JP2013170204A - Pigment, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bismuth oxychloride pigment having an excellent photostability, and in addition, capable of maintaining the brightening gloss of a peculiar opal color, and a method for producing the same.SOLUTION: A pigment obtained by incorporating an alkaline earth metal element such as barium, strontium, etc., into bismuth oxychloride is produced by mixing the bismuth compound, a chloride and an alkaline earth metal compound, and firing. The pigment can be used in various applications, eg. such as coating compositions, coated articles, cosmetics, etc., since the pigment is excellent in photostability.

Description

  The present invention relates to a pigment mainly composed of bismuth oxychloride and a method for producing the same. Furthermore, this invention relates to the coating composition containing the said pigment, a coated article, and cosmetics.

  As a pigment, bismuth oxychloride (BiOCl) which has a unique soft glitter luster and is non-toxic is known, and is used in various paints and cosmetics. However, bismuth oxychloride is easily reduced to black by being reduced to metal bismuth by irradiation with ultraviolet rays. To suppress such photochromic properties, soluble bismuth salt and chloride ions are mixed in an aqueous medium under hydrolysis conditions to produce an aqueous dispersion of bismuth oxychloride crystals and about 80% of crystal formation. When 95% is completed, a method of adding fine metal oxides such as zinc oxide and titanium oxide to the aqueous medium and embedding fine metal oxide particles almost on the surface of the bismuth oxychloride crystal is known. (See Patent Document 1). Patent Document 1 also discloses that light stability is improved when a trivalent metal ion such as aluminum or gallium or a rare earth metal ion such as lanthanum or cerium is contained in the crystal of bismuth oxychloride. It is described.

JP 2005-536592 A

  The above prior art is a method of embedding fine metal oxide particles such as zinc oxide and titanium oxide in the surface of bismuth oxychloride crystal. Although the light stability of bismuth oxychloride pigment is improved to some extent, bismuth oxychloride is improved. Since the process control is complicated because the metal oxide particles are added when about 80 to 95% of the crystal formation is completed, further improvement in light stability by a simpler method is desired.

  As a result of studying a method for improving the photostability of bismuth oxychloride, the present inventors have obtained an excellent photostability by adding an alkaline earth metal element to bismuth oxychloride, and a unique opal. The present inventors have found that the glossy gloss of the color can be maintained and the interference color does not appear so much, and the present invention has been completed.

  That is, the present invention includes (1) a pigment composed mainly of bismuth oxychloride containing an alkaline earth metal element, and (2) an alkaline earth metal obtained by mixing and calcining a bismuth compound, chloride, and alkaline earth metal compound. A process for producing bismuth oxychloride containing an element; (3) a coating composition containing the pigment, a coated article, a cosmetic;

Since the pigment of the present invention contains an alkaline earth metal element, the photochromic property of bismuth oxychloride can be suppressed, and it has a unique soft opal luster gloss. Moreover, the interference color does not appear so much.
In addition, the present invention is a method for producing bismuth oxychloride, in which a bismuth compound, a chloride, and an alkaline earth metal compound are mixed and calcined, and a pigment having excellent light stability can be easily produced.
Since the pigment of the present invention is excellent in light stability, it can be used in various applications. For example, it can be used in coating compositions, coated articles, cosmetics, and the like. Cars, trains, buildings, etc. that have been applied.

  The present invention is a pigment mainly composed of bismuth oxychloride containing an alkaline earth metal element. Examples of the alkaline earth metal element include beryllium, magnesium, calcium, strontium, and barium, and strontium and / or barium are preferable. The alkaline earth metal element only needs to be contained in bismuth oxychloride. For example, a solid solution or a part of the bismuth element may be substituted inside the crystal of bismuth oxychloride (generally referred to as dope). An alkaline earth metal element may be adhered to the surface of the bismuth particles, or an alkaline earth metal element may be inserted between bismuth oxychloride layers. Content of alkaline-earth metal element can be suitably set, for example, 5-50 mol% is preferable with respect to bismuth of bismuth oxychloride, 10-40 mol% is more preferable, 15-30 mol% is still more preferable. The particle shape of bismuth oxychloride is preferably a flaky shape in order to give a unique opal luster luster, and the particle diameter is the number average value of the long diameters in the width direction of the flaky particles (according to scanning electron micrograph) In terms of visual field observation, the average value of 30 flaky particles is preferably about 0.1 to 100 μm, more preferably about 1 to 50 μm. It is preferable to add a trivalent metal ion such as aluminum or gallium or a rare earth metal ion such as lanthanum or cerium in the crystal of bismuth oxychloride because the light stability is further improved. The pigment of the present invention contains the above-mentioned bismuth oxychloride as a main component, and the content thereof is preferably 50% by weight or more, more preferably 70 to 100% by weight, more preferably 90 to 100% by weight of the pigment. More preferred is weight percent.

  If the particle surface of bismuth oxychloride has a coating having a thickness of 1 to 100 nm composed of a metal oxide and / or a metal hydroxide, the coating can provide a pigment having excellent light stability. More preferable. By setting the thickness of the coating to a range of 1 to 100 nm, the interference color does not appear strongly. A preferred thickness is 10 to 100 nm, and a more preferred thickness is 20 to 100 nm. The coating of the metal oxide and / or metal hydroxide may be a single layer or a multilayer of two or more layers, and the thickness of each layer of the coating can be appropriately set in the range of 1 to 100 nm.

  The coating amount of the metal oxide and / or metal hydroxide can be appropriately set according to the thickness of the coating, and is preferably about 0.01 to 50% by weight with respect to the weight of bismuth oxychloride, for example, 0 About 1 to 10.0% by weight is more preferable, and about 0.5 to 5.0% by weight is most preferable. If the coating amount of the metal oxide and / or metal hydroxide is less than 0.01% by weight, it is not preferable because the improvement of the light stability is not sufficient. On the other hand, if it exceeds 50% by weight, the light stability is further improved. This is not preferred because it is difficult to improve.

Examples of the metal oxide and / or metal hydroxide constituting the coating include transition metals and oxides and hydroxides of typical metals including silicon. Typical metals include alkaline earth metal elements. Metal oxides include hydrous oxides and hydrated oxides. Specifically, a metal oxide and / or metal hydroxide containing at least one element selected from the group consisting of silicon, aluminum, titanium, tin, zinc, antimony, and iron is preferable, and has high ultraviolet shielding ability. Titanium oxide that can suppress the photochromic property of bismuth oxychloride is more preferred. The titanium oxide may be amorphous, but preferably has a crystal form such as rutile or anatase. Furthermore, it is more preferable to form a coating of a metal oxide and / or metal hydroxide of silicon or aluminum on titanium oxide because it can suppress the expression of photocatalytic activity of titanium oxide when exposed to ultraviolet rays. .
The metal oxide and / or metal hydroxide is preferably fired as described later. Since the crystallinity is improved by firing, the photochromic property of bismuth oxychloride can be further suppressed. Although the temperature of baking can be set suitably, the range of 200-1000 degreeC is preferable so that it may mention later, and the range of 300-700 degreeC is more preferable.

  If necessary, the pigment of the present invention is provided with a metal oxide and / or metal hydroxide coating on the surface of bismuth oxychloride particles, and then coated with an organic substance such as a coupling agent or an organic surface modifier. Also good. Examples of coupling agents include silane coupling agents, titanate coupling agents, and aluminate coupling agents. Silane coupling agents include aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxy. Silane, vinyltrichlorosilane, γ-glycidoxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like can be used. As the titanate coupling agent, an amine, phosphorous acid type, pyrophosphoric acid type, carboxylic acid type titanate coupling agent or the like can be used. As the aluminate coupling agent, acetoalkoxyaluminum diisopropylate or the like can be used. The organic surface modifier is used to further improve the dispersibility in solvents, coating compositions, plastics, and durability of the coating film, and the type of organic surface modifier depending on the purpose. Can be selected as appropriate, for example, silicone, lecithin, resin, adhesive, silane compound, fluorine compound, ultraviolet absorber, polyhydric alcohol, amino acid, dye, fatty acid, carboxylate, metal soap, oil, wax, etc. Is preferably used, and a plurality of treatment agents having different effects can be combined. The treatment amount of the coupling agent and / or the organic surface modifier can be appropriately set according to the purpose, and the range of 0.1 to 100% by weight in terms of the total amount of organic matter relative to the pigment is appropriate.

The pigment of the present invention has excellent light stability, and as an index thereof, it is preferably 0.5 to 10.0, more preferably 0.5, expressed by a color difference ΔE before and after BLB irradiation. It is -7.0, More preferably, it is 0.5-6.0. The color difference ΔE before and after the BLB irradiation is measured as follows. A pigment sample is spread on a medicine wrapping paper, irradiated with black light (BLB) having an intensity of 4.5 mW / cm ² for 24 hours, and a color difference ΔE between the sample before black light irradiation and the sample after black light irradiation. Is calculated from the following equation. The color difference was measured using a spectrocolorimeter SD-5000 manufactured by Nippon Denshoku Industries Co., Ltd.
Color difference ΔE = ((L * −L * 0) ² + (a * −a * 0) ² + (b * −b * 0) ² ) ^(1/2)
* L * 0, a * 0, b * 0; Powder L * value, a * value, b * value before black light irradiation * L *, a *, b *; Powder L * after black light irradiation Value, a * value, b * value

Next, the present invention is a method for producing bismuth oxychloride containing an alkaline earth metal element, wherein a bismuth compound, a chloride, and an alkaline earth metal compound are mixed and fired. As the bismuth compound, bismuth sulfate, bismuth nitrate, bismuth chloride, bismuth oxychloride, bismuth carbonate, bismuth oxide, and the like can be used. As the chloride, sodium chloride, potassium chloride, ammonium chloride, hydrochloric acid and the like can be used, and as the alkaline earth metal compound, an alkaline earth metal oxide, hydroxide, sulfate, nitrate, carbonate, Chloride and the like can be used. As the bismuth compound, bismuth oxychloride and bismuth oxide are preferable, and as the chloride and the alkaline earth metal compound, alkaline earth metal chlorides which are both compounds are preferable. These may be mixed dry using a mixer such as a mixer or mortar, or a pulverizer such as a jet mill, or may be wet mixed in a suspension. Alternatively, soluble bismuth salt and chloride ions may be mixed in an aqueous medium under hydrolysis conditions to produce bismuth oxychloride crystals, and then mixed with bismuth oxychloride crystals and an alkaline earth metal compound. Alternatively, soluble bismuth salt, chloride ions and alkaline earth metal compound may be mixed in an aqueous medium under hydrolysis conditions to produce bismuth oxychloride crystals containing an alkaline earth metal element. The hydrolysis conditions can be set as appropriate. For example, bismuth can be hydrolyzed by maintaining the pH of the aqueous medium at 1 or lower. The hydrolysis temperature is preferably about 50 to 100 ° C.
Next, the mixture is fired to produce a bismuth oxychloride pigment. The firing temperature can be appropriately set, and is preferably 200 to 1000 ° C, more preferably 300 to 700 ° C, and still more preferably 400 to 600 ° C. The firing time can be appropriately set, and about 0.5 to 10 hours is appropriate. The firing atmosphere is preferably air or an oxygen-containing atmosphere such as oxygen gas, and may be an inert atmosphere such as nitrogen gas or argon gas, or a reducing gas atmosphere such as hydrogen gas.

  In order to form a coating having a thickness of 1 to 100 nm composed of a metal oxide and / or a metal hydroxide on the particle surface of bismuth oxychloride, the following method can be employed. First, as raw materials, (1) calcined alkaline earth metal element-containing bismuth oxychloride, (2) uncalcined bismuth oxychloride crystal (containing an alkaline earth metal element), (3 It is possible to use baked bismuth oxychloride that does not contain alkaline earth metal elements, and (4) bismuth oxychloride crystals (that do not contain alkaline earth metal elements) before firing. These raw materials are suspended in a solvent to form a suspension. As the solvent, an aqueous solvent, an organic solvent such as an alcohol can be used, and an aqueous solvent, an alcohol solvent, or a mixed solvent of water and alcohol is preferable. Next, a metal compound is added to this suspension, pH adjustment, hydrolysis, etc. are performed, and a metal oxide and / or a metal hydroxide are deposited on the surface of the raw material bismuth oxychloride particles. When the pH adjustment or hydrolysis is performed, a coating having a thickness of 1 to 100 nm can be formed, and the metal oxide and / or metal hydroxide constituting the coating are preferably particles having a particle diameter of 0.5 to 50 nm. This is preferable.

  Examples of the metal compound include compounds of transition metal elements and typical metal elements including silicon. The typical metal element includes an alkaline earth metal element, and when the above (3) and (4) are used as raw materials, the alkaline earth metal compound is used because the raw material itself does not include an alkaline earth metal element. Will be used. Specifically, at least one compound selected from the group consisting of silicon, aluminum, titanium, tin, zinc, antimony, and iron is preferable as the metal compound, and a titanium compound that becomes titanium oxide having high ultraviolet shielding ability is more preferable. As the metal compound, compounds such as metal chloride, sulfate, nitrate, acetate, sodium salt, etc. can be used, adjusted to neutral precipitation pH, adjusted to pH and temperature to hydrolyze, Alternatively, metal hydroxide, hydrated oxide, hydrated oxide, oxide, or the like is deposited by an adsorption reaction. After depositing the metal oxide and / or metal hydroxide, the solvent may be removed, washed as necessary, and dried.

  Moreover, it is preferable to bake the bismuth oxychloride which precipitated the metal oxide and / or metal hydroxide as needed. When the above (2) and (4) are used as raw materials, the raw materials themselves are not fired, and are fired at this point. Moreover, when using said (3) as a raw material, although it has already baked, it is more preferable to bake at this time mixed with the alkaline earth metal compound. The firing temperature can be appropriately set. Specifically, the firing temperature is preferably 200 to 1000 ° C, more preferably 300 to 700 ° C, and still more preferably 400 to 600 ° C. If it is lower than 200 ° C., it is not preferable because the crystallinity is low and it is difficult to obtain sufficient light stability. On the other hand, if it is higher than 1000 ° C., the metal oxide itself or the metal hydroxide itself is likely to be sintered, yellowing, etc. It is not preferable because coloring is likely to occur. The firing time can be appropriately set, and about 0.5 to 10 hours is appropriate. The firing atmosphere may be any atmosphere, and may be air, an oxygen-containing atmosphere such as oxygen gas, an inert atmosphere such as nitrogen gas or argon gas, or a reducing gas atmosphere such as hydrogen gas.

  The pigment thus obtained may be pulverized as necessary to form a powder. Moreover, you may perform the surface treatment of the said inorganic substance and organic substance. Furthermore, the pigment of the present invention can be dispersed in an aqueous solvent and / or an organic solvent to form a dispersion. As the solvent, an aqueous solvent, an organic solvent such as alcohol or toluene can be used, and the content of the glitter pigment can be appropriately set. When manufacturing a dispersion, you may wet-grind or classify as needed.

  The pigment of the present invention and the dispersion containing the pigment can be used as a pigment imparting agent and a gloss imparting agent. Examples of the composition containing them include paint compositions and plastic molded products such as inks and films. Therefore, it is possible to utilize its excellent pigment property and glitter. In such a composition, the pigment of the present invention is blended in an arbitrary amount, preferably 0.01% by weight or more, and in addition, a composition forming material used in each field is blended, and various additions are added. An agent may be blended.

  For coating compositions and inks, film-forming materials or ink film-forming materials, solvents, dispersants, pigments, fillers, thickeners, flow control agents, leveling agents, curing agents, crosslinking agents, curing catalysts, etc. Is blended. Examples of coating film forming materials include organic components such as acrylic resins, alkyd resins, urethane resins, polyester resins, and amino resins, and inorganic components such as organosilicates and organotitanates. In this case, urethane resin, acrylic resin, polyamide resin, vinyl acetate resin, chlorinated propylene resin and the like can be used. Various materials such as thermosetting resin, room temperature curable resin, and ultraviolet curable resin can be used for these coating film forming material and ink film forming material. When a resin is used, a photopolymerization initiator or photosensitizer is blended, and UV light is applied and cured after application, a coating with excellent hardness and adhesion can be obtained without applying a thermal load to the substrate. Therefore, it is preferable.

  For plastic moldings, plastics, pigments, dyes, dispersants, lubricants, antioxidants, UV absorbers, light stabilizers, antistatic agents, flame retardants, bactericides, etc. are kneaded with the pigments of the present invention. The film is formed into an arbitrary shape such as a film. As the plastic, a thermoplastic resin such as polyolefin resin, polystyrene resin, polyester resin, acrylic resin, polycarbonate resin, fluororesin, polyamide resin, cellulose resin, polylactic acid resin, or thermosetting resin such as phenol resin or urethane resin is used. be able to.

  Next, examples of the coated article containing the pigment of the present invention include vehicles such as automobiles, motorcycles, trains and ships, buildings such as buildings, bridges and houses, electric products such as mobile phones, personal computers and televisions. . In these coated articles, a coating containing an arbitrary amount of pigment, preferably 0.01% by weight or more, is applied to the surface of the article.

  A conventionally known method can be used as the coating method, and the coating composition is applied to the surface of the article by electrodeposition coating, spraying, bar coater, dipping or the like, dried, and baked as necessary. For example, in the coating of an automobile outer plate, the “2-coat 1-bake method” is used as a general method for coating film formation, and the “3-coat 2-bake method”, “ A conventional method called “3-coat 1-bake method” can be employed.

  Next, in addition to the pigment of the present invention, the cosmetic includes other components that are usually used in cosmetics and pharmaceuticals, for example, other powder components, liquid fats and oils, solid fats and waxes, within a range that does not impair the effect. Hydrocarbon, higher alcohol, ester, silicone, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant, moisturizer, water-soluble polymer, thickener, film agent, UV absorber, Sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, organic amines, polymer emulsions, pH adjusters, skin nutrients, vitamins, antioxidants, antioxidant aids, fragrances, water, etc. as required And can be produced by a conventional method according to the intended dosage form.

  The cosmetic of the present invention can be widely applied to cosmetics, pharmaceuticals, and quasi-drugs applied to the outer skin. The dosage form is arbitrary, such as solution system, solubilization system, emulsification system, powder dispersion system, water-oil two-layer system, water-oil-powder three-layer system, gel, aerosol, mist, capsule, etc. It can be provided in the form. In addition, the product form of the cosmetic is also arbitrary, facial cosmetics such as lotion, milky lotion, cream and pack; makeup cosmetics such as foundation, funny, blusher, lipstick, eye shadow, eyeliner, mascara and sunscreen; Body cosmetics; Aromatic cosmetics; Makeup removers, facial cleansers, skin cleansers such as body shampoos; hair cosmetics such as hair rinses and shampoos; ointments; bath preparations; It can be applied in any form.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

Example 1
Bismuth oxychloride (BiOCl), barium chloride, bismuth oxide (Bi ₂ O ₃ ) were weighed at a molar ratio of 3.4 / 0.8 / 0.2, mixed in a mortar, and then at a temperature of 500 ° C. for 8 hours. By calcining, the bismuth oxychloride pigment (sample A) of the present invention was obtained.
The composition of Sample A was Bi _3.8 Ba _0.8 Cl ₅ O ₄ and the XRD pattern was almost the same as bismuth oxychloride. Moreover, it turned out that the particle | grain shape of the sample A is a flaky form from electron microscope observation.

Examples 2-4
In the above Example 1, the bismuth oxychloride pigment of the present invention (Samples B, C, and D) was the same as Example 1 except that the firing temperature was changed to 600 ° C, 700 ° C, and 800 ° C. Got.
The compositions of Samples B, C, and D were Bi _3.8 Ba _0.8 Cl ₅ O ₄ and the XRD pattern was almost the same as bismuth oxychloride. Moreover, it turned out that the particle shape of sample B, C, D is flake shape from electron microscope observation.

Examples 5-8
In the above Examples 1 to 4, bismuth oxychloride pigments (samples E to H) of the present invention were obtained in the same manner as in Examples 1 to 4 except that barium chloride was replaced with strontium chloride.
The compositions of Samples E to H were Bi _3.8 Sr _0.8 Cl ₅ O ₄ and the XRD pattern was almost the same as bismuth oxychloride. Moreover, it turned out that the particle | grain shape of the samples E, F, G, and H is a flaky form from electron microscope observation.

Examples 9-12
In the said Examples 1-4, except having replaced barium chloride with calcium chloride, it carried out similarly to Example 1, and obtained the bismuth oxychloride pigment (sample IL) of this invention.
The compositions of Samples I to L were Bi _3.8 Ca _0.8 Cl ₅ O ₄ and the XRD pattern was almost the same as bismuth oxychloride. Moreover, it turned out that the particle shape of sample I, J, K, and L is a flaky form from electron microscope observation.

Examples 13-16
In the said Examples 1-4, except having replaced barium chloride with magnesium chloride, it carried out similarly to Example 1, and obtained the bismuth oxychloride pigment | dye (sample MP) of this invention.
The compositions of samples M to P were Bi _3.8 Mg _0.8 Cl ₅ O ₄ and the XRD pattern was almost the same as bismuth oxychloride. Moreover, it turned out that the particle | grain shape of the samples M, N, O, and P is flaky form from electron microscope observation.

Comparative Examples 1-4
The bismuth oxychloride used in Examples 1 to 4 was calcined at 500 ° C., 600 ° C., 700 ° C., and 800 ° C. for 8 hours to obtain bismuth oxychloride pigments (samples Q to T). Moreover, it turned out that the particle shape of sample Q, R, S, T is flake shape from electron microscope observation.

Light Stability Evaluation Cellulose powder is packed in an aluminum ring, and each sample is spread on a medicine wrapping paper, and irradiated with black light having an intensity of 4.5 mW / cm ² for 24 hours and 48 hours. Light resistance was evaluated by a color difference ΔE from the sample. The color difference was measured using a spectrocolorimeter SD-5000 manufactured by Nippon Denshoku Industries Co., Ltd.
The color difference ΔE was calculated by the following formula. (JIS Z 8730 compliant)
Color difference ΔE = ((L * −L * 0) ² + (a * −a * 0) ² + (b * −b * 0) ² ) ^(1/2)
* L * 0, a * 0, b * 0; Powder L * value, a * value, b * value before black light irradiation * L *, a *, b *; Powder L * after black light irradiation Value, a * value, b * value Table 1 shows the powder color of the sample before black light irradiation, and Table 2 shows the color difference ΔE. It was confirmed that Samples A to T had substantially the same glossiness. Samples A, B, C, and G were found to have a smaller color difference ΔE, better light stability, and better light resistance than comparative samples Q, R, and S.

  The pigment of the present invention is bismuth oxychloride containing an alkaline earth metal element, can suppress the photochromic property of bismuth oxychloride, and has a unique soft opal luster gloss. For example, it can be used for coating compositions, coated articles, cosmetics, and the like.

Claims (7)

  A pigment mainly composed of bismuth oxychloride containing an alkaline earth metal element.   The pigment according to claim 1, wherein the alkaline earth metal element is barium and / or strontium.   The pigment according to claim 1, wherein the content of the alkaline earth metal element is 5 to 50 mol% with respect to bismuth.   A method for producing bismuth oxychloride containing an alkaline earth metal element, in which a bismuth compound, chloride, and an alkaline earth metal compound are mixed and fired.   The coating composition containing the pigment as described in any one of Claims 1-3.   The coated article containing the pigment as described in any one of Claims 1-3.   Cosmetics containing the pigment according to any one of claims 1 to 3.