Method for treating a substrate with a radiation and chemically curable coating composition

• US 4,212,901 A
• Filed: 07/10/1978
• Issued: 07/15/1980
• Est. Priority Date: 07/08/1977
• Status: Expired due to Term

• Current Assignee: AKZO NV (Nouryon BV)
• Original Assignee: AKZO NV (Nouryon BV)
• Inventors: van Neerbos, Abraham, van Oosterhout, Adrianus C. J.
• Primary Examiner(s): Newsome, John H.
• Application Number:
  US05/923,353
• Time in Patent Office: 736 Days
• Field of Search: 427/44, 427/54, 427/372 R, 427/53, 204/159.15, 560/26, 560/158, 260/18 TN, 528/68, 528/73, 96/35.1
• US Class Current: 427/517
• CPC Class Codes: C08F 299/06 from polyurethanes
• CPC Class Codes: C08G 18/672 Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
• CPC Class Codes: C08G 18/68 Unsaturated polyesters
• CPC Class Codes: C08J 2475/00 Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings

Abstract

A method is provided for treating a substrate with a radiation curable coating composition based on a polyester resin esterified with acrylic acid or methacrylic acid and having a hydroxyl number in the range of from 50 to 250 and an ethylenic unsaturation equivalent weight of from 200 to 10,000 grams and on a polyisocyanate that is present in an amount of 0.7 to 1.3 equivalents of isocyanate per equivalent of hydroxyl contained in the composition. The curing of the coating composition is effected in a first stage by subjecting the composition to radiation having a wave length of 200 to 600 nm and in a second stage by reaction between the isocyanate groups of the polyisocyanate and the hydroxyl groups of the polyester resin.

Claims

1. A method for treating a substrate with a radiation curable coating composition based on a polyester resin esterified with acrylic acid and/or methacrylic acid, a vinyl compound and a photoinitiator, the coating composition being dried under the influence of light having a wave length of 200 to 600 nm, characterized in that the polyester resin esterified with meth(acrylic) acid has a hydroxyl number in the range of 50 to 250 and an ethylenic unsaturation equivalent weight in the range of 200 to 10,000 grams, and in that the coating composition also contains a polyisocyanate in an amount of 0.7 to 1.3 equivalents of isocyanate per equivalent of hydroxyl contained in the composition.

2. The method of claim 1, characterized in that the polyester resin has an ethylenic unsaturation equivalent weight of 250 to 3500 grams.

3. The method of claim 1, characterized in that the unsaturation of the polyester resin is for 35 to 100% caused by the presence of acrylic acid and/or methacrylic acid groups.

4. The method of claim 1, characterized in that the polyisocyanate is present in an amount of 0.9 to 1.1 equivalents per equivalent of hydroxyl.

5. The method of claim 1, characterized in that the polyisocyanate has 2 or 3 isocyanate groups per molecule.

6. The method of claim 1, characterized in that the polyisocyanate used is an adduct based on hexamethylene diisocyanate, toluene diisocyanate or isophoron diisocyanate.

7. A method for treating a substrate with a radiation-curable coating composition comprising

applying to said substrate a coating composition comprising (1) a polyester resin esterified with acrylic acid and/or methacrylic acid and having an hydroxyl number in the range of 50 to 250 and an ethylenic unsaturation equivalent weight in the range of 200 to 10,000 grams, (2) a polyisocyanate present in an amount of about 0.7 to about 1.3 equivalents of isocyanate per equivalent of hydroxyl contained in said composition, (3) a vinyl compound, and (4) a photoinitiator,

initially curing the applied coating composition under the influence of light having a wave length of 200 to 600 nm, and

completing the curing by reacting the isocyanate groups of said polyisocyanate with the hydroxyl groups of said polyester resin.