JP2672609B2 - ▲ Ro ▼ material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention efficiently removes fine dust contained in a gas such as a high-performance air filter (HEPA) and an air filter for an automobile to clean it. Materials for air filters for obtaining gas, liquid materials for removing fine particles in liquids such as oil filters for automobiles, fuel filters for automobiles, filters for electric discharge machines, water treatment filters for collecting ultrapure water, etc. It is about.

(B) Conventional Technology As a high-performance material for removing fine particles contained in a liquid or a gas, glass is often used because it has a small diameter and can be manufactured at a relatively low cost. However, with materials that use ultrafine glass fibers, it is inevitable that the fine glass fibers contained in the material will fall off during use,
Since dust generation from the material itself due to vibration of the material is unavoidable, its use is restricted in high-performance materials and applications that pose a safety and health problem such as food applications, and the glass is resistant to chemicals such as hydrofluoric acid. Since it does not have the above, there is a problem that its use is limited in applications that may be exposed to hydrofluoric acid vapor, and that it cannot be used for nuclear applications because it cannot be reduced in volume by incineration.

Therefore, a material using fibrillated organic fibers has been developed as a solution to the drawbacks of the material using the glass ultrafine fibers (Japanese Patent Laid-Open No. 59-92011).
JP-A-63-232814, JP-A-63-236512).

However, even when such a fiber is used, it is not possible to obtain the characteristics satisfying both the high collection efficiency and the low currency resistance obtained by the ultrafine glass fiber, despite the small fiber diameter.

Further, when these fibrillated organic fibers are used, when they are produced by a general wet papermaking method, the runoff from the wire is large, and there is a problem in production such as clogging of the wire. Inevitable.

(C) Problems to be Solved by the Invention The present invention solves the above-mentioned drawbacks and problems, maximizes the capturing ability of fibrillated organic fibers as a material constituent element, does not contain glass fibers, and Is no problem,
It is an object of the present invention to provide a highly efficient and high performance material that could not be achieved without the micro glass fiber in the prior art.

(D) Means for Solving the Problems As a result of various studies as a method for solving these problems, it was found that a nonionic surfactant having an HLB value in a specific range is used in combination with fibrillated organic fibers. Thus, the inventors have found that it is possible to maximize the ability to capture fibrillated organic fibers, and have completed the present invention.

That is, the present invention is an aqueous slurry containing a material composed of two or more kinds of fibers, a part of which is fibrillated organic fibers having a fiber diameter of 1 μm or less and a nonionic surfactant having an HLB value of 10 or more and less than 20 as essential components. It is a material characterized in that it is manufactured by a wet papermaking method.

The fibrillated organic fibers in which a part of the fibers in the present invention have a fiber diameter of 1 μm or less include, for example, 1) a synthetic polymer solution which is made to flow down into a poor solvent of the polymer while applying a shearing force to form a fibrous fibril. (Fibrid method, Japanese Patent Publication No. 35-11851).

2) Method of precipitating fibrils by shearing while polymerizing synthetic monomer (polymerization shearing method, Japanese Patent Publication No. 47-21)
898 publication).

3) A method in which two or more incompatible polymers are mixed, melt-extruded or spun, and then cut into fibrous fibrils by mechanical means (split method, JP-B-35-9651).

4) A method in which two or more types of incompatible polymers are mixed, melt-extruded or spun, cut and then immersed in a solvent to dissolve one polymer, and to fibrillate into a fibrous form (polymer blend dissolution method, US Patent 3,382,305).

5) A method in which a synthetic polymer is explosively ejected from the high-pressure side to the low-pressure side above the boiling point of the solvent and then fibrillated into a fibrous state (flash spinning method, Japanese Patent Publication No. 36-16460).

6) A method in which a polyester polymer is blended with an insoluble alkali-soluble component in the polyester, and after molding, the mixture is reduced in weight with an alkali and then beaten to form fibrils (alkaline weight loss beating method, JP-A-56- No. 315).

7) A method in which highly crystalline and highly oriented fibers are cut into suitable fiber lengths, dispersed in water, and fibrillated using a homogenizer, a beater, a sand mill, etc. (JP-A-56-10).
No. 0801, JP-A-59-92011, US-4761203) and the like.

The amount of these fibrillated organic fibers is not particularly limited because it depends on the required properties of the material, but from the viewpoint of over-efficiency, it is preferably 3% or more of the total fiber weight.

Particularly preferred examples of these fibrillated organic fibers are highly crystalline, highly oriented fibers cut into suitable fiber lengths, dispersed in water, and then fibrillated using a homogenizer, a beater, a sand mill, etc. The ones that have been done are listed.

Examples of the highly crystalline and highly oriented fibers mentioned here include aromatic polyester (Econol manufactured by Sumitomo Chemical Co., Ltd.), aromatic polyamide (manufactured by Kevlar DuPont), and Technora (manufactured by Teijin).

MFC-400 (manufactured by Daicel Chemical Industries, Ltd.) is a specific example of fibrillated highly crystalline and highly oriented fibers.

A nonionic surfactant having an HLB value of 10 or more and less than 20 in the present invention has an HLB value (Hydrophile Lipophile Balance) of 1
It is a nonionic surfactant having a high hydrophilicity of 0 or more and less than 20, and the chemical structure is not particularly limited, and examples thereof include polyoxyethylene alkyl ether-based surfactants, polyoxyethylene alkylphenyl ether-based surfactants, and polyoxyethylene. Polystyryl phenyl ether type surfactant, polyoxyethylene-polyoxypropylene glycol type surfactant, polyoxyethylene-polyoxypropylene alkyl ether type surfactant, polyhydric alcohol fatty acid partial ester type surfactant, polyoxyethylene Polyhydric alcohol fatty acid partial ester type surfactant, polyoxyethylene fatty acid ester type surfactant, polyglycerin fatty acid ester type surfactant, polyoxyethylenated castor oil type surfactant, fatty acid diethanolamide type surfactant, po Nonionic surfactants such as oxyethylene alkylamine-based surfactants, triethanolamine fatty acid partial ester-based surfactants and trialkylamino oxide-based surfactants, and specific examples include, for example, Emulgen 108, 109P, 120, 123P, 14
7, 130K, 210, 220, 306P, 320P, 408, 409P, 420, 43
0, 705, 707, 709, 810, 840S, 906, 909, 910, PI-20
T, 911, 913, 920, 930, 931, 935, 950, 985, A-6
0, A-90, A-500, B-66, Leodoll TW-L120, TW
-L106, TW-P120, TW-S120, TW-S320, TW-O120, TW
-O106, TW-O320, 430, 440, 460, SEM, Emazol O
-105R, Emanone 1112, 3115, 3130, 3170, 3199, 32
99, 4110 (made by Kao Corporation), Nissan Nonion L
-4, F-2.5, P-6, S-4, S-6, S-10, S
-15, S-15.4, S-40, O-3, O-4, O-6, T
-15, K-207, K-211, K-220, K-230, P-20
8, P-210, P-213, P-223, P-240, E-212, E
-215, E-220, E-230, S-207, S-211, S-21
5, S-220, S-230, T-208.5, HS-206, HS-208,
HS-210, HS-215, HS-220, HS-240, NS-206, NS-2
08.5, NS-210, NS-212, NS-215, NS-220, NS-23
0, NS-240, NS-240, NS-270, LT-221, PT-221, ST
-221, OT-221, Unigri GL-102, GL-106, Uniox HC-40, HC-50, HC-60 (all manufactured by NOF Corporation) are exemplified.

The amount of the nonionic surfactant having an HLB value of 10 or more and less than 20 is not particularly limited, but if the content of the fiber is less than 0.1%, a sufficient effect cannot be obtained. Since it cannot be obtained, the range of 0.1% to 5% of the fiber content is preferable.

Further, nonionic surfactants other than the above, anionic surfactants, cationic surfactants, amphoteric surfactants and the like can be used in combination.

Fibers other than the fibrillated organic fibers used in the present invention include natural fibers such as wood pulp, hemp pulp, esparto and cotton fibers, polyester fibers, vinylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, polyamide fibers. , Synthetic fiber such as rayon fiber, regenerated fiber, glass fiber, ceramic fiber, rock wool, alumina fiber, beryllium oxide fiber, boron carbide fiber, silicon carbide fiber, silicon nitride fiber, potassium titanate fiber, graphite, silica and other inorganic materials Fiber is exemplified,
One or more may be appropriately selected and blended according to the application.

To the material of the present invention, a binder such as an acrylic emulsion, a water repellent such as a fluorine-based or silicon-based agent, a sticky agent, a yield improver, and a dye are added to the material of the present invention, as long as the characteristics of the material are not impaired. Agents can be added.

The material of the present invention is produced by a paper machine for producing general paper or wet non-woven fabric, for example, a Fourdrinier paper machine, a cylinder paper machine, an inclined wire type paper machine and the like.

(E) Action It is not clear why the combination of the fibrillated organic fiber and the nonionic surfactant in the material of the present invention is effective, but when the nonionic surfactant is not contained, the fibrillated organic fiber is effective. Even if the above is used, a high over-efficiency is not obtained despite the large over-resistance, and in the combination of the ultrafine glass fiber or general organic fiber and the surfactant, the obvious improvement in the over-efficiency as observed in the present invention is not obtained. Since it is not observed, the improvement of the over-efficiency according to the present invention is not considered to be solely due to the improvement of the dispersibility between the fibers, and the nonionic surfactant is dehydrated and finely divided by the surface tension of water during drying. It is presumed that this is because the fibrils are prevented from converging and as a result, each fine fibril functions excessively effectively.

(F) Examples Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited thereto.

 % In the examples and comparative examples represents% by weight.

The pressure loss, dust collection efficiency, overspeed, and in-liquid particle collection efficiency in Examples and Comparative Examples were measured by the following methods.

Pressure loss: The ventilation resistance when air was passed through the material at a flow rate of 4.75 cm / sec was determined by a water column manometer.

Dust collection efficiency: Dioctyl phthalate particles with an average particle size of 0.3 μm are generated, and the air containing these particles has a flow rate of 5.3c.
Pass the material at m / sec, measure the number of particles in the air sampled before and after the material using a light scattering particle counter (KC-11, manufactured by Rion Co., Ltd.) and calculate using the following formula did.

Dust collection efficiency (%) = (A−B) / A × 100 (A is the number of particles before B, B is the number after particles) Overspeed: 1000 mmAq of water column pressure on a circular surface with a diameter of 28 mm It was calculated from the amount of liquid passed in 1 minute when water was passed through.

In-liquid particle collection efficiency: A polystyrene standard particle diluted standard solution with an average particle size of 0.34 μm was passed through a material, and the number of particles in the solution before and after passing was measured using an in-liquid particle counter (manufactured by Lion Corporation). Then, it was calculated using the same formula as the dust collection efficiency.

Examples 1 to 4 Nonionic surfactant (Emanone 3299, polyoxyethylene fatty acid ester type, HLB value = 18.3, manufactured by Kao Corporation)
To the total fiber weight of 0.5%, 1.0%, 3.0%,
Kevlar fine fiber (MFC-400, manufactured by Daicel Chemical Industries, Ltd.) 18%, polyester fiber (manufactured by Asahi Kasei Corporation, 0.1 denier x 3 mm, diameter about 3) in an aqueous solution dissolved to 5.0%
μm) 8% and Y-type vinylon fiber (Kuraray Co., Ltd., 2 denier × 6 mm, maximum projected diameter of about 20 μm) 74% are mixed to prepare an aqueous slurry, and a standard square handmade paper machine is used from this slurry. After forming a sheet having a basis weight of 75 g / m ² , the sheet was lightly pressed and dried to obtain material sheets of Examples 1 to 4, respectively.

The physical properties of these sheets and the filter performance are shown in Table 1. The obtained material sheet showed a filter performance that was practically no problem as a HEPA filter, and showed good volume reduction property because it did not contain glass.

Example 5 Nonionic surfactant (Emanone 3199, polyoxyethylene fatty acid ester type, HLB value = 19.1, manufactured by Kao Corporation)
Kevlar fine fiber (MFC-400, manufactured by Daicel Chemical Industries, Ltd.) 18%, polyester fiber (manufactured by Asahi Kasei Corporation, 0.1 denier x 3 mm, diameter about 3 μm) ) 8%, Y type vinylon fiber (Kuraray Co., Ltd., 2 denier x 6 mm, maximum projected diameter of about 20μ)
m) 74% was mixed to form an aqueous slurry, and a sheet was formed from this slurry using a standard square handmade paper machine so that the basis weight was 75 g / m ² , then lightly pressed and dried. ,
Acrylic latex binder (Primal HA-8, manufactured by Nippon Acrylic Chemical Co., Ltd.) 0.25% and fluorine water repellent (FP-210, manufactured by Sumitomo Chemical Co., Ltd.) 0.15% on the obtained sheet.
A material sheet of Example 5 was obtained by impregnating an aqueous solution containing the above with a solid content of 1 g / m ² and drying. The physical properties and filter performance of this sheet are shown in Table 1. The obtained material sheet showed a filter performance that was practically no problem as a HEPA filter, and showed good volume reduction property because it did not contain glass.

Comparative Example 1 A material sheet of Comparative Example 1 was obtained in exactly the same manner as in Example 1 except that the nonionic surface activity was removed. The physical properties and filter performance of this sheet are shown in Table 1. The obtained material sheet had a lower dust collection efficiency than the sheets of Examples 1 to 4 and was inferior in performance.

Comparative Example 2 The nonionic surfactant of Example 3 (NS-204.5, polyoxyethylene alkylphenol ether type, HLB
Value = 9.5, manufactured by NOF CORPORATION)
A material sheet of Comparative Example 2 was obtained in the same manner as in. The physical properties and filter performance of this sheet are shown in Table 1. The obtained material sheet had a lower dust collection efficiency than the sheets of Examples 1 to 4 and was inferior in performance.

Example 6 Nonionic surfactant (Emanone 3115, polyoxyethylene fatty acid ester type, HLB value = 13.4, manufactured by Kao Corporation)
Kevlar fine fiber (MFC-400, manufactured by Daicel Chemical Industries, Ltd.) 3% and ultrafine polyester fiber (manufactured by Asahi Chemical Industry Co., Ltd., 0.
67% of 1 denier x 3 mm) and 30% of polyester binder fiber (Unitika Ltd., # 4080, 2 denier x 5 mm) 30% are mixed to prepare an aqueous slurry, and a standard square handmade paper machine is used to form an aqueous slurry. A sheet was formed so that the amount was 40 g / m ² , lightly pressed, dried, and further subjected to a heat calendar treatment to obtain a material sheet of Example 6. The physical properties of this sheet and the filter performance are shown in Table 2.

The obtained material sheet had a high efficiency of collecting particles in the liquid, a low overresistance, and a good filter performance.

Comparative Example 3 A sheet of Comparative Example 3 was obtained in the same manner as in Example 6 except that the nonionic surfactant of Example 6 was omitted. The physical properties of this sheet and the filter performance are shown in Table 2. The obtained material sheet had a lower collection efficiency than that of the material sheet of Example 6, and was inferior in filter performance.

(G) Effect of the Invention The present invention eliminates the drawbacks of materials using glass ultrafine fibers, and provides high-performance materials that have hitherto been unattainable except for glass ultrafine fibers. Solving problems such as self-dusting properties that are defects when used, mixing of fine glass into excess body, low incineration volume reduction property, weak to hydrofluoric acid, etc., no manufacturing problems, industrially useful It provides high performance materials. Further, the use of a surfactant makes it possible to reduce the amount of expensive fibrillated organic fibers used.

Claims (4)

(57) [Claims] 1. A material composed of two or more kinds of fibers, part of which is fibrillated organic fibers having a fiber diameter of 1 μm or less.
A material containing a nonionic surfactant having an HLB value of 10 or more and less than 20. 2. The nonionic surfactant is added in an amount of 0.1 to 5.0% based on the total fiber weight.
The listed material. 3. The material according to claim 1 or 2, wherein the fibrillated organic fibers partially having a fiber diameter of 1 μm or less are highly crystalline and highly oriented fibers. 4. The material according to claim 1, 2 or 3, wherein the content of the fibrillated organic fibers partially having a fiber diameter of 1 μm or less is 3% or more of the total fiber weight.