Water-based paints are actually made from an emulsion of polymer particles with a size varying between and nm, stabilized by surfactants. During the drying process ,the water evaporates, the particles come in contact with each other and a good particle-particle adhesion is necessary to form a homogeneous and cohesive film. The control of the interdiffusion process of the polymers contained in the particle is essential for this good adhesion between particles and hence to obtain a paint film of good aspect and mechanical properties.
Paint is any pigmented liquidliquefiable, or mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture to objects. Paint can be made or purchased in many colors—and in many different types, such as watercolor or synthetic.
Journal of Coatings Technology and Research. Water-based coatings require coalescing aids to achieve properties equivalent to solvent-borne paints. The relatively large quantity of TMPD-MIB used in latex paints has raised concerns regarding its emissions to both indoor and outdoor atmospheres.
We've made some changes to EPA. Innovation and Benefits: Latex paints require coalescents to help the paint particles flow together and cover surfaces well. This new coalescent has other performance advantages as well, such as lower odor, increased scrub resistance, and better opacity.
A coalescent aid is a small amount of solvent contained in latex coatings. It is not a true solvent because it does not actually dissolve the latex resins. The coalescent aid helps the latex resins flow together, aiding in film formation.
No medicine without side effects? Concentrating on aqueous emulsion paints latexesthe author reviews the most common classes of additives in use, and lists the effects these substances can cause apart from their original use? Latex paints are based on the aqueous dispersion of reactive or thermoplastic polymer or oligomer resins.
Eastman coalescents enable maximum film formation in latex paints, often improving overall paint performance. Coalescent works by softening the latex particles, allowing them to fuse into a tough, continuous film. Common coalescents include ester alcohols, esters, and glycol ethers.
As ramping up environmental regulations create a wider marketspace for low- to zero-VOC architectural coatings, more resources are being devoted to finding the optimum levels of coalescent required for achieving high performance finishes. Formulators are exploring the science to meet new regulations, while keeping a keen business eye on performance. What is the impact that an ultra-low VOC coalescent structure can have on coatings efficiency and performance properties, and why is one coalescent more effective than another? High-performance coating formulation has long relied on solvent coalescing aids to achieve the perfect finish.
Latex paints are currently used in a variety of applications and are well known in the art. Basically, they are low viscosity, aqueous emulsions of synthetic resins, pigments and other additives which are fast drying and most desirably have low odor. The formulation of a latex paint consists basically of combining pigment and additives with the latex.
To understand the function of coalescing aids, it is necessary to examine the film formation process of a latex paint see Figure 1. The emulsified polymer that will ultimately form the paint film exists as tiny droplets of solid material dispersed in water. On a porous substrate, some water and - depending on solubility - some coalescing aid will migrate into the substrate. As the amount of water decreases during the drying process, the latex particles are forced closer and closer together.