JPH04198330A - Ion-exchange cartridge filter - Google Patents

Abstract

PURPOSE:To provide the subject new cartridge containing an ion-exchange fiber having a specific polymer component exposed on the fiber surface, exhibiting excellent ion-exchanging characteristics and filtration characteristics and having the form of nonwoven fabric having excellent workability. CONSTITUTION:The objective cartridge filter contains ion-exchange fiber consisting of fiber aggregates containing 10wt.% (on an average) of a sheath- core conjugate fiber containing a syndiotactic 1,2-butadiene (1,2-SBD) having a melting point (Tm deg.C) of 75<=Tm<=150 and constituting the surface of the fiber and bonded with each other by the thermal welding of the 1,2-SBD. The main chain of the fiber has syndiotactic poly(1,2-butadiene) structure and a polymer component containing ion-exchange functional group introduced into a part of the side chain ethylene group is exposed on the surface of the fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel ion exchange cartridge filter.

[Prior art] Ion-exchange resins are porous, hard, and brittle, so they break easily when kept in a dry state.They are generally stored in a water seal.They also break easily when frozen, and when they expand or contract due to thermal changes, they are extremely fragile. Because they are easily friable and ion-exchange groups, such as sulfone groups, are susceptible to thermal oxidative deterioration, cartridge filters made by thermoforming, which are used in combination with thermally bonded fibers to uniformly disperse ion-exchange resin between the fibers, have not been put into practical use. do not have.

None of the sheet-like products of ion-exchange fibers found in JP-A-5.6-118937 and JP-A-63-90541 have a self-adhesive function between the base fiber and the ion-exchange fiber obtained therefrom; In order to achieve this, the ion exchange fibers are bonded in a dry state, using either a resin bonding process or a heat-adhesive process.

The ion-exchange fibers currently in practical use are as rigid as carbon fibers, with the exception of fibers that have been repurposed from highly absorbent fibers that have acrylic fibers as their base fibers, and are made using mechanical opening methods such as roller cards. However, sheet-like materials containing ion-exchange fibers are only paper-like materials that are mixed with other fibers to give flexibility, as in JP-A-59-1873, and others are not sheet-like materials. Currently, fibers are dispersed in water as fiber bundles or short fibers and used for ion exchange purposes.

The ion-exchange fibers and base fibers currently used in linings do not have a self-adhesive function and are poor in flexibility, so the use of hard and brittle polystyrene-based fibers has little improvement in flexibility and brittleness. Tame Unexamined Patent Publication No. 52-12098
Using a crosslinked material such as polystyrene as the sea component as in Publication No. 5,
Sea-island bicomponent fibers or multifilament composite fibers containing a fiber-formable thermoplastic resin as an island component are melt-spun and subjected to a chemical reaction treatment to crosslink and introduce ion-exchange groups into an aromatic vinyl resin such as polystyrene as a sea component. . In addition, ion exchange fibers obtained by methods other than melt spinning include:
JP-A-55-71815 and JP-A No. 62-1841
1, in which polyvinyl alcohol fiber obtained by a dry spinning method is fired, crosslinked and unsaturated bonds are added to the chemical structure similar to that of carbon fibers, and ion exchange groups are introduced into the bonds, and JP-A-Sho There are modacrylic fibers obtained by a dry spinning method as disclosed in Japanese Patent No. 55-50032.

In any case, when chemical reactions such as sulfonation reactions introduce and crosslink ion-exchange groups, the resulting ion-exchange fibers become considerably more rigid than the base fibers, so the fibers currently in practical use are not commonly used. It does not have the flexibility of synthetic fibers.

[Problems to be Solved by the Invention] As stated in the above-mentioned Japanese Unexamined Patent Publication No. 59-166073, ion exchange resins are brittle and easily crumble when dry. When made into a sheet containing resin, the resin breaks down and becomes fine powder.
There are problems in that the removal is easy to remove and deterioration due to thermal oxidation of the ion exchange group is likely to occur.

The ion-exchange fiber sheet as disclosed in JP-A No. 63-90541 mentioned above has neither the ion-exchange fiber nor its base fibers having a self-adhesive function. Because of the unavoidable mixing of ion-exchange fibers, it is impossible to produce a sheet-like product made only of ion-exchange fibers, resulting in a decrease in ion-exchange properties and the unavoidable thermal alteration of ion-exchange groups.

The fibers are rigid and inflexible and cannot withstand mechanical opening such as roller cards and will be damaged, and the fibers are poorly organized and it is extremely difficult to make into a web, which is a big problem. In general, ion exchange fibers are disclosed in JP-A-59
-As in Publication No. 18731, other fibers are mixed with other fibers for paper-like use, and cannot be used as a dry non-woven fabric. Therefore, it is not possible to wrap a cartridge filter in the form of a bulky and flexible non-woven fabric with ion-exchange ability. The problem was that it couldn't be done.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, an object of the present invention is to provide an ion exchange cartridge filter that has excellent ion exchange properties and is in the form of a nonwoven fabric and has excellent processability.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a main chain having a syndiotactic poly(1,2-butadiene) structure, and at least a part of the ethylene groups in the side chains are ionized. The present invention is an ion-exchange cartridge filter that includes ion-exchange fibers in which a polymer component into which exchangeable functional groups have been introduced exists at least on the surface of the fibers.

Further, the present invention provides melting point (T m 'C) or 75≦Tm<1
50 syndiotactic-1,2-polybutadiene (
A fiber aggregate containing at least an average of 10% by weight of sheath-core type composite fibers having a fiber surface of 1.2-SBD) is heat-melted and bonded with at least 1.2-SBD. This is an ion-exchange cartridge filter in which at least a part of the filter medium is made up of a fiber aggregate in which a functional group having ion-exchange ability is introduced into the side chain of 2-SBD.

[Function] According to the configuration of the present invention described above, the main chain has a syndiotactic poly(1,2-butadiene) structure, and an ion-exchangeable functional group is introduced into at least a part of the ethylene groups in the side chain. This is an ion exchange cartridge filter containing ion exchange fibers in which the polymer component is present at least on the surface of the fibers, so the ion exchange cartridge filter has excellent ion exchange characteristics and filtration characteristics, and is nonwoven and has excellent processability. It can be done.

In addition, syndiotactic-1,2-polybutadiene (1,2-
A fiber aggregate containing at least 10% by weight on average of sheath-core composite fibers having a fiber surface of SBD) is at least 1.2% by weight.
- one of the fibers is bonded by hot melt bonding by SBD;
．． According to the structure of the present invention, which is an ion-exchange cartridge filter in which a fiber aggregate in which a functional group having ion-exchange ability is introduced into the side chain of 2-SBD occupies at least a part of the filter medium, the above-mentioned Similarly, an ion exchange cartridge filter having excellent ion exchange characteristics and filtration characteristics, and having a nonwoven fabric shape and excellent processability can be obtained.

In the present invention, at least a portion of the polymer constituting the fiber surface is at least the following [A], [B], and [C].
It is preferable to have a unit represented by the following formula.

-(C)L! -CH) -[Al CH=CH2 -(CH2-CH)-[B1 CHX-CH2Y -(C)L! -CH) -[C] υ- c+ (However, at least one of X and Y is a sulfonic acid group or an alkali metal base thereof, a carboxyl group or an alkali metal base thereof, a phosphine group or an alkali metal base thereof, an amino group, an alkylamino group) group, alkoxyamino group, )\rogenated alkylamino group, polyamine group, or the above-mentioned derivative group. ) The reason for this is that, as described above, the polymer can sufficiently satisfy ion exchange performance and be flexible.

Here, since unit [A] mainly exhibits flexibility of the polymer, it is preferably present in an amount of 5 to 99 mol%, more preferably 15 to 90 mol%.

Unit [B] is a unit (x
, y is an ion exchange functional group), 1 to 85 mol%
Preferably present, more preferably 5 to 70 mol%
It is.

Unit [C] is a crosslinking part. This unit [C]
For example, in the case of ion exchange for gases, it is not necessary to exist, or in the case of ion exchange for liquids, it is preferable to exist in order to prevent dissolution of the main chain skeleton. For this reason, the existence ratio of unit [C] is O~10
The mole level is preferable, and in the case of liquid ion exchange, it is 2 to 9 molar.
It is preferable that the amount is about mol%.

In addition, the units [A], [B], [C]
In addition, other copolymerization units and arbitrary additives (compositions) may be included within a range that can achieve the functions and effects of the present invention. For example, one unit of the polymer may contain a side chain carboxyl group represented by the following formula [D].

-(C)L! -CH) -[D OOH [Example code] The present invention will be explained in more detail below with reference to Examples.

Note that the present invention is not limited to the following examples.

Since the present invention has a high density of unsaturated ethylene groups in its side chains, chemical treatments such as intermolecular cross-linking treatment and introduction of a functional group (ion exchange group) having ion exchange ability through chemical treatment or physicochemical treatment are required. Processing involving reactions is easy;
The base fiber is a highly flexible sheath-core composite fiber whose sheath component is ion-exchanged SBD, which has a melting point 50 to 100 degrees Celsius lower than the thermal crosslinking temperature, making it easy to use in melt extrusion and as a thermal adhesive component. This is an ion exchange cartridge filter that uses ion exchange fibers as an ion exchanger.

The inventors have discovered that 1,2-SBD with a melting point of 75-120°C
A sheath-core composite fiber (indicated by core component/sheath component) with polypropylene (PP) as the fiber surface and core component can be easily melt-spun and hot-stretched, resulting in a staple (short fiber)
Although it is more flexible than ordinary fibers, it can be made into a carded web using a carding machine, and at a processing temperature of 110 to 150°C, the sheath component 1.2-SBD melts and PP does not melt. .2-SBD can be thermally bonded to form an extremely flexible thermally bonded nonwoven fabric, and 1°2-SBD can be easily crosslinked into macromolecules by irradiation with radiation such as ultraviolet rays or gamma rays; When this nonwoven fabric is treated with hot concentrated sulfuric acid, a sulfone group can be easily introduced into the ethylene side chain of 1,2-SBD, and the resulting nonwoven fabric with ion exchange ability has the same flexibility as a general heat-bonded nonwoven fabric and can be easily bonded. The inventors have discovered that it is possible to form a cartridge filter by wrapping the nonwoven fabric around a porous cylinder and wrapping a general heat-adhesive nonwoven fabric around the outermost periphery and heat-sealing the nonwoven fabric, leading to the present invention.

The present invention relates to 1゜2-SB obtained by melt spinning technique.
A spread fiber aggregate containing a sheath-core composite fiber with D as the fiber surface is at least 1. A nonwoven fabric or cylinder bonded by heat melting with 2-SBD is chemically or physicochemically treated, and an ion exchange group is introduced into the 1,2-SBD component, and these are used to finish it in the shape of a cartridge filter. It is an ion exchange cartridge filter.

1. Crosslinking and ion exchange group introduction components used in the present invention.
2-SBD has a melting point of 75≦Tm<150 (T m 'C
), melting point: 75-120°C, crystallinity: 15-50%, 1.2 bonds, 90% or more, melt index (Ml; according to JIS K7210, measurement temperature: 190°C, weight: 2169g) ;20-150 g/
10 minutes is preferable, and Ml is particularly preferably 40 to 120 g/10 minutes.

The heat-melting resin serving as the core component is preferably a polyolefin with a melting point of less than 180°C, and PP is convenient, but depending on the chemical solution used for chemical treatment, non-olefin thermoplastic resins such as polyesters and polyamides with a melting point of less than 180°C may be used. can be selected. PP is a propylene homopolymer or copolymer, a copolymer such as a king polymer, and has a melting point of 130 to 170°C and an MI of 20 to 15.
0 g/10 min is preferable, melting point 150-165℃ MI3
PP of 0 to 70 g/10 min is preferred.

The melt spinning temperature (T °C) of the composite fiber used in the present invention is 1
65<T<200 is preferable, and T≦180 is particularly preferable. The fiber structure is preferably a sheath-core type conjugate fiber having a core of PP and a sheath of 1,2-SBD, and may be eccentric, with the core PP exposed on the fiber surface.

The thermally bonded nonwoven fabric, cylinder, and cylinder used in the present invention are
It is preferable to use the composite fibers used in the present invention alone or in combination with heat-adhesive fibers that bond at a processing temperature of less than 150°C, and it is also permissible to use them in combination with non-thermally-adhesive fibers or fibrous materials whose melting point exceeds 150°C. In this case, from the viewpoint of the strength of the resulting thermally bonded nonwoven fabric, the mixing ratio of the composite fibers should be 30%.
% or more is preferable. The thermal bonding processing temperature for these is preferably in the range of 10 to 150° C. above the melting point of 1.2-SBD. When mixed with other fibers, each fiber material may be layered or mixed.

The thermally bonded nonwoven fabric, cylinder, and cylinder used in the present invention are
It is preferable to crosslink the 1.2-SBD component by irradiating it with ultraviolet rays or gamma rays during or after the bonding process, and because the stiffness of the nonwoven fabric obtained by crosslinking increases, the amount of crosslinking should be less than 20% of the total ethylene groups. desirable. It is usually convenient to irradiate nonwoven fabrics, etc. with ultraviolet rays at 20 to 30 cm under an 800W high-pressure mercury lamp for 5 to 20 minutes. When using the pleated nonwoven fabric of the present invention, it is preferable to perform pleating before or after crosslinking treatment.

The crosslinked nonwoven fabric or thermoformed article obtained by the above method was
When sulfonated by immersion in dilute fuming sulfuric acid cooled below °C or 80-98% concentrated sulfuric acid heated above 80 °C, the weight increases by 15-50% and the ethylene group of the 1.2-SBD side chain A sulfone group is introduced. When this nonwoven fabric is iced and immersed in an IN sodium hydroxide solution, the sulfone groups are converted to sodium sulfonate bases, exhibiting remarkable ion exchange properties. A non-crosslinked non-woven fabric will partially dissolve when immersed in a sodium hydroxide solution, but a -502- crosslinking reaction will also occur during the sulfonation process, resulting in crosslinking, so depending on the application, non-crosslinking may not be inconvenient.

The introduction of a thermal ion exchange group is not limited to the above reaction, and any chemical group having ion exchange ability such as an amino group, carbonyl group, or phosphinate group may be used, or a group that collects chemical species such as a crown ring may be used.

The ion-exchangeable nonwoven fabric obtained by the above method is wrapped or pleated in a layer around a cylinder made of polyethylene or polypropylene that has many through holes on the side surface, or a fiber molded article made of a commercially available polyolefin thermal adhesive fiber formed into a cylindrical shape. After the molded product is installed, it is fixed and applied to an ion exchange cartridge filter. In addition, when processing into a cartridge filter in the form of a nonwoven fabric, it is preferable to use an undried nonwoven fabric for the processing in order to prevent oxidative deterioration of the exchange group. The ion-exchange nonwoven fabric used in the ion-exchange cartridge filter should contain as much ion-exchange fiber as possible, but depending on the application, the filter function may be important, and even in this case, it should contain an average of 10 wt% of ion-exchange fiber. is more preferable in terms of ion exchange.

The above-mentioned cylindrical shape is obtained by winding it up in a hot state during thermal bonding processing, and it can be directly sulfonated and used in the same way.After directly sulfonating a cylindrical shape such as a rod, It is convenient to accommodate the cylinder in a water-impermeable tubular object with the side surface of the cylinder in close contact with the cylinder and use it as a cartridge filter with supply ports and discharge ports for the liquid to be treated, etc. provided in the upper and lower directions of the cylinder.

The ion exchange cartridge filter of the present invention uses the 1,2-SBD, which has a relatively low melting point of 75 to 150°C and is highly chemically reactive.
The sheath-core composite fiber used in the present invention, which has a fiber surface of at least 1.
2-Thermobonded nonwoven fabrics containing SBD as a thermobonding component, crosslinked nonwoven fabrics, and nonwoven fabrics with ion-exchange groups have the same flexibility as commercially available heatbonded nonwoven fabrics, and are extremely easy to wrap around cylinders. It is easy and does not require special attention to processing and moldability.

Since the ion-exchange cartridge filter of the present invention uses ion-exchange fibers, it has the same characteristics as conventional ion-exchange fibers. It has features such as being able to separate and extract concentrated substances.

The manufacturing method of the ion-exchange cartridge filter of the present invention is to first heat-bond the ion-exchange fiber, compared to the conventional method in which the ion-exchange fiber is subjected to various processing after the ion-exchange fiber is completed.
Because the ion exchange group is introduced after processing into a form close to the final use state, the ion exchange group is less susceptible to thermal oxidative deterioration and damage due to drying.

"Example Examples 1 to 5 Comparative Example 1 Melting point 90°C, MI 45g/10 minutes Japan Synthetic Rubber Co., Ltd.
1,2-SBD manufactured by JSR-RBT-871 as a sheath component, melting point 160℃, MI 45 g/10 min. Core-sheath type composite fibers as a core component of PP are discharged using a spinneret nozzle with 700 holes. Amount: 240 g/min, spinning temperature: 180°C,
Melt-spun at a composite ratio of 1:1 expressed as fiber cross-section ratio, and heated at 60°C.
It was stretched 3.6 times in hot water, mechanically crimped in a cooled tuffa box, dried in a net conveyor type hot air dryer at 50°C, and cut into 51 mm pieces to form staple fibers. . This staple alone and our company's NB
F (H) A mixed product with 2dX51mm stable is made into a web using a roller card, and the former is 1
The latter group was heat-treated at 20°C for 1 minute using a hot air penetrating heat processing machine at 140°C, and the former was 1.2-SBD and the latter was 1.2-SBD.
SBD and high-density polyethylene (HDPE) were thermally bonded using a thermal adhesive component, and a nonwoven fabric having a thickness of 1, 5 mm, and a basis weight of 40 g/m2 was crosslinked under the following conditions.

b) Cross-linking treatment by ultraviolet irradiation Ushio Inc. Unicure UV with emission length of 100 mm and 800 W
-800 high pressure mercury lamp was irradiated with air at a distance of 200 mm.

(1) Crosslinking treatment by γ-ray irradiation A nonwoven fabric sample was placed in a stainless steel container and irradiated with γ-rays at a rate of 4.36 MR/h from a 0060 radiation source through water.

The above-mentioned crosslinked nonwoven fabric was treated in 92.5% concentrated sulfuric acid at 92°C for 12 hours, washed with water to obtain a sulfonated nonwoven fabric, and the water was roughly squeezed out using a nip roll.
Inner diameter 300mm, outer diameter 5 made using dx51mm
5 Wrap about 30 g around a cylindrical fiber molded body with a length of 250 mm and a weight of 125 g, and wrap a thermally bonded nonwoven fabric using our NBF (H)2dX51nun three times around the outside and adhere it with an electric iron. , and a cartridge filter. This cartridge filter is housed in a cartridge housing that has been washed with distilled water, and a 50 ppm chloride power Ruthymno aqueous solution is applied at a rate of 211/min. Water was passed through the tube and the calcium concentration was measured. The results are shown in Table 1.

Example 6 The PP/1.2-SBD core-sheath-core fiber of Example 1 and our company's NBF (H) 2dx51 mm were mixed at a ratio of 1:1, made into a web using a roller card, and heated with hot air at 145°C. Adhesion was performed using a thermal processing machine for 1 minute, and then the same ultraviolet irradiation machine as in the example was used for 3 seconds to irradiate the product from a height of a distance of IQ mm while applying pressure while winding up the inner diameter. 300mm, outer diameter 65. A cylindrical product of mm mm was obtained. This was heated to 18% in 92.5% concentrated sulfuric acid at 92°C.
The filter was treated for a period of time, washed with water to obtain an ion exchange cartridge filter, and a 500 ppm calcium aqueous solution was passed therethrough in the same manner as in the example, to obtain water with a calcium concentration of 0.0111 ul.

Example 7 A rod-shaped product with an outer diameter of 200 mm was molded in the same manner as in Example 6, sulfonated in the same manner, and pressed into an acrylic pipe with an inner diameter of 200 mm. A 50 ppm calcium aqueous solution 21
0. Water with a calcium concentration of 5 ppm or less was obtained.

Table 1 Note that the cartridge filter of the present invention may have any shape and structure, for example,
No. 1922, Japanese Patent Publication No. 1-53565, and even Japanese Patent Application No. 2-1502' which the present applicant has already proposed.
Structures such as No. 84 and No. 2-150285 can also be used.

As explained above, the ion-exchange cartridge filter of the present invention uses fiber as a filter medium, so it has both filtration performance and ion-exchange performance, and since it is easy to desorb, it can be recycled easily compared to ion-exchange resins. It is easy to understand.

[Effects of the Invention] As described above, according to the present invention, the main chain has a syndiotactic poly(1,2-butadiene) structure, and at least a part of the ethylene groups in the side chain has an ion exchange functional group. Since the introduced polymer component is an ion exchange cartridge filter containing ion exchange fibers present at least on the surface of the fibers, it has excellent ion exchange properties and filtration properties, and has ion exchange properties that are non-woven and have excellent processability. Can be used as a cartridge filter.

In addition, syndiotactic-1,2-polybutadiene (1,2-S
A fiber aggregate containing at least an average of 10% by weight of sheath-core composite fibers having a fiber surface of BD) is at least 1.2-
1. of the fibers are bonded by hot melt bonding by SBD.
According to the present invention, which is an ion-exchange cartridge filter in which at least a part of the filter medium is made up of a fiber aggregate into which a functional group having ion-exchange ability is introduced into the side chain of 2-5BD, the same ion It is possible to obtain an ion exchange cartridge filter that has excellent exchange characteristics and filtration characteristics, and is in the form of a nonwoven fabric and has excellent processability.

Claims (2)

[Claims] (1) A polymer component whose main chain has a syndiotactic poly(1,2-butadiene) structure and an ion-exchange functional group has been introduced into at least a portion of the ethylene groups in the side chain is applied to at least the surface of the fiber. An ion exchange cartridge filter containing ion exchange fibers present. (2) Syndiotactic-1,2-polybutadiene (1,2-SBD) with a melting point (Tm°C) of 75≦Tm<150
) is a fiber aggregate containing at least 10% by weight on average of sheath-core type composite fibers having a fiber surface of at least 1,2-SB.
The 1,2-
An ion-exchange cartridge filter comprising at least a part of a filter medium made up of a fiber aggregate in which a functional group having ion-exchange ability is introduced into the side chain of SBD.