Structure of polyurethane asphalt adhesive with interlayer synergistic effect

Abstract

The utility model discloses a structure of a polyurethane asphalt adhesive with an interlayer synergistic effect. The structure comprises a four-layer composite structure consisting of a base material bonding layer, a transition buffer layer, an anti-permeation functional layer and a surface protection layer. According to the utility model, a novel anti-corrosion structure layer which integrates the advantages of high interface strength, high toughness, stress dispersion, wear resistance, low expansion, flame retardance and the like is formed through multi-layer compounding, and the anti-corrosion structure layer can be used for a concrete structure or a metal matrix of an anti-corrosion lining system.

Description

Technical Field

[0001] This utility model relates to the structure of a polyurethane asphalt adhesive with interlayer synergistic effect, and belongs to the field of polyurethane asphalt adhesives. Background Technology

[0002] With advancements in polyurethane chemical research, product manufacturing, and application technologies, as well as the continuous expansion of its application areas, six major synthetic material systems have gradually formed worldwide, including the polyurethane asphalt industrial system. Over the past 20 years, the variety, application areas, and scale of polyurethane products have expanded rapidly, making it one of the most important polymer synthetic materials and accounting for an increasingly larger proportion in the entire chemical industry. New technologies, materials, and processes are constantly emerging. However, in the field of industrial corrosion protection, especially in the corrosion protection of chimneys in power plants, the problems encountered are more severe. Chimneys, as key facilities for industrial waste gas emissions, are exposed for long periods to high temperatures, high humidity, and highly corrosive gases (such as SO3 and NO). x In extreme environments such as those containing sulfur dioxide (HCl, etc.) and condensate corrosion, especially in coal-fired power plants, chemical plants, and metallurgical plants, the interior of the chimney is a high-temperature environment. Sulfur-containing flue gas can generate strong acids such as H2SO4 and H2SO3 when it comes into contact with condensate. Frequent start-ups and shutdowns or fluctuations in operating conditions cause drastic temperature changes, and the ash particles carried by the flue gas can also cause erosion and wear on the anti-corrosion coating inside the chimney.

[0003] To date, commonly used chimney anti-corrosion materials include the following: epoxy resin coatings, characterized by strong adhesion and good chemical corrosion resistance, but with poor temperature resistance, prone to embrittlement and cracking at high temperatures, and a significant difference in thermal expansion coefficient compared to concrete chimney substrates, making them prone to peeling due to thermal stress; glass flake coatings, characterized by excellent impermeability and ability to block the diffusion of acidic media, but with insufficient resilience and poor thermal shock resistance (the flake interface is prone to detachment after thermal cycling), and complex construction process (requiring multiple layers of coating); and silicone rubber coatings, which have good elasticity and high temperature resistance (short-term temperature resistance up to 300℃), but low bonding strength with the chimney substrate metal or concrete, and are prone to aging under long-term high temperatures.

[0004] Polyurethane products have gradually reached a significant scale and are closely related to people's lives. Polyurethane foam was the first type of polyurethane product developed, and its lightweight, low density, and high strength characteristics have gained widespread acceptance. In the petrochemical industry, polyurethane asphalt adhesives have been developed, and due to their superior tensile strength, elongation, and other chemical properties, they are also used in industrial corrosion protection. Polyurethane adhesives, widely used in industrial corrosion protection, often encounter problems such as delamination, blistering, cracking, and peeling of the original anti-corrosion layer during actual industrial equipment corrosion protection, especially in power plant chimney corrosion. This leads to corrosion, leakage, and even perforation of the absorption tower during use. Therefore, developing anti-corrosion materials with excellent corrosion resistance and long-term performance is particularly important. Summary of the Invention

[0005] The problem to be solved by this utility model is to provide a structure of a polyurethane asphalt adhesive with interlayer synergistic effect that is long-lasting, corrosion-resistant, aging-resistant, and highly elastic. It can save costs while ensuring the stability of the matrix itself, and can prevent problems such as leakage, corrosion, maintenance and safety hazards in the later stage.

[0006] To address the aforementioned technical problems, this invention provides a polyurethane asphalt adhesive composite structure with interlayer synergistic reinforcement. Through multi-layer composite, it forms a high-strength, high-toughness, stress-dispersing, wear-resistant, low-expansion, and flame-retardant material that permanently protects the underlying substrate from external impacts and wear. The novel polyurethane asphalt adhesive composite structure mainly consists of four composite layers: a substrate bonding layer close to the substrate, a second impermeable and anti-seepage layer, a third reinforcing and anti-corrosion layer, and finally a surface protective layer, which is in contact with corrosive substances, with a total thickness of 0.65–1.5 mm.

[0007] Preferably, the modulus of the four layers decreases in a gradient distribution.

[0008] Preferably, the transition buffer layer is an interpenetrating network structure containing thermoplastic elastomer microspheres.

[0009] More preferably, the particle size of the thermoplastic elastomer microspheres is 10–50 μm.

[0010] More preferably, the volume percentage of the thermoplastic elastomer microspheres is 3% to 8%.

[0011] Preferably, the anti-permeability functional layer is a labyrinthine barrier path structure.

[0012] More preferably, the anti-permeability functional layer is a labyrinthine barrier path structure formed by the horizontally oriented arrangement of graphene layers.

[0013] Preferably, the polyurethane asphalt adhesive composite structure is a polyurethane asphalt adhesive composite structure with interlayer synergistic reinforcement. For the substrate bonding layer, its thickness is approximately 0.1 to 0.3 mm. It can mainly improve the high surface roughness of the substrate and enhance the mechanical interlocking effect with the concrete substrate or steel substrate.

[0014] Preferably, the polyurethane asphalt adhesive composite structure is a polyurethane asphalt adhesive composite structure with interlayer synergistic reinforcement. For the second layer, its thickness is approximately 0.2 to 0.5 mm. Its main function is to serve as a transition layer between the matrix and the main anti-corrosion layer, which can absorb thermal stress and reduce interlayer shear force.

[0015] Preferably, the polyurethane asphalt adhesive composite structure is a polyurethane asphalt adhesive composite structure with interlayer synergistic reinforcement. The thickness of the third layer is approximately 0.3 to 0.6 mm, and its main function is to prevent penetration, so that corrosive liquids can be completely blocked in this layer.

[0016] Preferably, the polyurethane asphalt adhesive composite structure is a polyurethane asphalt adhesive composite structure with interlayer synergistic reinforcement. For the surface layer, its thickness is approximately 0.05 to 0.1 mm. Ultraviolet absorbers (3% to 4%) can be added to its surface, and microcapsule repair agents can be incorporated. When the surface is scratched with a diameter of ≤0.15 mm due to particulate matter, it can perform self-repair function with a self-repair rate of over 80%.

[0017] This invention utilizes multi-layer composite technology to form a novel anti-corrosion structural layer that integrates advantages such as high interface strength, high toughness, stress dispersion, wear resistance, low expansion, and flame retardancy. It can be used in concrete structures or metal substrates for anti-corrosion lining systems. Application areas include anti-corrosion technology for building systems such as chimneys, large-scale decarbonization and desulfurization systems, and large towers in the chemical and metallurgical industries. Compared with existing technologies, the beneficial effects of this invention are:

[0018] 1. A composite structure with different functions is designed based on the roles of each layer. In the transition layer, thermoplastic elastic microspheres with a particle size of approximately 10–50 μm are added. This structure allows for a gradient change in interlayer modulus, mitigating the interlayer shear stress caused by material differences, thus acting as a buffer layer. When this buffer layer encounters corrosive liquids, it enhances corrosion resistance, thereby improving the overall corrosion resistance of the anti-corrosion system.

[0019] 2. The multi-layered structure enhances the skeletal support of polyurethane asphalt adhesive during use. This is particularly evident in the anti-seepage layer, where appropriate amounts of montmorillonite and graphene sheets can be added. The montmorillonite and graphene form a "brick-mud" structure, improving impermeability and mechanical strength.

[0020] 3. Microencapsulated repair agents (such as liquid silane) are incorporated into the protective layer, which can be released to fill defects after scratches. Attached Figure Description

[0021] Figure 1 A cross-sectional view of the structure of the polyurethane asphalt adhesive provided by this utility model;

[0022] Figure 2 A schematic diagram of the structure of the polyurethane asphalt adhesive provided by this utility model.

[0023] Figure 1-2In the middle, 1-substrate adhesive layer, 2-transition buffer layer, 3-anti-permeability functional layer, 4-surface protective layer. Detailed Implementation

[0024] To make this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1-2 As shown, this utility model provides a polyurethane asphalt adhesive with interlayer synergistic effect, which includes a four-layer composite structure consisting of a substrate bonding layer 1, a transition buffer layer 2, an anti-permeability functional layer 3, and a surface protective layer 4, with a total thickness of 0.65 to 1.5 mm and a gradient decreasing distribution of modulus among the four layers.

[0026] The transition buffer layer 2 is an interpenetrating network structure containing thermoplastic elastomer microspheres. The particle size of the thermoplastic elastomer microspheres is 10-50 μm, and the volume percentage of the thermoplastic elastomer microspheres is 3%-8%.

[0027] The anti-permeability functional layer 3 has a labyrinthine barrier path structure (such as...). Figure 2 As shown in the diagram, it resembles a Z-shaped continuous structure. The impermeable functional layer is a labyrinthine barrier path structure formed by the horizontally oriented arrangement of graphene layers.

[0028] The thickness of the substrate bonding layer 1 is 0.1-0.3 mm, the thickness of the transition buffer layer 2 is 0.2-0.5 mm, the thickness of the anti-permeability functional layer 3 is 0.3-0.6 mm, and the thickness of the surface protective layer 4 is 0.05-0.1 mm.

[0029] Example

[0030] In this embodiment, the substrate surface to be contacted is ground. If it is a steel substrate, it needs to be sandblasted to Sa2.5 grade. An interface agent is then applied, and a polyurethane asphalt adhesive is coated on the surface of the interface agent. This polyurethane asphalt adhesive consists of four layers: a substrate bonding layer, a transition buffer layer, an anti-permeability functional layer, and a surface protective layer. The thickness of these four composite adhesive layers is 0.65mm to 1.5mm. Finally, a V-Kool sheet is placed on top of the adhesive layers. This sheet effectively improves the erosion resistance of the anti-corrosion system. For the entire anti-corrosion system, this improved adhesive not only significantly enhances corrosion protection but also plays a crucial role in the insulation of desulfurization and flue gas equipment.

[0031] The interface agent is made of epoxy resin, and its main function is to smooth the substrate and prevent rusting. It also has a good bonding effect with the adhesive.

[0032] The polyurethane asphalt adhesive consists of four main layers: a matrix bonding layer, a transition buffer layer, an anti-permeability functional layer, and a surface protective layer. The matrix bonding layer, with a thickness of 0.1–0.3 mm, is primarily composed of polyurethane asphalt (80%–90%), a silane coupling agent (5%–10%), and nano-silicon carbide (5%–10%), and its main function is to enhance the mechanical bonding between subsequent anti-corrosion materials and the concrete / metal substrate.

[0033] The transition buffer layer in the polyurethane asphalt adhesive has a thickness of 0.2 to 0.5 mm and is mainly composed of polyurethane asphalt interpenetrating network (mass ratio 6:4) and thermoplastic elastomer microspheres (particle size 10 to 50) μm, accounting for 3% to 8%. The buffer layer mainly absorbs thermal stress and reduces interlayer shear force.

[0034] The anti-permeability functional layer in the polyurethane asphalt adhesive has a thickness of 0.3–0.6 mm and is mainly composed of sulfur asphalt (70%), graphene sheets (2%–5%), and montmorillonite (8%–15%). The structure of the anti-permeability functional layer consists of graphene sheets arranged horizontally along the interlayer, forming a "maze-like" barrier path. In the actual absorption tower spraying section, because the spraying layer requires a large amount of lime water to spray the flue gas coming from the bottom of the absorption tower, this spraying liquid causes the anti-corrosion layer to be in a state of liquid immersion for a long time, and it has a strong scouring force. As a result, the polyurethane asphalt adhesive is also washed away by the spraying liquid. Traditional materials will be washed off by the spraying liquid in the long run, but the improved polyurethane asphalt material has an anti-permeability functional layer that forms a "maze-like" barrier path, improving impermeability and mechanical strength.

[0035] The surface protective layer of the polyurethane asphalt adhesive has a thickness of 0.05–0.1 mm and is mainly composed of polyurethane (95%), ultraviolet absorber (2%–3%), and hydrophobic silica (3%–5%). Regarding acid corrosion resistance, experiments show that after immersion in strong acids (such as H2SO4 and HCl) with pH = 1–3 for 30 days, the mass loss rate of polyurethane asphalt is ≤1.5%, with no blistering or peeling. This is attributed to the fact that sulfonation or SBS modification of the asphalt densifies the molecular structure, hindering the penetration of acidic media. Furthermore, the urethane bonds (-NHCOO-) in polyurethane exhibit high chemical stability and stronger acid resistance. Regarding salt corrosion resistance, experiments show that when metal materials coated with polyurethane asphalt are placed in a neutral salt spray for 2000 hours, the polyurethane asphalt coating on the metal surface shows no rust, no cracks, and an adhesion decrease of ≤10%. This is attributed to the fact that the polyurethane sealing coating blocks Cl-. - The penetration process makes polyurethane asphalt less susceptible to corrosion in saline conditions.

[0036] Corrosion in power plant chimneys primarily occurs due to the increased susceptibility of acidic substances to corrosion. Polyurethane asphalt adhesives exhibit outstanding corrosion resistance, making them particularly suitable for complex environments characterized by high temperature, high humidity, and strong chemical corrosion. Further applications in energy, chemical, and marine industries can be expanded through material modification, structural optimization, and the addition of functional additives.

Claims

1. A structure of interlayer synergistic polyurethane bitumen adhesive, characterized by, It consists of a four-layer composite structure comprising a substrate adhesive layer, a transition buffer layer, an anti-permeability functional layer, and a surface protective layer, with a total thickness of 0.65–1.5 mm.

2. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 1, characterized in that, The modulus of the four layers decreases in a gradient.

3. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 1, wherein, The transition buffer layer is an interpenetrating network structure containing thermoplastic elastomer microspheres.

4. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 3, wherein, The particle size of the thermoplastic elastomer microspheres is 10–50 μm.

5. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 3, wherein, The volume fraction of the thermoplastic elastomer microspheres is 3% to 8%.

6. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 1, wherein, The anti-permeability functional layer has a labyrinthine barrier path structure.

7. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 6, wherein, The anti-permeability functional layer is a labyrinthine barrier structure formed by the horizontally oriented arrangement of graphene layers.

8. The interlayer synergistic polyurethane bitumen adhesive structure according to claim 1, wherein, The thickness of the substrate bonding layer is 0.1–0.3 mm, the thickness of the transition buffer layer is 0.2–0.5 mm, the thickness of the anti-permeability functional layer is 0.3–0.6 mm, and the thickness of the surface protective layer is 0.05–0.1 mm.

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