E962-788 Low-Odor Acrylic Insulating Varnish for Coils
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Short Product Description:
E962-788 is a low-odor acrylic insulating varnish designed for coils, high-frequency transformers, and computer-related electronic components. Based on modified acrylic resin, this solvent-based varnish combines strong adhesion with Class B heat resistance at 130°C. It supports surface coating and impregnation, with reference oven-drying schedules at 90°C and 100°C.
- Description
- Technical Data
- FAQ
Description
Product Overview:
E962-788 is an electrical insulating varnish formulated with modified acrylic resin and an alcohol/glycol-ether-based solvent system. It is designed for coating and impregnation of electrical and electronic components where adhesion, electrical insulation, and low odor are important selection requirements.
This Class B insulating varnish provides a specified dielectric strength of ≥60 kV/mm under normal conditions. Its volume resistivity is ≥1 × 10¹⁴ Ω·m under normal conditions and ≥1 × 10¹² Ω·m after 24 hours of water immersion, providing useful reference data for insulation selection.
E962-788 offers strong bonding and defined oven-drying options for production use. The product is supplied as a slightly yellow, transparent to slightly cloudy liquid, with viscosity adjustable using the specified X-08 thinner.
The TDS identifies the thermal class as Class B, 130°C. Suitability for finished equipment should be verified using the complete insulation system, actual component materials, and operating conditions.
Key Features and Benefits：
· Modified Acrylic Formulation: Provides an acrylic resin option for electrical component coating and coil impregnation.
· Low-Odor Solvent System: Uses an alcohol/glycol-ether-based formulation. Low odor does not eliminate the need for ventilation during application and drying.
· Strong Adhesion: Supports bonding within coated or impregnated component assemblies.
· Class B Heat Resistance: Rated Class B, 130°C, in the product specification, supporting selection for corresponding insulation requirements.
· Electrical Insulation Performance: Specified dielectric strength is ≥60 kV/mm under normal conditions.
· Resistivity After Water Exposure: Maintains volume resistivity of ≥1 × 10¹² Ω·m after the stated 24-hour water immersion test.
· Defined Oven-Drying Options: Reference drying schedules of 3–5 hours at 90°C or 2–4 hours at 100°C allow process selection according to component requirements.
· Adjustable Application Viscosity: The specified X-08 thinner enables viscosity adjustment for the selected coating or impregnation process.
Typical Applications：
E962-788 insulating varnish is intended for surface coating or impregnation of:
· High-Frequency Transformers: Insulation treatment of transformer coils and associated electronic components.
· Inductor Coils: Coating or impregnation of inductive components requiring electrical insulation and adhesion.
· Electrical Coil Assemblies: Insulation treatment of coils used in electrical and electronic products.
· Computer-Related Electronic Components: Coating of suitable components used in computer equipment.
· Other Transformer and Electronic Assemblies: Applications requiring a low-odor acrylic insulating varnish with Class B heat resistance.
Confirm compatibility with wire enamel, plastics, insulation materials, and other assembly components before production use.
Physical Properties：
| Item | Specification | |
| Varnish Properties | Appearance | Slightly yellow, transparent to slightly turbid liquid |
| Viscosity (25℃, Tu-4 Cup, s) | 52±3″ | |
| Specific Gravity (25℃) | 0.94±0.03 | |
| Non-Volatile Content (105℃/3h, %) | 37±3 | |
| Drying Time | 90℃, H | 3-5 h |
| 100℃, H | 2-4 h | |
| Volume Resistivity | Normal State (Ω·m) | ≥1014 |
| After 24h Water Immersion (Ω·m) | ≥1012 | |
| Dielectric Strength | Normal State (kV/mm) | ≥60 |
| Matching Thinner | X-08 | |
Technical Notes:
· Viscosity is expressed as cup flow time in seconds.
· Specific gravity is dimensionless.
· Volume resistivity is reported in Ω·m.
Application Guidance：
· Preparation and Thinning
Use the specified X-08 thinner when viscosity adjustment is required. Determine the dilution ratio through trials based on component geometry, application method, and the required coating or impregnation result.
Verify compatibility with the actual substrates and assembly materials before introducing E962-788 into production.
· Coating and Impregnation
Apply E962-788 electrical insulating varnish using a surface-coating or impregnation process suited to the component. Establish application parameters through trials to achieve the required coverage, adhesion, and insulation performance.
For winding assemblies, confirm adequate impregnation and solvent removal throughout the component before approving the production process.
· Reference Oven-Drying Conditions
| Drying Temperature | Reference Drying Time |
|---|---|
| 90°C | 3–5 h |
| 100°C | 2–4 h |
Select and validate the drying schedule according to the component’s size, construction, coating thickness, and production requirements.
Actual drying may vary with solvent retention, airflow, oven loading, and the time required for the component to reach the target temperature. Confirm complete drying before electrical testing or service.
· Humidity Considerations
E962-788 may absorb moisture and develop a whitish appearance under high-humidity conditions. The TDS states that product performance is not affected after baking.
Control application humidity and verify the coating appearance and drying condition before accepting finished components.
Precautions：
· Determine the dilution ratio, baking temperature, and baking time experimentally based on product shape, size, and specific requirements.
· The product may absorb moisture and turn whitish under high humidity; performance remains unaffected after baking.
· This product is flammable; keep away from fire and heat sources.
Packaging, Storage/Transport & Shelf Life：
· Packaging: metal pails, 18 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℃.
Frequently Asked Questions About E962-788 Insulating Varnish
1. What is E962-788 insulating varnish used for?
E962-788 is a modified acrylic electrical insulating varnish designed for surface coating and impregnation of electrical and electronic components. Typical applications include high-frequency transformers, inductor coils, electrical coil assemblies, and suitable components used in computer equipment.
It provides electrical insulation and adhesion within coated or impregnated assemblies. Verify compatibility with wire enamel, plastics, and other insulation materials before production use.
2. Is E962-788 a low-odor, solvent-free varnish?
E962-788 is a low-odor, solvent-based insulating varnish formulated with modified acrylic resin and an alcohol/glycol-ether solvent system. It is not solvent-free.
Low odor does not establish low VOC content or eliminate ventilation requirements. Request the applicable VOC content test report when evaluating emissions requirements, and provide suitable ventilation during application and drying.
3. What is the thermal class of E962-788?
E962-788 is rated Class B, 130°C, in the product specification. This thermal classification supports selection for corresponding electrical insulation requirements.
The 130°C classification is separate from the reference oven-drying temperatures of 90°C and 100°C. Suitability for finished equipment depends on the complete insulation system, component materials, and operating conditions.
4. What drying temperature and time does E962-788 require?
E962-788 has two reference oven-drying schedules: 3–5 hours at 90°C or 2–4 hours at 100°C.
Select and validate the schedule using the actual component. Drying time depends on coating thickness, winding construction, retained solvent, airflow, oven loading, and the time required for the component to reach the target temperature. Confirm complete drying before electrical testing or service.
5. Can E962-788 insulating varnish dry at room temperature?
The supplied E962-788 TDS does not specify room-temperature surface-dry or through-dry times. An ambient-drying production schedule therefore requires confirmation and application testing.
For process planning, use the documented oven-drying schedules as reference conditions: 90°C for 3–5 hours or 100°C for 2–4 hours.
6. What electrical insulation performance does E962-788 provide?
E962-788 has a specified dielectric strength of at least 60 kV/mm and volume resistivity of at least 1 × 10¹⁴ Ω·m under normal conditions.
These material test values support insulation selection but do not directly establish the allowable operating voltage of finished equipment. Assembly design, coating quality, and the complete insulation system must also be evaluated.
7. How does E962-788 perform after moisture exposure?
E962-788 has a specified volume resistivity of at least 1 × 10¹² Ω·m after the stated 24-hour water immersion test.
The supplied TDS does not report dielectric strength after water immersion. The resistivity result should not be interpreted as a waterproof rating or confirmation of suitability for continuous underwater service.
8. Which thinner should be used with E962-788?
Use the specified X-08 thinner when adjusting E962-788’s application viscosity. The supplied varnish has a specified flow time of 52 ± 3 seconds at 25°C, measured with a Tu-4 cup.
Determine the dilution ratio through trials based on component geometry, application method, and the required coating or impregnation result. Cup flow time in seconds is not a dynamic viscosity value in mPa·s.
9. What should be checked before impregnating transformer or inductor coils?
Confirm compatibility with the actual wire enamel, insulation materials, plastics, and other assembly components. Establish working viscosity and application parameters using representative coils.
Before approving the process, verify adequate varnish penetration, adhesion, and solvent removal throughout the winding. A dry outer surface alone does not confirm complete drying inside the assembly.
10. Why can E962-788 develop a whitish appearance?
E962-788 may absorb moisture and develop a whitish appearance under high-humidity application conditions. The TDS states that performance is not affected after baking.
Control application humidity and verify the coating’s appearance and drying condition before accepting finished components. Establish the baking schedule according to the actual assembly and the documented drying guidance.
11. What safety and compliance documents are available for E962-788?
Our Insulating Varnish downloads section lists an MSDS, RoHS documentation, and a VOC content test report. Specify E962-788 when requesting documents so the applicable report or declaration and its product coverage can be confirmed.
The Thinners section separately lists RoHS documentation and a halogen content test report. If using X-08, request documentation for that exact thinner grade and review it separately from the varnish documentation.
12. How is E962-788 packaged, and what is its shelf life?
E962-788 is supplied in 18 kg metal pails. Its stated shelf life is six months when stored sealed at 5–25°C.
Store the varnish in a cool, dark, dry location away from fire and heat sources. E962-788 is flammable; follow the applicable safety data sheet for handling, storage, and transport.
13. What information is needed to request an E962-788 quotation?
Provide your component type, application method, available oven-drying conditions, and electrical insulation requirements. These details help assess suitability for your production process.
Include the required quantity, delivery destination, target delivery date, and any trial-material or compliance-document requirements so availability, relevant documentation, and lead time can be confirmed.