Silicon-free defoaming agent and preparation method thereof

Abstract

The invention discloses a silicon-free defoaming agent and a preparation method thereof, and relates to the technical field of defoaming agents, the silicon-free defoaming agent comprises, by mass, 6-8% of a dynamic response oil phase, 2-4% of a gradient crystallization agent, 1-2% of an amphiphilic emulsifier, 1-2% of an interface disturbance synergist, and the balance pure water; the invention also provides a preparation method of the silicon-free defoaming agent. The preparation method comprises the following steps: S1, completely dissolving the amphiphilic emulsifier in pure water accounting for 30% of the total mass of the pure water; s2, adding a dynamic response oil phase into the solution prepared in S1, uniformly mixing, and performing ultrasonic treatment to obtain a white emulsion; s3, heating the white emulsion obtained in S2 to 60 DEG C, adding a gradient crystallizing agent and pure water accounting for 30% of the total mass of the pure water, and uniformly stirring to obtain a mixed emulsion; and S4, after the temperature of the mixed emulsion prepared in S3 is reduced to room temperature, adding the interface disturbance synergist and the residual pure water, and fully and uniformly mixing to obtain the silicon-free defoaming agent.

Description

Technical Field

[0001] The present invention relates to the technical field of defoamers, and particularly relates to a silicone-free defoamer and a preparation method thereof. Background Art

[0002] In the application field of industrial defoamers, silicone-containing defoamers are widely used due to their excellent spreading performance and high defoaming efficiency. However, the inherent hydrophobicity of such defoamers makes them prone to phase separation in hydrophilic systems. Specifically, under the action of dynamic shear force or after long-term static settlement, the silicone-based components dissociate from the continuous phase due to interfacial energy differences, forming micron-sized hydrophobic particles. This dynamic migration behavior not only destroys the homogeneity of the system but also poses a risk of secondary pollution. The precipitated silicone oxide particles are easily adsorbed on the inner wall of equipment or at pipe bends, forming stubborn silicone spot residues, significantly increasing the equipment maintenance frequency and energy consumption costs. Therefore, in view of the limitations of silicone-containing defoamers in terms of environmental and process compatibility, the development of silicone-free defoamers has become an important research direction.

[0003] However, existing silicone-free systems are basically based on polyethers or fatty alcohols as the main active ingredients. In systems rich in anionic surfactants, they will be competitively inhibited due to intermolecular hydrogen bonding, resulting in an increase in the critical micelle concentration, making the defoaming half-life 30 - 50% lower than that of silicone-containing systems and difficult to meet the requirements of continuous production.

[0004] In addition, existing silicone-free defoamers basically rely on mineral oils or metal stearate soaps, with single formulation design and stability defects, making it impossible to balance rapid defoaming and long-term stability in the scenario of paint mist circulating water treatment; especially for high ionic strength paint mist wastewater (conductivity > 2000 μS / cm), the prior art has not solved the problem of synergistic optimization of the stability and long-term foam inhibition of silicone-free defoamers.

[0005] At the same time, existing silicone-free defoamers also face the contradiction between cost and environmental friendliness. Although polyether defoamers can improve temperature responsiveness through block copolymerization, their synthesis requires precious metal catalysts and the biodegradability of the products is poor; while environmentally friendly natural oil derivatives are biodegradable, but the cost surges due to high requirements for raw material purity. Summary of the Invention

[0006] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a silicone-free defoamer and a preparation method thereof to solve the problems of poor defoaming performance, complex process, high cost, and environmental risks of silicone-free defoamers in the prior art.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A silicone-free defoamer, calculated by mass fraction, includes 6-8% of a dynamic response oil phase, 2-4% of a gradient crystallizer, 1-2% of an amphiphilic emulsifier, and 1-2% of an interfacial disturbance synergist, with the balance being pure water.

[0009] Preferably, the dynamic response oil phase is composed of a mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3.

[0010] Preferably, the gradient crystallizer is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1.

[0011] Preferably, the amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1, where the hydrophilic-lipophilic balance value HLB of EL-10 is 10 and the hydrophilic-lipophilic balance value HLB of Span 80 is 4.3.

[0012] Preferably, the interfacial disturbance synergist includes a propylene oxide / ethylene oxide block polyether, where the mass ratio of propylene oxide to ethylene oxide is 3:1, and the molecular weight of the propylene oxide / ethylene oxide block polyether is 2500 ± 200.

[0013] The present invention also provides a preparation method of a silicone-free defoamer, including the following steps:

[0014] S1. Completely dissolve the amphiphilic emulsifier in pure water accounting for 30% of the total mass of pure water;

[0015] S2. Add the dynamic response oil phase to the solution obtained in S1, mix evenly, and then ultrasonicate to obtain a white emulsion;

[0016] S3. After heating the white emulsion obtained in S2 to 60°C, add the gradient crystallizer and pure water accounting for 30% of the total mass of pure water, and stir evenly to obtain a mixed emulsion;

[0017] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add the interfacial disturbance synergist and the remaining pure water, and mix thoroughly to obtain a silicone-free defoamer.

[0018] Preferably, in step S2, the mixing method is to intermittently homogenize for 1-2 times at 5000-10000 r / min, and the ultrasonic frequency is 40 kHz and the ultrasonic time is 10 min.

[0019] Preferably, in step S3, the mixing method is to intermittently homogenize for 3-5 times at 8000-12000 r / min.

[0020] Preferably, in step S4, the mixing method is to intermittently homogenize for 1-2 times at 8000-12000 r / min.

[0021] Preferably, in step S4, the criterion for judging sufficient and uniform mixing is that the dispersion coefficient PDI of the mixed emulsion is < 0.2, and the Zeta potential is between -10 mV and -50 mV.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. In the present invention, compared with the traditional single oil phase, the dynamic response oil phase obtained by compounding mineral oil / castor oil methyl ester has a synergistic effect of polarity-hydrophobicity, and can have good biodegradability and diffusion performance. Its surface spreading coefficient is 21 mN / m, which is significantly lower than 35 mN / m of the single oil phase, and the surface spreading efficiency is increased by 40%. At the same time, the critical micelle concentration of the dynamic response oil phase is also significantly reduced; moreover, the crystallization stability of the dynamic response oil phase combined with the gradient crystallizer in the present invention can significantly improve and enhance the penetration ability of the foam liquid film, so as to be able to destroy the foam layer structure and eliminate foam in a short time to achieve the purpose of rapid defoaming.

[0024] 2. The gradient crystallizer in the present invention is a B-type crystal network structure with a crystallinity ≥ 85%. It can cooperate with the interface disturbance synergist to form a dynamic interfacial tension gradient, thereby jointly enhancing the emulsification and diffusibility of the defoamer, further enhancing the penetration ability of the foam liquid film, and still maintaining stable foam suppression performance under high temperature and high shear conditions.

[0025] 3. The defoamer prepared by the present invention does not contain organosilicon components, can effectively avoid the problem of silicon spot residue, reduces the frequency of equipment maintenance and energy consumption cost, and at the same time has good biodegradability. The defoamer prepared by the present invention can maintain good performance within the range of pH value 5 - 9 and temperature 5 - 50 °C, and is especially suitable for high ionic strength environments (conductivity > 2000 μS / cm), making the defoamer have good process adaptability.

[0026] Other advantages, objectives and features of the present invention will be partially reflected by the following description, and partially will be understood by those skilled in the art through the research and practice of the present invention. Description of the Drawings

[0027] Figure 1 It is a comparison chart of the CMC values of the compound system of mineral oil and castor oil methyl ester and the single oil phase.

[0028] Figure 2 It is a curve of the particle size change of D90 of the defoamer prepared in Example 1 under different temperature conditions. Detailed Embodiments

[0029] In order to make the technical means, creative features, achieved objectives and functions of the present invention clearer and easier to understand, the present invention will be further described below in conjunction with specific embodiments:

[0030] Example 1

[0031] S1. Weigh a 1% amphiphilic emulsifier at room temperature and dissolve it in pure water accounting for 30% of the total mass of pure water. Stir it thoroughly until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1.

[0032] S2. Then add a 6% dynamic response oil phase component to the solution prepared in S1, and then homogenize it intermittently for a short time once at 10000 r / min to mix evenly. Then, ultrasonicate it at 40 kHz for 10 min to obtain a white emulsion. The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3.

[0033] S3. After heating the white emulsion obtained in S2 to 60 °C, add a 2% gradient crystallizer and homogenize it intermittently for a short time 3 times at 12000 r / min. During the stirring process, add pure water accounting for 30% of the total mass of pure water to obtain a mixed emulsion. The gradient crystallizer is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1.

[0034] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 1% of propylene oxide / ethylene oxide block polyether, homogenize it intermittently for a short time once at 12000 r / min, and add the remaining pure water during the stirring process. Mix thoroughly until the dispersion coefficient PDI of the mixed emulsion is <0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0035] Example 2

[0036] S1. Weigh a 1.5% amphiphilic emulsifier at room temperature and dissolve it in pure water accounting for 30% of the total mass of pure water. Stir it thoroughly until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1.

[0037] S2. Then add a 6% dynamic response oil phase component to the solution prepared in S1, and then homogenize it intermittently for a short time 2 times at 5000 r / min to mix evenly. Then, ultrasonicate it at 40 kHz for 10 min to obtain a white emulsion. The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3.

[0038] S3. After heating the white emulsion obtained in S2 to 60° C., adding a gradient crystallizer with a mass fraction of 3%, and intermittently short-term homogenization at 8000 r / min for 5 times, adding pure water accounting for 30% of the total mass of pure water during the stirring process to obtain a mixed emulsion, wherein the gradient crystallizer is a mixture of glyceryl monostearate and aluminum behenate in a mass ratio of 10:1;

[0039] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 1.5% of propylene oxide / ethylene oxide block polyether, intermittently homogenize for a short time twice at 8000r / min, add the remaining pure water during stirring, and mix thoroughly until the dispersion coefficient PDI of the mixed emulsion is less than 0.2, and the Zeta potential is between -10mV and -50mV, so as to obtain a silicone-free defoaming agent.

[0040] Example 3

[0041] S1. Weigh 2% of the mass fraction of an amphiphilic emulsifier at room temperature, dissolve it in pure water accounting for 30% of the total mass of pure water, and stir it thoroughly to completely dissolve it into a transparent solution, wherein the amphiphilic emulsifier is a mixture of EL-10 and Span 80 in a mass ratio of 2:1;

[0042] S2. Subsequently, a 6% by mass fraction of a dynamic response oil phase component was added to the solution prepared in S1, and then the mixture was homogenized once at 7000 r / min for a short time to be uniformly mixed, and then ultrasonicated at 40 kHz for 10 min to obtain a white emulsion, wherein the dynamic response oil phase was a mixture of mineral oil and methyl ricinoleate in a mass ratio of 5:3;

[0043] S3. After the white emulsion obtained in S2 is heated to 60° C., a gradient crystallizer having a mass fraction of 4% is added, and intermittent short-term homogenization is performed 4 times at 10000 r / min, and pure water accounting for 30% of the total mass of pure water is added during the stirring process to obtain a mixed emulsion, wherein the gradient crystallizer is a mixture of glyceryl monostearate and aluminum behenate in a mass ratio of 10:1;

[0044] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 2% of propylene oxide / ethylene oxide block polyether, intermittently homogenize for a short time at 10000r / min, add the remaining pure water during the stirring process, and mix thoroughly until the dispersion coefficient PDI of the mixed emulsion is less than 0.2, and the Zeta potential is between -10mV and -50mV, so as to obtain a silicone-free defoaming agent.

[0045] Example 4

[0046] S1. Weigh an amphiphilic emulsifier with a mass fraction of 1.5% at room temperature, dissolve it in pure water accounting for 30% of the total mass of pure water, and stir it thoroughly until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1;

[0047] S2. Subsequently, add a dynamic response oil phase component with a mass fraction of 7% to the solution prepared in S1, then homogenize it intermittently for 2 times at 6000 r / min to mix evenly, and then ultrasonicate it at 40 kHz for 10 min to obtain a white emulsion. The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3;

[0048] S3. After heating the white emulsion obtained in S2 to 60 °C, add a gradient crystallizing agent with a mass fraction of 2%, and homogenize it intermittently for 5 times at 9000 r / min. During the stirring process, add pure water accounting for 30% of the total mass of pure water to obtain a mixed emulsion. The gradient crystallizing agent is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1;

[0049] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 2% of propylene oxide / ethylene oxide block polyether, homogenize it intermittently for 2 times at 9000 r / min, and add the remaining pure water during the stirring process. Mix thoroughly until the dispersion coefficient PDI of the mixed emulsion < 0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0050] Example 5

[0051] S1. Weigh an amphiphilic emulsifier with a mass fraction of 2% at room temperature, dissolve it in pure water accounting for 30% of the total mass of pure water, and stir it thoroughly until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1;

[0052] S2. Subsequently, add a dynamic response oil phase component with a mass fraction of 7% to the solution prepared in S1, then homogenize it intermittently for 1 time at 8000 r / min to mix evenly, and then ultrasonicate it at 40 kHz for 10 min to obtain a white emulsion. The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3;

[0053] S3. After heating the white emulsion obtained in S2 to 60 °C, add a gradient crystallizing agent with a mass fraction of 3%, and homogenize it intermittently for 3 times at 11000 r / min. During the stirring process, add pure water accounting for 30% of the total mass of pure water to obtain a mixed emulsion. The gradient crystallizing agent is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1;

[0054] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 1% of propylene oxide / ethylene oxide block polyether, and homogenize intermittently for a short time once at 11,000 r / min. During the stirring process, add the remaining pure water, and mix well until the dispersion coefficient PDI of the mixed emulsion is <0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0055] Example 6

[0056] S1. Weigh 1% of amphiphilic emulsifier at room temperature, dissolve it in 30% of the total mass of pure water, and stir well until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1.

[0057] S2. Subsequently, add 7% of the dynamic response oil phase component to the solution prepared in S1, then homogenize intermittently for a short time once at 9,000 r / min to mix evenly, and then ultrasonicate at 40 kHz for 10 min to obtain a white emulsion. The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3.

[0058] S3. After heating the white emulsion obtained in S2 to 60 °C, add 4% of the gradient crystallizer, and homogenize intermittently for a short time 3 times at 12,000 r / min. During the stirring process, supplement 30% of the total mass of pure water, and obtain a mixed emulsion. The gradient crystallizer is composed of glycerol monostearate and aluminum behenate mixed in a mass ratio of 10:1.

[0059] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 1.5% of propylene oxide / ethylene oxide block polyether, and homogenize intermittently for a short time once at 12,000 r / min. During the stirring process, add the remaining pure water, and mix well until the dispersion coefficient PDI of the mixed emulsion is <0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0060] Example 7

[0061] S1. Weigh 2% of amphiphilic emulsifier at room temperature, dissolve it in 30% of the total mass of pure water, and stir well until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1.

[0062] S2. Subsequently, add the dynamic response oil phase component with a mass fraction of 8% to the solution prepared in S1, then homogenize intermittently for a short time once at 10000 r / min to mix evenly, and then ultrasonicate at 40 kHz for 10 min to obtain a white emulsion, wherein the dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3;

[0063] S3. After heating the white emulsion obtained in S2 to 60 °C, add the gradient crystallizing agent with a mass fraction of 2%, and homogenize intermittently for a short time 5 times at 8000 r / min. During the stirring process, add pure water accounting for 30% of the total mass of pure water to obtain a mixed emulsion, wherein the gradient crystallizing agent is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1;

[0064] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 1.5% of propylene oxide / ethylene oxide block polyether, homogenize intermittently for a short time 2 times at 8000 r / min, and add the remaining pure water during the stirring process, and mix thoroughly until the dispersion coefficient PDI of the mixed emulsion < 0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0065] Example 8

[0066] S1. Weigh the amphiphilic emulsifier with a mass fraction of 1% at room temperature, dissolve it in pure water accounting for 30% of the total mass of pure water, and stir thoroughly to completely dissolve it into a transparent solution, wherein the amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1;

[0067] S2. Subsequently, add the dynamic response oil phase component with a mass fraction of 8% to the solution prepared in S1, then homogenize intermittently for a short time 2 times at 5000 r / min to mix evenly, and then ultrasonicate at 40 kHz for 10 min to obtain a white emulsion, wherein the dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3;

[0068] S3. After heating the white emulsion obtained in S2 to 60 °C, add the gradient crystallizing agent with a mass fraction of 3%, and homogenize intermittently for a short time 4 times at 10000 r / min. During the stirring process, add pure water accounting for 30% of the total mass of pure water to obtain a mixed emulsion, wherein the gradient crystallizing agent is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1;

[0069] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 2% of propylene oxide / ethylene oxide block polyether, and homogenize intermittently for a short time 2 times at 10000 r / min. During the stirring process, add the remaining pure water and mix thoroughly until the dispersion coefficient PDI of the mixed emulsion is <0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0070] Example 9

[0071] S1. Weigh 1.5% of amphiphilic emulsifier at room temperature and dissolve it in 30% of the total mass of pure water. Stir it thoroughly until it is completely dissolved into a transparent solution. The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1.

[0072] S2. Subsequently, add 8% of the dynamic response oil phase component to the solution prepared in S1, then homogenize intermittently for a short time 2 times at 8000 r / min to mix evenly, and then sonicate at 40 kHz for 10 min to obtain a white emulsion. The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:3.

[0073] S3. After heating the white emulsion obtained in S2 to 60 °C, add 4% of the gradient crystallizing agent, and homogenize intermittently for a short time 3 times at 12000 r / min. During the stirring process, supplement 30% of the total mass of pure water, and a mixed emulsion is obtained. The gradient crystallizing agent is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:1.

[0074] S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add 1% of propylene oxide / ethylene oxide block polyether, and homogenize intermittently for a short time 2 times at 8000 r / min. During the stirring process, add the remaining pure water and mix thoroughly until the dispersion coefficient PDI of the mixed emulsion is <0.2 and the Zeta potential is between -10 mV and -50 mV, then the silicone-free defoamer is obtained.

[0075] As Figure 1 shown, the critical micelle concentration of the dynamic response oil phase in the present invention is significantly less than that of a single oil phase. This is because the mineral oil in the dynamic response oil phase is a long-chain alkane hydrophobic substance, while methyl ricinoleate contains an ester group and a hydroxyl group and has certain amphiphilicity. After compounding, the polar group of methyl ricinoleate can enhance the directional arrangement of surfactant molecules in water and promote micelle formation; and the mineral oil, as the hydrophobic phase, can increase the volume of the micelle core, while the ester group of methyl ricinoleate can optimize the intermolecular interaction and further reduce the critical micelle concentration.

[0076] As Figure 2As shown, Example 1 exhibits acceptable stability within the range of 0 to 50 °C. Especially under the synergistic effect of the dynamic corresponding oil phase and the gradient crystallizing agent, it is significantly superior to the traditional silicone-free defoaming agent system.

[0077] Subsequently, the performance of the silicone-free defoaming agents prepared in Examples 1-9 was measured, and the addition amount of the silicone-free defoaming agent accounted for 0.01 to 0.3% of the volume of the water sample.

[0078] The specific test method is as follows:

[0079] First, add 150 mL of the water sample to a 250 mL graduated cylinder, and use an aeration pump to aerate the bottom of the graduated cylinder at a flow rate of 3 L / min. When the foam reaches the maximum volume, record the foam volume V1. Immediately add the corresponding amount of the defoaming agent to be tested, and then record the foam volume V2 after 5 minutes and the foam volume V3 again after 0.5 h.

[0080] Subsequently, the foam stability, immediate defoaming rate, and continuous defoaming rate were calculated. The specific calculation methods are as follows:

[0081] Foam stability FS = V3 / V1 × 100%

[0082] Immediate defoaming rate = (V1 - V2) / V1 × 100%

[0083] Continuous defoaming rate = (V1 - V3) / V1 × 100%

[0084] In addition, add 150 mL of the water sample to another 250 mL graduated cylinder, add the same amount of the defoaming agent as above, and then use an aeration pump to aerate the bottom of the graduated cylinder at a flow rate of 3 L / min. When the foam reaches the maximum volume, record the foam volume V4, and then calculate the foam inhibition rate. The specific calculation method is as follows:

[0085] Foam inhibition rate = (V1 - V4) / V1 × 100%

[0086] The final test results are shown in the following table.

[0087]

[0088]

[0089]

[0090] As can be seen from the above table, as the addition amount of the defoaming agents prepared in Examples 1-9 gradually increases, the immediate defoaming efficiency and continuous defoaming efficiency in each example gradually increase, and the stability of the foam gradually decreases. At the same time, the foam inhibition rate also gradually increases, indicating that the defoaming agent prepared by the present invention can achieve rapid defoaming while also taking into account long-term foam inhibition.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A silicon-free defoamer, characterized in that, By mass fraction, it includes 6-8% of dynamic response oil phase, 2-4% of gradient crystallizing agent, 1-2% of amphiphilic emulsifier and 1-2% of interface disturbance synergist, and the balance is pure water.

2. The silicone-free defoamer according to claim 1, characterized in that, The dynamic response oil phase is composed of mineral oil and methyl ricinoleate mixed in a mass ratio of 5:

3.

3. The silicone-free defoamer according to claim 1, characterized in that, The gradient crystallizing agent is composed of glycerol monostearate and aluminum docosanoate mixed in a mass ratio of 10:

1.

4. The silicone-free defoamer according to claim 1, wherein The amphiphilic emulsifier is composed of EL-10 and Span 80 mixed in a mass ratio of 2:1, where the hydrophilic-lipophilic balance value HLB of EL-10 is 10 and the hydrophilic-lipophilic balance value HLB of Span 80 is 4.

3.

5. The non-silicon defoamer according to claim 1, characterized in that, The interface disturbance synergist includes propylene oxide / ethylene oxide block polyether, where the mass ratio of propylene oxide to ethylene oxide is 3:1, and the molecular weight of the propylene oxide / ethylene oxide block polyether is 2500±200.

6. The preparation method of a silicone-free defoamer according to any one of claims 1-5, characterized in that, It includes the following steps: S1. Completely dissolve the amphiphilic emulsifier in pure water accounting for 30% of the total mass of pure water. S2. Add the dynamic response oil phase to the solution obtained in S1, mix evenly and then ultrasonicate to obtain a white emulsion. S3. After heating the white emulsion obtained in S2 to 60°C, add the gradient crystallizing agent and pure water accounting for 30% of the total mass of pure water, and stir evenly to obtain a mixed emulsion. S4. After the temperature of the mixed emulsion prepared in S3 drops to room temperature, add the interface disturbance synergist and the remaining pure water, and mix thoroughly to obtain a silicon-free defoamer.

7. The preparation method of a silicon-free defoamer according to claim 6, characterized in that, In step S2, the mixing method is to intermittently homogenize for 1-2 times at 5000-10000 r / min for a short time, and the ultrasonic frequency is 40 kHz and the ultrasonic time is 10 min.

8. The preparation method of a silicon-free defoaming agent according to claim 6, characterized in that, In step S3, the mixing method is to intermittently homogenize for 3-5 times at 8000-12000 r / min for a short time.

9. According to the preparation method of a silicon-free defoamer described in claim 6, in step S4, the mixing method is to intermittently homogenize for 1-2 times at 8000-12000 r / min for a short time.

10. The preparation method of a silicon-free defoamer according to claim 6, characterized in that, In step S4, the judgment criterion for thorough mixing is: the dispersion coefficient PDI of the mixed emulsion < 0.2, and the Zeta potential is between -10 mV and -50 mV.

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