Film coalescing agent

DEMULSIFICATION TESTS. Demulsification tests were conducted using standard bottle test procedures to evaluate the relative performance of Thin Film Spreading Agents in coalescing emulsions of formation brine in crude oil under reservoir conditions. 

Alkoxylated phenol formaldehyde resins are a well-known class of demulsifier, and the emulsion coalescence data in Table III confirm that Thin Film Spreading Agents, which belong to this class, can also function as chemical demulsifiers. When water in... 

Coalescing agents are, in reality, temporary plasticizers, which promote the coalescence by increasing the amount of plastic flow in latex paints. The types of materials used are ether-alcohol (such as butyl glycol), tributyl phosphate, pine oil, or other strong solvents. All of these have a degree of volatility so that within a period of time they are lost from the film so that the latex hardens to its required properties. 

Dalpad [Dow]. TM for a coalescing agent, a stable, low-odor, low-temperature film-forming aid for polyvinyl acetate and acrylic latex paints. 

A latex paint is an aqueous emulsion. After the paint dries, the surfactant is still present and may interfere with the resistance of the paint to washing to remove fingerprints or other marks. A destructible surfactant would be valuable in this application. It would have to destruct by the action of light or air. Latex paints are not entirely free of solvent. A few percent of a higher-boiling solvent, a coalescing agent, is usually, but not always, necessary to form a pinhole-free film from the particles of polymer after the water evaporates. A typical one (8.45) is derived from isobutyraldehyde. 

Polymer Dispersions (Emulsion Polymers). Waterborne paints based on polymer dispersions (usually referred to as emulsion paints) are not water soluble. They are water-thinnable systems composed of dispersions of polymer particles in water (see Section 3.5). The particles consist of high molecular mass polymers (e.g., of styrene, butadiene, acrylate, or vinyl monomers) and are produced by emulsion polymerization. These waterborne paints also contain small amounts of organic solvents (< 5 wt %) that serve as film-forming (coalescing) agents that partially evaporate on drying. 

Chem. Deserp. Ester Uses Coalescing agent for latex disp. paints Featixes Reduces paint odor and VOC s reduces min. film-formation temp, and facilitates film formation... 

Uses Plasticizer, flame retardant for plastics incl. acrylics, ceiiuiosics, epoxy, nitrile, phenolic, thermoset po ester, PP, PS, PVAc, PVC, clear vinyl films, vinyl-coated fabrics, flexible PU foam, syn. rubber, wire/ cable insulation, plastisols plasticizer, coalescing agent for coatings Manuf./Dlstrlb. Akzo Nobel FMC Rhodia/Phosphorus Perf. Derivs. Trade Names Antiblaze 519... 

Aqueous acrylic dispersions have been used as binders for coatings for over 60 years. Their main advantages include low cost and excellent tolerance of additives or pigments however, they have several drawbacks such as the presence of relatively large amounts of water-sensitive additives (protective colloids, emulsifiers, etc.) and the need to use coalescing agents when a continuous film is desired. 

In the prepolymer-ionomer process , the compound which contains the moieties which are the precursors of ionic groups is incorporated in the polymer chain already at the stage of urethane prepolymer formation. Then they are neutralised, which results in the formation of a prepolymer-ionomer which is emulsified in water and eventually crosslinked. In this process, the prepolymer-ionomer is usually dissolved in a small amount of water-miscible solvent of high boiling point, e.g., N-methylpyrolidone, which plays the role of coalescing agent in the process of film formation. It is then possible to obtain DPUR which contain either cationic DPUR with a pH of less than 7 (cationic moieties are attached to the polyurethane or polyurethane-urea chain) or anionic DPUR with a pH of greater than 7 (anionic moieties are attached to the polyurethane or polyurethane-urea chain). If non ionic hydrophilic moieties are attached to or incorporated in the polyurethane or polyurethane-urea chain, then a nonionic DPUR may be obtained. 

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