A highly substituted carboxymethyl cellulose and a digital printing paste based thereon.

Abstract

This invention discloses a highly substituted carboxymethyl cellulose and a digital printing paste based on this carboxymethyl cellulose, belonging to the field of cellulose ether technology. The preparation method of the highly substituted carboxymethyl cellulose is as follows: a) Mix refined cotton with banana peel cellulose; b) Add sodium hydroxide solution and ethanol-isopropanol mixed solvent to a reaction vessel, mix evenly, and then add the cellulose mixture for alkalization; then add sodium chloroacetate and chloroacetic acid for etherification; then add sodium hydroxide solution again, raise the temperature to continue etherification; after the reaction, cool to room temperature, neutralize with acid to neutral, filter, wash, and dry to obtain highly substituted carboxymethyl cellulose. This invention improves the method for preparing highly substituted carboxymethyl cellulose, and uses it as a raw material to formulate digital printing paste, which has the characteristics of high desizing rate, high printing clarity, high color yield, and high base paste stability, and is more suitable for acidic digital printing.

Description

Technical Field

[0001] This invention relates to the field of cellulose ether technology, and more specifically, to a highly substituted carboxymethyl cellulose and a digital printing paste based on the carboxymethyl cellulose. Background Technology

[0002] Acidic digital printing paste is a key component of digital base paste, affecting crucial indicators such as color yield, clarity, and hand feel of printed products. Modified starch is a traditional and important component in acidic digital printing pastes; however, modified starch pastes have a low desizing rate, which can negatively impact the clarity of printed patterns, color vibrancy, and the hand feel and wearability of fabrics. Carboxymethyl cellulose paste has a high paste-forming rate, but its color yield is relatively light, failing to meet the needs of the acidic digital printing market. Therefore, developing a novel carboxymethyl cellulose for acidic digital printing pastes would be of significant practical importance. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly substituted carboxymethyl cellulose and a digital printing paste based on the carboxymethyl cellulose. To achieve the above objective, this invention adopts the following technical solution:

[0004] A highly substituted carboxymethyl cellulose, which is prepared by the following method:

[0005] a. Crushing and mixing: The crushed refined cotton is mixed with banana peel cellulose to obtain a cellulose mixture; the mass ratio of banana peel cellulose to refined cotton is 0.5-3:1;

[0006] b. Alkalization and Etherification: Add 30wt% sodium hydroxide solution and ethanol-isopropanol mixed solvent to the reaction vessel, mix well, and then add the cellulose mixture. Alkalize at 20-30℃, controlling the mass ratio of sodium hydroxide to cellulose mixture to be (1-2.5):1. Then add sodium chloroacetate and chloroacetic acid, and heat to 55-60℃ for etherification reaction for 1-2 hours, controlling the mass ratio of sodium chloroacetate, chloroacetic acid and cellulose mixture to be (0.8-1.3):(0.5-1.2):1. Add 30wt% sodium hydroxide solution at 3-4 times the mass ratio of cellulose mixture, and heat to 70-80℃ to continue etherification. After the reaction is completed, cool to room temperature, neutralize with glacial acetic acid to neutral, filter, wash with ethanol, and dry to obtain the final product.

[0007] Further configured, in step b, the ethanol-isopropanol mixed solvent contains 85wt% ethanol and 15wt% isopropanol, and the ratio of the amount of cellulose mixture to the ethanol-isopropanol mixed solvent is 1g:15-30ml.

[0008] Further, in step b, the alkalization reaction time is set to 1-2 hours.

[0009] Further, in step b, the etherification reaction time at 70-80℃ is 1-1.5h.

[0010] Further settings include a cotton bulk density of 150-170 g / L.

[0011] A digital printing paste based on highly substituted carboxymethyl cellulose is prepared by uniformly mixing 20-40 parts by weight of highly substituted carboxymethyl cellulose with 15-30 parts by weight of modified starch, 10-20 parts by weight of propylene glycol alginate, 5-15 parts by weight of hydroxyethyl methyl cellulose, 3-10 parts by weight of modified polyacrylate, and 8-15 parts by weight of kiwifruit leaf extract.

[0012] Further, the modified polyacrylate is set to modified polyacrylate ZY-1100.

[0013] Further, the kiwifruit leaf extract is prepared by the following method: fresh kiwifruit tree leaves are chopped, washed, and soaked in water at a constant temperature for 12-15 days. After removing the impurities, the turbid liquid is left to stand for 20-25 hours, filtered, concentrated, and spray-dried to obtain the kiwifruit leaf extract.

[0014] Further, 32.6 parts by weight of highly substituted carboxymethyl cellulose, 25 parts by weight of modified starch, 15 parts by weight of propylene glycol alginate, 11 parts by weight of hydroxyethyl methyl cellulose, 6 parts by weight of modified polyacrylate ZY-1100, and 10.4 parts by weight of kiwifruit leaf extract were mixed to prepare a digital printing paste.

[0015] In summary, the present invention has the following beneficial effects:

[0016] By replacing some cotton with banana peels and preparing highly substituted carboxymethyl cellulose through an improved method of alkalization and two-step etherification, acidic digital printing pastes were formulated, improving the material's desizing rate, printing clarity, color yield, and base paste stability. In particular, when this highly substituted carboxymethyl cellulose was compounded with modified polyacrylate ZY-1100 and kiwifruit leaf extract to prepare printing pastes, a synergistic effect was found between modified polyacrylate ZY-1100 and kiwifruit leaf extract, which could further enhance printing performance and base paste stability, meeting higher usage requirements. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The highly substituted carboxymethyl cellulose of this invention is prepared by the following method:

[0019] a. Crushing and mixing: Crush the refined cotton (bulk density of 150-170 g / L) and mix it with banana peel cellulose to obtain a cellulose mixture; the mass ratio of banana peel cellulose to refined cotton is 0.5-3:1.

[0020] The banana peel cellulose was prepared by the following method: Banana peels were boiled in water for 5 minutes, then cooled to room temperature, cut into uniform small pieces, dried, pulverized, and passed through a 50-mesh sieve. The banana peel powder was then added to a 7.2 wt% NaOH solution and hydrolyzed in a 75°C constant temperature water bath with stirring for 60 minutes. The resulting filter residue was washed with ethanol, dried for 12 hours, and then soaked in 0.7% hydrogen peroxide at 75°C for 50 minutes. The pH was then adjusted to neutral, centrifuged, and dried to obtain banana peel cellulose.

[0021] b. Alkalization and Etherification: Add 30wt% sodium hydroxide solution and an ethanol-isopropanol mixed solvent (containing 85wt% ethanol and 15wt% isopropanol) to the reaction vessel. After mixing thoroughly, add the cellulose mixture. The ratio of the cellulose mixture to the ethanol-isopropanol mixed solvent is 1g:15-30ml. Alkalize at 20-30℃ for 1-2 hours, controlling the mass ratio of sodium hydroxide (referring to the sodium hydroxide contained in the 30wt% sodium hydroxide solution) to the cellulose mixture to be (1-2.5):1. Sodium chloroacetate and chloroacetic acid were then added, and the temperature was raised to 55-60℃ for etherification reaction for 1-2 hours. The mass ratio of sodium chloroacetate, chloroacetic acid and cellulose mixture was controlled at (0.8-1.3):(0.5-1.2):1. Sodium hydroxide solution with a concentration of 30wt% was added at 3-4 times the mass ratio of cellulose mixture, and the temperature was raised to 70-80℃ to continue the etherification reaction for 1-1.5 hours. After the reaction was completed, the mixture was cooled to room temperature, neutralized with glacial acetic acid, filtered, washed with ethanol, and dried to obtain highly substituted carboxymethyl cellulose with a degree of substitution of 1-2.

[0022] The highly substituted carboxymethyl cellulose prepared by this invention can be used to prepare digital printing paste: 20-40 parts by weight of highly substituted carboxymethyl cellulose, 15-30 parts by weight of modified starch, 10-20 parts by weight of propylene glycol alginate, 5-15 parts by weight of hydroxyethyl methyl cellulose, 3-10 parts by weight of modified polyacrylate, and 8-15 parts by weight of kiwifruit leaf extract are mixed evenly to obtain the digital printing paste.

[0023] The kiwifruit leaf extract was prepared by the following method: fresh kiwifruit tree leaves were chopped, washed, and soaked in water at a constant temperature for 12-15 days. After removing impurities, the turbid liquid was allowed to stand for 20-25 hours, filtered, concentrated, and spray-dried to obtain the kiwifruit leaf extract. The modified polyacrylate, ZY-1100, is a specially modified polyacrylate polymer compound containing a large number of carboxylic acid groups on its molecular chain. These carboxylic acid groups endow it with good water solubility and hydrophilicity, while also possessing excellent thickening and stability properties. Preferred embodiments are as follows:

[0024] Example 1

[0025] a. Crushing and mixing: The crushed refined cotton is mixed with banana peel cellulose to obtain a cellulose mixture; the mass ratio of banana peel cellulose to refined cotton is 1:1;

[0026] b. Alkalization and Etherification: Add 30wt% sodium hydroxide solution and ethanol-isopropanol mixed solvent (containing 85wt% ethanol and 15wt% isopropanol) to the reaction vessel, mix well, and then add the cellulose mixture. The ratio of the cellulose mixture to the ethanol-isopropanol mixed solvent is 1g:25ml. Alkalize at 30℃ for 1h, controlling the mass ratio of sodium hydroxide to the cellulose mixture at 1.5:1. Then add sodium chloroacetate and chloroacetic acid, and heat to 55℃ for etherification reaction for 1h, controlling the mass ratio of sodium chloroacetate, chloroacetic acid, and the cellulose mixture at 1.1:0.8:1. Add 30wt% sodium hydroxide solution at 3.5 times the mass ratio of the cellulose mixture, and heat to 80℃ to continue the etherification reaction for 1h. After the reaction is completed, cool to room temperature, neutralize with glacial acetic acid, filter, wash with ethanol, and dry to obtain carboxymethyl cellulose with a degree of substitution of 1.35.

[0027] c. Mix 32.6 parts by weight of highly substituted carboxymethyl cellulose with 25 parts by weight of modified starch, 15 parts by weight of propylene glycol alginate, 11 parts by weight of hydroxyethyl methyl cellulose, 6 parts by weight of modified polyacrylate ZY-1100, and 10.4 parts by weight of kiwifruit leaf extract (fresh kiwifruit leaves are chopped, washed, soaked in water at a constant temperature for 14 days, the residue is removed, and the turbid liquid is left to stand for 24 hours, filtered, concentrated, and spray-dried to obtain kiwifruit leaf extract) evenly to prepare digital printing paste.

[0028] Comparative Example 1

[0029] Highly substituted carboxymethyl cellulose was prepared according to the method in Example 1, and then applied to the preparation of digital printing paste, but without the addition of modified polyacrylate ZY-1100.

[0030] Comparative Example 2

[0031] Highly substituted carboxymethyl cellulose was prepared according to the method in Example 1, and then applied to the preparation of digital printing paste, but without the addition of kiwifruit leaf extract.

[0032] Comparative Example 3

[0033] Digital printing paste was prepared by replacing the highly substituted carboxymethyl cellulose in step c of Example 1 with commercially available carboxymethyl cellulose of a degree of substitution of 0.8.

[0034] The digital printing pastes prepared in Example 1 and Comparative Examples 1-3 were used for acidic digital printing on silk, and the performance test results are shown in Table 1. It can be seen that the highly substituted carboxymethyl cellulose prepared in this invention has better acid resistance, which helps to improve the performance of the printing paste; and when this highly substituted carboxymethyl cellulose is compounded with modified polyacrylate ZY-1100 and kiwifruit leaf extract, the performance of the printing paste can be further improved.

[0035] Table 1

[0036]

[0037] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A highly substituted carboxymethyl cellulose, characterized in that, This highly substituted carboxymethyl cellulose was prepared by the following method: a. Crushing and mixing: The crushed refined cotton is mixed with banana peel cellulose to obtain a cellulose mixture; the mass ratio of banana peel cellulose to refined cotton is 0.5-3:1; b. Alkalization and Etherification: Add 30wt% sodium hydroxide solution and ethanol-isopropanol mixed solvent to the reaction vessel, mix well, then add the cellulose mixture, and alkalize at 20-30℃, controlling the mass ratio of sodium hydroxide to cellulose mixture to be (1-2.5):1; then add sodium chloroacetate and chloroacetic acid, and heat to 55-60℃ for etherification reaction for 1-2 hours, controlling the mass ratio of sodium chloroacetate, chloroacetic acid to cellulose mixture to be (0.8-1.3):(0.5-1.2):1; add 3-4 times the mass ratio of cellulose mixture to 30wt% sodium hydroxide solution, and heat to 70-80℃ to continue etherification; after the reaction is completed, cool to room temperature, neutralize with glacial acetic acid to neutral, filter, wash with ethanol, and dry to obtain the final product; In step b, the ethanol-isopropanol mixed solvent contains 85wt% ethanol and 15wt% isopropanol, and the ratio of the cellulose mixture to the ethanol-isopropanol mixed solvent is 1g:15-30ml; the alkalization reaction time is 1-2h; and the etherification reaction time at 70-80℃ is 1-1.5h.

2. A digital printing paste based on the highly substituted carboxymethyl cellulose as described in claim 1, characterized in that, A digital printing paste is prepared by uniformly mixing 20-40 parts by weight of highly substituted carboxymethyl cellulose, 15-30 parts by weight of modified starch, 10-20 parts by weight of propylene glycol alginate, 5-15 parts by weight of hydroxyethyl methyl cellulose, 3-10 parts by weight of modified polyacrylate, and 8-15 parts by weight of kiwifruit leaf extract.

3. The digital printing paste based on highly substituted carboxymethyl cellulose according to claim 2, characterized in that, The modified polyacrylate is modified polyacrylate ZY-1100.

4. A digital printing paste based on highly substituted carboxymethyl cellulose according to claim 2, characterized in that, Kiwifruit leaf extract was prepared by the following method: fresh kiwifruit tree leaves were chopped, washed, and soaked in water at a constant temperature for 12-15 days. After removing the impurities, the turbid liquid was allowed to stand for 20-25 hours, filtered, concentrated, and spray-dried to obtain kiwifruit leaf extract.

5. A digital printing paste based on highly substituted carboxymethyl cellulose according to claim 2, characterized in that, A digital printing paste was prepared by mixing 32.6 parts by weight of highly substituted carboxymethyl cellulose with 25 parts by weight of modified starch, 15 parts by weight of propylene glycol alginate, 11 parts by weight of hydroxyethyl methyl cellulose, 6 parts by weight of modified polyacrylate ZY-1100, and 10.4 parts by weight of kiwifruit leaf extract.

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