Device and method for preparing nano calcium carbonate PVC composite resin

Abstract

The invention discloses a device and a method for preparing nano calcium carbonate PVC (polyvinyl chloride) composite resin, a supergravity device and a polymerization kettle are connected to form a circulating closed loop, and a supergravity technology is introduced in a PVC suspension polymerization process, so that the interphase mass transfer rate is improved by 1-3 orders of magnitude compared with that of a traditional tower, the micro-mixing and mass transfer processes are greatly enhanced, and the production efficiency is improved. The homogenization time is greatly shortened, and the efficiency is improved; the nano calcium carbonate used in the invention is a transparent nano calcium carbonate oil phase dispersion, has good dispersibility in an organic phase and good compatibility with a polymer, and the nano calcium carbonate, a vinyl chloride monomer and a dispersant are homogenized through a circulating closed loop formed by a supergravity device and a polymerization kettle to form a nano-scale dispersion. The problems that the nano calcium carbonate is easy to agglomerate and the compatibility with a polymer is poor in the polymerization process are solved, and the toughening and reinforcing functions of the nano calcium carbonate are exerted.

Description

Technical Field

[0001] This invention relates to the fields of supergravity technology and nano-calcium carbonate dispersion technology, specifically to an apparatus and method for preparing nano-calcium carbonate PVC composite resin. Background Technology

[0002] Hypergravity technology is a novel technology that enhances multiphase flow transfer and reaction processes. Due to its wide applicability and advantages not found in traditional equipment, such as small size, light weight, low energy consumption, ease of operation and maintenance, safety, reliability, flexibility, and better environmental adaptability, hypergravity technology has broad commercial application prospects in environmental protection, materials, biology, chemical engineering, and other industrial fields. The basic principle of hypergravity engineering technology is to utilize the unique flow behavior of multiphase flow systems under hypergravity conditions to enhance the relative velocity and contact between phases, thereby achieving efficient momentum, mass, and heat transfer processes. A hypergravity field is formed by using a motor to rotate the entire device or its components to create a centrifugal force field.

[0003] Patent CN207385225U discloses a high-gravity rotary emulsification system suitable for mixing immiscible first and second fluids. The system comprises: a storage tank with a circulation port; a rotary emulsification device connected to the storage tank, including: a housing; a rotary packed bed disposed within the housing, having a central pivot extending axially from the housing and forming a flow space located in the middle of the rotary packed bed and within the housing; and a conduit unit adapted to supply the first and second fluids, extending from outside the housing into the flow space of the rotary packed bed, including a circulation conduit connecting the circulation port and the flow space. This high-gravity rotary emulsification system achieves emulsification uniformity through repeated emulsification via the self-circulation of the storage tank, thus reducing the emulsification efficiency of the system.

[0004] The disadvantages of the aforementioned existing technologies are: ① Traditional emulsifiers require premixing of materials before emulsification, and often require multiple tanks for storing fluids and a complex conveying system. The multiple starts and stops required for batch production not only result in high energy consumption but also make it difficult to ensure consistent emulsification levels across batches, leading to high costs, complex processes, low efficiency, difficult equipment maintenance, and a high failure rate. ② The high-gravity rotary emulsification system achieves uniform emulsification through repeated emulsification via self-circulation in the storage tank, requiring multiple cycles. This results in uneven material circulation, lower production efficiency, higher energy consumption, and a wider particle size distribution after emulsification.

[0005] Currently, the main approaches to modifying PVC with nanofillers are blending modification and in-situ polymerization modification, but both encounter a common problem—agglomeration. Because nanofiller particles are extremely fine, reaching the nanoscale, their surfaces have a large specific surface energy, making them highly prone to agglomeration. This prevents them from achieving nanoscale dispersion in PVC resin, resulting in uneven nanoparticle dispersion. Consequently, this manifests as minimal improvement in resin performance, or even an abnormal decrease in performance.

[0006] Chinese patent CN100368444C discloses a method for preparing vinyl chloride / nano-calcium carbonate in-situ polymerized resin, comprising the following steps: polymerizing raw materials including vinyl chloride monomer, initiator, dispersant, water, pH adjuster, and nano-calcium carbonate filler using conventional methods; characterized in that the nano-calcium carbonate filler is surface-treated, and the preparation method is as follows: mixing and homogenizing nano-calcium carbonate emulsion and PVC seed emulsion, then adding dispersant, and then homogenizing again to obtain surface-treated nano-calcium carbonate filler; the dry weight of PVC seed emulsion: the dry weight of nano-calcium carbonate = 1 to 1:30; the PVC seed emulsion is prepared from raw materials comprising the following components and weight contents: 100 parts vinyl chloride, ... The emulsifier comprises 0.5 to 5 parts, the initiator comprises 0.5 to 5 parts, the pH adjuster comprises 0.01 to 0.2 parts, and the water comprises 115 to 125 parts. The emulsifier is selected from one or more of alkyl alcohol sulfates, alkyl alcohol sulfonates, or alkyl naphthalene sulfonates. The average particle size of the PVC seed emulsion is 50 to 100 nm. The initiator is selected from ammonium persulfate, potassium persulfate, or organic peroxides.

[0007] The disadvantages of the above-mentioned existing technology are: ① Due to the use of conventional methods for the polymerization reaction of vinyl chloride suspension polymerization, the presence of a large amount of water affects the bonding efficiency between the nano-calcium carbonate filler and the vinyl chloride monomer; ② The process also requires the preparation of PVC seed emulsion, which increases the production control steps, increases costs, and is cumbersome and difficult to control; ③ The stirring intensity of the polymerization reactor cannot make the nano-calcium carbonate truly achieve nanoscale dispersion, and the agglomeration phenomenon still exists. Summary of the Invention

[0008] The present invention aims to solve the problems of long homogenization time, wide particle size distribution, high operating cost and unstable product quality in existing technologies, and provides a device for preparing nano-calcium carbonate PVC composite resin with short homogenization time, narrow particle size distribution, low operating cost and stable product quality.

[0009] The present invention aims to solve the problems of easy agglomeration of nano-calcium carbonate during polymerization, poor compatibility with polymers, and unstable product quality in existing technologies, and to provide a method for preparing nano-calcium carbonate PVC composite resin with good dispersibility of nano-calcium carbonate during polymerization, good compatibility with polymers, and stable product quality.

[0010] The invention is made possible by the inclusion of a flow guiding device in the hypergravity emulsification chamber. This device increases the number of rotating packed beds within the chamber, thereby improving homogenization efficiency. By altering the form of the rotating packed beds, the hypergravity emulsification chamber becomes a multifunctional one. The flow guiding device further enhances the mixing effect. Multiple liquids can be dispersed, sheared, and then homogenized using this device. Under hypergravity conditions, material dispersion, shearing, and homogenization can be completed in a very short time, resulting in a narrow particle size distribution and uniform size, significantly improving production efficiency. This device simultaneously functions as a shearing pump, a mixing pump, and a mixing and conveying pump. It is compact, requires little space, and is easy to use. This invention connects a device for nano-calcium carbonate PVC composite resin to a polymerization reactor to form a closed-loop circulation system. It introduces hypergravity technology into the PVC suspension polymerization process. Under hypergravity, molecular diffusion and interphase mass transfer between molecules of different sizes are much faster than under conventional gravity. Gas-liquid, liquid-liquid, and liquid-solid phases flow and contact in porous media or channels under hypergravity conditions hundreds to thousands of times stronger than Earth's gravity. The enormous shear forces and rapidly renewing phase interfaces increase the interphase mass transfer rate by 1 to 3 orders of magnitude compared to traditional tower reactors. The mixing and mass transfer processes are greatly enhanced, the homogenization time is significantly shortened, and the efficiency is improved. The nano-calcium carbonate used in this invention is a transparent nano-calcium carbonate oil phase dispersion, which has good dispersibility in the organic phase and good compatibility with polymers. First, nano-calcium carbonate, vinyl chloride monomer, and dispersant are homogenized through a closed-loop circulation formed by the nano-calcium carbonate PVC composite resin device and the polymerization kettle to form a nano-scale dispersion. This solves the problems of easy agglomeration of nano-calcium carbonate and poor compatibility with polymers during the polymerization process, and gives full play to the toughening and reinforcing functions of nano-calcium carbonate.

[0011] The technical solution adopted by this invention to solve the problems existing in the homogenization device is as follows: An apparatus for preparing nano-calcium carbonate PVC composite resin includes a frame, a motor, a coupling, a drive shaft, a housing, and a jacket. The motor, drive shaft, and housing are mounted on the frame. The housing consists of a cylindrical body, a front end cover, and a rear end cover. The motor is connected to the drive shaft via the coupling. The drive shaft extends into the housing through the rear end cover. A discharge port is located on the side of the cylindrical body near the rear end cover, and a feed port is located at the center of the front end cover. A flow guiding device is provided inside the housing, dividing the housing into a shearing chamber and a hypergravity emulsification chamber in a front-to-back direction. The chamber is equipped with a rotating packed bed. The flow guiding device includes a frustum-shaped turntable and a flow guiding cylinder. The frustum-shaped turntable is vertically mounted on the drive shaft and driven to rotate. The larger diameter end of the frustum-shaped turntable is located in the direction of the feed inlet, and its diameter is smaller than the inner wall diameter of the cylinder. The flow guiding cylinder is located at the smaller diameter end of the frustum-shaped turntable, and its outer wall is fixed to the inner wall of the cylinder. The smaller diameter end of the frustum-shaped turntable has a diameter smaller than the inner wall diameter of the flow guiding cylinder. Shearing teeth are vertically arranged on the larger diameter end face of the frustum-shaped turntable. The flow guiding device increases the number of rotating packed beds within the ultragravity emulsification chamber, improving emulsification efficiency. Changing the form of the rotating packed bed transforms the ultragravity emulsification chamber into a multi-functional ultragravity emulsification chamber. Furthermore, the flow guiding device can guide the material to flow in a specific direction. An external jacket around the ultragravity emulsification chamber helps control the material temperature within a suitable range, improving product quality.

[0012] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a cylindrical guide tube with a wall thickness of 6-25 mm. The inner wall of the guide tube has 4-8 rectangular guide grooves along the axial direction. A fixed boss is provided on the inner wall of the tube, and the guide tube is located on the fixed boss and connected by bolts. The cylindrical guide tube is simple to manufacture; the bolt connection facilitates disassembly and cleaning.

[0013] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a cylindrical guide tube with an inner wall that is a frustum-shaped cone with a taper of 30°~75°. The larger opening of the guide tube is located in the direction of the feed inlet. A fixed boss is provided on the inner wall of the cylinder, and the guide tube is located on the fixed boss on the inner wall of the cylinder and connected by bolts. The high-efficiency ultragravity emulsification apparatus also includes a spiral pattern on the inner wall of the guide tube. The spiral pattern on the inner wall improves the mixing effect; the bolt connection facilitates disassembly and cleaning.

[0014] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a cylindrical guide tube with stepped annular pedestals on its inner wall. The diameter of these pedestals gradually decreases along the discharge port direction, with 3 to 7 steps. A fixed boss is located on the inner wall of the cylinder, and the guide tube is bolted to this fixed boss. The stepped guide tube enhances the mixing effect of the material and improves emulsification efficiency.

[0015] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a flow guide tube in the shape of a frustum cone. The wall thickness of the flow guide tube is 2-6 mm, and the taper is 30°~75°. The larger opening end of the flow guide tube is located in the direction of the feed inlet. The inner wall of the tube has an annular boss with several grooves, and the outer wall of the flow guide tube has several protrusions that fit into the grooves of the annular boss on the inner wall of the tube. The thin-skinned, smooth-inner-walled conical flow guide tube is simple and lightweight to manufacture.

[0016] The apparatus for preparing nano-calcium carbonate PVC composite resin has shearing teeth arranged concentrically on the larger diameter end face of a frustum-shaped turntable, forming at least two circles. These shearing teeth provide strong shearing force, transforming large solid particles into smaller ones.

[0017] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a stator disk with a central hole on the inner wall of the front cover. The feed inlet communicates with the central hole. Shearing teeth are vertically arranged on the stator disk, forming at least two concentric circles. The diameter of the outermost shearing teeth is smaller than the diameter of the inner wall of the cylinder. The shearing teeth on the stator disk alternate with those on the frustum-shaped turntable, and the length of each shearing tooth is less than the distance between the stator disk and the frustum-shaped turntable. The stator disk with a central hole and the shearing teeth on the inner wall of the front cover further enhance the shearing effect.

[0018] The apparatus for preparing nano-calcium carbonate PVC composite resin features an alternating arrangement of the inner and outer rings of the shearing teeth on a frustum-shaped turntable, as well as an alternating arrangement of the inner and outer rings of the shearing teeth on the stator plate. This alternating arrangement of the inner and outer rings of the shearing teeth enhances the shearing effect.

[0019] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a rectangular shearing blade on the larger diameter end face of a frustum-shaped turntable. The plane of the shearing blade is perpendicular to the larger diameter end face of the frustum-shaped turntable. The shearing blades are evenly arranged along the diameter of the larger diameter end face of the frustum-shaped turntable, and the length of the shearing blade is less than the radius of the inner shearing teeth. The shearing blades provide power to propel the material in a directional manner, achieving the desired effect.

[0020] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a shearing blade on the larger diameter end face of a frustum-shaped turntable. The shearing blade is fan-shaped and its plane is perpendicular to the larger diameter end face of the turntable. The shearing blades are evenly arranged along the diameter of the larger diameter end face of the turntable, and the length of the shearing blade is less than the radius of the inner shearing teeth. This shearing blade design further enhances the directional movement of the material.

[0021] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a shearing blade on the larger diameter end face of a frustum-shaped turntable. The shearing blade is crescent-shaped, and its plane is perpendicular to the larger diameter end face of the turntable. The shearing blades are evenly arranged along the diameter of the larger diameter end face of the turntable, and their length is less than the radius of the inner shearing teeth. This shearing blade design further enhances the directional movement of the material.

[0022] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a shearing blade on the larger diameter end face of a frustum-shaped turntable. The shearing blades are twisted, staggered, crescent-shaped, and their planes are perpendicular to the larger diameter end face of the turntable. The shearing blades are evenly arranged along the diameter of the larger diameter end face, and their length is less than the radius of the inner shearing teeth. This shearing blade design further enhances the directional movement of the material.

[0023] The apparatus for preparing nano-calcium carbonate PVC composite resin includes a rotating packed bed comprising a hollow cylindrical rotor and an emulsifying mesh rotor. The rotating packed bed is fixedly connected to the drive shaft by bolts. The rotating packed bed generates hypergravity within the hypergravity emulsification chamber. Under hypergravity, the liquid is torn into extremely fine droplets, liquid films, and liquid filaments by the strong shear force of the emulsifying mesh stator, thereby increasing the phase interface area and interface renewal rate, enhancing the interphase mass transfer process, and improving the material emulsification efficiency.

[0024] The apparatus for preparing nano-calcium carbonate PVC composite resin includes at least two flow guiding devices within the hypergravity emulsification chamber. The hypergravity emulsification chamber is further equipped with flow guiding devices to divide it into multiple hypergravity emulsification chambers, which can be equipped with multi-stage rotating packed beds to further improve emulsification efficiency.

[0025] The apparatus for preparing nano-calcium carbonate PVC composite resin is horizontal. The versatility of the apparatus expands its applicability.

[0026] The apparatus for preparing nano-calcium carbonate PVC composite resin is vertical. The versatility of the apparatus expands its applicability.

[0027] The technical solution adopted by this invention to solve the problems existing in the production of nano-calcium carbonate PVC composite resin is as follows: The present invention provides a method for preparing nano-calcium carbonate PVC composite resin, comprising the following steps in sequence: A. Preparation process 1) A closed-loop external circulation device is formed by connecting the polymerization reactor a, the circulating pump, and the device for preparing nano-calcium carbonate PVC composite resin using a stainless steel pressure-resistant metal hose. The bottom outlet of the polymerization reactor a is connected to the inlet of the circulating pump, the outlet of the circulating pump is connected to the inlet of the device for preparing nano-calcium carbonate PVC composite resin, and the outlet of the device for preparing nano-calcium carbonate PVC composite resin is connected to the top inlet of the polymerization reactor a. 2) After the polymerization reactor a, the circulating pump, and the device for preparing nano-calcium carbonate PVC composite resin are connected, nitrogen pressure is applied and leak test is performed. If the airtightness is good, the pressure is released and a vacuum is drawn. Then the circulation inlet and outlet of the polymerization reactor a are closed. B. Homogenization process 1) Add nano-calcium carbonate, vinyl chloride, and dispersant to polymerization reactor a according to the experimental formula. Turn on polymerization reactor a and stir at 300~1000 rpm for 5 min to premix. Then adjust the stirring to 30~70 rpm. 2) The homogenization of the material was mainly accomplished using the aforementioned device for preparing nano-calcium carbonate PVC composite resin. First, the bottom outlet valve and the top inlet valve of polymerization reactor a were opened. Then, the circulating pump was turned on at 30~50Hz and the rotor speed of the device for preparing nano-calcium carbonate PVC composite resin was turned on at 1000~3000rpm to circulate and homogenize the material. The circulation and homogenization time was 5~20 minutes. During the circulation and homogenization process, the internal temperature of polymerization reactor a was controlled at 5~20℃ by controlling the jacket cooling water of polymerization reactor a and the device for preparing nano-calcium carbonate PVC composite resin. After the homogenization was completed, the circulating pump and the device for preparing nano-calcium carbonate PVC composite resin were turned off first, and then the bottom outlet valve and the top inlet valve of polymerization reactor a were turned off. C. Feeding process Add the homogenized materials, initiator, soft water, and pH adjuster from step B to polymerization reactor b according to the formula requirements, and start the polymerization reactor b to stir at 300~1500 rpm for 10-40 min for premixing. D. Reaction process Start heating the polymerization reactor b to 54~64℃ to carry out the polymerization reaction. Smoothly control the polymerization reaction. When the reaction pressure drops by 2 bar, add the defoamer and terminator, and continue stirring for 10 minutes. E. Discharge and drying process The temperature inside the reactor is reduced to below 40°C. Unreacted monomers are depressurized from the top of reactor b and sent to the separation and recovery system. The material is discharged from the bottom of reactor b into the drying system. The resin after drying is nano-calcium carbonate PVC composite resin.

[0028] The method for preparing nano-calcium carbonate PVC composite resin describes a process where, in step B (homogenization), the nano-calcium carbonate is a transparent nano-calcium carbonate oil-phase dispersion. The selection of this nano-calcium carbonate oil-phase dispersion improves the dispersibility and compatibility of the nano-calcium carbonate in the PVC resin matrix, thereby enhancing product performance.

[0029] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention discloses an apparatus for preparing nano-calcium carbonate PVC composite resin. This apparatus involves shearing and dispersing multiple liquids before mixing and homogenizing them. Under hypergravity conditions, it can complete the dispersion, shearing, and emulsification of materials in a very short time, resulting in a narrow and uniform particle size distribution, significantly improving production efficiency. This apparatus simultaneously functions as an emulsification shearing pump, a mixing pump, and a mixing and conveying pump. It is compact, occupies little space, and is easy to use. The jacket of this invention allows for precise temperature control of the material, reducing the impact of heat generated during the shearing process on the initiator of the emulsion system, while also improving the stability of the emulsion system and preventing the formation of slag. The flow guiding device of this invention increases the number of rotating packed beds within the hypergravity emulsification chamber, improving homogenization efficiency. Changing the form of the rotating packed beds transforms the hypergravity emulsification chamber into a multi-functional hypergravity emulsification chamber. Furthermore, the flow guiding device can guide the material to flow in a specific direction.

[0030] The present invention discloses a method for preparing nano-calcium carbonate PVC composite resin. The nano-calcium carbonate used is a transparent nano-calcium carbonate oil-phase dispersion, which has good dispersibility in the organic phase and good compatibility with polymers. First, nano-calcium carbonate, vinyl chloride monomer, and dispersant are homogenized in a closed-loop circulation formed by the nano-calcium carbonate PVC composite resin device and the polymerization kettle to form a nano-scale dispersion. This solves the problems of easy agglomeration of nano-calcium carbonate and poor compatibility with polymers during the polymerization process, giving full play to the toughening and reinforcing functions of nano-calcium carbonate and improving the physicochemical properties of nano-calcium carbonate PVC composite resin.

[0031] The present invention provides an apparatus for preparing nano-calcium carbonate PVC composite resin. Under a hypergravity environment, the micro-mixing and mass transfer processes are greatly enhanced, the homogenization time is significantly shortened, and the homogenization efficiency is greatly improved. The material enters the shear chamber for the first dispersion, shearing, and emulsification to complete the pre-dispersion and homogenization process. Then, it enters the hypergravity emulsification chamber through a flow guide device for further homogenization, resulting in an emulsion with fine particle size, narrow particle size distribution, and uniformity. The apparatus has low operating costs and is suitable for homogenization and material mixing processes in the synthesis of polyvinyl chloride and other polymers.

[0032] This invention is used in fine chemical production. The main reaction device is a hypergravity homogenization device and a suspension polymerization reactor. Hypergravity technology is introduced into the PVC suspension polymerization process to enhance the micro-mixing and mass transfer process of materials, improve the mixing and homogenization efficiency of materials, solve the problem of nanoparticle agglomeration in the polymer matrix, and enable nanoparticles to achieve true nanoscale dispersion, giving full play to the "small size, large surface effect" of nanoparticles. This greatly enhances the strength, toughness and lightweight of the material. Compared with the prior art, this invention improves the production efficiency, product quality and resin product processing performance of suspension polymerization reactants. Attached Figure Description

[0033] Figure 1 This is a flow chart of the homogenization process of the present invention.

[0034] Figure 2 This is a cross-sectional view of the device (horizontal) of the present invention.

[0035] Figure 3 This is a cross-sectional view of the straight guide tube of the device of the present invention.

[0036] Figure 4 This is a cross-sectional view of the tapered guide tube on the threaded inner wall surface of the device of the present invention.

[0037] Figure 5 This is a cross-sectional view of the stepped guide tube of the device of the present invention.

[0038] Figure 6 This is a cross-sectional view of the tapered guide tube with a smooth inner wall surface of the device of the present invention.

[0039] Figure 7 This is a cross-sectional view of the frustum-shaped turntable and shearing teeth of the device of the present invention.

[0040] Figure 8 This is a cross-sectional view of the frustum-shaped turntable and shearing teeth of the device of the present invention.

[0041] Figure 9 This is a cross-sectional view of the frustum-shaped turntable, shearing teeth, and shearing blades of the device of the present invention.

[0042] Figure 10 This is a cross-sectional view of the frustum-shaped turntable, shearing teeth, and shearing blades of the device of the present invention.

[0043] Figure 11 This is a cross-sectional view of the frustum-shaped turntable, shearing teeth, and shearing blades of the device of the present invention.

[0044] Figure 12 This is a cross-sectional view of the frustum-shaped turntable, shearing teeth, and shearing blades of the device of the present invention.

[0045] Figure 13This is a cross-sectional view of the device (horizontal) of the present invention with added stator disk and shearing teeth.

[0046] Figure 14 This is a cross-sectional view of the device (vertical) of the present invention.

[0047] Figure 15 This is a cross-sectional view of the two flow guiding devices of the vertical device of the present invention.

[0048] In the diagram, 1 is the frame, 2 is the motor, 3 is the coupling, 4 is the drive shaft, 5 is the housing, 6 is the jacket, 7 is the discharge port, 8 is the supergravity emulsification chamber, 9 is the flow guiding device, 10 is the jacket outlet, 11 is the shearing chamber, 12 is the shearing teeth, 13 is the feed port, 14 is the jacket inlet, 15 is the truncated cone turntable, 16 is the flow guiding cylinder, 17 is the rotating packed bed, 18 is the circulating pump, 19 is the discharge port, 20 is the bottom external circulation inlet of the polymerization reactor, 21 is the polymerization reactor, 22 is the feeding port, 23 is the top external circulation outlet of the polymerization reactor, and 24 is the stator plate.

[0049] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited thereto. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0051] To facilitate understanding of the present invention, a more comprehensive description of the invention will be given below with reference to the accompanying drawings, and several embodiments of the invention will be provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0052] Example 1: Refer to Appendix Figure 2 Appendix Figure 3 and attached Figure 7This invention discloses a horizontal apparatus for preparing nano-calcium carbonate PVC composite resin. It includes a frame 1, a motor 2, a coupling 3, a drive shaft 4, a housing 5, and a jacket 6. The motor 2, drive shaft 4, and housing 5 are mounted on the frame 1. The housing 5 consists of a cylindrical body, a front end cover, and a rear end cover. The motor 2 is connected to the drive shaft 4 via the coupling 3. The drive shaft 4 extends into the housing 5 through the rear end cover. A discharge port 7 is located on the side of the cylindrical body near the rear end cover, and a feed port 13 is located at the center of the front end cover. A flow guiding device 9 is provided inside the housing 5, dividing it into a shearing chamber 11 and a high-gravity emulsification chamber 8 from front to back. A rotating filled bed 17 is provided in the high-gravity emulsification chamber 8, comprising a hollow cylindrical rotor and an emulsification mesh rotor. The rotating filled bed 17 is fixedly connected to the drive shaft 4 by bolts. The flow guiding device 9 includes a frustum-shaped turntable 15 and a flow guiding cylinder 16. A frustum-shaped turntable 15 is vertically mounted on the drive shaft 4 and driven to rotate by the drive shaft 4. The larger diameter end of the frustum-shaped turntable 15 is located in the direction of the feed inlet 13. The diameter of the larger diameter end of the frustum-shaped turntable 15 is smaller than the diameter of the inner wall of the cylinder. A guide tube 16 is located at the smaller diameter end of the frustum-shaped turntable 15. The outer wall of the guide tube 16 is fixed to the inner wall of the cylinder. The smaller diameter end of the frustum-shaped turntable 15 is smaller than the diameter of the inner wall of the guide tube 16. Shearing teeth 12 are vertically provided on the larger diameter end face of the frustum-shaped turntable 15. The guide tube 16 of the guide device 9 is cylindrical with a wall thickness of 25mm. Eight rectangular guide grooves are opened along the axial direction on the inner wall surface of the guide tube 16. A fixed boss is provided on the inner wall of the cylinder. The guide tube 16 is located on the fixed boss on the inner wall of the cylinder and is connected by bolts. The shearing teeth 12 on the larger diameter end face of the frustum-shaped turntable 15 are arranged in concentric circles and there are two circles. The shearing teeth on the larger diameter end face of the aforementioned frustum-shaped turntable can also have 3, 4, or 5 or more turns.

[0053] Example 2: Refer to Appendix Figure 13 The difference between Embodiment 2 and Embodiment 1 is that the inner wall of the front cover is provided with a stator disk with a central hole, the feed inlet communicates with the central hole, and shearing teeth are vertically arranged on the stator disk. The shearing teeth are arranged in concentric circles in two rings, and the diameter of the outermost shearing teeth is smaller than the diameter of the inner wall of the cylinder. The shearing teeth on the stator disk and the shearing teeth on the frustum-shaped turntable are arranged alternately, and the length of the shearing teeth is less than the distance between the stator disk and the frustum-shaped turntable. The guide cylinder has a wall thickness of 12mm, and the inner wall of the guide cylinder has 6 rectangular guide grooves opened along the axial direction. The shearing teeth on the stator disk can also be 3, 4, 5 or more rings.

[0054] Example 3: Refer to Appendix Figure 8The difference between Example 3 and Example 2 is that the inner and outer rings of the shearing teeth on the truncated cone turntable are arranged alternately, and the inner and outer rings of the shearing teeth on the stator plate are arranged alternately; the wall thickness of the guide tube is 6mm, and four rectangular guide grooves are opened along the axial direction on the inner wall surface of the guide tube.

[0055] Example 4: Refer to Appendix Figure 4 The difference between Example 4 and Example 1 is that the inner wall of the guide tube is a frustum cone with a taper of 45°. The large opening end of the guide tube is located in the direction of the feed inlet. The inner wall of the tube is provided with a fixed boss. The guide tube is located on the fixed boss on the inner wall of the tube and is connected by bolts.

[0056] Example 5: The difference between Example 5 and Example 4 is that the taper of the guide tube is 75° and the inner wall surface of the guide tube is provided with a spiral line.

[0057] Example 6: The difference between Example 6 and Example 5 is that the taper of the guide tube is 30°.

[0058] Example 7: Refer to Appendix Figure 5 The difference between Example 7 and Example 1 is that the inner wall of the guide tube is provided with a stepped ring platform. The diameter of the ring platform on the inner wall of the guide tube gradually decreases along the direction of the discharge port. The number of stepped ring platforms of the guide tube is 3. The inner wall of the tube is provided with a fixed boss. The guide tube is located on the fixed boss on the inner wall of the tube and is connected by bolts.

[0059] Example 8: The difference between Example 8 and Example 7 is that the number of stepped rings in the guide tube is 5.

[0060] Example 9: The difference between Example 9 and Example 7 is that the number of stepped rings in the guide tube is 7.

[0061] Example 10: Refer to Appendix Figure 6 The difference between Example 7 and Example 1 is that the guide tube is a truncated cone shape, the wall thickness of the guide tube is 2mm and the taper is 30°, the large opening end of the guide tube is located in the direction of the feed inlet, the inner wall of the tube is provided with an annular boss and the annular boss is provided with several grooves, and the outer wall of the guide tube is provided with several protrusions that fit into the grooves of the annular boss on the inner wall of the tube.

[0062] Example 11: The difference between Example 11 and Example 10 is that the wall thickness of the guide tube is 4mm and the taper is 45°.

[0063] Example 12: The difference between Example 12 and Example 10 is that the wall thickness of the guide tube is 6mm and the taper is 75°.

[0064] Example 13: Refer to Appendix Figure 9The difference between Example 13 and Example 2 is that the larger diameter end face of the truncated cone turntable is provided with a shearing blade. The shearing blade is rectangular, and the plane on which the shearing blade is located is perpendicular to the larger diameter end face of the truncated cone turntable. The length of the shearing blade is less than the radius of the inner ring shearing teeth. The inner and outer rings of the shearing teeth of the truncated cone turntable are arranged alternately, and the inner and outer rings of the shearing teeth on the stator plate are also arranged alternately.

[0065] Example 14: Refer to Appendix Figure 10 The difference between Example 14 and Example 13 is that the shear blade is a fan-shaped ring.

[0066] Example 15: Refer to Appendix Figure 11 The difference between Example 15 and Example 13 is that the cut blade is crescent-shaped.

[0067] Example 16: Refer to Appendix Figure 12 The difference between Example 16 and Example 13 is that the shear blade is a twisted, interlaced crescent shape.

[0068] Example 17: Refer to Appendix Figure 14 The difference between Example 17 and Example 1 is that the ultragravity emulsification device is in the form of a vertical device.

[0069] Example 18: Refer to Appendix Figure 15 The difference between Example 18 and Example 17 is that there are two flow guiding devices in the hypergravity emulsification chamber. The number of flow guiding devices in the above-mentioned horizontal or vertical nano-calcium carbonate PVC composite resin apparatus can also be three, four, five, or more.

[0070] Example 19: Taking a 5L polymerization reactor as an example, refer to the attached... Figure 1 Using the apparatus for nano-calcium carbonate PVC composite resin of Example 1, the present invention provides a method for preparing nano-calcium carbonate PVC composite resin, comprising the following steps in sequence: A. Preparation process: 1) Use stainless steel pressure-resistant metal hoses to connect the polymerization reactor a, the circulating pump, and the nano-calcium carbonate PVC composite resin device to form an external circulation closed-loop device. The bottom outlet of the polymerization reactor a is connected to the inlet of the circulating pump, the outlet of the circulating pump is connected to the inlet of the nano-calcium carbonate PVC composite resin device, and the outlet of the nano-calcium carbonate PVC composite resin device is connected to the top inlet of the polymerization reactor a; 2) After the polymerization reactor a, the circulating pump, and the nano-calcium carbonate PVC composite resin device are connected, nitrogen pressure is applied and leak is tested. If the airtightness is good, the pressure is released and a vacuum is drawn, and then the circulation inlet and outlet of the polymerization reactor a are closed. B. Homogenization process: 1) Add nano-calcium carbonate, vinyl chloride, and dispersant to polymerization reactor a according to the experimental formula. Start the stirring of polymerization reactor a at 1000 rpm for 5 minutes to premix, and then adjust the stirring to 30 rpm; 2) The homogenization of the materials is mainly accomplished using the device in Example 1. First, open the bottom outlet valve and the top inlet valve of polymerization reactor a. Then, start the circulating pump at 50 Hz and the rotor speed of the nano-calcium carbonate PVC composite resin device at 1500 rpm to circulate and homogenize the materials. The circulation and homogenization time is 10 minutes. During the circulation and homogenization process, control the cooling water of the jacket of polymerization reactor a and the nano-calcium carbonate PVC composite resin device to control the internal temperature of polymerization reactor a at 5~20℃; After the homogenization is completed, first turn off the circulating pump and the nano-calcium carbonate PVC composite resin device, and then close the bottom outlet valve and the top inlet valve of polymerization reactor a. C. Feeding process: Add the homogenized materials, initiator, soft water and pH adjuster from step B to polymerization reactor b according to the formula requirements, and start the polymerization reactor b to stir at 1000 rpm for 10 min for premixing. D. Reaction process: Start heating the polymerization reactor b to 57°C to carry out the polymerization reaction. Smoothly control the polymerization reaction. When the reaction pressure drops by 2 bar, add the defoamer and terminator, and continue stirring for 10 minutes. E. Discharge and drying process: The temperature inside the reactor is reduced to below 40°C. Unreacted monomers are depressurized from the top of the polymerization reactor b and sent to the separation and recovery system. The material is discharged from the bottom of the polymerization reactor b into the drying system. The resin after drying is nano-calcium carbonate PVC composite resin.

[0071] Product formulation: 100 parts resin, 3 parts stabilizer, 1 part lubricant.

[0072] The performance test data of the resin and its products are shown in Table 1 (the same applies below).

[0073] Example 20: The difference between Example 20 and Example 19 is that the apparatus of Example 2 is used, the circulating pump is 30Hz, the rotor speed of the nano-calcium carbonate PVC composite resin is 2000rpm, and the circulation homogenization time is 15min.

[0074] Example 21: The difference between Example 21 and Example 20 is that the device of Example 3 is used, the circulating pump is 40Hz, the device rotor speed of nano-calcium carbonate PVC composite resin is 2500rpm, and the circulation homogenization time is 20min.

[0075] Example 22: The difference between Example 22 and Example 19 is that the apparatus of Example 4 is used.

[0076] Example 23: The difference between Example 23 and Example 19 is that the apparatus of Example 7 is used and the polymerization reaction temperature is 54°C.

[0077] Example 24: The difference between Example 24 and Example 19 is that the apparatus of Example 10 is used and the polymerization reaction temperature is 64°C.

[0078] Example 25: The difference between Example 25 and Example 20 is that the apparatus of Example 13 is used.

[0079] Example 26: The difference between Example 26 and Example 19 is that the apparatus of Example 17 is used.

[0080] Example 27: The difference between Example 27 and Example 19 is that the apparatus of Example 18 is used.

[0081] Comparative Example: Polymerization reactor B was pressurized with nitrogen and leak-tested. If the seal was good, the pressure was released and a vacuum was drawn. Nano-calcium carbonate, vinyl chloride, dispersant, initiator, soft water, and pH adjuster were added to polymerization reactor B according to the experimental formula. The polymerization reactor B was stirred at 1000 rpm for 30 minutes for premixing. Then, the temperature of polymerization reactor B was increased to 57°C for polymerization reaction. The polymerization reaction was controlled stably. When the reaction pressure dropped by 2 bar, defoamer and terminator were added, and stirring was continued for 10 minutes. The temperature inside the reactor was reduced to below 40°C. Unreacted monomers were released from the top of polymerization reactor B and sent to the separation and recovery system. The material was discharged from the bottom of polymerization reactor B into the drying system. The resin after drying is PVC resin.

[0082] Table 1. Performance test data of resins and products The methods described in the above embodiments are also suitable for 20L, 50L, 7m3, 14m3, and 30m3 reactors.

[0083] The principle and operation process of this invention are as follows: (Refer to the appendix) Figure 2 The motor drives the drive shaft to rotate via a coupling. The drive shaft drives the truncated cone-shaped turntable and the rotating filling bed mounted on the drive shaft to rotate. The material enters the shearing chamber from the feed port of this device. After passing through the truncated cone-shaped turntable and shearing teeth, the material is pre-homogenized. The pre-homogenized material is directed into the rotating filling bed in the ultragravity emulsification chamber under the action of the guide tube. Then, ultragravity homogenization is carried out in the ultragravity emulsification chamber. After the material is homogenized, it flows out from the discharge port.

[0084] This invention features a flow guiding device within the hypergravity emulsification chamber. This device divides the shell into a shearing chamber and a hypergravity emulsification chamber. Materials are first pre-homogenized in the shearing chamber and then homogenized in the hypergravity emulsification chamber. Under hypergravity conditions, material dispersion, shearing, and homogenization can be completed in a very short time, resulting in a narrow particle size distribution and uniform size, significantly improving production efficiency. This device simultaneously functions as an emulsification shear pump, a mixing pump, and a mixing conveying pump. Its compact size and small footprint make it convenient to use. The flow guiding device increases the number of rotating packed beds within the hypergravity emulsification chamber, thereby improving emulsification efficiency. The design of the flow guiding device also further enhances the mixing effect.

[0085] The device of this invention, connected in series with the polymerization reactor to form a closed-loop circulation, first homogenizes nano-calcium carbonate, vinyl chloride monomer, and dispersant to form a nano-scale dispersion. The nano-calcium carbonate is uniformly dispersed in the vinyl chloride monomer, and the surface modifier of the nano-calcium carbonate is tightly bonded to the interior of the vinyl chloride monomer. This solves the problems of easy agglomeration of nano-calcium carbonate and poor compatibility with polymers during the polymerization process. In the subsequent polymerization process, the nano-scale dispersion participates in the polymerization reaction just like the original vinyl chloride monomer, without affecting the overall polymerization reaction. This allows the nano-calcium carbonate to exert its toughening and reinforcing functions, thereby improving the physical and chemical properties of the nano-calcium carbonate PVC composite resin.

[0086] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

[0087] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for preparing nano calcium carbonate PVC composite resin, comprising a frame, a motor, a shaft coupling, a drive shaft, a shell and a jacket, the motor barrel, the drive shaft and the shell are arranged on the frame, the shell is composed of a barrel, a front end cover and a rear end cover, the motor is connected with the drive shaft through the shaft coupling, the drive shaft penetrates through the rear end cover and extends into the shell, characterized in that: The body side close to the rear end cover is provided with a discharge port, the center of the front end cover is provided with a feed port, the shell is provided with a flow guide device, the flow guide device divides the shell into a shearing cavity and a supergravity emulsification cavity in the direction from front to back, the supergravity emulsification cavity is provided with a rotating packed bed, the flow guide device comprises a conical frustum-shaped rotating disc and a flow guide cylinder, the conical frustum-shaped rotating disc is vertically arranged on the driving shaft and is driven to rotate by the driving shaft, the large-diameter end of the conical frustum-shaped rotating disc is located in the direction of the feed port, the diameter of the large-diameter end of the conical frustum-shaped rotating disc is smaller than the diameter of the inner wall of the cylinder, the flow guide cylinder is located at the small-diameter end of the conical frustum-shaped rotating disc, the outer wall of the flow guide cylinder is fixed to the inner wall of the cylinder, the diameter of the small-diameter end of the conical frustum-shaped rotating disc is smaller than the diameter of the inner wall of the flow guide cylinder, and a shearing tooth is vertically arranged on the large-diameter end surface of the conical frustum-shaped rotating disc. ​ 2. The device for preparing nanocarbonated calcium PVC composite resin according to claim 1, characterized in that: The flow guide cylinder of the flow guide device is in a cylindrical shape, the wall thickness of the flow guide cylinder is 6-25 mm, and 4-8 rectangular flow guide grooves are formed in the inner wall surface of the flow guide cylinder in the axial direction; the inner wall surface of the flow guide cylinder is in a conical frustum shape and has a taper of 30°-75°, and the large opening end of the flow guide cylinder is located in the direction of the feed port; the inner wall of the cylinder is provided with a fixed boss, and the flow guide cylinder is located on the fixed boss of the inner wall of the cylinder and is connected by bolts.

3. The apparatus for preparing nanocarbonated calcium PVC composite resin according to claim 2, characterized in that: A helical line is arranged on the inner wall surface of the flow guide cylinder.

4. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 1, characterized in that: The flow guide cylinder of the flow guide device is in a cylindrical shape, the inner wall of the flow guide cylinder is provided with a stepped ring platform, the diameter of the ring platform of the inner wall of the flow guide cylinder gradually decreases in the direction of the discharge port, the number of the stepped ring platforms of the flow guide cylinder is 3-7, the inner wall of the cylinder is provided with a fixed boss, and the flow guide cylinder is located on the fixed boss of the inner wall of the cylinder and is connected by bolts.

5. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 1, characterized in that: The flow guide cylinder of the flow guide device is in a conical frustum shape, the wall thickness of the flow guide cylinder is 2-6 mm and the taper is 30°-75°, the large opening end of the flow guide cylinder is located in the direction of the feed port, the inner wall of the cylinder is provided with an annular boss which is provided with a plurality of grooves, the outer wall of the flow guide cylinder is provided with a plurality of protrusions which are clamped into the grooves of the annular boss of the inner wall of the cylinder; the shearing teeth on the large-diameter end surface of the conical frustum-shaped rotating disc are arranged in concentric circles and are at least two circles.

6. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 5, characterized in that: A stator disc with a center hole is arranged on the inner wall surface of the front end cover, the feed port is communicated with the center hole, and shearing teeth are vertically arranged on the surface of the stator disc; the shearing teeth are arranged in concentric circles and are at least two circles, the diameter of the position where the shearing teeth of the outermost circle are located is smaller than the diameter of the inner wall of the cylinder, the shearing teeth on the surface of the stator disc and the shearing teeth on the conical frustum-shaped rotating disc are alternately arranged, and the length of the shearing teeth is smaller than the distance between the stator disc and the conical frustum-shaped rotating disc.

7. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 6, characterized in that: The shearing teeth of the conical frustum-shaped rotating disc are staggered between the inner and outer circles, and the shearing teeth of the stator disc are staggered between the inner and outer circles.

8. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 7, characterized in that: The large-diameter end surface of the conical frustum-shaped rotating disc is provided with shearing blades, the shearing blades are one of rectangular, fan ring, half-moon, and twisted staggered half-moon shapes, the plane where the shearing blades are located is perpendicular to the large-diameter end surface of the conical frustum-shaped rotating disc, the shearing blades are located on the diameter of the large-diameter end surface of the conical frustum-shaped rotating disc and are uniformly distributed, and the length of the shearing blades is smaller than the radius of the inner circle shearing teeth.

9. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 1, characterized in that: The rotating packed bed comprises a hollow cylindrical rotor and an emulsification net rotor, and the rotating packed bed is fixedly connected with the driving shaft by bolts.

10. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 1, characterized in that: The flow guide device in the supergravity emulsification cavity is at least two.

11. The apparatus for preparing nano calcium carbonate PVC composite resin according to claim 1, characterized in that: The device for preparing the nano calcium carbonate PVC composite resin is one of horizontal type and vertical type.

12. A method for preparing nano calcium carbonate PVC composite resin by using the device for preparing nano calcium carbonate PVC composite resin according to any one of claims 1-11, comprising the following steps in sequence: A, preparation process 1) A stainless steel pressure-resistant metal hose is used to connect the polymerization kettle a, the circulating pump and the device for preparing nano calcium carbonate PVC composite resin to form an external circulation closed loop device, the bottom outlet of the polymerization kettle a is connected with the inlet of the circulating pump, the outlet of the circulating pump is connected with the inlet of the device for preparing nano calcium carbonate PVC composite resin, and the outlet of the device for preparing nano calcium carbonate PVC composite resin is connected with the top inlet of the polymerization kettle a; 2) After the connection of the polymerization kettle a, the circulating pump and the device for preparing nano calcium carbonate PVC composite resin is completed, nitrogen is pressurized, and leakage is tested, and if the sealing property is good, the pressure is released, vacuum is drawn, and then the circulating inlet and outlet of the polymerization kettle a are closed; B, homogenization process 1) Nano calcium carbonate, vinyl chloride and dispersant are respectively measured and added into the polymerization kettle a according to the experimental formula, the polymerization kettle a is started to stir at 300-1000 rpm for pre-mixing for 5 min, and then the stirring is adjusted to 30-70 rpm; 2) The homogenization of the material is mainly completed by using the above-mentioned device for preparing nano calcium carbonate PVC composite resin, the bottom outlet valve of the polymerization kettle a and the top inlet valve of the polymerization kettle a are opened, and then the circulating pump is started to 30-50 Hz, so that the rotor speed of the device for preparing nano calcium carbonate PVC composite resin reaches 1000-3000 rpm, the material is circulated and homogenized, the circulation homogenization time is 5-20 min, and in the circulation homogenization process, the temperature in the polymerization kettle a is controlled to be 5-20℃ by controlling the jacket cooling water of the polymerization kettle a and the device for preparing nano calcium carbonate PVC composite resin; after the homogenization is completed, the circulating pump and the device for preparing nano calcium carbonate PVC composite resin are closed, and then the bottom outlet valve of the polymerization kettle a and the top inlet valve of the polymerization kettle a are closed; C, feeding process The material homogenized in step B, initiator, soft water and pH regulator are respectively measured and added into the polymerization kettle b according to the formula requirement, the polymerization kettle b is started to stir at 300-1500 rpm for pre-mixing for 10-40 min; D, reaction process The polymerization kettle b is started to be heated, and the polymerization is carried out at 54-64℃, the polymerization reaction is stably controlled, when the reaction pressure drops by 2 bar, the defoaming agent and the terminating agent are added, and the stirring is continued for 10 min; E, discharging and drying process The temperature in the kettle is reduced to below 40℃, the unreacted monomer is discharged from the top of the polymerization kettle b to a separation and recovery system under pressure, the material is discharged from the bottom of the polymerization kettle b to a drying system, and the resin after drying is the nano calcium carbonate PVC composite resin.

13. The method of making a nanocarbonated calcium PVC composite resin according to claim 12, wherein: The nano calcium carbonate in the homogenization process of step B is transparent nano calcium carbonate oil phase dispersion.

Images