Epoxy resin splicing adhesive with high compression strength

Abstract

This invention discloses an epoxy resin bonding adhesive with high compressive strength, comprising component A and component B mixed and cured in a 1:1 mass ratio. Component A, by weight, includes: 20-25 parts epoxy resin, 2-5 parts reactive diluent, 1-3 parts anti-settling thixotropic agent, and 70-80 parts reinforcing filler. Component B, by weight, includes: 20-30 parts curing agent, 1-2 parts accelerator, 1-3 parts anti-settling thixotropic agent, and 70-80 parts reinforcing filler. This invention significantly improves the final cured compressive strength, exhibits balanced overall performance, is convenient to apply, and demonstrates stable performance.

Description

Technical Field

[0001] This invention belongs to the field of splicing adhesive technology, specifically relating to an epoxy resin splicing adhesive with high compressive strength. Background Technology

[0002] As a key functional material for splicing and bonding various components, the mechanical properties (especially compressive strength) of spliced ​​components after curing directly affect the connection stability, structural load-bearing capacity, and service life of the spliced ​​components. It is widely used in wind power, construction, bridges, machinery, and other fields. With the rapid development of infrastructure construction and the new energy industry in my country, the performance requirements for splicing adhesives are constantly increasing. Especially in the field of wind power concrete towers, as wind turbine blades gradually become larger, the compressive strength requirements for ultra-high-rise concrete towers have increased from the traditional C80-C100 grade to C100-C120 grade. This necessitates that the compressive strength of the splicing adhesive used in conjunction with it after curing must be higher than the compressive strength of the concrete itself to ensure the safety and stability of the entire structure.

[0003] However, existing epoxy resin splicing adhesives generally have the following core defects, making it difficult to meet the usage requirements of high-end scenarios such as ultra-high hybrid towers for future wind turbine blades: The final cured compressive strength is too low: the compressive strength of conventional epoxy resin splicing adhesive after curing is mostly between 80-110MPa. However, in high-end scenarios such as precast components, heavy building components, and precast bridge segments, the final cured compressive strength of the splicing adhesive is required to be no less than 120MPa. Existing products cannot meet this standard. Under long-term high load, it is easy to cause deformation, cracking, and detachment at the splice, which seriously affects the structural safety.

[0004] Uneven performance: In existing technologies, some solutions increase the amount of inorganic fillers to improve compressive strength, but this will significantly increase the viscosity of the splicing adhesive, reduce the process performance, greatly increase the construction difficulty, and easily lead to defects such as uneven mixing, insufficient curing, and difficulty in removing internal air bubbles, which will reduce the stability and consistency of compressive strength. Other solutions sacrifice bonding toughness and aging resistance when improving compressive strength, which makes the splice joint prone to brittle fracture and greatly shortens the service life of the structure.

[0005] Poor construction adaptability: Some high-compression-strength modified splicing adhesives require special construction equipment or complex construction processes, such as high-temperature curing and high-pressure injection, which are not conducive to on-site construction operations, making it difficult to promote and apply on a large scale, and increasing project costs and construction cycle.

[0006] Therefore, there is an urgent need for an epoxy resin splicing adhesive with high compressive strength to solve the above problems. Summary of the Invention

[0007] In view of the problems mentioned in the background art, the purpose of the present invention is to provide an epoxy resin splicing adhesive with high compressive strength.

[0008] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: An epoxy resin bonding adhesive with high compressive strength comprises component A and component B mixed and cured in a 1:1 mass ratio; component A, by weight, comprises: 20-25 parts epoxy resin, 2-5 parts reactive diluent, 1-3 parts anti-settling thixotropic agent, and 70-80 parts reinforcing filler; component B, by weight, comprises: 20-30 parts curing agent, 1-2 parts accelerator, 1-3 parts anti-settling thixotropic agent, and 70-80 parts reinforcing filler.

[0009] Further specified, the epoxy resin is a compound of bisphenol A epoxy resin and bisphenol F epoxy resin at a mass ratio of 20:1, wherein the bisphenol A epoxy resin is type E-51 and the bisphenol F epoxy resin is a low-viscosity type. The selection of epoxy resins ensures basic bond strength and mechanical properties, reduces the viscosity of the product system, and the compounding of the two can achieve synergistic enhancement of mechanical properties.

[0010] Furthermore, the reactive diluent is a C12-C14 alkyl glycidyl ether. This reduces the viscosity of component A, improves its flowability during application, and participates in the curing reaction without affecting the final compressive strength and bonding performance, thus avoiding the performance degradation issues caused by conventional diluents.

[0011] Furthermore, the anti-settling thixotropic agent is made of fumed silica. This gives the system good thixotropic properties. In a static state, the system is in a paste form, which can effectively fix the filler and prevent it from settling. When the system is subjected to external forces such as stirring, spreading, or pouring, its viscosity decreases and its fluidity increases, which is beneficial for the application of engineering adhesives. After construction, once the external force is removed, the system quickly returns to a gel state, which can avoid dripping and sagging. It is especially suitable for construction on vertical and sloping surfaces and can reduce construction defects.

[0012] Further specifying, the reinforcing filler is composed of silica powder and quartz sand in a mass ratio of 4:1, wherein the silica powder has a particle size of 48–74 nm and the quartz sand has a particle size of 70–100 mesh. As a reinforcing filler, when used in combination with nano-level reinforcing fillers and quartz sand, it can fill the internal gaps of the resin system, improve the density of the engineering adhesive and pultrusion resin after curing, thereby helping to improve the compressive strength of the engineering adhesive, while also enhancing the product's hardness and wear resistance, and preventing deformation and cracking during use.

[0013] Furthermore, the curing agent is a compound of polyetheramine and phenolic amine curing agents in a mass ratio of 1:3. Polyetheramine curing agents have controllable reactivity and strong compatibility. Their flexible polyether main chain structure effectively improves the brittleness of the cured engineering adhesive, enhances the system's toughness, and forms a dense cross-linked structure, significantly improving the final cured compressive strength and temperature resistance of the adhesive, ensuring that the compressive strength meets the standards after curing.

[0014] Furthermore, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol. This can lower the curing temperature, accelerate the curing reaction rate, ensure that the adhesive can be fully cured at room temperature or low temperature, avoid the decrease in compressive strength caused by insufficient curing, and reduce the generation of bubbles during the curing process.

[0015] The beneficial effects of this invention are as follows: 1. The final cured compressive strength of the present invention is significantly improved. The compressive strength of the splicing adhesive after curing can reach 120-130MPa, which far exceeds the 80-110MPa of existing conventional products. It fully meets the usage requirements of high-end scenarios such as precast components, heavy building components, and precast bridge segments, and can effectively avoid problems such as deformation, cracking, and detachment at the splicing joint, thus significantly improving structural safety.

[0016] 2. The present invention has a balanced overall performance. While significantly improving compressive strength, it also takes into account bonding toughness and strength. The elongation at break is ≥0.3%, and the compressive shear strength between concrete and concrete is ≥20MPa. This avoids the defect of improving only one performance while sacrificing other performances in the prior art, ensuring stable connection at the joint and long service life.

[0017] 3. This invention is easy to apply. By using epoxy resin compounding and reactive diluents, the viscosity of the mixed components A and B is controlled within a reasonable range, resulting in good fluidity. No special construction equipment is required; it can be applied using conventional troweling or pouring methods. It cures at room temperature, adapting to on-site construction needs and facilitating large-scale promotion and application. 4. The present invention has stable performance, with no obvious defects such as bubbles, delamination, or insufficient curing during the curing process. The product has a dense structure, small fluctuation in compressive strength, high reliability, and can withstand longitudinal and transverse pressure for a long time, making it suitable for use in complex working conditions. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to embodiments. Example

[0019] The present invention discloses an epoxy resin system splicing adhesive with high compressive strength, which is formed by mixing and curing component A and component B in a mass ratio of 1:1. Component A includes, by weight, 23 parts of bisphenol A epoxy resin (E-51), 2 parts of bisphenol F epoxy resin, 3 parts of C12-C14 alkyl glycidyl ether, 2 parts of fumed silica, 60 parts of silica powder, and 15 parts of quartz sand. Component B includes, by weight, 6 parts of polyetheramine curing agent, 18 parts of phenolic amine curing agent, 1.5 parts of 2,4,6-tris(dimethylaminomethyl)phenol, 2 parts of fumed silica, 60 parts of silica powder, and 15 parts of quartz sand.

[0020] Preparation of Component A: Bisphenol A epoxy resin, bisphenol F epoxy resin and C12-C14 alkyl glycidyl ether were added to a reaction vessel and stirred evenly. Then, fumed silica was added and dispersed at high speed. Finally, silica powder and quartz sand were added and dispersed at high speed. After vacuum degassing, Component A was obtained.

[0021] Preparation of Component B: Polyetheramine curing agent, phenolic amine curing agent and 2,4,6-tris(dimethylaminomethyl)phenol were added to the reaction vessel and stirred evenly. Then, fumed silica was added and dispersed at high speed. Finally, silica powder and quartz sand were added and dispersed at high speed. After vacuum degassing, Component B was obtained.

[0022] When using, mix component A and component B evenly at a mass ratio of 1:1, and then apply or pour the mixture. It will be fully cured in 24 hours at room temperature.

[0023] By using a blend of bisphenol A epoxy resin and bisphenol F epoxy resin, the bisphenol A epoxy resin provides the basic adhesive strength and mechanical properties, while the bisphenol F epoxy resin effectively reduces the viscosity of the system. The two work synergistically to improve the flowability of the application while ensuring mechanical properties.

[0024] Using C12-C14 alkyl glycidyl ether as an active diluent not only significantly reduces the viscosity of component A and improves its flowability during application, but also allows it to participate in the curing reaction and become part of the cross-linking network, thus avoiding the problems of decreased final compressive strength and bonding performance caused by conventional inactive diluents.

[0025] The mixture of nano-sized silica powder and micron-sized quartz sand is used. The nano-sized silica powder can fill the tiny gaps inside the resin system and improve the density of the cured product, while the quartz sand acts as a skeleton material to provide rigid support, which significantly improves the compressive strength, hardness and wear resistance of the splicing adhesive after curing.

[0026] The adhesive is formulated with a combination of polyetheramine and phenolic amine curing agents. The polyetheramine curing agent has a flexible polyether structure in its main chain, which can effectively improve the brittleness of the cured product and enhance the toughness of the system. The phenolic amine curing agent has high reactivity and can form a dense cross-linked structure, which significantly improves the final curing compressive strength and temperature resistance of the adhesive. The two work synergistically to achieve a balance between compressive strength and toughness.

[0027] Using 2,4,6-tris(dimethylaminomethyl)phenol as an accelerator can lower the curing temperature and accelerate the curing reaction rate, ensuring that the splicing adhesive can be fully cured at room temperature or even low temperature, avoiding the decrease in compressive strength caused by insufficient curing, and reducing the generation of bubbles during the curing process.

[0028] Fumed silica is added to both components A and B as an anti-settling thixotropic agent, giving the system good thixotropic properties. In a static state, the system is in the form of a paste, which can effectively fix the filler and prevent it from settling. When the system is subjected to external forces such as stirring, spreading, or pouring, its viscosity decreases rapidly and its fluidity increases, which is beneficial for construction operations. After construction is completed and the external force is removed, the system quickly returns to the gel state, which can avoid the phenomenon of flowing and hanging. It is especially suitable for construction on vertical and sloping surfaces.

[0029] The splicing adhesive prepared in the example has a compressive strength of 120-130 MPa, a fracture toughness of ≥0.3%, and a concrete-to-concrete compressive shear strength of ≥20%, which far exceeds that of existing conventional products. It also has good toughness and adhesion properties, and the application viscosity is moderate, which fully meets the application requirements of high-end engineering scenarios.

[0030] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An epoxy resin bonding adhesive with high compressive strength, characterized in that: It comprises a mixture of component A and component B in a 1:1 mass ratio, cured together. Component A, by weight, includes: 20-25 parts epoxy resin, 2-5 parts reactive diluent, 1-3 parts anti-settling thixotropic agent, and 70-80 parts reinforcing filler. Component B, by weight, includes: 20-30 parts curing agent, 1-2 parts accelerator, 1-3 parts anti-settling thixotropic agent, and 70-80 parts reinforcing filler.

2. The epoxy resin splicing adhesive with high compressive strength according to claim 1, characterized in that: The epoxy resin is prepared by compounding bisphenol A epoxy resin and bisphenol F epoxy resin at a mass ratio of 20:

1. The bisphenol A epoxy resin is of type E-51, and the bisphenol F epoxy resin is of low viscosity type.

3. The epoxy resin splicing adhesive with high compressive strength according to claim 2, characterized in that: The active diluent is a C12-C14 alkyl glycidyl ether.

4. The epoxy resin splicing adhesive with high compressive strength according to claim 3, characterized in that: The anti-settling thixotropic agent is fumed silica.

5. The epoxy resin splicing adhesive with high compressive strength according to claim 4, characterized in that: The reinforcing filler is made by compounding silica powder and quartz sand in a mass ratio of 4:

1. The silica powder has a particle size of 48-74 nm and the quartz sand has a particle size of 70-100 mesh.

6. The epoxy resin splicing adhesive with high compressive strength according to claim 5, characterized in that: The curing agent is a mixture of polyetheramine and phenolic amine curing agents in a mass ratio of 1:

3.

7. The epoxy resin splicing adhesive with high compressive strength according to claim 6, characterized in that: The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.