Polyurea material for underground pipeline trenchless lining repair as well as preparation and application of polyurea material

Abstract

The invention provides a polyurea material for underground pipeline trenchless lining repair as well as preparation and application of the polyurea material. The polyurea material comprises a component A and a component B, wherein the component A comprises 31-55 parts of isocyanate, 45-69 parts of polyol and 2-10 parts of a silane coupling agent; the component B comprises 40-80 parts of polyaspartic acid ester resin, 2-5 parts of a defoaming agent, 1-6 parts of a flatting agent, 1-5 parts of an antioxidant and 40-65 parts of pigment and filler; when in use, the mass ratio of the component A to the component B is (2: 1)-(1: 1). The inner surface of an underground pipeline to be repaired is coated with the polyurea material obtained by uniformly mixing the two components in a high-pressure airless spraying manner, so that the aim of reinforcing and repairing is fulfilled. The preparation method is simple and easy to implement, large-scale production can be achieved, the material has a good bonding effect on a wet base plane, the lining layer formed through curing is tightly attached to an old pipeline, the lining layer is compact and smooth and excellent in mechanical property, and the performance of the lining layer is slightly affected by environmental factors such as humidity corrosion.

Description

Technical Field

[0001] The invention relates to the technical field of trenchless lining repair materials for underground pipelines, and in particular to a polyurea material for trenchless lining repair of underground pipelines, and a preparation method and application thereof. Background Art

[0002] At present, there are a large number of underground water diversion pipelines, water conservancy culverts and drainage pipelines in my country that are in over-age service. These pipelines (culverts) are mostly made of concrete or reinforced concrete. Under the long-term effects of overlying soil load, internal water pressure, water flow scouring and corrosive media, various diseases such as leakage, cracking, corrosion and thinning are becoming increasingly prominent, resulting in a series of engineering safety problems such as leakage, pipe burst, hollowing, and subsidence. Reinforcement and repair of underground pipelines (culverts) is the key to ensuring their long-term safe operation. Trenchless repair technology for underground pipelines (culverts) refers to the use of in-situ space resources to reinforce and repair pipelines (culverts) with diseases without excavation or only a small amount of excavation. Compared with traditional excavation repair methods, trenchless repair technology for underground pipelines (culverts) has the advantages of high construction efficiency, short cycle, low cost, and little impact on ground transportation and the surrounding environment.

[0003] The in-situ spraying method is one of the non-excavation repair technologies for underground pipelines (culverts). Specifically, it refers to spraying repair materials on the inner wall of the old pipeline or culvert to construct a new complete inner lining. Existing in-situ spraying materials for underground pipelines (culverts) are mainly divided into inorganic and organic types, among which inorganic materials are cement mortar; organic materials include epoxy resin, polyurethane and polyurea. The strength of inorganic cement mortar is relatively high, and the bearing capacity of the old pipeline can be significantly improved after the new inner lining is constructed, but its durability is poor and its impermeability is weak. It is easy to suffer secondary damage under the scouring or erosion of the fluid in the pipe, and the long-term repair effect is difficult to guarantee; organic materials such as epoxy resin, polyurethane and polyurea have good durability and strong impermeability, but have the disadvantage of insufficient adhesion to the moist base surface. After repair, the inner lining is easy to fall off during long-term use. In addition, organic materials have obvious advantages in improving the impermeability and corrosion resistance of old pipelines, but the effect of enhancing the bearing performance of old pipelines is not obvious.

[0004] Polyurea is an elastomeric substance generated by the reaction of an isocyanate component and an amino compound component. In practical applications, in order to further improve the performance of polyurea materials, modification is usually used to improve the performance of polyurea. For example, the existing Chinese patent document CN113667086A discloses a siloxane-modified polyurea material and its preparation method and use. The siloxane-modified polyurea material in this scheme is prepared according to the following steps: under an inert gas or vacuum, a polyaspartic acid ester resin is first stirred and reacted with a diisocyanate to make it prepolymerized, and then a silane coupling agent is added, and the siloxane-modified polyaspartic acid ester resin is obtained after stirring and reacting for 0.5 to 4 hours; a curing agent containing two or more isocyanate groups is added to the siloxane-modified polyaspartic acid ester resin, stirred for 0.2 to 2 minutes, mixed evenly, and cured to obtain a siloxane-modified polyurea material, which can improve the adhesion of the polyurea material to cement mortar to a certain extent. However, this material still cannot solve the problem of insufficient adhesion on wet base surfaces, and its strength is low. Spraying it on old pipes still cannot enhance their load-bearing performance. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a polyurea material for trenchless lining repair of underground pipelines and its preparation method and application in view of the defects of the prior art. The preparation method of the polyurea material provided by the present invention is simple and easy to implement, and can achieve mass production. The material has a good bonding effect with the moist base surface. The lining layer formed by curing fits tightly with the old pipeline, and is dense and smooth with excellent mechanical properties. Its performance is less affected by environmental factors such as moisture corrosion. While significantly improving the anti-seepage and corrosion resistance of the old pipeline, it can also enhance the bearing performance and reduce the resistance of liquid circulation, and the long-term repair effect is more guaranteed.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, a polyurea material for trenchless lining repair of underground pipelines is provided, comprising component A and component B, wherein component A comprises the following raw materials in parts by weight: 31 to 55 parts of isocyanate, 45 to 69 parts of polyol, and 2 to 10 parts of silane coupling agent; component B comprises the following raw materials in parts by weight: 40 to 80 parts of polyaspartic acid ester resin, 2 to 5 parts of defoamer, 1 to 6 parts of leveling agent, 1 to 5 parts of antioxidant, and 40 to 65 parts of pigments and fillers;

[0008] When in use, the mass ratio of component A to component B is 2:1 to 1:1.

[0009] Further,

[0010] The isocyanate is at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (4,4'HMDI), p-phenylene diisocyanate (PPDI), hexamethylene diisocyanate (HDI) or oligomers thereof (HDI trimer).

[0011] Further,

[0012] The polyol is at least one of polyoxypropylene ether polyol, polyester polyol and plant-based refined polyol.

[0013] Preferably, the polyoxypropylene ether polyol is selected from at least one of polyoxypropylene ether diol and polyoxypropylene ether triol having molecular weights of 1000, 2000 and 3000 respectively.

[0014] Preferably, the polyester polyol is selected from at least one of polycaprolactone diol and polycarbonate diol having molecular weights of 1000 and 2000 respectively.

[0015] Preferably, the plant-based refined polyol is at least one selected from castor oil and its modified products.

[0016] Further,

[0017] The silane coupling agent is at least one of γ-aminopropyltriethoxysilane (KH-550), γ-glycidyloxypropyltrimethoxysilane (KH-560), N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and bis(3-trimethoxysilylpropyl)amine.

[0018] Further,

[0019] The polyaspartic acid resin is selected from at least one of polyaspartic acid resin Desmophen NH 1420, polyaspartic acid resin Desmophen NH 1520, polyaspartic acid resin Desmophen NH 1220, polyaspartic acid resin F420, polyaspartic acid resin F520 and polyaspartic acid resin F220.

[0020] The above-mentioned polyaspartic acid ester resins are all selected from the commercially available products of the corresponding models of Covestro.

[0021] Further,

[0022] The defoaming agent is at least one of BYK-065 (BASF Chemical Co., Ltd.), BYK-A535 (BASF Chemical Co., Ltd.), Deqian-6800 (Deqian (Shanghai) Chemical Co., Ltd.), FoamStar ST2410AC (BASF Chemical Co., Ltd.), etc.

[0023] The above defoamers are all known commercial products of the corresponding manufacturers, among which: BYK-065 and BYK-A535 are chemically composed of foam-breaking polysiloxane solutions, the main component of Deqian-6800 is a polysiloxane mixture containing hydrophobic particles, and FomaStartST2410AC is a new mineral oil-based compound.

[0024] Furthermore, the leveling agent is at least one of BYK-350 (BYK Chemical Company, Germany), BYK-356 (BYK Chemical Company, Germany), BYK-361 (BYK Chemical Company, Germany), etc.

[0025] The above-mentioned leveling agents are all commercially available products of corresponding manufacturers, and their main chemical components are polyacrylates.

[0026] Furthermore, the antioxidant is at least one of the commercially available antioxidant 1076 (BASF Chemical Co., Ltd.), antioxidant 1098 (BASF Chemical Co., Ltd.), antioxidant 1330 (BASF Chemical Co., Ltd.), etc.

[0027] The above antioxidants are all commercially available products from corresponding manufacturers.

[0028] Furthermore, the pigment filler is at least one of rutile titanium dioxide, carbon black, 400 mesh talc powder, 1250 mesh heavy calcium powder, and 1250 mesh wollastonite powder.

[0029] In a second aspect, the present invention further provides a method for preparing the polyurea material for trenchless lining repair of underground pipelines, comprising the following steps:

[0030] S1. Preparation of component A materials: weigh the above-mentioned polyols in parts by weight, add the polyols to a reaction vessel (such as a reactor), and start stirring; heat to 105-115°C; evacuate to -0.1-0.09MPa to remove moisture from the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; cool the liquid material to 50-60°C; weigh the above-mentioned isocyanate in parts by weight and add it to the reaction vessel, stir and disperse for 0.5-1 hour, slowly heat to 80-90°C for reaction for 2-3 hours, and detect the NCO value; when the NCO value reaches the designed value of 98-105%, weigh the above-mentioned silane coupling agent in parts by weight and add it to the reaction vessel, and keep warm for 0.5-1 hour; cool the liquid material to 50-60°C, discharge the material, and obtain component A materials;

[0031] S2, preparation of component B materials: weigh the above-mentioned polyaspartic acid ester resin and antioxidant in parts by weight, add them into a vacuum stirring reaction vessel (such as a vacuum stirring reaction kettle), start stirring, and heat the liquid material to 105-115° C.; add the pigment and filler into the vacuum stirring reaction vessel and stir for 0.5 hour; maintain 105-115° C., evacuate to -0.1-0.09 MPa to dehydrate and remove moisture from the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; add the above-mentioned defoamer and leveling agent and stir for 0.5 hour; cool to 50-60° C., discharge the material, and obtain component B materials;

[0032] When in use, the component A prepared in step S1 and the component B prepared in step S2 are stirred (such as mechanically or manually) for 5 to 10 minutes according to a preset ratio and mixed evenly.

[0033] The NCO value in the scheme of the present invention represents the mass of NCO groups (i.e., isocyanate groups), specifically, the mass of isocyanate (-NCO) groups contained in 100 g of a sample. The method for detecting NCO% in the present invention is the di-n-butylamine titration method.

[0034] In a third aspect, the present invention provides an application of the polyurea material or the polyurea material obtained by the method in trenchless pipeline lining repair. Specifically, the polyurea material obtained by uniformly mixing component A and component B is applied to the substrate or the surface of the primer to be repaired by high-pressure airless spraying, and is used to reinforce and repair underground pipelines.

[0035] In the polyurea material provided by the present invention, the active group of component A is an isocyanate group, and the active group of component B is an amine group. The two are mixed and reacted to generate a urea group. This molecular chain segment has high cohesive energy, which can give the material excellent mechanical properties. In addition, the system contains a large number of flexible segments, which can give the material excellent flexibility. Finally, the isocyanate and amine groups have strong reaction selectivity and are not affected by moisture. The spraying process is used to make the formed coating more dense.

[0036] Beneficial effects of the present invention:

[0037] 1. The polyurea material provided by the present invention is a two-component system. The A and B components can be used after being accurately weighed and stirred evenly, and the operation is simple and convenient.

[0038] 2. The polyurea material provided by the present invention has a good bonding effect with a wet concrete base: the bonding strength is greater than 3.0 MPa (or the concrete base is damaged), the adhesion retention rate in a long-term immersion environment is greater than 80%, and the fit with the underground pipeline is good.

[0039] 3. The polyurea material provided by the present invention has a gel time of 20 to 40 minutes, a surface dry time of 1 to 2 hours, and a curing time that is less affected by environmental humidity. It can be used to repair the lining of underground pipelines and can quickly restore the water transport function.

[0040] 4. The inner lining layer formed after the polyurea material provided by the present invention is cured is continuous, dense, impermeable and smoother, with a friction coefficient of about 0.4, which can significantly improve the impermeability of old pipes and reduce the resistance to liquid circulation in the pipes.

[0041] 5. The polyurea material provided by the present invention has excellent mechanical properties and good chemical corrosion resistance after curing. The formed lining layer can enhance the corrosion resistance of old pipelines and improve the bearing performance of old pipelines.

[0042] 6. The preparation method of the polyurea material provided by the present invention is simple and easy, and can achieve mass production. In addition, the composition of the colorant and filler of the polyurea material can be adjusted according to customer needs to prepare various colors.

[0043] 7. The polyurea material provided by the present invention is easy to operate when used for trenchless lining repair of underground pipelines, and can be constructed by high-pressure airless spraying or manual scraping. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 The present invention is a schematic flow chart of a method for preparing a polyurea material for trenchless lining repair of underground pipelines. DETAILED DESCRIPTION

[0046] As used herein:

[0047] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0048] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0049] When each parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0050] In these examples, parts and percentages are by mass unless otherwise indicated.

[0051] "Weight parts" / "mass parts" refers to the basic measurement unit that indicates the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g, 2g, etc. If we say that the mass parts of component A are a parts and the mass parts of component B are b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Or, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0053] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0054] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0055] 1. Preparation of polyurea materials for trenchless lining repair of underground pipelines

[0056] Example 1

[0057] This embodiment provides a polyurea material for trenchless lining repair of underground pipelines, including component A and component B, and the mass ratio of component A to component B is 1:1. Component A includes the following raw materials in parts by weight: 36 parts of isocyanate (this embodiment uses diphenylmethane diisocyanate, specifically containing 50% of 2,4'-diphenylmethane diisocyanate and 50% of 4,4'-diphenylmethane diisocyanate), 62 parts of polyether polyol (this embodiment uses polyoxypropylene ether diol with a molecular weight of 2000), and 2 parts of silane coupling agent (this embodiment uses γ-glycidyloxypropyl trimethoxysilane). The preparation method of component A is as follows: weigh the above-mentioned weight portion of polyether polyol and add it to the reactor, stir and heat it to 110°C; use a vacuum pump to evacuate to -0.1MPa to dehydrate and remove the moisture in the raw material until the moisture content of the raw material drops to less than 5 parts per 10,000; cool the liquid material to 55°C; weigh the above-mentioned weight portion of isocyanate and add it to the reactor, stir and disperse for 0.5 hours, slowly heat it to 85°C and react for 2 hours, and use di-n-butylamine titration method to detect the NCO value during the process; when the NCO value reaches the design value of 100%, weigh the above-mentioned weight portion of silane coupling agent and add it to the reactor, keep it warm for 0.5 hours; cool the liquid material to 55°C, discharge it, and obtain component A material. The NCO design value in the scheme is the theoretical NCO value calculated by formula design.

[0058] Component B includes the following raw materials in parts by weight: 62 parts of polyaspartic acid resin F420 (Covestro), 1 part of antioxidant 1076 (BASF Chemical Co., Ltd.), 1 part of defoamer 6800 (Deqian (Shanghai) Chemical Co., Ltd.), 1 part of leveling agent BYK-356 (BYK Chemical Company, Germany), and 35 parts of pigments and fillers; the pigments and fillers are composed of 1 part of white slurry (rutile titanium dioxide is used in this embodiment), 0.2 parts of black slurry (carbon black is used in this embodiment), 20 parts of 400 mesh talc, 7 parts of 1250 mesh heavy calcium, and 6.8 parts of 1250 mesh wollastonite powder. The preparation method of component B is as follows: weigh the above-mentioned polyaspartic acid ester resin F420 and antioxidant 1076 in parts by weight, add them into a vacuum stirring kettle, start stirring, and heat the liquid to 110°C; add pigments and fillers into the vacuum stirring kettle and stir for 0.5 hours; maintain 110°C, evacuate the vacuum pump to -0.1MPa to dehydrate and remove moisture from the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; add the above-mentioned defoamer 6800 and leveling agent BYK-356 and stir for 0.5 hours; cool to 55°C, discharge the material, and obtain component B material.

[0059] Example 2

[0060] This embodiment provides a polyurea material for trenchless lining repair of underground pipelines, including component A and component B, and the mass ratio of component A to component B is 1:1. Component A includes the following raw materials in parts by weight: 44 parts of isocyanate (this embodiment uses diphenylmethane diisocyanate, specifically containing 50% of 2,4'-diphenylmethane diisocyanate and 50% of 4,4'-diphenylmethane diisocyanate), 55 parts of polyether polyol (this embodiment uses polyoxypropylene ether diol with a molecular weight of 2000), and 1 part of silane coupling agent (this embodiment uses γ-glycidyloxypropyl trimethoxysilane). The preparation method of component A is as follows: weigh the above-mentioned weight portion of polyether polyol and add it to the reactor, stir and heat it to 105°C; use a vacuum pump to evacuate to -0.1MPa to dehydrate and remove the moisture in the raw material until the moisture content of the raw material drops to less than 5 parts per 10,000; cool the liquid material to 50°C; weigh the above-mentioned weight portion of isocyanate and add it to the reactor, stir and disperse for 0.5 hours, slowly heat it to 80°C and react for 2 hours, and use di-n-butylamine titration method to detect the NCO value during the process; when the NCO value reaches 98% of the design value, weigh the above-mentioned weight portion of silane coupling agent and add it to the reactor, keep it warm for 0.5 hours; cool the liquid material to 50°C, discharge it, and obtain component A material. The NCO design value in the scheme is the theoretical NCO value calculated by formula design.

[0061] Component B includes the following raw materials in parts by weight: 60 parts of polyaspartic acid resin F420 (Covestro), 2 parts of antioxidant 1076 (BASF Chemical Co., Ltd.), 2 parts of defoamer 6800 (Deqian (Shanghai) Chemical Co., Ltd.), 2 parts of leveling agent BYK-356 (BYK Chemical Company, Germany), and 34 parts of pigments and fillers; the pigments and fillers are composed of 3.5 parts of white slurry (rutile titanium dioxide is used in this embodiment), 0.5 parts of black slurry (carbon black is used in this embodiment), 10 parts of 400 mesh talc, 10 parts of 1250 mesh heavy calcium, and 10 parts of 1250 mesh wollastonite powder. The preparation method of component B is as follows: weigh the above-mentioned weight portions of polyaspartic acid ester resin F420 and antioxidant 1076, add them into a vacuum stirring kettle, start stirring, and heat the liquid to 105°C; add pigments and fillers into the vacuum stirring kettle and stir for 0.5 hour; maintain 105°C, evacuate the vacuum pump to -0.1MPa to dehydrate and remove moisture in the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; add the above-mentioned defoamer 6800 and leveling agent BYK-356 and stir for 0.5 hour; cool to 50°C, discharge the material, and obtain component B material.

[0062] Example 3

[0063] The present embodiment provides a polyurea material for trenchless lining repair of underground pipelines, including component A and component B, and the mass ratio of component A to component B is 1:1. Among them, component A includes the following raw materials in parts by weight: 42 parts of isocyanate (this embodiment uses diphenylmethane diisocyanate, specifically containing 50% of 2,4'-diphenylmethane diisocyanate and 50% of 4,4'-diphenylmethane diisocyanate), 28 parts of polyether polyol DL-1000 (this embodiment uses polyoxypropylene ether diol with a molecular weight of 1000), 28 parts of polyether polyol DL-2000 (this embodiment uses polyoxypropylene ether diol with a molecular weight of 2000), and 2 parts of silane coupling agent (this embodiment uses γ-glycidyloxypropyl trimethoxysilane). The preparation method of component A is as follows: weigh the above-mentioned weight portions of polyether polyol DL-1000 and DL-2000 and add them to the reactor, stir and heat to 115°C; vacuum pump evacuates to -0.09MPa to dehydrate and remove moisture in the raw materials until the moisture content of the raw materials drops to less than 5 parts per 10,000; cool the liquid material to 60°C; weigh the above-mentioned weight portions of isocyanate and add them to the reactor, stir and disperse for 1 hour, slowly heat to 90°C and react for 3 hours, and use di-n-butylamine titration method to detect the NCO value; when the NCO value reaches the design value of 105%, weigh the above-mentioned weight portions of silane coupling agent and add them to the reactor, keep warm for 1 hour; cool the liquid material to 60°C, discharge the material, and obtain component A material. The NCO design value in the scheme is the theoretical NCO value calculated through formula design.

[0064] Component B includes the following raw materials in parts by weight: 50 parts of polyaspartic acid resin F420 (Covestro), 2 parts of antioxidant 1076 (BASF Chemical Co., Ltd.), 2 parts of defoamer 6800 (Deqian (Shanghai) Chemical Co., Ltd.), 2 parts of leveling agent BYK-356, and 44 parts of pigments and fillers; the pigments and fillers are composed of 2 parts of white slurry (rutile titanium dioxide is used in this embodiment), 0.5 parts of black slurry (carbon black is used in this embodiment), 11.5 parts of 400 mesh talc, 15 parts of 1250 mesh heavy calcium, and 15 parts of 1250 mesh wollastonite powder. The preparation method of component B is as follows: weigh the above-mentioned polyaspartic acid ester resin F420 and antioxidant 1076 in parts by weight, add them into a vacuum stirring kettle, start stirring, and heat the liquid to 115°C; add pigments and fillers into the vacuum stirring kettle, stir for 0.5 hours, and maintain 115°C; vacuum pump is evacuated to -0.09MPa to dehydrate and remove moisture in the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; add the above-mentioned defoamer 6800 and leveling agent BYK-356 and stir for 0.5 hours; cool to 60°C, discharge the material, and obtain component B material.

[0065] Example 4

[0066] This embodiment provides a polyurea material for trenchless lining repair of underground pipelines, including component A and component B, and the mass ratio of component A to component B is 1:1. Among them, component A includes the following raw materials in parts by weight: 20 parts of diphenylmethane diisocyanate (specifically containing 50% of 2,4'-diphenylmethane diisocyanate and 50% of 4,4'-diphenylmethane diisocyanate), 25 parts of 1,6-hexamethylene monoisocyanate, 53 parts of refined castor oil, and 2 parts of γ-glycidyloxypropyltrimethoxysilane. The preparation method refers to Example 1.

[0067] Component B includes the following raw materials in parts by weight: 56 parts of polyaspartic acid resin F420 (Covestro), 2 parts of antioxidant 1076 (BASF Chemical Co., Ltd.), 2 parts of defoamer 6800 (Deqian (Shanghai) Chemical Co., Ltd.), 2 parts of leveling agent BYK-356, 38 parts of pigments and fillers; the pigments and fillers are composed of 2 parts of white slurry (rutile titanium dioxide), 0.5 parts of black slurry (carbon black), 10 parts of 400 mesh talc, 10.5 parts of 1250 mesh heavy calcium, and 15 parts of 1250 mesh wollastonite powder. The preparation method is based on Example 1.

[0068] Example 5

[0069] This embodiment provides a polyurea material for trenchless lining repair of underground pipelines, including component A and component B, and the mass ratio of component A to component B is 1.5:1. Among them, component A includes the following raw materials in parts by weight: 20 parts of toluene diisocyanate, 20 parts of diphenylmethane diisocyanate, 5 parts of polyester polyol (polycaprolactone diol with a molecular weight of 2000 is used in this embodiment), 40 parts of polyether polyol DL-2000 (polyoxypropylene ether diol with a molecular weight of 2000), and 1 part of γ-glycidyl ether oxypropyl trimethoxy silane. The preparation method refers to Example 1.

[0070] Component B includes the following raw materials in parts by weight: 45 parts of polyaspartic acid resin F420 (Covestro), 5 parts of polyaspartic acid resin Desmophen NH 1520, 5 parts of polyaspartic acid resin Desmophen NH 1220, 1 part of defoamer FoamStar ST2410AC (BASF Chemical Co., Ltd.), 1 part of defoamer BYK-A535 (BASF Chemical Co., Ltd.), 1 part of leveling agent BYK-350 (Bick Chemical Co., Ltd., Germany), 1 part of leveling agent BYK-356 (Bick Chemical Co., Ltd., Germany), 2 parts of antioxidant 1098 (BASF Chemical Co., Ltd.), 60 parts of pigments and fillers; the pigments and fillers are composed of 4 parts of white slurry (rutile titanium dioxide), 1.5 parts of black slurry (carbon black), 20 parts of 400 mesh talc, 12.5 parts of 1250 mesh heavy calcium, and 22 parts of 1250 mesh wollastonite powder. The preparation method is based on Example 1.

[0071] Example 6

[0072] This embodiment provides a polyurea material for trenchless lining repair of underground pipelines, including component A and component B, and the mass ratio of component A to component B is 2:1. Among them, component A includes the following raw materials in parts by weight: 10 parts of diphenylmethane diisocyanate (specifically containing 50% of 2,4'-diphenylmethane diisocyanate and 50% of 4,4'-diphenylmethane diisocyanate), 25 parts of hexamethylene diisocyanate trimer, 20 parts of refined castor oil, 30 parts of polyether polyol DL-2000 (polyoxypropylene ether glycol with a molecular weight of 2000), and 1 part of N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane. The preparation method refers to Example 1.

[0073] Component B includes the following raw materials in parts by weight: 30 parts of polyaspartic acid resin F420 (Covestro), 20 parts of polyaspartic acid resin Desmophen NH 1420, 5 parts of polyaspartic acid resin Desmophen NH 1220, and 1 part of defoamer FoamStar ST2410AC (BASF Chemical Co., Ltd.), 1 part of defoamer BYK-A535 (BASF Chemical Co., Ltd.), 2 parts of leveling agent BYK-356 (BASF Chemical Co., Ltd.), 2 parts of leveling agent BYK-361 (Bick Chemical Co., Ltd., Germany), 2 parts of antioxidant 1098 (BASF Chemical Co., Ltd.), 1 part of antioxidant 1076 (BASF Chemical Co., Ltd.), 55 parts of pigments and fillers; the pigments and fillers are composed of 3 parts of white slurry (rutile titanium dioxide), 1.5 parts of black slurry (carbon black), 18 parts of 400 mesh talc, 12.5 parts of 1250 mesh heavy calcium, and 20 parts of 1250 mesh wollastonite powder. The preparation method is based on Example 1.

[0074] Comparative Example 1

[0075] The component A and its preparation method provided in Comparative Example 1 are the same as those in Example 1. The difference from Example 1 is that in the preparation of the component B material, 62 parts of polyaspartic acid resin F420 (Covestro) are replaced by 32 parts of polyetheramine D2000 (Huntsman Polyurethane (China) Co., Ltd.) and 30 parts of diethyltoluenediamine (Zhangjiagang Yarui Chemical Co., Ltd.), and the other components remain unchanged. The preparation method of component B is as follows: weigh the above-mentioned polyetheramine D2000 and diethyltoluenediamine in parts by weight and add them to a vacuum stirring kettle, start stirring, and heat the liquid to 110°C; add the pigment and filler to the vacuum stirring kettle and stir for 0.5 hours; maintain 110°C, vacuum pump to -0.1MPa to dehydrate and remove moisture from the raw material until the moisture content of the raw material drops to less than 5 parts per 10,000; add defoamer 6800 and leveling agent BYK-356 and stir for 0.5 hours; cool to 55°C, discharge, and obtain the component B material. When in use, the mass ratio of component A to component B is 1:1.

[0076] Comparative Example 2

[0077] The A component and its preparation method provided in Comparative Example 2 are the same as those in Example 6. The difference from Example 6 is that in the preparation of the B component material, 30 parts of polyaspartic acid resin F420 (Covestro) and 20 parts of polyaspartic acid resin Desmophen NH 1420 are replaced by 30 parts of polyetheramine D2000 (Huntsman Polyurethane (China) Co., Ltd.) and 20 parts of diethyltoluenediamine (Zhangjiagang Yarui Chemical Co., Ltd.) in equal amounts, and the other components remain unchanged. The preparation method of component B is as follows: weigh the weight fraction of polyetheramine D2000, diethyltoluenediamine and polyaspartic acid ester resin DesmophenNH 1220 and add them into a vacuum stirring kettle, start stirring, and heat the liquid to 110°C; add pigments and fillers into the vacuum stirring kettle and stir for 0.5 hours; maintain 110°C, vacuum pump to -0.1MPa to dehydrate and remove moisture in the raw materials until the moisture content of the raw materials drops to less than 5 parts per thousand; add defoamer 6800 and leveling agent BYK-356 and stir for 0.5 hours; cool to 55°C, discharge, and obtain component B. When used, the mass ratio of component A to component B is 2:1.

[0078] The performance index parameters of the polyurea materials obtained in different embodiments and comparative examples are shown in Table 1. Among them, the surface drying time is measured by the finger touch method in the "Determination of Drying Time of Paint Film and Putty Film" (GB / T 1728-2020), the tensile strength is measured by the "Plastic Tensile Properties Test Method" (GB / T1040-92), and the flexural strength is measured by the "Plastic Flexural Properties Test Method" (GB / T9341-2000).

[0079] The test method of wet concrete adhesion test is as follows: prepare several C30 concrete samples with a size of 70×70×20mm in advance, with a flat upper surface without obvious depressions or pits, dry them and remove the dust on the surface, immerse them in water for 24 hours, wipe off the surface water after taking them out, and then pour a layer of the material prepared in the above embodiment and comparative example with an area of ​​40×40mm and a thickness of 3mm on the middle part of the upper surface of each C30 concrete sample. After curing for 7 days at room temperature, use a QJ211S electronic universal testing machine to test the bonding properties (i.e. adhesion) of the interface between concrete and the test material.

[0080] Table 1 Main performance index parameters of polyurea materials obtained in Examples 1 to 6 and Comparative Examples 1-2

[0081]

[0082] 2. Application of polyurea materials for trenchless lining repair of underground pipelines

[0083] The method for trenchless lining repair of underground pipelines using the polyurea material prepared in the above embodiment comprises the following steps:

[0084] Step (1): Deeply clean the interior of the concrete pipe with corrosion damage to remove attachments, debris, etc. in the pipe.

[0085] Step (2), artificially pre-treating the cleaned inner wall of the old pipe, filling the depressions or cracks in the old pipe with quick-hardening cement, removing the hard spots or crisp layers on the inner wall of the old pipe, and ensuring that the inner wall of the old pipe is round.

[0086] Step (3), ventilate and dry the old pipe to remove the clear water on the inner surface of the old pipe.

[0087] Step (4), weigh the raw materials of component A and component B in Examples 1 to 6 and Comparative Examples 1 and 2 according to the corresponding weight ratio and pour them into different containers for later use.

[0088] Step (5), after the weighed raw materials of component A and component B are quickly mixed evenly, they are evenly coated on the inner wall of the old pipe according to the designed thickness requirements by manual scraping or high-pressure airless spraying to form a uniform and complete polyurea repair layer.

[0089] Step (6): In step (5), in order to prevent the polyurea lining layer from sagging, the single coating thickness of the polyurea material does not exceed 0.5 mm.

[0090] Step (7): In step (5), the spraying operation is carried out by the construction personnel or equipment moving backwards until the entire repair section is coated and the surface is completely dry, and then the second layer of spraying is carried out at the starting point. This cycle is repeated multiple times until the total thickness of the polyurea lining layer reaches the design requirement and is round and smooth.

[0091] The repaired pipes were tested and the test results were recorded as shown in Tables 2 and 3. The bearing capacity of the pipes was tested using the Test Methods for Concrete and Reinforced Concrete Drainage Pipes (GB / T 16752-2017). The test method for the concrete adhesion test is as follows: the concrete pipes repaired by spraying in each test case were placed for one year, the coating shedding was observed, and then the areas where no shedding occurred on each pipe were cut to obtain adhesion test specimens, and the adhesion test was performed using a QJ211S electronic universal testing machine.

[0092] Table 2 Recovery of bearing capacity of each concrete pipe after repair

[0093]

[0094] Table 3 Adhesion retention of each coating after repair

[0095] time Coating integrity Adhesion Adhesion retention rate Example 1 1 year Complete, no damage 3.0MPa 85.7％ Example 2 1 year Complete, no damage 3.1MPa 88.5％ Example 3 1 year Complete, no damage 2.8MPa 84.8％ Example 4 1 year Complete, no damage 4.4MPa 97.7％ Example 5 1 year Complete, no damage 4.0MPa 95.2％ Example 6 1 year Complete, no damage 4.1MPa 100％ Comparative Example 1 1 year Large area shedding 1.0MPa 45.5％ Comparative Example 2 1 year Large area shedding 1.3MPa 52.0％

[0096] The integrity and adhesion retention of the coating during use are key indicators for evaluating the repair system.

[0097] By combining the test data in Tables 1 to 3 and comparing the data of the materials obtained by the embodiments of the present invention with those of Comparative Examples 1 and 2, it can be seen that the polyurea material provided by the present invention has the advantages of short curing time, impermeability, good corrosion resistance, excellent mechanical properties, etc., and can significantly improve the anti-seepage, anti-corrosion and water erosion resistance of old pipes, and the long-term repair effect is more guaranteed. In addition, it fits tightly with the inner wall of the old pipe to form a composite bearing structure, which greatly improves the bearing capacity of the old pipe and realizes structural repair.

[0098] This is due to the fact that the polyurea material provided by the present invention is a two-component system, in which the active group of component A is an isocyanate group, and the active group of component B is an amine group. The two are mixed and reacted to generate a urea group. This molecular chain segment has high cohesive energy, which can give the material excellent mechanical properties; in addition, the system contains a large number of flexible segments, which can give the material excellent flexibility; finally, the isocyanate and amine reactions are highly selective and are not affected by moisture. The spraying process is used to make the formed coating denser.

[0099] Therefore, the polyurea material for in-situ repair of the inner wall of the pipeline provided by the present invention can solve the three difficulties of insufficient adhesion of traditional organic spray materials on wet base surfaces, unsatisfactory adhesion of the coating during long-term use after repair, and lack of obvious effect on enhancing the bearing capacity of the pipeline. It is suitable for pipelines of various materials and various diameters such as metal pipes, concrete pipes, and glass fiber reinforced plastic sand-filled pipes, and is suitable for pressurized and non-pressurized pipelines, and can also achieve significant reinforcement effects when the thickness is relatively small. Therefore, in practice, better repair effects can be achieved without significantly reducing the flow capacity of the old pipeline.

[0100] The above descriptions are only some preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A polyurea material for trenchless lining repair of underground pipelines, characterized in that: The invention comprises component A and component B, wherein component A comprises the following raw materials in parts by weight: 31 to 55 parts of isocyanate, 45 to 69 parts of polyol, and 2 to 10 parts of silane coupling agent; component B comprises the following raw materials in parts by weight: 40 to 80 parts of polyaspartic acid ester resin, 2 to 5 parts of defoamer, 1 to 6 parts of leveling agent, 1 to 5 parts of antioxidant, and 40 to 65 parts of pigment and filler; When in use, the mass ratio of component A to component B is 2:1 to 1:

1.

2. The polyurea material for trenchless lining repair of underground pipelines according to claim 1, characterized in that: The isocyanate is at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate or oligomers thereof.

3. The polyurea material for trenchless lining repair of underground pipelines according to claim 1, characterized in that: The polyol is at least one of polyoxypropylene ether polyol, polyester polyol and plant-based refined polyol.

4. The polyurea material for trenchless lining repair of underground pipelines according to claim 3, characterized in that: The polyoxypropylene ether polyol is selected from at least one of polyoxypropylene ether diol and polyoxypropylene ether triol having molecular weights of 1000, 2000 and 3000 respectively; The polyester polyol is selected from at least one of polycaprolactone diol and polycarbonate diol having molecular weights of 1000 and 2000 respectively; The plant-based refined polyol is selected from at least one of castor oil and its modified products.

5. The polyurea material for trenchless lining repair of underground pipelines according to claim 1, characterized in that: The silane coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and bis(3-trimethoxysilylpropyl)amine.

6. The polyurea material for trenchless lining repair of underground pipelines according to claim 1, characterized in that: The polyaspartic acid ester resin is selected from at least one of Desmophen NH 1420, Desmophen NH 1520, Desmophen NH 1220, F420, F520 and F220.

7. The polyurea material for trenchless lining repair of underground pipelines according to claim 1, characterized in that: The defoaming agent is at least one of BYK-065, BYK-A535, Deqian-6800, FoamStar ST2410AC, etc.; The leveling agent is at least one of BYK-350, BYK-356, BYK-361, etc.; The antioxidant is at least one of antioxidant 1076, antioxidant 1098, antioxidant 1330, etc.

8. The polyurea material for trenchless lining repair of underground pipelines according to claim 1, characterized in that: The pigment and filler is at least one of rutile titanium dioxide, carbon black, 400-mesh talcum powder, 1250-mesh heavy calcium powder, and 1250-mesh wollastonite powder.

9. A method for preparing a polyurea material for trenchless lining repair of underground pipelines according to any one of claims 1 to 8, characterized in that: The steps include: S1. Preparation of component A materials: weigh the above-mentioned polyols in parts by weight, add the polyols to a reaction vessel, and start stirring; heat to 105-115°C; evacuate to -0.1-0.09MPa to remove moisture from the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; cool the liquid material to 50-60°C; weigh the above-mentioned isocyanate in parts by weight and add it to a reaction vessel, stir and disperse for 0.5-1 hour, slowly heat to 80-90°C for reaction for 2-3 hours, and detect the NCO value; when the NCO value reaches the designed value of 98-105%, weigh the above-mentioned silane coupling agent in parts by weight and add it to the reaction vessel, and keep warm for 0.5-1 hour; cool the liquid material to 50-60°C, discharge the material, and obtain component A materials; S2, preparation of component B materials: weigh the above-mentioned polyaspartic acid ester resin and antioxidant in parts by weight, add them into a vacuum stirring reaction vessel, start stirring, and heat the liquid material to 105-115° C.; add pigments and fillers into the vacuum stirring reaction vessel and stir for 0.5 hour; maintain 105-115° C., evacuate to -0.1-0.09 MPa to dehydrate and remove moisture from the raw materials until the moisture content of the raw materials drops to less than 0.5 parts per million; add the above-mentioned defoaming agent and leveling agent and stir for 0.5 hour; cool to 50-60° C., discharge the material, and obtain component B materials; When in use, the component A prepared in step S1 and the component B prepared in step S2 are mixed evenly according to a preset ratio and stirred for 5 to 10 minutes to obtain the product.

10. Use of the polyurea material according to any one of claims 1 to 8 or the polyurea material obtained by the method according to claim 9 in trenchless lining repair of underground pipelines, characterized in that: Specifically, the polyurea material obtained by evenly mixing component A and component B is applied to the inner surface of the underground pipeline to be repaired by high-pressure airless spraying to reinforce and repair the underground pipeline.

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