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Manufacture and products of hollow fiber membrane of outer pressured polyvinylidene fluoride by immersion gelation

A polyvinylidene fluoride and fiber membrane technology, which is applied in membrane technology, semi-permeable membrane separation, chemical instruments and methods, etc., can solve the problem of affecting the mechanical properties and service life of hollow fibers, hollow fiber membranes are easy to be crushed, and manufacturing Difficult preparation of membrane solution, etc., to avoid melting difficulties, easy control of the process, and low equipment requirements

Active Publication Date: 2005-02-23
ZHEJIANG OMEX ENVIRONMENTAL ENG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The present invention mainly solves the unreasonable ratio of the lower molecular weight PVDF film-making liquid in the prior art, the preparation of the film-making liquid is relatively difficult, the film-making process is relatively complicated, and the water permeability is not very high; or in order to increase the water permeability, Usually, the porous support layer of the hollow fiber adopts a finger-like pore structure (it will affect the overall mechanical properties and service life of the hollow fiber, and the hollow fiber membrane is easily crushed) and other technical problems.

Method used

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  • Manufacture and products of hollow fiber membrane of outer pressured polyvinylidene fluoride by immersion gelation
  • Manufacture and products of hollow fiber membrane of outer pressured polyvinylidene fluoride by immersion gelation
  • Manufacture and products of hollow fiber membrane of outer pressured polyvinylidene fluoride by immersion gelation

Examples

Experimental program
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Effect test

Embodiment 1

[0039] Example 1: 18% (wt) polyvinylidene fluoride resin with brand name FR904 (weight average molecular weight: 800,000 Daltons) produced by Shanghai Sanaifu Materials Co., Ltd. was selected, and the intrinsic viscosity was 1.95. The (PVP) polyvinylpyrrolidone K-30 (weight-average molecular weight 45,000 Daltons) produced by Shanghai Shengpu New Material Co., Ltd. is 12.5% ​​(wt), and the polyethylene glycol PEG-600 imported from Japan is 8% (wt). Tween-80 imported from Japan is 1.5% (wt), lithium nitrate 0.5% (wt), N-methylpyrrolidone 29.5% (wt) produced by Shanghai Chemical Reagent Company, 30% dimethylacetamide produced by BASF (wt), put the above substances (see Table 1) into the dissolution tank in order, stir at 85°C to obtain a uniform film-forming solution, circulate and degas the film-forming solution at 80°C, and keep the film-forming solution passing through at 80°C Double casing spinneret, which is sprayed together with the composite support liquid in the center t...

Embodiment 11

[0041] Embodiment 11: select polyvinylidene fluoride resin 18% (wt) of FR904 (weight average molecular weight 800,000 Daltons) produced by Shanghai Sanaifu Materials Co., Ltd. (PVP) produced by Shanghai Shengpu New Material Co., Ltd. Polyvinylpyrrolidone (weight-average molecular weight 45,000 Daltons) 12.0% (wt), Nanjing Jinlong Chemical Plant (weight-average molecular weight 1,000,000 Daltons) polyvinylpyrrolidone 0.5%, polyethylene glycol PEG-600 imported from Japan 8% (wt), Tween-80 1.5% (wt) imported from Japan, lithium nitrate 0.5% (wt), N-methylpyrrolidone 29.5% (wt) produced by Shanghai Chemical Reagent Company, dimethyl pyrrolidone produced by BASF Base acetamide 30% (wt), put the above substances into the dissolution tank in order, stir at 85°C to obtain a uniform film-forming liquid, circulate and degas the film-forming liquid at 80°C, and keep the film-forming liquid at 80°C The double-tube spinneret is ejected together with the composite support liquid in the cent...

Embodiment 12

[0042] Embodiment 12: select the polyvinylidene fluoride resin 20.5% (wt) that Japan Kureha Chemical Industry Co., Ltd. produces the grade to be 1700 (weight average molecular weight 500,000 Daltons), produced by Shanghai Shengpu New Material Co., Ltd. (weight average molecular weight 45000 Dal) polyvinylpyrrolidone 9.5% (wt), polyethylene glycol PEG-400 (imported from Japan) 12% (wt), emulsifier 1.0% (wt), chemical reagent lithium chloride 0.5% (wt), BASF Dimethylacetamide 56.5% (wt) produced by the company, the above-mentioned material is made into a film according to the method of Example 1, and after about 0.02 seconds of evaporation, it enters the primary immersion solution of 60% (wt) polyvinylidene fluoride resin solvent In 1.5 seconds, by pulling into 30% (wt) polyvinylidene fluoride resin solvent secondary gel solution for precipitation for 30 seconds, the obtained hollow fiber external pressure ultrafiltration membrane double skin layer, the membrane cross section pre...

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Abstract

The invention relates to a preparation method of exo-pressure type poly (vinylidene fluoride) hollow fiber membrane spinned utilizing an immersion-coagulation method and the product thereof. The invention is performed mainly through the following steps: dissolving and stirring at a certain temperature to obtain a membrane forming solution; by means of a double-tube orifice, spinning the membrane forming solution together with a composite supporting solution which is in the inner tube of the orifice; after a rapid evaporation, performing the two-stage phase-separating coagulations; after a potch, hydrophilizating the resulted phase inversion membrane; thus, obtaining integrally and continuously the exo-pressure type hollow fiber membrane having double barrier layers and a completely spongy supporting layer. Therefore, the invention is provided with a lot of characteristics, such as the formulation of the membrane forming solution being reasonable, the evaporation and immersion spinning method, the two-stage phase-separation coagulations, and the hydrophilization treatment, as well as the technique for forming membrane integrally and continuously being simple and easy without high restricts to device, the technique process being controlled easily, etc. And the membrane is provided with high compression strength and large water permeation flux, and its property is deteriorated very slowly, and cut-off deposits are difficult to form on the membrane surface.

Description

technical field [0001] The present invention relates to a method for preparing hollow fiber membranes, in particular to a method for manufacturing hollow fiber membranes of polyvinylidene fluoride with high molecular weight and a high proportion of organic additives A combined film-forming liquid formula and products obtained therefrom. Background technique [0002] Polyvinylidene fluoride (PVDF) has gradually gained attention in membrane separation technology because of its excellent separation performance and chemical stability. In the prior art, polyvinylidene fluoride with a molecular weight (MW) of 30,000-200,000 is often used, and the prepared hollow fiber membrane obtains sufficient strength by increasing the concentration of PVDF in the membrane-forming solution. For example, US Pat. No. 5,066,401 discloses a membrane material based on PVDF material, and the ratio of PVDF in the membrane-forming solution reaches 70%-98%. However, the result of adopting a high conce...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/08B01D71/34
Inventor 李翔汪晓迈
Owner ZHEJIANG OMEX ENVIRONMENTAL ENG CO LTD
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