JP4998938B2 - Copier toner filter - Google Patents

Description

  The present invention relates to an air filter having a small installation area and a long life. More specifically, the present invention relates to a filter for a copier toner that is flame retardant, has low pressure loss, is highly efficient, economical, and can withstand long-term use. Is.

  In recent years, the air environment in offices has become more and more clean due to the smoking of cigarettes and the increase in non-smoking rooms. On the other hand, the outflow of toner from copiers used in offices tends to be regarded as a problem. . For this reason, as countermeasures against spilled particles from copiers, there are various documents as filters for preventing spillage of toner that is the source of spilled particles, but flame retardancy, low pressure loss, high efficiency, long life, and cost There is nothing that satisfies all the items.

Patent Document 1 uses a filter material of a stretched porous PTFE (polytetrafluoroethylene) film for the purpose of preventing the toner particles from flowing out of a copying machine. The stretched porous PTFE film is a fine particle such as toner. On the other hand, it is a very expensive filter.
Patent Document 2 discloses a two-layer toner image fixing device filter composed of an electret nonwoven filter medium and a glass fiber filter medium. However, since glass fiber has an environmental problem of scattering of crushed glass fibers during production of the filter medium. It is not preferable. Moreover, although there is disclosure of the electret non-woven filter medium, the material, flame retardancy and the like are not disclosed at all.

JP 2002-311711 A JP 2002-18217 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner filter for a copying machine having a high toner dust holding capacity, that is, a long life, a high collection efficiency, and a flame retardancy if necessary.

  The present invention is a web layer A (hereinafter also referred to as “A layer”) formed by an airlaid method mainly composed of a synthetic fiber made of a thermoplastic polymer having a fiber length of 1 to 10 mm and having no hydrophilic group in the molecular structure. And a web layer B (hereinafter also referred to as “B layer”) formed mainly by a polyester-based thermoadhesive conjugate fiber having a fiber length of 1 to 10 mm and formed by an airlaid method. The present invention relates to a copier toner filter, characterized in that it is made of an airlaid nonwoven fabric, part or all of which are bonded by hot-melt bonding.

Here, the thermoplastic polymer having no hydrophilic group in the molecular structure used in the A layer is selected from the group consisting of polyethylene, polypropylene, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, and modified products thereof. And at least one of them.
Moreover, it is preferable that the fiber which comprises A layer and B layer is the flame retardant fiber which the one part or all kneaded the non-halogen-type flame retardant.
Furthermore, it is preferable that the filter is pleated and the peripheral portion thereof is heat-melt bonded to a molded resin plate that becomes a frame of the filter.
Moreover, in this invention, it is preferable that a part or all of the said air-laid nonwoven fabric is electretized.
Furthermore, the adhesive surface with the molded resin plate is preferably on the B layer side.
The molded resin plate is preferably an ABS resin.

  The filter for a copying machine toner of the present invention has a fiber layer 1 to 10 mm in length, a web layer A formed mainly by a synthetic fiber made of a thermoplastic polymer that does not have a hydrophilic group in the molecular structure, and is formed by an airlaid method. Airlaid mainly composed of polyester-based heat-adhesive conjugate fibers having a length of 1 to 10 mm, which is composed of a web layer B formed by an airlaid method, and a part or all of the fibers of each layer A and B are heat-melted and integrated. Since it is a copying machine toner filter made of non-woven fabric, the following effects can be expected.

That is, since many of the synthetic fibers constituting the nonwoven fabric are heat-melted and bonded, the degree of freedom of the fibers is reduced and the fibers have hardness, so that pleating can be performed.
In addition, when the airlaid nonwoven fabric used in the present invention is electretized, it becomes a highly efficient filter with low-pressure loss against fine particles.
Furthermore, since the airlaid A and B layers used in the present invention can be composed of one layer or two or more layers, respectively, if an airlaid nonwoven fabric having a density gradient is manufactured, it can be a long-life filter.
Furthermore, since one side of the filter of the present invention is composed of a polyester-based heat-adhesive composite fiber layer that is a B layer, it has excellent adhesion to a molded resin plate such as an ABS resin that serves as a frame of the filter. Excellent.
Furthermore, a non-halogen flame retardant may be incorporated into some or all of the fibers. In this case, the filter is flame retardant and can be a filter that does not generate dioxins even when burned at a high temperature.
Furthermore, the used fiber of the present invention is less expensive than PTFE or the like.

Airlaid nonwoven fabric The airlaid nonwoven fabric used in the present invention is formed by an airlaid nonwoven fabric manufacturing method. That is, a composite fiber having a fiber length of 1 to 10 mm made of a thermoplastic polymer having no hydrophilic group in the molecular structure is arranged on the lower surface of the jet net conveyor from a single jet unit or a plurality of jet parts located on the porous net conveyor. The web layer A is formed on the net conveyor while being sucked by the air suction section, and then the web layer B is formed in the same manner. At this time, two layers with different synthetic fiber configurations are sequentially ejected to produce a laminated web. Thereafter, some or all of the fibers of the A layer and the B layer are fused by heat melting and integrated with a heat oven. Here, as hot melt bonding, if the melting point differs between fibers by 5 ° C. or more, troubles such as poor fusion are likely to occur during production. Therefore, the fiber forming the nonwoven fabric is preferably a composite fiber of the same material as an adhesive component. . For example, when a composite fiber having a sheath / core component of polyethylene / polypropylene is used as the A layer, a modified polyethylene / polyester-based thermoadhesive conjugate fiber of the B layer has a sheath component close to the melting point of 135 ° C. of polyethylene. Polyester or polyethylene / polyester composite fibers are preferably used.

At this time, preferably, the thick fiber layer is sequentially laminated from the upper layer side (fluid inflow side) to the lower layer side (fluid outflow side), and the laminated fiber layer is placed in a heat oven. Bring it in and combine the fibers with hot air to integrate them as a nonwoven fabric.
The air-laid nonwoven fabric used in the present invention can be obtained by finishing to a predetermined density and thickness according to the amount of fibers, ejection conditions, air suction conditions, hot air conditions, and the like. The temperature at the time of heat-melt bonding with a heat oven is appropriately selected depending on the type of composite fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure to be used or the polyester-based heat-adhesive composite fiber, and the overall basis weight, Usually, it is 120-200 degreeC, More preferably, it is 130-170 degreeC.

  In the case of a conventional dry nonwoven fabric manufacturing method known in the past, that is, a short fiber carding method or a continuous fiber spunbond method, the fibers constituting the layer are arranged in a substantially planar shape and have a thickness. It is difficult to orient in the direction. Therefore, when it uses for the air filter which this invention intends, it has the fault that a pressure loss is high. By adding mechanical fiber entanglement methods such as needle punching and spunlace, the fibers can be rearranged relatively in the thickness direction, but fine dust is generated because the through-holes due to water streaks in the needle or spunlace remain. It will be lacking in the trapping action.

In contrast, the non-woven fabric used in the air filter of the present invention is based on the air-laid non-woven fabric manufacturing method using short fibers, so that the fibers are easily arranged in the thickness direction, and fibers of different fiber diameters are mixed between the layers. The fiber diameter gradient between the fiber layers is relatively continuous.
Accordingly, the pressure loss is small, clogging is reduced, the life (filterable time) is increased, and the increase in pressure loss is small. In addition, according to the airlaid nonwoven fabric manufacturing method using such short fibers as raw fibers, it has a great feature that a filter with extremely good texture, that is, good uniformity can be obtained. Uniformity is extremely important in the application of the air filter intended by the present invention, and is difficult to obtain with the above-described existing dry nonwoven fabric.

  Furthermore, since no needle is used, the problem of performance degradation due to needle marks is also eliminated. In addition, since no chemical binder is used, there is no adverse effect of pressure loss and collection efficiency due to film formation, and there is no fear of environmental pollution.

  The fibers used in the present invention have a fiber length of 1 to 10 mm for both the A layer and the B layer. If fibers exceeding 10 mm are used, it is not only difficult to obtain uniformity as a non-woven fabric, but productivity is lowered, which is not preferable. On the other hand, when the thickness is less than 1 mm, not only the strength of the nonwoven fabric is lowered, but also the falling fibers are easily generated, which is not preferable. Preferably it is 2-7 mm, More preferably, it is 3-5 mm.

The thermoadhesive conjugate fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure mainly constituting the layer A of the airlaid nonwoven fabric of the present invention has no hydrophilicity in the molecular structure, that is, is non-hydrophilic, preferably Further, it is made of a thermoplastic polymer having excellent properties such as chemical resistance, heat resistance, durability, strength and hardness. Here, one of the purposes of using a thermoplastic polymer having no hydrophilic group in the molecular structure is to impart chargeability. That is, a thermoplastic polymer having no hydrophilic group is intended to be easily charged, and has the effect that fine particles can be collected on the surface of the fiber for a long time by electrostatic adsorption.
Examples of the thermoplastic polymer having no hydrophilic group in its molecular structure include polyolefins such as polyethylene and polypropylene, halogen-containing polymers such as polytetrafluoroethylene (PTFE), polyvinyl chloride, and polyvinylidene chloride, and / or Alternatively, modified products thereof may be mentioned, but from the viewpoint of cost performance, polyolefins such as polyethylene and polypropylene are preferable. Here, as the modified body, known means such as addition of a third component and copolymerization can be applied for the purpose of controlling the melting point, the viscosity at the time of melting, the adhesion to other fibers, the electret effect, and the like.
These non-hydrophilic thermoplastic synthetic polymers can be used alone or in combination of two or more.

Further, the thermoadhesive conjugate fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure constituting the layer A of the airlaid nonwoven fabric of the present invention has a short thermoadhesiveness of a composite structure comprising two or more components having different melting points. It is preferable that fiber is a main component.
In this case, preferably, the above-mentioned heat-adhesive short fibers are composed of polypropylene and polyethylene, polypropylene and modified polyethylene, or polypropylene and modified polypropylene, and are side-by-side type or core-sheath type composite short fibers. In this case, the modified product may be an isomer.
The ratio of the heat-adhesive conjugate fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure in all the fibers in the layer A is usually 30% by weight or more, preferably 50 to 100% by weight, more preferably 70 to 100% by weight. When the amount is less than 30% by weight, dropped fibers are likely to be generated and become unsuitable as a filter.

In addition to the thermoadhesive conjugate fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure, the A layer has various functions as necessary. An agent or the like may be included.
In this case, the mixing ratio of the thermoplastic polymer having no hydrophilic group in the molecular structure may be 5% by weight or more depending on the purpose. If it is less than 5% by weight, the effect does not appear, and if the cost is good, it may be 100% by weight. The single yarn fineness of the fibers constituting the A layer is usually 1.0 to 10 dtex, preferably 1.5 to 6.6 dtex. Moreover, the fabric weight of A layer is 30-200 g / m < ² > normally, Preferably it is 100-150 g / m < ² >.

On the other hand, the effect of the B layer aims at adhesion of the toner to the case material (filter frame), and the affinity with the case material is important.
The polyester-based heat-adhesive conjugate fiber used for the B layer of the airlaid nonwoven fabric is preferably a core / sheath type or side-by-side type conjugate fiber. In this case, the polymer constituting the core component or the inside of the fiber is preferably a polymer having a melting point higher than that of the sheath and not denatured at the heat bonding temperature. Examples of such a polymer include polyalkylene arylates mainly composed of fatty acid diol units and aromatic dicarboxylic acid units. For example, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyethylene naphthalate and the like. As will be described later, the polyester-based heat-adhesive conjugate fiber constituting the B layer is excellent in adhesiveness with a molding resin such as an ABS resin. Fiber is preferred. For example, the core / sheath may be PET / copolymerized PET, PET / PE, PET / PP, or the like. These may be used singly or in combination of two or more, and may contain a copolymer component as necessary. Moreover, you may denature | modify in the range which does not inhibit the effect | action and effect of this invention.

In addition to the polyester-based heat-adhesive conjugate fiber, the B layer may contain a flame retardant, a fungicide, a water repellent and the like in order to have various functions as necessary.
In this case, the mixing ratio of the polyester-based heat-adhesive conjugate fiber may be 5% by weight or more depending on the purpose. If it is less than 5% by weight, the effect is not obtained, and if the cost is suitable, 100% by weight may be used.

In addition, the single yarn fineness of the fiber which comprises the said B layer is 1.0-10 dtex normally, Preferably it is 1.5-6.6 dtex. Moreover, the fabric weight of B layer is 20-50 g / m < ² > normally, Preferably it is 20-30 g / m < ² >.

Further, the air-laid nonwoven fabric composed of the A layer and the B layer was laminated with a density gradient so that the lowermost layer on the air outflow side was a thin fiber layer and gradually became a thick fiber layer toward the upper layer on the air inflow side. Those are preferred.
However, the layer B improves the adhesion with the case material (filter frame) as described above, and the filter function is not so important, so it does not necessarily need to be thinner than the upper layer.

Further, the air-laid nonwoven fabric composed of the A layer and the B layer may be two or more layers. In this case, the A layer is at least two layers and the B layer is at least one layer. Further, the entire air laid nonwoven fabric has a thickness of 0.5 to 2.0 mm, preferably 1.0 to 1.5 mm, and a basis weight of 80 to 200 g / m ² , preferably 100 to 150 g / m ² .

  Next, non-halogen flame retardants that may be kneaded into the fibers constituting the A layer and B layer include ammonium phosphate, tricresyl phosphate (TCP), triethyl phosphate (TEP), cresyl phenyl phosphate. (CCP), xylenyl diphenyl phosphate (XDP), acidic phosphate ester, nitrogen-containing phosphorus compound, HALS, etc., but are not limited to these as long as they are non-halogen and exhibit a substantially flame-retardant effect. It is not something. These flame retardants can be used alone or in combination. When the filter burns, the flame retardant effect can be expected to melt the surface of the fiber and volatilize the flame retardant contained therein to increase flame retardancy.

The purpose of kneading these non-halogen flame retardants into the fiber is that the filter with a conventional flame retardant adhering to the fiber surface by dipping or spraying at the time of electret processing is not sufficient for electret processing. is there.
From the viewpoint of cost, it is not necessary to incorporate a flame retardant into all layers in the A layer or the B layer. In that case, if the non-flame retardant blending rate is within 20% by weight of the entire A layer and B layer, The level of HF-2 in the UL combustion test can be maintained.

  Furthermore, the filter of the present invention may contain fibers having antibacterial properties, water repellency, and other functions as long as the functions and effects of the present invention are not impaired.

  Since the filter of the present invention is pleated and then incorporated into a copying machine toner filtration device, the filter is integrally formed with a resin plate as a frame of the filter by an insert injection molding method. In the insert injection molding at this time, thermal adhesiveness with the molten resin at the time of molding may be required. In the case where the molding resin is not a polyolefin, particularly in the case of an ABS resin, the polyester-based heat-adhesive conjugate fiber constituting the B layer is suitable because high adhesion to the ABS resin can be obtained. In this case, it is good to apply the said polyester-type heat-adhesive conjugate fiber only to a contact surface, ie, one side.

In the pleating process of the present invention, a pleat having a height of 5 mm or more is formed by a reciprocating or rotary pleating machine, and then fed onto a hot plate heated to 100 ° C. or less, preferably 60 to 90 ° C. It is a habit.
Next, the processed pleated product is inserted into a horizontal injection resin molding machine, and the periphery of the pleated product is covered with resin to obtain a filter for a pleated copying machine toner.

The airlaid nonwoven fabric used in the present invention is preferably used as the air filter of the present invention by performing electret processing.
Here, the electret processing is a processing method disclosed in, for example, Japanese Patent Application Laid-Open No. 61-186568, and various known electret methods such as a thermal electret method, an electro electret method, a radio electret method, This is a processing method in which a sheet or the like is charged by applying a mechano-electret method or the like.
When electret processing, in order to remove the surface oil agent etc. adhering to the fibers constituting the airlaid nonwoven fabric used, it was washed with hot water at 50 to 100 ° C. for about 5 to 10 seconds. After that, it is preferable to perform a drying treatment for several tens of seconds to several tens of minutes at a temperature lower than the melting point of the polymer constituting the heat-bondable short fibers, for example, 80 to 140 ° C. In addition, the oil agent may be removed by water jet treatment.

  As a specific example of electret processing, in the case of a polyolefin airlaid nonwoven fabric, it is preferably 80 to 150 ° C., more preferably on the heating roller of about 90 ° C. to 110 ° C., −30 to −5 KV or +5 to Apply a DC voltage of +30 KV, more preferably about −30 to −5 KV, and then apply a DC voltage of about −30 to −5 KV or +5 to +30 KV, more preferably about −30 to −5 KV on the cooling roll. The method of doing is mentioned. Since most of the minute dust present in the living space is relatively positively charged, it is preferable that the applied voltage be negative.

Examples of the present invention will be described below, but the present invention is not limited to the following examples.
Example 1
BTC-1 is an ETC type (weight ratio of polyethylene and polyester = 50) manufactured by Chisso Corporation, which is a core-sheath type composite fiber (polyester-based heat-bonding composite fiber) having a sheath part made of polyethylene and a core part made of polyester. : 50, fineness 2.2 dtex, fiber length 5 mm) is formed on the net by the airlaid method so as to be 20 g / m ^2, and the sheath part is polyethylene on B layer-1 as A layer-1 An ESC flame retardant type (polyethylene and polypropylene) manufactured by Chisso Corporation, which is a core-sheath type composite fiber (a thermo-adhesive composite fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure). Weight ratio = 50: 50, fineness of 1.7 dtex, fiber thickness of about 15 μm, fiber length of 3 mm, and nitrogen / phosphorus flame retardant kneaded). Formed by air-laid process so as to ² (A layer -1), further thereon, manufactured by the same company, ESC type (polyethylene and polypropylene weight ratio = 50: 50, fineness 3.3 dtex, fiber thickness of about 21μm A web made of 3 mm nitrogen / phosphorous flame retardant kneaded) was formed by airlaid method so as to be 50 g / m ² (A layer-2), and a laminated web was prepared.
Next, hot air of 135 ° C. was blown onto the web, and the fibers were heat-sealed to form an airlaid nonwoven fabric having a thickness of 1.47 mm and a basis weight of 140 g / m ² . The airlaid nonwoven fabric was heated to a temperature of 100 ° C. and then subjected to electret processing by applying a direct current of −15 Kv with a needle electrode for 1 second to obtain a filter for a copier toner of Example 1 of the present invention.
Table 1 shows the test results of the filter characteristics of Example 1 of the present invention.
The filter for toner of the copier of Example 1 was pleated at a height of 30 mm, and the filter was welded to an ABS case of 100 mmW × 100 mmL to obtain 14 pleated copier toner filters.

Example 2
A copier toner filter of Example 2 was obtained by the procedure of Example 1 except that the basis weight of the A layer-2 of Example 1 was changed to 30 g / m ² . Table 1 shows the test results of the filter characteristics of Example 2 of the present invention.
The filter for the copier toner of Example 2 was pleated at a height of 30 mm, and the filter was welded to an ABS case of 100 mmW × 100 mmL to obtain 16 pleated copier toner filters.

Example 3
As Example 3, 30 g of composite PET fiber (fineness: 2.2 dt, fiber length: 3 mm, sheath melting point 150 ° C.) manufactured by Teijin Limited of B layer core polyester / sheath modified polyester (PET / PET) / a ^{m 2} spun as B-2, including the flame retardant further 1.7dt containing no flame retardant a layer-1 used in example 1 thereon at a 100 g ^{/ m} 2, a layer-2 3.3 dt of 30 g / m ² was spun and Example 3 was prepared in the same procedure as Example 1, and the results are shown in Table 1.

Comparative Example 1
As Comparative Example 1, A layer-1 of Example 1 was 90 g / m ² , A layer-2 was 50 g / m ^2, and one without B layer was Comparative Example 1 and the others were prepared according to the procedure of Example 1. did. The test results of Comparative Example 1 are shown in Table 1.

The filter cloth performance of the present invention and the filter characteristics of the present invention when using 8 types of JIS dust are as follows.
Filter fabric performance Breathability: KES method ABS adhesion strength: 10N / 25mm or more Flame resistance: HF-2 or more
Filter characteristics Dust pressure loss: 60 Pa or less DHC: 300 g / m ² or more Dust collection efficiency: 99.5% or more

Test conditions:
1) Breathability: KES method 2) Pressure loss: 15 L / min, pressure loss at 90 mmφ 3) Collection efficiency: 0.3-5 μm atmospheric dust at 15 L / min, 90 mmφ at a particle counter 4) ABS adhesion Strength test method Asahi Kasei's injection grade # 190 ABS resin was bonded to an injection extrusion filter at 230 ° C. on a 25 mm × 10 mm sample, and then the peel strength between the filter and the ABS plate was measured.
5) Flame retardancy: UL95
6) Dust pressure loss: Initial pressure loss at a wind speed of 50 cm / sec 7) DHC: DHC when JIS 8 type was dropped at a wind speed of 50 cm / sec and the resistance increase reached 300 Pa
8) Dust collection efficiency Collection efficiency until the resistance increase reaches 300Pa

The flame retardant standards shown in Table 1 are as follows according to the flammability test of UL94 plastic material (the number of samples is 5).
* 1) HF-1: After the flame has been moved away, 4/5 sheets of the sample were burned within 2 seconds, or 1/5 were burned within 10 seconds. Do not ignite absorbent cotton underneath by dripping.
* 2) HF-2: Same as HF-1, but the absorbent cotton underneath may be ignited by dripping flame.
* 3) HBF: Combustion speed within 40 mm / min, and combustion ends within 125 mm marked line.

Table 1 shows the relationship between the peel strength of the ABS molded resin plate and the filter material.
In the B layer of Examples 1 and 2 of the present invention, the core is a regular polyester fiber and the sheath part is polyethylene fiber, so that part of the sheath part melts during production by the airlaid method, and the polyethylene fiber in the sheath part of the A layer melts. The adhesion between the A-B interlayer becomes stronger by bonding to the part, and the adhesion between the polyester part of the core part after melting the sheath part of the B layer and the ABS resin is stronger than that of Comparative Example 1, and as a whole It is estimated that peel strength, that is, adhesive strength is increased.
Comparative Example 1 in Table 1 shows that there is almost no peel strength between the heat-adhesive conjugate fiber made of a thermoplastic polymer having no hydrophilic group in the molecular structure and the ABS molded resin plate, that is, almost no adhesive strength. Although the core is a regular polyester fiber and the sheath is a modified polyester fiber having a low melting point and good adhesion to the ABS molded resin plate, the flame retardant classification is HBF because it does not contain a flame retardant in the A layer. Depending on the intended use, it can be used in the flame retardant section of this HBF.
However, in Example 3, although the sheath is made of a modified polyester fiber having a low melting point, 150 ° C. and the melting point are 15 ° C. higher than the 135 ° C. melting point of polyethylene. Therefore, when the heating oven temperature at the time of production is set near the 135 ° C. melting point of polyethylene, sufficient adhesive strength between the fiber layers cannot be obtained, and there is a possibility that delamination and fiber dropping may occur. On the contrary, when the temperature of the heating oven at the time of production is set near the 150 ° C. melting point of the modified polyester fiber, cracks (cracks) due to shrinkage may occur in the polyethylene layer.

From Table 1, Example 1 and Example 2 of the present invention satisfy the target values of the filter characteristics that are the object of the present invention. The ratio of the B layer fiber of Example 1 made of non-flame retardant fiber is 20/140 = 14.3%, and the ratio of the B layer fiber of Example 2 is 20/118 = 17.0%. Although it is the level of UL standard HF-2, in Example 3, since the non-flame retardant fiber ratio of the B layer fiber was increased by 30/167 = 18.0%, the flame retardant level was HBF. When the fiber layer is made by kneading a flame retardant into all layers as in Comparative Example 1, the standard of HF-1 is satisfied.
However, Comparative Example 1 is a product obtained by removing the modified polyester fiber layer of the B layer of the present invention and has a low adhesive strength with the ABS resin. However, when the toner case is replaced with an olefin-based resin such as polypropylene, it is bonded. Power is up and there is no problem in use.

  The copying machine toner filter of the present invention is useful not only for copying machine toner filters, but also for masks, indoor air conditioning filters such as buildings, automobile cabin filters, and fuel cell intake filters. is there.

FIG. 1 is a sectional view of a copying machine toner filter according to the present invention.

Explanation of symbols

1: A layer-2
2: A layer-1
3: B layer

Claims (5)

A web layer A mainly composed of a synthetic fiber made of a thermoplastic polymer having a fiber length of 1 to 10 mm and having no hydrophilic group in the molecular structure, and a polyester-based thermal bonding having a fiber length of 1 to 10 mm. This is a filter for a copying machine toner composed of an airlaid nonwoven fabric composed of a web layer B mainly composed of a functional composite fiber and formed by an airlaid method, and a part or all of the fibers of each layer A and B are fused together by heat fusion. A filter for a copier toner, wherein the web B side is hot-melt bonded to a molded resin plate that is a filter frame, and the molded resin plate is an ABS resin.   2. The thermoplastic polymer having no hydrophilic group in the molecular structure is at least one selected from the group consisting of polyethylene, polypropylene, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, and modified products thereof. Filter for copier toner.   3. The copying machine toner filter according to claim 1, wherein a part or all of the fibers constituting the web layer A and the web layer B are flame retardant fibers in which a non-halogen flame retardant is kneaded.   The copier toner filter according to any one of claims 1 to 3, wherein the filter is pleated, and a peripheral portion thereof is heat-melt bonded to a molded resin plate serving as a frame of the filter. The copying machine toner filter according to any one of claims 1 to 4, wherein a part or all of the air laid nonwoven fabric is electretized.

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