Key Performance Requirements for UV-Curable Resins in Gel Polish Top Coats

The top coat is a critical component in gel nail systems. It serves to protect the color layer, enhance gloss, and improve durability. Therefore, the UV-curable resins used in top coat must meet high-performance standards. Below are the main performance requirements:

1. Excellent Anti-Yellowing Properties

This is one of the most essential criteria. Since the top coat is directly exposed to UV light, insufficient resistance can cause discoloration or yellowing over time.

Resins must use UV-stable monomers and photoinitiators to ensure long-term clarity and color retention.

2. High Transparency and Gloss

The resin should be crystal clear with a high refractive index to deliver a long-lasting mirror-like finish after curing.

3. Strong Adhesion

It must adhere firmly to the color layer, preventing peeling, chipping, or delamination for improved wear resistance.

4. Superior Hardness and Abrasion Resistance

Once cured, the top coat should have a hard surface to withstand scratches and daily wear, extending the life of the manicure.

5. Balanced Flexibility

While providing hardness, the cured film should also retain some flexibility to accommodate natural nail movement and avoid cracking.

6. Fast Curing / High Reactivity

The resin should cure quickly under LED/UV lamps to reduce application time and improve salon efficiency.

7. Low Shrinkage, Low Odor, Low Irritation

To enhance user comfort and product safety, resins should exhibit minimal shrinkage to prevent cracking or lifting, and low VOC emissions to reduce odor and irritation.

Recommended Types of UV-Curable Resin Components:

Epoxy Acrylates---Ever Ray Epoxy Acrylate 6200D
Offer excellent hardness and adhesion; commonly used as the main resin base for top coats.

Polyurethane Acrylates (PUA)---Ever Ray Polyurethane Acrylate 7296-1
Provide flexibility, wear resistance, and a good hardness–toughness balance—ideal for modifying top coat systems.

Functional Reactive Diluents---Ever Ray Monomer
Low-odor, low-yellowing trifunctional acrylates can help reduce viscosity, enhance curing speed, and fine-tune film properties.