CARBON-COATED BiOCl PIGMENTS

Abstract

BiOCl pigments coated with an amorphous carbon. A process for the preparation of the pigments. And use of the pigments prepared in this way, inter alia in paints, coatings, printing inks, plastics and cosmetics.

Claims

1. A coated BiOCl pigment, which comprises a flake-form BiOCl pigment coated on the surface with an amorphous carbon layer.

2. The BiOCl pigment according to claim 1, wherein the flake-form BiOCl pigment has a particle size of 1-30 μm.

3. The BiOCl pigment according to claim 1, wherein the BiOCl pigment has a thickness of 50-100 nm.

4. The BiOCl pigment according to claim 1, wherein the BiOCl pigment has a volume-weighted D.sub.50 value of <25 μm (determined using a Malvern).

5. The BiOCl pigment according claim 1, wherein the BiOCl pigment has an aspect ratio (ratio of length or width to thickness) of 10-600.

6. The BiOCl pigment according to claim 1, wherein the amorphous carbon layer has a geometrical layer thickness of 1 to 5 nm.

7. The BiOCl pigment according to claim 1, wherein the proportion of the amorphous carbon layer, based on the weight of the coated BiOCl pigment, is 0.5-5% by weight.

8. A process for the preparation of the coated BiOCl pigment according to claim 1, which comprises covering the flake-form BiOCl pigment as substrate with a layer of amorphous carbon in a reactor in a stream of carrier gas at a temperature of 150-400° C. in the presence of one or more carbon-containing compounds by pyrolytic decomposition of the carbon-containing compound(s).

9. The process according to claim 8, wherein one or more carbon-containing compound is acetone, ethine or a pulverulent compound selected from the group consisting of mono-, di- or trisaccharides.

10. The process according to claim 8, wherein one or more carbon-containing compound is fructose, glucose, dextrose, galactose, xylose, mannose, lactose, sucrose, maltose or a mixture of the said compounds.

11. The process according to claim 8, wherein the flake-form BiOCl pigment is kept in motion in the reactor.

12. A paint, coating, industrial coating, automotive paint, printing ink, paper, plastic, film, cosmetic, button paste or RADAR-permeable coating formulation or a dry preparation for pigment preparations, comprising a coated BiOCl pigment according to claim 1.

13. A three-coat paint system, comprising a coated BiOCl pigment according to claim 1.

14. A composition comprising the coated BiOCl pigment according to claim 1 and a further component.

15. The composition according to claim 14, wherein the further component is a component used in an industrial coating or automotive paint.

16. The composition according to claim 14 wherein the further component is a component used in a cosmetic.

17. The composition according to claim 14, wherein the further component is at least one constituent selected from the group consisting of absorbents, astringents, antimicrobial substances, antioxidants, antiperspirants, antifoaming agents, antidandruff active compounds, antistatics, binders, biological additives, bleaches, chelating agents, deodorants, emollients, emulsifiers, emulsion stabilisers, dyes, humectants, film formers, fillers, fragrances, flavours, insect repellents, preservatives, anticorrosion agents, cosmetic oils, solvents, oxidants, plant constituents, buffer substances, reducing agents, surfactants, propellant gases, opacifiers, UV filters, UV absorbers, denaturing agents, aloe vera, avocado oil, coenzyme Q10, green tea extract, viscosity regulators, perfumes, vitamins, enzymes, trace elements, proteins, carbohydrates, organic pigments and inorganic pigments.

Description

EXAMPLES

Example 1

[0092] In a Turbula mixer (WAB), 100 g of dried flake-form BiOCl pigments having a particle size <20 μm and a thickness of 60-80 nm, D.sub.50=15 μm and D.sub.80=20 μm (Malvern Mastersizer MS 3000) are mixed with 2 g of sucrose (powdered sugar) for 30 min at a frequency of 34 rpm. The carbon coating is carried out in a fluidised-bed reactor (DI=100 mm) at a reaction temperature of 250° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 30 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0093] The amorphous-carbon-coated BiOCl pigment obtained is distinguished by a metallic silver-grey lustre.

Example 2

[0094] In a Turbula mixer (WAB), 100 g of dried flake-form BiOCl pigments having a particle size <20 μm and a thickness of 50-80 nm, D.sub.50=15 μm and D.sub.80=20 μm (Malvern Mastersizer MS 3000) are mixed with 1 g of sucrose (powdered sugar) for 30 min at a frequency of 72 rpm. The carbon coating is carried out in a fluidised-bed reactor (DI=100 mm) at a reaction temperature of 200° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 30 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0095] The pigment from Example 2 exhibits a darker metallic silver-grey lustre compared with Example 1.

Example 3

[0096] In a Turbula mixer (WAB), 100 g of flake-form BiOCl pigments of the RonaFlair® LF-2000 type (Merck, BiOCl pigment with D.sub.50=8-20 μm, D.sub.80<35 μm, thickness 200-500 nm) are mixed with 3 g of D-fructose for 30 min at a frequency of 200 rpm. The carbon coating is carried out in a fluidised-bed reactor (DI=100 mm) at a reaction temperature of 220° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 20 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0097] A dark pigment with a silver-white lustre is obtained.

Example 4

[0098] In a Turbula mixer (WAB), 100 g of flake-form BiOCl pigments of the RonaFlair® B-50 type (2-35 μm, D.sub.50=9-15 μm, D.sub.80 2-35 μm, thickness 200-500 nm) are mixed with 2.5 g of glucose for 30 min at a frequency of 150 rpm. The carbon coating is carried out in a fluidised-bed reactor (DI=100 mm) at a reaction temperature of 150° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 20 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0099] A dark pigment with a silver-white lustre is obtained.

Example 5

[0100] In a Turbula mixer (WAB), 100 g of flake-form BiOCl pigments of the RonaFlair® ESQ type (product from Merck KGaA having a particle size of 2-35 μm, D.sub.50=11-17 μm, D.sub.80 2-35 μm, thickness 200-500 nm) are mixed with 5 g of lactose for 40 min at a frequency of 45 rpm. The carbon coating is carried out in a fluidised-bed reactor (DI=100 mm) at a reaction temperature of 280° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 20 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0101] A very dark pigment with a silver lustre is obtained.

Example 6

[0102] In a Turbula mixer (WAB), 100 g of flake-form BiOCl pigments of the RonaFlair® Fines type (product from Merck KGaA having a particle size of 2-35 μm, D.sub.50=9-15 μm, D.sub.80 2-35 μm, thickness 50-100 nm) are mixed with 1 g of glucose for 30 min at a frequency of 60 rpm. The carbon coating is carried out in a fluidised-bed reactor (DI=100 mm) at a reaction temperature of 250° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 30 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0103] A pale pigment with a silver lustre is obtained.

Example 7

[0104] 100 g of flake-form BiOCl pigments of the RonaFlair® MTU type (product from Merck KGaA having a particle size of 2-35 μm, thickness 500 700 nm) are mixed with 2.5 g of sucrose (powdered sugar) in a fluidised-bed reactor (DI=100 mm) for 30 min at the minimum fluidisation velocity. The carbon coating is carried out in the fluidised-bed reactor at a reaction temperature of 180° C. The fluidisation gas used is N.sub.2. The fluidisation velocity corresponds to 10 times the value of the expected theoretical minimum fluidisation velocity of 2 mm/s. The carbon coating is carried out under inert conditions for 30 min. The fluidised BiOCl particle bed is then cooled to room temperature, likewise under inert gas. The carbon coating is subsequently sieved.

[0105] A pale pigment with a silver lustre is obtained.

[0106] The pinhole-free, amorphous carbon coating of the BiOCl flakes is demonstrated using confocal RAMAN spectroscopy and with the aid of transmission electron microscopy (TEM).

[0107] The BiOCl pigments coated with amorphous carbon are distinguished by increased stability, by a metallic silver lustre and high hiding power and can be dispersed and re-dispersed very well in application media.

USE EXAMPLES

Use Example 1: Paint

[0108] 20.35 g of BiOCl pigment from Example 1 are incorporated into 679.65 g of a commercially available water-based base coat (Mipa WBC000, Mipa).

[0109] The drying is carried out at 80° C. for 5 min. The pigmented paint is applied to a metal panel and subsequently overcoated with 805 g of 2-component clear coat (Mipa CC4, Mipa).

[0110] The drying is carried out at room temperature for 15 min and subsequently at 80° C. for 5 min.

Use Example 2: Paint

[0111] 20.35 g of BiOCl pigment from Example 2 are incorporated into 679.65 g of a commercially available water-based base coat (Mipa WBC000, Mipa).

[0112] The drying is carried out at 80° C. for 5 min. The pigmented paint is applied to a metal panel and subsequently overcoated with 805 g of 2-component clear coat (Mipa CC4, Mipa).

[0113] The drying is carried out at room temperature for 15 min and subsequently at 80° C. for 5 min.

[0114] The liquid-metal effect of the painted panels is investigated in accordance with Equation 1 using a BYK-mac i from BYK Gardner GmbH, a multi-angle colour measuring instrument.

[0115] The liquid-metal effect of a coating system is measured and evaluated by means of the liquid index LI, which is defined as the ratio of the flop index FI and the graininess G and is calculated as follows:

[00001]$\begin{array}{cc}\mathrm{LI}=\frac{\mathrm{FI}}{G}=\frac{\frac{{\left(L_{15.Math.°}^{*}-L_{110.Math.°}^{*}\right)}^{1,11}}{L_{4.Math.5}^{*0,86}}}{G}.& \left(I\right)\end{array}$

[0116] FI describes the lightness difference L* at flat (L*(15°)) and steep (L*(110°)) viewing angles. The coating texture is described by the quantity G (graininess). Layer-like application of paint, irrespective of the use in an automotive paint or a cosmetic coating, only exhibits the liquid-metal effect in the case where FI is greater than 21. At the same time, G must have values less than three, so that the LI in the case of a liquid-metal finish is always greater than seven (see measurement values for Example 1 in the table).

TABLE-US-00001 FI G LI (flop index) (graininess) (liquid index) Coated BiOCl 21.7 2.4 8.9 pigment from Example 1 Uncoated BiOCl 18.5 2.8 6.6 pigment from Example 1

[0117] The pigments according to the invention from Examples 1 and exhibit a pronounced liquid-metal effect in the paint.

Use Example 3—Eye Shadow

[0118]

TABLE-US-00002 Raw INCI material (CTFA) wt.-% Phase A Pigment from (1) 30.00 Example 1 Parteck ® (1) TALC 10.00 LUB Talc Phase B RonaCare ® AP (1) BIS-ETHYLHEXYL 0.50 HYDROXYDIMETHOXY BENZYLMALONATE Oxynex ® K (1) PEG-8, TOCOPHEROL, 0.10 liquid ASCORBYL PALMITATE, ASCORBIC ACID, CITRIC ACID all-rac-alpha- (1) TOCOPHERYL ACETATE 0.50 Tocopheryl acetate Parteck ® (1) STEARIC ACID 3.00 LUB STA 50 SP Crodamol PMP (2) PPG-2 MYRISTYL 30.90 MBAL-LQ-(MH) ETHER PROPIONATE Syncrowax HGLC (2) C18-36 ACID 10.00 TRIGLYCERIDE Miglyol ® 812 N (3) CAPRYLIC/CAPRIC 8.00 TRIGLYCERIDE Syncrowax HRC (2) TRIBEHENIN 3.00 Ganex ™ V-216 (4) PVP/HEXADECENE 2.00 COPOLYMER Sunflower oil, (5) HELIANTHUS ANNUUS SEED 1.00 refined OIL (HELIANTHUS ANNUUS (SUNFLOWER) SEED OIL) Sensiva ® PA (6) PHENETHYL ALCOHOL, 1.00 20 ETHYLHEXYL GLYCERIN

[0119] Preparation:

[0120] Heat phase B to 80° C. until all constituents have melted. Cool to 65° C. and add the constituents of phase A with stirring. Transfer the material into the desired container at 65° C. Cool to room temperature.

[0121] Manufacturers:

[0122] (2) Croda

[0123] (3) 101 Oleo GmbH (4) Ashland

[0124] (5) Gustav Heess GmbH (6) Schulke & Mayr GmbH

Use Example 4—Eye Shadow Gel

[0125] Phase A

TABLE-US-00003 Raw Source of material supply INCI wt.-% Pigment from Merck KGaA/ 15.00 Example 2 Rona ® Micronasphere ® M Merck KGaA/ MICA, SILICA 8.00 Rona ® Carbopol Noveon ACRYLATES/C10-30 0.40 Ultrez 21 ALKYL ACRYLATE CROSSPOLYMER Citric acid Merck KGaA/ CITRIC ACID 0.00 monohydrate Rona ® Water AQUA (WATER) to 100

[0126] Phase B

TABLE-US-00004 Raw Source of material supply INCI wt.-% Glycerin Merck KGaA/ GLYCERIN 3.00 Rona ® Preservative q.s. Triethanolamine TRIETHANOLAMINE 0.70 Water AQUA (WATER) 13.00 

[0127] Phase C

TABLE-US-00005 Raw Source of material supply INCI wt.-% Lubrajel DV PROPYLENE GLYCOL, 5.00 POLYGLYCERYL METHACRYLATE

[0128] Preparation:

[0129] Disperse the pigment and the Micronasphere® in the water of phase A. Acidify using a few drops of citric acid in order to reduce the viscosity, scatter in the Carbopol with stirring. When dissolution is complete, slowly stir in the pre-dissolved phase B and subsequently phase C. Finally, adjust the pH to between 7.0-7.5.

Use Example 5—Lipstick

[0130] Phase A

TABLE-US-00006 Raw Source of material supply INCI wt.-% Pigment from 12.00 Example 2 Ronastar ® Merck KGaA/ Calcium Aluminum 3.00 Purple Sparks Rona ® Borosilicate, CI77891 (Titanium Dioxide), Silica, Tin Oxide

[0131] Phase B

TABLE-US-00007 Raw Source of material supply INCI wt-% Beeswax Merck KGaA/ Cera Alba 8.75 Rona ® (Beeswax) Paracera Paramelt COPERNICIA 5.25 C44 CERIFERA (CARNAUBA WAX), CERESIN Adeps Lanae Henry Lamotte LANOLIN 3.50 GmbH Isopropyl Cognis GmbH Isopropyl 5.60 myristate Myristate Viscous Merck KGaA/ PARAFFINUM 2.10 paraffin Rona ® LIQUIDUM (MINERAL OIL) Castor oil Henry Lamotte RICINUS 59.65 GmbH COMMUNIS (CASTOR OIL) Oxynex ® Merck KGaA/ PEG-8, 0.05 K liquid Rona ® TOCOPHEROL, ASCORBYL PALMITATE ASCORBIC ACID, CITRIC ACID Propyl Merck KGaA/ PROPYLPARABEN 0.10 4-hydroxy- Rona ® benzoate

[0132] Preparation:

[0133] The constituents of phase Bare heated to 75° C. and melted. The pigments of phase Aare added, and everything is stirred well. The lipstick composition is then stirred for 15 minutes in the casting apparatus held at a temperature of 65° C. The homogeneous melt is poured into the casting mould prewarmed to 5500. The moulds are subsequently cooled and the cold castings are removed. After warming to room temperature, the lipsticks are briefly flame-treated.

Use Example 6—Nail Varnish

[0134]

TABLE-US-00008 Raw Source of material supply INCI wt.-% Pigment from 2.00 Example 3 Nailsyn ® Merck KGaA/ CI 77163 (Bismuth 1.00 Sterling 60 Rona ® Oxychloride), Butyl Silver Acetate, Nitrocellulose, Isopropyl Alcohol, Ethyl Acetate, Stearnalkonium Hectorite Thixotropic Durlin/ BUTYL ACETATE, 97.00 nail varnish Bergerac NC ETHYL ACETATE base 155 NITROCELLULOSE, ACETYL TRIBUTYL CITRATE, PHTHALIC ANHYDRIDE/ TRIMELLITIC ANHYDRIDE/GLYCOLS COPOLYMER, ISOPROPYL ALCOHOL, STEARALKONIUM HECTORITE, ADIPIC ACID/FUMARIC ACID/PHTHALIC ACID/TRICYCLODECANE DIMETHANOL COPOLYMER, CITRIC ACID

[0135] Preparation:

[0136] The pigment and the Nailsyn® Sterling 60 Silver are weighed out together with the varnish base, mixed well by hand using a spatula and subsequently stirred at 1000 rpm for 10 min.

Use Example 7—Soap

[0137]

TABLE-US-00009 Raw Source of material supply INCI wt-% Pigment from 1.50 Example 1 Ronastar ® Merck KGaA/ Calcium Aluminum 0.50 Noble Sparks Rona ® Borosilicate, Silica, CI 77891 (Titanium Dioxide), Tin Oxide Transparent Jean Charles SODIUM PALMATE, 98.00 soap base (USA) SODIUM LAURETH SULFATE, SODIUM STEARATE, SODIUM MYRISTATE, SODIUM COCOYL ISETHIONATE, TRIETHANOLAMINE, AQUA (WATER), GLYCERIN, SORBITOL, PROPYLENE GLYCOL, FRAGRANCE

[0138] Preparation:

[0139] All constituents are mixed homogeneously.

[0140] The entire disclosure[s] of all applications, patents and publications, cited herein and of corresponding German Patent Application No. 102019008593.0, filed Dec. 11, 2019, is [are] incorporated by reference herein.

[0141] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

[0142] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.