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

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.

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
 the light-emitting nanocrystals have a core/shell structure or a core/shell/shell structure, and the core or the cell comprises at least one semiconductor material selected from the group consisting of group II-VI semiconductors, group III-V semiconductors, group I-III-VI semiconductors, group IV semiconductors, and group I-II-IV-VI semiconductors.   
     
     
         2 . The dispersion according to  claim 1 , wherein the light-emitting nanocrystals having the core/shell structure is selected from the group consisting of:
 nanocrystals with a CdS shell portion and an inner core portion of ZnSe, a mixed crystal of CdSe and ZnS, or InP;   nanocrystals with a ZnS shell portion and an InP inner core portion;   nanocrystals with a ZnSe shell portion and an InP inner core portion;   nanocrystals with a shell portion of a mixed crystal of ZnS and ZnSeS, and an InP inner core portion; and   nanocrystals with a shell portion of a mixed crystal of ZnS and ZnSeS, and an inner core portion of InP, a mixed crystal of CdSe and CdS, or a mixed crystal of ZnSe and CdS.   
     
     
         3 . The dispersion according to  claim 1 , wherein the light-emitting nanocrystals having the core/shell/shell structure is selected from the group consisting of:
 nanocrystals with a ZnSe first shell portion, a ZnS second shell portion, and an InP inner core portion;   nanocrystals with a first shell portion of a mixed crystal of ZnS and ZnSe, a ZnS second shell portion, and an InP inner core portion;   nanocrystals with a ZnSeS first shell portion, a ZnS second shell portion, and an InP inner core portion;   nanocrystals with a ZnS first shell portion, a ZnSeS second shell portion, and an InP inner core portion.   
     
     
         4 . The dispersion according to  claim 1 , wherein the at least one semiconductor material selected from the group consisting of group II-VI semiconductors, group III-V semiconductors, group I-III-VI semiconductors, group IV semiconductors, and group I-II-IV-VI semiconductors comprises at least one selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, CdHgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe; GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; Si, Ge, SiC, SiGe, AgInSe 2 , CuGaSe 2 , CuInS 2 , CuGaS 2 , CuInSez, AgInS 2 , AgGaSe 2 , AgGaS 2 , C, Si and Ge. 
     
     
         5 . The dispersion according to  claim 1 , wherein further comprising, as essential ingredients, light-diffusing particles and an organic ligand. 
     
     
         6 . The dispersion according to  claim 1 , wherein the polymeric dispersant has an acid value of 50 mg KOH/g or less. 
     
     
         7 . The dispersion according to  claim 1 , wherein the polymeric dispersant has a weight-average molecular weight of 1000 or more. 
     
     
         8 . 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. 
     
     
         9 . The dispersion according to  claim 5 , 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. 
     
     
         10 . The dispersion according to  claim 1 , wherein the active radiation-curable monomer is a monofunctional (meth)acrylate and/or a multifunctional (meth)acrylate. 
     
     
         11 . The dispersion according to  claim 10 , further comprising a solvent having a boiling point higher than or equal to 180° C. 
     
     
         12 . The dispersion according to  claim 11 , wherein the dispersion has a surface tension of 20 to 40 mN/m. 
     
     
         13 . The dispersion according to  claim 12 , wherein the dispersion has a viscosity of 2 to 20 mPa·s. 
     
     
         14 . An ink composition comprising a dispersion according to  claim 1 . 
     
     
         15 . The ink composition according to  claim 14 , wherein the ink composition is used by inkjetting. 
     
     
         16 . The ink composition according to  claim 14 , wherein the ink composition is for a color filter. 
     
     
         17 . A light conversion layer comprising an ink composition according to  claim 14  applied to a substrate by inkjetting and cured. 
     
     
         18 . 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 an ink composition according to  claim 14 .   
     
     
         19 . A light conversion layer comprising a plurality of pixel units and 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, and wherein the first pixel unit and/or the second pixel unit include a cured form of an ink composition according to  claim 14 .   
     
     
         20 . The light conversion layer according to  claim 19 , wherein the pixel units further include a third pixel unit that transmits 30% or more of light with a wavelength between 420 and 480 nm.