1. Technical definition and core characteristics of OCA resin
Optically Clear Adhesive (OCA) is a high-transparency special adhesive material made of acrylic polymer, polyurethane or silicone system, with the following industry standard characteristics:
Optical performance: light transmittance>98% (some high-end products>99%), haze ≤0.1, low reflectivity (<1%), eliminating optical interference of display devices;
Mechanical strength: peel strength ≥2000g/25mm (normal temperature), shear strength ≥4MPa, annular initial adhesion of 1800g/25mm;
Environmental stability: high temperature and humidity resistance (85℃/85%RH), anti-yellowing (1000 hours QUV aging ΔE<1.5), anti-bubble;
Process adaptability: supports micron-level thin layer coating (adhesive layer thickness can be up to 35μm), suitable for rigid/flexible substrate lamination.
2. OCA resin cross-domain application scenarios and technological breakthroughs
1. Coatings: Improve surface functionality and durability
Cover glass fixation: light transmittance ≥ 95%, peeling force remains 45N/25mm after 3 days of double 85 aging, displacement ≤ 1mm;
AF antifouling coating: adhesion to AF coating 50g/25mm, excellent wettability, no bubbles when fitted;
Innovation direction: U-Sunny's T-7333 resin solves the problem of insufficient adhesion and shrinkage deformation of plastic substrates through aliphatic polyurethane structure, with a shrinkage rate of <3%.
2. Ink field: Promote environmental protection and high-precision printing
Water-white resin (Gardner chromaticity ≤ 1) has become the core material of food packaging ink, which meets FDA standards;
Hydrogenated rosin resin improves ink adhesion and forms a highly transparent protective layer, which is suitable for PET/PC film printing.
3. Adhesives and pressure-sensitive adhesives: domestic breakthroughs in the high-end market
Electronic-grade bonding: OCA is used in 4 layers/panel in smartphones/OLED screens, and the global market size will exceed 4 billion yuan in 2024;
Medical pressure-sensitive adhesive: T-7333 resin achieves repeated peeling and sticking of medical tape with a viscosity of 8000cPa·s and a Tg value of -45℃, and has passed ISO 10993 biocompatibility certification;
Industrial scenarios: 180° peel strength of metal coating is 8N/cm, and hydrolysis resistance is 500 hours without delamination.
Three major application scenarios
Electronic optical film: PET/PC substrate bonding, 40% peel strength improvement;
Medical pressure-sensitive tape: support non-destructive peeling, material recycling rate +30%;
Outdoor weather-resistant tape: 1000 hours QUV aging color difference ΔE <1.5.
The technological evolution of OCA resins is driving breakthroughs in the display, medical, automotive and other industries. Shenzhen U-Sunny and other companies have achieved domestic substitution through high-functional resins such as T-7333, and will need to continue to innovate in the fields of bio-based materials and ultra-thin coatings in the future. For material developers, balancing optical performance, environmental tolerance and cost efficiency will be the key to occupying a market worth hundreds of billions of yuan.