Modified organic hydrotalcite paste for cotton fabric insoluble azo dye printing and preparation method and application thereof

Abstract

The present application relates to modified organic hydrotalcite paste for cotton fabric insoluble azo dye printing and its preparation method and application. The modified organic hydrotalcite paste is prepared by the following method: firstly, hydrotalcite is prepared by using nitrate and sodium salt; then, organic polymer is prepared by using acrylic acid, diallyl dimethyl ammonium chloride and allyl polyoxyethylene ether; finally, modified organic hydrotalcite is prepared by reacting hydrotalcite and organic polymer. The modified organic hydrotalcite paste prepared by the present application is used for cotton fabric insoluble azo dye printing, and the printed fabric prepared has the characteristics of higher paste removal rate (higher than 92%), good softness, high profile definition, higher penetration rate (higher than 87%), higher dry rubbing fastness and higher soaping color fastness grade, and has good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of paste preparation and application technology, specifically relating to modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes, its preparation method and application. Background Technology

[0002] Printing paste is a high-molecular-weight compound that acts as a thickener and dye transfer agent in textile printing pastes. It is soluble in water or swells and disperses fully in water to form a thick colloidal solution. As an essential component of printing pastes, its rheological properties, water-holding capacity, reactivity with reactive dyes, and ease of washing directly affect the printing effect, such as the color of the printed fabric, the amount of color applied to the surface, the clarity of the pattern outline, the uniformity of printing, and the hand feel.

[0003] Insoluble azo dyes, also known as ice dyes, are a class of water-insoluble azo dyes that form on fabrics under ice cooling. Insoluble azo dyes have excellent fastness properties, and they can produce bright colors in any shade, making them more economical than vat dyes. Insoluble azo dyes can generally be used to dye cotton textiles of any shape.

[0004] Hydrotalcite is an anionic layered compound. Layered compounds are a class of compounds with a layered structure, interlayer ions, and exchangeability. Utilizing the intercalation capability of the main layered compound under the influence of strongly polar molecules and the exchangeability of interlayer ions, functional guest substances can be introduced into the interlayer voids, widening the gaps between the layers to form a columnar compound. The structural characteristics of hydrotalcite and its compounds allow their interlayer anions to exchange with various anions, including inorganic ions, organic ions, homologous ions, heteropolyacid ions, and anions from coordination compounds. This property of hydrotalcite and its compounds allows for the modulation of the types of interlayer anions to synthesize different types of hydrotalcite and endow them with different properties, thus obtaining a new class of materials with different functions. Since hydrotalcite does not have a fixed chemical composition, the elemental types and proportions of its main layers, the types and quantities of interlayer anions, and the two-dimensional pore structure can be modified over a wide range as needed, thereby obtaining materials with special structures and properties. The tunable composition and structure of hydrotalcite, and the resulting multifunctionality, make it a novel material with great research potential and application prospects.

[0005] In recent years, organically modified hydrotalcite has developed rapidly and has been applied in many fields, such as adsorbents. However, literature review indicates that its application in pastes is currently unreported. Ordinary hydrotalcite is difficult to paste, while organically modified hydrotalcite can increase its paste-forming potential by adjusting the molecular structure of organic compounds. Ordinary hydrotalcite cannot uniformly disperse chemical auxiliaries and dyes in colloidal systems, and its viscosity changes significantly upon dilution; furthermore, its dye transfer ability is weak. These disadvantages limit the application of hydrotalcite in printing pastes, and technological breakthroughs are necessary. Pastes commonly used for printing insoluble azo dyes on cotton fabrics include wheat starch, synthetic linalool, and sodium alginate, which are expensive, increasing usage costs. Given these shortcomings, the application of organically modified hydrotalcite in pastes for printing insoluble azo dyes on cotton fabrics is of great significance. Summary of the Invention

[0006] In view of the above-mentioned drawbacks of the prior art, the purpose of this invention is to provide a modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes, its preparation method and application.

[0007] The purpose of this invention is to provide a modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes. The paste is prepared by the following method: first, hydrotalcite is prepared by using nitrates and sodium salts; then, an organic polymer is prepared by using acrylic acid, diallyl dimethyl ammonium chloride and allyl polyoxyethylene ether; finally, the hydrotalcite is reacted with the organic polymer to obtain the modified organic hydrotalcite.

[0008] The purpose of this invention is to provide a method for preparing a modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes, the specific method comprising the following steps:

[0009] (1) Preparation of hydrotalcite: Magnesium nitrate, calcium nitrate and aluminum nitrate were dissolved in distilled water to prepare a mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate. Sodium carbonate, sodium oxalate and sodium bicarbonate were dissolved in distilled water to prepare a mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate. Under stirring conditions, the mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate was added dropwise to the mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate for 2 to 4 hours. After the addition was completed, the pH of the reaction solution was adjusted to 10 to 11 with 20 to 30 wt% sodium hydroxide aqueous solution. The reaction was stirred and the reaction temperature was adjusted to 50 to 70 °C for 3 to 5 hours. After the reaction was completed, the solution was filtered, washed with distilled water, and finally dried to obtain hydrotalcite.

[0010] Preferably, the ratio of magnesium nitrate (mol), calcium nitrate (mol), and aluminum nitrate (mol) to distilled water (mL) in the magnesium nitrate, calcium nitrate, and aluminum nitrate is 1:0.1-0.2:0.2-0.4:1000-1200; and the ratio of sodium carbonate (mol), sodium oxalate (mol), and sodium bicarbonate (mol) to distilled water (mL) is 1:0.1-0.2:1-2:1000-1200.

[0011] (2) Preparation of organic polymer: Acrylic acid, diallyl dimethyl ammonium chloride and allyl polyoxyethylene ether (n=23) monomers were simultaneously dissolved in distilled water to prepare a monomer solution. Ammonium persulfate initiator was dissolved in distilled water to prepare an aqueous solution of ammonium persulfate initiator for later use. Then, under stirring conditions and with the temperature controlled at 79-81℃, the prepared monomer solution and the aqueous solution of ammonium persulfate initiator were added dropwise to a four-necked flask containing distilled water. The addition time was controlled at 2-3 hours. After the addition was completed, the temperature was kept for 3-4 hours. Finally, the solution was cooled to obtain the polymer aqueous solution.

[0012] Preferably, the molar ratio of acrylic acid, diallyl dimethyl ammonium chloride, and allyl polyoxyethylene ether (n=23) is 1:0.3-0.5:0.03-0.05; and the mass of ammonium persulfate accounts for 1-3% of the mass of acrylic acid.

[0013] (3) Preparation of modified organic hydrotalcite: The polymer aqueous solution prepared in step (2) is diluted with distilled water to a mass fraction of 1-2%; the hydrotalcite prepared in step (1) is added to the diluted polymer aqueous solution, stirred and reacted, the reaction temperature is adjusted to 50-70℃, and the reaction time is 3-5 hours; after the reaction is completed, it is filtered; washed with distilled water, then dried, ground, and the ground powder is sieved through a 100-200 mesh sieve to obtain modified organic hydrotalcite.

[0014] Preferably, the ratio of the amount of hydrotalcite (g) prepared in step (1) to the amount of diluted polymer aqueous solution (mL) is 1:10-12.

[0015] Another objective of this invention is to provide an application of a modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics. The application method is as follows: weigh the dyes and chemicals according to the color paste formula, mix the insoluble azo dye with 10 mL of cold water to form a paste, dissolve the leveling agent O in 10 mL of hot water and allow it to cool, dissolve the paste-like insoluble azo dye, leveling agent O and 98 wt% acetic acid in distilled water, mix them evenly and dissolve them; finally, add the modified organic hydrotalcite paste, stir evenly, and obtain a printing color paste for insoluble azo dyes on cotton fabrics; print the obtained color paste on cotton fabrics.

[0016] Preferably, the pigment paste formulation is as follows: 20-24g of the modified organic hydrotalcite paste prepared in this invention; 3-5g of insoluble azo dye; 1-2g of leveling agent O; 5-10mL of 98wt% acetic acid; and water to 100g.

[0017] Preferably, the insoluble azo dye is any one of the following insoluble azo dyes: naphthol AS, naphthol AS-TR, naphthol AS-D, and naphthol AS-BS.

[0018] Preferably, the printing process is as follows: flat screen printing (scraping once) → drying (100℃, 3min) → steaming (102℃, 10min) → rinsing twice with cold water → soaping → washing with cold water → drying.

[0019] The present invention has the following significant advantages:

[0020] (1) The present invention uses an ion exchange method to exchange the anions between the interlayer of hydrotalcite with the anions in the organic polymer in the solution, thereby obtaining modified organic hydrotalcite.

[0021] (2) The inventors of this application unexpectedly discovered that hydrotalcite modified into a high-value cotton fabric insoluble azo dye printing paste has good performance, and this discovery expands the application field of hydrotalcite.

[0022] (3) The modified organic hydrotalcite paste prepared by the present invention is used for printing cotton fabrics with insoluble azo dyes. The printed fabrics produced have the advantages of a desizing rate of more than 92%, good softness, high outline clarity, penetration rate of more than 87%, and high fastness to dry rubbing and fastness to soaping. It has a good application prospect.

[0023] (4) In view of the poor paste-forming properties of hydrotalcite, the present invention increases the wettability of hydrotalcite by inserting long polyethylene glycol branches into the layered structure of hydrotalcite, which is beneficial to the transfer of dye molecules. Detailed Implementation

[0024] The present invention is described in detail below with reference to the embodiments and comparative examples.

[0025] Main raw material sources: Naphthophenol AS and leveling agent O were purchased from Zhejiang Runtu Co., Ltd.; printing paste SV-14 was purchased from Xiamen Anke Chemical Co., Ltd.

[0026] Example 1

[0027] A method for preparing modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes includes the following steps:

[0028] (1) Preparation of hydrotalcite: 1 mol magnesium nitrate, 0.15 mol calcium nitrate and 0.3 mol aluminum nitrate were dissolved in 1100 mL of distilled water to prepare a mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate. 1 mol sodium carbonate, 0.15 mol sodium oxalate and 1.5 mol sodium bicarbonate were dissolved in 1100 mL of distilled water to prepare a mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate. Under stirring conditions, the mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate was added dropwise to the mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate over a period of 3 hours. After the addition was complete, the pH of the reaction solution was adjusted to 10.5 with 25 wt% sodium hydroxide aqueous solution, the reaction was stirred, the reaction temperature was adjusted to 60℃, and the reaction time was 4 hours. After the reaction was completed, the solution was filtered, washed with distilled water, and finally dried to obtain hydrotalcite.

[0029] (2) Preparation of organic polymer: 1 mol of acrylic acid, 0.4 mol of diallyl dimethyl ammonium chloride and 0.04 mol of allyl polyoxyethylene ether (n=23) monomers were simultaneously dissolved in 300 mL of distilled water to prepare a monomer solution. 1.44 g of ammonium persulfate initiator was dissolved in 50 mL of distilled water to prepare an ammonium persulfate initiator aqueous solution for later use. Then, under stirring conditions and with the temperature controlled at 80 °C, the prepared monomer solution and the ammonium persulfate initiator aqueous solution were added dropwise to a four-necked flask containing 100 mL of distilled water. The addition time was controlled at 2.5 h. After the addition was completed, the temperature was kept warm for 3.5 h. Finally, the solution was cooled to obtain the polymer aqueous solution.

[0030] (3) Preparation of modified organic hydrotalcite: The polymer aqueous solution prepared in step (2) was diluted with distilled water to a mass fraction of 1.5%; 10g of hydrotalcite prepared in step (1) was added to 110mL of the diluted polymer aqueous solution, stirred and reacted, the reaction temperature was adjusted to 60℃, and the reaction time was 4 hours; after the reaction was completed, it was filtered; washed with distilled water, then dried, ground, and the ground powder was sieved through a 150-mesh sieve to obtain modified organic hydrotalcite.

[0031] The application of modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics is described below. The method involves selecting the following pigment paste formula: 22g of the modified organic hydrotalcite paste prepared according to this invention; 4g of the insoluble azo dye Naphthoquinone AS; 1.5g of leveling agent O; 7.5mL of 98wt% acetic acid; and adding water to a final volume of 100g. The dyes and chemicals are weighed according to the pigment paste formula. The insoluble azo dye Naphthoquinone AS is mixed into a paste with 10mL of cold water. The leveling agent O is dissolved in 10mL of hot water and allowed to cool. The paste-like insoluble azo dye Naphthoquinone AS, leveling agent O, and 98wt% acetic acid are dissolved in distilled water and mixed thoroughly until dissolved. Finally, the modified organic hydrotalcite paste is added and stirred evenly to obtain the printing pigment paste for insoluble azo dyes on cotton fabrics. The obtained pigment paste is then used for printing on cotton fabrics. The printing process is as follows: flat screen printing (scraping once) → drying (100℃, 3min) → steaming (102℃, 10min) → rinsing twice with cold water → soaping → washing with cold water → drying.

[0032] Example 2

[0033] A method for preparing modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes includes the following steps:

[0034] (1) Preparation of hydrotalcite: 1 mol magnesium nitrate, 0.1 mol calcium nitrate and 0.2 mol aluminum nitrate were dissolved in 1000 mL of distilled water to prepare a mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate. 1 mol sodium carbonate, 0.1 mol sodium oxalate and 1 mol sodium bicarbonate were dissolved in 1000 mL of distilled water to prepare a mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate. Under stirring conditions, the mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate was added dropwise to the mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate over a period of 2 hours. After the addition was completed, the pH of the reaction solution was adjusted to 10 with 20 wt% sodium hydroxide solution, the reaction was stirred, the reaction temperature was adjusted to 50 °C, and the reaction time was 3 hours. After the reaction was completed, the solution was filtered, washed with distilled water, and finally dried to obtain hydrotalcite.

[0035] (2) Preparation of organic polymer: 1 mol acrylic acid, 0.3 mol diallyl dimethyl ammonium chloride and 0.03 mol allyl polyoxyethylene ether (n=23) monomers were simultaneously dissolved in 200 mL of distilled water to prepare a monomer solution. 0.72 g ammonium persulfate initiator was dissolved in 50 mL of distilled water to prepare an ammonium persulfate initiator aqueous solution for later use. Then, under stirring conditions and with the temperature controlled at 79 °C, the prepared monomers and ammonium persulfate initiator were added dropwise to a four-necked flask containing 100 mL of distilled water. The addition time was controlled at 2 h. After the addition was completed, the temperature was kept for 3 h. Finally, the solution was cooled to obtain the polymer aqueous solution.

[0036] (3) Preparation of modified organic hydrotalcite: The polymer aqueous solution prepared in step (2) was diluted with distilled water to a mass fraction of 1%; 10g of hydrotalcite prepared in step (1) was added to 100mL of the diluted polymer aqueous solution, stirred and reacted, the reaction temperature was adjusted to 50℃, and the reaction time was 3 hours; after the reaction was completed, it was filtered; washed with distilled water, then dried, ground, and the ground powder was sieved through a 100-mesh sieve to obtain modified organic hydrotalcite.

[0037] The application of modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics is described below. The method involves selecting the following pigment paste formula: 20g of the modified organic hydrotalcite paste prepared according to this invention; 3g of the insoluble azo dye Naphthoquinone AS; 1g of leveling agent O; 5mL of 98wt% acetic acid; and adding water to a final volume of 100g. The dyes and chemicals are weighed according to the pigment paste formula. The insoluble azo dye Naphthoquinone AS is mixed into a paste with 10mL of cold water. The leveling agent O is dissolved in 10mL of hot water and allowed to cool. The paste-like insoluble azo dye Naphthoquinone AS, leveling agent O, and 98wt% acetic acid are dissolved in distilled water and mixed thoroughly until dissolved. Finally, the modified organic hydrotalcite paste is added and stirred evenly to obtain the printing pigment paste for insoluble azo dyes on cotton fabrics. The obtained pigment paste is then used for printing on cotton fabrics. The printing process is as follows: flat screen printing (scraping once) → drying (100℃, 3min) → steaming (102℃, 10min) → rinsing twice with cold water → soaping → washing with cold water → drying.

[0038] Example 3

[0039] A method for preparing modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes includes the following steps:

[0040] (1) Preparation of hydrotalcite: 1 mol magnesium nitrate, 0.2 mol calcium nitrate and 0.4 mol aluminum nitrate were dissolved in 1200 mL of distilled water to prepare a mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate. 1 mol sodium carbonate, 0.2 mol sodium oxalate and 2 mol sodium bicarbonate were dissolved in 1200 mL of distilled water to prepare a mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate. Under stirring conditions, the mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate was added dropwise to the mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate over a period of 4 hours. After the addition was completed, the pH of the reaction solution was adjusted to 11 with 30 wt% sodium hydroxide solution. The reaction was stirred and the reaction temperature was adjusted to 70 °C for a reaction time of 5 hours. After the reaction was completed, the solution was filtered, washed with distilled water, and finally dried to obtain hydrotalcite.

[0041] (2) Preparation of organic polymer: 1 mol of acrylic acid, 0.5 mol of diallyl dimethyl ammonium chloride and 0.05 mol of allyl polyoxyethylene ether (n=23) monomers were simultaneously dissolved in 400 mL of distilled water to prepare a monomer solution. 2.16 g of ammonium persulfate initiator was dissolved in 50 mL of distilled water to prepare an ammonium persulfate initiator aqueous solution for later use. Then, under stirring conditions and with the temperature controlled at 79-81℃, the prepared monomers and ammonium persulfate initiator were added dropwise to a four-necked flask containing 100 mL of distilled water. The addition time was controlled at 2-3 h. After the addition was completed, the temperature was kept warm for 3-4 h. Finally, the solution was cooled to obtain the polymer aqueous solution.

[0042] (3) Preparation of modified organic hydrotalcite: The polymer aqueous solution prepared in step (2) was diluted with distilled water to a mass fraction of 2%; 10g of hydrotalcite prepared in step (1) was added to 120mL of the diluted polymer aqueous solution, stirred and reacted, the reaction temperature was adjusted to 70℃, and the reaction time was 5 hours; after the reaction was completed, it was filtered; washed with distilled water, then dried, ground, and the ground powder was sieved through a 200-mesh sieve to obtain modified organic hydrotalcite.

[0043] The application of modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics is described below. The method involves selecting the following pigment paste formula: 24g of the modified organic hydrotalcite paste prepared according to this invention; 5g of the insoluble azo dye Naphthoquinone AS; 2g of leveling agent O; 10mL of 98wt% acetic acid; and adding water to a final volume of 100g. The dyes and chemicals are weighed according to the pigment paste formula. The insoluble azo dye Naphthoquinone AS is mixed into a paste with 10mL of cold water. The leveling agent O is dissolved in 10mL of hot water and allowed to cool. The paste-like insoluble azo dye Naphthoquinone AS, leveling agent O, and 98wt% acetic acid are dissolved in distilled water and mixed thoroughly until dissolved. Finally, the modified organic hydrotalcite paste is added and stirred evenly to obtain the printing pigment paste for insoluble azo dyes on cotton fabrics. The obtained pigment paste is then used for printing on cotton fabrics. The printing process is as follows: flat screen printing (scraping once) → drying (100℃, 3min) → steaming (102℃, 10min) → rinsing twice with cold water → soaping → washing with cold water → drying.

[0044] Comparative Example A

[0045] Compared with Example 1, the "0.4 mol diallyl dimethyl ammonium chloride" in step (2) was increased to "4 mol diallyl dimethyl ammonium chloride"; other preparation methods and application methods remained unchanged from Example 1.

[0046] Comparative Example B

[0047] Compared with Example 1, the "0.4 mol diallyl dimethyl ammonium chloride" in step (2) was reduced to "0.04 mol diallyl dimethyl ammonium chloride"; other preparation methods and application methods remained unchanged from Example 1.

[0048] Comparative Example C

[0049] Compared with Example 1, the "0.04 mol allyl polyoxyethylene ether" in step (2) was increased to "0.4 mol allyl polyoxyethylene ether"; other preparation methods and application methods remained unchanged from Example 1.

[0050] Comparative Example D

[0051] Compared with Example 1, the "0.04 mol allyl polyoxyethylene ether" in step (2) was reduced to "0.004 mol allyl polyoxyethylene ether"; other preparation methods and application methods remained unchanged from Example 1.

[0052] Comparative Example E

[0053] The printing paste SV-14 purchased from the market was used as the paste in this embodiment. The color paste was prepared using the method of Example 1 and printed on cotton fabric.

[0054] Application performance testing:

[0055] The viscosity of the pastes prepared in Examples 1-3 and Comparative Example AE was tested using a digital viscometer. The printing viscosity index (PVI value) was calculated as follows: Among them, η6 and η 0.6 The values ​​represent the viscosity of the paste at 6 r / min and 0.6 r / min, respectively. The test results are shown in Table 1.

[0056] The printed cotton fabrics obtained from Examples 1-3 and Comparative Example AE were subjected to relevant tests: the K / S value was measured using a computer colorimeter; the penetration rate was expressed as the ratio of the K / S value on the reverse side to the K / S value on the front side of the fabric; the color fastness to washing was tested according to GB / T3921-2008 "Textiles - Tests for Color Fastness - Color Fastness to Washing"; the color fastness to dry rubbing was tested according to GB / T3920-2008 "Textiles - Tests for Color Fastness - Color Fastness to Rubbing"; the formula for calculating the desizing rate is: m1 represents the mass of the printed and dried fabric, m2 represents the mass of the printed fabric after washing, and m0 represents the mass of the unprinted fabric; Fabric softness test: The softness of the printed fabric was tested using a fabric style meter; Outline sharpness test: The sharpness level was assessed visually; The test results are shown in Table 1.

[0057] Table 1. Evaluation of the application performance of modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes.

[0058]

[0059]

[0060] As shown in Table 1, by comparing Example 1, Comparative Examples A and B, it can be found that an appropriate amount of diallyl dimethyl ammonium chloride is beneficial to improving the printing performance of the modified organic hydrotalcite paste. By comparing Example 1, Comparative Examples C and D, it can be found that an appropriate amount of long-branched allyl polyoxyethylene ether is beneficial to improving the printing performance of the modified organic hydrotalcite paste. By comparing Examples 1-3 and Comparative Example E, it can be found that compared with existing commercial printing pastes on the market, the modified organic hydrotalcite paste prepared by this invention and the cotton fabric printed from it meet or exceed the standards of existing commercial printing pastes and their printed cotton fabrics in many test indicators.

Claims

1. A method for preparing a modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes, characterized in that, The preparation method includes the following steps: (1) Preparation of hydrotalcite: Magnesium nitrate, calcium nitrate and aluminum nitrate were dissolved in distilled water to prepare a mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate. Sodium carbonate, sodium oxalate and sodium bicarbonate were dissolved in distilled water to prepare a mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate. Under stirring conditions, the mixed aqueous solution of sodium carbonate, sodium oxalate and sodium bicarbonate was added dropwise to the mixed aqueous solution of magnesium nitrate, calcium nitrate and aluminum nitrate for 2 to 4 hours. After the addition was completed, the pH of the reaction solution was adjusted to 10 to 11 with 20 to 30 wt% sodium hydroxide aqueous solution. The reaction was stirred and the reaction temperature was adjusted to 50 to 70 °C for 3 to 5 hours. After the reaction was completed, the solution was filtered, washed with distilled water, and finally dried to obtain hydrotalcite. (2) Preparation of organic polymer: Acrylic acid, diallyl dimethyl ammonium chloride and allyl polyoxyethylene ether monomer with a degree of polymerization of 23 were simultaneously dissolved in distilled water to prepare a monomer solution. Ammonium persulfate initiator was dissolved in distilled water to prepare an aqueous solution of ammonium persulfate initiator for later use. Then, under stirring conditions and with the temperature controlled at 79-81℃, the prepared monomer solution and the aqueous solution of ammonium persulfate initiator were added dropwise to a four-necked flask containing distilled water. The addition time was controlled at 2-3 hours. After the addition was completed, the temperature was kept for 3-4 hours. Finally, the solution was cooled to obtain a polymer aqueous solution. (3) Preparation of modified organic hydrotalcite: The polymer aqueous solution prepared in step (2) is diluted with distilled water to a mass fraction of 1-2%; the hydrotalcite prepared in step (1) is added to the diluted polymer aqueous solution, stirred and reacted, the reaction temperature is adjusted to 50-70℃, and the reaction time is 3-5 hours; after the reaction is completed, it is filtered; washed with distilled water, then dried, ground, and the ground powder is sieved through a 100-200 mesh sieve to obtain modified organic hydrotalcite paste; In step (2), the molar ratio of acrylic acid, diallyl dimethyl ammonium chloride and allyl polyoxyethylene ether with a degree of polymerization of 23 is 1:(0.3-0.5):(0.03-0.05); the amount of ammonium persulfate in acrylic acid is 1-3 wt%.

2. The method for preparing the modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes according to claim 1, characterized in that, The ratio of magnesium nitrate, calcium nitrate, aluminum nitrate to distilled water in step (1) is 1 mol: (0.1-0.2) mol: (0.2-0.4) mol: (1000-1200) mL; the ratio of sodium carbonate, sodium oxalate, and sodium bicarbonate to distilled water is 1 mol: (0.1-0.2) mol: (1-2) mol: (1000-1200) mL.

3. The method for preparing the modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes according to claim 1, characterized in that, The ratio of the amount of hydrotalcite prepared in step (1) to the amount of diluted polymer aqueous solution in step (3) is 1 g: (10-12) mL.

4. A modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes, characterized in that, It is prepared by the method for preparing modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes as described in any one of claims 1 to 3.

5. The application of a modified organic hydrotalcite paste for printing cotton fabrics with insoluble azo dyes as described in claim 4, characterized in that, The application method is as follows: Weigh the dyes and chemicals according to the color paste formula, mix the insoluble azo dye with 10 mL of cold water to form a paste, dissolve the leveling agent O in 10 mL of hot water and let it cool, dissolve the paste-like insoluble azo dye, leveling agent O and 98 wt% acetic acid in distilled water, mix evenly and let it dissolve; finally add the modified organic hydrotalcite paste, stir evenly, and obtain the cotton fabric insoluble azo dye printing color paste; print the obtained color paste on the cotton fabric.

6. The application of the modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics according to claim 5, characterized in that, The pigment paste formula is as follows: modified organic hydrotalcite paste: 20-24g; insoluble azo dye: 3-5g; leveling agent O: 1-2g; 98wt% acetic acid: 5-10mL; add water to 100g.

7. The application of the modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics according to claim 5, characterized in that, The insoluble azo dye is any one of naphthol AS, naphthol AS-TR, naphthol AS-D, and naphthol AS-BS.

8. The application of the modified organic hydrotalcite paste for printing insoluble azo dyes on cotton fabrics according to claim 5, characterized in that, The printing process is as follows: flat screen printing, squeegee printing once → drying at 100℃ for 3 minutes → steaming at 102℃ for 10 minutes → rinsing twice with cold water → soaping → washing with cold water → drying.

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