JP2013034923A - Flame-resistant filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-resistant filter which is excellent especially in flame resistance, does not cause the problem that fiber is broken and its broken pieces pierce the hands and/or the body, is able to meet sufficiently requirements of the market as a disposable application and is suitable for ventilation fan filters and range hood filters.SOLUTION: The flame-resistant filter includes an opened nonwoven fabric having a large number of openings in a nonwoven fabric containing a flame-resistant fiber and having a pressure loss at a wind velocity of 2 m/s of ≥50 Pa and a nonwoven fabric, laminated in an integrated way, and has a pressure loss at the wind velocity of 2 m/s of ≤30 Pa. A particle-fused fiber sheet having a fiber diameter smaller than the average fiber diameter of a plastic fiber is also provided.

Description

  The present invention relates to a flame retardant filter used in a place where flame retardancy is particularly required, such as a ventilation fan or a range hood used in a kitchen or a kitchen.

  A non-woven ventilation fan filter that has conventionally used flame-retardant synthetic fibers to collect oily smoke and dust generated during cooking in places where flame retardancy is particularly required, for example, in kitchens and kitchens And range hood filters are known. However, when such a filter is heated to a high temperature due to a flame generated in a flambe or the like, the filter may contract or melt and have a hole to lose its function as a filter.

  On the other hand, ventilation fan filters and range hood filters that use nonflammable glass fibers instead of flame retardant synthetic fibers are known. For example, Cited Document 1 discloses a flame retardant range hood filter characterized in that a flame retardant mainly composed of guanidine phosphate is attached to a glass fiber filter material. It is disclosed that the filter material made can be in the form of a non-woven fabric. However, in the case of a non-woven fabric, it is necessary to use a glass fiber having a relatively large fiber diameter in order to maintain a bulky shape with little airflow resistance. There was a problem of being stuck in the body.

  In order to solve such a problem, Reference 2 discloses a disposable filter material attached to a ventilation fan or a range hood in which a glass fiber mat is covered with a glass fiber fabric. Coating has been shown to prevent glass fibers from scattering or falling from the glass fiber mat. However, glass fiber fabrics are expensive, and filter materials using such expensive materials have a problem of poor marketability as disposable applications.

JP 05-168830 A JP 2004-313870 A

  The present invention solves the above-mentioned problems, and is particularly excellent in flame retardancy, and there is no problem that the fiber breaks and the fragments are stuck in the hand or body, and can fully meet the market demand as a disposable application An object of the present invention is to provide a flame-retardant filter suitable as a ventilation fan filter or a range hood filter.

  In order to solve the above-mentioned problems, in the invention according to claim 1, an open nonwoven fabric in which a large number of openings are provided in a nonwoven fabric containing flame retardant fibers and having a pressure loss of 50 Pa or more at a wind speed of 2 m / second; A non-woven fabric is laminated and integrated, and the flame retardant filter is characterized in that the pressure loss at a wind speed of 2 m / sec is 30 Pa or less.

  By the present invention, it is particularly excellent in flame retardancy, there is no problem that the fiber breaks and its fragments get into the eyes and there is no problem of sticking in the hand or body, and it can fully respond to the market demand as a disposable use, It has become possible to provide a flame-retardant filter suitable as a ventilation fan filter or a range hood filter.

It is a perspective view which shows an example of the flame-retardant filter of this invention.

  Hereinafter, embodiments of the flame-retardant filter according to the present invention will be described in detail.

  As illustrated in FIG. 1, the flame retardant filter 10 of the present invention contains a flame retardant fiber and has a pressure loss of 50 Pa or more at a wind speed of 2 m / second (hereinafter referred to as a nonwoven sheet). The non-woven fabric 20 having a large number of openings and a non-woven fabric 30 (hereinafter sometimes referred to as non-woven mat) are laminated and integrated, and the pressure loss at a wind speed of 2 m / sec is 30 Pa. It is characterized by the following.

  The opening nonwoven fabric 20 contains flame retardant fibers, and a number of openings are provided in a nonwoven fabric sheet having a pressure loss of 50 Pa or more at a wind speed of 2 m / sec. The nonwoven fabric sheet is a sheet-like nonwoven fabric, contains flame retardant fibers, and is not particularly limited as long as the pressure loss at a wind speed of 2 m / second is 50 Pa or more. As a form of, for example, after forming a fiber called a normal staple fiber having a fiber length of 15 to 100 mm and having 5 to 30 crimps / inch into a fiber web using a card machine or an air lay apparatus, There is a non-woven fabric obtained by a manufacturing method generally called a dry method, in which constituent fibers are bonded together using an adhesive fiber or an adhesive. In the present invention, in order to enhance the effect of protecting the nonwoven fabric mat from flame by the nonwoven fabric sheet, in the case of a nonwoven fabric by a dry method, the thickness is reduced by calendering to form a dense structure, and the wind speed is 2 m / second. It is desirable that the pressure loss at the time be 50 Pa or more.

  The nonwoven fabric sheet is also preferably a nonwoven fabric obtained by a wet method. Nonwoven fabric by wet method, for example, by using a papermaking net to make a slurry in which fibers or pulp-like fibers cut to a fiber length of 3 to 20 mm are dispersed in water, and if necessary, the fibers are bonded with an adhesive or an adhesive fiber Non-woven fabric obtained by adhering and including what is generally referred to as paper or synthetic paper in the present invention. If the nonwoven fabric is formed by a wet method, a dense structure can be obtained without reducing the thickness by calendering. In addition, when glass fiber is used, the glass fiber is damaged by calendering. Therefore, the wet method is a preferable aspect in obtaining a dense structure with glass fiber.

  In addition to the dry method, the nonwoven fabric sheet includes a nonwoven fabric obtained by a production method called a spunbond method or a melt blow method. In addition, the nonwoven fabric obtained by these production methods can be formed into a dense structure by reducing the thickness by calendering so that the pressure loss at a wind speed of 2 m / sec is 50 Pa or more.

  The fiber constituting the nonwoven fabric sheet is not particularly limited as long as it contains flame retardant fiber, and examples of the flame retardant fiber include inorganic fiber. Examples of the inorganic fiber include glass fiber, quartz fiber, alumina-silica fiber, Tyranno fiber, carbon fiber, activated carbon fiber, alumina fiber, silicon carbide fiber, zirconia fiber, potassium titanate fiber, silicon nitride fiber, boron fiber, basic Examples thereof include magnesium sulfate fiber, gypsum fiber, silicon carbide whisker, and silicon nitride whisker. Among these, glass fiber is preferable.

Moreover, it is preferable to use the glass fiber which a fiber does not break easily among glass fibers. As such a glass fiber, for example, the SiO ₂ component is 85 to 99% by weight, the Al ₂ O ₃ component is 1 to 10% by weight, and the other components have a composition of 0 to 10% by weight. There are silica fibers. This modified silica fiber is, for example, a glass fiber having a composition such as SiO ₂ , Na ₂ O, K ₂ O, Al ₂ O ₃ , CaO, MgO, Fe ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO _2. It is a fiber obtained by removing a necessary amount of components other than SiO ₂ and Al ₂ O ₃ by pickling, and has better heat resistance than the starting glass fiber. The composition of the modified silica fiber is such that the SiO ₂ component is 90 to 98% by weight, the Al ₂ O ₃ component is 2 to 5% by weight, and components other than SiO ₂ and Al ₂ O ₃ are 0 to 5% by weight. % Is preferable because the flame resistance is more excellent. As the modified silica fiber, for example, the brand name Bercotex manufactured by Berchem Corporation can be mentioned. Since the modified fiber can be crimped, a dry nonwoven fabric can be formed using a card machine.

  Examples of the organic flame retardant fiber include polyclar fiber and modacrylic fiber. Furthermore, aromatic polyamide fiber having heat resistance, novoloid fiber having flame resistance, acrylic flame resistant fiber, and melamine flame resistant fiber. And so on. If these heat-resistant fibers and flame-resistant fibers are contained, they will not shrink or deform significantly even when high heat is applied due to the flame of the kitchen, etc., and they are difficult to melt and have holes. There is almost no and there exists a more preferable effect. In addition, as the organic flame retardant fiber, a flame retardant fiber obtained by subjecting an organic fiber to flame retardant processing can also be used. In the flame retardant processing, it is desirable to use a flame retardant containing no halogen, for example, a phosphorus-based or guanidine-based flame retardant.

  The nonwoven fabric sheet can contain fibers other than flame retardant fibers. Examples of fibers other than flame retardant fibers include regenerated fibers such as rayon, natural fibers such as cotton and wool, and semisynthetic materials such as acetate. Synthetic fibers such as fibers, polyamide fibers, polyolefin fibers, and polyester fibers are possible. In the case of synthetic fibers, the nonwoven sheet can be easily thermoformed. The synthetic fiber may be a heat-bonding fiber. Such heat-adhesive fibers include, for example, fibers made of a single resin component having a lower melting point than other fibers and capable of thermally bonding other fibers, and other fibers having a lower melting point than other fibers. There is a composite fiber having a low melting point component that can be thermally bonded to the fiber surface. Such composite fibers include, for example, core-sheath type and side-by-side type composite fibers having a low melting point component on the fiber surface, and the material thereof is, for example, copolymer polyester / polyester, copolymer There are composite fibers made of a combination of fiber-forming polymers such as polypropylene / polypropylene, polypropylene / polyamide, polyethylene / polypropylene, polypropylene / polyester, and polyethylene / polyester.

  The nonwoven fabric sheet is preferably composed of 50 to 100% by weight of the flame retardant fiber and 50 to 0% by weight of organic fiber. By being such a weight ratio, the effect which protects the said nonwoven fabric mat from a flame by a nonwoven fabric sheet becomes more remarkable.

Preferably the surface density of the nonwoven sheet is 10 to 250 g / ^{m 2,} more preferably from 15~150g / ^{m 2,} and still more preferably from 25~100g / ^{m 2.} When the surface density is less than 10 g / m ² , the effect of protecting the nonwoven fabric mat from the flame may be reduced. When the surface density exceeds 250 g / m ² , the material cost is reduced with respect to the effect of protecting the nonwoven fabric mat from the flame. May be higher.

The nonwoven fabric sheet preferably has a thickness of 0.3 to 3 mm, more preferably 0.5 to 1.5 mm, and still more preferably 0.8 to 1.2 mm. When the thickness is less than 0.3 mm, the effect of protecting the nonwoven fabric mat from the flame may decrease, and when the thickness exceeds 3 mm, the material cost increases for the effect of protecting the nonwoven fabric mat from the flame There is. The thickness measured under a load of 0.5 g / cm ² is applied.

Preferably the apparent density of the nonwoven fabric sheet is 0.015~0.15g / cm ^3, more preferably ^{0.025~0.10g / cm 3, 0.035~0.075g / cm} 3 More preferably. If the apparent density is less than 0.015 g / cm ³ to decrease density of the nonwoven sheet, effect may be lowered to protect the nonwoven mat from the flame, exceeds 0.15 g / cm ³ non-woven fabric In some cases, the density of the sheet becomes too high, and the nonwoven sheet becomes hard and difficult to handle. The apparent density can be determined from the value obtained by dividing the surface density of the nonwoven fabric sheet by the thickness.

  The nonwoven fabric sheet is required to have a pressure loss of 50 Pa or more when the wind speed is 2 m / sec, the pressure loss is preferably 50 to 500 Pa, more preferably 50 to 400 Pa, and 50 to 300 Pa. More preferably it is. When the pressure loss is 50 Pa or more, the effect of protecting the nonwoven fabric mat from the flame generated during cooking can be sufficiently obtained. Moreover, when exceeding 500 Pa, the density of a nonwoven fabric sheet may become high too much, and a nonwoven fabric sheet may become hard and it may become difficult to handle. In general, a filter used for a ventilation fan or a range hood desirably has an initial pressure loss of 30 Pa or less at a wind speed of 2 m / sec. If the pressure loss exceeds 30 Pa, it is because the structure of the filter becomes too dense. In this case, troubles such as a decrease in the capacity of the blower occur. In the present invention, the dense nonwoven fabric sheet having a high pressure loss of 50 Pa or higher that is not normally used is provided on the air inflow side, thereby providing an effect of protecting the nonwoven fabric mat from the flame generated during cooking. .

Although the said nonwoven fabric sheet contains a flame retardant fiber, when it assumes that oil smoke etc. adhere to this nonwoven fabric sheet or an opening nonwoven fabric, and it becomes easy to burn, it is desirable to raise a flame retardance level further. Therefore, it is preferable to apply a flame retardant together with an adhesive to the nonwoven fabric sheet. As the flame retardant, it is preferable to use a phosphorus-based or guanidine-based flame retardant containing no halogen. The mass ratio of the flame retardant to the adhesive is preferably 80:20 to 40:60, more preferably 70:30 to 50:50, and even more preferably 65:35 to 55:45. . The coating amount of the adhesive containing a flame retardant is preferably from 20 to 500 g / ^{m 2,} more preferably from 35~300g / ^{m 2,} still to be 50 to 200 g / ^{m 2} preferable.

Preferably the surface density of the nonwoven fabric sheet after application of the flame retardant with the adhesive is a 35~850g / ^{m 2,} more preferably from 55~500g / ^{m 2,} it is 85~350g / ^{m 2} Is more preferable. Moreover, it is preferable that it is 0.3-3 mm like thickness before application | coating, It is more preferable that it is 0.5-1.5 mm, It is still more preferable that it is 0.8-1.2 mm. Moreover, it is preferable that the pressure loss at the time of the wind speed of 2 m / sec after application | coating is 50-700 Pa, It is more preferable that it is 50-600 Pa, It is still more preferable that it is 50-500 Pa.

  In addition, the non-woven sheet has not only an effect of protecting the non-woven mat from the flame, but also the non-woven sheet itself has a filtering action, and is simply a hole punched on a metal plate or metal foil. Is different from the point of action and effect. In addition, because the nonwoven fabric sheet has a dense structure, even if oil adheres due to oily smoke generated during cooking, the nonwoven fabric sheet is adsorbed and held without dripping like a metal plate or metal foil. It also has the effect of Further, the nonwoven fabric sheet is lighter in weight, more flexible than a metal plate or metal foil, and is easy to be laminated and integrated.

  In addition, when evaluating the pressure loss of the nonwoven fabric sheet coated with the nonwoven fabric sheet or the flame retardant in the opening nonwoven fabric 20, the area of the unsealed portion is calculated after the opening portion is sealed. It is possible to measure the pressure loss of the nonwoven fabric sheet to which the nonwoven fabric sheet or the flame retardant is applied by adjusting the air flow rate so as to be 2 m / second.

As shown in FIG. 1, the nonwoven fabric sheet is provided with a large number of openings 21. This opening means a through hole, and does not mean a hole surrounded by fibers constituting the nonwoven fabric. Further, the number means a number of about 30 / m ² or more. The shape, size, and opening ratio of the opening are not particularly limited as long as the pressure loss of the opening nonwoven fabric 20 is less than 30 Pa. The shape of the opening is not limited to a circle as shown in FIG. Square, alphabet, etc. can be applied. Further, as the size of the opening, when the diameter of a circle having the same area as the area of the opening is used as the size of the opening (sometimes referred to as an opening diameter), the opening diameter is preferably 4 to 20 mm. More preferably, it is -12 mm, and it is still more preferable that it is 4-10 mm. If the opening diameter is less than 4 mm, clogging may easily occur due to particles contained in the smoke, and if it exceeds 20 mm, the effect of protecting the nonwoven fabric mat from flame may be reduced.

  The arrangement of the openings is not particularly limited, but it is desirable that the openings are arranged uniformly over the entire opening nonwoven fabric. FIG. 1 is an example in which circular openings are uniformly arranged, and the rows of openings are arranged at equal intervals, and the distances between the centers of the nearest openings are the same. The center of the opening can be the center of the opening. In the present invention, it is preferable that the distance between the centers of the openings at the closest distance is the same, even if there is some variation in the distance between the centers, there is an effect of protecting the nonwoven fabric mat from the flame, The degree of the variation is preferably a deviation within ± 30% of the average value between the centers. The distance between the centers is preferably 5 to 14 mm, more preferably 6 to 13 mm, and still more preferably 7 to 12 mm, although it depends on the above-mentioned opening diameter and the aperture ratio described later.

  The open area ratio of the open nonwoven fabric is obtained from a value obtained by dividing a value obtained by multiplying the area of the opening by the number of openings by the area of the nonwoven fabric sheet before opening. The aperture ratio is not particularly limited as long as the pressure loss of the apertured nonwoven fabric 20 is less than 30 Pa, and as long as the nonwoven fabric mat has an effect of protecting the nonwoven fabric mat from flame, and is preferably 16 to 60%. It is more preferably 18 to 50%, and further preferably 20 to 45%. If it is less than 16%, the pressure loss of the open nonwoven fabric may increase, and if it exceeds 60%, the effect of protecting the nonwoven fabric mat from flame may be reduced. As will be apparent from Example 1 described later, if the aperture ratio is about 22%, the pressure loss of the nonwoven fabric sheet can be reduced to about 1/5.

Preferably the surface density of openings nonwoven is 8~200g / ^{m 2,} more preferably from 15~130g / ^{m 2,} and still more preferably from 20~90g / ^{m 2.} Also it is preferable that the surface density of the opening nonwoven fabric after and flame retardant has been applied is 30~700g / ^{m 2,} more preferably from 50~450g / ^{m 2,} a 70~300g / ^{m 2} Is more preferable.

  The pressure loss of the open nonwoven fabric when the wind speed is 2 m / sec is preferably 1 to 29 Pa, more preferably 2 to 25 Pa, and further preferably 3 to 22 Pa. Moreover, it is preferable that the pressure loss at the time of the wind speed of 2 m / sec of the open nonwoven fabric after a flame retardant etc. are apply | coated is similarly 1-29 Pa, It is more preferable that it is 2-25 Pa, It is 3-22 Pa Is more preferable. If the pressure loss is less than 1 Pa, the effect of protecting the nonwoven fabric mat from the flame may be reduced.

  In the present invention, the open nonwoven fabric and the nonwoven fabric mat are laminated and integrated. The nonwoven fabric mat is not particularly limited as long as it can be laminated and integrated with the nonwoven fabric mat, but the thickness is relatively large so that as many particles as possible can be adhered and held in the oil smoke. A mat shape is preferred. As a form of the mat-like non-woven fabric, for example, a fiber called a normal staple fiber having a fiber length of 15 to 100 mm and having a number of crimps of 5 to 30 / inch is used as a fiber web by using a card machine or an air lay apparatus. After forming, there is a non-woven fabric obtained by a process generally referred to as a dry process, in which constituent fibers are bonded together using adhesive fibers or adhesives. Also, when bonding by bonding, it is desirable to bond without crushing the thickness, adopting an air-through method when using thermal bonding fibers, or spraying a binder liquid onto the fiber web when using adhesives Is preferably adopted. In addition, by adopting a system in which a binder liquid is sprayed onto the fiber web, the open nonwoven fabric and the fiber web (precursor of the nonwoven fabric mat) can be laminated and integrated together with the adhesion of the fiber web.

  The nonwoven fabric mat includes a nonwoven fabric obtained by a production method called a spunbond method, in addition to the dry method. Nonwoven fabrics obtained by spinning glass fibers and depositing them on a movable support are also possible.

  Examples of the fibers constituting the nonwoven fabric mat include recycled fibers such as rayon, natural fibers such as cotton and wool, semi-synthetic fibers such as acetate, synthetic fibers such as polyamide fibers, polyolefin fibers, and polyester fibers. It is. In the case of synthetic fibers, the fiber web can be thermoformed and easily processed into a bulky nonwoven fabric mat. The synthetic fiber may be a heat-bonding fiber. Such heat-adhesive fibers include, for example, fibers made of a single resin component having a lower melting point than other fibers and capable of thermally bonding other fibers, and other fibers having a lower melting point than other fibers. There is a composite fiber having a low melting point component that can be thermally bonded to the fiber surface. Such composite fibers include, for example, core-sheath type and side-by-side type composite fibers having a low melting point component on the fiber surface, and the material thereof is, for example, copolymer polyester / polyester, copolymer There are composite fibers made of a combination of fiber-forming polymers such as polypropylene / polypropylene, polypropylene / polyamide, polyethylene / polypropylene, polypropylene / polyester, and polyethylene / polyester. It is also desirable to mix a certain amount of fiber such as rayon which does not have a melting point and therefore does not melt as the fibers constituting the nonwoven fabric mat, and has the effect of preventing the through-holes from being opened in the nonwoven fabric mat by flame.

  It is also preferable to contain a flame retardant fiber as the fiber constituting the nonwoven fabric mat. Examples of the flame retardant fiber include inorganic fibers. Examples of the inorganic fiber include glass fiber, quartz fiber, alumina-silica fiber, Tyranno fiber, carbon fiber, activated carbon fiber, alumina fiber, silicon carbide fiber, zirconia fiber, potassium titanate fiber, silicon nitride fiber, boron fiber, basic Examples thereof include magnesium sulfate fiber, gypsum fiber, silicon carbide whisker, and silicon nitride whisker. Among these, glass fiber is preferable.

Moreover, it is preferable to use the glass fiber which a fiber does not break easily among glass fibers. As such a glass fiber, for example, the SiO ₂ component is 85 to 99% by weight, the Al ₂ O ₃ component is 1 to 10% by weight, and the other components have a composition of 0 to 10% by weight. There are silica fibers. This modified silica fiber is, for example, a glass fiber having a composition such as SiO ₂ , Na ₂ O, K ₂ O, Al ₂ O ₃ , CaO, MgO, Fe ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO _2. It is a fiber obtained by removing a necessary amount of components other than SiO ₂ and Al ₂ O ₃ by pickling, and has better heat resistance than the starting glass fiber. The composition of the modified silica fiber is such that the SiO ₂ component is 90 to 98% by weight, the Al ₂ O ₃ component is 2 to 5% by weight, and components other than SiO ₂ and Al ₂ O ₃ are 0 to 5% by weight. % Is preferable because the flame resistance is more excellent. As the modified silica fiber, for example, the brand name Bercotex manufactured by Berchem Corporation can be mentioned. Since the modified fiber can be crimped, a dry nonwoven fabric can be formed using a card machine.

  Examples of the organic flame retardant fiber include polyclar fiber and modacrylic fiber. Furthermore, aromatic polyamide fiber having heat resistance, novoloid fiber having flame resistance, acrylic flame resistant fiber, and melamine flame resistant fiber. And so on. If these heat-resistant fibers and flame-resistant fibers are contained, they will not shrink or deform significantly even when high heat is applied due to the flame of the kitchen, etc., and they are difficult to melt and have holes. There is almost no and there exists a more preferable effect. In addition, as the organic flame retardant fiber, a flame retardant fiber obtained by subjecting an organic fiber to flame retardant processing can also be used. In the flame retardant processing, it is desirable to use a flame retardant containing no halogen, for example, a phosphorus-based or guanidine-based flame retardant.

  The nonwoven fabric mat preferably comprises 0 to 95% by weight of the flame retardant fiber and 100 to 5% by weight of organic fiber.

Preferably the surface density of the nonwoven fabric mat is 15~350g / ^{m 2,} more preferably from 25~200g / ^{m 2,} and still more preferably from 35~150g / ^{m 2.} When the surface density is less than 15 g / m ² , the dust holding capacity may decrease, and when it exceeds 150 g / m ² , the pressure loss may increase.

  The nonwoven fabric mat preferably has a thickness of 4 to 30 mm, more preferably 5 to 20 mm, and still more preferably 7 to 15 mm. When the thickness is less than 4 mm, the dust holding capacity may decrease, and when it exceeds 30 mm, the pressure loss may increase.

Preferably the apparent density of the nonwoven fabric mat is 0.002~0.02g / cm ^3, more preferably ^{0.003~0.014g / cm 3, 0.005~0.01g / cm} 3 More preferably. When the apparent density is less than 0.002 g / cm ³ , the particle collection efficiency may decrease, and when it exceeds 0.02 g / cm ³ , the pressure loss may increase.

  The nonwoven fabric mat preferably has a pressure loss of 1 to 20 Pa at a wind speed of 2 m / sec, more preferably 2 to 15 Pa, and still more preferably 3 to 10 Pa.

The nonwoven fabric mat is desirably flame retardant, and there is a method of making the nonwoven fabric mat contain flame retardant fibers as described above. In addition, there is a method in which a flame retardant is mixed in an adhesive when the fiber web is bonded with an adhesive in the manufacturing process of the nonwoven mat. In particular, when the non-woven mat does not contain flame retardant fibers, it is preferable to apply a method of mixing a flame retardant into the adhesive. As the flame retardant, it is preferable to use a phosphorus-based or guanidine-based flame retardant containing no halogen. The mass ratio of the flame retardant to the adhesive is preferably 80:20 to 40:60, more preferably 70:30 to 50:50, and still more preferably 65: 350 to 55:45. . The coating amount of the adhesive containing a flame retardant is preferably from 20 to 500 g / ^{m 2,} more preferably from 35~300g / ^{m 2,} still to be 50 to 200 g / ^{m 2} preferable.

Preferably the surface density of the nonwoven mat after application of the flame retardant with the adhesive is a 35~850g / ^{m 2,} more preferably from 55~500g / ^{m 2,} it is 85~350g / ^{m 2} Is more preferable. Further, the thickness is preferably 4 to 30 mm, more preferably 5 to 20 mm, even more preferably 7 to 15 mm, as before application. Moreover, it is preferable that the pressure loss at the time of the wind speed of 2 m / sec after application | coating is 1-20 Pa similarly to before application | coating, It is more preferable that it is 2-15 Pa, It is still more preferable that it is 3-10 Pa.

In the present invention, the opening nonwoven fabric and the nonwoven fabric mat are laminated and integrated. However, the laminated integration is different from a simple overlapping mode, and the opening nonwoven fabric and the nonwoven fabric mat are overlapped and separated from each other. Means the form. As a method of laminating and integrating, after applying an aqueous solution or a water-dispersed adhesive on at least one surface of the open nonwoven fabric or nonwoven fabric mat, they are stacked, dried and cured. There are forms. Moreover, after apply | coating hot-melt resin with a spray etc. to the surface to overlap at least one of an opening nonwoven fabric or a nonwoven fabric mat, there exists a form obtained by superimposing both. In addition, as described above, in the manufacturing process of the nonwoven fabric mat, a binder liquid made of an adhesive mixed with a flame retardant is sprayed on the fiber web, and the open nonwoven fabric and the fiber web (precursor of the nonwoven fabric mat) are bonded together with the fiber web. It is also possible to improve the flame retardancy of the open nonwoven fabric. As the flame retardant, it is preferable to use a phosphorus-based or guanidine-based flame retardant containing no halogen. The mass ratio of the flame retardant to the adhesive is preferably 80:20 to 40:60, more preferably 70:30 to 50:50, and still more preferably 65: 350 to 55:45. The coating amount of the adhesive containing a flame retardant is preferably 40~1000g / ^{m 2,} more preferably from 70~600g / ^{m 2,} still to be 100 to 400 g / ^{m 2} preferable.

Preferably the surface density of the flame retardant filter of the present invention is 60~1500g / ^{m 2,} more preferably from 100 to 1000 g / ^{m 2,} and still more preferably from 150~650g / ^{m 2.} The thickness of the flame retardant filter is preferably 5 to 33 mm, more preferably 6 to 22 mm, and still more preferably 8 to 17 mm.

  In the flame-retardant filter of the present invention, the pressure loss at a wind speed of 2 m / sec is required to be 30 Pa or less, the pressure loss is preferably 5 to 27 Pa, more preferably 5 to 25 Pa. More preferably, it is 5-20 Pa. If the pressure loss exceeds 30 Pa, it will be difficult to use as a fan or range hood. If the pressure loss is less than 5 Pa, the dust holding capacity may be too small, or the performance of removing oil mist may be too low.

  The flame retardancy of the flame retardant filter of the present invention can be evaluated by a method defined in JIS L1091 A-1 method (45 ° micro burner method) or A-2 method (45 ° Meckel burner method). According to this evaluation method, it is preferable that the flame-retardant filter of the present invention is in Category 3 or higher. Moreover, it is preferable that it is a division 3 and exhibits high flame retardance in a state where a through hole is not opened by flame.

  Examples of the present invention will be described below, but these are only suitable examples for facilitating the understanding of the present invention, and the present invention is not limited to the contents of these examples.

Example 1
Using 100% modified silica fiber (Belchem, product name: Bercotex, fiber diameter: 9 μm, cut length: 10 mm), surface density is 50 g / m ² , thickness is 1 mm, and wind speed is 2 m / sec. As shown in FIG. 1, in a wet nonwoven fabric with a pressure loss of 120 Pa, circular holes 21 having a diameter of 6 mm are formed so that the columns and rows are equidistant, and the center distance is 11.3 mm. Opened nonwoven fabric 20 having an opening rate of 22%, an area density of 39 g / m ² , and a pressure loss of 20 Pa when the wind speed was 2 m / sec was obtained.
Next, using a card machine, the surface density is 70 g / m ² consisting of 70% polyester fiber (fineness: 14 dtex, fiber length 51 mm) and 30% rayon fiber (fineness: 7.8 dtex, fiber length 51 mm). A fiber web having a thickness of 10 mm is formed, placed on the open nonwoven fabric 20, and an acrylic adhesive mixed with a guanidine flame retardant from above the fiber web (the mass ratio of flame retardant to adhesive is 60). : 40), the constituent fibers of the fiber web are bonded to each other by spraying, drying and curing, and the fiber web and the open nonwoven fabric 20 are bonded to each other so that the open nonwoven fabric 20 and the nonwoven fabric mat 30 are laminated and integrated. A flame-retardant filter 10 having an areal density of 309 g / m ² and a thickness of 11 mm was obtained.
As a result of the binder 100 g / m ² adhering to the open nonwoven fabric, the surface density of the open nonwoven fabric was 139 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / second was large at about 20 Pa. There was no change. Further, the pressure loss at a wind speed of 2 m / sec of the wet nonwoven fabric was about 150 Pa, and a slight increase in pressure loss was observed. Further, as a result of the binder 100 g / m ² adhering to the nonwoven fabric mat, the surface density of the nonwoven fabric mat was 170 g / m ² .
The obtained flame-retardant filter has a pressure loss of 25 Pa when the wind speed is 2 m / second, and the flame retardancy is opened using a method defined in the JIS L1091 A-1 method (45 ° micro burner method). When the open nonwoven fabric is placed on the lower side and measured so that the nonwoven fabric hits the flame, it is Category 3, and the through hole is not opened by the flame, and has excellent flame retardancy, as a ventilation fan or range hood filter It was suitable.

(Example 2)
In Example 1, a circular hole 21 having a diameter of 7 mm is formed in a wet nonwoven fabric to obtain an apertured nonwoven fabric 20 having an opening rate of 30%, an areal density of 35 g / m ² , and a pressure loss of 13 Pa when the wind speed is 2 m / second. Except that, the flame-retardant filter 10 having an area density of 305 g / m ² and a thickness of 11 mm, in which the apertured nonwoven fabric 20 and the nonwoven fabric mat 30 were laminated and integrated, was obtained in the same manner as in Example 1.
As a result of the binder 100 g / m ² adhering to the apertured nonwoven fabric, the surface density of the apertured nonwoven fabric was 135 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / second was large at about 13 Pa. There was no change.
The obtained flame-retardant filter has a pressure loss of 18 Pa when the wind speed is 2 m / sec, and the flame retardancy is opened using a method defined in the JIS L1091 A-1 method (45 ° micro burner method). When the open nonwoven fabric is placed on the lower side and measured so that the nonwoven fabric hits the flame, it is Category 3, and the through hole is not opened by the flame, and has excellent flame retardancy, as a ventilation fan or range hood filter It was suitable.

(Example 3)
In Example 1, a circular hole 21 having a diameter of 8 mm is formed in a wet nonwoven fabric to obtain an apertured nonwoven fabric 20 having an opening rate of 39%, a surface density of 30 g / m ² , and a pressure loss of 9 Pa when the wind speed is 2 m / second. Except that, a flame-retardant filter 10 having an area density of 300 g / m ² and a thickness of 11 mm, in which the apertured nonwoven fabric 20 and the nonwoven fabric mat 30 were laminated and integrated, was obtained in the same manner as in Example 1.
As a result of the binder 100 g / m ² adhering to the open nonwoven fabric, the surface density of the open nonwoven fabric was 130 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / sec was large at about 9 Pa. There was no change.
The obtained flame retardant filter has a pressure loss of 14 Pa when the wind speed is 2 m / second, and the flame retardant is opened using a method defined in the JIS L1091 A-1 method (45 ° micro burner method). When the open nonwoven fabric is placed on the lower side and measured so that the nonwoven fabric hits the flame, it is Category 3, and the through hole is not opened by the flame, and has excellent flame retardancy, as a ventilation fan or range hood filter It was suitable.

Example 4
In Example 1, circular holes 21 having a diameter of 5 mm are formed in the wet nonwoven fabric so that the columns and rows are equally spaced, and the center-to-center distance is 9.5 mm, and the opening ratio is 22%. Open nonwoven fabric 20 and nonwoven fabric mat 30 were laminated and integrated in the same manner as in Example 1 except that an open nonwoven fabric 20 having a surface loss of 39 g / m ² and a pressure loss of 20 Pa at a wind speed of 2 m / second was obtained. A flame retardant filter 10 having an areal density of 309 g / m ² and a thickness of 11 mm was obtained.
As a result of the binder 100 g / m ² adhering to the open nonwoven fabric, the surface density of the open nonwoven fabric was 139 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / second was large at about 20 Pa. There was no change.
The obtained flame-retardant filter has a pressure loss of 25 Pa when the wind speed is 2 m / second, and the flame retardancy is opened using a method defined in the JIS L1091 A-1 method (45 ° micro burner method). When the open nonwoven fabric is placed on the lower side and measured so that the nonwoven fabric hits the flame, it is Category 3, and the through hole is not opened by the flame, and has excellent flame retardancy, as a ventilation fan or range hood filter It was suitable.

(Example 5)
In Example 1, circular holes 21 having a diameter of 4 mm are formed in the wet nonwoven fabric so that the columns and rows are equally spaced, and the center-to-center distance is 7.5 mm, and the opening ratio is 22%. Open nonwoven fabric 20 and nonwoven fabric mat 30 were laminated and integrated in the same manner as in Example 1 except that an open nonwoven fabric 20 having a surface loss of 39 g / m ² and a pressure loss of 20 Pa at a wind speed of 2 m / second was obtained. A flame retardant filter 10 having an areal density of 309 g / m ² and a thickness of 11 mm was obtained.
As a result of the binder 100 g / m ² adhering to the open nonwoven fabric, the surface density of the open nonwoven fabric was 139 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / second was large at about 20 Pa. There was no change.
The obtained flame-retardant filter has a pressure loss of 25 Pa when the wind speed is 2 m / second, and the flame retardancy is opened using a method defined in the JIS L1091 A-1 method (45 ° micro burner method). When the open nonwoven fabric is placed on the lower side and measured so that the nonwoven fabric hits the flame, it is Category 3, and the through hole is not opened by the flame, and has excellent flame retardancy, as a ventilation fan or range hood filter It was suitable.

(Comparative Example 1)
In Example 1, a circular hole 21 having a diameter of 5 mm is formed in a wet nonwoven fabric to obtain an apertured nonwoven fabric 20 having an opening rate of 15%, a surface density of 43 g / m ² , and a pressure loss of 33 Pa when the wind speed is 2 m / second. In the same manner as in Example 1 except that the open nonwoven fabric 20 and the nonwoven fabric mat 30 are laminated and integrated, the surface density is 313 g / m ² , the thickness is 11 mm, and the pressure loss is 38 Pa when the wind speed is 2 m / second. A flame retardant filter 10 was obtained.
As a result of the binder 100 g / m ² adhering to the open nonwoven fabric, the surface density of the open nonwoven fabric was 143 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / second was large at about 33 Pa. There was no change.
The obtained flame retardant filter had high pressure loss and was not suitable as a ventilation fan or a range hood filter.

(Comparative Example 2)
In Example 1, a circular hole 21 having a diameter of 4 mm is formed in a wet nonwoven fabric to obtain an apertured nonwoven fabric 20 having an opening rate of 10%, a surface density of 45 g / m ² , and a pressure loss of 66 Pa when the wind speed is 2 m / second. In the same manner as in Example 1 except that the open nonwoven fabric 20 and the nonwoven fabric mat 30 are laminated and integrated, the surface density is 315 g / m ² , the thickness is 11 mm, and the pressure loss when the wind speed is 2 m / second is 71 Pa. A flame retardant filter 10 was obtained.
As a result of the binder 100 g / m ² adhering to the apertured nonwoven fabric, the surface density of the apertured nonwoven fabric was 145 g / m ² and the thickness was 1 mm, but the pressure loss at a wind speed of 2 m / sec was large at about 66 Pa. There was no change.
The obtained flame retardant filter had high pressure loss and was not suitable as a ventilation fan or a range hood filter.

(Comparative Example 3)
In Example 1, the flame retardant filter was obtained like Example 1 except not having used the opening nonwoven fabric 20. FIG. That is, using a card machine, the surface density is 70 g / m ² composed of 70% polyester fiber (fineness: 13 dtex, fiber length 51 mm) and 30% rayon fiber (fineness: 7.8 dtex, fiber length 51 mm). A fiber web having a thickness of 10 mm is formed, placed on the open nonwoven fabric 20, and an acrylic adhesive mixed with a guanidine flame retardant from above the fiber web (the mass ratio of flame retardant to adhesive is 60). : 40) A binder consisting of 40) is sprayed, dried and cured to bond the constituent fibers of the fiber web together, and the pressure loss is 5 Pa when the surface density is 170 g / m ² , the thickness is 10 mm, and the wind speed is 2 m / sec. The flame retardant filter 10 was obtained. The flame retardancy of this flame retardant filter was measured by the method specified in JIS L1091 A-1 method (45 ° micro burner method), but it was Category 3. It was inferior.

10 Flame Retardant Filter 20 Opening Nonwoven Fabric 21 Opening 30 Nonwoven Fabric, Nonwoven Fabric Mat

Claims (1)

  A nonwoven fabric that contains flame retardant fibers and has a pressure loss of 50 Pa or more when the wind speed is 2 m / sec. A flame-retardant filter characterized in that the pressure loss at the time is 30 Pa or less.

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