JPH08294608A - Filter medium - Google Patents

Abstract

PURPOSE: To obtain a filter medium which can sufficiently remove turbidity and is hardly clogged by sticking cationized porous fine particles to a fibrous base material. CONSTITUTION: A filter medium is prepared by sticking cationized porous particles 2 to a fibrous base material 1. The average pore diameter of the porous particles 2 is made 0.001-10μm, and fibers constituting the base material 1 are cationized. Since the filter media, in which the porous particles are stuck to the fibrous base material 1, are arranged to be distributed three-dimensionally keeping an appropriate distance from each other, even when fine particles which cause muddiness are caught by the porous particles, the media are hardly clogged because passages can be secured. Since the porous particles are cathionized, they can adsorb fine particles which pass apart somewhat from them by an ionic adsorption effect, the fine particles can not pass through the filter medium so that muddiness can be removed efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter material, and more particularly to a filter material for a liquid used for removing turbidity of water.

[0002]

2. Description of the Related Art Conventionally, in order to remove turbidity of water in pools, circulating baths, etc., a filtration layer in which porous powder particles such as diatomaceous earth are deposited is used. Since these filter layers have a structure filled with diatomaceous earth having very fine pores, they are excellent in the effect of removing turbidity, but they have a drawback of causing clogging immediately.

On the other hand, a filter material made of a fibrous base material such as a non-woven fabric is known. However, since the pore size is large, clogging is less likely to occur, but fine particles that cause turbidity are sufficient. There was a drawback that it could not be captured.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and provides a filter material capable of sufficiently removing turbidity, etc. and less likely to cause clogging. Is an issue.

[0005]

The above problems can be solved by a filter material according to the present invention, characterized in that the cationized porous granular material is attached to a fibrous base material. it can.

That is, since the porous powdery particles are attached to the fibrous base material and are arranged in a three-dimensional distribution with a proper space therebetween, the porous powdery particles are caused to be turbid. Even if the fine particles to be collected are collected, the flow path is secured, so clogging is less likely to occur. Further, since the porous granular material is subjected to cationization treatment, even fine particles passing a position slightly apart from the porous granular material can be adsorbed by the action of ion adsorption, so that the fine particles do not pass through the filter material and the efficiency is improved. It can remove turbidity well.

The present invention will be described below with reference to the drawings. The fibrous base material 1 used in the present invention includes, for example, non-woven fabric,
Paper, woven fabric, knitted fabric, composites thereof, or the like can be used, but in particular, non-woven fabric in which constituent fibers are three-dimensionally entangled such as hydroentangled non-woven fabric, needle punched non-woven fabric, and fiber-bonded non-woven fabric are preferable. The basis weight of these fibrous base materials is 20 to 400 g / m ² , and more preferably 40 to 300.
The range is preferably g / m ² , and when the basis weight is larger than this range, when the porous powdery particles are carried on the fibrous base material,
It becomes difficult for the powder and granules to penetrate into the intermediate layer, and it becomes difficult to form a uniform filtration layer. On the other hand, when the basis weight is smaller than this range, the amount of powdery particles that can be attached to the fibrous base material decreases. Further, the average pore size of the fibrous base material is preferably in the range of 10 to 2000 μm, more preferably 20 to 1000 μm, and if it exceeds this range, the voids between the powder and granules attached to the fibrous base material become large. The effect of removing turbidity is reduced. On the other hand, when the amount is less than this range, it becomes difficult for the granular material to permeate when the porous granular material is supported on the fibrous base material.

The fibers used for the fibrous base material include synthetic fibers such as polyester fibers, polyamide fibers, acrylic fibers and polyolefin fibers, recycled fibers such as rayon fibers, polyamide / polyester, polypropylene / polyethylene and polypropylene. / Split fibers composed of composite components such as polyamide and polypropylene / polyester can be used. The split fibers are preferably those that are split into fine fibers by the action of mechanical impact, heat, chemicals, etc. For example, those that cause fiber entanglement along with fiber entanglement in a process such as hydroentangling treatment are preferred. .

Suitable diatomaceous earth, pearlite, activated alumina, shirasu, activated carbon, etc. are suitable for the porous powdery particles 2 used in the present invention. The average pore diameter of the porous powdery particles 2 is 0.
It is desirable to be in the range of 001 to 10 μm, and more preferably 0.01 to 5 μm. If the average aperture diameter is smaller than this range, the surface apertures are likely to be clogged, and therefore the ability to collect turbid fine particles is reduced. Becomes harder to sustain, while
If the average opening diameter is larger than this range, it is difficult to collect fine particles from the beginning and it is difficult to sufficiently remove turbidity.

The average particle diameter of the porous powdery or granular material 2 is not particularly limited, but 0.1 to 100 μm is suitable. In addition, the ratio of the volume of the porous granular material to the apparent volume (1 m ² × thickness) of the fibrous base material per 1 m ^{2 of} the filter material is 20 to 300 vol%, more preferably 40 to 100 vol%. Is desirable. If the proportion of the porous powdery particles is smaller than the above range, the space (void) between the powdery particles becomes relatively large, and the turbidity removing effect is reduced. On the other hand, when the amount exceeds the above range, cracks are likely to occur on the surface, resulting in a decrease in the effect of removing turbidity and difficulty in processing such as bending.

The above-mentioned porous powdery particles 2 are attached to the constituent fibers of the fibrous base material 1 via an adhesive resin. Examples of the attaching means include a means in which an adhesive resin is used as an emulsion solution, and a nonwoven fabric is impregnated with or coated with a solution in which porous particles are dispersed, and then dried. In particular, when it is desired to increase the volume ratio of the porous powdery particles 2 per unit volume, the porous powdery particles are attached to the bulky fibrous base material by the above-mentioned attaching means, and then the fibrous material is added. The base material may be compressed into a predetermined thickness by compressing it with a press or the like. Examples of the adhesive resin include acrylic resin, ethylene-vinyl acetate copolymer, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, urethane resin. Those containing an adhesive resin such as styrene resin as a main component are suitable.

The amount of the above-mentioned adhesive resin is the amount of the porous powdery particles 10
0 to 60 parts by weight, more preferably 2 parts by weight
It is preferably 0 to 50 parts by weight. When the amount of the adhesive resin is less than 10 parts by weight, the adhesive force of the porous powder or granular material to the fibrous base material becomes weak, and the porous powder or granular material may fall out into water when used in, for example, a circulating bath. It tends to occur. If the amount of the adhesive resin exceeds 60 parts by weight, the surface of the porous granular material may be covered and the porous structure may not be used. The optimum amount of the adhesive resin is greatly influenced by the type of the porous granular material used, the type of the adhesive resin, or the combination thereof, and therefore is not necessarily limited to the above range and deviates from the above range. There may be cases.

In the present invention, the porous granular material 2 is subjected to a cationization treatment. The cationization treatment is performed by adhering the cationization treatment agent 3 to the porous granular material 2. Examples of the cationization treatment agent 3 include polystyrylpolyamine, polyethyleneimine, polyamide-epichlorohydryl, polyallylamine, polycation-acrylic copolymer, polyvinylpyridine-styrene copolymer quaternary chloride, and styrylpyridinium group as crosslinking groups. Polyvinyl alcohol and the like can be used, but polyallylamine and polyvinyl alcohol having a styrylpyridinium group as a cross-linking group, which are particularly excellent in the adsorption effect of fine particles, are preferable.

The cationizing agent 3 is the fibrous base material 1.
If it is also attached to the constituent fibers, the fine particles that cause turbidity can be collected even in the fibrous base material portion by the ionic adsorption action. In this case, the cationization treatment may be performed by, for example, impregnating a cationization treatment agent after adhering the porous granular material to the fibrous base material. The amount of the cationization treatment agent attached varies depending on the cationization treatment agent, the porous powdery particles, and the fibrous base material used, and is appropriately set.

[0015]

【Example】

Example 1 A fiber web made of a core-sheath type polyester composite fiber having an average fineness of 20 denier (sheath: low melting point polyester having a melting point of 140 ° C., core: polyethylene terephthalate) was needle punched, and then fiber-bonded at 140 ° C. to give a basis weight 24.
Nonwoven fabric with 0 g / m ² and thickness of 7 mm (average opening diameter of 480μ
m) was obtained. In this non-woven fabric, 350 g / m ² of diatomaceous earth having an average particle diameter of 13 μm (opening diameter of about 0.1 to 1 μm) was dispersed in an ethylene-vinyl acetate-vinyl chloride copolymer emulsion (solid content: 70 g / m ² ). The paste was impregnated and dried. Then, this non-woven fabric is pressed with a press machine at a temperature of 160 ° C. and a pressure of 10 kg / cm ² for 30 times.
It was pressed for 2 seconds and compressed to a thickness of 1 mm. The volume of diatomaceous earth was 73 vol% with respect to the volume of the nonwoven fabric.
Then, the above non-woven fabric was made into 0.25% polyallylamine (manufactured by Senka Co., Ltd .: trade name Senka KCF-215).
It was dipped in the solution, pulled up and dried to obtain a filter material.

A filtration experiment was conducted using the above filter material. As shown in FIG. 2, a funnel 5 containing test water 4
Place the filter material 6 underneath, and the flow rate to the filter material is 2 cm.
^Under the condition of ³ / cm ² · min, 0.2 liters of test water was passed once to measure the number of times filtration was possible. In addition, when the turbidity of the test water 7 after filtration is not 0.4 or less,
When the flow rate and the flow rate dropped extremely, it was determined that filtration was impossible. The filter material 6 used was a piece cut into a circle with a diameter of 3.6 cm, and the test water 4 was bath water having a turbidity of 1.0. Turbidity was measured by the formazine standard method. As a result, the number of times filtration was possible was 10 or more (measurement was performed up to 10 times, and filtration was possible thereafter).

Comparative Example 1 A filter material was obtained in the same manner as in Example 1 except that the cationization treatment with polyallylamine was not carried out.
When a filtration experiment was performed using this filter material in the same manner as in Example 1, the turbidity of the test water after filtration was 0.6 in the first filtration, and it was determined that filtration was impossible. Therefore, the number of times filtration is possible is zero.

Comparative Example 2 The nonwoven fabric used in Example 1 was heated at a temperature of 1 with a press.
After pressing for 30 seconds at a temperature of 60 ° C. and a pressure of 10 kg / cm ² and compressing to a thickness of 1 mm, 0.25% polyallylamine (manufactured by Senka Co., Ltd .: trade name Senka KCF-21)
5) Immersed in the solution, pulled up and dried to obtain a filter material. That is, a filter material was obtained in the same manner as in Example 1 except that diatomaceous earth was not attached to the nonwoven fabric. When a filtration experiment was conducted using this filter material in the same manner as in Example 1, the turbidity of the test water after filtration was 0.8 in the first filtration, and it was determined that filtration was impossible. Therefore, the number of times filtration is possible is zero.

Comparative Example 3 Example 1 was placed on a filter paper (Whatman 3) having an average particle size of 6 μm.
A filtration experiment was conducted in the same manner as in Example 1 using a filter material in which the same amount of diatomaceous earth (350 g / m ² ) was laminated. As a result, a remarkable decrease in flow rate due to clogging was observed at the fifth time, and the number of times filtration was possible was four times.

Example 2 A fiber web made of core-sheath type polyester composite fibers (sheath: low melting point polyester having a melting point of 140 ° C., core: polyethylene terephthalate) having an average fineness of 20 denier was needle punched and then fiber-bonded at 140 ° C. Unit weight 24
Nonwoven fabric with 0 g / m ² and thickness of 7 mm (average opening diameter of 480μ
m) was obtained. In this non-woven fabric, 350 g / m ² of diatomaceous earth having an average particle diameter of 13 μm (opening diameter of about 0.1 to 1 μm) was dispersed in an ethylene-vinyl acetate-vinyl chloride copolymer emulsion (solid content: 70 g / m ² ). The paste was impregnated and dried. Then, this non-woven fabric is pressed with a press machine at a temperature of 160 ° C. and a pressure of 10 kg / cm ² for 30 times.
It was pressed for 2 seconds and compressed to a thickness of 1 mm. The volume of diatomaceous earth was 73 vol% with respect to the volume of the nonwoven fabric.
Then, the above non-woven fabric was impregnated with a 5% by weight aqueous solution of polyvinyl alcohol having a styrylpyridinium group as a cross-linking group so that the pick-up was 100%, and after drying,
Polyvinyl alcohol having a styrylpyridinium group as a crosslinking group was crosslinked and insolubilized by ultraviolet irradiation to obtain a filter material. When a filtering experiment was performed using this filter material in the same manner as in Example 1, the number of times filtration was possible was 10 or more.

Example 3 A fiber web made of a core-sheath type polyester composite fiber having an average fineness of 20 denier (sheath: low melting point polyester having a melting point of 140 ° C., core: polyethylene terephthalate) was needle-punched and then heated and pressurized at 140 ° C. By fiber bonding, a non-woven fabric having a basis weight of 240 g / m ² and a thickness of 2.5 mm (average aperture diameter 260 μm) was obtained. To this non-woven fabric, diatomaceous earth with an average particle size of 75 μm (open pore size of about 0.1 to 1 μm) 40
A paste prepared by dispersing 0 g / m ² in an acrylic resin emulsion (solid content 80 g / m ² ) was impregnated and dried. The volume of diatomaceous earth relative to the volume of nonwoven fabric is 46
It was vol%. Then, add 0.25% of the above non-woven fabric.
A polyallylamine (manufactured by Senka Co., Ltd .: trade name Senka KCF-215) was immersed in the solution, pulled up and dried to obtain a filter material. When a filtration experiment was conducted using this filter material in the same manner as in Example 1, the number of times filtration was possible was 1
It was 0 times or more.

Example 4 A fiber web composed of orange type split fibers composed of a polyamide / polyester component was subjected to a hydroentangling treatment to divide the split fibers and to entangle the fibers to give a basis weight of 150 g / m 2.
^2. A hydroentangled nonwoven fabric having a thickness of 1.2 mm was obtained. To this hydroentangled nonwoven fabric, diatomaceous earth (opening diameter about 0.1 to 1 μm)
A paste prepared by dispersing 400 g / m ² in an acrylic resin emulsion (solid content 80 g / m ² ) was coated and dried. The volume of diatomaceous earth was 95 vol% with respect to the volume of the non-woven fabric. Then, the above nonwoven fabric was immersed in a 0.25% polyallylamine (Senka Corporation: trade name Senka KCF-215) solution, pulled up, and dried to obtain a filter material. With this filter material,
When a filtration experiment was conducted in the same manner as in Example 1, the number of times filtration was possible was 10 or more.

[0023]

EFFECTS OF THE INVENTION The filter material of the present invention is porous because the porous powder and granules are attached to the fibrous base material so that they are three-dimensionally distributed at appropriate intervals. Even if fine particles that cause turbidity are collected in the powder or granular material, the flow path is secured, and thus clogging is less likely to occur. Further, since the porous granular material is subjected to cationization treatment, even fine particles passing a position slightly apart from the porous granular material can be adsorbed by the action of ion adsorption, so that the fine particles do not pass through the filter material and the efficiency is improved. It can remove turbidity well. Also, when the cationization treatment agent is also attached to the constituent fibers of the fibrous base material, the ionic adsorption action can collect fine particles that cause turbidity in the fibrous base material. It is possible to obtain a filter material that has a high ability to remove the clogs and is less likely to cause clogging.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a filter material of the present invention.

FIG. 2 is an explanatory diagram of a filtration experiment.

[Explanation of symbols]

 1 ... Fibrous base material 2 ... Porous powder and granules 3 ... Cationizing agent

Claims (3)

[Claims] 1. A filter material, characterized in that a cationized porous granular material is attached to a fibrous base material. 2. The average open pore diameter of the porous powdery material is 0.001.
It is 10 micrometers, The filter material of Claim 1 characterized by the above-mentioned. 3. The filter material according to claim 1, wherein the cationization treatment is also applied to the constituent fibers of the fibrous base material.