Silicones, ultraviolet-curing

Ultraviolet curing UV curing adhesives use ultraviolet light to initiate curing. This allows a permanent bond to develop without any need for heating. UV curable adhesives use various chemical systems, which include acrylics and acrylates, epoxies, polyurethanes (PUR), polyesters, silicones, vinyl and vinyl esters Aaylics are the most common components of UV curable adhesives. 

In 1983, radiation curable 100 % solvent-free silicone acrylates were introduced into the market [4], This system provide the opportunity to be cured by either ultraviolet light (UV) or electron beam (EB). Similar in concept to peroxide initiation, silicone acrylate systems employ photoinitiators to generate free radicals and initiate cure, which is based on the polymerization of the acrylic C=C double bond via a radical chain reaction. 

Technology which couples fast ultraviolet (UV) cure response with silicone performance characteristics suitable for integrated circuit protection has been developed. One-part silicones which can be cured in several seconds to provide products of excellent purity, stress relief, thermal stability, and protection against harsh environments are the result. 

Ferrocene fer-6- Sen [ferro- -F cycV -F -ene] (1952) (dicyclopentadienyl iron) n. (C5H5)2pe. A coordination compound of ferrous iron and cyclopentadiene, soluble in PVC and stable to 400°C. Its uses include smoke suppression, a curing agent for silicone resins, an intermediate for high-temperature polymers, and an ultraviolet absorber. Wickson EJ (ed) (1993) Handbook of polyvinyl chloride formulating. John Wiley and Sons Inc., New York. 

Majof silicone suppliers have been developing radiation-curable coatings for some time now the solventless systems lend themselves to this approach since all the space radiant energy can be directed at the polymer system for curing, and none wasted for solvent evaporation or in the substrate. The energy source referred to may be either ultraviolet or electron-beam radiation, and the objective is a very rapid zero-temperature controllable cure, with much of the control occurring through the intensity of the source. 

Abstract In this chapter, classification of adhesive and sealant materials is presented. For this purpose, various categories are considered depending on the polymer base (i.e., natural or synthetic), functionality in the polymer backbone (i.e., thermoplastic or thermoset), physical forms (i.e., one or multiple components, films), chemical families (i.e., epoxy, silicon), functional types (i.e., structural, hot melt, pressure sensitive, water-base, ultraviolet/ electron beam cured, conductive, etc.), and methods of application. The classification covers high-temperature adhesives, sealants, conductive adhesives, nanocomposite adhesives, primers, solvent-activated adhesives, water-activated adhesives, and hybrid adhesives. 

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