Long oil alkyds

Long oil alkyds can contain from 55% oil, even up to 80%. Long oil alkyds are typically used for trade (professional painting) and DIY (do-it-yourself) applications. Application is mostly by brush and roller and the paints are supplied in white spirit. 

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The specific solvents that make up the three solvency categories depend on the solute in question. For example, an aUphatic hydrocarbon may have adequate solvency for a long oil alkyd, but would be a diluent for an acryUc or vinyl resin, which require stronger solvents such as ketones or esters. The formulator must understand the solvency requirements of the solute to know which category a particular solvent would occupy. 

Another approach to high soHds alkyd coatings is the partial replacement of solvent in a conventional long-oil alkyd with a reactive diluent. Eor example, dicyclopentenyloxyethyl methacrylate [70191-60-9J, mixed amides from the condensation of acrylamide (qv) (2-propeneamide)... 

Long-oil alkyd Flexible Fair Poor Poor Poor Good Good Easy... 

Fig. 72 Pigment Orange 34 samples of different particle sizes (above small, below large) in a long-oil alkyd resin system. Pigment concentration in the system 6% thickness of the wet film 75 pm.

Fig. 77 P. 0.34 in a long-oil alkyd resin system. Influence of the particle size on the dispersibility. Dispersion unit paint shaker, organic pigment Ti02 = l 5. Sample 1 fine particle pigment,...

Fig. 81 Scanning electron micrographs of long-oil alkyd resin systems containing P.R.3, (a) nonhazing, (b) hazing. Drying time 1 day.

Figure 4, Solution viscosity of long oil alkyd (Aeroplaz 1273,...

The wide spectrum of properties of all alkyd resins is broadened by its use with a variety of reactive chemicals and other resinous materials. In fact, alkyd resins have the distinction of participating in more of what we might term "polymeric mergers" than any other single class of resins. It is of value to examine the idealized structure of both a long oil III and a short oil IV alkyd resin. The long oil alkyd illustrated is based on a 1 1 1 mol ratio... 

Idealized structure of a long oil alkyd based on a 1 1 1 mol ratio of glycerine-phthalic anhydride-fatty acids, ca. 60.57o oil.)... 

Medium-oil alkyds are typically used in architectural paints and as co-resin in some original equipment manufacturer (OEM) coatings. These alkyds are 46-55% oil and 30—35% phthalic anhydride. They are viscous, soluble in mineral spirits and aromatic solvents, and slightly harder, and have poorer application properties than long-oil alkyds. 

Short-oil alkyds are used typically for OEM and do not dry well unless force-air dried or baked. These resins contain <45% oil and >35% phthalic anhydride. They are soluble in aromatics but not in mineral spirits, and are significandy harder than medium- or long-oil alkyds. 

A one-pack primer based on chlorinated rubber or chlorosulfonated polyethylene (as is conventional with galvanized surfaces) or a two-pack epoxy primer is then applied. The primer can be coated with a topcoat system that is usually formulated with medium or long oil alkyd resins [11.39]. 

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