M78H-86 Modified Polyurethane Conformal Coating
Product Applications:
M78H-86 is a one-component polyurethane conformal coating formulated with modified polyurethane resin, ester and hydrocarbon solvents, and specialized performance additives. It cures through an oxidative curing mechanism to form a uniform, glossy, and durable protective film on electronic assemblies and printed circuit boards (PCBs).
This high-solids, low-viscosity conformal coating offers excellent electrical insulation properties and strong resistance to thermal shock under both high- and low-temperature conditions. It is suitable for protecting PCBs, electronic circuits, and related components from environmental exposure in a wide range of electronic manufacturing applications.
M78H-86 is designed for convenient manual or production-line application by brushing and spraying, helping achieve efficient and consistent coating coverage.
The product complies with applicable RoHS, REACH, and halogen-free environmental requirements. Supporting compliance documentation is available upon request.
- Description
- Technical Data
- FAQ
Description
Product Features:
· High-Performance Film
· Easy Application
· Eco-Compliant & Versatile
Physical Properties：
| Item | Specification | Test Method |
| Appearance | Yellowish-brown transparent liquid | Visual |
| Solid Content | 33±3% | — |
| Relative Density | 0.90±0.05 | — |
| Viscosity (25℃, Ford cup #4) | 12-18 s | — |
| Drying Time — 25℃, 55%RH | Tack-free: 5-15 min | — |
| Drying Time — 60-80℃ | Tack-free: ≤5 min | — |
| Recommended Drying | 60-80℃, 1-5 min + RT drying | — |
| Time to Best Performance | 7 days | — |
| Film Thickness | 25-50 μm | — |
| Adhesion | Grade 0-1 | — |
| Dielectric Withstand Voltage | >1500 V | MIL-46058C |
| Insulation Resistance | >10¹²Ω | MIL-46058C |
| Moisture Resistance | ≥5×10⁹Ω | MIL-46058C |
| Neutral Salt Spray (5% NaCl, 35±2℃, 72 h) | No blistering, whitening, cracking or rust | — |
| Flame Retardancy | Meets HB class | IPC-CC-830B |
| Operating Temperature | -40℃ to 125℃ | — |
| Recommended Thinners | X-86, X-86D | — |
Process & Precautions：
· Workplace control: good ventilation; temperature 10-30℃; humidity <75%.
· Board cleaning: generally no special cleaning is required; ensure the coated surface is dry, clean, and free of oil and impurities.
· Suitable for brushing, dipping and spraying. A single coat is generally 25-50 μm; adjust viscosity and film thickness with thinner to best suit your process.
· Keep the container sealed during use to prevent moisture ingress. Do not blow air directly at the open container, to avoid solvent evaporation or surface whitening.
· If production pauses, seal the container and soak the nozzle in cleaning agent to prevent clogging.
· Baking temperature depends on component heat resistance and process, max 100℃. Do not touch freshly baked products until cooled, to avoid burns or film damage.
· Unused coating should be stored sealed in a dedicated container; do not mix it with fresh coating.
· If unused for long, clean pipes and nozzles; pour the coating out and store sealed; do not return used product to the original pail.
· Used containers, pipes and nozzles can be cleaned with thinner.
Packaging, Storage/Transport & Shelf Life：
· Packaging: metal pails, 4 KG/pail, 20 KG/pail
· Storage & transport: flammable chemical — keep away from fire and heat; handle per regulations; store cool (RT), dark and dry.
· Shelf life: stored sealed, 6 months at 5-25℃.
Conformal Coatings：
Thinners：
Frequently Asked Questions
What is the minimum order quantity (MOQ) for M78H-86?
The standard MOQ for M78H-86 is one 4 kg pail. For trial quantities below the standard MOQ, please contact us for sample availability and a customized quotation.
What packaging options are available?
M78H-86 is available in the following standard packaging options:
- 4 kg per pail
- 20 kg per pail
Please contact us for bulk-order pricing, OEM labeling, or customized packaging requirements.
Can I request a sample before placing a bulk order?
Yes. Free samples are available for quality evaluation and application testing. Please contact us to confirm sample availability and quantity. The customer is responsible for shipping costs.
What is M78H-86 used for?
M78H-86 is a one-component polyurethane conformal coating designed to protect printed circuit boards (PCBs), electronic circuits, and related electronic assemblies. It helps provide electrical insulation and environmental protection for electronic components.
How does M78H-86 cure?
M78H-86 cures through an oxidative curing mechanism. Actual curing time may vary depending on coating thickness, ambient temperature, humidity, ventilation, and application conditions. Please contact us for recommended process parameters.
What application methods are suitable for M78H-86?
M78H-86 is a high-solids, low-viscosity conformal coating suitable for brushing and spraying. Please conduct application trials to determine the appropriate process settings, coating thickness, and production conditions for your assembly.
What protection does the coating provide?
After curing, M78H-86 forms a uniform, glossy protective film with excellent electrical properties and resistance to high- and low-temperature thermal shock. For specific performance data, please refer to the Technical Data Sheet (TDS).
How should M78H-86 be stored?
Store the product in a cool, dry, well-ventilated place away from direct sunlight, ignition sources, excessive heat, and moisture. Keep the pail tightly sealed when not in use. Refer to the TDS and SDS for complete storage and handling instructions.
What is the shelf life?
The shelf life is 6 months shelf life if unopened when stored under recommended conditions. Please refer to the product label or contact us for batch-specific information.
Can the coating be repaired or removed?
Repairability and removal methods depend on the cured coating condition, substrate, and production requirements. Please contact our technical team for recommended rework or removal guidance before use in mass production.
Does M78H-86 meet environmental compliance requirements?
M78H-86 complies with applicable RoHS, REACH, and halogen-free requirements. Technical and compliance documents, including TDS, SDS, COA, and available declarations, can be provided upon request.
Do you offer technical support?
Yes. Our technical team can provide support for coating selection, PCB compatibility testing, application-process optimization, spray parameters, and customized packaging requirements.