JPH10309417A - Manufacture of filter material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a function for eliminating pathogenic and antigenic fine particles for a long time by developing sufficiently adsorption capability by a method wherein glucan aqueous solution is applied to a filter base material, and after drying to a semi-dry state, porous apatite particles are stuck by dispersion onto a surface of the filter base material, and fixed. SOLUTION: Water soluble glucan aqueous solution is applied by spraying from an aqueous solution spray 5 onto a surface of nonwoven fabric 2 unwound from a nonwoven fabric roll 1. Excess solution held with surface tension or the like is removed by vibration of a vibrator 6. When drying has advanced to the state where the water soluble glucan aqueous solution comes in a semi- dry state (for example, tens sec later from spraying), porous apatite particles 9 are stuck by scattering onto a surface of the nonwoven fabric 2 with a porous apatite particle scattering machine 8. Thereafter, it is fixed by drying, and wound on a winding roll 3. The porous apatite particle 9 used herein is that of about 0.1 to 1000 μm average diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a filter material. This filter material is particularly suitable for air cleaning.

[0002]

2. Description of the Related Art Air purifying filters are used in air conditioners and air purifiers. For example, in an air conditioner, a pre-filter is provided behind a front panel, and an air purifying filter is further provided behind the pre-filter. After removing relatively large floating dust with a pre-filter, fine dust such as pollen and mold spores is removed with an air purifying filter. Then, the air that has passed through the air purifying filter passes through a heat exchanger or the like, is temperature-controlled, and is then sent out indoors. In the air purifier, the air in the room is sucked in and returned to the room after passing through the air purifying filter.

[0003]

Such a conventional air purifying filter hardly adsorbs pathogenic or antigenic fine particles such as viruses, bacteria, fungi and pollen. For this reason, circulating pathogenic or antigenic fine particles indoors causes allergies such as asthma and atopic dermatitis. On the other hand, according to the air purifying filter manufactured by the applicant's manufacturing patent “Method for manufacturing filter material” (Japanese Patent No. 1953846, see Japanese Patent Publication No. 6-85852), pathogenicity or antigenicity Fine particles can be adsorbed and removed. However, since this sterilization ability can be maintained for only about two weeks, there is no particular inconvenience when the filter can be easily replaced like a sanitary mask. In the case of a large and expensive, there is a problem that it is not suitable for use because it cannot be replaced frequently.

[0004] It is an object of the present invention to solve the above-mentioned problems and to provide an air purifying filter having a long-term ability to remove pathogenic or antigenic fine particles.

[0005]

In the above-mentioned production method, the porous apatite particles and the water-soluble glucan are dispersed in water, and the aqueous solution obtained by dissolving the glucan is coated on the fiber filter medium. As a result, the adsorption capacity of the porous apatite particles is greatly reduced. In order to prevent this, heat setting is performed as a post-processing, utilizing the difference in thermal expansion of the material, breaking the glucan layer on the top surface of the porous apatite particles, while maintaining the adhesion with glucan on the bottom surface of the porous apatite particles, The adsorptive ability of porous apatite particles is exhibited. However, according to subsequent studies by the present inventors, some of the surfaces of the porous apatite particles that are not involved in the adhesive fixation with the fibrous filter medium are still covered with a glucan layer, which removes pathogenic or antigenic fine particles. This caused the ability to remove to not last long. To prevent the surface of porous apatite particles that are not involved in the adhesion to the fiber filter medium from being covered with the glucan layer, apply an aqueous solution of water-soluble glucan, dry it in a semi-dry state, The present inventors have found that it is preferable to spray and adhere hydrophilic apatite particles, and have reached the present invention.

That is, in the present invention, an aqueous solution of a water-soluble glucan is applied to a filter substrate. Next, the water-soluble glucan is dried to a semi-dry state, and then porous apatite particles are dispersed and adhered to the surface of the filter substrate, and fixed. Further, an aqueous solution of the water-soluble glucan to which an antibacterial substance is added may be used.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a filter manufacturing process according to the manufacturing method of the present invention. Reference numeral 1 denotes a nonwoven fabric roll around which a nonwoven fabric 2 serving as a filter substrate is wound. The nonwoven fabric 2 is made of a mixed yarn of polyester fiber and cellulose fiber and has a thickness of 2
mm. Reference numeral 3 denotes a take-up roll. The non-woven fabric 2 discharged from the non-woven fabric roll 1 is subjected to various treatments and then wound up by the take-up roll 3. Reference numeral 4 denotes a nonwoven fabric feed roller, which applies auxiliary power for transporting the nonwoven fabric 2 from the nonwoven fabric roll 1 to the winding roll 3. Then, a glucan aqueous solution spray 5, a vibrator 6, and an air drying device 7 are provided in this order on the transport path of the nonwoven fabric 2. And
After the nonwoven fabric 2 that has passed through the air drying device 7 is conveyed to the porous apatite particle dispersion device 8, the nonwoven fabric 2 passes under another air drying device 7 and then reaches the winding roll 3.

The manufacture of the filter material is performed as follows.
First, an aqueous solution of a water-soluble glucan is sprayed from an aqueous solution spray 5 onto the surface of the nonwoven fabric 2 unwound from the nonwoven fabric roll 1 and applied. Excess solution held by surface tension or the like is removed by the vibration of the vibrator 6. This aqueous solution of water-soluble glucan is an aqueous solution using a water-soluble glucan such as triose glucan having a molecular weight of about 30,000 to 300,000 as a solute, and has a concentration of 0.1 to 50% by weight. This triose has abundant hydroxyl groups in the molecule, and captures and adsorbs particles such as spores, pollen, and fungi whose surfaces are covered with sugar chains or mucopolysaccharides by the action of hydrogen bonding or the like.

When the drying of the aqueous solution of the water-soluble glucan has progressed to a semi-dry state (for example, several tens of seconds after spraying), the nonwoven fabric 2 is dispersed by the porous apatite particle dispersing machine 8.
The porous apatite particles 9 are scattered and adhered to the surface of. Thereafter, the film is dried and fixed, and is wound around a winding roll 3. The porous apatite particles 9 used here have an average diameter of about 0.1
~ 1000 microns. Then, hydroxycalcium apatite (hereinafter, referred to as “HAP”), fluorinated apatite (hereinafter, referred to as “FAP”), or HAP, in which the surface is provided with a pore diameter equal to or larger than the size of the fine particles to be adsorbed and formed porous. It is most preferable that any one of the mixture of FAP and FAP is made into particles. The porous apatite granules are produced by kneading a gas generating substance such as polyvinyl alcohol with primary apatite particle powder, calcining, pulverizing, and classifying the size.

The filter material thus manufactured is formed into an air purifying filter having a predetermined shape. The porous apatite in the air purification filter is highly surface activated and entraps fine particles in the pores, and has various bonding modes by ionic bonding, hydrogen bonding, van der Waals force, or interaction between dipole moments. By conformation, prokaryotic cells, fungi, pollen and the like are adsorbed and captured on the surface. In addition, the glucan layer serving as an immobilizer forms hydrogen bonds with surface sugar chains such as fungi and pollen and mucopolysaccharides due to abundant hydroxyl groups in the molecule, and adsorbs fungi and pollen. In the filter material according to the method of the present invention, water molecules are successively hydrogen-bonded to the surface of a hydroxyl group of a glucan or apatite molecule, so that multiple bonds are formed to expand the network. Then, it becomes easier to capture the fine particles as if the prey hangs on a spider web thread. Due to the action of the physicochemical structure and physical properties of these two substances, and the synergistic action of both, the ability to adsorb pathogenic or antigenic fine particles is remarkably improved. In order to further improve the ability to adsorb pathogenic or antigenic fine particles, a filter material may be stacked.

After the porous apatite particles are sprayed and adhered to the surface, an aqueous solution of a water-soluble glucan may be applied to the back surface and sprayed with activated carbon particles or zeolite particles.
Further, the filter material to which the porous apatite particles are sprayed and adhered and the filter material to which the activated carbon particles or the zeolite particles are sprayed may be double overlapped. Here, the activated carbon particles and zeolite particles used have the same average diameter as that of the porous apatite particles 9 of about 0.1 to 1000 microns. With this configuration, in addition to the adsorption of pathogenic or antigenic fine particles by the porous apatite particles, the ability to adsorb fine dust and odors by activated carbon particles and zeolite particles is added.

Further, an antibacterial metal such as silver, copper and zinc, an antibacterial organic substance such as catechin and catechol, and activated fine particles such as titanium oxide and zinc oxide are added to the aqueous solution of the water-soluble glucan of the above embodiment. In addition, antibacterial properties may be imparted in addition to the adsorption of pathogenic or antigenic fine particles. Activated fine particles such as titanium oxide and zinc oxide exhibit a bactericidal effect by receiving visible light or ultraviolet light. Therefore, when the activated fine particles are used, a means for introducing light is required. Furthermore, it is also possible to add water-soluble polyvinyl alcohol to water-soluble glucan to improve the adhesive strength of the particles.

Furthermore, a fiber layer made of electretized fibers may be joined to a filter material to form a permanent charge layer on the filter material, thereby improving the ability to adsorb fine dust.

[0014]

As described above, according to the present invention, an aqueous solution of a water-soluble glucan is applied to a filter substrate and dried to a semi-dry state.
Since the porous apatite particles are dispersed and adhered to the surface of the filter substrate and further fixed, the adsorptive capacity of the porous apatite particles can be sufficiently exhibited, and the ability to remove pathogenic or antigenic fine particles can be maintained for a long time. In addition, since heat set as post treatment is not required, manufacturing is easy,
Manufacturing costs can be reduced. When an antibacterial substance is added to an aqueous solution of a water-soluble glucan, an antibacterial effect is added to the effect of adsorbing pathogenic or antigenic fine particles.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram according to a manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nonwoven fabric roll 2 Nonwoven fabric 3 Take-up roll 5 Glucan aqueous solution spray 8 Porous apatite particle sprayer 9 Porous apatite particles

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 53/04 B01D 53/04 A

Claims (2)

[Claims] 1. A filter material, comprising applying an aqueous solution of a water-soluble glucan to a filter substrate and drying it in a semi-dry state, and then spraying and fixing porous apatite particles on the surface of the filter substrate. Production method. 2. The method according to claim 1, wherein the aqueous solution of the water-soluble glucan contains an antibacterial substance.