Composite defoaming agent for printing and dyeing as well as preparation method and application of composite defoaming agent

Abstract

The invention provides a composite defoaming agent for printing and dyeing as well as a preparation method and application thereof, and the composite defoaming agent for printing and dyeing comprises the following components in parts by weight: 17-23 parts of modified polysiloxane, 0.1-0.8 part of a pH regulator, 4-5.5 parts of a nonionic surfactant, 1-1.5 parts of acrylamide sulfonate and 2-5 parts of hydrophobic nano zinc oxide, wherein the modified polysiloxane is prepared from zucchinic acid and hydrogen-containing silicone oil through a reaction. The composite defoaming agent for printing and dyeing, which is prepared by using the components and content provided by the invention, has excellent defoaming and foam-inhibiting properties, and also has relatively excellent defoaming and foam-inhibiting properties even under a high-temperature condition.

Description

Technical Field

[0001] The present invention relates to the field of defoaming agents, in particular to a composite defoaming agent for printing and dyeing, and a preparation method and application thereof. Background Art

[0002] Foam is a common phenomenon in daily life and production. Sometimes, foam can be used to its full potential, such as in washing, flotation, fire extinguishing, dust removal, and the manufacture of foamed plastics and ceramics. To produce a large amount of bubbles and foam, a certain amount of foaming agent is often required. Sometimes, however, foam must be eliminated, as in fermentation, coatings, papermaking, boiler water, wastewater treatment, printing and dyeing, and prism manufacturing. The presence of foam can affect production and product quality. To eliminate or suppress the formation of foam, a certain amount of defoaming agent is often added.

[0003] Compounds suitable for use as defoamers must easily spread on the surface of a solution. This spread will remove a layer of solution adjacent to the surface, thinning the liquid film locally and causing it to rupture, thus destroying the foam. Generally, the faster the defoamer spreads on the surface, the thinner the liquid film becomes, reaching the critical thickness more quickly, accelerating foam destruction and enhancing the defoaming effect. Liquids that can typically spread on surfaces and act as defoamers have low surface tension and are easily adsorbed onto the surface, causing a localized decrease in surface tension (i.e., an increase in surface pressure) and an imbalance. Spreading then occurs locally, simultaneously removing a layer of liquid beneath the surface, thinning the liquid film and ultimately destroying the bubble membrane.

[0004] Defoamers based on organic compounds such as mineral oils, fatty acids, fatty amides, and lower alcohols, as well as those based on polyethers, do exhibit some defoaming activity under certain conditions. However, their structural characteristics dictate that they also exhibit a certain foaming effect. Therefore, to address the varying defoaming requirements and operating conditions, organosilicon defoamers have been developed. Researchers have discovered that defoamers modified with polyethers combine the inherent low surface tension and high activity of polysiloxanes with the advantages of polyethers' ease of dispersion in water. However, polyether-modified polysiloxanes exhibit inverse solubility: as temperature rises, the hydrophilicity of the polyether chains deteriorates, ultimately losing this property at the cloud point. Therefore, polyether-modified polysiloxanes must be applied at an appropriate temperature to fully exert their defoaming effect. Summary of the Invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention aims to provide a composite defoaming agent suitable for printing and dyeing systems, and a preparation method and application thereof.

[0006] On the one hand, the present invention provides a composite defoamer for printing and dyeing, comprising the following components, calculated by weight: 17-23 parts of modified polysiloxane, 0.1-0.8 parts of a pH regulator, 4-5.5 parts of a nonionic surfactant, 1-1.5 parts of acrylamide sulfonate, and 2-5 parts of hydrophobic nano zinc oxide; wherein the modified polysiloxane is prepared by reacting zucchini acid with hydrogen-containing silicone oil.

[0007] When the modified polysiloxane prepared from zucchini acid is used as a defoaming agent for printing and dyeing, it can prevent the hydrophobic nano-zinc oxide in the system from being entangled and surrounded, causing the defoaming agent to precipitate before it has time to spread and defoam, thereby avoiding increasing the defoaming time.

[0008] Furthermore, in order to improve the defoaming and anti-foaming performance of the composite defoamer for printing and dyeing, the mass ratio of the modified polysiloxane to the hydrophobic nano zinc oxide is 1:0.01-0.025, and more preferably, the mass ratio of the modified polysiloxane to the hydrophobic nano zinc oxide is 1:0.02-0.025.

[0009] In some embodiments of the present invention, the method for preparing the modified polysiloxane comprises the following steps: S1: dissolving zucchini acid in an organic solvent, adding trimethylsilyldiazomethane at room temperature, stirring and reacting for 5-10 minutes, and then performing rotary evaporation on the reaction system to remove the solvent to obtain carboxyl-protected zucchini acid; S2: The carboxyl-protected zucchini acid and hydrogenated silicone oil obtained in S1 are sequentially added to a reaction vessel, an inert gas is introduced and stirred for 10-20 minutes, the temperature is raised to 70-110° C., a platinum catalyst is added dropwise over 30-40 minutes to react, and after 3-5 hours, low-boiling substances are removed by distillation under reduced pressure to obtain the modified polysiloxane intermediate; S3: The modified polysiloxane intermediate obtained in S2 is placed in phenol, trifluoroacetic acid is added thereto, and the reaction is carried out at 45-60°C for 1-2 hours. The reaction solution is then added dropwise to a mixture of dichloromethane and 10-15wt% of a weak base salt, and the liquids are extracted and separated. The organic phases are combined, washed with water, dried, and concentrated to obtain the modified polysiloxane.

[0010] Furthermore, the organic solvent in S1 is at least one of xylene, toluene, benzene, ethanol, isopropanol, dichloromethane, and carbon tetrachloride.

[0011] Furthermore, the molar ratio of trimethylsilyldiazomethane to cucurbitacin is 1.1-1.5:1.

[0012] Furthermore, the molecular weight of the hydrogen-containing silicone oil in S2 is 1000-3000, and its hydrogen content is 0.2-0.5% by mass.

[0013] Furthermore, the mass ratio of zucchini acid to hydrogenated silicone oil in S2 is 0.42-1.14:1.

[0014] The preparation principle of the modified polysiloxane described above involves first protecting the carboxyl groups in zucchini acid with trimethylsilyldiazomethane. This then allows the double bonds in the zucchini acid to react with the Si-H bonds in the hydrogenated silicone oil via silylation, forming stable Si-C bonds. Condensation reactions between the Si-H bonds in the hydrogenated silicone oil and the hydroxyl groups in the zucchini acid also occur, forming Si-OC bonds. However, these bonds are susceptible to hydrolysis in aqueous solution, regenerating silanols.

[0015] When preparing the modified polysiloxane, the inventors found that the amount of zucchini acid introduced should not be too much, because too much zucchini acid will cause the viscosity of the modified polysiloxane to increase, which is not conducive to its performance as a defoaming agent. More importantly, the excess zucchini acid not only undergoes a double bond addition reaction with the hydrogenated silicone oil, but also a condensation reaction. The Si-OC bond formed by the condensation reaction is unstable and easily hydrolyzed. When the modified polysiloxane is applied to the printing and dyeing system as a defoaming agent component, the silanol bonds produced by hydrolysis increase. Combined with the existing carboxyl and hydroxyl groups, the surface tension of the composite defoamer for printing and dyeing in the printing and dyeing system increases, resulting in a weakening of the defoaming and anti-foaming properties, and even the occurrence of foaming. Therefore, after experimental comparison, the inventors believe that the best mass ratio of zucchini acid to the hydrogenated silicone oil is 0.42-1.14:1.

[0016] In some embodiments of the present invention, the pH adjuster is at least one of malic acid, citric acid, tartaric acid, and lactic acid; and the nonionic surfactant is an alkylphenol polyoxyethylene ether. Specifically, the alkylphenol polyoxyethylene ether can be nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dodecylphenol polyoxyethylene ether, phenylethylphenol polyoxyethylene ether, or the like.

[0017] In some embodiments of the present invention, the preparation method of the hydrophobic nano zinc oxide comprises the following steps: mixing bis(3,3,3-trifluoropropyl)-methylsilane with hydrophilic nano zinc oxide, reacting at 80-100°C for 2-3 hours under the action of a transition metal catalyst, and filtering and drying to obtain the hydrophobic nano zinc oxide.

[0018] Furthermore, the particle size of the hydrophilic nano zinc oxide is 20-35 nm.

[0019] On the other hand, the present invention also provides a method for preparing a composite defoaming agent for printing and dyeing, comprising the following steps: weighing modified polysiloxane, nonionic surfactant, acrylamide sulfonate and hydrophobic nano zinc oxide in parts by weight, adding them sequentially into a stirring device, mixing them evenly, and adding a pH regulator while stirring to obtain a uniform and stable liquid, which is the composite defoaming agent for printing and dyeing.

[0020] On the other hand, the present invention also provides the use of the composite defoamer for printing and dyeing in the field of printing and dyeing defoaming. When used, the composite defoamer is prepared into an aqueous solution with a mass fraction of 1.5-3.5%.

[0021] The composite defoamer for printing and dyeing described herein works by virtue of the carboxyl and hydroxyl groups in the modified polysiloxane acting as hydrophilic groups, enabling the composite defoamer to rapidly spread across the air-liquid interface. The hydrophobic nano-zinc oxide in the system, carried by the cyclopentyl groups, is unevenly adsorbed at the air-liquid interface, thereby reducing local surface tension and causing the bubble membrane to rupture or prevent formation, achieving defoaming and foam suppression.

[0022] Beneficial effects: Compared with the prior art, the composite defoamer for printing and dyeing of the present invention is simple to prepare, and there is no need to adjust the ratio and molecular weight of the raw materials according to the requirements of the application conditions. When used in the printing and dyeing system, it is easy to disperse. Combined with the presence of hydrophobic nano zinc oxide, it can achieve excellent defoaming and foam suppression. Due to the characteristics of the modified polysiloxane structure, the molecular chains are arranged in an orderly manner in the solution. Due to the presence of cyclopentyl groups, the molecular chains are not easy to agglomerate when the temperature rises, and are less affected by high temperature changes. DETAILED DESCRIPTION

[0023] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are illustrative of the present invention and are intended only to illustrate the present invention and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention may be made without departing from the spirit or scope of the present invention.

[0024] The following exemplary description of the preparation process of the modified polysiloxane used in the embodiment and the preparation of the hydrophobic nano zinc oxide used, wherein the hydrogen-containing silicone oil used was customized by Jiashan Jiangnan Textile Materials Co., Ltd.; nonylphenol polyoxyethylene ether was purchased from Shandong Xiangzhao New Materials Co., Ltd., model NP-10; octylphenol polyoxyethylene ether was purchased from Xingtai Xinlanxing Technology Co., Ltd., model OP-4; phenylethylphenol polyoxyethylene ether was purchased from Xingtai Xinlanxing Technology Co., Ltd., model Nongru 600.

[0025] Modified polysiloxane-1 S1: 212 g (1 mol) of zucchini acid was dissolved in toluene. 125.4 g (1.1 mol) of trimethylsilyldiazomethane was added thereto at room temperature. After stirring for 5 min, the reaction system was subjected to rotary evaporation to remove the solvent to obtain carboxyl-protected zucchini acid. S2: 66.36 g of the carboxyl-protected zucchini acid obtained in S1 and 158 g of hydrogenated silicone oil (Mw=1580, hydrogen content 0.2%) were added sequentially to a reaction vessel, nitrogen was introduced and stirred for 10 min, the temperature was raised to 70°C, and 10 ml of a 2% by mass solution of chloroplatinic acid in isopropanol was added dropwise over 30 min to react. After 3 h, low-boiling substances were removed by distillation under reduced pressure to obtain the modified polysiloxane intermediate. S3: The modified polysiloxane intermediate obtained in S2 was placed in 50 ml of phenol, 20 ml of trifluoroacetic acid was added thereto, and the mixture was reacted at 45°C for 1 hour. The reaction solution was then added dropwise to a mixture of 100 ml of dichloromethane and 10 wt% sodium carbonate solution (the volume ratio of dichloromethane to sodium bicarbonate solution was 3:2). The liquids were extracted and separated, and the organic phases were combined, washed with water, dried, and concentrated to obtain the modified polysiloxane-1.

[0026] Modified polysiloxane-2 S1: 212 g (1 mol) of zucchini acid was dissolved in toluene. 148.2 g (1.3 mol) of trimethylsilyldiazomethane was added thereto at room temperature. After stirring for 8 minutes, the reaction system was subjected to rotary evaporation to remove the solvent to obtain carboxyl-protected zucchini acid. S2: 227.39 g of the carboxyl-protected zucchini acid obtained in S1 and 199.7 g of hydrogenated silicone oil (Mw=1997, hydrogen content 0.3%) were added sequentially to a reaction vessel, nitrogen was introduced, and stirring was performed for 15 min. The temperature was raised to 80°C, and 20 ml of a 2% by mass solution of chloroplatinic acid in isopropanol was added dropwise over 35 min to react. After 4 h, low-boiling substances were removed by distillation under reduced pressure to obtain the modified polysiloxane intermediate. S3: The modified polysiloxane intermediate obtained in S2 was placed in 100 ml of phenol, 25 ml of trifluoroacetic acid was added thereto, and the mixture was reacted at 50°C for 2 h. The reaction solution was then added dropwise to a mixture of 300 ml of dichloromethane and 10 wt% sodium bicarbonate solution (the volume ratio of dichloromethane to sodium bicarbonate solution was 2:1). The liquids were extracted and separated, and the organic phases were combined, washed with water, dried, and concentrated to obtain the modified polysiloxane-2.

[0027] Modified polysiloxane-3 S1: 212 g (1 mol) of zucchini acid was dissolved in toluene. 171 g (1.5 mol) of trimethylsilyldiazomethane was added thereto at room temperature. The mixture was stirred and reacted for 10 min. The reaction system was then subjected to rotary evaporation to remove the solvent to obtain carboxyl-protected zucchini acid. S2: 345.83 g of the carboxyl-protected zucchini acid obtained in S1 and 233 g of hydrogenated silicone oil (Mw=2330, hydrogen content 0.5%) were added sequentially to a reaction vessel, nitrogen was introduced and stirred for 20 min, the temperature was raised to 90°C, and 30 ml of a 2% by mass solution of chloroplatinic acid in isopropanol was added dropwise over 40 min to react. After 5 h, low-boiling substances were removed by distillation under reduced pressure to obtain the modified polysiloxane intermediate. S3: The modified polysiloxane intermediate obtained in S2 was placed in 200 ml of phenol, 35 ml of trifluoroacetic acid was added thereto, and the mixture was reacted at 60°C for 2 h. The reaction solution was then added dropwise to a mixture of 500 ml of dichloromethane and 10 wt% sodium bicarbonate solution (the volume ratio of dichloromethane to sodium bicarbonate solution was 3:1). The liquids were extracted and separated, and the organic phases were combined, washed with water, dried, and concentrated to obtain the modified polysiloxane-3.

[0028] Modified polysiloxane-4 The preparation process is similar to that of modified polysiloxane-3, except that the mass of the carboxyl-protected zucchini acid used is 375 g.

[0029] Modified polysiloxane-5 The preparation process is similar to that of modified polysilicone-3, except that 4-hydroxy-7,10-undecadienoic acid (CAS: 90162-80-4) is used instead of cucurbitacin.

[0030] Hydrophobic Nano Zinc Oxide-1 2.38 g (0.01 mol) of bis(3,3,3-trifluoropropyl)-methylsilane (CAS=659-73-4) and 1.62 g (0.02 mol) of hydrophilic nano-zinc oxide were mixed, reacted at 80° C. for 2 h in the presence of 2 ml of a 1% by mass chloroplatinic acid isopropanol solution, and filtered and dried to obtain the hydrophobic nano-zinc oxide.

[0031] Hydrophobic Nano Zinc Oxide-2 2.38 g (0.01 mol) of bis(3,3,3-trifluoropropyl)-methylsilane and 0.81 g (0.01 mol) of hydrophilic nano-zinc oxide were mixed, reacted at 100° C. for 3 h in the presence of 0.5 ml of a 2% by mass chloroplatinic acid isopropanol solution, and filtered and dried to obtain the hydrophobic nano-zinc oxide-2.

[0032] The composition ratios of the composite defoamers for printing and dyeing described in Examples 1-5 and Comparative Examples 1-3 are detailed in Tables 1-1 and 1-2: Table 1-1 Raw material ratio

[0033] Table 1-2 Raw material ratio

[0034] According to the raw material formula shown in Table 1-1 and Table 1-2, a composite defoamer was prepared. The preparation process was as follows: modified polysiloxane, nonionic surfactant, acrylamide sulfonate and hydrophobic nano zinc oxide were weighed in parts by weight, added to a stirring device in sequence, mixed evenly, and a pH regulator was added thereto while stirring to obtain a uniform and stable liquid. The composite defoamers for printing and dyeing obtained in Example 1-2, Example 4 and Comparative Example 1-4 were then formulated into aqueous solutions with a mass fraction of 2% to be tested. At the same time, the composite defoamer for printing and dyeing obtained in Example 3 was formulated into aqueous solutions with mass fractions of 1.5%, 2%, 3% and 3.5% to be tested, respectively. The mass dispersion is the proportion of the composite defoamer for printing and dyeing in the aqueous solution.

[0035] Performance Testing Shake flask test: Use a stoppered graduated cylinder to take 50 ml of a specified standard foaming medium (5‰ sodium dodecylbenzenesulfonate aqueous solution). At a constant temperature of 60°C, add 0.5 ml of the defoamer sample obtained in Examples 1-4 and Comparative Examples 1-4, respectively. Cover the bottle with a stopper and shake it on a shaker at 100 rpm for 5 minutes. Then remove the bottle and let it stand for 5 minutes. Start timing and record the time from when the foam disappears until the liquid surface appears. This is the foam elimination and suppression time of this shake flask. High temperature resistance: Use a stoppered graduated cylinder to take 50 ml of the specified standard foaming medium (5‰ sodium dodecylbenzenesulfonate aqueous solution), add 0.5 ml of the defoamer samples (mass fraction 2%) obtained in Examples 1-4 and Comparative Examples 1-4, respectively, and shake at 100°C. Record the defoaming time.

[0036] The test results are detailed in Table 2: Table 2 Defoaming effect of the composite defoamers obtained in Examples 1-4 and Comparative Examples 1-4 at constant temperatures of 60°C and 100°C

[0037] It can be seen from Examples 3 and 4 in Table 2 that when the mass ratio of carboxyl-protected zucchini acid to hydrogenated silicone oil in S2 is within an appropriate range and the proportion of the composite defoamer for printing and dyeing in the aqueous solution is certain, the defoaming and anti-foaming properties of the aqueous solution prepared using the composite defoamer for printing and dyeing can be improved; From the comparison of Example 3 and Comparative Example 1 in Table 2, it can be seen that the composite defoamer for printing and dyeing prepared using zucchini acid has better defoaming and anti-foaming performance than the composite defoamer for printing and dyeing prepared using 4-hydroxy-7,10-undecadienoic acid when the proportion in the aqueous solution is certain.

[0038] From the comparison of Example 3 and Comparative Example 2 in Table 2, it can be seen that when the proportion of the composite defoamer for printing and dyeing prepared using the modified polysiloxane provided by the present application in the aqueous solution is certain, the defoaming and anti-foaming performance of the aqueous solution prepared using the composite defoamer for printing and dyeing can be improved; From the comparison of Example 3 and Comparative Examples 3-4 in Table 2, it can be seen that when the proportion of the composite defoamer for printing and dyeing prepared by using the hydrophobic nano zinc oxide provided by the present application in the aqueous solution is certain, the defoaming and anti-foaming performance of the aqueous solution prepared by using the composite defoamer for printing and dyeing can be improved; From the comparison between Example 3 and Comparative Examples 2 and 4 in Table 2, it can be seen that the modified polysiloxane provided by the present application and the hydrophobic nano zinc oxide have a synergistic effect, and the composite defoamer for printing and dyeing prepared by using the two together has better defoaming and anti-foaming properties; From the comparison of Examples 1-5 and Comparative Examples 2-3 in Table 2, it can be seen that when the proportion of the composite defoamer for printing and dyeing in the aqueous solution is certain, the composite defoamer for printing and dyeing provided by the present application has good defoaming and anti-foaming performance even at high temperatures, and the defoaming time can be controlled within 15 seconds; In summary, the composite defoamer for printing and dyeing prepared using the components and contents provided by the present invention has excellent defoaming and foaming inhibition properties, and has relatively good defoaming and foaming inhibition properties even under high temperature conditions.

Claims

1. A composite defoamer for printing and dyeing, characterized in that: The invention comprises the following components in parts by weight: 17-23 parts of modified polysiloxane, 0.1-0.8 parts of pH regulator, 4-5.5 parts of nonionic surfactant, 1-1.5 parts of acrylamide sulfonate and 0.2-0.5 parts of hydrophobic nano zinc oxide; wherein the modified polysiloxane is prepared by reacting zucchini acid with hydrogen-containing silicone oil.

2. The composite defoamer for printing and dyeing according to claim 1, wherein The preparation method of the modified polysiloxane comprises the following steps: S1: dissolving zucchini acid in an organic solvent, adding trimethylsilyldiazomethane at room temperature, stirring and reacting for 5-10 minutes, and then performing rotary evaporation on the reaction system to remove the solvent to obtain carboxyl-protected zucchini acid; S2: The carboxyl-protected zucchini acid and hydrogenated silicone oil obtained in S1 are sequentially added to a reaction vessel, an inert gas is introduced and stirred for 10-20 minutes, the temperature is raised to 70-90° C., a platinum catalyst is added dropwise over 30-40 minutes to react, and after 3-5 hours, low-boiling substances are removed by distillation under reduced pressure to obtain the modified polysiloxane intermediate; S3: The modified polysiloxane intermediate obtained in S2 is placed in phenol, trifluoroacetic acid is added thereto, and the reaction is carried out at 45-60°C for 1-2 hours. The reaction solution is then added dropwise to a mixture of dichloromethane and 10-15 wt% weak base salt solution, and the liquids are extracted and separated. The organic phases are combined, washed with water, dried, and concentrated to obtain the modified polysiloxane.

3. The composite defoamer for printing and dyeing according to claim 2, wherein The organic solvent in S1 is at least one of xylene, toluene, benzene, ethanol, isopropanol, dichloromethane, and carbon tetrachloride.

4. The composite defoamer for printing and dyeing according to claim 2, wherein The molar ratio of trimethylsilyldiazomethane to cucurbitacin is 1.1-1.5:

1.

5. The composite defoamer for printing and dyeing according to claim 2, wherein The molecular weight of the hydrogen-containing silicone oil in S2 is 1000-3000, and its hydrogen content is 0.2-0.5% by mass.

6. The composite defoamer for printing and dyeing according to claim 5, characterized in that The mass ratio of the carboxyl-protected zucchini acid to the hydrogenated silicone oil in S2 is 0.42-1.14:

1.

7. The composite defoamer for printing and dyeing according to claim 1, wherein The pH regulator is at least one of malic acid, citric acid, tartaric acid and lactic acid; and the nonionic surfactant is alkylphenol polyoxyethylene ether.

8. The composite defoamer for printing and dyeing according to claim 1, characterized in that The preparation method of the hydrophobic nano zinc oxide comprises the following steps: mixing bis(3,3,3-trifluoropropyl)-methylsilane with hydrophilic nano zinc oxide with a particle size of 20-35 nm, reacting at 80-100° C. for 2-3 hours under the action of a transition metal catalyst, and filtering and drying to obtain the hydrophobic nano zinc oxide; preferably, the mass ratio of the modified polysiloxane to the hydrophobic nano zinc oxide is 1:0.01-0.

025.

9. The method for preparing the composite defoamer for printing and dyeing according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: weighing modified polysiloxane, nonionic surfactant, acrylamide sulfonate and hydrophobic nano zinc oxide in parts by weight, adding them into a stirring device in sequence, mixing them evenly, and adding a pH regulator while stirring to obtain a uniform and stable liquid, which is the composite defoaming agent for printing and dyeing.

10. Use of the composite defoamer for printing and dyeing according to any one of claims 1 to 8 in the field of printing and dyeing, characterized in that: When used, prepare it into an aqueous solution with a mass fraction of 1.5-3.5%.

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