Preparation method of dye solvent red 196 crystal transformation product

Abstract

The invention discloses a preparation method of a dye solvent red 196 crystal transformation product, which comprises the following steps: mixing a wet filter cake formed by reaction of solvent red 197 and concentrated hydrochloric acid with a mixed solution of an aliphatic organic solvent and water, and then dropwise adding alkali liquor for neutralization and crystal transformation; if the pH value of the filter cake is neutral or weakly alkaline after the alkali pulping is carried out once, carrying out water pulping treatment, and if the filter cake is still acidic, repeating the alkali pulping operation for at least one time until the filter cake meets the requirement; and pulping the filter cake meeting the requirements for 2-3 times to obtain a dye solvent red 196 crystal transformation product. The method is simple in process and short in time consumption, and the obtained product is blackish green, high in quality and more suitable for silk spray dyeing and plastic wire drawing industries.

Description

Technical Field

[0001] The invention relates to a method for preparing a dye solvent red 196 crystal-transformed product, in particular to a method for preparing a spray dye solvent red 196 crystal-transformed product for silk and plastic drawing. Background Art

[0002] Solvent Red 196 is a red powder with fluorescence. Its microscopic morphology is amorphous metastable. Its Chinese alias is Fluorescent Red BK. Its chemical formula is C 23 H 18 N4O2, CAS No. 52372-36-8, has excellent heat resistance and light resistance, good migration resistance and high tinting strength, and is recommended for coloring plastics and fibers. Solvent Red 196 is a commonly used spray dye in the silk or plastic drawing industry. Traditional silk printing and dyeing uses dye vat bath dyeing, which easily causes silk to have defects such as creases, abrasions and wrinkles. A new process has been developed: when the silk is in a flat state, the dye liquid is sprayed onto the silk with a high-pressure nozzle for dyeing. After PET is colored with solvent red 196, it can be drawn into long filaments and then woven into cloth and made into clothes. The method of drawing plastic polymer materials is: first melt and mix the plastic and solvent red 196 (of course, there are other colors of dyes), then pressurize the melt through the nozzle and spray and cool it while drawing. Whether it is silk spraying or plastic coloring and drawing, nozzles are used in both production processes, and the dye particle size requirements are high.

[0003] The particle size of the common red solvent red 196 currently sold on the market is generally 30-40μm. Because it is an amorphous metastable shape, it is difficult to crush into a finer particle size, and secondary aggregation will occur during use. Therefore, the red solvent red 196 used for silk spray dyeing or plastic drawn silk textiles needs to be crystallized into green fine powder before use. The purpose of crystallization is to transform the red solvent red 196 from a metastable state to a stable state. After the crystal transformation, the appearance color changes to dark green. In addition, after the crystal transformation, the dark green solvent red 196 is easier to ultrafinely grind, the particle size is finer, the particle size distribution is more uniform, and no secondary aggregation occurs.

[0004] Currently, the crystallization process of Solvent Red 196 is as follows: First, neutralize and wash: neutralize the wet filter cake of Solvent Red 196 formed by the reaction of Solvent Red 197 and concentrated hydrochloric acid with sodium hydroxide solution, and then thoroughly wash the inorganic salts in the filter cake with a large amount of soft water. Repeat this 2-3 times, and then dry the clean filter cake.

[0005] Secondly, crystallization: put the dried filter cake into the reactor, add solvent DMF in proportion, heat to 120-130℃ to dissolve and keep at this temperature for 3 hours, then cool to 60-80℃, add a certain amount of methanol in proportion, keep at this temperature for 2 hours, and finally cool to 0±25℃.

[0006] Finally, washing and drying: the above materials are filtered, the filter cake is washed with a certain amount of methanol, then soaked and washed with a certain amount of soft water, filtered, dried, and ultrafinely crushed to obtain the crystallized Solvent Red 196.

[0007] In the above-mentioned crystallization process, the solvent red 196 wet filter cake is agglomerated, so it is severely coated with hydrochloric acid adsorption, and it is difficult to adjust the pH to neutral by alkali neutralization. It needs repeated adjustments, filtration and washing, which is quite complicated and tedious, and the cycle is long. Summary of the invention In view of the shortcomings of the prior art solvent red 196 crystallization process such as complicated process and long cycle, the present invention provides a preparation method of a dye solvent red 196 crystallization product, which has simple process, short production cycle, small amount of wastewater generation and high quality of the obtained product. When used in the silk spray-dyeing industry and the plastic wire drawing industry, the particle size can be crushed to a smaller size and distributed more evenly, and there will be no problems such as nozzle clogging, wire breakage during drawing and uneven spray-dyeing.

[0008] The specific technical solutions of the present invention are as follows: A method for preparing a dye solvent red 196 crystal transformation product, which may also be referred to as a crystal transformation method of solvent red 196, comprises the following steps: (1) Mixing the solvent red 196 wet cake and the aliphatic organic solvent-water mixture, then dropping alkali solution, stopping the dropping of alkali solution when the pH is 8-10, keeping the temperature to react, filtering and washing with water after the reaction to obtain a wet cake; (2) After the insulation reaction in step (1) is completed, the pH of the feed solution is detected. If the pH is neutral or weakly alkaline, the wet filter cake obtained after water washing in step (1) is directly subjected to the water pulping treatment step in step (3); if the pH is acidic, the wet filter cake obtained after water washing in step (1) is subjected to the above step (1) at least once until the pH of the feed solution after the insulation reaction is neutral or weakly alkaline, and then the wet filter cake obtained after water washing is subjected to the water pulping treatment step in step (3); (3) The wet filter cake that meets the requirements is added with water for pulping, and then filtered and washed with water; (4) Repeat the operation of step (3) 1-2 times, then wash the filter cake with water and dry it to obtain a dye solvent red 196 crystal product, which has a dark green appearance.

[0009] Furthermore, in step (1), the solvent red 196 wet cake is dispersed in a mixture of an organic solvent and water, and then alkali solution is added dropwise for pulping. The alkali in the alkali solution reacts with the hydrochloric acid in the wet cake to neutralize. During the reaction, the solvent red 196 also undergoes a crystal transformation to form a dark green crystal.

[0010] Furthermore, in step (1), a surfactant may be added, and the surfactant is added before the alkali solution is added. There is no special requirement for the mixing order of the solvent red 196 wet cake, the surfactant and the aliphatic organic solvent-water mixture. The solvent red 196 wet cake and the aliphatic organic solvent-water mixture may be mixed first, and then the surfactant is added. Alternatively, the surfactant and the aliphatic organic solvent-water mixture may be mixed first, and then the wet cake is added. Alternatively, the three may be mixed simultaneously. The surfactant is an OP series product, a Tween series product or a Span series product, and a Tween series product is preferred.

[0011] Further, in step (1), the aliphatic organic solvent is a low molecular weight fatty alcohol, a low molecular weight fatty acid ester, dioxane, dioxane, a short chain aliphatic ketone, morpholine, ethylene glycol monoether or ethylene glycol diether. Wherein, the low molecular weight fatty alcohol is a fatty alcohol having 1-5 carbon atoms, such as methanol, ethanol, isopropanol, butanediol. The low molecular weight fatty acid ester is a fatty acid ester having 1-5 carbon atoms, such as ethyl acetate, butyl acetate, etc. The short chain aliphatic ketone is an aliphatic ketone having 1-6 carbon atoms, such as acetone, methyl isobutyl ketone, etc. The ethylene glycol monoether includes ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. The ethylene glycol diether includes ethylene glycol dimethyl ether, ethylene glycol diethyl ether, etc. Preferably, the aliphatic organic solvent is a low molecular weight fatty alcohol, more preferably methanol.

[0012] Furthermore, in step (1), the amount of surfactant used is 1%-5% of the wet filter weight of Solvent Red 196, preferably 2%.

[0013] Furthermore, in step (1), in the mixture of the aliphatic organic solvent and water, the mass percentage of the aliphatic organic solvent is 20-40%, for example, 20%, 30%, 40%, and correspondingly, the water content is 60-80%, for example, 60%, 70%, 80%.

[0014] Furthermore, in step (1), the mass ratio of the solvent red 196 wet cake to the mixture of the aliphatic organic solvent and water is 1:4-8, for example 1:4, 1:5, 1:6, 1:7, 1:8. The solid content of the wet cake is generally between 30-60%.

[0015] Furthermore, in step (1), the alkali solution is a metal hydroxide aqueous solution, a metal carbonate aqueous solution or a metal bicarbonate aqueous solution. The metal hydroxide includes sodium hydroxide, potassium hydroxide, etc. The metal carbonate includes sodium carbonate, potassium carbonate, etc. The metal bicarbonate includes sodium bicarbonate, potassium bicarbonate, etc. Preferably, the alkali solution is a bicarbonate aqueous solution.

[0016] Furthermore, in step (1), if the concentration of the alkali solution is too high, the reaction will be violent during the alkali pulping neutralization process, resulting in a coating phenomenon which is not favorable. In addition, a large number of bubbles will be generated when carbonates and bicarbonates are neutralized with hydrochloric acid. If the concentration is too high, there will be a risk of increased foam overflow. Therefore, the concentration of the alkali solution is less than or equal to 15wt%.

[0017] Preferably, in step (1), the concentration of the alkali solution is 5wt%-15wt%, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%.

[0018] Preferably, in step (1), the alkali solution is an aqueous solution of sodium bicarbonate with a concentration of 8%-10%.

[0019] Furthermore, in step (1), there is no special requirement for the temperature of adding alkali solution and heat-keeping reaction, and it can be carried out at any temperature between 0 and 100°C, such as 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, etc. The increase of reaction temperature is conducive to the neutralization reaction and the migration of hydrochloric acid from the agglomerated material coating. From an economic point of view, the addition of alkali solution and the neutralization reaction are carried out at 55±1°C.

[0020] Furthermore, in step (1), the addition of alkali solution and the heat preservation reaction are carried out under stirring, and stirring is conducive to breaking up the agglomerated materials in the kettle, making the reaction more uniform and sufficient. Preferably, the stirring speed is 200-300 rpm, for example, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, 300 rpm.

[0021] Furthermore, in step (1), after the addition of the alkali solution is stopped, the reaction is kept warm for 1-4 hours, for example, 1 hour, 2 hours, 3 hours, or 4 hours. Because the hydrochloric acid may be encapsulated by the product, some hydrochloric acid may remain after the solution is added to a specified pH, resulting in a false neutralization. Therefore, after the alkali solution is added, it is preferred to continue the reaction with the stirring and keeping warm for a period of time.

[0022] Furthermore, in step (1), after one heat preservation reaction, the obtained material is filtered by filter pressing or suction filtration, and then washed with water to obtain a wet filter cake, and the water washing is generally 1-3 times.

[0023] Furthermore, in step (2), generally after one heat preservation reaction, some hydrochloric acid will still remain, so it is necessary to repeat the treatment of step (1) at least once to obtain a neutral or slightly alkaline wet cake. When using the above reaction conditions of the present invention, generally only one alkali neutralization treatment or one repetition of the alkali neutralization operation of step (1) is required to obtain a suitable wet cake.

[0024] Furthermore, in step (3), the mass ratio of the wet filter cake to water is 1:4-8, for example, 1:4, 1:5, 1:6, 1:7, 1:8.

[0025] Furthermore, in step (3), there is no special requirement for the pulping temperature, as long as the filter cake is neutral. The pulping can be carried out at any temperature between 0 and 100°C, for example, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, etc. Appropriate temperature increase is beneficial to improving the washing efficiency, so pulping is preferably carried out at 45-55°C.

[0026] Furthermore, in step (3), the beating time is 1-4 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours.

[0027] Furthermore, in step (3), beating is performed under stirring, and stirring is conducive to breaking up the materials, so that the beating effect is better. Preferably, the stirring speed is 200-300 rpm, for example, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, 300 rpm.

[0028] The present invention has the following beneficial effects: 1. The process of the present invention is simple and has a short cycle. As the pH is adjusted by alkali beating, the crystal form transformation (from red to dark green crystal form) is also achieved, which simplifies the operation, shortens the process time, reduces the amount of waste water, and improves the production efficiency.

[0029] 2. The present invention adds a surfactant before alkali beating, which is beneficial for the rapid and uniform dispersion of Solvent Red 196 particles in the dispersion medium aliphatic organic solvent-water, making beating neutralization and crystal transformation faster and easier.

[0030] 3. The present invention selects a mixed solution of aliphatic organic solvent and water as the dispersion medium for alkali neutralization, which can deagglomerate the solvent red 196 filter cake, improve the uniformity of dispersion of the solvent red 196 wet filter cake in the liquid phase, make the particles finer, weaken or eliminate the adsorption and coating effect of hydrochloric acid on the solvent red 196 filter cake particles, and make the alkali beating to adjust the pH faster and more thoroughly, thereby improving the alkali beating efficiency.

[0031] 4. The present invention transforms the red Solvent Red 196 metastable crystal state into a stable dark green crystal state. The crystal state is easier to ultrafinely grind, has a finer particle size and a more uniform particle size distribution, and does not produce secondary aggregation during use. When in use, the pressure of the silk spray-dyeing nozzle and the plastic machine head is lower than 1.0 MPa, and the spraying is smoother, thereby improving the quality and added value of the product, and is more suitable for the silk spray-dyeing and plastic wire drawing industries. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with specific examples to make the advantages of the present invention more obvious. It should be understood that the contents thereof are only used for illustration and are by no means intended to limit the scope of protection of the present invention. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0033] Unless otherwise specified, the following concentrations are all mass percentages.

[0034] In the following examples and comparative examples, the solvent red 196 wet filter cake used was purchased from a fine chemical company in Nantong, Jiangsu Province. The main components of the wet filter cake were red solvent red 196 and hydrochloric acid.

[0035] Example 1 The first step is the crystal transfer process Weigh 80 grams of solvent red 196 wet cake (solid content 45%, 36 grams dry) in a 1000 ml four-necked reactor, add 1.6 grams of Tween 20, add 480 grams of methanol-water (mass ratio 3:7) mixture, start stirring, stirring speed 260 rpm, turn on the water bath to heat up. When the temperature of the material in the kettle rises to 55±1°C, start dripping 10% sodium bicarbonate solution, and constantly observe the online pH meter reading during the period. When the pH meter reading is 9-10, stop dripping sodium bicarbonate solution, keep warm and beat the reaction for 1 hour. Then take the slurry from the kettle and drop it on the PH test paper, observe the dark green halo around the material, filter the slurry, wash the filter cake with 100 ml of soft water, repeat the washing twice, and obtain a dark green crystal filter cake, and proceed to the next step.

[0036] The second step is water beating and washing process Put the first step filter cake into a 1000ml four-necked flask, add 600g of soft water, start stirring, stir at 260 rpm, and heat in a water bath. When the temperature of the material in the kettle rises to about 55±1℃, keep it warm for 1 hour, then filter the slurry, wash the filter cake with 100ml of soft water, and repeat this washing twice.

[0037] The third step is to put the filter cake from the second step into a 1000ml four-necked flask, repeat the operation of the second step once, and then dry the obtained filter cake under vacuum at 105±1℃, and then crush the filter cake with a laboratory ultrafine grinder CWF300. The crushing conditions are: room temperature, 4500r / min, and crushing for 8 minutes to obtain the solvent red 196 crystal product, which has the appearance of dark green fine powder.

[0038] Example 2 The solvent red 196 crystal product was prepared according to the operation of the above example 1, except that methanol was replaced by ethanol and Tween 20 was replaced by OP-10.

[0039] Example 3 The solvent red 196 crystal product was prepared according to the operation of the above embodiment 1, except that methanol was replaced by ethylene glycol monomethyl ether, Tween 20 was replaced by Span 20, and the crystal process required two times to complete; the crystal process was as follows: Weigh 80 grams of solvent red 196 wet cake (solid content 45%, 36 grams dry) in a 1000 ml four-necked reactor, add 1.6 grams of Span 20, add 480 grams of ethylene glycol monomethyl ether-water (mass ratio 3:7) mixture, start stirring, stirring speed 260 rpm, turn on the water bath to heat up. When the temperature of the material in the kettle rises to 55±1°C, start dripping 10% sodium bicarbonate solution, and constantly observe the online pH meter reading during the period. When the pH meter reading is 9-10, stop dripping sodium bicarbonate solution, keep warm and beat for 1 hour. Then take the slurry from the kettle and drop it on the pH test paper, observe the red halo around the material, filter the slurry, wash the filter cake with 100 ml of soft water, repeat the washing twice to obtain a wet filter cake.

[0040] The wet filter cake was added into the four-necked reactor again, and the alkaline beating operation was repeated once according to the above operation. The slurry after heat preservation and beating for 1 hour was dropped onto the pH test paper. A dark green halo was observed around the material. The slurry was filtered and the filter cake was washed with 100 ml of soft water. This washing was repeated twice to obtain a wet filter cake.

[0041] Example 4 The solvent red 196 crystallization product was prepared according to the operation of the above embodiment 1, except that no surfactant was added and the crystallization process required two times to complete.

[0042] Comparative Example 1 First step, neutralization and washing process Put 80g of solvent red 196 wet cake (solid content 45%, 36g in dry form) into a 1000ml four-necked flask, add 480g of soft water, start stirring at 260 rpm, then heat in a water bath, drop 32% liquid alkali solution at 90±1℃, stop dropping liquid alkali when the online pH meter reads 8-10, keep warm for 4 hours, filter, wash with 160ml of soft water, repeat washing three times, then drop the last washing water on pH test paper, and observe whether there is a reddish brown halo; The washed wet filter cake was added back into the four-necked flask, and 600 g of soft water was added. The neutralization and washing steps were repeated according to the above operation. Then the last washing water was dropped onto the pH test paper and a pink halo was observed.

[0043] The washed filter cake was put into a four-necked flask, and 600 g of soft water was added for pulping. The mixture was pulped at 90±1°C for 1 hour, and then filtered and washed with 160 ml of soft water. This process was repeated twice, and the filter cake was dried.

[0044] The second step is the crystal transfer process The dried filter cake was put into a reactor, 240 g of DMF solvent was added in proportion, the temperature was raised to 120-130°C to dissolve and kept at this temperature for 3 hours, then the temperature was lowered to 60-80°C, 960 g of methanol was slowly added dropwise in proportion within 1 hour, the temperature was kept at this temperature for 2 hours to grow the crystal, and finally the temperature was slowly lowered to 0±15°C.

[0045] Step 3: Washing and drying process The material from the second step was filtered, and the filter cake was soaked and washed with 400 g of methanol, filtered, and then soaked and washed with 400 g of soft water for 2 h, filtered, dried, and crushed with a laboratory ultrafine grinder CWF300 at room temperature, 4500 r / min, and 8 minutes to obtain the crystallized Solvent Red 196.

[0046] Comparative Example 2 The commercially available red powdered Solvent Red 196 product was crushed using a laboratory ultrafine grinder CWF300 at room temperature, 4500 r / min, and 8 minutes to obtain ultrafinely crushed un-crystallized red Solvent Red 196.

[0047] Performance Testing The particle size distribution index of the products prepared in the above embodiments and comparative examples was tested according to the particle size distribution laser diffraction method of GB / T 19077-2016.

[0048] The products prepared in the above-mentioned embodiments and comparative examples were used in silk spray-dyeing, and then the nozzle pressure of the machine head for successfully spraying the silk spray-dyeing material was recorded.

[0049] The test results of Example 1 are shown in Table 1 below.

[0050] The test results of Example 2 are shown in Table 2 below.

[0051] The test results of Example 3 are shown in Table 3 below.

[0052] The test results of Example 4 are shown in Table 4 below.

[0053] The test results of Comparative Example 1 are shown in Table 5 below.

[0054] The test results of Comparative Example 2 are shown in Table 6 below.

[0055] The conductivity, intensity and color index of the products of each embodiment and comparative example were tested, as shown in Table 7 below.

[0056] The conductivity measurement method is as follows: take 2 grams of powdered solvent dye into a 100ml beaker, add 50ml of Wahaha bottled pure water, stir and moisten it with a glass rod, then put it into an ultrasonic bath for 10 minutes, take it out and filter it with filter paper, place the beaker containing the filtrate in a constant temperature water bath to maintain a constant temperature of 25±1℃, and perform the test according to the instructions of the conductivity meter.

[0057] The intensity and color light are tested in accordance with the relevant provisions of GB / T6688-2008 "Instrumental method for determination of relative intensity and color difference of dyes".

[0058] .

Claims

1. A method for preparing a dye solvent red 196 crystal product, characterized in that The following steps are involved: (1) Mixing the solvent red 196 wet cake with a mixture of an aliphatic organic solvent and water, then dropping alkali solution, stopping the dropping of alkali solution when the pH is 8-10, keeping the temperature to react, filtering and washing with water after the reaction to obtain a wet cake; (2) After the insulation reaction in step (1) is completed, the pH of the feed solution is detected. If the pH is neutral or weakly alkaline, the wet filter cake obtained after water washing in step (1) is directly subjected to the water pulping treatment step in step (3); if the pH is acidic, the wet filter cake obtained after water washing in step (1) is subjected to the above step (1) at least once until the pH of the feed solution after the insulation reaction is neutral or weakly alkaline, and then the wet filter cake obtained after water washing is subjected to the water pulping treatment step in step (3); (3) The wet filter cake that meets the requirements is added with water for pulping, and then filtered and washed with water; (4) Repeat step (3) 1-2 times, then wash the filter cake with water and dry it to obtain the dye solvent red 196 crystal product.

2. The preparation method according to claim 1, characterized in that: In step (1), at least one of the following conditions is included: Condition 1: The aliphatic organic solvent is a low molecular weight fatty alcohol, a low molecular weight fatty acid ester, dioxane, dioxolane, a short chain aliphatic ketone, morpholine, ethylene glycol monoether or ethylene glycol diether; Condition 2: In the mixture of aliphatic organic solvent and water, the mass percentage of aliphatic organic solvent is 20-40%, and the mass percentage of water is 60-80%; Condition 3: In step (1), the mass ratio of the solvent red 196 wet cake to the mixture of the aliphatic organic solvent and water is 1:4-8; Condition 4: In step (1), the alkali solution is a metal hydroxide aqueous solution, a metal carbonate aqueous solution or a metal bicarbonate aqueous solution; Condition 5: In step (1), the concentration of the alkali solution is less than or equal to 15 wt %.

3. The preparation method according to claim 1, characterized in that: In step (1), a surfactant is also added, and the surfactant is added before the alkali solution is added dropwise; preferably, the surfactant is an OP series product, a Tween series product or a Span series product.

4. The preparation method according to claim 2, characterized in that: In step (1), the low molecular weight fatty alcohol is a fatty alcohol having 1 to 5 carbon atoms, the low molecular weight fatty acid ester is a fatty acid ester having 1 to 5 carbon atoms, and the short chain aliphatic ketone is an aliphatic ketone having 1 to 6 carbon atoms.

5. The preparation method according to claim 1, 2, 3 or 4, characterized in that: In step (1), the alkali solution is added dropwise and the reaction is carried out at a temperature of 0-100°C.

6. The preparation method according to claim 1, 2, 3 or 4, characterized in that: In step (1), after stopping the addition of the alkali solution, the reaction is kept warm for 1-4 hours.

7. The preparation method according to claim 1, 2, 3 or 4, characterized in that: In step (1), the addition of alkali solution and the heat preservation reaction are carried out under stirring. Preferably, the stirring speed is 200-300 rpm.

8. The preparation method according to claim 1, characterized in that: In step (3), the mass ratio of wet filter cake to water is 1:4-8.

9. The preparation method according to claim 1 or 8, characterized in that: In step (3), pulping is performed at 0-100°C; preferably, the pulping time is 1-4 hours.

10. The preparation method according to claim 1 or 8, characterized in that: In step (3), slurrying is performed under stirring, and preferably, the stirring speed is 200-300 rpm.

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