The company prioritizes the EN 1504-2 certification, presenting “active substance content + penetration depth + certification” as the selling point for the high-end market, mainly targeting the markets of concrete bridges, tunnels, offshore engineering anti-corrosion and cement fiber boards.
II. Research and Development Progress in This Phase
2.1 Synthesis of Organic Siloxane Prepolymers
The catalytic ring-opening polymerization process of D4 (octamethylcyclotetrasiloxane) was optimized, and the ratio of acid catalyst and end-capping agent was determined.
The problem of wide molecular weight distribution of the prepolymers was overcome, with the PDI (polydispersity index) reduced from 1.8 to 1.3, significantly improving batch reproducibility.
An online monitoring method for viscosity and conversion rate of the prepolymers was established, controlling the reaction endpoint error within ±3%.
2.2 Modification of Siloxane Resin
Phenyl monomers were introduced for copolymerization modification, effectively improving the thermal stability and toughness of the resin.
The temperature resistance grade of the coating was increased from 180℃ to 250℃, meeting the requirements of customers in high-temperature working conditions.
The hardness-flexibility balance was adjusted, achieving a pencil hardness of 2H while maintaining no cracking during bending.
III. Pilot-scale Expansion and Process Verification
3.1 50L Reactor Expansion
Three batches of continuous expansion tests were completed, with the single batch feeding amount increased from 1kg to 8kg, and the yield stabilized at over 92%.
Local overheating occurred during the expansion process, which was solved by optimizing heat exchange and dripping rhythm.
3.2 Solidification of Key Process Parameters
The temperature curve, stirring rate, and the timing of end-capping agent addition were written into the SOP, forming a replicable operation card.
The second-party review of raw material suppliers was completed, and the key monomers achieved dual-source supply.
IV. Performance Testing and Third-Party Characterization
Thermal gravimetric analysis (TGA) showed that the 5% weight loss temperature reached 420℃, superior to the industry benchmark of 380℃.
Gel permeation chromatography (GPC) confirmed that the molecular weight distribution was within the designed range.
Contact angle testing indicated that the water contact angle of the cured film was >105°, demonstrating good hydrophobic properties.
The RoHS and salt spray resistance tests have been completed by a third-party institution, and the report is expected to be returned next month.
V. Current Issues and Next-Step Plans
5.1 Issues to be Addressed
There is a slight fluctuation in batch color during large-scale continuous production, requiring further investigation into the impact of raw material impurities.
The cost of phenyl monomers is relatively high, and the evaluation of alternative monomers and recycling processes is underway.
5.2 Next-Step Plans
In Q4, a 100-kilogram pilot-scale test will be completed, and the complete process package and cost calculation will be output.
Two key customers will be sent samples for testing and joint verification.
The application evaluation of MQ siloxane resin in the field of electronic packaging will be laid out.
