Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Patent
1995-09-21
1997-11-25
McGinty, Douglas J.
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
510202, 510203, 510413, 510407, 510406, 510438, 510439, 510242, 510401, 134 38, C11D 332, C11D 344, C11D 750, B08B 308
Patent
active
056912900
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a cleaning composition to remove unwanted paint and graffiti from a substrate and to a method of removing unwanted paint, graffiti and other coatings from a substrate.
The application of graffiti and other unwanted paintings or coatings on a surface of buildings etc. is a great concern, particularly in the Western urban areas. Usually, the graffiti are applied by spray cans on to various types of surfaces, the cleaning of which, if at all possible, is a very time-consuming and costly affair and not seldom leads to irreparable damage of the substrate.
A number of removing compositions have been proposed in the past. Thus, it has been proposed in WO-A-88/08445 (Coroman Industries Inc.) to prepare.graffiti-removing compositions from a solvent, such as mineral spirit, toluene, glycol ethers, fatty acids and chlorinated hydrocarbons, the solvent also comprising an effective amount of N-methyl-2-pyrrolidone and a surface-active agent.
The use of such solvents is highly undesirable, however, owing to their flammability, volatility and sometimes also toxicity and to the fact that they are not, or only partially, biodegradable. A number of these solvents are also not miscible with water so that, for instance, high-pressure water jet cleaning methods entail problems.
In order to avoid the use of toxic organic solvents such as the chlorinated hydrocarbons, it has also been proposed in WO-A-88/06640 (GAF Corp.) to use a mixture of 10-50 wt. % of N-methyl-2-pyrrolidone, 30-65 wt. % of an alkylene glycol ether and 5-35 wt. % of a C2-C11 organic carboxylic acid (preferably formic and acetic acid). The composition may also contain surfactants, corrosion inhibitors and thickeners. Although the toxicity and flammability of these compositions are indeed reduced, there is still the inconvenience of working with appreciable amounts of corrosive and rather aggressive acids.
Finally, it has been proposed in U.S. Pat. No. 4,780,235 (E.I. DuPont de Nemours and Corp.) to prepare a paint remover from 1-80 wt. % of at least one non-halogen-containing organic solvent, such as N-methyl-2-pyrrolidone and at least 20 wt. % of at least one C.sub.1 -C.sub.4 dialkyl ester of a C.sub.4 -C.sub.6 aliphatic dibasic acid, together with an activator (basic or acidic), a thickener and compatible surfactant. The presence of the activator is mandatory.
The present invention provides a cleaning composition to remove unwanted paint, graffiti or other coatings from surfaces or substrates, which has a very low volatility (low V.O.C.) and flammability, is water-miscible and biodegradable, and has a high dissolving power for the material to be removed from the substrate. It has been found in extensive experiments that a binary composition comprising a five-membered ring lactam and glycerol triacetate (triacetin) exhibits these optimal cleaning properties and at the same time meets the other requirements of low volatility, flammability, toxicity, high biodegradability and water-miscibility. The action of the binary composition can even be improved if certain esters are present as a third component.
Therefore, the present invention relates to a cleaning composition to remove unwanted paint, graffiti and other coatings from a substrate, which consists of: ##STR1## in which R represents a hydrogen atom, or a methyl, an ethyl, a propyl, an isopropyl or a vinyl group, and having from 1 to 4 carbon atoms.
Preferably, the five-membered ring lactam is N-methyl-2-pyrrolidone, which is, for example, sold under the Trade Mark MPyrol by the General Aniline and Film Corp (USA) having a flash point (open cup) of 95.degree. C.
The glycerol triester of a C1-C4 aliphatic saturated monocarboxylic acid preferably is the glycerol triester of acetic acid (or triacetin). The glycerol triester may be derived from more than one monocarboxylic acid and also mixtures of esters may be used.
The action of the binary mixture is even enhanced if also diethyl phthalate, diisopropyl adipate and/or esters of lactic acid and saturated aliphatic monohydric a
REFERENCES:
patent: 3954648 (1976-05-01), Belcak et el.
patent: 4293347 (1981-10-01), Haschke et al.
patent: 4376118 (1983-03-01), Daher et al.
patent: 5145671 (1992-09-01), Castrogiovanni et al.
patent: 5466390 (1995-11-01), Houghton et al.
Mellan, I., Industrial Solvents Handbook second edition, Noyes Data Corporation NJ 1977 (p. 500)
Heymann Anette
Vonk Pieter
McGinty Douglas J.
Unichema Chemie B.V.
LandOfFree
Cleaning composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cleaning composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cleaning composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2107046