BACKGROUND OF THE INVENTION

Field of the Invention

The present invention is directed generally to methods of repairing damaged paint on metal, rubber, and plastic surfaces and more particularly to methods of repairing and re-applying automobile paint.

Description of the Background of the Invention

Automobiles and trucks today are typically provided with a complex interrelated system of finishes designed to protect the underlying metal as well as add beauty to the design and shape of the vehicle. The sheet metal of the exterior and under body are first put through a complex system of coatings to help prevent rust. Then a primer coat is applied to aid in the adhesion of the top coat painting system. The final coating system is generally a single stage system or a base coat and clear coat system. While such coating systems are designed to yield, and do yield, good results when the coating system remains intact, it is known that normal vehicular use exposes the vehicle, and hence the coating system, to extremely harsh environments.

One relatively universal hazard is the potential for the coating system to become chipped and scratched. Chips typically result when a stone, or other projectile, strikes an automobile or truck while the projectile, vehicle, or both are traveling at a high rate of speed. Impacts between the vehicle and the projectile cause chips in the coating system which may be of several different types. Some chips may result in just the removal of the clear coat. Other chips may result in the removal of the clear coat and a portion of the paint, thereby leaving a depression. Still other chips may remove the clear coat and paint thereby

exposing the primer. Such chips are easy to detect because the primer is typically of a different color than the paint. Finally, other chips may result in the entire coating system being removed such that bare metal is exposed.

All types of chips result in a weakening of the coating system which protects the vehicle's body. Certain types of chips, such as those exposing the primer and bare metal, will result in rust if not repaired, and are additionally aesthetically unpleasant. Because of the use of aerodynamic designs for cars, chips, particularly in the area of the hood, are becoming more and more of a problem. As the automobile manufacturers are forced to comply with clean air and pollution restrictions, lead is being removed from all paint finishes by 1993 year end making the inishes on automobiles and trucks even more vulnerable to chipping, scratching, and acid rain.

The general prior art method of repairing chips in a vehicle's coating system is to repaint the entire area affected by the chips. For example, U.S. Patent No. 4,265,936 discloses a vehicle refinishing process for repainting whole portions of an automobile finish. There are, however, many drawbacks to such repainting. First, for older vehicles, aging makes it difficult to precisely match the vehicle's color. The larger the area repainted, the more likely that a mismatch in color will be detected. The prior art method often requires painting a large section of the car to avoid color mismatches within those parts. Additionally, large repainted areas may lead to suspicion that major body work or repair work was done rather than merely repainting to eliminate chips in the paint. Finally, repainting large areas of the vehicle is not cost effective either from the point of view of materials used or labor expended. Furthermore, today's finishes

are baked at 400 degrees and it is very difficult to get a good chemical bond with such finishes with conventional repainting methods.

To avoid the disadvantages of those methods, alternative methods have been advanced for repainting just a chip or scratch and the immediately surrounding area of an automobile finish. For example, U.S. Patent Nos. 5,077,086 and 5,082,692 disclose methods for the touch up of scratched, painted, metal products. In those patents, a chip or scratch in a painted finish is touched up with a matching paint, and after that paint has partially set, a soft flexible sheet material which has been wetted with touch up paint solvent is rubbed over the painted chip or scratch to remove any paint which has covered the original finish around the chip or scratch. In this manner the chip or scratch is filled in with matching paint while eliminating the noticeable buildup of the touch up paint on the surrounding undamaged area. Likewise, U.S. Patent No. 4,814,200 discloses a method for restoring a painted surface in which paint is sprayed onto a chip or scratch and the surrounding area of an automobile surface. A wax film is then contacted with the wet paint, and finally the excess wax and paint are wiped away. Nevertheless, these alternative methods suffer from drawbacks such as difficulties in using the methods. Thus, a need exists for a simple and easily used method for repainting chips in an automobile finish without complete repainting of the surrounding undamaged finish.

SUMMARY OF THE PRESENT INVENTION The present invention provides a simplified, efficient, economical, and, environmentally speaking, a more desirable method of repairing chip damage, scratches, and blemishes in the original factory finish

of metal, rubber, and plastic surfaces by applying specially treated paint to the damaged areas only and therefore keeping the integrity of the original factory finish with virtually no detectable overspray to the naked eye. The present invention also has the capability of covering a desired area of an item with a dust coat of matching paint and one or more protective clear coats which can be chemically removed at a later date, if desired, so that additional repairs can be made without damaging or even having to remove the original factory finish. The dust coat and protective layers can be applied and removed any number of times.

According to its broadest aspects, the present invention is directed to a method for providing an easily removable protective finish over a desired portion of an item's surface comprised of the steps of: a) applying a first agent (e.g. AP100, PC52P) to the desired portion of the item's surface which is effective for cleaning contaminants and providing a layer of film; b) preparing paint which matches the color of the item's finish; c) mixing a first additive (e.g. DZ4) and a second additive (e.g. PC52A) with the paint which causes the paint to interact with the layer of film to adhere only where the finish is removed and to release from the item's finish; d) applying a dust coat of the paint from step c) to the desired portion of the item's surface; and e) applying a substantially clear protective coating (e.g. PC52) over the dust coat and surrounding area in a manner which is effective for blending the dust coat into the item's original finish. The protective coating and dust coating thus applied can be removed at a later date without harming the item's original finish. If desired, the protective clear coats and the dust coat can easily be added and removed any number of times depending on the wishes of the customer, even years later, without damaging the

original factory finish. That capability allows chip repairs, performed before the dust coat is applied, to be performed over and over again without ever having to completely cover the factory finish with more than two mils of paint, and eliminates the need to strip, sand, etc.

The method of the present invention presents several advantages over the prior art. As previously mentioned, the dust coat and clear protective coats provide removable protection for the item's finish.

The dust coat can be applied virtually anywhere without leaving tell tale paint lines because it is so thin. With respect to the chip repair aspects of the present invention, only the chip, i.e. the area of damage, is repainted. Thus, there are no large repainted areas which could raise suspicions of major body work. Secondly, because only the chip area is painted, it is very difficult to recognize that the vehicle's factory finish was ever damaged, assuming that the color of the prepared paint is a close match to the vehicle's color. The amount of paint actually used is extremely small, generally less than thirty grams, thus leading to cost savings in terms of materials. Also, because no masking of chrome, windows, pinstripes, other paint, plastic, rubber, or the like is required, manpower requirements are kept to a minimum. Paint can be mixed, applied with an airbrush, and stored for use at a later date in the same bottle such that cleanup and the use of environmentally dangerous solvents is kept to a minimum. Also, because the painting is performed with the use of an air brush and only small areas are repainted, the need for ventilators, spray booths, and the like is eliminated. The disclosed method of applying the paint circumvents many governmental regulations applicable to spray painting. Those and other advantages and benefits of

the present invention will become apparent from the Description of a Preferred Embodiment hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS For the present invention to be easily understood and readily practiced, a preferred embodiment will be described, by way of example only, in conjunction with the following figures in which;

FIGs. 1 and 2 are cross-sectional views illustrating chips in a vehicle's coating system; FIG. 3 is a flow chart illustrating the steps for preparing the paint and repairing a chip or scratch in accordance with the method of the present invention;

FIG. 4 is a flow chart illustrating the steps of applying removable, protective layers of paint according to the techniques of the present invention; and

FIGs. 5, 6, 7, and 8 are cross-sectional views illustrating the chip as it appears after each step of the method of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

The present invention is directed to a method of repairing, by repainting, a chip in a vehicle's paint and then providing an easily removable protective overlayer over portions of the vehicle surf ce that are often chipped. Although the present invention is described in terms of a vehicle's finish, the methods of the present invention are equally applicable to boats, planes, kitchen appliances, virtually any surface, i.e. steel, plastic, rubber, etc., which has received a finish at the factory. FIG. 1 is a cross- sectional view illustrating a chip 22 in coating system 18 of, for example, a vehicle such as an automobile or a truck (not shown) . In FIG. 1, which is not drawn to scale, a portion of the vehicle body 10 is illustrated.

- 1 -

As is known in the art, the vehicle body 10 is constructed primarily of metal. The coating system 18 applied to the metal 10 is typically comprised of a primer layer 12, a layer of paint 14 which contains the desired pigments, and a clear coat or top layer 16.

The primer layer 12 is typically a bonding agent between the metal and the paint. The paint 14 and clear coat 16 are typically enamel paints. Vehicles manufactured in the United States typically use acrylic based enamel paints while vehicles manufactured in the United Kingdom and Europe typically use urethane based enamel paints. The method of the present invention works particularly well with urethane based enamel paints. The chip 22 in the coating system 18 is representative of the type of chip resulting from a projectile, such as a rock, striking the vehicle body 10 at a high rate of speed. Such chips typically have steep sides, are deep, and extend into the primer layer 12. Chips of that type are normally found in the front of the vehicle.

A second type of chip 24 is illustrated in FIG. 2. The chip 24 is representative of the type of chip produced by low speed impacts. Such chips are normally smaller, have sloped sides, and do not extend as deeply into the primer layer 12. Chips of that type are normally found in the sides of the vehicle.

The method of the present invention is particularly well suited for repainting chips of the type illustrated in FIG. 1 and FIG. 2 and providing easily removable protective overlayers over those repairs. According to a preferred embodiment of the present invention, the following equipment is desirable. 1 - 3/4 hp compressor with storage tank

1 - full size microfiche viewer

1 - AC/DC Digital scale 1 - Paasche Air Brush Kit 1 - Complete Set of Colored Tints 1 - Complete Set of Chemical Products including:

AP100, DZX1, DZ4, DZX, DZXD, PC52, PC52A, PC52W, PC52R, PC52P, and Clean & Shine 1 - 55' high pressure reinforced air hose

1 - set (17 pages) international paint formula microfiche 1 - page international paint formula microfiche index 1 - set (17 pages) -paint shading tips microfiche for international paint formulas 1 - page paint shading tips microfiche index mixing/inventory bottles 1 - International Paint Code Directory with color chips 5 - overspray remover rubber blocks 1 - respirator One aspect of the present invention is to specially prepare the paint which is used in the process for repairing the chip. FIG. 3 is a flow chart illustrating the steps necessary to prepare the paint and repair a chip.

In FIG. 3, the first step 26 is to look up the paint code which is found on the vehicle's name plate. In step 28, the paint code is then located in the International Paint Code Directory which provides the formula designation for that paint code. After the formula designation has been located, the set of microfiche international paint formulas is consulted using the microfiche viewer to ascertain the exact

paint formula for that formula designation as shown at step 30. Then the paint is mixed in step 32 by using the set of color tints (paint) and the digital scale. Shading, if necessary, can be performed. Those of ordinary skill in the art will recognize that looking up the paint code from the vehicle name plate, using that paint code to ascertain the formula designation, which in turn is used to ascertain the paint formula, and mixing the paint according to that formula, are steps which are known in the art and are carried out by those persons engaged in touch up painting, or other types of vehicular painting, which do not involve a complete repaint of the entire vehicle.

It is anticipated that the present invention may be practiced by mixing the paint in a small mixing/inventory bottle. After the paint has been mixed, that bottle may be attached to the air brush for application to the vehicle. Any remaining paint may be stored in the same mixing bottle for use at a later date.

After the paint has been mixed in step 32, four drops of DZX1 are added in step 34. Although the addition of DZX1 is not absolutely necessary to practice the invention, better results are achieved when it is used. DZX1 is an additive added to the

.paint to activate chemicals in the factory paint. The preparation of the paint is completed at step 36 by adding five percent by weight of another chemical additive, DZ4. DZX1 is comprised of approximately 98% xlyene, CAS No. 1330-20-7, and 2% silicon resin, CAS No. 9016-00-6. (Percentages used herein are in volume percent unless otherwise expressly indicated) . DZ4 is a mixture of 74% acetone, CAS No. 67-84-1, 16% toluene, CAS No. 108-88-3, and 10% ethanol, CAS No. 64-17-5. The purpose for adding DZX1 and DZ4 is to activate

chemicals in the factory finish such that the paint will adhere only in those areas in which the finish is missing, i.e., chips, scratches, etc., and will not adhere to the factory finish. The value of that characteristic will become apparent from the description of the method of the present invention presented below.

The steps of repairing a chip according to the preferred embodiment of the present invention are illustrated in FIG. 3. In FIG. 3, step 38 is to apply a first agent AP100 to the area of the vehicle's surface where the chip is located. AP100 is available from Lico Chemical Co. of McKeesport, PA as product no. 703. Lico product no. 703 is a mixture of 80% of a first component and 20% of a second component. The first component consists of 50% hydrocarbon solvent, CAS No. 64742-88-7, and 50% aromatic solvent, CAS No. 64742-96-8. The second component consists of 74% acetone, CAS No. 67-84-1, 16% toluene, CAS No. 108-88-3, and 10% ethanol CAS No. 64-17-5. After the application of the APIOO in step 38, the chip 22 appears as illustrated in FIG. 5. As seen in FIG. 5, a thin layer 40 of AP100 covers the clear coat layer 16 and the primer layer 12. The purpose of applying the layer 40 of AP 100 is threefold. First, the application of the layer 40 of AP100 removes contaminants within the chip 22. The layer 40 of AP100 prepares the primer layer 12 to bond to the paint which* has been specially prepared as discussed hereinabove. The layer 40 of AP100 overlaying clear coat layer-16 prevents the specially prepared paint from adhering to the clear coat layer 16 or, if a clear coat is not used, from adhering to the layer of paint 14.

After the chemical APIOO has been applied, the prepared paint is color matched to the vehicle. If the match is not sufficiently close due to aging.

weathering, or the like, the prepared paint may be shaded again at step 41. Using the index of paint shading tips, a shading tip may be found for each paint formula in the seventeen page set of shading tips for international paint formulas.

After the prepared paint has been color matched, the prepared paint is applied in step 42 through the use of an air brush connected to a compressor through a high pressure, reinforced air hose. Each chip is now sprayed using a very small pattern only slightly larger than the chip to be repaired. The sprayed area is typically about the size of one quarter of a dime. After the paint has been sprayed, the chip 22 may appear as illustrated in FIG. 6. As seen in FIG. 6, the chip 22 is filled with paint 44. Depending upon the depth of the chip 22, it may take two or three coats of paint 44 before the profile appears as shown in FIG. 6.

The last step of the chip repair method of the present invention is step 46 of FIG. 3 in which the overspray is removed. The term overspray refers to that paint 44 which overlies the clear coat layer 16 or, if the clear coat layer is absent, the paint layer 14. The result after the overspray has been removed is illustrated in FIG. 7.

The overspray is removed through the use of a chemical, either DZX or DZXD. Both DZX and DZXD are available from Lico, which has been previously identified, as product nos. 701 and 702. DZX is a mixture of 90% of a first component and 10% of a second component. The first component consists of 50% hydrocarbon solvent, CAS No. 64742-88-7, and 50% aromatic solvent, CAS No. 64742-96-8. The second component consists of 74% acetone, CAS No. 67-84-1, 16% toluene, CAS No. 108-88-3, and 10% ethanol, CAS No. 64-17-5. In the event that there is substantial

overspray, or the overspray is not noticed until the paint 44 cures, use of the stronger DZXD may be necessary. DZXD is a mixture of 50% of the first component and 50% of the second component previously defined in conjunction with DZX. Application of either of the nonabrasive DZX or DZXD causes the oversprayed paint 44 to release from the factory finish so that the overspray can be easily wiped away. The DZX or DZXD may be applied to a rag which has be wrapped around a rubber block.

As seen from FIG. 7, the chip 22 is now completely filled with paint 44. However, paint 44 covers no portion of the vehicle body 10 for which the coating system 18 is intact. Thus, only the chip has been painted. And, by building up layers of paint 44 if necessary, a smooth finish is provided.

The chip repair aspect of the method of the present invention presents several advantages over the prior art. First, only the chip, i.e. the area of damage, is repainted. Those portions of the coating system 18 which are undamaged are not painted. Thus, there are no large repainted areas which could raise suspicions of major body work. Secondly, because only very small areas actually retain any paint 44, it is very difficult to recognize that the coating system 18 was ever damaged, assuming that the color of the prepared paint is a close match to the vehicle's color. The amount of paint actually used is extremely small, less than ten grams, thus leading to cost savings in terms of materials. Also, because no masking of chrome, windows, pinstripes, other paint, plastic, rubber, or the like is required, manpower requirements are kept to a minimum. Further, because of the simplicity of the system, less skilled workers may be employed.

Cleanup and the use of environmentally dangerous solvents is kept to a minimum. Also, because the painting is performed with the use of an air brush and only small areas are repainted, the need for ventilators, paint-booths, and the like is eliminated. Also, the disclosed method of applying the paint circumvents many governmental regulations applicable to spray painting.

After the chip has been repaired or, alternatively, instead of repairing the chip, the method of the present invention includes a second series of steps in which a protective, easily removable, finish layer is provided over a portion of the vehicle surface which may include chips or repaired chips. Referring to Fig. 4, in the first step 48, PC52P is applied to a clean dry rag and rubbed vigorously over the desired portion of the vehicle surface to provide a clean noncontaminated bonding area. PC52P is a mixture of 20% DZ4 and 80% of another component comprised of 50% hydrocarbon solvent, CAS No. 69742-88-7, and 50% aromatic solvent, CAS No. 64742-96- 8. Step 48 may be eliminated if the process of FIG. 4 is being practiced immediately after a chip repair according to FIG. 3 has been performed. In the second step 50, the mixed, color matched paint, or some portion thereof if the mixed, color matched paint is to be saved for later use, is altered by mixing it with 25% by weight of PC52A. PC52A is a mixture of 60-65% acetone, CAS No. 67-64-1, 10-15% toluene, CAS No. 108-88-3, and 20-25% isopropyl alcohol awnydrous, CAS No. 67-63-0. The altered paint is applied to the desired portion of the vehicle surface with an airbrush in a dull, even, flat manner resembling primer. The paint is applied as a dust coat approximate one mil or less in thickness.

In the next step 54, one or more coats of PC52 are then sprayed over the applied paint coat with an airbrush using a No. 5 tip at approximately 10-15 pounds of air pressure and an oil-less compressor. PC52 is a mixture of 18-20% acrylic resin, 2-4% aromatic hydrocarbon, CAS No. 647-2-95-6, 1-3% butyl acetate, CAS No. 123-86-4, 28% methyl ethyl ketone, CAS No. 78-93-3, 2-4% propylene glycol monomethyl ether acetate, CAS No. 108-65-6, 28% toluene, CAS No. 108-88- 3, and 17% xylene, CAS No. 1330-22-7.

Step 54 is actually a three step process used for applying each coat of the PC52. In the first step of each coat, PC52 is sprayed four to six inches above the vehicle surface in a parallel manner with a 40% overlap of the spray to cover the desired portion of the vehicle surface. In the second step of each coat, spraying is continued in an indiscriminate pattern over the desired portion of the vehicle surface to coat and even out the base paint applied in step 52. In the third step of each coat, spraying is continued in a light dusting manner going beyond the edges of the spraying in the first and second steps for each coat. The second and third coats of PC52 are applied in the same three step manner as the first coat with a short drying time of approximately five-seven minutes between each coat. AT this time, the chip appears as shown in FIG. 8 with the colored dust coat represented by numeral 60 and the clear coats of PC52 represented by numeral 62. In the next step 55, after allowing a brief drying time of about 10-20 minutes, PC52W is applied directly to a damp clean rag and gently rubbed in a back and forth motion over the desired portion of the vehicle surface to remove texture and improve gloss and clarity of the finish. PC52W is a mixture of 90% of a first component and 10% Dupont nonpenetrating thinner product

code 3613S. The first componet is comprised of 12-20% aliphatic hydrocarbons, CAS No. 8008-20-6, 15-20% diatomacous earth, CAS No. 7631-86-9, 2-8% blended oil and 52-71% wax. Dupont product code 36135 consists of 74% acetone, CAS No. 67-84-1, 16% toluene, CAS No. 108- 88-3, and 10% ethanol, CAS No. 64-17-5.

If the protective overlayer does not look satisfactory, then it can be easily removed with PC52R in another step 56. PC52R is a mixture of 50% DZ4 and 50% of another component comprised of 50% hydrocarbon solvent, CAS No. 6474-88-7, and 50% aromatic solvent, CAS No. 64742-96-8. In particular, PC52R is applied to a dry clean cloth and rubbed over the portion of the vehicle surface. The protective layer and the dust coat are then removed by rubbing vigorously with a dry clean cloth. This removal procedure may be repeated multiple times as necessary to remove the protective overlayer and dust coat without harming the factory finish. As a last step, it may be necessary to clean and shine the entire area where a repair has been made or the PC52 process carried out because the newly painted area may be brighter and shinier than the original finish. Buffing of the appropriate area with Clean & Shine will yield the desired results. Clean & Shine is a stronger version of PC52W: it contains 80% of the first componet of PC52W and 20% Dupont nonpenetrating thinner.

It should be appreciated that the steps of the method relating to the easily removable protective overlayer may be used on a desired portion of the vehicle surface which has not been chipped and repaired. Best results are obtained if any chips are first repaired, but such chip repair is not required before using the PC52 process. The PC52 process provides an attractive yet removable finish which can

be removed and reapplied numerous times without harming, the vehicle's factory finish.

The present invention has been described in conjunction with a preferred embodiment thereof. Those of ordinary skill in the art will recognize that many changes and modifications are possible. Such changes and modifications are intended to be covered by the following claims.