EP2092022A2

EP2092022A2 - Pearlescent pigments

Info

Publication number: EP2092022A2
Application number: EP07856617A
Authority: EP
Inventors: Carsten Handrosch; Marcus Mathias; Nicole Schupp; Meike Willius
Original assignee: Merck Patent GmbH
Current assignee: Merck Patent GmbH
Priority date: 2006-12-20
Filing date: 2007-12-12
Publication date: 2009-08-26
Also published as: WO2008077487A2; DE102006060997A1; US20100021565A1; JP2010513614A; US8114211B2; WO2008077487A3

Abstract

The invention relates to pearlescent pigments based on platelet-shaped substrates containing at least one FeOOH layer and at least one TiO2 layer or at least one TiO2-SiO2-TiO2 multilayer, as well as the use thereof, among other things in paints, lacquers, printing inks, coating powders, plastics, and particularly in treatment cosmetics and decorative cosmetics.

Description

pearlescent

The present invention relates to pearlescent pigments based on platelet-shaped substrates which contain at least one FeOOH layer and at least one TiO ₂ layer or a TiO ₂ -SiO ₂ -TiO ₂ layer package, and their use in paints, coatings, printing inks, powder coatings and in particular in the care and decorative cosmetics.

Pearlescent pigments with iron oxide deposits are known in the art. As a rule, mica platelets are coated with Fe ₂ O ₃ or Fe ₂ TiO ₅ . Frequently, however, iron oxide deposits on mica cause cracks, which reduce color brilliance.

The object of the present invention is to provide pearlescent pigments with iron oxide coatings which do not have such disadvantages.

Wurdenun surprisingly found that platelet-shaped substrates having both a FeOOH-layer and a TiO ₂ film or a TiO ₂ -SiO ₂ -TiO ₂ having -Schichtpaket which combine a novel combination of brilliant interference color and brilliant, pure body color in itself , Due to the lower

Annealing temperatures also prevents the formation of pseudobrookite at the boundary layers between Ti and Fe-containing layers.

The invention therefore pearlescent pigments, which are characterized in that they

(A) at least one FeOOH layer

and

(B) at least one TiO ₂ layer or at least one TiO ₂ -SiO ₂ - TiO ₂ layer package and

(C) optionally an outer colorless coating of one or more

Layers with a refractive index of <1, 8

exhibit.

In the pearlescent pigments according to the invention, it is possible to combine any TiO ₂ interference color with any FeOOH body color, which leads to interesting color variants; it is possible to deposit both a layer sequence (A) (B) and the layer sequence (B) (A) on the substrate, ie on the substrate is a layer sequence TiO ₂ + FeOOH, FeOOH + TiO ₂ ,

TiO ₂ + SiO ₂ + TiO ₂ + FeOOH or FeOOH + TiO ₂ + SiO ₂ + TiO ₂ .

Since the pearlescent pigments according to the invention have a very smooth surface, they are particularly suitable for nourishing and decorative cosmetics because of their very good skin feel. Furthermore, they are suitable for pigmenting paints, lacquers, powder coatings, printing inks, plastics, seed coloring, for finishing, coloring or coating food and pharmaceutical products, including

Medicament coatings and for the preparation of pigment preparations and dry preparations suitable.

The pearlescent pigments according to the invention are very attractive, in particular for topical applications, because of the achievable combinations of interference color and body color in the beige and skin-colored color range.

Suitable base substrates for the pearlescent pigments according to the invention are, on the one hand, opaque and, on the other hand, transparent platelet-shaped substrates. Particularly preferred are transparent platelet-shaped substrates. Suitable substrates are in particular natural and synthetic mica, talc, kaolin, platelet-shaped iron or aluminum oxides, glass, SiO ₂ , TiO ₂ , graphite platelets, synthetic carrier-free platelets.

Liquid crystal polymers (LCPs), holographic pigments, BiOCl platelets, metal platelets, optionally passivated, e.g. Aluminum flakes, aluminum bronze flakes, brass bronzes, zinc bronzes, titanium bronzes or other similar materials.

Of the substrates mentioned, glass flakes are particularly preferred, furthermore natural mica flakes and synthetic mica flakes, for example of fluorophlogophite. Very particularly preferred substrates are glass plates which are coated with an SiO ₂ layer.

The size of the base substrates is not critical per se and can be tailored to the particular application. As a rule, the platelet-shaped substrates have an average thickness of <10 μm, in particular an average thickness of 0.15-5 μm. The expansion in the other two ranges is on average usually from 1 to 1000 μm, preferably from 2 to 250 μm, in particular from 5 to 150 μm.

If the substrate is a glass plate, it is preferably silicate glasses, such as soda lime glass, borosilicate glass, aluminosilicate glass, lead crystal glass, window glass, E, A, C, ECR glass, Duranglas.

The glass platelets preferably have an average thickness of <10 .mu.m, in particular on average from 50 nm to 5 .mu.m, particularly preferably from 50 to 800 nm and very particularly preferably from 50 to 600 nm.

The glass platelets are furthermore preferably characterized by a refractive index of 1.2 to 2.1, preferably of 1.3 to 1.9, and very particularly preferably of 1.4 to 1.6.

Suitable substrate platelets preferably have an aspect ratio

(Ratio: diameter / thickness) of 5-750, in particular from 10 to 300, very particularly preferably from 20 to 200 on. - A -

The thickness of the individual layers (A), (B) and (C) is essential for the optical properties of the pigment. In order to obtain a particularly intense interference color in a pigment u.a. the thickness of the individual layers must be exactly matched to one another. Regardless of the type and refractive index of the individual layers, the thickness of each layer is generally 1 to 1000 nm, in particular 10 to 800 nm and particularly preferably 20 to 600 nm.

The FeOOH layer (A) has on average preferably layer thicknesses of 10 to 550 nm, in particular 15 to 400 nm and very particularly preferably 20 to 350 nm. The FeOOH layer usually makes up 0.01-300% by weight, in particular 1-200% by weight and very particularly preferably 2-100% by weight, based on the substrate.

If layer (B) is a TiO ₂ layer, it can be present in both anatase and rutile form. Preferably, it is a rutile layer. On average, the TiO ₂ layer preferably has layer thicknesses of 5 to 550 nm, in particular 10 to 400 nm and very particularly preferably 15 to 350 nm. For the rutilization of TiO ₂ , numerous methods are known from the literature. Is preferably used as a host for the epitaxial overgrowth of TiO ₂ in the rutile modification SnO _2, that is, usually, prior to the occupancy of TiO _2, a thin SnO ₂ layer is applied, which usually layer thicknesses of 1 - 50 nm, in particular 1 - 40 nm and most preferably from 1 to 30 nm.

If the layer (B) is a TiO ₂ -SiO ₂ -TiO ₂ layer package, the layer thicknesses of the TiO ₂ layers may be the same or different. The product may contain a TiO ₂ -SiO ₂ -TiO ₂ layer package, but also several layers above one another. However, the sum of all layers deposited on the substrate should not exceed a total thickness of 3 μm. The individual TiO ₂ layers in the package can each _. in the anatase or rutile modification. Preferably, they are present as a rutile layer. The individual TiO ₂ layer in the layer package preferably has layer thicknesses of 5 to 550 nm, in particular 10 to 400 nm, very particularly preferably 15 to 350 nm. The SiO ₂ layer in the Layer package preferably has layer thicknesses of 1 to 1000 nm, in particular of 10 to 800 nm and very particularly preferably of 20 to 600 nm. The total layer thickness of the TiO ₂ -SiO ₂ -TiO ₂ is preferably

Accordingly, layer packages are <2,100 nm, in particular <1,600 nm and very particularly preferably <1,300 nm.

Materials suitable for layer (C) are colorless low-index materials, preferably metal oxides or the corresponding ones

Oxide hydrates. Examples include: SiO ₂ , Al ₂ O ₃ , AIO (OH), B ₂ O ₃ , MgF ₂ , MgSiO ₃ or a mixture of the compounds mentioned. The thickness of the layer (C) is on average preferably 1-1000 nm, in particular 10-800 nm and very particularly preferably 20-600 nm. This layer may occur once or even several times in the layer sequence. But it can also be completely missing.

It is often advisable to introduce an SiO ₂ interlayer between the substrate and the first layer on the substrate and / or after the FeOOH layer, if at least one further layer follows. This intermediate layer (Z) preferably has layer thicknesses of 1 to 1000 nm, in particular of 1 to 500 nm and very particularly preferably of 1 to 300 nm.

In the case of glass as a substrate, the SiO ₂ layer protects the substrate surface from chemical changes such as swelling, leaching of glass components or dissolution in the aggressive acidic coating solutions. However, regardless of the nature of the substrate, the adhesion of the coating (s) following the SiO ₂ layer also generally increases. In this way, the overall stability of the

Coating and thus of the pigment increases. Furthermore, the SiO ₂ intermediate layer has a positive effect on the gloss of the pigment.

Particularly preferred pearlescent pigments have the following layer sequences:

Substrate + SiO ₂ + TiO ₂ + FeOOH Substrate + SiO ₂ + TiO ₂ + SiO ₂ + FeOOH Substrate + SiO ₂ + FeOOH + TiO ₂

Substrate + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂ + FeOOH Substrate + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂ + SiO ₂ + FeOOH

Substrate + SiO ₂ + FeOOH + SiO ₂ + TiO ₂

Substrate + SiO ₂ + FeOOH + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂

Substrate + SiO ₂ + FeOOH + TiO ₂ + SiO ₂ + TiO ₂

Substrate + TiO ₂ + FeOOH substrate + TiO ₂ + SiO ₂ + FeOOH

Substrate + FeOOH + TiO ₂

Substrate + TiO ₂ + SiO ₂ + TiO ₂ + FeOOH

Substrate + TiO ₂ + SiO ₂ + TiO ₂ + SiO ₂ + FeOOH

Substrate + FeOOH + SiO ₂ + TiO ₂ Substrate + FeOOH + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂

Substrate + FeOOH + TiO ₂ + SiO ₂ + TiO ₂

The pearlescent pigments according to the invention can be prepared relatively easily. The layers are preferably applied wet-chemically, whereby the wet-chemical coating processes developed for the production of pearlescent pigments can be used. Such methods are described for example in DE 14 67 468, DE 19 59 988, DE 20 09 566, DE 22 14 545, DE 22 15 191, DE 22 44 298, DE 23 13 331, DE 25 22 572, DE 31 37 808 DE 31 37 809, DE 31 51 343, DE 31 51 355, DE 32 11 602, DE 32 35 017 or in further the

Specialist in known patent documents and other publications.

In the case of wet coating, the substrate particles are suspended in water and admixed with one or more hydrolyzable metal salts at a pH suitable for the hydrolysis, which is chosen such that the metal oxides or metal oxide hydrates are precipitated directly on the platelets without being too substantial Precipitation comes. The pH is usually kept constant by simultaneous addition of a base and / or acid. Subsequently, the pigments are separated, washed and dried at 50-180 ⁰ C.

Furthermore, the coating can also be carried out in a fluidized bed reactor by gas phase coating, wherein z. B. in EP 0 045 851 A1 and EP 0 106 235 A1 can be used correspondingly for the production of pearlescent pigments.

If the pearlescent pigments mentioned contain a TiO ₂ layer, this may be present in the rutile or in the anatase modification. Preferably, it is present as rutile. The rutilization is known to the person skilled in the art and can be carried out, for example, as described in US Pat. Nos. 4,038,099, 5,433,779, 6,626,989, WO 03/097749, 4,086,100, US Pat

4,867,794. Particularly preferred is rutilization using tin oxide, e.g. in U.S. Pat. 4,867,794.

The pearlescent pigments of the invention may also be provided with a protective layer to increase the light, weather and chemical stability or to increase the compatibility in different media. Depending on the type of secondary coating, this may possibly still be applied in the reaction suspension of the base pigment directly after the precipitation of the last pigment layer has ended. For some coats, however, it is recommended to re-suspend the already finished pearlescent pigment in a suitable medium and then re-coat it. As post-coatings or post-treatments are, for example, in DE-PS 22 15 191, DE-OS 31 51 354, DE-OS 32 35 017 or DE-OS 33 34 598 described methods in question. Through this

Postcoating further increases the chemical stability or facilitates the handling of the pigment, in particular the incorporation into different media. To improve the wettability, dispersibility and / or compatibility with the application media, functional coatings of Al ₂ O 3 or ZrO ₂ or mixtures thereof or mixed phases can be applied to the pigment surface. Furthermore, organic or organically / organically combined secondary coatings are possible, for example with silanes, as described, for example, in EP 0090259, EP 0 634 459, WO 99/57204, WO 96/32446, WO 99/57204, US Pat. No. 5,759,255, US Pat 5,571, 851, WO 01/92425 or in JJ. Ponjee, Philips Technical Review, Vol.

3, 81 ff. And P.H. Harding J.C. Berg, J. Adhesion Sci. Technol. Vol. 11 no.

4, p. 471-493. The pearlescent pigments according to the invention are compatible with a large number of color systems, preferably from the field of lacquers, paints, printing inks and cosmetic formulations. For the

Production of printing inks, z. B. for gravure printing, flexographic printing, offset printing, offset overprinting, a variety of binders, especially water-soluble types, suitable as z. B. from the companies BASF, Marabu, Pröll, Sericol, Hartmann, Gebr. Schmidt, Sicpa, Aarberg, Siegberg, GSB election, Follmann, Ruco or Coates Screen INKS GmbH. The printing inks may be water-based or solvent-based. Furthermore, the pearlescent pigments are also suitable for agricultural applications, eg. As for greenhouse films, for seed coloring, and z. B. for the color of tarpaulins suitable.

Since the pearlescent pigments according to the invention combine a particularly clear color with intense interference colors and high brilliance, they can be used to achieve particularly effective effects in the various application media, eg. As in cosmetic formulations, such as nail polishes, lipsticks, compressed powders, gels, lotions, emulsions, soaps, toothpastes.

It goes without saying that, for the various purposes, the pearlescent pigments according to the invention can also be advantageously used in admixture with organic dyes, organic pigments or other pigments, such as e.g. transparent and opaque white, colored and black pigments as well as with platelet-shaped iron oxides, organic pigments, holographic pigments, LCPs (Liquid Crystal Polymers) and conventional transparent, colored and black

Luster pigments based on metal oxide-coated mica and SiO ₂ flakes, etc., can be used. The pigments according to the invention can be mixed in any ratio with commercially available pigments and fillers.

As fillers z. Examples include natural and synthetic mica, glass beads or glass powder, nylon powder, pure or filled melamine resins, talc, glasses, kaolin, oxides or hydroxides of Aluminum, magnesium, calcium, zinc, BiOCl, barium sulfate, calcium sulfate, calcium carbonate, magnesium carbonate, carbon, as well as physical or chemical combinations of these substances.

There are no restrictions on the particle shape of the filler. It can meet the requirements according to z. B. platy, spherical, acicular, crystalline or amorphous.

Of course, the pigments according to the invention in the formulations can also be combined with any type of raw materials and excipients. These include u.a. Oils, fats, waxes, film formers, preservatives and general application properties determining auxiliaries, such. B. thickened and theological

Additives such as bentonites, hectorites, silicas, ca silicates, gelatins, high molecular weight carbohydrates and / or surface active aids, etc.

The pigments according to the invention can furthermore also be combined with cosmetic active ingredients. Suitable active ingredients are, for example, insect repellents, inorganic UV filters, such as TiO ₂ , UVA / BC protective filters (eg OMC, B3, MBC), also in encapsulated form, anti-aging active ingredients, vitamins and their derivatives (eg A, C, E, etc.), self-tanner (eg DHA, erytrolysis, etc.) and other cosmetic active ingredients, such as bisabolol, LPO, VTA, ectoine, emblica, allantoin, bioflavanoids and their derivatives.

Organic UV filters are usually incorporated in an amount of 0.5 to 10 percent by weight, preferably 1-8%, inorganic filters from 0.1 to 30% in cosmetic formulations.

In self-tanning creams, lotions, sprays, etc. containing, for example, the self-tanner DHA (dihydroxyacetone) and an effect pigment with final TiO ₂ or iron oxide layer, for example a TiO ₂ (anatase) coated glass plate, the DHA is slowly in the Degraded formulation. When using the pearlescent pigments of the invention in the formulation, the DHA remains effective fully preserved or the degradation is at least noticeably slowed down if a secondary coating, in particular a final layer of SiO ₂ , was applied.

The preparations according to the invention may additionally contain further customary skin-sparing or skin-care active substances. In principle, these can be all active ingredients known to the person skilled in the art.

Particularly preferred active ingredients are pyrimidinecarboxylic acids and / or aryloximes.

Among the cosmetic applications, the use of ectoine and ectoine derivatives for the care of aged, dry or irritated skin should be mentioned in particular. For example, EP-A-0 671 161 describes that ectoine and hydroxyectoine are used in cosmetic preparations such as powders, soaps, surfactant-containing cleansing products, lipsticks, blushes, make-up, care creams and sunscreen preparations.

As an application form of the cosmetic formulations, e.g. solutions, suspensions, emulsions, PIT emulsions, pastes, ointments, gels, creams, lotions, powders, soaps, surfactant-containing cleansing preparations, oils, aerosols and sprays. Other applications are e.g. Sticks, shampoos and shower baths. Any customary carrier substances, adjuvants and optionally further active ingredients can be added to the preparation.

Ointments, pastes, creams and gels may contain the usual excipients, e.g. animal and vegetable fats, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide or mixtures of these substances.

Powders and sprays may contain the usual excipients, for example lactose, talc, silicic acid, aluminum hydroxide, calcium silicate and polyamide powder or mixtures of these substances. Sprays can additionally the usual propellants, eg chlorofluorohydrocarbons, propane / butane or dimethyl ether.

Solutions and emulsions may contain the usual excipients such as solvents, solubilizers and emulsifiers, e.g. Water, ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylglycol, oils, in particular cottonseed oil, peanut oil, corn oil, olive oil, castor oil and sesame oil, glycerol fatty acid esters, polyethylene glycols and fatty acid esters of sorbitan or mixtures contain these substances.

Suspensions may include the usual carriers such as liquid diluents, e.g. Water, ethanol or propylene glycol,

Suspending agent, e.g. ethoxylated isostearyl alcohols, polyoxyethylene sorbitol esters and polyoxyethylene sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth or mixtures of these substances.

Soaps may contain the usual excipients such as alkali metal salts of fatty acids, salts of fatty acid monoesters, fatty acid protein hydrolysates, isothionates, lanolin, fatty alcohol, vegetable oils, plant extracts, glycerol, sugars or mixtures of these substances.

Surfactant-containing cleaning products may include the usual excipients such as salts of fatty alcohol sulfates, fatty alcohol ether sulfates, sulfosuccinic monoesters, fatty acid protein hydrolysates, isothionates, imidazolinium derivatives, methyl taurates, sarcosinates, fatty acid amide ether sulfates, alkyl amidobetaines, fatty alcohols, fatty acid glycerides, fatty acid diethanolamides, vegetable and synthetic oils, lanolin derivatives, ethoxylated glycerol - Contain fatty acid esters or mixtures of these substances.

Facial and body oils may contain the usual excipients such as synthetic oils such as fatty acid esters, fatty alcohols, silicone oils, natural oils such as vegetable oils and oily vegetable extracts, paraffin oils, lanolin oils or mixtures of these substances. The cosmetic preparations can be in various forms. So they can z. As a solution, an anhydrous preparation, an emulsion or micro emulsion of the type water-in-oil (W / O) or from

Oil-in-water type (O / W), a multiple emulsion, for example of the water-in-oil-in-water (W / O / W) type, a gel, a solid stick, an ointment or even an aerosol , It is also advantageous to present Ectoine in encapsulated form, e.g. In collagen matrices and other common encapsulating materials, e.g. As encapsulated cellulose, in gelatin, wax matrices or liposomally encapsulated. In particular wax matrices as described in DE-OS 43 08 282, have been found to be favorable. Preference is given to emulsions. O / W emulsions are particularly preferred. Emulsions, W / O emulsions and O / W emulsions are available in the usual way.

Other embodiments provide oily lotions based on natural or synthetic oils and waxes, lanolin, fatty acid esters, especially triglycerides of fatty acids, or oily alcoholic lotions based on a lower alcohol, such as ethanol, or a glycerol, such as propylene glycol, and / or a polyol. such as glycerine, and oils, waxes and fatty acid esters, such as triglycerides of fatty acids.

Solid pens are made of natural or synthetic waxes and oils, fatty alcohols, fatty acids, fatty acid esters, lanolin and other fatty substances.

If a preparation is formulated as an aerosol, the usual blowing agents are generally used, such as alkanes, fluoroalkanes and chlorofluoroalkanes.

The concentration of the pearlescent pigment according to the invention in the application system to be pigmented is generally between 0.01 and 70% by weight, preferably between 0.1 and 50% by weight and in particular between 1, 0 and 10% by weight, based on the total solids content of system. It is usually dependent on the specific application and can be up to 100% for loose powders. The operational The concentration of the pigment mixture according to the invention ranges from 0.01% by weight in the shampoo to up to 70% by weight in the pressed powder.

The concentrations of the pigment mixtures according to the invention in the formulation are unlimited. Depending on the application, they may be between 0.001 (rinse-off products, e.g., shower gels) - 100% (e.g., gloss effect items for particular applications).

The use concentration of the pearlescent pigment with organic and inorganic color pigments and dyes, of natural or synthetic origin, such as chromium oxide, ultramarine, spherical SiO ₂ or TiO ₂ pigments, depending on the application medium and the effect to be achieved.

The formulations containing the pigment mixtures according to the invention may belong to the lipophilic, hydrophilic or hydrophobic type. In heterogeneous formulations with discrete aqueous and non-aqueous phases, the inventive

Pigment mixtures in each case contain only one of the two phases or be distributed over both phases.

The pH values of the formulations may be between 1 and 14, preferably between 2 and 11 and more preferably between 5 and 8.

The coloring and / or finishing of the pharmaceutical and food products is carried out by the pearlescent pigment of the invention alone or in combination with colorants, such. natural or nature-identical dyes, in the desired proportions, preferably in amounts of 0.005 to 30 wt.%, In particular 0.001 to 20 wt.%, Is added to the product to be dyed.

The admixture of approved for the food industry, natural or nature-identical dyes, organic or inorganic color pigments or coloring natural fruit and plant extracts, the color effect can be influenced in the product and at the same time novel color effects can be achieved. Suitable natural or nature-identical dyes are, in particular, E 101, E 104, E 110, E 124, E 131, E 132, E 140, E 141, E 151, E 160 a. Furthermore, color pigments can also be used according to the invention

Pearlescent pigment are mixed, such. E 171, E 172, E 153. The proportion of colorants in addition to the pearlescent pigment based on the food or pharmaceutical product is preferably in the range of 0.5 to 25 wt.%. Fruit and plant extracts, such as e.g. Carrot juice, beetroot juice, elderberry juice, hibiscus juice, paprika extract, aronia extract.

The total concentration of all pigments in the product to be pigmented should not exceed 50% by weight of the product. It is usually dependent on the specific application.

The food and pharmaceutical products may also contain different drug admixtures, e.g. Vitamins, enzymes, trace elements, proteins, carbohydrates, essential fats and / or minerals may be added, the total amount of active ingredients based on the

Food or pharmaceutical product should not exceed 25% by weight. The amount of active substances or active substance mixtures is preferably 0.01-20% by weight, based on the product.

The coloring of the products is carried out by the pearlescent pigment alone or in combination with other colorants directly or in the presence of water and / or an organic solvent in the desired proportions, simultaneously or sequentially, during or after their preparation, before or after molding (eg in extrusion, pelleting, pinning, granulation, etc.) to be colored

Product is added. An admixture of the pearlescent pigments according to the invention to pulverulent or loose powders is likewise possible.

When incorporated into the product matrix itself, the amount used of the pearlescent pigments according to the invention is preferably 0.005-15% by weight, in particular 1-10% by weight. In the surface staining of Food and pharmaceutical products, the use concentration of the pigments according to the invention is preferably <10 wt.%.

Products suitable for coloring or coating are, for example, sugar confectionery, cake decorations, compresses, dragées, chewing gums, rubber products, fondant products, marzipan products, fillers, cocoa and fat glazes, chocolate and chocolate-containing products, ice cream, cereals, snack products, coating compositions, Cake glazes, sugar sprinkles, nonpareilles, jelly and gelatin products, candies, licorice, frosting, cotton candy, fat, sugar and cream masses, puddings, desserts, cake sprinkles, cold dishes, lemonades and effervescent drinks, beverages with stabilizing additives, such as. As carboxymethylcellulose, acidified and unleavened milk products, such as. Curd cheese, yogurt, cheese, cheese rinds, sausage casings, etc.

In the case of coated or coated food and pharmaceutical products, the combination of the pearlescent pigments according to the invention with flavorings (powder or liquid aromas), acids and / or with sweeteners, such as, for example, Aspartame, possible to accentuate the visual effect and taste.

The invention thus relates to all formulations from the food and pharmaceutical sector containing the inventive

Pearlescent pigments, alone or in combination with other colorants, e.g. natural and / or nature-identical dyes, fruit and plant extracts, color pigments, and / or with one or more active ingredients, such as. Vitamins, enzymes, trace elements, proteins, carbohydrates, essential fats.

The invention thus also relates to the use of the pearlescent pigments in formulations such as paints, lacquers, automotive coatings, powder coatings, printing inks, security printing inks, plastics, ceramic materials, glasses, paper, in the paper coating, in toners for electrophotographic printing processes, for the dyeing of seeds, in greenhouse films and tarpaulins, as absorbers in the laser marking of paper and polymers, such as plastics, for coating and / or coloring of food and pharmaceutical products, in cosmetic formulations, for the preparation of Pigmentanteigungen with water, organic and / or aqueous solvents, for the preparation of pigment preparations and dry preparations, such as. B. granules.

The following examples are intended to illustrate the invention without, however, limiting it.

Examples

example 1

200 g of mica flakes (natural Kaliglimmer) fraction 10-60 microns are filled with deionized water to a concentration of 100 g / l. The suspension is heated to 80 ⁰ C. The pH is then adjusted to 1.8 with hydrochloric acid (15% HCl). At a constant pH, approx. 30 ml of a TiOCl ₂ solution (400 g / l) are metered in and countercitrated with a 32% w / w NaOH. After completion of metering is stirred for 10 min. Subsequently, a pH of 4.0 is set with NaOH. By metering in a FeCb solution (14.25% Fe), a FeOOH layer is then precipitated to a gold-green color at constant pH and stirred for a further 30 minutes.

The pigment with bright green interference and gold-ocher body color is filtered off after cooling to room temperature, washed salt-free and dried at 110 ⁰ C.

Example 2

200 g of synthetic mica flakes of the fraction of 10-60 .mu.m are made up to a concentration of 100 g / l with deionised water. The suspension is heated to 80 ⁰ C. With vigorous stirring, about 430 g of a FeCb solution (14.25% Fe) are added. The pH is kept constant at 4.0 with sodium hydroxide solution (32% NaOH). The pH is then lowered to 1.8 with hydrochloric acid (15% HCl) and about 30 ml of a TiOCl ₂ solution (400 g / l TiCl ₄ ) are metered in at this pH. The pH is kept constant with sodium hydroxide solution (32% NaOH).

To the subsequent SiO ₂ layer noticed, the pH is first treated with sodium hydroxide solution (32% NaOH) was brought to 7.5. Then about 400 g of a waterglass solution (13% SiO ₂ ) are added. After completion of the addition of the pH with hydrochloric acid (15% HCl) is lowered to 2.0 and at this pH, a solution of 3 g SnCl ₄ x 5 H ₂ O in 10 ml of hydrochloric acid (37% HCl) and 90 ml dosed demineralized water. The pH is kept constant again by counter-titration with sodium hydroxide solution (32% NaOH). For the following TiO ₂ layer, the pH of the reaction suspension is first lowered to 1.8 with hydrochloric acid (15% HCl) and at this pH 476 ml of TiCl ₄ solution (400 g / l) are metered in. The pH is kept constant with sodium hydroxide solution (32% NaOH). It is stirred for 15 min. The product obtained is filtered off after cooling to room temperature, washed salt-free and dried at 110 ° C. It shows a blue-violet-colored interference and ocher yellow body color.

Example 3

200 g glass slides with an average thickness of 850 nm and the fraction of 10-100 microns are made up to a concentration of 100 g / l with demineralised water. The suspension is heated to 75 ^° C. with stirring. With sodium hydroxide solution (32% NaOH), a pH of 9 is set. Subsequently, 112 g of a sodium silicate solution (26.8% SiO ₂ ) are added. The pH is kept constant at 9 by counter-titration with hydrochloric acid (18% HCl). After completion of the metering is stirred for 30 min. With hydrochloric acid (18% HCl) is then adjusted to a pH = 1, 8 and stirred for 15 min. At constant pH = 1.8, a SnCl ₄ solution (3 g SnCl ₄ × 5H ₂ O in 15 ml concentrated HCl (25% strength) / 85 ml DI water) is metered in with sodium hydroxide solution (32% NaOH ) counter-titrated. Thereafter, the metered addition of a TiCl ₄ solution (400 g TiCl ₄ g / l). The pH is determined by counter-titration with sodium hydroxide solution (32% NaOH). kept constant. The dosing takes place until a red interference color is reached. The precipitation process is controlled according to the hue (hue angle arc tan b ^* / a ^* ) ° by means of inline control via COPRA measurement of the suspension.

Subsequently, a pH of 3.0 is adjusted with sodium hydroxide solution (32% NaOH). By metering in a FeCb solution (14.25% Fe), a FeOOH layer is then precipitated at constant pH to a light green interference color and stirred for 30 min. Finally, the pH is adjusted to 6 with NaOH.

The pigment with gold-green interference and gold-ocher body color is filtered off after cooling to room temperature, washed salt-free and dried at 110 ⁰ C.

applications

Example A1: shower gel

production:

Phase A: Put water in the kettle and stir in the pigment. Sprinkle in Keltrol CG-SFT slowly while stirring and stir until completely dissolved (do not homogenize). Add the components of phase B individually to phase A. Dissolve citric acid monohydrate in water and add to the mixture and stir slowly until everything is homogeneously distributed. Adjust the pH to 6.0-6.5 with the addition of citric acid (as needed).

Sources:

(1) Merck KGaA / ^Rona®

(2) C.P. Kelco

(3) Cognis GmbH

(4) drom

(5) BASF AG

(6) Symrise Example A2: Eyeshadow

production:

Combine Phase A ingredients and premix. Then add the powder mixture with the molten phase B drop by drop while stirring. The powders are filled in powder pans with a large diameter and pressed at 80 bar.

Sources:

(1) Merck KGaA / ^Rona®

(2) Suedstaerke GmbH

(3) Cognis GmbH

(4) H. Erhard Wagner GmbH

(5) Symrise Example A3: Creamy Eye Shadow

production:

Heat phase B to about 80 ^° C. until everything has melted and cool to 65 ^° C. With stirring, the pearlescent pigment and the ground phase chromium oxide are added. The eye shadow is filled at 65 ⁰ C.

Sources:

(1) Merck KGaA / ^Rona®

(2) Les Colorants Wackherr

(3) Croda GmbH

(4) Sasol Germany GmbH

(5) ISP Global Technologies Example A4: shampoo

production:

For phase A, stir the filler into the water. Acidify with a few drops of citric acid (10%) to reduce the viscosity and slowly pour in the Carbopol while stirring. After complete dissolution, add Phase B slowly. Successively, the ingredients of phase C are added. Adjust the pH to 6.0-6.5.

Sources:

(1) Merck KGaA / ^Rona®

(2) Noveon (3) Cognis GmbH

(4) Fragrance Resources

Example A5: Nail polish

production:

The pigments are weighed together with the lacquer base, mixed well with a spatula by hand and then stirred for 10 min at 1000 rpm.

Sources:

(1) Merck KGaA / ^Rona®

(2) Durlin / Bergerac NC

Claims

claims

1. pearlescent pigment based on a platelet-shaped substrate, characterized in that it

(A) at least one FeOOH layer

and

(B) at least one TiO ₂ layer or at least one TiO ₂ - SiO ₂ -TiO ₂ layer package

and

(C) optionally a colorless coating of one or more layers with a refractive index of <1, 8

having.

2. pearlescent pigments according to claim 1, characterized in that the substrate is selected from the group of natural or synthetic mica, BiOCl platelets, glass flakes, Fe ₂ O ₃ - platelets, graphite platelets, Al ₂ O ₃ platelets, SiO ₂ platelets or

TiO ₂ platelets.

3. pearlescent pigments according to claim 1 or 2, characterized in that the substrate is a glass plate of silicate glass, soda lime glass, borosilicate glass, aluminosilicate glass, lead crystal glass,

Window glass, A, C, E, ECR, Duranglas or window glass is.

4. pearlescent pigments according to one or more of claims 1 to

3, characterized in that the substrate has an average thickness of <10 microns.

5. pearlescent pigments according to one or more of claims 1 to

4, characterized in that the substrate in the middle a Particle diameter of 1 - 1000 .mu.m, preferably from 2 to 250 .mu.m, in particular from 5 to 150 .mu.m.

6. pearlescent pigment according to one or more of claims 1 to 5, characterized in that the pigment has an aspect ratio ((ratio: diameter / thickness) of 5-750.

7. pearlescent pigment according to one or more of claims 1 to 6, characterized in that the FeOOH layer (A) on average has layer thicknesses of 10 - 550 nm.

8. pearlescent pigments according to one or more of claims 1 to 7, characterized in that the Tiθ ₂ layer (B) in the middle

Has layer thicknesses of 5 - 550 nm.

9. pearlescent pigments according to one or more of claims 1 to

8, characterized in that the TiO ₂ -Siθ ₂ -TiO ₂ layer has a total layer thickness of <2,100 nm.

10. pearlescent pigments according to one or more of claims 1 to

9, characterized in that the layer (C) on average has a layer thickness of 1-1000 nm.

11. pearlescent pigments according to one or more of claims 1 to

10, characterized in that the substrate has a layer sequence (A) (B) or (B) (A).

12. pearlescent pigments according to one or more of claims 1 to

11, characterized in that there is an SiO ₂ layer (Z) on the substrate between the substrate and the first coating.

13. pearlescent pigments according to one or more of claims 1 to

12, characterized in that between the layer (A) and the layer (B) or the layer (B) and the layer (A) is a SiO ₂ - layer (intermediate layer Z).

14. pearlescent pigments according to one or more of claims 1 to 13, characterized in that they have the following sequence of layers:

Substrate + SiO ₂ + TiO ₂ + FeOOH

Substrate + SiO ₂ + TiO ₂ + SiO ₂ + FeOOH

Substrate + SiO ₂ + FeOOH + TiO ₂ Substrate + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂ + FeOOH

Substrate + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂ + SiO ₂ + FeOOH

Substrate + SiO ₂ + FeOOH + SiO ₂ + TiO ₂

Substrate + SiO ₂ + FeOOH + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂

Substrate + SiO ₂ + FeOOH + TiO ₂ + SiO ₂ + TiO ₂ Substrate + TiO ₂ + FeOOH

Substrate + TiO ₂ + SiO ₂ + FeOOH

Substrate + FeOOH + TiO ₂

Substrate + TiO ₂ + SiO ₂ + TiO ₂ + FeOOH

Substrate + TiO ₂ + SiO ₂ + TiO ₂ + SiO ₂ + FeOOH Substrate + FeOOH + SiO ₂ + TiO ₂

Substrate + FeOOH + SiO ₂ + TiO ₂ + SiO ₂ + TiO ₂

Substrate + FeOOH + TiO ₂ + SiO ₂ + TiO ₂

15. pearlescent pigments according to one or more of claims 1 to 14, characterized in that the TiO ₂ layer is present in the rutile modification.

16. A process for the preparation of pearlescent pigments according to one or more of claims 1 to 15, characterized in that the coating of the platelet-shaped substrates wet-chemically, by

CVD or PVD method is performed.

17. Use of the pearlescent pigments according to one or more of claims 1 to 16 in paints, varnishes, powder coatings, printing inks, plastics, for the dyeing of seeds, for coating or for

Dyeing of food and pharmaceutical products, as an absorber in the laser marking of paper and polymers, in the caring and decorative cosmetics, for the preparation of pigment preparations and dry preparations.

18. Dry preparations according to claim 17 in the form of granules, chips, briquettes, rods containing pearlescent pigments according to one or more of claims 1 to 15.