A novel bright purple-red inorganic colorant

Abstract

The application belongs to the coloring technical field of decorative products, and provides a novel purple-red inorganic colorant. 1‑x Co x B4O7, wherein the value range of x is 0-1, and the purple-red inorganic colorant can exhibit bright purple or purple-red in a low-temperature environment (lower than 800 DEG C) and has excellent coloring characteristics; the application prepares a novel purple-red inorganic colorant through the magnesium borate doped with cobalt material Mg 1‑ x Co x B4O7, which is bright in color, strong in coloring power and capable of meeting coloring requirements in different fields; meanwhile, different shades of purple or purple-red can be obtained by adjusting the doping amount (x value) of Co, so that diversified color requirements are met.

Description

Technical Field

[0001] This invention belongs to the field of coloring technology for decorative products, specifically a novel purplish-red inorganic pigment. Background Technology

[0002] Inorganic pigments are widely used for coloring and protecting decorative products due to their good weather resistance, excellent hiding power, good solvent resistance, and strong high-temperature applicability. Purple and purplish-red inorganic pigments, as special hues, have unique color charm and market demand. However, the types of purplish-red inorganic pigments with strong coloring ability are relatively scarce in the market at present. This is mainly because the color realization mechanism of purplish-red pigments is different from that of common direct bandgap semiconductor pigments, and their bright purple or purplish-red hues cannot be achieved simply through light absorption.

[0003] Current research on purplish-red inorganic pigments mainly focuses on manganese-containing and cobalt-containing compounds; however, the valence state of Mn is easily variable and difficult to maintain stability, thus limiting the variety and stability of manganese-containing purplish-red pigments; in contrast, Co... 2+ The coloring ions used as purplish-red pigments are more stable, but research on them is still relatively scarce, leaving a huge room for further research.

[0004] To address this issue, those skilled in the art have proposed a novel purplish-red inorganic pigment to solve the problems raised in the background section. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a novel purplish-red inorganic pigment and its preparation method. This solves the problem that in existing technologies, the valence state of Mn is easily variable and difficult to stabilize, thus limiting the types and stability of manganese-containing purplish-red pigments. In contrast, Co... 2+ As a purplish-red pigment, the coloring ions of purplish-red pigments are more stable, but research on them is still relatively scarce, and there are still huge research gaps.

[0006] A novel purplish-red inorganic pigment, wherein the general chemical formula of the purplish-red inorganic pigment is Mg 1-x Co x B4O7, where x ranges from 0 to 1, and this purple pigment can exhibit a bright purple or purplish-red color in medium and low temperature environments (below 800℃) and has excellent coloring properties.

[0007] Preferably, the color of the purplish-red inorganic pigment is controlled by the content of Co. By adjusting the amount of Co doping (x value), different colors ranging from purplish-red to dark purple can be obtained.

[0008] A novel method for preparing a purplish-red inorganic pigment, which employs a solid-state synthesis method to synthesize Mg 1-x Co xThe specific preparation method of B4O7 purple pigment is as follows:

[0009] S1. Weigh out boric acid (H3BO3), magnesium carbonate (MgCO3), and cobalt acetate tetrahydrate (CH3COO)2Co·4H2O, and grind and mix them thoroughly.

[0010] S2. Next, the mixed raw materials are loaded into the crucible;

[0011] S3. Place in a muffle furnace and preheat at 620°C for 1 hour;

[0012] S4. After cooling to room temperature, grind and mix the pre-calcined powder again.

[0013] S5. Place it back in the muffle furnace and sinter at 800℃ for 2 hours;

[0014] S6. Grind the sintered powder and wash it with water three times and with alcohol once in sequence to obtain the final product.

[0015] Preferably, the purplish-red inorganic pigment can be used for coloring enamel, plastic and other products, showing good application effect and stability.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This invention utilizes cobalt-doped magnesium borate material Mg 1-x Co x A novel purplish-red inorganic pigment was prepared using B4O7. It has a bright color and strong tinting strength, which can meet the coloring needs of different fields.

[0018] 2. By adjusting the amount of Co doping (x value), this invention can obtain different shades of purple or purplish-red, satisfying the demand for diverse colors;

[0019] 3. The pigment of the present invention exhibits excellent performance and stability in medium and low temperature environments below 800°C.

[0020] 4. The colorant of the present invention can be applied to the coloring of various products such as enamel, ceramics, and plastics, thus expanding the application range of purple colorant. Attached Figure Description

[0021] Figure 1 The Mg of the present invention 1-x Co x Diffuse reflectance spectrum of B4O7 when used as a colorant;

[0022] Figure 2 To obtain Mg with different Co doping amounts according to the present invention 1-x Co xXRD patterns of B4O7 (x = 0, 10, 20, 30, 40, 50, 100);

[0023] Figure 3 The images show the colorants with different Co doping levels and acrylic glass according to the present invention. Detailed Implementation

[0024] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0025] This invention provides a cobalt-doped magnesium borate purple pigment with the chemical formula Mg. 1-x Co x B4O7, x = 0~1, is a new type of purple pigment that can be used in medium and low temperature environments below 800℃; it has excellent coloring properties.

[0026] like Figure 1 As shown, Figure 1 Mg was shown 1-x Co x The diffuse reflectance spectrum of MgB4O7 when used as a colorant; pure phase MgB4O7 is white without cobalt; cobalt ions are introduced for coloring, Co... 2+ The characteristic absorption produced in the visible light range gives the powder a bright purple color.

[0027] Example: This invention uses a solid-state method to synthesize Mg. 1-x Co x The experimental raw materials for B4O7 purple pigment include: boric acid (H3BO3), magnesium carbonate (MgCO3), and cobalt acetate tetrahydrate [(CH3COO)2Co·4H2O];

[0028] The specific steps for synthesizing pigments using the solid-state method are as follows:

[0029] 1) Weigh out H3BO3, MgCO3 and (CH3COO)2Co·4H2O, and grind and mix them thoroughly;

[0030] 2) Place the contents into a crucible of appropriate size;

[0031] 3) Preheat in a muffle furnace at 620℃ for 1 hour;

[0032] 4) After cooling to room temperature, grind and mix the pre-calcined powder again;

[0033] 5) Sinter in a muffle furnace at 800℃ for 2 hours;

[0034] 6) Grind the powder and then wash it: wash it with water 3 times + wash it with alcohol once.

[0035] Application Example 1: Adjusting the Co doping amount from 0% to 100%, specifically 10%, 20%, 30%, 40%, 50%, and 100%, and synthesizing using the solid-state method described in the previous example, with the synthesis temperature controlled at 600-900℃, Mg was obtained. 1-x Co x The XRD values ​​of B4O7 (x=0,10,20,30,40,50,100) are as follows: Figure 2 As shown, by Figure 2 get:

[0036] 1) Through XRD patterns, it can be observed that as the Co doping amount (x value) increases, Mg... 1-x Co x The crystal structure of B4O7 has undergone corresponding changes, which reflect the influence of different Co contents on the crystal structure of the material.

[0037] 2) Each diffraction peak in the spectrum corresponds to a different crystal phase and crystal plane; by observing the intensity, position and shape of the diffraction peaks, the purity of the prepared material and whether the crystal structure is complete can be evaluated.

[0038] In conclusion, Figure 2 XRD patterns were used to illustrate the effect of different Co doping levels on Mg. 1-x Co x The influence of the crystal structure of B4O7 purple pigment provides an important basis for understanding the structural characteristics of this material, which is of great significance for further optimizing the preparation process and performance of the material.

[0039] Acrylic glass is prepared by mixing pigments with Co doping levels of 10%, 20%, 30%, 40%, 50%, and 100% with AB adhesive. Simultaneously, 1–5 wt% of pigment is added and mixed with AB adhesive, then allowed to solidify. After curing, the coating is removed from the mold or peeled off to obtain colored acrylic glass or colored products. Figure 3 As shown, by Figure 3 As the cobalt content increases, the color of the pigment changes from purplish-red to deep purple, resulting in a more vibrant color.

[0040] This invention presents a magnesium borate-cobalt-doped material (Mg 1-x Co x B4O7 (x = 0 to 1) has the potential to be used as a purple pigment, which has a bright color and strong tinting strength.

[0041] In cobalt-based colorants, Co 2+ The crystal structure and coordination of the pigment have a strong influence on the coloring intensity and hue of the pigment. This invention relates to Mg... 1-x Co x In B4O7, Co 2+ Located at the five coordination sites, forming a square pyramid, Co2+ Electron transitions in the 3d orbitals produce selective absorption of visible light. The absorption bands are mainly located in the orange, yellow, and green light regions. It can reflect most of the visible light in the violet and red bands, thus displaying a bright purple or purplish-red color. Its color is controlled by the Co content.

[0042] Application Example 2: Investigating Cobalt-Doped Magnesium Borate Materials (Mg 1-x Co x B4O7 (x = 0~1) is used for coloring enamel, plastic and other products;

[0043] 1) Experimental materials and methods:

[0044] ① Magnesium borate doped with cobalt purple pigment (Mg 1-x Co x B4O7 (x = 0~1) was synthesized by a solid-state method, and the specific steps are as described in the examples.

[0045] ②Enamel, plastic and other substrates;

[0046] ③ Appropriate adhesives or additives (such as AB glue, resin, etc.) are used to bond the colorant to the substrate;

[0047] 2) Experimental methods:

[0048] ① Enamel coloring: The synthetic purple pigment is mixed with enamel glaze in a certain proportion and evenly coated on the enamel substrate. After appropriate sintering process, the pigment and glaze are firmly bonded and the color is displayed.

[0049] ② Ceramic coloring: The purple pigment is mixed with ceramic glaze or body material and applied to the ceramic substrate by means of slurry casting, pressing or spraying. After high-temperature firing, the pigment and ceramic substrate are integrated and the color is revealed.

[0050] ③ Plastic coloring: Purple pigment is mixed with plastic resin in a certain proportion, and colored plastic products are prepared through molding processes such as injection molding, extrusion or blow molding.

[0051] By using the above steps in multiple groups, the following experimental results were obtained:

[0052] 1) Enamel coloring:

[0053] ① The surface of enamel products is bright purple or purplish-red, with uniform color, high gloss, and good weather resistance and corrosion resistance;

[0054] ② By adjusting the amount of Co doping (x value), different shades of purple or purplish-red can be obtained to meet diverse decorative needs;

[0055] 3) Plastic coloring:

[0056] ① After molding, the plastic products have bright and uniform colors, with no obvious color difference or spots;

[0057] ② The colorant has good compatibility with the plastic resin and does not affect the mechanical properties and processing performance of the plastic.

[0058] As can be seen from the above, magnesium borate doped with cobalt (Mg 1-x Co x Cobalt-doped magnesium borate (B4O7, x = 0-1) is a novel purple pigment that performs exceptionally well in coloring enamel, ceramics, and plastics. This pigment boasts vibrant colors, strong tinting strength, and the ability to diversify colors by adjusting the amount of Co doping. Furthermore, it exhibits excellent stability at medium and low temperatures, bonding firmly to the substrate and resisting detachment. Therefore, cobalt-doped magnesium borate purple pigment has broad application prospects in the coloring of enamel and plastics.

[0059] Comparative example: The current composition and preparation method of purple pigment are as follows:

[0060] Purple pigment components: cobalt purple (a compound of the metallic element cobalt), manganese purple (a compound of manganese), and ultramarine purple (made by heating ultramarine blue pigment with ammonium chloride);

[0061] A method for preparing a purple perylene pigment according to the above-mentioned components includes the following steps:

[0062] S101. First, dissolve the inorganic base and organic base in the polar haloaromatic hydrocarbon;

[0063] S102. Heat to 80-120°C with stirring. After the solid is completely dissolved, add the above material, then raise the temperature to 170-190°C and react for 8-14 hours. Then stop heating and let it cool naturally to room temperature.

[0064] S103, and then after a series of post-processing steps (such as filtration, washing, drying, etc.), a dark red solid is obtained;

[0065] S104. The prepared dark red solid was processed into a pigment by adding ball milling material through ball milling to obtain the final purple perylene pigment.

[0066] The preparation steps for plexiglass using the above-mentioned method for preparing purple perylene pigments are as follows:

[0067] 1) Raw material preparation: Weigh the methyl methacrylate monomer and the initiator separately and then mix them;

[0068] 2) Prepolymerization: Place the mixture of monomer and initiator in a reaction vessel, heat it in a water bath and stir continuously until the viscosity of the system increases but it can still flow smoothly;

[0069] 3) Casting and pouring: Carefully pour the prepolymer liquid into the pre-prepared mold;

[0070] 4) Post-polymerization: Place the mold filled with prepolymer liquid in a water bath at a low temperature for a period of time, and then put it in an oven to heat to a higher temperature to complete the final polymerization step;

[0071] 5) Removal and post-processing: Remove the polymerized acrylic glass and perform necessary post-processing such as cutting and polishing.

[0072] The performance of the examples and comparative examples was compared by means of components and methods, as shown in the table below:

[0073]

[0074]

[0075] As can be seen from the above, the embodiments of the present invention exhibit certain advantages in terms of composition, application effect, color adjustability, stability and scalability. At the same time, the preparation method of the present invention is relatively simple, low in cost, and suitable for large-scale production.

[0076] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a purplish-red inorganic pigment, wherein the method employs a solid-state synthesis of Mg 1-x Co x B4O7 is a purplish-red pigment, where the value of x ranges from 0 to 1. Its preparation method is as follows; S1. Weigh out boric acid (H3BO3), magnesium carbonate (MgCO3), and cobalt acetate tetrahydrate (CH3COO)2Co·4H2O, and grind and mix them thoroughly. S2. Next, the mixed raw materials are loaded into the crucible; S3. Place in a muffle furnace and preheat at 400-650℃ for 30-90 minutes; S4. After cooling to room temperature, grind and mix the pre-calcined powder again. S5. Place it back in the muffle furnace and sinter at 600-900℃ for 1-4 hours; S6. Grind the sintered powder and wash it with water 2 to 4 times and with alcohol once to obtain the final product.

2. An application of a purplish-red inorganic pigment prepared by the method described in claim 1, characterized in that: The purplish-red inorganic pigment is used for coloring enamel and plastic products.

Images