Water dispersible silanes as corrosion-protection coatings and paint primers for metal pretreatment

A method of improving paint adhesion to a metal surface comprising the steps of:

• applying to said metal surface a paint primer, and drying the surface for crosslinking, which primer comprises a dispersion in one or more solvents of the reaction product of (1) a compound comprising a polyamine in which a plurality of amine groups are bonded to at least one radical selected from the group consisting of hydrocarbon and hydrocarbon ether groups that separate nitrogen atoms of said amine groups by at least four intermediate atoms in a chain, and (2) a silane which carries a plurality of silicon-bonded hydrolyzable groups and a silicon-bonded organic group that is covalently reactive to and which bonds with said amine group, comprising hydrolyzable silane groups, to provide a reaction product molecule which comprises an average at least 2.5 of said hydrolyzable silane groups per molecule;
• and followed by the step of applying paint to the primed surface.

A method of improving corrosion resistance to a metal surface comprising the steps of:

• reacting (1) an alkylene ether polyamine containing at least a pair of primary amine groups separated from each other by at least four intermediate atoms in a chain, with (2) a silane comprising a silicon atom bonded to a plurality of hydrolyzable groups and to at least one organic epoxy radical, said silane comprising hydrolyzable silane groups, with stoichiometry and reaction conditions where essentially all of the epoxy is reacted with amine groups, to obtain a composition with molecules containing both silicon and amine groups and at least 2.5 of said hydrolyzable silane groups per molecule;
• and thereafter applying a dispersion of said composition in one or more solvents to a metal surface, and drying the composition on said surface for crosslinking.

A method of improving corrosion resistance to a metal surface comprising the steps of:

• applying to a metal surface a composition and drying the surface for crosslinking, which composition comprises a dispersion in one or more solvents of a compound comprising the reaction product of (1) a polyamine in which a plurality of amine groups are bonded to at least one radical selected from the group consisting of alkylene and arylene groups that separate amine nitrogen atoms by at least four intermediate atoms in a chain, and (2) a silane which carries a plurality of silicon-bonded hydrolyzable groups, and a silicon-bonded organic group that is covalently reactive with said amine group, comprising hydrolyzable silane groups, to provide a reaction product molecule which comprises an average of at least about 3 of said hydrolyzable silane groups per molecule.

A composition which comprises the reaction product of (1) an alkylene ether polyamine containing at least a pair of primary amine groups separated from each other by at least four intermediate atoms in a chain with (2) a silane comprising silicon bonded to a plurality of hydrolyzable groups and to at least one organic epoxy radical, said silane comprising hydrolyzable silane groups, said reaction product being substantially free of unreacted epoxy groups and exhibiting at least 2.5 of said hydrolyzable silane groups per molecule.