# US 5,344,486 A · Platelet-like pigments

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- Number: US 5,344,486 A
- Document ID: US5344486A
- Status: Granted
- Kind: A
- Application number: 08/013,840
- Filed: 1993-02-05
- Granted: 1994-09-06
- Earliest claimed: 1992-02-07
- Assignees: Merck Patent GmbH
- Inventors: Bernhard Mainz
- Web page: https://patentgrep.com/patent/US5344486A

## CPC

- A61K 8/0216: {Solid or semisolid forms}
- A61K 8/0254: {Platelets; Flakes}
- A61K 8/19: containing inorganic ingredients
- A61Q 1/02: Preparations containing skin colorants, e.g. pigments (preparations in powder form A61Q1/12)
- C09C 1/00: Treatment of specific inorganic materials other than fibrous fillers (tenebrescent materials C09K9/00; luminescent materials C09K11/00); Preparation of carbon black
- C09C 1/0015: {Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings}
- C09C 1/0021: {comprising a core coated with only one layer having a high or low refractive index}
- A61K 2800/412: Microsized, i.e. having sizes between 0.1 and 100 microns
- A61K 2800/43: Pigments; Dyes
- A61K 2800/651: The particulate/core comprising inorganic material
- C01P 2004/20: extending in two dimensions, e.g. plate-like
- C01P 2004/84: one phase coated with the other
- C09C 2200/1087: the core consisting of bismuth oxychloride, magnesium fluoride, nitrides, carbides, borides, lead carbonate, barium or calcium sulfate, zinc sulphide, molybdenum disulphide or graphite
- C09C 2200/301: Thickness of the core
- C09C 2200/403: Low molecular weight materials, e.g. fatty acids
- C09C 2200/404: comprising additional functional groups, e.g. -NH2, -C=C- or -SO3
- C09C 2220/103: comprising a drying or calcination step after applying each layer
- Y10T 428/2993: Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS}
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention relates to pigments based on platelet-like substrates substantially composed of nitridic material and coated with at least one dye and/or one metal oxide, and to processes for their preparation and also to their use in cosmetic preparations.

## Claims

### Claim 1

A pigment comprising a platelet-shaped substrate which is a metal nitride, having coated on the surface thereof at least one dye, at least one metal oxide or a mixture thereof.

### Claim 2 (depends on 1)

A pigment according to claim 1, wherein the metal nitride is boron nitride or aluminum nitride.

### Claim 3 (depends on 1)

A pigment according to claim 1, wherein the dye is an inorganic dye.

### Claim 4 (depends on 1)

A pigment according to claim 1, wherein the dye is an organic dye.

### Claim 5 (depends on 3)

A pigment according to claim 3, wherein the dye is Prussian blue.

### Claim 6 (depends on 4)

A pigment according to claim 4, wherein the dye is carmine or 1,4-diketopyrrolo- (3,4-c)pyrrole.

### Claim 7 (depends on 1)

A pigment according to claim 1, wherein the substrate is coated with at least one metal oxide, which is Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4, Al.sub.2 O.sub.3, ZrO.sub.2, Cr.sub.2 O.sub.3, Fe.sub.2 TiO.sub.5 or TiO.sub.2.

### Claim 8 (depends on 1)

In a cosmetic preparation comprising a pigment, the improvement wherein the pigment is one of claim 1.

### Claim 9 (depends on 2)

In a cosmetic preparation comprising a pigment, the improvement wherein the pigment is one of claim 2.

### Claim 10 (depends on 1)

A pigment according to claim 1, prepared by a process comprising precipitating at least one metal oxide onto the surface of the platelet-shaped substrate.

### Claim 11 (depends on 1)

A pigment according to claim 1, prepared by a process comprising converting a dye precursor into a dye in the presence of a suspension of the substrate, whereby the dye is coated onto the substrate.

### Claim 12 (depends on 1)

A pigment according to claim 1, prepared by a process comprising coating the substrate with a precursor of the metal oxide or dye, and converting the precursor to metal oxide or dye after said coating.

### Claim 13 (depends on 1)

A pigment according to claim 1, wherein the substrate is coated with the metal oxide, and the metal oxide is a colored metal oxide.