Pigment-binder composites

A variety of organic-polymeric-based materials have been investigated for optical recording, including dyes (pigments), dye (pigment)-polymer composites, dye-polymer solutions, and polymer-metal-layered or particulate structures. In all instances, the light absorption function is provided by the dye or metal, and the polymer serves the role of binder and film former. 

In the case of complaints, the binder and pigment (extender) composition of the individual layers have to be established to determine the origin of the paint material in doubtful cases. Establishing the cause of coating defects (e.g., inclusions, delamination, peeling) is also important. These and other analytical investigations are time-consuming and expensive. Optimal utilization of analytical resources therefore requires a clear definition of the problem in hand. 

Paints or lacquers are composites of, in general, three components pigments, binders, and solvents. Depending on application, the nature of the pigment can vary between extremely wide limits (see also Chapter 34). The binders are also known as film formers they are exclusively polymers or prepolymers, that is, thermoplasts, thermosets, elastomers, and elastoplasts. The nature of the solvent can also vary within wide limits according to the type of film former and the desired application. Here, solvents are described as good in the paints industry when they lead to low-viscosity paints or lacquers. Such good solvents are usually poor solvents in the thermodynamic sense (see also Chapters 4 and 6). 

Paints are represented by primarily liquid compositions that form a thin opaque film on substrates to either decorate, protect, or functionalize them. To achieve these performances, paints are formulated with pigments, binders, a carrier vehicle, and other additives. Discussing each of these ingredients briefly and their respective chemistries will facilitate a focused examination of paint application methodologies where adhesion promotion is highly critical. 

The most important phosphate-containing pigment is zinc phosphate [7779-90-0], Zn3(P04)2-4 H20, Mr 458.1. It can be used with a large number of binders (see Table 39) and has a very wide range of uses [5.67], [5.68], [5.70], [5.71], [5.82], Zinc phosphate is usually produced on an industrial scale from zinc oxide and phosphoric acid, or from zinc salts and phosphates [5.83], Composition and properties are given in Table 40. 

The compositions and properties of some commercial multiphase anticorrosive pigments are listed in Table 43. Their anticorrosive properties in various binders are shown in Table 39. 

Pigments. These arc finely divided powders (particles between 0.1 and 50 micrometers in diameter) which are dispersed throughout llie binder. In addition to reinforcing the final film, much as they do in composite plastics, they influence a coating s resistance to abrasion and corrosion, and they also are the major factor in the gloss, color, and opacity of a coating. 

It can be seen that, historically, a paint is anything that contains pigment, a colored, powdered substance, and a binder, a material that evenly disperses the pigment and adheres to a surface when the paint is applied and then dries. A pigment combined with a binder makes a paint. A medium is used to dilute a paint. The composition of watercolor, egg tempera, oil, and acrylic paints is discussed in this chapter. 

We have discussed the composition of paint, the attributes of various types of paint, and the place of paint in a classification of matter. Now you will produce paint by preparing paint pigments and combining these pigments with binders. In addition to preparing paints, you will examine the physical properties of the substances produced in your activities. 

Most binders are solutions, such as linseed oil, which is composed of a number of fat and fatty acid molecules. Egg yolk is composed of water, fat molecules, lecithin, protein, dextrose, cholesterol, lutein, and other trace substances. These compositions of binding solutions allow more opportunities for uniform pigment adhesion and permanent paint qualities. 

Intumescent types of nonaqueous coatings have been produced containing an amine aldehyde resin, ammonium salt of polyhydric acid, and pigments, with an appropriate binder. This type of coating possesses excellent fire and flame resistance and good paint properties. There are probably other types of intumescent paints, but their exact composition is not available. 

Often, the presence of very small impurities makes comparison possible. For example, cars are painted with paints prepared to certain specifications of color and composition, and pigments and binders used vary from one manufacturer to another and even between models from the same distributor. A small sample of paint left at the scene of an accident may be... 

Universal product code marking composition containing a photosensitive dye former, a pigment and a binder. Dessauer, Rolf (du Pont de Nemours, E. I., and Co.) U.S. Patent 4,029,506 (Cl. 96-48R G03C5/24), 14 Jun 1977, Appl. 516,483,... 

Coating vehicle usually identifies a combination of binder and volatile liquid. It may be a solution or a dispersion of fine binder particles in a nonsolvent formulation. No pigments are included if a clear, transparent coating is required. The composition of the volatile liquid provides enough viscosity for packaging and other application, but the liquid itself rarely becomes part of the finished coating. 

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