Provided are a microcapsule pigment, though it is a microcapsule pigment obtained by microcapsulating a pigment having a large specific gravity such as titanium oxide and carbon black having a little difficulty in dispersibility, which makes it easier to be improved in dispersibility and which makes it possible to control a specific gravity and a particle diameter as desired, and an aqueous ink composition for writing instruments prepared by using the same. The microcapsule pigment described above is characterized by comprising at least a pigment and a poorly water-soluble medium having a specific gravity of less than 1 at 20? C., and the aqueous ink composition for writing instruments described above is characterized by containing the microcapsule pigment described above.

The present disclosure provides white pigment dispersions, which can include an aqueous liquid vehicle, and from 5 wt % to 70 wt % of a white metal oxide pigment dispersed by two co-dispersants. The metal oxide pigment can have an average particulate size from 100 nm to 1 m, and the co-dispersants can include both i) a short-chain anionic dispersant having a weight average molecular weight ranging from 1,000 Mw to 30,000 Mw, and ii) a non-ionic or predominantly non-ionic dispersant.

A particle is provided that includes a first material and a second material, arranged to provide a Fano resonance effect, for example in the visible portion of electromagnetic spectrum. The first and second materials may be substantially clear in the visible portion of the electromagnetic spectrum. The first material may include an inorganic material, such as SiO.sub.2, TiO.sub.2, HfO.sub.2, ZrO.sub.2, diamond, or a combination thereof. The second material may include a polymer. The first material has a first refractive index and the second material has a second refractive index, where the first refractive index and second refractive index have a difference of 0.5 or greater, and 1.0 or less. The first material may form a core and the second material may form a shell surrounding the core. Alternatively, the first and second materials may form a Janus particle, an asymmetric dimer, or an aggregate.

This invention relates to particles comprising a core particle and a polymeric shell, electrophoretic fluids comprising such particles, and electrophoretic display devices comprising such fluids.

The present invention is directed to a display fluid comprising charged composite color particles dispersed in a solvent. The composite color particle comprises core particles which are at least one color core particle and at least one core particle having a high refractive index, a shell in which the color core particles and the high refractive index core particles are completely or partially embedded, and steric stabilizer molecules on the surface of the composite color particle. A display fluid comprising the composite color particles of the present invention provides improved optical performance.

A novel polymer comprising a water soluble polymer backbone, at least one functional group attached to the polymer backbone and having an affinity for titanium dioxide, and at least one hydrophobic functional group attached to the polymer backbone and having an affinity for latex is provided. A titanium dioxide pigment composition including the novel polymer is also provided. Also provided is a method of manufacturing a titanium dioxide pigment composition that includes the novel polymer.

An aqueous personal care composition comprising 0.5 to 10 wt % polymer encapsulated particles of titanium dioxide or zinc oxide; said polymer encapsulated particles comprising: (i) particles of titanium dioxide or zinc oxide having an average particle diameter from 10 to 200 nm; (ii) 0.25 to 10 wt % water-soluble sulfur acid-functional first polymer, based on weight of said particles of titanium dioxide or zinc oxide; and (iii) from 10% to 200%, by weight second polymer, based on weight of said particles of titanium dioxide or zinc oxide, wherein the second polymer at least partially encapsulates said particle of titanium dioxide or zinc oxide.

This invention relates to particles comprising a pigment core particle encapsulated by a polymer, a process for their preparation, electrophoretic fluids comprising such particles, and electrophoretic display devices comprising such fluids.

Disclosed is an organic/inorganic composite filler that contains: inorganic agglomerated particles comprising agglomerations of inorganic primary particles having a mean diameter between 10 and 1000 nm; an organic resin phase that covers the surface of each inorganic primary particle and binds the inorganic primary particles to each other; and intra-agglomerate voids, formed between the organic resin phase covering the surface of each inorganic primary particle, with a pore volume (here, pore refers to holes with diameters between 1 and 500 nm) between 0.01 and 0.30 cm.sup.3/g as measured by mercury intrusion porosimetry. Also disclosed is a method for manufacturing the above organic/inorganic composite filler.

Provided in one example herein is a liquid electrophotographic ink composition. The composition comprises: a carrier fluid comprising a polymer; ink particles each comprising a non-aqueous polymeric resin and pigment particles distributed in the polymeric resin; and a charge director. The pigment particles comprise a metal oxide and have a hydrophobic surface. The hydrophobic surface comprises at least one of the following: (i) nanoparticles attached to each of the pigment particles, the nanoparticles comprising at least one of an oxide, a phosphate, and a nitrate; (ii) a coating disposed over each of the pigment particles, the coating comprising at least one of an oxide, a phosphate, and a nitrate; and (iii) a coating disposed over each of the pigment particles, the coating comprising at least one of a polymer and an oligomer.