Process for preparing aqueous coatings comprising dispersible epoxy resin-acid polymer ester

• US 4,444,923 A
• Filed: 12/30/1982
• Issued: 04/24/1984
• Est. Priority Date: 12/30/1982
• Status: Expired due to Term

• Current Assignee: Valspar Corporation (Sherwin-Williams Company)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: McCarty, William H.
• Primary Examiner(s): GRIFFIN, RONALD
• Application Number:
  US06/454,817
• Time in Patent Office: 481 Days
• Field of Search: 523/100, 523/406, 523/407, 523/408, 523/409, 523/412, 523/423, 525/63, 525/65, 525/107, 525/108, 525/112
• US Class Current: 523/406
• CPC Class Codes: C08F 283/10 on to polymers containing more than one epoxy radical per molecule C08F283/004 takes precedence
• 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: C09D 163/00 Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins

Abstract

An improved process for preparing epoxy acrylate dispersions from the reaction product of an epoxy resin and carboxyl containing polymer in the presence of tertiary amine in which the carboxyl containing polymer is formed, in situ, in the presence of a solvent solution of the epoxy resin and then subjected to the esterification reaction which can be conducted in a single pot.

Claims

1. A process for preparing an aqueous dispersion composition comprising:

A. copolymerizing a monomer mixture which includes at least 30 percent by weight of carboxyl-containing monomer to form a carboxyl containing copolymer in the presence of an epoxy resin containing aliphatic carbon atoms and 1,2-epoxy groups in which said epoxy resin constitutes at least 40 weight percent of the solids in the resulting composition;

B. reacting the composition obtained in A under esterification conditions in the presence of a tertiary amine esterification catalyst wherein the equivalents of 1,2-epoxy groups in said epoxy resin are in excess of the equivalents of tertiary amine, to obtain a product substantially free of epoxy groups and containing hydroxy ester groups from the reaction between said carboxyl group and at least 5 percent of said 1,2-epoxy groups; and

C. dispersing said composition in water with the addition of ammonia or amine neutralizing agent;

in which a polymer different from said carboxyl containing copolymer of step A is prepared in situ prior to dispersing the mixture in water in step C.

2. The process of claim 1 in which said different polymer is substantially free of carboxylic acid groups.

3. The process of claim 1 in which said different polymer is a copolymer of styrene and butyl acrylate.

4. The process of claim 1 in which said carboxyl containing monomer is methacrylic acid.

5. The process of claim 1 in which said carboxyl containing copolymer is a copolymer of ethyl acrylate, styrene and methacrylate acid.

6. The process of claim 1 in which said epoxy resin is an epichlorohyrin-bisphenol A epoxy resin.

7. The process of claim 1 in which said tertiary amine and said neutralizing agent are dimethylaminoethanol.

8. The process of claim 1 in which said copolymerization in step A is conducted under conditions which result in grafting of said carboxyl containing copolymer to aliphatic carbon atoms on said epoxy resin.

9. The process of claim 1 in which copolymerization in step A is conducted under conditions which result in substantially no grafting of said carboxyl containing polymer to aliphatic carbon atoms on said epoxy resin.

10. The process of claim 1 in which said epoxy resin is an epichlorohydrin-bisphenol A epoxy resin;

said carboxyl containing copolymer is a copolymer of ethyl acrylate, styrene and methacrylate acid;

said tertiary amine and said neutralizing agent are dimethylaminoethanol.

11. The process of claim 10 in which the weight ratio of said epoxy resin to said carboxyl polymer is at least 1:

1.

12. The process of claim 10 in which the weight ratio of said epoxy resin to said carboxyl polymer is at least 2:

1.

13. The process of claim 10 in which the weight ratio of said epoxy resin to said carboxyl polymer is at least 3:

1.

14. The process of claim 10 in which said copolymerization in step A is conducted under conditions which result in grafting of said carboxyl containing copolymer to aliphatic carbon atoms on said epoxy resin.

15. The process of claim 10 in which copolymerization in step A is conducted under conditions which result in substantially no grafting of said carboxyl containing polymer to aliphatic carbon atoms on said epoxy resin.