Preparation method and application of pigment red P.R170 with high covering power

Abstract

The invention discloses a preparation method and application of pigment red P.R170 with high covering power, and relates to the technical field of organic pigments, the preparation method comprises the following steps: S1, preparing a diazo component; s2, low-temperature preparation of a coupling component; step S3, coupling reaction; and step S4, pigmentation treatment. According to the preparation method of the high-covering-power pigment red P.R170, a coupling component is prepared under a low-temperature condition by optimizing a process, so that the prepared high-covering-power pigment red P.R170 is high in covering power and tinting strength and excellent in weather resistance, and can be widely applied to the fields of coatings, printing ink, plastics and rubber.

Description

Technical Field

[0001] The present invention relates to the technical field of organic pigments, and particularly relates to a preparation method and application of pigment red P.R170 with high hiding power. Background Art

[0002] Organic pigments have the advantages of bright color, high coloring strength, a wide variety of chromatographic varieties, and low toxicity, and are currently widely used in coatings, inks, plastics, and rubbers. However, most organic pigments on the market have disadvantages such as low lightfastness, poor heat resistance, and poor weather resistance. Pigment red P.R170 is an important high-performance pigment and has a very important position in the fields of high-end industrial coatings and automotive coatings due to its excellent light resistance, heat resistance, and solvent resistance.

[0003] Traditional pigment red P.R170 has some limitations in practical applications. The most prominent problem is insufficient hiding power. Hiding power is one of the important performance indicators of pigments and directly affects the covering effect and use cost of pigments on substrates. Insufficient hiding power will cause the coating to be applied multiple times to achieve the ideal covering effect, which not only increases the production cost but also reduces the production efficiency. In addition, insufficient hiding power will also affect the uniformity and appearance quality of the coating, especially on dark substrates.

[0004] The preparation of existing pigment red P.R170 usually uses diazo component DB-70 and coupling component naphthol AS-PH as raw materials. The coupling component naphthol AS-PH is a water-insoluble substance and must be in a dissolved state to effectively participate in chemical reactions. Currently, the widely used synthesis processes of pigment red P.R170 at home and abroad dissolve naphthol AS-PH in an alkaline medium at high temperature (about 85°C). Under this condition, the hydroxyl group (-OH) on the molecular structure of naphthol AS-PH forms a water-soluble sodium hydroxyl group (-ONa) and is dispersed in the aqueous system in a molecular state to carry out a coupling reaction. However, naphthol AS-PH is formed by the condensation of 2-hydroxy-3-naphthoic acid and ethoxynaphthylamine and is connected by an amide group. Under high temperature and alkaline conditions, while naphthol AS-PH is dissolved, the amide group on its molecular structure will hydrolyze to form ethoxyaniline and 2-hydroxy-3-naphthoic acid, resulting in poor quality of the pigment red P.R170 prepared by this synthesis process, and its stability, weather resistance, and hiding power need to be further improved. In addition, this synthesis process also has the defect of relatively high consumption of public works energy.

[0005] For example, a Chinese invention patent with the authorization announcement number CN106046844B discloses a production method of an environment-friendly organic pigment red 170, which includes the following steps: 1. Add water, hydrochloric acid, acetic acid and p-aminobenzamide into a diazotization tank, dissolve at room temperature; 2. Blow ice into the diazotization tank to cool down, add sodium nitrite for diazotization to obtain a diazo solution; 3. Add water, liquid alkali, ethanol, naphthol AS-PH and naphthol AS-OL into a material dissolving tank in sequence, heat up to 80 °C to obtain a coupling solution; 4. Add ice water and emulsifier OP-10 into a coupling tank, put the diazo solution into the coupling tank; 5. Add diisopropylbenzene peroxide, triethanolamine oleate, titanium dioxide, and ethanol, and heat up, then wash with water, filter by suction, and dry. The organic pigment red 170 produced by this invention method does not use aromatic amines prohibited by the EU REACH regulation as intermediates for synthesizing organic pigments, the raw material supply is sufficient, it has the advantage of low cost, and reduces the discharge of three wastes. However, naphthol AS-PH is prone to hydrolysis in an alkaline solution at 80 °C, resulting in poor product quality and insufficient hiding power; moreover, the public works energy consumption of this production method is relatively large, which is not conducive to energy conservation and emission reduction.

[0006] It can be seen that developing a preparation method and application of pigment red P.R170 with excellent hiding power, coloring power and weather resistance meet the market demand, have broad market value and social value, and are of great significance for promoting the development of the high hiding power organic pigment field. Summary of the Invention

[0007] The purpose of the present invention is to provide a preparation method and application of pigment red P.R170 with high hiding power to overcome the deficiencies of the prior art; this method not only improves the application performance of the pigment itself but also greatly reduces the preparation cost and energy consumption, and has significant economic and social benefits; the pigment red P.R170 prepared by this method has high hiding power and coloring power and excellent weather resistance.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is: A preparation method of pigment red P.R170 with high hiding power, which includes the following steps:

[0009] Step S1, preparation of diazo component: Add water, p-aminobenzamide and hydrochloric acid into a diazotization kettle in sequence, stir until completely dissolved and clear, cool down to 0-5 °C with ice, add sodium nitrite for diazotization reaction, after the reaction is completed, dropwise add an aqueous solution of sulfamic acid or an aqueous solution of urea until the starch-iodide test paper does not show color, to obtain a diazo component solution;

[0010] Step S2, Preparation of the coupling component: Add water, Turkey red oil, EDTA and other additives into the dissolution tank in sequence, heat up to 35 - 38 °C, add Naphthol AS - PH, stir for 18 - 25 min, then add the lye, continue to stir for 20 - 30 min, after ultrasonic treatment and magnetic field treatment, obtain the coupling component liquid;

[0011] Step S3, Coupling reaction: Put the diazo component solution into the coupling reaction kettle, add non - ionic surfactant while stirring, then dropwise add the coupling component liquid thereto, the dropping time is 20 - 30 min, after the dropping is completed, continue to stir and react for 50 - 70 min to obtain the coupling product;

[0012] Step S4, Pigmentation treatment: Add sulfuric acid to the coupling product to adjust the pH to 6.5 - 7.5, then heat up to 70 - 90 °C, keep warm for 1 - 2 h, then cool to below 40 °C, filter, wash with water until neutral, dry, and pulverize to obtain the high - hiding - power pigment red P.R170.

[0013] Preferably, the mass ratio of the water, p - aminobenzamide, hydrochloric acid, and sodium nitrite in step S1 is 500:35:69:18.2.

[0014] Preferably, the mass percentage concentration of the hydrochloric acid in step S1 is 30% - 31.5%.

[0015] Preferably, the time of the diazotization reaction in step S1 is 1 - 2 h.

[0016] Preferably, the mass percentage concentration of the aqueous solution of sulfamic acid in step S1 is 10% - 15%; the mass percentage concentration of the aqueous solution of urea is 10 - 20%.

[0017] Preferably, the mass ratio of the water, Turkey red oil, EDTA, other additives, Naphthol AS - PH, and lye in step S2 is 800:30:3:(2 - 4):79:770.

[0018] Preferably, the other additives in step S2 include the following components by weight: 4 - 6 parts of 3 - tris(hydroxymethyl)methylamine - 2 - hydroxypropanesulfonate, 2 - 4 parts of 3 - (N - morpholino)-2 - hydroxypropanesulfonate, and 1 - 3 parts of pyridinium hydroxypropylsulfonate.

[0019] Preferably, the mass percentage concentration of the lye in step S2 is 25% - 35%.

[0020] Preferably, the lye in step S2 is at least one of sodium hydroxide aqueous solution, pyridine aqueous solution, and ethylenediamine aqueous solution.

[0021] Preferably, in step S2, the ultrasonic frequency of the ultrasonic treatment is 50 - 100 kHz, the power is 300 - 500 W, and the treatment time is 3 - 6 min; the magnetic field strength of the magnetic field treatment is 5000 - 12000 Gs, and the treatment time is 3 - 5 min.

[0022] Preferably, in step S3, the mass ratio of the non-ionic surfactant to naphthol AS-PH in the diazo component solution is 79:50.

[0023] Preferably, in step S3, the non-ionic surfactant is fatty alcohol polyoxyethylene ether AEO-9.

[0024] Preferably, in step S3, the mass percentage concentration of sulfuric acid is 5% - 8%.

[0025] Another object of the present invention is to provide an application of the high hiding power pigment red P.R170 in the fields of coatings, inks, plastics, and rubbers.

[0026] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0027] (1) The preparation method of the high hiding power pigment red P.R170 disclosed by the present invention has a simple preparation process, convenient operation control, high preparation efficiency and finished product qualification rate, low dependence on equipment, is suitable for continuous large-scale production, and has high popularization and application value.

[0028] (2) The preparation method of the high hiding power pigment red P.R170 disclosed by the present invention can completely dissolve naphthol AS-PH under the synergistic solubilization action of Turkey red oil, EDTA and other additives at a relatively low temperature (35°C - 38°C), which greatly reduces the degree of hydrolysis of naphthol AS-PH during the dissolution process, thereby synthesizing a pigment red P.R170 with high quality, good stability, strong weather resistance, high hiding power and low manufacturing cost; the energy consumption of the public works in the preparation process is low, which is beneficial to energy conservation and emission reduction.

[0029] (3) The preparation method of high hiding power pigment red P.R170 disclosed by the present invention, wherein the other additives include the following components by weight: 4-6 parts of 3-tris(hydroxymethyl)methylamine-2-hydroxypropanesulfonate sodium, 2-4 parts of 3-(N-morpholino)-2-hydroxypropanesulfonate sodium, 1-3 parts of pyridinium hydroxypropanesulfonate; the alkali solution is at least one of sodium hydroxide aqueous solution, pyridine aqueous solution, and ethylenediamine aqueous solution. Through the reasonable selection of the specific composition of the other additives and the alkali solution, especially the first introduction of the zwitterionic salt pyridinium hydroxypropanesulfonate, the organic alkali solution, and the energy field treatment, the low-temperature dissolution of the coupling component naphthol AS-PH can be effectively improved, avoiding hydrolysis while dissolving under high-temperature alkali conditions, increasing the rate of the coupling reaction, and further improving the quality of pigment red P.R170, making its hiding power sufficient, coloring power, and weather resistance excellent.

[0030] (4) The preparation method of high hiding power pigment red P.R170 disclosed by the present invention, through the combination of process optimization and pigmentation treatment, significantly improves the hiding power and comprehensive performance of pigment red P.R170, solves the problem of insufficient hiding power of pigment red P.R170 prepared by traditional processes, and expands its application range; using water as the main solvent reduces the use of organic solvents, and by optimizing the reaction conditions, the emissions of waste gas and waste water are reduced, making this preparation method relatively more environmentally friendly. Detailed implementation manners

[0031] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0032] Example 1

[0033] A preparation method of high hiding power pigment red P.R170 includes the following steps:

[0034] Step S1, preparation of the diazo component: Add water, p-aminobenzamide, and hydrochloric acid to the diazotization kettle in sequence, stir until completely dissolved and clear, cool down to 5°C with ice, add sodium nitrite for diazotization reaction, and after the reaction is completed, dropwise add an aqueous solution of sulfamic acid until the starch-potassium iodide test paper does not show color, obtaining a diazo component solution;

[0035] Step S2, preparation of the coupling component: Add water, turkey red oil, EDTA, and other additives to the dissolution tank in sequence, heat up to 35°C, add naphthol AS-PH, stir for 18 min, then add the alkali solution, continue to stir for 20 min, and after ultrasonic treatment and magnetic field treatment, obtain a coupling component solution;

[0036] Step S3, coupling reaction: Put the diazo component solution into the coupling reaction kettle, add a non-ionic surfactant while stirring, then dropwise add the coupling component solution thereto. The dropping time is 20 min. After the dropping is completed, continue to stir and react for 50 min to obtain a coupling product;

[0037] Step S4, pigmentation treatment: Add sulfuric acid to the coupling product to adjust the pH to 6.5, then heat up to 70 °C and keep warm for 1 h. Then cool to below 40 °C, filter, wash with water until neutral, dry, and pulverize to obtain the high hiding power pigment red P.R170.

[0038] In step S1, the mass ratio of water, p-aminobenzamide, hydrochloric acid, and sodium nitrite is 500:35:69:18.2; the mass percentage concentration of hydrochloric acid in step S1 is 30%; the time of the diazotization reaction in step S1 is 1 h; the mass percentage concentration of the aqueous solution of sulfamic acid in step S1 is 10%.

[0039] In step S2, the mass ratio of water, Turkey red oil, EDTA, other additives, naphthol AS-PH, and alkali solution is 800:30:3:2:79:770; the other additives in step S2 include the following components by weight: 4 parts of 3-tris(hydroxymethyl)methylamine-2-hydroxypropanesulfonate, 2 parts of 3-(N-morpholino)-2-hydroxypropanesulfonate, and 1 part of pyridinium hydroxypropylsulfonate; the mass percentage concentration of the alkali solution in step S2 is 25%; the alkali solution in step S2 is an aqueous sodium hydroxide solution; the ultrasonic frequency of the ultrasonic treatment in step S2 is 50 kHz, the power is 300 W, and the treatment time is 3 min; the magnetic field strength of the magnetic field treatment is 5000 Gs, and the treatment time is 3 min.

[0040] In step S3, the mass ratio of the non-ionic surfactant to naphthol AS-PH in the diazo component solution is 79:50; the non-ionic surfactant in step S3 is fatty alcohol polyoxyethylene ether AEO-9; the mass percentage concentration of sulfuric acid in step S3 is 5%.

[0041] Example 2

[0042] A preparation method of high hiding power pigment red P.R170, comprising the following steps:

[0043] Step S1, preparation of diazo component: Sequentially add water, p-aminobenzamide, and hydrochloric acid to the diazotization kettle, stir until completely dissolved and clear, cool with ice to 4 °C, add sodium nitrite for diazotization reaction. After the reaction is completed, dropwise add the aqueous solution of urea until the starch-potassium iodide test paper does not show color to obtain the diazo component solution;

[0044] Step S2, Preparation of the coupling component: Add water, Turkey red oil, EDTA and other additives into the dissolution tank in sequence, heat up to 36 °C, add Naphtol AS-PH, stir for 20 min, then add the lye, continue to stir for 22 min, after ultrasonic treatment and magnetic field treatment, obtain the coupling component liquid;

[0045] Step S3, Coupling reaction: Put the diazo component solution into the coupling reaction kettle, add the non-ionic surfactant while stirring, then dropwise add the coupling component liquid thereto, the dropping time is 23 min, after the dropping is completed, continue to stir and react for 55 min to obtain the coupling product;

[0046] Step S4, Pigmentation treatment: Add sulfuric acid to the coupling product to adjust the pH to 6.7, then heat up to 75 °C, keep warm for 1.2 h, then cool to below 40 °C, filter, wash with water until neutral, dry, and pulverize to obtain the high hiding power pigment red P.R170.

[0047] In step S1, the mass ratio of the water, p-aminobenzamide, hydrochloric acid, and sodium nitrite is 500:35:69:18.2; the mass percentage concentration of the hydrochloric acid in step S1 is 30.5%; the time of the diazotization reaction in step S1 is 1.2 h; the mass percentage concentration of the aqueous solution of urea in step S1 is 13%.

[0048] In step S2, the mass ratio of the water, Turkey red oil, EDTA, other additives, Naphtol AS-PH, and lye is 800:30:3:2.5:79:770; the other additives in step S2 include the following components by weight: 4.5 parts of 3-tris(hydroxymethyl)methylamine-2-hydroxypropanesulfonate, 2.5 parts of 3-(N-morpholino)-2-hydroxypropanesulfonate, 1.5 parts of pyridinium hydroxypropylsulfonate; the mass percentage concentration of the lye in step S2 is 27%; the lye in step S2 is an aqueous solution of pyridine; the ultrasonic frequency of the ultrasonic treatment in step S2 is 70 kHz, the power is 350 W, and the treatment time is 4 min; the magnetic field strength of the magnetic field treatment is 7000 Gs, and the treatment time is 3.5 min.

[0049] In step S3, the mass ratio of the non-ionic surfactant to Naphtol AS-PH in the diazo component solution is 79:50; the non-ionic surfactant in step S3 is fatty alcohol polyoxyethylene ether AEO-9; the mass percentage concentration of the sulfuric acid in step S3 is 6%.

[0050] Example 3

[0051] A preparation method of high hiding power pigment red P.R170, comprising the following steps:

[0052] Step S1, Preparation of diazo component: Add water, p-aminobenzamide and hydrochloric acid into the diazotization kettle in sequence, stir until completely dissolved and clear, cool with ice to 3°C, add sodium nitrite for diazotization reaction. After the reaction ends, add an aqueous solution of sulfamic acid drop by drop until the starch-iodide test paper does not show color, obtaining a diazo component solution;

[0053] Step S2, Preparation of coupling component: Add water, Turkey red oil, EDTA and other additives into the dissolution barrel in sequence, heat up to 36.5°C, add naphthol AS-PH, stir for 22 min, then add alkali solution, continue to stir for 25 min. After ultrasonic treatment and magnetic field treatment, obtain a coupling component solution;

[0054] Step S3, Coupling reaction: Put the diazo component solution into the coupling reaction kettle, add a non-ionic surfactant while stirring, then add the coupling component solution drop by drop thereto, the dropping time is 25 min. After the dropping is completed, continue to stir and react for 60 min to obtain a coupling product;

[0055] Step S4, Pigmentation treatment: Add sulfuric acid to the coupling product to adjust the pH to 7, then heat up to 80°C, keep warm for 1.5 h, then cool to below 40°C, filter, wash with water until neutral, dry, and pulverize to obtain high hiding power pigment red P.R170.

[0056] The mass ratio of the water, p-aminobenzamide, hydrochloric acid, and sodium nitrite described in Step S1 is 500:35:69:18.2; the mass percentage concentration of the hydrochloric acid described in Step S1 is 31%; the time of the diazotization reaction described in Step S1 is 1.5 h.

[0057] The mass percentage concentration of the aqueous solution of sulfamic acid described in Step S1 is 13%; the mass ratio of the water, Turkey red oil, EDTA, other additives, naphthol AS-PH, and alkali solution described in Step S2 is 800:30:3:3:79:770; the other additives described in Step S2 include the following components by weight: 5 parts of 3-tris(hydroxymethyl)methylamine-2-hydroxypropanesulfonate, 3 parts of 3-(N-morpholino)-2-hydroxypropanesulfonate, and 2 parts of pyridinium hydroxypropylsulfonate.

[0058] The mass percentage concentration of the alkali solution described in Step S2 is 30%; the alkali solution described in Step S2 is an aqueous solution of ethylenediamine; the ultrasonic frequency of the ultrasonic treatment described in Step S2 is 75 kHz, the power is 400 W, and the treatment time is 4.5 min; the magnetic field strength of the magnetic field treatment is 9000 Gs, and the treatment time is 4 min; the mass ratio of the non-ionic surfactant to naphthol AS-PH in the diazo component solution described in Step S3 is 79:50; the non-ionic surfactant described in Step S3 is fatty alcohol polyoxyethylene ether AEO-9; the mass percentage concentration of the sulfuric acid described in Step S3 is 7.5%.

[0059] Example 4

[0060] A preparation method of high hiding power pigment red P.R170 comprises the following steps:

[0061] Step S1, preparation of diazo component: Add water, p-aminobenzamide and hydrochloric acid into the diazotization kettle in sequence, stir until completely dissolved and clear, cool down to 2°C by adding ice, add sodium nitrite for diazotization reaction, after the reaction ends, dropwise add an aqueous solution of urea until the starch-iodide test paper does not show color, and obtain the diazo component solution;

[0062] Step S2, preparation of coupling component: Add water, Turkey red oil, EDTA and other additives into the dissolution barrel in sequence, heat up to 37°C, add naphthol AS-PH, stir for 23 min, then add the lye, continue to stir for 28 min, after ultrasonic treatment and magnetic field treatment, obtain the coupling component liquid;

[0063] Step S3, coupling reaction: Put the diazo component solution into the coupling reaction kettle, add a non-ionic surfactant while stirring, then dropwise add the coupling component liquid thereto, the dropping time is 28 min, after the dropping is completed, continue to stir and react for 67 min to obtain the coupling product;

[0064] Step S4, pigmentation treatment: Add sulfuric acid to the coupling product to adjust the pH to 7.3, then heat up to 85°C, keep warm for 1.8 h, then cool down to below 40°C, filter, wash with water until neutral, dry, and pulverize to obtain high hiding power pigment red P.R170.

[0065] The mass ratio of the water, p-aminobenzamide, hydrochloric acid, and sodium nitrite in Step S1 is 500:35:69:18.2; the mass percentage concentration of the hydrochloric acid in Step S1 is 31.3%; the time of the diazotization reaction in Step S1 is 1.8 h; the mass percentage concentration of the aqueous solution of urea in Step S1 is 18%.

[0066] The mass ratio of the water, Turkey red oil, EDTA, other additives, naphthol AS-PH, and lye in Step S2 is 800:30:3:3.5:79:770; the other additives in Step S2 include the following components by weight: 5.5 parts of 3-tris(hydroxymethyl)methylamine-2-hydroxypropanesulfonate, 3.5 parts of 3-(N-morpholino)-2-hydroxypropanesulfonate, 2.5 parts of pyridinium hydroxypropanesulfonate; the mass percentage concentration of the lye in Step S2 is 33%; the lye in Step S2 is an aqueous solution of sodium hydroxide; the ultrasonic frequency of the ultrasonic treatment in Step S2 is 90 kHz, the power is 450 W, and the treatment time is 5.5 min; the magnetic field strength of the magnetic field treatment is 11000 Gs, and the treatment time is 4.5 min.

[0067] The mass ratio of the non-ionic surfactant described in step S3 to Naphtol AS-PH in the diazo component solution is 79:50; the non-ionic surfactant described in step S3 is fatty alcohol polyoxyethylene ether AEO-9; the mass percentage concentration of sulfuric acid described in step S3 is 7.7%.

[0068] Example 5

[0069] A preparation method of high hiding power Pigment Red P.R170 comprises the following steps:

[0070] Step S1, preparation of diazo component: Add water, p-aminobenzamide and hydrochloric acid into the diazotization kettle in sequence, stir until completely dissolved and clear, cool down to 1°C with ice, add sodium nitrite for diazotization reaction, after the reaction ends, dropwise add an aqueous solution of sulfamic acid until the starch-iodide test paper does not show color, and obtain the diazo component solution;

[0071] Step S2, preparation of coupling component: Add water, Turkey red oil, EDTA and other additives into the dissolution barrel in sequence, heat up to 38°C, add Naphtol AS-PH, stir for 25 min, then add the alkali solution, continue to stir for 30 min, after ultrasonic treatment and magnetic field treatment, obtain the coupling component solution;

[0072] Step S3, coupling reaction: Put the diazo component solution into the coupling reaction kettle, add the non-ionic surfactant while stirring, then dropwise add the coupling component solution thereto, the dropping time is 30 min, after the dropping is completed, continue to stir and react for 70 min to obtain the coupling product;

[0073] Step S4, pigmentation treatment: Add sulfuric acid to the coupling product to adjust the pH to 7.5, then heat up to 90°C, keep warm for 2 h, then cool down to below 40°C, filter, wash with water until neutral, dry, and pulverize to obtain high hiding power Pigment Red P.R170.

[0074] The mass ratio of water, p-aminobenzamide, hydrochloric acid, and sodium nitrite described in step S1 is 500:35:69:18.2; the mass percentage concentration of hydrochloric acid described in step S1 is 31.5%; the time of the diazotization reaction described in step S1 is 2 h; the mass percentage concentration of the aqueous solution of sulfamic acid described in step S1 is 15%.

[0075] The mass ratio of water, Turkey red oil, EDTA, other additives, Naphtol AS-PH, and alkali solution described in step S2 is 800:30:3:4:79:770; the other additives described in step S2 include the following components by weight: 6 parts of 3-tris(hydroxymethyl)methylamine-2-hydroxypropanesulfonate, 4 parts of 3-(N-morpholino)-2-hydroxypropanesulfonate, and 3 parts of pyridinium hydroxypropylsulfonate.

[0076] The mass percentage concentration of the lye described in step S2 is 35%; the lye described in step S2 is an aqueous pyridine solution; the ultrasonic frequency of the ultrasonic treatment described in step S2 is 100 kHz, the power is 500 W, and the treatment time is 6 min; the magnetic field strength of the magnetic field treatment is 12,000 Gs, and the treatment time is 5 min.

[0077] The mass ratio of the non-ionic surfactant to naphthol AS-PH in the diazo component solution described in step S3 is 79:50; the non-ionic surfactant described in step S3 is fatty alcohol polyoxyethylene ether AEO-9; the mass percentage concentration of the sulfuric acid described in step S3 is 8%.

[0078] Comparative Example 1

[0079] A preparation method of high hiding power pigment red P.R170 is basically the same as that of Example 1, except that EDTA and other additives are not added, and ultrasonic treatment is not carried out, and the magnetic field treatment time is 6 min.

[0080] Comparative Example 2

[0081] A preparation method of high hiding power pigment red P.R170 is basically the same as that of Example 1, except that during the preparation process of the coupling component, the temperature is raised to 85°C, and magnetic field treatment is not carried out, and the ultrasonic treatment time is 6 min.

[0082] To further illustrate the beneficial technical effects of the preparation methods of high hiding power pigment red P.R170 involved in each embodiment of the present invention, the pigment red P.R170 prepared by the preparation methods of high hiding power pigment red P.R170 involved in Examples 1-5 and Comparative Examples 1-2 was subjected to relevant performance tests. The test results are shown in Table 1, and the test methods are as follows: The hiding power was detected in accordance with GB / T 5211.17-2013 General Test Methods for Pigments and Extenders - Part 17: Determination of Hiding Power; the tinting strength was detected in accordance with GB / T 5211.19-2013 General Test Methods for Pigments and Extenders - Part 19: Determination of Tinting Strength; the weather resistance was evaluated with reference to GB / T 1766-2008 Rating Methods for Degradation of Paints and Varnishes, and an artificial accelerated aging test was carried out using a xenon lamp aging test chamber, with a light intensity of 0.55 W / m 2 ; Light cycle: 8 h of light and 4 h of darkness; Temperature and humidity: 65°C and 60% RH during light, 45°C and 95% RH during darkness; Spraying cycle: Spraying for 18 min every 120 min; Test time: 1000 h.

[0083] Table 1

[0084]

[0085] As can be seen from Table 1, the high hiding power pigment red P.R170 prepared by the preparation method involved in the embodiments of the present invention has higher hiding power, coloring power and weather resistance than the products of the comparative examples; the combined use and design of EDTA, other additives, ultrasonic treatment, magnetic field treatment and low-temperature dissolution of the coupling component are beneficial to improving the above properties.

[0086] The above embodiments are only used to illustrate the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a high hiding power pigment red P.R170, characterized in that: The steps include: Step S1, preparation of diazo component: add water, p-aminobenzamide and hydrochloric acid to a diazotization kettle in sequence, stir until completely dissolved and clear, add ice to cool to 0-5°C, add sodium nitrite to carry out diazotization reaction, and after the reaction is completed, add an aqueous solution of aminosulfonic acid or an aqueous solution of urea dropwise until the starch-potassium iodide test paper does not show color, thereby obtaining a diazo component solution; Step S2, preparation of coupling component: water, Taiko oil, EDTA and other additives are added to a dissolving barrel in sequence, the temperature is raised to 35-38° C., naphthol AS-PH is added, stirred for 18-25 min, then alkali solution is added, stirring is continued for 20-30 min, and after ultrasonic treatment and magnetic field treatment, a coupling component liquid is obtained; Step S3, coupling reaction: placing the diazo component solution into a coupling reaction kettle, adding a nonionic surfactant while stirring, and then adding the coupling component solution dropwise thereto, the dropping time is 20-30 minutes, and after the dropwise addition is completed, continuing to stir the reaction for 50-70 minutes to obtain a coupling product; Step S4, pigmentation treatment: add sulfuric acid to the coupling product to adjust the pH to 6.5-7.5, then heat to 70-90°C, keep warm for 1-2h, then cool to below 40°C, filter, wash with water to neutrality, dry, and crush to obtain high hiding power pigment red P.R170.

2. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The mass ratio of water, p-aminobenzamide, hydrochloric acid and sodium nitrite in step S1 is 500:35:69:18.

2.

3. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The mass percentage concentration of the hydrochloric acid in step S1 is 30%-31.5%; the time of the diazotization reaction in step S1 is 1-2h.

4. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The mass percentage concentration of the aqueous solution of aminosulfonic acid in step S1 is 10%-15%; the mass percentage concentration of the aqueous solution of urea is 10-20%.

5. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The mass ratio of water, Taiko oil, EDTA, other additives, Naphthol AS-PH, and alkali solution in step S2 is 800:30:3:(2-4):79:

770.

6. The method for preparing the high hiding power pigment red P.R170 according to claim 5, characterized in that: The other additives in step S2 include the following components in parts by weight: 4-6 parts of sodium 3-trimethylolmethylamine-2-hydroxypropanesulfonate, 2-4 parts of sodium 3-(N-morpholinyl)-2-hydroxypropanesulfonate, and 1-3 parts of pyridinium hydroxypropanesulfonate.

7. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The mass percentage concentration of the alkali solution in step S2 is 25%-35%; the alkali solution in step S2 is at least one of a sodium hydroxide aqueous solution, a pyridine aqueous solution, and an ethylenediamine aqueous solution.

8. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic treatment in step S2 is 50-100kHz, the power is 300-500W, and the treatment time is 3-6min; the magnetic field intensity of the magnetic field treatment is 5000-12000Gs, and the treatment time is 3-5min.

9. The method for preparing the high hiding power pigment red P.R170 according to claim 1, characterized in that: The mass ratio of the nonionic surfactant in step S3 to the phenol AS-PH in the diazo component solution is 79:50; the nonionic surfactant in step S3 is fatty alcohol polyoxyethylene ether AEO-9; the mass percentage concentration of sulfuric acid in step S3 is 5%-8%.

10. Application of high hiding power Pigment Red P.R170 prepared by the preparation method of high hiding power Pigment Red P.R170 according to any one of claims 1 to 9 in the fields of coatings, inks, plastics and rubber.

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