JP2005218947A - Cartridge filter for ion removal and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cartridge filter for ion removal capable of enhancing the efficiency of ion removal by increasing the effective surface area of ion exchange resin powder thereby exhibiting an ion exchange function to the utmost. <P>SOLUTION: The cartridge filter for ion removal is provided with a pleated type filter attached to the outer periphery of a core by folding at least two sheets of support material between which filter material is interposed. Therein, the ion exchange resin powder is adhered to the filter material of the filter while partially forming micro apertures due to the contraction of the powder on the interface with the binder. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cartridge filter provided with a pleated filter used for microfiltration of a liquid, and more particularly to an ion removal cartridge filter capable of removing ions in the liquid and a method for manufacturing the same.

In general, a cartridge filter provided with a pleated filter is used for liquid microfiltration. This type of cartridge filter is formed by incorporating a pleated filter body, which is attached to the outer periphery of a cylindrical core, in an outer cover provided with an end plate that is liquid-tightly sealed at the upper and lower ends. In the pleated filter, a filter medium made of a nonwoven fabric or a porous film is sandwiched between at least two support members, and the pleat filter body is folded in the longitudinal direction, rounded into a cylindrical shape, and arranged on the outer periphery of the core.
JP, 11-99307, A In addition, the cartridge filter which removes the ions in the liquid employs means for fixing the ion exchange resin powder to the constituent fibers of the filter medium with a binder. However, according to the prior art, since the ion exchange resin powder is not a little covered with the binder, the contact area with the treatment liquid (hereinafter referred to as effective surface area) tends to be extremely small. Therefore, the ion exchange function cannot be sufficiently exhibited, and it is difficult to improve the ion removal efficiency.

  An object of the present invention is to increase the effective surface area of the ion exchange resin powder, to maximize the ion exchange function, and to improve the ion removal efficiency.

  The cartridge filter for ion removal according to the first aspect of the present invention is a cartridge filter including a pleated filter body that is folded around a filter medium with at least two support members sandwiched between the support members, It is characterized in that the ion exchange resin powder is fixed to the filter medium of the filter body, and is adhered to the interface with the binder partially having a minute gap formed by the shrinkage of the powder.

  In addition, a method for manufacturing an ion removal cartridge filter according to a second aspect of the present invention includes an ion removal device including a pleated filter body that is folded around a filter medium with at least two support members sandwiched between the support members and is placed around the outer periphery of the core A method for producing a cartridge filter for a filter, wherein an ion exchange resin powder is fixed to a filter medium of the filter body with a binder, and then an active portion is formed so as to partially form a minute gap at an interface between the powder and the binder. It is characterized by performing the conversion process.

  In this invention, considering that a minute gap due to the shrinkage of the powder is partially formed at the interface between the ion exchange resin powder and the binder, the ion exchange resin powder is other than the H form, A configuration in which a carboxylic acid form weakly acidic cation exchange resin powder and / or an iminodiacetic acid form chelate resin powder, preferably in the Na form, is converted into an H form by acid treatment (mineral acid such as hydrochloric acid). Is preferred.

Further, the ion exchange resin powder is made into a weakly basic anion exchange resin powder whose ion form is other than OH form, preferably CO ₃ form or HCO ₃ form, and is made into OH form by alkali treatment (sodium hydroxide). This configuration is preferable because the time required for cleaning with pure water is greatly shortened.

  In consideration of the fact that the binder is fixed in part by point or line contact with the ion exchange resin powder, the ethylene resin or ethylene terpolymer of glycidyl methacrylate having an epoxy group is added to the polyethylene resin in a weight ratio of 5% to It is preferable to add 20%. If it is set as this structure, the chemical adhesive force of a binder can be improved by the crosslinking effect by an epoxy. If it is less than 5%, the effect tends to be difficult to produce in terms of improvement in chemical adhesion, and if it exceeds 20%, the organic solvent resistance of polyethylene tends to be lowered.

  When the cartridge filter for ion removal of the present invention is used, since the minute gap is partially present at the interface between the ion exchange resin powder and the binder, the effective surface area of the ion exchange resin powder is greatly increased. Therefore, the treatment liquid can be contacted at a portion other than the exposed portion of the ion exchange resin powder, the ion exchange function of the ion exchange resin powder is sufficiently exhibited, and the ion removal efficiency can be improved.

  In addition, according to the method for producing an ion removing cartridge filter of the present invention, a minute gap can be partially formed at the interface between the ion exchange resin powder fixed to the filter medium and the binder. Therefore, the effective surface area of the ion exchange resin powder is increased, and a cartridge filter with improved ion removal efficiency can be easily manufactured.

  By the way, the volume of the ion exchange resin changes depending on the type of the counter ion when activated. For example, in the case of a weakly acidic cation exchange resin, when the Na form is changed to the H form, about 10% to 50% of the original volume is contracted. On the other hand, the volume of the binder that fixes the powder does not change. For this reason, fine gaps are partially formed at the interface between the powder and the binder. Here, the fact that the fine gaps are scattered means that the ion-exchange resin powder is fixed to the binder at the minimum necessary contact points, and there are gaps at all the interfaces between the powder and the binder. Does not mean that

  In the present invention, the ion-exchange resin powder is obtained by pulverizing a commercially available ion-exchange resin to a size that can be uniformly fixed to the filter medium of the cartridge filter by an impact pulverizer, a jet mill, a pot mill, or the like. As the size thereof, an average particle diameter of 1 μm to 50 μm, preferably 5 μm to 30 μm is suitable.

  As the filter medium, a non-woven fabric or a porous membrane to which a binder for fixing ion-exchange resin powder can be bonded can be used. Specifically, for example, PP, PE, PTFE, PES (polyethersulfone), cellulose Acetate or the like can be used.

  The pore diameter of the filter medium is 1 μm to 100 μm, preferably 3 μm to 50 μm, and more preferably 5 μm to 20 μm. If it is less than 1 μm, the initial pressure loss due to the fixation of the ion exchange resin powder becomes too large, which is unsuitable for practical use. On the other hand, when the thickness exceeds 100 μm, the treatment liquid tends to flow without contacting the ion exchange resin powder, and the ion removal efficiency tends to decrease.

  The binder for fixing the ion-exchange resin powder may be any binder that can adhere to the filter medium. Among thermoplastic resins, ethylene resins (ethylene-butene copolymer, ethylene-hexene copolymer) may be used. , Ethylene / acrylic acid ester / maleic anhydride terpolymer, ethylene / glycidyl methacrylate copolymer, ethylene / glycidyl methacrylate terpolymer), polypropylene resin, fluorine resin, polyester resin, styrene resin {styrene / ethylene / butylene・ Styrene block copolymer (SEBS), styrene / butadiene / styrene block copolymer (SBS), styrene / butadiene / butylene / styrene (SBBS)}, urethane resin, silicone resin (deoxime type, dealcohol type and addition) Thailand ) Are preferred, may be used in a state in which either individually or in combination of two or more as necessary. When these binders are attached to a filter medium and processed, when the organic solvent evaporates, a large number of micropores are formed in the binder along with the evaporation. Therefore, the treatment liquid can freely come into contact with the ion exchange resin through these fine holes, and the ion exchange reaction can be performed more efficiently.

  Among these, a polyethylene resin is preferable in consideration of the olefin resin system, especially the flexibility of the filter medium, organic solvent resistance, economy, and workability.

  This is because polar solvents used in washing processes and organic solvents such as dilution of raw materials for electronics industry, such as NMP (N-methyl 2-pyrrolidone), MEA (monoethanolamine), hydrofluoroether (manufactured by Sumitomo 3M) ), PGMEA (propylene glycol monomethyl ether acetate), and GBL (γ-butyrolactone) hardly exhibit physical changes such as dissolution and swelling, and can exhibit stable performance.

  By the way, as shown in FIG. 1, the cartridge filter of the present invention has a minute gap 3 partially at the interface between the ion exchange resin powder 1 and the binder 2, and the ion exchange resin powder and the binder resin. It is fixed only at a plurality of adhesion points 4.

  For this reason, depending on the use conditions, the ion-exchange resin powder may easily flow out due to the fluid pressure caused by the flow rate. Considering this point, it is preferable to improve the chemical adhesive force by adding 5% to 20% by weight of ethylene copolymer or ethylene terpolymer of glycidyl methacrylate having an epoxy group to the polyethylene resin.

  As a means for fixing the ion exchange resin powder to the filter medium, any method such as a spraying method, an impregnation method, and a coating method may be used. The filter medium to which the ion exchange resin powder is fixed by these methods is pleated into a pleat shape, and is attached to the outer periphery of a cylindrical core to form a filter body. Can be manufactured.

  Further, the binder liquid in which the ion-exchange resin powder is dispersed can be fixed to the filter medium by sucking the preliminarily molded cartridge filter from the inflow side to the outflow side.

In Examples 1-5 and Comparative Example 1 below, the filter medium is a cartridge filter having an outer peripheral cover diameter of 55 mm and a cylinder height of 65 mm (filtration accuracy 10 μm, filter medium width 6 cm, pleat width 10 mm, number of peaks 75, filter medium area 900 cm ^2. ) PP non-woven fabric.

  As a representative of the weak acid cation exchange resin, a weak acid cation exchange resin (ionic Na + form) having carboxylic acid as an exchange group was pulverized by a mechanical pulverizer to obtain a powder having an average particle size of 22 μm. 7.0 g of this powder was uniformly attached to a PP filter medium using a xylene-diluted solution of an olefin binder, and the organic solvent was evaporated and fixed by drying. Thereafter, the cartridge was immersed in a sufficient amount of 1N (normal) hydrochloric acid solution, sufficiently passed to convert it into H groups, thoroughly washed with pure water, and then dried.

Iminodisuccinic acid type chelate resin (ionic form NH ⁴ +) was pulverized by a mechanical pulverizer to obtain a powder having an average particle diameter of 18 μm. In the same manner as in Example 1, 7.0 g of this powder was uniformly attached to a PP filter medium using a xylene-diluted solution of an olefin binder, and the organic solvent was evaporated and fixed by drying. Thereafter, the cartridge was immersed in a sufficient amount of 1N (normal) hydrochloric acid solution, sufficiently passed to convert it into H groups, thoroughly washed with pure water, and then dried.

  A basic anion exchange resin (ionic form Cl-) in polyamine was pulverized by a mechanical pulverizer to obtain a powder having an average particle diameter of 20 μm. In the same manner as in Example 1, 7.0 g of this powder was uniformly attached to a PP filter medium using a xylene-diluted solution of an olefin binder, and the organic solvent was evaporated and fixed by drying. Thereafter, the cartridge was immersed in a sufficient amount of 1N (normal) sodium hydroxide solution, sufficiently passed through to convert it into OH groups, thoroughly washed with pure water, and then dried. Here, the term “basic basic” means that the basic strength is weak, and is medium when divided into medium and strong.

A basic anion exchange resin (ionic form Cl-) in polyamine is immersed in a 5% sodium hydrogen carbonate solution to convert the ionic form to HCO _3- , and then pulverized by a mechanical pulverizer, with an average particle size of 20 μm. A powder was obtained. In the same manner as in Example 1, 7.0 g of this powder was uniformly attached to a PP filter medium using a xylene-diluted solution of an olefin binder, and the organic solvent was evaporated and fixed by drying. Thereafter, the cartridge was immersed in a sufficient amount of 1N (normal) sodium hydroxide solution, sufficiently passed through to convert it into OH groups, thoroughly washed with pure water, and then dried.

The iminodi-type chelate resin (ionic form NH ⁴ +) was pulverized by a mechanical pulverizer to obtain a powder having an average particle size of 22 μm. In the same manner as in Example 1, 7.0 g of the powder was uniformly attached to a PP filter medium using a xylene-diluted solution of SEBS binder, and the organic solvent was evaporated and fixed by drying. Thereafter, the cartridge was immersed in a sufficient amount of 1N (normal) hydrochloric acid solution, sufficiently passed to convert it into H groups, thoroughly washed with pure water, and then dried.
(Comparative Example 1)

  A basic anion exchange resin (ionic form Cl-) in polyamine is regenerated into an OH form with 1N (normal) sodium hydroxide solution and pulverized with a mechanical pulverizer to obtain a powder having an average particle size of 20 μm. Obtained. In the same manner as in Example 1, 7.0 g of this powder was uniformly attached to a PP filter medium using a xylene-diluted solution of an olefin binder, and the organic solvent was evaporated and fixed by drying.

  Using the anion exchange resin-fixed cartridge filters obtained in Examples 3 and 4 and Comparative Example 1, a comparative test of chlorine ion removal performance was performed by the following method.

  After each cartridge filter is immersed in isopropyl alcohol, it is replaced with pure water, and the filter medium is sufficiently wetted. Then, 0.01 mol / L hydrochloric acid is passed to 1 L at a rate of 100 mol / min. The filtrate was sampled. The sampled solution was subjected to neutralization titration to quantify the exchanged chloride ions. The result is shown in FIG.

  As is clear from the results of FIG. 2, it was confirmed that the ion removal efficiency of the example was significantly improved as compared with the comparative example.

It is a schematic sectional drawing which shows the adhering state of ion exchange resin powder. It is comparative explanatory drawing of the ion removal efficiency of an Example and a comparative example.

Explanation of symbols

1 Ion exchange resin powder 2 Binder 3 Small gap 4 Adhesion between ion exchange resin powder and binder

Claims (5)

A cartridge filter provided with a pleated filter body having a filter medium sandwiched between at least two support materials and folded around the core, and an ion exchange resin powder is bonded to the filter medium of the filter medium. A cartridge filter for removing ions, characterized in that it has a small gap partially formed by shrinkage of the powder, and is fixed to the interface. A method of manufacturing a cartridge filter for ion removal comprising a pleated filter body having a filter medium sandwiched between at least two support media and folded around the outer periphery of the core, wherein the filter medium is subjected to ion exchange A method for producing a cartridge filter for ion removal, characterized in that after the resin powder is fixed with a binder, an activation treatment is performed so as to partially form a minute gap at the interface between the powder and the binder. . The ion exchange resin powder is a weakly acidic cation exchange resin powder and / or an iminodiacetic acid type chelate resin powder and an ion form other than the H form, and the ion form is converted to H by acid treatment after fixing the binder. The manufacturing method of the cartridge filter for ion removal of Claim 2 made into a shape. 2. The method for producing a cartridge filter for ion removal according to claim 1, wherein the ion exchange resin powder is a weakly basic anion exchange resin powder and is in an ionic form other than the OH form, and is converted into an OH form by alkali treatment. . The production of a cartridge filter for ion removal according to claim 2, wherein the binder is a polyethylene resin, and an ethylene copolymer or ethylene terpolymer of glycidyl methacrylate having an epoxy group is added by 5 to 20% by weight. Method.

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