Oligomeric silicon coating compositions, articles coated therewith and method for forming coating composition and coated articles based thereon
First Claim
1. An aqueous coating composition comprising a dispersion of divalent metal cations in lower aliphatic alcohol-water solution of the partial condensate of at least one silanol of the formula RSi(OH)3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, at least about 70 percent by weight of the silanol being CH3 Si(OH)3, acid in amount to provide a pH in the range of from about 2.5 to about 6.2, and said divalent metal cations in an amount of from about 1.2 millimoles to about 2.4 millimoles, per molar equivalent of the partial condensate, calculated as methyl silane sesquioxide.
5 Assignments
0 Petitions
Accused Products
Abstract
Corrosion resistant coatings are provided by aqueous-alcoholic acidic dispersions of the partial condensate of monomethyl silanol (by hydrolysis of monomethyl alkoxysilane) alone or in admixture with minor amounts of other silanol, e.g., gamma-glycidyloxy silanol, phenyl silanol, etc, wherein the dispersions contain divalent metal cations, e.g., Ca+2, in place of all or most of colloidal silica used in prior formulations of this type. The coatings may be applied to boat hulls, including aluminum hulls and are effective in preventing corrosion from salt water for extended periods.
36 Citations
25 Claims
- 1. An aqueous coating composition comprising a dispersion of divalent metal cations in lower aliphatic alcohol-water solution of the partial condensate of at least one silanol of the formula RSi(OH)3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, at least about 70 percent by weight of the silanol being CH3 Si(OH)3, acid in amount to provide a pH in the range of from about 2.5 to about 6.2, and said divalent metal cations in an amount of from about 1.2 millimoles to about 2.4 millimoles, per molar equivalent of the partial condensate, calculated as methyl silane sesquioxide.
-
13. A two part aqueous coating composition comprising, as first part thereof an acidic aqueous dispersion of divalent metal cation selected from the group consisting of Ca+2, Mn+2, Zn+2, and Cu+2, said dispersion containing sufficient acid to provide a pH of from about 2.2 to about 2.8;
- and as second part thereof a non-aqueous composition comprising at least one trialkoxy silane of the formula RSi(OR'"'"')3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, and R'"'"' is a hydrolyzable hydrocarbyl group, at least about 70 percent by weight of the silane being CH3 Si(OCH3)3, at least one of the first and second parts further comprising a volatile organic solvent;
whereby, upon mixing the first and second parts, silane will be hydrolyzed to silanol and the silanol will be partially condensed to siloxanol polymer precursor of silane sesquioxide; and
wherein the amount of divalent metal cation in the first part is from about 1.2 to about 2.4 millimoles, per molar equivalent of the silane sesquioxide, calculated as methyl silane sesquioxide.
- and as second part thereof a non-aqueous composition comprising at least one trialkoxy silane of the formula RSi(OR'"'"')3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, and R'"'"' is a hydrolyzable hydrocarbyl group, at least about 70 percent by weight of the silane being CH3 Si(OCH3)3, at least one of the first and second parts further comprising a volatile organic solvent;
-
14. A method of forming a hard corrosion resistant coating on a substrate, comprising mixing an acidic aqueous dispersion of divalent metal cation selected from the group consisting of Ca+2, Mn+2, Zn+2, and Cu+2, said dispersion containing sufficient acid to provide a pH of from about 2.2 to about 2.8;
- with a non-aqueous composition comprising at least one trialkoxy silane of the formula RSi(OR'"'"')3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, and R'"'"' is a hydrolyzable hydrocarbyl group, at least about 70 percent by weight of the silane being CH3 Si(OCH3)3, allowing the resulting mixture to stand until the pH increases to at least about 2.5, whereby the silane is hydrolyzed to silanol and the silanol is partially condensed to a siloxanol polymer;
wherein the amount of divalent metal cation in the acidic aqueous dispersion is from about 1.2 to about 2.4 millimoles, per molar equivalent of the silane sesquioxide, calculated as methyl silane sesquioxide, and further wherein at least one of the aqueous dispersion and the non-aqueous composition further comprises a volatile organic solvent;
applying the resulting mixture containing the siloxanol polymer to a substrate, and allowing the water and volatile organic solvent to evaporate and the siloxanol polymer to cure to silane sesquioxide. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 25)
- with a non-aqueous composition comprising at least one trialkoxy silane of the formula RSi(OR'"'"')3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, and R'"'"' is a hydrolyzable hydrocarbyl group, at least about 70 percent by weight of the silane being CH3 Si(OCH3)3, allowing the resulting mixture to stand until the pH increases to at least about 2.5, whereby the silane is hydrolyzed to silanol and the silanol is partially condensed to a siloxanol polymer;
- 23. A method of forming a hard corrosion resistant coating on a metal or plastic substrate, comprising applying to the substrate an aqueous coating composition comprising a dispersion of divalent metal cations in lower aliphatic alcohol-water solution of the partial condensate of at least one silanol of the formula RSi(OH)3, wherein R is a radical selected from the group consisting of lower alkyl, vinyl, phenyl, 3,3,3-trifluoropropyl, gamma-glycidyloxypropyl, and gamma-methacryloxypropyl, at least about 70 percent by weight of the silanol being CH3 Si(OH)3, acid in amount to provide a pH in the range of from about 2.5 to about 6.2, and said divalent metal cations in an amount of from about 1.2 millimoles to about 2.4 millimoles, per molar equivalent of the partial condensate, calculated as methyl silane sesquioxide, and allowing the aliphatic alcohol and water of the aqueous coating composition to evaporate and the partial condensate to cure to the corresponding silane sesquioxide, whereby a hard corrosion resistant coating is formed on said substrate.
Specification