JPH01164411A - Functional electret material - Google Patents

Abstract

PURPOSE:To give an electret material multifunctional characteristic without impairing the electret characteristic by electrically attracting a chemically or physically acting material to the surface of an electret material having >=5X10<-11>C/cm<2> surface charge density. CONSTITUTION:A powdery or misty chemically or physically acting material such as a sterilizer, deodorant, odor eliminating agent, antimold, aromatics, insecticide, magnet, temp.-sensitive discoloring material, etc., is attracted electrically to the surface of an electret material having >=5X10<-11>C/cm<2> surface charge density made of melt-blown nonwoven fabric of polypropylene fiber, etc. By this constitution, several plural kinds of functions are imparted to an electret material leaving effective electret characteristic unimpaired since adhesives are not used in the present invention as in conventional inventions.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a special electret material, and more specifically, in addition to the performance as an electret, it also has antibacterial properties, antibacterial properties, and deodorizing properties. gender, aroma, etc.
This article relates to an electret material that has high functionality and is effectively endowed with a specific desired chemical or physical function.

[Prior Art] In recent years, attempts have been made to use electret materials in the field of filters and dust-proofing products, but such filters inevitably become dirty as they are used. However, in addition to having the function of an electret shrine, there is a growing demand for the ability to provide specific functions such as antibacterial and antifungal properties. Ta.

Here, a general method of imparting a specific function to an object is to mix and disperse a substance that performs the function in a binder, or to dissolve it in a solvent and attach it together with the binder or solvent. However, in the method using a solvent, it is necessary to remove the solvent afterwards, and when this method is applied to an electret sheet, it is generally necessary to remove the electret in the solvent removal step.
~Retability decreased and was not appropriate.

In addition, in the method of dispersing a substance with a specific action function in a binder, some parts of the substance are buried in the binder, so in order to expect the action by being present on the surface of the object, It was necessary to add more mother than necessary, resulting in poor efficiency.

In addition, l is added dispersedly in the rope material raw material of the electret object.
However, in such a method, for example, when synthetic fiber is used as an electret object, it will withstand the heat of melting the polymer (the heat resistance and heat stability of the polymer will depend on the functional material). However, the selection range of functional materials has been narrowed, and the method cannot be called a general-purpose method because its applications and functions are limited.

Furthermore, Japanese Patent Application Laid-Open No. 62-42715 proposes a method in which a separate nonwoven fabric that has been treated with antibacterial treatment using a padding method or a spraying method is superimposed on one side of an electret nonwoven fabric. This method of using multiple nonwoven fabrics requires a complicated manufacturing process, does not provide a fundamental solution, and has the disadvantage that the overall pressure loss as a 1m filter must increase. there were.

Furthermore, Japanese Patent Application Laid-open No. 62-42716 discloses that after producing a nonwoven material 5 using a fiber mass that has been subjected to antibacterial treatment by dipping or spraying at the raw material fiber stage, A method has been proposed in which fabric I is made into an electret, but the manufacturing process is complicated, and there are problems such as the above-mentioned solvent removal and embedding of specific substances, and it is not always possible to effectively identify the desired material. However, there was a problem in that it did not provide the functional functions of the conventional method.

[Problems to be Solved by the Present Invention] An object of the present invention is to solve the above-mentioned problems and to provide an electret material with a desired specific functionality while maintaining good characteristics of the electret material. It is an object of the present invention to simply provide an electret material that is effective.

[Means for Solving the Problems] The functional electret material of the present invention that achieves the above-mentioned objects has the following configuration.

In other words, the functional electret material of the present invention has a substance having a chemical action function or a physical action function attached to the surface of an electret body having a surface charge density of 5X10-11 coulombs/cm2 or more by at least electroadsorption action. It is made of functional electret material that is characterized by the ability to

[Function] Hereinafter, the functional electret material of the present invention will be described in detail based on the drawings and the like.

FIG. 1 is a schematic structural model diagram showing one embodiment of the functional electret material of the present invention, showing a state in which a substance having a specific chemical action function or physical action function is attached to an electret nonwoven fabric. show.

In the same figure, the electret nonwoven fabric 1 of the present invention is composed of electret fibers 2 and 2', and a substance having a desired specific physical or chemical function is further coated on the surface of the electret fibers. 3.3' or at least electrically adsorbed. Also, the second
The figure is an enlarged cross-sectional model diagram illustrating how the substance 3.3' is electrically adsorbed and attached to the electret fibers, and in the same figure, 4 indicates the cross section of the electret fiber. The substance 3.3' having the above-mentioned specific physical or chemical function is adsorbed on the surface of the fiber at an appropriate density.

Briefly explaining this adsorption state, an electret body has an electrostatic adsorption effect because lines of electric force are generated from the surface of the object due to its surface charge. By bringing powder or mist, which is a substance that controls chemical action, close to the surface of the electret material, the powder or mist is electrically adsorbed on the surface of the electret material, and the electret material is When the body is made of a fibrous mass, M is adsorbed inside the mass and cannot be easily removed. If used, it is possible to obtain the functional electret material of the present invention that satisfactorily has specific functions as desired.

To explain in more detail the general state of attachment of substance 3.3' to the surface of the electret body, when the substance is in the form of powder, the electrolytically adsorbed substance may be attached to the electret body in a small amount. On the other hand, in the case of large H, powder particles adhere on top of the adhered powder particles, forming beads-like protrusions. The adhesion form is generally in the direction of tl+7i.

Even when the substance is in the form of a lump, its adhesion form is
The same tendency as in the case of the powder described above is shown.

Generally, when the substance is a liquid mist, it initially adheres to the surface of the electret body in dots, but as the mist spreads on the surface of the electret body, it tends to adhere in an amoeboid shape. is. In particular, when the electret body is a nonwoven fabric, when the above-mentioned mist-like substance is adsorbed, the amount of adhesion on the outer layer generally tends to be larger than the amount of adhesion on the inner layer. In addition, compared to the pad method, it tends to adhere to individual fibers in a relatively uniform amount, and there is a particularly large amount (
= There is virtually no tendency for J-adhesion, and the adhesion state is well-dispersed and uniform.

For example, it is possible to IH an antibacterial electret nonwoven fabric by using an antibacterial agent as a powder and electrostatically adsorbing it to an electret nonwoven fabric, or
As the powder and/or mist, a bactericide, a deodorant, a deodorant, an antifungal agent, a fragrance, an insect repellent, and the like can be used as appropriate. In addition, as the substance to be adhered, in addition to powder and mist, appropriate fibrous materials and lumps can also be used.

The surface charge density of the electret body used in the present invention must be 5×10” coulomb/i or more, in order to ensure that the electrostatic adsorption effect is well applied to the above-mentioned powder or mist. However, if it is less than 5 x 10" coulombs/d, the electrostatic adsorption effect is so small that the attached substance may fall off and the desired function cannot be fully exerted, which is undesirable. In this, the electret helium which is particularly preferably used has a surface charge density of 2×10” coulombs/clI.
It is more than f.

It should be noted that an appropriate binder may also be attached by electroadsorption along with the above-mentioned powder or mist. In this way, substances that have a chemical or physical action function can be attached in addition to the electroadsorption action. , the adhesive force is also applied by the action of the binder, making it possible to maintain a stronger adhesion state.

The material of the electret body is not particularly limited, and various materials such as film, microporous film, knitted woven fabric, nonwoven fabric, or thread-like material can be used depending on the purpose, but among them, Melt-blown nonwoven fabrics and spunbond nonwoven fabrics made of polypropylene fibers are preferably used in terms of their performance and ease of manufacture.

In addition, the number of substances that have a specific chemical or physical function to avoid adsorption to the electret body is not limited to one type, but multiple types of substances may be adsorbed, and two or more types of substances may be adsorbed. An electret body formed by adsorbing a substance can easily be made into a high-performance electret material that has two or more types of functions at the same time.

In the present invention, a substance that has no chemical action function is a substance that can bring about a chemically active action, and refers to a chemical agent or chemical substance that has the above-mentioned function. The chemical methoxysilyl-propyl-methoxy-octadecyl-ammonium chloride has excellent antibacterial properties and is also effective against DDT and BH.
C has insect repellent properties. Furthermore, activated carbon has deodorizing properties. In addition, a substance having a physical action function is a substance that can bring about a physical activation action, such as a substance that generates magnetic force like a magnet,
Or something that changes hue when it senses a change in temperature.

Note that the amount of a specific functional substance deposited varies depending on the desired function, but according to the various findings of the present inventors, for example, if the substance is intended to have antibacterial properties, generally It is best to set the amount within the range of about 0.05 to 5.0 g/m2, while if the purpose is to have deodorizing properties, it is generally within the range of about 0.1 to 10 g/m2. Good.

In addition, in the present invention, the measurement of the surface charge density is performed in the third step.
This is done using the method shown in the figure.

That is, in FIG. 3, a sample 9 is sandwiched between a grounded metal tube 6 and a metal plate electrode (area: 100 cd, made of brass) 5, and the charge generated by electrostatic induction is transferred via a capacitor 7. The voltage is measured by an electrometer 8, and the surface charge density is determined from the measured potential using the following formula.

Q=CXV/S Q: Surface charge density (coulombs/-) C: Capacitor customer traffic V: Voltage S: Area of sample (art) [Examples] The following describes the structure of the functional electret material of the present invention based on the examples. , the effects will be explained in detail.

Example 1 Treatment solution of 3-trimethyl-xysilyl-propyl-dimethyl-octadecyl-ammonium chloride (concentration 10
%) using an atomizer, and air containing mist was heated to a surface charge density of 6゜0
/m2 of polypropylene electret non-woven fabric, and the antibacterial agent was applied at 0.3Q/m2.

Next, the antibacterial bacteria from Sea 1 to which this antibacterial agent was attached were removed using the shake flask method (ATOO4352>).
Sterilization rate was evaluated using Pneumonia.

Sterilization rate (%>=L-Y-x 1o.

X: Number of bacteria after 0 hours Y: Number of bacteria after 1 hour culture As a result, the sterilization rate was 100%, which was very good, and also had good performance as an electret body. Ta.

Comparative Example The sterilization rate of the electret nonwoven fabric (no antibacterial treatment) used in Example 1 was evaluated in the same manner as in Example 1 without any antibacterial agent attached, and the sterilization rate was 40%.
This was completely inferior to that described in Example 1.

Example 2 Activated carbon (PK350# manufactured by Kuraray Chemical II) was dispersed in the air at a concentration of 7.11 g/rn", and a polypropylene electret filter (fineness 4 denier, surface charge density 3.X10" coulombs/d) was used. , weight 200
CI, "m2, thickness 1.7 mm) was aerated to obtain an electret nonwoven fabric having a deodorizing function and having an activated carbon adhesion matrix of 5 g/Tl12.

When we created a filter element using this electret nonwoven fabric and used it as a ventilation filter in an animal housing, we were able to confirm that it was a ventilation filter that very effectively reduced animal odors.

[Effects of the Invention] According to the present invention as described above, powders, droplets, and fibrous materials having a specific chemical action function or physical action function are produced based on the electrostatic adsorption effect of the electret. By attaching such materials to the surface of the electret body, it is possible to easily produce 1 q of electret material that retains almost 100% of the functions of the powder, mist, droplets, and fibrous material.

That is, according to the present invention, a substance that exerts a specific function is adsorbed on the electret surface without using a binder or other adhesive, so that the function of the substance can be highly enhanced and the electret can be improved. It can be effectively utilized without substantially impairing its properties. In particular, when the binder is also electrically adsorbed to adhere the substance, a very high adhesion force can be obtained.

In addition, electret bodies that have adsorbed substances with various specific functions can easily be made into electret materials that have multiple functions at the same time, such as antibacterial, antifungal, and deodorizing properties. It is also easily possible to provide various types of multiple functionalities that are desirable to coexist, such as a combination of the following.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural model diagram of an electret nonwoven fabric that is an embodiment of the functional electret material of the present invention. FIG. 2 is an enlarged cross-sectional model diagram showing how a substance having a specific function is attached to the electret fibers in the electret nonwoven 5 shown in FIG. 1 by electroadsorption action. . FIG. 3 is a schematic diagram illustrating a method for measuring surface charge density. 1: Functional electret material 2.2': Electraf 1 to fiber 3.3': Substance with chemical or physical action Patent applicant: Toshi Co., Ltd. 3'

Claims (2)

[Claims] (1) Surface charge density is 5×10^-^1^1 coulomb/
A functional electret material characterized in that a substance having a chemical action function or a physical action function is adhered to the surface of an electret body of cm^2 or more by at least electroadsorption action. (2) The functional electret material according to claim (1), wherein a substance having a chemical action function or a physical action function is attached by the adhesive action of a binder.