Preparation process of efficient sodium lignin sulfonate dye dispersant

Abstract

The preparation process comprises the following steps: (1) adding a sodium hydroxide solution and lignin which is extracted from papermaking black liquor and has a relative molecular weight of more than 50 * 10 < 3 > into a reaction kettle, adding monochloroacetic acid to carry out carboxymethylation reaction, adjusting the pH value of the system to 10-11, and adding formaldehyde and sodium hydrogen sulfite to carry out reaction; and (2) carrying out spray drying on the reaction liquid obtained in the step (1), and mixing the obtained sodium lignin sulfonate with plant polyene phenol polyoxyethylene ether sulfate and a super penetrating agent BG-300P according to a mass ratio of 1: (0-0.2): (0-0.2) to prepare the sodium lignin sulfonate dye dispersant. The sodium lignin sulfonate prepared by the method has excellent heat-resistant stability and high-temperature dispersity, and can be compounded with the plant polyenol polyoxyethylene ether sulfate and the super penetrating agent BG-300P, so that the high-temperature dispersity and the heat-resistant stability are further improved, and the dye uptake is improved.

Description

Technical Field

[0001] The invention relates to the technical field of dispersants, and more specifically to a preparation process of a high-efficiency sodium lignin sulfonate dye dispersant. Background Art

[0002] Lignin is a complex polymer compound found in the woody parts of most terrestrial plants. It is the only renewable aromatic compound in nature and together with cellulose and hemicellulose, it constitutes the main component of the plant skeleton. At present, there are more than 200 lignin products in the world, which are used in many industries, mainly taking advantage of the dispersibility, adhesion, chelation and emulsification stability of lignin macromolecules. Lignin sulfonates with less impurity content are often used as dye dispersants, but the quality of current lignin-based dye dispersants is generally not high, and their heat stability and high-temperature dispersibility are poor, which affects the high-temperature dispersion performance of dyes. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a preparation process of an efficient sodium lignin sulfonate dye dispersant. The prepared sodium lignin sulfonate has excellent heat stability and high-temperature dispersibility, and can be compounded with a surfactant, plant polyphenol polyoxyethylene ether sulfate, and a super penetrant BG-300P to form a combined dispersant, thereby further improving the high-temperature dispersibility and heat stability and improving the dyeing rate.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A preparation process of a high-efficiency sodium lignin sulfonate dye dispersant comprises the following steps:

[0006] (1) Add a 20% sodium hydroxide solution and a relative molecular weight of more than 50×10 3 lignin, stir evenly, add monochloroacetic acid to carry out carboxymethylation reaction, then adjust the pH of the system to 10-11, add formaldehyde and sodium bisulfite to react;

[0007] (2) spray drying the reaction solution obtained in step (1), mixing the obtained sodium lignin sulfonate with plant polyphenol polyoxyethylene ether sulfate and super penetrant BG-300P in a mass ratio of 1:0-0.2:0-0.2 to prepare a sodium lignin sulfonate dye dispersant.

[0008] Furthermore, in step (1), during the carboxymethylation reaction, the mass ratio of crude lignin to monochloroacetic acid and sodium hydroxide solution is 1:0.3-0.5:3-5.

[0009] Furthermore, in step (1), the carboxymethylation reaction temperature is 70-80° C., and the reaction time is 70-90 min.

[0010] Furthermore, in step (1), formaldehyde and sodium bisulfite are added to react in a mass ratio of lignin to formaldehyde to sodium bisulfite of 1:0.2-0.4:0.3-0.6.

[0011] Furthermore, in step (1), after adding formaldehyde and sodium bisulfite, the reaction is carried out at 70° C.-80° C. for 2-3 hours, and then the temperature is raised to 90-110° C. and the reaction is continued for 4-8 hours.

[0012] Furthermore, in step (2), the mass ratio of sodium lignin sulfonate to plant polyphenol polyoxyethylene ether sulfate and super penetrant BG-300P is 1:0.1:0.1.

[0013] Furthermore, in step (1), lignin is extracted by the following method: firstly, the papermaking black liquor is allowed to settle and then filtered, a flocculant is added to flocculate and precipitate, and then filtered, and the obtained filtrate is subjected to membrane concentration treatment and the cut-off molecular weight is greater than 50×10 3 The crude lignin is then subjected to acid precipitation and filter pressing treatment.

[0014] The beneficial effects of the present invention are:

[0015] Using lignin as raw material, high-efficiency sodium lignin sulfonate is prepared through carboxymethylation with monochloroacetic acid, hydroxymethylation and sulfonation with formaldehyde and sodium bisulfite. It has excellent heat stability and high-temperature dispersibility, and can be compounded with surfactant plant polyphenol polyoxyethylene ether sulfate and super penetrant BG-300P to form a combined dispersant, which can further improve high-temperature dispersibility and heat stability and improve dyeing rate. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The preparation process of the high-efficiency sodium lignin sulfonate dye dispersant of the present invention comprises the following steps:

[0018] (1) First, the papermaking black liquor is allowed to settle for 20-24 hours and then filtered. Then, polyacrylamide flocculant is added for flocculation and precipitation. The filtrate is concentrated by membrane and the cut-off molecular weight is greater than 50×10 3crude lignin, and then adding sulfuric acid to acid-precipitate the crude lignin, and filtering to obtain high-purity lignin; adding a sodium hydroxide solution with a mass concentration of 20% and lignin extracted from papermaking black liquor to a reactor, stirring evenly, adding monochloroacetic acid to carry out carboxymethylation reaction (the mass ratio of crude lignin to monochloroacetic acid and sodium hydroxide solution during the carboxymethylation reaction is 1:0.3-0.5:3-5, the carboxymethylation reaction temperature is 70-80°C, and the reaction time is 70-90min), then adjusting the system pH to 10-11 with sodium hydroxide, adding formaldehyde and sodium bisulfite (adding formaldehyde and sodium bisulfite at a mass ratio of lignin to formaldehyde to sodium bisulfite of 1:0.2-0.4:0.3-0.6), reacting at 70°C-80°C for 2-3 hours, and then heating to 90-110°C to continue the reaction for 4-8h;

[0019] (2) spray drying the reaction solution obtained in step (1), mixing the obtained sodium lignin sulfonate with plant polyphenol polyoxyethylene ether sulfate and super penetrant BG-300P in a mass ratio of 1:0-0.2:0-0.2 to prepare a sodium lignin sulfonate dye dispersant.

[0020] Example 1

[0021] Preparation of High Efficiency Sodium Lignosulfonate Dye Dispersant

[0022] (1) The papermaking black liquor was first allowed to settle for 24 hours and then filtered. Then, polyacrylamide flocculant was added for flocculation and precipitation. The filtrate was filtered and the obtained filtrate was concentrated by membrane and the cut-off molecular weight was greater than 50×10 3 crude lignin, and then adding sulfuric acid to acid-precipitate the crude lignin, and filtering to obtain high-purity lignin; adding a sodium hydroxide solution with a mass concentration of 20% and lignin extracted from papermaking black liquor to the reactor, stirring evenly, adding monochloroacetic acid to carry out carboxymethylation reaction (the mass ratio of crude lignin to monochloroacetic acid and sodium hydroxide solution during the carboxymethylation reaction is 1:0.4:5, the carboxymethylation reaction temperature is 70°C, and the reaction time is 90min), and then adjusting the system pH to 10 with sodium hydroxide solution, adding formaldehyde and sodium bisulfite (adding formaldehyde and sodium bisulfite at a mass ratio of lignin to formaldehyde and sodium bisulfite of 1:0.28:0.5), reacting at 70°C for 3 hours, and then heating to 95°C to continue the reaction for 5h;

[0023] (2) spray drying the reaction solution obtained in step (1) to obtain a sodium lignin sulfonate dye dispersant.

[0024] Example 2

[0025] Preparation of High Efficiency Sodium Lignosulfonate Dye Dispersant

[0026] (1) The papermaking black liquor was first allowed to settle for 24 hours and then filtered. Then, polyacrylamide flocculant was added for flocculation and precipitation. The filtrate was filtered and the obtained filtrate was concentrated by membrane and the cut-off molecular weight was greater than 50×10 3 crude lignin, and then adding sulfuric acid to acid-precipitate the crude lignin, and filtering to obtain high-purity lignin; adding a sodium hydroxide solution with a mass concentration of 20% and lignin extracted from papermaking black liquor to the reactor, stirring evenly, adding monochloroacetic acid to carry out carboxymethylation reaction (the mass ratio of crude lignin to monochloroacetic acid and sodium hydroxide solution during the carboxymethylation reaction is 1:0.4:5, the carboxymethylation reaction temperature is 70°C, and the reaction time is 90min), and then adjusting the system pH to 10 with a sodium hydroxide solution with a mass concentration of 20%, adding formaldehyde and sodium bisulfite (adding formaldehyde and sodium bisulfite at a mass ratio of lignin to formaldehyde and sodium bisulfite of 1:0.28:0.5), reacting at 70°C for 3 hours, and then heating to 95°C to continue the reaction for 5h;

[0027] (2) spray-drying the reaction solution obtained in step (1), and uniformly mixing the obtained sodium lignin sulfonate with plant polyphenol polyoxyethylene ether sulfate (model NSN 3530, purchased from Changshu Naisu Biomaterial Technology Co., Ltd., with good high-temperature dispersibility) and super penetrant BG-300P (purchased from Shanghai Banggao Chemical Co., Ltd., with acid and alkali resistance, hard water resistance, inorganic salt resistance, high temperature resistance, and good biodegradability) at a mass ratio of 1:0.1:0.1 at 80° C. to obtain a sodium lignin sulfonate dye dispersant.

[0028] Comparative Example 1

[0029] A high-efficiency sodium lignin sulfonate dye dispersant was prepared according to the method of Example 2, except that the carboxymethylation reaction was omitted in step (1): the papermaking black liquor was first allowed to settle for 24 hours and then filtered, and then polyacrylamide flocculant was added for flocculation and precipitation, and filtered. The obtained filtrate was concentrated by membrane and the cut-off molecular weight was greater than 50×10 3 crude lignin, and then adding sulfuric acid to acidify the crude lignin, and obtaining high-purity lignin after filtration; adding lignin extracted from papermaking black liquor into the reactor, and then adjusting the pH of the system to 10 with a sodium hydroxide solution with a mass concentration of 20%, adding formaldehyde and sodium bisulfite (adding formaldehyde and sodium bisulfite in a mass ratio of lignin to formaldehyde and sodium bisulfite of 1:0.28:0.5), reacting at 70°C for 3 hours, and then heating to 95°C to continue reacting for 5 hours.

[0030] Comparative Example 2

[0031] A high-efficiency sodium lignin sulfonate dye dispersant was prepared according to the method of Example 2, except that in step (2), the plant polyphenol polyoxyethylene ether sulfate was replaced by sodium lignin sulfonate in equal mass.

[0032] Comparative Example 3

[0033] The method of Example 2 is used to prepare a highly efficient sodium lignin sulfonate dye dispersant, except that in step (2), the plant polyphenol polyoxyethylene ether sulfate is replaced by an equal amount of super penetrant BG-300P.

[0034] Comparative Example 4

[0035] A high-efficiency sodium lignin sulfonate dye dispersant was prepared according to the method of Example 2, except that in step (2), the super penetrant BG-300P was replaced by sodium lignin sulfonate of equal mass.

[0036] Comparative Example 5

[0037] A high-efficiency sodium lignin sulfonate dye dispersant was prepared according to the method of Example 2, except that in step (2), the super penetrant BG-300P was replaced by plant polyphenol polyoxyethylene ether sulfate in equal mass.

[0038] The performance tests of the dye dispersants prepared in Examples 1-2 and Comparative Examples 2-5 were performed, and the results are shown in the following table:

[0039]

[0040] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A preparation process for a highly efficient sodium lignin sulfonate dye dispersant, characterized in that: The following steps are involved: (1) Add a 20% sodium hydroxide solution and a relative molecular weight of more than 50×10 3 lignin, stir evenly, add monochloroacetic acid to carry out carboxymethylation reaction, then adjust the pH of the system to 10-11, add formaldehyde and sodium bisulfite to react; (2) spray drying the reaction solution obtained in step (1), mixing the obtained sodium lignin sulfonate with plant polyphenol polyoxyethylene ether sulfate and super penetrant BG-300P in a mass ratio of 1:0-0.2:0-0.2 to prepare a sodium lignin sulfonate dye dispersant.

2. The preparation process of a high-efficiency sodium lignin sulfonate dye dispersant according to claim 1, characterized in that: In step (1), during the carboxymethylation reaction, the mass ratio of crude lignin to monochloroacetic acid and sodium hydroxide solution is 1:0.3-0.5:3-5.

3. The preparation process of a high-efficiency sodium lignin sulfonate dye dispersant according to claim 1, characterized in that: In step (1), the carboxymethylation reaction temperature is 70-80° C. and the reaction time is 70-90 min.

4. The preparation process of a high-efficiency sodium lignin sulfonate dye dispersant according to claim 1, characterized in that: In step (1), formaldehyde and sodium bisulfite are added in a mass ratio of lignin to formaldehyde to sodium bisulfite of 1:0.2-0.4:0.3-0.6 for reaction.

5. The preparation process of a high-efficiency sodium lignin sulfonate dye dispersant according to claim 1, characterized in that: In step (1), after adding formaldehyde and sodium bisulfite, react at 70°C-80°C for 2-3 hours, then heat to 90-110°C and continue to react for 4-8 hours.

6. The preparation process of a high-efficiency sodium lignin sulfonate dye dispersant according to claim 1, characterized in that: In step (2), the mass ratio of sodium lignin sulfonate to plant polyphenol polyoxyethylene ether sulfate and super penetrant BG-300P is 1:0.1:0.

1.

7. The preparation process of a high-efficiency sodium lignin sulfonate dye dispersant according to claim 1, characterized in that: In step (1), lignin is extracted by the following method: firstly, the papermaking black liquor is allowed to settle and then filtered, a flocculant is added to flocculate and precipitate, and then filtered, and the obtained filtrate is subjected to membrane concentration treatment and the cut-off molecular weight is greater than 50×10 3 The crude lignin is then subjected to acid precipitation and filter pressing treatment.

Images