Cationic electrodepositable compositions through the use of sulfamic acid and derivatives thereof
AssigneePPG Industries, Inc.
InventorsVictor G. Corrigan, Steven R. Zawacky
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Abstract
A cationic electrodepositable composition containing a resinous phase dispersed in an aqueous medium is disclosed. The resinous phase has basic nitrogen groups which are at least partially neutralized with sulfamic acid or a derivative thereof, that is, an acid of the formula: ##STR1## where R is H or C.sub.1 to C.sub.4 alkyl. The compositions are in the form of relatively small particle size aqueous dispersions, and when used in the process of cationic electrodeposition, enable the formation of thick films with high throwpower. Also, the use of sulfamic acid passivates the anode.
Claims10
A cationic electrodepositable composition comprising a resinous phase dispersed in an aqueous medium, said composition having a pH of at least 5 and containing less than 2,000 ppm lead, said resinous phase having basic nitrogen groups which are at least partially neutralized at a temperature of from about 20.degree. C., to about 100.degree. C. with an acid of the formula:
- ##STR6## where R is H or C.sub.1 to C.sub.4 alkyl.
A method for coating a conductive substrate serving as a cathode in an electrical circuit comprising said cathode and an anode immersed in an aqueous cationic electrocoating composition comprising passing electric current between said anode and said cathode so as to cause the electrocoating composition to deposit as a coating on the cathode, characterized in that the electrocoating composition comprises a resinous phase dispersed in an aqueous medium, said composition having a pH of at least 5 and containing less than 2,000 ppm lead, said resinous phase having basic nitrogen groups which are at least partially neutralized at a temperature of from about 20.degree. C. to about 100.degree. C. with an acid of the formula:
- ##STR7## where R is H or C.sub.1 to C.sub.4 alkyl.
Dependencies are inferred from the claim text.