A metallic nanoparticle dispersion includes a dispersion medium characterized in that the dispersion medium includes a solvent according to Formula I, ##STR00001## wherein R.sub.1 and R.sub.2 represent an optionally substituted alkyl group, and R.sub.1 and R.sub.2 may form a ring. When using a solvent according to Formula I as a dispersion medium, no polymeric dispersants are necessary to obtain stable metallic nanoparticle dispersions.

Copper inks are provided that include a plurality of core-shell nanostructures, with each nanostructure including a copper core and a barrier metal shell, a diameter of less than about 500 nm, and a distinct boundary between the copper core and the barrier metal shell. Methods of forming a copper ink are further provided and include an initial step of synthesizing an amount of copper nanoparticles in an aqueous solution. An amount of a barrier metal is then added to the copper nanoparticles to form a dispersion of the barrier metal and the copper nanoparticles, and a reducing agent is subsequently added to the dispersion to produce a copper ink comprising core-shell nanostructures having a copper core and a barrier metal shell. Copper films are then formed by applying that copper ink to a substrate and sintering the copper ink.

Provided are thin leaf-like indium particles having a first peak and a second peak at a greater particle diameter than a particle diameter at which the first peak appears in a volume-based particle size distribution representing a relationship between particle diameters of indium particles and ratios by volume of the indium particles at the particle diameters, wherein a volume V1 of the indium particles at the first peak and a volume V2 of the indium particles at the second peak satisfy a formula (V1/V2)×100≥25%.

The present invention relates to [1] a dispersion of metal fine particles containing hydroxyacetone and propylene glycol, in which a cumulant average particle size of the metal fine particles is not less than 0.01 μm and not more than 0.1 μm, and [2] an ink containing the dispersion of metal fine particles as described in the above [1].

An inorganic particle dispersion having high spinnability comprises an inorganic powder, hydrophilic fumed silica, and a resin having a hydroxyl group.

A pigment comprising a plurality of photonic crystal particles dispersed in a medium, each photonic crystal particles containing a plurality of spectrally selective absorbing components dispersed within each photonic crystal particle that selectively absorb electromagnetic radiation without substantially absorbing electromagnetic radiation near a resonant wavelength of each photonic crystal particle, wherein each photonic crystal particle has a predetermined minimum number of repeat units of a photonic crystal structure, wherein the predetermined minimum number of repeat units is related to the resonant wavelength, the full-width at half maximum of the resonant wavelength, and the refractive index contrast in the photonic crystal.

An aqueous coloring composition contains a metal pigment and water. The metal pigment is metal particles having a surface treated with at least one surface treatment agent, and the surface treatment agent is at least one compound represented by general formula (1) or (2). The volume-average particle diameter D50 of the metal pigment is 9 μm or less.

(A.sup.1-R.sup.1—)P(O)(OH).sub.2  (1)

(A.sup.2-R.sup.2—O—).sub.aP(O)(OH).sub.3-a  (2)

(In the formulae, A.sup.1 and A.sup.2 each independently represent a hydrogen atom or a group selected from a carboxyl group, a hydroxyl group, an amino group, and an oxyalkylene-containing group, R.sup.1 and R.sup.2 each independently represent a hydrocarbon group having 12 or more carbon atoms, and a represents an integer of 1 or 2.)

A method for increasing a detection distance of a surface of an object illuminated by near-IR electromagnetic radiation, including: (a) directing near-IR electromagnetic radiation from a near-IR electromagnetic radiation source towards an object at least partially coated with a near-IR reflective coating that increases a near-IR electromagnetic radiation detection distance by at least 15% as measured at a wavelength in a near-IR range as compared to the same object coated with a color matched coating which absorbs more of the same near-IR radiation, where the color matched coating has a ΔE color matched value of 1.5 or less when compared to the near-IR reflective coating; and (b) detecting reflected near-IR electromagnetic radiation reflected from the near-IR reflective coating. A system for detecting proximity of vehicles is also disclosed.

Described herein is a process for producing an effect pigment paste including at least steps (1) and (2), namely producing a mixture including at least one effect pigment (a) and at least one polymer (b) in a liquid medium (c) (step (1)), and dispersing the mixture obtained after step (1) to obtain the effect pigment paste (step (2)), where step (2) is performed using a shaker and the effect pigment paste obtained after the performance of step (2) has ended is free of grinding media. Also described herein are an effect pigment paste producible by this process, containing an amount of effect pigment of at least 5% by weight, based on the total weight of the effect pigment paste, and a method of using a shaker for dispersing of effect pigments for production of an effect pigment paste.

Described herein is a mixer system for producing aqueous coating materials from at least one aqueous pigment paste A, including at least one effect pigment, and at least one pigment-free component B, including an aqueous, acrylate-based microgel dispersion having a glass transition temperature T.sub.g of 50 to 60° C., where both the aqueous pigment paste A and the component B each have a VOC value of less than or equal to 250 g/L. Further described herein is a method for producing aqueous coating materials having a VOC content of 0 to 250 g/L, in which the individual components A and B are stored separately and not mixed until shortly before application, to give the aqueous coating material. Further described herein is a method of using the mixer system of for producing aqueous coating materials for refinishing and/or for coating automobile bodies and/or plastics parts.