JP2000189734A - Durable filtering adsorption sheet and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filtering adsorption material without staining by rubbing, being excellent in rigidity, namely durability, and small in pressure drop. SOLUTION: This filtering adsorption sheet consists of a charcoal sheet 1 that charcoal powder is adhered to a sheet base cloth having air permeability by using a binder, and a nonwoven cloth 2 subjected to an electret treatment, and the particle size of the charcoal powder of the charcoal sheet 1 is <=100 μm and the average particle size is 5-30 μm and a sticking quantity of the charcoal powder is 10-100 g/m2, and as the binder both binders consisting of one binder having <=1% a weight decrease ratio under a hot water treatment containing NaOH, and the other binder having >=1% to <3% weight decrease ratio are used to stick the charcoal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorbent, and more particularly, to a filter adsorbent having charcoal powder adhered to a sheet base cloth. This filter adsorbent is widely used as a filter element for air purifiers for household appliances, air purifiers for automobiles, air purifiers for buildings, cleanroom air conditioners, mask filters, air cleaners and the like.

[0002]

2. Description of the Related Art Conventionally, activated carbon has been widely used as an adsorbent for removing trace dust in the air. This adsorbent using activated carbon is obtained by impregnating an emulsion in which activated carbon fine powder is dispersed into a base material such as a net material, a woven fabric or a nonwoven fabric, or by immobilizing activated carbon fine powder in a porous material such as a foam material. Things are used a lot. These types of adsorbents have the disadvantage that only a small part of the adsorption capacity can be used, since most of the activated carbon fine powder is covered with a binder or surrounded by a porous substance.

[0003] For this reason, for example, Japanese Patent Laid-Open No.
As described in Japanese Patent Publication No. 285531, by passing a sheet of woven fabric or the like provided with an adhesive through a flowing carbon layer and adhering activated carbon to the sheet surface, a large part of the surface of the activated carbon fine powder is obtained. An adsorption sheet manufactured by exposing the sheet to an exposed state has been developed. Since the adsorbent sheet does not cover much of the activated carbon fine powder with the synthetic resin, the disadvantage that the adsorbability is greatly reduced has been overcome. However, this adsorption sheet has a large amount of activated carbon applied to the activated carbon composite sheet (for example, 150 to 190 g / m ² ),
If it is used, problems such as dirt occur.

[0004] Originally, in the case of an adsorption sheet used as a filter, an excessive pressure loss occurs when a large amount of charcoal powder is applied, and so-called pressure loss, which is the most important function of the filter, increases. In particular, activated carbon subjected to activation treatment has many micropores on its surface and tends to have relatively large pressure loss.

[0005] In addition, the robustness when activated carbon fine particles adhere to the adsorption sheet, that is, the durability, has not always been sufficient so far.
Poor durability. Further, activated carbon has a characteristic that once an odor is adsorbed, it is not released, so that although the adsorption performance is good, the adsorption is easily saturated and the life is short as a result.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a filter adsorbent that is free from dirt, has good robustness, that is, has good durability, and has low pressure loss, and a method for producing the same.

[0007]

Means for Solving the Problems Thus, the present inventors have conducted intensive studies on such problems, and as a result,
It has been found that when charcoal without activation treatment is used instead of activated carbon and certain conditions are provided as a binder, the durability is extremely improved, and the present invention has been achieved based on this finding.

More specifically, the present invention provides (1) a filter adsorbing sheet comprising a charcoal sheet obtained by adhering charcoal powder to a breathable sheet base fabric using a binder, and another nonwoven fabric. Particle size of charcoal powder in
00 μm or less, an average particle size of 5 to 30 μm, an adhesion amount of charcoal powder of 10 to 100 g / m ² , and the binder is a charcoal charcoal using a binder having a weight loss rate of less than 3% in hot water treatment containing caustic soda. The powder resides on the adsorbed filter sheet.

And (2) a filter adsorbing sheet comprising a charcoal sheet obtained by attaching a charcoal powder to a breathable sheet base fabric using a binder and an electret-treated nonwoven fabric, wherein the charcoal powder in the charcoal sheet is used. A binder having a particle size of 100 μm or less, an average particle size of 5 to 30 μm, and an adhesion amount of charcoal powder of 10 to 100 g / m ² , wherein the binder has a weight reduction rate of 1% or less in hot water treatment containing caustic soda; The charcoal powder is present on the filter adsorption sheet to which the charcoal powder is fixed using both the binder whose weight reduction ratio is 1% or more and less than 3%.

(3) A filter adsorbing sheet composed of a charcoal sheet obtained by adhering charcoal powder to a breathable sheet base fabric using a binder and a conductive nonwoven fabric, wherein the charcoal powder in the charcoal sheet is used. Particle size of 10
0 μm or less, average particle size of 5 to 30 μm, adhesion amount of charcoal powder is 10 to 100 g / m ² , and the binder has a weight loss rate of 1% or less in hot water treatment containing caustic soda, and a weight loss rate of 1% or less. The charcoal powder is present in the filter adsorption sheet to which the charcoal powder is fixed using both the binder of 1% or more and less than 3%.

Further, (4) the filter base sheet according to (2) above, wherein the basis weight of the sheet base fabric is 10 to 800 g / m ² .

(5) The filter adsorbing sheet according to (2), wherein the charcoal sheet and the electret-treated nonwoven fabric are appropriately combined in number and temporarily bonded by pleating.

(6) The filter adsorbing sheet according to (3), wherein the charcoal sheet and the conductive nonwoven fabric are appropriately combined in number and temporarily joined by pleating.

(7) The filter adsorbing sheet according to any one of the above (1) to (6), wherein the binder contains at least one of an antibacterial agent, a fungicide, a fragrance and an insect repellent. Exist.

(8) a step of mixing the charcoal powder and the binder, a step of adhering the binder containing the charcoal powder to the sheet base cloth, a step of drying the sheet base cloth to which the binder is adhered, a step of drying the dried sheet base The present invention provides a method for producing a filter adsorbing sheet, comprising a step of curing a cloth, a step of superimposing a dried charcoal sheet on an electret-treated nonwoven fabric, pleating and temporarily bonding the sheet.

(9) a step of mixing the charcoal powder and the binder, a step of adhering the binder containing the charcoal powder to the sheet base cloth, a step of drying the sheet base cloth to which the binder is adhered, and a step of drying the dried sheet base. The present invention relates to a method for producing a filter adsorbing sheet, comprising a step of curing a cloth, a step of superimposing a dried charcoal sheet on a conductive nonwoven fabric, pleating and temporarily bonding the sheet.

The present invention also provides (10) the method for producing a filter adsorption sheet according to (8) or (9), wherein a binder which reduces the weight loss of hot water treatment containing caustic soda to less than 3%.

(11) The filter according to the above (10), wherein charcoal powder is applied in an amount of 10 to 100 g / m ² , the powder diameter is 100 μm or less, and the average particle diameter is 5 to 30 μm. The present invention resides in a method for producing an adsorption sheet.

(12) The basis weight is 10 to 80.
The present invention relates to the method for producing a filter adsorption sheet according to the above (11) using a sheet base cloth of 0 g / m ² . The present invention can employ any structure of the filter adsorption sheet in which two or more selected from the above 1 to 7 are combined as long as the object is attained for this purpose. Any method of manufacturing a filter adsorption sheet combining two or more selected from the above can be adopted.

[0020]

Next, the main structure of the filter adsorption sheet of the present invention will be described. The filter adsorption sheet of the present invention comprises a charcoal sheet and an electret-treated nonwoven fabric, and comprises a charcoal sheet and a conductive nonwoven fabric. Here, the charcoal sheet has a charcoal powder, which is not subjected to activation treatment using a binder, attached to a breathable sheet base fabric. This binder is one of the features of the present invention, which will be described later. Also, a filter adsorbing sheet may be formed by appropriately combining and laminating a charcoal sheet and an electret-treated nonwoven fabric, or a filter adsorbing sheet may be formed by appropriately laminating a charcoal sheet and a conductive nonwoven fabric.

The air-permeable sheet base fabric is basically provided with air permeability, and as a form thereof, a knitted fabric, a woven fabric, a knitted woven fabric, a nonwoven fabric, a felt, or the like is employed.
In addition, natural fibers such as wool, cotton and hemp, recycled fibers such as rayon, and synthetic fibers such as polyester and polyamide are used as the material. Further, as the yarn constituting these, a single yarn or a mixed yarn is used. The sheet base fabric is
Since it is formed of such a fiber material, it is lightweight and highly air-permeable.

In the present invention, the basis weight of the sheet base cloth is 10
８００800 g / m ² are employed. If the basis weight of the sheet base fabric is smaller than 10 g / m ² , the charcoal powder cannot be sufficiently held (supported), and if the basis weight is larger than 800 g / m ² , the air permeability deteriorates. The basis weight of the sheet base fabric is more preferably 20
４００400 g / m ² . As the charcoal powder fixed to the sheet base fabric, charcoal obtained by carbonizing an organic substance, particularly, charcoal obtained by carbonizing a raw wood is used. And this charcoal which does not perform activation treatment is used. By the way, charcoal has an adsorption area of about 1/6 smaller than activated carbon, but it has excellent characteristics of absorbing and removing odors according to the surrounding environment and repeating it. If this property is used, the life is longer than activated carbon be able to.

The amount of charcoal fine powder (charcoal fine particles) of the present invention to be applied to the sheet base fabric (that is, the supported amount) depends on the type of the sheet base fabric.
100 g / m ² is employed. If the carrying amount is less than 10 g / m ² , the deodorizing power will be small, and if it exceeds 100 g / m ² , the air permeability will be reduced and disadvantageous from the viewpoint of pressure loss. The charcoal powder has a particle size of 100 μm or less, preferably 1 to 50 μm.
m. If it is too small, the deodorizing and humidity control effects will decrease, and 1
If it is larger than 00 μm, the rigidity is reduced and the workability is also deteriorated, and many of the materials drop off from the applied surface due to friction or the like.

[0024] The sheet base fabric of the present invention is provided with at least one of an antibacterial agent, a fungicide, a fragrance, and an insect repellent (including a termiticide) provided together with the charcoal powder. Is desirable. Here, examples of the antibacterial agent include a silver-based compound as an inorganic compound, and an organic iodine-based compound, an organic nitrogen-sulfur-based compound, and a benzimidazole compound as an organic-based compound.

Examples of the antifungal agent include metal compounds and quaternary nitrogen compounds as cationic compounds, organic nitrogen sulfur compounds and highly sulfated oil compounds as anionic compounds, and thiocyan compounds as nonionic compounds. .

Examples of the fragrance include microencapsulated natural lavender, jasmine, lemon, rose, hinoki and the like. As insect repellents, for example,
Organic ester compounds and the like can be mentioned. These antibacterial agents,
The fungicide, the fragrance, and the insect repellent are contained in a binder described below and adhere to the sheet base fabric together with the fine charcoal powder.
Next, the binder used in the adsorption sheet of the present invention will be described.

In the present invention, the binder for fixing the charcoal powder on the sheet base fabric is characterized in that specific conditions are required. The binder of the present invention is, in principle, caustic soda (caustic soda 4 per liter of water).
(0 g solution) with a binder of less than 3% weight loss. Then, a binder having the same weight loss ratio of less than 1% (the binder under these conditions is referred to as “B-type binder”) and a binder having a weight loss of 1% to less than 3% (the binder under these conditions is referred to as “A-type binder”) Binders that combine both are more preferred.

As the A-type binder, acrylic resins, for example, acrylates, acrylic acid and other copolymers, vinyl acetate resins, and other copolymers thereof are mainly used.

As the B-type binder, a copolymer of polyacrylic acid and styrene, a copolymer of polyacrylic acid and acrylonitrile, and the like are mainly used.

In the present invention, the reason why the binder under the above conditions is selected is that when the carbon sheet of the filter adsorbent is washed, the weight of the binder is greatly reduced by the aqueous alkali solution (washing water). Since the coal powder cannot be retained and is desorbed, it was expected that the weight loss rate due to the aqueous alkali solution was small. Based on the findings, the present inventors have conducted a number of experiments. As a result, those having a weight loss ratio of 3% or more due to alkali caustic soda (a solution of 40 g caustic soda per liter of water) are considered to be robust as binders. This is because they have been found to be unsuitable in terms of degree and have a weight reduction rate of less than 3%.

When the weight loss rate is less than 3%, it is most likely that a binder containing both a binder having a weight reduction rate of 1% or less and a binder having a weight loss rate of 1% or more and less than 3% is used. Experiments have also shown that it is suitable. It is considered that by using such a binder, a secure anchoring floor for the charcoal powder is formed in the sheet body, and the robustness is improved.

By the way, 0.001 to 0.001
It is said that dust particles in the range of 100 μm are floating. In particular, it has been found that dust of fine particles having a diameter of 0.3 μm or less blocks fine pores of charcoal and thus causes deterioration of the intrinsic function of charcoal. Therefore, in the present invention, the electret-treated nonwoven fabric or conductive nonwoven fabric is used in an overlapping manner to efficiently remove dust particles having a wide range of sizes.

In the filter adsorbent, by using electret-treated nonwoven fabric, charcoal adsorbs relatively large dust particles among dust particles floating in the atmosphere, and a particularly problematic particle diameter of 0.3 μm or less. The electret-treated nonwoven fabric or conductive nonwoven fabric adsorbs the fine dust particles, and each of them plays a role of selective adsorption. Therefore, most of the dust particles floating in the atmosphere can be effectively adsorbed. The non-woven fabric after the electret treatment is described in, for example, JP-B-56-472.
As described in JP-A-99-99, it is already known, and of course, the electret treatment itself is also known.

In the filter adsorbent of the present invention, a conductive non-woven fabric is used instead of the non-woven fabric electret-treated on the charcoal sheet. The conductive nonwoven fabric has a function of efficiently removing dust particles having a wide range of sizes, like the nonwoven fabric subjected to electret treatment. As described above, the filter-adsorbing sheet of the present invention may be a multilayered sheet obtained by stacking electret-treated nonwoven fabric on a charcoal sheet, or a multilayered sheet obtained by stacking conductive nonwoven fabric.

In both the former and the latter, the number of charcoal sheets, electretized nonwoven fabric, and conductive nonwoven fabric can be freely selected. For example, a filter-adsorbing sheet in a state in which a charcoal sheet is sandwiched from both sides of the electret-treated nonwoven fabric can be used (see FIG. 2). In this state, the sheets are temporarily joined without using an adhesive. It is preferable that they are stacked. Therefore, for example, a pleated forming process is performed on a non-woven fabric or a conductive non-woven fabric that has been electretized on a charcoal sheet. By this pleating, a bent mountain interval (several millimeters to several centimeters) is formed, and a bonding force acts at the bent portion, so that the plurality of layers are in a temporarily bonded state.

Next, a process for producing such a filter adsorption sheet will be described. The filter adsorption sheet of the present invention includes: 1) a step of mixing charcoal powder and a binder, 2) a step of adhering a binder containing charcoal powder to a sheet base cloth, and 3) a step of drying the sheet base cloth to which the binder is attached. 4) a step of curing the dried sheet base fabric; and 5) a step of pleating the dried charcoal sheet with another sheet (an electret-treated nonwoven fabric or a conductive nonwoven fabric). It is manufactured by sequentially passing through the above five steps.

1) Step of Mixing Charcoal Powder and Binder The charcoal powder having been pulverized to 100 μm or less and having an average particle size of 5 to 30 μm is mixed with the binder without activation treatment. As a binder, hot water treatment using caustic soda (solution of 40 g caustic soda per liter of water, 3
Time treatment), a binder having a weight reduction rate of less than 3% is used. In particular, when a binder of a combination of the A-type binder and the B-type binder described above is used, the performance such as the robustness is more improved. improves. Here, as the treatment liquid in this case, in addition to the charcoal powder and the binder, a thickening stabilizer and the like are added as necessary.

2) Step of Attaching Binder Containing Charcoal Powder to Sheet Base Cloth Next, the binder containing charcoal powder produced in the first step is made uniform in the amount of charcoal carried on the sheet base cloth. As described above, a constant amount is applied by a roll method using a pad mangle, a gravure roll, a printing method, a spraying method, a coating method, or the like.

3) Step of drying the sheet base cloth to which the binder is attached The binder applied to the sheet base cloth is heated at 100 to 130 ° C.
Dry to the extent. This drying cures the binder.

4) Step of curing the dried sheet base cloth The dried sheet base cloth is further cured at 140 to 160 ° C. At this time, the charcoal powder is securely fixed to the anchoring floor formed by the binder, and the deodorized carbon sheet body is finished. 5) a step of pleating the dried charcoal sheet with another sheet (an electret-treated nonwoven fabric or a conductive nonwoven fabric). Here, a charcoal sheet and an electretized nonwoven fabric or a conductive nonwoven fabric are stacked without using an adhesive,
Pleated by a pleating machine at 60-70 ° C,
Provide a mountain interval of a certain width (about several millimeters to several centimeters).
This completes the filter adsorption sheet.

[0041]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not necessarily limited to the following Examples. The measuring method of various characteristics in the present invention is as follows. [Degree of washing falling off] Before pleating according to JIS L 0217 103 method, the charcoal sheet was washed 5 times, and before and after washing, the amount of binder falling off, including charcoal powder, was determined. Then, the quality of the durability was judged by determining the degree of falling off of the binder. Then, from the degree of shedding, the washing shedding property was evaluated according to the following categories. ：: Dropout degree 15% or less △: Dropout degree 15 to 30% ×: Dropout degree 30% or more

[Pressure loss] The pressure loss was measured with a Manostar gauge at a flow rate of 1 m ² / min. [Dust collection efficiency] In a 1 m ² box, air at a temperature of 23 ° C., a humidity of 60% RH, and an initial dust amount of 50 to 100,000 particles / 2.83 liters was passed through a filter serving as a test object, and the air flow was 1
Circulation was performed at m ² / min for 1 minute, and the amount of dust before and after circulation was measured and calculated by a particle counter.

[Ammonia deodorizing property] The ammonia concentration is 1
The sample was placed in a 500 cc plastic container under an atmosphere of 00 ppm, and the temperature was measured at 23 ° C. for 30 minutes using a Kitagawa detector tube.

[Antibacterial activity] A method for determining the number of bacteria (according to the evaluation manual of the Textile Sanitary Processing Association) The test bacteria used Staphylococcus aureus IFO12732 and exhibited the following effects. Judgment ○: Large antibacterial effect, △: Medium antibacterial effect, ×: Small antibacterial effect

[Method of Adjusting Binder Containing Charcoal Powder] As the sheet base fabric of the charcoal sheet, 45 ± 5 g / m ² 100% polyester non-woven fabric [manufactured by Kurashiki Sensei Kako Co., Ltd.]
And 100% polyester nonwoven fabric of 35 ± 5 g / m ² (manufactured by Mitsubishi Rayon Co., Ltd.). The specifications used for preparing the coal powder-containing binder are as follows. Charcoal: Carbotech 21 [manufactured by Hinomaru Carbo Techno Co., Ltd.] Particle size: 30 μm or less, average particle size: 9.7 μm Activated carbon: Kuraray Coal Activated Carbon 4TF (manufactured by Kuraray Chemical Co., Ltd.) Particle size: 5-70 μm, average particle size: 15-25 μm Binder: Z5211-2R1 [manufactured by Takamatsu Yushi Co., Ltd.] Acrylic resin (A-type binder) Ultrasol M46 (manufactured by Ganz Kasei Co., Ltd.) Copolymer of ethyl polyacrylate and styrene (B-type binder) Thickening stabilizer: carboxymethylcellulose 6.0% concentration antibacterial agent: silica impregnated with inorganic silver based antibacterial agent fragrance: natural hinoki essential oil

For the charcoal sheet, each of the sheets shown in Table 1 was NO1 to NO6, and: 24% by weight of charcoal or activated carbon; 20% by weight of A type binder Z5211-2R1 (manufactured by Takamatsu Yushi Co., Ltd.); Type binder Ultrasol M46 (manufactured by Guts Kasei Co., Ltd.) 20% by weight ・ Thickening stabilizer: 1.5% by weight ・ Antibacterial agent: Sylwell B-03 (manufactured by Fuji Silysia Ltd.) 0.25% by weight ・ Fragrance : Micron SUN-U (manufactured by Daiwa Chemical Industry Co., Ltd.) 2.0% by weight ・ Others (water): 33.75% by weight

A treatment liquid is prepared by mixing the above, and applied to a non-woven fabric with a mangle so that the amount of charcoal carried (g / m ² ) becomes a predetermined amount on a polyester base fabric, and intermediately dried at 120 ° C. And further cured at 150 ° C. The composition table of the charcoal and activated carbon sheets is shown in [Table 1]. Other sheets superimposed on the charcoal sheet are as follows.

[Electric treated nonwoven fabric] Product name: Filterlet [manufactured by Sumitomo 3M Co., Ltd.] Material: polypropylene Thickness: 1 mm Weight: 70 g / m ²

[Conductive non-woven fabric] Product name: Tetron Luana (manufactured by Teijin Limited) Material: Composite fiber composed of carbon and polyester Thickness: 1.1 mm Weight: 85 g / m ²

Example 1 Sheet No. 1 in Table 1
Sheets and one electret sheet are stacked without using an adhesive, and at 60 to 70 ° C. using a pleating machine,
Pleating with a peak interval of 8.2 mm (see Fig. 1)
The filter was evaluated for its performance (washing loss, pressure loss, dust collection efficiency, ammonia deodorization rate, antibacterial properties).

[0051]

[Table 1]

The results are shown in [Table 2].

[0053]

[Table 2]

As compared with the conventional activated carbon adsorption sheet, remarkable effects were observed on the degree of washing-off and pressure loss. Example 2 One sheet No. 2 in Table 1 and one electret sheet were stacked without using an adhesive, pleated and molded in the same manner as in Example 1, and the performance was evaluated as a filter. Was. The results are shown in [Table 2]. Although the pressure loss is slightly small, almost the same results as in Example 1 are obtained.

Example 3 1 of Sheet No. 1 in Table 1
No. 2 and one No. 2 were laminated on both sides of one electret sheet without using an adhesive, and pleated molding was performed in the same manner as in Example 1 (see FIG. 2), and the performance was evaluated as a filter. Was. The results are shown in [Table 2]. As compared with Example 1, although the pressure loss property is slightly deteriorated, the ammonia deodorizing rate is remarkably improved.

Example 4 A filter was evaluated in the same manner as in Example 1 except that a conductive nonwoven fabric was used instead of the electret sheet. The results are shown in [Table 2]. Compared to Example 1, the dust collection efficiency was slightly inferior, but almost the same result.

Comparative Example 1 Sheet No. 1 in Table 1
Sheet and one electret sheet using an adhesive,
Using a pleating machine, make pleats at 8.2-mm intervals at 60-70 ° C and evaluate the performance (wash-off, pressure loss, dust collection efficiency, ammonia deodorization rate, antibacterial properties) as a filter. Was. The results are shown in [Table 3].

[0058]

[Table 3]

As compared with Example 1, although the degree of washing falling off was not changed, the ammonia deodorization rate was reduced, and the pressure loss was markedly reduced.

Comparative Example 2 Sheet No. 3 in Table 1
Sheet and one electret sheet using an adhesive,
Pleating was performed in the same manner as in Comparative Example 1, and the performance as a filter was evaluated. The results are shown in [Table 3]. Although the antibacterial property was slightly lowered, the result was almost the same as that of Comparative Example 1.

Comparative Example 3 Sheet No. 4 in Table 1
The sheet and one electret sheet were pleated in the same manner as in Comparative Example 1 without using an adhesive, and the performance as a filter was evaluated. The results are shown in [Table 3]. Compared with Example 1, the antibacterial property is poor and the pressure loss property is slightly poor.

Comparative Example 4 Sheet No. 4 in Table 1
Sheet and one electret sheet using an adhesive,
Pleating was performed in the same manner as in Comparative Example 1, and the performance as a filter was evaluated. The results are shown in [Table 3].

Comparative Example 5 Sheet No. 5 in Table 1
The sheet and one electret sheet were pleated in the same manner as in Comparative Example 1 without using an adhesive, and the performance as a filter was evaluated. The results are shown in [Table 3]. The pressure loss property is poor as compared with Comparative Example 3.

Comparative Example 6 Sheet No. 6 in Table 1
The sheet and one electret sheet were pleated in the same manner as in Comparative Example 1 without using an adhesive, and the performance as a filter was evaluated. The results are shown in [Table 3]. The pressure loss is extremely poor.

[Comparative Example 7] In the sheet of sheet No. 1 in [Table 1], type A, which becomes a weight reduction rate of not less than% (specifically, 4%) when treated with hot water containing caustic soda as a binder for 3 hours. Using a sheet (sheet No. 7) using a binder other than the B-type (shown below), performance evaluation as a filter was performed in the same manner as in Example 1. Binder used: Seikaplane ER-50
(Dainippon Seika Co., Ltd.) Acrylic ester copolymer The results are shown in [Table 3]. As a result, the fastness was particularly poor in the washing-off property as compared with the case of Example 1.

[0066]

The filter-adsorbing sheet of the present invention has good robustness and fine charcoal particles do not peel off from the charcoal sheet.
There is no rubbing stain as a filter, and it is rich in durability.
Since charcoal without activation treatment is used and the amount of the charcoal powder attached is relatively small, the filter has a good pressure loss property. In addition, it can be reused by releasing the adsorption of dust. Since other nonwoven fabrics, for example, electret-treated nonwoven fabrics or conductive nonwoven fabrics are provided,
Particles having a diameter different from that of the charcoal sheet can be selected and adsorbed. If necessary, a function as a filter adsorption sheet can be added by adding an antibacterial agent, a fungicide, a fragrance, an insect repellent, etc. to the binder.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.
It is the schematic of the filter adsorption sheet which pleated and formed the charcoal sheet which made charcoal adhere to the nonwoven fabric, and the electret-treated nonwoven fabric.

FIG. 2 shows another embodiment of the present invention, in which a pleated filter adsorption sheet is formed by gripping a charcoal sheet having charcoal adhered to a nonwoven fabric from both sides of an electret-treated nonwoven fabric. FIG.

[Explanation of symbols]

 1: charcoal sheet 2: electret-treated nonwoven fabric P: charcoal powder Q: bent part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuru Ishikawa 1-10-1 Kiya, Fukui City, Fukui Prefecture F-term in Reference: 4D012 BA03 CA10 CB01 CG05 CH01 4D019 AA01 AA10 BA03 BA12 BA13 BA18 BB02 BB03 BB04 BB10 BC01 BC05 BC06 BC20 BD01 CA02 CB06

Claims (12)

[Claims] 1. A filter adsorbing sheet comprising a charcoal sheet obtained by adhering charcoal powder using a binder to a breathable sheet base fabric and another nonwoven fabric, wherein the charcoal powder in the charcoal sheet has a particle size of 100 μm. Hereinafter, the average particle size is 5 to 30 μm, the adhesion amount of the charcoal powder is 10 to 100 g / m ² , and the binder is a charcoal powder using a binder having a weight loss rate of less than 3% in hot water treatment containing caustic soda. A filter adsorption sheet, characterized in that a filter is fixed. 2. A filter adsorption sheet comprising a charcoal sheet obtained by adhering a charcoal powder to a breathable sheet base fabric using a binder and an electret-treated nonwoven fabric, wherein the charcoal powder has a particle size of charcoal powder. 100
μm or less, an average particle size of 5 to 30 μm, an adhesion amount of charcoal powder is 10 to 100 g / m ² , and the binder has a weight reduction rate of 1% or less in a hot water treatment containing caustic soda, and a weight reduction rate of 1% or less. A filter-adsorbing sheet, wherein the charcoal powder is fixed using both a binder of 1% or more and less than 3%. 3. A filter adsorbing sheet comprising a charcoal sheet obtained by adhering a charcoal powder to a breathable sheet base fabric using a binder and a conductive nonwoven fabric, wherein the charcoal powder in the charcoal sheet has a particle size of 100 μm. Hereinafter, an average particle size of 5 to 30 μm, the amount of charcoal powder attached is 10 to 100 g / m ² , and the binder has a weight reduction rate of 1% or less in hot water treatment containing caustic soda;
A filter adsorption sheet, wherein the charcoal powder is fixed using both a binder having a weight reduction ratio of 1% or more and less than 3%. 4. The basis weight of the sheet base fabric is 10 to 800 g /
^3. The filter adsorption sheet according to claim ² , wherein m ² . 5. The filter adsorption sheet according to claim 2, wherein a suitable number of charcoal sheets and electret-treated nonwoven fabrics are combined and tentatively joined by pleating. 6. The filter adsorbing sheet according to claim 3, wherein a suitable number of charcoal sheets and conductive nonwoven fabrics are combined and tentatively joined by pleating. 7. An antibacterial agent, a fungicide, a fragrance, and a binder.
The filter adsorption sheet according to any one of claims 1 to 6, wherein the sheet comprises at least one of insecticides and insect repellents. 8. A step of mixing the charcoal powder with a binder, a step of attaching a binder containing the charcoal powder to a sheet base cloth, a step of drying the sheet base cloth to which the binder is attached, and a step of curing the dried sheet base cloth. A method for producing a filter adsorbing sheet, comprising the steps of: laminating a dried charcoal sheet with an electret-treated nonwoven fabric, pleating and temporarily bonding the resulting sheet. 9. A step of mixing the charcoal powder with a binder, a step of attaching a binder containing the charcoal powder to a sheet base cloth, a step of drying the sheet base cloth to which the binder is attached, and a step of curing the dried sheet base cloth. A method for producing a filter adsorbing sheet, comprising the steps of: laminating a dried charcoal sheet with a conductive nonwoven fabric, pleating the charcoal sheet, and temporarily bonding. 10. The method for producing a filter adsorbing sheet according to claim 8, wherein a binder which reduces the weight loss rate of hot water treatment containing caustic soda to less than 3% is used. 11. The amount of charcoal powder applied is 10 to 100 g / m.
² , the powder diameter is 100 μm or less, and the average particle diameter is 5 to 30.
2. Charcoal powder having a size of μm is used.
0. The method for producing a filter adsorption sheet according to 0. 12. The method according to claim 11, wherein a sheet base fabric having a basis weight of 10 to 800 g / m ² is used.