JP2021041378A - Porous molding - Google Patents

Abstract

To provide a porous molding which can adsorb and remove ions in treated water, in particular, phosphate ions, and can reduce outflow of impurity fine particles into the treated water as much as possible.SOLUTION: The porous molding contains an organic polymer resin and an inorganic ion adsorbent, in which the number of outflow of impurity fine particles with a diameter of larger than 1.3 μm measured with a fine particle meter when being subjected to a fine particle outflow test is less than 1,000 pieces/ml.SELECTED DRAWING: None

Description

The present invention relates to a porous molded product. More specifically, the present invention provides an organic polymer resin and an inorganic ion adsorbent that can adsorb and remove ions in the water to be treated, especially phosphate ions, and reduce the outflow of impurity fine particles into the water to be treated as much as possible. With respect to the porous molded body including.

In recent years, due to the problem of eutrophication due to environmental pollution, environmental standards for harmful substances such as drinking water, industrial water, industrial wastewater, treated sewage water, and various environmental waters such as phosphorus, boron, arsenic, and fluorine have been strengthened. There is an increasing demand for technology to remove water. Furthermore, in recent years, there has been an increasing demand for technology for removing them, especially in metal plating, pharmaceutical manufacturing, medical applications, and the like.

Phosphorus is one of the causative agents of eutrophication and is increasingly regulated, especially in closed waters. In addition, since it is an element that is feared to be depleted, a technology for recovering it from wastewater and reusing it is required. In addition, renal disease patients with impaired renal function, such as patients with chronic renal failure, cannot properly excrete excess phosphorus from the body, so that phosphorus gradually accumulates in the body, resulting in hyperphosphatemia and the like. Since it causes diseases, there is a need for a technique for removing phosphorus from blood to prevent hyperphosphatemia and appropriately controlling the amount of phosphorus in the body.
In addition to controlling the amount of phosphorus in the blood, control of the following elements is being investigated.
Boron is an essential element for plant growth, but it is known that its excessive presence has an adverse effect on plant growth. Furthermore, it has been pointed out that when it is contained in drinking water, it may affect the health of the human body, and in particular, cause health problems such as deterioration of reproductive function.
Arsenic is contained in wastewater from the non-ferrous metal refining industry, thermal wastewater from geothermal power plants, and groundwater in specific areas. The toxicity of arsenic has been known for a long time, and it is said that it accumulates in the living body and causes chronic poisoning, weight loss, sensory disturbance, liver disorder, skin deposition, skin cancer and the like.
Fluorine is abundant in wastewater from the metal refining industry, glass industry, electronic material industry, etc. There is concern about the effects of fluorine on the human body, and it is known that excessive intake of fluorine causes chronic fluorine poisoning such as patchy teeth, osteosclerosis, and thyroid disorders.

Emissions of these various harmful substances are increasing year by year, and a technique for efficiently removing these harmful substances is required. Further, in addition to the conventional wastewater treatment field, there is an increasing demand for selectively removing specific ions such as phosphorus and boron from water used for metal plating, pharmaceutical production and the like.
As a technique for removing these various harmful substances, for example, a technique using an adsorbent in which an inorganic ion adsorbent powder such as zirconium hydrous ferrate or cerium hydrate is supported on a polymer material is known. ..
Further, it is known that a porous molded body containing an organic polymer resin and an inorganic ion adsorbent adsorbs phosphorus, boron and the like.
As a method for producing such a porous molded body, for example, in Patent Document 1 below, an organic polymer resin is dissolved in an appropriate good solvent, and further, the organic polymer resin is soluble in the good solvent. By a method in which an inorganic ion adsorbent powder, which is an adsorption substrate, is turbid in a polymer solution in which an affinityable water-soluble polymer is dissolved and mixed, and a poor solvent is used as a coagulation bath, the surface has no skin layer and the surface is formed. It is disclosed that a molded product having excellent openness can be obtained.
Further, Patent Document 2 below discloses that a porous molded article having a small amount of secondary aggregates of inorganic ion adsorbents in the porous molded article has excellent adsorption performance and high strength.
Further, in Patent Document 3, a porous molded product containing an organic polymer resin having a hydroxyl group and an inorganic ion adsorbent powder has high durability against a cleaning agent such as an oxidizing agent, and can be used repeatedly. It is disclosed that it is a suitable porous molded product.
The adsorbent made of a porous molded product disclosed in Patent Documents 1 to 3 does not have a thin film called a skin layer on the surface of the porous molded product, and the inside of the adsorbent is also excellent in porosity. It is characterized by a high diffusion rate into the adsorbent of the adsorbent such as. Further, Patent Documents 1 to 3 disclose that the adsorption treatment is carried out at a liquid passing rate (SV) of 30 hr- ^1.

On the other hand, in recent years, especially in applications used for metal plating, pharmaceutical manufacturing, medical equipment, etc., it has been required to process at ultra-high speeds such as ^SV120hr-1 and SV240hr- ^{1, which} are much faster than the ^{conventional liquid passing speed of SV30hr-1.} However, in Patent Document 4 below, the most frequent pore diameter measured by a mercury porosimeter is controlled to increase the diffusion rate of substances to be adsorbed such as phosphorus and boron into the porous molded body. It is disclosed that high-speed processing is performed.
Further, in Patent Document 5 below, phosphorus having a porous fiber having a powder or granular material containing a carbonate of a rare earth element having an average particle size of more than 100 nm and 100 μm or less or a group 4 oxide supported therein is incorporated. Adsorption columns are disclosed.
Further, Patent Document 6 below discloses that the pore volume of the inorganic ion adsorbent supported on the porous molded body is controlled to increase the adsorption rate of the substance to be adsorbed, thereby enabling ultra-high-speed processing. Has been done.

However, in particular, in applications used for pharmaceutical manufacturing, medical equipment, etc., there are concerns about quality deterioration and adverse effects on the human body due to impurity fine particles flowing out of the porous molded product.
For example, when the porous molded body is used for removing phosphate ions from the blood, fine particles such as inorganic ion adsorbents contained in the porous molded body flow out into the blood, resulting in serious cerebral infarction and the like. May cause adverse effects.
Therefore, in order to reduce the outflow of impurity fine particles from the porous molded product as much as possible, further improvement of the conventional porous molded product and the porous fiber as disclosed in Patent Documents 1 to 5 is desired.

International Publication No. 2005/056175 JP-A-2009-297707 International Publication No. 2011/062277 International Publication No. 2017/0842420 International Publication No. 2017/094478 Japanese Unexamined Patent Publication No. 2019-118879

In view of the above-mentioned prior art, the problem to be solved by the present invention is porous molding capable of adsorbing ions in the water to be treated, particularly phosphate ions, and reducing the outflow of impurity fine particles into the water to be treated as much as possible. To provide the body.

As a result of diligent research and experiments to solve the above problems, the present inventors measured a porous molded body containing an organic polymer resin and an inorganic ion adsorbent with a fine particle meter when subjected to a fine particle outflow test. It has been found that the above-mentioned problems can be solved by forming the porous molded body having an outflow number of impurity fine particles having a diameter of more than 1.3 μm of less than 1000 pieces / ml, and the present invention has been completed.

That is, the present invention is as follows.
[1] A porous molded product containing an organic polymer resin and an inorganic ion adsorbent, and when subjected to the following fine particle outflow test, the number of outflow of impurity fine particles having a diameter of more than 1.3 μm measured under the following conditions is Porous molded article, characterized by less than 1000 pieces / ml:
[conditions]
Fine particle outflow test solution: 5 mL of a porous molded body and 50 mL of pure water are placed in a container having a height of 5 cm or more and 10 cm or less and a volume of 100 mL, and then reciprocated for 30 minutes at a rotation speed of 250 rpm. Was collected with a 5 mL pipette;
Fine particle meter: (manufactured by Rion Co., Ltd., KL-05 (trade name)), set values: syringe capacity 25 mL, suction flow rate 25 mL / min, discharge flow rate 100 mL / min, air suction volume 0.5 mL, measurement capacity 5.0 mL , Empty measurement times 1 time, measurement times 3 times, measurement particle size more than 1.3 μm.
[2] The above-mentioned [1], wherein the number of fine particles outflow including the inorganic ion adsorbent measured by the following SEM observation method when subjected to the fine particle outflow test is ^{less than 200 / (23,000 μm 2).} Porous molded body:
[SEM observation method]
SEM observation test: 25 mL of the fine particle outflow test solution was separated, suction filtered with a PVDF circular filter paper having a diameter of 47 mm and a mesh size of 0.1 μm, and the fine particles were captured on the filter paper, and then the filter paper was coated with silica gel. After storing in a desiccator containing the filter paper and drying it until there is no change in weight, the central 5 mm square of the filter paper is cut out with a cutter knife and fixed on an SEM sample table with carbon tape;
SEM observation device: SEM (manufactured by Hitachi High-Technologies Co., Ltd., TM-1000), observation mode: charge reduction mode, image: reflected electron image, image magnification: 1,000 times, brightness / contrast: auto brightness, focus : After shooting an SEM image with auto focus and capturing the SEM image with image analysis software (ImageJ), ^{select the area (23,000 μm 2} ) of the shot SEM image and invert the black and white of the image (Dark Background). (Selection) After converting white fine particles to black, measure the number of fine particles that can be seen when the threshold value is set to 0.2%, repeat the above operation three times, and measure the average value by SEM observation method for inorganic ion adsorption. The number of fine particles outflow including the body.
[3] the sum of the pore diameter 1nm or more 80nm or less of the pore volume measured by nitrogen gas adsorption method, is the 0.03cm per unit mass of the inorganic ion absorbing material ³ / g or more 0.7 cm ³ / g or less , The porous molded body according to the above [1] or [2].
[4] a nitrogen gas adsorption method the total pore diameters 1nm or 80nm or less of pore volume measured by the said unit mass per porous formed article 0.03 cm ³ / g or more 0.6cm is ³ / g or less , The porous molded body according to any one of the above [1] to [3].
[5] The porous molded body according to any one of [1] to [4] above, wherein the specific surface area measured by the nitrogen gas adsorption method is 50 m ² / g or more and 400 m ^{2 / g or less.}
[6] The porous molded product according to any one of [1] to [5], wherein the amount of the inorganic ion adsorbent contained in the porous molded product is 20% by mass or more and 85% by mass or less.
[7] The porous molded article according to any one of [1] to [6] above, which is in the form of spherical particles having an average particle size of 100 μm or more and 2500 μm or less.
[8] The porous molded product according to any one of [1] to [7], wherein the bulk density of the porous molded product is 0.2 g / ml or more and 0.7 g / ml or less.
[9] The inorganic ion adsorbent has the following formula (I):
MNxOn · mH ₂ O. .. .. (I)
{In the formula, x is 0 or more and 3 or less, n is 1 or more and 4 or less, m is 0 or more and 6 or less, and M and N are Ti, Zr, Sn, Sc, Y. , La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Si, Cr, Co, Ga, Fe, Mn, Ni, V, Ge, Nb It is a metal element selected from the group consisting of and Ta, and is different from each other. } And / or the following formula (III):
QyRz (CO ₃ ) s · tH ₂ O. .. .. (III)
{In the formula, y is 1 or more and 2 or less, z is 0 or more and 1 or less, s is 1 or more and 3 or less, t is 0 or more and 8 or less, and Q and R are. , Mg, Ca, Sr, Ba, Sc, Mn, Fe, Co, Ni, Ag, Zn, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , And a metal element selected from the group consisting of Lu, which are different from each other. } At least one kind of metal carbonate,
The porous molded article according to any one of the above [1] to [8], which contains.
[10] The metal oxide is the following group (a) to (c):
(A) Titanium hydrate, zirconium hydrate, tin hydrate, cerium hydrate, lanthanum hydrate, and yttrium hydrate;
(B) A composite metal oxide of at least one metal element selected from the group consisting of titanium, zirconium, tin, cerium, lanthanum and yttrium and at least one metal element selected from the group consisting of aluminum, silicon and iron;
(C) Activated alumina;
The porous molded article according to the above [9], which is selected from the above.
[11] The metal carbonate is the following group (d):
(D) Magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, scandium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, nickel carbonate, silver carbonate, zinc carbonate, yttrium carbonate, lantern carbonate, cerium carbonate, placeodium carbonate, neodymium carbonate , Samalium Carbonate, Europium Carbonate, Gadrinium Carbonate, Terbium Carbonate, Disprosium Carbonate, Formium Carbonate, Elbium Carbonate, Thurium Carbonate, Itterbium Carbonate, and Rutetium Carbonate;
The porous molded article according to the above [9], which is selected from the above.
[12] The organic polymer resin is ethylene vinyl alcohol copolymer (EVOH), polyacrylonitrile (PAN), polysulfone (PS), polyethersulfone (PES), polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA). ), Polyaryl ether sulfone, polypropylene, polystyrene, polycarbonate, cellulose, and cellulose triacetate. The porous molded product according to any one of [1] to [11] above, which is at least one selected from the group.
[13] A column filled with the porous molded product according to any one of the above [1] to [12].
[14] An upward flow in which the cleaning liquid and / or the filling liquid flows from below the column according to the above [13], a downward flow in which the cleaning liquid and / or the filling liquid flows from above the column, or both of the cleaning liquid and / or A method for cleaning and / or filling a porous molded article, which comprises a step of passing a filling liquid through the column.
[15] The method according to the above [14], wherein the cleaning liquid and / or the filling liquid is passed at a liquid passing speed of SV1hr ^-1 or more and SV300hr ^{-1 or less.}
[16] The method according to the above [14] or [15], wherein the cleaning liquid and / or the filling liquid is passed in an amount of 1 times or more and 10,000 times or less the bulk volume of the porous molded product.

The porous molded product according to the present invention can adsorb and remove ions in the water to be treated, particularly phosphate ions, and the outflow of impurity fine particles into the water to be treated is small, so that it is particularly used in pharmaceutical manufacturing and medical applications. Etc., it can be preferably used.

Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as the present embodiment) will be described in detail. The present invention is not limited to the following embodiments, and can be modified in various ways within the scope of the gist thereof.

[Perforated molded product]
The porous molded article of the present embodiment is a porous molded article containing an organic polymer resin and an inorganic ion adsorbent, and when subjected to a fine particle outflow test described later, the number of impurity fine particle outflows exceeding 1.3 μm is 1000. It is characterized by less than 1 piece / ml.

In the present embodiment, when subjected to the fine particle outflow test described later, the number of impurity fine particles outflow exceeding 1.3 μm is less than 1000 pieces / ml, preferably less than 500 pieces / ml, and more preferably 100 pieces / ml. Is less than.
The fine particle outflow test is carried out by the following procedure.
First, the equipment to be used is ultrasonically cleaned to remove contaminant particles. The instruments used are a dropper for collecting a porous molded body, a pipette for 5 ml for collecting a test solution, a container having a height of 5 cm or more and 10 cm or less and a volume of 100 mL, and a graduated cylinder. These instruments are immersed in pure water filtered through an ultrafiltration membrane (UF membrane), ultrasonically applied for 10 minutes, and then the pure water is discarded. This operation is repeated 5 times to obtain a fine particle-cleaned instrument.
Next, 5 ml of the porous molded product is weighed in bulk volume. If the porous molded body is particulate, columnar, hollow columnar, etc. and the shape is short, a wet porous molded body is collected using a washed dropper, and a washed graduated cylinder is used. Use to measure bulk volume with 1 mL as 1 cm ^3.
Next, 5 mL of the weighed porous molded body and 50 mL of pure water filtered through an ultrafiltration membrane (UF membrane) are put into a container having a washed height of 5 cm or more and 10 cm or less and a volume of 100 mL, and then 250 rpm. Perform reciprocating shaking at speed for 30 minutes. After shaking, the supernatant is collected with a washed 5 mL pipette to prepare a fine particle outflow test solution.
The number of fine particles in the fine particle outflow test solution is measured using a fine particle meter (particle counter). The number of fine particles of pure water filtered by the ultrafiltration membrane (UF membrane) used in the test is measured 5 times, the average value is obtained, and the difference from the number of fine particles in the fine particle outflow test solution is obtained as the number of fine particles.
The above operation is repeated three times, and the average value is taken as the number of fine particles outflow in the fine particle outflow test liquid flow.
When the number of impurity fine particles exceeding 1.3 μm that flowed out in the fine particle outflow test is 1000 / ml or less, the amount of impurity fine particles that flow out into the liquid to be treated is small.

In the present embodiment, when the porous molded body is subjected to the fine particle outflow test, the number of fine particle outflows including the inorganic ion adsorbent measured by the SEM observation method described later is less than ^{200 pieces / 23,000 μm 2, preferably.} It is less than 100 pieces / 23,000 μm ² , and more preferably less than 20 pieces / 23,000 μm ^2.
The number of fine particles discharged including the inorganic ion exchanger is measured by the SEM observation method according to the following procedure.
First, 25 mL of the sample solution collected in the above-mentioned fine particle test is separated and suction-filtered with a PVDF circular filter paper having a diameter of 47 mm and a mesh size of 0.1 μm to capture the fine particles on the filter paper.
Next, the filter paper is stored in a desiccator containing silica gel and dried until the weight does not change. Then, the central 5 mm square of the filter paper is cut out with a cutter knife, fixed with carbon tape on the SEM sample table, and observed by SEM. Use as a sample for use.
A sample for SEM observation is set in the SEM, and a reflected electron image is taken. When the back electron image is taken, the fine particles containing the inorganic ion adsorbents are taken as white fine particles on the PVDF filter paper, so that only the fine particles containing the inorganic ion adsorbents can be measured.
After taking the SEM image, the number of fine particles observed within ^{the range (23,000 μm 2} ) of the SEM image is measured by using the binarization function of the image analysis software.
The above operation is repeated three times, and the average value is taken as the number of fine particles outflow including the inorganic ion adsorbent measured by the SEM observation method.
When the number of fine particles outflow containing the inorganic ion adsorbent measured by the SEM observation method is ^{less than 200 / 23,000 μm 2} , the amount of impurity fine particles outflow into the liquid to be treated is small.

In the present embodiment, the total pore volume of the pore diameter of 1 nm or more and 80 nm or less measured by the nitrogen gas adsorption method is 0.03 cm ³ / g or more per unit mass of the inorganic ion adsorbent supported on the porous molded body. 0.7 cm ³ / g or less, preferably not more than 0.1 cm ³ / g or more 0.6 cm ³ / g, more preferably 0.2 cm ³ / g or more 0.5 cm ³ / g or less.
The total pore volume is calculated by the BJH method by measuring the freeze-dried porous molded body by the nitrogen gas adsorption method.
The total Porosity Va per unit mass of the inorganic ion adsorbent is Vb (cm ³ / g), which is the porosity of the porous molded body calculated from the dried porous molded body. When the amount of the inorganic ion adsorbent carried in the molded body is Sa (mass%), the following formula:
Va = Vb / Sa x 100
Is required by.
When the supported amount (% by mass) Sa of the inorganic ion adsorbent of the porous molded body is the mass Wa (g) of the porous molded body when dried and the mass Wb (g) of the ash content, the following formula:
Sa = Wb / Wa x 100
Is required by.
Here, the ash content is the residue when the porous molded product is fired at 800 ° C. for 2 hours.

The pore volume of the pore diameter of 1 nm or more and 80 nm or less measured by the nitrogen gas adsorption method is a value that mainly reflects the pore volume of the inorganic ion adsorbent contained in the porous molded body. The larger the pore volume of the pore diameter of 1 nm or more and 80 nm or less measured by the nitrogen gas adsorption method, the higher the diffusion efficiency of ions into the inorganic ion adsorbent and the higher the adsorption capacity.
Further, the larger the pore volume of the pore diameter of 1 nm or more and 80 nm or less measured by the nitrogen gas adsorption method, the more the organic polymer resin enters the inside of the inorganic ion exchanger, and the inorganic ion exchanger is better retained by the anchor effect. And the outflow of fine particles is reduced.
When the total pore volume per unit mass of the inorganic ion adsorbent is ^{smaller than 0.03 cm 3} / g, the pore volume of the inorganic ion adsorbent is small and the substance to be adsorbed is diffused inside the inorganic ion adsorbent. It is difficult and the adsorption capacity is significantly reduced. Further, it is difficult for the organic polymer resin to enter the inside of the inorganic ion exchanger, it is difficult to hold the inorganic ion exchanger, and the amount of fine particles discharged increases. On the other hand, when this value is ^{larger than 0.7 cm 3} / g, the bulk density of the inorganic ion adsorbent is low, the viscosity of the stock solution slurry tends to increase, and granulation becomes difficult.

In the present embodiment, the sum of the following pore volume pore diameter 1nm or more 80nm measured by nitrogen gas adsorption method, 0.03 cm per unit mass of the porous formed body ³ / g or more 0.6 cm ³ / g or less There, preferably not more than 0.08 cm ³ / g or more 0.55 cm ³ / g, more preferably not more than 0.12 cm ³ / g or more 0.5 cm ³ / g.
As will be described below, the amount of the inorganic ion adsorbent contained in the porous molded body is preferably 20% by mass or more and 85% by mass or less, more preferably 30% by mass or more and 80% by mass or less, further preferably. Is 40% by mass or more and 75% by mass or less.
The pore volume is calculated by the BJH method by measuring the freeze-dried porous molded body by the nitrogen gas adsorption method.
When this value is ^{smaller than 0.02 cm 3} / g, the substance to be adsorbed is less likely to diffuse into the inside of the porous molded body, and the adsorption capacity is lowered. On the other hand, if this value is ^{larger than 0.6 cm 3} / g, the viscosity of the undiluted slurry tends to increase, which makes granulation difficult.

In the present embodiment, the specific surface area of the porous molded body measured by the nitrogen gas adsorption method is preferably 50 m ² / g or more and 400 m ² / g or less, more preferably 70 m ² / g or more and 350 m ² / g or less, further preferably. Is 100 m ² / g or more and 300 m ² / g or less.
The specific surface area is calculated by measuring the freeze-dried porous molded body by the nitrogen gas adsorption method and by the BET method.
The specific surface area of the porous molded body measured by the nitrogen gas adsorption method is a value that mainly reflects the specific surface area of the inorganic ion adsorbent contained in the porous molded body. Therefore, the larger the value, the more ions are adsorbed. This means that the number of sites increases and the adsorption capacity increases. Further, since the contact surface property between the inorganic ion adsorbent and the organic polymer resin is increased, it becomes easier to hold the organic polymer resin multi-inorganic ion adsorbent, and the outflow amount of fine particles is reduced.
When the specific surface area of the porous molded body is ^{smaller than 50 m 2} / g, there are few adsorption sites of the inorganic ion adsorbent, and the adsorption capacity is significantly reduced. On the other hand, when this value is ^{larger than 400 m 2} / g, the bulk density of the inorganic ion adsorbent is low, the viscosity of the stock solution slurry increases, and granulation becomes difficult.

In the present embodiment, the amount of the inorganic ion adsorbent contained in the porous molded body is preferably 20% by mass or more and 85% by mass or less, more preferably 30% by mass or more and 80% by mass or less, and further preferably 40% by mass. It is 75% by mass or less.
The supported amount Sa of the inorganic ion adsorbent is measured as described above.
If the amount carried is less than 30% by mass, the frequency of contact between the substance to be adsorbed with ions and the inorganic ion adsorbent as an adsorption substrate tends to be insufficient, and sufficient adsorption performance cannot be obtained. On the other hand, if it exceeds 85% by mass, the strength of the porous molded product tends to be insufficient. Further, the amount of the inorganic ion adsorbent is larger than the amount of the organic polymer resin, the organic polymer resin cannot hold the inorganic ion adsorbent, and the amount of fine particles discharged increases.

The porous molded article of the present embodiment preferably has an average particle size of 100 μm or more and 2500 μm or less and is substantially in the form of spherical particles, and the average grain shape is 150 μm or more and 2000 μm or less. It is more preferably 200 μm or more and 1500 μm or less, and even more preferably 300 μm or more and 1000 μm or less.
The porous molded product of the present embodiment is preferably in the form of spherical particles, and the spherical particles may be not only true spherical particles but also elliptical spherical particles.
In the present embodiment, the average particle size means a median diameter having a sphere-equivalent diameter obtained from an angular distribution of scattered light intensity of diffraction by laser light, regarding the porous molded body as a sphere.
When the average particle size is 100 μm or more, the pressure loss is small when the porous molded body is filled in a column, a tank, or the like, so that it is suitable for ultra-high-speed water flow treatment. In particular, when the average particle size is 300 μm or more, the flow path between the particles becomes wide, and in medical applications, for example, even when whole blood is passed, the pressure does not easily increase, and it can be preferably used. it can. On the other hand, if the average particle size is 2500 μm or less, the surface area in contact between the porous molded body and the treatment liquid can be increased when the column or tank is filled, and the ions can be reliably adsorbed even when the liquid is passed through at ultra-high speed. Can be adsorbed.

In the present embodiment, the bulk density of the porous molded body is preferably 0.2 g / mL or more and 0.7 g / mL or less, more preferably 0.25 g / mL or more and 0.65 g / mL or less, and further preferably 0. It is 3 g / mL or more and 0.6 g / mL or less.
The bulk density of the porous molded product is measured by the following method.
If the porous molded body is in the form of particles, a columnar shape, a hollow columnar shape, or the like, and the shape is short, the porous molded body in a wet state is made into a bulk volume of ^{1 cm 3 by using a measuring cylinder or the like.} Measure. If the porous molded body has a thread-like shape, a hollow thread-like shape, a sheet-like shape, or the like and has a long shape, the cross-sectional area and length when wet are measured, and the bulk volume is calculated from the product of both. Then, freeze-drying is performed to determine the weight, and the bulk density is calculated as weight / bulk volume.
If the porous molded body has a thread-like shape, a hollow thread-like shape, a sheet-like shape, or the like, and the shape is long, the cross-sectional area and the length when wet are measured, and the volume is calculated from the product of both. Then, it is freeze-dried to obtain the weight, and the bulk density is calculated as the weight / bulk volume.
If the bulk density value is less than 0.2 g / mL, the strength is insufficient and the porous compacts are easily deformed during transportation and handling, while if it is larger than 0.7 g / mL, the porous compacts are easily deformed. The impact at the time of collision becomes large, and the amount of fine particles flowing out increases.

[Inorganic ion adsorbent]
The inorganic ion adsorbent constituting the porous molded body of the present embodiment means an inorganic substance exhibiting an ion adsorption phenomenon or an ion exchange phenomenon.
Examples of natural product-based inorganic ion adsorbents include various mineral substances such as zeolite and montmorillonite.
Specific examples of various mineral substances include kaolin minerals with aluminosilicates and a single-layer lattice, muscovite with a two-layer lattice structure, glauconite, kanuma soil, pyrophyllite, talc, and feldspar with a three-dimensional frame structure. , Zeolite, montmorillonite and the like.
Examples of the synthetic inorganic ion adsorbent include metal oxides, salts of polyvalent metals, insoluble hydrous oxides, and metal carbonates. The metal oxide may include a composite metal oxide, a composite metal hydroxide, a metal hydrous oxide, and the like.

The inorganic ion adsorbent has the following formula (I): from the viewpoint of adsorption performance and elution property of the object to be adsorbed.
MNxOn · mH ₂ O. .. .. (I)
{In the formula, x is 0 or more and 3 or less, n is 1 or more and 4 or less, m is 0 or more and 6 or less, and M and N are Ti, Zr, Sn, Sc, Y. , La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Si, Cr, Co, Ga, Fe, Mn, Ni, V, Ge, Nb It is a metal element selected from the group consisting of and Ta, and is different from each other. } Can contain at least one kind of metal oxide represented by.

The metal oxide may be a non-hydrated (unhydrated) metal oxide in which m is 0 in the above formula (I), or a metal hydroxide (water) in which m is a value other than 0. Japanese metal oxide) may be used.
X, n, and m in the above formula (I) do not necessarily have to be integers. For example, iron oxyhydroxide (FeOOH) can be represented as x = 0, n = 1.5, m = 0.5.
In the metal oxide when x in the above formula (I) is a numerical value other than 0, each contained metal element is regularly distributed throughout the oxide and is contained in the metal oxide. It is a composite metal oxide represented by a chemical formula in which the composition ratio of each metal element is fixed.
Specifically, a perovskite structure, a spinel structure, etc. are formed, and nickel ferrite (NiFe ₂ O ₄ ) and zirconium hydrous arsenate (Zr · Fe ₂ O ₄ · mH ₂ O, where m is 0. 5 or more and 6 or less.) And the like.
The inorganic ion adsorbent may contain a plurality of types of metal oxides represented by the above formula (I).

From the viewpoint of excellent adsorption performance of phosphorus, boron, fluorine and / or arsenic as the inorganic ion adsorbent, the metal oxides are the following groups (a) to (c):
(A) Titanium hydrate, zirconium hydrate, tin hydrate, cerium hydrate, lanthanum hydrate, and yttrium hydrate;
(B) A composite metal oxide of at least one metal element selected from the group consisting of titanium, zirconium, tin, cerium, lanthanum and yttrium and at least one metal element selected from the group consisting of aluminum, silicon and iron;
(C) Activated alumina;
It is preferable to be selected from.
The metal oxide may be a material selected from any of the groups (a) to (c), or a combination of materials selected from any of the groups (a) to (c). It may be used in combination, or the materials in each of the groups (a) to (c) may be used in combination. When used in combination, it may be a mixture of two or more materials selected from any of the groups (a) to (c), and two or more groups of groups (a) to (c). It may be a mixture of two or more materials selected from.
The inorganic ion adsorbent may contain activated alumina impregnated with aluminum sulfate from the viewpoint of being inexpensive and having high adsorptivity.
As the inorganic ion adsorbent, in addition to the metal oxide represented by the above formula (I), a solid solution of a metal element other than M and N is obtained from the viewpoint of the adsorptivity of inorganic ions and the production cost. More preferred.
For example, _{iron is dissolved in hydrated zirconium oxide represented by ZrO 2} · mH ₂ O (m is a numerical value other than 0).

Examples of the salt of the polyvalent metal include the following formula (II):
_{^{M 2+ (1-p) M}} 3+ p (OH -) (2 + p-q) (A n-) q / r ······ (II)
{In the formula, M ²⁺ is at least one divalent metal ion selected from the group consisting of ^{Mg 2+} , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Ca ²⁺ and Cu ^{2+ , and M 3+} is Al ³⁺ and Fe. is at least one trivalent metal ion selected from the group consisting of ^{3+, a n-is} an n-valent anion is 0.1 ≦ p ≦ 0.5, 0.1 ≦ q ≦ 0. 5 and r is 1 or 2. } Can be mentioned as a hydrotalcite-based compound.
The hydrotalcite compound represented by the above formula (II) is preferable because the raw material is inexpensive as an inorganic ion adsorbent and the adsorptivity is high.
Examples of the insoluble hydrous oxide include insoluble heteropolylates and insoluble hexacyanoferrates.

As an inorganic ion adsorbent, metal carbonate has excellent performance from the viewpoint of adsorption performance, but from the viewpoint of elution, it is necessary to study the application when using carbonate.
From the viewpoint that an ion exchange reaction with carbonate ions can be expected as the metal carbonate, the following formula (III):
QyRz (CO ₃ ) s · tH ₂ O. .. .. (III)
{In the formula, y is 1 or more and 2 or less, z is 0 or more and 1 or less, s is 1 or more and 3 or less, t is 0 or more and 8 or less, and Q and R are. , Mg, Ca, Sr, Ba, Sc, Mn, Fe, Co, Ni, Ag, Zn, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , And a metal element selected from the group consisting of Lu, which are different from each other. } Can contain at least one kind of metal carbonate.
The metal carbonate may be a non-hydrated (unhydrated) metal carbonate in which t is 0 in the above formula (III), or a hydrate having a value other than 0. Good.
As the inorganic ion adsorbent, from the viewpoint of low elution and excellent adsorption performance of phosphorus, boron, fluorine and / or arsenic, the following group (d):
(D) Magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, scandium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, nickel carbonate, silver carbonate, zinc carbonate, yttrium carbonate, lantern carbonate, cerium carbonate, placeodium carbonate, neodymium carbonate , Samalium Carbonate, Europium Carbonate, Gadrinium Carbonate, Terbium Carbonate, Disprosium Carbonate, Formium Carbonate, Elbium Carbonate, Thurium Carbonate, Itterbium Carbonate, and Rutetium Carbonate;
It is preferable to be selected from.
As the mechanism for adsorbing inorganic ions of metal carbonate, elution of metal carbonate and recrystallization of inorganic ions and metal ions on the metal carbonate are expected. Therefore, the higher the solubility of metal carbonate, the more inorganic ions are adsorbed. The amount is high, and excellent adsorption performance can be expected. At the same time, there is a concern about metal elution from the inorganic ion adsorbent, so sufficient consideration is required for use in applications where metal elution is a problem.

The inorganic ion adsorbent constituting the porous molded article of the present embodiment contains impurity elements mixed due to the manufacturing method or the like within a range that does not impair the function of the porous molded article of the present embodiment. May be good. Examples of impurity elements that may be mixed include nitrogen (nitrite, nitrite, ammonium), sodium, magnesium, sulfur, chlorine, potassium, calcium, copper, zinc, bromine, barium, hafnium and the like.

It is preferable that the inorganic ion adsorbent constituting the porous molded article of the present embodiment can prevent aggregation during drying. In order to suppress aggregation during drying, it is preferable to replace the water contained in the production with an organic liquid and then dry.
By replacing the water contained in the inorganic ion adsorbent with an organic liquid and then drying, the aggregation during drying can be suppressed, the pore volume of the inorganic ion adsorbent can be increased, and the inorganic ion adsorbent can be adsorbed. The adsorption capacity of the body can be increased.
The organic liquid used for the substitution is not particularly limited as long as it has the effect of suppressing the aggregation of the inorganic ion adsorbent, but it is preferable to use a liquid having high hydrophilicity. For example, alcohols, ketones, esters, ethers and the like can be mentioned. Further, the organic liquid used for the substitution may be a mixture thereof or a mixture with water.
The effect of suppressing aggregation of the inorganic ion adsorbent is exhibited by the low surface tension of the organic liquid.
The surface tension of the organic liquid contained in the inorganic ion adsorbent during drying is preferably 0 or more and 30 mN / m or less, more preferably 0 or more and 27 mN / m or less, and 0 or more and 25 mN / m or less. More preferred.
When the surface tension of the liquid contained in the inorganic ion adsorbent is larger than 30 mN / m, the particles aggregate with each other during drying, the pore volume of the inorganic ion adsorbent decreases, and the amount of fine particles discharged increases.

The substitution rate of the water contained in the inorganic ion adsorbent with the organic liquid may be, for example, 40% by mass or more and 100% by mass or less in order to satisfy the surface tension in the case of ethanol at 20 ° C. It is preferably 60% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less.
The substitution rate of the organic liquid is lower when the substitution rate with the organic liquid is Sb (mass%) and the water content of the filtrate after treating the inorganic ion adsorbent containing water with the organic liquid is Wc (mass%). The value represented by the expression.
Sb = 100-Wc
The water content of the filtrate after treatment with an organic liquid can be determined by measuring with the Karl Fischer method.
When the substitution rate of ethanol is less than 40% by mass, the effect of suppressing aggregation during drying is low, and the effect of increasing the pore volume of the inorganic ion adsorbent is small.

The method of substituting with an organic liquid is not particularly limited, and the inorganic ion adsorbent containing water may be dispersed in the organic liquid and then centrifuged and filtered, or filtered with a filter press or the like. After that, an organic liquid may be passed through. In order to increase the substitution rate, it is preferable to repeat the method of dispersing the inorganic ion adsorbent in the organic liquid and then filtering.

The water content of the inorganic ion adsorbent constituting the porous molded body of the present embodiment is 3% by mass or more and 15% by mass or less, preferably 3% by mass or more and 10% by mass or less, and more preferably 3% by mass. It is 5% by mass or less.
The water content Sc (mass%) of the inorganic ion adsorbent is Wd (g) for the initial weight of the inorganic ion adsorbent and We (g) for the weight after heating the inorganic ion adsorbent at 120 ° C. until there is no weight change. Then, the following formula:
Sc = (Wd-We) / Wd x 100
Is required by.
When the water content of the inorganic ion adsorbent is smaller than 3% by mass, the amount of phosphate ions adsorbed is significantly reduced.
If the water content of the inorganic ion adsorbent is larger than 15% by mass, water, which is a poor solvent, is mixed into the slurry in the slurry preparation step described later, and phase separation of some organic polymer resins occurs in the slurry, resulting in non-uniformity. As a result, the porous molded body becomes brittle and the amount of fine particles discharged increases.

[Organic polymer resin]
The organic polymer resin constituting the porous molded product of the present embodiment is preferably a resin that can be made porous.
Examples of the organic polymer resin include polysulfone polymers, polyvinylidene fluoride polymers, vinylidene chloride polymers, acrylonitrile polymers, methyl methyl methacrylate polymers, polyamide polymers, polyimide polymers, cellulose polymers, and ethylene vinyl. Examples thereof include alcohol copolymer polymer, polyaryl ether sulfone, polypropylene polymer, polystyrene polymer, polycarbonate polymer, and many other types.
Among them, ethylene vinyl alcohol copolymer (EVOH), polyacrylonitrile (PAN), polysulfone (PS), polyethersulfone (PES), and polyvinylidene fluoride because of their non-swelling property and biodegradation resistance in water, and their ease of production. It is preferably at least one selected from the group consisting of vinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), polyarylethersulfone, polypropylene, polystyrene, polycarbonate, cellulose, and cellulose triacetate.
From the viewpoint of supportability, the organic polymer resin is preferably a polyether sulfone having a hydroxyl group at the terminal. By having a hydroxyl group as a terminal group, the porous molded article of the present embodiment can exhibit excellent carrying performance of an inorganic ion adsorbent. In addition, since the highly hydrophobic organic polymer resin has a hydroxyl group at the end, the hydrophilicity is improved, and fouling occurs even when the porous molded product of the present embodiment is used for water treatment. Hateful.

[column]
When the porous molded product of the present embodiment is used as an adsorbent, it is used by filling it in a column or an adsorption tower. By filling the column or adsorption tower with water to be treated and bringing them into contact with each other, the high contact efficiency of the porous molded body can be sufficiently brought out. Further, since the porous molded body of the present embodiment has a high abundance of inorganic ion adsorbents on the surface of the adsorbent, the adsorbed object does not leak (break) from the initial stage of water flow, and has sufficient adsorption performance. Ultra-high-speed processing can be performed with.
The column means a tubular container provided with solid-liquid separating means such as a perforated plate or a mesh at least one of the lower part and the upper part so that the porous molded body does not flow out.
The material of the column is not particularly limited, but for example, stainless steel, FRP (reinforced plastic containing glass fiber), glass, PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), PC (polycarbonate). ) And other various plastics.
The inner surface of the column may be lined with rubber or fluororesin in consideration of acid resistance and basic resistance.

[Washing method]
When the porous molded product of the present embodiment is used as an adsorbent, it can be washed while being filled in the column or the adsorption tower.
In the present embodiment, the cleaning liquid of the porous molded product can be passed through the cleaning liquid by an upward flow flowing from the bottom of the column, a downward flow flowing the cleaning liquid from the top of the column, or both. When the cleaning liquid is flowed in an upward flow, the cleaning liquid can be filled in the entire inside of the column without embracing air at the initial stage of passing the liquid. When the cleaning liquid is flowed in a downward flow, the porous molded products do not move due to the flow of the cleaning liquid, and there is no possibility that the porous molded products will be worn by contact with each other and fine particles will be generated.

In the present embodiment, the flow rate of the cleaning liquid of the porous molded product is preferably SV1hr ^-1 or more and SV300hr ^-1 or less, more preferably SV1hr ^-1 or more and SV250hr ^-1 or less, and further preferably SV1hr ^-1 or more and SV200hr ^-1. It is as follows. Cleaning of impurities existing inside the porous molded body is mainly due to the effect of diffusion, and if the SV is ^{smaller than 1} hr-1, impurities stay in the cleaning liquid and the cleaning effect due to diffusion is reduced. If the SV is ^{larger than 300 hr-1} , the porous molded body may be deformed due to high pressure loss when flowing in the downward flow, and the porous molded body moves violently inside the column when flowing in the upward flow. There is a risk that the porous molded bodies will wear out due to contact with each other and fine particles will be generated.

In the present embodiment, the flow rate of the cleaning liquid of the porous molded product is preferably 1 times or more and 10,000 times or less, more preferably 2 times or more and 7 times the bulk volume of the porous molded product. The amount is 5,000 times or less, more preferably 3 times or more and 5,000 times or less.
As for the bulk volume of the porous molded body, if the shape is short, such as particle-like, columnar, or hollow columnar, the apparent volume of the wet molded body is measured using a measuring cylinder or the like.
When the amount of the cleaning liquid passing through is 1 times or more the bulk volume of the porous molded product, the impurity fine particles physically attached to the porous molded product can be sufficiently cleaned.

In the present embodiment, the cleaning liquid for the porous molded product is not particularly limited, and one having a high removing effect on impurities contained can be selected. For example, when it is desired to remove impurities adsorbed on the metal oxide which is an inorganic ion adsorbent, a sodium hydroxide solution may be used, and when it is desired to remove liberated impurities, it may be washed with pure water.
Normally, anions, which are impurities mixed in from the raw material and the manufacturing process, are often adsorbed on the inorganic ion exchanger, and the impurity fine particles mixed in from the raw material and the manufacturing process are electrostatically charged on the surface of the porous molded body. Therefore, it is preferable to perform cleaning with a sodium hydroxide solution and then further with pure water.
Further, a preferable cleaning liquid may be selected depending on the intended use after cleaning. For example, when the porous molded product is used for wastewater treatment, it may be washed with pure water, and when it is used for medical purposes, physiological saline or physiological saline containing a blood anticoagulant may be used. ..
The cleaning liquid may be one kind, or a plurality of cleaning liquids may be used in combination.

[Manufacturing method of porous molded product]
The method for producing the porous molded article of the present embodiment is, for example, (1) a step of drying the inorganic ion adsorbent, (2) a step of crushing the inorganic ion adsorbent obtained in step (1), (3). A step of mixing the inorganic ion adsorbent obtained in step (2), a good solvent for an organic polymer resin, an organic polymer resin, and a water-soluble polymer to prepare a slurry, obtained in step (4) (3). A step of molding the obtained slurry, a step of solidifying the molded product obtained in (5) step (4) in a poor solvent, and a step of immersing the molded product obtained in (6) step (5) in an organic liquid. , (7) A step of washing the porous molded product obtained in the step (5) or the step (6).

[Step (1): Drying step of inorganic ion adsorbent]
In step (1), the inorganic ion adsorbent is dried to obtain a powder. At this time, in order to suppress aggregation during drying, it is preferable to replace the water contained in the production with an organic liquid and then dry. By replacing the water contained in the inorganic ion adsorbent with an organic liquid and then drying, the aggregation during drying can be suppressed, the pore volume of the inorganic ion adsorbent can be increased, and the inorganic ion adsorbent can be adsorbed. The adsorption capacity of the body can be increased.
The organic liquid is not particularly limited as long as it has the effect of suppressing the aggregation of the inorganic ion adsorbent, but it is preferable to use a liquid having high hydrophilicity. For example, alcohols, ketones, esters, ethers and the like can be mentioned. Further, the organic liquid used for the substitution may be a mixture thereof or a mixture with water.
The effect of suppressing aggregation of the inorganic ion adsorbent is exhibited by the low surface tension of the organic liquid.
The surface tension of the organic liquid contained in the inorganic ion adsorbent during drying is preferably 0 or more and 30 mN / m or less, more preferably 0 or more and 27 mN / m or less, and 0 or more and 25 mN / m or less. More preferred.
When the surface tension of the liquid contained in the inorganic ion adsorbent is larger than 30 mN / m, the particles aggregate during drying, the pore volume of the inorganic ion adsorbent decreases, and the adsorption capacity decreases.
The substitution rate of the water contained in the inorganic ion adsorbent with the organic liquid may be, for example, 40% by mass or more and 100% by mass or less in order to satisfy the surface tension of ethanol at 20 ° C., preferably. It may be 60% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less.
The substitution rate of the organic liquid is lower when the substitution rate with the organic liquid is Sb (mass%) and the water content of the filtrate after treating the inorganic ion adsorbent containing water with the organic liquid is Wc (mass%). The value represented by the expression.
Sb = 100-Wc
The water content of the filtrate after treatment with an organic liquid can be determined by measuring with the Karl Fischer method.
When the substitution rate of ethanol is less than 40% by mass, the effect of suppressing aggregation during drying is reduced and the pore volume of the inorganic ion adsorbent does not increase.

In order to achieve the water content of the inorganic ion adsorbent described above, the inorganic ion adsorbent is dried and then immediately before the crushing step of the inorganic ion exchanger described later, and after crushing and immediately before the slurry preparation step described later. It is preferable to store in an environment with a relative humidity of 25% RH or less so as not to come into contact with moisture in the air as much as possible. For example, silica gel may be mixed and stored in a desiccator, or may be stored in a vacuum desiccator.
Once it comes into contact with the moisture in the air and absorbs moisture, it may be dried again until the weight change disappears to remove the moisture. For example, a heating type dryer may be used, or a vacuum dryer may be used. It may be stored in an environment with a relative humidity of 25% RH or less and dried until there is no change in weight. At this time, it is preferable to replace the water with an organic liquid by the above-mentioned method and then dry the product. As a result, aggregation during drying can be suppressed, and the decrease in pore volume of the inorganic ion adsorbent can be suppressed.

[Step (2): Crushing step of inorganic ion adsorbent]
In the step (2), the powder of the inorganic ion adsorbent obtained in the step (1) is pulverized. The pulverization method is not particularly limited, and dry pulverization or wet pulverization can be used.
The dry crushing method is not particularly limited, and an impact crusher such as a hammer mill, an airflow crusher such as a jet mill, a medium crusher such as a ball mill, a compression crusher such as a roller mill, or the like is used. be able to.
Among them, the airflow type crusher is preferable because the particle size distribution of the crushed inorganic ion adsorbent can be sharpened.
When the dry pulverization method is used, it is preferable to pulverize in an environment where the amount of water in the air is as small as possible. For example, it is preferable to perform pulverization in a room or booth in which the relative humidity is controlled to 25% RH or less. As a result, moisture absorption to the inorganic ion adsorbent can be prevented, and the water content of the inorganic ion adsorbent can be appropriately controlled.
The wet pulverization method is not particularly limited as long as it can pulverize and mix a good solvent of an inorganic ion adsorbent and an organic polymer resin, such as pressure type fracture, mechanical grinding, and sonication. The means used for the physical crushing method of can be used.
Specific examples of the pulverizing and mixing means include a generator shaft type homogenizer, a blender such as a waring blender, a medium stirring type mill such as a sand mill, a ball mill, an attritor, and a bead mill, a jet mill, a mortar and pestle, a mortar, an ultrasonic processor, etc. Can be mentioned.
Among them, a medium stirring type mill is preferable because it has high pulverization efficiency and can pulverize even a highly viscous one.
The ball diameter used in the medium stirring type mill is not particularly limited, but is preferably 0.1 mm or more and 10 mm or less. If the ball diameter is 0.1 mm or more, the ball mass is sufficient, so that there is crushing power and the crushing efficiency is high, and if the ball diameter is 10 mm or less, the fine crushing ability is excellent.
The material of the balls used in the medium stirring type mill is not particularly limited, but various types of metals such as iron and stainless steel, oxides such as alumina and zirconia, and non-oxides such as silicon nitride and silicon carbide. Examples include ceramics. Among them, zirconia is excellent in that it has excellent wear resistance and there is little contamination (mixture of wear) into the product.

[Step (3): Slurry preparation step]
In the step (3), the inorganic ion adsorbent obtained in the step (2) is mixed with a good solvent of the organic polymer resin, the organic polymer resin, and in some cases, a water-soluble polymer to prepare a slurry.

The good solvent for the organic polymer resin used in the steps (2) and (3) is particularly long as it stably dissolves the organic polymer resin in an amount of more than 1% by mass under the manufacturing conditions of the porous molded product. Not limited to this, conventionally known ones can be used.
Examples of the good solvent include N-methyl-2pyrrolidone (NMP), N, N-dimethylacetamide (DMAC), N, N-dimethylformamide (DMF) and the like.
Only one kind of good solvent may be used, or two or more kinds may be mixed and used.

Regarding the amount of the organic polymer resin added in the step (3), the ratio of the organic polymer resin / (organic polymer resin + water-soluble polymer + good solvent of the organic polymer resin) is 3% by mass or more and 40% by mass or less. It is preferable that the content is 4% by mass or more and 30% by mass or less. When the content of the organic polymer resin is 3% by mass or more, a porous molded product having high strength can be obtained, and when it is 40% by mass or less, a porous molded product having a high porosity can be obtained.

In the step (3), the water-soluble polymer does not necessarily have to be added, but by adding the water-soluble polymer, a fibrous structure that forms a three-dimensionally continuous network structure on the outer surface and the inside of the porous molded body. A porous molded product containing a body can be uniformly obtained, and a porous molded product capable of reliably adsorbing ions even when liquid-passing treatment is performed at an ultra-high speed can be obtained.
The water-soluble polymer used in the step (3) is not particularly limited as long as it is compatible with the good solvent of the organic polymer resin and the organic polymer resin.
As the water-soluble polymer, any of a natural polymer, a semi-synthetic polymer, and a synthetic polymer can be used.
Examples of the natural polymer include guar gum, locust bean gum, color ginan, gum arabic, tragant, pectin, starch, dextrin, gelatin, casein, collagen and the like.
Examples of the semi-synthetic polymer include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl starch, methyl starch and the like.
Examples of the synthetic polymer include polyvinyl alcohol, polyvinylpyrrolidone, polyvinylmethyl ether, carboxyvinyl polymer, polyethylene glycols such as sodium polyacrylate, tetraethylene glycol, and triethylene glycol.
Among them, synthetic polymers are preferable from the viewpoint of enhancing the supportability of the inorganic ion adsorbent, and polyvinylpyrrolidone and polyethylene glycol are more preferable from the viewpoint of improving porosity.
The mass average molecular weight of polyvinylpyrrolidone and polyethylene glycols is preferably 400 or more and 350,000 or less, more preferably 1,000 or more and 1,000,000 or less, and 2,000 or more and 100,000 or less. The following is more preferable.
If the mass average molecular weight is 400 or more, a porous molded product having a high surface opening property can be obtained, and if it is 35,000,000 or less, the viscosity of the slurry at the time of molding is low, so that molding tends to be easy. is there.
The mass average molecular weight of the water-soluble polymer can be measured by dissolving the water-soluble polymer in a predetermined solvent and performing gel permeation chromatography (GPC) analysis.

The amount of the water-soluble polymer added is such that the ratio of the water-soluble polymer / (water-soluble polymer + organic polymer resin + good solvent of the organic polymer resin) is 0.1% by mass or more and 40% by mass or less. It is more preferably 0.1% by mass or more and 30% by mass or less, and further preferably 0.1% by mass or more and 10% by mass or less.
When the amount of the water-soluble polymer added is 0.1% by mass or more, the porous molded product contains a fibrous structure that forms a three-dimensionally continuous network structure on the outer surface and inside of the porous molded product. Is uniformly obtained. When the amount of the water-soluble polymer added is 40% by mass or less, the outer surface opening ratio is appropriate, and the amount of inorganic ion adsorbents on the outer surface of the porous molded product is large, so that the liquid is passed through at ultra-high speed. Even so, a porous molded body capable of reliably adsorbing ions can be obtained.

In the present embodiment, the viscosity of the slurry produced in step (3) is 500 mPa · s.
It is preferably 10,000 mPa · s or less, more preferably 1,000 mPa · s or more and 8000 mPa · s or less, and further preferably 1,500 mPa · s or more and 6,000 mPa · s or less. When the viscosity of the slurry is smaller than 500 mPa · s, the porous molded body is easily deformed when it lands on the coagulating liquid in the step (4) molding step. On the other hand, if the viscosity of the slurry is larger than 10,000 mPa · s, the discharge rate is lowered and the discharge is clogged in the step (4) molding step, which makes molding difficult.

In the present embodiment, the water content of the good solvent of the organic polymer resin used may be less than 10% by mass, preferably less than 6% by mass, and more preferably less than 2% by mass.
The water content of a good solvent of an organic polymer resin can be determined by measuring with the Karl Fischer method.
If the water content of the good solvent of the organic polymer resin is larger than 10% by mass, water, which is a poor solvent, is mixed in the slurry in the slurry preparation process, and phase separation of a part of the organic polymer resin occurs in the slurry, which is not possible. It becomes uniform, the porous molded body becomes brittle, and the amount of fine particles discharged increases.

In the present embodiment, the weight change rate of the slurry in the mixing due to the mixing of water may be less than 6% by mass, preferably less than 4% by mass, and more preferably less than 2% by mass.
The weight change rate Sd of the slurry during mixing due to the mixing of water is Wf (g) before the start of mixing and Wg (g) after the completion of mixing.
Sd = (Wg-Wf) / Wf x 100
Is required by.
When water, which is a poor solvent, is mixed into the slurry during mixing, phase separation of a part of the organic polymer resin occurs in the slurry and becomes non-uniform, the porous molded body becomes brittle, and the amount of fine particles discharged increases.

In order to achieve the weight change rate due to the mixing of water in the slurry, it is preferable to use a mixing method in which water in the air is not mixed as much as possible. For example, the humidity of the mixing room may be lowered, the mixing device may be surrounded by a dedicated box, and dry air or nitrogen may be blown to prevent water from entering the slurry, or a closed system such as a sealing mixer may be agitated. An apparatus may be used, or the raw material may be placed in a closed container and then shaken until uniform.

[Step (4): Molding step]
In the step (4), the slurry (molding slurry) obtained in the step (3) is molded. The molding slurry is a mixed slurry of an organic polymer resin, a good solvent of the organic polymer resin, an inorganic ion adsorbent, and a water-soluble polymer.
The form of the porous molded body of the present embodiment can take any form such as a particle shape, a thread shape, a sheet shape, a hollow thread shape, a columnar shape, and a hollow columnar shape, depending on the method of molding the molding slurry.

The method of molding into particles, for example, spherical particles is not particularly limited, but for example, the molding slurry stored in the container is scattered from a nozzle provided on the side surface of the rotating container to form a liquid. Examples thereof include a rotary nozzle method for forming droplets. By the rotary nozzle method, it can be formed into a particulate form having a uniform particle size distribution.
Specifically, a method of spraying a molding slurry from a one-fluid nozzle or a two-fluid nozzle to coagulate in a coagulation bath can be mentioned.
The diameter of the nozzle is preferably 0.1 mm or more and 10 mm or less, and more preferably 0.1 mm or more and 5 mm or less. If the diameter of the nozzle is 0.1 mm or more, the droplets are likely to scatter, and if it is 10 mm or less, the particle size distribution can be made uniform.
The centrifugal force is expressed by centrifugal acceleration, and is preferably 5 G or more and 1500 G or less, more preferably 10 G or more and 1000 G or less, and further preferably 10 G or more and 800 G or less.
When the centrifugal acceleration is 5 G or more, the droplets are easily formed and scattered, and when the centrifugal acceleration is 1500 G or less, the molding slurry is discharged without forming a thread, and it is possible to suppress the widening of the particle size distribution. Due to the narrow particle size distribution, the water flow path becomes uniform when the column is filled with the porous compact, so ions (adsorption objects) leak out from the initial stage of water flow even when used for ultra-high-speed water flow treatment ( It has the advantage that it does not break through.

Examples of the method of molding into a thread-like or sheet-like form include a method of extruding a molding slurry from a spun or die having a corresponding shape and coagulating it in a poor solvent.
As a method for forming the hollow filament-shaped porous molded body, by using a spun made of an annular orifice, it can be molded in the same manner as the method for forming the filamentous or sheet-shaped porous molded body.
As a method for forming a cylindrical or hollow cylindrical porous molded body, when the molding slurry is extruded from the spun, it may be solidified in a poor solvent while being cut, or it may be solidified into a thread and then cut. It doesn't matter.

In the present embodiment, when molding the slurry, it is preferable to mold the slurry so as not to come into contact with moisture in the air as much as possible. For example, the humidity of the molding room may be lowered, or the molding apparatus may be surrounded by a dedicated box and dry air, nitrogen, or the like may be blown to prevent moisture from being mixed into the slurry.
When the time of contact with moisture in the air is long and the amount of moisture mixed increases, phase separation of some organic polymer resins occurs in the slurry and becomes non-uniform, the porous molded body becomes brittle, and the amount of fine particles discharged increases. .. In addition, the surface opening diameter of the molded porous molded product becomes large, and fine particles easily flow out from the inside of the porous molded product.

[Step (5): Solidification step]
In the step (5), the solidified molded product obtained in the step (4) is solidified in a poor solvent to obtain a porous molded product.

[Poor solvent]
As the poor solvent used in the step (5), a solvent having a solubility of 1% by mass or less of the organic polymer resin under the conditions of the step (5) can be used, and for example, alcohols such as water, methanol and ethanol, etc. Examples thereof include aliphatic hydrocarbons such as ethers, n-hexane and n-heptane. Of these, water is preferable as the poor solvent.
In the step (5), a good solvent is brought in from the preceding step, and the concentration of the good solvent changes at the start and the end of the solidification step. Therefore, it may be a poor solvent to which a good solvent is added in advance, and it is preferable to perform the coagulation step by controlling the concentration while separately adding water or the like so as to maintain the initial concentration.
By adjusting the concentration and temperature of the good solvent, the structure (outer surface aperture ratio and particle shape) of the porous molded product can be controlled.
When the poor solvent is water or a mixture of a good solvent of an organic polymer resin and water, the content of the good solvent of the organic polymer resin with respect to water is preferably 0% by mass or more and 80% by mass or less in the coagulation step. , 0% by mass or more and 70% by mass or less, and further preferably 0% by mass or more and 60% by mass or less.
When the content of the good solvent of the organic polymer resin is 80% by mass or less, the effect of improving the shape of the porous molded product can be obtained.
The temperature of the poor solvent is preferably 10 ° C. or higher and 60 ° C. or lower, more preferably 15 ° C. or higher and 50 ° C. or lower, and 20 ° C. or higher and 40 ° C. or lower from the viewpoint of controlling the temperature and humidity of the space. It is more preferable to have.
When the temperature of the poor solvent is higher than 60 ° C., the surface opening diameter of the porous molded product becomes large, and the number of fine particles flowing out from the inside of the porous molded product increases. Further, when the temperature of the poor solvent is lower than 10 ° C., the interfacial tension of the poor solvent becomes high, and the molding slurry stored in the container is scattered from the nozzle provided on the side surface of the rotating container to cause a liquid. When particles are formed by a rotary nozzle method or the like for forming droplets, when the droplets land on a poor solvent, they float and deform without sinking, and spherical particles cannot be obtained.

[Step 6: Organic liquid immersion step of porous molded product]
The porous molded product obtained in the step (5) may be immersed in an organic liquid.
After immersing in an organic liquid having twice the bulk density of the porous molded product for 24 hours, the supernatant organic liquid is discarded. Next, the operation of immersing the porous molded product in 10 times the amount of pure water and discarding the supernatant is repeated 5 times or more to remove the organic liquid.
By carrying out this operation, the organic polymer resin on the surface of the porous molded product is slightly dissolved, and then immersed in water, which is a poor solvent, and reprecipitated on the surface to cause fine particles on the surface of the porous molded product. Can be coated with an organic polymer resin, and the amount of outflow of fine particles can be reduced.

[Organic liquid]
The organic liquid used in the step (6) is not particularly limited as long as it has the effect of slightly dissolving the organic polymer resin, and examples thereof include alcohols, ketones, esters, ethers and the like. Further, the organic liquid to be immersed may be a mixture thereof or a mixture with water.
Using the solubility parameter (HSP value) defined by Hansen et al., The distance between the Hansen solubility parameter of the organic liquid and the solubility parameter of the organic polymer (HSP value distance) is 10 or more and 30 or less. Is preferable. The solubility parameter distance of Hansen is more preferably 12 or more and 25 or less, and further preferably 14 or more and 20 or less.
The HSP value distance is calculated by the following formula.
HSP value distance = [4 × (dDp ^2- dDs ² ) + (dPp ^2- dPs ² ) + (dHp ^2- dHs ² )] ^1/2
Here, dDp is a dispersion component of the solubility parameter of the organic polymer resin, dPp is a polar component of the solubility parameter of the organic polymer resin, dHp is a hydrogen bond component of the solubility parameter of the organic polymer resin, and dDs is a solubility parameter of the organic liquid. The dispersion component, dPs, is the solubility parameter of the organic liquid and the polar component of the parameter, and dHs is the hydrogen bond component of the solubility parameter of the organic liquid.
When the HSP value distance is larger than 30, the organic polymer resin is not sufficiently dissolved, so that the surface coating is small and the effect of suppressing the outflow of fine particles is not sufficient. On the other hand, if the HSP value distance is smaller than 10, the organic polymer resin melts too much, the structure of the porous molded body cannot be maintained, and the molded body becomes brittle, and the outflow amount of fine particles increases.

[Step (7): Cleaning step of porous molded product]
In step 7, the porous molded product obtained in step (5) or step (6) is washed to remove fine particles adhering to the surface of the porous molded product.

[column]
The cleaning of the porous molded product is performed with the porous molded product filled in the column.
The column means a tubular container provided with solid-liquid separating means such as a perforated plate or a mesh at least one of the lower part and the upper part so that the porous molded body does not flow out.
The material of the column is not particularly limited, but for example, stainless steel, FRP (reinforced plastic containing glass fiber), glass, PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), PC (polycarbonate). Various plastics such as.
The inner surface of the column may be lined with rubber or fluororesin in consideration of acid resistance and basic resistance.

[Washing method]
When the porous molded product of the present embodiment is used as an adsorbent, it can be washed while being filled in the column or the adsorption tower.
In the present embodiment, the cleaning liquid of the porous molded product can be passed through the cleaning liquid by an upward flow flowing from the bottom of the column, a downward flow flowing the cleaning liquid from the top of the column, or both. When the cleaning liquid is flowed in an upward flow, the cleaning liquid can be filled in the entire inside of the column without embracing air at the initial stage of passing the liquid. When the cleaning liquid is flowed in a downward flow, the porous molded products do not move due to the flow of the cleaning liquid, and there is no risk of wear due to contact between the porous molded products and generation of fine particles.

In the present embodiment, the flow rate of the cleaning liquid of the porous molded product is preferably SV1hr ^-1 or more and SV300hr ^-1 or less, more preferably SV1hr ^-1 or more and SV250hr ^-1 or less, and further preferably SV1hr ^-1 or more and SV200hr ^-1. Is. Cleaning of impurities existing inside the porous molded body is mainly due to the effect of diffusion, and if the SV is ^{smaller than 1} hr-1, impurities stay in the cleaning liquid and the cleaning effect due to diffusion is reduced. If the SV is ^{larger than 300 hr-1} , the porous molded body may be deformed due to high pressure loss when flowing in the downward flow, and the porous molded body moves violently inside the column when flowing in the upward flow. There is a risk that the porous molded bodies will wear out due to contact with each other and fine particles will be generated.

In the present embodiment, the flow rate of the cleaning liquid of the porous molded product is preferably 1 times or more and 10,000 times or less, more preferably 2 times or more and 7 times the bulk volume of the porous molded product. The amount is 5,000 times or less, more preferably 3 times or more and 5,000 times or less.
As for the bulk volume of the porous molded body, if the shape is short, such as particle-like, columnar, or hollow columnar, the apparent volume of the wet molded body is measured using a measuring cylinder or the like.
When the amount of the cleaning liquid passing through is 1 times or more the bulk volume of the porous molded product, the impurity fine particles physically attached to the porous molded product can be sufficiently cleaned.

In the present embodiment, the cleaning liquid for the porous molded product is not particularly limited, and one having a high removing effect on impurities contained can be selected. For example, when it is desired to remove impurities adsorbed on the metal oxide which is an inorganic ion adsorbent, a sodium hydroxide solution may be used, and when it is desired to remove liberated impurities, it may be washed with pure water.
Normally, anions, which are impurities mixed from the raw material or the manufacturing process, are often adsorbed on the inorganic ion exchanger, and impurity fine particles mixed from the raw material or the manufacturing process are electrostatically charged on the surface of the porous molded body. Therefore, it is preferable to perform cleaning with a sodium hydroxide solution and then further with pure water.
Further, a preferable cleaning liquid may be selected depending on the intended use after cleaning. For example, when the porous molded product is used for wastewater treatment, it may be washed with pure water, and when it is used for medical purposes, physiological saline or physiological saline containing a blood anticoagulant may be used. ..
The cleaning liquid may be one kind, or a plurality of cleaning liquids may be used in combination.

[Manufacturing equipment for porous molded products]
The apparatus for producing a porous molded product of the present embodiment includes, for example, a rotary container for scattering droplets by centrifugal force and a coagulation tank for storing a coagulating liquid.
The rotary container that scatters the droplets by centrifugal force is not limited to one having a specific structure as long as it has a function of making the molding slurry into spherical droplets and scatters by centrifugal force. Examples include a rotary nozzle.
In the rotating disk, the forming slurry is supplied to the center of the rotating disk, and the forming slurry is developed into a film with a uniform thickness along the surface of the rotating disk, and is split into drops by centrifugal force from the periphery of the disk. To scatter fine droplets.
For the rotary nozzle, a large number of through holes are formed in the peripheral wall of the hollow disk-shaped rotary container, or the nozzle is attached by penetrating the peripheral wall to supply the molding slurry into the rotary container and rotate the rotary container at that time. A molding slurry is discharged from a through hole or a nozzle by centrifugal force to form droplets.

The coagulation tank for storing the coagulation liquid is not limited to one having a specific structure as long as it has a function of storing the coagulation liquid. Examples thereof include a coagulation tank having a structure in which a coagulation liquid naturally flows down along the inner surface of the body by gravity.
The coagulation tank with an open top surface is a device that naturally drops droplets scattered in the horizontal direction from a rotary container and captures the droplets on the water surface of the coagulation liquid stored in the coagulation tank with an open top surface.
The coagulation tank, which has a structure in which the coagulation liquid naturally flows down by gravity along the inner surface of the cylinder arranged so as to surround the rotating container, allows the coagulation liquid to flow out along the inner surface of the cylinder at a substantially uniform flow rate in the circumferential direction. , A device that captures and coagulates droplets in a coagulating liquid flow that naturally flows down along the inner surface.

[Use of porous molded products]
Since the porous molded article of the present embodiment has a small amount of impurity fine particles flowing out from the porous molded article, phosphorus, boron, arsenic, and fluorine are particularly used in manufacturing process water applications such as pharmaceutical production and as medical devices. It can be suitably used as an adsorbent for ions such as. Among them, it is more preferable to use it as an adsorbent for phosphate ions.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The physical characteristics of the molded product were measured by the following method.

(1) Number of fine particles outflow measured by a fine particle meter The porous molded body was subjected to the above-mentioned fine particle outflow test, and the number of fine particles was measured using a fine particle meter (manufactured by Rion Co., Ltd., KL-05 (trade name)). ..
The set values at the time of measurement were set as follows. Syringe capacity 25 mL, suction flow rate 25 mL / min, discharge flow rate 100 mL / min, empty suction amount 0.5 mL, measurement capacity 5.0 mL, empty measurement number 1 time, measurement number 3 times, measurement particle size more than 1.3 μm.

(2) Number of Inorganic Ion Adsorbent Fine Particle Outflow Measured by SEM Observation Method The porous molded body was subjected to the fine particle outflow test as described above, the test solution was filtered through a PVDF filter paper, and an SEM observation sample was prepared to prepare an SEM (SEM). Fine particles were observed using TM-1000) manufactured by Hitachi High-Technologies Corporation. The settings for observation were as follows: Observation mode: Charge reduction mode, Photographed image: Reflected electron image, Shooting magnification: 1,000 times, Brightness / Contrast: Adjusted by auto-brightness, Focus: Adjusted by autofocus ..
The captured backscattered electron image was image-analyzed using image analysis software (ImageJ). After capturing the SEM image with image analysis software, ^{select the area of the captured SEM image (23,000 μm 2} ), invert the black and white of the image (select Dark Background), convert the white fine particles to black, and then set the threshold to 0. The number of fine particles visible when set to 2% was measured.

(3) Porosity and specific surface area measured by the nitrogen gas adsorption method After lyophilizing the porous molded body, the specific surface area and pore distribution measuring device (manufactured by Microtrac Bell Co., Ltd., BELSORP-miniII (trade name)) )).
Approximately 0.3 g of freeze-dried porous molded body is measured, placed in a dedicated 5 mL glass cell, and the pore volume and specific surface area are measured by adsorption and desorption of nitrogen gas while cooling the glass cell with liquid nitrogen. Was done.
Nitrogen gas having a purity of 99.99% by volume or more was used as the adsorbent, and helium gas having a purity of 99.99% by volume or more was used as the purge gas.
As a reference cell, an empty glass cell having the same volume as the glass cell for measurement was used, and the measurement was performed with the setting to correct the measured value.
The measurement method was a simple method, and the measurement was performed by setting the suction relative pressure upper limit to 0.95 and the desorption relative pressure lower limit to 0.3.
The analysis by the BET method and the BJH method after the measurement was performed using analysis software (BEL Master (Version 6.3.1.0) manufactured by Microtrack Bell Co., Ltd.).

(4) Freeze-drying of the porous molded product Freeze-drying was carried out using a freeze-dryer (FDS-1000 type (trade name) manufactured by EYELA).
Weigh 1 mL or more and 10 mL or less of a wet porous molded body using a measuring cylinder or the like, put it in a 100 mL glass eggplant flask, and then leave it in a freezer at -18 degrees or less for 6 hours or more to include it. After freezing the water, the eggplant flask was connected to a freeze-dryer, and freeze-dried for 10 hours or more under the conditions of a vacuum degree of 20 Pa or less and a trap temperature of −80 ° C. or less.

(5) Average particle size of the porous molded body The average particle size of the porous molded body was measured by a laser diffraction / scattering type particle size distribution measuring device (LA-950 (trade name) manufactured by HORIBA). Water was used as the dispersion medium. When measuring the sample using cerium hydrated oxide as the inorganic ion adsorbent, the value of cerium oxide was used for the refractive index. Similarly, when measuring a sample using hydrated zirconium oxide for the inorganic ion adsorbent, the value of zirconium oxide was used for the refractive index.

(6) Viscosity measurement of slurry The viscosity of the slurry produced in the above-mentioned step (3): slurry preparation step is controlled to a temperature of 25 ° C ± 1 ° C., and then placed in a cylindrical container having a diameter of 50 mm and a depth of 70 mm. Was charged and measured using a B-type viscometer (RB-85L (trade name) manufactured by Toki Sangyo Co., Ltd.). Rotor No. Using No. 3 (trade name), the viscosity was measured at a rotation speed of 0.3 rpm or more and 60 rpm or less.

(7) a phosphorus adsorption amount trisodium phosphate _{(Na 3 PO 4 · 12H 2} O) was dissolved in distilled water to prepare a liquid phosphorus concentration 9 mg-P / L, adsorption stock liquid prepared to pH7 with sulfuric acid And said.
The porous formed article 8mL weighed repeatedly tapping using measuring cylinder and packed in a column (internal diameter 10 mm), the adsorption stock solution 960mL / hr (SV120hr ^-1), and 1,920mL / hr (SV240hr ^-1 ), Each of the liquids was passed.
The effluent from the column (treatment liquid) is sampled every 10 minutes, the phosphorus concentration in the treatment water is measured, and the cumulative adsorption amount of phosphorus (g-P / L-porous) up to 4 hours when the liquid is passed. Molded body) was obtained.
The phosphate ion concentration was measured using a phosphoric acid measuring device Phosfax Compact (trade name) manufactured by HACH.
When the cumulative adsorption amount of phosphorus is ^{1.8 (g-P / L-porous molded product) or more at the speed of SV120hr-1} , the adsorption capacity of the porous molded product is large and it is good as a phosphorus adsorbent. Yes, if it was 2.5 (g-P / L-porous molded product) or more, it was judged to be even better.

[Example 1]
2000 g of cerium sulfate tetrahydrate (Wako Junyaku Co., Ltd.) is put into 50 L of pure water, dissolved using a stirring blade, and then 8 M caustic soda (Wako Pure Chemical Co., Ltd.) 3 L is 20 mL / min. The mixture was added dropwise at this rate to obtain a precipitate of hydrated cerium oxide. After filtering the obtained precipitate with a filter press, 500 L of pure water is passed through the solution for washing, and 80 L of ethanol (Wako Pure Chemical Industries, Ltd.) is passed through the solution to remove the water contained in the hydrated cerium oxide. Replaced with ethanol. At this time, 10 mL of the filtrate at the end of filtration was collected, and the water content was measured with a Karl Fischer titer (CA-200 (trade name) manufactured by Mitsubishi Chemical Analytech Co., Ltd.). Was 5% by mass, and the substitution rate of the organic liquid was 95% by mass. The hydrated cerium oxide containing the obtained organic liquid was air-dried to obtain a dried hydrated cerium oxide. The dried hydrated cerium oxide was stored in a desiccator with a relative humidity of 20% RH.
The obtained dry hydrated cerium oxide was used in a jet mill device (SJ-100 (trade name) manufactured by Nisshin Engineering Co., Ltd.) under the conditions of a pressure pressure of 0.8 MPa and a raw material feed rate of 100 g / hr. Crushed. The hydrated cerium oxide after grinding was stored in a desiccator having a relative humidity of 20% RH.
Immediately before the stirring operation, the water content of the raw material N-methyl-2pyrrolidone (NMP, Mitsubishi Chemical Corporation) was measured to be 0.0% by mass, and the water content of hydrated cerium oxide after pulverization was measured. It was 4.8% by mass. Add 220 g of the above N-methyl-2pyrrolidone (NMP, Mitsubishi Chemical Corporation), 120 g of the hydrated cerium oxide powder after crushing, and 40 g of the polyether sulfone, and bring the temperature to 60 ° C. using a closed stirrer. Stirring and dissolving while heating to obtain a uniform molding slurry solution. When the weight measured immediately before stirring the raw material and the weight measured after stirring the raw material were measured, the change in slurry weight due to moisture absorption was 0.0% by mass.
The obtained molding slurry was supplied into a cylindrical rotary container having a nozzle having a diameter of 4 mm on the side surface, and the container was rotated to form droplets from the nozzle by centrifugal force (15 G). At this time, the cylindrical rotary container was installed in a booth in which dry air was blown, and the operating environment was room temperature 25 ° C. and relative humidity 25% RH.
The coagulation liquid having an NMP content of 50% by mass with respect to water was adjusted to 25 ° C. and stored, and the droplets were landed in a coagulation tank having an upper opening to solidify the molding slurry.
The solidified porous molded product was collected, 150 mL of the porous molded product was filled in a column having an inner diameter of 20 mmφ, and 1500 mL of a 0.4 mass% sodium hydroxide aqueous solution heated to 70 ° C. was added to the column under the condition of ^SV10hr-1. Alkaline cleaning was performed by passing the liquid from the upper part to the lower part. Further, 450 L of pure water was passed through the column from the upper part to the lower part under the condition of ^{SV80hr-1, and washed with water to obtain a washed porous molded product.}

[Example 2]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of ethanol passed through cerium hydrated oxide was 60 L and the substitution rate with an organic liquid was 83% by mass. It was.

[Example 3]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of ethanol passed through cerium hydrated oxide was 40 L and the substitution rate with the organic liquid was 72% by mass. It was.

[Example 4]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of ethanol passed through cerium hydrated oxide was 20 L and the substitution rate with an organic liquid was 54% by mass. It was.

[Example 5]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of ethanol to be passed was 4 L and the substitution rate with the organic liquid was 14% by mass.

[Example 6]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 200 g.

[Example 7]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 150 g.

[Example 8]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 50 g.

[Example 9]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 30 g.

[Example 10]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 20 g.

[Example 11]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 10 g.

[Example 12]
The hydrated cerium oxide powder after pulverization was stored in a container controlled to a relative humidity of 50% RH, and the water content was set to 8.6% by mass in the same manner as in the method described in Example 1. A spherical porous molded body was obtained.

[Example 13]
The hydrated cerium oxide powder after pulverization was stored in a container controlled to a relative humidity of 80% RH, and the water content was set to 13.9% by mass in the same manner as in the method described in Example 1. A spherical porous molded body was obtained.

[Example 14]
Spherical porosity in the same manner as in Example 1 except that the raw material N-methyl-2pyrrolidone was transferred to an open container and left in the air to have a water content of 1.8% by mass. A molded body was obtained.

[Example 15]
Spherical porosity in the same manner as in Example 1 except that the raw material N-methyl-2pyrrolidone was transferred to an open container and left in the air to have a water content of 5.3% by mass. A molded body was obtained.

[Example 16]
Spherical porosity in the same manner as in Example 1 except that the raw material N-methyl-2pyrrolidone was transferred to an open container and left in the air to have a water content of 7.7% by mass. A molded body was obtained.

[Example 17]
A spherical porous molded product was prepared in the same manner as in Example 1 except that the slurry was stirred by an open system and the weight change before and after stirring by moisture absorption was 1.5% by mass. Obtained.

[Example 18]
A spherical porous molded product was prepared in the same manner as in Example 1 except that the slurry was stirred by an open system and the weight change before and after stirring by moisture absorption was 3.3% by mass. Obtained.

[Example 19]
A spherical porous molded product was prepared in the same manner as in Example 1 except that the slurry was stirred by an open system and the weight change before and after stirring by moisture absorption was 5.7% by mass. Obtained.

[Example 20]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the porous molded product was immersed in an ethanol solution having a concentration of 100% by mass.

[Comparative Example 1]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of ethanol to be passed was set to 0 L and the substitution rate with the organic liquid was set to 0% by mass.

[Comparative Example 2]
A spherical porous molded product was obtained in the same manner as in Example 1 except that the amount of the hydrated cerium oxide powder used as a raw material was 300 g.

[Comparative Example 3]
The hydrated cerium oxide powder after pulverization was stored in a container controlled to a relative humidity of 90% RH, and the water content was set to 15.8% by mass in the same manner as in the method described in Example 1. A spherical porous molded body was obtained.

[Comparative Example 4]
Spherical porosity in the same manner as in Example 1 except that the raw material N-methyl-2pyrrolidone was transferred to an open container and left in the air to have a water content of 11.2% by mass. A molded body was obtained.

[Comparative Example 5]
A spherical porous molded product was prepared in the same manner as in Comparative Example 1 except that the slurry was stirred by an open system and the weight change before and after stirring by moisture absorption was 6.8% by mass. Obtained.

The physical characteristics of the porous molded products obtained in Examples 1 to 20 and Comparative Examples 1 to 5 are shown in Tables 1-1 to 1-3 below (Tables 1-2 and 1-3 are Table 1-1. It is a continuation of.).

In the slurry, based on the results shown in Tables 1-1 to 1-3 above, that is, based on "MOX water content (mass%)", "solvent water content (mass%)", and "slurry weight change (mass%)". It was found that if the amount of water mixed into the particle is small, a porous molded body having a small amount of fine particles flowing out when subjected to the fine particle test can be obtained.

The porous molded product according to the present invention can remove ions in the water to be treated, particularly phosphate ions, and the outflow of impurity fine particles into the water to be treated is small. It can be suitably used for removing harmful substances in.

Claims (16)

A porous molded body containing an organic polymer resin and an inorganic ion adsorbent, and when subjected to the following fine particle outflow test, the number of outflow of impurity fine particles having a diameter of more than 1.3 μm measured under the following conditions is 1000 / Porous molded article, characterized by less than ml:
[conditions]
Fine particle outflow test solution: 5 mL of a porous molded body and 50 mL of pure water are placed in a container having a height of 5 cm or more and 10 cm or less and a volume of 100 mL, and then reciprocated for 30 minutes at a rotation speed of 250 rpm. Was collected with a 5 mL pipette;
Fine particle meter: (manufactured by Rion Co., Ltd., KL-05 (trade name)), set values: syringe capacity 25 mL, suction flow rate 25 mL / min, discharge flow rate 100 mL / min, air suction volume 0.5 mL, measurement capacity 5.0 mL , Empty measurement times 1 time, measurement times 3 times, measurement particle size more than 1.3 μm. The porous molding according to claim 1, wherein the number of fine particles outflow including the inorganic ion adsorbent measured by the following SEM observation method when subjected to the fine particle outflow test is ^{less than 200 pieces / (23,000 μm 2).} body:
[SEM observation method]
SEM observation test: 25 mL of the fine particle outflow test solution was separated, suction filtered with a PVDF circular filter paper having a diameter of 47 mm and a mesh size of 0.1 μm, and the fine particles were captured on the filter paper, and then the filter paper was coated with silica gel. After storing in a desiccator containing the filter paper and drying it until there is no change in weight, the central 5 mm square of the filter paper is cut out with a cutter knife and fixed on an SEM sample table with carbon tape;
SEM observation device: SEM (manufactured by Hitachi High-Technologies Co., Ltd., TM-1000), observation mode: charge reduction mode, image: reflected electron image, image magnification: 1,000 times, brightness / contrast: auto brightness, focus : After shooting an SEM image with auto focus and capturing the SEM image with image analysis software (ImageJ), ^{select the area (23,000 μm 2} ) of the shot SEM image and invert the black and white of the image (Dark Background). (Selection) After converting white fine particles to black, measure the number of fine particles that can be seen when the threshold value is set to 0.2%, repeat the above operation three times, and measure the average value by SEM observation method for inorganic ion adsorption. The number of fine particles outflow including the body. Total pore diameters 1nm or 80nm or less of pore volume as measured by nitrogen gas adsorption method, is less than the inorganic per unit mass 0.03 cm ³ / g or more 0.7 cm ³ / g of the ion adsorbent, claim The porous molded body according to 1 or 2. Total pore diameters 1nm or 80nm or less of pore volume as measured by nitrogen gas adsorption method, wherein at unit mass per porous formed article 0.03 cm ³ / g or more 0.6 cm ³ / g or less, claims The porous molded body according to any one of 1 to 3. The porous molded body according to any one of claims 1 to 4, wherein the specific surface area measured by the nitrogen gas adsorption method is 50 m ² / g or more and 400 m ^{2 / g or less.} The porous molded body according to any one of claims 1 to 5, wherein the amount of the inorganic ion adsorbent contained in the porous molded body is 20% by mass or more and 85% by mass or less. The porous molded article according to any one of claims 1 to 6, which is in the form of spherical particles having an average particle size of 100 μm or more and 2500 μm or less. The porous molded body according to any one of claims 1 to 7, wherein the bulk density of the porous molded body is 0.2 g / ml or more and 0.7 g / ml or less. The inorganic ion adsorbent has the following formula (I):
MNxOn · mH ₂ O. .. .. (I)
{In the formula, x is 0 or more and 3 or less, n is 1 or more and 4 or less, m is 0 or more and 6 or less, and M and N are Ti, Zr, Sn, Sc, Y. , La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Si, Cr, Co, Ga, Fe, Mn, Ni, V, Ge, Nb It is a metal element selected from the group consisting of and Ta, and is different from each other. } And / or the following formula (III):
QyRz (CO ₃ ) s · tH ₂ O. .. .. (III)
{In the formula, y is 1 or more and 2 or less, z is 0 or more and 1 or less, s is 1 or more and 3 or less, t is 0 or more and 8 or less, and Q and R are. , Mg, Ca, Sr, Ba, Sc, Mn, Fe, Co, Ni, Ag, Zn, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , And a metal element selected from the group consisting of Lu, which are different from each other. } At least one kind of metal carbonate,
The porous molded article according to any one of claims 1 to 8, which contains. The metal oxides are the following groups (a) to (c):
(A) Titanium hydrate, zirconium hydrate, tin hydrate, cerium hydrate, lanthanum hydrate, and yttrium hydrate;
(B) A composite metal oxide of at least one metal element selected from the group consisting of titanium, zirconium, tin, cerium, lanthanum and yttrium and at least one metal element selected from the group consisting of aluminum, silicon and iron;
(C) Activated alumina;
The porous molded article according to claim 9, which is selected from. The metal carbonate is the following group (d):
(D) Magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, scandium carbonate, manganese carbonate, iron carbonate, cobalt carbonate, nickel carbonate, silver carbonate, zinc carbonate, yttrium carbonate, lantern carbonate, cerium carbonate, placeodium carbonate, neodymium carbonate , Samalium Carbonate, Europium Carbonate, Gadrinium Carbonate, Terbium Carbonate, Disprosium Carbonate, Formium Carbonate, Elbium Carbonate, Thurium Carbonate, Itterbium Carbonate, and Rutetium Carbonate;
The porous molded article according to claim 9, which is selected from. The organic polymer resin is ethylene vinyl alcohol copolymer (EVOH), polyacrylonitrile (PAN), polysulfone (PS), polyethersulfone (PES), polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), poly. The porous molded product according to any one of claims 1 to 11, which is at least one selected from the group consisting of aryl ether sulfone, polypropylene, polystyrene, polycarbonate, cellulose, and cellulose triacetate. A column filled with the porous molded product according to any one of claims 1 to 12. The porous molded product according to any one of claims 1 to 12 is packed in the column according to claim 13, and the cleaning liquid and / or the filling liquid flows from under the column in an upward flow, a cleaning liquid and / or a filling. A method for cleaning and / or filling a porous molded article, which comprises a step of passing a cleaning liquid and / or a filling liquid through the column by a downward flow in which the liquid flows from above the column, or both. The method according to claim 14, wherein the cleaning liquid and / or the filling liquid is passed at a liquid passing speed of SV1hr ^-1 or more and SV300hr ^{-1 or less.} The method according to claim 14 or 15, wherein the cleaning liquid and / or the filling liquid is passed in an amount of 1 times or more and 10,000 times or less the bulk volume of the porous molded product.