Dispersions paint pigments

Glyceryl laurate dl-Limonene PEG-2 hydrogenated tallowamine PEG-20 hydrogenated tallowamine dispersant, ore flotation N-Oleyl-1,3-propanediamine Pentasodium ethylene diamine tetramethylene phosphonate Tallow propylene diamine dispersant, paint pigments Glass... 

Available Forms. Phthalocyanines are available as powders, in paste, or Hquid forms. They can be dispersed in various media suitable for aqueous, nonaqueous, or multipurpose systems, eg, polyethylene, polyamide, or nitrocellulose. Inert materials like clay, barium sulfate, calcium carbonates, or aluminum hydrate are the most common soHd extenders. Predispersed concentrates of the pigments, like flushes, are interesting for manufacturers of paints and inks (156), who do not own grinding or dispersing equipment. Pigment—water pastes, ie, presscakes, containing 50—75% weight of water, are also available. 

Dispersed Systems. Many fluids of commercial and biological importance are dispersed systems, such as soflds suspended in Hquids (dispersions) and Hquid-Hquid suspensions (emulsions). Examples of the former include inks, paints, pigment slurries, and concrete examples of the latter include mayonnaise, butter, margarine, oil-and-vinegar salad dressing, and milk. Blood seems to fall in between as it is a suspension of deformable but not hquid particles, and it does not behave like either a dispersion or an emulsion (69) it thus has an interesting rheology (70). 

In the case of paints and printing inks, the initial preparations will be in the semi-solid state because solvents are needed both in the process of dispersing the pigment in the paint or ink medium and for application purposes. These solvents dry out after the paint or ink is applied. When making coloured plastic articles, both heating and solvents may be used to aid dispersion in the plastic medium as part of the moulding process. However, from the viewpoint of the optical properties in all of these pigment uses, what is most important is that each of these media has a refractive index close to 1.5. 

Fig. 36 Dispersion of Pigment Violet 19, (l-modification, in an alkyd-melamine resin baking enamel with a paint shaker. Reduction 1 2 with Ti02. Tinctorial strength-time curve.

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. 

It evenly disperses the pigment to form a homogenous paint solution. 

Example. A colloidal system can exhibit several of these characteristics at once. For example, paint must be plastic and thixotropic so that it will flow when brushed on and (only) immediately after brushing (for a smooth finish) a further benefit is that vigorous mixing readily disperses the pigments which then stay dispersed for some time when standing (high yield stress). 

Although the effect of the concentration of suspension on the results of the measurement of pigments has never been proven, the development of techniques able to cope with concentrations closer to the applications if of interest These would make it possible, for example, to determine the particle size distribution in a dispersion paint or in a reaction vessel where a pigment is produced by the precipitation process. A measurement technique having no problems, in principle, with high concentration dispersions is the scattering of ultrasonic waves. Nevertheless the instruments on the market have up to now failed to realize the great expectations of this technique. 

A hydrophobic emulsifier and dispersing agent, is an excellent co-emulsifier exhibiting foam control properties for chlorinated and aromatic solvents. In water-based paints, it aids the dispersion of pigment slurries and improves gloss and freeze-thaw resistance. TRYLOX 5900 is also a clay dispersant and carrier for paper coatings. Textile uses include foam control and emulsification in low foaming dye carriers. 

Magnesium silicate is used as a filler and pigment in dispersive paints. 

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