Radiation curable coating

Polymers. The molecular weights of polymers used in high energy electron radiation-curable coating systems are ca 1,000—25,000 and the polymers usually contain acryUc, methacrylic, or fumaric vinyl unsaturation along or attached to the polymer backbone (4,48). Aromatic or aUphatic diisocyanates react with glycols or alcohol-terrninated polyether or polyester to form either isocyanate or hydroxyl functional polyurethane intermediates. The isocyanate functional polyurethane intermediates react with hydroxyl functional polyurethane and with acryUc or methacrylic acids to form reactive p olyurethanes. 

Fig. 10. Generalized formulation design outline for radiation-curable coatings and adhesive systems. The cross-linker is a multifimctional unsaturated cross-linking agent or oligomer, rj = viscosity CR = cure rate S = shrinl ge H = hardness F = flexibility A = adhesion 7 = surface energy ...

The majority of the commercial radiation-curable coating systems (high energy electron and light-cured coating systems) are clear or contain siflca... 

The purpose of work described here is to develop a coating which can be used on naval vessels for touch up purposes while a ship is underway. Radiation curable coatings are of special interest because of the extremely low level of volatile organic compounds emitted during curing. To be useful the coating should be Navy gray and suitable for application to cold surfaces. When used in confined spaces a further limitation is that the application should not produce ozone and for some Naval applications mercury is not... 

VDC polymer degradation via, 25 713 Radiation-curable coatings, 10 442 liquid, 10 438... 

The effect of environmental concerns on future developments in the paint industry is discussed. Particular attention is paid to volatile organic compound regulations, developments in powder coatings, and radiation-curable coatings. Tabulated information is presented on applications, backbone type and typical mechanical properties of Incorez W830 series PU dispersions and Incorez W2000 series uiethane/aciylic hybrids. 10 refs. EUROPEAN COMMUNITY EUROPEAN UNION UK WESTERN EUROPE... 

The cost of radiation curable coatings in large volume can be equivalent to, or slightly more expensive than conventional coatings depending on the polymer desired, the cost of the starting materials and added manufacturing processes. This conclusion is based on hypothetical comparison s of costs as discussed below. 

The individual RMC for polymer materials is not the only factor in cost analysis of a coating system. In order to make a fair comparison between conventional and radiation curable coatings one must consider the entire coatings formulation. Shown below is a cost range calculated for a conventional solvent-... 

The cost of the radiation curable coatings formulation is 5.13/gal, but it covers 2 to 2.5 times more surface area than the solvent-based coating. The cost for equal coverage of radiation curable coating is 18.50 gal/hr 2 or 2.5 times 5.13/g l = 37.96/hr to 47.45/hr. 

Radiation-curable coatings were developed by W. J. Burlant (of the Ford Motor Company) in 1962. Acceptance of finishes designed for radiation curing (high-solids materials formulated to be cured by UV and EB systems) is growing at roughly 8 percent per year with a market size of approximately 85 million lb. 

Prepolymers especially di, trl, and tetrafunc-tional acrylates or diallylpthalates sensitized by triplet or radical photosensitizers form the third class of negative resists. These resists are also useful as examples of radiation curable coatings, paints, or inks. 

Free Radical Initiated Radiation Curable Coating Compositions... 

Free Radical Initiated Radiation Curable Coating Compositions. Conventional thermally cured coating systems are generally based on the following polymer backbone chemical structures ... 

The monomer in radiation-curable coatings is the analog of the solvent in a conventional paint. Although it performs like a solvent by being a medium for all of the other ingredients and by providing the necessary liquid physical properties and rheology, it differs in that it enters into the copolymerization and is not lost on cure. 

Acid Intermediate Initiated Radiation Curable Coating Compositions. In this process, photogenerated acid intermediates can cause ring opening reactions of various oxirane monomers and prepolymers that can then further polymerize into three-dimensional network structures. 

Radiation-curable coatings (RC) should enjoy a dramatic growth as the full extent of their solvent-free, rapid, and ambient-curing properties is realized and materials and application systems are perfected. UV-curable coatings are currently the most important in this category however, electron beam (EB) curable coatings should show excellent growth to 1987 and beyond. 

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