Blue-red effect pigment

Abstract

This application relates to a blue-toned red effect pigment comprising (a) an intermediate 1 comprising optionally passivated metal flakes coated with silica and iron oxide, and (b) an intermediate 2 comprising synthetic or natural mica flakes coated with a first layer of Fe2O3 or TiO2, a second layer of SiO2, and a third layer of Fe2O3 or TiO2. The pigment of this disclosure has better color properties than known blue-toned red effect pigments.

Description

[Technical Field]

[0001] Luminous pigments, or effect pigments, are used in many fields, such as automotive paints, cosmetic paints, plastics, paints, printing inks, and cosmetics. The optical effect is primarily based on the directed reflection of light from flake-like, parallel-oriented, metallic, or highly refractive pigment particles. Depending on the composition of the pigment's plate-like crystals, interference, reflection, and absorption phenomena exist, creating angle-dependent color and brightness effects. [Background technology]

[0002] Metallic effect pigments are made from plate-like crystalline substrates known to those skilled in the art, examples of which are aluminum plate-like crystals / flakes or metal oxide-coated aluminum plate-like crystals / flakes. Plate-like crystalline aluminum pigments with iron oxide coatings are well known, and are mentioned, for example, in EP-A-0033457 or by W. Ostertag et al., Farbe und Lack 12 (1987) 973-976. They belong to the class of effect pigments and, due to their specific color properties, are widely used for coloring paints, coatings, printing inks, plastics, ceramic compositions and glazes, as well as cosmetics.

[0003] Iron oxide-coated aluminum pigments derive their specific optical profiles from a combination of specular reflection on the surface of the aluminum plate-like crystals, selective light absorption of the iron oxide layer, and optical interference on the film-like surface of the iron oxide layer. The light interference results in a color primarily determined by the thickness of the iron oxide coating. Therefore, as the thickness of the iron oxide layer increases, the dry pigment powder exhibits the following hues in air, which are classified as either due to primary or secondary interference: Primary interference colors: pale yellow, green-gold, gold, reddish-gold, red, purple, gray-violet. Secondary interference colors: yellow, gold, reddish-gold, reddish-gold, red.

[0004] Iron oxide-coated metal flakes, particularly aluminum-based flakes, are widely used in automotive paints due to their extremely high brightness and opacity. Pigments commonly used in this field are based on aluminum plate-like crystals and exhibit a metallic mirror effect. Iron oxide-coated aluminum pigments are known for their vivid colors ranging from gold to red.

[0005] The iron oxide layer of the effect pigment can be applied to metal substrate particles by gas-phase decomposition of volatile iron compounds in the presence of oxygen and / or water vapor (so-called chemical vapor deposition), or by a wet chemical coating process (e.g., a sol-gel or precipitation process).

[0006] US7,387,669 refers to a luminous pigment having a prominent sparkle based on aluminum plate crystals coated with iron oxide, with an average plate crystal size of 8–30 μm, an average plate crystal thickness of 300–600 nm, and an aspect ratio of 15–70 in a pre-coated state.

[0007] US5,277,711 refers to a dry mixture useful as a luminous pigment, comprising, as essential components, A) iron oxide-coated aluminum particles and B) iron oxide-coated mica particles, pre-coated or uncoated with a colorless, high refractive index metal oxide. Its synthesis was carried out via CVD coating of an Al / mica blend with iron oxide. The main objective of this patent was to reduce or eliminate the flammability of iron oxide, particularly Fe2O3-coated aluminum pigments, and the resulting dust explosion hazard.

[0008] EP2838956B1 refers to the synthesis of iron oxide-coated aluminum flakes by means other than chemical vapor deposition and describes a wet chemical preparation method that avoids handling dry pigment powders that could induce the risk of aluminothermic (e.g., thermite) reactions.

[0009] WO2015 / 040537A1 (US10800926B2) refers to a wet chemical synthesis for coating Al flakes with iron oxide. This claims that doping an iron oxide layer with aluminum on an aluminum-based substrate (which may optionally be passivated) results in an effect pigment that is non-magnetic or demagnetizable while exhibiting remarkable flop properties (light / dark contrast) and vivid color.

[0010] WO2018 / 186838A1 refers to effect pigments in the red, light reddish-purple, and magenta color space. These multilayer effect pigments include a plate-like substrate having an absorbing optically active metal oxide layer having an optical thickness of about 20 nm to about 400 nm, a low refractive index material layer having an optical thickness of about 10 nm to about 500 nm on the absorbing optically active metal oxide layer, and an optically active outermost layer of a non-absorbing high refractive index material having an optical thickness of about 50 nm to about 1000 nm on the low refractive index material. In some embodiments, the plate-like substrate includes natural mica, synthetic mica, glass flakes, SiO2, Al2O3, talc, bismuth oxychloride, natural pearl, perlite, boron nitride, zinc oxide, natural silicates, synthetic silicates, or any two or more combinations thereof.

[0011] US8,529,876 / EP2 675 423B1) refers to a mixture of mica-based effect pigments exhibiting a hue comparable to carmine for cosmetic use. A first effect pigment, such as iron oxide-coated mica, is blended with a second effect pigment consisting of a transparent substrate and one or more colorless metal oxide layers. The resulting composition has a carmine-like color angle of approximately 340–360°.

[0012] EP881998B1 refers to pearlescent pigments improved for exterior use. Pearlescent pigments with improved moisture resistance and weather resistance are achieved by metal oxide coated mica pearlescent pigments having a combination of aluminum or aluminum-cerium treatment on the surface and a hydrolyzed silane coupling agent treated surface.

[0013] US9957370 refers to a coated metallic effect pigment comprising a platelet-shaped crystalline substrate, the coating comprising at least one hybrid inorganic / organic layer, the hybrid layer having at least partially an inorganic network having one or more inorganic oxide components and having at least one organic component, at least a part of the organic component being an organic oligomer and / or polymer at least partially covalently bonded to the inorganic network via one or more organic network-forming components.

[0014] Iron oxide-coated aluminum pigments are widely used in automotive paints because they are very high in brightness, colored, and opaque. Gold and orange iron oxide-coated aluminum flakes have been used in automotive base coats for about 30 years. More recently, redder grades have been used. On the other hand, designers are demanding more blue-toned red effect pigments to enable new color spaces, which are only possible with new advanced effect pigments.

Prior Art Documents

Patent Documents

[0015]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Non-Patent Literature

[0016]

Non-Patent Literature 1

Summary of the Invention

Problems to be Solved by the Invention

[0017] The problem to be solved by the present invention is to improve the apparent appearance defects when an existing blue-toned red effect pigment is used in the base coat of an automobile. The appearance defects can be considered as, for example, a low distinctness of image (DOI) value where the mirror image of the base coat / clear coat is blurred due to the roughness of the base coat and insufficient hiding power caused by the thick Al flakes. The thick Al flakes have the hiding power of a single flake and the weight of 2 to 3 thin flakes. The improvement in the appearance of the pigment of the present invention is shown in the characteristics shown in Table 1 in the Examples section below. Furthermore, it is known that using a wet chemical process instead of dry pigment powder is a safer method for handling pigments.

[0018] The pigment of the present invention is produced by a combination of process steps not heretofore described, resulting in an effect pigment heretofore impossible.

[0019] Blue-toned red iron oxide-coated aluminum flakes require a thick oxide layer, which typically increases the oxide concentration and thus enhances safety regarding aluminothermic reactions. Effect pigments based on oxide-coated aluminum flakes can induce aluminothermic reactions at higher temperatures or after ignition. Aluminothermic reactions are highly exothermic chemical reactions between aluminum, acting as a reducing agent, and metal oxides such as iron oxide or titanium oxide. The most prominent example is the thermite reaction between aluminum and iron oxide. However, aluminum can also react with titanium oxide or other oxides, such as SiO2.

[0020] Therefore, pigments, especially those with concentrations of aluminum and oxides close to the stoichiometric ratios for the thermite reaction, must be handled safely on a production scale by minimizing the risk of initiating an aluminothermic reaction.

[0021] The opportunity to obtain more bluish iron oxide, including aluminum flakes, is also limited by the selective absorption of iron oxide. That is, the bluer the interference color of the iron oxide film, the thicker it is and the weaker the saturation of the observed pigment. Thus, the end of the first series of interference colors appears as a dull grayish-purple, and the second series also ends with a chromatic red that becomes achromatic as the thickness of Fe2O3 increases further.

[0022] The only pigment considered a true blue-toned red effect pigment is mentioned in US7,387,669. That pigment (Paliocrom® Sparkling Red L 3505, Sunchemical) is based on Al flakes with an average plate size of 8–30 μm, an average plate thickness of 300–600 nm, and an aspect ratio of 15–70. The thick iron oxide layer required for the blue-toned red at the end of the second interference color series can be safely applied to the CVD process due to its low aspect ratio. The low aspect ratio of the Al flakes results in a smaller BET surface area, allowing for an iron oxide layer of 100 nm or more with smaller, and therefore safer, amounts of Fe2O3.

[0023] On the other hand, a low aspect ratio limits the appearance and opacity of the color when a normal or greater amount of flake is used for coloring. Limited color appearance refers to a decrease in the gloss of the base coat / clear coat, a decrease in DOI (image discrimination), a decrease in haze and flop index, and an increase in granularity.

[0024] The reduced concealment is also a result of thicker flakes; in other words, thicker, and therefore heavier, flakes have fewer flakes per unit weight compared to thinner flakes of the same flake diameter.

[0025] Al flakes with a significantly low average thickness (i.e., flakes with a high aspect ratio) cannot be safely coated with iron oxide tones such as the bluish-red of Paliocrom Sparkling Red L 3505 using dry CVD processes. Dry bluish-red powders based on thin-walled Al flakes can lead to unsafe handling in relation to ignition or aluminothermic reactions.

[0026] An alternative wet chemical process for iron oxide-coated Al flakes requires, in the first step, passivation of the Al flakes using a thin layer of silica. In the second step, an Fe2O3 layer is coated. All previous attempts to obtain a bluish-red based on Al / SiO2 / Fe2O3 have failed to yield the desired chromatic bluish-red of the standard Paliocrom Sparkling Red. While a deeper red could be achieved with increasing Fe2O3 layers, a decrease in saturation was observed as the thickness of the Fe2O3 increased further. This means that a highly chromatic bluish-red of the Al / SiO2 / Fe2O3 composition has so far been impossible to achieve through wet chemical synthesis.

[0027] No reference or specification of any document in this application constitutes an endorsement that such document represents prior art of the present invention. [Means for solving the problem]

[0028] The present invention relates to a surface-treated blue-toned red effect pigment comprising an optionally passivated metal flake substrate coated with silica and iron oxide layers, and a blend of multiple oxide layers, i.e., mica flakes (natural or synthetic) coated with iron oxide or titanium oxide, silica, and other iron oxide or titanium oxide layers.

[0029] Furthermore, the present invention relates to a process for producing the blue-toned red effect pigment by a wet chemical preparation method. [Modes for carrying out the invention]

[0030] The process is Synthesis of intermediate 1 by coating metal flakes (preferably Al flakes) with silica and iron oxide. Synthesis of intermediate 2 by coating synthetic or natural mica flakes with a first layer of Fe2O3 or TiO2, a second layer of SiO2, and a third layer of Fe2O3 or TiO2. To obtain a blue-toned red effect according to this specification, the method includes blending intermediate 1 and intermediate 2, and any surface treatment with one or more of silica, Al2O3, Ce oxide, and silane.

[0031] Furthermore, the present invention relates to a combination of pigments comprising the blue-toned red effect pigment and a color-absorbing pigment in a specific weight ratio, as well as articles coated with a composition comprising the blue-toned red effect pigment or the combination of pigments, and the use of the blue-toned red effect pigment or the combination of pigments for coloring paint compositions, such as paints, printing inks, varnishes, plastics, fibers, films, or cosmetics. In one embodiment, the composition is an automotive, architectural, or industrial paint composition.

[0032] The only "Paliocrom-type" blue-toned red effect pigment currently available on the paint market (i.e., a blue-toned red effect pigment based on iron oxide-coated aluminum flakes) is Paliocrom Sparkling Red L 3505. The subject of this application is to provide a superior alternative to the pigment that has a good color appearance and improved safety during the synthesis process at production scale.

[0033] A blue-toned red effect pigment with superior performance to that of state-of-the-art technology was obtained by synthesizing two intermediates and mixing them in an optimized ratio (as shown in the examples) before, after, or without surface treatment. Preferably, to obtain the desired superior blue-toned red effect pigment, the mixed intermediates were surface-treated as a blend in a finishing step. However, it is also possible to surface-treat intermediates 1 and 2 separately and then blend them in an optimized ratio. For applications where exterior properties are not required, intermediates 1 and 2 are preferably blended in a suspension of, for example, iso-PrOH or propylene glycol, or mineral spirits. Dry blending of intermediates 1 and 2 is possible in principle but is less preferred due to potential safety concerns with intermediate 1.

[0034] The synthesis can be a three-step process: 1. Synthesis of Intermediate 1 (Paliocrom Red, preferably based on high-quality silver dollar-type flakes. Pigment structure: Al / SiO2 / Fe2O3) 2. Synthesis of Intermediate 2 (a mica or synthetic mica-based interference pigment with high saturation ranging from blue-red to blue. Pigment structure: (synthetic) mica / (TiO2 or Fe2O3) / SiO2 / (TiO2 or Fe2O3)) 3. Intermediate 1 and 2 are mixed (blended), and if exterior properties are required, surface treatment is optionally combined with them.

[0035] In the first embodiment, intermediates 1 and 2 are mixed (blended) without surface treatment.

[0036] In the second embodiment, intermediates 1 and 2 are first subjected to separate surface treatments before being mixed.

[0037] In the third embodiment, intermediates 1 and 2 are first mixed and then surface-treated simultaneously during or after the blending step.

[0038] The ratio of intermediate 1 to intermediate 2 is a mass ratio based on the dry form of the intermediates, ranging from 99:1 to 60:40, preferably from 97:3 to 70:30, and more preferably from 80:20 to 70:30. The ratio of intermediate 1 to intermediate 2 is also a mass ratio based on the dry form of the intermediates, ranging from 95:5 to 80:20 or from 95:5 to 88:12.

[0039] In a preferred embodiment, the ratio of intermediate 1 to intermediate 2 is in the range of 97:3 to 70:30, particularly 80:20 to 70:30, based on the dry state of the intermediates by mass, and the metal flake substrate of intermediate 1 is an aluminum flake substrate, which can be optionally passivated. The optionally passivated aluminum flake substrate is coated with silica and iron oxide.

[0040] The resulting pigments, in their primary colors (sprayed with master tone), exhibit the following characteristics compared to state-of-the-art technology (Paliocrom Sparkling Red L 3505): Similar blue-toned red Higher saturation and / or Higher brightness and / or Higher flop metrics and / or Better sparkle and / or Lower granularity and / or Better concealment and / or Better DOI

[0041] The surface treatment blend of the present invention has not yet been disclosed: Al / SiO2 / Fe2O3 + Mica / TiO2 / SiO2 / TiO2 Al / SiO2 / Fe2O3 + Mica / Fe2O3 / SiO2 / TiO2 Al / SiO2 / Fe2O3 + Mica / TiO2 / SiO2 / Fe2O3 Al / SiO2 / Fe2O3 + Mica / Fe2O3 / SiO2 / Fe2O3 Al / SiO2 / Fe2O3 + Synthetic Mica / TiO2 / SiO2 / TiO2 Al / SiO2 / Fe2O3 + Synthetic Mica / Fe2O3 / SiO2 / TiO2 Al / SiO2 / Fe2O3 + Synthetic Mica / TiO2 / SiO2 / Fe2O3 Al / SiO2 / Fe2O3 + Synthetic Mica / Fe2O3 / SiO2 / Fe2O3

[0042] Details of how excellent the pigments of the present invention are can be found in the Examples section.

[0043] The particle size range (d50 value) of the raw materials for intermediate 1 and intermediate 2 is typically 5 to 200 μm, preferably 7 to 70 μm. The median particle size d50 is preferably selected between 9 and 22 μm. Starting materials with a d50 greater than 23 μm are already unsuitable for automotive applications and cause appearance problems.

[0044] The cumulative frequency distribution of the volume-average particle size distribution function obtained by laser scattering is d 50 The values ​​(median diameter, particle size distribution) indicate that 50% of the effect pigment has a diameter equal to or smaller than the indicated value. In this case, the particle size distribution curve is determined using a Malvern Instruments Ltd. instrument (Mastersizer 3000) according to the manufacturer's instructions. Samples are typically prepared by dispersing the sample to be analyzed in 2-propanol using an ultrasonic disperser.

[0045] To ensure understanding, the term “laser scattering” as used herein preferably refers to laser diffraction performed as described in the preceding paragraph. The particle size distribution and d50 values ​​of the substrates described herein are measured using laser scattering (i.e., laser diffraction).

[0046] Passivation and oxide coating of Al flakes (intermediate 1) According to one embodiment, the present invention relates to a blue-toned red effect pigment, the effect pigment comprising an aluminum substrate which is passivated in a layer of metal phosphate, aluminum oxide, hydrated aluminum oxide, or a combination thereof.

[0047] Intermediate 1 metal substrate (PVD aluminum, classic cornflake Al, or silver dollar) The metal substrate can be a wide range of metals used in the field of effect pigments. The metal substrate is usually in the form of plate-like crystals or flakes. The metal substrate can be selected from, for example, aluminum, steel, silver, copper, gold bronze (brass), zinc, zirconium, tin, titanium, their alloys, and combinations thereof. The metal substrate is preferably aluminum-based, iron, copper, or gold bronze. Aluminum substrates are most preferred.

[0048] The metal substrate may be optionally passivated. A passivated metal substrate is coated with one or more passivation layers. As will be understood by those skilled in the art in light of this disclosure, the silica layer present on the metal substrate of intermediate 1 functions as the passivation layer. However, the substrate may also have a further passivation layer beneath the silica layer, in which case the substrate is described herein as passivated (if such a layer is not present beneath the silica layer, the substrate is described herein as unpassivated). For example, if the metal substrate of intermediate 1 is an aluminum metal flake substrate, preferably, an aluminum oxide layer may be present on the substrate as a passivation layer. Such a layer is generally formed directly on the aluminum surface and is called "natural passivation." In the present invention, when such a substrate is used, the silica and iron oxide layers are coated on top of the aluminum substrate coated with an aluminum oxide passivation layer. The silica layer is coated before the iron oxide layer. Alternatively, different materials, as further described below, such as an aluminum substrate passivated with a metal phosphate, may be used. In such a case, an aluminum substrate passivated with a metal phosphate is used for intermediate 1, and then a silica layer is coated onto this substrate, after which an iron oxide layer is coated on top of the silica layer.

[0049] In other embodiments, the metal substrate is an aluminum-based substrate. Suitable aluminum-based substrate particles are generally known to those skilled in the art. The aluminum-based substrate particles may consist of an aluminum core or an aluminum alloy core that can be coated at least partially with one or more passivation layers.

[0050] The core of the aluminum or aluminum alloy is usually in the form of plate-like crystals or flakes, and is, for example, an aluminum alloy or aluminum.

[0051] The plate-like crystals or flakes of aluminum or aluminum alloy may be obtained by PVD (physical vapor deposition) technology or by general atomization and grinding techniques. Suitable plate-like crystals of aluminum or aluminum alloy are produced, for example, by the Hall process by wet grinding in volatile oil. The starting material is atomized aluminum grit, which is ball-milled into plate-like crystalline particles in volatile oil in the presence of a lubricant and then classified. Dry grinding of aluminum powder is also possible.

[0052] The metal substrate is more preferably aluminum. Depending on the quality and shape of the starting granules and the milling conditions, the aluminum substrate may be of the "cornflake" type or the "silver dollar" type.

[0053] Alternatively, the aluminum plate-like crystals may be produced by PVD technology, also known as VMP (vacuum metallized pigment). The aluminum is preferably coated in a vacuum onto a plastic foil with a pre-prepared release layer. By dissolving the release layer, aluminum flakes are typically produced, which are further reduced in size by mechanical agitation, such as stirring, and classified into the desired particle size. The average thickness of the resulting flakes is generally about 5–100 nm, preferably about 10–50 nm. Typically, the prepared flakes exhibit a uniform thickness distribution and high opacity.

[0054] The average thickness and average grain size of the metal substrate, particularly aluminum or aluminum alloy plate-like crystals, can vary over a wide range. Typically, the average geometric thickness of the metal plate-like crystals, especially aluminum-based plate-like crystals, may be in the range of 10 nm to 1500 nm, preferably 70 to 1000 nm, more preferably 80 to 500 nm, and most preferably 80 to 400 nm.

[0055] The thickness of the plate-like crystals is typically determined by transmission electron microscopy (TEM) or scanning electron microscopy (SEM) observations, which present the results in cross-cuts of approximately 100 flakes. For this purpose, thin films of paint containing aligned flakes are cut and analyzed by SEM or TEM. Here, the geometric thickness values ​​of approximately 100 plate-like crystals are examined and statistically averaged.

[0056] The average diameter of the plate-like crystals, particularly aluminum-based plate-like crystals, may be in the range of 3 μm to 100 μm, preferably 5 to 25 μm. Preferably, d50 is in the range of about 9 μm to about 22 μm, as measured by laser scattering. The average diameter (d50) can be determined by laser scattering (laser diffraction) particle size measurement, as described in more detail above.

[0057] Typically, the aspect ratio of the average diameter to the average thickness can be in the range of 10 to 1000, preferably 50 to 250.

[0058] The metal plate-like crystals, particularly aluminum or aluminum alloy plate-like crystals, are 0.5 to 80 mm thick. 2 / g, preferably 0.8 to 50m 2 It has a BET surface area of ​​1 / g (measured by nitrogen adsorption).

[0059] As described above, the aluminum or aluminum alloy core of the aluminum-based substrate particles may be at least partially covered with one or more passivation layers, or for example, completely covered with one or more passivation layers.

[0060] Suitable passivation layers are generally known to those skilled in the art. The passivation layer is preferably an inorganic layer, such as a metal phosphate layer or an inorganic oxide layer. If the inorganic passivation layer is a metal phosphate layer, the metal may be selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Zr, Nb, Mo, Ta, or W. If the inorganic passivation layer is an inorganic oxide layer, the oxide may be selected from oxides of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Zr, Nb, Mo, Ta, W, Ge, Sn, and Bi, or any combination thereof.

[0061] Preferably, the passivation layer is a “natural” passivation layer selected from a metal phosphate layer, an aluminum oxide layer, a hydrated aluminum oxide (AlOOH) layer, or a combination thereof.

[0062] Methods for preparing a passivation layer on effect pigment substrates such as aluminum plate-like crystals are generally known to those skilled in the art.

[0063] In principle, the passivation layer can be produced by wet chemical processes or chemical vapor deposition (CVD). For example, aluminum pigments passivated with a layer of aluminum oxide and / or hydrated aluminum oxide are described in WO-A-96 / 38505 or WO-A-2005 / 049739.

[0064] In a wet chemical process, a suitable precursor compound, such as organosilicon and / or aluminum compounds in which an organic group is bonded to a metal via an oxygen atom, is hydrolyzed in the presence of substrate particles (e.g., aluminum flakes or plate-like crystals) and an organic solvent in which the metal compound dissolves. Preferably, metal alkoxides (particularly tetraethoxysilane and aluminum triisopropoxide) are hydrolyzed with water in the presence of an alcohol (e.g., ethanol or 2-propanol) and a basic and / or acid catalyst (e.g., aqueous ammonia and / or an amine as a basic catalyst, such as phosphoric acid or an organic acid like acetic acid or oxalic acid). This is preferably done by first adding the substrate particles, ethanol, water, and ammonia, heating the mixture to 40°C to 90°C while stirring, and continuously adding aqueous ethanol and water or ammonia solution of the metal alkoxide. After stirring, usually for 1 to 15 hours, the mixture is cooled to room temperature, and the coated pigment is isolated by filtration, washing, and optionally drying. Further details regarding methods for preparing a passivation layer on aluminum are described, for example, in EP-A-0708154, DE-A-4405492, or WO-A-2011 / 95341. Such methods may be used to form a silica layer on intermediate 1.

[0065] The plate-like crystalline metal substrate of intermediate 1, preferably an aluminum substrate, is coated with silica and iron oxide. The silica layer is applied before the iron oxide layer. The geometric thickness of the silica layer is preferably in the range of about 20 nm to about 100 nm, more preferably in the range of about 50 nm to about 70 nm.

[0066] Iron oxide coating on Al substrate -> Intermediate 1 Intermediate 1 can be prepared by coating a plate-like crystalline metal substrate, optionally passivated and coated with silica as described above, with an iron(III) salt by a wet chemical process in which iron(III) salt is hydrolyzed in a liquid medium. The synthesis of intermediate 1 is as follows: (a) Prepare a plate-shaped crystalline metal substrate coated with silica, which has been optionally passivated, and (b) The substrate is coated in a liquid medium containing an iron oxide precursor compound.

[0067] Therefore, the iron oxide layer is generally coated onto the silica layer.

[0068] As described above, the substrate is coated in a liquid medium, the liquid medium containing an iron oxide precursor compound and optionally an aluminum compound. Typically, the liquid medium is an aqueous medium, and usually contains 10-100 wt% or 30-100 wt% water based on the total amount of liquid in the aqueous medium.

[0069] The aluminum compound may be an aluminum salt, such as aluminum sulfate, aluminum halide, aluminum nitrate, aluminum phosphate, a hydrolyzable aluminum compound, such as aluminum alkoxide, or a mixture thereof.

[0070] The iron oxide layer can be produced by a wet chemical process. This wet chemical process may be carried out by hydrolyzing a suitable iron oxide precursor compound, such as an inorganic salt, such as iron nitrate, iron sulfate, or iron chloride, in the presence of substrate particles suspended in water and / or an organic solvent, with or without co-oxidation of other, particularly organoiron compounds, such as iron acetate, iron formate, iron citrate, iron acetylacetone, and ferrocene, and then with or without calcination. The coating process is generally carried out until the desired interference color is obtained. Heat treatment converts the hydroxyl-containing iron oxide layer into a hematite (Fe2O3)-containing layer.

[0071] The iron oxide layer can be coated onto the substrate at an acidic or basic pH. Preferably, the liquid medium has a pH of 5 or less, more preferably 4 to 2. Preferably, the pH of the aqueous medium is kept constant while the iron oxide layer or the Al-doped iron oxide layer is coated onto the substrate. The temperature can vary over a wide range, for example, at least 20 to 100°C.

[0072] Preferably, the pigment obtained in step b) is then subjected to a heat treatment step, for example, to dry the pigment and / or to bring about further condensation in the iron oxide layer. The heat treatment step may be carried out by calcination at about 280–340°C for at least 15 minutes. Alternatively, the effect pigment obtained in step b) may be subjected to a medium containing one or more high-boiling point solvents and heated at a temperature of at least 90°C for at least 0.5 hours.

[0073] High-boiling point solvents typically have a boiling point of 90 to 400°C, more preferably 100 to 300°C. Examples include monohydroxy alcohols, diols or polyols, glycol ethers, polyglycol ethers, aldehydes, esters, carbonate esters, lactams, such as NMPs, ethers, alkanes, or mineral oils.

[0074] The effect pigment may be filtered to obtain a wet paste.

[0075] Preferably, the intermediate 1 of the blue-toned red effect pigment has only one iron oxide layer. Typically, the intermediate 1 does not have a further metal oxide layer with a high refractive index, i.e., a refractive index higher than 1.8.

[0076] The refractive index referred to herein is measured at 633 nm.

[0077] Properties of the iron oxide layer of intermediate 1 As used herein, the term “iron oxide” means in particular α-iron(III) oxide. However, the term iron oxide also includes mixtures of α-iron(III) oxide with small amounts of γ-iron(III) oxide, magnetite (Fe3O4), hydrated iron oxide, or hydroxylated iron oxide (e.g., FeO(OH), Fe2O3.H2O, Fe2O3.nH2O with n=2 or more, Fe(OH)3, Fe(OH)2, or a mixture of two or more of these hydroxyl-containing iron oxides). Preferably, the Fe atom exists as Fe(III). However, within the scope of the present invention, the Fe atom may also exist as Fe(II).

[0078] The iron oxide layer may be doped with up to 10 wt% aluminum, based on the total amount of iron and aluminum atoms in the aluminum-doped iron oxide layer. The aluminum concentration in the iron oxide layer may be determined by TEM combined with EDXS (energy-dispersive X-ray spectroscopy), for example, as referred to in WO-2015 / 040537.

[0079] Preferably, the aluminum-doped iron oxide layer contains 0.05 wt% to 10 wt% Al, or 0.5 to 8 wt%, or 0.5 to 6 wt%, based on the total amount of Fe and Al atoms in the Al-doped iron oxide layer.

[0080] Typically, the Al concentration in the portion of the Al-doped iron oxide layer closest to the substrate is higher than the Al concentration in the portion of the Al-doped iron oxide layer further from the substrate.

[0081] The geometric thickness of the iron oxide film is preferably about 120 nm to about 500 nm, more preferably about 130 nm to about 450 nm, and even more preferably about 150 nm to about 350 nm.

[0082] Therefore, the substrate of intermediate 1, preferably an aluminum metal flake substrate, is preferably coated with a silica layer having a geometric thickness of about 20 nm to about 100 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 120 nm to about 500 nm. More preferably, the substrate of intermediate 1, preferably an aluminum metal flake substrate, is coated with a silica layer having a geometric thickness of about 50 nm to about 70 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 150 nm to about 350 nm.

[0083] The geometric thickness of the layer can be determined based on a cross-cut TEM micrograph of the intermediate.

[0084] Optical thickness is the product of geometric thickness and refractive index.

[0085] Intermediate 2 base material (synthetic mica or natural mica is preferred) Any encapsulable, smooth, transparent, plate-like crystal can be used as the substrate of the present invention. Examples of usable plate-like crystals include natural or synthetic mica, kaolin, glass flakes, etc. The size of the plate-like crystalline substrate is not important in itself and can be adapted to specific uses. Generally, the particles have a maximum principal dimension of about 5 to 250 microns on average, preferably 5 to 100 microns, and an aspect ratio greater than about 5. Thus, d50 can be in the range of about 5 to 250 microns, preferably 5 to 100 microns, as measured by laser scattering. Most preferred d50 values ​​are in the range of about 9 to 22 microns, as measured by laser scattering. The laser scattering method is preferably performed as described in more detail above. Their specific free surface area (BET) is generally about 0.2 to 25 m². 2 It is / g.

[0086] A suitable natural or synthetic plate-like substrate may be transparent or translucent and may be sufficiently strong to function as a stable support for the metal oxide layer.

[0087] In some embodiments, the plate-like substrate may include, but is not limited to, natural mica, synthetic mica, aluminum, glass flakes, SiO2, Al2O3, talc, bismuth oxychloride, natural pearl, perlite, boron nitride, zinc oxide, natural silicates, synthetic silicates, or combinations thereof. In certain embodiments, the plate-like substrate may include, but is not limited to, synthetic mica, such as fluorophlogopite.

[0088] Oxide coating of the substrate of intermediate 2 Intermediate 2 contains several metal oxides, which form a so-called multilayer system of thin films with different refractive indices. The preferred layer order on the substrate is high refractive index / low refractive index / high refractive index.

[0089] Intermediate 2 comprises a first coating, which is a highly refractive and therefore optically active metal oxide layer, on the plate-like substrate, and this layer may be absorbent or non-absorbent. The first coating layer is typically Fe2O3 or TiO2. In some embodiments, the optically active metal oxide layer may be SnO2-doped titanium oxide, iron oxide, iron hydroxide, or combinations thereof. In some embodiments, the first optically active metal oxide layer is iron oxide or SnO2-doped titanium oxide. Suitable iron oxides may or may not be hematite, magnetite, or maghemite. In one embodiment, the iron oxide layer includes hematite or maghemite.

[0090] Suitable titanium dioxide is rutile or anatase.

[0091] The geometric thickness of the first layer on the intermediate 2 is typically about 5 nm to about 150 nm, preferably about 15 nm to about 70 nm.

[0092] Intermediate 2 comprises a low refractive index material layer, which is a second coating applied to the first optically active metal oxide layer. In some embodiments, the low refractive index material has a refractive index of 1.8 or less. This includes, but is not limited to, refractive indices of about 1.30 to about 1.80. In one embodiment, the refractive index is about 1.30 to about 1.50. In other embodiments, the refractive index is about 1.40 to about 1.50.

[0093] In some embodiments, the low refractive index material may be, but is not limited to, silica, magnesium oxide, aluminum oxide, or a combination thereof. In some embodiments, the low refractive index material is silica, which includes amorphous silica.

[0094] The geometric thickness of the second layer on the intermediate 2 is typically about 5 nm to about 300 nm, preferably about 10 nm to about 110 nm.

[0095] Intermediate 2 includes a third coating, which is a high-refractive and therefore optically active metal oxide layer, on the plate-like substrate, which may be absorbing or non-absorbing. In some embodiments, the third layer is made of a high-refractive-index material and includes, but is not limited to, titania, zirconium oxide, tin oxide, zinc oxide, iron oxide, or a combination thereof. In some embodiments, the high-refractive-index material is titania. It is preferable that the third coating on intermediate 2 is titania.

[0096] Suitable types of titania include, but are not limited to, anatase, rutile, or mixtures thereof. In one embodiment, the high refractive index material layer comprises rutile and / or anatase-type titania. Advantages of using titania as the high refractive index material include, but are not limited to, titania having a refractive index of about 2.55.

[0097] In one embodiment, the high refractive index material layer is selectively absorbent and contains iron oxide. Suitable iron oxides may or may not be hematite, magnetite, or maghemite. In one embodiment, the iron oxide layer contains hematite or maghemite.

[0098] The geometric thickness of the third layer on the intermediate 2, preferably the TiO2 layer, is typically about 5 nm to about 400 nm, preferably about 15 nm to about 200 nm.

[0099] Therefore, intermediate 2 preferably comprises the synthetic or natural mica flakes described above, which are coated with a first layer of Fe2O3 or TiO2 having a geometric thickness of about 5 nm to about 150 nm, a second layer of silica having a geometric thickness of about 5 nm to about 300 nm, and a third layer of Fe2O3 or TiO2 having a geometric thickness of about 5 nm to about 400 nm. The pigment of the present invention preferably comprises a blend of this intermediate 2 and intermediate 1 as defined above, wherein the substrate of intermediate 1, preferably an aluminum metal flake substrate, is preferably coated with a silica layer having a geometric thickness of about 20 nm to about 100 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 120 nm to about 500 nm. In the blend, the ratio of intermediate 1 to intermediate 2 is a mass ratio based on the dry form of the intermediates, preferably in the range of 99:1 to 60:40, more preferably 97:3 to 70:30, and most preferably 80:20 to 70:30.

[0100] More preferably, intermediate 2 comprises the above-described synthetic or natural mica flakes, which are coated with a first layer of Fe2O3 or TiO2 (preferably Fe2O3 or SnO2-doped titanium oxide) having a geometric thickness of about 15 nm to about 70 nm, a second layer of silica having a geometric thickness of about 10 nm to about 110 nm, and a third layer of Fe2O3 or TiO2 having a geometric thickness of about 15 nm to about 200 nm. The pigment of the present invention preferably comprises a blend of this intermediate 2 and intermediate 1 as defined above, for example, a substrate of intermediate 1, preferably an aluminum metal flake substrate, coated with a silica layer having a geometric thickness of about 50 nm to about 70 nm, and on the silica layer, an iron oxide layer having a geometric thickness of about 150 nm to about 350 nm. In the blend, the ratio of intermediate 1 to intermediate 2 is a mass ratio based on the dry form of the intermediates, preferably in the range of 99:1 to 60:40, more preferably 97:3 to 70:30, and most preferably 80:20 to 70:30.

[0101] Surface treatment of the blend of intermediate 1 + intermediate 2 Methods for surface modification of effect pigments and suitable surface modifiers, such as silanes having surface-reactive functional groups (e.g., alkoxysilanes), are known to those skilled in the art and can improve the compatibility of effect pigments with varnishes or lacquers. Surface modification methods and agents are described, for example, in EP-A-1682622, EP-A-1904587, WO-A-99 / 57204, EP-A-1812519, EP-A-0688833, and EP0881998.

[0102] The blue-toned red effect pigment, comprising intermediates 1 and 2, may be treated with one or more further layers, which are preferably selected from a silica layer, a polymer layer, an organic silane layer, or any combination or mixture thereof.

[0103] The geometric thickness of the final layer may be 2 to about 50 nm, preferably 2 to 30 nm, and more preferably 2 to 20 nm. The appropriate geometric thickness of this layer depends on the type of surface modification.

[0104] In one embodiment, the blue-toned red effect pigment includes a final layer, which is selected from an SiO2 layer, a polymer layer, an organic silane layer, or a combination thereof. The term “final layer” is synonymous with “outermost layer.” Such surface modification is typically adapted to a specific end use. Such a final layer may adjust the surface polarity of the blue-toned red effect pigment, which in turn may improve the binding of the effect pigment to a binder system, such as a paint or ink binder system.

[0105] In the surface modification step of the pigment, the effect pigment may be provided in a liquid medium containing at least one surface modifier. However, it is also possible to bring the surface modifier into contact with the effect pigment in the calcination step via the gas phase.

[0106] In other embodiments, the blue-toned red effect pigment is surface-treated with Al oxide and cerium oxide in an aqueous suspension, followed by silane treatment. Other salts can be used, but nitrates are preferred. It is also preferable to deposit about 0.01 to 1.5% cerium hydroxide, more preferably 0.2 to 0.6%, and about 0.1 to 1%, more preferably 0.2 to 0.6%, aluminum hydroxide, calculated by weight percentage of aluminum, based on the weight of the pigment. The salts can be added to the slurry individually and precipitated in either order, or preferably simultaneously and precipitated.

[0107] Precipitation is controlled by raising the pH to a value greater than approximately 5, preferably between approximately 5.5 and 7.5.

[0108] Following that step, further treatment is carried out with a hydrolyzed silane coupling agent or a mixture of such coupling agents. As is known, these are compounds that act as interfaces between organic and inorganic materials, increasing the affinity between the two. Therefore, the silane coupling agent usually has both an organic functional group and a silicon functional group directly or indirectly bonded to silicon. The silicon functional group is usually an alkoxy group, preferably a CIA alkoxy group.

[0109] Examples of silane coupling agents that can be used in the present invention include gamma-(2-aminoethyl)aminopropyltrimethoxysilane, aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, gamma-(2-aminoethyl)aminopropylmethyldimethoxysilane, gammamethacrylateoxypropylmethyltrimethoxysilane, gammamethacrylateoxypropyltrimethoxysilane, gammaglycidoxypropyltrimethoxysilane, gamma-mercaptopropyltrimethoxysilane, vinyltriacetoxysilane, gammachloropropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl-[3-(trimethoxysilyl)-propyl]ammonium chloride, gamma-mercaptopropyl-methyl-dimethoxysilane, methyltrichlorosilane, dimethyl-dichlorosilane, trimethylchlorosilane, gamma-isocyanatopropyltriethoxysilane, and the like.

[0110] The silane coupling agent should be selected to be suitable for any organic material in the paint binder to be mixed with the pigment at the time of use. If the organic material is a polyester, the organic functional group preferably contains a methacrylic group. If it is a urethane, an amino-functional coupling agent is preferred. For acrylic binders, aminoethyl, aminopropyl, methacrylateoxypropyl, and glycidoxypropyltrimethoxysilane are suitable. Recent results have shown that the best results are obtained with a combination of amino and non-amino coupling agents.

[0111] The pigment is treated with a silane coupling agent by wet mixing. For example, an aqueous solution containing the coupling agent in water or a mixture of water and an organic solvent may be added to an aqueous slurry of the pearlescent pigment. The silane is preferably pre-hydrolyzed, for example, by stirring the coupling agent in water for an appropriate amount of time.

[0112] Hydrolysis can also be induced during mixing. Typically, about 0.1 to 10 wt%, preferably about 0.25 to 5 wt%, of the silane coupling agent is used per 100 parts by weight of the pigment to be treated.

[0113] The coupling agent and the pigment can be mixed for a sufficient amount of time to cause a reaction, which may be several minutes to several hours or longer, preferably about 3 to 24 hours. The treated pigment can then be recovered by conventional methods, such as filtration or centrifugation, and dried.

[0114] Furthermore, it is possible to add the silane after the Al / Ce treatment without the prior hydrolysis step.

[0115] If necessary, the coupling agent treatment can be combined with the aluminum / cerium treatment.

[0116] The most preferred surface treatment protocol in the present invention is to surface treat intermediates 1 and 2 separately and then blend them together. In this case, intermediate 1 is surface treated with silica and at least one polymer, preferably a polymer formed from silane and acrylate monomer (e.g., trimethylolpropane trimethacrylate (TMPTMA)), and intermediate 2 is surface treated with aluminum oxide, cerium oxide, and at least one silane. The most preferred surface treatment of intermediate 1 involves coating the silica layer and polymer described above with a further silane, for example, a mixture of octyltriethoxysilane and 3-aminopropyltrimethoxysilane. The most preferred silane for use in surface treatment of intermediate 2 is a mixture of 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

[0117] Application of blue-toned red effect pigments in combination with transparent absorbent pigments and other effect pigments. The blue-toned red effect pigment can be appropriately mixed with any further pigments, preferably color-absorbing pigments, and optionally, further effect pigments different from the blue-toned red effect pigment, in order to provide a combination of pigments.

[0118] The pigment combination of the present invention comprises at least two or three components, wherein the effect pigment (a) is a blue-toned red effect pigment as defined herein, the second pigment (b) is at least one color-absorbing pigment, and the optional third pigment (c) is a further effect pigment.

[0119] Typically, pigment (b) can be at least one pigment that is neither an effect pigment nor a white pigment. Pigment (b) can be any pigment of any hue, preferably a pigment having a yellow, red, or greenish hue. Combinations with other coloring pigments, such as black or brown pigments, may also be possible to achieve the effect.

[0120] Preferably, the colored absorbent pigment (b) may be any transparent colored absorbent pigment in shades ranging from green to yellow to purple or even blue, depending on the application, preferably the desired color of the paint. It may also be combined with other colored pigments, such as black or brown pigments, for example, transparent carbon black pigment or transparent black perylene pigment.

[0121] As used herein, transparent pigments refer to pigments that provide paints that are substantially transparent in the wavelength range of 400 to 700 nm, without scattering radiation in such a way that it can be detected.

[0122] Pigment (b) may be an organic pigment, an inorganic pigment, or a mixture thereof. Preferably, pigment (b) has a hue suitable for shading the effect pigment, such as yellow, red, or greenish.

[0123] Therefore, in a preferred embodiment, pigment (b) is a transparent pigment, and is selected in particular from the group consisting of organic pigments, inorganic pigments, and mixtures thereof.

[0124] Suitable organic colored absorbent pigments for this pigment combination typically include organic colored pigments and black pigments. Suitable examples include pigments selected from the group consisting of monoazo, disazo, disazo condensation, antantrone, anthraquinone, anthrapyrimidine, benzimimidazolone, quinacridone, quinophthalone, diketopyrrolopyrrole, dithioketopyrrolopyrrole, dioxazine, flavanthrone, indanthrone, isoindoline, isoindolinone, isobiolantrone, metal complexes, perinone, perylene, phthalocyanine, pyrantrone, pyrazoloquinazolone, indigo, thioindigo, triarylcarbonium pigments, and mixtures thereof, including their solid solutions or mixed crystals.

[0125] Appropriate examples include: Monoazo pigments: CI Pigment Yellow 1, 3, 62, 65, 73, 74, 97, 183, and 191; CI Pigment Orange 5, 38, and 64; CI Pigment Red 1, 2, 3, 4, 5, 23, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 51, 51:1, 52:1, 52:2, 53, 53:1, 53:3, 57:1, 58:2, 58:4, 63, 112, 146, 148, 170, 184, 187, 191:1, 210, 245, 247, and 251. Disazo pigments: CI Pigment Yellow 12, 13, 14, 16, 17, 81, 83, 106, 113, 126, 127, 155, 170, 174, 176, and 188; CI Pigment Orange 16, 34, and 44. Disazo condensation pigments: CI Pigment Yellow 93, 95, and 128; CI Pigment Red 144, 166, 214, 220, 221, 242, and 262; CI Pigment Brown 23 and 41. Antantron pigment: CI Pigment Red 168, Anthraquinone pigments: CI Pigment Yellow 147 and 199, CI Pigment Red 177, Anthrapyrimidine pigment: CI Pigment Yellow 108, Benzimidazolone pigments: CI Pigment Yellow 120, 151, 154, 180, 181, CI Pigment Orange 36 and 72, CI Pigment Red 175, 185, 208, CI Pigment Violet 32, CI Pigment Brown 25, Quinacridone pigments: CI Pigment Orange 48 and 49, CI Pigment Red 122, 202, 206, and 209, CI Pigment Violet 19, Quinophthalone pigment: CI Pigment Yellow 138, Diketopyrrolopyrrole pigments: CI Pigment Orange 71, 73, and 81, CI Pigment Red 254, 255, 264, 270, and 272, Dioxazine pigments: CI Pigment Violet 23 and 37, Flavantron pigment: CI Pigment Yellow 24, Indanthron pigments: CI Pigment Blue 60 and 64, Isoindoline pigments: CI Pigment Yellow 139 and 185, CI Pigment Orange 69, CI Pigment Red 260, Isoindolinone pigments: CI Pigment Yellow 109, 110, and 173, CI Pigment Orange 61, Isobiolantron pigment: CI Pigment Violet 31, Metal complex pigments: CI Pigment Red 257, CI Pigment Yellow 117, 129, 150, 153, and 177, CI Pigment Green 8, Perinon pigments: CI Pigment Orange 43, CI Pigment Red 194, Perylene pigments: CI Pigment Red 123, 149, 178, 179, and 224, CI Pigment Violet 29, CI Pigment Black 31, 32 Phthalocyanine pigments: CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16; CI Pigment Green 7, 36 Pyrantron pigments: CI Pigment Orange 51, CI Pigment Red 216, Pyrazoloquinazolone pigments: CI Pigment Orange 67 and CI Pigment Red 216, Indigo pigment: CI Pigment Red 282, Thioindigo pigments: CI Pigment Red 88 and 181, CI Pigment Violet 38, Triarylcarbonium pigments: CI Pigment Red 81, 81:1, and 169, CI Pigment Violet 1, 2, 3, and 27, CI Pigment Blue 1, 61, and 62, CI Pigment Green 1, CI Pigment Yellow 101 (Aldazin yellow), CI Pigment Brown 22.

[0126] Preferably, the organic pigment is a CI pigment red or blue selected from red or blue-toned red organic pigments, i.e., anthraquinone, diketopyrrolopyrrole, perylene, indanthron pigment, or any mixture thereof, including solid solutions or mixed crystals.

[0127] Suitable organic pigments are commercially available under trademarks such as Irgazin Rubine L 4030, Irgazin DPP Orange RA, Irgazin Red L 3630, Irgazin Yellow L 0800, Paliogen® Red L 3885, or Paliogen Red L 3920 and Paliogen Blue L 6480.

[0128] Suitable inorganic pigments may be transparent red iron oxide pigment (CI Pigment Red 101) or mixtures thereof. Red iron oxide pigment is particularly preferred.

[0129] Suitable inorganic black or brown pigments may be carbon black (CI Pigment Black 7), graphite (CI Pigment Black 10), or chromium iron oxide (CI Pigment Brown 29).

[0130] Suitable inorganic pigments are commercially available, for example, under the trademark Sicotrans®.

[0131] The colored absorbing pigment (b) is preferably transparent.

[0132] Furthermore, a small amount of opaque colored absorbing pigment may be used for special effects, typically in an amount of less than 10% by weight, preferably less than 5% by weight, based on the total weight of the pigments in the composition.

[0133] The pigments used herein are preferably in a fine dispersion. Typically, the organic pigments have an average primary particle size of 200 nm or less, preferably about 80 to 200 nm.

[0134] The average particle size can be determined according to DIN ISO 13320:2009. In this regard, "average particle size" refers to the d in the cumulative frequency distribution of the volume-average particle size distribution function. 50 This refers to the median diameter and particle size distribution, indicating that 50% of the effect pigment has a diameter equal to or smaller than the indicated value.

[0135] The effect pigment (c) may be a metallic pigment such as aluminum flakes, or an effect pigment based on a transparent substrate such as natural mica, synthetic mica, or glass flakes. The transparent substrate is usually coated with one or more layers of a metal oxide such as TiO2, TiO2 (doped with SnO2), SiO2, and / or Fe2O3. Preferably, the pigment reflects gold to red light due to interference and absorption phenomena of the thin film. Thus, the metallic blue-red sheen of the opaque blue-red effect pigment of the present invention can be modified with a translucent pigment of a similar color. The color effect is a three-dimensional concentration of the (two-dimensional) metallic sheen.

[0136] Suitable effect pigments (c) are commercially available, for example, under the trademarks Lumina® or Mearlin®.

[0137] The weight ratio of the blue-toned red effect pigment (a) to pigment (b) and any other pigment (c) can vary over a wide range.

[0138] In further embodiments, the present invention relates to the following: (a) Blue-toned red effect pigments comprising intermediates 1 and 2 (optionally surface-treated), (b) Colored absorbent pigments, (c) Optionally, regarding pigment formulations including further effect pigments, The weight ratio of the blue-toned red effect pigment (a) to the other pigments (b+c) is 95:5 to 5:95, preferably 80:20 to 5:95, and more preferably 75:25 to 20:80.

[0139] The weight ratio of pigment (b) to pigment (c) may be 100:0 to 50:50, preferably 75:25 to 60:40.

[0140] Preferably, pigment (b) is a transparent pigment, and is selected in particular from the group consisting of organic pigments, inorganic pigments, and mixtures thereof.

[0141] In particular, the organic pigment is a yellow, red, or orange organic pigment selected from yellow or red organic pigments, such as anthraquinone, diketopyrrolopyrrole, isoindolinone, metal complexes, perinone, perylene, indigo pigment, or any mixture thereof, including solid solutions or mixed crystals.

[0142] The inorganic pigment may be a transparent red iron oxide pigment (CI Pigment Red 101).

[0143] Pigment (c) may be a metal pigment or an effect pigment selected from effect pigments based on a transparent substrate selected from natural mica, synthetic mica, or glass. Preferably, pigment (c) comprises a plate-like crystalline substrate selected from natural mica, synthetic mica, or glass, which is coated with one or more layers of metal oxide selected from TiO2, TiO2 (doped with SnO2), SiO2, and / or Fe2O3.

[0144] The metallic pigment may be an aluminum-based plate-like crystal, preferably an aluminum plate-like crystal.

[0145] The blue-toned red effect pigment can be incorporated into a coating system in a conventional manner, for example, as a slurry or paste.

[0146] Therefore, the present invention provides a composition comprising the blue-toned red effect pigment.

[0147] The pigment combination can be incorporated into a coating system in a conventional manner. The blue-toned red effect pigment as defined herein above may be added as a slurry, similar to any effect pigment (c). Typically, pigment (b) is added in a pre-dispersed state.

[0148] Application of effect pigments or combinations of pigments This effect pigment or combination of this pigment is suitable for all end-use applications of pigments, particularly for coloring organic or inorganic materials of natural and synthetic origin, for example: a) For example, for undiluted colored polymers in the form of resins, rubbers, or plastics, including films and fibers, b) For the preparation of paints, coatings, and paint compositions, such as automotive, architectural, and industrial paint compositions. c) Printing inks, for example, digital printing such as inkjet printing, and electrophotography, for example, toner for laser printers. d) Colorants, for example, as additives to pigments and dyes, e) Cosmetics, Suitable for, etc.

[0149] The paint is water-based or solvent-based, and this pigment combination may be used. Possible organic film-forming binders include all binders commonly used in the paint sector. More specifically, examples of binder materials that can be colored using the pigment combination of the present invention include: Oil-based materials (linseed oil or polyurethane oil-based), Cellulose-based materials (NC, CAB, CAP), Chlorinated rubber materials, Vinyl materials (PVC, PVDF, VC copolymer, polyvinyl acetate, polyvinyl ester dispersion, polyvinyl alcohol, polyvinyl acetal, polyvinyl ether, polystyrene, styrene copolymer system), Acrylic materials, Alkyd materials, Saturated polyester material, Unsaturated polyester material, Polyurethane materials (one-component, two-component), Epoxy material, Silicone material.

[0150] These systems are described in detail in D. Stoye and W. Freitag, Paints, Coatings and Solvents, Second Edition, 1998, Wiley-VCH.

[0151] Preferably, the effect pigment or combination thereof is used in water-based and solvent-based paint applications, and more preferably in cosmetic paint compositions such as architectural, automotive, or industrial paint compositions, for example, any consumer goods.

[0152] These effect pigments or combinations of these pigments are typically incorporated into their respective application media in a conventional manner. Articles may then be coated with these application media and subsequently colored. Such articles may include, for example, vehicle bodies, industrial equipment, and architectural finishing elements.

[0153] In the case of plastics, the effect pigment or combination of the pigments may also be incorporated into the stock solution of the application medium for coloring. The article includes the effect pigment or combination of the pigments.

[0154] Suitable compositions for cosmetics into which the blue-toned red effect pigment may be introduced are known in the art. The formulation of cosmetics using the blue-toned red effect pigment of the present invention is achieved by standards and methods well known to those skilled in the art. The blue-toned red effect pigment can be suitablely used, for example, in nail polish.

[0155] This blue-toned red effect pigment or combination thereof may be used in an appropriate amount depending on the application. It may range from 0.01 to 30% by weight, preferably from 0.01 to 15% by weight, based on the total weight of the material to be colored in a wet state.

[0156] In further embodiments, the present invention relates to the use of blue-toned red effect pigments or combinations of pigments, as defined in any embodiment herein, for coloring or pigmenting paint compositions, such as paints, printing inks, varnishes, plastics, fibers, films, or cosmetics, preferably automotive, architectural, or industrial paint compositions. In particular, the blue-toned red effect pigments or combinations of pigments are used as colorants for automotive OEM or refinish paint compositions.

[0157] In a further embodiment, the present invention relates to an article coated with a composition comprising a blue-toned red effect pigment or combination of pigments as defined in any embodiment.

[0158] Any material of an article, including materials such as glass, ceramics, plastics, smooth surface composites, and metal substrates, may be coated with a composition containing the blue-toned red effect pigment or a combination thereof. In particular, the composition is specifically adapted for metal or plastic articles. The article may be an untreated substrate material, or, in the case of a metal substrate, may be pre-treated by phosphate treatment, electrodeposition such as cathode dipping coating, or other similar treatments well known in the art to impart corrosion resistance.

[0159] Paints containing this effect pigment or a combination thereof are particularly suitable for multilayer coatings used in the automotive industry. The blue-toned red effect pigment or a combination thereof is typically incorporated into the basecoat layer of basecoat / clearcoat coating systems known in the art.

[0160] Accordingly, the present invention relates to automotive paints that are colored or pigmented with blue-toned red effect pigments or combinations of pigments as defined in any aspect herein.

[0161] The blue-toned red effect pigment of the present invention exhibits excellent color properties, particularly significantly higher saturation compared to prior art blue-toned red effect pigments, while maintaining opacity. The blue-toned red effect is highly chromatic with excellent sparkle effect.

[0162] A significant increase in saturation is mainly observed at so-called interfacial angles of -15°, 15°, and 25°.

[0163] Furthermore, the pigment combinations of the present invention exhibit excellent color properties, particularly saturation. By mixing a color-absorbing pigment (b), particularly one with red to purple or blue tones, and optionally an additional effect pigment, with the blue-toned red effect pigment (a), a paint with superior color properties is possible compared to similar pigment combinations with blue-toned red effect pigments known in the prior art. The paint exhibits high clarity, represented by a combination of high saturation and optionally high brightness, while maintaining opacity.

[0164] Therefore, by including an additional effect pigment (c) that reflects blue-red to red light due to interference and absorption phenomena of the thin film, the metallic blue-red gloss of the opaque blue-red effect pigment of the present invention can be modified to a similar color with the translucent pigment (c). This color effect is a three-dimensional concentration of the (two-dimensional) metallic gloss.

[0165] Furthermore, the performance characteristics such as weather resistance and light resistance required for exterior paints are not adversely affected.

[0166] The definitions and preferences given herein for the pigments referred to herein apply in any combination and in any combination for other aspects of the present invention.

[0167] The present invention will now be described in more detail with reference to the following examples. These examples should not be construed as limiting. Unless otherwise stated, "%" always refers to weight percent (wt%).

[0168] Coating Test Hue h[°], saturation C * , and brightness L * To determine the CIELAB value, the resulting (mast tone) dried and cured coating is coated and measured as follows: Pigments (as a 50:50 slurry of pigments (or more) in the solvent, which is part of the varnish) are incorporated (based on the total weight of the wet varnish) at a total coloring level of 5 wt% in conventional solvent-type medium-solids cellulose butyrate acetate (CAB) / polyester varnish (pigment / binder 20 / 100) by stirring until the pigments are dispersed. The finished varnish is applied to an aluminum panel by pneumatic spray coating to a wet film thickness of approximately 150-160 μm, and then dried at room temperature. After drying, the base coat is applied as a 1K overcoat. 1Overcoat, dry, and cure at 135 °C. The cured base coat is about 20 μm and the clear coat is about 40 μm. This color data is specified with a constant incident angle of 45° and a D65 light source using a multi-angle colorimeter BYK-MAC (manufactured by BYK Gardner). Value C * , L * , a * , b * , and h are measured at 15°, -15° (relative to the reflection angle), and higher angles of 25°, 45°, 75°, and 110°.

[0169] 1 In this application, OEM urethane acrylate was used, but any suitable 1K or 2K overcoat can be used to test the examples. Usually, 1K (one-component) overcoats are baked at high temperature (130 °C), while 2K (two-component) overcoats are used in temperature-sensitive coatings (e.g., automotive repair and refinishing) and cured at room temperature. A typical 2K component can be polyacrylate / polyurethane.

[0170] Quantification of angle-dependent sparking effect: Measure the sparking effect of the pigments of the examples using a Byk-mac device manufactured by Byk-Gardner GmbH (LausitzerStraBe 8, 82538 Geretsried, Germany). This device is used to measure sparkle and granularity for the characterization of flake properties. Thus, the sparking effect of the examples is characterized by the following parameters for three different illumination angles (direct illumination: 15°, 45°, and 75° from the vertical, camera detection: 0°): The sparking area (Sa) corresponds to the number of light reflections within a given measurement, The sparking intensity (Si) corresponds to the intensity of the light reflection, The total sparkle SG is calculated by the BykMac software based on Sa and Si.

[0171] Under scattered light, the sparkling effect cannot be observed. The visual appearance of sparkling pigments under scattered light conditions is represented by texture, roughness, or granularity. Byk-mac measures the granularity value G to represent the effect.

[0172] The flop index is calculated according to the following formula (published by ABJ Rodriguez (DuPont), JOCCA 1992(4), pp. 150-153):

number

[0173] Embodiments of the present invention The present invention is further explained by the following numbered paragraphs: 1. a. Intermediate 1 comprising a metal flake substrate coated with silica and iron oxide, b. A blue-toned red effect pigment comprising a blend with intermediate 2, which includes a first layer of Fe2O3 or TiO2, a second layer of SiO2, and a third layer of Fe2O3 or TiO2-coated synthetic or natural mica flakes.

[0174] 2. The pigment according to paragraph 1, wherein the intermediate 1 and / or the intermediate 2 are surface-treated either during the blending process, or after blending, before blending with a material selected from the group consisting of silica, Al2O3, Ce oxide, silane, or a blend thereof, in order to obtain a blue-toned red effect.

[0175] 3. The pigment according to paragraph 2, wherein the silane is selected from the group consisting of aminosilanes, epoxysilanes, and blends thereof.

[0176] 4. The pigment according to paragraph 2, wherein the silane is selected from the group consisting of aminopropyltrimethoxysilane, n-octyltriethoxysilane, methacrylateoxypropyltrimethoxysilane, and blends thereof.

[0177] 5. The pigment according to any one of paragraphs 1 to 4, wherein the metal flake substrate contains aluminum.

[0178] 6. The pigment according to any one of paragraphs 1 to 5, wherein the d50 median particle size of the raw materials for intermediate 1 and intermediate 2 is 5 to 200 μm, or 7 to 70 μm, or 5 to 25 μm, or 9 to 22 μm, preferably 9 to 22 μm.

[0179] 7. The pigment according to paragraph 5, wherein the aluminum substrate is passivated with a layer of metal phosphate, aluminum oxide, hydrated aluminum oxide, or a combination thereof.

[0180] 8. The pigment according to any one of paragraphs 1 to 7, wherein the average thickness of the metal substrate is 10 to 1500 nm, or 70 to 1000 nm, or 80 to 500 nm, or 80 to 400 nm.

[0181] 9. The pigment according to any one of paragraphs 1 to 8, wherein the metal substrate comprises aluminum-based plate-like crystals having an average diameter of 3 to 100 μm, or 5 to 25 μm, preferably 9 to 22 μm, an average thickness of 80 to 500 nm, and an aspect ratio of 50 to 250.

[0182] 10. The metal substrate has a BET surface area of ​​0.5 to 80 m². 2 / g, or 0.8~50m 2 A pigment according to any one of paragraphs 1 to 9, containing aluminum-based plate-like crystals in a quantity of / g.

[0183] 11. The pigment according to any one of paragraphs 1 to 10, wherein the silica layer on the intermediate 2 has a geometric thickness of about 5 nm to about 300 nm, preferably about 10 nm to about 110 nm.

[0184] 12. The pigment according to paragraph 11, wherein the silica layer has a refractive index of 1.8 or less, or 1.30 to 1.80, or 1.30 to 1.50, or 1.40 to 1.50.

[0185] 13. The pigment according to any one of paragraphs 1 to 12, wherein the outermost layer of the intermediate 2 has a geometric thickness of about 5 nm to about 400 nm, preferably about 15 nm to about 200 nm.

[0186] 14. The pigment according to paragraph 13, wherein the outermost layer of the intermediate 2 has a refractive index greater than 1.80, or 2.00 to 4.00, or 2.00 to 3.30, or 2.20 to 3.00, or 2.20 to 2.60.

[0187] 15. A pigment according to any one of paragraphs 1 to 14, which is surface-treated with Al oxide and cerium oxide in an aqueous suspension, followed by silane treatment.

[0188] 16. A pigment according to any one of paragraphs 1 to 15, which exhibits one or more improvements over a comparative example (preferably Paliocrom Sparkling Red L 3505), selected from the group consisting of higher saturation, higher flop index, better sparkle, lower granularity, better opacity, and better DOI.

[0189] 17. The pigment described in any one of paragraphs 1 to 16, wherein the pigment exhibits a flop index of 20.0 or higher.

[0190] 18. The pigment according to any one of paragraphs 1 to 17, wherein the metal flake substrate of the intermediate 1 is passivated.

[0191] 19. The pigment according to any one of paragraphs 1 to 18, wherein the metal flake substrate is a passivated aluminum flake substrate.

[0192] 20. The pigment according to any one of paragraphs 1 to 19, wherein the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the dry form of the intermediates by mass.

[0193] 21. The pigment according to any one of paragraphs 1 to 20, wherein the ratio of intermediate 1 to intermediate 2 is in the range of 80:20 to 70:30, based on the dry form of the intermediates by mass.

[0194] 22. The pigment according to any one of paragraphs 1 to 21, wherein the substrate of the intermediate 1 is coated with a silica layer having a geometric thickness of about 20 nm to about 100 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 120 nm to about 500 nm.

[0195] 23. The pigment according to paragraph 22, wherein the substrate of the intermediate 1 is coated with a silica layer having a geometric thickness of about 50 nm to about 70 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 150 nm to about 350 nm.

[0196] 24. The pigment according to any one of paragraphs 1 to 23, wherein the substrate of the intermediate 2 is coated with a first layer of Fe2O3 or TiO2 having a geometric thickness of about 5 nm to about 150 nm, a second layer of silica having a geometric thickness of about 5 nm to about 300 nm, and a third layer of Fe2O3 or TiO2 having a geometric thickness of about 5 nm to about 400 nm.

[0197] 25. The pigment according to paragraph 24, wherein the substrate of the intermediate 2 is coated with a first layer of Fe2O3 or TiO2 having a geometric thickness of about 15 nm to about 70 nm, a second layer of silica having a geometric thickness of about 10 nm to about 110 nm, and a third layer of Fe2O3 or TiO2 having a geometric thickness of about 15 nm to about 200 nm.

[0198] 26. The pigment according to any one of paragraphs 1 to 21, wherein the substrate of intermediate 1 is coated with a silica layer having a geometric thickness of about 20 nm to about 100 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 120 nm to about 500 nm, and the substrate of intermediate 2 is coated with a first layer of Fe2O3 or TiO2 having a geometric thickness of about 5 nm to about 150 nm, a second layer of silica having a geometric thickness of about 5 nm to about 300 nm, and a third layer of Fe2O3 or TiO2 having a geometric thickness of about 15 nm to about 200 nm, and the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the dry state of the intermediates by mass ratio.

[0199] 27. The pigment according to any one of paragraphs 1 to 21, wherein the substrate of intermediate 1 is coated with a silica layer having a geometric thickness of about 50 nm to about 70 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 150 nm to about 350 nm, and the substrate of intermediate 2 is coated with a first layer of Fe2O3 or TiO2 having a geometric thickness of about 15 nm to about 70 nm, a second layer of silica having a geometric thickness of about 10 nm to about 110 nm, and a third layer of Fe2O3 or TiO2 having a geometric thickness of about 15 nm to about 200 nm, and the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the mass ratio of the dry form of the intermediates.

[0200] 28. The pigment according to any one of paragraphs 1 to 27, wherein the third layer of the intermediate 2 contains TiO2.

[0201] 29. A combination of pigments comprising (a) an effect pigment described in any one or more paragraphs 1 to 28, in combination with one or more pigments selected from the group consisting of (b) a color-absorbing pigment and (c) one or more further effect pigments.

[0202] 30. The pigment combination described in paragraph 29, wherein the weight ratio of pigment (a) to pigments (b) and (c) is 95:5 to 5:95, or 80:20 to 5:95, or 75:25 to 20:80.

[0203] 31. Paints, printing inks, coatings, varnishes, plastics, textiles, films, or cosmetics containing pigments described in one or more of paragraphs 1 to 28.

[0204] 32. An automotive or industrial ink or paint composition comprising one or more of the pigments described in paragraphs 1 to 28.

[0205] 33. A printed or coated article comprising the composition described in paragraph 31 or 32.

[0206] 34. A process for producing a blue-toned red effect pigment described in any one of paragraphs 1 to 28 by a wet chemical preparation method, a. Synthesis of intermediate 1 by coating a metal flake substrate with silica and iron oxide. b. Synthesis of intermediate 2 by coating synthetic or natural mica flakes with a first layer of Fe2O3 or TiO2, a second layer of SiO2, and a third layer of Fe2O3 or TiO2, and c. A process that includes blending intermediate 1 and intermediate 2.

[0207] 35. The process according to paragraph 34, wherein the intermediate 1 and / or the intermediate 2 are surface-treated either during the blending process or after blending, before being blended with silica, Al2O3, Ce oxide, and / or silane, in order to obtain a blue-toned red effect.

[0208] 36. The process according to paragraph 35, wherein the silane is selected from the group consisting of aminosilanes, epoxysilanes, and blends thereof.

[0209] 37. The process according to any one of paragraphs 34 to 36, wherein the metal flake substrate contains aluminum.

[0210] 38. The process according to any one of paragraphs 34 to 37, wherein the median particle size of the raw materials for intermediate 1 and intermediate 2 is 5 to 200 μm or 7 to 70 μm.

[0211] 39. The process described in paragraph 38, wherein the median particle size (d50) of the raw material is 9 to 22 μm.

[0212] 40. The process according to paragraph 37, wherein the aluminum is passivated in a layer of material selected from the group consisting of metal phosphates, aluminum oxides, hydrated aluminum oxides, or combinations thereof.

[0213] 41. The process according to any one of paragraphs 34 to 40, wherein the average thickness of the metal substrate is 10 to 1500 nm, or 70 to 1000 nm, or 80 to 500 nm, preferably 80 to 400 nm.

[0214] 42. The process according to any one of paragraphs 34-38 or 40-41, wherein the metal substrate comprises aluminum-based plate-like crystals having an average diameter of 3-100 μm, or 5-25 μm, preferably 9-22 μm, an average thickness of 80-250 nm, and an aspect ratio of 50-250.

[0215] 43. The metal substrate has a BET surface area of ​​0.5 to 80 m². 2 / g, or 0.8~50m 2 The process described in any one of paragraphs 34 to 42, comprising aluminum-based plate-like crystals of / g.

[0216] 44. The process according to any one or more of paragraphs 34 to 43, wherein the pigment obtained in step b) is subjected to a heat treatment step selected from the group consisting of (i) calcining at 280 to 340°C for at least 15 minutes, and (ii) being subjected to a medium containing one or more high-boiling point solvents and heating at a temperature of at least 90°C for at least 0.5 hours.

[0217] 45. The process according to any one of paragraphs 34 to 44, wherein the intermediate 2 comprises a silica layer having a geometric thickness of about 5 nm to about 300 nm, preferably about 10 nm to about 110 nm.

[0218] 46. ​​The process according to paragraph 45, wherein the silica layer has a refractive index of 1.8 or less, or 1.30 to 1.80, or 1.30 to 1.50, or 1.40 to 1.50.

[0219] 47. The process according to any one of paragraphs 34 to 46, wherein the outermost layer of the intermediate 2 has a geometric thickness of about 5 nm to about 400 nm, preferably about 15 nm to about 200 nm.

[0220] 48. The process according to paragraph 47, wherein the outermost layer of the intermediate 2 has a refractive index greater than 1.80, or 2.00 to 4.00, or 2.00 to 3.30, or 2.20 to 3.00, or 2.20 to 2.60.

[0221] 49. The process according to paragraph 34, wherein the red effect pigment is surface-treated with Al oxide and cerium oxide in an aqueous suspension, followed by silane treatment.

[0222] 50. The process according to any one of paragraphs 34 to 49, wherein the metal flake substrate of the intermediate 1 is passivated.

[0223] 51. The process according to any one of paragraphs 34 to 49, wherein, prior to step c, the intermediate 1 is surface-treated with silica and at least one polymer, preferably a polymer formed from silane and acrylate monomer, and the intermediate 2 is surface-treated with aluminum oxide, cerium oxide, and at least one silane.

[0224] 52. A blue-toned red effect pigment obtained from one or more of the processes described in paragraphs 34-50.

[0225] 53. The pigment according to any one of paragraphs 1 to 28, wherein the intermediate 1 is surface-treated with silica and at least one polymer, preferably a polymer formed from silane and acrylate monomer, and the intermediate 2 is surface-treated with aluminum oxide, cerium oxide, and at least one silane (preferably 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane).

[0226] The present invention has been described in detail, including preferred embodiments. However, those skilled in the art will understand that, taking into consideration this disclosure, modifications and / or improvements can be made to the present invention within the scope and spirit of the invention. [Examples]

[0227] Example 1 Synthesis of intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50 = 18 μm, exhibiting an intermediate shade of red. Surface area of ​​2-3 m 2A 140g dry aluminum paste with a particle size d50 of 17-23 μm per g is suspended in 1300-1600 mL of ethanol. Passivation with SiO2 is carried out according to the method described in Example 1 of US5,607,504, EP-A-0708154, or JP-A-54081337. The resulting suspension of passivated aluminum, ethanol, ammonia, water, and non-hydrolyzed / partially hydrolyzed tetraethoxysilane is filtered and washed with a total of 1500 mL of ethanol. The resulting paste has a solid concentration of 50-60%, and the dry pigment has an Al-to-SiO2 ratio of approximately 4:1.

[0228] Disperse SiO2-coated aluminum paste (75 g of dry powder) in 700 mL of desalted water, stir, and heat the slurry to 78°C. Adjust the pH to 5 with 10 wt.% HNO3, then adjust to 3.1 with 30 mL of desalted aqueous solution containing 0.2-0.3 g of Al2(SO4)3·16H2O, and maintain the pH at 2.8 while adding Fe(NO3)3 solution with a weight concentration of 6-9% Fe, first with 10 g of 12.5% ​​NH3, then with 25 wt.% KOH, until the desired red color is achieved. The usual incubation time is in the range of 12-25 hours, and the final pigment has an Al:SiO2:Fe2O3 content of approximately 4:1:7. The slurry is filtered and washed with desalted water and ethanol until, for example, a conductivity level of 200 μS is achieved, and the press cake is vacuum-dried and held as an alcohol-containing paste with a solid concentration of 60-80% for use in the next step.

[0229] The obtained pigment paste (60 g of dry powder) is dispersed in 730-750 g of isoparaffin fluid. The reaction mixture is heated to 220°C for 10 hours and stirred at 220°C for 6 hours under a nitrogen atmosphere. The slurry is filtered, washed with ethanol, and the press cake is vacuum-dried at room temperature for a further 5 minutes. The resulting paste has a solid concentration of approximately 70%.

[0230] The resulting product, namely the isoparaffin paste of intermediate 1, exhibited a highly vivid red color in the intermediate shade.

[0231] Synthesis of Intermediate 2: A synthetic mica with a d50 of 20 μm coated with Fe2O3, SiO2, and TiO2, exhibiting a purple color. A 6.5% aqueous slurry containing 130g of synthetic mica flakes (d50 approximately 20μm) was heated to 82°C and stirred. The pH of the slurry was adjusted to 3.0 with HCl. Next, 600g of 39% FeCl3·5H2O was added at a rate of 2g / min while maintaining the pH with NaOH solution. Firing of the pigment sample yielded a hue of 20°. At the point of the desired shade, the pH of the slurry was raised to 7.8 with NaOH, and while maintaining the pH at 7.8 by adding HCl solution, 600g of 20% Na2SiO3x5H2O was added at a rate of 2g / min. After the addition of 20% Na2SiO3x5H2O was complete, the pH of the slurry was adjusted to 1.5 with HCl. Then, while maintaining the pH by adding NaOH solution, 20g of 20% SnCl45H2O was added at a rate of 1.5g / min. The slurry was stirred, and then 800 g of 40% TiCl4 was added at a rate of 2 g / min while maintaining the pH at 1.50 by adding NaOH solution. Next, 50 mL of the slurry was filtered, the press cake was washed with water, and it was baked at 850°C for 20 minutes. The resulting product was purple in color.

[0232] Surface treatment of a blend of intermediate 1 / intermediate 2 in a weight ratio of 85 / 15 for dry pigments. 95 g of a blend consisting of 85 parts of intermediate 1 and 15 parts of intermediate 2 is dispersed in 310 ml of isopropanol, and the dispersion is heated to its boiling point. Next, 9 g of tetraethoxysilane is added, followed immediately by 9 g of H2O. Then, a 25% aqueous NH4OH solution is introduced over 3 hours via an automated weighing unit at a rate that ensures pH 8.7 is achieved and maintained during this time. One hour after the start of this weighing, solution A (see below) is also weighed over 85 minutes using a laboratory automated weighing unit (IKA STEPDOS). Five minutes after the start of this supply, polymerization is initiated by adding 2,2'-azobis(isobutyronitrile) (AIBN) on the tip of a spatula. The reaction mixture is then stirred at 88°C for 4 hours. Next, a mixture of 0.8 g of Dynasylan OCTEO (octyltriethoxysilane) and 0.5 g of Dynasylan AMMO (3-aminopropyltrimethoxysilane) is added. The reaction mixture is stirred overnight and filtered the following day. The filtered cake is dried in a vacuum drying cabinet at 100°C for 6 hours.

[0233] (Solution A: 116 ml of ethanol solution containing 0.59 g of Dynasylan MEMO (3-methacrylateoxypropyltrimethoxysilane) and 2.51 g of trimethylolpropane trimethacrylate (TMPTMA)).

[0234] The resulting blue-toned red effect pigment of Example 1, in its primary color (master tone), exhibited similar hue, higher saturation, higher lightness, improved opacity, lower granularity, stronger flop index, and better DOI compared to the reference Paliochrom Sparkling Red L 3505 (Table 1).

[0235] Example 2 Synthesis of intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50 = 18 μm, exhibiting an intermediate shade of red. Surface area 2-3m 2A 140g dry aluminum paste with a particle size d50 of 17-23 μm per g is suspended in 1300-1600 mL of ethanol. Passivation with SiO2 is carried out according to the method described in Example 1 of US5,607,504, EP-A-0708154, or JP-A-54081337. The resulting suspension of passivated aluminum, ethanol, ammonia, water, and non-hydrolyzed / partially hydrolyzed tetraethoxysilane is filtered and washed with a total of 1500 mL of ethanol. The resulting paste has a solid concentration of 50-60%, and the dry pigment has an Al-to-SiO2 ratio of approximately 4:1.

[0236] Disperse SiO2-coated aluminum paste (75 g of dry powder) in 700 mL of desalted water, stir, and heat the slurry to 78°C. Adjust the pH to 3.35 with 10 wt.% HNO3, then adjust to 3.1 with 30 mL of desalted aqueous solution containing 0.2-0.3 g of Al2(SO4)3·16H2O, and maintain at 2.8 while adding 25 wt.% NaOH, with an Fe(NO3)3 solution containing 6-9% Fe by weight, until the desired red color is achieved. The usual incubation time is in the range of 12-25 hours, and the final pigment has an Al:SiO2:Fe2O3 content of approximately 4:1:7. Filter the slurry and wash with desalted water and ethanol until, for example, a conductivity level of 200 μS is achieved, then vacuum dry the press cake and hold it as an alcohol-containing paste with a solid concentration of 60-80% for use in the next step.

[0237] The obtained pigment paste (60 g of dry powder) is dispersed in 730-750 g of isoparaffin fluid. The reaction mixture is heated to 195°C for 10 hours, and then stirred at 195°C for 6 hours under a nitrogen atmosphere. The slurry is filtered, washed with ethanol, and the press cake is vacuum-dried at room temperature for a further 5 minutes. The resulting paste has a solid concentration of approximately 60-80%.

[0238] The resulting product exhibited a highly vivid yellow-red color.

[0239] Synthesis of intermediate 2: Same as intermediate 2 in Example 1. Surface treatment of the intermediate 1 / intermediate 2 blend in a weight ratio of 85 / 15 for the dry pigment: Same as the surface treatment of Example 1. The resulting blue-toned red effect pigment of Example 2 was slightly redder, had higher saturation and brightness, better sparkle and opacity, a stronger flop index, and a better DOI compared to the reference Paliochrom Sparkling Red L 3505 (Table 1).

[0240] Example 3 Synthesis of Intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50=18μm - shows red intermediate shade. The procedure is the same as for Intermediate 1 in Example 2. The obtained pigment paste (60 g of dry powder) is dispersed in 730-750 g of isoparaffin fluid. The reaction mixture is heated to 195-220°C for 10 hours and stirred under a nitrogen atmosphere at 195-220°C for 6 hours. The slurry is filtered, washed with ethanol, and the press cake is vacuum-dried at room temperature for a further 5 minutes. The resulting paste has a solid concentration of approximately 70%.

[0241] Synthesis of Intermediate 2: Same as Intermediate 2 in Example 1 (synthetic mica with d50 = 20 μm coated with Fe2O3, SiO2, and TiO2, which exhibit a purple color). Surface treatment of a blend of intermediate 1 / intermediate 2 in a weight ratio of 80 / 20 for dry pigments. 80 g of intermediate 1 and 20 g of intermediate 2 were dispersed in 1 liter of desalted water and heated to 75°C. The pH was adjusted to 3 with dilute nitric acid, and 2 g of 20.2% Ce(NO3)3 solution, 7 g of 4.3% Al(NO3)3 solution, and 0.48 g of NaH2PO2H2O were added to the slurry and stirred for about 20 minutes. The slurry was slowly raised to pH 8 over 30 minutes with 3.5% NaOH. 3 g of 3-glycidoxypropyltrimethoxysilane and 3 g of 3-aminopropyltriethoxysilane were added over 10 minutes. Stirring was continued at 75°C for 2 hours. The slurry was filtered, washed, and dried at 140°C.

[0242] The obtained blue-toned red effect pigment of Example 3 has the same shade, chroma, and lightness as the reference Paliocrom Sparkling Red L 3505, but has good floppiness index, sparkle, granularity, hiding power, and DOI (Table 1).

[0243] Example 4 The same raw materials as in Example 3 were used. The supply of the Fe2O3 precursor was stopped later. Synthesis of Intermediate 1: Aluminum paste (140 g of dry powder) with a surface area of 2 - 4 m 2 / g and a particle size d50 of 15 - 21 μm is suspended in 1570 mL of ethanol. Passivation with SiO2 is carried out according to the method described in Example 1 of US 5,607,504 or EP - A - 0708154 or JP - A - 54081337. The obtained suspension of passivated aluminum, ethanol, ammonia, water, and non - hydrolyzed / partially hydrolyzed tetraethoxysilane is filtered and washed with a total of 1250 mL of ethanol. The resulting paste has a solid concentration of 50 - 60%, and the dried pigment has a ratio of Al to SiO2 of about 4:1.

[0244] The SiO2 - coated aluminum paste (75 g of dry powder) is dispersed in about 700 mL of deionized water, and the stirred slurry is heated to 78 °C. The pH value is adjusted to 3.35 with 10 wt.% HNO3, then adjusted to 3.1 with a 30 mL deionized water solution containing 0.2 - 0.4 g of Al2(SO4)3·16H2O, and maintained at 2.8 while adding a Fe(NO3)3 solution with a Fe weight concentration of 6 - 9% with 25 wt.% NaOH until the desired red color is achieved. However, to obtain a slightly more blue - tinged Intermediate 1, the supply of the Fe(NO3)3 solution was stopped about 15 minutes later compared to Intermediate 1 of Example 3. The normal supply time ranges from 12 - 25 hours, and the final pigment has an Al:SiO2:Fe2O3 content of about 4:1:7. The slurry is filtered, washed with deionized water and then ethanol until a conductivity level of, for example, 200 μS is achieved, and the presscake is vacuum - dried and retained as an alcohol - containing paste with a solid concentration of 60 - 80% for use in the next step.

[0245] The obtained pigment paste (60 g of dry powder) is dispersed in 730-750 g of isoparaffin fluid. The reaction mixture is heated to 195-220°C for 10 hours, and then stirred under a nitrogen atmosphere at 195-220°C for 6 hours. The slurry is filtered, washed with ethanol, and the press cake is vacuum-dried at room temperature for a further 5 minutes. The resulting paste has a solid concentration of approximately 70%.

[0246] Intermediate 2 was synthesized as described in Example 3.

[0247] The surface treatment of the 80 / 20 blend of intermediates 1 and 2 was carried out as described in Example 3.

[0248] The resulting blue-toned red effect pigment of Example 4 exhibits better saturation, flop index, sparkle, granularity, opacity, and DOI compared to the reference Paliocrom Sparkling Red L 3505 (Table 1).

[0249] Example 5 Synthesis of Intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50=18μm - shows red intermediate shade. Intermediate 1 was synthesized as described in Example 2. To obtain a slightly bluer product, the supply of Fe(NO3)3 solution was stopped approximately 15 minutes later compared to intermediate 1 in Example 2.

[0250] Synthesis of Intermediate 2 (Natural mica with d50=18μm coated with TiO2, SiO2, and TiO2 exhibiting magenta interference color) A 6.5% aqueous slurry containing 130g of mica flakes (average particle size approximately 18μm) was heated to 82°C and stirred. The pH of the slurry was adjusted to 1.6 with 28% HCl. Next, 15g of 20% SnCl4·5H2O was added at a rate of 2.0g / min while maintaining the pH at 1.60 by adding 10% NaOH. The slurry was stirred for 30 minutes. Then, 40% TiCl4 was added at a rate of 2.0g / min while maintaining the pH at 1.50 by adding 35% NaOH. When the desired pearlescent appearance was achieved, the pH of the slurry was raised to 7.8 with 35% NaOH. Subsequently, 150g of 20% Na2SiO3·5H2O was added at a rate of 2.0g / min while maintaining the pH at 7.80 by adding 28% HCl. After the addition of 20% Na2SiO3·5H2O was complete, the pH of the slurry was adjusted to 1.7 with 28% HCl. Then, while maintaining the pH at 1.70 by adding 10% NaOH, 28 g of 20% SnCl4·5H2O was added at a rate of 2.0 g / min. The slurry was stirred for 30 minutes. Then, while maintaining the pH at 1.50 by adding 35% NaOH, 40% TiCl4 was added at a rate of 2.0 g / min.

[0251] At the desired shade, the slurry was filtered, the press cake was washed with water, and baked at 850°C for 20 minutes. The resulting interference color was a deep magenta tone.

[0252] Intermediate 1 and Intermediate 2 were blended in a propylene glycol slurry. 85 g of Intermediate 1 (with respect to dry pigment) and 15 g of dry Intermediate 2 were stirred in 1 liter of propylene glycol. After stirring for 30 minutes, the mixture was filtered. The resulting paste contained pigment with a solid content of 65%.

[0253] The pigment obtained in Example 5 had the same shade as the comparison, but the saturation, lightness, and flop index were significantly improved. DOI, opacity, and sparkle were also improved (Table 1).

[0254] Example 6 Synthesis of Intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50=18μm - shows red intermediate shade. Intermediate 1 was synthesized as described for Intermediate 1 in Example 2. To obtain a slightly bluer product, the supply of Fe(NO3)3 solution was stopped approximately 15 minutes later than for Intermediate 1 in Example 2.

[0255] Synthesis of Intermediate 2 (TiO2, SiO2, and TiO2-coated natural mica with a d50 of 18 μm exhibiting indigo interference color) A 6.5% aqueous slurry containing 130g of mica flakes (average particle size approximately 18μm) was heated to 82°C and stirred. The pH of the slurry was adjusted to 1.6 with 28% HCl. Next, 15g of 20% SnCl4·5H2O was added at a rate of 2.0g / min while maintaining the pH at 1.60 by adding 10% NaOH. The slurry was stirred for 30 minutes. Then, 40% TiCl4 was added at a rate of 2.0g / min while maintaining the pH at 1.50 by adding 35% NaOH. When the desired pearlescent appearance was achieved, the pH of the slurry was raised to 7.8 with 35% NaOH. Subsequently, 412g of 20% Na2SiO3·5H2O was added at a rate of 2.0g / min while maintaining the pH at 7.80 by adding 28% HCl. After the addition of 20% Na2SiO3·5H2O was complete, the pH of the slurry was adjusted to 1.7 with 28% HCl. Then, while maintaining the pH at 1.70 by adding 10% NaOH, 28 g of 20% SnCl4·5H2O was added at a rate of 2.0 g / min. The slurry was stirred for 30 minutes. Then, while maintaining the pH at 1.50 by adding 35% NaOH, 40% TiCl4 was added at a rate of 2.0 g / min.

[0256] At the desired shade, the slurry was filtered, the press cake was washed with water, and baked at 850°C for 20 minutes. The resulting interference color was vivid indigo.

[0257] Intermediate 1 and Intermediate 2 were surface-treated separately and then blended in a propylene glycol slurry.

[0258] 100 g of intermediate 1 (for the dry pigment) is dispersed in 310 ml of isopropanol, and the dispersion is heated to its boiling point. Next, 9 g of tetraethoxysilane is added, followed immediately by 9 g of H2O. Then, a 25% aqueous NH4OH solution is introduced over 3 hours via an automated weighing unit at a rate that ensures pH 8.7 is achieved and maintained during this time. One hour after the start of this weighing, solution A (see below) is also weighed over 85 minutes using a laboratory automated weighing unit (IKA STEPDOS). Five minutes after the start of this supply, polymerization is initiated by adding 2,2'-azobis(isobutyronitrile) (AIBN) on the tip of a spatula. The reaction mixture is then stirred at 88°C for 4 hours. Subsequently, a mixture of 0.8 g of Dynasylan OCTEO (octyltriethoxysilane) and 0.5 g of Dynasylan AMMO (3-aminopropyltrimethoxysilane) is added. The reaction mixture is stirred overnight and filtered the following day. The filtered cake is dried in a vacuum drying cabinet at 100°C for 6 hours. (Solution A: 116 ml of ethanol solution of 0.59 g of Dynasylan MEMO (3-methacrylateoxypropyltrimethoxysilane) and 2.51 g of trimethylolpropane trimethacrylate (TMPTMA)).

[0259] 100 g of intermediate 2 was dispersed in 1 liter of desalted water and heated to 75°C. The pH was adjusted to 3 with dilute nitric acid, and 2 g of 20.2% Ce(NO3)3 solution, 7 g of 4.3% Al(NO3)3 solution, and 0.48 g of NaH2PO2H2O were added to the slurry and stirred for about 20 minutes. The slurry was slowly raised to pH 8 over 30 minutes with 3.5% NaOH. 3 g of 3-glycidoxypropyltrimethoxysilane and 3 g of 3-aminopropyltriethoxysilane were added over 10 minutes. Stirring was continued at 75°C for 2 hours. The slurry was filtered, washed, and dried at 140°C.

[0260] Finally, 86 g of individually surface-treated Intermediate 1 and 14 g of individually surface-treated Intermediate 2 were dispersed in 1 liter of iso-prOH and subsequently filtered. The resulting paste of Example 6 had a solids content of 65%. Compared to the reference, this blueish-red pigment showed high chroma, high lightness, good flop index, DOI, sparkle, and hiding power (Table 1).

[0261] Example 7 Synthesis of Intermediate 1: Al silver-dollar with d50 = 18 μm coated with SiO2 and Fe2O3, showing a red intermediate shade Procedure according to Intermediate 1 of Example 2. To obtain a slightly more blueish product, the supply of Fe(NO3)3 solution was stopped about 15 minutes later compared to Intermediate 1 of Example 2.

[0262] Synthesis of Intermediate 2: Natural mica with d50 = 18 μm coated with TiO2, SiO2, and TiO2, showing a blue interference color A 6.5% aqueous slurry containing 130 g of mica flakes (average particle size of about 18 μm) was heated to 82 °C and stirred. The pH of the slurry was adjusted to 1.6 with 28% HCl. Next, while maintaining the pH at 1.60 with 10% NaOH, 15 g of 20% SnCl4·5H2O was added at a rate of 2.0 g / min. The slurry was stirred for 30 minutes. Then, while maintaining the pH at 1.50 with 35% NaOH, 40% TiCl4 was added at a rate of 2.0 g / min. When the desired pearl tone was achieved, the pH of the slurry was raised to 7.8 with 35% NaOH. Thereafter, while maintaining the pH at 7.80 with 28% HCl, 550 g of 20% Na2SiO3·5H2O was added at a rate of 2.0 g / min. After the addition of 20% Na2SiO3·5H2O was completed, the pH of the slurry was adjusted to 1.7 with 28% HCl. Next, while maintaining the pH at 1.70 with 10% NaOH, 28 g of 20% SnCl4·5H2O was added at a rate of 2.0 g / min. The slurry was stirred for 30 minutes. Then, while maintaining the pH at 1.50 with 35% NaOH, 40% TiCl4 was added at a rate of 2.0 g / min.

[0263] At the desired shade, the slurry was filtered, the press cake was washed with water, and baked at 850°C for 20 minutes. The resulting interference colors were vivid red and blue.

[0264] Surface treatment of a 91:9 ratio blend of intermediate 1 / intermediate 2. The surface treatment of this 91:9 blend is similar to that of the blend in Example 1. This 91:9 blend was related to a dry pigment.

[0265] The resulting blue-toned red effect pigment of Example 7 was slightly redder, had higher saturation and brightness, better sparkle and opacity, a stronger flop index, and a better DOI compared to the reference Paliochrom Sparkling Red L 3505 (Table 1).

[0266] Example 8 Synthesis of Intermediate 1: (Al silver dollar coated with SiO2 and Fe2O3, d50=18μm - showing red in the intermediate shade) The procedure followed the intermediate 1 of Example 2. To obtain a slightly bluer product, the supply of Fe(NO3)3 solution was stopped approximately 15 minutes later compared to intermediate 1 of Example 2.

[0267] Synthesis of Intermediate 2: (Synthetic mica with d50=20μm coated with TiO2, SiO2, and TiO2 exhibiting blue interference colors) A 6.5% aqueous slurry containing 130g of synthetic mica flakes (average particle size approximately 20μm) was heated to 82°C and stirred. The pH of the slurry was adjusted to 1.6 with 28% HCl. Next, 15g of 20% SnCl4·5H2O was added at a rate of 2.0g / min while maintaining the pH at 1.60 by adding 10% NaOH. The slurry was stirred for 30 minutes. Then, 40% TiCl4 was added at a rate of 2.0g / min while maintaining the pH at 1.50 by adding 35% NaOH. When the desired pearlescent appearance was achieved, the pH of the slurry was raised to 7.8 with 35% NaOH. Subsequently, 340g of 20% Na2SiO3·5H2O was added at a rate of 2.0g / min while maintaining the pH at 7.80 by adding 28% HCl. After the addition of 20% Na2SiO3·5H2O was complete, the pH of the slurry was adjusted to 1.7 with 28% HCl. Then, while maintaining the pH at 1.70 by adding 10% NaOH, 28 g of 20% SnCl4·5H2O was added at a rate of 2.0 g / min. The slurry was stirred for 30 minutes. Then, while maintaining the pH at 1.50 by adding 35% NaOH, 40% TiCl4 was added at a rate of 2.0 g / min.

[0268] At the desired shade, the slurry was filtered, the press cake was washed with water, dried, and baked at 850°C for 20 minutes. The resulting interference color was a vivid blue.

[0269] Intermediate 1 / Intermediate 2 were surface-treated with a 92 / 8 blend. This surface treatment of the 92:8 blend is similar to that of the blend in Example 1. This 92:8 blend was related to the dry pigment.

[0270] The resulting blue-toned red effect pigment of Example 8 was slightly redder, had higher saturation and brightness, better sparkle and opacity, a stronger flop index, and a better DOI compared to the reference Paliochrom Sparkling Red L 3505 (Table 1).

[0271] Example 9 Synthesis of Intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50=18μm - shows red intermediate shade. The procedure followed the intermediate 1 of Example 2. To obtain a slightly bluer product, the supply of Fe(NO3)3 solution was stopped approximately 15 minutes later compared to intermediate 1 of Example 2.

[0272] Synthesis of Intermediate 2: (Synthetic mica with a d50 of 20 μm coated with Fe2O3, SiO2, and TiO2, which exhibit a purple color) This synthesis was already described in Intermediate 2 of Example 1.

[0273] The surface treatment of the intermediate 1 / intermediate 2 blend was carried out as described in Example 3, but with respect to the dry pigment, in a weight ratio of 86 / 14.

[0274] The resulting blue-toned red effect pigment of Example 9 exhibits similar shade, saturation, and brightness to the reference Paliochrom Sparkling Red L 3505, but with better flop index, sparkle, opacity, and DOI (Table 1).

[0275] Example 10 Synthesis of Intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50=18μm - shows red intermediate shade. The procedure followed the intermediate 1 of Example 2. To obtain a slightly bluer product, the supply of Fe(NO3)3 solution was stopped approximately 15 minutes later compared to intermediate 1 of Example 2.

[0276] Synthesis of Intermediate 2: (Synthetic mica with a d50 of 20 μm coated with Fe2O3, SiO2, and TiO2 exhibiting a bluish-brown color) A 6.5% aqueous slurry containing 130g of synthetic mica flakes (d50 approximately 20μη) was heated to 82°C and stirred. The pH of the slurry was adjusted to 3.0 with HCl. Next, 600g of 39% FeCl35H2O was added at a rate of 2g / min while maintaining the pH with NaOH solution. Firing of the pigment sample yielded a hue of 20°. At the desired shade, the pH of the slurry was raised to 7.8 with NaOH, and while maintaining the pH at 7.8 by adding HCl solution, 600g of 20% Na2SiO3x5H2O was added at a rate of 2g / min. After the addition of 20% Na2SiO3x5H2O was complete, the pH of the slurry was adjusted to 1.5 with HCl. Then, while maintaining the pH by adding NaOH solution, 20g of 20% SnCl45H2O was added at a rate of 1.5g / min. The slurry was stirred, and then 800 g of 40% TiCl4 was added at a rate of 2 g / min while maintaining the pH at 1.50 by adding NaOH solution. Next, 50 mL of the slurry was filtered, the press cake was washed with water, and it was baked at 850°C for 20 minutes. The resulting product was bluish-brown in color.

[0277] Intermediate 1 and Intermediate 2 were blended in a ratio of 75:25 (no surface treatment, dry powder). 75 g of Intermediate 1 and 25 g of Intermediate 2 were dispersed in 500 ml of isopropanol, followed by filtration and drying at 70°C.

[0278] The dried powder of the blue-toned red effect pigment obtained in Example 10 exhibits similar hue, higher saturation, stronger sparkle and flop index, and better DOI compared to the reference Paliochrom Sparkling Red L 3505 in its primary color (master tone) (Table 1).

[0279] Example 11 Synthesis of intermediate 1: Al silver dollar coated with SiO2 and Fe2O3, d50 = 18 μm, exhibiting an intermediate shade of red. The procedure followed the intermediate 1 of Example 2. To obtain a slightly bluer product, the supply of Fe(NO3)3 solution was stopped approximately 15 minutes later compared to intermediate 1 of Example 2.

[0280] Synthesis of Intermediate 2: (Synthetic mica with a d50 of 11 μm coated with Fe2O3, SiO2, and TiO2 exhibiting a bluish-brown color) A 6.5% aqueous slurry containing 130g of synthetic mica flakes (d50 approximately 11μη) was heated to 82°C and stirred. The pH of the slurry was adjusted to 3.0 with HCl. Next, 600g of 39% FeCl35H2O was added at a rate of 2g / min while maintaining the pH with NaOH solution. Firing of the pigment sample yielded a hue of 20°. At the desired shade, the pH of the slurry was raised to 7.8 with NaOH, and 700g of 20% Na2SiO3x5H2O was added at a rate of 2g / min while maintaining the pH at 7.8 with the addition of HCl solution. After the addition of 20% Na2SiO3x5H2O was complete, the pH of the slurry was adjusted to 1.5 with HCl. Then, 25g of 20% SnCl45H2O was added at a rate of 1.5g / min while maintaining the pH with the addition of NaOH solution. The slurry was stirred, and then 900 g of 40% TiCl4 was added at a rate of 2 g / min while maintaining the pH at 1.50 by adding NaOH solution. Next, 50 mL of the slurry was filtered, the press cake was washed with water, and it was baked at 850°C for 20 minutes. The resulting product was bluish-brown in color.

[0281] Intermediate 1 and Intermediate 2 were blended in a 70 / 30 ratio (no surface treatment, dry powder). 70 g of Intermediate 1 and 30 g of Intermediate 2 were dispersed in 500 ml of isopropanol, followed by filtration and drying at 70°C.

[0282] The dried powder of the blue-toned red effect pigment obtained in Example 11 showed similar hue and higher saturation in its primary color (master tone) compared to the reference Paliocrom Sparkling Red L 3505. Due to the use of finer mica components, the resulting pigment had a smoother appearance, less pronounced flop index, and a much better DOI (Table 1). [Table 1] 1The Index of Performance (PI) is a composite measure of overall color characteristics calculated using the following formula (higher PI indicates better performance):

number

Claims

1. a. Intermediate 1 comprising a metal flake substrate coated with silica and iron oxide, b. Fe of the first layer ２ O ３ or TiO ２ , second layer SiO ２ , and the third layer Fe ２ O ３ or TiO ２ A blue-toned red effect pigment comprising a blend with intermediate 2, which contains synthetic or natural mica flakes coated with a substance.

2. The pigment according to claim 1, wherein the metal flake substrate of the intermediate 1 is passivated.

3. The pigment according to claim 2, wherein the metal flake substrate is passivated with one or more layers of a material selected from the group consisting of metal phosphates, aluminum oxides, hydrated aluminum oxides, and combinations thereof.

4. The intermediate 1 and / or the intermediate 2 is surface-treated before being blended with a material selected from the group consisting of silica, Al ２ O ３ , Ce oxide, silane, or a blend thereof to obtain a blue-toned red effect, and preferably, both the intermediate 1 and the intermediate 2 are surface-treated before being blended with a material selected from the group. The pigment according to any one of claims 1 to 3.

5. The pigment according to any one of claims 1 to 4, wherein the metal flake substrate comprises aluminum.

6. The pigment according to any one of claims 1 to 5, wherein the d50 median particle size of the metal flake substrate and the synthetic or natural mica flakes is 9 to 22 μm.

7. The pigment according to any one of claims 1 to 6, wherein the intermediate 2 comprises a silica layer having a geometric thickness of about 5 nm to about 300 nm, preferably about 10 nm to about 110 nm.

8. The pigment according to claim 7, wherein the silica material layer has a refractive index of 1.8 or less, or 1.30 to 1.80, or 1.30 to 1.50, or 1.40 to 1.

50.

9. The third layer of the intermediate 2 is TiO2 having a geometric thickness of about 5 nm to about 400 nm, preferably about 15 nm to about 200 nm. ２ The pigment according to any one of claims 1 to 8, preferably comprising rutile and / or anatase-type titania.

10. The pigment according to any one of claims 1 to 9, wherein the third layer of the intermediate 2 has a geometric thickness of about 5 nm to about 400 nm and a refractive index greater than 1.80, or 2.00 to 4.00, or 2.00 to 3.30, or 2.20 to 3.00, or 2.20 to 2.

60.

11. The pigment according to any one of claims 1 to 10, wherein the intermediate 1 and / or the intermediate 2 are surface-treated with aluminum oxide and cerium oxide in an aqueous suspension, followed by a silane treatment.

12. The pigment according to any one of claims 1 to 11, wherein the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the dry state of the intermediates by mass.

13. The pigment according to any one of claims 1 to 12, wherein the ratio of intermediate 1 to intermediate 2 is in the range of 80:20 to 70:30, based on the dry state of the intermediates.

14. The pigment according to any one of claims 1 to 13, wherein the substrate of the intermediate 1 is coated with a silica layer having a geometric thickness of about 20 nm to about 100 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 120 nm to about 500 nm.

15. The pigment according to claim 14, wherein the substrate of the intermediate 1 is coated with a silica layer having a geometric thickness of about 50 nm to about 70 nm, and the silica layer is coated with an iron oxide layer having a geometric thickness of about 150 nm to about 350 nm.

16. The substrate of the intermediate 2 is the Fe of the first layer ２ O ３ or TiO ２ The material comprises a first layer having a geometric thickness of approximately 5 nm to approximately 150 nm, a second layer of silica having a geometric thickness of approximately 5 nm to approximately 300 nm, and a third layer of Fe ２ O ３ or TiO ２ The pigment according to any one of claims 1 to 15, wherein it is coated with a third layer having a geometric thickness of about 5 nm to about 400 nm.

17. The substrate of the intermediate 2 is the Fe of the first layer ２ O ３ or TiO ２ The first layer has a geometric thickness of about 15 nm to about 70 nm, the second layer is silica with a geometric thickness of about 10 nm to about 110 nm, and the third layer is Fe ２ O ３ or TiO ２ The pigment according to claim 16, wherein it is coated with a third layer having a geometric thickness of about 15 nm to about 200 nm.

18. The substrate of the intermediate 1 is a silica layer having a geometric thickness of about 20 nm to about 100 nm, and the silica layer is covered with an iron oxide layer having a geometric thickness of about 120 nm to about 500 nm, and the substrate of the intermediate 2 is the first layer Fe ２ O ３ or TiO ２ The material comprises a first layer having a geometric thickness of approximately 5 nm to approximately 150 nm, a second layer of silica having a geometric thickness of approximately 5 nm to approximately 300 nm, and a third layer of Fe ２ O ３ or TiO ２ The pigment according to any one of claims 1 to 12, wherein it is coated with a third layer having a geometric thickness of about 5 nm to about 400 nm, and the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the dry state of the intermediates by mass.

19. The substrate of the intermediate 1 is a silica layer having a geometric thickness of about 50 nm to about 70 nm, and the silica layer is covered with an iron oxide layer having a geometric thickness of about 150 nm to about 350 nm, and the substrate of the intermediate 2 is the first layer Fe ２ O ３ or TiO ２ The first layer has a geometric thickness of about 15 nm to about 70 nm, the second layer is silica with a geometric thickness of about 10 nm to about 110 nm, and the third layer is Fe ２ O ３ or TiO ２ The pigment according to any one of claims 1 to 12, wherein it is coated with a third layer having a geometric thickness of about 15 nm to about 200 nm, and the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the dry state of the intermediates by mass.

20. The third layer on the intermediate 2 is TiO ２ The pigment according to any one of claims 14 to 19.

21. The pigment according to any one of claims 1 to 20, wherein the intermediate 1, the intermediate 2, or both the intermediate 1 and the intermediate 2 are surface-treated with a substance selected from aluminum oxide, cerium oxide, and a silane coupling agent, or a combination thereof.

22. The pigment according to any one of claims 1 to 21, wherein the intermediate 1, the intermediate 2, or both the intermediate 1 and the intermediate 2 are surface-treated with a silane coupling agent.

23. The pigment according to any one of claims 1 to 22, wherein the intermediate 1, the intermediate 2, or both the intermediate 1 and the intermediate 2 are surface-treated with aluminum oxide, cerium oxide, and at least one silane coupling agent.

24. The pigment according to any one of claims 1 to 23, wherein the d50 median particle size of the metal flake substrate of the intermediate 1 is 9 to 22 μm, the average thickness of the metal flake substrate is 10 nm to 1500 nm, preferably 80 to 500 nm, and the aspect ratio of d50 to the average thickness is 10 to 1000, preferably 50 to 250.

25. The pigment according to any one of claims 1 to 24, wherein the d50 median particle size of the synthetic or natural mica flakes of the intermediate 2 is 9 to 22 μm, and the aspect ratio of the d50 to the average thickness is greater than about 5.

26. The d50 median particle size of the metal flake substrate of the intermediate 1 is 9 to 22 μm, the average thickness of the metal flake substrate is 10 nm to 1500 nm, preferably 80 to 500 nm, and the aspect ratio of d50 to the average thickness is 10 to 1000, preferably 50 to 250. The pigment according to any one of claims 1 to 25, wherein the d50 median particle size of the synthetic or natural mica flakes of the intermediate 2 is 9 to 22 μm, and the aspect ratio of the d50 to the average thickness is greater than about 5.

27. The pigment according to any one of claims 1 to 20, wherein the intermediate 1 is surface-treated with silica and at least one polymer, preferably a polymer formed from silane and acrylate monomer, and the intermediate 2 is surface-treated with aluminum oxide, cerium oxide, and at least one silane.

28. Paints, automotive inks, industrial inks, printing inks, coatings, varnishes, plastics, fibers, films, or cosmetics comprising the pigment described in any one or more of claims 1 to 27.

29. A process for producing a blue-toned red effect pigment according to any one of claims 1 to 27 by a wet chemical preparation method, a. Synthesis of intermediate 1 by coating a metal flake substrate with silica and iron oxide. b. Synthetic or natural mica flakes in the first layer of Fe ２ O ３ or TiO ２ , second layer SiO ２ , and the third layer Fe ２ O ３ or TiO ２ Synthesis of intermediate 2 by coating with, c. A process including blending intermediate 1 and intermediate 2.

30. The process according to claim 29, wherein the intermediate 1 and the intermediate 2 undergo separate surface treatments after steps a and b and before being blended in step c.

31. The intermediate 1 and the intermediate 2 are silica, Al ２ O ３ The process according to claim 30, wherein the surface is treated with a material selected from the group consisting of cerium oxide and a silane coupling agent, or a combination thereof.

32. The intermediate 1 and / or the intermediate 2 are silica, Al, etc., in order to obtain a blue-toned red effect. ２ O ３ The process according to claim 29, wherein the surface is treated before being blended with cerium oxide and / or silane.

33. The process according to claim 29, wherein the red effect pigment is surface-treated with aluminum oxide and cerium oxide in an aqueous suspension, followed by a silane treatment.

34. The process according to claim 29, wherein, prior to step c, the intermediate 1 is surface-treated with silica and at least one polymer, preferably a polymer formed from silane and acrylate monomer, and the intermediate 2 is surface-treated with aluminum oxide, cerium oxide, and at least one silane.

35. The process according to any one of claims 30 to 34, wherein the geometric thickness of the layer coated in the surface treatment step is 2 to 50 nm, preferably 2 to 30 nm, and more preferably 2 to 20 nm.

36. The process according to any one of claims 29 to 35, wherein the ratio of intermediate 1 to intermediate 2 is in the range of 99:1 to 60:40, preferably 97:3 to 70:30, based on the dry form of the intermediates.

37. The process according to any one of claims 29 to 36, wherein the ratio of intermediate 1 to intermediate 2 is in the range of 80:20 to 70:30, based on the dried form of the intermediates.

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