Novel brilliant purple-red inorganic pigment

Abstract

The invention belongs to the technical field of coloring of decorative products, and provides a novel purplish red inorganic pigment, the chemical general formula of the purplish red inorganic pigment is Mg1-xCoxB4O7, the value range of x is 0-1, and the purplish red inorganic pigment can show bright purple or purplish red in a medium and low temperature environment (lower than 800 DEG C) and has excellent coloring characteristics; the novel purple-red inorganic pigment is prepared from the magnesium borate cobalt-doped material Mg (1-x) CoxB4O7, is bright in color and high in tinting strength, and can meet the tinting requirements in different fields; meanwhile, by adjusting the doping amount (x value) of Co, purple or purplish red with different shades can be obtained, and the requirement for diversified colors is met.

Description

Technical Field

[0001] The invention belongs to the technical field of coloring decorative products, in particular to a novel purple-red inorganic pigment. Background Art

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

[0003] The existing research on purple-red inorganic pigments mainly focuses on manganese-containing compounds and cobalt-containing compounds; however, the valence state of Mn is volatile and difficult to exist stably, so the types and stability of manganese-containing purple-red pigments are limited; in contrast, Co 2+ As a purple-red pigment, the coloring ion is more stable, but its research is still relatively scarce, and there is huge room for research.

[0004] Therefore, those skilled in the art have proposed a novel purple-red inorganic pigment to solve the problems raised in the background art. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a new purple-red inorganic pigment and its preparation method, so as to solve the problem that the valence state of Mn element is changeable and difficult to exist stably in the prior art, so the types and stability of manganese-containing purple-red pigments are limited; in contrast, Co 2+ As a purple-red pigment, the coloring ions of purple-red pigments are more stable, but their research is still relatively scarce, and there is a huge research space.

[0006] A new type of purple-red inorganic pigment, the chemical formula of which is Mg 1-x Co x B4O7, wherein the value of x ranges from 0 to 1, and the purple pigment can show bright purple or purple-red in a medium to low temperature environment (below 800°C) and has excellent coloring properties.

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

[0008] A method for preparing a new purple-red inorganic pigment, which uses a solid-phase method to synthesize Mg 1-x Co xThe preparation method of B4O7 purple pigment is as follows:

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

[0010] S2, then putting the mixed raw materials into a crucible;

[0011] S3, placed in a muffle furnace, pre-fired at 620 ° C for 1 hour;

[0012] S4, after cooling to room temperature, grinding and mixing the pre-calcined powder again;

[0013] S5, placing it in the muffle furnace again and sintering it at 800 ° C 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 purple-red inorganic pigment can be used for coloring products such as enamel and plastic, and exhibits good application effect and stability.

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

[0017] 1. The present invention uses magnesium borate doped cobalt material Mg 1-x Co x A new type of purple-red inorganic pigment was prepared using B4O7, which has bright colors and strong tinting power and can meet the coloring needs of different fields.

[0018] 2. The present invention can obtain different shades of purple or purple-red by adjusting the doping amount of Co (x value), meeting the demand for diversified colors;

[0019] 3. The pigment of the present invention performs well in a medium-low temperature environment below 800°C and shows excellent stability;

[0020] 4. The pigment of the present invention can be used for coloring various products such as enamel, ceramics, plastics, etc., which expands the application range of purple pigments. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 2 The MgO obtained by different Co doping amounts in the present invention is 1-x Co xXRD patterns of B4O7 (x = 0, 10, 20, 30, 40, 50, 100);

[0023] Figure 3 The following are photographs showing pigments and organic glass with different Co doping amounts according to the present invention. DETAILED DESCRIPTION

[0024] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

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

[0026] like Figure 1 As shown, Figure 1 Shows Mg 1-x Co x Diffuse reflectance spectrum of B4O7 when used as a pigment; When it does not contain cobalt, pure phase MgB4O7 is white, and when cobalt ions are introduced for coloring, Co 2+ The characteristic absorption in the visible light range makes the powder appear bright purple.

[0027] Example: The present invention adopts solid phase method to synthesize Mg 1-x Co x B4O7 purple pigment, its experimental raw materials include: boric acid (H3BO3), magnesium carbonate (MgCO3), cobalt acetate tetrahydrate [(CH3COO)2Co·4H2O];

[0028] The specific operation of solid phase method for synthesizing pigments is as follows:

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

[0030] 2) Place in a crucible of suitable size;

[0031] 3) Pre-calculate in a muffle furnace at 620°C for 1 hour;

[0032] 4) After cooling to room temperature, the pre-calcined powder is ground and mixed again;

[0033] 5) Place in a muffle furnace and sinter at 800℃ for 2h;

[0034] 6) Wash the powder after grinding: wash with water 3 times + alcohol once.

[0035] Application Example 1: Adjust the doping amount of Co from 0 to 100%, specifically 10%, 20%, 30%, 40%, 50%, 100%, and synthesize it according to the solid phase method of the embodiment, and control the synthesis temperature at 600-900℃ to obtain Mg 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 with the increase of Co doping amount (x value), Mg 1-x Co x The crystal structure of B4O7 has changed accordingly, which reflects the effect 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 the integrity of the crystal structure can be evaluated;

[0038] In summary, Figure 2 The XRD patterns show that different Co doping amounts have an effect 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 the material, which is of great significance for further optimizing the preparation process and performance of the material;

[0039] The pigment doped with 10%, 20%, 30%, 40%, 50%, or 100% Co is mixed with AB glue to prepare organic glass. At the same time, 1 to 5 wt% of pigment is added and mixed with AB glue. The mixture is allowed to stand and solidify. After solidification, the coating is removed from the mold or peeled off to obtain colored organic glass or colored products, such as Figure 3 As shown by Figure 3 It can be seen that with the increase of cobalt content, the color of the pigment changes from purple-red to dark purple, and the color is bright;

[0040] The present invention presents magnesium borate doped cobalt material (Mg 1-x Co x B4O7, x=0~1) can be used as a purple pigment, which has bright color and strong tinting power.

[0041] In cobalt-based pigments, Co 2+ The crystal structure and its coordination have a strong influence on the coloring strength and hue of the pigment. 1-x Co x In B4O7, Co 2+ Located in the five-coordinate site, forming a tetrahedral structure, Co2+ The electron transition in the 3d orbit produces 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 purple and red bands, thus showing bright purple or purple-red. Its color is controlled by the Co content.

[0042] Application Example 2: Exploring the cobalt-doped magnesium borate material (Mg 1-x Co x B4O7, x = 0 ~ 1) in the coloring of enamel, plastic and other products;

[0043] 1) Materials and methods

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

[0045] ② Enamel, plastic and other substrates;

[0046] ③ Appropriate adhesives or additives (such as AB glue, resin, etc.) to combine the pigment with the substrate;

[0047] 2) Experimental methods:

[0048] ① Enamel coloring: Mix the synthesized purple colorant with the enamel glaze in a certain proportion, apply it evenly on the enamel substrate, and go through an appropriate sintering process to make the colorant and glaze firmly bonded and color developed;

[0049] ② Ceramic coloring: Mix the purple colorant with the ceramic glaze or body material, apply it to the ceramic substrate by grouting, pressing or spraying, and then burn it at high temperature to make the colorant and ceramic substrate blend into one and develop color;

[0050] ③Plastic coloring: Mix purple colorant with plastic resin in a certain proportion, and prepare colored plastic products through molding processes such as injection molding, extrusion or blow molding;

[0051] The above steps were used for multiple groups and the following experimental results were obtained:

[0052] 1) Enamel coloring:

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

[0054] ② By adjusting the doping amount of Co (x value), different shades of purple or purple-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 without obvious color differences or color spots;

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

[0058] From the above, we can see that magnesium borate doped cobalt material (Mg 1-x Co x B4O7 (x=0-1) is a new purple pigment that performs well in the coloring of products such as enamel, ceramics, and plastics. This pigment has bright colors and strong tinting power, and the color can be diversified by adjusting the Co doping level. At the same time, this pigment shows excellent stability in medium and low temperature environments, firmly bonding to the substrate and not easily falling off. Therefore, magnesium borate-doped cobalt purple pigment has broad application prospects in the field of coloring enamel, plastics and other products.

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

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

[0061] A method for preparing a purple perylene pigment according to the above ingredients comprises the following steps:

[0062] S101, first dissolving an inorganic base and an organic base in a polar halogenated aromatic hydrocarbon;

[0063] S102, heating to 80-120° C. with stirring, until the solid is completely dissolved, adding the above materials, then heating to 170-190° C., reacting for 8-14 hours, then stopping heating and naturally cooling to room temperature;

[0064] S103, then through a series of post-processing steps (such as filtration, washing, drying, etc.) to obtain a dark red solid;

[0065] S104, the prepared dark red solid is subjected to pigmentation processing by ball milling and adding ball milling material to obtain a final purple perylene pigment;

[0066] The steps for preparing organic glass using the above-mentioned preparation method of purple perylene pigment are as follows:

[0067] 1) Raw material preparation: Weigh the methyl methacrylate monomer and initiator separately and 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 still flows smoothly;

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

[0070] 4) Post-polymerization: The mold filled with the pre-polymer solution is placed in a water bath at a relatively low temperature to react for a period of time, and then placed in an oven and heated to a higher temperature to complete the final polymerization step;

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

[0072] The following table is obtained by comparing the performance of the embodiment and the comparative example by performing the composition and method operation:

[0073]

[0074]

[0075] From the above, it can be seen that by comparison, the embodiments of the present invention have 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 provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A new type of bright purple inorganic pigment, characterized by: The chemical formula of the purple-red inorganic pigment is Mg 1-x Co x B4O7, wherein the value of x ranges from 0 to 1, and the purple-red inorganic pigment can show bright purple or purple-red in medium and low temperature environments and has excellent coloring properties.

2. A novel purple-red inorganic pigment as claimed in claim 1, characterized in that: The color of the purple-red inorganic pigment is controlled by the content of Co. By adjusting the doping amount of Co, different colors ranging from purple-red to dark purple can be obtained.

3. A method for preparing a novel purple-red inorganic pigment as described in any one of claims 1-2, characterized in that: This method uses a solid phase method to synthesize Mg 1-x Co x B4O7 purple colorant, the preparation method thereof is as follows: S1. Weigh boric acid H3BO3, magnesium carbonate MgCO3 and cobalt acetate tetrahydrate (CH3COO)2Co·4H2O, and grind and mix them thoroughly; S2, then putting the mixed raw materials into a crucible; S3, placed in a muffle furnace, pre-burned at 400-650°C for 30-90 minutes; S4, after cooling to room temperature, grinding and mixing the pre-burned powder again; S5, placing in the muffle furnace again, and sintering at 600-900° C. 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.

4. The purple-red inorganic pigment prepared by the novel purple-red inorganic pigment preparation method according to claim 3, characterized in that: The purple colorant can be used for coloring enamel and plastic products, and exhibits good application effect and stability.

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