Dry powder type reflective blue pigment and preparation method thereof

Abstract

The invention provides a dry powder type reflective blue pigment and a preparation method thereof. The preparation method comprises the following steps: (1) adding an alkaline solution into an aqueous solution containing a reflex blue crude product filter cake to adjust the pH value to be greater than or equal to 12, stirring and heating, then adding an anionic auxiliary agent and a nonionic auxiliary agent, heating to a boiling state, and fully dissolving the reflex blue crude product filter cake to obtain a mixed solution; (2) under a stirring condition, adding an acidic solution into the mixed solution to adjust the pH value to be less than or equal to 2, and stirring for 15 minutes to completely separate out the reflective blue to obtain a suspension; and (3) adding an emulsifier into the turbid liquid, stirring for 30 minutes, cooling to 70 DEG C, filtering, washing with water to be neutral, and drying to obtain the dry powder type reflective blue pigment. According to the invention, the specific surfactant is added by stages, so that aggregation of pigment particles can be effectively prevented, and the dry powder type soft reflective blue pigment can be prepared by directly drying, so that the dry powder type soft reflective blue pigment is convenient to transport and has excellent dispersity and tinting strength in an application medium.

Description

Technical Field

[0001] The invention relates to the technical field of pigment synthesis, in particular to a dry powder type radiant blue pigment and a preparation method thereof. Background Art

[0002] With the development of modern industry, the requirements for pigment performance are getting higher and higher, especially in the printing, coating and plastic industries, the tinting strength, dispersibility and stability of pigments have become important indicators for measuring product quality. As an organic pigment with excellent performance, Radiant Blue is widely used due to its high tinting strength and bright color. However, in the traditional production process of Radiant Blue pigment, due to the extremely fine pigment particles and high surface energy, the pigment particles are easily agglomerated to form lumps during the drying process, thus losing the application performance of the pigment.

[0003] In order to solve this problem, manufacturers generally use the "water squeezing and phase exchange" method to transfer pigments to ink for use. Although this method can prevent pigment agglomeration to a certain extent, it has the following problems: 1) Since the water squeezing and phase exchange process takes a long time, the whole process consumes a lot of energy and cost, which is not conducive to environmental protection and sustainable development; 2) The kneading machine and three-roller machine are required in the pigment transfer process, and the purchase and maintenance costs of the equipment are high; 3) The transfer and dispersion process of the pigment involves multiple steps, the operation is complicated, the production efficiency is low, and the product quality is unstable. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a dry powder type radiant blue pigment and a preparation method thereof, which effectively prevents pigment particles from agglomerating by adding specific surfactants in stages, thereby solving the problems raised in the above background technology.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided a method for preparing a dry powder type luminous blue pigment, comprising the following steps:

[0009] (1) adding an alkaline solution to an aqueous solution containing a crude filter cake of radiant blue to adjust the pH to ≥ 12, stirring and heating, then adding anionic additives and nonionic additives, and heating to a boiling state to fully dissolve the crude filter cake of radiant blue to obtain a mixed solution;

[0010] (2) Under stirring conditions, an acidic solution is rapidly added to the mixed solution to adjust the pH to ≤ 2, and stirred for 15 minutes to allow all the radiolucent blue to precipitate to obtain a suspension;

[0011] (3) Add an emulsifier to the suspension, stir for 30 minutes, cool to 70° C., filter, wash with water until neutral, and dry to obtain a dry powder type radiant blue pigment.

[0012] The invention first disperses the pigment particles of the radiant blue crude filter cake in an alkaline environment to increase the negative charge on the surface of the pigment particles and the stability in water, then adds anionic additives and nonionic additives to reduce the interfacial tension between water and the pigment particles and promotes the dispersion of the pigment particles in water; then adds an acidic solution to precipitate the pigment particles, and the precipitation process can be carried out under stirring to ensure that fine pigment particles are uniformly formed; then adds an emulsifier to help the formed pigment particles form a stable dispersion system and prevent the particles from precipitating and aggregating; finally, dries to obtain soft brown radiant blue dry powder, and the pigment particles have a porous structure, which helps to improve the dispersibility and coloring power of the pigment particles in the application medium.

[0013] The alkaline solution in the present invention can be selected from sodium hydroxide or potassium hydroxide, and the acidic solution can be selected from sulfuric acid or hydrochloric acid.

[0014] Preferably, in step (1), the anionic auxiliary agent is selected from OS series auxiliary agents or T series penetrants;

[0015] The amount of the anionic auxiliary agent added is 0.5-5wt% of the crude filter cake of the radio-blue product.

[0016] Preferably, the polymerization degree of the OS series additives is 30-50.

[0017] Preferably, the anionic auxiliary agent is selected from at least one of alkylphenol ether sulfosuccinate sodium salt, sodium dodecylbenzene sulfonate, anionic polyacrylamide, and diisooctyl maleate sulfonate.

[0018] Preferably, in step (1), the nonionic additive is selected from OPE series additives or OP series additives;

[0019] The amount of the non-ionic auxiliary agent added is 0.5-5wt% of the crude filter cake of the radio-blue product.

[0020] Preferably, the nonionic auxiliary agent is selected from at least one of ethylene oxide-propylene oxide copolymer, fatty alcohol polyoxyethylene ether, polyglycerol ester polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester or polyether modified silane, polyethylene glycol or block copolyether.

[0021] Preferably, in step (3), the emulsifier is selected from FM series emulsifiers or EL series emulsifiers;

[0022] The amount of the emulsifier added is 0.5-5 wt % of the crude filter cake of the radio blue product.

[0023] Preferably, the emulsifier is selected from at least one of fatty acid monoglycerides, polysantols, polyoxyethylene fatty alcohol ethers, polyoxyethylene fatty acid esters, polyoxyethylene glycerides, polyoxyethylene polyethers or polyoxyethylene block copolymers.

[0024] Preferably, the drying temperature is 60-70°C.

[0025] According to a second aspect of the present invention, there is provided a dry powder type luminous blue pigment obtained according to the above preparation method, wherein the dry powder type luminous blue pigment has a porous structure.

[0026] (III) Beneficial effects

[0027] The present invention provides a dry powder type radiant blue pigment and a preparation method thereof. It has the following beneficial effects:

[0028] (1) The present invention provides a method for preparing a dry powder type radiant blue pigment. By adding a specific surfactant in stages, the aggregation of pigment particles can be effectively prevented, and a soft dry powder type radiant blue pigment can be directly prepared by drying, thereby simplifying the process, using simple equipment, and reducing the preparation cost.

[0029] (2) The present invention provides a dry powder type radiant blue pigment, which is directly prepared into pigment particles with a porous structure after being dried at 60-70°C. The pigment particles are not only convenient for transportation but also have excellent dispersibility and tinting power in the application medium. DETAILED DESCRIPTION

[0030] In order to better illustrate the content of the present invention, a detailed description is given below in conjunction with specific embodiments.

[0031] Example 1

[0032] Add 20 kg of the crude filter cake of radiant blue to 50 L of water, add a 30% sodium hydroxide solution to adjust the pH of the system to 12, stir and heat, then add 0.2 kg of alkylphenol ether sodium sulfosuccinate and 0.2 kg of fatty alcohol polyoxyethylene ether, heat to boiling state, and fully dissolve the crude filter cake of radiant blue to obtain a mixed solution; under the condition of intense stirring, quickly add a 60% sulfuric acid solution to the mixed solution to adjust the pH of the system to 2, continue stirring for 15 minutes, so that all the radiant blue is precipitated to obtain a suspension; then add 0.2 kg of fatty acid monoglyceride to the suspension, continue stirring for 30 minutes, cool to 70°C, filter, wash with water to neutrality, and dry at 60°C to obtain a soft brown dry powder type radiant blue product.

[0033] Example 2

[0034] 20 kg of the crude filter cake of radiant blue was added to 50 L of water, and a 30% sodium hydroxide solution was added to adjust the pH of the system to 13, and the mixture was stirred and heated, and then 0.1 kg of sodium dodecylbenzene sulfonate and 0.2 kg of alkylphenol polyoxyethylene ether were added, and the mixture was heated to a boiling state to fully dissolve the crude filter cake of radiant blue to obtain a mixed solution; under the condition of intense stirring, a 60% sulfuric acid solution was quickly added to the mixed solution to adjust the pH of the system to 2, and the mixture was stirred continuously for 15 minutes to precipitate all the radiant blue to obtain a suspension; and then 0.2 kg of polysantolide was added to the suspension, and the mixture was stirred continuously for 30 minutes, and then the mixture was cooled to 70° C., filtered, washed with water until neutral, and dried at 65° C. to obtain a soft brown dry powder type radiant blue product.

[0035] Example 3

[0036] 20 kg of the crude filter cake of radiant blue was added to 50 L of water, and a 30% sodium hydroxide solution was added to adjust the pH of the system to 13, and the mixture was stirred and heated, and then 0.4 kg of anionic polyacrylamide and 0.3 kg of fatty acid polyoxyethylene ester were added, and the mixture was heated to a boiling state to fully dissolve the crude filter cake of radiant blue to obtain a mixed solution; under the condition of intense stirring, a 60% sulfuric acid solution was quickly added to the mixed solution to adjust the pH of the system to 2, and the stirring was continued for 15 minutes to precipitate all the radiant blue to obtain a suspension; and then 0.4 kg of polyoxyethylene fatty alcohol ether was added to the suspension, and the mixture was stirred for 30 minutes, cooled to 70°C, filtered, washed with water until neutral, and dried at 65°C to obtain a soft brown dry powder type radiant blue product.

[0037] Comparative Example 1

[0038] The preparation method of this comparative example is the same as that of Example 1, except that the emulsifier fatty acid monoglyceride is not added. After filtering, washing with water to neutrality and drying, the obtained luminous blue is in block form.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a dry powder type radiant blue pigment, Features: The following steps are involved: (1) adding an alkaline solution to an aqueous solution containing a crude filter cake of radiant blue to adjust the pH to ≥ 12, stirring and heating, then adding anionic additives and nonionic additives, and heating to a boiling state to fully dissolve the crude filter cake of radiant blue to obtain a mixed solution; (2) Under stirring conditions, an acidic solution is rapidly added to the mixed solution to adjust the pH to ≤ 2, and stirred for 15 minutes to allow all the radiolucent blue to precipitate to obtain a suspension; (3) Add an emulsifier to the suspension, stir for 30 minutes, cool to 70° C., filter, wash with water until neutral, and dry to obtain a dry powder type radiant blue pigment.

2. A method for preparing a dry powder type radiant blue pigment according to claim 1, Features: In step (1), the anionic auxiliary agent is selected from OS series auxiliary agents or T series penetrants; The amount of the anionic auxiliary agent added is 0.5-5wt% of the crude filter cake of the radio-blue product.

3. A method for preparing a dry powder type radiant blue pigment according to claim 2, Features: The polymerization degree of the OS series additives is 30-50.

4. A method for preparing a dry powder type radiant blue pigment according to claim 1, Features: The anionic auxiliary agent is selected from at least one of alkylphenol ether sulfosuccinate sodium salt, sodium dodecylbenzene sulfonate, anionic polyacrylamide, and diisooctyl maleate sulfonate.

5. A method for preparing a dry powder type radiant blue pigment according to claim 1, Features: In step (1), the nonionic additive is selected from OPE series additives or OP series additives; The amount of the non-ionic auxiliary agent added is 0.5-5wt% of the crude filter cake of the radio-blue product.

6. A method for preparing a dry powder type radiant blue pigment according to claim 1, Features: The nonionic auxiliary agent is selected from at least one of ethylene oxide-propylene oxide copolymer, fatty alcohol polyoxyethylene ether, polyglycerol ester polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester or polyether modified silane, polyethylene glycol or block copolyether.

7. A method for preparing a dry powder type radiant blue pigment according to claim 1, Features: In step (3), the emulsifier is selected from FM series emulsifiers or EL series emulsifiers; The amount of the emulsifier added is 0.5-5 wt % of the crude filter cake of the radio blue product.

8. A method for preparing a dry powder type radiant blue pigment according to claim 1, Features: The emulsifier is selected from at least one of fatty acid monoglycerides, polysantols, polyoxyethylene fatty alcohol ethers, polyoxyethylene fatty acid esters, polyoxyethylene glycerides, polyoxyethylene polyethers or polyoxyethylene block copolymers.

9. The method for preparing a dry powder type radiant blue pigment according to claim 1, Features: The drying temperature is 60-70°C.

10. A dry powder type radiant blue pigment obtained according to the preparation method according to any one of claims 1 to 9, Features: The dry powder type radiant blue pigment has a porous structure.