Dispersion and inkjet ink composition, light conversion layer, and liquid crystal display element using the dispersion

• US 10,947,403 B2
• Filed: 12/21/2017
• Issued: 03/16/2021
• Est. Priority Date: 12/28/2016
• Status: Active Grant

• Current Assignee: DIC Corporation
• Original Assignee: DIC Corporation
• Inventors: Isonaka, Takeshi, Umezu, Yasuo, Yamaguchi, Hidehiko, Aoki, Yoshio, Sasaki, Hirotomo, Yoshihara, Sunao, Miki, Takayuki, Ishizuka, Aya, Kizaki, Takeo
• Primary Examiner(s): McPherson, John A
• Application Number:
  US16/474,357
• Publication Number:
  US 20190390076A1
• Time in Patent Office: 1,181 Days
• Field of Search: 430 7, 349106
• CPC Class Codes: B41J 2/2107 characterised by the ink properties supplying ink in a solid state B41J2/17593
• CPC Class Codes: B41M 5/00 Duplicating or marking methods; Sheet materials for use therein by using light-sensitive materials G03; electrography, magnetography G03G ; repeatedly usable boards or tablets for writing or drawing B43L1/00
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C09D 11/10 based on artificial resins
• CPC Class Codes: C09D 11/101 Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/326 characterised by the pigment dispersant
• CPC Class Codes: C09D 11/38 characterised by non-macromolecular additives other than solvents, pigments or dyes
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: G02F 2/02 Frequency-changing of light, e.g. by quantum counters
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials

Abstract

A dispersion contains, as essential ingredients, light-emitting nanocrystals, a polymeric dispersant having an amine value of 5 mg/KOH g or more, and a stimulation-responsive curable material that cures in response to an external stimulus.

Claims

1. A dispersion comprising, as essential ingredients, light-emitting nanocrystals, a polymeric dispersant having an amine value of 5 mg KOH/g or more, and at least one stimulation-responsive curable material that cures in response to an external stimulus, wherein

a solubility of a coating film made from the dispersion in a 1% by mass aqueous solution of potassium hydroxide at 25°

C. is 3% by mass or less.

2. The dispersion according to claim 1, wherein the polymeric dispersant has an acid value of 50 mg KOH/g or less.

3. The dispersion according to claim 1, wherein the polymeric dispersant has a weight-average molecular weight of 1000 or more.

4. The dispersion according to claim 1, further comprising at least one type of light-diffusing particles.

5. The dispersion according to claim 4, wherein the light-diffusing particles include at least one selected from the group consisting of titanium oxide, alumina, zirconium oxide, zinc oxide, calcium carbonate, barium sulfate, and silica.

6. The dispersion according to claim 1, wherein the stimulation-responsive curable material is at least one active radiation-curable monomer or thermosetting resin.

7. The dispersion according to claim 6, wherein the dispersion is an active radiation-curable dispersion that contains, as essential ingredients, the light-emitting nanocrystals, the polymeric dispersant having an amine value of 8 to 50 mg KOH/g, and the active radiation-curable monomer.

8. The dispersion according to claim 7, wherein the active radiation-curable monomer is a radically photopolymerizable compound.

9. The dispersion according to claim 7, further comprising, besides the light-emitting nanocrystals, the basic polymeric dispersant having an amine value of 8 to 50 mg KOH/g, and the active radiation-curable monomer, an active radiation-curable resin selected from the group consisting of urethane (meth)acrylate resins, polyester (meth)acrylate resins, and epoxy (meth)acrylate resins.

10. The dispersion according to claim 7, wherein the active radiation-curable monomer is a monofunctional (meth)acrylate and/or a multifunctional (meth)acrylate.

11. The dispersion according to claim 7, further comprising a polymerization initiator.

12. The dispersion according to claim 6, wherein the stimulation-responsive curable material is a thermosetting resin, the dispersion contains the light-emitting nanocrystals, the light-diffusing particles, the polymeric dispersant, and the thermosetting resin, and the amine value of the polymeric dispersant is 5 mg KOH/g or more.

13. The dispersion according to claim 1, wherein the stimulation-responsive curable material is insoluble in alkalis.

14. The dispersion according to claim 1, wherein the dispersion is not a dispersion containing a polymer soluble in alkalis.

15. The dispersion according to claim 1, wherein a percentage of the light-emitting nanocrystals in the dispersant is between 10% and 70% by mass.

16. The dispersion according to claim 1, wherein the light-emitting nanocrystals have a core that contains at least one or two or more first semiconductor materials;

and

a shell that covers the core and contains a second semiconductor material that is the same as or different than in the core.

17. The dispersion according to claim 1, wherein the polymeric dispersant has a backbone polyether, polyester, polyalkylene imine, or polyolefin chain and a basic functional group in a resin structure thereof.

18. The dispersion according to claim 1, further comprising a solvent having a boiling point higher than or equal to 180°

C.

19. A light conversion layer comprising a plurality of pixel units, wherein

the pixel units include at least one pixel unit that includes a cured form of a dispersion,

the dispersion comprises, as essential ingredients, light-emitting nanocrystals, a polymeric dispersant having an amine value of 5 mg KOH/g or more, and at least one stimulation-responsive curable material that cures in response to an external stimulus, and

a solubility of a coating film made from the dispersion in a 1% by mass aqueous solution of potassium hydroxide at 25°

C. is 3% by mass or less.

20. The light conversion layer according to claim 19, further comprising a light shield between the pixel units, wherein

the pixel units include:

a first pixel unit that includes the cured form and contains, as the luminescent nanocrystal particles, light-emitting nanocrystals that absorb light with a wavelength between 420 and 480 nm and emit light that has a peak emission wavelength in a range of 605 to 665 nm; and

a second pixel unit that includes the cured form and contains, as the luminescent nanocrystal particles, light-emitting nanocrystals that absorb light with a wavelength between 420 and 480 nm and emit light that has a peak emission wavelength in a range of 500 to 560 nm.