Reinforced composite structure material for road well lid and well lid

Abstract

The invention discloses a reinforced composite structure material for a road well lid and the well lid. The reinforced composite structure material for the road well lid comprises the following raw materials in parts by weight: 20-25 parts of thermosetting resin; 25 to 35 parts of reinforced fiber; 5 to 30 parts of filler; 5-15 parts of a thermoplastic polymer; 0.1 to 0.5 part of an initiator; 0.5-1 part of a release agent; 2-25 parts of a flame retardant; 6.5-19 parts of a curing agent; and 1-2 parts of pigment. The well lid prepared from the reinforced composite structure material for the road well lid has the advantages of high strength, light weight, high flame retardance, corrosion resistance, super toughening, cold resistance and heat resistance.

Description

Technical Field

[0001] This application relates to the fields of municipal engineering and new materials technology, and particularly relates to a reinforced composite structural material for road manhole covers and manhole covers. Background Art

[0002] Most of the existing manhole covers for various types of pipe galleries and inspection wells in cities are made of cast iron materials, cement, and steel bars. Using cast iron materials not only wastes energy and has high carbon emissions, but also, due to its recyclable value, it is often lost. Without a manhole cover for the inspection well, it will cause great harm; cast iron manhole covers are very heavy, making handling and use inconvenient. Cement and steel bar manhole covers also bear more than twice the weight of ordinary composite materials. Moreover, after long-term use, the cement will fall off, the bearing capacity will decrease, and accidents are likely to occur. With the use of intelligent equipment inside the pipe gallery, the wave transmission performance of cast iron manhole covers and cement and steel bar manhole covers is relatively poor, which is not conducive to the input and output of underground signals. Now, the inspection wells in the market are becoming larger and larger, and the products with heavy-duty bearing are very heavy, which is not conducive to on-site construction installation and subsequent maintenance, increasing the labor cost. In the prior art, the composite materials used for manhole covers of various types of pipe galleries and inspection wells in cities all have certain defects and cannot meet the characteristics of low carbon emissions, high strength, light weight, high flame retardancy, corrosion resistance, super toughening, cold and heat resistance, and high wave transmission. Summary of the Invention

[0003] Based on this, it is necessary to provide a reinforced composite structural material for road manhole covers. The manhole cover prepared from the reinforced composite structural material of the present invention has the advantages of high strength, light weight, high flame retardancy, corrosion resistance, super toughening, cold and heat resistance.

[0004] An embodiment of this application provides a reinforced composite structural material for road manhole covers.

[0005] A reinforced composite structural material for road manhole covers comprises raw materials in the following parts by weight:

[0006] 20 - 25 parts of thermosetting resin;

[0007] 25 - 35 parts of reinforcing fiber;

[0008] 5 - 30 parts of filler;

[0009] 5 - 15 parts of thermoplastic polymer;

[0010] 0.1 - 0.5 part of initiator;

[0011] 0.5 - 1 part of demolding agent;

[0012] 2 - 25 parts of flame retardant;

[0013] 6.5 - 19 parts of curing agent;

[0014] 1 - 2 parts of pigment.

[0015] In some of these embodiments, the thermosetting resin includes one or more of unsaturated polyester resin, epoxy resin, and vinyl ester resin.

[0016] In some of these embodiments, the thermosetting resin includes a modified maleic resin, which is obtained by modifying the maleic resin using one or more of copolymer modification, crosslinking modification, introduction of flexible chain segments, addition of functional functional groups, compounding with filling and reinforcing materials, electrical conductivity modification, and biodegradability modification.

[0017] In some of these embodiments, the reinforcing fibers include glass fibers, carbon fibers, or other synthetic fibers.

[0018] In some of these embodiments, the filler includes one or more of quartz sand, calcium carbonate, talcum powder, rubber, and reinforcing ribs.

[0019] In some of these embodiments, the thermoplastic polymer includes one or more of polystyrene, polypropylene, polyvinyl chloride, polyethylene, nylon, polycarbonate, ABS resin, modified polypropylene, and thermoplastic polyurethane.

[0020] In some of these embodiments, the initiator includes one or more of peroxide initiators, azo initiators, photoinitiators, red phosphorus and organometallic compounds, anhydride initiators, and amine initiators.

[0021] In some of these embodiments, the mold release agent is one or a mixture of zinc stearate, calcium stearate, and a solution of a copolymer of low molecular weight unsaturated acidic polycarboxylic acid polyester and polysiloxane.

[0022] In some of these embodiments, the flame retardant includes one or more of halogen-based flame retardants, phosphorus-based flame retardants, metal hydroxides, intumescent flame retardants, nitrogen-based flame retardants, nanomaterials, and boron compounds.

[0023] In some of these embodiments, the curing agent includes one or more of amine curing agents, anhydride curing agents, peroxide curing agents, imidazole curing agents, phenolic resin curing agents, mercaptan curing agents, and metal salt curing agents.

[0024] In some of these embodiments, the pigment includes one or more of inorganic pigments, organic pigments, pearlescent pigments, fluorescent pigments, metallic pigments, conductive pigments, and heat-insulating pigments.

[0025] In some of these embodiments, the reinforced composite structural material for road manhole covers further includes 0.1 - 0.5 parts of an ultraviolet stabilizer.

[0026] In some of these embodiments, the ultraviolet stabilizer includes a hindered amine light stabilizer.

[0027] In some of these embodiments, the reinforced composite structural material for road manhole covers further includes 0.4 - 1 part of magnesium oxide paste, wherein the magnesium oxide paste is magnesium oxide with a 50% content and a viscosity less than 6000 mPa·s.

[0028] In some of these embodiments, the reinforced composite structural material for road manhole covers further includes a luminescent material, and the weight part of the luminescent material is 1 - 10 parts. The luminescent material includes one or several of LED lights, phosphor coatings, photoluminescent ceramics, optical fibers, self-luminous coatings, and solar panels.

[0029] In some of these embodiments, the reinforced composite structural material for road manhole covers further includes graphene material, and the weight part of the luminescent material is 1 - 10 parts.

[0030] One embodiment of the present application also provides a manhole cover.

[0031] A manhole cover is prepared from the reinforced composite structural material for road manhole covers in any of the above embodiments.

[0032] For the above-mentioned reinforced composite structural material for road manhole covers, the beneficial effects of the embodiments of the present invention are as follows:

[0033] (1) This application uses a thermosetting resin as the matrix material, such as unsaturated polyester resin, epoxy resin, or vinyl ester resin, etc. The thermosetting resin provides good mechanical properties, corrosion resistance, and moldability. Specifically, the modified maleic resin used herein improves the weather resistance of the material, reduces the water absorption rate, and increases the electrical properties of the material.

[0034] (2) In order to improve the strength and stiffness of the material, this application adds reinforcing fibers, such as glass fibers, carbon fibers, or other synthetic fibers, making the material have a high strength-to-weight ratio and cost-effectiveness. Preferably, the reinforcing fibers in this application are reinforcing fibers with a low dielectric constant and a length exceeding 100 mm, which improve the wave transmission performance and mechanical properties of the material.

[0035] (3) This application increases the volume stability and reduces the shrinkage rate by adding fillers, such as adding inorganic fillers like quartz sand, calcium carbonate, and talcum powder, and can adjust the density and cost of the product.

[0036] (4) An initiator is added during the manufacturing process of the manhole cover material. The initiator is usually used to promote or accelerate chemical reactions, especially when dealing with polymer-based composite materials. The main role of the initiator is to initiate the polymerization reaction between monomer molecules, enabling these small molecules to connect into long-chain macromolecules (i.e., polymers).

[0037] (5) The present application adds a flame retardant to the manhole cover material to improve the fire resistance of the material, reduce the fire risk, and delay the spread of flames. Different types of flame retardants act through different mechanisms, such as absorbing heat, diluting combustible gases, forming a protective layer, or inhibiting the combustion chain reaction, etc.

[0038] (6) The curing agent (also known as the hardener or crosslinking agent) used in the present application plays a crucial role in the manhole cover material. Especially in the resin-based composite material system, the curing agent is used to promote or accelerate the crosslinking reaction of thermosetting resins, thereby converting the liquid or semi-solid resin into a hard and stable solid structure.

[0039] (7) The present application uses fillers such as adding inorganic fillers like quartz sand, calcium carbonate, talcum powder, etc. to increase the volume stability, reduce the shrinkage rate, and can adjust the density and cost of the product.

[0040] (8) The UV color paste is used with a viscosity less than 6000 mPa·s, a solid content > 50%, and the ultraviolet absorber is a hindered amine light stabilizer to improve the weather resistance of the material.

[0041] (9) The pigments added to the manhole cover material in the present application not only give the product the required color but also can provide additional functions, such as improving weather resistance, enhancing recognition, and aesthetics. Detailed implementation mode

[0042] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0043] In the description of the present invention, the meaning of several is more than one, and the meaning of multiple is more than two. Understand greater than, less than, exceeding, etc. as not including the number itself, and understand above, below, within, etc. as including the number itself. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0044] In this article, "optionally", "optional", "optional" mean having or not having, that is, any one selected from two parallel options of "having" or "not having". If there are multiple "optional" in a technical solution, without special instructions and without contradictions or mutual restrictions, each "optional" is independent. In the present application, descriptions such as "optionally contain" and "optionally include" mean "contain or not contain".

[0045] In the present invention, unless otherwise specified, the sum of the parts by weight of the components in the composition may be 100 parts by weight. Unless otherwise indicated, the basis of the percentages (including weight percentages) in the present invention is the total weight of the composition. Additionally, "wt%" herein represents mass percentage.

[0046] In this application, when it comes to numerical ranges (i.e., numerical intervals), unless otherwise specified, the distribution of the optional numerical values within the numerical range is considered continuous and includes the two numerical endpoints of the numerical range (i.e., the minimum value and the maximum value), as well as each numerical value between these two numerical endpoints. Unless otherwise specified, when the numerical range only refers to integers within the numerical range, it includes the two endpoint integers of the numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all sub-ranges subsumed therein. The "numerical values" in the numerical range can be any quantitative values, such as numbers, percentages, ratios, etc. The "numerical range" allows for a broad inclusion of quantitative intervals such as percentage intervals, ratio intervals, and ratio value intervals.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention pertains. 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. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0048] The embodiments of this application provide a reinforced composite structural material for road manhole covers to solve the problem that in the prior art, composite materials for manhole covers of various types of urban pipe corridors and manholes all have certain defects and cannot meet the characteristics of low carbon emissions, high strength, light weight, high flame retardancy, corrosion resistance, super toughening, cold and heat resistance, and high wave transmission. The following will describe the reinforced composite structural material for road manhole covers. The reinforced composite structural material for road manhole covers provided by the embodiments of this application can be used for the preparation of manhole covers.

[0049] Exemplarily, a reinforced composite structural material for road manhole covers includes the following raw materials in parts by weight:

[0050] 20 - 25 parts of thermosetting resin;

[0051] 25 - 35 parts of reinforcing fiber;

[0052] 5 - 30 parts of filler;

[0053] 5 - 15 parts of thermoplastic polymer;

[0054] Initiator: 0.1 - 0.5 parts;

[0055] Release agent: 0.5 - 1 part;

[0056] Flame retardant: 2 - 25 parts;

[0057] Curing agent: 6.5 - 19 parts;

[0058] Pigment: 1 - 2 parts.

[0059] In some embodiments, the thermosetting resin includes one or more of unsaturated polyester resin, epoxy resin, and vinyl ester resin.

[0060] In some embodiments, the thermosetting resin includes a modified maleic resin, and the modified maleic resin is obtained by modifying the maleic resin using one or more of copolymer modification, crosslinking modification, introduction of flexible chain segments, addition of functional functional groups, compounding of filler and reinforcing materials, conductivity modification, and biodegradability modification.

[0061] In some embodiments, the reinforcing fiber includes glass fiber, carbon fiber, or other synthetic fibers. When glass fiber, carbon fiber, or other synthetic fibers are combined with matrix materials such as resin, a composite material is formed, and this composite material has a high strength - to - weight ratio, good corrosion resistance, and fatigue resistance.

[0062] In some of these embodiments, the filler includes one or several of quartz sand, calcium carbonate, talcum powder, rubber, and reinforcing ribs. Quartz sand, calcium carbonate, talcum powder, rubber, and reinforcing ribs each play different roles, and they work together to improve the performance of the manhole cover. The following are the specific functions of these materials in the manhole cover: (1) Quartz sand: Enhance wear resistance: Quartz sand is a mineral with relatively high hardness. Adding it to the manhole cover material can significantly improve the wear resistance of its surface. Filler: It is used as a filler in the composite material, helping to adjust the density and cost of the material. (2) Calcium carbonate: Reduce cost: As an inexpensive filler, calcium carbonate can help reduce the cost of the composite material. Improve processing performance: It can improve the fluidity of some matrix materials (such as plastics), making the production process smoother. Adjust hardness and toughness: Appropriate addition can affect the hardness and toughness of the final product, making it more in line with the usage requirements. (3) Talcum powder: Lubricating effect: Talcum powder has good lubricating properties. It can reduce die wear during the manufacturing process and make the product easier to demold. Increase flexibility: It helps to improve the flexibility and impact resistance of the material while maintaining a relatively low density. Enhance heat resistance: For some application scenarios that need to withstand relatively high temperatures, talcum powder can provide additional heat protection. (4) Rubber: Sealing and shock absorption: Rubber is often used at the edge or bottom of the manhole cover as a sealing strip or gasket to prevent water and dirt from entering. At the same time, it also plays a shock-absorbing role, reducing the noise generated when vehicles pass by. Elastic recovery: Due to its excellent elasticity and small compression set, rubber can enable the manhole cover to better adapt to uneven ground conditions and ensure a tight fit with the road surface after long-term use. (5) Reinforcing ribs: Structural support: Reinforcing ribs are usually made of metal (such as steel bars) or non-metallic fibers (such as glass fibers). They are embedded inside the manhole cover to provide additional structural support, enhancing the overall stiffness and load-bearing capacity. Disperse stress: Effectively disperse the pressure applied to the manhole cover, avoiding breakage caused by local overload. In summary, these components improve the functionality and durability of the manhole cover in different ways, meeting the requirements of modern urban infrastructure for safety, efficiency, and economy.

[0063] In some of these embodiments, the thermoplastic polymer includes one or several of polystyrene, polypropylene, polyvinyl chloride, polyethylene, nylon, polycarbonate, ABS resin, modified polypropylene, and thermoplastic polyurethane.

[0064] Among them, Polyethylene (PE): including High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE), has good impact resistance and chemical corrosion resistance. Polypropylene (PP): has relatively high strength, hardness and elastic modulus, and also shows good wear resistance and chemical resistance. Polyvinyl Chloride (PVC-U or PVC-C): Unplasticized Polyvinyl Chloride (PVC-U) is widely used in applications requiring good mechanical properties and chemical resistance; Chlorinated Polyvinyl Chloride (PVC-C) has higher temperature stability and chemical resistance. Polystyrene (PS): including General-Purpose Polystyrene (GPPS) and High-Impact Polystyrene (HIPS), although its mechanical properties are not as good as the above-mentioned materials, it can provide sufficient performance under specific circumstances. Nylon (Nylon, PA): varieties such as Nylon 6 or Nylon 66, have excellent mechanical properties, wear resistance and self-lubrication, and are suitable for manufacturing components with high strength requirements. Polycarbonate (PC): Polycarbonate is famous for its excellent impact strength and transparency, but in the application of manhole covers, its strength and toughness are more utilized. ABS resin (Acrylonitrile Butadiene Styrene): ABS is an engineering plastic that combines the hardness of acrylonitrile, the toughness of butadiene and the processability of styrene, and is often used to make products with complex shapes. Modified Polypropylene (MPP): Modified polypropylene can improve its mechanical properties and dimensional stability by adding glass fibers, mineral fillers, etc. Thermoplastic Polyurethane (TPU): provides excellent elasticity and wear resistance, and can be used to strengthen the edge of the manhole cover or other parts requiring high elasticity.

[0065] In some of these embodiments, the initiator is one or more of peroxide initiators, azo initiators, photoinitiators, red phosphorus and organometallic compounds, anhydride initiators, amine initiators.

[0066] In some of these embodiments, the initiator may specifically include the following types. Peroxide initiators: Peroxides such as benzoyl peroxide (BPO) and di-tert-butyl peroxide are commonly used in thermosetting resins such as unsaturated polyester resins. They decompose to generate free radicals under heating conditions, thereby initiating the polymerization reaction of monomers. Azo initiators: Azobisisobutyronitrile (AIBN) is a common azo initiator suitable for various types of free radical polymerization reactions. It can decompose into free radicals at relatively low temperatures, making it suitable for some applications that require low-temperature curing. Photoinitiators: If the manufacturing process of the manhole cover material involves ultraviolet curing technology, photoinitiators such as acetophenone derivatives and benzophenone will be used. Photoinitiators decompose under ultraviolet light irradiation to generate free radicals or other reactive species, promoting the rapid curing of the resin. Red phosphorus and organometallic compounds: In some special cases, red phosphorus or organometallic compounds may be used as initiators, especially when specific catalytic effects are required. However, the application of such initiators is relatively rare. Acid anhydride initiators: For example, maleic anhydride can participate in the reaction as a comonomer or crosslinking agent, which helps to improve the heat resistance and mechanical properties of the final product. Amine initiators: Certain amine substances can also be used as initiators. Especially in the epoxy resin system, amines can not only act as curing agents but also play an initiating role.

[0067] In some of these embodiments, the release agent is one or a mixture of zinc stearate, calcium stearate, and a solution of a copolymer of a low molecular weight unsaturated acidic polycarboxylic acid polyester and polysiloxane.

[0068] In some of these embodiments, the flame retardant includes one or more of halogen-based flame retardants, phosphorus-based flame retardants, metal hydroxides, intumescent flame retardants, nitrogen-based flame retardants, nanomaterials, and boron compounds.

[0069] In some of these embodiments, the flame retardant may specifically include the following types:

[0070] Halogen-based flame retardants: Include bromine-based (such as decabromodiphenyl ether) and chlorine-based flame retardants. These flame retardants release hydrogen halide gas during combustion, which can dilute combustible gases and interrupt the combustion chain reaction. However, due to the possible generation of toxic smoke and corrosive gases during combustion, their use is restricted to some extent.

[0071] Phosphorus-based flame retardants: Such as red phosphorus, phosphate esters, etc. These substances can form a char layer on the material surface through dehydration and carbonization, playing the role of heat insulation and oxygen isolation, thereby preventing the spread of flames. Phosphorus-based flame retardants are relatively environmentally friendly and are widely used.

[0072] Metal hydroxides: mainly include aluminum hydroxide (Al(OH) 3 ) and magnesium hydroxide (Mg(OH) 2 ). When these two substances decompose upon heating, they absorb a large amount of heat and release water vapor simultaneously, which helps to cool down and dilute combustible gases. They are considered environmentally friendly flame retardants, but usually a relatively large addition amount is required to achieve an ideal flame retardant effect.

[0073] Intumescent flame retardants: composed of an acid source, a carbon source, and a gas source. When exposed to fire, they will expand to form a porous foam-like carbon layer, effectively isolating the flame from the substrate and preventing heat transfer. Intumescent flame retardants are commonly used in composite materials, such as modified polypropylene or polyethylene.

[0074] Nitrogen-based flame retardants: include melamine and its derivatives. These flame retardants mainly dilute the concentration of combustible gases by releasing non-combustible gases (such as ammonia), and at the same time can also promote the carbonization process.

[0075] Nanomaterials: Nanoscale fillers such as nanoclay, nanosilica, etc. can be dispersed in the polymer matrix, improving the mechanical properties of the material while also providing a certain degree of flame retardancy. Nanomaterials can enhance the thermal stability of the material and reduce its thermal conductivity.

[0076] Boron compounds: such as zinc borate, have a certain smoke suppression effect and can be used in combination with other flame retardant systems to improve the overall flame retardant performance.

[0077] In some of the embodiments, the curing agent includes one or more of amine curing agents, acid anhydride curing agents, peroxide curing agents, imidazole curing agents, phenolic resin curing agents, mercaptan curing agents, and metal salt curing agents.

[0078] In some of the embodiments, the curing agent may include the following specific types:

[0079] Amine curing agents: commonly found in epoxy resin systems, such as aliphatic amines, aromatic amines, and modified amines. Amine curing agents can react with epoxy groups to form a three-dimensional network structure, improving the mechanical properties and chemical resistance of the material.

[0080] Acid anhydride curing agents: such as phthalic anhydride, maleic anhydride, etc., are suitable for unsaturated polyester resins and vinyl ester resins. Acid anhydride curing agents achieve curing by undergoing a cycloaddition reaction with the double bonds in the resin, and usually heating is required to accelerate the reaction rate.

[0081] Peroxide curing agents: such as methyl ethyl ketone peroxide (MEKP), dicumyl peroxide (DCP), etc., are widely used in unsaturated polyester resins. These curing agents decompose to generate free radicals, initiating polymerization reactions, and are particularly suitable for room temperature curing application scenarios.

[0082] Imidazole curing agents: Belonging to high-efficiency low-temperature curing agents, mainly used in epoxy resin systems. Imidazole and its derivatives can promote the curing of epoxy resins at relatively low temperatures and can provide good physical properties and heat resistance.

[0083] Phenolic resin curing agents: Phenolic resins themselves can be used as curing agents in combination with other types of resins, especially showing excellent thermal stability and mechanical strength under high-temperature conditions.

[0084] Thiol curing agents: Thiols and their derivatives can be used as curing agents for certain special resins, providing fast curing characteristics as well as good flexibility and impact resistance.

[0085] Metal salt curing agents: Certain metal salts, such as cobalt salts, manganese salts, etc., can be used as catalysts or auxiliary curing agents to promote the action of peroxide curing agents, accelerate the curing speed and improve the surface quality.

[0086] In some of the embodiments, the pigment includes one or more of inorganic pigments, organic pigments, pearlescent pigments, fluorescent pigments, metallic pigments, conductive pigments, and heat-insulating pigments.

[0087] In some of the embodiments, the pigments may specifically include the following types:

[0088] (1) Inorganic pigments: Iron oxide (Fe 2 O 3 ): Red or yellow, having good weather resistance and chemical resistance, and widely used in concrete and composite materials. Titanium dioxide (TiO 2):White, one of the most commonly used white pigments, has high hiding power and excellent weather resistance, and is suitable for a variety of substrates. Carbon black: Black, provides extremely high ultraviolet absorption ability and wear resistance, and is commonly used in plastic and rubber products. Ultramarine: Blue, composed of sodium aluminosilicate, has good weather resistance and chemical resistance. Lead Chromate: Yellow, but its use is strictly restricted due to the presence of lead. (2) Organic pigments: Azo pigments: Have a wide range of colors, from yellow to red, have good light fastness and solvent resistance, but are generally less durable than inorganic pigments. Phthalocyanine Blue / Green: Provide bright blue and green colors, have excellent light fastness and chemical resistance, and are commonly used pigments in modern coatings and plastics. Quinacridone: Provide bright red-violet colors, have good light fastness and chemical resistance. (3) Pearlescent pigments: Such as mica titanium, can produce a pearl-like luster effect and increase the visual appeal of the product. (4) Fluorescent pigments: Emit light under ultraviolet light, can be used to improve night visibility, but generally have poor durability. (5) Metallic pigments: Such as aluminum powder or copper gold powder, can provide a metallic luster to the surface, enhancing the decorative property and recognition. (5) Functional pigments: Conductive pigments: Such as conductive carbon black or metal powders, can provide electrostatic dissipation function in specific applications. Heat-insulating pigments: Certain ceramic pigments or hollow microspheres can reflect infrared rays, helping to reduce the surface temperature of the material. It should be noted that the enhanced composite structural material for road manhole covers in this application can select the corresponding pigments according to the actual application scenario.

[0089] In some of these embodiments, the enhanced composite structural material for the road manhole cover further includes 0.1 to 0.5 parts of an ultraviolet light stabilizer. The role of the ultraviolet light stabilizer in the manhole cover material is mainly reflected in protecting the material from damage by ultraviolet (UV) radiation, thereby extending the service life of the manhole cover and maintaining its performance. The following are the specific functions of the ultraviolet light stabilizer: (1) Preventing material aging: Ultraviolet rays can cause photo-oxidative degradation of polymer materials (such as plastics, rubbers, etc.). This degradation causes the material to gradually lose its original mechanical strength, flexibility, and other physical properties. The ultraviolet light stabilizer can absorb or reflect ultraviolet rays, inhibit the occurrence of photo-oxidation reactions, and thus slow down the aging process of the material. (2) Maintaining appearance quality: When exposed to ultraviolet rays for a long time, the surface of the manhole cover may fade, turn yellow, or become powdered, affecting its appearance. Adding an ultraviolet light stabilizer helps to maintain the color and surface gloss of the manhole cover, ensuring that its appearance remains in good condition for a long time. (3) Enhancing weather resistance: In an outdoor environment, the manhole cover has to face not only ultraviolet radiation but also the influence of factors such as temperature changes and humidity fluctuations. The ultraviolet light stabilizer can improve the overall resistance of the material to these environmental factors, making it more durable. (4) Reducing maintenance costs: By effectively preventing material damage caused by ultraviolet rays, the ultraviolet light stabilizer can help reduce the frequent repair or replacement requirements due to material deterioration, thereby reducing long-term maintenance costs. (5) Ensuring safety and functionality: For some specific application scenarios, such as busy roads or special areas (such as airport runways), the safety and functionality of the manhole cover are crucial. The ultraviolet light stabilizer ensures that the manhole cover can maintain its due structural integrity and usage function for a long time, avoiding potential safety hazards caused by material failure. (6) Environmental protection: Using an ultraviolet light stabilizer can extend the product life cycle, reduce waste generation, conform to modern environmental protection concepts, and contribute to sustainable development.

[0090] In some of these embodiments, the ultraviolet light stabilizer includes a hindered amine light stabilizer.

[0091] In some of these embodiments, the enhanced composite structural material for the road manhole cover further includes 0.4 to 1 part of magnesium oxide paste. The application of magnesium oxide paste (usually made by mixing magnesium oxide powder with other liquids) in the manhole cover material is relatively rare, but in specific cases, it can indeed play some unique roles. The following are the possible roles of magnesium oxide paste in the manhole cover material: (1) Enhancing corrosion resistance: Magnesium oxide has good chemical stability and a certain resistance to acids and alkalis. When used in the manhole cover material, especially in the surface treatment of metal manhole covers or as part of a composite material, it can provide additional anti-corrosion protection. (2) Improving thermal stability: Magnesium oxide is a high-temperature resistant material that can withstand relatively high temperatures without significant physical or chemical changes. Therefore, in some application scenarios that require good thermal stability, such as areas close to heat sources, magnesium oxide paste can be used to improve the heat resistance of the manhole cover material. (3) Promoting curing and bonding: In some cement-based or other inorganic matrix manhole cover materials, magnesium oxide can be used as a coagulant or strengthening agent to help accelerate the hardening process of the material and enhance the bonding strength between different material layers. (4) Adjusting the pH value: Due to its alkaline properties, magnesium oxide can play a neutralizing role in an environment containing acidic components, thereby maintaining the pH balance of the internal environment of the material system and helping to prevent material deterioration.

[0092] In some of these embodiments, the magnesium oxide paste is magnesium oxide with a 50% content and a viscosity less than 6000 mPa·s.

[0093] In some of these embodiments, the enhanced composite structural material for the road manhole cover further includes a luminescent material, and the weight part of the luminescent material is 1 to 10 parts. The luminescent material includes one or more of an LED lamp, a phosphor coating, a photoluminescent ceramic, an optical fiber, a self-luminous coating, and a solar panel.

[0094] LED Lights: LEDs (Light Emitting Diodes) are currently one of the most commonly used lighting technologies and are widely popular due to their high efficiency, low power consumption, and long lifespan. LEDs can be designed in different colors and their blinking patterns or brightness can be controlled through programming. Phosphor Coating: Phosphor is a substance that can emit visible light after absorbing light of a certain wavelength. When exposed to natural light during the day, it stores energy and releases it at night or in dark environments. This material is usually combined with resin or other protective layers to enhance its wear resistance and impact resistance. Photoluminescent Ceramics: Photoluminescent ceramics are a new type of material that can continue to emit light for several hours or even longer after being illuminated. This material has good chemical stability and mechanical strength and is suitable for long-term outdoor use. Optical Fibers: Optical fibers can transmit light sources from a distance to the surface of the manhole cover to achieve an indirect lighting effect. Their advantages include being almost unaffected by electromagnetic interference and being able to provide a uniform and soft light distribution. Self-luminous Paint: Self-luminous paint contains radioactive isotopes or non-radioactive self-luminous compounds, such as certain types of sulfides. This type of paint can continue to emit light without an external power source, but it is necessary to ensure that the materials used are harmless to human health and meet environmental protection standards. Solar Panel + Energy Storage System: Combine solar panels to collect solar energy and store it in an internal battery to power the LED and other lighting components at night.

[0095] In some of these embodiments, the enhanced composite structural material for the road manhole cover further includes graphene material, and the weight portion of the luminescent material is 1 part to 10 parts. As a two-dimensional material with unique physical and chemical properties, graphene has extremely high strength, excellent electrical conductivity and thermal conductivity, as well as good flexibility. These characteristics enable graphene to be used in the manufacture of road manhole covers. In this application, the beneficial effects of graphene material applied to road manhole covers include: High Strength-to-Weight Ratio: The strength of graphene is 200 times that of steel, but its density is much lower than that of steel. Therefore, adding graphene can significantly improve the mechanical properties of the manhole cover, such as compressive strength, impact resistance, etc., while maintaining a lower weight, which is convenient for installation and maintenance. Corrosion Resistance: Graphene has excellent chemical stability and is not easily eroded by substances such as acids, alkalis, and salts, which helps to extend the service life of the manhole cover, especially in areas with severe corrosion environments such as coastal areas or chemical industrial zones. Electrical Conductivity and Anti-static Function: If the manhole cover needs to have a certain electrical conductivity (for example, for electromagnetic shielding) or prevent static electricity accumulation, the high electrical conductivity of graphene is an ideal choice. Thermal Management: The excellent thermal conductivity of graphene can help the manhole cover dissipate heat better and avoid problems such as material aging caused by excessive temperature. Self-repair and Intelligent Features: Combining graphene with other intelligent materials endows the manhole cover with the ability of self-repair or integrates sensors to monitor the status of the manhole cover and timely feedback information to the management department.

[0096] In some of these embodiments, the graphene material includes one or more of monolayer graphene, bilayer or multilayer graphene, graphene oxide, reduced graphene oxide, graphene quantum dots, graphene nanoribbons, graphene foam / aerogel.

[0097] An embodiment of the present application also provides a manhole cover.

[0098] A manhole cover is prepared from the enhanced composite structural material for road manhole covers in any of the above embodiments.

[0099] Example 1

[0100] This example provides an enhanced composite structural material for road manhole covers.

[0101] The enhanced composite structural material for road manhole covers in this example includes the following components:

[0102] Thermosetting resin: 25 parts of modified maleic resin;

[0103] Reinforcing fiber: 35 parts of glass fiber;

[0104] Filler: 30 parts of quartz sand;

[0105] Thermoplastic polymer: 15 parts of polystyrene and polyethylene, wherein the mass ratio of polystyrene to styrene is 1:2;

[0106] Initiator: 0.5 part of di-tert-butyl peroxide;

[0107] Release agent: 1 part of zinc stearate;

[0108] Flame retardant: 20 parts of aluminum hydroxide;

[0109] Curing agent: 10 parts of dicumyl peroxide;

[0110] Pigment: 2 parts of iron oxide;

[0111] Ultraviolet stabilizer: 0.5 part of hindered amine light stabilizer;

[0112] 1 part of magnesium oxide paste.

[0113] When preparing the enhanced composite structural material for road manhole covers in this example, the following steps are included:

[0114] 1), Add the thermosetting resin modified maleic resin, glass fiber, filler quartz sand, polystyrene, styrene, and initiator to the reaction kettle and stir for 20 minutes at a stirring speed of 2000 revolutions per minute.

[0115] 2), Add a mold release agent, aluminum hydroxide as a flame retardant, dicumyl peroxide as a curing agent, aluminum powder as a pigment, and hindered amine light stabilizer as an anti-ultraviolet stabilizer to the stirred reaction kettle, and continue stirring for 30 minutes at a rotation speed of 2000 revolutions per minute until the temperature reaches 50°C.

[0116] 3), After stopping the stirring, add magnesium oxide paste, continue stirring for 5 minutes, and let the mixture flow into a molding machine for molding to obtain a high-strength reinforced composite structure material.

[0117] Example 2

[0118] This example provides a reinforced composite structure material for road manhole covers.

[0119] The reinforced composite structure material for road manhole covers in this example includes the following components:

[0120] Thermosetting resin: 20 parts of modified maleic resin;

[0121] Reinforcing fiber: 25 parts of glass fiber;

[0122] Filler: 5 parts of quartz sand;

[0123] Thermoplastic polymer: 5 parts of polystyrene and styrene, where the mass ratio of polystyrene to styrene is 1:3;

[0124] Initiator: 0.1 part of di-tert-butyl peroxide;

[0125] Mold release agent: 0.5 part of zinc stearate;

[0126] Flame retardant: 0.5 part;

[0127] Curing agent: 6.5 parts of dicumyl peroxide;

[0128] Pigment: 1 part;

[0129] Anti-ultraviolet stabilizer: 0.1 part of hindered amine light stabilizer;

[0130] 0.4 part of magnesium oxide paste.

[0131] When preparing the reinforced composite structure material for road manhole covers in this example, the following steps are included:

[0132] 1), Add the thermosetting resin modified maleic resin, glass fiber, filler quartz sand, polystyrene, styrene, and initiator to the reaction kettle and stir for 20 minutes at a stirring speed of 2000 revolutions per minute.

[0133] 2), Add a mold release agent, aluminum hydroxide as a flame retardant, dicumyl peroxide as a curing agent, aluminum powder as a pigment, and hindered amine light stabilizer as an anti-ultraviolet stabilizer to the stirred reaction kettle, and continue stirring for 30 minutes at a rotation speed of 2000 revolutions per minute until the temperature reaches 45°C.

[0134] 3), After stopping the stirring, add magnesium oxide paste, continue stirring for 3 minutes, and let the mixture flow into a molding machine for molding to obtain a high-strength reinforced composite structural material.

[0135] Example 3

[0136] This example provides a reinforced composite structural material for road manhole covers.

[0137] The reinforced composite structural material for road manhole covers in this example includes the following components:

[0138] Thermosetting resin: 23 parts of modified maleic resin;

[0139] Reinforcing fiber: 30 parts of glass fiber;

[0140] Filler: 15 parts of quartz sand;

[0141] Thermoplastic polymer: 10 parts of polystyrene and styrene, where the mass ratio of polystyrene to styrene is 1:2.5;

[0142] Initiator: 0.3 part of di-tert-butyl peroxide;

[0143] Mold release agent: 0.8 part of zinc stearate;

[0144] Flame retardant: 1 part of decabromodiphenyl ether;

[0145] Curing agent: 20 parts of dicumyl peroxide;

[0146] Pigment: 1.5 parts of iron oxide;

[0147] Anti-ultraviolet stabilizer: 0.25 part of hindered amine light stabilizer;

[0148] 0.7 part of magnesium oxide paste;

[0149] Luminescent material: 5 parts of fluorescent powder;

[0150] Graphene material: 5 parts of graphene quantum dots.

[0151] When preparing the reinforced composite structural material for road manhole covers in this example, the following steps are included:

[0152] 1), Add the thermosetting resin modified maleic resin, glass fiber, filler quartz sand, polystyrene, styrene, and initiator to the reaction kettle and stir for 20 minutes at a stirring speed of 2000 revolutions per minute.

[0153] 2), Add a mold release agent, aluminum hydroxide as a flame retardant, dicumyl peroxide as a curing agent, aluminum powder as a pigment, and hindered amine light stabilizer as an anti-ultraviolet stabilizer to the stirred reaction kettle, and continue stirring for 30 minutes at a rotation speed of 2000 revolutions per minute until the temperature reaches 48°C.

[0154] 3), After stopping stirring, add magnesium oxide paste, continue stirring for 4 minutes, and let the mixture flow into a molding machine for molding to obtain a high-strength reinforced composite structural material.

[0155] Comparative Example 1

[0156] This comparative example provides a reinforced composite structural material for road manhole covers.

[0157] The reinforced composite structural material for road manhole covers in this comparative example is basically the same as that in Example 1, except that Comparative Example 1 does not contain reinforcing fibers. The reinforced composite structural material for road manhole covers is prepared according to the preparation method of Example 1.

[0158] Comparative Example 2

[0159] This comparative example provides a reinforced composite structural material for road manhole covers.

[0160] The reinforced composite structural material for road manhole covers in this comparative example is basically the same as that in Example 1, except that Comparative Example 2 does not contain quartz sand as a filler. The reinforced composite structural material for road manhole covers is prepared according to the preparation method of Example 1.

[0161] Comparative Example 3

[0162] This comparative example provides a reinforced composite structural material for road manhole covers.

[0163] The reinforced composite structural material for road manhole covers in this comparative example is basically the same as that in Example 2, except that the thermoplastic polymer in Comparative Example 3 does not contain polyethylene. The reinforced composite structural material for road manhole covers is prepared according to the preparation method of Example 2.

[0164] Comparative Example 4

[0165] This comparative example provides a reinforced composite structural material for road manhole covers.

[0166] The reinforced composite structural material for road manhole covers in this comparative example is basically the same as that in Example 2, except that Comparative Example 4 does not contain an anti-ultraviolet stabilizer. The reinforced composite structural material for road manhole covers is prepared according to the preparation method of Example 2.

[0167] Comparative Example 5

[0168] This comparative example provides a reinforced composite structural material for road manhole covers.

[0169] The reinforced composite structural material for road manhole covers in this comparative example is basically the same as that in Example 3, except that magnesium oxide paste is not contained in Comparative Example 5. The reinforced composite structural material for road manhole covers is prepared according to the preparation method of Example 3.

[0170] The materials of Examples 1-3 and Comparative Examples 1-5 were tested, and the results are shown in Table 1:

[0171] Table 1

[0172]

[0173]

[0174] In summary, for the above-mentioned reinforced composite structural material for road manhole covers, the beneficial effects of the embodiments of the present invention are as follows:

[0175] (1) This application uses thermosetting resin as the matrix material, such as unsaturated polyester resin, epoxy resin or vinyl ester resin, etc. Thermosetting resin provides good mechanical properties, corrosion resistance and moldability. Specifically, the modified maleic resin used herein improves the weather resistance of the material, reduces the water absorption rate, and increases the electrical properties of the material.

[0176] (2) In order to improve the strength and stiffness of the material, this application adds reinforcing fibers, such as glass fibers, carbon fibers or other synthetic fibers, so that the material has a high strength-to-weight ratio and cost-effectiveness. Preferably, the reinforcing fiber in this application is a reinforcing fiber with a low dielectric constant and a length exceeding 100 mm, which improves the wave transmission performance and mechanical properties of the material.

[0177] (3) This application increases the volume stability and reduces the shrinkage rate by adding fillers, such as adding inorganic fillers such as quartz sand, calcium carbonate, and talcum powder, and can adjust the density and cost of the product.

[0178] (4) An initiator is added during the manufacturing process of the manhole cover material. Initiators are usually used to promote or accelerate chemical reactions, especially when dealing with polymer-based composite materials. The main role of the initiator is to initiate the polymerization reaction between monomer molecules, enabling these small molecules to connect into long-chain macromolecules (i.e., polymers).

[0179] (5) A flame retardant is added to the manhole cover material to improve the fire resistance of the material, reduce the fire risk, and delay the spread of flames. Different types of flame retardants act through different mechanisms, such as absorbing heat, diluting combustible gases, forming a protective layer, or inhibiting the combustion chain reaction, etc.

[0180] (6) The curing agent (also known as hardener or crosslinking agent) used in this application plays a crucial role in the manhole cover material. Especially in a resin-based composite material system, the curing agent is used to promote or accelerate the crosslinking reaction of thermosetting resins, thereby converting the liquid or semi-solid resin into a hard and stable solid structure.

[0181] (7) This application uses fillers such as inorganic fillers like quartz sand, calcium carbonate, and talc powder to increase volume stability, reduce shrinkage rate, and can adjust the density and cost of the product.

[0182] (8) The UV color paste used has a viscosity less than 6000 mPa.s, a solid content > 50%, and the UV absorber is a hindered amine light stabilizer to improve the weather resistance of the material.

[0183] (9) The pigments added to the manhole cover material in this application not only give the product the required color but also provide additional functions such as improving weather resistance, enhancing recognition, and aesthetics.

[0184] (9) This application adds luminescent materials to the manhole cover material to improve the recognition of the manhole cover and enhance safety.

[0185] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0186] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0187] The above-described embodiments only represent several implementation manners of the present invention. The descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be subject to the appended claims.

Claims

1. A reinforced composite structural material for road manhole covers, characterized in that: The invention comprises the following raw materials in parts by weight: 20-25 parts of thermosetting resin; Reinforcement fiber 25-35 parts; 5 to 30 portions of filling; 5-15 parts of thermoplastic polymer; Initiator 0.1-0.5 parts; 0.5-1 part of release agent; Flame retardant 2-25 parts; 6.5-19 parts of curing agent; 1 to 2 parts of pigment.

2. The reinforced composite structural material for road manhole covers according to claim 1, characterized in that: The thermosetting resin includes one or more of unsaturated polyester resin, epoxy resin and vinyl ester resin; And / or, the thermosetting resin includes a modified maleic acid resin, and the modified maleic acid resin is obtained by one or more of the following methods: copolymer modification, cross-linking modification, introduction of flexible segments, addition of functional groups, composite filling and reinforcing materials, conductivity modification, and biodegradability modification of maleic acid resin; And / or, the reinforcing fibers include glass fibers, carbon fibers or other synthetic fibers.

3. The reinforced composite structural material for road manhole covers according to claim 1, characterized in that: The filler includes one or more of quartz sand, calcium carbonate, talcum powder, rubber, and reinforcing ribs; And / or, the thermoplastic polymer includes one or more of polystyrene, polypropylene, polyvinyl chloride, polyethylene, nylon, polycarbonate, ABS resin, modified polypropylene, and thermoplastic polyurethane; And / or, the initiator is one or more of peroxide initiators, azo initiators, photoinitiators, red phosphorus and organic metal compounds, anhydride initiators, and amine initiators.

4. The reinforced composite structural material for road manhole covers according to claim 1, characterized in that: The release agent is one or a mixture of zinc stearate, calcium stearate, and a solution of a low molecular weight unsaturated acidic polycarboxylic acid polyester and a polysiloxane copolymer; And / or, the flame retardant includes one or more of halogen flame retardants, phosphorus flame retardants, metal hydroxides, intumescent flame retardants, nitrogen flame retardants, nanomaterials, and boron compounds; And / or, the curing agent includes one or more of an amine curing agent, an acid anhydride curing agent, a peroxide curing agent, an imidazole curing agent, a phenolic resin curing agent, a thiol curing agent, and a metal salt curing agent.

5. The reinforced composite structural material for road manhole cover according to any one of claims 1 to 4, characterized in that: The pigment includes one or more of inorganic pigments, organic pigments, pearlescent pigments, fluorescent pigments, metallic pigments, conductive pigments, and heat-insulating pigments.

6. The reinforced composite structural material for road manhole cover according to any one of claims 1 to 4, characterized in that: The reinforced composite structural material for road manhole covers also includes 0.1 to 0.5 parts of an anti-ultraviolet stabilizer.

7. The reinforced composite structural material for road manhole covers according to claim 6, characterized in that: The anti-ultraviolet light stabilizer includes a hindered amine light stabilizer.

8. The reinforced composite structural material for road manhole covers according to any one of claims 1 to 4 and 7, characterized in that: The reinforced composite structural material for road manhole covers also includes 0.4 to 1 part of magnesium oxide paste, wherein the magnesium oxide paste contains 50% magnesium oxide and has a viscosity of less than 6000 mPa.s.

9. The reinforced composite structural material for road manhole cover according to any one of claims 1 to 4 and 7, characterized in that: The reinforced composite structural material for road manhole covers also includes a luminescent material, the weight portion of the luminescent material is 1 to 10 parts, and the luminescent material includes one or more of LED lamps, fluorescent powder coatings, photoluminescent ceramics, optical fibers, self-luminous coatings, and solar panels; And / or, the reinforced composite structural material for road manhole covers also includes graphene material, and the weight proportion of the luminescent material is 1 to 10 parts.

10. A manhole cover, characterized in that: The manhole cover is made of the reinforced composite structural material for road manhole covers as claimed in any one of claims 1 to 9.

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