Method for the touch up of scratched painted metal products

A method for repairing damaged metal surfaces. A marred painted surface, for example, the painted sheet metal forming automobile or truck bodies, which has been damaged by scratching or chipping of the paint to expose metal, is touched up so as to renew the continuous painted appearance and to prevent corrosion of the exposed metal by applying touch-up paint to the marred metal surface, and rubbing the touched-up surface and the immediately surrounding unmarred finished surface with a soft, flexible sheet material which has been wetted with a touch-up paint solvent composition, to remove the excess paint inadvertently spread over the old finish surrounding the scratch or chip. The flexible sheet material with the solvent is rubbed over the touched-up area only after the touch-up paint has partially set, generally from about 1 to about 15 minutes after application. The solvent composition comprises a paraffinic liquid solvent, and preferably also a stronger, more active solvent selected from the group of lower alkyl-substituted benzene and oxygenated aliphatic and cycloaliphatic hydrocarbon compounds and halogen substituted such compounds.

This invention relates to a method and composition for repairing damaged 
painted metal surfaces. More particularly, the invention relates to a 
method and composition for touching up painted metal, such as for example 
automobile bodies formed from sheet metal, wherein the painted, enameled 
or lacquered finish has been inadvertently removed, as by a scratch or a 
chip. 
It is a common practice, when the painted surface of, e.g., painted sheet 
metal automobile and truck bodies, are damaged by the scratching or 
chipping of the paint to expose the metal, to touch up the surface so as 
to renew the continuous painted appearance, and to prevent corrosion of 
the exposed metal. Generally, even a minor scratch or chip is considered 
to be a highly visible blemish to the appearance of, especially, passenger 
automobiles. The industry has long responded by providing relatively small 
containers, e.g. two fluid ounces, of a paint or enamel or lacquer 
(hereinafter broadly referred to as "paint") having a cap generally 
including a fine brush, for applying the coating to the scratch or chip 
and thus repairing the appearance of the automobile body. 
A problem often met with in applying the paint is the difficulty of 
applying the paint to the scratched or chipped portion without also 
overpainting the surrounding unmarred finish with excess paint. Generally, 
the overpainted portion no longer matches the remainder of the surface and 
thus continues to lack an unblemished appearance which is desirable for a 
complete repair of the original finish. Although, individuals may have 
attempted to wipe away the excess new paint with a dry cloth, the problem 
has always been to remove the excess paint without, on the one hand, 
marring the original finish in those areas immediately adjacent the 
scratch or chip and, on the other hand, removing all of the paint applied 
to the chipped or scratched portion. Up to the present time there has been 
a notable lack of success in achieving a truly effective touch-up method 
which can be easily used by the general public. 
It is an object of the present invention to provide a composition suitable 
for removing excess paint surrounding a repaired scratch or chip on a 
painted metal surface without either marring the old finish or removing 
the new coating. 
It is a further object of this invention to provide a method for repairing 
scratches or chips on a painted metal automobile body surface so as to 
remove any excess new coating from above the original finish without 
either marring the original finish or removing the new paint from the chip 
or scratch. 
It is yet another object of the present invention to provide a method, and 
a kit for carrying out the method and including a solvent composition, 
wherein excess touch-up paint applied to a blemished area of an automobile 
body surface, from which any excess new paint is removed from the 
immediately adjacent old finish surface, without either marring the old 
finished surface or removing the new paint from the exposed metal 
substrate. 
In the method of this invention, after the touch-up paint is applied to 
scratched or chipped painted metal, the surface is rubbed with a soft 
flexible sheet material, which has been wetted with a touch-up solvent 
composition, to remove the excess paint inadvertently spread over the old 
finish surrounding the scratch or chip. The touch-up solvent composition 
can be any suitable paint solvent, including, e.g., mineral spirits, or 
other paraffinic liquid solvent. Preferably, however, the touch-up solvent 
composition comprises from about 1% to about 35% by wt. of an additional 
active solvent added to the above-described suitable paint solvent, which 
is wholly miscible with the paraffinic solvent in the proportions set 
forth. Preferably, there is present at least about 2% by wt. and most 
preferably at least about 5% by wt. of the active solvent. Further in 
accordance with this invention, the active solvent is a liquid which in 
substantially pure form is too strong of a solvent to be readily used 
without marring the original surface finish appearance. 
The suitable paint solvents include, preferably, paraffinic solvents having 
a boiling point above about 200.degree. centigrade, such as heptane, the 
ISOS, including ISO C, ISO E, ISO G, ISO H and ISO K, as 
well as various mineral spirits having a boiling point in the range of 
between about 200.degree. and about 400.degree. centigrade. The above 
paint solvent can be used as a touch-up solvent composition alone, or as a 
diluent with the afore-described active solvents. 
For ease of use, the solvent composition is preferably provided in a kit 
form; A preferred kit comprises a container of the touch-up solvent 
composition suitable as a dispenser, and a soft flexible sheet, buffing 
aid, such as a piece of woven or non-woven fabric, which can absorb the 
solvent composition from the container and buff the painted surface. 
Alternatively, a buffing aid comprising a soft surface on an otherwise 
rigid substrate can also be used. 
The active solvent comprises lower alkyl- substituted benzene, such as 
toluene, xylene, ethyl benzene, methylethyl benzene and propyl benzene; 
oxygenated aliphatic and cycloaliphatic hydrocarbon compounds, including 
carbonyl-containing aliphatic and cycloaliphatic compounds, such as 
methylethyl ketone, acetone, methylisobutylketone, diacetone alcohol, and 
other alkyl ketones and esters, preferably having up to about eight (8) 
carbon atoms; lower aliphatic esters, such as ethyl acetate, butyl 
acetate, propylacetate, ethyl proprionate, and preferably having up to 
about eight (8) carbon atoms; and the hydroxylated ethers, such as the 
various CELLOSOLVE compounds, i.e., mono-and di-alkly ethers of ethylene 
glycol having up to about 14 carbon atoms, the aromatic-substituted such 
ethers, such as phenyl cellosolve, and the esters of such compounds, such 
as methylcellosolve acetate, n-hexyl cellosolve acetate, dibutyl 
cellosolve propionate and methylcellosolve acetate; and chlorinated 
benzenes and chlorinated aliphatic and cycloaliphatic hydrocarbons, such 
as 1,1,1-trichloroethane, and o-dichlorobenzene and dichlorotoluene. 
For reasons of safety, it is preferred that the least volatile materials be 
used; these are customarily referred to in the trade as "odorless" 
solvents It is of course also necessary that the solvents be liquid at 
room temperature. 
It is preferred that the touch-up paint be permitted to at least partially 
set, i.e., bond to the metal substrate, before rubbing with the touch-up 
solvent. This further improves the final appearance of the touched-up 
surface, and avoids interfering with the bonding of the touch-up paint to 
the metal, without reducing the effectiveness of the touch-up solvent in 
removing the excess paint applied over the original surface. It is 
recognized that the amount of time needed to partially set the touch-up 
paint varies depending upon the particular paint composition, and also 
possibly the precise nature of the metal substrate; it has been found that 
for the touch-up paints generally recommended by most contemporary 
automobile manufacturers, the touch-up paint should be permitted to rest 
for between about 1 and about 15 minutes, and preferably at least about 
three (3) minutes, before rubbing with the wetted buffing material, e.g., 
wetted soft cloth.

Embodiments of this invention which are presently preferred are set forth 
by way of example only in the following Working Examples. In the Working 
Examples, those materials which are commonly available to the ordinary 
consumer in the United States market are referred to by their common or 
generic name, where known, as well as by the trade marks under which they 
are sold at retail. 
EXAMPLE 1 
The right fender panel of a 1988 Chevrolet Station Wagon, formed of sheet 
steel, has a scratch of removed paint (approximately 1/8th of an inch in 
width and 2 inches long), extending at least partially down to the bare 
metal, so that the top layer of paint has been removed. Touch-up paint 
matching the color of the automobile is applied, utilizing paint from a 
bottle of touch-up paint recommended by the automobile company; the bottle 
has a brush extending from the interior of the cap. The paint is allowed 
to dry for five (5) minutes. 
Although the touch-up paint was applied with great care, it was practically 
impossible not to leave a thin smear of the touch-up paint over the 
original finish immediately surrounding the chipped area. A touch-up 
solvent composition, formed by dissolving ten (10) parts by weight of 
toluene into ninety (90) parts by weight of painters' naphtha, sold as 
ISO C, was used to thoroughly wet a soft cloth. The cloth is then used 
to gently rub over the touched-up, chipped area and the surrounding 
portions of the original paint finish, to remove all excess paint outside 
of the chip area. This was accomplished without removing the paint from 
the exposed metal surface. 
The paint in the chipped area should then be left to dry for at least two 
(2) hours before buffing and waxing or otherwise polishing the surface. 
The repaired chipped area was almost indistinguishable from the 
surrounding original finish, and there was substantially no extra paint 
over the original finish in the area surrounding the touched up chipped 
portion. 
EXAMPLE 2 
The procedure in accordance with Example 1, above, was repeated but 
utilizing as the touch-up liquid composition painters' naphtha, as 
purchased. It was found to be necessary to rub with greater force, and 
that greater care needed to be taken to avoid removing paint from the 
scratched area and to avoid marring the original surrounding finish. 
EXAMPLES 3-10 
The procedure in accordance with Example 1, above was repeated but 
utilizing the touch-up liquid compositions shown in Table I, below. 
TABLE I 
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Active Solvent Solvent 
Ex. Parts Parts 
No. Compound by Wt. Material by Wt. 
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3 Xylene 15 Heptane 85 
4 Methyl Ethyl 10 #140 Solvent 
90 
Ketone 
5 Diacetone alcohol 
20 ISO G 80 
6 Butyl CELLOSOLVE 
12 IOS H 88 
7 Ethyl Acetate 25 ISO K 75 
8 1,1,1-trichloroethane 
15 ISO E 85 
9 dichlorotoluene 15 ISO C 85 
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In each case, substantially the same results were obtained as in Example 1.