Daño,Judelle Stephen T.
EXERCISE No. 15
1.By means of a schematic diagram, show the composition of atypical paint.
* A paint is formulated as a mixture of four ingredients:
* Binder is the main ingredient of paints. Binders are polymers (resins) forming a continuous film on the substrate surface.Binders are responsible for good adhesion of the coating to the substrate.
* Solvent (water or organic solvent) is a medium where the binder, pigment and additives are dispersed in molecular form (true solutions) or ascolloidal dispersions (emulsions or sols).
* Pigment is a solid substance dispersed throughout the coating to impart it a color, opacity ...view middle of the document...
3.What are the main functions of the ff. Constituents of paints?
* Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food and other materials.
* The binder in the paint system plays a key role in terms of determining the pigment and the type of solvent in which it is dissolved. A common choice for a solvent is water as it is compatible with most polymers, except some toners.
* Solvents are used in paint manufacture to dissolve the different compounds used in the paint formulation such as colour and binder, making the paint the correct consistency for application. Once the paint has been applied the solvent evaporates, allowing the resin and pigment to produce a film of paint and to dry rapidly. Without solvents it would be impossible to produce durable, decorative and, in particular, glossy paints for use both indoors and outdoors to withstand all conditions.
* Dow Corning offers additives for solvent-borne, water-borne, solventless and radiation cure systems. They are compatible with a wide array of binder systems and diluents. Many offer multiple benefits, and all are effective at low concentrations.
4.For each of the ff. Types of paints, give specific properties and related application
ARCYLIC PHENOLIC EPOXY OILS ALKYD
* Acrylic paints are an art and commercial product that people put on different surfaces to add color or, in some cases, achieve a special effect. Essentially mixtures made with plastic and pigment, they are suitable for a variety of projects ranging from house painting to fine arts. Although their chemical properties can create problems, such as difficulty cleaning, many people like them for their positive qualities, such as their ability to resist water after drying. Experts are still examining how they hold up over time.
* Phenolic resins offer such favorable properties as heat resistance, flame retardancy, low smoking, adhesiveness, good mechanical strength and good electrical properties, and great potential for modification. Commercial production of phenolic resins began in the early 20th century. Over this nearly 100-year history, phenolic resins have been used with good results in an incredible array of applications.
Today, phenolic resins play a crucial role in a wide range of industries. For example, they are used as a binger for abrasives and as an electronics material.
* Epoxy paints consist of two components that react with each other to form a hard, inert coating. Part A typically consists of an epoxy resin with pigments & extenders and Part B is the epoxy-curing agent, often called the hardener. Epoxy paints are typically referred to as anticorrosive barrier coatings. The excellent adhesion of epoxies coatings is due to the strong polar bonds it forms with the surfaces when it comes in...