JPH0813324B2 - Adsorbent filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adsorptive filter, and more particularly to an adsorptive filter having both high adsorptivity and high strength.

[Conventional technology]

For convenience of handling, powdered or crushed adsorbent is
Usually, it is sold and used by putting it in a container such as a bag or a case, but the work of filling the container with the adsorbent is complicated, and if the container is accidentally damaged, the adsorbent as the content will be scattered. There was a problem of polluting the surroundings.

For this reason, recently, an adsorbent filter, which does not require a container, has been favored in which the adsorbent itself is formed into a cylindrical shape, a flat plate shape, a cylindrical shape, or the like.

Thus, the conventional adsorptive filter has been produced, for example, by binding the adsorbent particles using latex as a binder and then molding the particles into a predetermined shape by an extrusion molding method.

[Problems to be Solved by the Invention]

By the way, if a small amount of latex is blended to bind the adsorbent particles, it is difficult to obtain an adsorptive filter having a strength that can be practically used. This tendency is particularly strong in the case of a large adsorptive filter.

Further, if the strength is low, there is a problem in continuous production. That is, for example, in the case of a plate-shaped adsorptive filter having a thickness of 10 mm and a width of 1 m × 1 m, it may be broken by its own weight.

Therefore, it was necessary to increase the amount of latex used.

However, although it is possible to maintain the hardness of the adsorptive filter by increasing the amount of latex, it is difficult to obtain a flexible material having a high breaking strength. This has been a particular problem for large adsorptive filters.

Further, when a large amount of latex is used, the surface of the adsorbent particles wraps around the latex, which leads to a decrease in adsorbability and the gap between the adsorbent particles tends to be filled by the latex, so that the particle size is large. When the adsorbent particles are used as a raw material, there is a problem that it is difficult to obtain an adsorptive filter with a small pressure loss that allows the adsorbent to flow through efficiently.

In addition, there is a device to obtain a strong adsorptive filter by increasing the molding pressure during molding, but when the molding pressure is increased, the adsorbent particles are crushed and micronized to reduce the gaps between the particles. There is a problem that the pressure loss increases when the adsorbent flows, and the adsorption efficiency decreases.

The present invention has been made in view of the above circumstances,
The purpose is to have a large adsorption capacity and strength, and depending on the application, the adsorbent can be in the form of a large block,
By forming into an arbitrary shape such as a tubular shape, a pipe shape, or a cylindrical shape, an adsorbent filter suitable for continuous production that can be directly loaded into an air conditioning filter, a water purifier, a filter tube, etc. without using a container is provided. It is in.

[Means for solving the problem]

The adsorbent filter according to the present invention for achieving the above object comprises an adsorbent, a fine powder binder, and a reinforcing fiber.

The adsorbent in the present invention is not particularly limited, and for example, activated carbon, natural or synthetic zeolite, silica gel, alumina gel, etc. can be used. Usually several 100m per 1g
Adsorbents having a surface area of ² or more are suitable.

The particle size of the adsorbent is not particularly limited and is appropriately selected according to the purpose of use of the adsorbent filter. Usually, a particle size of several μm to several mm is suitable.

Further, various shapes such as a crushed shape, a pellet shape, a granular shape, a fibrous shape, a felt shape, a woven shape and a sheet shape can be used.

When an adsorptive filter having a particularly small pressure loss and excellent workability at the time of replacement is desired, a sheet-like adsorbent obtained by binding granulated carbon to form a sheet is suitable. .

The above granulated coal can be obtained, for example, by adding 30 to 60 parts of petroleum pitch, coal tar or the like as a binder to 100 parts of a carbon material by a conventional method, kneading the mixture, and then activating the compact.

As the reinforcing fiber in the present invention, polyester,
Nylon, glass fiber, polyester-polyethylene composite fiber and the like are exemplified as preferable ones. Among them, glass fiber is particularly suitable.

As the glass fiber, either a monofilament or a multifilament can be used, but a multifilament having a good binder impregnation property is preferable. In addition,
It is preferable to use glass fibers that have undergone pretreatment such as coating treatment and silane coupling treatment to have improved compatibility with the binder. By improving the conformability, molding becomes easy and the reinforcing effect of the reinforcing material is efficiently exhibited. In this case, the plastic for the coating treatment is preferably one that can be heat-sealed without using water or an organic solvent, and examples thereof include thermoplastics and mesophase pitch. When polyethylene fine powder is used as the binder, the same polyethylene fine powder is preferably used for the coating treatment.

The reinforcing fiber may be in various forms such as a linear shape, a plate shape, a punching shape, a surface shape such as a two-dimensional mesh shape, a three-dimensional mesh shape, a block shape such as a cell-free foam shape, or the like. .

The block-shaped reinforcing fiber can be easily obtained by laminating a plurality of planar reinforcing fibers, and by increasing the number of laminated layers, a larger fiber can be easily manufactured.

The reinforcing fibers may be incorporated inside the adsorbent molded body, or may be arranged so as to cover the outer surface of the adsorbent molded body. For example, the reinforcing fibers may be formed into a two-dimensional or three-dimensional mesh net, and a fine plastic powder serving as a binder may be sprinkled on the net, and then granular activated carbon may be adhered to the net. By doing so, it is possible to obtain an adsorptive filter having an extremely small pressure loss in which the adsorbent adheres only to the net.

The binder in the present invention is not particularly limited as long as it is in the form of fine powder. For example, when plastic is used as the binder, either thermoplastic or thermosetting plastic may be used. A particle size of 100 μm or less is suitable. This is because the pressure loss increases when the particle size exceeds 100 μm.

Examples of thermoplastics include polyethylene, polypropylene, ABS, PET, nylon, PBT, ethylene acrylic resin, PMMA resin, and mesophase pitch.

Examples of the thermosetting plastic include furan resin and phenol resin.

In addition, as a binder, the adsorbent has coloring, adhesiveness,
A hydrophilic resin, a conductive resin, or the like may be used to impart conductivity or the like.

Examples of the hydrophilic resin include polyvinyl alcohol resin and Eval resin, and examples of the conductive resin include polyvinyl pyrrole and polyacetylene.

The plastic as the binder is preferably selected according to the purpose of use of the adsorptive filter. For example,
When the adsorptive filter is used in an aqueous solution, it is preferable to use a hydrophilic polymer, and when it is used for filtration of oil, organic solvent, etc., a hydrophobic polymer is preferably used.

Next, a specific method for manufacturing the adsorptive filter according to the present invention will be described.

The adsorptive filter according to the present invention includes, for example, the following 1) to
It can be produced by the method described in any of 3).

1) A method in which an adsorbent coated with a fine plastic powder in advance and reinforcing fibers are mixed and then molded.

2) A method in which the fine plastic powder, the adsorbent and the reinforcing fiber are simultaneously mixed and then molded.

3) A method in which an adsorbent molded body is prepared from fine plastic powder and an adsorbent, and the outer surface of the molded body is covered with a reinforcing fiber such as a nonwoven fabric or a net.

The use ratio of the fine plastic powder varies depending on the particle size and specific gravity of the adsorbent, but 100 parts by weight of the adsorbent (hereinafter,
Abbreviated as “part”)
It is 10 parts, preferably 2 to 5 parts. It is needless to say that it is preferable to use the minimum necessary amount from the viewpoint of preventing a decrease in adsorption ability.

The kneading method is not particularly limited, and a conventionally widely used mixer such as a mixer, a ribbon mixer, a static mixer, a ball mill, a sample mill, or a kneader can be used.

At the time of kneading, the fine powder plastic can be adhered to the adsorbent only by kneading, but it is preferable to knead while heating in order to further strengthen the adhesion of both. In this case, the heat source is microwave, infrared, far infrared,
Although high frequency waves are exemplified, it is preferable to use a heat source that generates energy rays having a wavelength that can be efficiently absorbed by the fine plastic powder.

By using static electricity, the fine plastic powder can be uniformly attached to the adsorbent.

The adsorptive filter according to the present invention can be obtained, for example, by filling an adsorbent coated with the above-mentioned plastic fine powder in advance together with reinforcing fibers in a mold, and then thermocompressing the adsorbent. In this case, microwaves, infrared rays, far infrared rays, high frequencies, etc. can be used as the heat source.

In addition, in order to prevent the low boiling point organic compound generated from the adhesive from being attached to the adsorbent by heating and reducing the adsorptivity of the adsorptive filter, it is preferable to perform heating under reduced pressure ventilation.

Further, the molding needs to be performed at a temperature at which the fine plastic powder is melted but the reinforcing fiber is not melted.

Hereinafter, a specific method for producing the adsorptive filter having various shapes will be described.

[Method of manufacturing flat adsorptive filter]

Place a flat mold on a glass fiber net, and then fill the mold with an adsorbent coated with plastic fine powder or a kneaded product of the adsorbent and plastic fine powder, and When a glass fiber net is overlaid and pressure-molded while heating, a flat adsorptive filter is obtained.

The resulting flat plate-like adsorptive filter has high strength,
For example, even if it is 10 mm thick and 1 m wide x 3 m long, it will not be broken by its own weight.

[Method of manufacturing block-shaped adsorptive filter]

The fine plastic powder and the adsorbent are kneaded and molded into a block body. Next, this block body is coated with a heat-shrinkable non-woven fabric, and when heated, the non-woven fabric shrinks to obtain a block-shaped adsorptive filter reinforced by the non-woven fabric.

[Cylinder, manufacturing method of cylindrical adsorptive filter]

After forming the adsorbent into a cylindrical shape with a fine powder binder, the outer circumference of the adsorbent is covered with a bag-shaped glass fiber net or heat-shrinkable non-woven fabric. A filter is obtained.

Further, at the time of molding, a core material wound with a reinforcing fiber such as a thermoplastic nonwoven fabric or a thermoplastic net may be fitted into the cylinder to be molded. By doing so, a cylindrical adsorptive filter in which the inner peripheral portion as well as the outer peripheral portion of the cylinder is reinforced can be obtained. At this time, the non-woven fabric, net or the like functions as a release agent.

〔Example〕

Hereinafter, the present invention will be described based on Examples, but the present invention is not limited to the following Examples, and can be appropriately modified and implemented within the scope of the invention.

I. Production of Adsorbent Filter and Measurement of Breaking Strength [Example 1] A flat adsorbent filter was produced by the following method.

Particulate activated carbon having a particle size distribution of 10 to 32 mesh was mixed with 3 parts of polyethylene having a particle size of 25 μm and coated.

Then, on a polypropylene net, thickness 5 mm, 10 cm
Place a mold with a size of × 20 cm, fill the mold with the above-mentioned polyethylene-coated granular activated carbon, and then lay a polyethylene net on top of it and apply a pressure of 1 kg / cm.
^2. Molded at a temperature of 120 ° C to obtain a flat adsorbent filter.

When the breaking strength of this adsorptive filter was measured by the three-point support method, it was 100 kg / cm ² .

[Example 2] A cylindrical adsorptive filter was produced by the following method.

A 25 mm diameter core material wrapped with an EVA net is placed in the center of a cylinder with an inner diameter of 60 mm, and a mixture consisting of 100 parts of zeolite and 3 parts of polypropylene with a particle size of 30 μm is filled between the core and the cylinder. Molded by heating at 130 ° C. After cooling, the cylindrical molded body was taken out, the outer periphery of the cylindrical molded body was covered with a heat-shrinkable non-woven fabric, and this was heated again to obtain a cylindrical adsorptive filter.

A force was applied to the adsorptive filter from the outer peripheral portion, and the breaking strength at that time was measured, and it was 70 kg / cm ² .

[Example 3] A block-shaped adsorptive filter was produced by the following method.

100 parts of pelletized activated carbon with a diameter of 4 mm and 3 parts of polymethyl methacrylate with a particle size of 40 μm are mixed, and 10 cm × 20 cm ×
A 5 cm rectangular parallelepiped block was created.

The surface of this block was covered with a thermoplastic non-woven fabric and then heated to obtain a block-shaped adsorptive filter.

When the breaking strength of this adsorptive filter was measured,
It was 80 kg / cm ² .

Example 4 100 parts of pelletized activated carbon having a diameter of 4 mm and an average particle size of 20 μm
3 parts of polyethylene of m was mixed to prepare activated carbon having polyethylene attached to the surface.

A polyethylene mesh-coated 10 mesh glass fiber net (the thickness of the polyethylene film is 1/50 of the net thickness) is placed on the top and bottom surfaces of this activated carbon, and the pressure is 5 g / c.
Molding was performed at m ² and a temperature of 120 ° C. to obtain a plate-shaped adsorptive filter having a thickness of 10 mm and a size of 10 cm × 20 cm.

When the breaking strength of this adsorptive filter was measured,
It was 80 kg / cm ² .

[Comparative Example 1] A flat-plate adsorptive filter was obtained in the same manner as in Example 1 except that the net was not reinforced with a polypropylene net and a polyethylene net.

When the breaking strength of this adsorptive filter was measured by the three-point support method, it was 5 kg / cm ² .

Comparative Example 2 A cylindrical adsorptive filter was obtained in the same manner as in Example 2 except that it was not reinforced with a heat-shrinkable nonwoven fabric.

The breaking strength when a force was applied to the adsorptive filter from the outer peripheral portion was 7 kg / cm ² .

[Comparative Example 3] A block-shaped adsorptive filter was obtained in the same manner as in Example 3 except that the thermoplastic non-woven fabric was not used for reinforcement.

When the breaking strength of this adsorptive filter was measured,
It was 10 kg / cm ² .

[Comparative Example 4] A block-shaped adsorptive filter was obtained in the same manner as in Example 4 except that the glass fiber net was not used for reinforcement.

When the breaking strength of this adsorptive filter was measured,
It was 3 kg / cm ² .

From the above, it can be seen that the adsorptive filter according to the present invention has extremely high breaking strength.

II. Measurement of adsorption capacity According to JIS K1474, the benzene adsorption capacity of the granular activated carbon used in Example 1 was measured and found to be 35%.

Further, the benzene adsorption capacity per granular activated carbon of each of the adsorptive filters obtained in Example 1 and Comparative Example 1 was measured and found to be 34.3% and 34.5%.

From the above, it can be seen that the adsorptive capacity does not substantially decrease even when reinforced with a net.

〔The invention's effect〕

As described above in detail, the adsorptive filter according to the present invention has both excellent adsorptivity and strength, and the present invention has excellent unique effects.

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Claims (3)

[Claims] 1. An adsorbent filter comprising an adsorbent, a fine powder binder and a reinforcing fiber. 2. The adsorptive filter according to claim 1, wherein the reinforcing fiber is a non-woven fabric or a glass fiber formed in a mesh shape. 3. The adsorptive filter according to claim 1, wherein the fine powder binder is polyethylene fine powder having a particle diameter of 100 μm or less.