JPS60110305A - Hollow fiber film and body fluid treating device using the same - Google Patents

Abstract

PURPOSE:To enhance a body fluid treating effect, by specifying the shape of projections, in a hollow fiber film for treating a body fluid provided with projections on the outside surfaces thereof. CONSTITUTION:A hollow fiber consisting of a high molecular weight compound and having selectivity to substances is provided on the outside surface thereof with at least one streak of projection extended spirally at a predetermined angle against the fiber axis. By this, the hollow fibers can be prevented from making entangled contact with each other. Accordingly, when a hollow fiber type body fluid treating device provided with the hollow fibers as a separating means is used, for example, as a blood dialyzer, dialysis can be effectively performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to hollow fiber membranes for treating substance mixtures, in particular for treating body fluids.

Furthermore, the present invention relates to a hollow fiber membrane type body fluid treatment device with improved body fluid treatment effects.

<Prior Art> Hemodialyzers are currently used to purify the blood of patients with renal failure. This means that a large number of dialysis membranes, such as hollow fiber membranes, are housed in a housing, the patient's blood is allowed to flow inside the hollow fibers, and the dialysate is allowed to flow outside, that is, between the intermediate fiber membranes.
This method uses dialysis through a hollow fiber membrane to remove waste products from the blood and correct the electrolyte level, and also removes excess water from the blood through ultrafiltration by creating a pressure difference between the inside and outside of the hollow fiber membrane. be. Furthermore, hollow fiber membranes are used to treat autoimmune diseases and the like by separating only plasma from blood or removing specific components from the plasma. In this way, hollow fiber membranes for blood treatment must selectively allow specific substances to permeate depending on the purpose. Its performance depends on the hollow fiber membrane material, porosity (pore size,
(number, etc.), film thickness, etc. However, not only that, for example, how to focus a large number of hollow fiber membranes to make the entire membrane surface function effectively is also an important point I. that determines its performance. For example, during dialysis, when hollow fiber membranes come into close contact with each other along their length, it becomes difficult for the dialysate to flow evenly around each hollow fiber membrane in the vicinity of that area, forming a specific flow path. As a result, dialysis through hollow fiber membranes that do not participate in this flow is hardly performed, and the overall dialysis effect is reduced. In normal dialysis operation, the difference in concentration on both sides of the hollow fiber membrane becomes the driving force for mass transfer, so the dialysate flows as evenly as possible into the outer space of the hollow fiber membrane, and the outer membrane resistance is greater than the surrounding area. The hollow fiber membrane is housed in such a way as to reduce the volume of the hollow fiber membrane as much as possible and increase the concentration difference between the blood side (inside the hollow fiber membrane) and the dialysate side (outside the hollow fiber membrane). It is necessary to devise a shape. Regarding the former, we first focused the hollow fiber membranes in a crosswise manner and housed them in a housing to prevent the close contact between the hollow fiber membranes and, therefore, to reduce the right dynamic membrane area, and to prevent the dialysate from decreasing. flows evenly and reduces membrane resistance,
discovered that dialysis efficiency could be improved
38837). Regarding the latter, for example, a method can be used to avoid the same effect by providing a protrusion that we proposed earlier (Japanese Patent Laid-Open No. 48-754
81). However, in this case, depending on the shape of the protrusions, for example, the hollow fiber membranes may come into contact with each other and may not necessarily produce a satisfactory effect.

<Purpose and Structure of the Invention> From this perspective, the present inventors conducted extensive research with the aim of improving body fluid treatment efficiency, and as a result discovered that hollow fiber membranes of a specific shape are particularly effective. invention has been achieved.

That is, the present invention provides the following features: (1) A hollow fiber membrane made of a polymer compound and having selective permselectivity for a substance has a spirally extending structure on the outer surface of the hollow fiber membrane at an angle in a certain direction with respect to the fiber axis. (2) A hollow fiber type body fluid treatment device comprising, as a separation element, a hollow fiber membrane characterized by having at least one protrusion, and (2) a hollow fiber membrane made of a polymer compound and having substance selective permeability. The hollow 11-layer membrane has 1tIN of fibers on its outer surface.
To provide a body fluid treatment device characterized in that it has at least one protrusion extending in a spiral shape with an angle in a certain direction.

The fiber crotch according to the present invention has i on its outer surface.
It is characterized by having a protrusion extending spirally at an angle in a certain direction with respect to the ii axis. This spirally extended protrusion may be continuous, discontinuous, or both may coexist. Also, is there at least one spiral protrusion? l- is fine, but
Substantially, Articles 1 to 4 are effective. Even if the number of threads is further increased, the effect of preventing the hollow fibers from adhering to each other and improving the body fluid treatment efficiency does not increase significantly, and on the contrary, the treatment efficiency decreases due to the increase in the average membrane thickness of the hollow fiber membrane. This is not desirable because it causes Incidentally, it is preferable that the spiral protrusions extend from most of the longitudinal direction of the fibers in order to improve efficiency. Further, it is preferable that the protrusions continuously spiral around the outer circumferential surface of the fiber, not only to improve the body fluid treatment efficiency but also to facilitate uniform and stable production of the fiber.

The angle between the spiral protrusion and the fiber axis is 30 degrees or less,
Preferably, the temperature is 15 degrees or less in terms of the effect of improving body fluid treatment efficiency and stability during production. The angle may be constant or variable, but it is practical for it to be substantially constant.

The height and width of the protrusion can be appropriately selected depending on the inner diameter and membrane thickness of the hollow fiber membrane, but the range is 3 to 3.
It is desirable that the thickness be 100μ. Note that the height and width may be constant or may vary, but it is better that they remain substantially constant. If the protrusions are larger than this range, the average thickness of the hollow fiber membrane will increase and the packing density within the housing will decrease, making it difficult to stably manufacture hollow fiber membranes with uniform shape and performance. It is difficult to do so. On the other hand, if the protrusion is smaller than this, the desired effect cannot be fully exhibited.

Next, the pitch of the spiral of the protrusions is 1 to 1 in the length direction of the hollow fiber membrane.
50G is preferred, and 1-20cIR is particularly suitable. If the length is too short, the intended effect of the wood cannot be fully exhibited, and if it is too long, there is no point in spirally winding the protrusions, and the effect of improving body fluid treatment efficiency is small.

The polymer compounds used as materials for hollow fiber membranes that are the object of the present invention include cell L1-su ester, t-fluorose, polyamide, polyacrylonitrile, polymethyl methacrylate, and polyvinyl alcohol.

Polycarbonate, copolymers, mixtures thereof, etc. are preferred, and cellulose esters, cellulose, etc. are particularly preferred.

Hollow of the invention! There are various methods for producing the li ICF membrane, such as melt spinning, wet spinning, semi-dry semi-wet spinning, and dry spinning.1 An example of manufacturing by melt spinning is given below. That is, the spinning dope (melt or solution) of the hollow fiber membrane is extruded through the hollow hole of the spinning nozzle into a gas or spinning bath according to a conventional method, and a gas that does not dissolve the membrane material and does not substantially react with it is placed in the center. Or fill it with liquid and spin it while keeping it hollow. For example, a plasticizer such as polyethylene glycol is added to cellulose diacetate 1-flakes and melt-spun to form a hollow hole (A) in the spinning nozzle.
It is extruded into air and spun into hollow fibers while blowing nitrogen gas into the center. When the plasticizer is removed from the hollow fibers and, if necessary, chemically treated to produce a hollow fiber membrane with substance selective permeability, the hollow holes (A ) A small hole (B) is provided in the vicinity of the hole (B), from which a melt of the same membrane material is extruded at a high speed in the tangential direction to the outside of the hollow fiber immediately after exiting from the hole (A), so that it is deposited on C11. Accordingly, it is possible to form a hollow fiber in which the protrusions continuously surround the hollow fiber in a helical shape. The shape of the spiral protrusion is adjusted by the position, size, number, angle with respect to the hollow hole (A), (Δ), extrusion speed from both holes (B), etc. of the small hole (B). The hollow fiber 19 for blood processing has an inner diameter of 100 to 1000 μm.
, a film thickness of about 5 to 100 μm is used. In order to form the spiral protrusions of the present invention, it is preferable to use down-spinning, and in particular, it is preferable to use flow spinning to form the threads by melt spinning.
Uru materials are effective.

Also, body fluid treatment in the present invention! I! The device is characterized in that it is equipped with a substance selectively permeable hollow fiber membrane having the above-mentioned spiral projections as a separation element. However, the term "body fluid" as used in the present invention refers to blood, lymph fluid, and the like, but blood is often the target. The body fluid treatment device may be a commonly used hollow fiber separator, except that it is equipped with the hollow IIi membrane. Specific examples of the body fluid treatment device in the present invention include a dialyzer, a hemodialysis device, a plasma separator, and the like.

<Effects of the Invention> In a body fluid treatment device using a hollow fiber membrane according to the unique form of the present invention, reduction in effective membrane area due to close contact between hollow fiber IQs is prevented, and in particular, dialysate is separated from each other. It flows evenly and spirally around the hollow fiber membrane, reducing the outer membrane resistance and helping to significantly increase the dialysis efficiency ψJ.

The effectiveness of this hollow fiber membrane is significant not only for dialysis using dialysate but also for dialysis filtration (hemodiafiltration). 11 (plasmapheresis) and the like are also very effective.

Furthermore, in the hollow fiber membrane of the present invention, when the membrane thickness is reduced to increase the separation rate of body fluids, the membrane strength normally decreases, but due to the uniquely shaped protrusions, the shape retention is greater than expected. In addition, it is possible to reduce the outer membrane resistance, and as a result, the separation efficiency can be greatly improved.

Examples relating to the present invention will be described below in more detail, but the present invention is not limited to these Examples at all.

Example 1 and Comparative Example 1 Polyethylene glycol and diglycerin were added to cellulose/diaretate flakes, melt-spun, and these additives were extracted to produce cellulose/diacetate hollow fiber I19 with an inner diameter of 200 μm and a film thickness of 18 μm. did. Around it, there is a hollow fiber membrane (X) in which a single protrusion with a height and width of approximately 10 μm is arranged at a pitch of 5 cm, and a hollow fiber membrane in Stray 1 in which similar protrusions are provided parallel to the axis of the medium fibers. (Y) and
J: Sea urchins with the same membrane area were housed in a housing with the same large serrations, and the dialysis performance was measured in vitro. The results are shown in Table 1, and a particularly significant effect was observed in the clearance where the difference in concentration between the inside and outside of the membrane becomes the driving force.

/ l"7 r Small 6 \ Table 1 Example 2. and Comparative Example 2゜ Polyethylene glycol was added to cellulose diacede-1 flakes, melt-spun, the additives were extracted, and complexed with caustic soda. A hilulose hollow fiber membrane with an inner diameter of 200 μm and a membrane thickness of 13 μm was manufactured.A hollow fiber membrane (X) in which two protrusions each having a height and width of about 5 μm were wound around it at a pitch of 8 cm was manufactured. Stray 1~ hollow fiber membranes (Y) each having a protrusion with a length and width of about 5 μ in parallel to the hollow fiber axis are housed in a housing of the same size so that the membrane areas are the same,
Dialysis performance was measured in vitro. The results are shown in Table 2, and it was observed that the upper stomach had particularly remarkable urea clearance.

(Leaving space below) Procedural City Official Book February 74, 1985 1. To the Chief of the Temple Hospital 1. Indication of the incident Patent Application No. 58-217699 2. Name of the invention Hollow AI fibrous membrane and body fluid using the same. Processor 3, Relationship with the case of the person making the amendment Special feature n' This is the casing,” he corrected.

(2) In the second line from the bottom of page 5, "from most of the time" is corrected to "over most of the time."

(3) In the 7th line from the bottom of page 6, "Nozomasite." is corrected to "Nozomashi."

(4) On page 8, line 4, "spinning nozzle" is corrected to "1 spinning nozzle."

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Claims (2)

[Claims] (1) In a hollow fiber membrane made of a polymer compound and having substance selective permeability, a protrusion extending spirally at an angle in a certain direction with respect to the fiber axis on the outer surface of the hollow fiber membrane. A hollow fiber membrane characterized in that it contains at least one stone. (2) In a hollow fiber type body fluid treatment device equipped with a hollow fiber membrane made of a polymer compound and having substance selective permeability as a separation element, the hollow fiber membrane has an angle on its outer surface in a certain direction with respect to the fiber axis. 1. A body fluid treatment device characterized by having at least one spirally extending protrusion.