II. Disadvantages
1. Relatively Limited Properties
       Compared with medium - and high - temperature - curing epoxy adhesives, the performance of room - temperature - curing epoxy adhesives still has a certain gap. In terms of heat resistance, the thermal resistance performance will decrease significantly as the temperature rises, and the long - term use temperature is generally limited to below 80°C. In a high - temperature environment, problems such as softening of the adhesive layer and a decrease in bonding strength may occur, and it can't meet the application scenarios with high requirements for high - temperature tolerance, such as the bonding of high - temperature engine components. In terms of electrical properties and so on, it is also not as good as some adhesives that have undergone special high - temperature - curing treatment.
2. Longer Curing Time
      The curing process is relatively slow. It usually takes 24 hours to reach the basic strength and 3 - 7 days to reach the maximum strength, and this time will also be affected by the environmental temperature. In some situations where bonding needs to be completed quickly and put into use, this longer curing time may bring inconvenience. For example, in some automated production lines, the adhesive may need to be cured in a shorter time to improve production efficiency.
3. Shorter Service Life
       Under room - temperature conditions, this kind of adhesive has a relatively short service life. Once it is prepared, it needs to be used in a relatively short time. Otherwise, the adhesive may lose part of its bonding performance due to its own chemical changes, resulting in the failure to achieve the expected bonding effect. This requires accurate estimation of the amount used during the use process to avoid adhesive waste.