Water Dispersions Of Non-Uniform Polyurethane Particles

• US 20100048765A1
• Filed: 08/24/2009
• Published: 02/25/2010
• Est. Priority Date: 07/02/2003
• Status: Active Grant

• Current Assignee: Lubrizol Advanced Materials Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: Lubrizol Advanced Materials Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Stanislawczyk, Vic, Malaba, Dennis, Calhoun, Gary D., Lubnin, Alexander V.
• Granted Patent: US 8,242,205 B2
• Time in Patent Office: Days
• US Class Current: 523/201
• CPC Class Codes: C08G 18/0823 containing carboxylate salt groups or groups forming them
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/3231 Hydrazine or derivatives thereof
• CPC Class Codes: C08G 18/4009 Two or more macromolecular compounds not provided for in one single group of groups C08G18/42 - C08G18/64
• CPC Class Codes: C08G 18/4238 derived from dicarboxylic acids and dialcohols
• CPC Class Codes: C08G 18/4825 Polyethers containing two hydroxy groups C08G18/4833 - C08G18/5096 take precedence
• CPC Class Codes: C08G 18/6692 with compounds of group C08G18/34
• CPC Class Codes: C08G 18/755 and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate
• CPC Class Codes: C08G 18/758 containing two or more cycloaliphatic rings
• CPC Class Codes: Y10S 524/908 Composition having specified shape, e.g. rod, stick, or ball, and other than sheet, film, or fiber
• CPC Class Codes: Y10S 525/902 Core-shell
• CPC Class Codes: Y10S 525/903 Interpenetrating network
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]

Abstract

A novel method of preparing an aqueous dispersion of non-uniform polyurethane particles which comprises (a) preparing at least two isocyanate-terminated polyurethane prepolymers having different hydrophilicities; (b) preparing a uniform mixture of said prepolymers, and (c) dispersing the mixed prepolymers in an aqueous medium. The resulting dispersion of the prepolymers may optionally be chain extended. This method enables the preparation of core-shell particles as well as particles of other morphologies, including “raspberry”, interpenetrating network, “salt-and-pepper”, “ice-cream cone” and particles of gradient composition. Similarly, an aqueous dispersion of two different polyurethane polymers may be obtained by first preparing at least two different isocyanate-terminated polyurethane prepolymers, preparing a uniform mixture of such prepolymers and thereafter dispersing the mixture in an aqueous medium.

Claims

1-2. -2. (canceled)

3. A method of preparing an aqueous dispersion of non-uniform polyurethane particles which comprises

(a) preparing at least two isocyanate-terminated polyurethane prepolymers having different hydrophilicities;

(b) mixing said prepolymers to form a mixture; and

(c) dispersing said mixture of prepolymers in an aqueous medium to form non-uniform particles.

4. A method of claim 3 wherein different hydrophilicities are achieved by incorporating different levels of acid, as measured by weight percent, equivalents or acid number, in neutralized or unneutralized form.

7. A method of claim 3 wherein on prepolymer, that is relatively less hydrophilic, has an acid number from 0 to 10, and the other prepolymer, that is relatively more hydrophilic, has an acid number from 20 to 80.

8. A method of claim 7 wherein said less hydrophilic prepolymer has an acid number from 0 to 5 and said relatively more hydrophilic prepolymer has an acid number from 35 to 60.

9. A method of claim 7 wherein said less hydrophilic prepolymer has an acid number below 1 and said relatively more hydrophilic prepolymer has an acid number from 25 to 80.

10. A method of claim 3 wherein said prepolymers have the isocyanate (NCO) to active hydrogen equivalent ratio of about 1.3:

1 to about 2.5;

1.

13. A method of claim 3 wherein said prepolymers are neutralized prior to mixing or after mixing the prepolymers but before forming a water dispersion.

18. A method of claim 3 wherein either prepolymer or both prepolymers containing a water-dispersibility compound that contains both non-ionic and anionic groups.

25. A method of claim 3 wherein at least one reactive diluent is employed.

26. A method of claim 25 wherein the reactive diluent is a polymerizable monomer.

27. A method of claim 3 wherein at least one solvent is employed.

31. A method of claim 3 wherein chain extension is carried out.

32. A method of claim 3 wherein said non-uniform particles have primarily core-shell morphology.

33. A method of claim 3 wherein said non-uniform particles have primarily gradient morphology.

34. A method of claim 3 wherein said non-uniform particles have primarily “

ice-cream cone”

morphology.

35. A method of claim 3 wherein said non-uniform particles have primarily “

raspberry”

morphology.

5-6. -6. (canceled)

11-12. -12. (canceled)

14-17. -17. (canceled)

19-24. -24. (canceled)

28-30. -30. (canceled)

36-37. -37. (canceled)

38. An aqueous dispersion of polyurethane particles having primarily non-uniform morphology.

39. An aqueous dispersion of claim 38 wherein said non-uniform morphology is primarily of gradient core-shell.

40. An aqueous dispersion of claim 38 wherein said non-uniform morphology is primarily of gradient morphology.

41. An aqueous dispersion of claim 38 wherein said non-uniform morphology is primarily of “

raspberry”

morphology.

52. A polyurethane composition in dry form obtained from an aqueous dispersion of claim 38.

53. A polyurethane composition in dry form obtained from an aqueous dispersion of claim 39.

42-44. -44. (canceled)

45. An aqueous dispersion of urethane particles having primarily non-uniform particles prepared by a method which comprises

(a) preparing at least two isocyanate-terminated polyurethane prepolymers having different hydrophilicities;

(b) mixing said prepolymers to form a mixture; and

(c) dispersing said mixture of prepolymers in all aqueous medium.

46-51. -51. (canceled)

54-59. -59. (canceled)