Aqueous coating composition

• US 4,518,724 A
• Filed: 10/03/1983
• Issued: 05/21/1985
• Est. Priority Date: 10/04/1982
• Status: Expired due to Term

• Current Assignee: Nippon Paint Company Limited (Rainbow Light Limited)
• Original Assignee: Nippon Paint Company Limited (Rainbow Light Limited)
• Inventors: Kuwajima, Teruaki, Ishikura, Shinichi, Kida, Katsuaki
• Primary Examiner(s): GRIFFIN, RONALD
• Application Number:
  US06/538,651
• Time in Patent Office: 596 Days
• Field of Search: 523/501, 524/457, 524/458, 524/460, 524/501, 524/502, 524/515
• US Class Current: 523/501
• CPC Class Codes: C08L 101/00 Compositions of unspecified macromolecular compounds
• CPC Class Codes: C08L 2205/18 Spheres
• 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 57/00 Compositions of unspecified polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C09D 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09D 167/00 Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain based on polyester-amides C09D177/12; based on polyester-imides C09D179/08; Coating compositions based on derivatives of such polymers

Abstract

An aqueous coating composition which comprises (A) at least one aqueous resin selected from acryl, alkyd, polyester, acryl-modified alkyd and acryl-modified polyester resins, (B) at least one component selected from water-insoluble resinous particles having an average grain diameter of 0.3 to 6μ, obtained by a polymerization of ethylenically unsaturated compound(s), and (C) optional additives, the weight ratio of said (A) to (B) (in solid) being 99:1˜15:85. This aqueous paint is especially useful as a top-coat.

Claims

1. An aqueous coating composition comprising:

(A) at least one aqueous resin selected from the group consisting of alkyd resin, polyester resin, acryl resin, acryl-modified alkyl resin and acryl-modified polyester resin and

(B) at least one component selected from water-insoluble resinous particles obtained by the polymerization of at least one ethylenically unsaturated compound, the average grain diameter of said particles being 0.3 to 6μ

, the solid weight ratio of said (A) to (B) being 99;

1 to 15;

85.

2. A composition according to claim 1 wherein the average grain diameter of the water-insoluble resinous particles is 0.4 to 5μ

.

3. A composition according to claim 1 wherein the polymerization of the ethylenically unsaturated compound is effected by emulsion polymerization.

4. A composition according to claim 1 wherein the solid weight ratio of aqueous resin to water-insoluble resinous particles is 99:

1 to 40;

60.

5. A composition according to claim 1, further comprising, a surface regulator having a melting point of 80°

˜

180°

C.

6. A composition according to claim 1 wherein the number average molecular weight of said water-insoluble resinous particles is within a range of 2,500˜

50,000.

7. A composition according to claim 1 wherein the solubility parameter of said water-insoluble resinous particles is less than 10.8.

8. A composition according to claim 1 wherein the water-insoluble resinous particles are composed of inner and outer portions of polymers each having different properties.

9. A composition according to claim 8 wherein the resinous particles are composed of an inner portion of polymer with relatively low hydrophilic property and an outer portion of polymer with relatively high hydrophilic property.

10. A composition according to claim 9 wherein the outer portion of polymer is formed by the polymerization of monomers, 0.5 to 100% by weight of said monomers being hydrophilic group bearing monomers.

11. A composition according to claim 9 wherein the inner portion of polymer is formed by the polymerization of monomers, 0 to 50% by weight of said monomers being hydrophilic group bearing monomers.

12. A composition according to claim 11 wherein the hydrophilic group bearing monomer is carboxyl, hydroxyl and/or amide bonding bearing, ethylenically unsaturated compound.

13. A composition according to claim 10 wherein the hydrophilic group bearing monomer is carboxyl, hydroxyl and/or amide bearing, ethylenically unsaturated compound.

14. A composition according to claim 9 wherein the weight ratio of polymers constituting the inner and the outer portions of water-insoluble resinous particles is 7:

3˜

40;

60.

15. A composition according to claim 9 wherein the outer portion polymer is crosslinked.

16. A composition according to claim 8 wherein the water-insoluble resinous particles are obtained by two stage emulsion polymerization from α

,β

-ethylenically unsaturated monomers using a chain transfer agent in an amount corresponding to 0.3 to 7% by weight, expressed in terms of dodecyl mercaptan, of the total monomers in the first stage polymerization and 0 or less than 0.3 to 7% by weight in the second stage polymerization.

17. A composition according to claim 16 wherein the α

,β

-ethylenically unsaturated monomers in the second stage polymerization include a croslinking monomer with bi- or more functionality.

18. A composition according to claim 16 wherein the chain transfer agent is alkyl mercaptan or carbon halide.

19. A composition according to claim 16 wherein the chain transfer agent is used in the second stage polymerization in an amount corresponding to 0.3 to 5% by weight, expressed in terms of dodecylmercaptan, of the total monomers.

20. A composition according to claim 8 wherein the water-insoluble resinous particles are obtained by two stage emulsion polymerization from α

,β

-ethylenically unsaturated monomers using a chain transfer agent in an amount corresponding to 0.3 to 7% by weight, expressed in terms of dodecylmercaptan, of the total monomer in the second stage polymerization and 0 or less than 0.3 to 7% by weight in the first stage polymerization.

21. A composition according to claim 20 wherein the α

,β

-ethylenically unsaturated monomers used in the first stage emulsion polymerization include a crosslinking monomer with bi- or more functionality.

22. A composition according to claim 20 wherein the chain transfer agent is alkyl mercaptan or carbon halide.

23. A composition according to claim 20 wherein the chain transfer agent in the first stage polymerization is used in an amount corresponding to 0.3 to 5% by weight, expressed in terms of dodecyl mercaptan, of the total monomers.

24. A composition according to claim 8 wherein the water-insoluble resinous particles are composed of hard outer portion polymer of α

,β

-ethylenically unsaturated compounds having relatively high glass transition temperature and soft inner portion polymer having relatively low glass transition temperature.

25. A composition according to claim 24 wherein the weight ratio of polymers constituting the inner and the outer portions is 7:

3˜

40;

60.

26. A composition according to claim 24 wherein the number average molecular weight of the inner portion polymer is 2,500 to 50,000.

27. A composition according to claim 8 wherein the water-insoluble resinous particles are composed of hard inner portion polymer of α

,β

-ethylenically unsaturated compounds having relatively high glass transition temperature and soft outer portion polymer having relatively low glass transition temperature.

28. A composition according to claim 27 wherein the weight ratio of polymers constituting the inner and the outer portions is 97:

3˜

40;

60.

29. A composition according to claim 27 wherein the number average molecular weight of the polymer constituting the outer portion is 2,500 to 50,000.

30. A composition according to claim 1 wherein the solubility parameter of said water-insoluble resinous particles is less than 10.4.