An object of the present invention is to provide a method for producing oxide particles with controlled color characteristics and to provide oxide particles with controlled color characteristics. The present invention provides a method for producing oxide particles, comprising controlling color characteristics of the oxide particles by controlling the ratio of M-OH bonds, the binding of one or more different elements (M) other than oxygen or hydrogen with hydroxyl group (OH), in oxide particles selected from metal oxide particles and metalloid oxide particles. According to the present invention, oxide particles having controlled color characteristics of any one of reflectance, transmittance, molar absorption coefficient, hue, or color saturation can be provided by controlling the percentage of the M-OH bonds contained in metal oxide particles or metalloid oxide particles.

The present invention relates to silicon-compound-coated fine metal particles, with which surfaces of fine metal particles, composed of at least one type of metal element or metalloid element, are at least partially coated with a silicon compound and a ratio of SiOH bonds contained in the silicon-compound-coated fine metal particles is controlled to be 0.1% or more and 70% or less. By the present invention, silicon-compound-coated fine metal particles that are controlled in dispersibility and other properties can be provided by controlling the ratio of SiOH bonds or the ratio of SiOH bonds/SiO bonds contained in the silicon-compound-coated fine metal particles. By controlling the ratio of SiOH bonds or the ratio of SiOH bonds/SiO bonds, a composition that is more appropriate for diversifying applications and targeted properties of silicon-compound-coated fine metal particles than was conventionally possible can be designed easily.

With an aim to provide a method for producing an oxide particle with controlled color characteristics and also provide an oxide particle with controlled color characteristics, the present invention provides a method for producing an oxide particle, wherein the color characteristics of the oxide particle are controlled by controlling a ratio of an M-OH bond between an element (M) and a hydroxide group (OH) or an M-OH bond/M-O bond ratio, where the element (M) is one element or plural different elements other than oxygen or hydrogen included in the oxide particle selected from metal oxide particles and semi-metal oxide particles. According to the present invention, by controlling the M-OH bond or the M-OH bond/M-O bond ratio of the metal oxide particle or the semi-metal oxide particle, the oxide particle with controlled color characteristics of any of reflectance, transmittance, molar absorption coefficient, hue, and saturation can be provided.

The present invention involves pigments derived from compounds with the LiSbO.sub.3-type or LiNbO.sub.3-type structures. These compounds possess the following formulations M.sup.1M.sup.5Z.sub.3, M.sup.1M.sup.2M.sup.4M.sup.5Z.sub.6, M.sup.1M.sup.3.sub.2M.sup.5Z.sub.6, M.sup.1M.sup.2M.sup.3M.sup.6Z.sub.6, M.sup.1.sub.2M.sup.4M.sup.6Z.sub.6, M.sup.1M.sup.5M.sup.6Z.sub.6, or a combination thereof. The cation M.sup.1 represents an element with a valence of +1 or a mixture thereof, the cation M.sup.2 represents an element with a valence of +2 or a mixture thereof, the cation M.sup.3 represents an element with a valence of +3 or a mixture thereof, the cation M.sup.4 represents an element with a valence of +4 or a mixture thereof, the cation M.sup.5 represents an element with a valence of +5 or a mixture thereof, and the cation M.sup.6 represents an element with a valence of +6 or a mixture thereof. The cation M is selected from H, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Cu, Ag, Zn, B, Al, Ga, In, Si, Ge, Sn, P, Sb, or Te. The anion Z is selected from N, O, S, Se, Cl, F, hydroxide ion or a mixture thereof. Along with the elements mentioned above vacancies may also reside on the M or Z sites of the above formulations such that the structural type is retained. The above formula may also include M dopant additions below 20 atomic %, where the dopant is selected from H, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Cu, Ag, Zn, B, Al, Ga, In, Si, Ge, Sn, P, Sb, Bi, Te, or mixtures thereof.

An asymmetric pigment including a first Fabry-Perot structure; and a second Fabry-Perot structure; wherein the first Fabry-Perot structure and the second Fabry-Perot structure have a similar hue angle within +/45 degrees is disclosed. Other asymmetric pigments are also disclosed as well as methods of making the disclosed pigments.

The present invention is a method of producing silicon compound coated oxide particles in which at least a part of a surface of a metal oxide particle is coated with a silicon compound, wherein wettability and color characteristics are controlled by controlling a ratio of SiOH bonds contained in the silicon compound coated oxide particles. By the present invention, silicon compound coated oxide particles having controlled wettability such as hydrophilicity, water repellency or oil repellency, and controlled color characteristics of either reflectivity, molar absorption coefficient or transmittance can be provided.

In a coloring ultraviolet protective agent, the average molar absorption coefficient in the wavelength range from 200 nm to 380 nm is increased, and the color characteristics in the visible region are controlled. The coloring ultraviolet protective agent is useful for shielding ultraviolet rays and coloring. The coloring ultraviolet protective agent comprises M2 doped oxide particles in which oxide particles (M1Ox) including at least M1 being a metal element or metalloid element, are doped with at least one M2 selected from metal elements or metalloid elements other than M1, wherein x is an arbitrary positive number, wherein an average molar absorption coefficient in the wavelength range of 200 nm to 380 nm of a dispersion in which the M2 doped oxide particles are dispersed in a dispersion medium, is improved as compared with one of a dispersion in which the oxide particles (M1Ox) are dispersed in a dispersion medium, and wherein a hue or chroma of color characteristics in the visible region of the M2 doped oxide particles is controlled.

With an aim to provide an oxide particle with controlled color characteristics, the present invention provides a method for producing an oxide particle, wherein the color characteristics of the oxide particle are controlled by controlling a M-OH bond/M-O bond ratio, which is a ratio of a M-OH bond between an element (M) and a hydroxide group (OH) to a ratio of an M-O bond between the element (M) and oxygen (O), where the element (M) is one or plural different elements other than oxygen or hydrogen included in the oxide particle selected from metal oxide particles and semi-metal oxide particles. According to the present invention, by controlling the M-OH bond/M-O bond ratio of the metal oxide particle or the semi-metal oxide particle, the oxide particle with controlled color characteristics of any of reflectance, transmittance, molar absorption coefficient, hue, and saturation can be provided.

The present invention involves pigments derived from compounds with the LiSbO.sub.3-type or LiNbO.sub.3-type structures. These compounds possess the following formulations M.sup.1M.sup.5Z.sub.3, M.sup.1M.sup.2M.sup.4M.sup.5Z.sub.6, M.sup.1M.sup.3.sub.2M.sup.5Z.sub.6, M.sup.1M.sup.2M.sup.3M.sup.6Z.sub.6, M.sup.1.sub.2M.sup.4M.sup.6Z.sub.6, M.sup.1M.sup.5M.sup.6Z.sub.6, or a combination thereof. The cation M.sup.1 represents an element with a valence of +1 or a mixture thereof, the cation M.sup.2 represents an element with a valence of +2 or a mixture thereof, the cation M.sup.3 represents an element with a valence of +3 or a mixture thereof, the cation M.sup.4 represents an element with a valence of +4 or a mixture thereof, the cation M.sup.5 represents an element with a valence of +5 or a mixture thereof, and the cation M.sup.6 represents an element with a valence of +6 or a mixture thereof. The cation M is selected from H, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Cu, Ag, Zn, B, Al, Ga, In, Si, Ge, Sn, P, Sb, or Te. The anion Z is selected from N, O, S, Se, Cl, F, hydroxide ion or a mixture thereof. Along with the elements mentioned above vacancies may also reside on the M or Z sites of the above formulations such that the structural type is retained. The above formula may also include M dopant additions below 20 atomic %, where the dopant is selected from H, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Cu, Ag, Zn, B, Al, Ga, In, Si, Ge, Sn, P, Sb, Bi, Te, or mixtures thereof.

A colorant including a mixture of pigments is disclosed. The pigments have a similar coloration but different resistance to corrosion. The mixing ratio is selected to optimize the corrosion resistance against color brightness, and/or acidic corrosion resistance against alkali corrosion resistance of the colorant.