Editing Paint (section)

====Thermoplastic Mechanisms====
Some films are formed by simply cooling the binder. For example, [[Encaustic painting|encaustic]] or [[wax]] paints are liquid when warm, and harden upon cooling. In many cases, they re-soften or liquify if reheated.

Paints that dry by solvent evaporation and contain the solid binder dissolved in a solvent are known as [[lacquer]]s. A solid film forms when the solvent evaporates. Because no chemical crosslinking is involved, the film can re-dissolve in solvent; lacquers are unsuitable for applications where chemical resistance is important. Classic [[nitrocellulose]] lacquers fall into this category, as do non-grain raising stains composed of [[dyes]] dissolved in solvent. Performance varies by formulation, but lacquers generally tend to have better [[UV coating|UV resistance]] and lower corrosion resistance than comparable systems that cure by polymerization or coalescence.

The paint type known as [[Emulsion]] in the UK and [[Latex]] in the United States is a water-borne dispersion of sub-micrometer polymer particles. These terms in their respective countries cover all paints that use synthetic polymers such as acrylic, vinyl acrylic ([[Polyvinyl acetate|PVA]]), styrene acrylic, etc. as binders.<ref>{{cite web |url=http://dundean.com/tips_what_is_latex_paint.shtml |title=Water-based Alchemy |access-date=August 11, 2012 |archive-url=https://web.archive.org/web/20120829153753/http://dundean.com/tips_what_is_latex_paint.shtml |archive-date=August 29, 2012 |url-status=dead }}</ref> The term "latex" in the context of paint in the United States simply means an aqueous dispersion; [[latex]] rubber from the rubber tree is not an ingredient. These dispersions are prepared by [[emulsion polymerization]]. Such paints cure by a process called coalescence where first the water and then the trace, or coalescing, solvent, evaporate and draw together and soften the  binder particles and fuse them together into irreversibly bound networked structures, so that the paint cannot redissolve in the solvent/water that originally carried it. The residual [[surfactants in paint]], as well as [[Hydrolysis|hydrolytic]] effects with some polymers cause the paint to remain susceptible to softening and, over time, degradation by water. The general term of latex paint is usually used in the United States, while the term emulsion paint is used for the same products in the UK, and the term latex paint is not used at all.

=====Thermosetting Mechanisms=====
Paints that cure by polymerization are generally one- or two-package coatings that polymerize by way of a chemical reaction and cure into a cross-linked film. Depending on composition, they may need to dry first by evaporation of solvent. Classic two-package [[epoxy|epoxies]] or [[polyurethane]]s <ref>Gite, V. V., et al. "Polyurethane coatings using trimer of isophorone diisocyanate." (2004).</ref> would fall into this category.<ref name="Ber114">Berendsen, A. M., & Berendsen, A. M. (1989). ''Marine painting manual''. London: Graham & Trotman. {{ISBN|1-85333-286-0}} p. 114.</ref>

The "drying oils", counter-intuitively, cure by a crosslinking reaction even if they are not put through an oven cycle and seem to dry in air. The film formation mechanism of the simplest examples involves the first evaporation of solvents followed by a reaction with oxygen from the environment over a period of days, weeks, and even months to create a crosslinked network.<ref name="Wicks_5"/> Classic [[alkyd]] enamels would fall into this category. Oxidative cure coatings are catalyzed by metal complex driers such as [[cobalt naphthenate]] though cobalt octoate is more common.

Recent environmental requirements restrict the use of [[volatile organic compound]]s (VOCs), and alternative means of curing have been developed, generally for industrial purposes. [[UV curing]] paints, for example, enable formulation with very low amounts of solvent, or even none at all. This can be achieved because of the monomers and oligomers used in the coating have relatively very low molecular weight, and are therefore low enough in viscosity to enable good fluid flow without the need for additional thinner. If solvent is present in significant amounts, generally it is mostly evaporated first and then crosslinking is initiated by ultraviolet light. Similarly, [[powder coating]]s contain no solvent. Flow and cure are produced by the heating of the substrate after electrostatic application of the dry powder.<ref>{{cite web |url=https://coatings.specialchem.com/selection-guide/powder-coatings-formulation-tips |title=Powder Coating 101 |access-date=April 26, 2024 }}</ref>

=====Combination mechanisms=====
So-called "catalyzed" lacquers" or "crosslinking latex" coatings are designed to form films by a combination of methods: classic drying plus a curing reaction that benefits from the catalyst. There are paints called plastisols/organosols, which are made by blending PVC granules with a plasticiser. These are stoved and the mix coalesces.