JPH0538414A - Deodorizing filter - Google Patents

Abstract

PURPOSE:To provide a long-life deodorizing filter having a low pressure loss and a high deodorization capacity as compared with conventional deodorizing filters using an activated carbon structure of carbonized foamed plastics and having a bulk density at most 0.4g/cm<3> and a relatively short life. CONSTITUTION:A cured product of a composition comprising 100 pts.wt. of a resol-type phenolic resin (a), 1-100 pts.wt. of a lipophilic compound (b) which is liquid at room temperature and has a boiling point of 100 deg.C or higher, and 1-100 pts.wt. of a hydrophilic liquid compound (c) having a boiling point of 100 deg.C or higher is carbonized and activated to obtain a porous structure of activated carbon. The structures are allocated in the air passage of a deodorizing filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing filter used in air purifiers, air conditioners and the like.

[0002]

2. Description of the Related Art In recent years, interest in health, particularly awareness of smoke caused by smoking, has increased, and there has been a strong demand to clean the room by removing cigarette smoke from a device. A variety of air purifiers have been sold to meet such demands, and recently, air conditioners having a deodorizing performance have begun to be used. By the way, air cleaning filters are roughly classified into a dust collecting type that removes dust, microorganisms, smoke, and the like in the air, and a deodorizing type that removes malodorous components. Of these, deodorizing filters have conventionally used activated carbon fibers, granular activated carbon, or the like.

However, the filter using activated carbon fiber as an adsorbent has a problem that the life as a deodorizing filter is short because of high pressure loss and low bulk density. In addition, granular activated carbon has a high bulk density but does not have a self-shape-retaining property, so a structure supporting it is required. As a result, the pressure loss becomes high. Could not be used as.

On the other hand, when a urethane foam carrying activated carbon is used as a deodorizing filter, increasing the amount of activated carbon supported on the urethane foam increases the pressure loss, and conversely, decreasing the amount of activated carbon causes the pressure loss to decrease. Although it can be lowered, there is a problem that the ability to adsorb malodorous components is also reduced, the life of the deodorizing filter is shortened, and the deodorizing performance is lost within a short period of time.

It is generally considered that the deodorizing performance of a deodorizing filter depends on the adsorption performance per unit weight of the activated carbon constituting the filter x the total weight of the activated carbon. Further, it is considered that the pressure loss of the deodorizing filter depends on the magnitude of the resistance of the gas flow passing through the filter, in other words, the size of the passage, that is, the aperture ratio. Therefore, many attempts have been made so far, but no satisfactory deodorizing filter has been obtained so far.

The present inventors have found that when an activated carbon structure obtained by carbonizing and activating a plastic foam is used for a deodorizing filter, it has a self-shape-retaining property, so that it is possible to obtain a large aperture ratio and a bulk density. Since it is higher than activated carbon-supporting urethane foam and activated carbon fiber, we have found and proposed that the above two requirements can be satisfied. But,
The activated carbon porous material that can be stably produced by this method has a limit of 0.4 g / cm3 in bulk density, and when industrially producing activated carbon having a bulk density higher than that, it is often used in the carbonization and activation steps. It was found to crack and explode.

[0007]

The present invention has reached the present invention as a result of further studies on a deodorizing filter having lower pressure loss and high deodorizing performance and having a long life.

[0008]

Means for Solving the Problems That is, the present invention is based on 100 parts by weight of a resol type phenolic resin (a) and 10 parts by lipophilicity.
A cured product of a composition comprising 1 to 100 parts by weight of a liquid compound (b) having a boiling point of 0 ° C. or higher at room temperature and 1 to 100 parts by weight of a hydrophilic liquid compound (c) having a boiling point of 100 ° C. or higher. The deodorizing filter is characterized in that the activated carbon porous body structure obtained by carbonizing and activating is disposed in an air passage.

The present invention will be described in more detail. The resol type phenolic resin (a) used in the present invention means, for example, 1 mol of phenol and 1 to 3 mol of formalin as an alkaline catalyst such as NaOH, KOH, Ca (OH) 2, Ba.
In the presence of (OH) 2, NH2 (CH2CH3), etc.
It is a liquid having a viscosity at room temperature of 1000 to 20000 cps, which is obtained by condensing by heating at 100 ° C. and then distilling off water under reduced pressure until the solid content becomes 60 to 80%.

In the present invention, the lipophilic compound having a boiling point of 100 ° C. or higher and liquid at room temperature is, for example, a straight-chain compound such as octane, nonane, decane, undecane, dodecane, kerosene, mineral oil, liquid paraffin, or the like. Examples thereof include branched alkyl compounds and cyclic alkylene compounds such as toluene and xylene. Among these, liquid paraffin is preferable because it has a viscosity similar to that of resole and a stable oil-in-water dispersion system can be prepared when mixed.

The lipophilic compound (b) is usually added in an amount of 1 to 1 with respect to 100 parts by weight of the resol type phenol resin (a).
00 parts by weight, preferably 10 to 60 parts by weight. If the amount of the lipophilic compound (b) is too small, the porous structure of the activated carbon porous body will be small, resulting in poor adsorption performance and liquid impregnation property. In addition, explosion occurs during carbonization and activation, making it difficult to produce activated carbon. On the other hand, when the amount exceeds the above range, the curing property of the resole becomes poor. In addition, the shrinkage of the cured product is large during carbonization, and cracking is likely to occur.

The liquid compound (c) having a boiling point of 100 ° C. or higher in the present invention means, for example, an oxyalkylene compound having a degree of polymerization of 2 or higher, such as diethylene glycol, triethylene glycol, polyethylene glycol having a molecular weight of less than 1000. , Dipropylene glycol,
Examples thereof include polypropylene glycol having a molecular weight of less than 1000 or glycerin. Among these, polyethylene glycol having a molecular weight of 400 to 600 or dipropylene glycol is preferable because it is relatively close to the viscosity of the resole and has a suitable compatibility.

Resol type phenolic resin (a) 10 of this liquid compound (c) having a boiling point of 100 ° C. or higher
The compounding amount with respect to 0 part by weight is usually 1 to 100 parts by weight, preferably 10 to 60 parts by weight. When the amount of the hydrophilic compound (c) is too small, the dispersion stability of the lipophilic compound (b) is poor, and phase separation easily occurs. On the other hand, when the amount exceeds the above range, the curing property of the resole is impaired, and the hydrophilicity is high. The compound and the resole are easily phase separated.

In the present invention, the compounding ratio of the lipophilic compound (b) and the hydrophilic compound (c) is preferably in the range of 0.3 to 3. If it is out of this range, the mixture is likely to undergo phase separation. Become.

As the curing agent used for curing the resol type phenolic resin (a) in the present invention, various known strongly acidic compounds, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, pyrophosphoric acid and polyphosphoric acid are used. , Organic acids such as phenolsulfonic acid, benzenesulfonic acid, toluenesulfonic acid, and metacresolsulfonic acid, or a mixture thereof. The amount of the curing agent used is usually in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the resol type phenol resin.

The resin composition that can be used as a raw material for the activated carbon porous material structure used in the deodorizing filter of the present invention contains the above-mentioned components as essential components, but a small amount of other components other than the above, for example, activated carbon porous material. As a pore forming agent for improving the gas adsorption performance of, for example, fugitive fillers, such as polyethylene, flour, etc., other carbon materials for diversifying the pore size, such as activated carbon, carbon black, mesophase pitch powder, graphite It may contain a metal salt compound or the like for promoting activation, such as powder.

In the present invention, the resol type phenolic resin (a) is a lipophilic compound having a boiling point of 100 ° C. or higher and liquid at room temperature (b), and a hydrophilic liquid compound having a boiling point of 100 ° C. or higher (c). If necessary, a mixture of a surfactant, other filler, etc. is stirred and mixed, and / or at the same time, a curing agent is mixed. As a method of mixing the above components, a method of continuously, batchwise, or simultaneously using a mixer having a stirring blade that rotates at high speed can be preferably used.

In the deodorizing filter of the present invention, the viscosity of the resin composition immediately after stirring and mixing is usually 50,000 cp.
The viscosity is s or less. Due to such a low viscosity, bubbles can not be mixed during stirring, and a homogeneous activated carbon porous material structure can be obtained in terms of bulk density and the like.

In the activated carbon porous material structure for a deodorizing filter of the present invention, the resin cured product thus obtained is used as it is,
Alternatively, after cutting into a plate-like body, it is carbonized in a non-oxidizing atmosphere to form a carbon porous body. The non-oxidizing atmosphere means, for example, Ar gas, He gas, N2 gas, halogen gas, ammonia gas, CO gas, hydrogen gas, a mixed gas thereof, a water gas or the like. The temperature for carbonization is preferably from 500 ° C to 1200 ° C, especially from 600 to 900.
The range of ° C is preferred.

The carbon porous body obtained as described above is
Further, activation treatment is applied to activate. The activation step may be continuous with the carbonization step or may be a step separate from the carbonization step. Activation of the carbon porous body is performed by heating the carbon porous body in an atmosphere of an oxidizing gas or a mixed gas of an oxidizing gas and an inert gas. Heating temperature is 600 ° C-120
The temperature is 0 ° C, preferably 750 to 1000 ° C. As the oxidizing gas, known oxidizing gases such as water vapor, carbon dioxide, oxygen, air and the like are used. These are usually mixed with an inert gas such as N2 for easy control.

The activated carbon porous material produced by the above method has a bulk density of preferably 0.3 g / cm 3 or more, particularly 0.4 g / cm 3 or more and 0.7 g / cm 3 or less,
It has a specific surface area of 700 m 2 / g or more.

The deodorizing filter according to the present invention has such an activated carbon porous body disposed in a flow path of air containing a malodorous component and the like.

Various shapes are conceivable as the shape of the activated carbon porous material structure, for example, a plate shape, a rod shape, or a hole as described in Japanese Patent Application No. 1-96161. The plate shape may be mentioned. Since the above-mentioned resin composition used in the present invention has a low viscosity, even such a complicated shape can be easily produced by casting or another molding method.

In the deodorizing filter according to the present invention, the activated carbon porous material structure may have a grid structure constituted by arranging a plurality of active carbon porous material structures at predetermined intervals as described in Japanese Patent Application No. 1-96157. .. Such a grid structure is
It is preferable because it is easy to manufacture and the pressure loss is small. For example, the standard that the wind speed is 1 m / s and the pressure loss is 0.5 mmH2O or less can be reached.

[0025]

The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples unless it exceeds the gist. Example 1 {Production of activated carbon porous material structure} 100 parts by weight of a resole-type phenol resin (abbreviation: resole) having a viscosity at 25 ° C. of 4800 cps was used as a surfactant, and a sulfuric acid ester of a polyoxyethylene 2 mol adduct of castor oil was used. 5 parts by weight of sodium salt, a high boiling point hydrophilic compound having a molecular weight of 6
25 parts by weight of polyethylene glycol (abbreviated as PEG) of 00 and 25 parts by weight of liquid paraffin (abbreviated as flow para) as a high-boiling lipophilic compound are stirred for 5 minutes at a speed of 6000 rpm with a stirrer having three stages of pin blades. Stir well. The viscosity of this mixture was 3500 cps.

20 parts by weight of paratoluene sulfonic acid was added to this mixture as a curing agent and stirred at the same stirring speed for 1 minute. After mixing, the mixture was left in an air oven at 70 ° C. for 5 minutes and then taken out. After passing, the plate was cured completely in an air oven to prepare a plate of a polymer cured product.

The plate of the polymer cured product was placed in an electric furnace and N
2 In an atmosphere, raise the temperature to 700 ° C at a rate of 1.5 ° C / min,
After holding at the same temperature for 1 hour, it was cooled. The carbon porous plate obtained by the above method was placed in a ceramic fiber board box having a thickness of 3 mm, and the box was placed in an electric furnace to raise the temperature to 900 ° C. at a rate of 3 ° C./min N 2 atmosphere, Then N2 /
After introducing the activating gas at a ratio of H2O = 9/1 for 4 hours, it was cooled and taken out. In this way, specific surface area of 1100g
/ M @ 2, bulk density 0.45 g / cm @ 3, and a plate of activated carbon porous body A having a thickness of 2 mm was obtained.

{Production of filter} A plate having a length of 100 mm and a width of 10 mm was cut out from the above plate-like activated carbon porous body,
Nine pieces were arranged at intervals of 10 mm on a plastic frame to manufacture a deodorizing filter having a grit structure of 100 mm x 100 mm.

{Performance Evaluation} [Pressure Loss] Chamber (Internal dimensions 1 mx 1 mx 1.3
The filter structure is set in a filter holder formed in a part of a 67 mmφ conduit in which the upstream and the downstream are connected to m), and a pressure gauge is arranged on each of the upstream and downstream sides of the holder, and An air blower for discharging and circulating the air inside the chamber was attached to the chamber, and the pressure loss due to the filter structure was measured as follows by operating these pressure gauges and blowers. That is, after mounting the filter structure on the holder, the blower is driven to move the air in the chamber to 100 cm /
Discharge through the conduit at a speed of sec, measure the pressure on the upstream side and the downstream side of the filter, and measure the pressure difference (mmH2
O) was used to measure the pressure loss.

[Deodorizing Performance] Acetaldehyde is introduced into the chamber so that the concentration in the system becomes 100 ppm, and the air blower is operated to circulate the air in the system. After stopping the blower, attach the deodorizing filter to the filter holder, and immediately restart the blower. The concentration of acetaldehyde in the chamber after 10 minutes had elapsed was determined by a gas detector tube, and the initial deodorization rate was measured by the following formula. Initial deodorization rate = (concentration before test−concentration after 10 minutes) /
Concentration before test x100 After 30 minutes of the above deodorization test, stop the blower, remove the deodorizing filter, and then introduce acetaldehyde into the system again to adjust the acetaldehyde concentration in the system to 100 ppm.
After that, attach the deodorizing filter used in the test again and repeat the test as before. After repeating this test once again, the concentration of acetaldehyde after 30 minutes was determined by a gas detector tube, and the long-term deodorization rate was determined by the same formula as above. The above measurement results are shown in the table. Shown in 1.

Example 2 In the filter structure of Example 1, the performance was evaluated in the same manner as in Example 1 except that the slit spacing was 15 mm and the number of activated carbon porous grids used was 6. It was The results are shown in the table. Shown in 1.

Example 3 Instead of the raw material resin composition used in Example 1, Example 1 was used.
100 parts by weight of the resole used in Example 5, 5 parts by weight of sodium sulfate of a polyoxyethylene 2 mol adduct of castor oil, 25 parts by weight of PEG having a molecular weight of 600, 25 parts by weight of liquid para, and 50 parts by weight of mesophase pitch powder. Example 1 was repeated except that the composition consisting of
Activated carbon porous material B was obtained. A deodorizing filter was produced from this activated carbon porous material in the same manner as in Example 1, and the performance of the filter was evaluated in the same manner. The results are shown in the table. Shown in 1.

Comparative Example 1 Using a commercially available urethane foam (UF) carrying powdered activated carbon as a deodorizing filter, pressure loss and deodorizing performance were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 Using a commercially available deodorizing filter made of activated carbon fiber (ACF) as a deodorizing filter, pressure loss and deodorizing performance were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 Instead of the raw material resin composition used in Example 1, Example 1 was used.
100 parts by weight of the resol used in step 1, 10 parts by weight of paratoluene sulfonic acid as a curing agent, and CFC 1 as a blowing agent.
23b 2 parts by weight of the composition as a raw material was stirred and poured into a wooden mold, and the wooden mold was left in an air oven at 80 ° C. for 1 hour to be foam-molded and then cured into a block-like cured product. Was cut in the same manner as in Example 1 except that a plate having a thickness of 7 mm was cut to obtain an activated carbon porous body C. A deodorizing filter was made from this activated carbon porous material in the same manner as in Example 1, and its performance was evaluated. The results are shown in the table. Shown in 1.

[0036]

[Table 1]

[0037]

INDUSTRIAL APPLICABILITY In the deodorizing filter of the present invention, a composition having excellent fluidity can be obtained by using a composition comprising a resole / lipophilic compound / hydrophilic compound as a raw material resin composition, so that a thin resin sheet is obtained. Can be molded, and thus can be formed into a thin wall having a thickness of about 1 mm and various shapes.
Therefore, the filter can be thinner than before. Further, the deodorizing filter of the present invention is excellent in deodorizing performance, particularly long-term deodorizing performance, because the activated carbon porous material used in the present invention has a high bulk specific gravity. In addition, since the activated carbon porous body, which is the main constituent material, has a large strength, no strength problem occurs. From the above points, the deodorizing filter of the present invention is more compact than conventional ones, and has an advantage that it does not take up much space in an air conditioner, an air purifier or the like.

Claims (1)

[Claims] 1. Resol type phenolic resin (a) 100 parts by weight, lipophilic compound (b) 1 to 100 parts by weight which is liquid at room temperature and has a boiling point of 100 ° C. or more, hydrophilic 100 ° C.
The activated carbon porous structure obtained by carbonizing and activating the cured product of the composition comprising 1 to 100 parts by weight of the liquid compound (c) having the above boiling point is disposed in the air passage. Characteristic deodorizing filter.