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

Abstract

The invention discloses environment-friendly shield tail sealing grease for a high-water-pressure shield tunnel and a preparation method. The shield tail sealing grease is prepared from the following materials in parts by weight: 240 to 305 parts of base oil, 25 to 140 parts of a viscosity index modifier, 40 to 140 parts of a thickening agent, 510 to 640 parts of a filling agent, 30 to 55 parts of a reinforcing agent, 10 to 35 parts of calcium-based lubricating grease and 8 to 25 parts of a composite modified additive. A mixture of recycled vegetable oil and C5 petroleum resin is used as base oil, plant fiber is used as a reinforcing agent, a mixture of polyisobutene, polymerized rosin, succinimide and polyisoprene is used as a viscosity index modifier, a mixture of polyisobutene, alginic acid and sodium polyacrylate is used as a thickening agent, and an organic lubricating material and a calcium filler are used as reinforcing agents. Calcium-based lubricating grease is added, and thymol, zinc borate and zinc dialkyl dithiophosphate form a composite modified additive. The environment-friendly shield tail sealing grease for the high-water-pressure shield tunnel is formed by adopting a preparation process of drying, filtering, heat preservation, constant temperature and speed-controlled physical kneading.

Description

Technical Field

[0001] The invention relates to shield tail sealing grease, in particular to an environmentally friendly shield tail sealing grease used for a high water pressure shield tunnel and a preparation method thereof. Background Art

[0002] In recent years, with the continuous development of my country's infrastructure, there are more and more large-scale high-water pressure and large-diameter shield tunnel projects, the demand for continued development and utilization of underground space is increasing, and more river-crossing and sea-crossing tunnel projects are also being planned. The working conditions faced by shield construction are becoming more and more complex, so higher requirements are put forward for shield excavation construction accordingly.

[0003] Failure of the shield tail seal is one of the common safety issues in shield construction. If the shield tail seal system leaks, it may cause hazards such as increased surface settlement and insufficient grouting pressure. In severe cases, it may also cause major safety accidents such as tunnel collapse. At present, the shield tail seal mainly adopts the method of filling sealing grease between multiple shield tail brushes. The quality of grease sealing directly determines the shield tail sealing ability and affects the safety of shield excavation. Therefore, the stability and reliability of the shield tail sealing grease is very important.

[0004] Shield tail sealing grease is a consumable material for shield tail sealing in shield construction of underground engineering, which mainly plays the role of sealing, waterproofing, lubrication and corrosion prevention. At present, there are many shield tail sealing grease manufacturers in China, and the quality is uneven. When encountering high water pressure and underwater tunnels, the performance is generally poor. For foreign imported products, such as French or Japanese grease products, although the quality is good, the price is generally much higher than that of domestic grease products, and the cost is relatively high.

[0005] In recent years, in response to the national call to achieve green and sustainable development, the environmental protection of shield tail sealing grease has also received widespread attention from all walks of life. The raw materials of mainstream sealing grease on the market are mainly derived from non-degradable petroleum derivatives, which are not environmentally friendly. Moreover, the small amount of heavy metals and benzene organic matter contained in them will cause environmental pollution through long-term contact with the surrounding soil, groundwater and seawater.

[0006] The existing patented technology of shield tail sealing grease has the following problems: 1. Difficulty in coping with sealing problems under high water pressure conditions: At present, most shield tail sealing greases can only cope with low construction water pressure, which is difficult to meet the construction needs of high water pressure environment. Moreover, when passing through a stratum with a permeability coefficient exceeding 50 m / day, due to the large porosity and strong water permeability of the stratum, the construction water and soil pressure will increase significantly, and the existing shield tail sealing grease technology is difficult to cope with. There is an urgent need for a shield tail sealing grease that can effectively cope with high water pressure and high stratum permeability conditions; 2. Lack of environmental protection performance: Most of the 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 content of arsenic, cadmium, mercury heavy metal ions and toxic benzene organic matter in the existing shield tail sealing grease is usually high. When the shield construction passes through agricultural cultivated land, rivers, lakes and oceans, it will pollute the surrounding environment. There is an urgent need for environmentally friendly shield tail sealing grease; 3. Insufficient pumping performance: Existing shield tail sealing grease is difficult to achieve a balance between high water pressure resistance and good pumping performance. During shield construction, the pumping performance of the shield tail sealing grease will affect the filling quality of the shield tail sealing grease, which not only brings many inconveniences to the construction, but also may pose a threat to the safety of the project. Therefore, there is an urgent need for shield tail sealing grease with good pumping performance and high water pressure resistance; 4. Lack of ability to deal with the problem of sand gushing at the shield tail: When crossing the water-rich sandy soil layer, sand and soil gushing at the shield tail often occurs. The existing shield tail sealing grease, after mixing with sand and soil, is difficult to ensure the safety and effectiveness of the shield tail seal, and cannot ensure its strong adhesion with 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 deal with the problem of sand gushing; 5. Insufficient protection for the shield tail brush: The existing shield tail sealing grease is prone to rust during use, and has limited protective effect on the shield tail brush, and cannot effectively extend its service life. The shield tail brush is prone to wear, deformation and rust during shield construction, and replacing the shield tail brush is not only complicated but also has high manpower and material costs. Therefore, there is an urgent need for shield tail sealing grease that can effectively extend the service life of the shield tail brush; 6. Low cost-effectiveness: The existing shield tail sealing grease is not cost-effective, especially the environmentally friendly shield tail sealing grease. The existing shield tail sealing grease has poor adhesion to the shield tail brush, resulting in a large consumption during construction. For example, the consumption of shield tail sealing grease in shield construction is usually 35-45 kg / ring. Taking the shield advancing 1000 rings as an example, the cost of using the existing grease is about 550,000 to 750,000 yuan, which puts great pressure on construction cost control. Therefore, there is an urgent need for cost-effective shield tail sealing grease. Summary of the invention

[0007] In view of the above problems, the present invention proposes an environmentally friendly shield tail sealing grease and preparation method suitable for high water pressure shield tunnels. In terms of weight, its ingredients include: 240-305 parts of base oil, 25-140 parts of viscosity index modifier, 40-140 parts of thickener, 510-640 parts of filler, 30-55 parts of enhancer, 10-35 parts of calcium-based grease, and 8-35 parts of composite modified additives. The invention provides an environmentally friendly grease formula for high water pressure shield engineering. On the premise of ensuring the water pressure resistance, sealing, pumpability and other properties of the grease, it selects raw materials that are non-polluting and easily degradable to the environment, reducing the impact on surrounding groundwater, seawater, soil and organisms.

[0008] The base oil is a mixture of recycled vegetable oil and C5 petroleum resin, wherein the mass fraction of the recycled vegetable oil is 168-290 parts, and the mass fraction of the C5 petroleum resin is 12-92 parts, wherein the vegetable oil is soybean oil or rapeseed oil.

[0009] Furthermore, the kinematic viscosity of the base oil is about 29.5-35.5 mm at 40°C. 2 / s, density greater than 0.9g / cm³, bromine value ≤70 gBr / 100g, and the softening point of the C5 petroleum resin is about 85-92°C.

[0010] The viscosity index modifier is a mixture of polyisobutylene, polymerized rosin, succinimide and polyisoprene, wherein the mass fraction of polyisobutylene is 17-70 parts, the mass fraction of polymerized rosin is 5-38 parts, the mass fraction of succinimide is 5-28 parts and the mass fraction of polyisoprene is 5-30 parts; and the viscosity index modifier is mainly used to improve the viscosity and pumpability of grease.

[0011] Furthermore, in the viscosity index modifier, the molecular weight of polyisobutylene is greater than 2000, the molecular weight of polyisoprene is greater than 50000, the density of the selected polymerized rosin at 20°C is about 1.08-1.1 g / cm³, and the softening point is 90°C.

[0012] The thickener is a mixture of polyisobutylene, alginic acid and sodium polyacrylate, wherein the mass fraction of polyisobutylene is 18-70 parts, the mass fraction of alginic acid is 8-68 parts, and the mass fraction of sodium polyacrylate is 4-55 parts; it is mainly used to improve the consistency of grease.

[0013] Furthermore, in the thickener, the molecular weight of polyisobutylene is greater than 2000, the density at 25°C is about 0.85-0.92 g / cm³, and the kinematic viscosity at 100°C is about 240-250 mm 2 / s.

[0014] The filler is a mixture of an organic lubricant and a calcium filler, wherein the mass fraction of the organic lubricant is 30-192 parts, and the mass fraction of the calcium filler is 357-579 parts; wherein the organic lubricant is a mixture of two or more of organic montmorillonite, talcum powder, and organic bentonite, wherein the mass fraction of the organic montmorillonite is 7-39 parts, the mass fraction of the talcum powder is 0-67 parts, and the mass fraction of the organic bentonite is 20-172 parts; the calcium filler is a mixture of two or more of light calcium carbonate, heavy calcium carbonate, and mica powder, wherein the mass fraction of the light calcium carbonate is 142-290 parts, the mass fraction of the heavy calcium carbonate is 142-290 parts, and the mass fraction of the mica powder is 0-115 parts; the invention is mainly used for reducing costs and increasing the sealing performance of grease.

[0015] 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 particle size of heavy calcium carbonate is 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.

[0016] The calcium-based grease is made of 1,2-hydroxystearic acid and 5% lime milk thickened vegetable oil, wherein the mass fraction of the recovered vegetable oil is 8-28 parts, the mass fraction of 1,2-hydroxystearic acid is 1-3 parts, and the mass fraction of 5% lime milk is 2-6 parts. The calcium 1,2-hydroxystearate contained in the calcium-based grease is the main component that plays a lubricating and thickening role.

[0017] The enhancer is a mixture of wood fiber, cotton fiber and bamboo fiber, wherein the weight fraction of wood fiber is 6-22 parts, the weight fraction of cotton fiber is 9-22 parts and the weight fraction of bamboo fiber is 6-22 parts; it is mainly used to improve the water pressure resistance of grease and improve the pumpability of grease to a certain extent.

[0018] Preferably, the curl shrinkage rate of the wood fiber is 20% to 40%, the curl shrinkage rate of the cotton fiber is 60% to 70%, and the curl shrinkage rate of the bamboo fiber is 15% to 20%. Preferably, the mass ratio of the fibers is: 0.5 to 1 mm wood fiber: 1 to 2 mm bamboo fiber: 2 to 3 mm cotton fiber: 3 to 4 mm cotton fiber = (2-4): (1-3): (1-2): (1-2).

[0019] The composite modification additive 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.

[0020] Preferably, the composite modified additive comprises thymol:zinc borate:zinc dialkyl dithiophosphate=(1-2):(1-3):(1-2).

[0021] The present invention provides a method for preparing an environmentally friendly shield tail sealing grease for a high water pressure shield tunnel, and the preparation method is as follows: Step 1, drying polyisobutylene in a vacuum drying oven at 50-60° C. for 40-60 minutes to obtain refined polyisobutylene; drying polyisoprene in a vacuum drying oven at 60-70° C. for 40-60 minutes to obtain refined polyisoprene; Step 2, putting the refined polyisobutylene and refined polyisoprene described in step 1 into a reaction kettle, stirring at a low speed of 100-300 rpm for 40-60 min at a constant temperature of 90° C. to obtain a mixed group I; Step 3, putting the polymerized rosin into a pulverizer and pulverizing it into particles with a diameter of 1-3 mm to obtain powdered polymerized rosin; adding the powdered polymerized rosin to the mixed group I described in step 2, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 120° C. to obtain a mixed group II; Step 4, drying the succinimide under nitrogen protection at a temperature of 40-50° C. for 40-60 min to obtain refined succinimide, adding the refined succinimide to the mixing group II described in step 3, stirring at a low speed of 200-300 rpm for 60-90 min, at a temperature of 150° C. and a pressure of 0.5 MPa to obtain a crude viscosity index modifier; Step 5, filtering the crude viscosity index modifier in step 4 through a filter with a pore size of 1-5 microns to obtain a viscosity index modifier; Step 6, grinding the C5 petroleum resin in a grinder at high speed for 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, and a rotation speed of 1000-1200 rpm to obtain a powdered petroleum resin; filtering the recovered vegetable oil through a filter with a pore size of 40-60 microns to obtain a base vegetable oil, and keeping it at a constant temperature of 40° C. for 30-50 minutes; Step 7, mixing the base vegetable oil after heat preservation in step 6, the powdered petroleum resin and the viscosity index modifier in step 5, stirring at a constant temperature of 120° C. at a low speed of 200-350 rpm for 40-60 minutes to obtain a mixture I; Step 8, sodium polyacrylate, alginic acid and polyisobutylene are mixed, and stirred at a constant temperature of 40° C. at a low speed of 150-300 rpm for 10-30 min to obtain a crude thickener I; the crude thickener I is stirred at a high speed of 300-500 rpm for 30-50 min at a constant temperature of 60° C. to obtain a crude thickener II; the pH value of the crude thickener II is adjusted to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain a crude thickener; the crude thickener is stirred at a constant temperature of 40° C. at a low speed of 100-200 rpm for 5-10 min to obtain a thickener; Step 9, adding the thickener described in step 8 to the mixture I described in step 7, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain a mixture II; then stirring at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain a mixture III, and keeping the mixture III at a constant temperature of 40°C for 30-50 minutes; Step 10, stirring 1,2-hydroxystearic acid and recovered vegetable oil at 80-90° C. and 100-200 rrpm for 10-20 min to obtain an intermediate product, adding 5% lime milk to the intermediate product and drying it at 100-110° C. for 10-20 min to obtain a calcium-based grease; Step 11, stirring an organic lubricant composed of organic montmorillonite, talc, and organic bentonite, and a calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder in a blender at a low speed of 50-100 rpm for 5-10 minutes to obtain a filler; Step 12, adding the calcium-based grease described in step 10 and the filler described in step 11 to the mixture III after the insulation described in step 9, stirring at a low speed of 150-300 rpm for 20-40 minutes at a constant temperature of 90° C. to obtain a mixture IV; Step 13, adding a reinforcing agent consisting of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, stirring at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40° C. to obtain a mixture V; Step 14, adding the composite modified additive consisting of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, stirring at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40°C to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0022] Beneficial effects of the present invention: 1. The present invention provides shield tail sealing grease for coping with high water pressure. The present invention uses organic montmorillonite, recycled vegetable oil, and viscosity index modifier to construct an organic nanocomposite composed of grease and inorganic filler, so that the grease of the present invention exhibits excellent water pressure resistance and sealing performance under high water pressure conditions; the present invention selects different curling rates and fiber lengths according to the different characteristics of wood fiber, cotton fiber, and bamboo fiber, so that the reinforcing agent forms a good blanket-like three-dimensional space skeleton in the grease, so that the grease of the present invention can withstand higher water pressure; the present invention uses the long-chain molecules of polyisobutylene in the thickener to interweave with the network structure of alginate and sodium polyacrylate to form a more stable three-dimensional network, so that the grease of the present invention can still maintain good sealing performance under high water pressure; 2. The present invention provides a shield tail sealing grease that maintains good pumpability while ensuring water pressure resistance and sealing. The present invention utilizes organic montmorillonite and light calcium carbonate with a smaller particle size added to the filler to achieve excellent pumpability. The lamellar structure of the organic montmorillonite makes it more susceptible to shear slippage, and the fine light calcium carbonate can reduce the friction between the grease and the pumping pipeline. The present invention adds 0.5-1 mm wood fiber to the enhancer, and utilizes its good liquid coercive force to allow the grease to maintain uniformity and good fluidity during the pumping process, thereby enhancing the pumpability of the grease of the present invention; 3. The present invention provides a shield tail sealing grease that can resist groundwater with high ion concentration, seawater and sand gushing. The present invention utilizes calcium-based grease, polymerized rosin and sodium polyacrylate to enable the shield tail sealing grease to maintain good consistency in a water environment and stably adhere to the shield tail brush, thereby maintaining good resistance to groundwater and seawater. By increasing the proportion of polyisobutylene, the present invention makes the grease of the present invention have good chemical stability and acid and alkali resistance, and can cope with different groundwater and seawater erosion. The present invention utilizes alginate and calcium-based grease to undergo a cross-linking reaction to form a gel structure, which effectively enhances the water-blocking and sand-blocking properties of the grease and copes with the problem of sand gushing in engineering; 4. The present invention provides a shield tail sealing grease that is pollution-free to the environment. The present invention uses recycled vegetable oil as the base oil, adds polymerized rosin to the viscosity index modifier, adds alginic acid to the thickener, uses natural plant fiber as a reinforcing agent, natural mineral materials as a filler, and plant mildew preventer thymol, thereby reducing the proportion of non-natural materials in the formula and achieving green, environmentally friendly and degradable properties. The grease of the present invention has low content of heavy metal ions of arsenic, cadmium and mercury, does not contain toxic benzene organic matter, and effectively reduces the impact on surrounding soil, groundwater and seawater; 5. The present invention provides a shield tail sealing grease that helps reduce the wear, deformation and rust of the shield tail brush. The present invention utilizes the extreme pressure anti-wear property of zinc dialkyl dithiophosphate in the composite modification additive and the excellent lubricity of calcium-based grease to reduce the friction of the shield tail brush, and utilizes the antioxidant property of polymerized rosin in the viscosity index modifier to reduce the oxidation rust of the shield tail brush, thereby increasing the service life of the shield tail brush; 6. The present invention provides a shield tail sealing grease with high economic benefits and the ability to reduce construction costs. The present invention reduces the cost of shield tail sealing grease by using recycled vegetable oil, and uses a polymer compound with good rheological properties and a gel network structure formed by polyisobutylene, alginic acid, and sodium polyacrylate to enhance the adhesion of grease to the shield tail brush, thereby reducing the consumption of grease during the construction process and reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic diagram of the preparation process of the environmentally friendly shield tail sealing grease for high water pressure shield tunnels. DETAILED DESCRIPTION

[0024] The following embodiments will demonstrate and illustrate the concept, technical solution and purpose of the present invention. The present invention can be better understood by combining the drawings and embodiments. The following embodiments are obviously only representative examples of the present invention and play a certain role in explaining the present invention.

[0025] Example 1: Environmentally friendly shield tail sealing grease for high water pressure shield tunnel and preparation method Its components and mass fractions are as follows: 240 pieces of soybean oil were recovered C5 petroleum resin 65 parts Enhancer 45 parts Viscosity index modifier 50 parts Thickener 140 parts Filler 575 parts Calcium-based grease 20 parts 15 parts of composite modified admixture The preparation method is as follows: Step 1, drying polyisobutylene in a vacuum drying oven at 50-60° C. for 40-60 minutes to obtain refined polyisobutylene; drying polyisoprene in a vacuum drying oven at 60-70° C. for 40-60 minutes to obtain refined polyisoprene; Step 2, putting the refined polyisobutylene and refined polyisoprene described in step 1 into a reaction kettle, stirring at a low speed of 100-300 rpm for 40-60 min at a constant temperature of 90° C. to obtain a mixed group I; Step 3, putting the polymerized rosin into a pulverizer and pulverizing it into particles with a diameter of 1-3 mm to obtain powdered polymerized rosin; adding the powdered polymerized rosin to the mixed group I described in step 2, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 120° C. to obtain a mixed group II; Step 4, drying the succinimide under nitrogen protection at a temperature of 40-50° C. for 40-60 min to obtain refined succinimide, adding the refined succinimide to the mixing group II described in step 3, stirring at a low speed of 200-300 rpm for 60-90 min, at a temperature of 150° C. and a pressure of 0.5 MPa to obtain a crude viscosity index modifier; Step 5, filtering the crude viscosity index modifier in step 4 through a filter with a pore size of 1-5 microns to obtain a viscosity index modifier; Step 6, grinding the C5 petroleum resin in a grinder at high speed for 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, and a rotation speed of 1000-1200 rpm to obtain a powdered petroleum resin; filtering the recovered vegetable oil through a filter with a pore size of 40-60 microns to obtain a base vegetable oil, and keeping it at a constant temperature of 40° C. for 30-50 minutes; Step 7, mixing the base vegetable oil after heat preservation in step 6, the powdered petroleum resin and the viscosity index modifier in step 5, stirring at a constant temperature of 120° C. at a low speed of 200-350 rpm for 40-60 minutes to obtain a mixture I; Step 8, sodium polyacrylate, alginic acid and polyisobutylene are mixed, and stirred at a constant temperature of 40° C. at a low speed of 150-300 rpm for 10-30 min to obtain a crude thickener I; the crude thickener I is stirred at a high speed of 300-500 rpm for 30-50 min at a constant temperature of 60° C. to obtain a crude thickener II; the pH value of the crude thickener II is adjusted to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain a crude thickener; the crude thickener is stirred at a constant temperature of 40° C. at a low speed of 100-200 rpm for 5-10 min to obtain a thickener; Step 9, adding the thickener described in step 8 to the mixture I described in step 7, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain a mixture II; then stirring at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain a mixture III, and keeping the mixture III at a constant temperature of 40°C for 30-50 minutes; Step 10, stirring 1,2-hydroxystearic acid and recovered vegetable oil at 80-90° C. and 100-200 rrpm for 10-20 min to obtain an intermediate product, adding 5% lime milk to the intermediate product and drying it at 100-110° C. for 10-20 min to obtain a calcium-based grease; Step 11, stirring an organic lubricant composed of organic montmorillonite, talc, and organic bentonite, and a calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder in a blender at a low speed of 50-100 rpm for 5-10 minutes to obtain a filler; Step 12, adding the calcium-based grease described in step 10 and the filler described in step 11 to the mixture III after the insulation described in step 9, stirring at a low speed of 150-300 rpm for 20-40 minutes at a constant temperature of 90° C. to obtain a mixture IV; Step 13, adding a reinforcing agent consisting of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, stirring at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40° C. to obtain a mixture V; Step 14, adding the composite modified additive consisting of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, stirring at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40°C to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0026] Example 2: Environmentally friendly shield tail sealing grease for high water pressure shield tunnel and preparation method Its components and mass fractions are as follows: 230 pieces of rapeseed oil were recovered 140 parts of viscosity index modifier 40 parts of C5 petroleum resin Enhancer 40 parts Thickener 40 parts Filler 640 parts Calcium-based grease 15 parts 20 copies of composite modified admixture The preparation method is as follows: Step 1, drying polyisobutylene in a vacuum drying oven at 50-60° C. for 40-60 minutes to obtain refined polyisobutylene; drying polyisoprene in a vacuum drying oven at 60-70° C. for 40-60 minutes to obtain refined polyisoprene; Step 2, putting the refined polyisobutylene and refined polyisoprene described in step 1 into a reaction kettle, stirring at a low speed of 100-300 rpm for 40-60 min at a constant temperature of 90° C. to obtain a mixed group I; Step 3, putting the polymerized rosin into a pulverizer and pulverizing it into particles with a diameter of 1-3 mm to obtain powdered polymerized rosin; adding the powdered polymerized rosin to the mixed group I described in step 2, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 120° C. to obtain a mixed group II; Step 4, drying the succinimide under nitrogen protection at a temperature of 40-50° C. for 40-60 min to obtain refined succinimide, adding the refined succinimide to the mixing group II described in step 3, stirring at a low speed of 200-300 rpm for 60-90 min, at a temperature of 150° C. and a pressure of 0.5 MPa to obtain a crude viscosity index modifier; Step 5, filtering the crude viscosity index modifier in step 4 through a filter with a pore size of 1-5 microns to obtain a viscosity index modifier; Step 6, grinding the C5 petroleum resin in a grinder at high speed for 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, and a rotation speed of 1000-1200 rpm to obtain a powdered petroleum resin; filtering the recovered vegetable oil through a filter with a pore size of 40-60 microns to obtain a base vegetable oil, and keeping it at a constant temperature of 40° C. for 30-50 minutes; Step 7, mixing the base vegetable oil after heat preservation in step 6, the powdered petroleum resin and the viscosity index modifier in step 5, stirring at a constant temperature of 120° C. at a low speed of 200-350 rpm for 40-60 minutes to obtain a mixture I; Step 8, sodium polyacrylate, alginic acid and polyisobutylene are mixed, and stirred at a constant temperature of 40° C. at a low speed of 150-300 rpm for 10-30 min to obtain a crude thickener I; the crude thickener I is stirred at a high speed of 300-500 rpm for 30-50 min at a constant temperature of 60° C. to obtain a crude thickener II; the pH value of the crude thickener II is adjusted to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain a crude thickener; the crude thickener is stirred at a constant temperature of 40° C. at a low speed of 100-200 rpm for 5-10 min to obtain a thickener; Step 9, adding the thickener described in step 8 to the mixture I described in step 7, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain a mixture II; then stirring at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain a mixture III, and keeping the mixture III at a constant temperature of 40°C for 30-50 minutes; Step 10, stirring 1,2-hydroxystearic acid and recovered vegetable oil at 80-90° C. and 100-200 rrpm for 10-20 min to obtain an intermediate product, adding 5% lime milk to the intermediate product and drying it at 100-110° C. for 10-20 min to obtain a calcium-based grease; Step 11, stirring an organic lubricant composed of organic montmorillonite, talc, and organic bentonite, and a calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder in a blender at a low speed of 50-100 rpm for 5-10 minutes to obtain a filler; Step 12, adding the calcium-based grease described in step 10 and the filler described in step 11 to the mixture III after the insulation described in step 9, stirring at a low speed of 150-300 rpm for 20-40 minutes at a constant temperature of 90° C. to obtain a mixture IV; Step 13, adding a reinforcing agent consisting of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, stirring at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40° C. to obtain a mixture V; Step 14, adding the composite modified additive consisting of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, stirring at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40°C to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0027] Example 3: Environmentally friendly shield tail sealing grease for high water pressure shield tunnel and preparation method Its components and mass fractions are as follows: 230 pieces of soybean oil were recovered C5 petroleum resin 20 parts 70 parts of viscosity index modifier Enhancer 30 parts Thickener 120 parts Filler 600 parts Calcium-based grease 20 parts 15 parts of composite modified admixture The preparation method is as follows: Step 1, drying polyisobutylene in a vacuum drying oven at 50-60° C. for 40-60 minutes to obtain refined polyisobutylene; drying polyisoprene in a vacuum drying oven at 60-70° C. for 40-60 minutes to obtain refined polyisoprene; Step 2, putting the refined polyisobutylene and refined polyisoprene described in step 1 into a reaction kettle, stirring at a low speed of 100-300 rpm for 40-60 min at a constant temperature of 90° C. to obtain a mixed group I; Step 3, putting the polymerized rosin into a pulverizer and pulverizing it into particles with a diameter of 1-3 mm to obtain powdered polymerized rosin; adding the powdered polymerized rosin to the mixed group I described in step 2, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 120° C. to obtain a mixed group II; Step 4, drying the succinimide under nitrogen protection at a temperature of 40-50° C. for 40-60 min to obtain refined succinimide, adding the refined succinimide to the mixing group II described in step 3, stirring at a low speed of 200-300 rpm for 60-90 min, at a temperature of 150° C. and a pressure of 0.5 MPa to obtain a crude viscosity index modifier; Step 5, filtering the crude viscosity index modifier in step 4 through a filter with a pore size of 1-5 microns to obtain a viscosity index modifier; Step 6, grinding the C5 petroleum resin in a grinder at high speed for 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, and a rotation speed of 1000-1200 rpm to obtain a powdered petroleum resin; filtering the recovered vegetable oil through a filter with a pore size of 40-60 microns to obtain a base vegetable oil, and keeping it at a constant temperature of 40° C. for 30-50 minutes; Step 7, mixing the base vegetable oil after heat preservation in step 6, the powdered petroleum resin and the viscosity index modifier in step 5, stirring at a constant temperature of 120° C. at a low speed of 200-350 rpm for 40-60 minutes to obtain a mixture I; Step 8, sodium polyacrylate, alginic acid and polyisobutylene are mixed, and stirred at a constant temperature of 40° C. at a low speed of 150-300 rpm for 10-30 min to obtain a crude thickener I; the crude thickener I is stirred at a high speed of 300-500 rpm for 30-50 min at a constant temperature of 60° C. to obtain a crude thickener II; the pH value of the crude thickener II is adjusted to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain a crude thickener; the crude thickener is stirred at a constant temperature of 40° C. at a low speed of 100-200 rpm for 5-10 min to obtain a thickener; Step 9, adding the thickener described in step 8 to the mixture I described in step 7, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain a mixture II; then stirring at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain a mixture III, and keeping the mixture III at a constant temperature of 40°C for 30-50 minutes; Step 10, stirring 1,2-hydroxystearic acid and recovered vegetable oil at 80-90° C. and 100-200 rrpm for 10-20 min to obtain an intermediate product, adding 5% lime milk to the intermediate product and drying it at 100-110° C. for 10-20 min to obtain a calcium-based grease; Step 11, stirring an organic lubricant composed of organic montmorillonite, talc, and organic bentonite, and a calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder in a blender at a low speed of 50-100 rpm for 5-10 minutes to obtain a filler; Step 12, adding the calcium-based grease described in step 10 and the filler described in step 11 to the mixture III after the insulation described in step 9, stirring at a low speed of 150-300 rpm for 20-40 minutes at a constant temperature of 90° C. to obtain a mixture IV; Step 13, adding a reinforcing agent consisting of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, stirring at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40° C. to obtain a mixture V; Step 14, adding the composite modified additive consisting of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, stirring at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40°C to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0028] Example 4: Environmentally friendly shield tail sealing grease for high water pressure shield tunnel and preparation method Its components and mass fractions are as follows: 240 pieces of soybean oil were recovered Viscosity index modifier 90 parts C5 petroleum resin 20 parts Enhancer 55 parts Thickener 70 parts Filler 510 parts Calcium-based grease 25 parts 25 parts of composite modified admixture The preparation method is as follows: Step 1, drying polyisobutylene in a vacuum drying oven at 50-60° C. for 40-60 minutes to obtain refined polyisobutylene; drying polyisoprene in a vacuum drying oven at 60-70° C. for 40-60 minutes to obtain refined polyisoprene; Step 2, putting the refined polyisobutylene and refined polyisoprene described in step 1 into a reaction kettle, stirring at a low speed of 100-300 rpm for 40-60 min at a constant temperature of 90° C. to obtain a mixed group I; Step 3, putting the polymerized rosin into a pulverizer and pulverizing it into particles with a diameter of 1-3 mm to obtain powdered polymerized rosin; adding the powdered polymerized rosin to the mixed group I described in step 2, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 120° C. to obtain a mixed group II; Step 4, drying the succinimide under nitrogen protection at a temperature of 40-50° C. for 40-60 min to obtain refined succinimide, adding the refined succinimide to the mixing group II described in step 3, stirring at a low speed of 200-300 rpm for 60-90 min, at a temperature of 150° C. and a pressure of 0.5 MPa to obtain a crude viscosity index modifier; Step 5, filtering the crude viscosity index modifier in step 4 through a filter with a pore size of 1-5 microns to obtain a viscosity index modifier; Step 6, grinding the C5 petroleum resin in a grinder at high speed for 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, and a rotation speed of 1000-1200 rpm to obtain a powdered petroleum resin; filtering the recovered vegetable oil through a filter with a pore size of 40-60 microns to obtain a base vegetable oil, and keeping it at a constant temperature of 40° C. for 30-50 minutes; Step 7, mixing the base vegetable oil after heat preservation in step 6, the powdered petroleum resin and the viscosity index modifier in step 5, stirring at a constant temperature of 120° C. at a low speed of 200-350 rpm for 40-60 minutes to obtain a mixture I; Step 8, sodium polyacrylate, alginic acid and polyisobutylene are mixed, and stirred at a constant temperature of 40° C. at a low speed of 150-300 rpm for 10-30 min to obtain a crude thickener I; the crude thickener I is stirred at a high speed of 300-500 rpm for 30-50 min at a constant temperature of 60° C. to obtain a crude thickener II; the pH value of the crude thickener II is adjusted to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain a crude thickener; the crude thickener is stirred at a constant temperature of 40° C. at a low speed of 100-200 rpm for 5-10 min to obtain a thickener; Step 9, adding the thickener described in step 8 to the mixture I described in step 7, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain a mixture II; then stirring at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain a mixture III, and keeping the mixture III at a constant temperature of 40°C for 30-50 minutes; Step 10, stirring 1,2-hydroxystearic acid and recovered vegetable oil at 80-90° C. and 100-200 rrpm for 10-20 min to obtain an intermediate product, adding 5% lime milk to the intermediate product and drying it at 100-110° C. for 10-20 min to obtain a calcium-based grease; Step 11, stirring an organic lubricant composed of organic montmorillonite, talc, and organic bentonite, and a calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder in a blender at a low speed of 50-100 rpm for 5-10 minutes to obtain a filler; Step 12, adding the calcium-based grease described in step 10 and the filler described in step 11 to the mixture III after the insulation described in step 9, stirring at a low speed of 150-300 rpm for 20-40 minutes at a constant temperature of 90° C. to obtain a mixture IV; Step 13, adding a reinforcing agent consisting of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, stirring at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40° C. to obtain a mixture V; Step 14, adding the composite modified additive consisting of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, stirring at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40°C to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

[0029] Comparative Example 1: The invention is composed of the following materials in parts by mass: 250 parts of 150N mineral oil, 150 parts of polyisobutylene, 50 parts of fiber, 210 parts of organic bentonite, 310 parts of heavy calcium carbonate, and 80 parts of calcium-based grease. The difference between the invention 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 organic montmorillonite, light calcium carbonate and mica powder; and no modifying admixture is added.

[0030] Comparative Example 2: The invention is composed of the following materials by weight: 230 parts of 150N mineral oil, 170 parts of polyisobutylene, 50 parts of fiber, 40 parts of organic bentonite, 230 parts of light calcium carbonate, 270 parts of heavy calcium carbonate, 20 parts of mica powder, 20 parts of organic montmorillonite, and 70 parts of calcium-based grease. The difference between the invention 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 only contains 1-2 mm wood fiber and 2-3 mm wood fiber.

[0031] The performance of the embodiments and comparative examples is shown in Table 1 Table 1 Water breakdown pressure / (MPa) Water flow resistance (%) Pumpability / (g / min) <![CDATA[Penetration / (×10 -1 mm)]]> Example 1 7 ≤2.0 31.5 230 Example 2 7 ≤1.8 28.5 220 Example 3 7 ≤1.8 29.3 225 Example 4 7 ≤1.8 29.5 225 Comparative Example 1 3.5 ≤3.5 17.3 215 Comparative Example 2 4.0 ≤3.5 18.4 210 It can be seen from the test data in Table 1 that the present invention exhibits good water pressure resistance, pumpability and adhesion. In the development of shield tail sealing grease, it is often difficult to achieve a balance between water pressure resistance and pumpability. Because the most effective way to improve the water pressure resistance of shield tail sealing grease is to increase its consistency, but grease that is too viscous cannot meet the corresponding pumping requirements. The present invention application has achieved a good balance between water pressure resistance, pumpability and adhesion, which is conducive to engineering construction convenience, energy saving, green environmental protection, and pollution reduction, and provides a new solution for the complex working conditions faced by high water pressure shield tunnel construction.

[0032] The differences in base oil, viscosity index modifier, and filler in Comparative Example 1 and the differences in base oil, viscosity index modifier, and enhancer in Comparative Example 2 and the examples result in the performance of the comparative examples being significantly lower than that of the examples. The difference in fillers in Comparative Example 1 results in its water pressure resistance being much lower than that of the examples, and the difference in enhancers in Comparative Example 2 results in its microstructure difference, resulting in the water pressure resistance of pumpability being much lower than that of the examples. At the same time, the composite modified additive also extends the service life of the shield tail brush and reduces the storage conditions of the grease. The improved preparation process is also one of the factors causing the performance differences.

[0033] The above examples are only for illustration of the present invention and do not limit the present invention. The protection scope of the present invention is not limited to the above examples, and all technical solutions under the concept of the present invention belong to the protection scope of the present invention.

Claims

1. Environmentally friendly shield tail sealing grease for high water pressure shield tunnels, characterized by: The environmentally friendly shield tail sealing grease for high water pressure shield tunnel is composed of the following components by mass: 240-305 parts of base oil, 25-140 parts of viscosity index modifier, 40-140 parts of thickener, 510-640 parts of filler, 30-55 parts of enhancer, 10-35 parts of calcium-based grease, and 8-35 parts of composite modification additive; The base oil is a mixture of recycled vegetable oil and C5 petroleum resin, the mass fraction of the recycled vegetable oil is 168-290 parts, the mass fraction of the C5 petroleum resin is 12-92 parts, and the recycled vegetable oil is recycled soybean oil or recycled rapeseed oil; The viscosity index modifier is a mixture of polyisobutylene, polymerized rosin, succinimide and polyisoprene, wherein the mass fraction of polyisobutylene is 17-70 parts, the mass fraction of polymerized 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, alginic acid and sodium polyacrylate, wherein the mass fraction of polyisobutylene is 18-70 parts, the mass fraction of alginic acid is 8-68 parts, and the mass fraction of sodium polyacrylate is 4-55 parts; The filler is a mixture of an organic lubricant and a calcium filler, wherein the mass fraction of the organic lubricant is 30-192 parts, and the mass fraction of the calcium filler is 357-579 parts; wherein the organic lubricant is a mixture of organic montmorillonite, talcum powder, and organic bentonite, wherein the mass fraction of the organic montmorillonite is 7-39 parts, the mass fraction of the talcum powder is 0-67 parts, and the mass fraction of the organic bentonite is 20-172 parts; the calcium filler is a mixture of light calcium carbonate, heavy calcium carbonate, and mica powder, wherein the mass fraction of the light calcium carbonate is 142-290 parts, the mass fraction of the heavy calcium carbonate is 142-290 parts, and the mass fraction of the mica powder is 0-115 parts; The reinforcing agent is a mixture of wood fiber, cotton fiber and bamboo fiber, wherein the weight fraction of wood fiber is 6-22 parts, the weight fraction of cotton fiber is 9-22 parts, and the weight fraction of bamboo fiber is 6-22 parts; The calcium-based grease is made of 1,2-hydroxystearic acid and 5% lime milk thickened recycled vegetable oil, wherein the mass fraction of the recycled vegetable oil is 8-28 parts, the mass fraction of 1,2-hydroxystearic acid is 1-3 parts, and the mass fraction of 5% lime milk is 2-6 parts; The composite modification additive 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.

2. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is characterized in that The preparation method is as follows: Step 1, drying polyisobutylene in a vacuum drying oven at 50-60° C. for 40-60 minutes to obtain refined polyisobutylene; drying polyisoprene in a vacuum drying oven at 60-70° C. for 40-60 minutes to obtain refined polyisoprene; Step 2, putting the refined polyisobutylene and refined polyisoprene described in step 1 into a reaction kettle, stirring at a low speed of 100-300 rpm for 40-60 min at a constant temperature of 90° C. to obtain a mixed group I; Step 3, putting the polymerized rosin into a pulverizer and pulverizing it into particles with a diameter of 1-3 mm to obtain powdered polymerized rosin; adding the powdered polymerized rosin to the mixed group I described in step 2, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 120° C. to obtain a mixed group II; Step 4, drying the succinimide under nitrogen protection at a temperature of 40-50° C. for 40-60 min to obtain refined succinimide, adding the refined succinimide to the mixing group II described in step 3, stirring at a low speed of 200-300 rpm for 60-90 min, at a temperature of 150° C. and a pressure of 0.5 MPa to obtain a crude viscosity index modifier; Step 5, filtering the crude viscosity index modifier in step 4 through a filter with a pore size of 1-5 microns to obtain a viscosity index modifier; Step 6, grinding the C5 petroleum resin in a grinder at high speed for 5 times, each time for 45-75 seconds, with an interval of 40-60 seconds, and a rotation speed of 1000-1200 rpm to obtain a powdered petroleum resin; filtering the recovered vegetable oil through a filter with a pore size of 40-60 microns to obtain a base vegetable oil, and keeping it at a constant temperature of 40° C. for 30-50 minutes; Step 7, mixing the base vegetable oil after heat preservation in step 6, the powdered petroleum resin and the viscosity index modifier in step 5, stirring at a constant temperature of 120° C. at a low speed of 200-350 rpm for 40-60 minutes to obtain a mixture I; Step 8, sodium polyacrylate, alginic acid and polyisobutylene are mixed, and stirred at a constant temperature of 40° C. at a low speed of 150-300 rpm for 10-30 min to obtain a crude thickener I; the crude thickener I is stirred at a high speed of 300-500 rpm for 30-50 min at a constant temperature of 60° C. to obtain a crude thickener II; the pH value of the crude thickener II is adjusted to 7-8 using dilute hydrochloric acid or sodium hydroxide to obtain a crude thickener; the crude thickener is stirred at a constant temperature of 40° C. at a low speed of 100-200 rpm for 5-10 min to obtain a thickener; Step 9, adding the thickener described in step 8 to the mixture I described in step 7, stirring at a low speed of 150-300 rpm for 40-60 minutes at a constant temperature of 80°C to obtain a mixture II; then stirring at a high speed of 150-300 rpm for 10-20 minutes at a constant temperature of 40°C to obtain a mixture III, and keeping the mixture III at a constant temperature of 40°C for 30-50 minutes; Step 10, stirring 1,2-hydroxystearic acid and recovered vegetable oil at 80-90° C. and 100-200 rrpm for 10-20 min to obtain an intermediate product, adding 5% lime milk to the intermediate product and drying it at 100-110° C. for 10-20 min to obtain a calcium-based grease; Step 11, stirring an organic lubricant composed of organic montmorillonite, talc, and organic bentonite, and a calcium filler composed of heavy calcium carbonate, light calcium carbonate, and mica powder in a blender at a low speed of 50-100 rpm for 5-10 minutes to obtain a filler; Step 12, adding the calcium-based grease described in step 10 and the filler described in step 11 to the mixture III after the insulation described in step 9, stirring at a low speed of 150-300 rpm for 20-40 minutes at a constant temperature of 90° C. to obtain a mixture IV; Step 13, adding a reinforcing agent consisting of wood fiber, cotton fiber and bamboo fiber to the mixture IV described in step 12, stirring at a low speed of 150-300 rpm for 20-40 min at a temperature of 30-40° C. to obtain a mixture V; Step 14, adding the composite modified additive consisting of thymol, zinc borate and zinc dialkyl dithiophosphate to the mixture V described in step 13, stirring at a low speed of 150-300 rpm for 15-30 minutes at a temperature of 30-40°C to obtain the environmentally friendly shield tail sealing grease for high water pressure shield tunnels.

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

4. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is 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, the density of the selected polymerized rosin at 20°C is about 1.08-1.1 g / cm³, and the softening point is 90°C.

5. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is characterized in that In the thickener, the molecular weight of polyisobutylene is greater than 2000, the density at 25°C is about 0.85-0.92 g / cm³, and the kinematic viscosity at 100°C is about 240-250 mm 2 / s.

6. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is characterized in that: Among the fillers, preferably, 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 particle size of heavy calcium carbonate is 625 mesh; 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.

7. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is characterized in that: Preferably, the curl shrinkage rate of the wood fiber is 20%~40%, the curl shrinkage rate of the cotton fiber is 60%~70%, and the curl 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: 3~4mm cotton fiber = (2-4): (1-3): (1-2): (1-2).

8. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is characterized in that The composite modified additive comprises thymol:zinc borate:zinc dialkyl dithiophosphate=(1-2):(1-3):(1-2).

9. As claimed in claim 1, the environmentally friendly shield tail sealing grease for high water pressure shield tunnel is characterized in that It is particularly suitable for high water pressure shield tunnel projects. It exhibits good water pressure sealing and pumpability under the conditions of high water pressure (greater than 4.0MPa) and high formation permeability (greater than 50m / day). The material formula and preparation method of environmentally friendly shield tail sealing grease are proposed for high water pressure shield tunnel projects.

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