Scratch resistance is a key requirement for UV-curable coatings used on plastics, wood, glass, 3C electronics, automotive interiors, and PVC/SPC flooring. However, a coating described as “high hardness” does not automatically provide the best scratch or abrasion resistance. Surface durability depends on the interaction between UV resin, cross-link density, formulation components, substrate, film thickness, and curing conditions.

What Controls Scratch Resistance in a UV Coating?

UV resin is one of the main film-forming components in a UV formulation. Resin functionality and molecular structure influence hardness, flexibility, adhesion, curing behavior, and surface durability.

Higher-functionality resins can form denser cross-linked networks and therefore provide greater potential for surface hardness and abrasion resistance. However, excessive cross-linking may reduce flexibility or increase brittleness. This is particularly important for leather, TPU, flexible films, and plastic substrates that undergo bending or impact.

A practical formulation therefore needs to balance hardness, flexibility, adhesion, and wear resistance rather than maximize hardness alone.

Other formulation components also matter. UV monomers affect reactivity and cross-link density; photoinitiators influence curing completeness; additives can modify wetting, leveling, and surface properties; and pigments or fillers may change curing behavior and mechanical performance.

The curing method is equally important. Mercury UV, UV LED, excimer, and dual-cure systems can produce different curing profiles and surface properties. A resin with strong scratch-resistance potential may still perform poorly if the film is under-cured or the curing conditions are not suitable for the formulation.

Lencolo UV Resins for Scratch-Resistant Applications

Guangdong Lencolo New Material Co., Ltd., operating under the Lencolo brand, offers UV-curable resins for coatings, inks, adhesives, flooring, PVD, electronics, and specialty surface applications. Its catalog contains 167 UV resin grades across 16 product families, providing different starting points for scratch- and abrasion-resistant formulations.

Polyurethane Acrylates

L-6207 is a two-functional polyurethane acrylate positioned for balanced wear resistance and flexibility, with fast curing and RCA resistance exceeding 200 times. Its indicated applications include 3C coatings, glass, plastic, and PVD.

L-6240 is an LED-curable resin described as providing high hardness, high gloss, high cross-link density, and excellent scratch resistance. It is indicated for coatings, inks, adhesives, OPV, plastic, paper, and nail applications.

For flooring and plastic coatings, L-6316 combines leveling, fullness, fast response, and scratch resistance. L-6360 combines scratch resistance with wetting, slipperiness, anti-yellowing properties, and toughness for PVC flooring, paper, plastic, and wood. L-6365 focuses on fast curing, scratch resistance, and substrate adhesion.

Matte UV Resins

Scratch resistance becomes more challenging when the coating must also maintain a stable matte appearance.

L-6380A is positioned for approximately 5°–10° gloss, high hardness, and good scratch resistance in a smooth soft-touch film. Related grades L-6380A-4 and L-6380A-10 provide additional low-odor or anti-yellowing characteristics.

For lower-gloss systems, L-6380M is described as an anti-scratch matte resin with approximately 1°–3° gloss without haze, together with compatibility, leveling, and adhesion.

High-Performance Abrasion Resistance

For more demanding surface durability requirements, L-6900 is positioned with high weather resistance, yellowing resistance, and scratch resistance.

L-6902 and L-6902X, both high-functionality grades, reference steel wool resistance exceeding 5,000 cycles, together with weatherability and yellowing resistance. The L-6905 series extends surface protection into anti-graffiti and anti-fingerprint coatings for plastic and film substrates.

For dual-cure applications, L-8469 is described as a steel-wool-resistant resin with fast surface drying, low shrinkage, and high hardness for applications including inks, mobile phone glass, and automotive interiors.

Specialty Surface Applications

Scratch resistance is also relevant to soft-touch and specialty coatings. L-8320 combines soft-touch properties with scratch and wear resistance for soft-touch coatings, PVC flooring, paper, and plastic.

The L-6367 excimer UV resin series is designed for soft skin-feel surfaces while incorporating scratch-resistance performance. L-8461 combines elasticity, a fine matte finish, weather resistance, and scratch resistance for applications such as inks, mobile phone glass, and automotive interiors.

For nail coatings, L-8443 is positioned as a topcoat resin offering high hardness, low shrinkage, and scratch resistance.

How Should Scratch Resistance Be Tested?

Product descriptions alone cannot determine the final scratch performance of a UV coating. The same resin can behave differently when the substrate, monomer system, additive package, film thickness, or curing conditions change.

A useful evaluation should measure scratch or abrasion resistance together with hardness, adhesion, flexibility, gloss, chemical resistance, yellowing, surface appearance, and curing completeness.

Testing should reproduce the intended substrate, coating method, film thickness, UV equipment, and curing conditions as closely as possible. When several resin grades meet the initial requirements, comparative formulation trials can provide a more reliable basis for selection.

A Formulation-Level Approach

Improving scratch resistance is ultimately a formulation-design problem rather than a search for one “hardest” UV resin. Resin functionality establishes an important foundation, but monomers, photoinitiators, additives, substrate characteristics, film build, and curing technology determine how that potential appears in the finished coating.

For formulators working with plastics, flooring, PVD, electronics, automotive interiors, matte coatings, inks, or specialty surfaces, Lencolo resin grades such as L-6207, L-6240, L-6316, L-6360, L-6380M, L-6902, and L-8469 provide different starting points for scratch- and abrasion-resistant UV formulations. Final suitability should be confirmed through application-specific formulation testing.

Guangdong Lencolo New Material Co., Ltd.
https://www.lencolo37.com/