CN1711321A - Novel light interference pigments - Google Patents

Abstract

The present invention relates to pigments, comprising (A) optionally a layer consisting of a metal, (B) at least one layer, which is located between the layers (A) and (C), if a layer (A) is 5 present, and consists of the metal, silicon (Si) and oxygen (O), and (C) optionally a layer consisting of SiOz with 0.70 <= z <= 2.0 on layer (B), a process for the production of the pigments and their use in ink-jet printing, for dyeing textiles, for pigmenting coatings, paints, printing inks, plastics, cosmetics, glazes for ceramics and glass.

Description

Novel optical interference pigments

The invention relates to (optical interference) pigments comprising at least one layer which is produced by calcining a metal and SiO_zWherein z is 0.70. ltoreq. z.ltoreq.2.0, in particular 1.1. ltoreq. z.ltoreq.2.0. The invention also relates to a method for producing said pigments and to the use thereof for ink-jet printing, for dyeing textiles, and for colouring paints, printing inks, plastics, cosmetics, glazes for ceramics and glass.

WO93/19131 discloses platelet-shaped coloured pigments comprising titanium dioxide, one or more titanium suboxides and one or more non-titanium metal or non-metal oxides or oxides, wherein the concentration of titanium oxide is highest in the coating layer closest to the substrate surface and decreases towards the pigment surface.

WO00/34395, WO00/69975 and WO02/31058 describe bright metal flakes SiO_y1Al/SiO_y1Wherein y1 is about 1 to about 2. The aluminum layer has a thickness of at least about 40nm, SiO_y1The thickness of the layer is at least 10 nm.

WO03/68868 describes a process for preparing SiO_yA method of sheeting. The SiO may be treated with a carbon-containing gas at 1500 ℃ and preferably 500 ℃ and 1000 ℃ and preferably in the absence of oxygen_yFlakes of SiO_yA SiC layer is formed on the sheet. Or SiO can be heated in an oxygen-containing atmosphere by heating_yConversion of flakes to SiO₂A sheet. The SiO₂The flakes can be used as substrates for optical interference pigments.

PCT/EP03/09296 discloses a process for the preparation of a catalyst comprising calcining TiO₂/SiO_zThe resulting laminar pigments of which z is 0.03. ltoreq. z.ltoreq.2.0, and their use in paints, textiles, ink-jet printing, cosmetics, coatings, plastics materials, printing inks, glazes for ceramics and glass, and security printing.

EP- ｃA-803549 discloses colored pigments comprising (ｃA) ｃA core consisting of ｃA substantially transparent or metallic reflective material, and (b) at least one coating layer consisting essentially of one or more oxides of silicon, the molar ratio of oxygen to silicon being from 0.25 to 0.95.

We have found that (colored) pigments are obtainable if the plane-parallel structures (flakes) comprising (A) at least one layer consisting of a metal and (C)At least one layer consisting of SiO_zA layer of composition wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.1. ltoreq. z.ltoreq.2.0.

It is assumed that the metal/SiO is formed by calcining the metal in a non-oxidizing atmosphere_yTo give a layer (i.e., layer (B)) or a composite layer (B)/layer (A)/layer (B)), thereby giving rise to a refractive indexIs changed. It is assumed that the change in refractive index is based on the metal being SiO_yAnd (4) oxidizing. For example, it is known that Si and Al are generated by heating SiO and Al at 650 DEG C₂O₃Heating SiO and Ti at 900 ℃ produces a silicide of titanium (new j. chem., 2001, 25, 994-.

Accordingly, the present invention relates to a pigment comprising:

(A) an optional layer consisting of a metal,

(B) at least one layer consisting of a metal, silicon (Si) and oxygen (O), which layer, if present, is located between the layer (A) and the layer (C), and

(C) optionally on layer (B) consisting of SiO_zWherein z is more than or equal to 0.70 and less than or equal to 2.0.

Layer (B) is prepared by calcining a pigment comprising the following layers at above 600 ℃ in a non-oxidizing atmosphere:

A) a layer consisting of a metal, and

(C) on the metal layer made of SiO_yWherein y is more than or equal to 0.70 and less than or equal to 1.80.

Preferably without the pigment of layer (a). That is, it is preferable that the entire layer (a) be converted into the layer (B) during the calcination in the non-oxidizing atmosphere.

The term "0.70. ltoreq. z.ltoreq.2.0 SiO_z"means that the average molar ratio of oxygen to silicon on the silicon oxide layer is 0.70 to 2.0. The composition of the silicon oxide layer can be determined by ESCA (electron spectroscopy for chemical analysis).

The term "0.70. ltoreq. y. ltoreq.1.8 SiO_y"means that the average molar ratio of oxygen to silicon on the silicon oxide layer is from 0.70 to 1.80. The composition of the silicon oxide layer can be determined by ESCA (electron spectroscopy for chemical analysis).

According to the present invention, the term "aluminum" includes aluminum and aluminum alloys. Aluminum alloys such as those described in Ullmanns Enzyklopadie der Industriellen Chemie, 4. aflage, Verlag Chemie, Weinheim, Band 7, pages S.281-292. Particularly suitable are the corrosion-resistant aluminum alloys described in WO00/12634 on pages 10 to 12, which, in addition to aluminum, also contain less than 20% by weight, preferably less than 10% by weight, of silicon, magnesium, manganese, copper, zinc, nickel, vanadium, lead, antimony, tin, cadmium, bismuth, titanium, chromium and/or iron.

To further improve light resistance, weather resistance and chemical resistance, SiO may be used_yThe layer, preferably in bulk form, is oxidized with an oxygen-containing gas, for example air, in a fluidized bed at a temperature of at least 200 c, in particular above 400 c, preferably 500 c and 1000 c, or is introduced into an oxidizing flame.

The invention also relates to the use of said pigments in ink-jet printing (EP 02405888), textile dyeing (EP 02405889), paint pigmentation, printing inks, plastics, cosmetics (PCT/EP03/09296), glazes for ceramics and glass, and security printing.

The pigments of the invention are particles, typically 2 μm to 5mm in length, 2 μm to 2mm in width, 20nm to 2 μm in thickness, and at least 2: 1 in length to thickness ratio, wherein the particles comprise a center having two substantially parallel planes and further layers deposited on the parallel planes but not on the sides or on the entire surface of the particle, the distance between the two parallel planes being the shortest axis of the center. The pigments of the invention are characterized by a precise thickness and a smooth surface.

In principle, the metal of layer (A) can be formed in a calcination step with SiO_yAny metal that reacts to form layer (B). Ag, Al, Cu, Cr, Mo, Ni, Ti or alloys thereof are preferred, with Al being most preferred.

Preferably layer (a) or layer (B) if layer (a) is not present forms the centre of the pigment. If layer (A) forms the center, additional layers (B) and/or (C) may be present in only one or two parallel planes of the pigment (A/B/C or C/B/A/B/C). If layer (A) is not present and layer (B) forms the center, layer (C) may be present only on one parallel plane or on both parallel planes (B/C or C/B/C) of the pigment. If layer (A) is present, layers (B) and (C) are preferably arranged symmetrically about the center. The symmetrically arranged layers (B) and/or (C) may have different thicknesses, but preferably have the same thickness.

If Al/SiO is calcined in a non-oxidizing atmosphere_yAl flakes, the following pigments and/or substrates for (optical interference pigments) are available:

(A1) a layer consisting of a metal, in particular aluminum,

(B) a layer located between layers (A1) and (A2) and consisting of metal, silicon and oxygen, and

(A2) a layer consisting of a metal, in particular aluminum; or

(A1) A layer consisting of a metal, in particular aluminum,

(B1) a layer located between layers (A1) and (C) and composed of metal, silicon and oxygen,

(C) from SiO_yThe layers of the composition are such that,

(B2) a layer located between layers (C) and (A2) and consisting of metal, silicon and oxygen, and

(A2) a layer consisting of a metal, in particular aluminum.

In a preferred embodiment, the pigment comprises:

(C1) from SiO_yThe layers of the composition are such that,

(B) a layer located between layers (C1) and (C2) and composed of metal, silicon and oxygen, and

(C2) from SiO_yA layer of composition.

The SiO of layer (C1) and layer (C2) can be_y(preferably in bulk form) at least 200 ℃, in particular above 400 ℃, preferably at a temperature of 500-:

(C1) from SiO_zThe layers of the composition are such that,

(B) a layer located between layers (C1) and (C2) and consisting of metal, silicon and oxygen, and

(C2) from SiO_zA layer of composition.

In this embodiment, it is preferred that layer (B) forms the center of the pigment, with layers (C1) and (C2) being present only in parallel planes to the center.

In another preferred embodiment, the pigment comprises:

(C1) from SiO_zThe layers of the composition are such that,

(B1) a layer located between layers (C1) and (A) and composed of metal, silicon and oxygen,

(A) a layer consisting of a metal, in particular aluminum,

(B2) a layer located between layers (A) and (C2) and consisting of metal, silicon and oxygen, and

(C2) from SiO_zA layer of composition;

the pigment is prepared by calcining SiO in a non-oxidizing atmosphere_ymetal/SiO_yThe flakes were obtained.

In this embodiment, it is preferred that layer (a) forms the center of the pigment, wherein (B1), (B2), (C1) and (C2) are present only on parallel planes to the center.

When the above pigments are coated with a material having a high refractive index, a colored (light interference) pigment having high color strength and color purity can be obtained.

Thus, in another embodiment, the present invention relates to a colored (light interference) pigment comprising:

(D1) layer of a material with a high refractive index, in particular TiO₂，

(C1) From SiO_zThe layers of the composition are such that,

(B) a layer consisting of metal, silicon and oxygen, located between layers (C1) and (C2), and

(C2) from SiO_zA layer of composition, and

(D2) layer of a material with a high refractive index, in particular TiO₂Wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0.

In this embodiment, it is preferred that layer (B) forms the center of the pigment, with layers (C1) and (C2) being present only in parallel planes to the center. High refractive index materials (especially TiO)₂) Layer (D2) of (a) may be present only on layer (C1) and layer (C2), but is preferably present over the entire surface of the pigment.

In a preferred embodiment of the present invention, the optical interference pigment comprises a material having a "high" refractive index (high refractive index as defined herein means a refractive index greater than about 1.65) and optionally a material having a "low" refractive index (low refractive index as defined herein means a refractive index of about 1.65 or less than 1.65). The various materials (dielectrics) that can be used include inorganic materials (e.g., metal oxides, suboxides of metals, metal fluorides, metal oxyhalides, metal sulfides, metal chalcogenides, metal nitrides, metal oxynitrides, metal carbides, combinations thereof, and the like) as well as organic dielectric materials. These materials are readily available and are readily applied by physical or chemical vapor deposition processes or by wet chemical coating processes.

In a particularly preferred embodiment, the silica/metal substrate-based optical interference pigment further comprises a layer of a dielectric material of "high" refractive index (i.e., a refractive index greater than about 1.65, preferably greater than about 2.0, and most preferably greater than about 2.2) applied to the entire surface of the silica/metal substrate. Examples of such dielectric materials are zinc sulfide (ZnS), zinc oxide (ZnO), zirconium oxide (ZrO)₂) Titanium dioxide (TiO)₂) Carbon, indium oxide (In)₂O₃) Indium Tin Oxide (ITO),Tantalum pentoxide (Ta)₂O₅) Chromium oxide (Cr)₂O₃) Cerium oxide (CeO)₂) Yttrium oxide (Y)₂O₃) Europium oxide (Eu)₂O₃) Iron oxides such as iron (II)/(III) oxide (Fe)₃O₄) And Iron (III) oxide (Fe)₂O₃) Hafnium nitride (HfN), hafnium carbide (HfC), hafnium oxide (HfO)₂) Lanthanum oxide (La)₂O₃) Magnesium oxide (MgO), neodymium oxide (Nd)₂O₃) Praseodymium oxide (Pr)₆O₁₁) Samarium oxide (Sm)₂O₃) Antimony trioxide (Sb)₂O₃) Silicon monoxide (SiO), selenium trioxide (Se)₂O₃) Tin oxide (SnO)₂) Tungsten trioxide (WO)₃) Or a combination thereof. Preferably, the dielectric material is a metal oxide. The metal oxide may be a single oxide or a mixture of oxides with or without absorbing properties, e.g. TiO₂、ZrO₂、Fe₂O₃、Fe₃O₄、Cr₂O₃Iron titanate, hydrated iron oxide, titanium suboxide or ZnO, particularly preferably TiO₂。

Or by reaction with TiO₂Coating a layer with a metal oxide of low refractive index gives a more intensely coloured and transparent pigment. Non-limiting examples of suitable low refractive index dielectric materials are: silicon dioxide (SiO)₂) Alumina (Al)₂O₃) Metal fluorides (e.g., magnesium fluoride (MgF)₂) Aluminum fluoride (AlF)₃) Cerium fluoride (CeF)₃) Lanthanum fluoride (LaF)₃) Sodium aluminum fluoride (e.g., Na)₃AlF₆Or Na₅Al₃F₁₄) Neodymium fluoride (NdF)₃) Samarium fluoride (SmF)₃) Barium fluoride (BaF)₂) Calcium fluoride (CaF)₂) Lithium fluoride (LiF), and mixtures thereof) or any other low refractive index material having a refractive index of about 1.65 or less than 1.65. Organic monomers and polymers useful as low refractive index materials are, for example, dienes or alkenes (e.g., acrylates such as methacrylates), polymers of perfluoroalkenes, polytetrafluoroethylene (TEFLON), polymers of Fluorinated Ethylene Propylene (FEP), parylene, p-xylene, combinations thereof, and the like. The above materials also include evaporated, condensed and cross-linked clear acrylate layers that can be deposited by the methods described in US-B-5,877,895, the disclosure of which is incorporated herein by reference. SiO is preferred₂、Al₂O₃、AlOOH、B₂O₃Or mixtures thereof. Most preferably SiO₂。

The metal oxide layer may be applied by CVD (chemical vapor deposition) or wet chemical coating. The metal oxide layer can be obtained by decomposing the metal carbonyl compound in the presence of water vapor (for the use of lower molecular weight metal oxides such as magnetite) or oxygen and, where appropriate, water vapor (for the use of, for example, nickel oxide and cobalt oxide). The metal oxide layer can be applied in particular by the following method: oxidative gas-phase decomposition of metal carbonyls (e.g.iron pentacarbonyl, chromium hexacarbonyl; EP-A-45851), or hydrolytic gas-phase decomposition of metal alcoholates (e.g.tetrｃA-n-propanol/titanium/zirconium tetraisopropoxide; DE-A-4140900) or metal halides (e.g.titanium tetrachloride; EP-A-338428), or oxidative decomposition of organotin compounds (in particular alkyltin compounds, such as tetrabutyltin and tetramethyltin; DE-A-4403678), or gas-phase hydrolysis of organosilicon compounds (in particular di-tert-butoxyacetoxysilanes) as described in EP-A-668329. The coating operation can be carried out in ｃA fluidized-bed reactor (EP-A-045851 and EP-A-106235). The Al2O3 layer (B) is preferably obtained by controlled oxidation reactions (which can be carried out in an inert gas) during the cooling of the aluminum-coated pigments (DE-A-19516181).

According to the passivation method described in DE-A-4236332 and EP-A-678561, the metal oxide-halide (e.g. CrO) is decomposed by hydrolysis or oxidation in the gas phase₂Cl₂、VOCl₃) In particular oxyhalides of phosphorus (e.g. POCl)₃) Phosphoric and phosphorous acid esters (e.g. dimethyl/ethyl phosphite and trimethyl/ethyl phosphite) and amino-containing organosilicon compounds (e.g. 3-aminopropyl-triethoxy/trimethoxy silane) to produce phosphate, chromate and/or titanate-containing and also phosphate and silica-containing metal oxide layers.

The oxides of the metals zirconium, titanium, iron and zinc are preferably applied by wet-chemical methods; hydrated oxides of these metals; titanates of iron; layers of titanium suboxides and mixtures thereof, where appropriate, can reduce the metal oxide. In the case of wet chemical coating methods, wet chemical coating methods developed for the preparation of pearlescent pigment products can be used, and these methods are described in: DE-A-1467468, DE-A-1959988, DE-A-2009566, DE-A-2214545, DE-A-2215191, DE-A-2244298, DE-A-2313331, DE-A-2522572, DE-A-3137808, DE-A-3137809, DE-A-3151343, DE-A-3151354, DE-A-3151355, DE-A-3211602, DE-A-3235017, DE-A-1959988, WO93/08237, WO 98/53001 and WO 03/6558.

Preferably, the high refractive index metal oxide is TiO₂And/or iron oxide, preferably the low refractive index metal oxide is SiO₂。TiO₂The layer may be of rutile modificationOr anatase modification, and among them, rutile modification is preferable. Known processes (e.g. ammoniｃA, hydrogen, hydrocarbon vapour or mixtures thereof or gold) as described, for example, in EP-A-735,114, DE-A-3433657, DE-A-4125134, EP-A-332071, EP-A-707,050 or WO93/19131 may be usedMetal powder) reduced TiO₂And (3) a layer.

For coating, the substrate particles are suspended in water and one or more hydrolysable metal salts are added at a pH suitable for hydrolysis, the pH being chosen such that the metal oxide or hydrated metal oxide precipitates directly on the particles without secondary precipitation (submiroadedness). The pH is generally kept stable by simultaneous metered addition of a base. The pigment is then isolated, washed, dried, and calcined, as appropriate, the calcination temperature being optimized for the particular coating. If desired, the pigments can be isolated, dried and, where appropriate, calcined and resuspended after the respective coating has been applied in order to precipitate further layers.

The metal oxide layer is prepared by controlled hydrolysis of one or more metal acid esters by a sol-gel process in the presence of a suitable organic solvent and a basic catalyst, using a process similar to that described in, for example, DE-A-19501307. Suitable basic catalysts are, for example, amines (e.g. triethylamine, ethylenediamine, tributylamine, dimethylethanolamine and methoxypropylamine). The organic solvent being a water-miscible organic solvent, e.g. C_1-4Alcohols, in particular isopropanol.

Suitable metal acid esters are selected from alkyl and aryl alcoholates of vanadium, titanium, zirconium, silicon, aluminum, and boron; carboxylates of vanadium, titanium, zirconium, silicon, aluminum, and boron; carboxy, alkyl or aryl substituted alkyl alcoholates or carboxylates of vanadium, titanium, zirconium, silicon, aluminum and boron. Preference is given to using triisopropyl aluminate, tetraisopropyl titanate, tetraisopropyl zirconate, tetraethyl orthosilicate and triethyl borate. In addition, acetylacetonates of the above metals and acetoacetonates can be used. Examples of preferred metal acid esters of this type are zirconium acetylacetonate, aluminum acetylacetonate, titanium acetylacetonate and diisobutyl oleylacetoacetyl aluminate (diisobutylolylacetyloacetylaluminium)ate) or diisopropyl acetoacetonate (diisopropoxyethyl acetoacetonate) and mixtures of metal acid esters (e.g. Dynasil)^®(H ü ls), a mixture of aluminum/silicon metal acid esters).

According to one embodiment of the present invention, it is preferred to use titanium dioxide as the high refractive index metal oxide, and the method of coating the titanium dioxide layer is described in US-B-3553001.

The aqueous solution of the titanium salt is slowly added to the suspension of the material to be coated which has been preheated to approximately 50 to 100 ℃, in particular 70 to 80 ℃, by simultaneous metered addition of a base (for example an aqueous ammonia solution)Liquid or aqueous alkali metal hydroxide) to maintain a substantially stable pH of about 0.5 to about 5, particularly about 1.2 to about 2.5. Once the desired thickness of TiO is achieved₂And precipitating the layer, and stopping adding the titanium salt solution and the alkali.

This method (also called "titration" method) differs in that an excess of titanium salt is avoided. This is achieved by adding only hydrated TiO to the hydrolysate per unit time₂The amount of titanium salt required for uniform coating and the amount which can be adsorbed per unit time by the active surface of the particles to be coated. TiO formed in principle in the anatase form on the surface of the starting pigment₂. But by adding small amounts of SnO₂The rutile structure may be forced. For example, as described in WO93/08237, tin dioxide may be deposited prior to the precipitation of titanium dioxide and the titanium dioxide-coated product calcined at 800-900 ℃.

Optionally reducing the TiO by conventional methods as described in the following documents₂：US-B-4,948,631(NH₃，750-850℃)、WO93/19131(H₂At > 900 ℃ or DE-A-19843014 (solid reducing agents, for example silicon, > 600 ℃).

The following method may suitably be used on TiO₂Coating SiO on the layer₂Layer (protective layer): a metered quantity of soda water glass solution is added to the suspension of the material to be coated which has been heated to approximately 50-100 ℃, preferably 70-80 ℃, the pH being maintained at 4-10, preferably 6.5-8.5, by simultaneous addition of 10% hydrochloric acid, and stirring is carried out for a further 30 minutes after the addition of the water glass solution has been completed.

Can be prepared by reacting with TiO₂The layer is coated with a metal oxide (e.g., SiO) having a low refractive index (i.e., a refractive index of less than about 1.65)₂、Al₂O₃、AlOOH、B₂O₃Or mixtures thereof, preferably SiO₂) Then coating a layer of Fe on the metal oxide layer₂O₃And/or TiO₂Layer, resulting in a more intensely colored and more transparent pigment. Such multicoat optical interference pigments comprising a silica/metal substrate and alternating high and low refractive index metal oxide layers can be prepared in a manner similar to that described in WO98/53011 and WO 99/20695.

Furthermore, the color of the pigment powder can be improved by applying further layers, for example colored metal oxides, berlin blue, compounds of transition metals (e.g. Fe, Cu, Ni, Co, Cr) or organic compounds (e.g. dyes or lakes).

In addition, the pigments of the invention may also be coated with sparingly soluble, firmly adhering inorganic or organic colorants. Preference is given to using lakes, in particular aluminum lakes. In order to precipitate the aluminium hydroxide lake layer, in a second step, precipitation is carried out using lakes (DE-A-2429762 and DE-A-2928287).

Furthermore, the pigments according to the invention may also have an additional coating which is coated with complex salt pigments, in particular with cyanoferrate complexes (EP-A-141173 and DE-A-2313332).

The multilayer silicon oxide sheet may be surface-treated for the purpose of improving weather resistance and light resistance, depending on the application. Useful surface treatment methods are described, for example, in the following documents: DE-C-2215191, DE-A-3151354, DE-A-3235017, DE-A-3334598, DE-A-4030727, EP-A-649886, WO97/29059, WO99/57204 and US-A-5,759,255. The surface treatment may also facilitate handling of the pigment, especially for incorporation into various application media.

Instead of a layer of high refractive index material, a translucent metal layer may be applied. Examples of metals suitable as the translucent metal layer include: cr, Ti, Mo, W, Al, Cu, Ag, Au or Ni. The thickness of the semitransparent metal layer is usually 5 to 25nm, in particular 5 to 15 nm. The translucent metal layer may be applied by PVD.

Alternatively, the metal layer may be obtained by wet chemical coating or chemical vapor deposition (e.g., by vapor deposition of a metal carbonyl compound). The metal layer is deposited on the substrate by adding a reducing agent in the presence of a metal compound by suspending the substrate in an aqueous and/or organic solvent containing medium. The metal compound is, for example, silver nitrate or nickel acetylacetonate (WO 03/37993).

According to U.S. Pat. No. 4,3,536,520, nickel chloride is used as the metal compound and hypophosphite is used as the reducing agent. According to EP-A-353544, the following compounds can be used as reducing agents for wet-chemical coating processes: aldehydes (formaldehyde, acetaldehyde, benzaldehyde), ketones (acetone), carboxylic acids and their salts (tartaric acid, ascorbic acid), reductones (erythorbic acid, triose reductone, reducing acids) and reducing sugars (glucose).

In another preferred embodiment of the present invention, layer (B) in the above preferred embodiment may be replaced by a layer (B)/layer (a)/layer (B) structure, wherein layer (B)/layer (a)/layer (B) forms the center of the pigment in place of layer (B).

If aluminum is used as metal in the above-described embodiments, the layer (B) and/or the layers (A) and (B), if present, are generally from 5 to 100nm, in particular from 30 to 60nm, in thickness.

SiO_zThe thickness of the layer (0.70. ltoreq. z.ltoreq.2.0) is usually from 10 to 1000 nm. SiO is preferred_zThe thickness of the layer depends on the desired color. SiO 2_zA layer thickness greater than 500nm can result in a dull color.

Deposition of TiO by wet-chemical methods is preferred₂And (3) a layer. TiO 2₂The thickness of the layer is generally from 5 to 200nm, in particular from 10 to 100nm, more particularly from 20 to 50 nm.

With aluminium as the metal, TiO₂The present invention will be further described in detail on the basis of a high-refractive-index material.

Preparation of SiO-coated films by a process comprising the following steps_yAluminum flakes (EP-B-990715):

a) vapor-depositing a separating agent on a (mobile) carrier to prepare a separating agent layer,

b) passing over a separating agent layerDeposition of SiO_yA layer, wherein y is more than or equal to 0.70 and less than or equal to 1.80,

c) in SiO_yAn aluminum layer is deposited on the layer by a deposition method,

d) deposition of SiO on aluminum layers_yA layer of a material selected from the group consisting of,

e) dissolving the separating agent layer in a solvent, and

f) separation of SiO from solvent_y。

SiO is formed by deposition from the material from a vaporizer_yA layer of said material comprising Si and SiO₂SiO_yOr mixtures thereof, Si and SiO₂Is preferably 0.15: 1 to 0.75: 1 and in particular comprises stoichiometric amounts of Si and SiO₂A mixture of (a). SiO is preferred_1.00-1.8The layer is formed by SiO vapor produced by reacting a mixture of Si and silica in a gasifier at a temperature above 1300 ℃. SiO is preferred_0.70-0.99The layer is formed by evaporating silicon monoxide with a silicon content of up to 20% by weight at above 1300 ℃.

Coated SiO by the above method_yHas a high degree of plane parallelism and is defined as having a mean thickness of + -10%, in particular + -5%, and a low reflectivity.

Deposition of SiO from the material from the vaporizer in steps b) and d)_yA layer of said material comprising Si and SiO₂SiO_yOr mixtures thereof, Si and SiO₂Is preferably 0.15: 1 to 0.75: 1 and in particular comprises stoichiometric amounts of Si and SiO₂A mixture of (a). Step e) is preferably carried out at a pressure higher than the pressure in steps a) and b) and lower than atmospheric pressureUnder the action of force. The SiO-coated film obtained by the method_yPreferably the thickness of the aluminium flakes is in the range of 20-2000nm, especially 20-500nm, most preferably 20-200nm, preferably the ratio of the thickness to the surface area of the plane parallel structures is less than 0.01 μm-1, and the aspect ratio is at least 2: 1. The silica/alumina flakes are not uniform in shape. However, for simplicity, the sheet is considered to have a "diameter". The silicon oxide/aluminum flakes are good in plane parallelism and definedThe thickness is the mean thickness. + -. 10%, in particular. + -. 5%. The thickness of the silica/alumina flakes is 20-2000nm, very particularly 100-350 nm. It is presently preferred that the flakes have a preferred diameter in the range of about 1-60 μm, more preferably about 5-40 μm. Therefore, it is preferred that the aspect ratio of the flakes of the present invention be about 14-400.

Preference is given to silicon oxide (SiO) in steps b) and d)_y) The layer is formed by SiO vapor produced by reacting a mixture of Si and silica in a gasifier at a temperature above 1300 ℃. SiO is preferred_0.70-0.9The layer is formed by evaporating silicon monoxide with a silicon content of up to 20% by weight at above 1300 ℃.

Preferably, the deposition in steps a) and b) is carried out under a vacuum of less than 0.5 Pa. Preferably, the separating agent in step e) is dissolved under a pressure of 1 to 5X 10⁴Pa, especially 600-10⁴Pa, more particularly 10³-5×10³Pa.

The release agent deposited on the support by deposition in step a) may be a lacquer, a polymer (e.g.those (thermoplastic) polymers described in U.S. Pat. No. 4, 6,398,999, in particular acrylic or styrene polymers or mixtures thereof), an organic substance soluble in an organic solvent or water and vaporizable under vacuum (e.g.anthracene, anthraquinone, acetamidophenol, acetylsalicylic acid, camphoric anhydride, benzimidazole, 1, 2, 4-benzenetricarboxylic acid, 2-biphenyldicarboxylic acid, bis (4-hydroxyphenyl) sulfone, dihydroxyanthraquinone, hexanoylurea, 3-hydroxybenzoic acid, 8-hydroxyquinoline-5-sulfonic acid monohydrate, 4-hydroxycoumarin, 7-hydroxycoumarin, 3-hydroxy-2-naphthoic acid, isophthalic acid, 4-methylene-bis-3-hydroxy-2-naphthoic acid, 1, 8-naphthalic anhydride, phthalimide and its potassium salt, phenolphthalein, phenothiazine, saccharin and its salts, tetraphenylmethane, benzo [9, 10] phenanthrene, triphenylmethanol, or a mixture of at least two of these). Preferably, the separating agent is an inorganic salt which is soluble in water and evaporable under vacuum (see, for example, DE-A-19844357), such as sodium chloride, potassium chloride, lithium chloride, sodium fluoride, potassium fluoride, lithium fluoride, calcium fluoride, sodium aluminium fluoride and disodium tetraborate.

The movable carrier may consist of one or more discs, cylinders or other rotationally symmetrical bodies rotating around an axis (see WO01/25500) and preferably consists of one or more continuous metal strips with or without a polymer coating, one or more polyimide or polyethylene terephthalate strips (U.S. Pat. No. 6,270,840).

Step f) may comprise washing and subsequent filtration, precipitation, centrifugation, decantation and/or evaporation. However, it is also possible to subject SiO to the reaction in step d)_yIs frozen together with a solvent, followed by freeze-drying, separation of the solvent by sublimation below the triple point, and residual dry SiO_yIs a separate plane parallel structure.

Except under a particularly high vacuum, at a few 10^-2In industrial vacuum of Pa, vaporized SiO is usually condensed to SiO_y(wherein 1. ltoreq. y.ltoreq.1.8, particularly wherein 1.1. ltoreq. y.ltoreq.1.8) because the high vacuum apparatus usually contains traces of water vapor due to the gas discharged from its surface, the water vapor reacting with the readily reactive SiO at the gasification temperature.

Next, the endless belt-shaped carrier is passed through a dynamic vacuum lock chamber of known construction (see U.S. Pat. No. 6,270,840) into a pressure of 1 to 5X 10⁴Pa, preferably from 600 to 10⁹Pa, especially 10³To 5X 10³Pa, in which the strip-like support is immersed in the separating bath. The temperature of the solvent should be selected so that its vapor pressure is within a specified pressure range. With the aid of machinery, the separating agent layer dissolves rapidly and the product layer breaks up into flakes which subsequently form a suspension in the solvent. Next, the tape was dried without any contaminants adhering thereto. The strip is passed through a second set of dynamic vacuum lock chambers and returned to the vaporization chamber where the coating of release agent and SiO is repeated_yAl/SiO_yAnd (5) processing a product layer.

The suspension obtained in the two steps, containing the product structure and the solvent in which the separating agent is dissolved, is then further separated using known techniques. For this purpose, the product structure is first concentrated in a liquid and washed several times with fresh solvent in order to wash away the dissolved separating agent. The product, still in the form of a wet solid, is then isolated by filtration, precipitation, centrifugation, decantation or evaporation.

The flakes are then dried either ultrasonically or mechanically using a high speed stirrer in a liquid medium or using a pneumatic mill with a rotary classifier or grinding or air sieving to obtain the desired particle size and delivered for further use.

Specifically, a salt (e.g., NaCl) and a silicon Suboxide (SiO) are sequentially mixed_y) Layer, aluminum layer and SiO_yThe layer is deposited by deposition on a support, which may be a continuous metal strip that is passed through a vaporizer in a vacuum of less than 0.5 Pa. The thickness of the salt deposited by deposition is about 20-100nm, preferably 30-60nm, and the thickness of the SiO deposited by deposition is 10-1000nm and the thickness of the aluminum is 10-100nm, depending on the intended use of the product.

Next, the endless belt-shaped carrier is passed through a dynamic vacuum lock chamber of known construction (see U.S. Pat. No. 6,270,840) into a pressure of 1 to 5X 10⁴Pa, preferably from 600 to 10⁹Pa, especially 10³To 5X 10³Pa, in which the strip-like support is immersed in the separating bath. The temperature of the solvent should be selected so that its vapor pressure is within a specified pressure range. With the aid of machinery, the separating agent layer dissolves rapidly and the product layer breaks up into flakes which subsequently form a suspension in the solvent. Next, the tape was dried without any contaminants adhering thereto. The strip is passed through a second set of dynamic vacuum lock chambers and returned to the vaporization chamber where the process of applying the release agent and the SiO product layer is repeated.

The suspension obtained in the two steps, containing the product structure and the solvent in which the separating agent is dissolved, is then further separated using known techniques. For this purpose, the product structure is first concentrated in a liquid and washed several times with fresh solvent in order to wash away the dissolved separating agent. The product, still in the form of a wet solid, is then isolated by filtration, precipitation, centrifugation, decantation or evaporation and dried.

The flakes are then dried either ultrasonically or mechanically using a high speed stirrer in a liquid medium or using a pneumatic mill with a rotary classifier or grinding or air sieving to obtain the desired particle size and delivered for further use.

After washing at atmospheric pressure, the plane-parallel structure can be separated by the following method: the suspension, which has been concentrated to about 50% solids content, is frozen under mild conditions and then freeze-dried in a known manner at about-10 ℃ and 50 Pa. The remaining dry matter is the product which can be subjected to further coating or chemical conversion processing steps.

Accordingly, another aspect of the present invention is a plane parallel structure comprising: (A) a layer consisting of a metal, in particular aluminum, and (C) at least one layer consisting of SiO_zA layer of composition wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0。

Different process variants can be used for SiO-coated substrates_yThe aluminum flakes of (a) are further processed:

method (1): calcination in a non-oxidizing atmosphere (→ layer (B)), calcination in the presence of oxygen (SiO)_z→SiO₂) And optionally with TiO₂Coating the resulting pigment (TiO)₂/SiO_zcenter/SiO_z/TiO₂) Wherein the center is layer (B) or layer (B)/layer (a)/layer (B).

Method (2): calcination in a non-oxidizing atmosphere (→ layer (B)), using TiO₂Coating the resulting pigment (TiO)₂/SiO_ycenter/SiO_y/TiO₂) And optionally calcined in the presence of oxygen (SiO)_y→SiO_z)(TiO₂/SiO_zcenter/SiO_z/TiO₂)。

Method (3): calcination in a non-oxidizing atmosphere (→ layer (B)), using TiO₂The pigment obtained was coated and calcined in a non-oxidizing atmosphere (→ layer (E)) (TiO)₂Layer (E)/SiO_ycenter/SiO_yLayer (E)/TiO₂) And optionally calcined in the presence of oxygen (SiO)_y→SiO_z)(TiO₂Layer (E)/SiO_zcenter/SiO_zLayer (E)/TiO₂)。

Method (4): by TiO₂The resulting pigment was coated and calcined in a non-oxidizing atmosphere (→ layers (B) and (E)) (TiO)₂Layer (E)/SiO_ycenter/SiO_yLayer (E)/TiO₂) And optionally calcined in the presence of oxygen (SiO)_y→SiO_z)(TiO₂Layer (E)/SiO_zcenter/SiO_zLayer (E)/TiO₂)。

Different process variants are further illustrated on the basis of processes (1) and (4):

process (1) (TiO)₂/SiO_zcenter/SiO_z/TiO₂)：

The SiO coating is carried out in a non-oxidizing atmosphere at a temperature of more than 600 ℃, preferably at a temperature of 700 ℃ and 1100 DEG C_yThe metal sheet (2) is calcined for 10 minutes or more, preferably several hours. Calcination in a non-oxidizing atmosphere (e.g. Ar and/or He, preferably Ar), optionally under reduced pressure (preferably at a pressure of less than 700 Torr (0.9333X 10)⁵N/m²) ) was performed.

Can be subsequently coated with SiO_yThe metal sheet of (2) is subjected to an oxidative heat treatment. For example, air or some other oxygen-containing gas is passed through the SiO-coated layer in bulk form or in a fluidized bed at temperatures above 200 ℃, preferably above 400 ℃, in particular 500-_yOf metal sheet of (2), wherein SiO_yOxidized to SiO_z。

The TiO can be readily formed by physical or chemical vapor deposition processes or by wet chemical coating methods₂Coating is applied to the SiO-coated layer_yOn the metal sheet of (2).

For coating, the substrate particles are suspended in water and one or more hydrolysable titanium salts are added at a pH suitable for hydrolysis, the pH being selected such that the metal oxide or hydrated metal oxide precipitates directly on the particles without auxiliary precipitation. The pH is generally kept stable by simultaneous metered addition of base. The pigment is then isolated, washed, dried, and calcined, as appropriate, the calcination temperature being optimized for the particular coating. If desired, the pigments can be isolated, dried and, where appropriate, calcined and resuspended after the respective coating has been applied in order to precipitate further layers.

The titanium oxide layer is prepared by controlled hydrolysis of one or more titanates by a sol-gel process in the presence of a suitable organic solvent and a basic catalyst, using a process similar to that described in, for example, DE-A-19501307. Suitable basic catalysts are, for example, amines (e.g. triethylamine, ethylenediamine, tributylamine, dimethylethanolamine and methoxypropylamine). The organic solvent being a water-miscible organic solvent, e.g. C_1-4Alcohols, in particular isopropanol.

Suitable titanates are selected from alkyl and aryl alcoholates of titanium; a carboxylated compound; carboxy, alkyl or aryl substituted alkyl alcoholates or carboxylates. Tetraisopropyl titanate is preferably used. Furthermore, titanium acetylacetonate and acetoacetonate may be used. An example of a preferred titanate of this type is titanium acetylacetonate.

According to one embodiment of the invention, the titanium dioxide layer is applied using the method described in US-B-3553001.

The aqueous solution of the titanium salt is slowly added to the suspension of the material to be coated which has been preheated to about 50 to 100 c, in particular 70 to 80 c, the pH being kept substantially constant at about 0.5 to 5, in particular about 1.2 to 2.5, by simultaneous metered addition of a base, for example an aqueous ammonia solution or an aqueous alkali metal hydroxide solution. Once the desired thickness of TiO is achieved₂And precipitating the layer, and stopping adding the titanium salt solution and the alkali.

This method (also called "titration" method) differs in that an excess of titanium salt is avoided. This is achieved by adding only hydrated TiO to the hydrolysate per unit time₂The amount of titanium salt required for uniform coating and the amount which can be adsorbed per unit time by the active surface of the particles to be coated. TiO formed in principle in the anatase form on the surface of the starting pigment₂. But by adding small amounts of SnO₂The rutile structure may be forced. For example, as described in WO93/08237, tin dioxide may be deposited prior to precipitating titanium dioxide and will be coated with titanium dioxideThe product of (a) is calcined at 800-900 ℃.

The flakes are then dried either ultrasonically or mechanically using a high speed stirrer in a liquid medium or using a pneumatic mill with a rotary classifier or grinding or air sieving to obtain the desired particle size and delivered for further use.

The weathering resistance can be increased by adding additional coatings, which at the same time allow optimum adaptation of the adhesive system (EP-A-268918 and EP-A-632109).

Method (4) (TiO)₂Layer (E)/SiO_zcenter/SiO_zLayer (E)/TiO₂：

As described above, with TiO₂Coated with SiO_yAnd then calcined in a non-oxidizing atmosphere. Thus, in addition to layer (B), by calcining the TiO₂/SiO_yAn additional layer (E) is generated. Suppose that TiO is calcined in a non-oxidizing atmosphere₂/SiO_yAn intermediate layer is produced which causes a change in the refractive index. However, it is also contemplated that the intermediate layer may not be a continuous layer, and may be simply TiO₂With SiO_yIndividual regions of the interface undergo transformations which cause a change in the refractive index. It is also hypothesized that the refractive index change is due to TiO₂Is coated with SiO_yAnd (4) reducing. The principle of the invention is therefore based on the use of SiO_yReduction of TiO₂An intermediate layer is prepared that causes a change in the refractive index.

It is also possible to use a refractive index of greater than 1.5 and which may be SiO_yReduced other metallic materials (e.g. Fe)₂O₃) Instead of TiO₂。

Therefore, another preferred embodiment of the present invention relates to TiO having a layered structure₂/SiO_zcenter/SiO_z/TiO₂Wherein the center is formed by layer (B) or layer (B)/layer (A)/layer (B), wherein layer (B) is applied only to the parallel planes of layer (A) and not to the sides of layer (A), wherein SiO_yLayers present only in parallel planes, not laterally, TiO₂Coated on the whole watchKneading; and TiO having a layered structure₂Layer (E)/SiO_ycenter/SiO_yLayer (E)/TiO₂Wherein the center is formed by layer (B) or layer (B)/layer (A)/layer (B), wherein layer (B) is applied only to the parallel planes of layer (A) and not to the sides of layer (A), wherein SiO_yLayers and layers (E) present only in parallel planes, not on the sides, TiO₂The layer is applied over the entire surface. In this embodiment, it is preferred that layer (a) consists of aluminum. Preferably, layer (B) is derived from aluminum.

If desired, the usual methods may be employed, for example US-A-4,948,631, JP H4-20031. The method described in DE-A-19618562 and DE-A-19843014 for the preparation of TiO₂Reduced to titanium suboxides.

Can be prepared by reacting with TiO₂The layer is coated with a metal oxide (e.g., SiO) having a low refractive index (i.e., a refractive index of less than about 1.65)₂、Al₂O₃、AlOOH、B₂O₃Or mixtures thereof, preferably SiO₂) Then coating a layer of Fe on the metal oxide layer₂O₃And/or TiO₂Layer, resulting in a more intensely colored and more transparent pigment. Such multicoat optical interference pigments comprising a silica substrate and alternating high and low refractive index metal oxide layers can be prepared in a manner similar to that described in WO98/53011 and WO 99/20695.

The following method may suitably be used on TiO₂Coating SiO on the layer₂Layer (protective layer): a metered quantity of soda water glass solution is added to the suspension of the material to be coated which has been heated to approximately 50-100 ℃, preferably 70-80 ℃, the pH being maintained at 4-10, preferably 6.5-8.5, by simultaneous addition of 10% hydrochloric acid, and stirring is carried out for a further 30 minutes after the addition of the water glass solution has been completed.

Furthermore, the color of the pigment powder can be improved by applying further layers, for example colored metal oxides, berlin blue, compounds of transition metals (e.g. Fe, Cu, Ni, Co, Cr) or organic compounds (e.g. dyes or lakes).

The finished pigment may also be post-coated or post-treated to further improve light, weather and chemical resistance or to facilitate handling of the pigment, particularly in various media. The processes described in DE-A-2215191, DE-A-3151354, DE-A-3235017, DE-A-3334598, DE-A-4030727, EP-A-649886, WO97/29059, WO99/57204 and US-A-5,759,255 are suitable for aftertreatment or post-coating, for example.

In addition, the pigments of the invention may also be coated with sparingly soluble, firmly adhering inorganic or organic colorants. Preference is given to using lakes, in particular aluminum lakes. For the precipitation of the aluminium hydroxide layer, in a second step, precipitation is carried out using a lake (DE-A-2429762 and DE-A-2928287).

Furthermore, the pigments according to the invention may also have an additional coating which is coated with complex salt pigments, in particular with cyanoferrate complexes (EP-A-141173 and DE-A-2313332).

As described in the method (1), the SiO coating is applied_yThe metal flakes of (a) are calcined in a non-oxidizing atmosphere at a temperature of above 600 ℃, preferably at 700 ℃ and 1100 ℃ for more than 10 minutes, preferably several hours,the calcined flakes, preferably in bulk form, optionally in admixture with an oxygen-containing compound (e.g., aldehydes, ketones, water, carbon monoxide, carbon dioxide, and the like or mixtures thereof), may also be reacted with a carbon-containing gas selected from the group consisting of alkynes (e.g., acetylene), alkanes (e.g., methane), alkenes, aromatics, and the like and mixtures thereof, and preferably oxygen is vented, in a gas-tight reactor heatable up to about 1500 c at 500-. In order to make the reaction milder, an inert gas (e.g. argon or helium) may be mixed with the carbon-containing gas (WO 03/68868).

At pressures below about 1Pa, the reaction generally proceeds very slowly, especially when the carbon-containing gas is poorly reactive, or is highly diluted with an inert gas, as is conventionally used, for example, in HIP ("hot isocratic pressing") systems, operating at pressures up to about 4000bar being entirely possible.

In this carbonization reaction, all SiO may be used_yReaction to form SiC, preferably 5-90% by weight of SiO_yAnd reacting to generate SiC. SiO 2_yThe temperature for conversion to SiC was 5From 00 ℃ to 1500 ℃, preferably from 500 ℃ to 1000 ℃, for a period of from about 1 hour to about 20 minutes. The reaction initially occurs at the surface of the plane parallel structure and is thus a step-wise conversion rather than a sharp change. This means that in this embodiment the SiC-containing layer consists of (SiO)_y)_aAnd (Si)_C)_bWherein a is more than or equal to 0 and less than 1, b is more than 0 and less than or equal to 1, b is 1 on the surface of the pigment, a is 0, and the surface is close to SiO_yAt the boundary of the substrate, the amount of SiC was close to 0. The SiO_yThe structure is sufficiently porous because such reactions are not limited to SiO_yThe uppermost layer of the molecule.

According to this process, a pigment having the following layer structure can be obtained: SiC/SiO_ycenter/SiO_y/SiC, in the presence of oxygen, the pigment is calcined to give a pigment having the following layer structure: SiC/SiO_zcenter/SiO_z/SiC。

The pigments obtained by this process are novel and are a further subject of the present invention.

Instead of a metal oxide layer with a high refractive index, the materials described in US-B-6,524,381, such as diamond-like carbon and amorphous carbon, can be deposited on a substrate by a plasma-assisted vacuum process as described in US-B-6,524,381 using a vibrating conveyor, a roller coater, a vibrating drum coater (oscillatorily drum coater) and a free-fall chamber (free-fall chamber)Coated with SiO_zOn a metal substrate.

The invention therefore also relates to plane-parallel structures (pigments) based on silicon oxide/metal substrates, which pigments have a carbon layer on the surface, in particular a diamond-like carbon layer with a thickness of 5 to 150nm, in particular 20 to 50 nm.

In a method such as described in US-B-6,015,597, a coating of a Diamond Like Network (DLN) is deposited on particles by plasma deposition from a carbon containing gas such as acetylene, methane, butadiene and mixtures thereof, and optionally Ar and optionally a gas containing other components. The deposition is carried out under reduced pressure (relative to atmospheric pressure) and a controlled environment. A carbon-rich plasma is generated in the reaction chamber by applying an electric field to the carbon-containing gas. The particles to be coated are placed in a tank or vessel located in the reactor and agitated while in close proximity to the plasma. And reacting substances in the plasma on the particle surface to form a covalent bond to obtain DLN on the particle surface.

The term "diamond-like network" (DLN) refers to an amorphous film or coating composed of carbon and optionally comprising one or more other components selected from the group consisting of hydrogen, nitrogen, oxygen, fluorine, silicon, sulfur, titanium and copper.

The diamond-like network includes about 30-100% carbon by total number of atoms, with the balance being optional other ingredients.

Metallic or non-metallic, inorganic platelet-shaped particles or pigments are effect pigments (in particular metallic effect pigments or optical interference pigments), that is to say pigments which, in addition to imparting a color to the coating medium, impart other properties, for example a change in color with angle (goniochromatic), sparkling (rather than surface gloss) or texturing. For metallic effect pigments, substantially direct reflection occurs on the directionally oriented pigment particles. For light interference pigments, the color effect results from the phenomenon of light interference in thin, highly refractive layers.

The pigments of the invention can be used for all customary purposes, for example for coloring polymeric materials, printing inks for coatings (including effect finishes, for automobiles) and printing inks (including offset, gravure, bronzing or flexographic printing), and can be used, for example, for cosmetics, ink-jet printing, textile dyeing, glazes for ceramics and glass, and for laser-marking paper and plastics. Such uses are described in references such as "industrille Organischeppigment" (W.Herbst and K.Hunger, VCH Verlagsgesellschaft mbHWeinheim/New York, 2 nd fully revised edition, 1995).

When the pigment of the present invention is an optical interference pigment (effect pigment), the pigment is a goniochromatic pigment and produces a bright, highly saturated (glossy) color. The pigments of the invention are therefore particularly suitable for use in combination with conventional transparent pigments, for example organic pigments such as diketopyrrolopyrroles, quinacridones, dioxazines, perylenes, isoindolinones and the like. The transparent pigment may have a similar color as the effect pigment. However, similarly to, for example, EP-A-388932 or EP-A-402943, particularly interesting combined effects are obtained when the color of the transparent pigment is complementary to the color of the effect pigment.

The pigments according to the invention can be used to color high molecular weight organic materials with excellent results.

The high molecular weight organic materials which can be pigmented with the pigments or pigment compositions of the invention can be high molecular weight organic materials of natural or synthetic origin. Generally, the molecular weight of the high molecular weight organic material is about 10³-10⁸g/mol or more. The high molecular weight organic material may be, for example, a natural resin, drying oil, rubber, casein or a derivative of a natural substance, such as chlorinated rubber, oil-modified alkyd resin, viscose, cellulose ether or ester, such as ethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetobutyrate or cellulose nitrate, but in particular a fully synthetic organic polymer (thermoset and thermoplastic) obtained by polymerization, polycondensation or polyaddition. From the class of polymeric resins, mention may in particular be made of polyolefins (such as polyethylene, polypropylene or polyisobutylene), substituted polyolefins (such as the polymerization products of vinyl chloride, vinyl acetate, styrene, acrylonitrile, acrylates, methacrylates or butadiene) and also the copolymerization products of said monomers, in particular ABS or EVA.

Among the various polyaddition resins and polycondensation resins, mention may be made, for example, of the condensation products of formaldehyde with phenol (known as "phenoplasts") and of formaldehyde with urea, thiourea or melamine (known as "aminoplasts") and also of the saturated polyesters (such as alkyd resins) or unsaturated polyesters (such as maleate resins) used as coating resins, and also of the linear polyesters, polyamides, polyurethanes or polysiloxanes.

The macromolecular compounds may be present individually or as mixtures in the form of plastic masses or melts. It is also possible to use in the form of dissolved monomers or in the polymerized state as film formers or binders for coatings or printing inks, for example linseed oil, nitrocellulose, alkyd resins, melamine resins, urea-formaldehyde resins or acrylic resins.

Depending on the intended use, it has proven advantageous to use the effect pigments or effect pigment compositions according to the invention as toners or in the form of preparations. Depending on the conditioning method or the intended use, it may be advantageous to add to the effect pigment, before or after the conditioning process, an amount of the texture-improving agent, provided that this does not adversely affect the use of the effect pigment in high molecular weight organic materials, in particular polyethylene. Suitable agents for improving the relief are, in particular, fatty acids containing at least 18 carbon atoms (e.g. stearic acid or behenic acid) or amides or metal salts thereof (in particular magnesium salts) and also plasticizers, waxes, resin acids (e.g. abietic acid), rosin soaps, alkylphenols or fatty alcohols (e.g. stearyl alcohol) or aliphatic 1, 2-dihydroxy compounds containing 8 to 22 carbon atoms (e.g. 1, 2-dodecanediol) and also modified rosin maleate resins or fumaric acid rosin resins. The amount of the texture-improving agent added is preferably from 0.1 to 30%, in particular from 2 to 15%, by weight based on the final product.

The (effect) pigments according to the invention can be added to the high molecular weight organic material to be dyed in any dyeing-effective amount. Advantageously, the pigmented composition of matter comprises a high molecular weight organic material and from 0.01 to 80%, preferably from 0.1 to 30%, by weight, based on the high molecular weight organic material, of a pigment according to the invention. Concentrations of from 1 to 20% by weight, in particular of about 10% by weight, are generally used in practice.

The pigmented compositions in high concentrations (for example greater than 30% by weight) are generally in the form of concentrates ("masterbatches") which can be used as colorants for preparing pigmented materials of relatively low pigment content, the pigments of the invention having a very low viscosity in conventional formulations which therefore still have good processability.

The effect pigments of the invention can be added separately to color organic materials. However, it is also possible to add, in addition to the effect pigments of the invention, other color-imparting components in any desired amounts (for example white, colored, black or effect pigments) to the polymeric organic substances in order to achieve different hues or color effects. When colored pigments are used in admixture with the effect pigments of the invention, the preferred total amount is a high molecular weight0.1-10% by weight of the organic material. Preferred combinations of the effect pigments of the invention with colored pigments of other colors, in particular complementary colors, provide particularly high angular isothromaticity, the color difference (. DELTA.HH) of the colorations obtained using the effect pigments and using the colored pigments being measured at an angle of 10 °^*) 20-340, in particular 150-210.

The (effect) pigments according to the invention are preferably used together with transparent colour pigments which may be present in the same medium as the effect pigments according to the invention or may also be present in an adjacent medium. One example of a distribution pattern in which the effect pigments and the colored pigments are advantageously present in adjacent media is a multi-layer effect finish.

The process for pigmenting high molecular weight organic material substances with the pigments of the invention is as follows: mixing such pigments (which may be in the form of a suitable masterbatch) with the substrate using a roller mill or mixing or grinding apparatus; the pigmented material is then prepared into the final desired form using known methods (e.g., calendering, compression molding, extrusion, coating, pouring or injection molding). Any conventional additives in the plastics industry, such as plasticizers, fillers or stabilizers, can be added to the polymer in conventional amounts, either before or after incorporation of the pigment. In particular, for the preparation of non-rigid shaped articles or for reducing the brittleness of shaped articles, it is necessary to add plasticizers (for example esters of phosphoric acid, phthalic acid or sebacic acid) to the macromolecular compounds prior to shaping.

For the coloring of coatings and printing inks, the high molecular weight organic materials and the (effect) pigments according to the invention and, where appropriate, conventional additives, such as fillers, other pigments, siccatives or plasticizers, are finely dispersed or dissolved in the same organic solvent or solvent mixture, it being possible for the individual components to be dissolved or dispersed separately or for a plurality of components to be dissolved or dispersed together and then for all the components to be mixed together.

The dispersion of the effect pigments of the invention in the high molecular weight organic material to be dyed, and the processing of the pigment compositions of the invention, is preferably carried out under conditions which keep the shear forces occurring only relatively low, so that the effect pigments are not broken up into smaller pieces.

The pigments according to the invention are used in the plastics in amounts of 0.1 to 50% by weight, in particular 0.5 to 7% by weight. The pigments according to the invention are used in the coating in amounts of 0.1 to 10% by weight. In the dyeing of binder systems, for example paints and printing inks for gravure, offset or screen printing, the pigments are incorporated in the printing inks in amounts of from 0.1 to 50% by weight, preferably from 5 to 30% by weight, in particular from 8 to 15% by weight.

The colorations obtained, for example, in plastics, paints or printing inks, in particular in paints or printing inks, more particularly in paints, are distinguished by very good properties, in particular by very high saturation, outstanding fastness and high goniochromicity.

When the polymeric material being dyed is a coating, the coating is preferably a specialty coating, most preferably an automotive finish.

The effect pigments according to the invention are also suitable for making up the lips or the skin, or for coloring hair or nails.

The present invention therefore also relates to cosmetic preparations comprising, based on their total weight, from 0.0001 to 90% of the pigments according to the invention, in particular effect pigments, and from 10 to 99.9999% of a cosmetically suitable carrier material.

Such cosmetic preparations are, for example, lipsticks, blushes, foundations, nail varnishes and hair shampoos.

The pigments of the invention may be used alone or in mixtures, and may also be used in combination with other pigments and/or colorants as described above or well known in cosmetic formulations.

Preferably, the cosmetic preparations according to the invention contain from 0.005 to 50% by weight of the pigment according to the invention, based on the total weight thereof.

Suitable carrier materials for the cosmetic preparations of the present invention include conventional materials used in such compositions.

The cosmetic preparation of the present invention may be in the form of: such as a stick, ointment, cream, emulsion, suspension, dispersion, powder or solution. For example, the cosmetic preparation is a lipstick, a mascara preparation, a blusher, an eye shadow, a foundation, an eyeliner, a powder or a nail varnish.

If the preparation is in the form of a stick (e.g. lipstick, eye shadow, blusher or foundation), the preparation contains a considerable amount of fatty ingredients, which may consist of one or more waxes, for example ozokerite; lanolin; lanolin alcohol; hydrogenating lanolin; acetylated lanolin; lanolin wax; beeswax; candelilla wax; microcrystalline wax; carnauba wax; cetyl alcohol; stearyl alcohol; cocoa butter; lanolin fatty acids; vaseline; petrolatum; mono-, di-or triglycerides or fatty acid esters thereof which are solid at 25 ℃; silicone waxes (e.g., methyl octadecanoxy polysiloxane and poly (dimethylsiloxy) stearoxysilane); stearic acid monoethanolamine; rosin and its derivatives (e.g., rosin esters of ethylene glycol and rosin esters of glycerol); hydrogenated oil solidified at 25 ℃; glycerol esters of sucrose, and calcium, magnesium, zirconium and aluminum salts of oleic acid, myristic acid, lanolin acid, stearic acid, dihydroxystearic acid.

The fatty component may also consist of at least one wax and at least one oil, in which case suitable oils are, for example: paraffin oil, purcelline oil, perhydrosqualene, sweet almond oil, avocado oil, crabapple oil, castor oil, sesame oil, jojoba oil, mineral oil having a boiling point of about 310-140 ℃, silicone oil (e.g., dimethylpolysiloxane), linoleyl alcohol, linolenyl alcohol, oleyl alcohol, grain fusel oil (e.g., wheat germ oil), isopropyl lanolate, isopropyl palmitate, isopropyl myristate, butyl myristate, cetyl stearate, butyl stearate, decyl oleate, acetyl glycerides, caprylic and capric esters of alcohols and polyols (e.g., ethylene glycol and glycerol), ricinoleic esters of alcohols and polyols (e.g., cetyl alcohol, isostearyl alcohol), isocetyl lanolate, isopropyl adipate, hexyl laurate and octyldodecanol.

The content of fatty constituents in such stick preparations is generally up to 99.91% by weight of the total weight of the preparation.

The cosmetic preparations according to the invention may also comprise further components, such as, for example, glycols, polyethylene glycols, polypropylene glycols, monoalkanolamides, colourless fillers (polymeric, inorganic or organic), preservatives, UV filters or other auxiliaries and additives conventionally used in cosmetics (for example, natural or synthetic or partially synthetic di-or triglycerides, mineral oils, silicone oils, waxes, fatty alcohols, Guerbet alcohols or esters thereof), lipophilic functional cosmetic active ingredients (including sun protection filters or mixtures of such substances)).

Lipophilic functional cosmetic active ingredients, active ingredient compositions or active ingredient extracts suitable for use in skin cosmetics are one or a mixture of ingredients which can be applied to the skin or topically. Mention may be made, for example, of the following:

active ingredients having a cleansing action on the skin surface and on the hair, including all substances which can be used for cleansing the skin, such as oils, soaps, synthetic detergents and solid substances;

active ingredients with deodorant and antiperspirant action, including antiperspirants based on aluminium or zinc salts, deodorants containing bactericidal or bacteriostatic deodorants (e.g. triclosan, hexachlorophene, alcohols or cationic substances (e.g. quaternary ammonium salts)) and odour absorbers (e.g. quaternary ammonium salts)^®Grillocin (combination of zinc ricinoleate with various additives) or triethyl citrate (optionally in combination with an antioxidant such as butyl hydroxy toluene) or ion exchange resins);

active ingredients for protection against the sun (uv filters), suitable active ingredients being filter substances (sunscreens) capable of absorbing the uv radiation from the sun and converting it into heat, the following agents for protection against the sun being preferred, depending on the desired action: light ageing inhibitors (UV-B absorbers) which selectively absorb the high-energy UV radiation in the wavelength range of approximately 280-315nm, which causes tanning, and transmit the UV radiation in the longer wavelength range (for example in the UV-a range of 315-400 nm), and light ageing inhibitors (UV-a absorbers) which absorb only the UV radiation in the UV-a range of 315-400nm, suitable light ageing inhibitors are, for example, the following types of UV absorbers: p-aminobenzoic acid derivatives, salicylic acid derivatives, benzophenone derivatives, dibenzoylmethane derivatives, diphenylacrylate derivatives, benzofuran derivatives, polymeric uv absorbers containing one or more organosilicon groups, cinnamic acid derivatives, camphor derivatives, triphenylamino-s-triazine derivatives, phenylbenzimidazolesulfonic acid and its salts, menthyl anthranilate, benzotriazole derivatives and/or inorganic microfine pigments selected from titanium dioxide, zinc oxide or mica coated with aluminum oxide or silicon dioxide;

active ingredients against insects (repellents), which are agents that prevent insects from touching and moving on the skin, which repel insects and evaporate slowly, the most commonly used repellent being diethyltoluamide (deet), other common repellents being found, for example, on page 161 of "pflegeko smetik" (w.raab and u.kindl, Gustav-Fischer-VerlagStuttgart/New York, 1991);

active ingredients to protect against chemical and physical influences, including all substances that form a barrier between the skin and external harmful substances, such as paraffin oil, silicone oil, vegetable oil, PCL products and lanolin to protect the skin from aqueous solutions, film-forming agents to protect the skin from the action of organic solvents (such as sodium alginate, triethanolamine alginate, polyacrylates, polyvinyl alcohols or cellulose ethers) or substances based on mineral, vegetable or silicone oils as "lubricants" to protect the skin against strong mechanical stresses on the skin;

wetting agents, for example the following substances can be used as moisture regulators (wetting agents): sodium lactate, urea, alcohol, sorbitol, glycerol, propylene glycol, collagen, elastin, and hyaluronic acid;

active ingredients with a keratinocyte proliferation effect: benzoyl peroxide, retinoic acid, colloidal sulfur, and resorcinol;

antimicrobial agents, such as triclosan or quaternary ammonium compounds;

-oily or oil-soluble vitamins or vitamin derivatives that can be applied to the skin, such as vitamin a (retinol in free acid or its derivative form), panthenol, pantothenic acid, folic acid and mixtures thereof, vitamin E (tocopherol), vitamin F, essential fatty acids or nicotinamide (nicotinic acid amide);

vitamin-based placenta extract, the active principle composition of which comprises in particular vitamin A, C, E, B₁、B₂、B₆、B₁₂Folic acid, vitamin H, amino acids and enzymes, and trace elements of magnesium, silicon, phosphorus, calcium, manganese, iron or copper;

-a skin repair complex obtained from a non-viable culture and a decomposed culture of lactobacillus bifidus bacteria;

plants and plant extracts, such as arnica, aloe vera, lichen, ivy, nettle, ginseng, henna, chamomile, marigold, rosemary, sage, equisetum or thyme;

-animal extracts, such as royal jelly, propolis, proteins or thymus extracts;

cosmetic oils which can be applied to the skin, such as: miglyol type 812 neutral oil, almond oil, avocado oil, babassu oil, cottonseed oil, borage oil, thistle oil, peanut oil, gamma-oryzanol, rose seed oil, hemp oil, hazelnut oil, blackcurrant seed oil, jojoba oil, cherry kernel oil, salmon oil, linseed oil, corn oil, macadamia nut oil, almond oil, evening primrose oil, mink oil, olive oil, pecan oil, peach kernel oil, pistachio nut oil, rape oil, rice-seed oil, castor oil, safflower oil, sesame oil, soybean oil, sunflower seed oil, tea tree oil, grape seed oil, or wheat germ oil.

Preferably, the stick formulation is anhydrous, but in some cases may contain water, typically not exceeding 40% of the total weight of the cosmetic formulation.

If the cosmetic preparations according to the invention are products in semisolid form, that is to say in the form of ointments or creams, they may likewise be anhydrous or aqueous. Such formulations are, for example, mascaras, eyeliners, foundations, blushers, eye shadows or compositions for treating bags under the eyes.

On the other hand, if such ointments or creams are aqueous, they are in particular emulsions of the water-in-oil or oil-in-water type which, in addition to the pigment, comprise from 1 to 98.8% by weight of a fatty phase, from 1 to 98.8% by weight of an aqueous phase and from 0.2 to 30% by weight of an emulsifier.

Such ointments and creams may also contain other conventional additives, such as perfumes, antioxidants, preservatives, gelling agents, UV filters, colorants, pigments, pearlizing agents, colorless polymers, and inorganic or organic fillers.

If the formulation is in powder form, it consists essentially of mineral, inorganic or organic fillers (e.g. talc, kaolin, starch, polyethylene powder or polyamide powder) and auxiliaries (e.g. binders, colorants), etc.

Such preparations may also contain various adjuvants conventionally used in cosmetics, such as perfumes, antioxidants, preservatives, and the like.

If the cosmetic preparation according to the invention is a nail varnish, this preparation consists essentially of nitrocellulose and a natural or synthetic polymer in the form of a solution in a solvent system, which may contain further auxiliaries (for example pearlescent agents).

In an embodiment of the invention, the amount of colored polymer is about 0.1 to 5% by weight.

The cosmetic preparations according to the invention can also be used for coloring hair, in which case preparations in the form of shampoos, creams or gels composed of the basic substances conventionally used in the cosmetics industry and the pigments according to the invention can be used.

The cosmetic formulations of the present invention may be prepared using conventional methods, for example by mixing or stirring the components together, optionally with heating to melt the mixture.

The following examples illustrate the invention without limiting its scope. Unless otherwise specified, percentages and parts are by weight.

Examples

Example 1

In less than about 10^-2PaThe sodium chloride is gasified in a vacuum chamber at a pressure of (2) to obtain a sodium chloride layer having a thickness of about 50nm on the metal support. Then, at the same pressure, the following layers were deposited in sequence: SiO, Al and SiO, wherein a thin film having the following layer structure is formed on the metal carrier: SiO (270 nm)/Al (40nm)/SiO (270nm), and the separation layer was dissolvedThe insoluble (SiO/aluminum/SiO) layer was broken up into flakes in deionized water. The suspension was concentrated by filtration at atmospheric pressure and washed several times with deionized water to remove sodium and chloride ions present. Drying to obtain the SiO-coated film_yThe aluminum sheet of (a), which exhibits a bright metallic color.

The resulting SiO coating was applied at a heating rate of 100 deg.C/min under an argon atmosphere_yThe aluminum flakes of (a) are gradually heated to 750 c, i.e. above the melting point of aluminum.

The resulting flakes exhibited a dull green/yellow color and were partially transparent.

With TiO by wet-chemical methods₂(20nm) coating the pigment thus obtained: coating the SiO_yThe aluminum flakes of (a) were suspended in fully deionized water and heated to 75 ℃. Mixing TiCl₄Is metered into the suspension. The pH was maintained at 2.2 by addition of 32% sodium hydroxide solution. After the addition of the solution, the mixture was stirred for an additional about 30 minutes at 75 ℃. The pigment thus obtained is characterized by a bright green/yellow colour and exhibits flop.

To further improve the light, weather and chemical resistance, the pigments in the form of loose materials in a fluidized bed can be oxidized with air at 200 ℃.

Example 2

In less than about 10^-2The following layers were sublimated sequentially in a vacuum chamber on a glass substrate under Pa: TiO 2₂(50nm), SiO (270nm), Al (50nm), SiO (270nm) and TiO₂(50 nm). One sample was used as a control sample (RS), and the other sample (S) was heated at 700 ℃ for 0.5 hour under an argon atmosphere.

At observation angles of 10 °, 30 ° and 50 °Using a standard light source D₆₅The reflected colors (CIE-L) of the sample (S) and the control sample (RS) were measured by irradiation^*C^*h)：

Test specimen	Whether or not to calcine	Viewing angle (degree)	L*	a*	b*	c*	h
								RS	Whether or not	10	98	9.7	5.2	11	28.1
RS	Whether or not	30	99.5	0.2	15.8	15.8	89.1
								RS	Whether or not	50	100	-8.5	16.5	18.6	117
S	Is that	10	70	-6.4	-3.0	7	205
								S	Is that	30	68.4	-11.7	-7.6	13.9	213
S	Is that	50	64.8	-13.8	-16.8	21.7	230.6

Claims (12)

1. A pigment, the pigment comprising:

(A) an optional layer consisting of a metal,

(B) at least one layer consisting of a metal, silicon (Si) and oxygen (O), said layer being located between layer (A) and layer (C) if layer (A) is present, and

(C) optionally from SiO_zA layer on layer (B) of composition wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0.

2. The pigment of claim 1, comprising:

(B) at least one layer consisting of a metal, silicon (Si) and oxygen (O), and

(C) at least one layer consisting of SiO_zA layer on layer (B) of composition, wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq.z.ltoreq.2.0, more particularly 1.40. ltoreq. z.ltoreq.2.0.

3. The pigment of claim 1 or 2, comprising:

(C1) from SiO_zThe layers of the composition are such that,

(B) at least one layer consisting of a metal, silicon (Si) and oxygen (O) between layers (C1) and (C2),

(C2) at least one layer consisting of SiO_zA layer on layer (B) of composition wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0.

4. The pigment of claim 3, comprising:

(D) additional layers of high refractive index material, in particular TiO, amorphous carbon, diamond-like carbon or silicon carbide₂。

5. The pigment of claim 4, comprising:

(D1) layer of a material of high refractive index, in particular TiO₂，

(C1) From SiO_zThe layers of the composition are such that,

(B) at least one layer consisting of a metal, silicon (Si) and oxygen (O) between layers (C1) and (C2),

(C2) from SiO_zA layer of composition, and

(D2) layer of a material of high refractive index, in particular TiO₂Wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0.

6. The pigment of any of claims 1 to 5, wherein the metal is selected from Ag, Al, Cu, Cr, Mo, Ni, Ti or alloys thereof, in particular aluminum.

7. The pigment of claim 3, having the following layer structure: TiO 2₂/SiO_zcenter/SiO_z/TiO₂WhereinThe center is formed by layer (B) or layer (B)/layer (A)/layer (B), wherein the layer (B) exists in the parallel plane of layer (A) but not the side of layer (A), wherein the SiO is_zLayers present only in parallel planes, not on the sides, said TiO₂Coating the layer on the whole surface; SiC/SiO_zcenter/SiO_z/SiC or C/SiO_zcenter/SiO_z/C, where 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0.

8. A pigment prepared by calcining in a non-oxidizing atmosphere plane-parallel structures (platelets) comprising: (A) at least one layer consisting of a metal, and (C) at least one layer consisting of SiO_zA layer of composition wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.1. ltoreq. z.ltoreq.2.0.

9. A plane parallel structure, the plane parallel structure comprising: (A) a layer consisting of a metal, in particular aluminum, and (C) at least one layer consisting of SiO_zA layer of composition wherein 0.70. ltoreq. z.ltoreq.2.0, in particular 1.10. ltoreq. z.ltoreq.2.0, more in particular 1.40. ltoreq. z.ltoreq.2.0.

10. Use of the pigments according to any of claims 1 to 8 in ink-jet printing, textile dyeing, and for pigmenting coatings, paints, printing inks, plastics, cosmetics, glazes for ceramics and glass.

11. A composition comprising the pigment of any one of claims 1 to 8.

12. A cosmetic preparation, paint, printing ink or coating which comprises a pigment according to any one of claims 1 to 8.