Multi-hued pearlescent pigment with improved sparkling effect and method for producing same

Abstract

The present invention discloses a pearlescent pigment and a method for producing the same, which has a multilayer structure including a low refractive index material layer between high refractive index material layers on a glass flake substrate, thereby having high color intensity, various hues depending on the viewing angle, and improved sparkling effect. The pearlescent pigment according to the present invention has a D of 40 to 80 μm. 10 Value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 a glass flake substrate having a thickness of 500 nm or more; a first metal oxide layer / MgO SiO 2 The metal oxide layer is coated with an intermediate oxide layer / second metal oxide layer structure comprising:

Description

[Technical Field]

[0001] The present invention relates to a pearlescent pigment, and more particularly to a pearlescent pigment having high color intensity and various hues depending on the viewing angle by utilizing the refractive index difference of multiple metal oxide layers coated on a platelet-shaped substrate, and having an improved sparkling effect by utilizing the physical properties of the substrate, and a method for producing the same. [Background technology]

[0002] Pearlescent pigments are used in various industrial sectors, in particular in the automotive, decorative coatings, plastics, paints, printing inks sector, and in cosmetic formulations.

[0003] Luster pigments based on transparent platelet substrates that do not have a "highly contrasting" metallic luster are coated with a mica platelet-like refractive index metal oxide layer (e.g., TiO2) and a selective absorption layer. When observed flat, these pigments exhibit a specific interference hue that depends on the thickness of the TiO2 layer. However, as the viewing angle becomes more inclined, the interference hue becomes increasingly faded, eventually turning gray or black. In this case, the interference hue remains unchanged, but the hue saturation is observed to decrease. In other words, the range of hue change due to changes in the viewing angle is narrow.

[0004] Recently, pearlescent pigments based on glass platelets or mica particles coated with layers of SiO2 and TiO2 alternating with opaque metal layers have been developed.

[0005] However, the previously known multilayer pigments are often made of layer materials that are barely able to transmit light or transmit only a small amount of light, and therefore can only be combined with absorbing pigments in a very limited range when applied. In addition, the interference hues of these pigments are very dependent on the viewing angle, which makes them undesirable in most applications. In addition, in some cases, it is very difficult to produce or reproduce these pigments.

[0006] In addition, pigments using platelet-shaped substrates currently widely used on the market have problems in that they lack optical properties, particularly sparkling effects, and as mentioned above, they have a narrow range of hue change depending on the viewing angle, making it difficult to realize various hues. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a novel pearlescent pigment having excellent optical properties such as sparkling and a wide range of hue change depending on the viewing angle, and a method for producing the same. [Means for solving the problem]

[0008] To achieve the above object, the pearlescent pigment according to an embodiment of the present invention comprises a glass flake substrate; a first metal oxide layer coated on top of the substrate; an intermediate oxide layer comprising MgO SiO2 coated on top of the first metal oxide layer; and a second metal oxide layer coated on top of the oxide layer; The glass flake substrate is D of 40 to 80 μm 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 The structural feature is that the film has a thickness of 500 nm or more.

[0009] Furthermore, in order to achieve the above object, a method for producing a pearlescent pigment according to an embodiment of the present invention comprises the steps of: (a) forming a pearlescent pigment having a D of 40 to 80 μm; 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90(b) titrating a first soluble inorganic metal salt solution into the suspension of step (a), and then hydrolyzing the first soluble inorganic metal salt solution to coat the surfaces of the flakes with a first metal oxide layer; (c) titrating a soluble inorganic salt solution containing MgO·SiO2 into the suspension of step (b), and then hydrolyzing the soluble inorganic salt solution to coat the surfaces of the first metal oxide layer with an intermediate oxide layer; and (d) titrating a second soluble inorganic metal salt solution into the suspension of step (c), and then hydrolyzing the second soluble inorganic metal salt solution to coat the surfaces of the intermediate oxide layer with a second metal oxide layer. [Effects of the Invention]

[0010] The pearlescent pigment according to the present invention uses glass flakes having a limited size distribution as a substrate, and is formed by coating a multilayered metal oxide layer on the substrate, the multilayered metal oxide layer including a low refractive index material layer between high refractive index material layers, thereby realizing an improved sparkling effect along with properties such as high brightness, high gloss, and high saturation.

[0011] Furthermore, the pearlescent pigment of the present invention can realize a wide range of hue changes depending on the viewing angle by using glass flakes with a limited size distribution as a substrate. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an SEM photograph showing a cross section of a pearlescent pigment according to an embodiment of the present invention. [Figure 2] 1 is a graph showing the range of color difference values of pearlescent pigments according to examples of the present invention and comparative examples. [Figure 3] 1 is a graph showing the range of color difference values of pearlescent pigments according to examples of the present invention and comparative examples. [Figure 4]1 is a graph showing the range of color difference values of pearlescent pigments according to examples of the present invention and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0013] The advantages and features of the present invention and the manner in which they are achieved will become apparent from the detailed description of the embodiments and drawings which follow.

[0014] However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. However, these embodiments are provided to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

[0015] The pearlescent pigment with improved sparkling effect and the method for producing the same according to the embodiments of the present invention will be described in detail below.

[0016] [Pearlescent pigments] FIG. 1 is an SEM photograph showing a cross section of a pearlescent pigment according to an embodiment of the present invention.

[0017] Referring to FIG. 1, a pearlescent pigment 100 according to an embodiment of the present invention is characterized by including a glass flake substrate 110, a first metal oxide layer 120 on the substrate 110, an intermediate oxide layer 130 formed of MgO·SiO2 on the first metal oxide layer 120, and a second metal oxide layer 140 on the intermediate oxide layer 130.

[0018] The pearlescent pigment of the present invention uses a glass flake substrate, and in particular, the glass flake substrate has a D of 40 to 80 μm. 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 value and has a thickness of 500 nm or more.

[0019] where D 10 , D 50 , D90 means the average particle diameter in the 10% region, the average particle diameter in the 50% region (i.e., the overall average particle diameter), and the average particle diameter in the 90% region, respectively.

[0020] Conventionally, pearlescent pigments have used multiple platelet-shaped substrates, such as glass flakes and synthetic mica. However, although conventional platelet-shaped substrates have been able to realize consistent color intensity, users have lacked research and understanding regarding the characteristics, size, and thickness of the substrates. Therefore, conventional pigments using platelet-shaped substrates have had problems such as a lack of sparkling effect and a narrow range of hue change depending on the viewing angle.

[0021] The present invention is a method for manufacturing a semiconductor device having a D of 40 to 80 μm. 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 It has been confirmed that by using a glass flake substrate having a thickness of 500 nm or more, the pearlescent pigment can have an improved sparkling effect.

[0022] The glass flake substrate of the present invention has a D of 40 to 80 μm. 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 As a result, the pigment of the present invention has high color strength and a sparkling effect, and can realize various hues depending on the viewing angle.

[0023] Furthermore, the glass flake substrate of the present invention has the above-mentioned size distribution and a thickness of 500 nm or more. This allows the pigment of the present invention to have high color intensity and a sparkling effect, and to realize various hues depending on the viewing angle. Preferably, the glass flake substrate of the present invention has a thickness of 1 to 6 μm.

[0024] The glass flake substrate of the present invention can be any flake substrate of glass components, and preferably includes borosilicate or borosilicate doped with one or more of Ti, Zn, and Ca.

[0025] The pearlescent pigment 100 is formed by coating a first metal oxide layer 120, an intermediate oxide layer 130, and a second metal oxide layer 140 on the substrate 110.

[0026] Here, the first and second metal oxide layers 120 and 140 refer to metal oxide layers having a higher refractive index than the intermediate oxide layer 130 formed of MgO·SiO2, and may preferably be formed of oxide layers containing TiO2 and Fe2O3 as main components.

[0027] The intermediate oxide layer 130 is formed from a metal oxide having a refractive index (n) of 1.8 or less, and in the present invention, can be formed using a metal oxide containing MgO.SiO2.

[0028] As a result, in the pearlescent pigment 100, metal oxide layers with high refractive index / low refractive index / high refractive index are formed on the surface of the platelet-shaped substrate 110. Preferably, (TiO2 or Fe2O3) / (MgO SiO2) / (TiO2 or Fe2O3) may be coated on the substrate.

[0029] On the other hand, the first and second metal oxide layers 120, 140 and the intermediate oxide layer 130 are preferably coated to a thickness of 20 nm to 500 nm, respectively.

[0030] More specifically, the thickness of the first and second metal oxide layers 120, 140 is preferably 30 nm to 130 nm, and the thickness of the intermediate oxide layer 130 is preferably 120 to 300 nm.

[0031] The visually recognized hue of the pearlescent pigment 100 varies depending on the sum of the thicknesses of the first and second metal oxide layers 120 and 140 and the intermediate oxide layer 130 and the thickness ratio of these layers. However, if the thickness is outside the above range, it is difficult to realize the desired hue.

[0032] The pearlescent pigment 100 according to the embodiment of the present invention can be advantageously used for various purposes such as coloring in various industrial fields where pearlescent pigments are used, for example, various paints, printing inks, floor mats for ondol, wallpaper, specialty paper, plastics, leather products, accessories, cosmetics, ceramics, artificial marble, etc., and has an improved sparkling effect along with a highly saturated hue.

[0033] [Manufacturing method of pearlescent pigments] The method for producing a pearlescent pigment according to the present invention comprises the steps of: (a) D of 40 to 80 μm 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 mixing a substrate containing glass flakes having a thickness of 500 nm or more into purified water (DI water), followed by stirring and dispersing to form a suspension; (b) titrating a first soluble inorganic metal salt solution into the suspension of step (a) and then hydrolyzing the first soluble inorganic metal salt solution to coat the surfaces of the flakes with a first metal oxide layer; (c) titrating a soluble inorganic salt solution containing MgO SiO2 into the suspension of step (b) and then hydrolyzing the soluble inorganic salt solution to form an intermediate oxide layer on the surface of the first metal oxide layer; and (d) titrating a second soluble inorganic metal salt solution into the suspension of step (c) and then hydrolyzing the second soluble inorganic metal salt solution so that a second metal oxide layer is coated on the surface of the intermediate oxide layer.

[0034] [Suspension formation] In the suspension formation step, glass flakes of a certain size used as a substrate are mixed with purified water (DI water), and then stirred and dispersed to form a suspension.

[0035] The characteristics of the glass flake substrate are as described above.

[0036] It is preferable that the substrate is mixed into the suspension so that the solid content of the substrate is 5 to 20% by weight.

[0037] If the solid content is less than 5 wt%, the subsequent oxidation layer formation reaction may not occur or may proceed insufficiently, and if the solid content is more than 20 wt%, the reaction efficiency may decrease.

[0038] Once the suspension is formed to produce the pigment, the temperature of the suspension is first raised to 60-90°C. The reason for heating the suspension in this manner is that if the temperature of the suspension is below 60°C, the coating state will be uneven and the size and shape of the coated material will be very irregular. If the temperature of the suspension exceeds 90°C, the coating reaction will occur vigorously, and a rough coating layer may be formed.

[0039] Here, as described above, if the state of the coating layer is unstable, the pigment will not have high saturation, so it is preferable to maintain the temperature range as described above. Furthermore, these temperature ranges can be similarly applied to all reactions forming the following first and second metal oxide layers and intermediate oxide layer.

[0040] [Formation of first metal oxide layer] After the steps of preparing the suspension and heating are completed, the next step is to titrate a first soluble inorganic metal salt solution into the suspension, and then hydrolyze the first soluble inorganic metal salt solution so that a first metal oxide layer is coated on the surface of the flakes.

[0041] In this case, the inorganic metal salt includes one or a mixture of one or more selected from SnCl4, TiCl4, TiOCl2, TiOSO4, FeCl3, FeSO4, SiCl4, ZrOCl2, Na2O·SiO2·5H2O, MnCl2, MgCl2, AlCl3, and CoCl2.

[0042] The first soluble inorganic metal salt solution in which the inorganic metal salt is dissolved is dropped dropwise into the suspension to allow hydrolysis to occur.

[0043] At this time, the pH value of the suspension should be 1 to 9. If the pH is less than 1, the first metal oxide layer is not coated properly, and if the pH is more than 9, the coating material is not uniform and has very irregular sizes and shapes. As a result, the coating state becomes very rough, and the pigment cannot have high saturation.

[0044] Furthermore, after the injection of the solution is completed, the suspension is refluxed for 10 to 30 minutes while maintaining the pH value constant.

[0045] At this time, the pH value is maintained constant so that the coverage of the first metal oxide layer formed on the surface of the substrate is 1 to 50%, and the refluxing process reduces the impact of the reaction pH and ensures that the material to be coated is sufficiently coated on the surface.

[0046] Therefore, if the reflux time is less than 10 minutes, sufficient coverage cannot be achieved and the substrate may be subjected to impact, causing cracks.If the reflux time exceeds 30 minutes, the substrate itself may crack due to agitation, or the coating layer may separate.

[0047] [Formation of intermediate oxide layer: MgO SiO2 layer] The temperature of the suspension containing the solid coated with the first metal oxide layer on the surface of the substrate through the above process is further increased to 60 to 90°C, which is the temperature range for forming an optimal coating layer as described above.

[0048] Next, a soluble inorganic salt solution containing MgO SiO2 is titrated into the heated suspension, and the soluble inorganic salt solution is then hydrolyzed so that MgO SiO2 is coated on the surface of the first metal oxide layer. In the present invention, a layer formed by coating MgO SiO2 alone or MgO SiO2 together with another oxide is referred to as an oxide layer.

[0049] In this case, the soluble inorganic salt solution is one or a mixture of one or more selected from water glass, MgCl2, silicate, AlCl3, KCl3, and boric acid.

[0050] The pH value of the suspension should be between 4 and 14. If the pH is less than 4, the oxide layer will not be coated properly, the coating material will be uneven, and the size and shape will be very irregular, preventing the pigment from having high saturation.

[0051] After the injection of the solution is completed, the suspension is refluxed for 30 to 60 minutes while maintaining the pH value constant.

[0052] In this case, it is preferable to adjust the pH value until the coverage of the oxide layer formed on the surface of the substrate is 1 to 30% in the case of a high saturation and high gloss pigment, and 30 to 90% in the case of a multi-hue pigment.

[0053] When multiple hues are used, the oxide layer coverage can be increased by up to three times over that of glossy pigments, but this can change the overall weight ratio of the oxide layer for pigments with high gloss and chroma characteristics versus pigments with multiple hues.

[0054] Pigments with high gloss and high saturation have optimal performance when the oxide layer is present in an amount of 5-10% by weight based on the total weight of the pigment in its entirety. In other words, when the oxide layer is present in an amount less than 5% by weight of the total weight of the pigment, the high gloss characteristics are reduced, and when the oxide layer is present in an amount greater than 10% by weight, the high saturation characteristics are reduced.

[0055] Furthermore, in the case of pigments with multiple hues, optimal performance is achieved when the oxide layer is present in a proportion of 5 to 35% by weight of the total weight of the pigment in its entirety. In other words, if the proportion of the oxide layer formed is less than 5% by weight of the total weight of the pigment, the pigment will only be displayed in a single color, and if the proportion of the oxide layer exceeds 35% by weight, the color change characteristics will be poor.

[0056] Therefore, although the preferred content of the oxide layer according to the present invention is 5 to 35% by weight, it is not limited to this range and may vary depending on the type of substrate, the material to be coated, and the thickness of the coating.

[0057] The oxide layer of the present invention formed as described above is mainly composed of MgO·SiO2, and may further contain one or a mixture of one or more selected from SiO2, MgO·Al2O3, K2O·SiO2, and Mg2SiO4.

[0058] These oxide layers act as low-refractive index layers in pigments, solving problems such as cracks that occur when only SiO2 is used as a low-refractive index layer. In addition, using an MgO·SiO2 oxide layer makes it easy to adjust the thickness of the low-refractive index layer, and it is easy to achieve the characteristics of high gloss, high saturation, and multiple hues.

[0059] [Formation of second metal oxide layer] In the present invention, a second metal oxide layer is coated on the intermediate oxide layer to protect the intermediate oxide layer and improve its properties such as high gloss, and the process is the same as the coating process of the first metal oxide.

[0060] Next, the suspension finally coated with the second metal oxide layer is filtered, washed with deionized water and dried, and the residue is calcined and screened to complete the production of the pearlescent pigment according to the present invention.

[0061] As described above, the pearlescent pigment of the present invention, which is coated with a multi-layer structure having a seven-layer structure, includes a low refractive index layer and a high refractive index layer formed on the top of a transparent substrate layer, and has the properties of high gloss, high saturation, and excellent multiple hues.

[0062] Furthermore, the present invention provides a method for manufacturing a semiconductor device having a D of 40 to 80 μm. 10 value, D of 160 to 250 μm 50 value, and D of 350 to 600 μm 90 By using a glass flake substrate having a value of 0.15 and a thickness of 500 nm or more, the pearlescent pigment can have an improved sparkling effect.

[0063] Below, we will discuss the sparkling effect along with the properties of high gloss, high chroma, and multiple hues through the use of the glass flake substrate and multi-layer structure.

[0064] [Example] The structure and operation of the present invention will be described in more detail below with reference to preferred embodiments of the present invention, which are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0065] The contents not described here will not be explained here because they can be fully inferred by those skilled in the art.

[0066] Example 1 D 10 65.334 μm, D 50 183.040 μm, D 90100 g of 1.2 μm thick borosilicate flakes having a size distribution of 412.243 μm were added to 1.5 L of demineralized water and stirred to form a slurry, which was then heated to 85° C. Upon reaching the temperature of 85° C., an HCl solution was added to adjust the pH of the slurry to 2.5.

[0067] The size distribution of the borosilicate flakes was measured using a particle size analyzer (Malvern Instrument's Master Sizer 2000), and the average thickness of the borosilicate flakes was measured by observation under an electron microscope.

[0068] Next, 100 g of SnCl solution (SnCl content 10.0 wt%) was weighed and titrated into the slurry at a constant rate over 1 hour while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the mixture was refluxed for 10 minutes.

[0069] Next, 120 g of TiCl solution (TiCl content 30.0 wt%) was weighed and titrated into the slurry at a constant rate over a period of 4 hours while maintaining the pH constant with 10-50% diluted NaOH solution. After titration, the slurry was refluxed for 10 minutes, and then adjusted to pH 6.0 with 10-30% diluted NaOH solution.

[0070] Next, 2200 g of MgO·SiO2 solution (MgO·SiO2 content 15.0 wt%) was weighed and titrated into the slurry at a constant rate over 10 hours while maintaining a constant pH of 6.0 with HCl solution. The pH of the slurry was adjusted to 2.5 by adding HCl solution, and the slurry was then stirred and refluxed for an additional 15 minutes.

[0071] Next, 200 g of SnCl solution (SnCl content 10.0 wt%) was weighed and titrated into the slurry at a constant rate over a period of 2 hours while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the mixture was refluxed for 10 minutes.

[0072] Next, 120 g of TiCl solution (TiCl content 30.0 wt%) was weighed and titrated into the slurry at a constant rate over 4 hours while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the slurry was refluxed for 10 minutes.

[0073] After refluxing, the final slurry was filtered and dehydrated, washed twice with demineralized water, and dried at 120°C for 10 hours to obtain a powdery residue, an intermediate product.

[0074] The final intermediate product (11 g) was calcined at 800° C. for 12 minutes to obtain a powder of Gold-Green Tone.

[0075] <Example 2> D 10 71.758 μm, D 50 193.732 μm, D 90 100 g of 1.3 μm thick borosilicate flakes with a size distribution of 429.438 μm were added to 1.5 L of demineralized water and stirred to form a slurry. The slurry was then heated to 85°C, and when the temperature reached 85°C, an HCl solution was added to adjust the pH of the slurry to 2.5.

[0076] The size distribution of the borosilicate flakes was measured using a particle size analyzer (Malvern Instrument's Master Sizer 2000), and the average thickness of the borosilicate flakes was measured by observation under an electron microscope.

[0077] Next, 100 g of SnCl solution (SnCl content 10.0 wt%) was weighed and titrated into the slurry at a constant rate over 1 hour while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the mixture was refluxed for 10 minutes.

[0078] Next, 120 g of TiCl solution (TiCl content 30.0 wt%) was weighed and titrated into the slurry at a constant rate over 4 hours while maintaining the pH constant with 10-50% diluted NaOH solution. After titration, the slurry was refluxed for 10 minutes, and then adjusted to pH 6.0 with 10-30% diluted NaOH solution.

[0079] Next, 1100 g of MgO·SiO2 solution (MgO·SiO2 content 15.0 wt%) was weighed and titrated into the slurry at a constant rate over 8 hours while maintaining a constant pH of 6.0 with HCl solution. After adjusting the pH of the slurry to 2.5 by adding HCl solution, the slurry was stirred and refluxed for an additional 15 minutes.

[0080] Next, 200 g of SnCl solution (SnCl content 10.0 wt%) was weighed and titrated into the slurry at a constant rate over a period of 2 hours while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the mixture was refluxed for 10 minutes.

[0081] Next, 120 g of TiCl solution (TiCl content 30.0 wt%) was weighed and titrated into the slurry at a constant rate over 4 hours while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the slurry was refluxed for 10 minutes.

[0082] After refluxing, the final slurry was filtered and dehydrated, washed twice with demineralized water, and dried at 120°C for 10 hours to obtain a powdery residue, an intermediate product.

[0083] The final intermediate product (11 g) was calcined at 800° C. for 12 minutes to obtain Red-Gold Tone powder.

[0084] Example 3 D 10 75.708 μm, D 50 177.288 μm, D 90100 g of 1.1 μm thick borosilicate flakes with a size distribution of 384.897 μm were added to 1.5 L of demineralized water and stirred to form a slurry. The slurry was then heated to 85°C, and when the temperature reached 85°C, an HCl solution was added to adjust the pH of the slurry to 2.5.

[0085] The size distribution of the borosilicate flakes was measured using a particle size analyzer (Malvern Instrument's Master Sizer 2000), and the average thickness of the borosilicate flakes was measured by observation under an electron microscope.

[0086] Next, 100 g of SnCl solution (SnCl content 10.0 wt%) was weighed and titrated into the slurry at a constant rate over 1 hour while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the mixture was refluxed for 10 minutes.

[0087] Next, 150 g of TiCl solution (TiCl content 30.0 wt%) was weighed and titrated into the slurry at a constant rate over 4 hours while maintaining the pH constant with 10-50% diluted NaOH solution. After titration, the slurry was refluxed for 10 minutes, and then adjusted to pH 6.0 with 10-30% diluted NaOH solution.

[0088] Next, 3000 g of MgO·SiO2 solution (MgO·SiO2 content 15.0 wt%) was weighed and titrated into the slurry at a constant rate over 15 hours while maintaining a constant pH of 6.0 with HCl solution. After adjusting the pH of the slurry to 2.5 by adding HCl solution, the slurry was stirred and refluxed for an additional 15 minutes.

[0089] Next, 200 g of SnCl solution (SnCl content 10.0 wt%) was weighed and titrated into the slurry at a constant rate over a period of 2 hours while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the mixture was refluxed for 10 minutes.

[0090] Next, 150 g of TiCl solution (TiCl content 30.0 wt%) was weighed and titrated into the slurry at a constant rate over 4 hours while maintaining the pH constant with a 10-50% NaOH dilution. After titration, the slurry was refluxed for 10 minutes.

[0091] After refluxing, the final slurry was filtered and dehydrated, washed twice with demineralized water, and dried at 120°C for 10 hours to obtain a powdery residue, an intermediate product.

[0092] The final intermediate product (11 g) was calcined at 800° C. for 12 minutes to obtain a powder of violet-orange tone.

[0093] [Comparative Examples 1 to 3] <Comparative Example 1> D 10 7.259 μm, D 50 18.366 μm, D 90 A pigment powder according to Comparative Example 1 was obtained in the same manner as in Example 1, except that 100 g of synthetic mica flakes having a size distribution of 36.876 μm and a thickness of 0.35 μm were used.

[0094] <Comparative Example 2> D 10 7.4759 μm, D 50 19.307 μm, D 90 A pigment powder according to Comparative Example 2 was obtained in the same manner as in Example 2, except that 100 g of synthetic mica flakes having a size distribution of 37.991 μm and a thickness of 0.37 μm were used.

[0095] <Comparative Example 3> D 10 10.672 μm, D 50 21.476 μm, D 90 A pigment powder according to Comparative Example 3 was obtained in the same manner as in Example 3, except that 100 g of synthetic mica flakes having a size distribution of 39.665 μm and a thickness of 0.39 μm were used.

[0096] [Evaluation of physical properties of examples and comparative examples] 1. Evaluation of gloss level The glossiness of the examples and comparative examples was evaluated as follows, and the results are shown in Tables 1 and 2 below.

[0097] The gloss was measured in two ways as follows.

[0098] 1) Clear coats containing the pigments of the Examples and Comparative Examples were prepared and sprayed, and the gloss values of the pigments of the Examples and Comparative Examples were evaluated. The evaluation results are shown in Table 1 below.

[0099] 2) NA clear coatings containing the pigments of the examples and comparative examples were prepared and applied to opacifying paper using the drawdown method, and the gloss values of the pigments of the examples and comparative examples were evaluated. The evaluation results are shown in Table 2 below.

[0100] [Table 1]

[0101] [Table 2]

[0102] As can be seen from the above results, the pigments according to the examples of the present invention have higher gloss values than the comparative examples, which can be understood as being due to the difference in substrate.

[0103] 2. Evaluation of sparkling effect In order to confirm the sparkling effect of the Examples and Comparative Examples, the Dsparkle value was measured, and the results are shown in Table 3 below.

[0104] The Dsparkle value was measured using a BYK-mac i 23mm.

[0105] The Dsparkle value of the pigment according to Example 1 is measured relative to the Dsparkle value of Comparative Example 1, which is 1; the Dsparkle value of the pigment according to Example 2 is measured relative to the Dsparkle value of Comparative Example 2, which is 1; and the Dsparkle value of the pigment according to Example 3 is measured relative to the Dsparkle value of Comparative Example 3, which is 1.

[0106] [Table 3]

[0107] As can be seen from the above results, the pigments according to the examples of the present invention have a significantly higher Dsparkle value than the comparative examples. This result can be understood to be due to the difference in substrate, and the higher Dsparkle value means that the examples have a better sparkling effect than the comparative examples.

[0108] 3.Evaluation of color difference value range The ranges of color difference values of Examples and Comparative Examples were evaluated, and the results are shown in the following Table 4. The results of the ranges of color difference values of Examples and Comparative Examples are also shown in graphs (see FIGS. 1 to 3).

[0109] The color difference values were measured using a BYK-mac i 23mm.

[0110] [Table 4]

[0111] The resulting range of color difference values indicates how many different colors the pigment can exhibit depending on the viewing angle.

[0112] 1 to 3, it can be seen that the range of color difference values of the pigments according to the Comparative Examples falls within the range of color difference values of the pigments according to the Examples. In other words, the pigments according to the Examples exhibit a wider range of colors than the pigments according to the Comparative Examples, and it can be seen that the pigments according to the Examples can express a wider variety of colors depending on the viewing angle than the pigments according to the Comparative Examples.

[0113] As can be seen from the above results, the pigments according to the examples of the present invention have a wider range of color difference values than the comparative examples. This result can be understood to be due to the difference in substrate, and the wider range of color difference values means that the examples can express various colors depending on the viewing angle.

[0114] Although the present invention has been described above with reference to the accompanying drawings, it should be understood that the present invention is not limited to the above-described embodiments and can be modified in various different forms, and that those skilled in the art will understand that the present invention can be embodied in other specific forms without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and are not limiting.

[0115] This invention was conceived through the technological development and commercialization research of metal oxide multilayer coating with flip-flop effect in the 2020 Chungcheongbuk-do and Chungbuk Science and Technology Innovation Institute's Technology Development Support Project in the field of materials, parts and equipment.

Claims

1. glass flake substrate; a first metal oxide layer coated on top of the substrate; MgO.SiO coated on top of the first metal oxide layer ２ an intermediate oxide layer comprising: a second metal oxide layer coated on top of the intermediate oxide layer; The glass flake substrate is D exceeding 40 μm and not exceeding 80 μm １０ D value, 160 μm or more and 250 μm or less ５０ value, and D of 350 μm or more and 600 μm or less ９０ value, having a thickness of 500 nm or more, and further comprising borosilicate or borosilicate doped with one or more of Ti, Zn, and Ca; the first metal oxide layer and the second metal oxide layer have a higher refractive index than the intermediate oxide layer; the intermediate oxide layer is coated directly on top of the first metal oxide layer; Pearlescent pigment.

2. The glass flake substrate is having a thickness of 1 to 6 μm; The pearlescent pigment of claim 1.

3. The intermediate oxide layer is SiO ２ , MgO·Al ２ O ３ , K. ２ O.SiO ２ , and Mg ２ SiO ４ Further comprising a mixture of one or more selected from the following: The pearlescent pigment of claim 1.

4. The pigment is It is used in at least one of paints, printing inks, ondol floor mats, wallpaper, special paper, plastics, leather products, accessories, cosmetics, ceramics, and artificial marble. The pearlescent pigment of claim 1.

5. (a) D exceeding 40 μm and not exceeding 80 μm １０ D value, 160 μm or more and 250 μm or less ５０ value, and D of 350 μm or more and 600 μm or less ９０ a glass flake substrate having a thickness of 500 nm or more, the glass flake substrate including borosilicate or borosilicate doped with one or more of Ti, Zn, and Ca, is mixed with purified water (DIwater), and then stirred and dispersed to form a suspension; (b) titrating a first soluble inorganic metal salt solution into the suspension of step (a) and then hydrolyzing the first soluble inorganic metal salt solution to coat the surfaces of the flakes with a first metal oxide layer; (c) Adding MgO.SiO to the suspension of step (b) ２ and then hydrolyzing the soluble inorganic salt solution to coat an intermediate oxide layer on the surface of the first metal oxide layer; and (d) titrating a second soluble inorganic metal salt solution into the suspension of step (c), and then hydrolyzing the second soluble inorganic metal salt solution so that a second metal oxide layer is coated on the surface of the intermediate oxide layer; the first metal oxide layer and the second metal oxide layer have a higher refractive index than the intermediate oxide layer; the intermediate oxide layer is coated directly on top of the first metal oxide layer; Method for producing pearlescent pigments.

6. The suspension in step (a) is The solid content is 5 to 20% by weight; The method for producing the pearlescent pigment according to claim 5 .

7. The suspension in steps (b) to (d) above is Maintaining the temperature at 60 to 90°C The method for producing the pearlescent pigment according to claim 5 .

8. The first soluble inorganic metal salt solution and the second soluble inorganic metal salt solution are SnCl ４ , TiCl ４ , TiOCl ２ , TiOSO ４ , FeCl ３ , FeSO ４ , SiCl ４ , ZrOCl ２ , Na ２ O.SiO ２ ・5H ２ O, MnCl ２ , MgCl ２ , AlCl ３ , and CoCl ２ Further comprising a mixture of one or more selected from the following: The method for producing the pearlescent pigment according to claim 5 .

9. The soluble inorganic salt solution comprises: Water glass, MgCl ２ , silicate, AlCl ３ , KCl ３ and boric acid, The method for producing the pearlescent pigment according to claim 5 .

10. The intermediate oxide layer is SiO ２ , MgO·Al ２ O ３ , K. ２ O.SiO ２ , and Mg ２ SiO ４ Further comprising a mixture of one or more selected from the following: The method for producing the pearlescent pigment according to claim 5 .

11. The intermediate oxide layer is The content is 5 to 35% by weight based on 100% by weight of the total gloss pigment composition. The method for producing the pearlescent pigment according to claim 5 .

12. The suspension in step (b) or step (d) is Adjust the pH value to 1-9, and reflux for 10-30 minutes after completing the titration of the solution; The method for producing the pearlescent pigment according to claim 5 .

13. The suspension in step (c) is Adjust the pH to 4-14, and after completing the titration of the solution, reflux for 30-60 minutes. The method for producing the pearlescent pigment according to claim 5 .

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