Scratch resistance is an important performance requirement for UV-curable coatings used on plastics, wood, glass, electronic devices, flooring, and decorative surfaces. A coating must withstand everyday contact, abrasion, and surface marking while maintaining its appearance and adhesion. Choosing the right UV resin is a key step, but scratch resistance depends on the entire formulation, substrate, and curing process rather than one ingredient alone.

Guangdong Lencolo New Material Co., Ltd., operating under the Lencolo brand, supplies UV-curable resins and functional materials for coatings, inks, adhesives, and related applications. Its product portfolio includes polyurethane acrylates and specialized matte and high-performance UV resins that can be evaluated for scratch-resistant and abrasion-resistant surface development.

1. What Determines Scratch Resistance in UV Coatings?

Resin chemistry and crosslink density influence surface hardness and resistance to mechanical damage. Higher-functionality UV resins can support the formation of highly crosslinked films, potentially improving hardness and scratch resistance. However, excessive crosslinking may also increase brittleness or affect adhesion and flexibility. The optimal resin depends on the balance required by the application.

Hardness and flexibility must be evaluated together. Rigid substrates such as glass may accommodate harder coatings, whereas flexible plastics, films, and leather-like materials may require better deformation resistance. A coating that performs well in a hardness test does not necessarily deliver the best scratch resistance under every service condition.

Curing efficiency is another critical factor. Mercury UV, UV LED, excimer, and dual-cure systems have different curing characteristics. Resin compatibility with the selected photoinitiator and light source, together with exposure conditions and film thickness, affects the final coating performance.

Finally, reactive monomers, additives, pigments, fillers, and substrate preparation can all influence surface properties. Formulators should validate candidate resins in the complete formulation rather than relying exclusively on catalog descriptions.

2. Polyurethane Acrylate Resins for Scratch and Wear Resistance

Lencolo offers several polyurethane acrylate grades with properties relevant to surface durability.

L-6207 is a difunctional polyurethane acrylate positioned for balanced wear resistance and flexibility, fast curing, and RCA resistance exceeding 200 cycles under the specified test conditions. Its indicated applications include 3C coatings, glass, plastics, and PVD coatings. It is a candidate for projects requiring a combination of surface durability and mechanical balance.

L-6240 is an LED-curable UV resin characterized by high hardness, high gloss, high crosslink density, and scratch resistance. Its listed application areas include coatings, inks, adhesives, overprint varnishes (OPV), plastics, paper, and nail gel. It can be evaluated where LED curing and a hard, glossy surface are required, subject to compatibility with the complete curing system.

L-6316 combines scratch resistance with leveling, fullness, and fast curing. Its target applications include SPC/PVC flooring and soft-touch plastic coatings, where surface appearance and resistance to everyday contact both matter.

L-6360 is described as offering wetting, scratch resistance, slip properties, anti-yellowing performance, and toughness. It is indicated for PVC flooring, paper, plastic, and wood applications. These characteristics make it a candidate for formulations that need both surface protection and a balance of film properties.

L-6365 is another option for evaluation, with fast curing, scratch resistance, and strong substrate adhesion among its stated features. Actual adhesion and scratch performance should be verified on the intended substrate.

3. Matte UV Resins for Scratch-Resistant Low-Gloss Surfaces

Matte coatings present a distinct challenge: they must maintain a consistent low-gloss appearance while controlling surface marking, haze, and tactile properties.

L-6380A is positioned for a stable gloss range of approximately 5°–10°, together with high hardness, scratch resistance, and a smooth soft-touch film. Its indicated applications include matte OPV, PVC flooring or leather, plastics, and inks.

Two related grades address additional formulation priorities. L-6380A-4 is associated with low-odor characteristics, while L-6380A-10 is positioned for anti-yellowing performance. Selection between these variants should be based on the relevant technical data and the requirements of the finished coating.

L-6380M is an anti-scratch matte resin designed for a low-gloss finish of approximately 1°–3°, with stated benefits including compatibility, leveling, and adhesion. It can be considered for applications requiring an especially low-gloss appearance without overlooking surface durability. Gloss, haze, scratch resistance, and tactile feel should be assessed together during formulation trials.

4. High-Performance UV Resins for Demanding Abrasion Tests

For applications involving more demanding abrasion requirements, Lencolo’s high-performance resin range includes several additional candidates.

L-6900, with a listed functionality of 9, is positioned for high weather resistance, yellowing resistance, and scratch resistance. L-6902 and the inorganic hybrid variant L-6902X, both listed at functionality 15, reference steel wool resistance exceeding 5,000 cycles, alongside weatherability and yellowing resistance. These figures should be interpreted according to the original test method, load, substrate, and evaluation criteria; they are not directly comparable with results from different testing protocols.

The L-6905 series, including L-6905A, L-6905B, and C-8, C-9, C-10, and E variants, extends the product range toward anti-graffiti and anti-fingerprint coatings for plastic and film substrates. The best grade depends on whether the primary target is scratch resistance, stain release, fingerprint visibility, or a combination of these properties.

For applications requiring additional curing mechanisms, L-8469 is a dual-cure resin described as offering steel wool resistance, fast surface drying, low shrinkage, and high hardness. Its indicated applications include inks, mobile phone glass, and automotive interior components. Compatibility with the complete dual-cure process must be confirmed before production.

5. How to Select and Validate a Scratch-Resistant UV Resin

Start by defining the substrate, target gloss, curing equipment, and required resistance to scratches, abrasion, chemicals, or weathering. Shortlist resins according to their chemistry, functionality, viscosity, and documented application experience. Then prepare trial formulations using compatible monomers, photoinitiators, and additives.

Testing should use consistent conditions and the intended substrate. Depending on the application, relevant evaluations may include pencil hardness, RCA abrasion, steel wool resistance, adhesion, flexibility, gloss retention, and chemical resistance. Results from different methods should not be treated as interchangeable.

Lencolo’s UV resin portfolio provides options for glossy coatings, matte surfaces, flooring, electronics, and other industrial applications. Grades such as L-6207, L-6240, L-6316, L-6360, L-6380A, L-6380M, L-6902X, and L-8469 offer distinct starting points for scratch-resistant coating development. Final selection should be based on current technical data and testing under actual formulation, substrate, and curing conditions.

The most reliable route to scratch resistance is a system-level approach: select a suitable resin, optimize the complete formulation, and verify performance using application-relevant tests.