Product Name
Permabond UV681 UV Curable Clear Coating Thin Flowable Low Viscosity to Smooth over Surfaces, Transparent, Crystal Clear Coating
Brief Description
Permabond UV681 is a single-part, UV-curable acrylate adhesive specifically developed as an optically clear, tack-free coating. It is designed to provide protection against environmental and vibrational damage, particularly for electronics and smart card microchips. Its low viscosity ensures an even, bubble-free application, and it boasts high-temperature resistance, allowing it to withstand processes like wave-soldering. This product is 100% solids, meaning it contains no solvents and offers fast curing on demand with low-power UV lamps.
Popular Applications & Uses
- Conformal coating for electronics to protect against environmental and vibrational damage.- Coating smart card microchips.- Protection of components during wave-soldering processes due to high temperature resistance.- Surface hardening and improving wear, corrosion, and high-temperature resistance on plastic products.- Applications requiring an optically clear, tack-free, and durable protective layer.- Clearcoats over molded-in-color body side moldings in automotive applications to prevent yellowing and provide toughness.- Coating for car headlights and paint in the automotive industry.- Used in optical components for transparency and wear resistance.
Industries that Commonly Use It
- LED/Electronics: For conformal coating, smart card microchips, and general electronics protection.- General Manufacturing: For broad coating and protection applications across various manufacturing processes.- Automotive Service/Repair: Utilized for clearcoats on exterior plastic parts, headlights, and paint.- Plastic Fabrication: Applied for surface hardening, wear resistance, and bonding of plastic components.- Chemical Industry: Involved in the production and supply of such specialized chemical coatings.- Distributers & Resellers: Companies like Perigee Direct and Chemical Concepts distribute this product.- Electrical Services or Products: Directly applicable for protecting electrical components and products.- Engineering Services: For the design, application, and integration of protective coatings in various systems.- Industrial Supply: As a specialized industrial coating product.- Transportation/ Specialty Vehicle: Related to automotive and other specialty vehicle applications requiring durable coatings.
Special and Unique Features
- Cure on demand, allowing for precise component alignment before curing.- Low viscosity ensures excellent coverage and an even, bubble-free finish.- Achieves a tack-free surface after curing.- Fast curing times, even with low-power UV lamps (e.g., 7 seconds with a low-power battery lamp, 2 seconds with an LED lamp).- 100% solids formulation, meaning no solvents are present, leading to low VOC emissions and an environmentally friendly profile.- High temperature resistance, capable of withstanding processes like wave-soldering and brief periods of high heat such as paint baking.- Optically clear and colorless appearance, maintaining transparency of coated surfaces.- Cures at room temperature, eliminating the need for heat and preventing distortion of heat-sensitive substrates.- Single-part product, requiring no mixing prior to application.
Key Properties
- Chemical Composition: Acrylate- Appearance: Colorless / Clear- Viscosity @ 25°C: 80-120 mPa.s (cP)- Specific Gravity: 1.1- Cure Wavelength: 320 – 420 nm- Tensile Strength (ISO37): 10-12 N/mm² (1450-1700 psi)- Light Transmittance: >98%- Refractive Index: >1.490- Elongation at break (ISO37): >50%- Hardness (ISO868): 50-65 Shore D- Water Absorption (ISO62) 2 hours in boiling water: <2%- Glass Transition (Tg) DSC 20°C/min rate: +55°C- Temperature Range (Cured Adhesive): -55°C to +120°C (continuous), up to +250°C for brief periods
Surface Compatibility
- Electronics components and assemblies.- Smart card microchips.- Glass (for bonding and coating).- Various metals, including aluminum, copper, and their alloys (surface preparation like light abrasion may be beneficial).- A wide variety of plastics (compatibility tests are recommended for thermoplastic surfaces, especially if mold release agents were used).- Surfaces should be clean, dry, and grease-free before application.- Special care should be taken to remove silicone-based cleaning agents from glass surfaces.
Known backups / known substitutes
- Other Permabond UV-curable adhesives with similar properties, such as Permabond UV645, UV648, UV649, UV670, UV675, UV683, UV685, and UV7141.- Permabond UV683 is noted as a tack-free doming adhesive, which may serve as a substitute for specific applications requiring a thicker dome.- General categories of UV-curable conformal coatings or clear protective coatings from other manufacturers.
Comparison Note
Permabond UV681 stands out from conventional coatings due to its rapid UV-curing mechanism, transforming from liquid to solid in seconds, which significantly boosts production efficiency and reduces process footprint. Unlike solvent-based alternatives, it is 100% solids and solvent-free, resulting in minimal to no volatile organic compound (VOC) emissions, making it an environmentally responsible choice. Its ability to cure at room temperature prevents heat distortion in sensitive substrates like plastics. The low viscosity ensures a smooth, bubble-free, and optically clear finish, crucial for electronic protection and aesthetic applications, while its high-temperature resistance is a key advantage for processes like wave soldering.
