Acceptable aerosol dispensed paint compositions must have sufficient mechanical stability to withstand the mechanical shearing forces which aerosol water based paint compositions normally experience as they are dispensed from conventional aerosol containers. Insufficient stability results in mechanical shearing of polymeric components of the composition. hand-painted oil paintings Agglomerated bits of the composition can clog the narrow orifices of the aerosol valve outlet and interfere with the even dispersement of paint. Agglomerated bits can also break away from the orifice and be delivered onto the surface of the substrate being painted, thereby marring the paint film thereon.
Mechanical stability of paint formulations has depended in large measure upon maintaining a solution of the polymer in the aerosolized formulation. Proper mechanical stability and low viscosity have been achieved in solvent based systems employing hydrocarbons, alcohols and other solvents. The volatility of the solvent causes rapid thickening of the paint as the aerosolized composition is dispensed and applied to a substrate. Oil Paintings The rapid thickening of the aerosol paint during and after it is dispensed is essential to commercial solvent based paint formulations which must be capable of adhering to vertical surfaces without running.
That property of a paint composition is referred to herein as vertical cling.
Although organic solvent based systems have been developed which have good mechanical stability and vertical cling properties, the solvents employed in such systems are flammable, toxic and environmentally undesirable. Thus, it was deemed desirable to develop a water based paint composition which would possess the degree of mechanical stability necessary for it to be dispensed with a minimum of breakup from a conventional aerosol valve, while at the same time possessing a high degree of vertical cling when the composition is sprayed onto a vertical substrate.
