UV-cured coatings

Maleate/Vinyl Ether UV-Cured Coatings Effects of Composition on Curing and Properties... 

Such oligomers are often used in ultraviolet (UV) cure coatings (free-radical chain polymerization, Sec. 2.3). 

A typical UV-cured coating has three or sometimes four main ingredients (1) a multifunctional acrylate monomer, (2) a reactive oligomer, (3) possibly a monoacrylate as reactive diluent, and (4) a photoinitiator (Table 2.20). 

The reactivity of cycloaliphatic epoxy monomers with cations is higher than that of glycidyl ether monomers. For this reason, cycloaliphatic epoxies are used for UV-cure coatings. The most efficient initiators are complex aromatic salts of Lewis acids such as diaryl iodonium, triarylsul-fonium, or arene diazonium (Table 2.23) (Crivello, 1999). 

Zwanenburg, R. C. W., How to Formulate UV-Curing Coatings, RadNews Highlights, Paint Research Association, Middlesex, UK, Spring 1998. 

The dielectric strength of polyethylene has been measured as a function of additive concentration while in stabilised polymers the depth of degradation was found to be uniform . HALS have been found to be effective stabilisers for UV cured coatings and do not influence the cure rate . Bleached wood pulps can be effectively stabilised by ascorbic acid and wool by hydroxy-benzotriazoles and HALS . Hydroxybenzotriazole stabilisers also protect wood pulp and polyurethanes by co-reaction . The spectroscopic properties of monomeric and polymeric benzotriazoles have also been compared . UV absorbers are effective in clear coats and when grafted to wood . Dihydroxybenzophenone stabilisers inhibit the chain scission in the photodegradation of poly(methoxyacrylophenone) while tin stabilisers have also been found to photostabilise PVC . 

Many recent studies have probed the polymerization mechanisms (3.4). UV stabilities (5) and physical properties (6) of UV-cured coatings. However little attention has been given to the aging properties of these materials and their effectiveness in long-term applications. We... 

HEYWARD ETAL. Antioxidant Effects on UV-Cured Coatings... 

Cyracure. [Unbn Carbide] Cycloaliphatic epoxy resins diluents and flexibilizers for uv-cured coatings and adhesives. 

Figure 3.3-1. Comparison of a dynamic headspace GC/MS analysis and b chamber air (Tenax sampling, GC/MS) for a water-based and UV-cured coating system 1 pentanal 2 hexanal 3 n-butyl acetate 4 cyclohexanone 5 2-butoxyethanol 6 a-pinene 7 benzaldehyde 8 3-pinene 9 ethyldiglycol 10 2-(2-butoxyethoxy)-ethanol.

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