1. The surface pretreatment
Amino silane coupling agent were prepared into 0.5-1% concentration of dilute solution, when used, only a thin layer on the clean surface to be adhered, and then glue can be applied after drying. Most of the solvents used are water, alcohol (methoxysilane chooses methanol, ethoxysilane chooses ethanol), or mixture of water and alcohol, and fluorine-free water, cheap and non-toxic ethanol and isopropanol are suitable. Except for aminoalkyl silane, acetic acid should be added into the solution prepared by other silane coupling agents as hydrolysis catalyst, and the PH value should be adjusted to 3.5-5.5. Because of the poor stability of long chain alkyl and phenylsilane, they are not suitable to be used as aqueous solution. Due to the hydrolysis of silane, it cannot be stored for a long time. It is better to prepare when in need, and it is better to use within one hour.
2. Direct addition
In general, the amount of amino silane coupling agent is 1-5% of the amount of matrix resin. After coating, the coupling agent molecules migrate to the bonding interface by the diffusion of molecules. For the adhesive that needs to be cured, it needs to be placed for a period of time after the adhesive is coated, so that the coupling agent can complete the migration process, so that a better effect can be obtained. In practice, the coupling agent often forms a deposition layer on the surface, but only the single molecular layer works. Therefore, the amount of coupling agent need not be too much.