A poly(4-methyl-1-pentene) / α-olefin copolymer, its preparation method and application

Abstract

This application relates to the field of polyolefin materials technology, specifically to a poly(4-methyl-1-pentene) / α-olefin copolymer, its preparation method, and its applications. In this application, an alcohol compound is added during the post-treatment of the polymerization solution. Because of its hydroxyl content, it can act as a catalyst quencher and a metal ion remover. Through the reaction of the alcohol with titanium and aluminum ions, metal compounds soluble in the liquid phase are generated, reducing residual metal ions in the polymer product and lowering VOC content. This is beneficial for the application of PMP in downstream medical materials and other demanding fields. Furthermore, the alcohol compound selected in this application has significant polarity and can act as a dispersant in the slurry system, making the polymer particles more dispersed in the solvent, reducing van der Waals adsorption between polymer particles, and decreasing particle agglomeration and clumping after drying, resulting in a more uniform particle distribution.

Description

Technical Field

[0001] This application relates to the field of polyolefin materials technology, specifically to a poly(4-methyl-1-pentene) / α-olefin copolymer, its preparation method, and its application. Background Technology

[0002] Poly(4-methyl-1-pentene) copolymer is a crystalline olefin resin obtained by copolymerization of 4-methyl-1-pentene and α-olefins. It has excellent transparency, heat resistance and chemical resistance, and is widely used in the production of electronic products, such as release films in the production of flexible printed circuit boards (FPCs) and release paper used in the manufacture of synthetic leather. In the medical field, PMP copolymer is also used as a core membrane material for extracorporeal membrane oxygenation (ECMO) due to its good airflow and biocompatibility.

[0003] Currently, the main method for preparing PMP copolymers is slurry polymerization, which uses alkane-based organic compounds as solvents or reaction media. This method offers mild polymerization conditions suitable for industrial production. However, existing technologies for producing PMP copolymers suffer from significant product quality fluctuations. For high-end applications (such as medical and electronics), PMP copolymers require even higher batch stability, particularly regarding the residual metal ions (titanium ions, aluminum ions, etc.), VOC content, and particle uniformity. The residual metal ions and VOC content determine whether the material can be used in the medical industry, while particle uniformity determines the difficulty and stability of downstream polymer processing. Reducing the residual metal content and improving the particle uniformity of PMP copolymers are development trends in industrial production.

[0004] In view of this, there is an urgent need to develop a method for producing poly(4-methyl-1-pentene / α-olefin copolymer) that can reduce metal residue, reduce VOC content, and improve product particle uniformity. Summary of the Invention

[0005] This application provides a poly(4-methyl-1-pentene) / α-olefin copolymer, its preparation method, and its application, in order to solve the problems of high metal residue and VOC content, and poor particle uniformity in poly(4-methyl-1-pentene) / α-olefin copolymers produced by existing technologies.

[0006] In a first aspect, this application provides a method for preparing a poly(4-methyl-1-pentene) / α-olefin copolymer, comprising the following steps: S1, 4-methyl-1-pentene and α-olefin are subjected to slurry polymerization to obtain a polymerization liquid; S2, the polymerization liquid is mixed with an alcohol compound, the solid-liquid separation is performed, and the mixture is dried to obtain a copolymer; The mass ratio of the alcohol compound to the polymerization liquid is 1:(10-30).

[0007] As an example, the mass ratio of the alcohol compound to the polymerization liquid is 1:10, 1:13, 1:15, 1:18, 1:20, 1:22, 1:25, 1:27, 1:30, or within any of the above ranges.

[0008] In one alternative embodiment, the alcohol compound includes at least one of alcohols having 1-6 carbon atoms; In one optional embodiment, the alcohol compound includes at least one selected from ethanol, n-propanol, n-butanol, isopropanol, and isobutanol. In one optional implementation, the mixing temperature in S2 is 20-40°C, and the mixing time is 10-30 minutes. As an example, the mixing temperature in S2 can be 20°C, 25°C, 30°C, 35°C, 40°C, or any range thereof; the mixing time can be 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, or any range thereof.

[0009] In one optional embodiment, the drying includes flash drying and rotary drum drying; In one optional embodiment, the temperature of the drying gas in the flash drying is 90-130°C, and the gas velocity is 20-40 m / s; as an example, the temperature of the drying gas in the flash drying can be 90°C, 95°C, 100°C, 110°C, 120°C, 130°C, or within any range of the above values; the gas velocity can be 20 m / s, 25 m / s, 30 m / s, 35 m / s, 40 m / s, or within any range of the above values. In one optional embodiment, the temperature of the drying gas in the rotary drum dryer is 90-130°C, and the gas velocity is 2-4 m / s. As an example, the temperature of the drying gas in the rotary drum dryer can be 90°C, 95°C, 100°C, 110°C, 120°C, 130°C, or any range thereof; the gas velocity can be 2 m / s, 2.5 m / s, 3 m / s, 3.5 m / s, 4 m / s, or any range thereof.

[0010] In an optional embodiment, in S2, the liquid phase obtained from the solid-liquid separation step is used to recover monomers, solvents, and alcohol compounds by distillation. In one alternative implementation, the operating conditions for recovering monomers include: a column top pressure of 0.01-0.1 MPa and a reflux ratio of 1.5-5. As an example, when recovering monomers, the column top pressure can be 0.01 MPa, 0.02 MPa, 0.04 MPa, 0.05 MPa, 0.07 MPa, 0.09 MPa, 0.1 MPa, or within any range of the above values; the reflux ratio can be 1.5, 2, 3, 4, 5, or within any range of the above values.

[0011] In one optional embodiment, the operating conditions for solvent recovery include: a column top pressure of 1-2 MPa and a reflux ratio of 1.5-5; as an example, when recovering solvent, the column top pressure can be 1 MPa, 1.2 MPa, 1.4 MPa, 1.5 MPa, 1.7 MPa, 1.9 MPa, 2 MPa, or within any range of the above values; the reflux ratio can be 1.5, 2, 3, 4, 5, or within any range of the above values.

[0012] In one optional embodiment, the operating conditions for recovering alcohol compounds include: a column top pressure of 0.01-0.1 MPa and a reflux ratio of 1.5-5. As an example, when recovering alcohol compounds, the column top pressure can be 0.01 MPa, 0.02 MPa, 0.04 MPa, 0.05 MPa, 0.07 MPa, 0.09 MPa, 0.1 MPa, or any range thereof; the reflux ratio can be 1.5, 2, 3, 4, 5, or any range thereof.

[0013] Secondly, this application provides a method for preparing the above-mentioned poly-4-methyl-1-pentene / α-olefin copolymer, wherein in S1, the slurry polymerization reaction includes the following steps: S11, 4-methyl-1-pentene, main catalyst and co-catalyst are prepolymerized in solvent to obtain prepolymer liquid; S12, the prepolymer liquid is subjected to slurry polymerization reaction with 4-methyl-1-pentene and α-olefin in a solvent to obtain a polymer liquid.

[0014] In one optional embodiment, the reaction temperature of the prepolymerization reaction is 10-40°C, and the reaction time is 5-180 minutes; as an example, the reaction temperature of the prepolymerization reaction can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, or within any range of the above values; the reaction time can be 5 minutes, 10 minutes, 30 minutes, 50 minutes, 80 minutes, 100 minutes, 130 minutes, 150 minutes, 180 minutes, or within any range of the above values. In one optional embodiment, the reaction temperature of the slurry polymerization reaction is 30-80°C, and the reaction time is 2-10 hours; as an example, the reaction temperature of the slurry polymerization reaction can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, or within any range of the above values; the reaction time can be 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, or within any range of the above values. In one optional embodiment, a regulator is added during the slurry polymerization reaction. Optionally, the regulator is hydrogen. Optionally, the molar ratio of the regulator to 4-methyl-1-pentene in S12 is 1:(500-2000). As an example, the molar ratio of the regulator to 4-methyl-1-pentene in S12 can be 1:500, 1:800, 1:1000, 1:1300, 1:1500, 1:1800, 1:2000, or within any range of the above values. In one optional embodiment, the molar ratio of the main catalyst to the co-catalyst is 1:(50-300); as an example, the molar ratio of the main catalyst to the co-catalyst can be 1:50, 1:70, 1:100, 1:150, 1:180, 1:200, 1:250, 1:300, or within any range of the above values. In an optional embodiment, in S11, the molar ratio of the main catalyst to 4-methyl-1-pentene is 1:(10-200); as an example, the molar ratio of the main catalyst to 4-methyl-1-pentene can be 1:10, 1:30, 1:50, 1:70, 1:90, 1:100, 1:130, 1:150, 1:180, 1:200, or within any range of the above values. In an optional embodiment, in S12, the mass ratio of 4-methyl-1-pentene to α-olefin is (10-100):1; as an example, the mass ratio of 4-methyl-1-pentene to α-olefin can be 10:1, 30:1, 50:1, 70:1, 90:1, 100:1, or within any of the above values. In an optional embodiment, in S11, the mass ratio of the solvent to 4-methyl-1-pentene is (2-20):1; as an example, the mass ratio of the solvent to 4-methyl-1-pentene can be 2:1, 5:1, 8:1, 10:1, 13:1, 15:1, 17:1, 20:1, or within any of the above values. In an optional embodiment, in S12, the mass ratio of 4-methyl-1-pentene to solvent is 1:(1-20). As an example, the mass ratio of 4-methyl-1-pentene to solvent can be 1:1, 1:3, 1:5, 1:7, 1:9, 1:10, 1:13, 1:15, 1:17, 1:20, or within any range of the above values.

[0015] In one alternative embodiment, the main catalyst comprises a Ziegler-Natta catalyst; In one alternative embodiment, the main catalyst can be obtained through commercial channels, and typically, without limitation, the Ziegler-Natta catalyst includes, but is not limited to, Clariant POLYMAX. TM 500, GraceLYNX ® PP, LyondellBasell Avant ZN and INEOS INcat TM At least one of P.

[0016] In one optional embodiment, the cocatalyst comprises at least one of alkylaluminum compounds and aluminum oxane compounds; optionally, it comprises at least one of triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-pentylaluminum, triisopentylaluminum, methyl diethylaluminum, methyl di-n-propylaluminum, methyl diisopropylaluminum, methyl di-n-butylaluminum, methyl diisobutylaluminum, diethyl-n-propylaluminum, diethyl-isopropylaluminum, diethyl-n-butylaluminum, diethyl-isobutylaluminum, diethylaluminum chloride, ethyl dialuminum chloride, methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, propylaluminoxane, isobutylaluminoxane, and diisobutylaluminoxane. In one alternative embodiment, the α-olefin comprises C6-C20 α-olefins, optionally including at least one selected from 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetracene, 1-tetradecene, 1-pentadecanene, 1-hexadecene, 1-heptadecene, 1-heptadecene, 1-octadecene, 1-nonadecanene, and 1-eicosene.

[0017] Thirdly, this application provides a poly(4-methyl-1-pentene) / α-olefin copolymer, which is prepared by the above-described preparation method.

[0018] Fourthly, this application provides an application of the above-mentioned poly4-methyl-1-pentene / α-olefin copolymer in the medical and electronic fields.

[0019] In one optional embodiment, the solvent used in the prepolymerization reaction and the slurry polymerization reaction is an alkane organic liquid, optionally including one or more of n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane.

[0020] In one optional embodiment, the process further includes a step of refining the raw materials. Optionally, 4-methyl-1-pentene and a solvent are passed through an adsorption column to remove water, oxygen, and alcohol impurities from the system.

[0021] In one optional embodiment, the adsorbent packed in the adsorption column is an oxygen-removing adsorbent and a water / alcohol-removing adsorbent, optionally including one or more of 3A molecular sieve, 4A molecular sieve, copper oxide, and manganese oxide.

[0022] In one optional embodiment, the temperature of the adsorption and removal of impurities process is 20-60°C, and the pressure is 0.1-0.4 MPa.

[0023] In one optional embodiment, the solid-liquid separation is performed by centrifugation, and optionally, the centrifugation factor during the centrifugation process is 2000-4500g.

[0024] Specifically, the method for continuous production of poly(4-methyl-1-pentene) / α-olefin copolymer provided in this application may include the following steps: (1) Raw material refining: 4-methyl-1-pentene and solvent are passed through an adsorption column to remove water, oxygen and alcohol impurities from the system; (2) Prepolymerization and polymerization reaction: The main catalyst, co-catalyst, a small amount of 4-methyl-1-pentene and solvent undergo a prepolymerization reaction in the prepolymerization reactor; the obtained prepolymer liquid is added to the polymerization reactor and undergoes a slurry polymerization reaction with 4-methyl-1-pentene and α-olefin under solvent conditions, and a regulator is added during the polymerization process; (3) Adding additives, centrifugation, and drying: The obtained polymer liquid is added to the additive mixing tank, and the additive alcohol compound is added and mixed; the reaction liquid after adding the alcohol compound enters the centrifuge for separation, the liquid phase at the centrifuge outlet enters the mother liquor tank, and the wet solid phase at the outlet enters the slurry buffer tank, and then enters the dryer for drying. The gas phase containing polymer at the dryer outlet is separated by a separator, and the solid phase at the outlet is the polymer product. The gas phase is condensed by a condenser and then enters the mother liquor tank; more specifically, the drying process includes: the wet solid phase enters the flash dryer, the gas phase containing polymer at the dryer outlet passes through a cyclone separator, the solid phase at the separator outlet enters the rotary dryer, the solid phase outlet of the rotary dryer is the polymer product, and the gas phases at the outlets of the cyclone separator and the rotary dryer are condensed by a condenser and then enter the mother liquor tank; (4) Distillation recovery: The mother liquor in the mother liquor tank enters the monomer separation tower. The vapor phase at the top of the tower is condensed and becomes the recovered monomer. The liquid at the bottom of the tower enters the solvent separation tower. The liquid at the bottom of the solvent separation tower is the recovered solvent. The vapor phase at the top of the tower is condensed and enters the alcohol separation tower. The liquid at the bottom of the alcohol separation tower is the recovered alcohol compound.

[0025] The technical solution of this application has the following advantages: The preparation method of poly(4-methyl-1-pentene) / α-olefin copolymer provided in this application includes the following steps: S1, 4-methyl-1-pentene and α-olefin are subjected to slurry polymerization to obtain a polymerization liquid; S2, the polymerization liquid is mixed with an alcohol compound, solid-liquid separation is performed, and the mixture is dried to obtain the copolymer; wherein, the mass ratio of the alcohol compound to the polymerization liquid is 1:(5-30). In this application, an alcohol compound is added during the post-treatment of the polymerization liquid. Because it contains hydroxyl groups, it can act as a catalyst quencher and a metal ion remover. Through the reaction of the alcohol with titanium and aluminum ions, metal compounds soluble in the liquid phase are generated, reducing metal ion residues in the polymer product and also reducing VOC residues, which is beneficial for the application of PMP in downstream medical materials and other high-requirement fields. On the other hand, the alcohol compound selected in this application has significant polarity and can act as a dispersant in the slurry system, making the polymer particles more dispersed in the solvent, reducing van der Waals adsorption between polymer particles, reducing particle agglomeration and clumping after drying, and resulting in a more uniform particle distribution. In addition, alcohol compounds can form azeotropes with solvents, which significantly lowers the boiling point of the slurry and effectively reduces the softening and sticking of PMP polymers to the walls during the drying process.

[0026] The preparation method of poly(4-methyl-1-pentene) / α-olefin copolymer provided in this application adopts a combination of flash dryer and rotary drum dryer, which significantly reduces the drying time required to achieve qualified VOC content (solvent residue < 50 ppm, monomer (4-methyl-1-pentene) < 20 ppm) and further avoids the softening and sticking of PMP polymer to the wall during the drying process.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Detailed Implementation

[0028] The following embodiments are provided to better understand this application. However, the following embodiments do not constitute a limitation on the content and scope of protection of this application. Any product that is the same as or similar to this application, derived by anyone under the guidance of this application or by combining the features of this application with other prior art, falls within the scope of protection of this application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having” and any variations thereof in the text of this application are intended to cover non-exclusive inclusion.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers from a to b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, and "0-5" is merely a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥ 2, it is equivalent to disclosing that the parameter can be, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0031] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0032] In the description of the embodiments of this application, the term "at least one" refers to one or more (including two).

[0033] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. Experimental steps or conditions not specifically described in the embodiments are performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagents or instruments.

[0034] The present application will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present application in any way.

[0035] Unless otherwise specified, the raw materials and reagents used in the following embodiments and comparative examples of this application are all commercially available; wherein, 4-Methyl-1-pentene, Tokyo Chemical Industry Co., Ltd. (TCI), purity >98%; 1-Pentene, Beijing Innocare Technology Co., Ltd., purity >99%; 1-Hexene, Beijing Innocare Technology Co., Ltd., purity >99%; 1-Eicosene, Beijing Innocare Technology Co., Ltd., purity >99%; hexane, heptane, and octane were all sourced from Shanghai Aladdin Biochemical Technology Co., Ltd., with a purity >99%. Triethylaluminum, methylaluminoxane, and triisopropylaluminum are all from Shanghai Aladdin Biochemical Technology Co., Ltd. Hydrogen, Yantai Mingju New Energy Co., Ltd., purity 99.999%.

[0036] Example 1 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene) / α-olefin copolymer, and the specific steps and operating parameters are as follows: (1) Raw material refining 4-Methyl-1-pentene and n-hexane were fed into a refining adsorption column via their respective buffer tanks. The refining adsorption column was packed with 3A molecular sieve and copper oxide, and operated at 30°C and 0.2 MPa. Water, oxygen, and alcohol impurities were effectively removed, with the outlet material containing <1 ppm moisture, <1 ppm oxygen, and <2 ppm alcohols.

[0037] (2) Prepolymerization and polymerization reactions Prepolymerization reaction: Ziegler-Natta catalyst (0.5 mmol / L, Clariant POLYMAX) was added to the prepolymerization reactor. TM The catalysts, triethylaluminum (25 mmol / L), and small amounts of 4-methyl-1-pentene and n-hexane were reacted at 30 °C for 30 minutes to complete the prepolymerization. The molar ratio of the main catalyst to the cocatalyst was 1:50, the molar ratio of the main catalyst to 4-methyl-1-pentene was 1:32, and the mass ratio of 4-methyl-1-pentene to the solvent n-hexane was 1:10.

[0038] Slurry polymerization reaction: 4-methyl-1-pentene, 1-hexene and n-hexane are added to the polymerization reactor. The prepolymer solution is added to the polymerization reactor. The reaction temperature is 60℃. Hydrogen gas is introduced (the molar ratio of H2 to 4-methyl-1-pentene is 1:1000). The reaction time is 6 hours. The mass ratio of 4-methyl-1-pentene to α-olefin is 50:1, and the mass ratio of 4-methyl-1-pentene to solvent n-hexane is 1:5.

[0039] (3) Add additives, centrifuge, and dry. Mixing Additives: After polymerization, the polymerization solution is transferred to an additive mixing tank, ethanol is added, and the mixture is stirred at 40°C for 30 minutes. The mass ratio of ethanol to polymerization solution is 1:10. The mixed reaction solution is then fed into a horizontal screw centrifuge (centrifugal force 4000g) to separate the moist solid phase (moisture content approximately 35wt%) and the mother liquor. The moist solid phase is fed into a slurry buffer tank, stirred evenly, and then pumped into a flash dryer. The drying gas temperature is 120°C, and the gas velocity is 30 m / s. The material instantly loses most of the solvent, forming a dry powder with a moisture content of approximately 2 wt%. The dry powder is fed into a cyclone separator. The separated gas phase is cooled and condensed in a hot air heat exchanger, and the condensate is returned to the mother liquor tank. The solid phase is fed into a rotary dryer for further drying to a moisture content of <0.01 wt%. The rotary dryer operates at a temperature (drying gas temperature) of 120°C and a gas velocity of 3 m / s, ultimately yielding the polymer product.

[0040] (4) Distillation recovery The liquid in the mother liquor tank is pumped into the monomer separation tower via a shielded pump. The top pressure of the tower is 0.03 MPa, and the reflux ratio is 4.2. After condensation at the top of the tower, 4-methyl-1-pentene is recovered and returned to the feed tank. The bottom liquid of the tower enters the solvent separation tower, where the top pressure is 2 MPa and the reflux ratio is 2. The bottom liquid of the solvent separation tower is used to recover n-hexane and is returned to the solvent tank. After condensation at the top of the solvent separation tower, the liquid is sent to the auxiliary agent separation tower, where the top pressure is 0.1 MPa and the reflux ratio is 3.4. The bottom liquid of the auxiliary agent separation tower is used to recover ethanol and is returned to the auxiliary agent tank. After condensation at the top of the auxiliary agent separation tower, the liquid is recycled to the solvent separation tower.

[0041] Product characteristics and production efficiency: The polymer's average molecular weight was tested to be 235,500 g / mol, with a PDI of 7.5. Residual VOCs were found to be 22 ppm for n-hexane and 4 ppm for 4-methyl-1-pentene, meeting VOC content standards. The total drying time from wet slurry to finished product was approximately 60 minutes. Solvent recovery was 98.1%, and ethanol recovery was 95.1%. ICP testing revealed residual Ti ions of 1.3 ppm and residual Al ions of 18.1 ppm. The particle size distribution span was 1.183.

[0042] Example 2 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that the operating parameters of steps (3) and (4) are different, as follows: (3) Add additives, centrifuge, and dry. Mixing Additives: After polymerization, the polymerization solution is transferred to an additive mixing tank, isopropanol is added, and the mixture is stirred at 40°C for 30 minutes. The mass ratio of isopropanol to the polymerization solution is 1:10. The mixed reaction solution is then fed into a horizontal screw centrifuge (centrifugation factor 4000g) to separate the moist solid phase (moisture content approximately 35 wt%) and the mother liquor. The slurry is pumped into a flash dryer at a drying gas temperature of 110°C and a gas velocity of 25 m / s. Most of the solvent is removed from the material instantly, forming a dry powder with a moisture content of approximately 2.6 wt%. The dry powder enters a cyclone separator. The separated gas phase is cooled and condensed in a hot air heat exchanger, and the condensate is returned to the mother liquor tank. The solid phase enters a rotary dryer for further drying to a moisture content of <0.01 wt%. The rotary dryer operates at a temperature of 120°C and a gas velocity of 3.5 m / s, ultimately yielding the polymer product.

[0043] (4) Distillation recovery The liquid in the mother liquor tank is pumped into the monomer separation tower via a shielded pump. The top pressure of the tower is 0.05 MPa, and the reflux ratio is 4.5. After condensation at the top of the tower, 4-methyl-1-pentene is recovered and returned to the feed tank. The bottom liquid of the tower enters the solvent separation tower, where the top pressure is 1.5 MPa and the reflux ratio is 1.6. The bottom liquid of the solvent separation tower is used to recover n-hexane and is returned to the solvent tank. After condensation at the top of the solvent separation tower, the liquid is sent to the auxiliary agent separation tower, where the top pressure is 0.05 MPa and the reflux ratio is 3.1. The bottom liquid of the auxiliary agent separation tower is used to recover isopropanol and is returned to the auxiliary agent tank. After condensation at the top of the auxiliary agent separation tower, the liquid is recycled to the solvent separation tower.

[0044] Product characteristics and production efficiency: The average molecular weight of the polymer is Mw = 248,900 g / mol, and the distribution index (PDI) is 13. Residual VOCs include 41 ppm hexane and 5 ppm 4-methyl-1-pentene, meeting VOC content standards. The total drying time from wet slurry to finished product is approximately 70 minutes. Solvent recovery rate is 99.3%, and additive recovery rate is 97.5%. ICP testing shows a Ti ion residue of 2.6 ppm and an Al ion residue of 68.7 ppm. The particle size distribution span is 1.245.

[0045] Example 3 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that the operating parameters of step (3) are different, as follows: (3) Add additives, centrifuge, and dry. Mixing Additives: After polymerization, the polymerization solution is transferred to an additive mixing tank, and n-propanol is added. The mixture is stirred at 20°C for 30 minutes, with a mass ratio of n-propanol to polymerization solution of 1:15. The mixed reaction solution is then fed into a horizontal screw centrifuge (centrifugal force 2500g) to separate the moist solid phase (approximately 45wt%) and mother liquor. The moist solid phase is fed into a slurry buffer tank, stirred evenly, and then pumped into a flash dryer. The drying gas temperature is 120°C, and the gas velocity is 20 m / s. Most of the solvent is removed from the material instantly, forming a dry powder with approximately 4wt% moisture content. The dry powder is fed into a cyclone separator. The separated gas phase is cooled and condensed in a hot air heat exchanger, and the condensate is returned to the mother liquor tank. The solid phase is fed into a rotary dryer for further drying to a moisture content of <0.01wt%. The rotary dryer operates at a temperature (drying gas temperature) of 90°C and a gas velocity of 4 m / s, ultimately yielding the polymer product.

[0046] Example 4 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that the operating parameters of step (3) are different, as follows: (3) Add additives, centrifuge, and dry. Mixing Additives: After polymerization, the polymerization solution is transferred to an additive mixing tank, and n-butanol is added. The mixture is stirred at 35°C for 15 minutes, with a mass ratio of n-butanol to polymerization solution of 1:20. The mixed reaction solution is then fed into a horizontal screw centrifuge (centrifugal force 3300g) to separate the moist solid phase (moisture content approximately 40wt%) and the mother liquor. The moist solid phase is then fed into a slurry buffer tank, stirred evenly, and then pumped into a flash dryer. The drying gas temperature is 100°C, and the gas velocity is 26m / s. Most of the solvent is removed from the material instantly, forming a dry powder with a moisture content of approximately 3wt%. The dry powder enters a cyclone separator. The separated gas phase is cooled and condensed in a hot air heat exchanger, and the condensate is returned to the mother liquor tank. The solid phase enters a rotary dryer for further drying to a moisture content of <0.01 wt%. The rotary dryer operates at a temperature (drying gas temperature) of 90°C and a gas velocity of 4m / s, ultimately yielding the polymer product.

[0047] Example 5 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that the operating parameters of step (2) are different, as follows: Prepolymerization reaction: Ziegler-Natta catalyst, co-catalyst methylaluminoxane, and small amounts of 4-methyl-1-pentene and n-heptane were added to a prepolymerization reactor and reacted at 40°C for 5 minutes to complete the prepolymerization. The molar ratio of the main catalyst to the co-catalyst was 1:150; the molar ratio of the main catalyst to 4-methyl-1-pentene was 1:200; and the mass ratio of 4-methyl-1-pentene to the solvent n-heptane was 1:4.

[0048] Slurry polymerization reaction: 4-methyl-1-pentene, 1-pentene and n-heptane were added to the polymerization reactor. The prepolymer solution was added to the polymerization reactor. The reaction temperature was 30℃. Hydrogen gas was introduced (the molar ratio of H2 to 4-methyl-1-pentene = 1:500). The reaction time was 10 hours. The mass ratio of 4-methyl-1-pentene to α-olefin was 25:1, and the mass ratio of 4-methyl-1-pentene to solvent n-heptane was 1:2.

[0049] Example 6 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that the operating parameters of step (2) are different, as follows: Prepolymerization reaction: Ziegler-Natta catalyst, triisopropylaluminum co-catalyst, and small amounts of 4-methyl-1-pentene and n-octane were added to a prepolymerization reactor and reacted at 10°C for 180 minutes to complete the prepolymerization. The molar ratio of the main catalyst to the co-catalyst was 1:300; the molar ratio of the main catalyst to 4-methyl-1-pentene was 1:10; and the mass ratio of 4-methyl-1-pentene to the solvent n-heptane was 1:4.

[0050] Slurry polymerization reaction: 4-methyl-1-pentene, 1-eicosene and n-octane are added to the polymerization reactor. The prepolymer liquid is added to the polymerization reactor. The reaction temperature is 80℃. Hydrogen gas is introduced (the molar ratio of H2 / 4-methyl-1-pentene = 1:2000). The reaction time is 2 hours. The mass ratio of 4-methyl-1-pentene to α-olefin is 10:1, and the mass ratio of 4-methyl-1-pentene to solvent n-heptane is 1:20.

[0051] Example 7 This embodiment provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer). The difference from Example 1 is that in step (3), the drying equipment is changed from flash dryer + rotary dryer to vacuum rake dryer, and the total drying time from wet slurry to finished product is about 360 minutes.

[0052] Comparative Example 1 This comparative example provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that ethanol is not added in step (3).

[0053] Comparative Example 2 This comparative example provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer). The difference from Example 1 is that in step (3), excess ethanol is added, and the mass ratio of ethanol to the polymerization liquid is 1:5.

[0054] Comparative Example 3 This comparative example provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that step (3) uses an equal mass of triethylamine instead of ethanol.

[0055] Comparative Example 4 This comparative example provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that step (3) uses an equal mass of water instead of ethanol.

[0056] Comparative Example 5 This comparative example provides a method for continuous production of poly(4-methyl-1-pentene / α-olefin copolymer), which differs from Example 1 in that a very small amount of ethanol is added in step (3) (only for quenching), and the mass ratio of ethanol to polymer solution is 1:1000.

[0057] Experimental Example The copolymers provided in each embodiment and comparative example were subjected to various performance tests. The specific test items and methods are as follows: 1. The molecular weight (Mw) and molecular weight distribution (PDI) of the polymers obtained in the examples and comparative examples were analyzed using a GPC-IR instrument. This instrument has three tandem MIXED columns, each 300 × 7.5 mm in size, and is equipped with infrared, viscosity, and laser detectors. The IR5 MCT polyolefin-specific infrared detector was commonly used for detection. 8 ml of trichlorobenzene solvent was automatically injected into the high-temperature zone (160 °C) of the instrument's autosampler. After shaking and dissolving for one hour, 200 μL was extracted for testing. The infrared detector temperature was 150 °C, and polystyrene (PS) was used as the molecular weight standard.

[0058] 2. The metal ion content of the samples obtained in the examples and comparative examples was analyzed using an Agilent 7900 ICP-OES instrument, equipped with a high-purity argon (Ar) gas supply system and an autosampler. After microwave digestion using a nitric acid-hydrogen peroxide system, the samples were diluted to a final volume of 50 mL in a volumetric flask. For analysis, the standard addition method was used for calibration, and the calibration curve was established based on a 10 μg / L standard solution. The samples were injected into the high-temperature zone (160°C) of the autosampler, with a nebulizer gas flow rate of 0.8 L / min, a plasma power of 1500 W, an auxiliary gas flow rate of 0.2 L / min, and a carrier gas flow rate of 1.0 L / min. Multi-wavelength detection was used to simultaneously determine Al and Ti elements. Each sample was measured three times, and the average value was taken.

[0059] 3. The particle size distribution span of the samples obtained in the examples and comparative examples was tested using a Bettersize 2600 laser particle size analyzer (dry method), which employs a dry sample introduction method. The air jet system was then activated to deliver the sample into the measurement chamber with a dry air stream at a pressure of 50 kPa, forming a stable aerosol. Scattering signals were acquired at a frequency of 100 times / second, at a test temperature of 25°C and a relative humidity of 40%, with a measurement range of 0.01~2000 μm. The test was repeated three times, and the average value was taken. The span was calculated as follows: Span = (Dv90 - Dv10) / Dv50 The meanings of the symbols are as follows: Dv10: Particles with a diameter smaller than this value account for 10% of the total number of particles; Dv50: Particles with a diameter smaller than this value account for 50% of the total number of particles; Dv90: Particles with a diameter smaller than this value account for 90% of the total number of particles.

[0060] 4. The VOC content of the samples obtained in the examples and comparative examples was analyzed using a headspace gas chromatograph (HS-GC) of an Agilent 8890 model equipped with a flame ionization detector (FID). Samples were weighed and sealed in 20 mL headspace vials. For analysis, external standard method was used for quantitative correction, and the calibration curve was established based on standard solutions of known concentrations. The vials were heated to equilibrium in the headspace sampler's isothermal zone (120°C) for 60 minutes, and 1.0 mL of gas from the upper part of the vial was injected into the gas chromatograph using a gas-tight syringe. After analysis, the residual concentration of the target VOC in the sample was calculated by comparing the chromatographic peak area with the standard curve. Each sample was measured three times, and the average value was taken as the final result.

[0061] The specific test results are shown in the table below: Table 1

[0062] From the above test results, we can conclude that: The residual metal ion content of the products from Examples 1, 2, and Comparative Example 1 shows that the addition of alcohol compound additives significantly reduces the levels of Ti and Al metal ions, with the metal ion content controlled below 70 ppm. In contrast, the residual metal ion content of the products without alcohol additives exceeds 400 ppm, failing to meet the application requirements of high-end medical products (ECMO membranes). The particle size distribution of the products from Examples 1, 2, and Comparative Example 1 shows that the addition of alcohol compound additives significantly improves the particle size uniformity, with the particle size distribution controlled below 1.25 mm. In contrast, the particle size distribution of the products without alcohol additives exceeds 1.9 mm, which is unfavorable for downstream processing applications. Furthermore, the product results and production efficiency of Examples 1 and Comparative Example 1 demonstrate that the alcohol compound added in this application effectively improves the drying unit efficiency, significantly reducing the VOC content in the product under the same drying time. The product results and production efficiency of Examples 1 and 7 show that the combination of flash drying and rotary drying significantly reduces drying time compared to traditional vacuum rake dryers, making it easier to meet VOC content standards. It solves the shortcomings of vacuum drying equipment, such as high cost, long drying time, and product sticking to the wall during the drying process.

[0063] As can be seen from the molecular weight and VOC residue of Example 1 and Comparative Example 2, the addition of excessive alcohol additives leads to an increase in VOC residue and a significant increase in the molecular weight of the product. This is because the excessive additives combine with the solvent, resulting in a large change in overall polarity, which causes some low molecular weight PMP oligomers to dissolve in the solution, increasing the solution viscosity and making drying more difficult. This leads to an increase in VOC residue, and the overall molecular weight increases due to the dissolution of low molecular weight PMPs, which is not conducive to downstream processing.

[0064] As can be seen from the VOC residue and metal ion content of Example 1 and Comparative Example 3, other additives (amines) have a certain effect on reducing VOC residue, which is slightly inferior to alcohols. However, amines cannot reduce the metal ion content in the product and cannot meet the application requirements of PMP copolymers as medical materials.

[0065] As can be seen from the VOC residue, Ti metal ion content and particle size range of Example 1 and Comparative Example 4, adding an equal amount of water only has the effect of reducing the Al metal content. Under the same drying conditions, it cannot reduce the VOC residue in the product. At the same time, water cannot reduce the Ti ion content, nor is it sufficient to improve dispersibility. Therefore, the Ti ion content and particle size range are both relatively high.

[0066] As can be seen from the VOC residue and particle size range of Example 1 and Comparative Example 5, adding a small amount of alcohol only has the effect of reducing the metal content. At this time, the alcohol only acts as a quencher and cannot reduce the VOC residue in the product under the same drying conditions. It is also insufficient to improve the dispersibility. Therefore, the particle size range is relatively high.

[0067] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a poly(4-methyl-1-pentene / α-olefin copolymer), characterized in that, Includes the following steps: S1, 4-methyl-1-pentene and α-olefin are subjected to slurry polymerization to obtain a polymerization liquid; S2, the polymerization liquid is mixed with an alcohol compound, the solid-liquid separation is performed, and the mixture is dried to obtain a copolymer; The mass ratio of the alcohol compound to the polymerization liquid is 1:(10-30).

2. The method for preparing the poly(4-methyl-1-pentene / α-olefin copolymer) according to claim 1, characterized in that, The alcohols include at least one of alcohols having 1 to 6 carbon atoms; Optionally, the alcohol compound includes at least one selected from ethanol, n-propanol, n-butanol, isopropanol, and isobutanol. And / or, the mixing temperature in S2 is 20-40℃, and the mixing time is 10-30 minutes.

3. The method for preparing the poly(4-methyl-1-pentene / α-olefin copolymer) according to claim 1, characterized in that, The drying process includes flash drying and rotary drum drying; Optionally, the temperature of the drying gas in the flash drying is 90-130℃, and the gas velocity is 20-40m / s; Optionally, the temperature of the drying gas in the rotary drum dryer is 90-130℃, and the gas velocity is 2-4m / s.

4. The method for preparing the poly(4-methyl-1-pentene / α-olefin copolymer) according to claim 1, characterized in that, In S2, the liquid phase obtained from the solid-liquid separation step is used to recover monomers, solvents, and alcohol compounds through distillation; Optionally, the operating conditions for recovering monomers include: a column top pressure of 0.01-0.1 MPa and a reflux ratio of 1.5-5; Optionally, the operating conditions for solvent recovery include: a column top pressure of 1-2 MPa and a reflux ratio of 1.5-5; Optionally, the operating conditions for recovering alcohol compounds include: a top pressure of 0.01-0.1 MPa and a reflux ratio of 1.5-5.

5. The method for preparing the poly-4-methyl-1-pentene / α-olefin copolymer according to any one of claims 1-4, characterized in that, In S1, the slurry polymerization reaction includes the following steps: S11, 4-methyl-1-pentene, main catalyst and co-catalyst are prepolymerized in solvent to obtain prepolymer liquid; S12, the prepolymer liquid is subjected to slurry polymerization reaction with 4-methyl-1-pentene and α-olefin in a solvent to obtain a polymer liquid.

6. The method for preparing the poly(4-methyl-1-pentene / α-olefin copolymer) according to claim 5, characterized in that, The reaction temperature of the prepolymerization reaction is 10-40℃, and the reaction time is 5-180 minutes; And / or, the reaction temperature of the slurry polymerization reaction is 30-80℃, and the reaction time is 2-10 hours; And / or, a regulator is added during the slurry polymerization reaction, optionally, the regulator is hydrogen; optionally, the molar ratio of the regulator to 4-methyl-1-pentene in S12 is 1:(500-2000).

7. The method for preparing the poly-4-methyl-1-pentene / α-olefin copolymer according to claim 5, characterized in that, The molar ratio of the main catalyst to the co-catalyst is 1:(50-300); And / or, in S11, the molar ratio of the main catalyst to 4-methyl-1-pentene is 1:(10-200); And / or, in S12, the mass ratio of 4-methyl-1-pentene to α-olefin is (10-100):1; And / or, in S11, the mass ratio of the solvent to 4-methyl-1-pentene is (2-20):1; And / or, in S12, the mass ratio of the 4-methyl-1-pentene to the solvent is 1:(1-20).

8. The method for preparing the poly-4-methyl-1-pentene / α-olefin copolymer according to any one of claims 5-7, characterized in that, The main catalyst includes a Ziegler-Natta catalyst; And / or, the cocatalyst comprises at least one of alkylaluminum compounds and aluminum oxane compounds; optionally, it comprises at least one of triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-pentylaluminum, triisopentylaluminum, methyl diethylaluminum, methyl di-n-propylaluminum, methyl diisopropylaluminum, methyl di-n-butylaluminum, methyl diisobutylaluminum, diethyl-n-propylaluminum, diethyl-isopropylaluminum, diethyl-n-butylaluminum, diethyl-isobutylaluminum, diethylaluminum chloride, ethyl dialuminum chloride, methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, propylaluminoxane, isobutylaluminoxane, and diisobutylaluminoxane. And / or, the α-olefin comprises C6-C20 α-olefins, optionally including at least one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetracene, 1-tetradecene, 1-pentadecanene, 1-hexadecene, 1-heptadecene, 1-heptadecene, 1-octadecene, 1-nonadecanene, and 1-eicosene.

9. A poly(4-methyl-1-pentene) / α-olefin copolymer, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the poly(4-methyl-1-pentene) / α-olefin copolymer of claim 9 in the medical and electronic fields.

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