Controllable dispersion system device suitable for micro-suspension emulsion

Abstract

The invention discloses a controllable dispersion system device suitable for micro-suspension emulsion. The controllable dispersion system device comprises a first static mixer, a first ultrasonic generator, a first ultrasonic transducer, a first homogenizing pump, a first three-way valve, a second static mixer, a second ultrasonic generator, a second ultrasonic transducer, a second homogenizing pump and a second three-way valve, through the system, the quality of monomer seeds can be improved, the controllability of the particle size of the emulsion is realized, the energy consumption is reduced, and the stability of the product quality is ensured. According to different internal parts and parameters, the particle size range of the controllable emulsion obtained after emulsification is 0.56-0.70 [mu] m, and the distribution index range is 0.320-0.400.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of micro-suspension emulsions, and in particular relates to a controllable dispersion system device suitable for micro-suspension emulsions. Background Art

[0002] Microsuspension polymerization is a technology for preparing polymer particles. It disperses monomers in a liquid medium to form tiny droplets and carries out polymerization reactions in these droplets. This method combines the advantages of suspension polymerization and emulsion polymerization and can prepare polymer particles with uniform particle size and narrow distribution. Microsuspension polymerization can be used to produce a variety of products, including polystyrene microspheres for laboratory reagents and biomedical applications, polyacrylate microspheres for coatings and adhesives, polyurethane microspheres for textile finishing and coatings, and polyvinyl chloride paste resins for flooring materials, coatings and synthetic leather.

[0003] Among them, the preparation of micro-suspension emulsion is crucial in the micro-suspension polymerization method. By accurately controlling the formation process of the emulsion, a uniform droplet size can be obtained, which plays a decisive role in the particle size and distribution of the final polymer particles. In the past, the micro-suspension method was used to prepare emulsions using a stirred tank. For example, the dispersion tank used in Chinese patent CN214327614U is used for mechanical homogenization, and Chinese patent application CN105498586A proposes to set up multiple layers and different types of stirring paddles to achieve a more dispersed and effective stirring and dispersion of the material. However, the above emulsification methods have problems such as uneven droplet size distribution, large amount of emulsifier, incomplete emulsification, and high energy consumption for long-term operation.

[0004] To solve the above problems, Chinese patent application CN106883331A introduced a homogenizing pump for emulsification based on the traditional process, and successfully prepared a finished product with an average particle size of 1.10μm. Although the process equipment has been improved, it still faces challenges such as high shear force causing increased wear of equipment parts, increased maintenance costs, temperature rise caused by the shear process requiring additional cooling, and high energy consumption caused by high-pressure operation.

[0005] Therefore, in view of the above technical difficulties, it is urgent to develop more efficient emulsification equipment to obtain higher quality monomer seeds. The present invention proposes a premixing system for improving the dispersion efficiency of microsuspension emulsion, and realizes efficient droplet dispersion and uniform mixing through internal structural design. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a controllable dispersion system device suitable for micro-suspension emulsion; the dispersion system device can solve many problems existing in the pre-treatment pre-mixing dispersion in the existing micro-suspension polymerization production process; through this system, the quality of monomer seeds can be improved, the controllability of the emulsion particle size can be achieved, energy consumption can be reduced, and the stability of product quality can be ensured. According to different internal components and parameters, the controllable emulsion particle size range obtained after emulsification is 0.56-0.70μm, and the distribution index range is 0.320-0.400.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A controllable dispersion system device suitable for micro-suspension emulsion, comprising a first static mixer, a first ultrasonic generator, a first ultrasonic transducer, a first homogenizing pump, a first three-way valve, a second static mixer, a second ultrasonic generator, a second ultrasonic transducer, a second homogenizing pump and a second three-way valve;

[0009] The first static mixer is coated with a first ultrasonic transducer;

[0010] The first ultrasonic generator transmits ultrasonic energy to the first static mixer via an ultrasonic transducer;

[0011] The inlet of the first static mixer is connected to the raw material liquid pipeline;

[0012] The outlet of the first static mixer is connected to the inlet of the first homogenizing pump through a pipeline;

[0013] The outlet of the first homogenizing pump is connected to the inlet of the first three-way valve through a pipeline.

[0014] An outlet of the first three-way valve flows back into the raw material liquid pipeline through a pipeline;

[0015] Another outlet of the first three-way valve leads to the inlet of a second static mixer through a pipeline; the second static mixer is coated with a second ultrasonic transducer;

[0016] The second ultrasonic generator transmits ultrasonic energy to the second static mixer via an ultrasonic transducer;

[0017] The outlet of the second static mixer is connected to the inlet of the second homogenizing pump through a pipeline;

[0018] The outlet of the second homogenizing pump is connected to the inlet of the second three-way valve through a pipeline.

[0019] An outlet of the second three-way valve flows back to the inlet pipeline of the second static mixer through a pipeline;

[0020] The other outlet of the second three-way valve leads to the product storage tank through a pipeline.

[0021] Preferably, the ultrasonic frequency setting range of the first ultrasonic generator is 10 to 30 kHz; the ultrasonic frequency setting range of the second ultrasonic generator is 30 to 50 kHz.

[0022] Preferably, the aspect ratio of the first static mixer and the second static mixer are both in the range of 6-10, and the diameter of the mixing pipe of the first static mixer and the second static mixer is less than 12 cm.

[0023] Preferably, when one outlet of the first three-way valve flows back into the raw liquid pipeline through a pipeline, the reflux ratio ranges from 2 to 5.

[0024] Preferably, the number of mixing elements in the first static mixer and the second static mixer is 4-8, and spiral blades are arranged inside the mixing pipes of the first static mixer and the second static mixer.

[0025] Preferably, when the mixing elements in the first static mixer and the second static mixer are installed, the staggered degrees of adjacent spiral sheets range from 45° to 90°.

[0026] Preferably, the first static mixer and the second static mixer are made of materials with high elastic modulus (such as titanium alloy, stainless steel); the maximum wall thickness of the mixing elements in the first static mixer and the second static mixer is set to 5 cm.

[0027] Preferably, the inner diameters of the first static mixer and the second static mixer gradually decrease from upstream to downstream, and the maximum reduction range does not exceed 6 cm.

[0028] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0029] Unless otherwise specified, all raw materials in the present invention can be purchased from the market, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The controllable dispersion system of the present invention couples a static mixer with an ultrasonic device to form an ultrasonic static mixer. Helical blades with different torsion angles are arranged inside the static mixer to enhance the static mixing effect of the emulsion. At the same time, the static mixer material is selected from materials that can effectively conduct ultrasonic amplitude, and is equipped with an external reflux system, which reduces the particle size of the final emulsion droplets and makes its particle size distribution narrower. The equipment is suitable for the preparation process of all micro-suspension emulsions and is of great significance to the optimization and improvement of the preparation process of micro-suspension emulsions; depending on the internal components and parameters, the controllable emulsion particle size range obtained after emulsification is 0.56-0.70μm, and the distribution index range is 0.320-0.400.

[0032] 2. The present invention optimizes the micro-suspension emulsion dispersion process, reduces the required processing time, energy consumption and material consumption, and thus significantly reduces the production cost. In addition, the controllable particle size emulsion prepared by the device can meet the production requirements of different processes, especially when used in the production of polyvinyl chloride paste resin, it can reduce the subsequent energy consumption of vinyl chloride monomer recovery, help reduce environmental pollution, and meet the requirements of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] Figure 1 It is a schematic diagram of the controllable dispersion system device of the present invention;

[0035] Figure 2 This is the structure of the mixing elements in the first static mixer and the second static mixer of the present invention.

[0036] Figure numerals: 1-first static mixer, 2-first ultrasonic generator, 3-first ultrasonic transducer, 4-first homogenizing pump, 5-first three-way valve, 6-second static mixer, 7-second ultrasonic generator, 8-second ultrasonic transducer, 9-second homogenizing pump, 10-second three-way valve. DETAILED DESCRIPTION

[0037] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0038] The trichloroethylene in the embodiments of the present invention was purchased from a high-purity trichloroethylene product produced by Shanghai Aladdin Biochemical Technology Co., Ltd., and sodium dodecyl sulfate and hexadecanol were purchased from Shanghai MacLean Biochemical Technology Co., Ltd., and were reagent-grade pure sodium dodecyl sulfate products and high-purity hexadecanol products, respectively.

[0039] See also Figure 1As shown, as one aspect of the present invention, the present invention is a controllable dispersion system device suitable for micro-suspension emulsion, comprising a first static mixer 1, a first ultrasonic generator 2, a first ultrasonic transducer 3, a first homogenizing pump 4, a first three-way valve 5, a second static mixer 6, a second ultrasonic generator 7, a second ultrasonic transducer 8, a second homogenizing pump 9 and a second three-way valve 10;

[0040] The first static mixer 1 is coated with a first ultrasonic transducer 3;

[0041] The first ultrasonic generator 2 transmits ultrasonic energy to the first static mixer 1 through the ultrasonic transducer 3;

[0042] The inlet of the first static mixer 1 is connected to the raw material liquid pipeline;

[0043] The outlet of the first static mixer 1 is connected to the inlet of the first homogenizing pump 4 through a pipeline;

[0044] The outlet of the first homogenizing pump 4 is connected to the inlet of the first three-way valve 5 through a pipeline.

[0045] One outlet of the first three-way valve 5 flows back into the raw material liquid pipeline through a pipeline;

[0046] The other outlet of the first three-way valve 5 leads to the inlet of the second static mixer 6 through a pipeline; the second static mixer 6 is covered with a second ultrasonic transducer 8;

[0047] The second ultrasonic generator 7 transmits ultrasonic energy to the second static mixer 8 via the ultrasonic transducer 8;

[0048] The outlet of the second static mixer 8 is connected to the inlet of the second homogenizing pump 9 through a pipeline;

[0049] The outlet of the second homogenizing pump 9 is connected to the inlet of the second three-way valve 10 through a pipeline.

[0050] An outlet of the second three-way valve 10 flows back to the inlet pipe of the second static mixer 6 through a pipe;

[0051] The other outlet of the second three-way valve 10 leads to a product storage tank through a pipeline.

[0052] According to some embodiments of the present invention, the ultrasonic frequency of the first ultrasonic generator is set in a range of 10 to 30 kHz; the ultrasonic frequency of the second ultrasonic generator is set in a range of 30 to 50 kHz. The low frequency and the high frequency are connected in series, a large number of cavitation bubbles are first generated by the low frequency, and then the bubbles are torn by the high frequency to obtain a lower emulsion particle size and a narrower emulsion particle size distribution.

[0053] According to some embodiments of the present invention, the aspect ratio of the first static mixer and the second static mixer is in the range of 6-10, and the diameter of the mixing pipeline of the first static mixer and the second static mixer is less than 12 cm. Setting a sufficiently long pipeline can ensure the dispersion effect of ultrasonic static mixing emulsion.

[0054] According to some embodiments of the present invention, when one outlet of the first three-way valve flows back to the raw liquid pipeline through the pipeline, the reflux ratio ranges from 2 to 5; when one outlet of the second three-way valve flows back to the inlet pipeline of the second static mixer 8 through the pipeline, the reflux ratio ranges from 2 to 5. A suitable reflux ratio can increase the residence time of the material in the system, ensure sufficient mixing and uniform emulsification, and achieve more precise control of the droplet size to obtain a more uniform particle size distribution.

[0055] According to some embodiments of the present invention, see Figure 2 As shown, the number of mixing elements in the first static mixer and the second static mixer is 4-8, preferably 6; spiral blades are provided inside the mixing pipes of the first static mixer and the second static mixer to promote full mixing of the liquid.

[0056] According to some embodiments of the present invention, the mixing elements in the first static mixer and the second static mixer are installed so that the adjacent spirals are staggered by 45° to 90°. The torsion angle of the mixing elements can be 180° clockwise or counterclockwise, and preferably, the mixing elements with different torsion directions are staggered and connected, and the staggered angle is 90°.

[0057] According to certain embodiments of the present invention, in order to improve the conduction of ultrasonic amplitude in the static mixer, materials with high elastic modulus (such as titanium alloy, stainless steel) are used in the first static mixer and the second static mixer; the maximum wall thickness of the mixing elements in the first static mixer and the second static mixer is set to 5 cm.

[0058] According to some embodiments of the present invention, the inner diameters of the first static mixer and the second static mixer gradually decrease from upstream to downstream, with the maximum reduction not exceeding 6 cm, so as to enhance the ultrasonic coverage area and thus improve the mixing effect of the static mixer.

[0059] Example 1

[0060] A controllable dispersion system device suitable for micro-suspension emulsion, comprising a first static mixer 1, a first ultrasonic generator 2, a first ultrasonic transducer 3, a first homogenizing pump 4, a first three-way valve 5, a second static mixer 6, a second ultrasonic generator 7, a second ultrasonic transducer 8, a second homogenizing pump 9 and a second three-way valve 10;

[0061] The first static mixer 1 is coated with a first ultrasonic transducer 3;

[0062] The first ultrasonic generator 2 transmits ultrasonic energy to the first static mixer 1 through the ultrasonic transducer 3;

[0063] The inlet of the first static mixer 1 is connected to the raw material liquid pipeline;

[0064] The outlet of the first static mixer 1 is connected to the inlet of the first homogenizing pump 4 through a pipeline;

[0065] The outlet of the first homogenizing pump 4 is connected to the inlet of the first three-way valve 5 through a pipeline.

[0066] One outlet of the first three-way valve 5 flows back into the raw material liquid pipeline through a pipeline;

[0067] The other outlet of the first three-way valve 5 leads to the inlet of the second static mixer 6 through a pipeline; the second static mixer 6 is covered with a second ultrasonic transducer 8;

[0068] The second ultrasonic generator 7 transmits ultrasonic energy to the second static mixer 8 via the ultrasonic transducer 8;

[0069] The outlet of the second static mixer 8 is connected to the inlet of the second homogenizing pump 9 through a pipeline;

[0070] The outlet of the second homogenizing pump 9 is connected to the inlet of the second three-way valve 10 through a pipeline.

[0071] An outlet of the second three-way valve 10 flows back to the inlet pipe of the second static mixer 6 through a pipe;

[0072] The other outlet of the second three-way valve 10 leads to a product storage tank through a pipeline.

[0073] A method for controllably dispersing a micro-suspension emulsion using the above system device comprises the following steps:

[0074] 1) adding a mixed solution containing 50 wt% of soft water, 0.73 wt% of sodium lauryl sulfate, 0.54 wt% of hexadecanol and 48.73 wt% of trichloroethylene into a first ultrasonic static mixer, subjecting the mixture to ultrasonic mixing (ultrasonic frequency 20 kHz), and then homogenizing with a first homogenizing pump,

[0075] 2) The homogenized liquid is then fed into a second ultrasonic static mixer (ultrasonic frequency 50 kHz), and a second homogenizing pump is started to obtain a final emulsion product. The reflux ratios of the two ultrasonic static mixers are both set to 3; the mixing elements in the static mixer are installed so that the interlacing degree of adjacent spiral sheets is 90°, and the number of mixing elements is 6;

[0076] 3) The micro-suspension emulsion product is led from one outlet of the second three-way valve to the product storage tank through a pipeline

[0077] Example 2

[0078] Example 1 was repeated, with the only difference being that the ultrasonic frequency of the first ultrasonic generator was 10 kHz.

[0079] Example 3

[0080] Example 1 was repeated, except that the ultrasonic frequency of the first ultrasonic generator was 35 kHz, when one outlet of the first three-way valve was refluxed to the raw liquid pipeline through a pipeline, the reflux ratio was 4; when one outlet of the second three-way valve was refluxed to the inlet pipeline of the second static mixer through a pipeline, the reflux ratio was 4. The reflux ratio was changed to 4, the number of mixing elements in the first static mixer and the second static mixer was set to 7, and the adjacent spiral sheets were staggered at 60° during installation, and the rest was completely the same as Example 2.

[0081] Example 4

[0082] Example 1 was repeated, except that the ultrasonic frequency of the first ultrasonic generator was 30 kHz, the interlacing degree of adjacent spiral sheets in the first static mixer and the second static mixer was 45° when the mixing elements were installed, the number of mixing elements in the first static mixer and the second static mixer was set to 8, and the rest was exactly the same as Example 1.

[0083] Comparative Example 1

[0084] Example 1 was repeated, with the only difference being that the ultrasonic frequency of the first ultrasonic static mixer was changed to 40 kHz, the ultrasonic frequency of the second ultrasonic static mixer was changed to 20 kHz, the reflux ratio of the two ultrasonic static mixers was changed to 1, the number of mixing elements was set to 8, and the staggered degree of adjacent spiral sheets during installation was 0°, and the rest was exactly the same as Example 1.

[0085] Comparative Example 2

[0086] A controllable dispersion system device suitable for micro-suspension emulsion, wherein two ultrasonic static mixers are replaced with homogenization tanks, 49.39 wt% of soft water, 1.44 wt% of sodium lauryl sulfate, 1.07 wt% of hexadecanol and 48.10 wt% of trichloroethylene are added to a first homogenization tank under stirring, fully stirred for 20 minutes, further homogenized by a homogenization pump, and sent to a second homogenization tank, and when the single tank liquid level reaches 10%, the second homogenization pump is started to obtain an emulsion. The rest is the same as in Example 1.

[0087] The product analysis indicators of Examples 1-4 and Comparative Examples 1-2 are shown in Table 1 below:

[0088] Table 1

[0089] content Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Average particle size (nm) 568.8 589.5 632.1 642.2 732.0 1380.0 Distribution Index 0.321 0.338 0.355 0.383 0.452 0.548 Emulsifier dosage (wt%) 0.73 0.73 0.73 0.73 0.73 1.44 Amount of emulsifier (wt%) 0.54 0.54 0.54 0.54 0.54 1.07 Number of mixing elements 6 6 7 8 8 ——

[0090] From Table 1 we can see that:

[0091] 1) Compared with Comparative Example 2 using two homogenizations, the average particle size and distribution index obtained by using two ultrasonic static mixers are better, and the amount of emulsifier and co-emulsifier used is significantly reduced.

[0092] 2) In Examples 1, 2, 3 and 4, the use of the ultrasonic static mixer makes the average particle size and distribution index far superior to those of Comparative Example 1 in the non-preferred operating parameter range.

[0093] 3) Comparative Example 1 uses a two-stage ultrasonic static mixing technology. Compared with the two-stage homogenization tank of Comparative Example 2, the average particle size of the emulsion is smaller and the distribution is more uniform.

[0094] It can be concluded from the results of the examples that the present invention can reduce material consumption, shorten mixing time, and prepare an emulsion with smaller particle size and more uniform distribution.

[0095] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A controllable dispersion system device suitable for micro-suspension emulsion, characterized in that: It includes a first static mixer, a first ultrasonic generator, a first ultrasonic transducer, a first homogenizing pump, a first three-way valve, a second static mixer, a second ultrasonic generator, a second ultrasonic transducer, a second homogenizing pump and a second three-way valve; The first static mixer is coated with a first ultrasonic transducer; The first ultrasonic generator transmits ultrasonic energy to the first static mixer via an ultrasonic transducer; The inlet of the first static mixer is connected to the raw material liquid pipeline; The outlet of the first static mixer is connected to the inlet of the first homogenizing pump through a pipeline; The outlet of the first homogenizing pump is connected to the inlet of the first three-way valve through a pipeline. An outlet of the first three-way valve flows back into the raw material liquid pipeline through a pipeline; Another outlet of the first three-way valve leads to the inlet of a second static mixer through a pipeline; the second static mixer is coated with a second ultrasonic transducer; The second ultrasonic generator transmits ultrasonic energy to the second static mixer via an ultrasonic transducer; The outlet of the second static mixer is connected to the inlet of the second homogenizing pump through a pipeline; The outlet of the second homogenizing pump is connected to the inlet of the second three-way valve through a pipeline. An outlet of the second three-way valve flows back to the inlet pipeline of the second static mixer through a pipeline; The other outlet of the second three-way valve leads to the product storage tank through a pipeline.

2. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: The ultrasonic frequency setting range of the first ultrasonic generator is 10 to 30 kHz; the ultrasonic frequency setting range of the second ultrasonic generator is 30 to 50 kHz.

3. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: The aspect ratio of the first static mixer and the second static mixer are both in the range of 6-10, and the diameter of the mixing pipe of the first static mixer and the second static mixer is less than 12 cm.

4. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: When one outlet of the first three-way valve flows back into the raw liquid pipeline through the pipeline, the reflux ratio ranges from 2 to 5.

5. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: The number of mixing elements in the first static mixer and the second static mixer are both 4-8, and spiral blades are arranged inside the mixing pipes of the first static mixer and the second static mixer.

6. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: When the mixing elements in the first static mixer and the second static mixer are installed, the interlacing degree of adjacent spiral sheets ranges from 45° to 90°.

7. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: The first static mixer and the second static mixer are made of titanium alloy or stainless steel; the wall thickness of the mixing elements in the first static mixer and the second static mixer is ≦5 cm.

8. The controllable dispersion system device suitable for micro-suspension emulsion according to claim 1, characterized in that: The inner diameters of the first static mixer and the second static mixer gradually decrease from upstream to downstream, with a reduction range of ≤6 cm.

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