Ultraviolet curing of electrocoating compositions

• US 4,105,518 A
• Filed: 04/14/1977
• Issued: 08/08/1978
• Est. Priority Date: 06/19/1974
• Status: Expired due to Term

• Current Assignee: Lilly Industries Limited
• Original Assignee: SCM Corporation (Heidelberg Materials AG)
• Inventors: McGinniss, Vincent D.
• Primary Examiner(s): Turer, Richard B.
• Application Number:
  US05/787,515
• Time in Patent Office: 481 Days
• Field of Search: 204/181 E, 204/181 R, 204/159.23, 204/159.14, 204/159.24, 204/159.15, 204/159.16, 204/159.18, 204/159.19, 260/29.2 N, 260/29.2 EP, 260/29.2 UA, 260/29.6 HN
• US Class Current: 522/35
• CPC Class Codes: C09D 5/4407 with polymers obtained by polymerisation reactions involving only carbon-to-carbon unsaturated bonds
• CPC Class Codes: Y10S 522/904 Monomer or polymer contains initiating group
• CPC Class Codes: Y10S 522/905 Benzophenone group
• CPC Class Codes: Y10S 524/901 Electrodepositable compositions

Abstract

An electrocoating composition useful for electrocoating a paint from an aqueous solution onto a cathode conductive substrate can be cured with ultraviolet energy. The electrocoating composition containing an ultraviolet sensitizer uniformly electrodeposits on the cathode substrate to provide a paint film thereon containing a constant level of ultraviolet sensitizer relative to a reactive ethylenically unsaturated polymer.

Claims

1. An electrocoating composition dispersed within an aqueous electrocoating bath for electrocoating a paint film onto a cathode substrate, the electrocoating composition comprising an ethylenically unsaturated polymer containing ethylenically unsaturated groups selected from acrylyl, acrylamide, and allyl, the improvement comprising:

said polymer containing at least about 2 percent by weight of an ultraviolet sensitizer attached to the polymer structure;

said polymer having pendent acrylyl unsaturation reacted with a secondary amine selected from morpholine, diethanolamine, methylethanol amine, and diallylamine prior to solubilizing and dispersing said polymer in water;

said secondary amine groups being neutralized with a proton donating solubilizing salt or acid for dispersing said polymer within water;

said polymer being electrocoatable onto a cathode substrate and reactive to ultraviolet energy to cross-link the ethylenic unsaturation and provide a cured paint film.

2. The composition in claim 1 wherein said ultraviolet sensitizer is a carboxylated phenyl nuclear ketone, and said sensitizer is contained in the polymer structure and comprises at least about 2% of said polymer on a weight basis.

3. The composition in claim 1 wherein said sensitizer is selected from benzaldehydes, acetophenones, and benzophenones.

4. The composition in claim 1 wherein the sensitizer comprises between about 3 and 20% of the polymer on a weight basis.