[0014] The base oil is a mixture of recycled vegetable oil and C5 petroleum resin, wherein the recycled vegetable oil has a mass fraction of 168-290 parts and the C5 petroleum resin has a mass fraction of 12-92 parts, wherein the vegetable oil is soybean oil or rapeseed oil.

[0015] Furthermore, the kinematic viscosity of the base oil is approximately 29.5~35.5 mm at 40°C. 2 / s, density greater than 0.9g / cm³, bromine value ≤70gBr / 100g, the softening point of the C5 petroleum resin is about 85~92℃.

[0016] The viscosity index modifier is a mixture of polyisobutylene, polymeric rosin, succinimide, and polyisoprene, wherein the mass fraction of polyisobutylene is 17-70 parts, the mass fraction of polymeric rosin is 5-38 parts, the mass fraction of succinimide is 5-28 parts, and the mass fraction of polyisoprene is 5-30 parts; it is mainly used to improve the viscosity and pumpability of greases.

[0017] Furthermore, in the viscosity index modifier, the molecular weight of polyisobutylene is greater than 2000, the molecular weight of polyisoprene is greater than 50000, and the density of the selected polymeric rosin at 20°C is approximately 1.08~1.1 g / cm³, with a softening point of 90°C.

[0018] The thickener is a mixture of polyisobutylene, alginate, and sodium polyacrylate, wherein the mass fraction of polyisobutylene is 18-70 parts, the mass fraction of alginate is 8-68 parts, and the mass fraction of sodium polyacrylate is 4-55 parts; it is mainly used to improve the consistency of oils.

[0019] Furthermore, in the thickener, the polyisobutylene has a molecular weight greater than 2000, a density of approximately 0.85~0.92 g / cm³ at 25°C, and a kinematic viscosity of approximately 240~250 mm³ at 100°C. 2 / s.

[0020] The filler is a mixture of organic lubricant and calcium filler, with the organic lubricant comprising 30-192 parts by mass and the calcium filler comprising 357-579 parts by mass. Specifically, the organic lubricant is a mixture of two or more of organomontmorillonite, talc, and organobentonite, with organomontmorillonite comprising 7-39 parts by mass, talc comprising 0-67 parts by mass, and organobentonite comprising 20-172 parts by mass. The calcium filler is a mixture of two or more of light calcium carbonate, heavy calcium carbonate, and mica powder, with light calcium carbonate comprising 142-290 parts by mass, heavy calcium carbonate comprising 142-290 parts by mass, and mica powder comprising 0-115 parts by mass. This mixture is primarily used to reduce costs and improve the sealing performance of greases.

[0021] Furthermore, in the filler, preferably, the talc powder is composed of two different mesh sizes, wherein the mass fraction of 325 mesh talc powder is 20-30 parts and the mass fraction of 625 mesh talc powder is 40-50 parts; the heavy calcium carbonate has a particle size of 625 mesh; and the light calcium carbonate is composed of two different mesh sizes, wherein the mass fraction of 1200 mesh light calcium carbonate is 57-174 parts and the mass fraction of 1500 mesh light calcium carbonate is 55-174 parts.

[0022] The calcium-based grease is made by thickening vegetable oil with 12-hydroxystearic acid and 5% lime milk. The recovered vegetable oil accounts for 8 to 28 parts by mass, 1 to 3 parts by mass of 12-hydroxystearic acid, and 2 to 6 parts by mass of 5% lime milk. Calcium 12-hydroxystearate contained in the calcium-based grease is the main component that plays a role in lubrication and thickening.

[0023] The reinforcing agent is a mixture of wood fiber, cotton fiber, and bamboo fiber, wherein the mass fraction of wood fiber is 6-22 parts, the mass fraction of cotton fiber is 9-22 parts, and the mass fraction of bamboo fiber is 6-22 parts; it is mainly used to improve the water pressure resistance of oils and to a certain extent improve the pumpability of oils.

[0024] Preferably, the crimp shrinkage rate of the wood fiber is 20%~40%, the crimp shrinkage rate of the cotton fiber is 60%~70%, and the crimp shrinkage rate of the bamboo fiber is 15%~20%. Preferably, the mass ratio of the fibers is: 0.5~1mm wood fiber: 1~2mm bamboo fiber: 2~3mm cotton fiber: (3~4)mm cotton fiber = (2~4): (1~3): (1~2): (1~2).

[0025] The composite modifier is a mixture of thymol, zinc borate, and zinc dialkyl dithiophosphate, wherein the mass fraction of thymol is 2-13 parts, the mass fraction of zinc borate is 5-12 parts, and the mass fraction of zinc dialkyl dithiophosphate is 8-14 parts.

[0026] Preferably, the composite modified additive contains thymol: zinc borate: zinc dialkyl dithiophosphate in a ratio of (1~2): (1~3): (1~2).

[0027] This invention provides a method for preparing an environmentally friendly shield tail sealing grease for high water pressure shield tunnels, the preparation method of which is as follows:

[0028] Step 1: Dry polyisobutylene in a vacuum drying oven at 50-60℃ for 40-60 min to obtain refined polyisobutylene; dry polyisoprene in a vacuum drying oven at 60-70℃ for 40-60 min to obtain refined polyisoprene.

[0029] Step 2: Place the refined polyisobutylene and refined polyisoprene from Step 1 into a reaction vessel, and stir at a low speed of 100-300 rpm for 40-60 minutes at a constant temperature of 90°C to obtain Mixture I.

[0030] Step 3: Put the polymerized rosin into a pulverizer and pulverize it into particles with a diameter of 1~3mm to obtain powdered polymerized rosin; add the powdered polymerized rosin to the mixing group I described in step 2, and stir at a low speed of 150~300rpm for 40~60min under a constant temperature of 120℃ to obtain mixing group II;

[0031] Step 4: Dry the succinimide under nitrogen protection at a temperature of 40-50°C for 40-60 minutes to obtain refined succinimide. Add the refined succinimide to the mixture group II described in step 3, and stir at a low speed of 200-300 rpm for 60-90 minutes at a temperature of 150°C and a pressure of 0.5 MPa to obtain the crude viscosity index modifier.

[0032] Step 5: Filter the crude viscosity index modifier described in step 4 through a filter screen with a pore size of 1-5 micrometers to obtain the viscosity index modifier.

[0033] Step 6: Grind the C5 petroleum resin in a grinder at high speed 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, at a speed of 1000-1200 rpm to obtain powdered petroleum resin; filter the recovered vegetable oil through a filter screen with a pore size of 40-60 micrometers to obtain the base vegetable oil, and keep it at a constant temperature of 40℃ for 30-50 minutes.

[0034] Step 7: Mix the heat-insulated base vegetable oil, powdered petroleum resin and viscosity index modifier described in Step 6, and stir at a low speed of 200~350 rpm for 40~60 min at a constant temperature of 120℃ to obtain mixture I.

[0035] Step 8: Mix sodium polyacrylate, alginate, and polyisobutylene, and stir at a low speed of 150-300 rpm for 10-30 minutes at a constant temperature of 40℃ to obtain crude thickener I; stir crude thickener I at a high speed of 300-500 rpm for 30-50 minutes at a constant temperature of 60℃ to obtain crude thickener II; adjust the pH value of crude thickener II to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain crude thickener; stir the crude thickener at a low speed of 100-200 rpm for 5-10 minutes at a constant temperature of 40℃ to obtain thickener.

[0036] Step 9: Add the thickener described in Step 8 to Mixture I described in Step 7, and stir at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain Mixture II; then stir at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain Mixture III, and keep Mixture III at a constant temperature of 40°C for 30-50 minutes.

[0037] Step 10: Stir 12-hydroxystearic acid and recycled vegetable oil at 80-90°C at a low speed of 100-200 rpm for 10-20 min to obtain an intermediate product. Add 5% lime milk to the intermediate product and dry it at 100-110°C for 10-20 min to obtain calcium-based grease.

[0038] Step 11: In a mixer, the organic lubricant composed of organic montmorillonite, talc powder, and organic bentonite, and the calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder are mixed at a low speed of 50-100 rpm for 5-10 minutes to obtain the filler.

[0039] Step 12: Add the calcium-based grease described in Step 10 and the filler described in Step 11 to the heat-preserved mixture III described in Step 9, and stir at a low speed of 150~300 rpm for 20~40 min at a constant temperature of 90℃ to obtain mixture IV.

[0040] Step 13: Add the reinforcing agent composed of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, and stir at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40℃ to obtain mixture V;

[0041] Step 14: Add the composite modifier composed of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, and stir at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40℃ to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0042] The beneficial effects of this invention:

[0043] 1. This invention provides a shield tail sealing grease for tunnel boring machines (TBMs) that withstands high water pressure. This invention utilizes organic montmorillonite, recycled vegetable oil, and a viscosity index modifier to construct an organic nanocomposite composed of grease and inorganic fillers, enabling the grease to exhibit excellent water pressure resistance and sealing performance under high water pressure conditions. Based on the different characteristics of wood fiber, cotton fiber, and bamboo fiber, this invention selectively chooses different crimp rates and fiber lengths, allowing the reinforcing agent to form a good blanket-like three-dimensional spatial skeleton in the grease, enabling the grease to withstand high water pressure. This invention utilizes the long-chain molecules of polyisobutylene in the thickener to intertwine with the network structure of alginate and sodium polyacrylate, forming a more stable three-dimensional network, thus enabling the grease to maintain good sealing performance under high water pressure.

[0044] 2. This invention provides a tail seal grease that maintains good pumpability while ensuring water pressure resistance and sealing performance. The invention utilizes organomontmorillonite and small-particle-size light calcium carbonate in the filler to achieve excellent pumpability. The lamellar structure of the organomontmorillonite facilitates shear slip, while the fine light calcium carbonate reduces friction between the grease and the pumping pipe. Furthermore, the invention adds 0.5-1 mm wood fibers to the reinforcing agent, utilizing their good liquid compressive force to maintain uniformity and good fluidity during pumping, thereby enhancing the pumpability of the grease.

[0045] 3. This invention provides a shield tail sealing grease that resists high-ion-concentration groundwater, seawater, and sand inrush. This invention utilizes calcium-based grease, polymerized rosin, and sodium polyacrylate to ensure the shield tail sealing grease maintains good consistency and stable adhesion to the shield tail brush in an aqueous environment, thus maintaining good resistance to groundwater and seawater. By increasing the proportion of polyisobutylene, this invention gives the grease good chemical stability and acid and alkali resistance, enabling it to cope with various groundwater and seawater erosion. This invention utilizes the cross-linking reaction between alginic acid and calcium-based grease to form a gel structure, effectively enhancing the grease's water-blocking and sand-retaining properties, addressing sand inrush problems in engineering projects.

[0046] 4. This invention provides an environmentally friendly, pollution-free shield-tail sealing grease. This invention utilizes recycled vegetable oil as the base oil, adds polymerized rosin to the viscosity index modifier, adds alginic acid to the thickener, uses natural plant fibers as a reinforcing agent, natural minerals as fillers, and plant-based antifungal agents such as thymol, reducing the proportion of non-natural materials in the formula and achieving green, environmentally friendly, and biodegradable properties. The grease of this invention has low levels of arsenic, cadmium, and mercury heavy metal ions and does not contain toxic benzene-based organic compounds, effectively reducing the impact on surrounding soil, groundwater, and seawater.

[0047] 5. This invention provides a shield tail sealing grease that helps reduce wear, deformation, and corrosion of the shield tail brush. This invention utilizes the extreme pressure anti-wear properties of zinc dialkyl dithiophosphate in the composite modified additive, the excellent lubricity of calcium-based grease to reduce friction of the shield tail brush, and the antioxidant properties of polymeric rosin in the viscosity index modifier to reduce oxidation and corrosion of the shield tail brush, thereby improving the service life of the shield tail brush.

[0048] 6. This invention provides a shield tail sealing grease that is highly economical and can reduce construction costs. This invention reduces the cost of the shield tail sealing grease by utilizing recycled vegetable oil, and enhances the adhesion of the grease to the shield tail brush by utilizing a polymer composite with good rheological properties and a gel network structure formed by polyisobutylene, alginate, and sodium polyacrylate, thereby reducing grease consumption during construction and lowering construction costs. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the preparation process of the environmentally friendly shield tail sealing grease used in high water pressure shield tunnels. Detailed Implementation

[0050] The following embodiments will demonstrate and illustrate the concept, technical solution, and purpose of this invention. A better understanding of this invention can be achieved by combining the accompanying drawings and embodiments. The following embodiments are obviously only representative examples of this invention and serve to illustrate the purpose of this application.

[0051] Example 1: Environmentally friendly shield tail sealing grease for high water pressure shield tunnels and its preparation method

[0052] Its components and mass fractions are as follows:

[0053] 240 portions of soybean oil were recycled.

[0054] 65 parts of C5 petroleum resin

[0055] 45 parts of reinforcing agent

[0056] 50 parts viscosity index modifier

[0057] 140 parts thickener

[0058] 575 parts of filler

[0059] 20 parts calcium-based grease

[0060] 15 parts of composite modified admixture

[0061] Its preparation method is as follows:

[0062] Step 1: Dry polyisobutylene in a vacuum drying oven at 50-60℃ for 40-60 min to obtain refined polyisobutylene; dry polyisoprene in a vacuum drying oven at 60-70℃ for 40-60 min to obtain refined polyisoprene.

[0063] Step 2: Place the refined polyisobutylene and refined polyisoprene from Step 1 into a reaction vessel, and stir at a low speed of 100-300 rpm for 40-60 minutes at a constant temperature of 90°C to obtain Mixture I.

[0064] Step 3: Put the polymerized rosin into a pulverizer and pulverize it into particles with a diameter of 1~3mm to obtain powdered polymerized rosin; add the powdered polymerized rosin to the mixing group I described in step 2, and stir at a low speed of 150~300rpm for 40~60min under a constant temperature of 120℃ to obtain mixing group II;

[0065] Step 4: Dry the succinimide under nitrogen protection at a temperature of 40-50°C for 40-60 minutes to obtain refined succinimide. Add the refined succinimide to the mixture group II described in step 3, and stir at a low speed of 200-300 rpm for 60-90 minutes at a temperature of 150°C and a pressure of 0.5 MPa to obtain the crude viscosity index modifier.

[0066] Step 5: Filter the crude viscosity index modifier described in step 4 through a filter screen with a pore size of 1-5 micrometers to obtain the viscosity index modifier.

[0067] Step 6: Grind the C5 petroleum resin in a grinder at high speed 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, at a speed of 1000-1200 rpm to obtain powdered petroleum resin; filter the recovered vegetable oil through a filter screen with a pore size of 40-60 micrometers to obtain the base vegetable oil, and keep it at a constant temperature of 40℃ for 30-50 minutes.

[0068] Step 7: Mix the heat-insulated base vegetable oil, powdered petroleum resin and viscosity index modifier described in Step 6, and stir at a low speed of 200~350 rpm for 40~60 min at a constant temperature of 120℃ to obtain mixture I.

[0069] Step 8: Mix sodium polyacrylate, alginate, and polyisobutylene, and stir at a low speed of 150-300 rpm for 10-30 minutes at a constant temperature of 40℃ to obtain crude thickener I; stir crude thickener I at a high speed of 300-500 rpm for 30-50 minutes at a constant temperature of 60℃ to obtain crude thickener II; adjust the pH value of crude thickener II to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain crude thickener; stir the crude thickener at a low speed of 100-200 rpm for 5-10 minutes at a constant temperature of 40℃ to obtain thickener.

[0070] Step 9: Add the thickener described in Step 8 to Mixture I described in Step 7, and stir at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain Mixture II; then stir at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain Mixture III, and keep Mixture III at a constant temperature of 40°C for 30-50 minutes.

[0071] Step 10: Stir 12-hydroxystearic acid and recycled vegetable oil at 80-90°C at a low speed of 100-200 rpm for 10-20 min to obtain an intermediate product. Add 5% lime milk to the intermediate product and dry it at 100-110°C for 10-20 min to obtain calcium-based grease.

[0072] Step 11: In a mixer, the organic lubricant composed of organic montmorillonite, talc powder, and organic bentonite, and the calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder are mixed at a low speed of 50-100 rpm for 5-10 minutes to obtain the filler.

[0073] Step 12: Add the calcium-based grease described in Step 10 and the filler described in Step 11 to the heat-preserved mixture III described in Step 9, and stir at a low speed of 150~300 rpm for 20~40 min at a constant temperature of 90℃ to obtain mixture IV.

[0074] Step 13: Add the reinforcing agent composed of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, and stir at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40℃ to obtain mixture V;

[0075] Step 14: Add the composite modifier composed of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, and stir at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40℃ to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0076] Example 2: Environmentally friendly shield tail sealing grease for high water pressure shield tunnels and its preparation method

[0077] Its components and mass fractions are as follows:

[0078] 230 portions of rapeseed oil were recycled.

[0079] 140 parts of viscosity index modifier

[0080] 40 parts of C5 petroleum resin

[0081] 40 parts of reinforcing agent

[0082] 40 parts thickener

[0083] 640 parts of filler

[0084] 15 parts calcium-based grease

[0085] 20 parts of composite modified admixture

[0086] Its preparation method is as follows:

[0087] Step 1: Dry polyisobutylene in a vacuum drying oven at 50-60℃ for 40-60 min to obtain refined polyisobutylene; dry polyisoprene in a vacuum drying oven at 60-70℃ for 40-60 min to obtain refined polyisoprene.

[0088] Step 2: Place the refined polyisobutylene and refined polyisoprene from Step 1 into a reaction vessel, and stir at a low speed of 100-300 rpm for 40-60 minutes at a constant temperature of 90°C to obtain Mixture I.

[0089] Step 3: Put the polymerized rosin into a pulverizer and pulverize it into particles with a diameter of 1~3mm to obtain powdered polymerized rosin; add the powdered polymerized rosin to the mixing group I described in step 2, and stir at a low speed of 150~300rpm for 40~60min under a constant temperature of 120℃ to obtain mixing group II;

[0090] Step 4: Dry the succinimide under nitrogen protection at a temperature of 40-50°C for 40-60 minutes to obtain refined succinimide. Add the refined succinimide to the mixture group II described in step 3, and stir at a low speed of 200-300 rpm for 60-90 minutes at a temperature of 150°C and a pressure of 0.5 MPa to obtain the crude viscosity index modifier.

[0091] Step 5: Filter the crude viscosity index modifier described in step 4 through a filter screen with a pore size of 1-5 micrometers to obtain the viscosity index modifier.

[0092] Step 6: Grind the C5 petroleum resin in a grinder at high speed 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, at a speed of 1000-1200 rpm to obtain powdered petroleum resin; filter the recovered vegetable oil through a filter screen with a pore size of 40-60 micrometers to obtain the base vegetable oil, and keep it at a constant temperature of 40℃ for 30-50 minutes.

[0093] Step 7: Mix the heat-insulated base vegetable oil, powdered petroleum resin and viscosity index modifier described in Step 6, and stir at a low speed of 200~350 rpm for 40~60 min at a constant temperature of 120℃ to obtain mixture I.

[0094] Step 8: Mix sodium polyacrylate, alginate, and polyisobutylene, and stir at a low speed of 150-300 rpm for 10-30 minutes at a constant temperature of 40℃ to obtain crude thickener I; stir crude thickener I at a high speed of 300-500 rpm for 30-50 minutes at a constant temperature of 60℃ to obtain crude thickener II; adjust the pH value of crude thickener II to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain crude thickener; stir the crude thickener at a low speed of 100-200 rpm for 5-10 minutes at a constant temperature of 40℃ to obtain thickener.

[0095] Step 9: Add the thickener described in Step 8 to Mixture I described in Step 7, and stir at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain Mixture II; then stir at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain Mixture III, and keep Mixture III at a constant temperature of 40°C for 30-50 minutes.

[0096] Step 10: Stir 12-hydroxystearic acid and recycled vegetable oil at 80-90°C at a low speed of 100-200 rpm for 10-20 min to obtain an intermediate product. Add 5% lime milk to the intermediate product and dry it at 100-110°C for 10-20 min to obtain calcium-based grease.

[0097] Step 11: In a mixer, the organic lubricant composed of organic montmorillonite, talc powder, and organic bentonite, and the calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder are mixed at a low speed of 50-100 rpm for 5-10 minutes to obtain the filler.

[0098] Step 12: Add the calcium-based grease described in Step 10 and the filler described in Step 11 to the heat-preserved mixture III described in Step 9, and stir at a low speed of 150~300 rpm for 20~40 min at a constant temperature of 90℃ to obtain mixture IV.

[0099] Step 13: Add the reinforcing agent composed of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, and stir at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40℃ to obtain mixture V;

[0100] Step 14: Add the composite modifier composed of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, and stir at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40℃ to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0101] Example 3: Environmentally friendly shield tail sealing grease for high water pressure shield tunnels and its preparation method

[0102] Its components and mass fractions are as follows:

[0103] 230 portions of soybean oil were recycled.

[0104] 20 parts of C5 petroleum resin

[0105] 70 parts viscosity index modifier

[0106] 30 parts of enhancer

[0107] 120 parts thickener

[0108] 600 parts of filler

[0109] 20 parts calcium-based grease

[0110] 15 parts of composite modified admixture

[0111] Its preparation method is as follows:

[0112] Step 1: Dry polyisobutylene in a vacuum drying oven at 50-60℃ for 40-60 min to obtain refined polyisobutylene; dry polyisoprene in a vacuum drying oven at 60-70℃ for 40-60 min to obtain refined polyisoprene.

[0113] Step 2: Place the refined polyisobutylene and refined polyisoprene from Step 1 into a reaction vessel, and stir at a low speed of 100-300 rpm for 40-60 minutes at a constant temperature of 90°C to obtain Mixture I.

[0114] Step 3: Put the polymerized rosin into a pulverizer and pulverize it into particles with a diameter of 1~3mm to obtain powdered polymerized rosin; add the powdered polymerized rosin to the mixing group I described in step 2, and stir at a low speed of 150~300rpm for 40~60min under a constant temperature of 120℃ to obtain mixing group II;

[0115] Step 4: Dry the succinimide under nitrogen protection at a temperature of 40-50°C for 40-60 minutes to obtain refined succinimide. Add the refined succinimide to the mixture group II described in step 3, and stir at a low speed of 200-300 rpm for 60-90 minutes at a temperature of 150°C and a pressure of 0.5 MPa to obtain the crude viscosity index modifier.

[0116] Step 5: Filter the crude viscosity index modifier described in step 4 through a filter screen with a pore size of 1-5 micrometers to obtain the viscosity index modifier.

[0117] Step 6: Grind the C5 petroleum resin in a grinder at high speed 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, at a speed of 1000-1200 rpm to obtain powdered petroleum resin; filter the recovered vegetable oil through a filter screen with a pore size of 40-60 micrometers to obtain the base vegetable oil, and keep it at a constant temperature of 40℃ for 30-50 minutes.

[0118] Step 7: Mix the heat-insulated base vegetable oil, powdered petroleum resin and viscosity index modifier described in Step 6, and stir at a low speed of 200~350 rpm for 40~60 min at a constant temperature of 120℃ to obtain mixture I.

[0119] Step 8: Mix sodium polyacrylate, alginate, and polyisobutylene, and stir at a low speed of 150-300 rpm for 10-30 minutes at a constant temperature of 40℃ to obtain crude thickener I; stir crude thickener I at a high speed of 300-500 rpm for 30-50 minutes at a constant temperature of 60℃ to obtain crude thickener II; adjust the pH value of crude thickener II to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain crude thickener; stir the crude thickener at a low speed of 100-200 rpm for 5-10 minutes at a constant temperature of 40℃ to obtain thickener.

[0120] Step 9: Add the thickener described in Step 8 to Mixture I described in Step 7, and stir at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain Mixture II; then stir at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain Mixture III, and keep Mixture III at a constant temperature of 40°C for 30-50 minutes.

[0121] Step 10: Stir 12-hydroxystearic acid and recycled vegetable oil at 80-90°C at a low speed of 100-200 rpm for 10-20 min to obtain an intermediate product. Add 5% lime milk to the intermediate product and dry it at 100-110°C for 10-20 min to obtain calcium-based grease.

[0122] Step 11: In a mixer, the organic lubricant composed of organic montmorillonite, talc powder, and organic bentonite, and the calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder are mixed at a low speed of 50-100 rpm for 5-10 minutes to obtain the filler.

[0123] Step 12: Add the calcium-based grease described in Step 10 and the filler described in Step 11 to the heat-preserved mixture III described in Step 9, and stir at a low speed of 150~300 rpm for 20~40 min at a constant temperature of 90℃ to obtain mixture IV.

[0124] Step 13: Add the reinforcing agent composed of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, and stir at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40℃ to obtain mixture V;

[0125] Step 14: Add the composite modifier composed of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, and stir at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40℃ to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0126] Example 4: Environmentally friendly shield tail sealing grease for high water pressure shield tunnels and its preparation method

[0127] Its components and mass fractions are as follows:

[0128] 240 portions of soybean oil were recycled.

[0129] 90 parts of viscosity index modifier

[0130] 20 parts of C5 petroleum resin

[0131] 55 parts of reinforcing agent

[0132] 70 parts thickener

[0133] 510 parts of filler

[0134] 25 parts calcium-based grease

[0135] 25 parts of composite modified admixture

[0136] Its preparation method is as follows:

[0137] Step 1: Dry polyisobutylene in a vacuum drying oven at 50-60℃ for 40-60 min to obtain refined polyisobutylene; dry polyisoprene in a vacuum drying oven at 60-70℃ for 40-60 min to obtain refined polyisoprene.

[0138] Step 2: Place the refined polyisobutylene and refined polyisoprene from Step 1 into a reaction vessel, and stir at a low speed of 100-300 rpm for 40-60 minutes at a constant temperature of 90°C to obtain Mixture I.

[0139] Step 3: Put the polymerized rosin into a pulverizer and pulverize it into particles with a diameter of 1~3mm to obtain powdered polymerized rosin; add the powdered polymerized rosin to the mixing group I described in step 2, and stir at a low speed of 150~300rpm for 40~60min under a constant temperature of 120℃ to obtain mixing group II;

[0140] Step 4: Dry the succinimide under nitrogen protection at a temperature of 40-50°C for 40-60 minutes to obtain refined succinimide. Add the refined succinimide to the mixture group II described in step 3, and stir at a low speed of 200-300 rpm for 60-90 minutes at a temperature of 150°C and a pressure of 0.5 MPa to obtain the crude viscosity index modifier.

[0141] Step 5: Filter the crude viscosity index modifier described in Step 4 through a filter screen with a pore size of 1-5 micrometers to obtain the viscosity index modifier; Step 6: Grind the C5 petroleum resin in a grinder at high speed 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, at a speed of 1000-1200 rpm to obtain powdered petroleum resin; Filter the recovered vegetable oil through a filter screen with a pore size of 40-60 micrometers to obtain the base vegetable oil, and keep it at a constant temperature of 40℃ for 30-50 minutes;

[0142] Step 7: Mix the heat-insulated base vegetable oil, powdered petroleum resin and viscosity index modifier described in Step 6, and stir at a low speed of 200~350 rpm for 40~60 min at a constant temperature of 120℃ to obtain mixture I.

[0143] Step 8: Mix sodium polyacrylate, alginate, and polyisobutylene, and stir at a low speed of 150-300 rpm for 10-30 minutes at a constant temperature of 40℃ to obtain crude thickener I; stir crude thickener I at a high speed of 300-500 rpm for 30-50 minutes at a constant temperature of 60℃ to obtain crude thickener II; adjust the pH value of crude thickener II to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain crude thickener; stir the crude thickener at a low speed of 100-200 rpm for 5-10 minutes at a constant temperature of 40℃ to obtain thickener.

[0144] Step 9: Add the thickener described in Step 8 to Mixture I described in Step 7, and stir at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain Mixture II; then stir at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain Mixture III, and keep Mixture III at a constant temperature of 40°C for 30-50 minutes.

[0145] Step 10: Stir 12-hydroxystearic acid and recycled vegetable oil at 80-90°C at a low speed of 100-200 rpm for 10-20 min to obtain an intermediate product. Add 5% lime milk to the intermediate product and dry it at 100-110°C for 10-20 min to obtain calcium-based grease.

[0146] Step 11: In a mixer, the organic lubricant composed of organic montmorillonite, talc powder, and organic bentonite, and the calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder are mixed at a low speed of 50-100 rpm for 5-10 minutes to obtain the filler.

[0147] Step 12: Add the calcium-based grease described in Step 10 and the filler described in Step 11 to the heat-preserved mixture III described in Step 9, and stir at a low speed of 150~300 rpm for 20~40 min at a constant temperature of 90℃ to obtain mixture IV.

[0148] Step 13: Add the reinforcing agent composed of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, and stir at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40℃ to obtain mixture V;

[0149] Step 14: Add the composite modifier composed of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, and stir at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40℃ to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0150] Comparative Example 1:

[0151] It is composed of the following materials in parts by weight: 250 parts 150N mineral oil, 150 parts polyisobutylene, 50 parts fiber, 210 parts organobentonite, 310 parts heavy calcium carbonate, and 80 parts calcium-based grease. The difference between this and Examples 1-4 is that: the base oil is mineral oil and does not contain C5 petroleum resin; the viscosity index modifier is only calcium-based grease; the filler does not contain organomontmorillonite, light calcium carbonate, or mica powder; and no additives are added.

[0152] Comparative Example 2:

[0153] It is composed of the following materials in parts by weight: 230 parts 150N mineral oil, 170 parts polyisobutylene, 50 parts fiber, 40 parts organobentonite, 230 parts light calcium carbonate, 270 parts heavy calcium carbonate, 20 parts mica powder, 20 parts organomontmorillonite, and 70 parts calcium-based grease. The difference between this and Examples 1-4 is that the base oil is mineral oil and does not contain C5 petroleum resin; the viscosity index modifier is only calcium-based grease; and the fiber contains only 1-2 mm and 2-3 mm wood fibers.

[0154] The performance of the embodiments and comparative examples is shown in Table 1.

[0155] Table 1

[0156]

[0157] As can be seen from the test data in Table 1, this invention exhibits excellent water pressure resistance, pumpability, and adhesion. In the development of shield tail sealing greases, achieving a balance between water pressure resistance and pumpability is often difficult. This is because the most effective way to improve the water pressure resistance of shield tail sealing greases is to increase their consistency, but excessively viscous greases cannot meet the corresponding pumping requirements. This invention achieves a good balance between water pressure resistance, pumpability, and adhesion, which is beneficial for convenient engineering construction, energy saving, environmental protection, and pollution reduction, providing a new solution for the complex working conditions faced in high water pressure shield tunnel construction.

[0158] The differences in base oil, viscosity index modifier, and filler between Comparative Example 1 and the Examples, and the differences in base oil, viscosity index modifier, and reinforcing agent between Comparative Example 2 and the Examples, resulted in significantly lower performance in the Comparative Examples compared to the Examples. The different fillers in Comparative Example 1 led to significantly lower water pressure resistance than the Examples, and the different reinforcing agents in Comparative Example 2 resulted in differences in microstructure, causing significantly lower pumpability and water pressure resistance compared to the Examples. Furthermore, the composite modified additives extended the service life of the shield tail brush and reduced the storage requirements of the grease; the improved preparation process was also a factor contributing to the performance differences.

[0159] The examples given above are merely illustrative of the present invention and do not limit the scope of the invention. The scope of protection of the present invention is not limited to the above examples, and all technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention.

Claims

1. An environmentally friendly shield tail sealing grease for high water pressure shield tunnels, characterized in that: The environmentally friendly shield tail sealing grease for high water pressure shield tunnels is composed of the following components in parts by weight: 240-305 parts base oil, 25-140 parts viscosity index modifier, 40-140 parts thickener, 510-640 parts filler, 30-55 parts reinforcing agent, 10-35 parts calcium-based grease, and 8-35 parts composite modified additives. The base oil is a mixture of recycled vegetable oil and C5 petroleum resin, wherein the recycled vegetable oil has a mass fraction of 168-290 parts and the C5 petroleum resin has a mass fraction of 12-92 parts, wherein the recycled vegetable oil is recycled soybean oil or recycled rapeseed oil. The viscosity index modifier is a mixture of polyisobutylene, polymeric rosin, succinimide, and polyisoprene, wherein the mass fraction of polyisobutylene is 17-70 parts, the mass fraction of polymeric rosin is 5-38 parts, the mass fraction of succinimide is 5-28 parts, and the mass fraction of polyisoprene is 5-30 parts. The thickener is a mixture of polyisobutylene, alginate, and sodium polyacrylate, wherein the mass fraction of polyisobutylene is 18-70 parts, the mass fraction of alginate is 8-68 parts, and the mass fraction of sodium polyacrylate is 4-55 parts. The filler is a mixture of organic lubricant and calcium filler, wherein the organic lubricant comprises 30-192 parts by mass and the calcium filler comprises 357-579 parts by mass; wherein the organic lubricant is a mixture of organomontmorillonite, talc, and organobentonite, wherein the organomontmorillonite comprises 7-39 parts by mass, the talc comprises 0-67 parts by mass and the organobentonite comprises 20-172 parts by mass; the calcium filler is a mixture of light calcium carbonate, heavy calcium carbonate, and mica powder, wherein the light calcium carbonate comprises 142-290 parts by mass, the heavy calcium carbonate comprises 142-290 parts by mass and the mica powder comprises 0-115 parts by mass. The reinforcing agent is a mixture of wood fiber, cotton fiber, and bamboo fiber, wherein the mass fraction of wood fiber is 6-22 parts, the mass fraction of cotton fiber is 9-22 parts, and the mass fraction of bamboo fiber is 6-22 parts. The crimp shrinkage rate of the wood fiber is 20%-40%, the crimp shrinkage rate of the cotton fiber is 60%-70%, and the crimp shrinkage rate of the bamboo fiber is 15%-20%. The mass ratio of the fibers is: 0.5-1 mm wood fiber : 1-2 mm bamboo fiber : 2-3 mm cotton fiber : 3-4 mm cotton fiber = 2-4 : 1-3 : 1-2 : 1-2. The calcium-based grease is made by thickening recycled vegetable oil with 12-hydroxystearic acid and 5% lime milk, wherein the mass fraction of recycled vegetable oil is 8-28 parts, the mass fraction of 12-hydroxystearic acid is 1-3 parts, and the mass fraction of 5% lime milk is 2-6 parts. The composite modifier is a mixture of thymol, zinc borate, and zinc dialkyl dithiophosphate, wherein the mass fraction of thymol is 2-13 parts, the mass fraction of zinc borate is 5-12 parts, and the mass fraction of zinc dialkyl dithiophosphate is 8-14 parts. The preparation method of the environmentally friendly shield tail sealing grease used in high water pressure shield tunnels is as follows: Step 1: Dry polyisobutylene in a vacuum drying oven at 50-60℃ for 40-60 min to obtain refined polyisobutylene; dry polyisoprene in a vacuum drying oven at 60-70℃ for 40-60 min to obtain refined polyisoprene. Step 2: Place the refined polyisobutylene and refined polyisoprene from Step 1 into a reaction vessel, and stir at a low speed of 100-300 rpm for 40-60 minutes at a constant temperature of 90°C to obtain Mixture I. Step 3: Put the polymerized rosin into a pulverizer and pulverize it into particles with a diameter of 1~3mm to obtain powdered polymerized rosin; add the powdered polymerized rosin to the mixing group I described in step 2, and stir at a low speed of 150~300rpm for 40~60min under a constant temperature of 120℃ to obtain mixing group II; Step 4: Dry the succinimide under nitrogen protection at a temperature of 40-50°C for 40-60 minutes to obtain refined succinimide. Add the refined succinimide to the mixture group II described in step 3, and stir at a low speed of 200-300 rpm for 60-90 minutes at a temperature of 150°C and a pressure of 0.5 MPa to obtain the crude viscosity index modifier. Step 5: Filter the crude viscosity index modifier described in step 4 through a filter screen with a pore size of 1-5 micrometers to obtain the viscosity index modifier. Step 6: Grind the C5 petroleum resin in a grinder at high speed 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, at a speed of 1000-1200 rpm to obtain powdered petroleum resin; filter the recovered vegetable oil through a filter screen with a pore size of 40-60 micrometers to obtain the base vegetable oil, and keep it at a constant temperature of 40℃ for 30-50 minutes. Step 7: Mix the heat-insulated base vegetable oil, powdered petroleum resin and viscosity index modifier described in Step 6, and stir at a low speed of 200~350 rpm for 40~60 min at a constant temperature of 120℃ to obtain mixture I. Step 8: Mix sodium polyacrylate, alginate, and polyisobutylene, and stir at a low speed of 150-300 rpm for 10-30 minutes at a constant temperature of 40℃ to obtain crude thickener I; stir crude thickener I at a high speed of 300-500 rpm for 30-50 minutes at a constant temperature of 60℃ to obtain crude thickener II; adjust the pH value of crude thickener II to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain crude thickener; stir the crude thickener at a low speed of 100-200 rpm for 5-10 minutes at a constant temperature of 40℃ to obtain thickener. Step 9: Add the thickener described in Step 8 to Mixture I described in Step 7, and stir at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain Mixture II; then stir at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain Mixture III, and keep Mixture III at a constant temperature of 40°C for 30-50 minutes. Step 10: Stir 12-hydroxystearic acid and recycled vegetable oil at 80-90°C at a low speed of 100-200 rpm for 10-20 min to obtain an intermediate product. Add 5% lime milk to the intermediate product and dry it at 100-110°C for 10-20 min to obtain calcium-based grease. Step 11: In a mixer, the organic lubricant composed of organic montmorillonite, talc powder, and organic bentonite, and the calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder are stirred at a low speed of 50-100 rpm for 5-10 min to obtain the filler. Step 12: Add the calcium-based grease described in Step 10 and the filler described in Step 11 to the heat-preserved mixture III described in Step 9, and stir at a low speed of 150~300 rpm for 20~40 min at a constant temperature of 90℃ to obtain mixture IV. Step 13: Add the reinforcing agent composed of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, and stir at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40℃ to obtain mixture V; Step 14: Add the composite modifier composed of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, and stir at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40℃ to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

2. The environmentally friendly shield tail sealing grease for high water pressure shield tunnels as described in claim 1, characterized in that, The kinematic viscosity of the base oil is 29.5~35.5 mm at 40°C. 2 / s, density greater than 0.9 g / cm³ 3 The bromine value is ≤70 gBr / 100g, and the softening point of the C5 petroleum resin is 85~92℃.

3. The environmentally friendly shield tail sealing grease for high water pressure shield tunnels as described in claim 1, characterized in that, In the viscosity index modifier, the molecular weight of polyisobutylene is greater than 2000, the molecular weight of polyisoprene is greater than 50000, and the density of the selected polymerized rosin at 20°C is 1.08~1.1 g / cm³. 3 Its softening point is 90℃.

4. The environmentally friendly shield tail sealing grease for high-water-pressure shield tunnels as described in claim 1, characterized in that, The thickener contains polyisobutylene with a molecular weight greater than 2000 and a density of 0.85~0.92 g / cm³ at 25°C. 3 The kinematic viscosity at 100℃ is 240~250 mm. 2 / s.

5. The environmentally friendly shield tail sealing grease for high water pressure shield tunnels as described in claim 1, characterized in that, The filler comprises talc powder of two different mesh sizes, wherein 325 mesh talc powder accounts for 20-30 parts by mass and 625 mesh talc powder accounts for 40-50 parts by mass; the heavy calcium carbonate has a particle size of 625 mesh; and the light calcium carbonate comprises two different mesh sizes, wherein 1200 mesh light calcium carbonate accounts for 57-174 parts by mass and 1500 mesh light calcium carbonate accounts for 55-174 parts by mass.

6. The environmentally friendly shield tail sealing grease for high water pressure shield tunnels as described in claim 1, characterized in that, The composite modified additive contains thymol: zinc borate: zinc dialkyl dithiophosphate in a ratio of 1~2:1~3:1~2.

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