A black direct liquid dye, its preparation method and application

Abstract

This application provides a black direct liquid dye, its preparation method, and its application, belonging to the field of dye synthesis technology. It is prepared by mixing products obtained from the coupling reactions of trimethylsalicylic acid, H acid, and gamma acid with diazonium salts of DSD acid. The black direct liquid dye prepared by this invention is liquid, has good solubility, high dyeing rate, is suitable for the papermaking industry, has good stability, requires low dosage, is easy to use, and produces no dust pollution.

Description

Technical Field

[0001] This invention relates to the field of dye synthesis technology, specifically to a black direct liquid dye, its preparation method, and its application. Background Technology

[0002] Direct dyes are a class of water-soluble anionic dyes primarily used for dyeing cellulosic fibers (such as cotton, linen, and viscose). Because their molecular structure contains hydrophilic groups (such as sulfonic acid groups -SO3H), they can be directly adsorbed and fixed onto the fibers without the need for mordants. Direct Black 168 and Direct Black 19 dyes on the market are both powders and mainly used in textiles. For use in papermaking, they need to be converted into liquid dyes. However, these methods suffer from poor stability, poor solubility, high usage volume, and significant dust pollution during application. Summary of the Invention

[0003] In view of the technical problems existing in the background art, this application provides a black direct liquid dye, its preparation method and application, aiming to solve the technical problems of poor stability, poor solubility, large usage amount and large dust pollution in the use of existing direct black dyes.

[0004] In a first aspect, embodiments of this application provide a black direct liquid dye, which, by mass parts, includes 20-30 parts of dye of formula I, 50-65 parts of dye of formula II and 50-60 parts of dye of formula III; dye of formula I is one of formula I1, formula I2 and formula I3.

[0005] ;

[0006] ;

[0007] ;

[0008] ;

[0009] .

[0010] Secondly, embodiments of this application provide a method for preparing a black direct liquid dye, comprising the following steps: mixing 20-30 parts of dye of formula I, 50-65 parts of dye of formula II and 50-60 parts of dye of formula III evenly to obtain a black direct liquid dye.

[0011] In some embodiments, the preparation method of the dye of formula I1 includes the following steps:

[0012] Trimethylsalicylic acid was mixed with water to obtain a trimethylsalicylic acid mixture.

[0013] The pH of the trimethylsalicylic acid mixture was adjusted to be greater than 12, and the temperature was set to 10°C. The diazonium salt of DSD acid was added dropwise to the trimethylsalicylic acid mixture to carry out a coupling reaction, thus obtaining dye of formula I1.

[0014] In some embodiments, the molar ratio of DSD acid diazonium salt to trimethylsalicylic acid is 1:2;

[0015] The coupling reaction temperature is 10~20℃, the pH is greater than 11.0, and the reaction time is 1.0~2.0 h.

[0016] In some embodiments, the method for preparing Formula II dye includes the following steps:

[0017] H acid is dispersed in water to obtain a H acid mixture;

[0018] The DSD acid diazonium salt was added dropwise to the H acid mixture to carry out a coupling reaction, thus obtaining dye of formula II.

[0019] In some embodiments, the molar ratio of DSD acid diazonium salt to H acid is 1:2;

[0020] The coupling reaction temperature is 25~30℃, and the reaction time is 2.0~3.0 h.

[0021] In some embodiments, the method for preparing Formula III dyes includes the following steps:

[0022] Gamma acid was dispersed in water to obtain a gamma acid mixture;

[0023] The DSD acid diazonium salt was added dropwise to a mixture of gamma acids to carry out a coupling reaction, yielding dye of formula III.

[0024] In some embodiments, the molar ratio of DSD acid diazonium salt to gamma acid is 1:2;

[0025] The coupling reaction temperature is 25~30℃, and the reaction time is 2.0~3.0 h.

[0026] In some embodiments, the DSD acid diazonium salt is prepared by diazotization reaction of DSD acid with sodium nitrite under acidic conditions.

[0027] Thirdly, embodiments of this application provide an application of a black direct liquid dye in the papermaking field.

[0028] The advantages of this application, which differ from existing technical solutions, include:

[0029] The black direct liquid dye prepared by this invention is liquid, has good solubility, high dyeing rate, is suitable for the papermaking industry, has good stability, requires less dosage, is easy to use, and does not cause dust pollution.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Detailed Implementation

[0031] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion.

[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0035] I. Preparation Method

[0036] Example 1

[0037] A method for preparing a black direct liquid dye includes the following steps:

[0038] (1) Mix trimethylsalicylic acid with water, adjust the pH to 12, and set the temperature to 10°C to obtain a 5% trimethylsalicylic acid mixture;

[0039] The DSD diazonium salt, generated from DSD acid and sodium nitrite under acidic conditions, was added dropwise to a mixture of trimethylsalicylic acid for a coupling reaction. The molar ratio of DSD acid diazonium salt to trimethylsalicylic acid was 1:2. The addition was carried out over 0.5 hours, followed by 1 hour of reaction after the addition was complete. The reaction temperature was controlled at 10°C and the pH at 11 to obtain dye of formula I1, as shown below:

[0040] .

[0041] (2) Disperse H acid in water to obtain a 5% H acid mixture;

[0042] The DSD acid diazonium salt was added dropwise to a H acid mixture to carry out a coupling reaction. The molar ratio of DSD acid diazonium salt to H acid was 1:2. The coupling reaction temperature was controlled at 25℃. After the addition was completed, the temperature was maintained for another 2 hours to obtain dye of formula II, which is shown below:

[0043] .

[0044] (3) Disperse gamma acid in water to obtain a 5% gamma acid mixture;

[0045] The diazonium salt was added dropwise to a mixture of gamma acid to carry out a coupling reaction. The molar ratio of DSD acid diazonium salt to gamma acid was 1:2. The coupling reaction temperature was controlled at 25°C. After the addition was completed, the temperature was maintained for another 2 hours to obtain dye of formula III, as shown below:

[0046] .

[0047] (4) After thoroughly mixing 25 parts of dye of formula I, 45 parts of dye of formula II and 30 parts of dye of formula III, a direct black liquid dye is obtained.

[0048] Example 2

[0049] The difference between Example 2 and Example 1 is that, after thoroughly mixing 23 parts of dye of Formula I, 47 parts of dye of Formula II, and 30 parts of dye of Formula III, a direct black liquid dye is obtained.

[0050] Example 3

[0051] The difference between Example 3 and Example 1 is that, after thoroughly mixing 25 parts of dye of Formula I, 48 parts of dye of Formula II, and 27 parts of dye of Formula III, a direct black liquid dye is obtained.

[0052] Example 4

[0053] The difference between Example 4 and Example 1 is that 30 parts of Formula I dye, 50 parts of Formula II dye, and 20 parts of Formula III dye are thoroughly mixed to obtain a direct black liquid dye.

[0054] Example 5

[0055] The difference between Example 5 and Example 1 is that 20 parts of dye of Formula I, 50 parts of dye of Formula II, and 30 parts of dye of Formula III are thoroughly mixed to obtain a direct black liquid dye.

[0056] Example 6

[0057] The difference between Example 6 and Example 1 is that, in Example 6, 25 parts of Formula I dye, 48 parts of Formula II dye, and 27 parts of Formula III dye were replaced with commercially available Yellow 11 (Formula I2) dye and thoroughly mixed to obtain a direct black liquid dye. Formula I2 dye is as follows:

[0058] .

[0059] Example 7

[0060] The difference between Example 7 and Example 1 is that, in Example 7, 25 parts of Formula I dye, 48 parts of Formula II dye, and 27 parts of Formula III dye were replaced with commercially available Yellow 23 (Formula I3) dye, and after thorough mixing, a direct black liquid dye was obtained. Formula I3 dye is as follows:

[0061] .

[0062] Comparative Example 1

[0063] Comparative Example 1 used Direct Black 168 dye.

[0064] Comparative Example 2

[0065] Comparative Example 2 used Direct Black 19 dye.

[0066] II. Testing Methods

[0067] 1. Overall yield detection method: actual number of moles generated / theoretical number of moles generated.

[0068] 2. Absorbance, brightness and intensity testing methods: Accurately weigh the sample, dilute it to 100 ppm, and measure the absorbance using a UV-2600i ultraviolet spectrophotometer. Weigh the standard sample at the same dilution factor, calculate the intensity of the sample, and measure the brightness in the STC color quality control system.

[0069] 3. Stability testing method: Under the same conditions, the absorbance values ​​of different samples were measured at regular intervals for 24 months. The absorbance values ​​of Direct Black 168 and Direct Black 19 dyes were measured after they were converted into liquid dyes.

[0070] 4. L-value detection method for 10% dyeing depth: Weigh an appropriate amount of sample and dilute it 500 times as a stock solution. Accurately weigh 150g of the stock solution and add it to 250g of 1.2% pulp (3g for dry paper). Make paper into dry paper and use a Datacolor colorimeter to measure the L-value.

[0071] 5. Relative colorimetric test method for dyeing residue: Weigh an appropriate amount of sample and dilute it 500 times as a stock solution. Accurately weigh 150g of the stock solution and add it to 250g of 1.2% pulp (3g based on dry paper). Measure the absorbance of the filtered filtrate with an ultraviolet spectrophotometer.

[0072] III. Analysis of Test Results for Each Embodiment and Comparative Example

[0073] (1) The total yield, absorbance, brightness and intensity of the direct black dyes prepared in each example and comparative example were tested. The test results are shown in Table 1 below.

[0074] Table 1. Performance test results of direct black dyes in each example and comparative example.

[0075]

[0076] As can be seen from Table 1, the black direct liquid dye prepared by the method of the present invention has high absorbance, brightness and intensity.

[0077] (2) The stability of the black direct dyes prepared in Examples 1-7 and Comparative Examples 1-2 was tested, and the test results are shown in Table 2 below.

[0078] Table 2. Stability test results of direct black dye in each example and comparative example.

[0079]

[0080] As can be seen from Table 2, the black direct liquid dye prepared by the method of the present invention has high stability. After 24 months, the absorbance value remains basically unchanged, and the stability is better than that of the existing Direct Black 168 dye and Direct Black 19 dye.

[0081] (3) The black direct liquid dye prepared in Examples 1-7 was diluted 500 times with water. 150g of the diluted sample was taken and 0.6% (based on dry paper) of polyacrylamide, 20% (based on dry paper) of liquid calcium, and 1.2% of pulp (3g dry paper) were added. After stirring evenly, the mixture was placed in a paper forming machine to form sheets and obtain black paper. The application performance of the black direct liquid dye in papermaking and the relative color of the dye liquor were tested. The test results are shown in Table 3 below.

[0082] Comparative Examples 1 and 2 were used in equal amounts of Direct Black 168 and Direct Black 91 to replace the black direct liquid dye in Example 1. Paper was made using the same method, and the application performance in papermaking and the relative color of the dye liquor were tested. The test results are shown in Table 3 below.

[0083] Table 3. Performance of dyes in papermaking and results of relative colorimetry of dye liquor.

[0084]

[0085] As can be seen from Table 3, compared with Direct Black 168 dye and Direct Black 91 dye in Comparative Examples 1 and 2, the Direct Black liquid dye prepared in this invention has good solubility, good dyeing rate, good stability, low dosage, convenient use, and no dust pollution.

[0086] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A black direct liquid dye, characterized in that, The black direct liquid dye comprises 20-30 parts of the dye of formula I2, 50-65 parts of the dye of formula II and 50-60 parts of the dye of formula III by mass fraction. ； ； 。 2. A process for the preparation of a black direct liquid dye as claimed in claim 1, characterized in that, The method comprises the following steps: uniformly mixing 20-30 parts of the dye of formula I2, 50-65 parts of the dye of formula II and 50-60 parts of the dye of formula III to prepare the black direct liquid dye.

3. The process for the preparation of black direct liquid dyes according to claim 2, characterized in that, The method for preparing the dye of formula II comprises the following steps: Dispersing H acid in water to obtain an H acid mixture; Coupling reaction is carried out by adding a diazonium salt of DSD acid dropwise into the H acid mixture to obtain the dye of formula II.

4. The method of claim 3, wherein the black direct liquid dye is prepared by the steps of: The molar ratio of the diazonium salt of DSD acid to H acid is 1:

2. The coupling reaction is carried out at a temperature of 25-30 DEG C for 2.0-3.0 hours.

5. The process for the preparation of black direct liquid dyes according to any one of claims 2 to 4, characterized in that, The diazonium salt of DSD acid is prepared by diazotization reaction of DSD acid and sodium nitrite under acidic conditions.

6. Use of a black direct liquid dye according to claim 1, characterized in that The application of the black direct liquid dye in the field of papermaking.

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