Electrophoretic particle, electrophoretic particle dispersion liquid, display medium, and display device
There is provided an electrophoretic particle which contains a core material particle formed of a composition containing a resin, a nitrogen-containing heterocyclic compound having any one of an imino group, a methylol group and an alkoxymethyl group in the molecule and a heterocyclic ring having a nitrogen atom, and a coloring agent.
1. An electrophoretic particle containing:
a core material particle formed of a composition containing a resin, a nitrogen-containing heterocyclic compound having an imino group, a methylol group, or an alkoxymethyl group in the molecule, and a coloring agent, wherein the nitrogen containing heterocyclic compound crosslinks the resin; and
a covering layer on a surface of the core material particle,
wherein the covering layer is formed of a composition containing a resin of a copolymer comprising at least a polymerization component having a silicone chain.
2. The electrophoretic particle according to claim 1 ,
wherein the nitrogen-containing heterocyclic compound is selected from the group consisting of a melamine compound and a guanamine compound each having any one of an imino group, a methylol group and an alkoxymethyl group in the molecule.
3. The electrophoretic particle according to claim 1 , wherein the covering layer is formed of a composition containing a resin having a dispersion medium-philic part soluble in a dispersion medium, wherein the electrophoretic particle is dispersed and a dispersion medium-phobic part insoluble in a dispersion medium wherein the electrophoretic particle is dispersed.
4. The electrophoretic particle according to claim 1 , wherein the content of the nitrogen-containing heterocyclic compound is about 0.5% by mass or more and about 50% by mass or less based on the total of the core material particle.
5. The electrophoretic particle according to claim 3 , wherein the covering layer is a covering layer composed of a resinous crosslinked product of the composition containing the resin.
6. An electrophoretic particle dispersion liquid comprising: a dispersion medium and an electrophoretic particle dispersed in the dispersion medium, wherein the electrophoretic particle is the electrophoretic particle according to claim 1 .
7. The electrophoretic particle dispersion liquid according to claim 6 , wherein the dispersion medium contains a solvent having a low dielectric constant.
8. A display medium comprising: a pair of substrates at least either one of which has light-transmitting property, and the electrophoretic particle dispersion liquid according to claim 6 , which is enclosed between the pair of substrates.
9. A display medium comprising: a pair of electrodes at least either one of which has light-transmitting property, and an area having the electrophoretic particle dispersion liquid according to claim 6 , which is enclosed between the pair of electrodes.
10. A display device comprising: the display medium according to claim 8 and a voltage-applying unit that applies a voltage between the pair of substrates of the display medium.
11. A display device comprising: the display medium according to claim 9 and a voltage-applying unit that applies a voltage between the pair of electrodes of the display medium.
12. An electrophoretic particle comprising a core formed of a resinous crosslinked product including:
a resin;
a melamine compound having an imino group, a methylol group or an alkoxymethyl group wherein the melamine compound crosslinks the resin; and
a coloring agent.
13. An electrophoretic particle comprising a core formed of a resinous cross linked product including:
a resin;
a guanamine compound having an imino group, a methylol group or an alkoxymethyl group wherein the guanamine compound crosslinks the resin; and
a coloring agent.
14. The electrophoretic particle of claim 1 , wherein the electrophoretic particle is heated to at least at 130° C. for at least one hour to cause the nitrogen containing heterocyclic compound to crosslink the resin.
15. The electrophoretic particle of claim 12 , wherein the melamine compound is of Formula (B)
wherein each of R 6 to R 11 independently represents a hydrogen atom, —CH 2 —OH, —CH 2 —O—R 12 , or —O—R 12 ; and
R 12 represents an alkyl group having 1 to 5 carbon atoms which may be branched.
16. The electrophoretic particle of claim 12 , wherein the electrophoretic particle is heated to at least at 130° C. for at least one hour to cause the melamine compound to crosslink the resin.
17. The electrophoretic particle of claim 13 , wherein the guanamine compound is of Formula (A)
wherein R 1 represents a straight chain or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 4 to 10 carbon atoms; each of R 2 to R 5 independently represents a hydrogen atom, —CH 2 —OH or —CH 2 —O—R 6 ; and R 6 represents a straight chain or branched alkyl group having 1 to 10 carbon atoms.
18. The electrophoretic particle of claim 13 , wherein the electrophoretic particle is heated at least at 130° C. for at least one hour to cause the guanamine compound to crosslink the resin.