UV-531

 

Product Name	UV-531
Chemical Name	2-Hydroxy-4-n-octyloxybenzophenone
CAS No.	1843-05-6
Type	Benzophenone UV Absorber
Molecular Formula	C21H26O3
Molecular Weight	326g/mol
Appearance	Sightly yellow powder
Melting Point	47-49℃
Ash	≤0.1%
Assay	≥99.0%

 

UV Absorber UV-531, also known as Octabenzone or 2-Hydroxy-4-n-octoxybenzophenone, is a benzophenone-type ultraviolet absorber designed to protect polymers, coatings and other materials from UV-induced degradation.With a CAS No. of 1843-05-6, UV-531 provides effective absorption of harmful UV radiation while offering good compatibility with a wide range of polymer systems. Its relatively low volatility and low migration characteristics make it suitable for applications where long-term light stability and retention of material properties are required.

 

Solubility at 20℃ (g 100/g solution)
Solvent	Solubility	Solvent	Solubility
Acetone	>50	n-Hexane	30
Xylene	>50	Water	<0.01
Methyl n-amyl ketone (MAK)	>50	Chloroform	61
100# Solvent Naphtha	>50	Ethyl acetate	44
Propylene glycol methyl ether acetate	>50	Methanol	2
Butyl acetate	>50	Chloromethane	67
Diethylene glycol butyl ether	36	Toluene	>50
Ethanol	3	\

 

 

One of the main advantages of UV-531 is its broad compatibility with different polymer systems. Technical information from commercial suppliers lists applications in PE, PP, PVC, PS, ABS, PC, polyester, PA, PVDC and EVA, among other materials.

UV-531 also has relatively low volatility and low migration characteristics. These properties are particularly relevant for thicker plastic articles and long-term outdoor applications where the UV stabilizer needs to remain in the polymer matrix for an extended period.

Its light color is another practical advantage. Properly formulated UV-531 can provide UV protection without causing significant changes to the appearance of the finished material.

 

 

When polymers are exposed to sunlight, ultraviolet radiation can initiate photochemical reactions that gradually damage polymer chains. This can result in yellowing, discoloration, loss of gloss, cracking, embrittlement and deterioration of mechanical properties.

As a benzophenone UV absorber, UV-531 absorbs a portion of the harmful UV radiation before it can cause extensive photochemical damage to the polymer. The absorbed energy is subsequently dissipated through a non-destructive process, helping reduce the rate of UV-induced degradation.

This makes UV-531 UV absorber useful for improving the weatherability and service life of plastics, coatings, elastomers and other outdoor polymer materials.

 

 

UV-531 for PE and PP：Polyethylene (PE) and polypropylene (PP) are important application areas for UV-531. UV-531 can be incorporated into PE and PP films, molded products, containers, pipes and other polymer articles to improve resistance to UV-induced degradation.

 

UV-531 for PVC：UV-531 for PVC is another established application. PVC products exposed to sunlight may gradually experience discoloration, surface degradation and deterioration of physical properties.UV-531 can be incorporated into rigid or flexible PVC formulations and is suitable for applications such as PVC profiles, films, sheets, synthetic materials and outdoor products.

 

UV-531 for EVA：UV-531 can also be used in ethylene-vinyl acetate (EVA) systems. EVA is widely used in films, encapsulation materials and other applications where exposure to light and heat can affect long-term performance.UV-531 can help reduce UV-induced degradation and improve the weathering resistance of EVA-based materials. Commercial product information specifically identifies EVA among its recommended polymer substrates.

 

UV-531 for Coatings：In coatings, UV radiation can gradually damage the resin binder and lead to color fading, gloss loss, cracking and loss of adhesion.UV Absorber UV-531 can be incorporated into polyurethane, acrylic, epoxy, alkyd and other coating systems to provide additional protection against UV radiation.

 

UV-531 for Elastomers and Rubber：UV-531 is also suitable for certain natural and synthetic rubber and elastomer systems. UV exposure can accelerate surface cracking and loss of physical properties in rubber materials.Adding a suitable UV absorber for rubber and elastomers can help reduce the effects of prolonged UV exposure and improve outdoor durability.