Sealcoating is a great way to rejuvenate your asphalt driveway or parking lot. It helps the surface look new, protects from water and oxidation, and fills small cracks.
The process is pretty simple. The first step is to block off the area to be sealed with traffic cones, sawhorses, and caution tape. Then, the blacktop must be cleaned of grease stains and raised spots. Visit https://www.rochesternysealcoating.com/ to learn more.
Coal tar emulsion is the most commonly used sealcoating material. It provides excellent protection for asphalt and can last up to five years before the surface needs to be resealed again. It also offers good resistance to oil and water, as well as UV rays. This type of sealcoat is often used for commercial parking lots and residential driveways.
A coal-tar sealcoating is dark in color and hard and durable. It can be applied to a smooth or rough surface and is typically mixed with sand or recycled rubber before it is spread. It is also often used to repair minor cracks or damage to an existing asphalt surface. However, if the asphalt is very deteriorated, a coal-tar sealcoating will only add a few years to its lifespan at best.
Whether or not you choose this type of sealcoating depends largely on your preferences and budget. Some homeowners and business owners are concerned about environmental concerns and prefer a less-toxic product. The volatile organic compounds in oil-based sealants are harmful to the environment, and some states and municipalities have banned them altogether. In addition, the application process requires ideal weather conditions to ensure that the coating adheres properly. If it’s too hot or cold, or if rain is expected within 24 hours, the project should be postponed until the conditions are better.
While there are a few different types of coal-tar emulsions, all contain similar chemical compositions. They consist of a mixture of phenols and other aromatic hydrocarbons. These include naphthalenes, anthracenes, and phenanthrenes. There is a small amount of paraffinic and olefinic hydrocarbons as well. This mixture is usually dispersed in water to form a semi-solid.
Another type of oil-based tar is creosote, which is derived from wood or coal and used as a preservative for wood and metal. It contains a variety of natural phenols, including guaiacol and creosol (4-methylguaiacol). These are mixed with hydrocarbons to form the creosote mixture, which is then diluted for use as a wood preservative.
When diluted, the mixture forms a thick, black liquid. It can be applied by brushing, spraying, or dipping and is easily mixed with other materials. It’s important to note, however, that the chemicals in these tars are harmful to the environment and can be toxic to plants and animals. They can also be a health hazard for people who are exposed to them by inhalation.
Coal Tar Emulsion
Coal-tar emulsion is a thick black protective substance used to coat asphalt parking lots, driveways, and playgrounds. Its durable qualities make it an excellent choice for protecting pavement from weather damage and typical deterioration, and it provides a rich dark color that’s very aesthetically pleasing. Unfortunately, coal tar sealant has recently come under increasing scrutiny for its harmful environmental effects and many municipalities have banned its use.
The application and drying of coal tar sealants releases a number of harmful volatile organic compounds (VOCs) and fumes, which contribute to air pollution. This pollution can lead to health issues such as coughing, headaches, irritation, and wheezing. It can also contaminate water streams, lakes, and surrounding soil, causing harm to plants and animals. The runoff of coal tar can also seep into underground sewers and storm drains, polluting groundwater supplies.
VOCs and other harmful chemicals from coal tar can also cause water pollution by seeping into underground water supplies. This contamination can lead to the death of aquatic life and threaten human health. Fortunately, there are safer alternatives to coal tar sealants, such as the odorless and fast-drying asphalt emulsion known as BioSEALSAFE®.
Asphalt emulsion is derived from asphalt itself, and can be blended with coal tar to create a darker sealer that’s easier for contractors to work with. The general mixing guidelines for this type of blend are 60-90% Coal Tar Emulsion to 10-40% Asphalt Emulsion.
Many types of additives are available to improve the performance of coal tar sealers, including polymer latex, ceramics, and other materials. Typically, the additive is added to the mix at the rate of 1-2% per undiluted gallon of the coal tar. It may be used to improve the drying time of the sealer, alter sand/aggregate suspension, increase water repellency, or provide resistance to deicing salts and other chemicals.
In addition to the binder, additives are responsible for a number of other essential sealcoating properties, such as cold temperature flexibility, toughness, and tack reduction at higher temperatures. Additive ingredients can also improve the appearance of the completed sealcoating job by enhancing the color, gloss and sheen.
Asphalt Emulsion
Asphalt emulsion is a type of sealcoat that consists of asphalt suspended in water. It can be mixed with sand or aggregate to create a thick, tough coating that protects the surface from harmful ultraviolet rays, oil and gasoline spills, and other damaging elements. Asphalt emulsion is safer and less toxic than coal-tar sealcoat, and it doesn’t emit the same amount of volatile organic compounds that contribute to smog formation.
The emulsion process involves using a colloid mill to reduce the size of asphalt cement particles and then mixing them with water. The resulting mixture is then stabilized with surfactants, which help to maintain the emulsion’s structure and prevent it from breaking apart. Additives such as fillers, anti-strips, stabilizers, polymers and latex can be added to improve the emulsion’s performance. The emulsion’s charge can also be adjusted to match its compatibility with available aggregates.
Different asphalt emulsions are available to meet the needs of specific applications, with each having its own set of advantages. For example, rapid-set emulsions are designed to set quickly and are ideal for fog seals, slurry seals and tack coats. Slow-set emulsions are formulated to take longer to set and are used in base coats or surface treatments.
Like all emulsions, asphalt emulsion requires care when applying to avoid premature separation or liquefaction. The mixture should be thoroughly stirred before application, and it’s important to use a large enough broom or squeegee to cover as much area as possible within the specified time frame. In addition, it’s crucial to apply the emulsion when temperatures are warm and dry, and to avoid applying it before, during or after rainfall.
As an environmentally friendly option, asphalt emulsion can be used for road and parking lot repairs. It’s particularly useful in cold-in-place recycling (CIR) and full-depth reclamation, which recycle existing asphalt pavement by grinding it up and mixing it with an emulsion before laying it back down. This minimizes the need to mine and transport new materials, which helps conserve natural resources and cuts down on energy consumption. Additionally, emulsion is odorless and doesn’t emit any polycyclic aromatic hydrocarbons, which are known carcinogens.
Acrylic
Acrylic emulsions are water-based and can contain a wide range of additives that improve performance. They are also safer and more environmentally friendly than oil-based products. They are typically used for paints, stains and wood sealers. In addition, they are sometimes used in medical and healthcare applications as adhesives for medical tapes and bandages.
The chemistry behind acrylic emulsion is quite complex. But once Rohm and Haas chemists mastered the technology, acrylic emulsion chemistry would transform their modest company into a dominant force in paints, plastics, textiles, coatings and many other industries.
Acrylic polymer emulsions consist of water and acrylic spheres, which are suspended in the water by chemical emulsifiers. Chemical emulsifiers work by breaking up the larger molecules in the acrylic resin so that they can interact with the smaller water droplets. This interaction creates a stable mixture that will remain in place until the water evaporates or is absorbed.
As the water evaporates, it leaves behind the acrylic spheres, which form an acrylic film that can be painted on or applied to surfaces. It is a flexible and durable product that offers excellent weather resistance, adhesion and color retention.
In the 1940s, Rohm and Haas began exploring water-based acrylic chemistry for use in leather and textile technology. By 1953, they had developed Rhoplex AC-33, a pure acrylic binder that was used in house paints. These new paints required less preparation, were easier to clean up, had lower odor and released much fewer polluting fumes than their oil-based counterparts. The paints also performed as well or better than traditional oils and were perfect for the growing do-it-yourself market.
During the 1970s and 1980s, Rohm and Haas further diversified their line of latex products. Additive based on 100% acrylics, poly/vinyl acrylic, styrene butadiene, nitrile and chloroprene rubbers were introduced for the purpose of thickening, sand/aggregate suspension and faster drying. These additives provide resistance to abrasion, moderate chemicals, acids and some hydrocarbon solvents.
However, these are more expensive products and they are not as suitable for large asphalt projects as coal tar emulsions. They are primarily used for sports courts, parking lots and similar specialty applications because they offer high-quality protection without the environmental hazards of other materials. When using any type of emulsion for a commercial application, it is important to train all staff and crew on how to properly prepare the surface, use equipment safely and mix the proper ratios.