Epovion SOL-S 40 is a brominated bisphenol-A solid epoxy resin produced from tetrabromobisphenol A diglycidyl ether chemistry, offering a high bromine content for outstanding flame-retardant performance while retaining the physical and electrical properties typical of standard bisphenol-A epoxy resins. It is formulated for use in electronic encapsulation compounds and copper-clad laminates where flame retardancy is a mandatory design requirement.
Epovion SOL-S 40 Overview
Epovion SOL-S 40 belongs to the family of brominated bisphenol-A solid epoxy resins, in which tetrabromobisphenol A is reacted with epichlorohydrin to build bromine directly into the resin backbone rather than relying on an additive-type flame retardant. Because the bromine is chemically bound within the molecule, Epovion SOL-S 40 delivers durable, non-blooming flame-retardant performance that does not migrate out of the cured part over time or under thermal cycling.
Despite its high halogen content, Epovion SOL-S 40 retains the electrical insulation, adhesion, and mechanical properties characteristic of conventional bisphenol-A epoxy resins, allowing formulators to add flame retardancy without redesigning the rest of the curing system.
Key Features
- Brominated bisphenol-A chemistry: Epovion SOL-S 40 is manufactured from tetrabromobisphenol A and epichlorohydrin.
- High bromine content: A bromine content of 46-50% provides strong, built-in flame-retardant performance.
- Solid supply form: The resin is supplied as a solid, low-color flake or lump suited to compounding and solution preparation.
- Retains standard epoxy performance: Physical and electrical properties match conventional bisphenol-A epoxy resin types.
- Low color: A Gardner color of 1.0 max supports light-colored and optically clean formulations.
Typical Applications
Epovion SOL-S 40 is primarily used in electronic encapsulation compounds, where flame retardancy is required to meet UL and other safety standards for components such as connectors, relays, and potted assemblies. It is also widely applied in copper-clad laminates (CCL) for printed circuit boards, where the resin’s flame-retardant backbone helps laminates meet UL 94 V-0 requirements without a separate additive package.
Beyond encapsulation and laminates, Epovion SOL-S 40 is suitable for flame-retardant coatings, adhesives, and molding compounds used in electrical and electronic equipment. For applications requiring an even higher softening point or epoxy equivalent weight, formulators may wish to evaluate Epovion SOL-S 90 alongside this grade.
Technical Specifications
- Chemical type: Brominated bisphenol-A epoxy resin (tetrabromobisphenol A + epichlorohydrin)
- Physical state: Solid
- Epoxide equivalent weight: 380-410 g/eq
- Bromine content: 46-50%
- Color (Gardner): 1.0 max
- Softening point: 64-74°C
- Density (25°C): 1.3 g/cm³
- Function: Flame-retardant solid epoxy resin base
Brominated Epoxy Chemistry & Flame-Retardant Performance
The flame retardancy of Epovion SOL-S 40 originates directly from its tetrabromobisphenol A backbone: when exposed to flame, the carbon-bromine bonds decompose to release bromine radicals that interrupt the free-radical combustion cycle in the gas phase, quenching the flame far more effectively than non-halogenated resin at equivalent loading. Because the bromine is covalently bound to the resin structure rather than physically blended in as a separate additive, Epovion SOL-S 40 avoids the blooming, leaching, and plasticization issues that can affect systems relying on additive-type brominated flame retardants.
The epoxide equivalent weight of 380-410 g/eq places Epovion SOL-S 40 in the lower-molecular-weight range of solid brominated resins, giving formulators good flow and impregnation behavior during laminate pressing and encapsulation molding while still delivering a bromine content of 46-50%, among the higher levels available in commercial brominated epoxy resins. This combination of high bromine content and manageable melt viscosity is what makes the resin particularly well suited to CCL prepreg formulation, where resin flow through glass fabric must remain controlled even as flame-retardant loading increases.
Storage Recommendations
- Store in the original, tightly sealed packaging, protected from moisture.
- Recommended storage: room temperature, away from direct sunlight and heat sources.
- Shelf life: Up to 12 months in the original, unopened packaging when stored under recommended conditions.
- Avoid prolonged exposure to elevated temperatures, which can cause caking or premature advancement of the resin.
Documentation & Compliance
Each shipment of the product is supported by standard quality and compliance documentation to help customers manage incoming inspection, formulation approval, and downstream regulatory reporting.
- Certificate of Analysis (COA): Provided per batch
- Safety Data Sheet (SDS): Mandatory prior to handling
- Labels: Prepared in accordance with applicable regulations
- Industrial and professional use only
Formulation Guidance
Epovion SOL-S 40 is typically dissolved in ketone, glycol ether, or aromatic solvent blends to prepare varnish-form resin solutions for laminate impregnation, with solids content and viscosity adjusted to suit the target prepreg process. In encapsulation compounds, the resin is generally compounded with an appropriate curing agent, such as a phenolic novolac or dicyandiamide hardener, along with fillers and flame-retardant synergists to reach the specific UL flammability rating required by the application.
Because Epovion SOL-S 40 is fully reacted and does not itself require further bromination, it can be blended directly with non-halogenated bisphenol-A resins to fine-tune the overall bromine content and mechanical properties of the final formulation. For applications needing a lower-viscosity liquid component to aid processing or reduce overall system viscosity, formulators may wish to evaluate Epovion BPA-L 17 as a complementary liquid resin.
Packaging & Logistics
- Packaging: Approved industrial packaging (25 kg bags standard)
- MOQ: Subject to packaging configuration
- Lead time: Indicative lead time, to be confirmed upon order acceptance
- Incoterms: Quoted case by case
Epovion SOL-S 40: Safety & Handling
Epovion SOL-S 40 should be handled in accordance with standard industrial hygiene practices for brominated epoxy resins. Users are advised to review the Safety Data Sheet prior to handling and to implement appropriate personal protective equipment and engineering controls as specified therein, including dust control measures during grinding or handling of the solid resin. As with all brominated flame-retardant resins, small-scale compatibility and cure trials are recommended before full-batch formulation to confirm flammability rating, mechanical properties, and processing behavior in the target system.
Safety Data Sheet and destination-compliant labeling information for the product are available upon request. For related epoxy resin options, see also Epovion SOL-S 90 and Epovion BPA-L 17.