An iron oxide powder includes a porous structure having the diameter of from 0.3 μm to 2 μm, wherein the iron oxide powder has an aluminum content of from 10 mol % to 80 mol %.

A method of manufacturing a graphene-tin oxide nanocomposite comprises dispersing graphene and tin oxide in an organic solvent to prepare a dispersion solution, drying the dispersion solution to obtain a powdery mixture, and irradiating the mixture with microwaves to obtain a graphene-tin oxide nanocomposite. Irradiation of graphene and tin oxide with microwaves results in the simplification of the manufacturing process of graphene-tin oxide nanocomposites and a decrease in manufacturing time and cost, and produce graphene-tin oxide nanocomposites at low temperatures. Further, the graphene-tin oxide nanocomposite with improved sensitivity to NO2 gas may be produced.

Provided is an iron oxide powder for a brake friction material which can be suitably used in a brake friction material that is less likely to cause problems regarding brake squealing and that provides superior braking performance. The iron oxide powder for a brake friction material according to a first embodiment of the present invention is characterized by having a sulfur content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less. The iron oxide powder for a brake friction material according to a second embodiment of the present invention is characterized by having an average particle size of 1.0 μm or more, a chlorine content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less.

A ceramic powder for a ceramic component, in particular based on zirconia and/or alumina, in particular for a timepiece or jewelry piece. The powder includes at least one noble metal among platinum, rhodium, osmium, palladium, ruthenium and iridium, at a quantity of less than or equal to 5% by weight.

Provided is a silica that exhibits a high matting property when utilized as a matting agent for a paint, and can also suppress the occurrence of cloudiness. The silica has an aggregated structure in which primary particles are aggregated, has a particle diameter ratio R represented by the following equation (1) of from 4.3 to 5.2, has an absorbance of 0.6 or less for light having a wavelength of 700 nm as an aqueous dispersion having a concentration of 1.48 mass %, and has a particle density measured with a He pycnometer of 2.18 g/cm.sup.3 or more: Equation (1) R=.sup.LD50/.sup.CD50 (in the equation (1), .sup.LD50 represents a volume-based 50% cumulative particle diameter (μm) of the silica measured based on a laser diffraction/scattering method, and .sup.CD50 represents a volume-based 50% cumulative particle diameter (μm) of the silica measured based on a Coulter counter method).

The present invention provides a glitter pigment suitable for imparting high brightness to reflected light toward a regular reflection direction and reducing unnaturalness caused by an observation angle-dependent variation in reflected light. The glitter pigment according to the present invention includes: a flaky substrate; an optical interference film formed on a surface of the flaky substrate; and fine light scattering particles attached to the optical interference film, wherein reflected light is represented by an L*(15) value of more than 100, a ΔL*(h−s) value of less than 30, and a Δh(h−s) value of less than 40° in an L*C*h color system. The L*(15) value is an L* value of the reflected light toward a 15° direction based on an angular representation in which, when an illuminant is disposed so that an incident angle is 45°, an angle at which light is regularly reflected is defined as 0° and a light incident direction is defined as positive. The ΔL*(h−s) value is a difference in L* between a highlight and shade, and the Δh(h−s) value is a difference in h between a highlight and shade. The Δh value expressed in angle is an angular difference. The highlight is an average of values measured at 15° and 25°, and the shade is an average of values measured at 75° and 110°.

The present invention provides a new glitter pigment suitable for providing high-brightness whitish reflected light. The glitter pigment according to the present invention includes: a flaky substrate 1; and a silicon oxide layer 2 and a titanium oxide layer 3 formed in this order on the flaky substrate 1, wherein in the case where the flaky substrate is the glass flake, the glass flake has a thickness of 284 to 322 nm, the silicon oxide layer has a thickness of 89 to 109 nm, and the titanium oxide layer has a thickness of 51 to 86 nm. In the case where the flaky substrate is the alumina flake, the alumina flake has a thickness of 260 to 280 nm, the silicon oxide layer has a thickness of 79 to 102 nm, and the titanium oxide layer has a thickness of 47 to 87 nm.

The present disclosure provides a photoelectric conversion element including a first electrode 3, a second electrode 7, a photoelectric conversion layer 5 between the first electrode 3 and the second electrode 7, and a reflection layer 6 between one of the first electrode 3 and the second electrode 7 and the photoelectric conversion layer 5. The wavelength at which the reflectance of the reflection layer 6 is maximum in the visible region is within the range of wavelengths in which the optical absorption coefficient of the photoelectric conversion layer 5 is ⅕ or more of the maximum optical absorption coefficient in the visible region.

An ultra-white granular silica-based filler comprises at least 99.5 wt. % silica, wherein the crystal structure of the silica is such that the silica-based filler comprises 40 to 80 wt. % cristobalite, 1 to 25 wt. % tridymite, 2-60 wt. % quartz and <5 wt. % amorphous silica, wherein the temperature of the ultra-white granular silica-based filler is no higher than 50° C. and further wherein the ultra-white granular silica-based filler exhibits an L* value in the CIELAB color space of 95-98. In addition, an ultra-white powder filler is obtained by milling, grinding or comminuting the ultra-white granular silica-based filler. The ultra-white powder filler exhibits an L* value in the CIELAB color space of 95-98.5.

According to an example aspect of the present invention, there is provided a tint base comprising titanium dioxide, a vehicle, and conventional additives, which tint base is capable of displaying a preselected colour upon the addition of a colorant, wherein at least 4% by weight of the titanium dioxide is present in the form of opaque aggregates of titanium dioxide and precipitated calcium carbonate particles wherein the titanium dioxide particles are at least partially encased by the particles of precipitated calcium carbonate.