Patent Publication Number: US-2007107636-A1

Title: Removable solvent based paint formulation and system

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims priority to copending U.S. provisional application entitled, “A Removable Paint Formulation and System,” having Ser. No. 60/736,487, filed Nov. 14, 2005, which is entirely incorporated herein by reference. 
    
    
     TECHNICAL FIELD  
      This invention relates to a solvent based coating or paint that can be easily removed by certain remover compositions without damaging the underlying paint or coating. This coating is basically a combination of cellulose acetate butyrate alcohol and diacetone alcohol. Pigment can be added to the coating to make it a paint.  
     BACKGROUND OF THE INVENTION  
      It is many times desirable to have a solvent based coating or paint formulation that can be applied over another paint or substrate and subsequently removed without damaging the underlying paint or substrate. This is difficult to accomplish because the solvents that will remove the paint that it is intended to remove may also remove the underlying paint or damage its luster. This type of application of a removable paint would be desirable for automobile signs or signs with temporary colors.  
     SUMMARY OF THE INVENTION  
      An easily removable solvent based coat or paint is provided by this invention. This paint is a lacquer formulation of approximately 20 to 30% by weight of cellulose acetate butyrate, 50 to 80% by weight of alcohol and 10 to 30% by weight of diacetone alcohol. Preferably approximately 23% by weight of cellulose acetate butyrate is used, 58% by weight of alcohol and 18.5% by weight of diacetone alcohol. For screen printing from 1 to 7% of sucrose acetate isobutyrate may be used. This coating may include a pigment which makes it into a paint.  
      A remover formulation is provided which is a mixture of diacetone alcohol, ethyl alcohol, hydroxypropylcellulose and a surfactant. The remover formulation is simply sprayed or brushed onto the removable paint and agitated with a sponge or brush and wiped off with a towel or washed away with water. This removable paint can be used on an automobile to form a clear coating or can be used as temporary paint for painting over a painted or unpainted surface and then easily removing it when it is desired to remove the temporary coating. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      An easily removable solvent based coating or paint is provided by this invention. This coating is basically a lacquer. This removable or temporary coating or paint can be easily removed by certain remover formulations.  
      The lacquer formulation consists of approximately 20 to 30% by weight of cellulose acetate butyrate, 50 to 80% by weight of alcohol and 10 to 30% by weight of diacetone alcohol. Preferably approximately 23% by weight of cellulose acetate butyrate is used, 58% by weight of alcohol and 18.5% by weight of diacetone alcohol. The alcohol may be ethyl alcohol or denatured with a small amount of isopropyl alcohol (e.g. 5%).  
      This paint or coating can be made more compatible for screen printing by adding from 1 to 7% of sucrose acetate isobutyrate to this formulation. Preferably from 3% to 5% of sucrose acetate isobutyrate is added, while approximately 4% is preferred. Preferably this formulation contains approximately 22% by weight of cellulose acetate butyrate, 56% by weight of alcohol, 18% of diacetone alcohol, and 4% of sucrose acetate isobutyrate.  
      Pigment can be added to the mixture to make a paint in the normal manner. Typically, pigment in an amount from 6 to 22% by weight is added depending upon the pigment and other factors. Special effect particles can be added to add texture, or reflection characteristics to the coating or paint in the normal manner.  
      The removable paint of this invention can be applied by any conventional means such as spraying, brushing or screen printing. In the case of automobiles it is preferable to spray the paint on the automobile.  
      As a part of this system a remover formulation is provided. The preferred remover formulation is a mixture of diacetone alcohol, ethyl alcohol, hydroxypropylcellulose (as a viscosity modifier) and a surfactant/emulsifier (for water wash off).  
      The remover formulation is simply sprayed or brushed onto the removable paint and agitated with a brush or sponge for a few minutes and the residue wiped off with a towel or washed away with water. The system of this invention will not damage the underlying paint.  
      It should be emphasized that the above-described embodiments of the present invention are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.  
     EXAMPLE I  
      An eight-gallon batch of the lacquer removable coating of this invention was made. Seven thousand grams of cellulose acetate butyrate (23.18% by weight) in powder form, Eastman Chemical CAB-553-0-4, was dissolved in 17,600 grams of a mixture of 95% ethyl alcohol and 5% isopropyl alcohol (58.28% by weight) and 5,600 grams of diacetone alcohol (18.54% by weight). This was spread on the lacquer finish of an automobile to form a clear coating.  
      This clear coating was removed by a remover which was a blend of diacetone alcohol 25% by weight, denatured alcohol 65% by weight, hydroxypropylcellulose, 5% by weight, and an emulsifying surfactant 5% by weight which was sprayed or brushed onto the removable paint, agitated with a sponge and allowed to set and then wiped with a towel for a few minutes. This removal did not damage the original painted surface to which the removable paint was applied.  
     EXAMPLE 2  
      An eight-gallon batch of the lacquer removable coating of this invention was made by mixing the following ingredients. Seven thousand grams of cellulose acetate butyrate (22.29% by weight) in powder form, Eastman Chemical CAB-553-0-4, was dissolved in 17,600 grams of a mixture of 95% ethyl alcohol and 5% isopropyl alcohol (56.05% by weight) and 5,600 grams of diacetone alcohol (17.83% by weight) with 1200 grams of sucrose acetate isobutyrate (3.82%). This formulation was sprayed on the finish of an automobile to form a clear coating. The clear coating was removed by using the remover and procedure set forth in Example 1.