Modified latex polymer composition

• US 4,814,373 A
• Filed: 09/03/1987
• Issued: 03/21/1989
• Est. Priority Date: 12/20/1984
• Status: Expired due to Term

• Current Assignee: Rohm and Haas Company (Dow, Inc.)
• Original Assignee: Rohm and Haas Company (Dow, Inc.)
• Inventors: Frankel, Lawrence S., Winey, Donald A., Jones, Gerald L.
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): Reddick, J. M.
• Application Number:
  US07/092,816
• Time in Patent Office: 565 Days
• Field of Search: 524/460, 524/457, 524/458
• US Class Current: 524/460
• CPC Class Codes: C08F 2/16 Aqueous medium
• CPC Class Codes: C08F 291/00 Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
• CPC Class Codes: C09D 151/00 Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds based on ABS polymers C09D155/02; Coating compositions based on derivatives of such polymers

Abstract

This invention relates to modified aqueous dispersions of water-insoluble latex polymer prepared by swelling an initial water-insoluble latex polymer, prepared by emulsion polymerization, with additional ethylenically unsaturated monomer, including at least one monomer with two or more sites of ethylenic unsaturation, and subsequently polymerizing the additional monomer within the swollen latex particles.

Claims

1. An aqueous polymeric dispersion prepared by the process comprising

(a) emulsion polymerizing at least one mono-ethylenically unsaturated monomer to form an initial dispersion of initial water insoluble latex polymer containing essentially no sites of ethylenic unsaturation,

(b) dispersing ethylenically unsaturated monomer including monomer having at least two sites of ethylenic unsaturation into said initial dispersion whereby said dispersed monomers swells said dispersed said initial latex polymer,

(c) polymerizing said dispersed ethenically unsaturated monomer within said monomer-swollen initial latex polymer;

and

(d) where the final composition of said latex polymer containing said polymerized ethylenically unsaturated monomer dispersed in said initial latex polymer comprises from about 67 to about 99 percent by weight initial latex polymer and from about 33 to about 1 percent by weight polymerized ethylenically unsaturated polymer dispersed therein.

2. An aqueous polymeric dispersion according to claim 1 wherein said mono-ethylenically unsaturated monomer is an α

,β

-ethylenically unssaturated monomer.

3. An aqueous polymeric dispersion according to claim 1 wherein said initial latex polymer is swollen essentially to equilibrium with said dispersed monomer prior to polymerizing said dispersed monomer within said monomer-swollen initial latex polymer.

4. The polymeric dispersion of claim 1 wherein said dispersed monomer comprises at least about 50 percent by weight, based on the dispersed monomer, of monomer which has a solubility in water at 20°

C. of less than about 0.2 g. per 100 g. of water.

5. The polymeric dispersion of claim 4 wherein said dispersed monomer comprises at least about 80 percent by weight, based on the dispersed monomer, of monomer which has a solubility in water at 20°

C. of less than about 0.2 g. per 100 g. of water.

6. The polymeric dispersion of claim 5 wherein the glass transition temperature of the initial latex polymer is less than about 20°

C.

7. The polymeric dispersion of claim 6 wherein the glass transition temperature of said initial latex polymer is less than about -10°

C.

8. The polymeric dispersion of claim 6 wherein said mono-ethylenically unsaturated monomer comprises

(a) from about 30 to 99.5 percent by weight, based on the total weight of solids of said initial latex polymer, of monomer selected from the (C₁ -C₁₂)alkyl esters of acrylic acid, the (C₁ -C₁₂)alkyl esters of methacrylic acids, and mixtures thereof, and

(b) from about 0.5 to 10 percent by weight, based on the total weight of the solids of said initial latex polymer, of carboxylic acid monomer selected from acrylic acid, methacrylic acid, itaconic acid, and beat-acryloxypropionic acid and the higher oligomers of acrylic acid, and mixtures thereof.

9. The polymeric dispersion of claim 8 wherein said mono-ethylenically unsaturated monomer additionally comprises from about 2 to 15 percent by weight, based on the total weight of the solids of said initial latex polymer, of monomer selected from acrylonitrile and methacrylonitrile.

10. The polymeric dispersion of claim 8 wherein said mono-ethylenically unsaturated monomer comprises

(a) from about 50 to 99 percent by weight, based on the total weight of the solids of said initial latex polymer, of monomer selected from the (C₁ -C₁₂)alkyl ester of acrylic acid, the (C₁ -C₁₂)alkyl esters of methacrylic acid, and mixtures thereof, and

(b) from about 1 to 5 percent by weight, based on the total weight of the solids of said initial latex polymer, of monomer selected from acrylic acid, methacrylic acid and mixtures thereof.

11. The polymeric dispersion of claim 8 wherein said initial latex polymer additionally comprises from about 0.005 to 2 percent by weight, based on the total weight of solids of said initial latex polymer, of monomer selected from monomers having at least two sites of ethylenic unsaturation.

12. The polymeric dispersion of claim 11 wherein said initial latex monomer having at least two sites of ethylenic unsaturation includes allyl methacrylate.

13. The polymeric dispersion of claim 1 wherein said dispersion monomer comprises at least about 5 percent by weight, based on the total weight of said dispersed monomer, of monomer having at least two sites of ethylenic unsaturation.

14. The polymeric dispersion of claim 13 wherein said dispersed monomer comprises at least about 50 percent by weight, based on the total weight of said dispersed monomer, of monomer having at least two sites ethylenic unsaturation.

15. The polymeric dispersion of claim 14 wherein said dispersed monomer comprises about 100 percent by weight, based on the total weight of said dispersed monomer, of monomer having at least two sites of ethylenic unsaturation.

16. The polymeric dispersion of claim 13 wherein said dispersed monomer having at least two sites of ethylenic unsaturation is selected from the group consisting of monomers having two sites of alpha, ethylenic unsaturation and monomers having three sites of beta-ethylenic unsaturation.

17. The polymeric dispersion of claim 16 wherein said dispersed monomer having two sites ethylenic unsaturation is selected from the diacrylates and dimethacrylates.

18. The polymeric dispersion of claim 16 wherein said dispersed monomer having three sites ethylenic unsaturation is selected from the triacrylates and trimethacrylates.

19. The polymeric dispersion of claim 16 wherein said dispersed monomer having two sites ethylenic unsaturation is selected from divinyl benzene and the aliphatic conjugated dienes.

20. The polymeric dispersion of claim 17 wherein said dispersed monomer having at least two sites of ethylenic unsaturation is selected from diethyleneglycol dimethacrylate, ethyleneglycol dimethacrylate, 1,6-hexenediol diacrylate, 1,3-butyleneglycol dimethacrylate, and tripropyleneglycol diacrylate.

21. The polymeric dispersion of claim 18 wherein said dispersed monomer having three sites of ethylenic unsaturation is selected from trimethylolpropane triacrylate and trimethylolpropane trimethacrylate.

22. The polymeric dispersion of claim 16 wherein said dispersed monomer having at least two sites of ethylenic unsaturation is selected from the reaction products of at least one compound selected from diisocynates and triisocyanates and at least one compound selected from hydroxy(C₁ -C₆)-alkyl acrylates and the hydroxy(C₁ -C₆)alkyl methacrylates.

23. The polymeric dispersion of claim 16 wherein said dispersed monomer having at least two sites of ethylenic saturation is selected from the reaction products of at least one compound selected from di- and tri-epoxy functional compounds and at least one compound selected from acrylic acid and methacrylic acid.

24. The polymeric dispersion of claim 16 wherein said dispersed monomer having at least two sites of ethylenic unsaturation is selected from the reaction products of at least one compound selected from the di(C₁ -C₄)alkoxylated (C₂ -C₈)alkane diols, tri(C₁ -C₄)-alkoxylated(C₄ -C₁₂)alkane triols, and di(C₁ -C₄)alkoxylated Bisphenol A, and at least one compound selected from acrylic acid and methacrylic acid.

25. The polymeric dispersion of claim 7 wherein the ratio of the weight of solids of said dispersed monomer to the weight of solids of said initial latex polymer is from about 1:

200 to 1;

2.

26. The polymeric dispersion of claim 25 wherein the ratio of the weight of solids of said dispersed monomer to the weight of solids of said initial latex polymer is about 1:

100 to 1;

4.

27. The polymeric dispersion of claim 26 wherein the ratio of the weight of solids of said dispersed monomer to the weight of solids of said initial latex polymer is from about 1:

19 to 1;

9.

28. The polymer dispersion of claim 1 wherein said dispersed monomer comprises no more than about 95 percent by weight, based on total weight of said dispersed monomer of mono-ethylenically unsaturated monomer.

29. The polymeric dispersion of claim 28 wherein said mono-ethylenically unsaturated dispersed monomer is selected from the (C₁ -C₁₂)alkyl esters of acrylic acid, the (C₁ -C₁₂)alkyl esters of methacrylic acid and isobornyl methacrylate.

30. The polymeric dispersion of claim 29 wherein said mono-ethylenically unsaturated dispersed monomer is selected from methyl methacrylate, butyl methacrylate, butyl acrylate and isobornyl methacrylate.

31. The polymeric dispersion of claim 1 wherein the polymerization of said dispersed monomer is initiated by the addition of a free radical generating initiator system to the dispersion of initial latex polymer and dispersed monomer.

32. The polymeric dispersion of claim 31 wherein said initiator system is a redox system selected from t-butyl hydroperoxide/sodium formaldehyde sulfoxylate/Fe(II), t-butyl hydroperoxide/isoascorbic acid, ammonium persulfate/sodium metabisulfite and t-butyl hydroperoxide/vanadyl sulfate.

33. The polymeric dispersion of claim 32 wherein said redox system is t-butyl hydroperoxide/vanadyl sulfate.

34. The polymeric dispersion of claim 31 wherein said initiator system comprises a thermally dissociating initiator species selected from ammonium persulfate, sodium persulfate and t-butyl peroxy pivilate.

35. The polymeric dispersion of claim 34 wherein said thermally dissociating initiator is ammonium peroxide.

36. A toughened polymeric binder for coatings comprising the polymeric dispersion of claim 5.

37. A toughened adhesive comprising the polymeric dispersion of claim 5 wherein the glass transition temperature of the initial latex polymer is at least 5°

C. less than the temperature of application of the adhesive.

38. A toughened roof mastic composition comprising the polymeric dispersion of claim 7.

39. A dirt-pickup resistant roof mastic composition comprising the polymeric dispersion of claim 33.

40. A toughened basecoat composition for leather comprising the polymeric dispersion of claim 5 wherein the glass transition temperature of the initial latex polymer is less than about 70°

C.

41. The toughened basecoat composition for leather of claim 40 wherein the initial latex polymer is polymerized from ethylenically unsaturated monomer comprising from about 30 to 99 percent by weight, based on the weight of solids of said initial latex polymer, of monomer selected from the (C₁ -C₁₂)alkyl acrylates and methacrylates and mixtures thereof.

42. The toughened basecoat composition of claim 41, wherein said ethylenically unsaturated monomer of said initial latex polymer additionally comprises up to about 20 percent by weight, based on the weight of solids of said initial latex polymer, of carboxylic acid monomer selected from acrylic acid, methacrylic acid, itaconic acid, beta-acryloxypropionic acid and the higher oligomers of acrylic acid, and mixtures thereof.

43. The toughened basecoat composition of claim 42, wherein said ethylenically unsaturated monomer of said initial latex polymer additionally comprises up to about 30 percent by weight, based on the weight of solids of said initial latex polymer, of monomer selected from acrylonitrile, methacrylonitrile, and mixtures thereof.

44. The toughened basecoat composition of claim 43, wherein said ethylenically unsaturated monomer of said initial latex polymer additionally comprises up to about 60 percent by weight, based on the weight of solids of said initial latex polymer, of aryl monovinylidene monomer.

45. The toughened basecoat composition of claim 44, wherein said monovinylidene monomer is selected from styrene and alpha-methyl styrene.

46. The toughened basecoat composition of claim 44 wherein the additional monomer comprises up to about 99% by weight, based on the total weight of additional monomer, of mono-ethylenically unsaturated monomer selected from methyl methacrylate, the (C₂ -C₁₂)alkyl acrylates and methacrylates, and mixtures thereof.

47. The toughened basecoat composition of claim 46 wherein said additional monomer additionally comprises up to about 5% by weight, based on the total weight of additional monomer, of carboxylic acid monomer selected from acrylic acid, methacrylic acid, itaconic acid, beta-acryloxypropionic acid and higher oligomers of acrylic acid, and mixtures thereof.

48. The toughened basecoat composition of claim 40 wherein the dispersed monomer comprises ethylenically unsaturated monomer having at least two sites of ethylenic unsaturated selected from 1,3-butyleneglycol dimethacrylate and trimethylol propane triacrylate.

49. A polymeric binder for roof mastic comprising the polymeric dispersion of claim 7.

50. A polymeric binder for leather coatings comprising the polymeric dispersion of claim 5.

55. The polymeric binder of claim 36 including a plasticizer sufficient to reduce the glass transition temperature of the initial latex polymer to at least 5°

C. less than the temperature of application of the coating.

51. An aqueous polymeric dispersion of improved water-insoluble latex polymer yielding films with increased toughness and hardness, comprising an initial latex polymer and a second polymeric phase in the form of a network of domains dispersed within said initial latex polymer, wherein said second phase is polymerized from ethylenically unsaturated monomer comprising at least about 5 percent by weight, based on the total weight of said ethylenically unsaturated monomer, of multifunctional monomer having at least two sites of ethylenic unsaturation, wherein the ratio of the weight of solids of said second polymeric phase to the weight of solids of said initial latex polymer is from about 1:

100 to 1;

4.

52. The aqueous polymeric dispersion of improved water-insoluble latex polymer of claim 51 wherein said second phase is polymerized from ethylenically unsaturated monomer comprising at least about 50 percent by weight, based on the total weight of said ethylenically unsaturated monomer, of multifunctional monomer having at least two sites of ethylenic unsaturation.

53. The aqueous polymeric dispersion of improved water-insoluble latex polymer of claim 52 wherein said network of domains of said second polymeric phase have diameters of from about 2 to 50 nm.

54. The aqueous polymeric dispersion of improved water-insoluble latex polymer of claim 53 wherein said network of domains of said second polymeric phase have diameters of from about 5 to 25 nm.