How to increase the solubility of silane coupling agent in water and improve the storage stability of the solution?
The alkoxysilyl groups of silane coupling agents become silanol groups when dissolved in water.
This silanol group is unstable and undergoes condensation reactions over time. This results in the formation of siloxane bonds, which eventually lead to gelation.
In general, silanol groups are unstable in aqueous solution, but are relatively stable in a mildly acidic.
Also, aminosilanes are very stable in aqueous solutions due to their interaction with amino groups. To improve the storage stability of the solution, the pH of the solution can be adjusted, alcohol can be used in combination with the solution, and the solution can be stored below room temperature.
Solubility and Stability at Optimum pH
| Product name | Solubility (pH of aqueous solution) | Storage stability |
|---|---|---|
| KBM-1003 | Soluble(3.9) | Within 10 days |
| KBE-1003 | Soluble(3.9) | Within 10 days |
| KBM-303 | Soluble(4.0) | Within 30 days |
| KBM-403 | Very soluble(5.3) | Within 30 days |
| KBE-402 | Soluble(4.0) | Within 10 days |
| KBE-403 | Soluble(4.0) | Within 10 days |
| KBM-1403 | Insoluble | ─ |
| KBM-502 | Soluble(4.0) | Within 1 day |
| KBM-503 | Soluble(4.2) | Within 1 day |
| KBM-5103 | Soluble(4.2) | Within 3 days |
| KBM-602 | Very soluble(10.0) | Within 30 days |
| KBM-603 | Very soluble(10.0) | Within 30 days |
| KBM-903 | Very soluble(10.0) | Within 30 days |
| KBE-903 | Very soluble(10.0) | Within 30 days |
| KBM-573 | Soluble(4.0) | Within 1 day |
| KBM-803 | Soluble(4.0) | Within 1 day |
＊Solubility
Very soluble： 1% silane aqueous solution can be prepared without adjusting the pH of the aqueous solution.
Soluble： 1% silane aqueous solution can be prepared by adjusting the pH of the aqueous solution.
Insoluble: Aqueous silane solution cannot be prepared.
＊Storage stability is only a guideline and may vary depending on usage conditions and purposes.
Related FAQ
- How to store pretreated inorganic materials or silane-doped resins?
- How to store silane coupling agents pretreated on inorganic materials or resins with silane added?
- How to store the solution after hydrolyzing the silane coupling agent?
- What precautions should be taken when storing silane coupling agents?
- How to confirm the silane treatment in silane coupling agents?
