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CN-122006504-A - High-flux high-strength regenerated cellulose virus-removing filter membrane and casting solution, preparation method and application thereof

CN122006504ACN 122006504 ACN122006504 ACN 122006504ACN-122006504-A

Abstract

The invention discloses a high-flux high-strength regenerated cellulose virus-removing filter membrane, a casting membrane liquid, a preparation method and application thereof. The invention has the advantages that the phase separation form is simply changed in the membrane preparation process without the crosslinking modification or other modes of modifying the cellulose surface, so that a unique membrane structure is obtained, the mechanical property of the membrane is effectively improved, and the membrane has higher membrane flux and loading capacity.

Inventors

  • GAO JIE
  • CHEN LIN

Assignees

  • 百林科医药科技(上海)股份有限公司

Dates

Publication Date
20260512
Application Date
20260409

Claims (18)

  1. 1. The high-flux high-strength regenerated cellulose virus-removing filtering membrane is characterized by comprising a three-dimensional structure of a porous liquid inlet surface and a porous liquid outlet surface, wherein spherical particle polymers are distributed on the porous liquid inlet surface.
  2. 2. The high-flux high-strength regenerated cellulose virus-removing filter membrane according to claim 1, wherein the pore diameter of the porous liquid inlet surface is 100-5000 nm, the pore diameter of the porous liquid outlet surface is 15-25 nm, the average pore diameter is 15-35 nm, the membrane porosity is 40-70%, and the membrane thickness is 30-80 μm.
  3. 3. The high-flux high-strength regenerated cellulose virus-removing filter membrane according to claim 1, wherein the membrane water flux of the filter membrane is 60-300 LMH@30psi, and the pp7 interception result is greater than or equal to 4.
  4. 4. The high-throughput high-strength regenerated cellulose virus-removing filter membrane according to claim 1, wherein the maximum force of the filter membrane is not less than 6N and the elongation at break is not less than 45%.
  5. 5. A casting solution for preparing the high-flux high-strength regenerated cellulose virus-removing filter membrane according to any one of claims 1 to 4, wherein the casting solution comprises, by weight, 15-25wt% of cellulose polymer, 40-60wt% of organic solvent, 20-40wt% of pore-forming agent and 0.2-2.5wt% of polyamine micromolecule substance, and the organic solvent is a low-boiling point solvent or a mixed solvent formed by combining a low-boiling point solvent and a high-boiling point solvent.
  6. 6. The casting solution according to claim 5, wherein the cellulose polymer is at least one selected from the group consisting of diacetylcellulose, triacetylcellulose, propionic acid cellulose, phthalic acid acetic acid cellulose, acetic acid butyric acid cellulose and acetic acid propionic acid cellulose.
  7. 7. The casting solution according to claim 5, wherein the low boiling point solvent is selected from one or more of acetone, 1, 4-dioxane, acetic acid and formic acid, the high boiling point solvent is selected from one or more of N, N-dimethylformamide, N-dimethylacetamide and N-methylpyrrolidone, and the mixing volume ratio of the low boiling point solvent and the high boiling point solvent in the mixed solvent is 1:1-1.5.
  8. 8. The casting solution according to claim 5, wherein the pore-forming agent is one or more selected from polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, methanol and ethanol.
  9. 9. The casting solution according to claim 5, wherein the polyamine-based small molecular substance is one or more selected from ethylenediamine, 1, 3-propylenediamine, diethylenetriamine, triethylenetetramine and spermidine.
  10. 10. A method for preparing a high-flux high-strength regenerated cellulose virus-removing filter membrane, which is characterized in that the membrane casting solution is adopted for preparation.
  11. 11. The method for preparing the high-flux high-strength regenerated cellulose virus-removing filter membrane according to claim 10, comprising the following steps: S1, sequentially adding cellulose polymers, solvents, pore-forming agents and polyamine micromolecule substances into a three-neck flask, then placing the three-neck flask into a water bath kettle for stirring and dissolving, obtaining casting solution after dissolving, taking out and placing the casting solution at room temperature for cooling for standby; s2, casting a film cooled to room temperature in a glass plate in a liquid casting way, scraping the film by using a scraper, immediately placing the scraped film in a coagulating bath, coagulating the film into a film, and then placing the film in pure water for cleaning to obtain the cellulose acetate porous film; And S3, immersing the prepared cellulose acetate membrane into sodium hydroxide solution for hydrolysis, and putting the cellulose acetate membrane into pure water after the hydrolysis is finished to wash off sodium hydroxide on the surface of the cellulose acetate membrane, thus obtaining the high-flux high-strength regenerated cellulose virus-removing filter membrane.
  12. 12. The method for preparing the high-flux high-strength regenerated cellulose virus-removing filtration membrane according to claim 11, wherein the dissolution temperature of the water bath kettle in the step S1 is 40-120 ℃, the stirring speed is 30-300 rpm, and the stirring time is 2-30 h.
  13. 13. The method for preparing the high-flux high-strength regenerated cellulose virus-removing filtration membrane according to claim 11, wherein in the step S2, the clearance of a scraper is 250 μm, the membrane scraping speed is 0.2-2 m/min, the membrane scraping temperature is 5-35 ℃, and the air flow rate is 0-10 m/S.
  14. 14. The method for preparing the high-flux high-strength regenerated cellulose virus-removing filtration membrane according to claim 11, wherein the coagulation bath in the step S2 is a blending solution of small molecular alcohols and water according to a mass ratio of 1:3-4, the temperature of the coagulation bath is 15-55 ℃, the standing time is 2-20 min, the pure water cleaning temperature is 15-55 ℃, and the cleaning time is 5-30 min.
  15. 15. The method for preparing a high-flux and high-strength regenerated cellulose virus-removing filter membrane according to claim 14, wherein the small molecule alcohol is selected from one of methanol, ethanol and propanol.
  16. 16. The method for preparing the high-flux high-strength regenerated cellulose virus-removing filtration membrane according to claim 11, wherein the concentration of the sodium hydroxide solution in the step S3 is 0.01-1 mol/L, the hydrolysis temperature is 25-90 ℃, the hydrolysis time is 3-24 h, and the temperature of the pure water for cleaning is 25 ℃.
  17. 17. Use of a high-throughput high-strength regenerated cellulose virus-removal filter membrane according to any one of claims 1 to 4 for virus removal.
  18. 18. The use according to claim 17, wherein the virus is present in a biologic, which is an immunoglobulin, vaccine or recombinant protein drug.

Description

High-flux high-strength regenerated cellulose virus-removing filter membrane and casting solution, preparation method and application thereof Technical Field The invention relates to the technical field of membrane separation, in particular to a high-flux high-strength regenerated cellulose virus-removing filter membrane, a casting membrane liquid thereof, a preparation method and application. Background Currently, virus-removing filtration membranes widely used include polyether sulfone (PES) and polyvinylidene fluoride (PVDF) synthetic polymer materials and Regenerated Cellulose (RC) natural polymers. Although these materials have certain virus removal properties, they all have some significant drawbacks. For example, PES has a high water flux, but it has a natural hydrophobicity, is liable to adsorb biomolecules such as proteins, and causes a rapid decrease in flux when filtering biological products, and requires frequent replacement of the filtration membrane, increasing production cost and operational complexity. PVDF also has similar problems as PES. Although the effect of alleviating flux attenuation to a certain extent can be achieved after hydrophilic modification, the modification process is complex and the uniformity is poor. Cellulose has a natural high hydrophilicity, which makes it potentially advantageous for low protein adsorption in protein feed filtration. However, cellulose itself has low strength and poor pressure resistance. When the filtration operation is carried out in a high-pressure environment, the membrane holes can be severely contracted or even collapsed, and the structural change can also cause great reduction of flux and loading capacity, so that the application of the membrane holes to the high-pressure and high-flux filtration scene in actual production is severely limited. The naturally excellent hydrophilic properties of cellulose have entered the public field of view. Planova series filters, which have the ability to retain viruses at 20nm and above, were developed and marketed by Asahi chemical medical Co., ltd., and filed a virus-removing membrane patent application publication No. CN105980038A, which contains cellulose and is effective in retaining porcine parvovirus (LRV 4). Although the natural hydrophilization of cellulose imparts a low protein adsorption capacity, cellulose itself is not strong enough that the pressure cannot be exceeded during use, excessive filtration pressure may cause the membrane pores to compress or collapse, resulting in a decrease in the final flux and loading of the membrane and possibly leakage of virus. To solve this problem, chinese enterprise cobra filed a high mechanical strength cellulose virus-removing membrane with publication number CN116712868A and its preparation process invention patent, the virus-removing membrane disclosed in this application comprises a microporous membrane supporting layer and a cellulose layer at least partially permeated into the microporous membrane supporting layer, the region of the microporous membrane supporting layer permeated with the cellulose layer is a permeation region, and the cellulose layer further comprises a prefilter region and a separation region. And (3) pouring the two casting solutions with different formulas on the microporous support layer in sequence by using a double casting solution mode, and manually regulating and controlling the longitudinal aperture gradient change of the cellulose membrane so as to improve the compressive strength of the final membrane. Although this innovative process has made some progress in improving the compressive strength of the film, there are also some disadvantages. On the one hand, the preparation process is relatively complex, the difficulty and the cost of production are increased, and on the other hand, the problem of non-ideal membrane loading is caused to a certain extent due to the fact that pore diameter mutation possibly exists in a transition region between cellulose and a microporous membrane. Cellulose is a crystalline polymer having crystalline regions and amorphous regions, which deform to varying degrees under a certain force. The cellulose molecules mainly depend on hydrogen bond interactions to maintain certain structural stability. Although hydrogen bonds have a certain force, the bond energy of hydrogen bonds is weaker than the strong chemical bonds such as covalent bonds. When subjected to pressure, these hydrogen bonds are easily broken, resulting in weakening of the intermolecular binding force. Once the intermolecular hydrogen bonds are broken, the cellulose molecular chains become more loose. The basic properties of cellulose itself result in poor pressure resistance. Thus, many students have improved the pressure resistance of cellulose by various methods, the most common of which is to crosslink and modify cellulose. The active hydroxyl groups on the surface of cellulose are used for grafting different crosslinking reagen