I. Mechanism of silane coupling agents

Clarifying the mechanism of silane coupling agents is very important to guide the application of silane coupling agent. Many theories have been put forward to explain, such as chemical bond theory, physical adsorption theory, deformation theory, constraint layer theory, hydrogen bond bonding theory and so on.

According to the chemical bond theory, the alkoxy group of silane coupling agents can react with hydroxyl or oxide on the surface of glass, metal, silicate and other materials to form a chemical bond, so that the two materials with very different properties can be coupled by chemical bond to form a good bonding.

According to the physical adsorption theory, it is very important for the adhesive to be well wetted when bonding with the adhesive. If it can be completely wetted, the physical adsorption of the adhesive on the high-energy surface will obtain a bonding strength higher than the cohesive strength of the adhesive.

II. Improvement of performance of silane coupling agents

Through hydrolysis, condensation, polycondensation and organic active functional group reaction, silane coupling agent realizes the chemical bond combination between the adherend and the adhesive and completes the coupling effect. It has significantly improved a variety of properties, and improved wettability, compatibility, adhesion, cohesion strength, adhesion strength, water resistance, moisture and heat aging resistance, durability and so on.

III. Application method of silane coupling agents

1. Surface treatment method, also known as primer method. Firstly, prepare silane coupling agent into 0.5 ~ 5% aqueous solution or alcohol, ketone, ester and other solutions by mass fraction. Treat the adherend or filler by soaking, spraying or brushing. After drying for a period of time, dry for a few hours or at room temperature.

2. Direct addition method. Coating additives, also known as integral mixing method, is to add 0.5 ~ 5% silane coupling agent stock solution into adhesive or sealant to fully stir evenly and mix together. Since the silane coupling agent molecules should migrate to the surface of the adherend after sizing, they should be placed for an appropriate time and cured after the migration process is completed.

3. Concurrent usage. The concurrent usage is that the surface of the adherend is treated with a dilute solution of silane coupling agent (i.e. surface treatment), and an appropriate amount of silane coupling agent should also be added to the adhesive. Although the operation is troublesome, the effect is very good.

Commercial products of Co-Formula include isocyanate silane, aminosilane, epoxy silane, mercaptosilane, phenylsilane, vinyl silane, chlorosilane, alkyl silane, long-chain silane, silane crosslinking agent, dimethyl silicone oil, methyl hydrogen silicone oil type siloxane. In addition to these general-purpose products, Co-Formula can also provide coatings and plastic additives, silicone polymers and customized solutions for customers around the world. If it is necessary, please feel free to consult us.