JP2008012418A - Prefilter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prefilter for air conditioners, on the surface of whose net a film of a specific fluorine-containing polymer is formed, and the film being excellent in durability and antifouling properties. <P>SOLUTION: This is a prefilter for air conditioners which has a synthetic resin-based net. In addition, the prefilter has a film, which is formed by applying a fluorine-containing paint composition to the surface of the prefilter's net and hardening it, on the surface of the net. The paint composition is a composition which is curable at ordinary-temperature and contains a fluorine-containing polymer having a functional group X, an antifouling component and a hardener. In addition, the antifouling component is a liquid poly-dialkylsiloxane, which has the functional group X or a functional group which can react with the hardener, or a liquid fluoropolyether having the functional group X or a functional group which can react with the hardener. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a prefilter used in an air conditioner such as an air conditioner or an air purifier.

  A pre-filter made of a net is provided at a place where air is sucked in an air conditioner such as an air conditioner or an air purifier so that dust and dirt in the air are not taken into the air conditioner. This prefilter is usually composed of a synthetic resin net and a support frame.

  Indoor dust and dirt include a wide variety of insoluble dust such as cotton dust, sand dust, mud and cigarette smoke, water-soluble dirt such as cigarette dust, and oil-soluble dirt such as oil smoke and haze. And the deposit | attachment adhering to a pre filter becomes the form which these combined. Such attached dirt changes due to light or oxygen in the air, and becomes more difficult to remove.

  In addition, the pre-filter captures what does not pass through the hole due to the size of the mesh (mesh), but there are fine dirt in the air (such as cigarette smoke, soot and dust). In order to collect dust, the net is charged and electrically captured. As one of the methods, it has been proposed that the outer surface of the fiber constituting the net is coated with a highly chargeable fluororesin, and it is described that washing with water is possible (Patent Document 1 and Patent Document 2). .

  Further, Patent Document 3 proposes coating a fluororesin with a binder or the like in order to prevent adhesion of dust containing oil.

Japanese Patent Laid-Open No. 08-224413 Japanese Patent Laid-Open No. 08-224414 JP 2006-122871 A

  However, these Patent Documents 1 and 2 only describe that a fluororesin is coated, and no specific solution is shown.

  For example, forming a fluororesin film usually requires firing at a high temperature, but how to form a fluororesin film on a prefilter made of a synthetic resin that is less heat resistant than fluororesin There is no teaching necessary for implementation, such as what kind of fluororesin is used.

  Furthermore, in general, fluororesin has poor adhesion to other synthetic resins, and simply attaching fluororesin will cause peeling due to frequent detachment, brush scrubbing and wiping operations, and there is a problem with durability. .

  In Patent Document 3, only the word fluororesin is described, and a binder is necessary. Therefore, the fluororesin particles are dispersed in a prefilter mesh synthetic resin and a binder having good adhesion to form a film. It is thought that it is supposed to do.

  However, it is difficult to efficiently utilize the effect of the fluororesin with such a dispersed coating of fluororesin particles, and the fluororesin also has poor adhesion with the binder, so that the fluororesin particles may fall off and there is a problem in durability. Remains.

  The problem of the present invention is that even if the prefilter is made of the same material as that of the conventional prefilter, a coating of a specific fluorine-containing polymer having excellent durability and excellent decontamination is formed on the surface of the mesh. An object of the present invention is to provide a prefilter for an air conditioner.

The present invention is a prefilter for an air conditioner having a net made of a synthetic resin, wherein a coating composition containing a fluorine-containing polymer is applied to a part or all of the surface of the net and cured. The coating composition having the obtained coating and containing the fluorine-containing polymer is a composition containing (A) a fluorine-containing polymer containing a functional group X, (B) an antifouling component, and (C) a curing agent. Wherein the antifouling component (B) is a liquid polydialkylsiloxane having (B1) a functional group X and / or a functional group Y ¹ capable of reacting with the curing agent (C), or (B2) a functional group X and / or The present invention relates to a prefilter which is a room temperature curable coating composition which is a liquid fluoropolyether having a functional group Y ² capable of reacting with the curing agent (C).

  According to the prefilter for an air conditioner of the present invention, a coating can be formed on the surface of the net by a coating composition containing a fluorine-containing polymer having excellent adhesion to a synthetic resin, and the prefilter surface can be rubbed, Even if the filter is bent, it does not fall off, and it is possible to provide a pre-filter that is highly durable against removal work or washing with water.

  The prefilter for an air conditioner having a net made of the synthetic resin of the present invention is obtained by applying a coating composition containing a specific fluoropolymer to a part or all of the surface of the net and curing it. It has the characteristic in having a coating film.

The coating composition containing this fluorine-containing polymer is a composition comprising (A) a fluorine-containing polymer containing a functional group X, (B) an antifouling component, and (C) a curing agent, wherein the antifouling component (B) Can react with the functional group X and / or the liquid polydialkylsiloxane having a functional group Y ¹ capable of reacting with the curing agent (C), or (B2) with the functional group X and / or the curing agent (C). it is a cold-curing of the coating composition is a fluoropolyether liquid having a functional group Y ^2.

  In this coating composition, both the fluorine-containing polymer (A) and the antifouling component (B) are water and oil repellency, and the formed film is also water and oil repellency.

  By making the surface of the prefilter water and oil repellent, both water-soluble dirt and oily dirt are attached to the dust side, and by removing relatively large dust, not only dust but also water-soluble dirt and oily dirt are removed. Can be removed. The reason for this is not clear, but in general, the main components of dust are cotton dust composed of various fibers and sand dust composed mainly of silicic acid, iron oxide, aluminum oxide, etc. All are intermediate properties. At that time, if the surface of the prefilter is in a state of high water repellency and oil repellency (both water and oil repels), the water-repellent stain is more compatible with the dust side than the surface of the prefilter and the Adhere to. Similarly, the oily soil has more affinity to the dust side than the prefilter surface and adheres to the dust because of the oil repellency of the prefilter surface.

  In the present invention, the water / oil repellency of the coating refers to the property that both the water contact angle and the oil contact angle of the coating surface are high. Specifically, it is a film having a water contact angle of 80 degrees or more and an oil contact angle of 35 degrees or more, and both water-soluble dirt and oil-soluble dirt have poor affinity with the film ( Therefore, it is preferable in that it is absorbed by cotton dust or sand dust. A method for measuring the water contact angle and the oil contact angle will be described later.

  A more preferable contact angle with water is 90 degrees or more, particularly 100 degrees or more, since the aqueous dirt adhesion preventing property is further excellent.

  A more preferable oil contact angle is 45 degrees or more because the oil dirt adhesion preventing property is further improved.

  In the coating according to the present invention, the antifouling component (B) is firmly bonded to the fluoropolymer (A) via the curing agent (C) by the function (reaction) of the functional group. Therefore, the antifouling component (B) does not fall off from the coating, and the durability is high.

  As a coating composition containing such a fluorine-containing polymer, the coating composition described in the international publication 2004/0676758 pamphlet can be illustrated with a specific example and a preferable range, for example.

  Among them, in the pre-filter of a resin product such as for an air conditioner for adjusting indoor air, as the functional group X of the fluoropolymer (A) of the coating composition, a hydroxyl group, a carboxyl group and / or An epoxy group is preferable in terms of good curability and adhesion to a prefilter net.

As the antifouling component (B), polydialkylsiloxane (B1) is preferable from the viewpoint of good water repellency, and the functional group Y ¹ possessed by the polydialkylsiloxane (B1) is a hydroxyl group, an amino group and / or an epoxy. A group is preferable from the viewpoint of good curability and adhesion to a prefilter net.

  As a hardening | curing agent (C), an isocyanate compound, an amino compound, and / or an epoxy compound are preferable from the point with favorable curability and the adhesiveness to the net | network of a prefilter.

Among these, in particular, the functional group X of the fluorine-containing polymer (A) is a hydroxyl group, the functional group Y ¹ or Y ^{2 of} the antifouling component (B) is a hydroxyl group or an amino group, and the curing agent (C) is A coating composition that is an isocyanate compound is particularly preferred from the viewpoint of excellent curability and adhesion to a prefilter net.

  Specific preferred fluorine-containing polymers (A) include, for example, tetrafluoroethylene (TFE) / alkyl vinyl ether / hydroxybutyl vinyl ether (HBVE) copolymer, TFE / alkyl vinyl ester / HBVE copolymer, chlorotrifluoro Examples include, but are not limited to, ethylene (CTFE) / alkyl vinyl ether / HBVE copolymers, TFE / alkyl vinyl ether / maleic acid copolymers, and CTFE / alkyl vinyl ether / maleic acid copolymers. Is not to be done. Among these, a TFE / alkyl vinyl ether / HBVE copolymer and a TFE / alkyl vinyl ester / HBVE copolymer are particularly preferable from the viewpoint of good antifouling property, oil resistance and curing agent compatibility.

  Among the antifouling components (B), preferred specific examples of the polydialkylsiloxane (B1) include amino-modified polydialkylsiloxane, carbinol-modified polydialkylsiloxane, carboxyl-modified polydialkylsiloxane, and epoxy-modified polydialkylsiloxane. In particular, amino-modified polydialkylsiloxane is preferable from the viewpoint of further good curability.

Specific examples of the liquid fluoropolyether (B2) having the functional group X ² and the functional group Y ² capable of reacting with the curing agent (C) in the antifouling component (B) include, for example, a hydroxyl group, an amino group, and an epoxy. And a fluoropolyether having a group, a carboxyl group, a thiol group, a nitrile group, an iodine atom and / or a hydrolyzable alkyl silicate residue.

  As described above, the antifouling component (B) is preferably polydialkylsiloxane (B1).

  The blending amount of the antifouling component (B) is 0.001 part by mass or more, further 0.01 part by mass or more, particularly 0.1 part by mass or more with respect to 100 parts by mass of the solid content of the fluoropolymer (A). Is preferred. If the amount is too small, the effect of preventing contamination and the removability will be insufficient. The upper limit is 30 parts by mass, further 10 parts by mass, especially 3 parts by mass. If the amount is too large, it becomes necessary to take into consideration that uniform formation of the coating film becomes difficult or tackiness is generated. .

Specific examples of the curing agent (C) include, for example, isocyanate compounds, amino compounds, and epoxy compounds, and the functional groups X, Y ^1, and Y ² of the fluorine-containing polymer (A) and the antifouling component (B). Select as appropriate in relation.

The isocyanate compound-based curing agent is effective when the functional groups X, Y ¹ and Y ^{2 of the} fluorine-containing polymer (A) and the antifouling component (B) are a hydroxyl group and / or an amino group. The isocyanate compound also includes a blocked isocyanate compound. Specific examples include 2,4-tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine methyl ester diisocyanate, methylcyclohexyl diisocyanate, Trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, n-pentane-1,4-diisocyanate, trimers thereof, adducts and burettes thereof, polymers having two or more isocyanate groups, Lysine triisocyanate (specifically 2-isocyanatoethyl 2,6-diisocyanatohexanoate, etc.), and blocked isocyanate Such bets compounds are exemplified, but not limited thereto.

In addition, an isocyanate compound having a hydrolyzable alkyl silicate residue can also be preferably used. Specific examples include, for example, OCNC ₃ H ₆ Si (OCH ₃ ) ₃ , OCNC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ , OCNC ₃ H ₆ Si (OCOCH ₃ ) ₃ , OCNC ₃ H ₆ Si (CH ₃ ) (OCH ₃ ) _{3 and the} like.

  The mixing ratio of the isocyanate compound and the fluoropolymer (A) is preferably NCO / OH (molar ratio) of 0.5 to 5.0, more preferably 0.8 to 1.5. Moreover, 1.1-1.5 are preferable when isocyanate is a moisture hardening type.

The amino compound curing agent is effective when the functional groups X, Y ¹ and Y ^{2 of the} fluorine-containing polymer (A) and the antifouling component (B) are a carboxyl group, an amino group or an epoxy group. Preferable specific examples include melamine resin, urea resin, guanamine resin, amine adduct, polyamide and the like.

  Commercially available products include Cymel (trade name) manufactured by Mitsui Cytec Co., Ltd .; Ancamine (trade name) manufactured by Air Products, Epilink (trade name); Versamine (trade name) manufactured by Henkel, Versamide (trade name) ); Tomide (trade name), Fuji Cure (trade name) manufactured by Fuji Chemical Industry Co., Ltd .; Versamide (trade name) manufactured by Daiichi General Co., Ltd .; Epicure (trade name) manufactured by Japan Epoxy Resin Co., Ltd .; Sanmide (trade name) manufactured by Sanwa Chemical Co., Ltd .; Epomate (trade name) manufactured by Ajinomoto Co., Inc.

The epoxy compound curing agent is effective when the functional groups X, Y ¹ and Y ^{2 of the} fluorine-containing polymer (A) and the antifouling component (B) are a carboxyl group, an amino group or an epoxy group. Examples include epoxy resins and epoxy-modified silane coupling agents. Commercially available products include Epicoat (trade name) and Epirec (trade name) manufactured by Japan Epoxy Resin Co., Ltd .; Cardlight (trade name) manufactured by Cardlight. And Coat Jill 1770 (trade name), A-187 (trade name) manufactured by Nippon Unicar Co., Ltd.

The compounding amount of the curing agent (C) is 0.3 equivalents or more when the total equivalent of the functional groups X, Y ¹ and Y ² of the fluoropolymer (A) and the antifouling component (B) is 1, and more 0.5 equivalent or more, particularly 0.8 equivalent or more is preferable. If it is too low, curing will be insufficient. The upper limit is 4 equivalents, further 2 equivalents, especially 1.5 equivalents. If the amount is too large, it will be necessary to consider such points as uniform formation of curing and increase in adhesiveness.

  It is particularly preferable that the coating composition used in the present invention is curable at room temperature (room temperature curable). By making it room temperature curable, an antifouling film can be formed without degrading the synthetic resin of the prefilter mesh. In addition, if it is to the heat-resistant temperature of the synthetic resin which is the material of the prefilter net | network, you may make it heat and harden.

  Various other additives may be blended in the coating composition used in the present invention. Typical additives include antibacterial agents, photocatalysts, antistatic agents, pigments, pigment dispersants, thickeners, leveling agents, antifoaming agents, film-forming aids, UV absorbers, matting agents, fillers, colloidal Silica, fungicides, silane coupling agents, anti-skinning agents, antioxidants, flame retardants, anti-sagging agents, rust inhibitors, water-soluble resins (polyvinyl alcohol, polyethylene oxide, etc.), antiseptics, anti-freezing agents, etc. These additives may be used as long as they do not impair the effects of the present invention.

  The form of the coating composition may be an aqueous dispersion type coating composition or a solvent type coating composition, but a solvent type coating composition is preferred from the viewpoint of good drying properties.

  In the case of a solvent-type coating composition, examples of the organic solvent include hydrocarbon solvents such as xylene and toluene; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate Ether solvents such as propylene glycol monobutyl ether, diethylene glycol dibutyl ether and tetrahydrofuran; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and acetone; N, N-dimethylacetamide, N-methylacetamide, acetamide, N, N-dimethyl Amide solvents such as formamide, N, N-diethylformamide and N-methylformamide; alcohol solvents such as methanol, ethanol and isopropanol; Such as sulfoxide can be exemplified. Of these, butyl acetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and methyl ethyl ketone are particularly preferred from the viewpoint of good solubility and drying properties.

  The solid content concentration of the coating composition is usually 1% by mass or more, preferably 10% by mass or more, and preferably 80% by mass or less, more preferably 50% by mass or less.

  The synthetic resin constituting the prefilter net may be currently used polypropylene, polyethylene, polyamide, polyvinyl chloride, polyester (for example, polyethylene terephthalate (PET)), polyvinylidene chloride, or the like.

  Specific examples of combinations of the fluorine-containing polymer (A), the antifouling component (B), the curing agent (C), and the optional component (D) in the particularly preferred coating composition are shown below, but the present invention is limited to these. It is not a thing.

Coating composition 1
Fluoropolymer (A): Hydroxyl group-containing fluoroolefin resin antifouling component (B): Amino group-containing polydialkylsiloxane curing agent (C): Hydrolyzable alkylsilicate residue-containing isocyanate (polyisocyanate if necessary)
Additive (D): Dibutyltin dilaurate (DBTDL) (optional)
Paint form: solvent type (solvent: butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monobutyl ether acetate, etc.)
Prefilter mesh material: Polyester (especially PET)

Coating composition 2
Fluorine-containing polymer (A): blend of fluoroolefin resin and hydroxyl group-containing non-fluorine resin Antifouling component (B): amino group-containing polydialkylsiloxane curing agent (C): polyisocyanate additive (D): dibutyltin dilaurate (DBTDL) (optional)
Paint form: solvent type (solvent: butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monobutyl ether acetate, etc.)
Prefilter mesh material: Polyester (especially PET)

Coating composition 3
Fluoropolymer (A): Hydroxyl group-containing fluoroolefin resin antifouling component (B): Amino group-containing polydialkylsiloxane curing agent (C): Amino compound additive (D): Paratoluenesulfonic acid Paint form: Solvent type (solvent : Butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monobutyl ether acetate, etc.)
Prefilter mesh material: Polyester (especially PET)

Coating composition 4
Resin (A): carboxyl group-containing fluoroolefin resin antifouling component (B): amino group-containing polydialkylsiloxane curing agent (C): amino compound additive (D): dibutyltin dilaurate (DBTDL) (optional)
Paint form: solvent type (solvent: butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monobutyl ether acetate, etc.)
Prefilter mesh material: Polyamide

  The prefilter of the present invention is a prefilter for an air conditioner. Air conditioners, whether for home or business use, include air conditioners, air purifiers, dehumidifiers, humidifiers, ventilation fans, etc. The shape and size of each air conditioner varies depending on the manufacturer and model. Although different, basically, as shown in a schematic perspective view in FIG. 1, a support frame 1 and a net 2 are formed, and the net 2 is composed of synthetic synthetic fibers 3. Of course, a woven fabric of fibers 3 may be used, but warps and wefts may be displaced, and the fibers are bonded to each other by heat or an adhesive.

  Various prefilter shapes can be adopted in consideration of ease of dust collection, reduction of pressure loss, ease of cleaning, frequency of cleaning, and the like. For example, as a method of weaving a mesh, solid weaving is often used because it has relatively fine eyes (easy to remove fine dust), and even if dust is collected, pressure loss does not increase easily (requires less frequent cleaning). However, in recent years, plain weaving types that have few irregularities and are easy to clean have come to be used.

  The mesh opening (mesh) varies depending on the type, model, application, form, etc. of the air conditioner to be applied, but is usually 25 to 80 mesh (about 250 μm to about 1 mm) in a home air conditioner.

  The prefilter used in the present invention may be plain weave, three-dimensional weave, turtle shell weave, spiral weave, with or without pleats, and can be provided in accordance with a known prefilter.

  As a method for applying the prefilter to the net, spray coating, dipping coating, roll coating or the like can be used, and an appropriate method may be adopted depending on the shape, size, material, and the like of the prefilter. Further, a primer paint may be applied in advance.

  After painting, it dries and can be cured with a curing agent. Although hardening may be heated, as described above, it is preferable to leave at room temperature from the viewpoint of preventing the deterioration of the net.

  The film thickness to be formed is usually 0.1 μm or more, more preferably 1 μm or more, particularly 2 μm or more, and the filter is easy to clean (adhesive dirt is difficult to stick to the filter and is easily absorbed by dust and sand). In view of the above, it is preferably 50 μm or less, more preferably 30 μm or less, particularly 10 μm or less in order to prevent clogging of the filter during coating, and to suppress an increase in pressure loss, and in addition, a paint for coating It is preferable because it suppresses the cost (does not use paint more than necessary) and the coating cost (does not apply more than necessary or does not require drying time) and prevents the paint from peeling off.

  The entire surface of the mesh (continuous coating) or part (discontinuous coating) may be used. Considering that the prefilter is flexible and deforms when handled, it is preferable to use a part (discontinuous film) because the film does not crack. In order to form a discontinuous film, there are, for example, a method of using a solvent having a low affinity for a synthetic resin as a solvent for a coating composition, a method of devising a coating method (spraying, gravure coating, etc.) and the like.

  In order to improve the wiping property, it is desirable to provide lubricity to the surface of the coated net. Good slipperiness means that the falling angle of a water droplet measured by a falling angle measurement method is 50 degrees or less and the falling angle of a hexadecane oil droplet is 10 degrees or less. In order to increase the water slidability, for example, a method of forming appropriate irregularities on the surface of the coated net can be exemplified.

  The falling angle is measured by forming a coating film on the substrate and measuring the falling angles of water and hexadecane with a contact angle measuring device.

  Depending on the coating method, the coating composition may remain in the meshes and the meshes may be crushed. If such clogging is excessive, the filter function is impaired and the pressure loss is increased. The degree of clogging is preferably 1/3 or less, more preferably 1/10 or less of the total number of meshes, from the viewpoint of good dust collection and suppression of pressure loss, and further the appearance of the filter is difficult to be damaged.

  Thus, the specific fluororesin coating formed on the surface of the pre-filter net has excellent removability not only for water-soluble dirt such as tobacco dust, but also for oil-soluble dirt such as oil smoke and soot. It can be easily removed regardless of oily water by simple washing and wiping, and also has excellent adhesion to the net, so it has excellent flexibility and durability that can withstand the use of brushes etc. Yes.

  As described above, the synthetic resin, which has been difficult to treat with a fluororesin, has been described as a material for the prefilter mesh. However, the coating composition used in the present invention is, of course, a metal, glass fiber or ceramic fiber. It can also be applied to heat-resistant prefilters such as.

  The metals and ceramics that make up the prefilter net are stainless steel (SUS304, SUS316, SUS316L, SUS430, SUS310S, etc.), nickel, monel, brass, red copper, phosphor bronze, copper, iron, zinc-drawn wire, steel, aluminum Examples thereof include metal fibers such as titanium, nichrome, hastelloy, and inconel, and ceramics such as aluminum oxide, zirconium oxide, mica, silicon nitride, glass, PZT, graphite, and carbon fiber.

  EXAMPLES Next, the present invention will be specifically described with reference to examples, but the present invention is not limited only to these examples.

Example 1
Zeffle GK-510 (hydroxyl group-containing tetrafluoroethylene copolymer. Hydroxyl value 60 mgKOH / g, acid value 9 mgKOH / g, number average molecular weight 12000, fluorine content 36 mass%, resin refractive index 1 as fluoropolymer (A) .4, 100 parts by mass of butyl acetate solution, solid content 50% by mass, and amino group-containing silicone oil (NUC SILICONE FZ3705 (trade name) as an antifouling component (B). Amino-modified silicone oil manufactured by Nihon Unicar Co., Ltd. 1 part by mass of viscosity 230 mm ² / s, amino equivalent 4000), 12 parts by mass of coronate HX (trade name) (an isocyanate curing agent manufactured by Nippon Polyurethane Co., Ltd.) as a curing agent (C), and a curing accelerator 2 parts by mass of 1% butyl acetate solution of dibutyltin dilaurate (DBTDL) as Butyl acetate 165 parts by mass of dilution agent, were blended 30 parts by mass of propylene glycol monomethyl ether acetate to prepare a solid concentration of 20 wt% of the coating composition.

  This coating composition is spray-coated on the next pre-filter by a conventional method, compressed air is applied to the filter to eliminate clogging, and then baked at 100 ° C. for 10 minutes, dried and cured, and fluorine on the film surface. The resin film was formed and the prefilter 1 of this invention was produced.

(Prefilter specifications)
Support frame: Polypropylene net: PET mesh mesh (mesh): 50 mesh length, 35 mesh fiber diameter: 75 denier Dimensions: 355 mm length, 400 mm width

  Clogging of the obtained prefilter 1 was 1% of the whole according to microscopic observation.

  Next, with respect to the base material (PET) of the prefilter 1 and the prefilter (comparative prefilter) before forming the coating, the water contact angle and the oil contact angle were examined. Since the contact angle of the prefilter itself cannot be measured, the contact angle between the PET sheet on which the fluororesin film was formed and the PET sheet before the film formation was measured in the same manner as described above. As a result, the contact angle with water of the PET sheet (corresponding to the prefilter 1) on which the fluororesin coating was formed was 103 degrees and the contact angle with oil was 50 degrees. The water contact angle of the PET sheet (corresponding to a comparative prefilter) before film formation was 80 degrees, and the oil contact angle was 15 degrees.

(Water contact angle)
Using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.), the contact angle at a liquid volume of 2 μl of pure water is measured. The measurement is made 1 second after placing the liquid.

(Oil contact angle)
Using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.), the contact angle at a liquid volume of 2 μl with a liquid paraffin viscosity of 70 cSt is measured. In order to stabilize the liquid, measurement is made 10 seconds after the liquid is placed.

  Further, as a result of performing a bending durability test on the prefilter 1, even after 10 foldings, almost no film was dropped.

(Bending durability test method)
An operation in which the prefilter is bent 180 degrees and then bent 180 degrees in the opposite direction is defined as one cycle, and is repeated 10 cycles. Thereafter, the bent portion is visually observed and the presence or absence of peeling is visually observed.

Next, the pre-filter 1 and the pre-filter before forming the coating (comparative pre-filter) are attached to the air conditioner installed on the upper part of the wall of the smoking room with a floor area of about 15 m ² , respectively, and are removed after operating for one month. And subjected to a cleaning test.

(Cleaning test method)
Apply water to the kitchen sink and wipe it back and forth twice using gauze. The evaluation is performed by visually checking the dirt state before and after wiping.

  As a result, in the prefilter 1 of the present invention, the cigarette stains fell to almost the same level as those at the time of attachment, and almost no dirt was found. However, in the comparative prefilter, the cigarette stains were hardly removed.

It is a schematic perspective view of the pre filter for air conditioners of this invention.

Explanation of symbols

1 Support frame 2 Net 3 Net fiber

Claims (10)

A prefilter for an air conditioner having a synthetic resin net, and a coating obtained by applying a coating composition containing a fluorine-containing polymer to a part or all of the surface of the net and curing the coating composition The coating composition is a composition comprising (A) a fluorine-containing polymer containing a functional group X, (B) an antifouling component and (C) a curing agent, wherein the antifouling component (B) Can react with the functional group X and / or the liquid polydialkylsiloxane having a functional group Y ¹ capable of reacting with the curing agent (C), or (B2) with the functional group X and / or the curing agent (C). prefilter is a cold-curing of the coating composition is a fluoropolyether liquid having a functional group Y ^2. The prefilter according to claim 1, wherein the functional group X of the fluoropolymer (A) is a hydroxyl group, a carboxyl group and / or an epoxy group. The polydialkylsiloxane (B1) is a functional group Y ¹ which has a hydroxyl group, according to claim 1 or 2 prefilter, wherein the amino and / or epoxy groups. The prefilter according to any one of claims 1 to 3, wherein the curing agent (C) is an isocyanate compound, an amino compound and / or an epoxy compound. The functional group X of the resin (A) is a hydroxyl group, the functional group Y ¹ or Y ^{2 of} the antifouling component (B) is a hydroxyl group or an amino group, and the curing agent (C) is an isocyanate compound. The prefilter according to 1. The prefilter according to any one of claims 1 to 5, wherein the room temperature curable coating composition further contains an antibacterial agent. The prefilter according to any one of claims 1 to 6, wherein the room temperature curable coating composition further contains a photocatalyst. The prefilter according to any one of claims 1 to 7, wherein the synthetic resin constituting the net is polypropylene, polyethylene, polyamide, polyvinyl chloride, or polyvinylidene chloride. It is a pre filter for air conditioners, The pre filter in any one of Claims 1-8. It is a pre filter for air purifiers, The pre filter in any one of Claims 1-8.

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