Polymer encapsulation of high aspect ratio materials and methods of making same

• US 20040146641A1
• Filed: 01/23/2003
• Published: 07/29/2004
• Est. Priority Date: 01/23/2003
• Status: Active Grant

• Current Assignee: SHPP Global Technologies BV
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: Sebastiaan van Hamersveld, Eelco Michiel, Hartshorn, Christopher Mark, Colborn, Robert Edgar, Steiger, Daniel, Seker, Fazila, Acar, Ali Ersin, Hobbs, Stanley Young
• Granted Patent: US 7,312,257 B2
• Time in Patent Office: Days
• US Class Current: 427/212
• CPC Class Codes: B01J 13/14 Polymerisation; cross-linking
• CPC Class Codes: C01P 2002/88 by thermal analysis data, e.g. TGA, DTA, DSC
• CPC Class Codes: C01P 2004/02 obtained by optical microscopy
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2004/54 Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C08K 9/10 Encapsulated ingredients
• CPC Class Codes: C09B 67/0097 Dye preparations of special physical nature; Tablets, films, extrusion, microcapsules, sheets, pads, bags with dyes
• CPC Class Codes: C09C 1/00 Treatment of specific inorganic materials other than fibrous fillers tenebrescent materials C09K9/00; luminescent materials C09K11/00; Preparation of carbon black
• CPC Class Codes: C09C 1/0015 Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings
• CPC Class Codes: C09C 1/0018 uncoated and unlayered plate-like particles
• CPC Class Codes: C09C 1/0021 comprising a core coated with only one layer having a high or low refractive index
• CPC Class Codes: C09C 1/28 Compounds of silicon C09C1/0009, C09C1/0015, C09C1/0078 take precedence
• CPC Class Codes: C09C 1/3063 Treatment with low-molecular organic compounds
• CPC Class Codes: C09C 1/62 Metallic pigments or fillers C09C1/0015 takes precedence
• CPC Class Codes: C09C 1/627 Copper
• CPC Class Codes: C09C 1/64 Aluminium
• CPC Class Codes: C09C 1/644 treated with organic compounds, e.g. polymers
• CPC Class Codes: C09C 2200/1004 the core comprising at least one inorganic oxide, e.g. Al2O3, TiO2 or SiO2
• CPC Class Codes: C09C 2200/102 the core consisting of glass or silicate material like mica or clays, e.g. kaolin
• CPC Class Codes: C09C 2200/1025 : comprising at least one metal layer adjacent to core material, e.g. core-M or M-core-M
• CPC Class Codes: C09C 2200/403 : Low molecular weight materials, e.g. fatty acids
• CPC Class Codes: C09C 2200/405 : High molecular weight materials, e.g. polymers
• CPC Class Codes: C09C 3/08 : Treatment with low-molecular-weight non-polymer organic compounds C09C3/006, C09C3/048 take precedence
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]

Abstract

Embodiments of this invention comprise a pigment comprising one or more substantially spherical-shaped beads, wherein each substantially spherical-shaped bead comprises one or more high aspect ratio particles encapsulated within an encapsulating material. Embodiments also comprise a resinous composition comprising said pigment. Yet further embodiments comprise a method of preparing said pigment via suspension polymerization. The substantially spherical-shaped beads of this invention may be used to produce resinous compositions having a flowline-free colored, sparkling and/or metallescent appearance.

Claims

16. A pigment comprising one or more substantially spherical-shaped beads, wherein each substantially spherical-shaped bead comprises one or more high aspect ratio aluminum flakes encapsulated within an encapsulating material comprising a polymer with structural units derived from at least one monomer which is styrene, wherein the flakes have an average aspect ratio of about 1.5:

1 to about 40;

1 and comprise about 0.1 to about 25 weight percent of the pigment bead.

17. A resinous composition comprising a plastic matrix material and a pigment, the pigment comprising one or more substantially spherical-shaped beads, wherein each substantially spherical-shaped bead comprises one or more high aspect ratio particles encapsulated within an encapsulating material.

18. The resinous composition of claim 17, wherein the plastic matrix material comprises at least one member selected from the group consisting of thermoplastics, polyesters, polyolefins, polyethylene, polypropylene, polybutylene, polymethylpentene;

resins comprising structural units derived from styrene monomer, polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-styrene-butadiene, acrylonitrile-styrene-acrylate;

polyamide;

polycarbonate;

bisphenol A polycarbonate;

polyphenylene ether;

polyimide;

polyamide imide;

polyetherimide;

polysulfone;

polyether sulfone;

polyketone;

polyether ketone;

polyether ether ketone;

polyarylate;

phenoxy resins;

fluorocarbon resins;

thermoplastic elastomers;

thermoplastic elastomers derived from polystyrene, from polyolefin, from polyurethane, from polyester, from polyamide, from polybutadiene, from polyisoprene, from fluorine-containing monomer;

a natural rubber, a synthetic rubber, copolymers or modifications of any of the these substances, and combinations of two or more of these substances.

19. The resinous composition of claim 17, wherein the high aspect ratio particles comprise at least one of:

aluminum, gold, silver, copper, nickel, titanium, stainless steel, nickel sulfide, cobalt sulfide, manganese sulfide, metal oxides, white mica, black mica, synthetic mica, mica coated with titanium dioxide, metal-coated glass flakes, or colorants.

20. The resinous composition of claim 17, wherein the encapsulating material comprises a polymer with structural units derived from at least one monomer selected from the group consisting of styrene, alpha-methyl styrene, para-methyl styrene, acrylonitrile, alkyl acrylate, alkyl methacrylate, methyl methacrylate, divinyl benzene, and mixtures thereof.

21. The resinous composition of claim 17, wherein the encapsulating material comprises at least one of:

polystyrene, polymethyl methacrylate, styrene acrylonitrile copolymer, methyl methacrylate styrene acrylonitrile copolymer, or an acrylonitrile-styrene-acrylate resin.

22. The resinous composition of claim 17, wherein the pigment further comprises at least one additive.

23. The resinous composition of claim 22, wherein the at least one additive comprises at least one of:

a colorant, a thermal stabilizer, an oxidation inhibitor, butylated hydroxytoluene, a radical scavenger, a vinyl-based monomer, a filler, an impact modifier, a UV absorber, or a fire retardant.

24. The resinous composition of claim 23, wherein the colorant comprises at least one of:

Solvent Blue 35, Solvent Blue 36, Disperse Violet 26, Solvent Green 3, Anaplast Orange LFP, Morplas Red 36, or Perylene Red.

25. The resinous composition of claim 17, wherein the encapsulating material is transparent.

26. The resinous composition of claim 17, wherein the encapsulating material is translucent.

27. The resinous composition of claim 17, wherein the refractive index difference between the plastic matrix and the encapsulating material of the pigment is less than about 0.01.

28. The resinous composition of claim 17, wherein the refractive index difference between the plastic matrix and the encapsulating material of the pigment is in the range of between about 0.01 and about 0.05.

29. The resinous composition of claim 17, wherein the substantially spherical-shaped beads have an average aspect ratio of about 1:

1 to about 2;

1.

30. The resinous composition of claim 17, wherein the high aspect ratio particles have an average aspect ratio of greater than about 1.5:

1

31. The resinous composition of claim 17, wherein the high aspect ratio particles have an average aspect ratio of about 1.5:

1 to about 40;

1.

32. The resinous composition of claim 17, wherein the substantially spherical-shaped beads have an average diameter of about 10 μ

m to about 300 μ

m.

33. The resinous composition of claim 17, wherein an average weight percent of high aspect ratio particles encapsulated within an encapsulating material comprises about 0.1 to about 25 weight percent, based on the weight of the pigment bead

34. The resinous composition of claim 17, wherein the high aspect ratio particles comprise about 2 to about 100 facets.

35. The resinous composition of claim 17, wherein unencapsulated high aspect ratio particles comprise no more than 1 weight percent of the composition.

36. The resinous composition of claim 17, wherein the pigment comprises colored, substantially spherical-shaped beads.

37. The resinous composition of claim 17, formed by a process which comprises at least one extrusion compounding step.

38. The resinous composition of claim 37, wherein at least a portion of pigment is fed to the extruder at a down-stream feed inlet.

39. A molded article made from the composition of claim 17.

40. The molded article of claim 39 which is substantially free of visible flowlines.

41. The molded article of claim 39 formed by a process which comprises compounding the composition during molding.

42. A resinous composition comprising an acrylonitrile-styrene-butadiene matrix material and a pigment comprising one or more substantially spherical-shaped beads, wherein each substantially spherical-shaped bead comprises one or more high aspect ratio aluminum flakes encapsulated within an encapsulating material comprising a polymer with structural units derived from styrene, optionally with at least one other monomer, wherein the flakes have an average aspect ratio of about 1.5:

1 to about 40;

1 and comprise about 0.1 to about 25 weight percent of the pigment bead.

43. The resinous composition of claim 42, wherein the matrix material further comprises at least one polycarbonate.

44. A molded article made from the composition of claim 42.

45. A molded article made from the composition of claim 43.

46. A method of preparing pigment via suspension polymerization, the pigment comprising one or more substantially spherical-shaped beads, wherein the substantially spherical-shaped beads comprise one or more high aspect ratio particles encapsulated within an encapsulating material, the method comprising the steps of:

dispersing high aspect ratio particles in at least one of a monomer or a polymer to form a suspension mixture;

adding the suspension mixture to an aqueous mixture comprising a suspension agent;

heating and mixing the aqueous reaction mixture to encourage the formation of substantially spherical-shaped beads, wherein most of the substantially spherical-shaped beads encapsulate one or more high aspect ratio particles to an extent that the high aspect ratio particles will not become delaminated during processing;

quenching the aqueous reaction mixture after the substantially spherical-shaped beads are formed; and

collecting the substantially spherical-shaped beads.

1. A pigment comprising one or more substantially spherical-shaped beads, wherein each substantially spherical-shaped bead comprises one or more high aspect ratio particles encapsulated within an encapsulating material.

2. The pigment of claim 1, wherein the high aspect ratio particles comprise at least one of:

aluminum, gold, silver, copper, nickel, titanium, stainless steel, nickel sulfide, cobalt sulfide, manganese sulfide, metal oxides, white mica, black mica, synthetic mica, mica coated with titanium dioxide, metal-coated glass flakes, or colorants.

3. The pigment of claim 1, wherein the encapsulating material comprises a polymer with structural units derived from at least one monomer selected from the group consisting of styrene, alpha-methyl styrene, para-methyl styrene, acrylonitrile, alkyl acrylate, alkyl methacrylate, methyl methacrylate, divinyl benzene, and mixtures thereof.

4. The pigment of claim 1, wherein the encapsulating material comprises at least one of:

polystyrene, polymethyl methacrylate, styrene acrylonitrile copolymer, methyl methacrylate styrene acrylonitrile copolymer, or an acrylonitrile-styrene-acrylate resin.

5. The pigment of claim 1, wherein the pigment further comprises at least one additive.

6. The pigment of claim 5, wherein the at least one additive comprises at least one of:

a colorant, a thermal stabilizer, an oxidation inhibitor, butylated hydroxytoluene, a radical scavenger, a vinyl-based monomer, a filler, an impact modifier, a UV absorber, or a fire retardant.

7. The pigment of claim 6, wherein the colorant comprises at least one of:

Solvent Blue 35, Solvent Blue 36, Disperse Violet 26, Solvent Green 3, Anaplast Orange LFP, Morplas Red 36, or Perylene Red.

8. The pigment of claim 1, wherein the encapsulating material is transparent.

9. The pigment of claim 1, wherein the encapsulating material is translucent.

10. The pigment of claim 1, wherein the substantially spherical-shaped beads have an average aspect ratio of about 1:

1 to about 2;

1.

11. The pigment of claim 1, wherein the high aspect ratio particles have an average aspect ratio of greater than about 1.5:

1

12. The pigment of claim 1, wherein the high aspect ratio particles have an average aspect ratio of about 1.5:

1 to about 40;

1.

13. The pigment of claim 1, wherein the substantially spherical-shaped beads have an average diameter of about 10 μ

m to about 300 μ

m.

14. The pigment of claim 1, wherein an average weight percent of high aspect ratio particles encapsulated within an encapsulating material comprises about 0.1 to about 25 weight percent, based on the weight of the pigment bead

15. The pigment of claim 1, wherein the high aspect ratio particles comprise about 2 to about 100 facets.

47. The method of claim 46, further comprising:

suspending the one or more high aspect ratio particles in the suspension mixture by sonicating the suspension mixture prior to adding the suspension mixture to the aqueous reaction mixture.

48. The method of claim 46, the method further comprising utilizing at least one of gravity sedimentation and centrifugation to separate the substantially spherical-shaped beads into various batches.

49. The method of claim 48, wherein the gravity sedimentation comprises:

a) reslurrying the substantially spherical-shaped beads in a slurry solution to form a separation system having an original volume;

b) mixing the separation system;

c) allowing the separation system to stand still to come to equilibrium;

d) removing a fraction of useable substantially spherical-shaped beads from the separation system;

e) filtering the fraction of useable substantially spherical-shaped beads that is obtained from the separation system;

f) washing the filtered fraction of useable substantially spherical-shaped beads to remove any excess slurry solution; and

g) adding a quantity of deionized water to the remaining substantially spherical-shaped beads and slurry solution in the separation system to bring the volume of the separation system back to the original volume; and

h) repeating steps b)-g) as necessary until all the substantially spherical-shaped beads have been removed from the separation system.

50. The method of claim 48, further comprising drying the substantially spherical-shaped beads.

51. The method of claim 50, further comprising utilizing the substantially spherical-shaped beads in a resinous composition.

52. The method of claim 46, wherein the pigment further comprises at least one member selected from the group consisting of:

a colorant, Solvent Blue 35, Solvent Blue 36, Disperse violet 26, Solvent Green 3, Anaplast Orange LFP, Morplas Red 36, and Perylene Red.

53. The method of claim 52, wherein the pigment is selected from the group consisting of:

Solvent Blue 35 and Solvent Blue 36.

54. The method of claim 46, wherein the high aspect ratio particles comprise at least one of:

aluminum, gold, silver, copper, nickel, titanium, stainless steel, nickel sulfide, cobalt sulfide, manganese sulfide, metal oxides, white mica, black mica, synthetic mica, mica coated with titanium dioxide, metal-coated glass flakes, or colorants.

55. A resinous composition comprising pigment prepared by the method of claim 46.

54-1. The method of claim 46, wherein the suspension mixture comprises at least one of:

styrene, methyl methacrylate, styrene acrylonitrile, divinylbenzene, or modified bisphenol A.