Low-temperature thermosetting waterborne peelable adhesive and preparation method thereof

Abstract

The invention provides a low-temperature thermosetting waterborne peelable adhesive and a preparation method thereof. The peelable adhesive comprises the following components: 50-70 parts of waterborne polyurethane resin, 3-7 parts of a silane coupling agent, 3-7 parts of nano graphene, 1-2 parts of a dispersing agent, 1-5 parts of a film-forming agent, 0.1-1 part of a wetting agent, 1-1.5 parts of a defoaming agent, 0.5-2 parts of a thickening agent, 0.3-0.5 part of color paste and 20-40 parts of filler. The preparation method comprises the following steps: weighing the raw materials; diluting the thickening agent and preparing a nano graphene dispersion liquid; uniformly mixing the nano graphene dispersion liquid and the waterborne polyurethane for three times, sequentially adding the silane coupling agent, the film-forming agent, the wetting agent, the defoaming agent, the color paste, the thickening agent and the filler, and uniformly stirring to obtain the low-temperature thermosetting waterborne peelable adhesive. The low-temperature thermosetting waterborne peelable adhesive is curable at low temperature, good in flexibility, good in adhesive force, peelable and capable of adapting to CNC operation, and the preparation method is simple and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of peelable glue, in particular to a low-temperature thermosetting water-based peelable glue and a preparation method thereof. Background technique [0002] Nowadays, the back cover of the mobile phone has a wide variety of materials, including metal, ceramics, glass and various composite materials. Among them, plastics are lightweight, easy to process, low cost, weak to signal interference, and impact resistance. It still occupies a certain position in the mobile phone back cover market. [0003] During the processing of the plastic back cover of the mobile phone, construction processes such as pressing and CNC are required, and it is very easy to scratch the plastic back cover to a certain extent during the machine or other operations. As an appearance part, at the same time, because of the low cost of its own material, it can only be discarded after being scratched. [0004] In order to avoid scratches,...

AI Technical Summary

Problems solved by technology

The film can protect the plastic back cover under the film very well, but the disadvantages of the film are also obvious. First, it is labor-intensive, and it takes manpower to attach the film to the plastic back cover one by one. Second, the protection for special-shaped workpieces is insufficient. Generally, it has good adsorption force on flat surfaces. For some grooves, bumps or curved surfaces of special-shaped workpieces, the film cannot be well adsorbed. At present, the back cover of mobile phones is mostly 2.5D or 3D workpieces, basically with curved surfaces. The third is that the film cannot be well adapted to CNC machining. If the film touches the CNC cutter head, the entire film will be taken up. The lower part of the exposed plastic back cover area is close to the CNC cutter head, and the probability of damage is very high

Protective inks have relatively low labor requirements and are suitable for large-scale production. At the same time, they can be well matched with special-shaped workpieces and can achieve all-round protection. However, the curing temperature of general protective inks is relatively high, much higher than that of plastic back covers. No higher than 80 The temperature requirement of ℃, and the protective ink is generally difficult to remove on the plastic, and the use of a deinking agent cannot guarantee that the plastic back cover itself will not be damaged

Then, we can also choose the peelable glue solution, which is different from the film, which can provide all-round coverage protection for the workpiece, and is different from the protective ink, which can be easily peeled off, but the general peelable glue is used for plastic back cover processing. also problematic

Problem 1, the general peelable glue is similar to the film, the film layer is relatively soft, can be pulled and pulled not easy to tear, can not adapt to the operation of CNC, and will wrap the CNC cutter head during processing

Question 2, the curing temperature of general polyester and polyvinyl chloride peelable adhesives also exceeds 80°C

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