Today, I will introduce the use of silane coupling agents, mainly including pretreatment method and overall blending method. When using silane coupling agents, you need to choose the appropriate method and conditions according to the specific situation. At the same time, you also need to pay attention to the amount and use time of silane coupling agents to ensure that it can play the best effect.
① Pretreatment method
Pretreatment method is to first use silane coupling agent to treat the surface of inorganic filler, and then add it to the polymer. According to different treatment methods, it can be divided into dry treatment method and wet treatment method. Dry treatment is to first add inorganic filler in a high-speed mixer, and then slowly add the pre-prepared silane coupling agent solution while stirring, and evenly disperse it on the filler surface for treatment. Wet treatment is to immerse the filler in the silane coupling agent treatment liquid or add the silane coupling agent to the filler slurry during the production process, and then dry it. Whether it is dry treatment or wet treatment, in order to make the silane coupling agent evenly coated on the surface of the inorganic filler, it is necessary to pay attention to the treatment process, especially the stirring and drying conditions.
② Overall blending method
In the case where pretreatment is not possible or the pretreatment method alone is not sufficient, the overall blending method can be used, that is, the silane coupling agent is mixed into the inorganic filler and the polymer and mixed together. The advantage of this method is that the amount of coupling agent can be adjusted at will and the ingredients are prepared in one step, so it is often used in industry. However, compared with the pretreatment method, if the same modification effect is to be achieved, the overall blending method must use more silane coupling agent.
Amount of coupling agent:
Since the actual coupling effect is a monomolecular layer formed by a small amount of coupling agent, it is unnecessary to add too much silane coupling agent. The amount of silane coupling agent used is related to its type and the surface area of the raw material.
When the filler area is uncertain, the amount of silane coupling agent can be determined to be about 1.0% of the filler amount. In addition, when the overall blending method is used, the amount can also be selected as 1.0% of the polymer mass. The optimal amount can be increased or decreased appropriately.
The silane coupling agents produced by our company are used as crosslinking agents and adhesion promoters in coatings, inks, and adhesives. The excellent wet adhesion performance is widely used on glass, metals and other inorganic substrates; it can also adhere well to organic materials that are difficult to adhere to, such as nylon and other plastic products. It can hydrolyze quickly in the presence of atmospheric humidity, does not turn yellow, and has very good thermal stability, chemical stability and UV stability. Suitable polymers: acrylic, silicone resin (Si), PU-prepolymer, etc.