Brush-on finish for footwear and similar articles

An item of footwear which has become scuffed or worn, or which is to be protected against wear, on its leather or leather-like external surfaces, is subjected to a preliminary cleaning. Thereafter, a coating of polyurethane elastomer dissolved in a solvent (preferably half toluene and half isopropyl alcohol), further including a colorant, a thickener and a gloss-lowering agent, is brushed or swabbed onto the surface. The solvent evaporates, leaving a thin, flexible, scuff-resistant coating the color of which covers and hides discoloration and scuffs on the original surface.

BACKGROUND OF THE INVENTION 
For the consumer and professional, there has been a variety of products 
available throughout the years for the recoloring of footwear. Aerosol, 
lacquer-type sprays, and brush-on recolor water-based type finishes have 
been on the market for a considerable time. These products have had 
inherent deficiencies. The fast-dry lacquer-type aerosols, or sprays, 
mostly become hard after they are applied, because the nature of the 
coating is a solvent-type lacquer, which has been manufactured by 
dissolving a resin into a solvent. The resulting coating, then, has the 
properties of the resin-solvent blend. If the resulting coating would be 
too hard, plasticizer is often added as an external agent to soften the 
resulting coating. What then happens is that the plasticizer migrates out 
of the coating, making it hard and brittle. Or, while in the coating, the 
plasticizer may render the surface tacky. That is the nature of 
plasticizers. Lacquer-type coatings, whether nitrocellulose, vinyl, or 
acrylic, do not have the requisite inherent flexibility. Therefore, 
coatings conventionally are mixtures of chemicals. The resulting coating 
can exhibit different qualities as it ages. There often is a considerable 
loss of flexibility, wear, abrasion resistance, etc. As a result, known 
recolor finishes for shoes, whether they be solvent blends or water-based 
blends, exhibit qualities of serious aging and deterioration because of 
the nature of how the coating was manufactured. Thus, a shoe recoloring 
product loses its washability, durability, and flexibility, because the 
mixed chemicals do not stay in the condition they were, at the time of 
mixing. 
Almost all new sneakers soon get dirty, and show signs of wear and tear 
after they are used in sports activities. The same is true for most shoes 
and footwear. It is not uncommon for sneakers and shoes to show 
considerable signs of use and wear shortly after being purchased. 
One popular product on the market now is a water-based color coating for 
ladies shoes. It has very poor water resistance and does not wear well. It 
is a color coating which is a mixed-together product. Professionals also 
have available a lacquer-type aerosol which colors shoes and leather, but 
exhibits the same poor tendencies of all mixed coatings and finishes. 
There are similar problems in protecting luggage and other leather and 
leather-like goods that, like footwear, are subject to scuffing, flexing 
and changes in humidity, since the finishes available to recolor and 
protect them are generally the same as those available for recoloring and 
protecting the outer surfaces of leather and leather-like portions of 
footwear. 
SUMMARY OF THE INVENTION 
An item of footwear which has become scuffed or worn, or which is to be 
protected against wear, on its leather or leather-like external surfaces, 
is subjected to a preliminary cleaning. Thereafter, a coating of 
polyurethane elastomer dissolved in a solvent (preferably half toluene and 
half isopropyl alcohol), further including a colorant, a thickener and a 
gloss-lowering agent, is brushed or swabbed onto the surface. The solvent 
evaporates, leaving a thin, flexible, scuff-resistant coating the color of 
which covers and hides discoloration and scuffs on the original surface.

DETAILED DESCRIPTION 
The surfaces that can be recolored and/or protected using the process and 
coating material of the present invention are generally the external 
surfaces, subject to wear and discoloration, of leather and leather-like 
footwear such as one would ordinarily think to protect using shoe polish, 
leather protector, vinyl protector and the like. 
In addition to leather (tanned animal skin), the following are examples of 
leather-like materials which can be protected using the method and coating 
material of the present invention: sneakers, tennis shoes, all types of 
men's and ladies' footwear, athletic shoes and equipment, belts, 
briefcases and other leather goods, as well as those made of synthetic or 
artificial leather, typically polyvinylchloride. 
An initial step in practicing the method of the invention is cleaning the 
surface which is to be coated. The surface may be cleaned by applying a 
cleaning agent, and then wiping the surface. More than one cleaning agent 
can be used in succession or mixed together, and any convenient means may 
be used for applying the cleaning agent then wiping the surface, e.g. 
spraying, swabbing, dipping, followed by wiping with a cloth, sponge, 
squeegee or the like. 
The preferred cleaning agent is acetone. In addition, the following are 
examples of cleaning agents which can be used: ethyl acetate, isopropyl 
alcohol, methyl ethyl ketone and methylisobutyl ketone. 
The coating composition used in the present invention includes a reacted 
polyurethane elastomer, dissolved in a solvent, a pigmented colorant, a 
thickener and, preferably, a gloss-lowering agent. 
The preferred polyurethane elastomer is Spencer Kellogg Products/NL 
Chemicals Spenlite L89-30S (product code No. 38489) which is believed to 
be 30% reacted polyurethane elastomer dissolved in 35% toluene and 35% 
isopropyl alcohol. 
The preferred polyurethane elastomer is believed to be a type 5 
thermoplastic polyester-type polyurethane elastomer. In addition to the 
preferred elastomer, the following are examples of polyurethane elastomer 
which could be used as the polyurethane ingredient of the coating 
composition of the present invention: QC10 available from K. J. Quinn & 
Co. of Malden, Mass., and Desmolac 4125, available from Mobay Chemical 
Corp. of Pittsburgh, Pa. 
The preferred solvent for the polyurethane elastomer is a 1:1 mixture of 
toluene and isopropyl alcohol (which is the same solvent system used by 
the manufacturer in Spenlite L89-30S). Examples of other solvents which 
could be used include: methyl ethyl ketone and/or isobutyl ketone mixed 
with isopropyl alcohol. 
Except where the coating is to be used as a clear protective coating on a 
non-worn surface, the coating composition includes a pigmented colorant. 
Examples of pigmented colorants which could be used include: thalo blue 
and titanium dioxide. Pigments must be ground into the resin, not mixed 
in, as is the case with a typical resin formulation. 
(The preference of colorant is dictated by the desired color of the 
resulting coating.) 
By preference, the coating composition further includes a thickener, in 
order to help keep the pigment evenly dispersed throughout the coating 
composition. The preferred thickener is Nuodex Nuvis HS, which is believed 
to consist of acid agents coated with powder which chemically cause a 
reaction which thickens the coating. Examples of other thickeners which 
could be used include: lecithin. 
By preference, except where the coating is meant to provide the coated 
surface with a patent leather-like shiny appearance, the coating 
composition further includes a gloss-reducing agent. A preferred 
gloss-reducing agent is Syloid, made by The Syloid Company, which is 
believed to consist of: powdered silica which reduces the gloss levels of 
paints and coatings. Examples of other gloss-reducing agents which could 
be used are: other powdered silicas, micron size. 
A specific example of a coating composition which is preferred for use in 
practicing the present invention is as follows: 
______________________________________ 
Parts by Weight 
Ingredient 
______________________________________ 
1 Spenlite L89-30S 
1.5 solvent (1:1 toluene and isopropyl 
alcohol) 
10 pigment 
1 Nuvis HS thickener 
1 Sylox gloss-lowering agent 
______________________________________ 
The ingredients may vary in percentage from the point values given above in 
the specific example of the preferred embodiment. In fact, the ingredients 
may vary as follows: 
______________________________________ 
Range of weight percent 
Ingredient 
______________________________________ 
20% to 40% polyurethane elastomer 
40% to 60% solvent 
10% to 20% pigment 
1% to 3% thickener 
1% to 2% gloss-lowering agent 
______________________________________ 
The coating composition is preferably applied by using a conventional 
brush, sponge, swab, wiper or the like to spread on a thin coating, which 
is preferably allowed to air dry at room temperature. 
The coating is preferably applied so thinly that one ounce of the coating 
composition covers from 10 to 25 square inches of the surface of the 
leather or leather-like substrate. 
The coating composition optionally may include additional ingredients for 
their respective qualities. Examples of such other possible ingredients, 
and the range of weight percentages that each may have in the coating 
composition are: lethicin, 1-3 percent, to improve gloss, slow drying time 
and increase pigment dispersion; N-methyl perrillidone to slow drying time 
of the lacquer; other slow solvents such as cellusolve acetate and/or 
xylene, may be used to slow down drying time. 
It should now be apparent that the brush-on finish for footwear and similar 
articles as described hereinabove, possesses each of the attributes set 
forth in the specification under the heading "Summary of the Invention" 
hereinbefore. Because it can be modified to some extent without departing 
from the principles thereof as they have been outlined and explained in 
this specification, the present invention should be understood as 
encompassing all such modifications as are within the spirit and scope of 
the following claims.