Stop Additive Migration and Blooming! Reactive UV Absorbing Monomer CAS 2035-72-5, Long-lasting UV Blocking & Anti-yellowing, Preferred Raw Material for High-end UV-curable Weather-resistant Formu

When developing formulations for UV-curable coatings, inks, optical films and outdoor plastic coatings, many R&D engineers encounter the same challenge: conventional small-molecule UV absorbers are simply blended into resin systems without chemical bonding. Over time, under temperature fluctuations, humidity and outdoor sunlight exposure, additives gradually migrate to the coating surface, causing blooming and whitening. Meanwhile, small molecules volatilize and leach away, leading to rapid loss of UV protection. The finished products suffer from yellowing, gloss loss and chalking, which shortens service life and severely damages end-users’ quality reputation.

CAS 2035-72-5, chemical name 2-Hydroxy-4-(methacryloyloxy)benzophenone, commonly known as UV725 in the industry, is a reactive UV absorbing monomer with methacrylic active double bonds. It breaks the limitation of traditional additives that rely merely on physical blending. Its molecular structure contains both benzophenone conjugated UV-absorbing segments and polymerizable methacrylic double bonds. During UV curing or thermal curing, this product copolymerizes with acrylic resins and reactive diluents, and is firmly anchored into the polymer coating network via covalent bonds. After curing, it no longer exists as free small molecules, fundamentally eliminating industry pain points such as migration, precipitation and volatilization.

Its UV absorption range covers 280–360 nm, efficiently capturing UVA and UVB radiation. It converts absorbed UV energy into harmless heat through intramolecular hydrogen bonding, restraining photodegradation of resin molecular chains and continuously resisting coating yellowing and aging. The product exhibits excellent compatibility with most acrylic UV curing systems. It will not disrupt the curing system or significantly reduce curing speed while maintaining good coating transparency, making it highly suitable for high-transparency optical materials.

Product Basic Information 

Chemical Name: 2-Hydroxy-4-(methacryloyloxy)benzophenone

English Name: 4-Methacryloxy-2-hydroxybenzophenone

CAS No.: 2035-72-5

Molecular Formula: C₁₇H₁₄O₄

Molecular Weight: 282.29

Appearance: White to pale yellow crystalline powder

Purity: ≥98% / ≥99% (by GC)

Melting Point: 77~79℃

Solubility: Insoluble in water, soluble in acetone, ethyl acetate, toluene and various acrylic reactive monomers

Polymerization Inhibitor: ~3000ppm MEHQ to prevent self-polymerization during storage

Storage: Keep sealed, away from light, store in cool and dry place, protect from moisture

Detailed Core Advantages

1. Reactive bonding, no migration or blooming. Covalently incorporated into resin network after curing; will not migrate to coating surface. No whitening or precipitation after long-term outdoor exposure for stable and durable protection.

2. Broad-band UV absorption, superior anti-yellowing and weather resistance. Efficiently absorbs UV light at 280-360 nm, slows down polymer photoaging and greatly improves outdoor durability of coatings.

3. Good system compatibility without affecting coating appearance. Compatible with UV acrylic resins, reactive diluents and photoinitiators. Will not raise haze in transparent systems and does not interfere with normal curing reactions.

4. High purity and stable batches. High-purity crystalline raw material with low impurities and controllable indicators for each batch. COA certificates available, suitable for lab trials, pilot scale-up and industrial mass production.

5. Wide application coverage. Used for UV-curable outdoor wood varnishes, plastic UV coatings, printing UV inks, optical protective films, UV adhesives for flexible substrates, PET/PC film coatings and UV curable protective coatings for outdoor building materials.

Comparison with Traditional Additive-type UV Absorbers: Ordinary UV absorbers are only physically dispersed. They tend to migrate and leach out under heat and UV irradiation, leading to obvious decay of weather resistance and frequent surface blooming. CAS 2035-72-5 participates in crosslinking copolymerization and is permanently fixed inside the coating. Its weathering performance remains stable long-term without contaminating coating surfaces, meeting stringent standards for high-end optical and outdoor products.

Application Recommendation: The recommended dosage is generally 0.5%–3% by weight of the total formulation. The optimal loading level should be determined via lab testing according to resin system, film thickness and outdoor weathering requirements. It can be used with suitable photoinitiators and must be stored away from light.

Supply Information: We provide samples for formulation R&D testing and support small & bulk orders. MSDS and COA documents are available to meet domestic manufacturing and export requirements. R&D engineers working on UV curing weather-resistant formulation upgrades are welcome to contact us for samples and testing.