CN118085940B - Shield tail lubricating grease for shield tunneling machine and preparation method thereof - Google Patents

Abstract

The present invention relates to the technical field of lubricating grease, and in particular to a shield tail lubricating grease for a shield machine and a preparation method thereof, which comprises the following components by weight: 25-55 parts of base oil, 10-25 parts of fiber material, 20-40 parts of filler, 10-30 parts of viscosity promoter and 15-25 parts of lubricant, wherein the lubricant is a modified nano-silicon dioxide-modified graphene composite material. The present invention adopts a shield tail lubricating grease for a shield machine with the above structure and a preparation method thereof, which solves the problems of low lubricity, poor adhesion and low pumping efficiency of the shield tail lubricating grease in the prior art.

Description

Shield tail lubricating grease for shield tunneling machine and preparation method thereof

Technical Field

The invention relates to the technical field of lubricating grease, in particular to shield tail lubricating grease for a shield machine and a preparation method thereof.

Background

At present, the underground traffic of China develops rapidly, and the construction method adopted at present is a shield method or a pipe jacking method in order to be able to construct underground engineering under the condition of not influencing the established ground building. The shield machine is a construction machine tool for constructing tunnels, and can play a role in excavating stratum and supporting when assembling lining.

In the construction process of the shield tunneling machine, shield tail lubricating grease is applied to a shield tunneling machine tail sealing device, plays roles of lubrication, waterproof sealing, corrosion resistance and the like, can effectively isolate groundwater, slurry and protect a shield tail brush, is a key material in the construction process of the shield, and directly influences the safety of construction.

However, the shield tail lubricating grease in the prior art has low lubricity, poor adhesiveness and low pumping efficiency, so that the friction force between the shield tail and the pipe piece cannot be well reduced, and the waterproof effect of the sealing layer and the filling effect of the sealing layer are affected.

Disclosure of Invention

The invention aims to provide shield tail lubricating grease for a shield machine and a preparation method thereof, and solves the problems of low lubricating property, poor adhesion and low pumping efficiency of shield tail lubricating grease in the prior art.

The invention provides shield tail lubricating grease for a shield machine, which comprises, by weight, 25-55 parts of base oil, 10-25 parts of fiber materials, 20-40 parts of fillers, 10-30 parts of viscosity promoters and 15-25 parts of lubricants, wherein the lubricants are modified nano silicon dioxide-modified graphene composite materials.

Preferably, the base oil is one or more of mineral oil, vegetable oil or synthetic oil. The source of the base oil is not particularly limited in the present invention, and commercially available products well known to those skilled in the art may be used.

Still more preferably, the mineral oil comprises one or more of naphthenic base oil, paraffinic base oil.

Still more preferably, the vegetable oil comprises one or more of corn oil, soybean oil, peanut oil, and castor oil.

Still more preferably, the synthetic oil comprises one or more of pentaerythritol ester, dioctyl terephthalate, and poly-alpha-olefin synthetic oil.

Preferably, the fibrous material is degradable wood fiber, and the length of the fibrous material is 0.1-2mm. The present invention is not particularly limited to the source of the fibrous material and may be practiced using commercially available products known to those skilled in the art.

Preferably, the filler comprises one or more of light calcium carbonate, bentonite, kaolin, mica and talcum powder. The present invention has no particular requirement for the source of the filler and may be practiced using commercially available products well known to those skilled in the art.

Preferably, the viscosity promoter is one or more of polyacrylamide, N-dimethylacrylamide, 2-hydroxysuccinic acid, and 3-hydroxy-1, 3, 5-pentanetriac acid. According to the invention, the viscosity of the grease is improved by adding the viscosity accelerator, so that the adhesiveness and the sealing property of the shield tail grease are improved.

Preferably, the modified nano-silica-modified graphene composite material comprises silane coupling agent modified nano-silica and silane coupling agent modified multi-layer graphene oxide. According to the invention, the modified nano silicon dioxide-modified graphene composite material is used as a lubricant, so that the lubricating property of the shield tail lubricating grease is improved through the lubricating property of the nano silicon dioxide and graphene, the friction force between the shield tail and the duct piece is reduced, and the pumping property of the shield tail lubricating grease is also improved.

According to the lubricant disclosed by the invention, the multilayer graphene oxide is taken as a skeleton, the nano silicon dioxide is grafted to the surface of the graphene, so that the dispersibility of the graphene in the base grease is improved, the graphene is prevented from being subjected to coagulation or agglomeration, and the nano silicon dioxide and the multilayer graphene oxide are grafted and modified through the silane coupling agent, so that the surfaces of the nano silicon dioxide and the multilayer graphene oxide have more crosslinking group numbers, the grafting rate of the nano silicon dioxide and the graphene is improved, the bonding capability of the nano silicon dioxide and the graphene to the base grease is further improved, the toughness and the bonding strength of the shield tail grease are enhanced, and the adhesive force of the shield tail grease is improved.

A preparation method of shield tail lubricating grease of a shield machine comprises the following steps:

(1) Adding a viscosity promoter into base oil, stirring at normal temperature until the base oil and the viscosity promoter are completely and uniformly mixed, and stopping stirring to obtain a mixture of the base oil and the viscosity promoter;

(2) Adding lubricant into the mixture of base oil and viscosity promoter, stirring for 1-1.5 hr, adding fiber material and filler, and stirring for 2-3 hr to obtain Shield tail grease.

Preferably, the preparation of the lubricant in (2) comprises the steps of:

S1, preparing modified nano silicon dioxide, dispersing nano silicon dioxide powder into an ethanol solution to prepare a suspension A, adding sodium hydroxide into the suspension A to adjust the pH, mixing a silane coupling agent and methyl methacrylate, dripping the mixture into the suspension A, raising the temperature to 80-90 ℃, dispersing the mixture for 2-3 hours under magnetic stirring, and cooling the mixture to room temperature to prepare modified nano silicon dioxide suspension;

S2, preparing modified graphene, namely adding the multilayer graphene oxide into absolute ethyl alcohol to prepare a suspension B, adding oxalic acid into the suspension B to adjust the pH, mixing a silane coupling agent with the absolute ethyl alcohol, dropwise adding the mixture into the suspension B, magnetically stirring the mixture at 40-60 ℃ to react for 5-6 hours, centrifuging, and drying to obtain the modified multilayer graphene oxide;

and S3, carrying out hydrolysis reaction on the modified nano silicon dioxide suspension and the modified multilayer graphene oxide in an ethanol solution to obtain the modified graphene composite material loaded with the modified nano silicon dioxide.

Preferably, the solid-liquid ratio of the nano silicon dioxide to the ethanol solution in S1 is 1:40-50, the mass fraction of sodium hydroxide is 8%, the pH is 7-8, the solid-liquid ratio of the multi-layer graphene oxide to the absolute ethanol in S2 is 1:40-50, and the pH is 5-6.

Preferably, the hydrolysis reaction in S3 is to mix the modified nano silicon dioxide suspension and the modified multi-layer graphene oxide with ethanol solution, pre-hydrolyze the mixture for 40-80 hours under the acidic condition at 15-35 ℃, and then continue hydrolyzing the mixture for 1-2 hours under the alkaline condition at 50-80 ℃.

The invention has the beneficial effects that:

According to the invention, the base oil, the fiber material and the filler are used as the base raw materials, the viscosity accelerator is added to improve the adhesion of the shield tail lubricating grease, the lubricant is added to improve the lubricity and the pumping performance of the shield tail lubricating grease, the lubricant used in the invention is a composite material of nano silicon dioxide modified by a silane coupling agent and multi-layer graphene oxide modified by the silane coupling agent, the lubricity of the shield tail lubricating grease is improved by the nano silicon dioxide and the graphene, the graphene is used as a framework, the nano silicon dioxide is loaded on the graphene, the dispersibility of the graphene and the silicon dioxide is improved, the nano silicon dioxide and the multi-layer graphene oxide are both modified by the silane coupling agent, the dispersibility of the nano silicon dioxide and the multi-layer graphene oxide is further improved, and the binding capacity of the nano silicon dioxide and the multi-layer graphene oxide with the base grease is improved, so that the adhesion of the shield tail lubricating grease is also improved. Namely, the shield tail lubricating grease prepared by the invention has excellent lubricity, pumpability and adhesion, low manufacturing cost, can be widely applied to shield engineering,

The technical scheme of the invention is further described in detail through examples.

Detailed Description

The invention is further described below by way of examples. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The above-mentioned features of the invention or the features mentioned in the specific examples can be combined in any desired manner, and these specific examples are only intended to illustrate the invention and are not intended to limit the scope of the invention.

The lubricant used in the invention is prepared by the following steps:

s1, preparing modified nano silicon dioxide, dispersing nano silicon dioxide powder into ethanol solution according to a solid-to-liquid ratio of 1:45 to prepare suspension A, adding sodium hydroxide with a mass fraction of 8% into the suspension A, and adjusting pH to 8;

S2, preparing modified graphene, namely adding the multilayer graphene oxide into absolute ethyl alcohol according to a solid-to-liquid ratio of 1:45 to prepare a suspension B, adding oxalic acid into the suspension B to adjust the pH to 6, mixing a silane coupling agent with the absolute ethyl alcohol, dropwise adding the mixture into the suspension B, magnetically stirring the mixture at 50 ℃ to react for 6 hours, and centrifuging and drying the mixture to obtain the modified multilayer graphene oxide;

And S3, mixing the modified nano silicon dioxide suspension and the modified multilayer graphene oxide with an ethanol solution, carrying out a prehydrolysis reaction for 60 hours under an acidic condition at 35 ℃, and then carrying out a continuous hydrolysis reaction for 2 hours under an alkaline condition at 72 ℃ to obtain the modified graphene composite material loaded with the modified nano silicon dioxide. I.e. the lubricant used in the present invention.

Example 1

The invention provides shield tail lubricating grease for a shield machine, which comprises the following components in parts by weight of 25 parts of cycloalkyl base oil, 10 parts of degradable wood fiber, 20 parts of light calcium carbonate, 10 parts of polyacrylamide and 15 parts of lubricant.

Example 2

The invention provides shield tail lubricating grease for a shield machine, which comprises the following components in parts by weight of 30 parts of soybean oil, 15 parts of degradable wood fibers, 25 parts of light calcium carbonate, 15 parts of polyacrylamide and 20 parts of lubricant.

Example 3

The invention provides shield tail lubricating grease for a shield machine, which comprises the following components in parts by weight of 35 parts of pentaerythritol ester, 20 parts of degradable wood fiber, 30 parts of mica, 20 parts of N, N-dimethylacrylamide and 20 parts of lubricant.

Example 4

The invention provides shield tail lubricating grease for a shield machine, which comprises the following components in parts by weight of 40 parts of paraffin-based base oil, 25 parts of degradable wood fiber, 35 parts of talcum powder, 25 parts of 2-hydroxysuccinic acid and 20 parts of lubricant.

Example 5

The invention provides shield tail lubricating grease for a shield machine, which comprises the following components, by weight, 55 parts of poly-alpha-olefin synthetic oil, 25 parts of degradable wood fibers, 40 parts of talcum powder, 30 parts of 3-hydroxy-1, 3, 5-glutaric acid and 25 parts of lubricant.

Example 6

Based on example 1, the preparation method of the shield tail lubricating grease for the shield machine provided by the invention comprises the following steps:

(1) 10 parts of polyacrylamide is first added to 25 parts of cycloalkyl base oil,

Stirring at normal temperature until the naphthenic base oil and the polyacrylamide are completely and uniformly mixed, and stopping stirring to obtain a base oil and viscosity promoter mixture;

(2) Adding 15 parts of lubricant into the mixture of the base oil and the viscosity promoter, continuously stirring for 1.5 hours, adding 10 parts of degradable wood fibers and 20 parts of light calcium carbonate, and continuously stirring for 3 hours to obtain the shield tail lubricating grease.

Comparative example 1

Based on example 5, the difference from example 5 is that no lubricant was added.

The shield tail greases prepared in examples 1 to 5 and comparative example 1 were subjected to performance test. The results of the performance test are shown in Table 1.

Table 1 performance data for examples 1-5 and comparative example 1

As shown in Table 1, the shield tail lubricating grease prepared by the invention has excellent pumping performance, greatly reduces the problem of blockage of a grease injection pipe easily caused in the use process of a shield machine, improves the working efficiency, has excellent adhesiveness and stability, and has sagging values of 50 ℃ and 5h of less than 0.2mm, and the washing out amount of water washing for 5min of less than 2% under the pressure of 38 ℃ and 2.8 bar.

It should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted by the same, and the modified or substituted technical solution may not deviate from the spirit and scope of the technical solution of the present invention.

Claims (6)

1. The shield tail lubricating grease for the shield machine is characterized by comprising, by weight, 25-55 parts of base oil, 10-25 parts of fiber materials, 20-40 parts of fillers, 10-30 parts of viscosity promoters and 15-25 parts of lubricants, wherein the lubricants are modified nano silicon dioxide-modified graphene composite materials;

the lubricant is prepared by the steps of,

S1, preparing modified nano silicon dioxide, dispersing nano silicon dioxide powder into an ethanol solution to prepare a suspension A, adding sodium hydroxide into the suspension A to adjust the pH, mixing a silane coupling agent and methyl methacrylate, dripping the mixture into the suspension A, raising the temperature to 80-90 ℃, dispersing the mixture for 2-3 hours under magnetic stirring, and cooling the mixture to room temperature to prepare modified nano silicon dioxide suspension;

S2, preparing modified graphene, namely adding the multilayer graphene oxide into absolute ethyl alcohol to prepare a suspension B, adding oxalic acid into the suspension B to adjust the pH, mixing a silane coupling agent with the absolute ethyl alcohol, dropwise adding the mixture into the suspension B, magnetically stirring the mixture at 40-60 ℃ to react for 5-6 hours, centrifuging, and drying to obtain the modified multilayer graphene oxide;

s3, carrying out hydrolysis reaction on the modified nano silicon dioxide suspension and the modified multilayer graphene oxide in an ethanol solution to obtain a modified graphene composite material loaded with the modified nano silicon dioxide;

The solid-liquid ratio of the nano silicon dioxide to the ethanol solution in the S1 is 1:40-50, the mass fraction of sodium hydroxide is 8%, and the pH value is 7-8;

s2, the solid-to-liquid ratio of the multilayer graphene oxide to the absolute ethyl alcohol is 1:40-50, and the pH value is 5-6;

And S3, the hydrolysis reaction is carried out by mixing the modified nano silicon dioxide suspension and the modified multi-layer graphene oxide with an ethanol solution, carrying out the pre-hydrolysis reaction for 40-80 hours under the acidic condition at 15-35 ℃, and then carrying out the continuous hydrolysis reaction for 1-2 hours under the alkaline condition at 50-80 ℃.

2. The shield tail lubricating grease of claim 1, wherein the base oil is one or more of mineral oil, vegetable oil and synthetic oil.

3. The shield tail lubricating grease of claim 1, wherein the fiber material is degradable wood fiber, and the length of the fiber material is 0.1-2mm.

4. The shield tail lubricating grease of claim 1, wherein the filler comprises one or more of light calcium carbonate, bentonite, kaolin, mica and talcum powder.

5. The shield tail lubricating grease of claim 1, wherein the viscosity promoter is one or more of polyacrylamide, N-dimethylacrylamide, 2-hydroxysuccinic acid and 3-hydroxy-1, 3, 5-glutaric acid.

6. A method for preparing the shield tail lubricating grease of the shield machine according to any one of claims 1 to 5, which is characterized by comprising the following steps:

(1) Adding a viscosity promoter into base oil, stirring at normal temperature until the base oil and the viscosity promoter are completely and uniformly mixed, and stopping stirring to obtain a mixture of the base oil and the viscosity promoter;

(2) Adding lubricant into the mixture of base oil and viscosity promoter, stirring for 1-1.5 hr, adding fiber material and filler, and stirring for 2-3 hr to obtain Shield tail grease.