Scratch Resistant Gradient Coating and Coated Articles

Abstract

A gradient coating is comprised of a basecoat derived from a polysiloxane prepolymer obtained from a mixture of one to three alkoxysilane monomers and at least one diepoxide monomer, and a lubricious reactant. The basecoat is applied to a substrate and dried. The lubricious reactant is then applied and allowed to permeate into the basecoat. The basecoat and lubricious reactant are then co-cured, resulting in a gradient coating composition. In addition to providing enhanced scratch and mar resistance, the gradient coating composition is solvent resistant and provides a durable hydrophobic and oleophobic surface, which makes it useful as a corrosion protectant and as a release agent.

1 - 59 . (canceled)  
   
   
       60 . A method to produce a stable prepolymer solution comprising: 
 a) partially hydrolyzing an aminoalkyltrialkoxysilane by adding a quantity of water equal to about 40 to about 80 percent of the molar amount necessary to hydrolyze all alkoxy groups of the aminoalkyltrialkoxysilane;    b) mixing the partially hydrolyzed aminoalkyltrialkoxysilane with at least one selected from the group consisting of: 
 i. a tetraalkoxysilane;  
 ii. an alkyltrialkoxysilane; and  
 iii. a non-silane-based epoxy resin;  
 and combinations and mixtures thereof;  
   c) adding a mixture of a ketone and an alcohol;    d) adding a quantity of water equal to about 50 to about 100 percent of the molar amount of hydrolysable groups on the tetraalkoxysilane and the alkyltrialkoxysilane diluted with about an equal volume of ethanol;    e) heating the mixture to a temperature in the range between about 40° C. and about 80° C. while monitoring the increase in viscosity;    f) adding a quantity of an aqueous solution of acetic acid such that the amount of acetic acid added is equal to about the molar amount of amine in the mixture; and    g) heating the mixture to substantially complete a prepolymer formation.    
   
   
       61 . A method to produce a stable prepolymer solution comprising: 
 a) partially hydrolyzing an alkoxysilane;    b) initiating a polymerization reaction with the partially hydrolyzed alkoxysilane;    c) quenching the polymerization reaction prior to gelation;    d) adding a mixture of water and alcohol;    e) heating the mixture to resume the polymerization reaction and monitoring the increase in viscosity;    f) quenching the polymerization reaction prior to gelation by adding a mixture of water and an organic acid; and    g) heating the mixture to substantially complete a prepolymer formation.    
   
   
       62 . The method of  claim 61 , wherein partially hydrolyzing the alkoxysilane further comprises adding about 40 percent to about 80 percent of the water required to hydrolyze all alkoxy groups at room temperature.  
   
   
       63 . The method of  claim 61 , wherein initiating a polymerization reaction with the partially hydrolyzed alkoxysilane further comprises adding at least one of a tetraalkoxysilane, an alkyltrialkoxysilane, and a non-silane-based expoxy resin, and combinations and mixtures thereof.  
   
   
       64 . The method of  claim 61 , wherein quenching the polymerization reaction prior to gelation further comprises adding a mixture of about equal volumes of a ketone and an alcohol.  
   
   
       65 . The method of  claim 64 , wherein adding a mixture of about equal volumes of a ketone and an alcohol further comprises adding a mixture of about equal volumes of methyl ethyl ketone and ethanol.  
   
   
       66 . The method of  claim 61 , wherein adding a mixture of water and alcohol further comprises adding a quantity of water mixed with an equal volume of ethanol, the quantity of water equal to about 50 percent to about 100 percent of the hydrolysable groups on the tetraalkoxysilane and the alkyltrialkoxysilane.  
   
   
       67 . The method of  claim 61 , wherein heating the mixture further comprises heating the mixture to a temperature in the range from about 40° C. to about 80° C.  
   
   
       68 . The method of  claim 61 , wherein quenching the polymerization reaction further comprises adding an amount of acetic acid and water, the amount of acetic acid equal to about the molar amount of amine in the solution.  
   
   
       69 . A stable prepolymer solution comprising: 
 a) a partially hydrolyzed first alkoxysilane prepared by mixing an aminoalkyltrialkoxysilane and a quantity of water equal to about 40 to about 80 percent of the molar amount necessary to hydrolyze all alkoxy groups of the aminoalkyltrialkoxysilane;    b) a second alkoxysilane comprising a tetraalkoxysilane or an alklytrialkoxysilane, or combinations and mixtures thereof.    c) a non-silane-based epoxy resin;    d) a mixture of about equal volumes of a ketone and an alcohol;    e) a mixture of water and alcohol, a resulting solution heated to a temperature in the range between about 40° C. and about 80° C. while monitoring the increase in viscosity; and    f) a mixture of water and an organic acid.    
   
   
       70 . The stable prepolymer solution of  claim 69 , wherein the mixture of about equal volumes of a ketone and an alcohol further comprises a mixture of about equal volumes of methyl ethyl ketone and ethanol.  
   
   
       71 . The stable prepolymer solution of  claim 69 , wherein the mixture of water and alcohol further comprises a quantity of water mixed with an equal volume of ethanol, the quantity of water equal to about 50 percent to about 100 percent of the hydrolysable groups on the tetraalkoxysilane and the alkyltrialkoxysilane.  
   
   
       72 . The stable prepolymer solution of  claim 69 , wherein the mixture of water and an organic acid further comprises an amount of acetic acid and water, the amount of acetic acid equal to about the molar amount of amine in the solution.