A kind of piperazine epoxy resin curing agent and its prepared epoxy resin composition and application

Abstract

The invention provides a piperazine epoxy resin curing agent and the prepared epoxy resin composition and application. The raw materials for the preparation of the curing agent are polyfunctional glycidyl ether, alcohol solvent and anhydrous piperazine. The curing agent has high reactivity at low temperature and normal temperature, and has good strength and weather resistance after reacting with the composition composed of epoxy resin. The curing agent provided by the invention can be widely used in the fields of construction emergency repair in winter, fast electronic packaging materials and adhesives.

Description

technical field [0001] The invention belongs to the field of epoxy resins, and in particular relates to a piperazine epoxy resin curing agent and the prepared epoxy resin composition and application thereof. Background technique [0002] Epoxy resin has excellent mechanical properties, aging resistance, water resistance, chemical medium resistance and good acid resistance, so it occupies an important position in synthetic adhesives. At present, more than 90% of the reinforcement adhesive products are epoxy-type, and even some reinforcement specifications require the use of epoxy-type adhesives. [0003] When the ambient temperature is lower than 10°C, the curing speed of conventional curing agents tends to be slow, and it is difficult to form a film at 0°C. In winter in the north, the outdoor temperature is often maintained below zero, and the use of epoxy curing agents will bring great harm to the construction. Great inconvenience will seriously affect the construction per...

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Problems solved by technology

[0003] When the ambient temperature is lower than 10°C, the curing speed of conventional curing agents tends to be slow, and it is difficult to form a film at 0°C. In winter in the north, the outdoor temperature is often maintained below zero, and the use of epoxy curing agents will bring great harm to the construction. Great inconvenience will seriously affect the construction period due to the inconvenience of construction and cause great economic losses. Therefore, a curing agent that can perform curing reaction at low temperature is needed

[0004] In the existing epoxy resin curing system, commonly used curing agents include acid anhydrides, amines and synthetic resins, etc., and it is difficult to maintain a normal curing speed at low temperatures.

The only curing agent that can maintain a fast curing rate at extremely low temperatures is polythiol curing agent, but mercaptan curing agent has a strong pungent odor, is expensive, has limited application range, and is difficult to carry out large-scale construction

Therefore, the existing epoxy resin curing agent is difficult to meet the needs of low temperature and fast curing during large-scale construction

[0005] CN106318302A discloses 3-mercapto acrylate as the accelerator of dicyandiamide / epoxy curing system, which can significantly shorten the curing time of epoxy resin adhesive and reduce the curing temperature, but the amount of polythiol curing accelerator must be appropriate, Because when the amount is too much, it will not only cause the curing time to be prolonged, but also cause the performance of the epoxy resin adhesive to decrease

[0006] US4092293 is initiator with pentaerythritol, initiates the polymerization of propylene oxide, with allyl capping, and H 2 S reaction obtains a polythiol curing agent used under low temperature conditions, but the disadvantage of this preparation method is that the reaction steps are complicated, the conditions are harsh, the raw material price is relatively expensive, and the cost is high

[0007] CN10607595.6 discloses a kind of menthanediamine modified by cardanol and formaldehyde, and mixed with imidazole accelerator to obtain a low-viscosity fast curing agent, which can be used for rapid prototyping in HP-RTM process, but the method obtained The actual curing speed of the curing system at room temperature still cannot reach the level of mercaptan curing agents, and heating is required for curing

[0008] CN108137792 discloses a kind of aminoalkylimidazole curing agent, which has lower viscosity and can bring higher glass transition temperature, and can be used for the preparation of glass fiber composite materials, but the curing agent has difficulty in preparation, At the same time, if you want to achieve a curing rate within 10 minutes, you need to heat it at a high temperature.

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