PRODUCTS

UV Absorber

UV-633

Equivalent:	Hostavin B-CAP (Clariant)
Chemical name:	p-Phenylenebis(methylenemalonic acid)tetraethyl ester
CAS NO.:	6337-43-5
Molecular formula:	C22H26O8
Molecular weight:	418.4
Chemical structure

Specification
Appearance	:	white to off white powder
Assay (HPLC)	:	99.0% min
Melting point	:	137-140°C
Loss on drying	:	0.5% max
Transmittance	:	425nm: 93%min 500nm: 97%min
Solubility	:	( 23°C) ( g/100g solvent) Acetone: 14, Dichloromethane 240, Dioxane 38, DMSO 4, Toluene 0.8, Ethylacetate 16, Methanol 0.4, Ethanol 0.7, Isopropano 0.3, Water 0.1max, n-Butanol 0.4, p-Xylene 0.6, Methylethylketone 1.0, N-Methylpyrrolidone 2.2

Use
UV-633 (Hostavin B-CAP) is recommended as a highly efficient and colorless UV absorber for plastic materials, particularly engineering plastics such as polycarbonate and polyesters.

UV-633 which is a benzylidene-bis-malonate type UV absorber with pronounced absorptivity in the high energy (low wavelength) range of the UV spectrum, shows a significant improvement of long term stability of polycarbonate. In addition to the stabilization of PC, UV-633 (Hostavin B-CAP) also can be advantageously used to improve the light stability of PET to UV light yellowing and brittleness may occur. UV-633 would be the good choice if the maintenace of transparency is required

To meet performance requirements of PC, the suitable UV absorbers should be critically choosed. However in some cases when exposed to more demanding climatic conditions (heat, UV radiation, water etc) even stabilized PC parts still continue to exhibit discoloration such as yellowing. The mechanism of this failure can be explained by the photodegradation of some UV absorber as shown as bellows leading to the loss of the UV protection followed by discoloration..

Package
25kg / carton box