Cartridge filter for removing ion and manufacturing method therefor

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

Generally, a cartridge filter provided with a pleated type filter is used for microfiltration of liquid. This type of cartridge filter is formed by incorporating a pleated filter body that circumvents the outer circumference of a cylindrical core in an outer peripheral cover having a liquid-tightly sealed end plate at the upper and lower ends. In the pleated filter, a filter medium made of a non-woven fabric or a porous film is sandwiched between at least two support materials, folds in the length direction, rolled into a cylindrical shape, and arranged on the outer periphery of the core.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 11-99307 Further, as a filter for removing ions in a liquid, a means for fixing an ion trapping powder to a filter medium with a binder is adopted. However, according to the prior art, the surface of the ion-capturing powder adheres to the binder and is not a little coated, so that the contact area with the liquid (hereinafter referred to as the effective surface area) tends to be extremely small. Therefore, the ion trapping function could not be sufficiently exerted, and it was difficult to improve the ion removal efficiency.</text></patcit>

<p> An object of the present invention is to provide a cartridge filter for ion removal and a method for manufacturing the same, which can increase the effective surface area of the ion trapping powder to maximize the ion trapping function and improve the ion removal efficiency. To do.</p>

<p> The ion removing cartridge filter according to the first invention is a cartridge filter provided with a pleated filter body having a filter medium sandwiched between at least two support materials, folded and wrapped around the outer periphery of the core. It is characterized in that the ion trapping powder is fixed to the filter medium of the filter medium by a binder having a substantially mesh-like continuous fine recess structure in the coated portion of the powder.</p><p> Further, in the method for manufacturing an ion removing cartridge fitter, which is the second invention, in the manufacturing process of the ion removing cartridge filter, a primary binder having no water resistance is adhered to the surface of the ion trapping powder in the form of particles to granulate. The first step of forming the ion trapping powder, the second step of fixing the granulated ion trapping powder to the filter medium before molding the filter medium or the filter medium after molding the filter medium with a secondary binder having water resistance, It is characterized by including a third step of dissolving the primary binder.</p>

<p> In the case of the ion removing cartridge filter of the first invention, since the binder to which the ion trapping powder is fixed has a substantially mesh-like continuous fine recess structure in the coating portion with the powder, the liquid captures ions. It becomes possible to contact the coated portion of the powder, and the effective surface area of the ion-capturing powder is greatly increased. Therefore, the ion trapping function of the ion trapping powder is fully exhibited, and the ion removing efficiency can be improved.</p><p> Further, when the method for producing an ion removing cartridge filter of the second invention is used, ion trapping powder is applied to at least a part of the fiber surface and the fiber entanglement portion of the filter medium, and particulate primary is applied to the coating portion of the powder. It is possible to easily manufacture an ion removing cartridge filter fixed with a secondary binder in which a substantially mesh-like continuous fine concave structure is formed by dissolving the binder.</p><p> In the present invention, the ion-capturing powder means a powder having a function of capturing ions in a liquid. Specifically, ion exchange resin, activated carbon, artificial zeolite, photocatalyst, chelate resin, charged substance, organic adsorbent, inorganic adsorbent, etc. are crushed to 100 μm or less by an impact type crusher, jet mill, pot mill, etc. Yes, preferably the powder has an average particle size in the range of 1 μm to 50 μm, more preferably 5 μm to 30 μm.</p><p> The material of the filter medium may be any material to which a secondary binder can be adhered, and for example, a non-woven fabric such as PP, PE, PTFE, PES (polyethersulfon), cellulose acetate, or a porous membrane can be used.</p><p> The pore diameter of the filter medium is preferably in the range of 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 adhesion of the ion trapping powder becomes too large, which is not suitable for practical use. On the other hand, if it exceeds 100 μm, the treatment liquid tends to flow easily without coming into contact with the ion trapping powder, and the ion removal efficiency tends to decrease.</p><p> As the primary binder having no water resistance, a binder that can be spray-sprayed with a sprayer, can be fixed to the filter medium without being dissolved in the secondary binder solution, and can be dissolved and removed by post-treatment is used. Specifically, synthetic polymers such as polyvinyl alcohol and sodium polyacrylate are suitable.</p><p> The secondary binder having water resistance may be one that can be adhered to the filter medium to be used without being dissolved in the third step of dissolving the primary binder. Among the thermoplastic resins, ethylene-based resins (ethylene, Butene copolymer, ethylene / hexene copolymer, ethylene / acrylic acid ester / maleic anhydride ternary copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / glycidyl methacrylateer polymer), 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, silicon Resins (deoxidized type, dealcoholic type and addition type) are preferable, and if necessary, they may be used alone or in a state where two or more kinds are mixed. Among these, it is particularly preferable to use an olefin resin type, and particularly a polyethylene resin. This is because the filter medium has excellent flexibility, and organic solvents such as polar solvents used in cleaning processes and dilution of raw materials for the electronic industry, such as NMP (N-methyl-2pyrrolidone) and MEA (monoethanolamine), Even if hydrofluoroether (manufactured by Sumitomo 3M), PGMEA (propylene glycol monomethyl ether acetate), and GBL (γ-butyrolactone) are used, there is almost no physical change such as dissolution or swelling, and stable performance can be exhibited. Because.</p><p> The ion removal cartridge filter according to the present invention can be manufactured by the following method.</p><p> First, the ion-capturing powder 1 pulverized to a predetermined average particle size is placed in, for example, a bread container of a tilt-type bread granulator, and the primary binder is sprayed with a sprayer while tilting and rotating to stir for a predetermined time. Then, by removing water by a drying treatment, the granulated ion-capturing powder A (hereinafter referred to as granulated ion-capturing powder A) adhered to the surface of the ion-capturing powder 1 in a continuous state in which at least a part of the particulate primary binders are in contact with each other. (Simply called granulated powder) is produced (Fig. 1).</p><p> In this case, the coverage of the primary binder is preferably in the range of 30 to 70% of the surface of the ion trapping powder. This is because if it is less than 30%, the ion removal efficiency tends to decrease, and if it exceeds 70%, the adhesive force between the ion trapping powder and the filter medium tends to be weakened and the ion trapping powder tends to fall off easily.</p><p> Next, the granulated powder A is mixed with the secondary binder 3 dissolved in a solvent in which the primary binder does not dissolve, and by any method appropriately selected from a spray spraying method, an impregnation method, a coating method and the like. , Adheres to at least a part of the fiber surface and fiber entanglement part of the filter medium, and is dried. Then, the filter medium is washed with a solvent that dissolves the primary binder. Therefore, the particulate primary binder 2 adhering to the surface of the granulated powder A is dissolved and removed, and the secondary binder 3 forms a substantially mesh-like continuous fine recess structure 4 in the coating portion of the ion trapping powder 1. (Fig. 2).</p><p> Then, using the filter medium processed through the above steps, the filter medium was sandwiched between at least two support members, fold-folded to a predetermined width, rolled into a cylindrical shape on the outer circumference of the core, and wound around the core to prepare a filter body. Later, the desired cartridge filter can be manufactured by incorporating the filter body into the outer peripheral cover.</p><p> By the way, in the above step, the granulated powder was fixed to the filter medium, but by sucking and filtering the secondary binder mixed with the granulated powder from the inflow side of the cartridge filter molded in advance, the filter medium of the filter body was formed. It can also be stuck.</p>

Hereinafter, examples of the present invention will be described.

Sulfonic acid type strong acid cation exchange resin (registered trademark "Diaion" SK1BH manufactured by Mitsubishi Chemical Co., Ltd.) is crushed with a crusher (trade name "Bantum Mill" model AP-B manufactured by Hosokawa Micron Co., Ltd.), and average grains are obtained. A powder having a diameter of 30 μm was obtained. This powder is placed in a tilted pan-type granulator, and while rotating the pan, a 1% polyvinyl alcohol aqueous solution (primary binder) is sprayed with a sprayer to prepare granulated ion exchange resin powder adhering to particles. did. The coverage of the primary binder was 50% of the surface area of the ion exchange resin powder.

Next, in a container in which granulated ion exchange resin powder is dispersed in toluene, a cartridge filter (diameter 70 mm, height 282 mm, filter medium pleats width 10 mm, number of ridges 125, filtration area 5400 cm)²) Was immersed, and suction and liquid flow were performed in the normal filtration direction to uniformly adhere the granulated ion exchange resin powder (adhesion amount 40 g / piece) to the filter medium of the filter body.

Subsequently, the cartridge filter is immersed in a 10 wt% ethylene-based binder solution (secondary binder), and then the filter medium of the filter medium is uniformly impregnated with the binder solution by suction and liquid passing treatment, and then at 60 ° C. 8 The solvent (toluene) was evaporated by hot air drying treatment for a long time, and the adhesion amount was 27 g / piece.

Further, after wetting the filter medium of the filter body of the cartridge filter with isopill alcohol, pure water is passed through the filter medium to dissolve and remove the particulate polyvinyl alcohol (primary binder) adhering to the granulated ion exchange resin powder. , Hot air drying treatment was performed to dry the washing water to prepare a desired ion removal cartridge filter.

Using the granulated ion exchange resin powder prepared in Example 1 and an ethylene-based binder (secondary binder), the mixing weight ratio was set to 150 parts of the granulated ion exchange resin powder and 100 parts of the ethylene-based binder (secondary binder). A xylene-dispersed slurry (solid content concentration: 10%) prepared in parts was prepared.

Next, the xylene-dispersed slurry has a basis weight of 64 g / m.², 0.30 mm thick polypropylene melt blown non-woven fabric (pore diameter distribution 2 μm ~ 12 μm), adhered to a filter medium by coating method 124 g / m²Adhered at the rate of.

The above filter media is sandwiched between the support media and folds to a fold width of 10 mm in the length direction. 125 folds are taken and rolled into a cylindrical shape on the outer circumference of the core to make the joints of the filter media liquid-tight. It was sealed and the filter body was formed. Then, the filter body was housed in the outer peripheral cover, and both ends of the outer peripheral cover were hermetically sealed with end plates to prepare a cartridge filter.

After wetting the filter medium of the filter medium of the cartridge filter with isopyl alcohol, pure water is passed through the filter medium to dissolve and remove the particulate polyvinyl alcohol (primary binder) adhering to the granulated ion exchange resin powder. The washing water was dried by hot air drying to prepare a desired ion removal cartridge filter.

<figref num="1">It is a schematic schematic diagram of the granulated ion trapping powder.</figref><figref num="2">It is a schematic schematic cross-sectional view which shows the fixed state of the ion trapping powder.</figref>

Code description

A Granulated ion trapping powder 1 Ion trapping powder 2 Primary binder 3 Secondary binder 4 Continuous fine depression structure