JPS6242716A - Filter material for electret filter - Google Patents

Abstract

PURPOSE:To effectively control the propagation of collected microbes without deteriorating the dust collection efficiency and pressure drop of an electret filter by producing the electret filter in the form of a nonwoven fabric from synthetic fibers treated with an antibacterial agent. CONSTITUTION:A filter in the form of a nonwoven fabric having 2-3mm thickness is composed of the fibers of polypropylene or polyfluoroethylene. Before the electret process is applied, treatment with an antibacterial agent is applied. The treatment with an antibacterial agent is carried out before or during the production of the nonwoven fabric. The antibacterial agent is incorporated to the extent of 0.1-1wt% into 100wt% nonwoven fabric. As the antibacterial agent, 3-trimethoxysilyl-propyl-dimethyl-octadecyl-ammonium chloride and 2,4,4'- trichloro-2'-hydroxydiphenyl ether are used. The agent is incorporated into the nonwoven fabric as a liq. and then dried at 80-130 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvement of filter materials for electret filters used in dust removal filters for vacuum cleaners, air cleaners, air conditioners, etc.

[Conventional technology]

Traditionally, electret filters filter soot, dust particles, black mold, etc. in the atmosphere? Electrical (due to polarization force, Coulomb force)
The electret filter is used as a dust removal filter in various devices to adsorb and collect particles, but if microorganisms are present in the collected material, they will multiply, resulting in a decrease in the electrical effectiveness of the electret filter. However, there were drawbacks such as rotting deposits and the generation of bad odors.

[Problem that the invention seeks to solve]

The object of the present invention is to effectively suppress the growth of microorganisms collected by the electret filter without the dust removal effect or pressure loss of the electret filter.

[Means to solve the problem]

The present invention provides a filter material for an electret filter in the form of a nonwoven fabric formed using synthetic fibers treated with an antibacterial agent.

The fibers constituting the non-woven filter material of the present invention are polypropylene fibers and polyfluoroethylene fibers (Teflon).
, polyester fibers, polyvinylidene chloride 1@ fibers, etc., but the most common are polypropylene fibers and Teflon fibers.

A feature of the present invention is that such an antibacterial treatment is performed prior to the electret treatment. The antimicrobial treatment can be performed before or during the nonwoven manufacturing process. For example, at the fiber manufacturing stage for non-woven fabric, an antibacterial agent is applied using rollers or guides in the same manner as oiling, or an antibacterial agent is applied to the fiber mass by spraying or dipping, and then the fiber material is used in a conventional manner. Manufacture non-woven fabrics. Alternatively, an antibacterial agent can be added to the water in the case of wet-process non-woven fabric production, or an antibacterial agent can be added to the binder resin for non-woven fabric production. Nonwoven fabrics can be manufactured by known methods. The thickness of the nonwoven fabric for the electret filter is generally 2 to 3 mm.

Known antibacterial agents can be used. Examples include organosilicone quaternary ammonium salts such as CH.

3-trimethoxysilyl-proyl- having the structure
Dimethyl-octadecyl-ammonium chloride (trade name DC5700, Dow Corning), halogenated aromatic compounds, such as 2,4,4'-)cyclo-2'-hydroxydiphenyl ether (trade name) having the structure H L; ilgasan np3
00) TBZ thiabendazole having the following structure, biguanite (B±guanide) having the following structure, etc.

Such an antibacterial agent is applied in liquid form as described above, but after being applied, it is dried (eg, dried at a temperature of 80 to 130° C.) and fixed onto the fibers. The amount of adhesion depends on the type of antibacterial agent, the type of fiber,
Although it can be changed appropriately depending on the thickness of the nonwoven fabric, it is usually 0.1 to 1.0% (by weight) based on the nonwoven fabric fibers.

After such antibacterial treatment, electretization is performed before and after producing the nonwoven fabric. For example, the fibers may be electretized after being treated with an antibacterial agent (prior to the production of the non-woven fabric) or after the production of the non-woven fabric by spraying from a corona wire connected to a high-voltage electric current. Such an electret processing method itself is already well known and does not constitute a feature of the present invention.

When a non-woven electret filter material made of synthetic fibers treated with an antibacterial agent is used as a filter material for vacuum cleaners, air purifiers, air conditioners, etc., there is no pressure loss. It is possible to electrically adsorb and collect soot, dust particles, mold, microorganisms, etc. in the atmosphere, and further suppress the growth of the collected microorganisms. The disadvantages of doing so are overcome.

Examples of the present invention will be described below.

Example: Nonwoven fabric (70 l/d) made of polypropylene fibers
-trimethoxysilyl-propyl-dimethyl-octadecyl-ammonium chloride treatment solution (concentration 0.75
%) and the antibacterial agent is 0.63% based on the nonwoven fiber weight ζζ.
% by a pad/mangle squeezing/dry method, and then converted to electret by corona discharge using a conventional method to produce a filter material.

Comparative Example A filter material was produced in exactly the same manner as in the above Example except that no antibacterial treatment was applied.The shake flask method (ATCC43
Antibacterial properties were evaluated by a method using 52) and an air purifier.

That is, in the shake flask method, Klebscilla pneumonia (ATCC4352) was used as the bacterium, and the sterilization rate was calculated using the following formula.

X-Y Sterilization rate (100 x 100) %
In contrast, it was only 7% in the comparative example.

Next, the filter material was attached to an air cleaner, and the air cleaner was operated for 3 hours in a room sprayed with black mold (Aspergillus niger 1149). When examining the amount of black mold passing through the filter using an air sampler, it was found to be very small.
The filter captured most of the black mold. Also,
Thereafter, the filters were removed and cultured in a medium for 3 days at 30°C, and no growth of black mold was observed in the samples of Examples of the present invention. On the other hand, in the comparative example, significant growth of black mold was observed.

Note that the pressure loss was the same for both the materials of Examples and Comparative Examples.

〔Effect of the invention〕

As described above, according to the present invention, the growth of microorganisms collected by the electret filter is effectively suppressed, thereby preventing a decrease in the electrical effectiveness of the electret filter, and preventing the rotting of deposits and the generation of unpleasant odors.

Procedural amendment (spontaneous) October 31, 1985 1, Indication of case 1985 Patent Application No. 179027 2
, Name of the invention Filter material for electret filter 3, Relationship with the case of the person making the amendment Patent 1i] 人hehehem\hehe name (316) Toyobo Co., Ltd. 4, Agent 4\, Noro, Contents of the amendment (1) Line 6 from the bottom of page 4 of the specification “(Biguanid
e) Insert "," after J.

(2) From the bottom of the 4th page, in the 5th line, "etc. are mentioned."
Examples include N/-(fluorodichloromethylthio)-sulfamide (briventol A4).

Such antibacterial agents may be used alone or in combination of two or more. ” he corrected.

that's all

Claims (1)

[Claims] 1. Filter material for non-woven electret filters made of synthetic fibers treated with antibacterial agents.