ent compositions and methods for the removal of paint from different substrates. For example, some paint stripping compositions utilized highly caustic, alkaline solutions as demonstrated by Murphy in U.S. Pat. No. 3,766,076 and by Sullivan in U.S. Pat. No. 3,980,587. However, caustic solutions aggressively attack most metal substrates such as aluminum, steel, copper, zinc and chromium. The prior art utilizes various other volatile organic solvents, such as pyrrolidones as reported in U.S. Pat. No. 4,120,810 and phenyl ethers or ethoxylated alcohols as disclosed in U.S. Pat. No. 4,619,706.
Other known stripping methods use blasting processes with materials like plastics, starches, water and sometimes solvents. These methods not only produce large amounts of waste, which must be treated, but also generate a significant amount of airborne pollutants. With the proliferation of resinous coatings for the protection of metal and composite surfaces has come the need for a method of removing these types of coatings from their substrates without damaging the underlying material. It has been observed, for example, that strong acids are effective in removing these coatings, but their indiscriminate oxidation of the metal substrates makes acids undesirable and unacceptable in the majority of cases.
Several other techniques have been developed in attempts to satisfactorily remove paint coatings. One technique is to debond or dissolve the organic coating in a chemical solvent. While these solvents are often effective for debonding the paint coating from the substrate, they generate chemical waste such as stripping sludges, which result in disposal and pollution problems. Some organic stripping materials such as methylene chloride are effective as stripping agents and do little harm to underlying substrates. However, these chemicals pose additional problems such as toxicity, high volatility and flammability. While efforts have been made to minimize the problems associated with solvents, organic chemicals are still relatively in