Application of Molecular Sieve Powder in Polyurethane Electronic Potting Adhesives

1. Core Pain Points in Electronic Potting Applications

In the field of electronic component encapsulation, polyurethane potting adhesives are widely used due to their excellent insulation, weather resistance, and elasticity.

However, two major technical challenges are frequently encountered in actual production:

Bubble Defects:

Trace moisture reacts with isocyanates to generate CO₂ gas, resulting in pinholes or a honeycomb structure in the cured adhesive, which directly affects insulation performance.

Uncontrolled Curing Time:

Fluctuations in ambient humidity or unstable formulations can easily cause a sudden drop in the fluidity of the adhesive, preventing it from fully filling the gaps between precision components

2. Efficiency Enhancement Mechanism of Activated Molecular Sieve Powder

(1) Synergistic Effect of Physical Adsorption and Chemical Protection

Ultramicroporous Structure:

CHEMXIN 5A activated molecular sieve powder features pore diameters around 0.5 nm, which precisely captures water molecules (diameter ~0.26 nm), while also blocking harmful gases such as CO₂ (0.33 nm) and H₂S (0.36 nm).

Improved Thermal Stability:

The crystalline structure, calcined at 1000°C, can withstand the thermal stress generated during long-term operation of electronic components, preventing interfacial delamination caused by mismatched thermal expansion coefficients

3. Typical Application Scenarios and Formulation Design

(1) Optimization of Electronic Potting Adhesive Formulation

Base Formula:

Polyether polyol (NCO% = 2.8%) 100 phr + MDI prepolymer 80 phr

+Catalyst 0.2 phr

(2)Key Process Points:

Premixing: Disperse CHEMXIIN activated molecular seive powder in polyol under vacuum at 60°C for 30 minutes

Dynamic Defoaming: Use a planetary mixer at 2000 rpm for 15 minutes

Dispensing Control: Ambient humidity ≤ 40% RH; adhesive viscosity ≤ 8000 mPa·s

About Chemxin:

Guangzhou Chemxin Environmental Material Co., Ltd. has been specializing in the production of molecular sieve, molecular sieve activated powder, activated alumina, ceramic ball for 23 years. Established in 2002, our factory covers an area of 42,000 square meters and employs over 250 people, including a dedicated R&D team.

If you have any needs or questions, please feel free to contact us at any time.

E: info@chemxin.com

www.chemxin.com