Sol for coating metals

A sol suitable for surface treatment of a metal to improve corrosion resistance and adhesion, comprising:

• in a deionized water carrier, a mixture made from,
• (a) about 1 vol % (R--O).sub.4 --Zr wherein R is a straight chain aliphatic having 2-5 carbon atoms for covalently bonding to the metal through the zirconium to form a metal-to-organic interface on the metal surface;
• (b) about 2 or about 3.4 vol % organosilane coupling agent selected from the group consisting of:
• 3-aminopropyltriethoxysilane,
• 3-glycidoxypropyltrimetheoxysilane,
• p-aminophenylsilane,
• allyltrimethoxysilane,
• n-(2-aminoethyl)-3-aminopropyltrimethoxysilane,
• 3-aminopropyltriethoxysilane,
• 3-aminopropyltrimethoxysilane,
• 3-glycidoxypropyldiisopropylethoxysilane,
• (3-glycidoxypropyl)methyldiethoxysilane,
• 3-glycidoxypropyltrimethoxysilane,
• 3-mercaptopropyltrimethoxysilane,
• 3-mercaptopropyltriethoxysilane,
• 3-methacryloxypropylmethyldiethoxysilane,
• 3-methacryloxypropylmethyldimethoxysilane,
• 3-methacryloxypropyltrimethoxysilane,
• n-phenylaminopropyltrimethoxysilane,
• vinylmethyldiethoxysilane,
• vinyltriethoxysilane, and
• vinyltrimethoxysilane;
• (c) an effective amount of acetic acid as a catalyst and hydrolysis rate stabilizer of the (R--O).sub.4 --Zr;
• and
• (d) an effective amount of ammonia or ammonium hydroxide to disrupt the Zr-acetate complex that otherwise forms.

An aqueous sol for coating titanium, made by mixing in deionized water without the addition of alcohol:

• (a) about 1 vol % (R--O).sub.4 --Zr wherein R is aliphatic having 2-5 carbon atoms, alicyclic, or aryl with
• (b) about 2 or 3.4 vol % of an organosilane from selected from the group consisting of:
• 3-aminopropyltriethoxysilane,
• 3-glycidoxypropyltrimethoxysilane,
• p-aminophenylsilane,
• allyltrimethoxysilane,
• n-(2-aminoethyl)-3-aminopropyltrimethoxysilane,
• 3-aminopropyltriethoxysilane,
• 3-aminopropyltrimethoxysilane,
• 3-glycidoxypropyldiisopropylethoxysilane,
• (3-glycidoxypropyl)methyldiethoxysilane,
• 3-glycidoxypropyltrimethoxysilane,
• 3-mercaptopropyltrimethoxysilane,
• 3-mercaptopropyltriethoxysilane,
• 3-methacryloxypropylmethyldiethoxysilane,
• 3-methacryloxypropylmethyldimethoxysilane,
• 3-methacryloxypropyltrimethoxysilane,
• n-phenylaminopropyltrimethoxysilane,
• vinylmethyldiethoxysilane,
• vinyltriethoxysilane, and
• vinyltrimethoxysilane;
• and with
• (c) an effective amount of a hydrolysis rate stabilizer for the (R--O).sub.4 --Zr the deionized water being a carrier.