In the field of high-end epoxy resin curing, high-stability thermal cationic initiators have become a key technology to solve the degradation of material performance under high-temperature conditions. Traditional cationic initiators are prone to decomposition or side reactions under continuous heat load, resulting in decreased curing efficiency, increased yellowing, and reduced mechanical strength. In response to this challenge, Shenzhen U-Sunny Technology has launched the CTI series of high-stability thermal initiators through molecular structure innovation and process optimization, providing long-term and stable solutions for electronic packaging, aerospace coatings, and new energy equipment.
1. Technological innovation of high-stability thermal cationic initiators
Improved molecular thermal stability
U-Sunny CTI-300 uses perfluoroalkyl sulfonium salts (such as triphenylsulfonium hexafluoroantimonate) as the core active component. By introducing strong electron-withdrawing groups and steric hindrance design, the ion pair dissociation rate at high temperature (150°C+) is significantly reduced. Experimental data show that after continuous aging at 180°C for 500 hours, the initiation efficiency still maintains more than 95% of the initial value, which is better than the 70% of traditional sulfonium salt products.
Dual-mode trigger mechanism
Combining thermal activation and light-assisted prepolymerization technology, this series of products can start cationic polymerization in the low temperature range of 80-120°C, and shorten the induction period through UV pre-initiation, achieving deep and uniform curing with a thickness of up to 2mm, and the curing rate is increased by 40% compared with the pure thermal initiation system.
Environmental interference resistance
The optimized initiator has reduced humidity sensitivity to 0.1% RH fluctuation range (traditional products are 0.5%), and is compatible with epoxy resin systems containing polar functional groups such as hydroxyl and amino groups, and is suitable for automotive electronic potting glue formulations in high humidity environments.
2. Typical application scenarios and formula design cases
5G high-frequency circuit board packaging materials
Recommended formula: bisphenol F epoxy resin (55%) + U-Sino T-305 initiator (2.5%) + silane coupling agent KH-560 (1%) + spherical silicon powder (41.5%)
Performance: Dielectric constant after curing ≤ 2.8 (10GHz), glass transition temperature (Tg) reaches 185°C, and there is no delamination and cracking after 1000 thermal cycles (-40°C ↔ 125°C).
High temperature resistant motor insulation paint
Technical highlights: With U-Sino U-9400 hybrid resin, it achieves H-level (180°C) temperature resistance, volume resistivity > 1×10¹⁶ Ω·cm, and has passed UL 1446 certification to meet the coating needs of electric vehicle drive motors.
Photothermal dual-curing optical adhesive
Process advantages: After UV pre-curing (365nm, 500mJ/cm²), thermal curing at 80°C for 30 minutes can complete the bonding, light transmittance>91%, haze<0.3%, suitable for AR/VR lens lamination.
3. Four core values of choosing U-Sunny high-stability initiator
Performance guarantee throughout the life cycle: verified by accelerated aging test, the CTI-300 series still maintains a mechanical strength retention rate of >90% in a high temperature and high humidity (85°C/85% RH) environment for 2000 hours.
Precise process window control: Provides gradient activation temperature options from 80°C to 220°C to adapt to the thermal management requirements of different production line equipment.
Environmental compliance: does not contain PFAS, heavy metals and VOCs, and complies with the latest restricted substances list of EU REACH Annex XVII.
Intelligent technical support: open online formula simulation platform, supporting real-time calculation and optimization of curing kinetic parameters (such as activation energy Ea, reaction order n).
Visit U-Sunny's official website to download the "High Temperature Epoxy Curing White Paper", or contact the technical team (+86-13686844208) to customize your own high-stability initiator solution!