Latex binder for coating composition

• US 6,465,562 B1
• Filed: 06/21/2000
• Issued: 10/15/2002
• Est. Priority Date: 10/06/1997
• Status: Expired due to Fees

• Current Assignee: Rhodia Chimie (Solvac SA)
• Original Assignee: Rhodia Chimie (Solvac SA)
• Inventors: Granier, Vincent, Charmot, Dominique, Bett, William
• Primary Examiner(s): REDDICK, MARIE L
• Application Number:
  US09/509,976
• Time in Patent Office: 846 Days
• Field of Search: 523/408, 523/402, 523/406, 523/409, 523/410, 523/412, 524/501, 524/517
• US Class Current: 524/501
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 33/064 containing anhydride, COOH or COOM groups, with M being metal or onium-cation
• CPC Class Codes: C08L 33/068 containing glycidyl groups
• CPC Class Codes: C09D 125/14 with unsaturated esters
• CPC Class Codes: C09D 133/064 containing anhydride, COOH or COOM groups, with M being metal or onium-cation

Abstract

The invention concerns a novel binder for aqueous coating composition, comprising: at least a latex (A) prepared from ethylenically unsaturated monomers and having a carboxylic acid function, and at least a latex (B) prepared from ethylenically unsaturated monomers and havinging an epoxide function, and for which said latex particle size is not more than 50 nm.

Claims

1. A binder for a coating composition, comprising:

at least one latex (A) comprising a polymer prepared from ethylenically unsaturated monomers and containing a carboxylic acid function, and

at least one latex (B) comprising a polymer prepared from ethylenically unsaturated monomers and containing an epoxide function, and wherein the particle size of said latices is not more than 50 nm.

2. A binder according to claim 1, wherein the polymer of the latex (A) containing a carboxylic acid function has a molecular mass {overscore (M)}_n between 40,000 and 500,000 g/mol.

3. A binder according to claim 1, wherein the polymer of the latex (B) containing an epoxide function has a molecular mass {overscore (M)}_n between 4000 and 50,000 g/mol.

4. A binder according to claim 1, wherein the Minimum Film Forming Temperature (MFFT) of the polymer in the latex (A) containing a carboxylic acid function is between 0 and 15°

C.

5. A binder according to claim 1, wherein the minimum film forming temperature of the polymer in the latex (B) containing an epoxide function is between 30 and 50°

C.

6. A binder according to claim 1, wherein the latex (A) containing a carboxylic acid function and the latex (B) containing an epoxide function are present in an equimolar ratio.

7. A binder according to claim 1, wherein, for the latex (B) containing an epoxide function, the epoxide groups are at the surface of the particles in said latex.

8. A binder according to claim 1, wherein the latex (B) containing an epoxide function is prepared by polymerization of monomers containing ethylenic unsaturation and of glycidyl (meth)acrylate.

9. A coating composition comprising a binder as defined in claim 1, said coating having only one glass transition temperature (Tg).

10. Coating composition containing common adjuvants and a binder as defined in claim 1.