Knowledge base

In the last few years, work in several laboratories has been directed to the preparation of novel cationic photoinitiators, onium salts. The latter include new structures, such as dialkyiphenacylsulfonium salts (1), as well as more standard onium salts, like the diaryliodonium salts recently registered and placed on the market by Ciba. All these ne

Clear and pigmented IR I UV curable powder systems based on the photo-induced cationic polymerization of solid, bisphenol-A based epoxy resins in the presence of a chain transfer agent have been developed. By extruding the solid resins on standard equipment with pigments and a recently developed co-initiator, it is now possible to coat temperature

The growing need for high speed fabrication, increasing quality requirements, combined with reduced styrene emissionNOC levels in fiber reinforced composites and gel coats is being met with new light cure technologies. Critical to the success of light curing of composites is understanding' how lamps, photoinitiators and the fiber reinforced resin s

Emission from rare gas excimers such as , and exhibiting photon energies of 7.2, 8.5 and 9.85 eV, respectively, can be used to induce strong surface modifications of polymers. In particular, argon excimer shows a number of interesting features: the 9.85 eV photons are absorbed within less than 100 nm from the polymer surface giving rise to electron

Quenching of imidazoyl radical (Im ) formed in photoinitiator systems comprising an aminostyryl dye and a radical generating reagent by a 2-mercaptobenzothiazole(MBT): radical generating reagent;2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyi-l, I '-bi-IH-imidazole (BI) in a poly(methyl methacrylate) film has been investigated by laser flash photoly

One of the biggest difficulties encountered when formulating UV curable matt coatings withmatting powders is rheology control. Because UV systems are normally 100% reactive, there is minimal loss of volume on application. With 100% UV curable systems, 10% matting powder in the liquid means 10% in the solid film. There is no effective increase in po

Thiol-ene photopolyrnerization technology has been known for mans' years and has been the subject of much 13 since the polymerization mechanism was first proposed by 4 in 1938. Despite their promise as photopolymerizable materials for coatings , this market has been dominated by acrylate photopolymerizations. More recently, there has been a renewed

Radiation curing including ultra-violet (UV) and electron beam (EB) curing technology is now being increasingly used in various sectors of applications, mainly in the coating industry, graphic arts, and microelectronics, replacing conventional thermally cured solvent-based coatings, inks and adhesives. This is due to their distinct advantages, such