Guangzhou Longkai Chemical Co., Ltd.
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What are the usage methods and dosage techniques of silane coupling agents
Author:LongKom  Time:2018-1-31

(1) The silane coupling agent is prepared into a dilute solution of 0.5-1% concentration by surface pretreatment. When used, only a thin layer of silane coupling agent is coated on the clean adhered surface. After drying, the silane coupling agent can be glued. Most of the solvents used are water, alcohol or mixture of water and alcohol, and water without fluoride ion and cheap non-toxic ethanol and isopropanol are suitable. In addition to aminoalkyl silane, acetic acid is added to the solution prepared by other silane coupling agents as hydrolysis catalyst, and the pH value is adjusted to 3.5-5.5. Long chain alkyl and phenylsilane are not suitable for use in aqueous solution because of their poor stability. The hydrolysis of chlorosilane and acetoxysilane is accompanied by serious condensation reaction. It is not suitable to be used in aqueous solution or aqueous alcohol solution, but in alcoholic solution. A silane coupling agent with poor water solubility can first add 0.1 to 0.2% (mass fraction) of non-ionic surfactant and then add water to produce water emulsion.

(2) Silane coupling agent is directly added to the adhesive component by migration method, and the general amount of silane coupling agent is 1-5% of the matrix resin content. After coating, the coupling agent molecules migrate to the bonding interface to produce the coupling effect depending on the diffusion of molecules. For the adhesives that need to be cured, they need to be placed for a period of time before curing, so that the coupling agent can complete the migration process, in order to achieve better results.

In practical use, the coupling agent often forms a deposit on the surface, but only the single molecule layer plays a real role, so the amount of coupling agent need not be too much.