What's in a Can of Paint?

Paint has to be one of the most common but underappreciated substances ever invented. There is nothing in your life that is not in some way affected by paint. We put paint on our walls, our appliances, and on the hood of our cars, to protect these valuable surfaces. Paint comes in thousands of different types, purposes, and colors, and line distributor shelves by the hundreds.

If you are in the paint business as a distributor or applicator, realistically, you probably don’t know everything there is to know about paint. Even chemists and chemical engineers who design and experiment with advanced paint formulas realize paint composition can be extremely complicated. However, the four basic components in a typical can of paint are actually quite straightforward. A paint can’s contents holds a balanced combination of pigments, binders, solvents, and additives.

In this article you will learn:

• Four different paint types
• High quality paints
• Four components of paint
• Paint pigments
• Paint binders
• Paint solvents
• Paint additives

Known as emulsions, latex, or water reducible liquids.

Organic and non-organic paint solvents

Liquids with non-aqueous properties like oil-based alkyd mixtures.

100% systems

Liquids use reactive monomers like epoxies, polyuria, and energy curables.

Powder coatings

Dry, solid compounds applied with an electrolysis process.

Waterborne and organic/non-organic solvent products compose the majority of paints. When special applications require extensive durability, you can use 100 percent systems. Powder coatings are highly popular for exterior metal finishes. All four paint types have varying levels of quality.

No matter what a paint is designed for, it contains four primary components. It does not matter if you apply paint as an aerosol by spraying, a liquid in brushing, or as a solid through powder coating. Paint is always a medium composed of four parts or raw materials. Each component has its purpose, and it is the properties and proportions which make a high-quality paint mixture.

Great paint systems are best understood in the context of mixed raw materials concurrently combining performance and allure. Like all systems, paint relies on each component simultaneously synchronizing its desired asset performance to maximize form and function. The purpose is usually protecting a surface, making it attractive, and enduring as long as possible under expected conditions.

The method and protocol of blending a paint is critical to its desired performance. First of all, paint is not mixed into equal proportions. Pigment, binder, solvent, and additive ratios or percentages are as diverse as the products they are applied to.

Binders are a paint’s backbone. They form a solid structure enabling pigments to cover and colorize a substrate’s surface. Binders do exactly what their name suggests, they bind pigment molecules to substrate structures and give paint its adhesion, surface tension, integrity, and durability. Properly bonded paint will not lift, peel, blister, or detach from its surface. That is, if both the substrate and binder possess the surface energies enabling adhesion and other physical properties. The science of pigment, binder, solvent, and additive blending is complex. Without proper binders, the failure rate of paints rises dramatically no matter how good the pigment or boosting additives are. Binders are the key to long-term paint performance. They allow permanent adhesion, give durability for cleaning, resist abuse from the elements, and allow recoating if eventually needed.

Two types of paint binders

The two types of paint binders are alkyd binders and latex binders. Alkyd binders are oil-based binders, and are naturally produced from vegetable oils or synthetic-based chemicals processed as petroleum byproducts.The term “latex” is usually associated with rubber, but is not the case with latex paints.

Alkyd binders dry by chemically converting reactions with air during evaporation. Whether vegetable or mineral oil-based, alkyd paints allow their pigments to flow onto a surface and bind at a relatively predictable rate. Temperature and humidity have an effect, but eventually oxygen absorbs oil and the paint dries to a hard, even surface with a different chemical signature. The problem with convertible binders is they are hard to repaint because old paint and new products are chemically different. Alkyd binders are called “non-convertible binders” because they stay chemically stable during their drying process.

Latex binders dry by a different process. Latex binders are known as non-convertible binders curing or chemically coalesce by reacting with the pigment and binding agent through a process called a “thermoplastic reaction.” However, when paints with latex binders dry, they remain chemically consistent and don’t convert their final signatures. This makes them easy to paint over or touch up. Latex binders and water-based solvents are excellent in the right conditions, but need time to chemically bond. Latex products are highly affected by high heat or sudden moisture loss from wind or fans, and are also susceptible to excess or insufficient water.

• Pigments + Binder = Solids
• Solids + Liquids = Coating

In liquid paint applications, there is no way around using some sort of solvent or diluent to uniformly apply to a surface. The question is what type of solvents are best with specific solid blends? The answer is your paint solvent(s), or carrier vehicle, must be compatible with your binding agent. Most pigments are adaptable with solvents, but is not the case with binders.We are back to two favorite liquid paint partners: oil and latex. There’s not much variation with water coalescing solvents. The only range is temperature, as in hot or cold.

Oil-based or organic hydrocarbon solvents

• White Mineral Spirits (turpentine and general, all-purpose paint thinner)
• Organic Linseed Oil
• Butyl Acetate
• Ethyl Alcohol
• Ketone
• Acetone
• Toluene
• Xylene

Chemical solvents often carry a negative connotation. Many applicators simply prefer waterborne products to avoid perceived potential toxicity as well as other environmental controls such as flammability. Waterborne systems simplify choices, and when properly formulated with the right additives, water-based paints are especially effective.

“Quality” is often over-used in sales and marketing, and this is true in paint like most other products and services. Basically, quality means the consumer will meet performance expectations at a fair and competitive price. The axiom “You get what you pay for” is the most common sentiment in the paint industry. Ask any painting professional what quality paint is and you will get the same immediate answer: It’s a paint they can easily work with and which will last. Quality paints come from properly blending pigments and binders inside a liquid solvent. Often, additives are put in for specific applications. The list is too extensive to mention here, but it is worth mentioning that quality paint producers use the broadest array of additives. Not all paints are created equal by any means. If you are looking for true quality in paint products, you are well advised to choose a quality distributor.