Water-repellent solution and method of forming water-repellent film on substrate by using the solution

A method of forming a water-repellent film on a substrate, comprising the steps of:

• preparing a water-repellent solution, said solution being produced by subjecting a fluoroalkyl-group contained silane compound to a hydrolysis and a condensation polymerization thereby to produce at least dimers and trimers of the silane compound;
• applying said water-repellent solution to a surface of said substrate;
• and
• heating said substrate to cause the fluoroalkyl-group in the solution to be bonded to the surface of said substrate thereby to form the water-repellent film on said substrate.

A water-repellent layered article comprising:

• a substrate;
• and
• a water-repellent film formed on a surface of said substrate, said film being prepared by applying a water-repellent solution to said surface, said water-repellent solution being prepared by subjecting a fluoroalkyl-group contained silane compound to a hydrolysis and a condensation polymerization, said fluoroalkyl-group contained silane compound being represented by the following general formula (5):
• CF3(CF2)m(CH2)2SiX3 (5)
• wherein “m” is equal to or greater than 7 (seven) and “X” represents halogen, isocyanate-group or alkoxy-group, said alkoxy-group including methoxy-group [OCH3], ethoxy-group [OC2H5] or isopropoxy-group [OC3H5].

A method of producing a water-repellent layered article, comprising the steps of:

• preparing a water-repellent solution and a substrate, said solution being produced by subjecting a fluoroalkyl-group contained silane compound to a hydrolysis and a condensation polymerization;
• applying said water-repellent solution to a surface of said substrate;
• and
• heating said substrate to cause the fluoroalkyl-group in the solution to be bonded to the surface of said substrate thereby to form the water-repellent film on said substrate,
• wherein said fluoroalkyl-group contained silane compound is represented by the following general formula (5):
• CF3(CF2)m(CH2)2SiX3 (5)
• wherein “m” is equal to or greater than 7 (seven) and “X” represents halogen, isocyanate-group or alkoxy-group, said alkoxy-group including methoxy-group [OCH3], ethoxy-group [OC2H5] or isopropoxy-group [OC3H5].