Paint Chemistry

   paint — a suspension pigment in an oil vehicle. It applies to virtually any surface coating designed for protection of a surface or for decoration, or both. Sometimes the word paint may be a general term and the term “surface coating” is more specific.

   vehicle — the portion of a surface coating other than the pigment, the purpose of which is to enable the pigment to be distributed over the surface. The vehicle includes solvents, binders, and other additives. The term vehicle is frequently used to indicate the oil or resin which forms a continuous film and binds the pigment to the substrate.

   lacquer — fast-drying coatings, clear or pigment, that dry by evaporation of the solvent rather than by oxidation or polymerization.

   varnish — a homogenous solution of drying oils and resins in organic solvents. The resins may be naturally occurring, for example, rosin or dammar, or synthetic, for example, products of the reaction of phenol and formaldehyde.

   stain — a solution of a dye or a suspension of a pigment in a vehicle designed to impart a color to wood surface rather than to form a protective coating.

   enamel — the term enamel does not intimate the chemical nature of the coating, but implies a pigmented coating which dries to a hard gloss. Increasingly, the term has come to mean a cross-linked thermosetting resin.

   latex — a suspension of a pigment in a water-based emulsion of any of several resins, for example, acrylic polymers, vinyl polymers, or styrene-butadiene polymers.

   pigment — a finely powdered solid which is essentially insoluble in the medium in which is dispersed. Pigments may be inorganic, such as titanium dioxide, or organic, such as phthalocyanine. White pigments are primarily intended to hide the underlying surface. A pigment is distinguished from a dye in that a dye is soluble in the vehicle while a pigment is not.

   drier — a material that promotes or accelerates the drying, curing, or hardening or oxidazable coating vehicles. The principal driers are metal soaps of a monocarboxylic acid.

   extender — a low cost white inorganic pigment used with other white pigment to modify the gloss, texture, viscosity, and other properties, and to reduce the cost of the finished product.

   solvent — organic liquids of various types having the function of dissolving the binder and thereby providing a consistency to the coating which is more suitable for application.

   drying oils — naturally occurring triglycerides which form films principally by air oxidation. The same oils may be used as feedstocks for varnishes, alkyd resins, epoxy ester resins, oil modified urethane resins, and some plasticizers.

   plasticizer — a material incorporated into a polymer to increase its flexibility or workability.

   thermoplastic polymer — a resin which polymerizes without the necessity of heat. If the resin is heated below its decomposition temperature it softens and hardens again upon cooling; hence, the term thermoplastic.

   thermosetting polymer — a resin which can be made to form cross-linkages when baked.

   binder — the actual film-former which binds the pigment particles to one another and to the substrate.

   palindrome — a DNA site where the base order in one strand is the reverse of that in the complementary strand, for example, 5’GAATTC3’, 3’CTTAAG5’.

   palmar zone — the elevated area just behind the fingers and above the center of the palm. Papillary ridges (friction ridges) The fingerprint ridges, which can be observed on the inner surfaces of the hand. Friction ridged skin is a highly specialized organ and differs from the skin on the rest of the body in more than simply its ridged appearance. It has no hair follicles and, thus, no apocrine or sebaceous glands. These ridges occur in certain definite formations, and they can be classified into specific types of patterns.