Polyester acrylate-based formulations

BENZOINETHERS (IBBE AND IPBE) Benzoinethers were one of the first classes of photoinitiators developed for the UV-curing industry and were used successfully in both polyester-styrene and acrylate based formulations. Various substitutions for R such as propyl, isopropyl (IPBE), butyl, and mixtures of butyl isomers (IBBE) results in photoinitiators which all undergo Norrish Type I photocleavage resulting in the formation of the benzylic and the benzylether radicals as shown in Fig. 3. Both radicals are known to initiate polymerization, although the relative reactivity appears to be somewhat system and condition dependent (2). ... 

Table 31. UV curing activity, as determined by Koenig pendulum hardness, of a Ti02-pigmented polyester acrylate formulation in the presence of polymeric and low-molecular-weight initiators based on thioxanthone and hydroxypropiophenone moieties, as a taction of irradiation conditions ...

Acrylic resin systems developed in Germany are similar to polyester resins but, by careful formulation, the problems due to shrinkage have been largely overcome. The acrylic resin-based systems are currently based on highly flammable materials (flash point 10°C), which can present hazards during laying. However, there are systems available that can take foot traffic 2-3 hours after application and full service conditions within 24 hours, even at very low temperatures. 

To conclude this discussion on zirconium, it is appropriate to look at the adhesion promotion effects of various zirconium compounds in flexographic and gravure ink printed on corona discharge-treated polyolefins and polyester. Flexographic and gravure inks are basically a pigment (often titanium dioxide) suspended in a polymer (normally called the binder) dissolved in a solvent. Actual commercial ink formulations are rather more complicated. These inks are either water-based when acrylic polymers and co-polymers are typically the binders, or solvent-based (usually ethanol-ethyl acetate mixtures) when the binder is typically nitrocellulose or cellulose acetate propionate. 

Both paints and adhesives are commonly formulated as polymer blends or grafts. In fact, some compositions resemble semi-IPN s or AB crosslinked copolymers (Section 8.7). For example, epoxy adhesive resins are often cured with polyamides (Bikerman, 1968). The product is tougher than materials cured with low-molecular-weight amines, possibly because of a separate amide phase in this AB crosslinked copolymer. A more complex molecular architecture is exhibited by the alkyd resins common in oil-based paints (Martens, 1968, Chapters 3 and 4). The major component is a polyester, which often forms a network structure on drying. The polyester component is reacted with various drying oils, such as linseed oil or tung oil (Martens, 1968, Chapters 3 and 4). These oils form an ester link to the polyester structures and also polymerize through their multiple double bonds. Latex paints always contain thickeners, such as cellulosics, poly(acrylic acid), casein. 

Commercial electropainting only dates from the early 1960s and the first processes to be introduced used anodic deposition. Some typical paint formulations would contain (i) polycarboxylic acids based on acrylic acid as monomer solubilized by an organic amine, (ii) alkyds, i.e. branched polyesters based on naturally occurring long-chain carboxylic acids and polyalcohols, e.g. glycerol, and (iii) epoxy resins based on phenols, e.g. 

As structural adhesives, epoxies are the most widely accepted and used. They typically contain several components, the most important being the resin. To the base resin is added a variety of materials, for example hardeners, flexibilisers, tougheners and fillers. These all contribute to the properties of the resulting adhesive. Formulations may be further varied to allow for curing at either ambient or elevated temperatures. The epoxies and polyesters, together with acrylics, polyurethanes and synthetic polymer lattices will be... 

Vinyl esters are thermosetting resins that consist of a polymer backbone with an acrylate or methacrylate termination. The backbone component of vinyl ester resins can be derived from epoxide, polyester or urethane but those based on epoxide resins have most commercial significance. Bisphenol A epoxy formed vinyl esters were designed for chemical resistance and commonly formulated for viscosity for use in filament winding of chemical containers. Typically styrene is used as a reactive dilutent to modify viscosity. Phenolic novolac epoxies are used to produce vinyl esters with higher temperature capability and good solvent resistance, particularly in corrosive environments, and their FRP composites have demonstrated initial economy and better life cycle costs compared with metals. 

Unlike UF and MF resins, acrylamide-based acrylic nitrogen resins need not be blended with another component to obtain flexibility this can be built into the acrylic copolymer by the appropriate choice of monomers (see examples on p. 193). Thus resins with ester linkages in their main polymer chains (e.g. alkyds, polyesters) can be avoided. A cross-linked polymer network can be built up which is resistant to hydrolysis by alkalis in detergents. Coatings can therefore be formulated which are suitable for domestic appliances, being additionally hard but flexible. 

Anaerobic adhesives, based on the acrylic polyester resins, are produced in viscosities ranging from thin liquids to viscous, thixotropic pastes. Within each viscosity band, individual formulations are available possessing specific strength characteristics. The whole family is unique in being the only one where interrelated strength/viscosity characteristics are provided by manufacturers. 

Recent developments in the dispersion technology such as the technique of surfactant selection, the optimisation of various parameters in the dispersion process and the enhancement to dispersion stability have made it possible to disperse a variety of curable oligomers such as acrylated EP, acrylated PU, acrylated polyester resins in water. Films based on the dispersions can have faster UV cure speed, better surface hardness and better flexibility compared with films based on undispersed resin systems [102]. UV curing offers many advantages including 100% solids with no solvents present in formulation and polymerisation is instantaneous leading to a large MW polymer [103]. 

AQ dyes are used for a broader spectrum of resins than that of the azo dyes. They are heavily used in styrene, ABS, SAN, polycarbonate, acrylics, cellulosics, polyesters etc. and are well known for excellent weatherability in the transparent mode such as red taillights, but in tint applications the light stability is greatly reduced. Heat, photo and chemical stability vary considerably as the pendants on the base AQ structure are substituted. Awareness of these differences is essential in color formulating. Most AQ dyes are not recommended for polyamide applications as these resins react with amine pendants and can remove the color. We are... 

A paint grade of cerium sulfide has also been developed. The pigment has been evaluated in several coatings formulations such as automotive refinish (acrylic-isocyanate binders), general industrial solvent-based systems (polyester-melamine bin-... 

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