Reactive Coatings

Fig. 3. Polymerization initiation and propagation by radiation-generated free radicals. A is the initiating radical produced by irradiating the Hquid coating. (1) represents the Hquid monomer—unsaturated polymer reactive coating system. R is functional. (2) is the growing polymer chain (free radical). The cured...

These photoinitiators or photocatalysts are usually added to the reactive coating formulations in concentration ranges from less than 1 to 20 wt % based on the total formulation. 

Examples of typical photoinitiator systems used to cure reactive coating systems are as follows (80,81). The reactive systems are primarily unsaturated acryUc acid esters of different alcohol and polymer stmctures. 

The diversity of release products and the wide range of release problems make classification difficult. One approach is by product form, with subdivisions such as emulsions, films, powders, reactive or iaert sprays, reactive coatings, and so on. Another approach is by appHcation, eg, metal casting, mbber processiag, thermoplastic iajection mol ding, and food preparation and packagiag. 

The appendix shows an example of a recursive procedure to calculate the pigment to binder ratio for a non-reactive coating formulation. We assume that a raw material data base contains raw material code, density, cost per unit weight, solids volume fraction, and pigment solids volume fraction. Formulas are stored in files that contain the identification and amount of... 

Monofunctional acrylates give a less reactive coating and are less desirable ingredients because of their volatility, odor and skin-irritating effects. Currently, the following bifunctional and polyfunctional acrylates are used in industrial applications (acronyms in parentheses) ... 

Photoinitiators are perhaps the most important component in uv cured radiation coatings. The photoinitiator is an ingredient that absorbs light and is responsible for the production of free radicals in a free radical polymerized system or cations in a cationic photoinitiated system. The photoinitiators are usually added to the reactive coating formulations in concentration ranges from less than 1 to 20 percent by weight based on the total formulation. The absorption bands of the photoinitiators should overlap the emission spectra of the various commercial light sources. 

Mortensen P. Light-Reactive Coating Cleans Surfaces. Photonics Spectra 2001 38. 

Figure 2. Radiation curing concepts (curing of reactive coatings).

Unsubstituted, heat-reactive coatings find use in a variety of applications on rigid metal substrates where maximum resistance is required. A few examples will suffice to illustrate their use. 

Polyrad. OPolymer Industries] Uv curable reactive coatings lacquer coating for graphic arts api s. 

Uses Corrosion inhibitor pigment for reactive coating systems and wash primers fungistat... 

EPON Resin 1001-Y-75 epoxy, raw material Epichlorohydrin epoxy, reactive coatings EPON Resin 815C epoxy, rebar coatings Araldite GT 7074 Araldite GT 9545 epoxy, sealants... 

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