JPS6014917A - Air filter - Google Patents

Abstract

PURPOSE:To increase the dust collecting efficiency while maintaining the air permeability by depositing a high polymer adhesive composition on a skeleton structure having air permeable fine pores. CONSTITUTION:The base material having air permeable fine pores is the material which is used heretofore as an air filter and contains innumerable communicated fine pores in an organic, inorganic or metallic skeleton structure. The high polymer adhesive composition is a material usually called an adhesive, and the adhesive which is not consumed by evaporation in company with the air current during the breathing is preferable. The high polymer adhesive composition is dissolved in an organic solvent or in water or made into a slurry, which is impregnated into the base material and dried. The impregnation is facilitated by enlarging the cell by swelling in case of a fine foam. Since the high polymer adhesive composition has poor fluidity, the compositon does not ooze out like oil.

Description

DETAILED DESCRIPTION OF THE INVENTION (Purpose and Background) The present invention relates to an air filter with improved dust collection efficiency. Air filters are installed at air intakes and ventilation openings for cooling air for various air conditioning equipment, engines such as automobiles and generators, air compressors, and cooling air for various electrical equipment. There is.

Materials used for air filters include materials with breathable micropores such as wire mesh, non-woven fabrics, fibers, various nets, plastic foam, and inorganic foams such as metals and ceramics, but dust collection efficiency is limited. Since it depends on the size of the mesh, if you want to obtain high dust collection efficiency, it is necessary to use one with fine mesh. However, ventilation resistance (
The finer the mesh, the higher the pressure loss), so there is an inverse relationship between ventilation resistance and dust collection efficiency. Since the air filter is installed on the intake side, it is undesirable to cause too large a pressure loss.Therefore, even if you are somewhat dissatisfied with the dust collection efficiency, choose a fine-mesh filter that is within the allowable pressure loss range for various devices. I have no choice but to do it.

Therefore, in order to increase dust collection efficiency without increasing pressure and loss, the fine mesh of the filter is impregnated with and adhered to a highly viscous oil such as lubricating oil, and the stickiness of the oil is used to adsorb dust. A method is being taken to do so.

However, although this method has some effect in terms of performance, 4. Due to the fluidity of the attached oil, (1) it tends to stain Nagisa's body and clothes when handling it; (2) for the same reason, there is a risk of staining the surrounding area when used on household or office equipment.
(3) The oil is carried away by the air passing through the filter, gradually reducing its effectiveness. (4) The oil decomposes due to heat. (5) Depending on the type of oil, the lifespan of the filter material may be shortened due to the effects of additives, etc. It has disadvantages such as:

The present invention eliminates the above-mentioned drawbacks of conventional air filters and improves dust collection efficiency while maintaining air permeability.

(Structure) That is, the present invention is an air filter characterized in that a polymer adhesive composition is attached to the skeleton structure of a base material having breathable micropores.

Here, the term "base material having breathable micropores" refers to materials conventionally generally used for air filters, such as wire mesh, nonwoven fabrics, fibers, various nets, plastic foam, or inorganic foams such as metals and ceramics. For example, materials with a large number of communicating micropores between organic, inorganic, or metallic skeletal structures are used. Although each of these materials has its own characteristics, they have in common that dust collection efficiency is improved by applying a polymeric adhesive composition according to the present invention.

The polymeric adhesive composition may be anything that is commonly referred to as an adhesive, and is not particularly limited. Typical examples include natural product-based, rubber-based, acrylic-based, oligomer-based, silicone-based adhesives, etc. Because it has a higher molecular weight than oil, it hardly evaporates and wears out due to airflow during ventilation, and generally has excellent heat resistance, so it can be used for long periods of time under harsh conditions. withstand

These polymer adhesive ml compositions have poor fluidity, so 1
The method for adhering it to a substrate is to dissolve it in an organic solvent or water to make a solution, or make it into an emulsion and impregnate it on the substrate, and then use it as it is, or squeeze out the excess solution or emulsion, and then dry it. Good. In addition, if a liquid curing adhesive or other adhesive having low fluidity is used, it may be used as is.

When using plastic foam as the base material,
When an adhesive composition is applied using a solvent such as a halogenated solvent as an organic solvent that significantly swells foam, the cells expand easily even in fine foams with a large number of cells, which are normally difficult to impregnate. It becomes possible to impregnate.

When using an adhesive composition in the form of an aqueous solution or emulsion, the same effect can be expected if the foam is swollen with a solvent in advance.

As mentioned above, the polymer nine-molecular adhesive composition used in the present invention has poor fluidity, so once it is attached to the skeletal structure of the base material, it oozes out like oil and stains hands and clothes. It is convenient to handle without getting dirty.

Example 1 Polyurethane foam was used as a substrate with breathable micropores. Everlight Scotto (Product name: Bridgestone Tire Co., Ltd.) HR-13 (Number of cells: 13/2
5mm), HR30 (26 cells/25mm),
H, R-50 (number of cells 50 care 25 mm) 3
The thickness of each brand is 10 mm and 20 mm, respectively.
A total of six types of samples were prepared.

Brominated butyl rubber 25 parts Polybutene 30OR75 parts SiO21/2 parts Archon P-125 (Manufactured by Arayo Kagaku, tackifier) 5 parts were sufficiently kneaded in a kneader to obtain an adhesive rubber composition.

Dissolve this in n-hexane to make a 5% by weight solution, sufficiently impregnate the six types of samples in this solution, and then take it out.
The excess liquid was squeezed out using a squeezing roll, and the mixture was air-dried to obtain an adhesive composition-adhered foam. For 6 types of this foam and 6 types of untreated foam, the wind speed was 1 m/see and 2 m/see.
/sec filtration performance (pressure loss and dust collection efficiency)
was measured. The results are shown in Tables 1 and 2.

The LA overperformance test method was based on the Japan Air Cleaning Association's 2nd Performance Test Method.

That is, the pressure loss was determined by setting the test sample in a wind tunnel, applying wind speed with a fan, and measuring the pressure difference before and after the test sample at each wind speed using an inclined tube manometer.

In addition, the dust collection efficiency was determined by placing a test sample in a wind tunnel using Seriton, applying wind speed with a fan, sending dust that was blown away by a dust machine, and measuring the dust collection rate at each wind speed by a colorimetric method.

Table 1 Pressure loss, unit: water column mm Table 2 In order to help understand the effects of the present invention shown in the above test results with dust collection efficiency of 0, the relationship between pressure loss and dust collection efficiency is shown in Figure 1. Shown below.

The horizontal axis is pressure loss (water column mm), and the vertical axis is dust collection efficiency (%).
) is shown. The symbols used in the diagram are: Wind speed 1 m/sec O thickness 10 mm Adhesive rubber attached (invention) Thickness lomm
Untreated Δ thickness 20 mm With adhesive rubber (invention) Mu thickness 20 m
m Untreated wind speed 2 m / sec Self-thickness 10 mm With rubber pasting (invention) ■ Thickness 10 mm
Untreated◇Thickness 20mm With adhesive rubber (this invention)◆Thickness 20mm
Untreated, that is, black marks represent untreated substrates, and white 5 marks represent air filters according to the present invention. Moreover, the arrows in the figure indicate states in which the performance of each base material has changed.

As is clear from Tables 1 and 2 and FIG. 1, the air filter of the present invention greatly improves the dust collection effect even with a slight increase in pressure loss. The degree of improvement is particularly high in the case of coarse substrates.

Further, although the air filter of the present invention was maintained at 70°C, there was almost no change in weight and almost no change in stickiness even after 30 days.

Polyurethane foam was used as the breathable base material because it has the advantage of making it easy to obtain samples of the same material but with different numbers of pores, and is suitable for tests with different numbers of pores. Since the skeletal structure of the base material is completely covered with the adhesive composition, the same relationship as shown in Figure 1 will be maintained regardless of the material of the base material used. This can be true.

Example 2 The same six samples used in Example 1 were mixed with 182 parts of natural rubber latex (solid content 55% by weight) and 250 parts of hydrogenated rosin ester emulsion (solid content 40% by weight) anti-aging agent dispersion. 4 parts of liquid (solid content 50% by weight) are stirred and mixed into an aqueous solution of the adhesive composition, squeezed with a roll, and dried in an oven heated to about 80"C to form a foam with the adhesive composition attached. I got it.

When the filtration performance of this sample was measured, it showed almost the same tendency as shown in FIG.

Example 3 The same six samples used in Example 1 were mixed with 50 parts of a 50% aqueous dispersion of a copolymer of 91 parts of acrylic ethyl and 9 parts of methacrylic acid, and 70 parts of a 70% solution of unbalanced rosin Na salt. Part glycerin 20 parts Urea 10 parts Water 80 parts are impregnated with an aqueous adhesive composition solution prepared by heating and stirring at 70°C for 30 minutes, squeezed with a roll, and dried in an oven heated to about 80°C to obtain an adhesive composition. A material adhesion form was obtained. When the filtration performance of this sample was measured, it showed almost the same tendency as shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between ventilation pressure loss (horizontal axis) and dust collection efficiency (vertical axis) of the air filter of the present invention and a conventional product. Applicant Brideston Tire Co., Ltd. Agent Patent Attorney Masa Ao Asa 2 Figure 1

Claims (1)

[Claims] 1. An air filter formed by adhering a polymeric adhesive composition to the skeletal structure of a base material having breathable micropores. 2. Claims in which the base material having breathable micropores is a polyurethane foam. Air filter in item 1. 3. The air filter according to claim 1 or 2, wherein the polymer adhesive composition is an adhesive rubber.