JP2010260027A - Terminal end structure for module element and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To create an element having no tube removal without passing through high-temperature heating treatment near PTFE having the fear of contraction of a PTFE porous tube and without requiring complicated work and being excellent in mechanical stability and chemical stability. <P>SOLUTION: In the terminal of the element for the module constituted by bundling a plurality of PTFE porous tubes 1, the terminal structure of the element A for the module forms a constitution that the whole of plurality of the PTFE porous tubes 1 is covered by a fluorinated polyether elastomer layer 3 for and is integrated by burying the PTFE porous tube 1 in a thick void part by the fluorinated polyether elastomer 3 and adhering the independent PTFE porous tubes 1 to each other by the fluorinated polyether elastomer 3 interposed on its outer peripheral part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an element used in a module used for gas-liquid contact or gas-liquid filtration in a gas-liquid contact device or a gas-liquid filtration device, and a plurality of polytetrafluoros constituting the module The present invention relates to a terminal structure of a module element in an element formed by bundling ethylene (hereinafter referred to as “PTFE”) porous tubes and a method for manufacturing the same.

  As the above-mentioned element, for example, an element composed of a PTFE porous tube used in a module of a gas adsorption device such as an ozone gas dissolving module of a high purity ozone water production apparatus or carbon dioxide gas, inside and outside the PTFE porous tube An element comprising a PTFE porous membrane and a PTFE porous tube used in a module of a high-purity chemical liquid filtration device that separates gas and liquid, and filtration of particle removal by the PTFE porous membrane inside and outside the PTFE porous tube There are elements that perform the action.

  The following patent document 1 introduces that PTFE forms an excellent porous film. Moreover, PTFE is known as a non-adhesive and releasable material because it belongs to the side with the smallest surface energy among solid substances. Therefore, special measures are required to integrate PTFE with other materials. That is, an adhesive for holding PTFE mechanically and fixing it secretly is necessary. Conventionally, it has been attempted to bond with a hydrocarbon resin such as polyethylene, but it cannot be bonded. Therefore, perfluorocarbon-based hot-melt resins have been used. For that purpose, a great effort and process have been required. As an example of the device, and as a specific application example of Patent Document 1, gas is brought into contact with water through a PTFE porous membrane as a device for dissolving ozone gas in water for the production of ozone water used in a semiconductor manufacturing process. An element in which a plurality of PTFE porous tubes that dissolve gas is bundled is introduced in Patent Document 2 below, and means for bundling PTFE porous tubes is introduced.

  According to Patent Document 2, a PTFE porous tube is covered with a tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter referred to as “FEP”) tube or an FEP film is wound and bundled to heat and melt the FEP. And how to integrate them. As another method, a PTFE plate with a drill or the like is used to provide a through hole slightly larger than the outer diameter of the PTFE porous tube, and a heat-melt type fluororesin is interposed between the through hole and the outer surface of the PTFE porous tube. A method of fusing and integrating the resin is introduced. Further, a tetrafluoroethylene-fluoroalkyl vinyl ether copolymer (hereinafter referred to as “PFA”) is similarly treated. The reason why FEP or PFA is used is that, in terms of surface energy, it has an adhesive fusion action with the surface of the PTFE porous tube as a heat-meltable resin.

JP 51-30277 JP 2001-314733 A

  However, the melting point of FEP is about 270 ° C., and the melting point of PFA is about 300 ° C. When making an element, these heat-melting fluororesins are sufficiently melted and practically fused and integrated with the PTFE porous tube. In order to achieve this, the substantial melting temperature must be heated at about 30 ° C. higher than the melting point of each, and since these temperatures are close to the melting point of PTFE, thermal contraction of the PTFE porous tube occurs. In order to prevent this heat shrinkage, a special device for heating only the terminal portion of the element without increasing the temperature of the entire PTFE porous tube is necessary.

  In addition, the hot-melt type fluororesin interposed outside the PTFE porous tube has a high melt viscosity, and can be effectively bonded to the concave portion on the surface portion of the thick pore portion constituting the porous PTFE tube. Since it does not fill the entire part, it does not enter into the thick pores of the PTFE porous tube at the time of melting, and is only in a close contact state along the irregularities of the outer wall surface. There was a problem that occurred.

  Furthermore, although it has been shown that an FEP tube is covered or a FEP film is wound as a method of interposing a heat-melt type fluororesin on the outside of the PTFE porous tube, it requires a complicated operation. In other words, in order to cover the FEP tube, it is necessary that the FEP tube fits exactly on the outer diameter of the PTFE porous tube. Otherwise, the fitted tube may fall off. Further, in the method of winding the FEP film, the FEP film is very easily charged, so that the films repel each other and it is difficult to stop the winding start portion and winding end portion of the FEP film.

  Further, there is a method in which a PTFE porous sheet is sandwiched between PFA meshes to form a cylinder, or in order to enlarge the area of the cylinder, the element is formed by folding (also referred to as pleats). In this case, the PTFE porous sheet is formed into a cylindrical shape by sandwiching it with a PFA mesh, and the connecting portion is easily sealed with a heat sealant (a kind of pressure welding device used for binding a plastic film bag). However, even when the both ends of the cylindrical portion are integrated as an element, especially when chemical resistance and heat resistance are required, the end portion of the element without increasing the temperature of the entire PTFE porous membrane as in the PTFE porous tube described above Only a special device was needed to heat only.

  Further, the PTFE porous tube is characterized by being very soft, weak in the waist, and easily deformed by an external force, although it varies somewhat depending on the tube diameter and wall thickness (A). In addition, if the liquid component can penetrate from inside and outside of the PTFE porous tube, gas components such as air in the center of the wall thickness cannot be completely removed, and sufficient filling of the liquid component may not occur easily. It is necessary to allow the liquid component to enter from either the inner diameter side or the outer diameter side of the tube (B).

  The present invention provides means for solving the above-mentioned problems (A) and (B). That is, in the present invention, in order to improve the self-supporting property of the PTFE porous tube and prevent the liquid fluorinated polyether elastomer component from entering, a glass, metal, or plastic shaft is inserted into the porous tube to form a liquid fluorine. It proposes a method for producing an element obtained by casting a molded polyether elastomer component and removing the shaft after curing (thermal effect treatment).

  The present invention is superior in mechanical stability and chemical stability without tube removal without requiring high-temperature heat treatment in the vicinity of the PTFE melting point, which may cause shrinkage of the PTFE porous tube, and without requiring complicated work. To create a new element.

  Therefore, the inventor of the present invention uses an elastomer component (that is, a fluorinated polyether elastomer) composed of an addition reaction type fluorinated polyether skeleton and a terminal silicone cross-linking reactive group, which is in a liquid state before curing, to provide a PTFE porous tube. The present inventors have found that a thick porous portion is impregnated with a fluorinated polyether elastomer, and that a plurality of PTFE porous tubes are integrated with the fluorinated polyether elastomer, leading to the present invention.

  The terminal structure of the module element according to the present invention is a module element terminal formed by bundling a plurality of PTFE porous tubes, and the PTFE porous tube has a thick pore portion in a fluorinated polyether elastomer. The individual PTFE porous tubes are bonded to each other by a fluorinated polyether elastomer interposed on the outer periphery thereof, so that the entire PTFE porous tube is covered with a fluorinated polyether elastomer layer. And an integrated configuration. In addition, you may comprise so that the PTFE porous sheet which bundles a plurality of PTFE porous tubes may interpose in a fluorinated polyether elastomer layer.

  The module element end structure manufacturing method according to the present invention includes a glass, metal or plastic shaft inserted into a plurality of PTFE porous tubes and bundled together to form a liquid fluorinated polyether elastomer. Is poured into a mold and heat-cured by an addition reaction in a state where the ends of the plurality of PTFE porous tubes after inserting the shaft are immersed in a liquid fluorinated polyether elastomer, thereby obtaining a liquid fluorinated polyether. After the elastomer is thermally cured to integrate the end portions of the plurality of PTFE porous tubes, the end portions of the plurality of PTFE porous tubes are released from the mold, and the shafts are removed from the plurality of PTFE porous tubes. It is characterized by extracting and manufacturing. The PTFE porous sheet may be wound around a plurality of PTFE porous tubes and bundled before being immersed in the liquid fluorinated polyether elastomer.

  By means of the above means, a PTFE porous tube is constituted by an element that acts via a PTFE porous membrane in a module that performs gas-liquid contact and gas-liquid filtration, that is, a PTFE porous membrane. Creation of bundled elements can be facilitated. Therefore, the elements in the ozone gas dissolution module in the high purity ozone water production device, the gas adsorption device module such as carbon dioxide gas, the module in the high purity chemical liquid filtration device, etc. need to be replaced over time, and the workability is good and the cost is low. There are advantages.

FIG. 3 is a partially omitted perspective view of an element. FIG. 2 is a schematic end view taken along line II-II in FIG. 1. FIG. 3 is a schematic end view taken along line III-III in FIG. 2. It is a partially omitted perspective view of a PTFE porous tube and a shaft. It is a partially-omission perspective view showing the work-in-process in the state where the PTFE porous tube with the shaft inserted is bundled. FIG. 6 is a partially omitted vertical end view of FIG. 5. FIG. 6 is a partially omitted vertical end view showing a state in which the work-in-process shown in FIG. 5 is put into a casting frame.

  The thick pores of the tube constituting the terminal PTFE porous tube in which a plurality of PTFE porous tubes are bundled are filled with the fluorinated polyether elastomer and integrated with the fluorinated polyether elastomer constituting the outer periphery. In the element, the PTFE porous tube is preferably an expanded PTFE porous tube in which the structure of the thick portion of the tube wall is composed of nodes and fibrils, and the fibrils constitute the pores.

  Further, it is also preferable that an unsintered expanded PTFE membrane is arbitrarily wound around a metal shaft, and in this state, a PTFE porous tube is prepared by heating and melting to a temperature equal to or higher than the melting point of PTFE.

The density of the solid state in which the pore portion of PTFE does not exist is 2.1 g / cm ^3, and the ratio of the apparent density calculated from the weight and volume of the PTFE porous tube is displayed as the porosity. .

  The porosity of the PTFE porous tube used in the present invention or the pore diameter and the tube diameter or the wall thickness of the tube wall is not particularly limited, and whether or not the elastomer component penetrates into the thick pore portion, One may be selected depending on the mechanical strength depending on the application.

  The elastomer used in the present invention has important chemical properties that are not inferior to PTFE. Further, it is important that the elastomer component is impregnated into the thick pores of the PTFE porous tube. From these points, a solvent-soluble elastomer or an elastomer that generates a gas component in the crosslinking reaction is not preferable. The reason for this is that the thick pores are not completely filled, the end portions are not completely sealed, and the dimensional stability before and after curing is lacking. From these points, an elastomer component composed of an addition reaction type fluorinated polyether skeleton and a terminal silicone cross-linking reactive group, which are liquid before curing and the catalyst is platinum, is preferably selected. A preferred fluorinated polyether elastomer component is commercially available under the trade name “SIFEL” manufactured by Shin-Etsu Chemical Co., Ltd.

  In the creation of the element, standing the PTFE porous tube bundled in the frame (pot, cup) into which the liquid component is poured, pouring the liquid component, performing a crosslinking reaction, and then removing from the frame, one end of the terminal is completed, Subsequently, both terminals are completed in the same manner at the other end to form an element.

  In this method, in the case of a metal wire coated with porous PTFE, for example, a copper wire, an element is created by arbitrarily cutting it, bundling a plurality of wires, performing terminal processing in the same manner as the present invention, and finally removing the metal wire. it can.

  Further, the present invention is naturally applicable to both end processing in which a PTFE porous sheet is sandwiched between PFA meshes to form a cylindrical shape, or an element is formed by folding in order to enlarge the area of the cylindrical portion.

  Further, the PTFE porous sheet becomes a suitable material for both ends of the element as a winding material for bundling the PTFE porous tube, and the amount of economically expensive fluorinated polyether elastomer material is reduced.

  Similarly, a chemically stable fluorine-based resin powder such as PTFE may be mixed as an extender of the fluorinated polyether elastomer, thereby reducing the cost.

  1 to 3, A represents a completed element, 1 represents seven PTFE porous tubes constituting element A, and 2 represents a PTFE porous sheet wound when the seven PTFE porous tubes 1 are bundled together. Reference numeral 3 denotes a fluorinated polyether elastomer layer for bundling seven PTFE porous tubes 1 at both ends of the element A and fixing them in a secret manner. Hereinafter, based on FIGS. 4-7, the manufacturing method of the element A is shown.

  Seven PTFE porous tubes 1 and stainless shafts 10 shown in FIG. 4 are prepared. The PTFE porous tube 1 is formed by extending in the longitudinal direction of the tube, and has an inner diameter of 6 mm, an outer diameter of 7.5 mm, a length of 600 mm, and a porosity of 80%. The stainless steel shaft 10 has an outer diameter of 6 mm and a length of 650 mm. Then, as shown in FIGS. 5 and 6, a stainless steel shaft 10 is inserted and bundled in each of the PTFE porous tubes 1, and the ends are aligned, and a position of 100 mm from both ends and a central portion are bound (not shown). ), The PTFE porous sheet 3 cut into a ribbon shape with a width of 40 mm from both ends is wound four times to produce an in-process product A ′ of the element A. At this time, the central PTFE porous tube 1 ′ is configured such that the stainless shaft 10 ′ protrudes downward. The PTFE porous sheet 3 uses “Fluoropore Membrane FP-500” manufactured by Sumitomo Electric Fine Polymer Co., Ltd.

  Next, as shown in FIG. 7, one end of the work-in-process A ′ is put into the casting frame 11. The casting frame 11 has a bowl shape in which carbon steel is chrome-plated, and has an upper inner diameter of 30 mm, a depth of 50 mm, and a bottom inner diameter of 28 mm. The center stainless steel shaft 10 'constituting the work-in-process A' is inserted to make the semi-finished product A 'self-supporting. Thereafter, the liquid fluorinated polyether elastomer component 3 ′ is injected so as not to overflow into the casting frame 11. As the liquid fluorinated polyether elastomer component 3 ', trade name "SIFEL 3155" manufactured by Shin-Etsu Chemical Co., Ltd. is used. Since the fluorinated polyether elastomer component 3 'penetrates into the porous pores of the PTFE porous material, the amount of the liquid is reduced accordingly, so that the reduced amount is added at any time and the liquid level is increased to 45 mm from the bottom. maintain. In this state, the PTFE porous tube was placed in a thermostatic bath at 150 ° C. for 2 hours, and the liquid fluorinated polyether elastomer component 3 ′ was cured, cured, returned to room temperature, and solidified integrally with the fluorinated polyether elastomer. 1 is released from the casting frame 11. If the other end of the PTFE porous tube 1 is solidified integrally with the fluorinated polyether elastomer through the same process as described above, and finally the stainless steel shaft 10 is extracted from each PTFE porous tube 1, FIG. ˜Element A shown in FIG. 3 is completed. In the element A, the thick pores of the PTFE porous tube 1 are filled with the fluorinated polyether elastomer at both ends. Moreover, each PTFE porous tube 1 is mutually adhere | attached and integrated by the fluorinated polyether elastomer interposed in the outer peripheral part. When the element A was cut at 10 mm from both ends and inspected, the thick part of the PTFE porous tube and the thick part of the PTFE porous sheet were impregnated with the fluorinated polyether elastomer component, and the PTFE porous Confirmed that the tubes were secretly united.

  Instead of the liquid fluorinated polyether elastomer component 3 ′ in Example 1, 30% by weight PTFE fine granulated particles (manufactured by Daikin Industries, Ltd.) are used as the liquid fluorinated polyether elastomer component and the filler. “Polyfluorocarbon molding powder M-139”) is mixed and degassed with a vacuum of 700 mm mercury under vacuum. Otherwise, the elements were prepared in the same manner as in Example 1. As a result of inspecting the cross section of the element prepared in Example 2, only the liquid component of the fluorinated polyether elastomer penetrates into the thick pores of the PTFE porous tube, and the PTFE fine granulated particles are in the PTFE porous tube. It remained in the outer periphery, and had the effect of reducing the amount of fluorinated polyether elastomer component used.

  The element of this invention can be used conveniently for the use of a gas-liquid contact apparatus, a deaeration apparatus, a bubble generator, a gas, and a liquid filtration apparatus.

A …… Element A ′ …… Work in progress of the element 1, 1 ′ …… PTFE porous tube 2 …… PTFE porous sheet 3 …… Fluorinated polyether elastomer layer 3 ′ …… Liquid fluorinated polyether elastomer component 10, 10 '... Stainless steel shaft 11 ... Cast frame 11' ... Recess of cast frame

Claims (4)

  In the terminal of the module element configured by bundling a plurality of polytetrafluoroethylene porous tubes, the polytetrafluoroethylene porous tube has a thick pore filled with a fluorinated polyether elastomer, and The individual polytetrafluoroethylene porous tubes are bonded to each other by a fluorinated polyether elastomer interposed on the outer periphery thereof, so that the entire polytetrafluoroethylene porous tube is covered with a fluorinated polyether elastomer layer. The terminal structure of a module element, characterized in that it has a unified structure.   The terminal structure of a module element according to claim 1, wherein a polytetrafluoroethylene porous sheet for bundling a plurality of polytetrafluoroethylene porous tubes is interposed in the fluorinated polyether elastomer layer. Insert a glass, metal or plastic shaft into a plurality of polytetrafluoroethylene porous tubes and bundle them,
A liquid fluorinated polyether elastomer is poured into a mold, and the end of the plurality of polytetrafluoroethylene porous tubes after inserting the shaft is immersed in the liquid fluorinated polyether elastomer and heat-cured by an addition reaction. After the treatment, the liquid fluorinated polyether elastomer is thermally cured to integrate the ends of the plurality of polytetrafluoroethylene porous tubes, and then the ends of the plurality of polytetrafluoroethylene porous tubes are A method for producing an element end structure for a module, which is produced by releasing from a mold and extracting a shaft from a plurality of polytetrafluoroethylene porous tubes.   4. The module element end according to claim 3, wherein the polytetrafluoroethylene porous sheet is wound and bundled around a plurality of polytetrafluoroethylene porous tubes before being immersed in the liquid fluorinated polyether elastomer. 5. Method for manufacturing substructure.

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