A kettle type series continuous polymerization method and a kettle type series device of FEVE fluorocarbon resin

Abstract

The application discloses a kettle type series continuous polymerization method and device of FEVE fluorocarbon resin, and the method comprises the following steps: continuously feeding: reaction raw materials are added into a prepolymerization kettle according to a formula proportion, the material in the prepolymerization kettle is monitored and controlled to keep in a set range, a prepolymerization reaction occurs, and a reaction material after the prepolymerization reaction is obtained; continuously polymerizing: the reaction material after the prepolymerization reaction sequentially passes through multiple post-polymerization kettles, a post-polymerization reaction occurs, continuous polymerization is carried out, and a FEVE fluorocarbon resin product is obtained; continuously discharging: the stable FEVE fluorocarbon resin product is collected at the outlet of the final post-polymerization kettle; and the reaction raw materials comprise fluorine-containing gas-phase monomers and hydrocarbon liquid-phase monomers, an initiator, a solvent and the like. Compared with the prior art, the application has the advantages of high automation degree, low energy consumption, good process stability and strong product quality consistency.

Description

Technical Field

[0001] This invention relates to the field of polymerization technology, and in particular to a continuous batch polymerization method and batch reactor apparatus for FEVE fluorocarbon resin. Background Technology

[0002] FEVE fluorocarbon resin (FEVE-type fluorocarbon resin) is widely used in heavy-duty anti-corrosion engineering projects such as buildings and bridges, as well as functional materials such as solar backsheet films, due to its unique physicochemical properties, such as excellent heat resistance, chemical resistance, weather resistance, and electrical insulation. Currently, the industrial production of FEVE fluorocarbon resin mainly adopts the batch polymerization method, which has the following prominent problems: long polymerization reaction time and low production efficiency; low monomer conversion rate and high unit consumption; frequent heating and cooling to maintain a constant temperature inside the reactor during the reaction process, resulting in low energy efficiency and the risk of local thermal runaway; in addition, there are large fluctuations in product quality between batches, making it difficult to guarantee consistency. Therefore, facing the above technical bottlenecks, the industry urgently needs to develop a continuous polymerization production process that can achieve a high degree of automation, low energy consumption, good process stability, and strong product quality consistency. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention presents a continuous batch polymerization method and apparatus for FEVE fluorocarbon resin, specifically a continuous reaction apparatus based on multiple batch reactors connected in series. This apparatus, building upon traditional batch reactors, achieves staged and continuous prepolymerization and post-polymerization processes of FEVE fluorocarbon resin in different reactors by sequentially connecting multiple reactors, thus completing the entire polymerization reaction. This process route offers advantages such as high automation, low energy consumption, good process stability, and strong product quality consistency. Furthermore, in traditional batch reactor reactions, to ensure complete reaction, fluorine-containing gaseous monomers often need to be added in excess to 105%~110% of the theoretical amount, which not only wastes raw materials and increases unit consumption but also increases the cost of subsequent separation and purification. This invention effectively alleviates these problems through continuous operation and process control.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The first objective of this invention is to provide a continuous batch polymerization method for FEVE fluorocarbon resin, the method comprising the following steps: (1) Continuous feeding: The reaction raw materials are added to the prepolymerization reactor according to the formula ratio. The material in the prepolymerization reactor is monitored and controlled to be kept within the set range. The prepolymerization reaction occurs and the reaction material after the prepolymerization reaction is obtained. (2) Continuous polymerization: The reactants after the prepolymerization reaction are passed through multiple postpolymerization reactors in sequence to undergo postpolymerization reaction and continuous polymerization to obtain FEVE fluorocarbon resin products; (3) Continuous discharge: Stable FEVE fluorocarbon resin products are collected at the outlet of the final post-polymerization reactor; Furthermore, the reaction raw materials include fluorine-containing gaseous monomers and hydrocarbon liquid monomers, initiators, solvents, and additives.

[0005] Furthermore, the inlet of the prepolymerization reactor is connected to a feed pump and / or a pressure reducing valve and / or a regulating valve to control the feed rate of the reaction raw materials and the reaction pressure.

[0006] Furthermore, the continuous feeding process controls the feed rate and reaction pressure of the reaction raw materials through a feed pump or pressure reducing valve. The feed rate depends on the size of the reactor, and the size of the reactor and the feed rate determine the residence time of the material in each reactor. No special requirements are made for the size of the reactor and the feed rate here, but in order to ensure the full progress of the polymerization reaction, the residence time of the material needs to be limited.

[0007] Furthermore, the outlet of the final post-polymerization reactor is connected to a discharge pump and / or a back pressure valve and / or a regulating valve to control the discharge rate of the FEVE fluorocarbon resin product.

[0008] Furthermore, after the reactants have completed polymerization in the last reactor, the resulting FEVE fluorocarbon resin product is discharged stably and continuously through the discharge control system (such as a regulating valve, back pressure valve, or discharge pump), ultimately obtaining a product with a high monomer conversion rate.

[0009] Furthermore, the continuous discharge process controls the discharge rate of the crude FEVE fluorocarbon resin product through the discharge valve (which can be a back pressure valve or a regulating valve) or discharge pump of the reactor, ensuring that the liquid level in all reactors is within a reasonable range. The sustainability of liquid level control determines the capacity of the continuous polymerization equipment.

[0010] Furthermore, the number of post-polymerization reactors is 2-n, where 2 < n ≤ 10.

[0011] Preferably, 3 < n ≤ 5.

[0012] Furthermore, multiple post-polymerization reactors are connected in sequence, with the inlet of the first post-polymerization reactor connected to the outlet of the pre-polymerization reactor, the inlet of the next post-polymerization reactor connected to the outlet of the previous post-polymerization reactor, and the outlet of the final post-polymerization reactor used to collect stable FEVE fluorocarbon resin products.

[0013] Furthermore, the material transfer between the prepolymerization reactor and the postpolymerization reactor is controlled by a transfer pump or by valves using pressure difference or liquid level difference.

[0014] Furthermore, material transfer between reactors can be achieved using a transfer pump or by using valves to control the transfer based on pressure or level differences. In other words, material transfer between adjacent post-polymerization reactors can be achieved using a pump or by using valves to control the transfer based on pressure or level differences.

[0015] Furthermore, the delivery pump includes, but is not limited to, gear pumps, screw pumps, plunger pumps, cycloidal pumps, and diaphragm pumps.

[0016] Furthermore, the residence time of the material in a single reactor (= effective volume of reactor / feed rate) is controlled within 10 min to 3 h, that is, the residence time of the material in a single prepolymerization reactor is controlled within 10 min to 3 h, and the residence time of the material in a single postpolymerization reactor is controlled within 10 min to 3 h.

[0017] Preferably, the residence time of the material in a single reactor is controlled within 30 min to 2 h, that is, the residence time of the material in a single prepolymerization reactor is controlled within 30 min to 2 h, and the residence time of the material in a single postpolymerization reactor is controlled within 30 min to 2 h.

[0018] Furthermore, the total residence time for the polymerization reaction is 1 h to 25 h.

[0019] Preferably, the total polymerization residence time is 3h to 22h.

[0020] More preferably, the total polymerization residence time is 6h to 16h.

[0021] Furthermore, the continuous polymerization process is carried out at a certain reaction temperature, with the reaction temperature in the prepolymerization reactor being 50~70℃ and the reaction temperature in the postpolymerization reactor being 71~100℃.

[0022] Preferably, the reaction temperature in the prepolymerization reactor is 50~65℃, and the reaction temperature in the postpolymerization reactor is 75~90℃.

[0023] Furthermore, the continuous polymerization process is carried out under a certain reaction pressure. The pressure range is related to the type of gaseous monomer and the reaction formulation, and is generally controlled at 0.2~2 MPa. That is, the pressure of the prepolymerization reaction is 0.2~2 MPa, and the pressure of the postpolymerization reaction is 0.2~2 MPa.

[0024] Preferably, the reaction pressure is controlled at 0.3~1.5 MPa, that is, the pressure of the prepolymerization reaction is 0.3~1.5 MPa, and the pressure of the postpolymerization reaction is 0.3~1.5 MPa.

[0025] Furthermore, the reactor can be a liquid-liquid phase full-bottle reaction or a gas-liquid phase reaction, that is, the prepolymerization reaction is a liquid-liquid phase full-bottle reaction or a gas-liquid phase reaction, and the postpolymerization reaction is a liquid-liquid phase full-bottle reaction or a gas-liquid phase reaction.

[0026] Furthermore, by controlling the liquid level in the reactor to control the utilization rate of the equipment, the utilization rate of the reactor equipment used for continuous polymerization is generally controlled at 70% to 98%.

[0027] Preferably, the utilization rate of the reactor equipment used for continuous polymerization is controlled at 80% to 95%.

[0028] Furthermore, the equipment utilization rate of the prepolymerization reactor is 70%~98%, and the equipment utilization rate of the prepolymerization reactor is controlled by controlling the liquid level of the prepolymerization reactor; the equipment utilization rate of the postpolymerization reactor is 70%~98%, and the equipment utilization rate of the postpolymerization reactor is controlled by controlling the liquid level of the postpolymerization reactor.

[0029] Preferably, the equipment utilization rate of the prepolymerization reactor is 80%~95%; the equipment utilization rate of the postpolymerization reactor is 80%~95%.

[0030] Furthermore, the solvent is an organic solvent, which may be one or more of xylene, toluene, ethyl acetate, butyl acetate, acetone, butanone, tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol methyl ether acetate, etc.

[0031] Furthermore, the fluorinated gaseous monomer is selected from one or more of tetrafluoroethylene, trifluorochloroethylene, fluoroethylene, vinylidene fluoride, hexafluoropropylene, HFO-1234ze, and HFO-1234yf.

[0032] Further, the hydrocarbon liquid phase monomer is an alkyl vinyl ether or an alkyl vinyl ester, selected from one or more monomers such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, heptyl vinyl ether, octyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, dodecyl vinyl ether, cyclobutyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxypentyl vinyl ether, hydroxyhexyl vinyl ether, hydroxydecyl vinyl ether, hydroxydodecyl vinyl ether, hydroxyhexadecyl vinyl ether, hydroxycyclopropyl vinyl ether, hydroxycyclobutyl vinyl ether, hydroxycyclopentyl vinyl ether, hydroxycyclohexyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, perfluoron-propyl vinyl ether, perfluorobutyl vinyl ester, vinyl acetate, and isopropyl acetate.

[0033] Further, the initiator is an organic peroxide initiator, which is selected from one or more of the following: tert-butyl peroxyneodecanate, bis(4-tert-butylcyclohexyl peroxydicarbonate), tert-butyl peroxypentanoate, dilauroyl peroxy, didecyl peroxy, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxypentanoate, and tert-pentylneovale peroxy.

[0034] Further, the adjuvant is one or more of triethylamine, ethanolamine, diethanolamine, hydroquinone, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1-(methyl)-8-(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and Tinuvin® 292.

[0035] Furthermore, the FEVE fluorocarbon resin prepared by the continuous polymerization method exhibits the same or even better product performance and index stability as the resin obtained by batch polymerization. The FEVE fluorocarbon resin prepared by the continuous polymerization method shows significantly higher CPK values ​​for various indices between different batches compared to batch polymerization, as well as superior aging resistance, storage time, and heat resistance compared to resin produced by continuous polymerization.

[0036] Furthermore, the method employs a series of reactors for continuous polymerization.

[0037] A second objective of this invention is to provide a batch reactor assembly for realizing the continuous batch polymerization method of the FEVE fluorocarbon resin, the batch reactor assembly comprising a prepolymerization reactor and a plurality of postpolymerization reactors connected in sequence.

[0038] Furthermore, the prepolymerization reactor is connected to the first postpolymerization reactor; both the prepolymerization reactor and the postpolymerization reactor are provided with an inlet and an outlet.

[0039] Furthermore, the prepolymerization reactor is connected to the first postpolymerization reactor via a pipeline, and adjacent postpolymerization reactors are connected via pipelines. A delivery pump or a valve can be installed on the pipeline to control material delivery using pressure difference or liquid level difference.

[0040] Furthermore, the aforementioned series-connected reactors, through different combinations of reactors, constitute a complete system capable of continuous feeding, continuous polymerization, and continuous discharge. Depending on the feed rate and equipment scale, it is suitable for various stages from pilot-scale to industrial-scale production.

[0041] The present invention relates to a batch-type series continuous polymerization method and batch-type series apparatus for FEVE fluorocarbon resin, wherein the method is a preparation method suitable for continuous polymerization of FEVE fluorocarbon resin.

[0042] It should be noted that the device and process principle of the present invention are universal and its application scope is not limited to FEVE fluorocarbon resin, but can also be extended to the synthesis of other types of resins. It also involves pilot-scale and conventional production equipment with two or more reactors for continuous polymerization reaction. The method and device together constitute a polymerization reaction process route that can realize continuous feeding, continuous polymerization and continuous discharge.

[0043] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects: 1) Compared with the traditional batch polymerization technology, the batch continuous polymerization method and batch reactor device for FEVE fluorocarbon resin of the present invention, based on the original batch reactor equipment and process, realizes the continuous production process of FEVE fluorocarbon resin, with minimal impact on product quality changes, but the product stability and consistency are far higher than the original batch reactor.

[0044] 2) Compared with the traditional batch polymerization technology, the batch continuous polymerization method and batch continuous polymerization device of FEVE fluorocarbon resin of the present invention has a higher utilization rate of fluorine-containing gaseous monomers. The actual excess addition of fluorine-containing gaseous monomers is 100.5~101% of the theoretical amount, while the batch process usually requires an actual excess addition of fluorine-containing gaseous monomers of up to 105% of the theoretical amount.

[0045] 3) Compared with the traditional batch polymerization technology, the batch continuous polymerization method and batch device for FEVE fluorocarbon resin of the present invention have the advantages of continuous monomer feeding, continuous polymerization reaction, controllable polymerization heat, and basically constant heat release and heat release range. Therefore, the reaction temperature fluctuates very little, temperature control is simpler, the polymerization process is highly controllable, and the quality of the obtained polymer product is more stable.

[0046] 4) Compared with the traditional batch polymerization technology, the batch continuous polymerization method and batch device for FEVE fluorocarbon resin of the present invention have lower requirements for feeding, and can feed in a continuous and constant manner, while also being compatible with batch feeding. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the tubular and batch mixing apparatus for the continuous polymerization method of FEVE fluorocarbon resin in a batch reactor according to the present invention.

[0048] The numbers in the diagram are as follows: 1. Prepolymerization reactor, 2. First post-polymerization reactor, 3. Second post-polymerization reactor, 4. Liquid phase discharge valve; a. Hydrocarbon liquid-phase monomers b. Fluorine-containing gaseous monomers c. Solvents, etc. e. FEVE fluorocarbon resin products. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to specific embodiments, but this is by no means a limitation thereof. Any preparation methods, materials, structures, or composition ratios not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] This invention relates to a continuous batch polymerization method and apparatus for FEVE fluorocarbon resin, specifically a method for continuous polymerization of FEVE fluorocarbon resin through a series of reactors. The method mainly includes: continuously feeding fluorine-containing gaseous monomers, hydrocarbon liquid monomers, initiators, and solvents into a pre-reaction vessel according to a specific formulation ratio; mixing and pre-polymerization of the materials in the pre-reaction vessel; and monitoring the liquid level within the vessel. When the liquid level in the reaction vessel reaches a set range, the material is sequentially fed into one or more subsequent series of reactors to continue the reaction, ultimately yielding crude FEVE fluorocarbon resin at the outlet of the last reactor. Once the liquid levels in all the series of reactors reach equilibrium, a continuous reaction process of continuous feeding, continuous polymerization, and continuous discharge is achieved. This batch-connected continuous polymerization process features uniform exothermic reaction rate, stable polymerization process control, high degree of continuity, and excellent batch-to-batch product consistency.

[0053] This invention provides a continuous polymerization method and apparatus for FEVE fluorocarbon resin using a series of reactors connected in series. The method comprises the following steps: (1) Continuous feeding: The reaction raw materials are added to the prepolymerization reactor 1 according to the formula ratio. The material in the prepolymerization reactor 1 is monitored and controlled to be kept within the set liquid level range. The prepolymerization reaction occurs and the reaction material after the prepolymerization reaction is obtained. (2) Continuous polymerization: The reactants after the prepolymerization reaction pass through multiple postpolymerization reactors in sequence to undergo postpolymerization reaction. The reaction is carried out continuously at a certain reaction temperature and reaction pressure to obtain FEVE fluorocarbon resin products. (3) Continuous discharge: Stable FEVE fluorocarbon resin products are collected at the outlet of the final post-polymerization reactor; The reaction raw materials include fluorine-containing gaseous monomers and hydrocarbon liquid monomers, initiators, auxiliaries, and solvents.

[0054] In some embodiments of the present invention, the inlet of the prepolymerization reactor 1 is connected to a feed pump and / or a pressure reducing valve and / or a regulating valve to control the feed rate of the reaction raw materials and the reaction pressure.

[0055] In some embodiments of the present invention, the continuous feeding process controls the feeding rate and reaction pressure of the reaction raw materials by means of a feed pump and / or a pressure reducing valve. The feeding rate depends on the size of the reactor. The size of the reactor and the feeding rate determine the residence time of the material in each reactor. No special requirements are made for the size of the reactor and the feeding rate, but in order to ensure the full progress of the polymerization reaction, the residence time of the material needs to be limited.

[0056] In some embodiments of the present invention, the outlet of the final post-polymerization reactor is connected to a discharge pump and / or a back pressure valve and / or a regulating valve to control the discharge rate of the FEVE fluorocarbon resin product.

[0057] In some embodiments of the present invention, after the reactants have completed polymerization in the last reactor, the resulting FEVE fluorocarbon resin product is discharged stably and continuously through a discharge control system (such as a regulating valve, back pressure valve, or discharge pump), ultimately obtaining a product with a high monomer conversion rate.

[0058] In some embodiments of the present invention, the continuous discharge process is controlled by the discharge valve (which may be a back pressure valve and / or a regulating valve) and / or discharge pump of the reactor to control the discharge rate of FEVE fluorocarbon resin products, ensuring that the liquid level in all reactors is within a reasonable range, and the sustainability of liquid level control determines the capacity of the continuous polymerization equipment.

[0059] In some embodiments of the present invention, the number of post-polymerization reactors is 2-n, where 2 < n ≤ 10.

[0060] In some embodiments of the present invention, 3 < n ≤ 5.

[0061] In some embodiments of the present invention, multiple post-polymerization reactors are connected in sequence, wherein the inlet of the first post-polymerization reactor is connected to the outlet of the pre-polymerization reactor 1, the inlet of the next post-polymerization reactor is connected to the outlet of the previous post-polymerization reactor, and the outlet of the final post-polymerization reactor is used to collect a stable FEVE fluorocarbon resin product.

[0062] In some embodiments of the present invention, the material transport between the prepolymerization reactor 1 and the postpolymerization reactor is controlled by a transport pump or by a valve using pressure difference or liquid level difference.

[0063] In some embodiments of the present invention, material transfer between reactors can be carried out using a transfer pump or by using valves to control the transfer using pressure difference or liquid level difference. That is, material transfer between adjacent post-polymerization reactors can be carried out using a pump or by using valves to control the transfer using pressure difference or liquid level difference.

[0064] In some embodiments of the present invention, the delivery pump includes, but is not limited to, gear pumps, screw pumps, plunger pumps, cycloidal pumps, and diaphragm pumps.

[0065] In some embodiments of the present invention, the residence time of the material in a single reactor (= effective volume of reactor / feed rate) is controlled to be 10 min to 3 h, that is, the residence time of the material in a single prepolymerization reactor 1 is controlled to be 10 min to 3 h, and the residence time of the material in a single postpolymerization reactor is controlled to be 10 min to 3 h.

[0066] In some embodiments of the present invention, the residence time of the material in a single reactor is controlled to be 30 min to 2 h, that is, the residence time of the material in a single prepolymerization reactor 1 is controlled to be 30 min to 2 h, and the residence time of the material in a single postpolymerization reactor is controlled to be 30 min to 2 h.

[0067] In some embodiments of the present invention, the total polymerization residence time is 1 h to 25 h.

[0068] In some embodiments of the present invention, the total polymerization residence time is 3h to 22h.

[0069] In some embodiments of the present invention, the total polymerization residence time is 6h to 16h.

[0070] In some embodiments of the present invention, the continuous polymerization process is carried out at a certain reaction temperature, with the reaction temperature in the prepolymerization reactor 1 being 50~70°C and the reaction temperature in the postpolymerization reactor being 71~100°C.

[0071] In some embodiments of the present invention, the reaction temperature in the prepolymerization reactor is 50~65°C, and the reaction temperature in the postpolymerization reactor is 75~90°C.

[0072] In some embodiments of the present invention, the continuous polymerization process is carried out under a certain reaction pressure. The pressure range is related to the type of gaseous monomer and the reaction formulation, and is generally controlled at 0.2~2 MPa. That is, the pressure of the prepolymerization reaction is 0.2~2 MPa, and the pressure of the postpolymerization reaction is 0.2~2 MPa.

[0073] In some embodiments of the present invention, the reaction pressure is controlled at 0.3 to 1.5 MPa, that is, the pressure of the prepolymerization reaction is 0.3 to 1.5 MPa, and the pressure of the postpolymerization reaction is 0.3 to 1.5 MPa.

[0074] In some embodiments of the present invention, the reactor can be a liquid-liquid phase full-bottle reaction or a gas-liquid phase reaction, that is, the prepolymerization reaction is a liquid-liquid phase full-bottle reaction or a gas-liquid phase reaction, and the postpolymerization reaction is a liquid-liquid phase full-bottle reaction or a gas-liquid phase reaction.

[0075] In some embodiments of the present invention, by controlling the utilization rate of the liquid level control equipment of the reactor, the utilization rate of the reactor equipment for continuous polymerization is generally controlled at 70% to 98%.

[0076] In some embodiments of the present invention, the utilization rate of the reactor equipment for continuous polymerization is controlled at 80% to 95%.

[0077] In some embodiments of the present invention, the equipment utilization rate of the prepolymerization reactor 1 is 70% to 98%, and the equipment utilization rate of the prepolymerization reactor 1 is controlled by controlling the liquid level of the prepolymerization reactor 1; the equipment utilization rate of the postpolymerization reactor is 70% to 98%, and the equipment utilization rate of the postpolymerization reactor is controlled by controlling the liquid level of the postpolymerization reactor.

[0078] In some embodiments of the present invention, the equipment utilization rate of the prepolymerization reactor 1 is 80%~95%; the equipment utilization rate of the postpolymerization reactor is 80%~95%.

[0079] The method includes the following steps: (1) Weigh different proportions of hydrocarbon liquid phase monomers, add a certain amount of solvent and additives, stir and mix evenly, and then place them in a liquid phase monomer tank.

[0080] The hydrocarbon liquid phase monomer is a vinyl ester or vinyl ether monomer, selected from one or more of the following: ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, heptyl vinyl ether, octyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, dodecyl vinyl ether, cyclobutyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxypentyl vinyl ether, hydroxyhexyl vinyl ether, hydroxydecyl vinyl ether, hydroxydodecyl vinyl ether, hydroxyhexadecyl vinyl ether, hydroxycyclopropyl vinyl ether, hydroxycyclobutyl vinyl ether, hydroxycyclopentyl vinyl ether, hydroxycyclohexyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, perfluoron-propyl vinyl ether, perfluorobutyl vinyl ester, vinyl acetate, and isopropyl acetate. The specific monomer ratio is determined according to the polymerization formulation requirements of the FEVE fluorocarbon resin and is not specifically limited.

[0081] The solvent is one or more of xylene, toluene, ethyl acetate, butyl acetate, tetrahydrofuran, acetone, butanone, ethylene glycol dimethyl ether, and propylene glycol methyl ether acetate. The ratio of solvent to liquid monomer is not specifically limited and is determined according to the polymerization formulation requirements of FEVE fluorocarbon resin.

[0082] The adjuvant is one or more of triethylamine, ethanolamine, diethanolamine, hydroquinone, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1-(methyl)-8-(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and Tinuvin® 292.

[0083] (2) The fluorine-containing gaseous monomer is a fluorine-containing olefin, which is filled in a steel cylinder and is selected from one or more of tetrafluoroethylene, trifluorochloroethylene, fluorinated vinylidene fluoride, hexafluoropropylene, HFO-1234ze, and HFO-1234yf.

[0084] (3) The initiator is an organic peroxide initiator selected from one or more of the following: tert-butyl peroxynedecanoate, bis(4-tert-butylcyclohexyl peroxydicarbonate), tert-butyl peroxypentanoate, dilauryl peroxydidecanoate, didecyl peroxydicarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxypentanoate, and tert-pentyl neopentanoate peroxydicarbonate.

[0085] (4) The mixed hydrocarbon liquid-phase monomer and initiator are continuously added to the prepolymerization reactor 1 in a certain proportion using a plunger metering pump. The fluorinated gaseous monomer is continuously added to the prepolymerization reactor 1 at a constant speed or pressure using a volumetric metering pump or a pressure reducing valve. The ratio (molar ratio) of the hydrocarbon liquid-phase monomer and the fluorinated gaseous monomer is 1:1 to 1.2, preferably 1:1.005 to 1.01. The proportion of the initiator is determined according to the polymerization formulation requirements of FEVE fluorocarbon resin. By weight, the amount is generally 0.2% to 1% of the monomer amount (total amount of hydrocarbon liquid-phase monomer and fluorinated gaseous monomer).

[0086] (5) The pre-reaction material is continuously fed into the post-polymerization reactor through the discharge valve or discharge pump for continuous polymerization reaction. In some embodiments of the present invention, the pre-polymerization reactor 1 performs the pre-polymerization reaction at a polymerization temperature of 50-70 ℃, preferably 50-65 ℃, and the first post-polymerization reactor 2 and the second post-polymerization reactor 3 (or more) perform the post-polymerization reaction at a polymerization temperature of 71-100 ℃, preferably 75-90 ℃.

[0087] (6) The polymerization reaction pressure is controlled by adding gaseous monomers through the fluorine-containing gaseous monomer replenishment valve. The prepolymerization and postpolymerization reaction pressures are generally controlled at 0.2-2 MPa, preferably 0.3-1.5 MPa. The specific pressure depends on the type of fluorine-containing gaseous monomer.

[0088] (7) FEVE fluorocarbon resin crude product is obtained by continuous polymerization, continuously discharged, collected and then post-processed and concentrated to obtain FEVE fluorocarbon resin finished product, and related resin performance analysis and testing are carried out.

[0089] The testing methods for solid content, viscosity, acid value, hydroxyl value, and fluorine content of FEVE fluorocarbon resin are based on the "Explanatory Notes (Draft for Comments) on Solvent-Based Fluorinated Vinyl Ether (Ester) Copolymer (FEVE) Resin". Specifically, the following processes are included: 1. Solid content test Dry the small aluminum cup to constant weight, cool it, and weigh it, recording the weight as W1 (unit: g). After tareing the balance, add about 1g of resin sample to the aluminum cup, weigh it, and record the weight as W2 (unit: g). Place the aluminum cup containing the sample in a forced-air drying oven to dry for 1 hour, remove it, cool it, and weigh it again, recording the weight as W3 (unit: g). Calculate the solid content Wt (unit: %) according to formula (1): (1).

[0090] 2. Viscosity test Place the sample in a cylindrical container and keep it at 25°C for more than 2 hours; select LV-03 (63)# rotor and set the test conditions of digital rotary viscometer: rotation speed 60 rpm, test time 90 seconds, and record the test results after the reading stabilizes.

[0091] 3. Acid value test Weigh 10g of sample into a glass beaker, add toluene-ethanol mixture, shake well to completely dissolve the sample, and add bromophenol blue indicator; titrate with 0.1mol / L KOH standard solution to the endpoint, and calculate the acid value X according to formula (2). 酸 (Unit: mgKOH / g): (2), In the formula: V—Volume of KOH standard solution consumed in the titration, in mL; Concentration of c-KOH standard solution, unit: mol / L; m—sample mass, in g; N V —Sample solid content, unit:%.

[0092] 4. Hydroxyl value test Weigh an appropriate amount of sample into a flat-bottomed flask, add the acetylation reagent and catalyst, shake well to completely dissolve the resin, let stand, add deionized water, and heat under reflux for 10 min; after cooling, add an appropriate amount of pyridine and ethanol, and add phenolphthalein indicator; titrate with 0.6 mol / L KOH standard solution to the endpoint, and perform a blank experiment at the same time. Calculate the hydroxyl value X according to formula (3). 羟 (Unit: mgKOH / g): (3), In the formula: V2—The volume of KOH standard solution used in the titration of the sample, in mL; V1—Volume of KOH standard solution used for titrating the blank sample, in mL; Concentration of c-KOH standard solution, unit: mol / L; m—sample mass, in g; NV—Sample solid content, unit:%.

[0093] 5. Fluorine content test Weigh 1.5~2.0 mg of resin sample, decompose it by combustion, and absorb it with deionized water; add 2.5 mL of glycine-sodium perchlorate buffer solution (pH=3.35) and 20 drops of 0.05% methyl thyme complex methanol indicator, and titrate with 0.01 mol / L thorium nitrate standard solution to the endpoint (the solution changes from yellow to light blue), while performing a blank experiment. Calculate the fluoride content X according to formula (4). F (unit:%): (4), In the formula: V4—Volume of thorium nitrate standard solution used in titration of the sample, in mL; V3—Volume of thorium nitrate standard solution used for titrating the blank sample, in mL; c—Concentration of thorium nitrate standard solution, in mol / L; m — Sample mass, unit: g.

[0094] In some embodiments of the present invention, a series reactor apparatus is provided for implementing the continuous polymerization method of FEVE fluorocarbon resin. The series reactor apparatus includes a prepolymerization reactor 1 and multiple postpolymerization reactors connected in sequence. The prepolymerization reactor 1 is connected to a first postpolymerization reactor; both the prepolymerization reactor 1 and the postpolymerization reactors have inlets and outlets. The prepolymerization reactor 1 and the first postpolymerization reactor are connected by pipelines, and adjacent postpolymerization reactors are connected by pipelines. Pumps or valves can be installed on these pipelines to control material transport using pressure or level differences.

[0095] like Figure 1 As shown, in some embodiments of the present invention, two post-polymerization reactors are provided, namely a first post-polymerization reactor 2 and a second post-polymerization reactor 3, connected in sequence. The first post-polymerization reactor 2 is connected to the pre-polymerization reactor 1 via a pipeline, and the second post-polymerization reactor 3 is connected to the first post-polymerization reactor 2 via a pipeline. Material is fed into the pre-polymerization reactor 1 through the inlet and discharged from the second post-polymerization reactor 3 through a liquid phase discharge valve 4. Relevant materials are added to the pipeline between the second post-polymerization reactor 3 and the first post-polymerization reactor 2 as needed or according to the formula.

[0096] In some embodiments of the present invention, a first post-polymerization reactor 2 is provided, which is connected in sequence. The first post-polymerization reactor 2 is connected to the pre-polymerization reactor 1 via a pipeline. The pre-polymerization reactor 1 is fed into the reactor and the first post-polymerization reactor 2 is discharged through a liquid phase discharge valve 4.

[0097] Example 1 This embodiment provides a batch-type tandem continuous polymerization method for FEVE fluorocarbon resin, using the method and apparatus described above.

[0098] Specifically, a prepolymerization reactor 1 is provided, and a postpolymerization reactor, namely the first postpolymerization reactor 2, is connected in sequence, and a liquid phase discharge valve 4 is connected to the outlet of the first postpolymerization reactor 2.

[0099] The gaseous monomer is trifluorochloroethylene, with a designed solid content of 64.6%.

[0100] Hydroxybutyl vinyl ether, cyclohexyl vinyl ether, ethyl vinyl ether, Tinuvin® 292, and xylene were premixed in a ratio of 226:368:350:12:1114 (by weight, the same below). The mixed liquid phase and tert-butyl peroxyneodecanate were then continuously and stably added to a 10 L prepolymerization reactor 1 at a ratio of 2070:12 and a total rate of 377 g / h, respectively. Trichlorofluoroethylene was added at a rate of approximately 200 g / h. The internal temperature is controlled at 54 ℃, and the pressure is controlled at 5 bar using a trichlorofluoroethylene feeding and pressure reducing valve. The pre-reacted material is sent to the 5 L first post-polymerization reactor 2 through the discharge valve (the liquid level is maintained between 75 and 85% by a capacitive level gauge) for post-polymerization reaction. The internal temperature is controlled at 75 ℃, and the pressure is controlled at 4 bar using a trichlorofluoroethylene feeding and pressure reducing valve. FEVE fluorocarbon resin crude product with a solid content of approximately 60.2% can be continuously collected at the liquid phase discharge valve 4 at the outlet of the 5 L first post-polymerization reactor 2. The reaction yield is 93.2% (the yield change is <1% after stabilization, with sampling intervals of 1 hour every 10 hours).

[0101] The crude FEVE fluorocarbon resin was concentrated to a solid content of 65% and then analyzed. The analytical data are shown in Table 1.

[0102] Example 2 The gaseous monomer is tetrafluoroethylene, with a designed solid content of 55.1%.

[0103] Hydroxybutyl vinyl ether, cyclohexyl vinyl ether, ethyl vinyl ether, Tinuvin® 292, and xylene were pre-mixed in a ratio of 226:368:350:12:994. The mixed liquid phase and the initiator tert-butyl peroxynedecanoate were continuously and stably fed into a 10 L prepolymerization reactor 1 at a ratio of 2496:10 and a total rate of 407 g / h for prepolymerization reaction. The internal temperature was controlled at 54 ℃, and the pressure was controlled at 3.5 bar using a tetrafluoroethylene feeding and pressure reducing valve. The pre-reacted material was sent to a 5 L postpolymerization reactor 2 for postpolymerization reaction through a discharge valve (the liquid level was kept between 75 and 85% by a capacitive level gauge). The internal temperature was controlled at 75 ℃, and the pressure was controlled at 2.5 bar using a tetrafluoroethylene feeding and pressure reducing valve. A crude FEVE fluorocarbon resin with a solid content of about 53.2% was continuously collected at the outlet of the liquid phase discharge valve [4] of the 5 L reactor [2], with a reaction yield of 96.6%. % (The change in yield after stabilization is <0.3% when sampling at 1-hour intervals over 10 hours).

[0104] The crude FEVE fluorocarbon resin was concentrated to a solid content of 65% and then analyzed. The analytical data are shown in Table 1.

[0105] Comparative Example 1 The formula ratio is exactly the same as in Example 1, and the 5L reactor is used for one-time feeding.

[0106] Hydroxybutyl vinyl ether, cyclohexyl vinyl ether, ethyl vinyl ether, Tinuvin® 292, xylene, tert-butyl peroxyneodecanate, and trifluorochloroethylene were added to a 5 L reactor in batches of 226 g, 368 g, 350 g, 12 g, 1114 g, 12 g, and 1200 g, respectively. The reactor temperature was then raised to 54 °C and maintained for 4 h. The temperature was then raised to 75 °C and maintained for 2 h. After cooling, the product was discharged, yielding crude FEVE fluorocarbon resin with a solid content of 58.8% and a yield of 91.0% (yield variation ±1.5% in 5 repeatability experiments).

[0107] The crude FEVE fluorocarbon resin was concentrated to a solid content of 65% and then analyzed. The analytical data are shown in Table 1.

[0108] Comparative Example 2 The formulation ratio is exactly the same as in Example 2, using a method of one-time feeding of liquid monomer in a reaction vessel and continuous replenishment of tetrafluoroethylene.

[0109] Hydroxybutyl vinyl ether, cyclohexyl vinyl ether, ethyl vinyl ether, Tinuvin® 292, xylene, and tert-butyl peroxyneodecanate were added to a 5 L reactor in batches of 226 g, 368 g, 350 g, 12 g, 1540 g, and 10 g, respectively. Tetrafluoroethylene was then introduced to bring the reactor pressure to positive. The reactor temperature was then raised to 54 °C, and tetrafluoroethylene was added at a constant pressure of 3 bar. The reaction continued for approximately 4 hours, after which the temperature was raised to 75 °C. Once the temperature reached 75 °C, the addition of tetrafluoroethylene was stopped, and the reaction was maintained at 75 °C for 2 hours. After cooling, the product was discharged, yielding crude FEVE fluorocarbon resin with a solid content of 50.9% and a yield of 92.4% (yield variation ±1% in three repeatability experiments).

[0110] The crude FEVE fluorocarbon resin was concentrated to a solid content of 65% and then analyzed. The analytical data are shown in Table 1.

[0111] Table 1. Analytical Data of FEVE Fluoropolymer Finished Product * Viscosity data was analyzed three times, and the average of the three analyses was taken as the integer value.

[0112] As shown in Table 1, the yield of crude FEVE fluorocarbon resin prepared by Examples 1 and 2 was significantly higher than that of Comparative Examples 1 and 2. The viscosity of crude FEVE fluorocarbon resin prepared by Examples 1 and 2 was also significantly lower than that of Comparative Examples 1 and 2. Although the acid value, hydroxyl value, and fluorine content were basically the same, the deviation of the reaction solid content of the methods in Examples 1 and 2 was basically <1%, while the deviation of the reaction solid content of the methods in Comparative Examples 1 and 2 was basically ±1~1.5~2%. Moreover, although the average values ​​of acid value and hydroxyl value of Examples 1, 2, Comparative Examples 1 and 2 were similar, the values ​​of multiple batches produced by Comparative Examples 1 and 2 varied greatly, unlike Examples 1 and 2. Even if samples were taken at intervals of several days, the changes in the analytical data were not significant.

[0113] In addition, in Examples 1 and 2, the actual amount of fluorine-containing gaseous monomers fed was 100.5% to 101% of the theoretical value, while Comparative Example 1 was 106% and Comparative Example 2 was 104%.

[0114] According to Examples 1 and 2, the molecular weight distribution (PDI) value of the product can be actively controlled as needed, with a wide control range.

[0115] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A continuous batch polymerization method for FEVE fluorocarbon resin, characterized in that, The method includes the following steps: (1) Continuous feeding: The reaction raw materials are added to the prepolymerization reactor according to the formula ratio. The liquid level of the material in the prepolymerization reactor is monitored and controlled to be kept within the set range. The prepolymerization reaction occurs, and the reaction material after the prepolymerization reaction is obtained. (2) Continuous polymerization: The reactants after the prepolymerization reaction are passed through multiple postpolymerization reactors in sequence to undergo postpolymerization reaction and continuous polymerization to obtain FEVE fluorocarbon resin products; (3) Continuous discharge: Stable FEVE fluorocarbon resin products are collected at the outlet of the final post-polymerization reactor; The reaction raw materials include fluorine-containing gaseous monomers and hydrocarbon liquid monomers, initiators, solvents, and additives.

2. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The inlet of the prepolymerization reactor is connected to a feed pump and / or a pressure reducing valve and / or a regulating valve; The outlet of the final post-polymerization reactor is connected to a discharge pump and / or a back pressure valve and / or a regulating valve.

3. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The number of post-polymerization reactors is 2-n, where 2 < n ≤ 10; Both the prepolymerization reactor and the postpolymerization reactor are polymerization reactors. Multiple polymerization reactors are connected in sequence, with the inlet of the previous polymerization reactor connected to the outlet of the next polymerization reactor, and FEVE fluorocarbon resin products can be stably collected at the outlet of the final polymerization reactor. The material transfer between the prepolymerization reactor and the postpolymerization reactor is controlled by a transfer pump or by valves using pressure difference or liquid level difference. Material transfer between adjacent post-polymerization reactors is controlled by pumps or valves using pressure or level differences.

4. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 3, characterized in that, The delivery pump is one or more of the following: gear pump, screw pump, plunger pump, cycloidal pump, and diaphragm pump.

5. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The residence time of materials in a single prepolymerization reactor is controlled between 10 min and 3 h; The residence time of materials in a single post-polymerization reactor is controlled between 10 min and 3 h. The total residence time for polymerization is 1 h to 25 h.

6. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The reaction temperature in the prepolymerization reactor is 50~70℃. The reaction temperature in the post-polymerization reactor is 71~100℃.

7. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The pressure of the prepolymerization reaction is 0.2~2 MPa; The pressure of the post-polymerization reaction is 0.2~2 MPa.

8. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The prepolymerization reaction is either a liquid-liquid phase full-boil reaction or a gas-liquid phase reaction; The post-polymerization reaction is either a liquid-liquid phase full-boil reaction or a gas-liquid phase reaction; The equipment utilization rate of the prepolymerization reactor is 70%~98%, and the equipment utilization rate of the prepolymerization reactor is controlled by controlling the liquid level of the prepolymerization reactor. The equipment utilization rate of the post-polymerization reactor is 70%~98%, and the equipment utilization rate of the post-polymerization reactor is controlled by controlling the liquid level of the post-polymerization reactor.

9. The batch-type tandem continuous polymerization method for FEVE fluorocarbon resin according to claim 1, characterized in that, The solvent is an organic solvent, which is one or more of xylene, toluene, ethyl acetate, butyl acetate, acetone, butanone, tetrahydrofuran, ethylene glycol dimethyl ether, and propylene glycol methyl ether acetate. The fluorine-containing gaseous monomer is selected from one or more of tetrafluoroethylene, trifluorochloroethylene, fluoroethylene, vinylidene fluoride, hexafluoropropylene, HFO-1234ze, and HFO-1234yf; The hydrocarbon liquid phase monomer is an alkyl vinyl ether or an alkyl vinyl ester, selected from one or more of the following: ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, heptyl vinyl ether, octyl vinyl ether, decyl vinyl ether, dodecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, dodecyl vinyl ether, cyclobutyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxypentyl vinyl ether, hydroxyhexyl vinyl ether, hydroxydecyl vinyl ether, hydroxydodecyl vinyl ether, hydroxyhexadecyl vinyl ether, hydroxycyclopropyl vinyl ether, hydroxycyclobutyl vinyl ether, hydroxycyclopentyl vinyl ether, hydroxycyclohexyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, perfluoron-propyl vinyl ether, perfluorobutyl vinyl ester, vinyl acetate, and isopropyl acetate. The initiator is an organic peroxide initiator, which is selected from one or more of the following: tert-butyl peroxyneodecanate, bis(4-tert-butylcyclohexyl peroxydicarbonate), tert-butyl peroxypentanoate, dilauroyl peroxide, didecyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxypentanoate, and tert-pentylneovalerate peroxide. The adjuvant is one or more of triethylamine, ethanolamine, diethanolamine, hydroquinone, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and 1-(methyl)-8-(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate.

10. A batch reactor apparatus for realizing the continuous batch polymerization method of FEVE fluorocarbon resin as described in any one of claims 1-9, characterized in that, The reactor-type series device includes a prepolymerization reactor and multiple postpolymerization reactors connected in sequence; The prepolymerization reactor is connected to the first postpolymerization reactor; Both the prepolymerization reactor and the postpolymerization reactor are equipped with inlets and outlets.

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