BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a composition and method for removing a coating, such as paint or polyurethane, from a surface without requiring the use of methylene chloride.

2. Description of Related Art

There are many prior art “paint stripper” compositions for removing a coating, such as a paint or polyurethane, from a surface. These compositions contain solvents that, when applied to a coated surface loosen or dissolve the coating so that at least most of the coating may be wiped or scraped off the surface. The solvents used in many prior art paint strippers contain methylene chloride, toluene, or xylene that may be toxic or harmful to the environment and to health of users. The U.S. Environmental Protection Agency recently issued a rule, effective in November 2019, banning the use of methylene chloride in paint strippers.

In an effort to reduce health, safety and environmental concerns with these solvents, there are several prior art paint stripper compositions that do not use methylene chloride. For example, U.S. Patent Application Publication No. 2008/0139437 discloses a paint stripper that is free of methylene chloride. The paint stripper composition comprises 1-50% aprotic solvent (preferably acetone), 1-70% of an ether containing compound (dioxolane), an evaporation retarder (such as wax), and 1-50% of a solvent for the evaporation retarder (preferably aromatic hydrocarbons such as xylene). Although the paint stripper in the '437 publication avoids the use of methylene chloride, it still uses solvents, such as xylene and acetone, that are known to be hazardous. It also still requires the use of wax. Although wax is an effective evaporation retarder, it typically requires heating and melting as an additional step in mixing and preparing the stripping composition. There is a need for effective and fast-acting stripping compositions that avoid the use of methylene chloride and other harmful solvents, such as acetone and xylene, to strip coatings and that preferably does not the addition of wax or other evaporation retarder ingredients.

SUMMARY OF THE INVENTION

The compositions and methods of the invention provide an effective way to remove coatings from a surface without requiring the use of methylene chloride, toluene, xylene, acetone, or n-methyl pyrrolidone. According to one preferred embodiment, a stripping composition comprises at least one ether, at least one ester, at least one amine, at least one alcohol, and at least one glycoside and does not contain any methylene chloride. Most preferably such composition also does not include any xylene, toluene, acetone, or n-methyl pyrrolidone. Preferably, a stripping composition comprises around 40-80% total of one or more ethers, 20-45% total of one of more esters, 5-45% total of one or more alcohols (which may include an amino alcohol), and 0.25-17% total of one or more glycosides, all by weight of the composition. More preferably, a stripping composition comprises around 40-80% total of one or more ethers, 20-45% total of one of more esters, 5-30% total of one or more amines (preferably an amino alcohol), 5-15% total of one or more alcohols (excluding any amino alcohol), and 0.25-17% total of one or more glycosides, all by weight of the composition.

According to another preferred embodiment, the ether comprises dioxolane, more preferably 1,3 dioxolane. According to another preferred embodiment, the ester comprises acetic acid methyl ester or a carbonate ester or both. According to another preferred embodiment, the carbonate ester is dimethyl carbonate.

According to another preferred embodiment, at least one alcohol is an aromatic alcohol, preferably benzene methanol. According to another preferred embodiment, an aromatic alcohol is the only aromatic compound in the composition. According to another preferred embodiment, another alcohol is an amino alcohol, most preferably 2-aminoethanol (MEA).

According to another preferred embodiment, the at least one glycoside is an alkyl polyglucoside. According to another preferred embodiment, butyl glycoside is the only glycoside in a stripping composition. According to another preferred embodiment, at least two glycosides or glucosides are used in a stripping composition.

According to still other preferred embodiments, a stripping composition may optionally comprise a thickener or emulsifier or colorant or a combination thereof. Most preferably, stripping compositions according to preferred embodiments do not include water as a separately added ingredient, although one or more added ingredients may be aqueous.

According to one preferred embodiment of the invention, a method of removing a coating from a surface comprises: (1) applying a stripping composition according to a preferred embodiment of the invention to the coating such as by pouring, wiping, or brushing it on the coating or dipping the coated surface into such composition; (2) allowing such composition to sit on the coating for a period of time of 5-90 minutes depending on the type of coating, and then (3) removing the stripping composition and coating by wiping, scraping, rubbing, or sanding after the composition has been in contact with the coating for the period of time.

The compositions and methods according to preferred embodiments provide an improved environmental, health, and safety profile as compared to prior art stripping products, particularly those containing methylene chloride, which is commonly used for removal of coatings from surfaces. The compositions and methods according to preferred embodiments are also more effective and work faster than many prior art stripping products, and are comparable to, if not better than, methylene chloride products in effectiveness and speed of removal, particularly for water-based coatings.

