Multi-layer coating composition incorporating migratory catalyst

• US 5,578,346 A
• Filed: 06/07/1995
• Issued: 11/26/1996
• Est. Priority Date: 11/24/1993
• Status: Expired due to Term

• Current Assignee: Sherwin-Williams Company
• Original Assignee: Sherwin-Williams Company
• Inventors: Moy, Wynn
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): CAMERON, ERMA C
• Application Number:
  US08/481,553
• Time in Patent Office: 538 Days
• Field of Search: 427/409, 427/333
• US Class Current: 427/333
• CPC Class Codes: B05D 1/36 Successively applying liquids or other fluent materials, e.g. without intermediate treatment
• CPC Class Codes: B05D 7/53 Base coat plus clear coat type
• CPC Class Codes: C08G 18/16 Catalysts catalysts in general B01J

Abstract

A multi-layer composite coating composition which comprises:

(a) a first coat which is substantially free of isocyanate functionality and which comprises:

(i) a film-forming composition capable of curing or drying;

(ii) a catalyst for the reaction of isocyanate groups and active hydrogen groups; and

(iii) optionally, a pigment;

(b) a second coat which is preferably substantially free of any catalyst for the reaction of isocyanate groups and active hydrogen groups, and which is applied to the surface of the first coat prior to the complete curing of said first coat, wherein the second coat comprises:

(i) an active hydrogen functional compound; and

(ii) a polyisocyanate;

whereby upon the application of said second coat onto the catalyst containing first coat, the reaction between the polyisocyanate and the active hydrogen functional compound of the second coat is catalyzed.

Claims

1. A process for coating a substrate with a multi-layer decorative and/or protective coating which process comprises:

(a) applying to the substrate at least one first coat which is substantially free of isocyanate functionality and which comprises;

(i) a film-forming composition capable of curing or drying; and

(ii) a catalyst for the reaction of isocyanate groups and active hydrogen groups; and

(b) applying to the first coat, prior to the complete cure of said first coat a second coat which is substantially free of any catalyst for the reaction of isocyanate groups and active hydrogen groups, and which second coat comprises;

(i) an active hydrogen functional compound; and

(ii) a polyisocyanate;

whereby upon application of said second coat onto the catalyst containing first coat, a reaction between the polyisocyanate and the active hydrogen functional compound of the second coat is catalyzed.

2. The process of claim 1 wherein the catalyst for the reaction of isocyanate groups and active hydrogen groups is a metal compound.

3. The process of claim 2 wherein the metal is selected from the group consisting of tin, zinc, bismuth, manganese, and copper.

4. The process of claim 1 wherein the active hydrogen functional compound of the second coat is a hydroxy functional compound.

5. The process of claim 4 wherein the hydroxy functional compound is a hydroxy functional polymer.

6. The process of claim 5 wherein the hydroxy functional polymer is a hydroxy functional acrylic polymer.

7. The process of claim 5 wherein the hydroxy functional polymer is a hydroxy functional polyester.