Solvent-activated color-forming compositions

Abstract

The present invention provides an object, which, in its outer surface contains a color-forming composition which comprises a solvent-absorbing material that is generally a polymer; a color-former compounded with the solvent-absorbing material, where the color-former functions as a metal chelating agent; and metal ions capable of forming a chelate complex with the color-former as the solvent-absorbing material absorbs a solvent, resulting in a detectable color change of the composition. The present invention also provides a method for indicating exposure of the color-forming composition to a solvent, wherein the color-forming composition is to be used on the outside surface of objects.

1 . An object which, in its outer surface contains a color-forming composition which comprises: 
 a. a solvent-absorbing material;    b. a color former compounded with said solvent-absorbing material, wherein said color former functions as a metal chelating agent; and    c. metal ions capable of forming a chelate complex with said color former as said solvent-absorbing material absorbs said solvent, resulting in a detectable color change of said composition.    
     
     
         2 . The object of  claim 1  wherein said solvent absorbing material is a polymer  
     
     
         3 . The object of  claim 2  wherein the solvent absorbing material is selected from the group consisting of polyethylene acrylic acid, polyethylene methacrylic acid, and copolymers thereof; terpolymers of polyethylene, an acrylic acid and an acrylate; polyurethane; poly-(acrylonitrile-butadiene-styrene); polyvinylchloride; polypropylene copolymer; polystyrene; polyurethane; silicon elastomers; organic rubbers; and combinations thereof.  
     
     
         4 . The object of  claim 3  wherein said solvent absorbing material is polyethylene methacrylic acid, polyethylene acrylic acid, and mixtures thereof.  
     
     
         5 . The object of  claim 4  wherein said color-forming composition exhibits thermoxidative stability at compounding temperatures of at least about 90° C.  
     
     
         6 . The object of  claim 5  wherein said color-forming composition exhibits thermoxidative stability at extrusion temperatures of at least about 180° C.  
     
     
         7 . The object of  claim 2  wherein said solvent absorbing material is a paint.  
     
     
         8 . The object of  claim 3  wherein said metal ions are selected from the group consisting of Na + , Li + , Zn 2+ , Fe 3+ , Fe 2+ , Ca 2+ , Mg 2+ , Li + , Ti 2+ , Ti 4+ , Mn 2+ , and combinations thereof.  
     
     
         9 . The object of  claim 8  wherein said metal ion is Zn 2+ .  
     
     
         10 . The object of  claim 8  wherein said metal ions are contained in said solvent absorbing material.  
     
     
         11 . The object of  claim 9  wherein the metal ions are provided by zinc acetate.  
     
     
         12 . The object of  claim 11  wherein the zinc acetate is present from about 0.1% to about 2.5%, by weight of the composition.  
     
     
         13 . The object of  claim 8  wherein said color former produces a permanent color change which is not reversed by removal of said solvent from said solvent absorbing material.  
     
     
         14 . The object of  claim 13  wherein said color former is a 1,2-dihydroxybenzene derivative.  
     
     
         15 . The object of  claim 14  wherein said color former is selected from the group consisting of 1,2-dihydroxybenzene, 3-methylcatechol, 4-methylcatechol, 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt and 1,2,3-trihydroxybenzene and mixtures thereof.  
     
     
         16 . The object of  claim 15  wherein said color former is 1,2-dihydroxybenzene and is present in the composition at from about 0.1% to about 2.5%, by weight.  
     
     
         17 . The object of  claim 8  wherein the color change is reversible when the absorbed solvent is removed from said outer covering.  
     
     
         18 . The object of  claim 17  wherein said color former is a substituted fluoran derivative with at least one amine group at positions 3 and 6.  
       
         
           
           
               
               
           
         
       
     
     
         19 . The object of  claim 18  wherein R1 and R2 of the amine group are alkyl groups containing from one to six carbon atoms independently.  
     
     
         20 . The object of  claim 19  wherein said color former is selected from the group consisting of 3-diethylamino-6-methyl-fluoran, 3-dimethylamino-6-methyl-fluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 2-anilino-3-methyl-6-dibutylaminofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, and 2-anilino-3-methyl-6-diethylaminofluoran and mixtures thereof.  
     
     
         21 . The object of  claim 18  wherein a fixative is added to retard reversal of said color change and wherein said fixative is present at from about 0.1% to about 2.5%, by weight.  
     
     
         22 . The object of  claim 21  wherein the fixative is a phenolic-based compound.  
     
     
         23 . The object of  claim 22  wherein the fixative is salicylic acid or bisphenol-A, the acetate derivatives thereof and mixtures thereof.  
     
     
         24 . The object of  claim 1  wherein the object is a golf ball.  
     
     
         25 . The object of  claim 25  wherein said solvent-absorbing material is polyethylene methacrylic acid; said color-former is from about 0.1% to about 2.5%, by weight of a 1,2-dihydroxybenzene derivative; and said metal ion is Zn 2+ , in an amount of from about 0.1% to about 2.5%, by weight.  
     
     
         26 . A solvent-activated, color-forming composition, comprising: 
 a. a solvent-absorbing material;    b. a color former compounded with said solvent-absorbing material, wherein said color former functions as a metal chelating agent; and    c. metal ions capable of forming a chelate complex with said color former as said solvent-absorbing material absorbs a solvent, resulting in a detectable color change of said composition.    
     
     
         27 . The composition of  claim 26  wherein said solvent absorbing material is a polymer selected from the group consisting of polyethylene acrylic acid, polyethylene methacrylic acid, and copolymers thereof, terpolymers of polyethylene, an acrylic acid and an acrylate; polyurethane; poly-(acrylonitrile-butadiene-styrene); polyvinylchloride; polypropylene copolymer; polystyrene; silicon elastomers; organic rubbers; and combinations thereof.  
     
     
         28 . The composition of  claim 27  wherein said solvent absorbing material is polyethylene methacrylic acid or polyethylene acrylic acid and mixtures thereof.  
     
     
         29 . The composition of  claim 27  wherein said metal ions are selected from the group consisting of Na + , Li + , Zn 2+ , Fe2+, Fe 3+ , Ca 2+ , Mg 2+ , Li + , Ti 2+ , Ti4+, Mn 2+ , and combinations thereof and wherein said metal ions are present at from about 0.1% to about 2.5%, by weight.  
     
     
         30 . The composition of  claim 29  wherein said metal ions are contained in said solvent absorbing material.  
     
     
         31 . The composition of  claim 29  wherein said metal ions are provided by zinc acetate.  
     
     
         32 . The composition of  claim 29  wherein said color former produces a permanent color change which is not reversed by removal of said solvent from said solvent absorbing material.  
     
     
         33 . The composition of  claim 32  wherein said color former is a 1,2-dihydroxybenzene derivative and wherein said color former is present at from about 0.1% to about 2.5%, by weight.  
     
     
         34 . The composition of  claim 33  wherein said color former is selected from the group consisting of 1,2-dihydroxybenzene, 3-methylcatechol, 4-methylcatechol, 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt and 1,2,3-trihydroxybenzene and mixtures thereof.  
     
     
         35 . The composition of  claim 29  wherein said color change is reversible when the absorbed solvent is removed from said composition.  
     
     
         36 . The composition of  claim 35  wherein said color former is a substituted fluoran derivative with at least one amine group at positions 3 and 6,  
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  of the amine group are alkyl groups containing from one to six carbon atoms independently and wherein said color former is present at from about 0.1% to about 2.5%, by weight.  
     
     
         37 . The composition of  claim 36  wherein said color former is selected from the group consisting of 3-diethylamino-6-methyl-fluoran, 3-dimethylamino-6-methyl-fluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 2-anilino-3-methyl-6-dibutylaminofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, and 2-anilino-3-methyl-6-diethylaminofluoran and mixtures thereof.  
     
     
         38 . The composition of  claim 36  wherein a fixative is added to retard reversal of said color change and wherein said fixative is present at from about 0.1% to about 2.5%, by weight.  
     
     
         39 . The composition of  claim 38  wherein said fixative is a phenolic-based compound.  
     
     
         40 . The composition of  claim 39  wherein said fixative is selected from salicylic acid, bisphenol-A, acetate derivatives of salicyclic acid and bisphenol A, and mixtures thereof.  
     
     
         41 . A method for indicating exposure of a color-forming composition to a solvent, said method comprising: 
 (a) providing a solvent;    (b) providing a solvent-absorbing material;    (c) compounding a color-former which functions as a metal chelating agent, with said solvent-absorbing material;    (d) providing metal ions; and    (e) contacting said solvent-absorbing material with said solvent,    whereby as said solvent is absorbed by said solvent-absorbing material, said metal ions contact and chelate with said color former resulting in a detectable color change of said composition.    
     
     
         42 . The method of claims  41  wherein 
 said solvent is water;  
 said solvent absorbing material is a polymer selected from the group consisting of polyethylene acrylic acid, polyethylene methacrylic acid, and copolymers thereof;  
 said color former is a 1,2-dihydroxybenzene derivative selected from the group consisting of 1,2-dihydroxybenzene, 3-methylcatechol, 4-methylcatechol, 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt and 1,2,3-trihydroxybenzene and mixtures thereof; and said metal ion is Zn 2+ .  
 
     
     
         43 . The method of claims  42  wherein 
 said solvent is water;  
 said solvent absorbing material is a polymer selected from the group consisting of polyethylene acrylic acid, polyethylene methacrylic acid, and copolymers thereof;  
 said color former is a substituted fluoran derivative with at least one amine group at positions 3 and 6, wherein R1 and R2 of the amine group are alkyl groups containing from one to six carbon atoms independently;  
 and said metal ion is Zn 2+ .  
 
     
     
         44 . The method of  claim 43  wherein a fixative is added to said composition, said fixative comprising acetylsalicylic acid or bisphenol diacetate and mixtures thereof.