Sheet and tape

Abstract

To provide a sheet and tape with excellent flame retardancy and low smoke emission.SOLUTION: A sheet comprises a fiber layer and a flame-retardant coating layer provided on the surface of the fiber layer. The flame-retardant coating layer includes a resin, a phosphorus-based flame retardant, and a metal compound composed of metal oxides and / or metal hydroxides. The ratio of the mass of the phosphorus-based flame retardant (WF1) to the mass of the resin (WR), (WF1 / WR), is 1.5 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sheet and a tape. [Background technology]

[0002] From the perspective of fire prevention, the covering materials used in cables for office equipment such as televisions, PCs, printers, and other electronic devices are required to be flame-retardant. In addition, the safety standards for such cables include the UL (Underwriters Laboratories Inc.) standard and the CPR (Construction Products Regulation), and low smoke emission is required to meet criteria such as smoke emission (light transmittance).

[0003] Therefore, conventionally, coating materials have been developed using halogen-containing flame retardants, but these generate harmful gases containing halogens during combustion. Therefore, phosphorus-containing flame retardants have been developed as halogen-free flame retardants.

[0004] However, as described in Patent Document 1, among phosphorus-based flame retardants, when red phosphorus-based flame retardants are added, a large amount of harmful phosphine gas is generated during combustion. Furthermore, when ammonium polyphosphate-based flame retardants are added, a large amount of smoke is generated. Therefore, the addition of such flame retardants may make it difficult to safely guide people to safety in the event of a fire. Therefore, Patent Document 1 discloses a flame-retardant cable tape that does not contain a phosphorus-based flame retardant but contains a metal hydrate such as magnesium hydroxide. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-44612 Summary of the Invention [Problem to be solved by the invention]

[0006] Flame-retardant cable tapes with a coating primarily composed of a metal hydrate such as magnesium hydroxide can reduce the amount of smoke emitted, but they have inferior flame retardancy compared to flame-retardant tapes with a coating primarily composed of ammonium polyphosphate.

[0007] The present invention aims to solve the above problems and to provide a sheet and tape that have excellent flame retardancy and low smoke generation. [Means for solving the problem]

[0008] The present invention has been made to solve the above problems, and the gist of the present invention is the following sheet and tape.

[0009] (1) a fiber layer; a flame-retardant coating layer provided on the surface of the fiber layer, the flame-retardant coating layer contains a resin, a phosphorus-based flame retardant, and a metal compound composed of a metal oxide and / or a metal hydroxide, The mass of the resin W R and the mass W of the phosphorus-based flame retardant F1 Ratio to (W F1 / W R ) is 1.5 or more, Sheet.

[0010] (2) Mass W of the phosphorus-based flame retardant F1 and the mass W of the metal compound F2 and the ratio (W F2 / W F1 ) is 0.01 or more, The sheet described in (1) above.

[0011] (3) Mass W of the resin R and the mass W of the phosphorus-based flame retardant F1 and the mass W of the metal compound F2 The ratio of the sum of [(W F1 +W F2 ) / W R ] is less than or equal to 10.0, The sheet described in (2) above.

[0012] (4) The metal compound is at least one selected from silicon oxide, magnesium oxide, aluminum oxide, zinc oxide, magnesium hydroxide, and aluminum hydroxide. The sheet described in (1) above.

[0013] (5) The fiber layer is composed of a first layer and a second layer, The flame-retardant coating layer is provided on one surface of the first layer, and the second layer is provided on the other surface of the first layer. The sheet described in (1) above.

[0014] (6) Using the sheet described in any one of (1) to (5) above, tape. [Effects of the Invention]

[0015] According to the present invention, a sheet and tape having excellent flame retardancy and low smoke generation can be obtained. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic cross-sectional view in the thickness direction of a sheet according to the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view in the thickness direction of the sheet according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The sheet according to the present invention will be described below.

[0018] (sheet) Fig. 1 is a schematic cross-sectional view in the thickness direction of a sheet 10 according to the present invention. As shown in Fig. 1, the sheet 10 according to the present invention comprises a fiber layer 12 and a flame-retardant coating layer 14 provided on one surface of the fiber layer 12. The thickness of the sheet 10 is preferably 300 µm or less, and from the viewpoint of improving the flexibility of the sheet 10, it is more preferably 250 µm or less, and even more preferably 230 µm or less.

[0019] An adhesive layer may be provided on the other surface 16 of the fiber layer 12. The type of adhesive used in the adhesive layer is not particularly limited, but examples include polyester resins, polyether resins, polyurethane resins, acrylic resins, styrene resins, acid-modified olefin resins, ethylene-vinyl acetate copolymer resins, epoxy resins, silicone resins, natural rubber resins, and synthetic rubber resins. The thickness of the adhesive layer is excluded from the thickness of the sheet 10 according to the present invention.

[0020] (Flame-retardant coating layer) The flame-retardant coating layer 14 contains a resin, a phosphorus-based flame retardant, and a metal compound composed of a metal oxide and / or a metal hydroxide. Each requirement will be explained below.

[0021] (Composition of flame-retardant coating layer) (1) Resin The type of resin contained in the flame-retardant coating layer 14 of the present invention is not particularly limited. Examples of resins include polyester resins, polyolefin resins, acrylic resins, polystyrene resins, polyamide resins, polyether resins, polycarbonate resins, polyvinyl resins, polyacetal resins, and elastomers. These may be homopolymers or copolymers. Furthermore, the resin may be a polymer alloy or the like that combines these. Resins that are soluble in solvents can be used.

[0022] The polyester resin is formed by copolymerizing a dicarboxylic acid component and a diol component. The polyester resin may also be a block copolymer of a polyester with a polyether, polyurethane, or the like. Examples of dicarboxylic acid components include terephthalic acid, isophthalic acid, adipic acid, and sepacic acid, which may be used alone or in combination of two or more. Examples of diol components include ethylene glycol, 1,3-butanediol, 1,4-butanediol, propylene diol, hexanediol, diethylene glycol, and neopentyl glycol, which may be used alone or in combination of two or more. The resin is preferably a polyester resin or a polyolefin resin, and more preferably a polyester resin.

[0023] A crosslinking agent can be used for these resins. Examples of crosslinking agents that can be used include isocyanate compounds, epoxy compounds, carbodiimide compounds, phenolic resins, and alkylated melamine resins, but isocyanate compounds are preferred. Examples of isocyanate compounds that can be used include aromatic compounds such as tolylene diisocyanate and 4,4'-diphenylmethane diisocyanate, aliphatic compounds such as xylylene diisocyanate, and monomers such as hexamethylene diisocyanate and isophorone diisocyanate modified into trimers, biuret compounds, or trimethylolpropane adducts. Isocyanate compounds in which the isocyanate group is blocked with methanol, phenol, ethyl acetoacetate, ε-caprolactam, or the like can also be used. The above compounds may be used alone or in combination as the crosslinking agent.

[0024] (2) Phosphorus-based flame retardants The flame-retardant coating layer 14 of the present invention contains a phosphorus-based flame retardant. R and the mass of the phosphorus-based flame retardant W F1 Ratio to (W F1 / W R ) must be 1.5 or more. F1 / W R) is 1.5 or more, the desired flame retardancy can be obtained. F1 / W R ) is preferably 7.0 or less, more preferably 5.0 or less. The reason for this is explained below. In the present invention, the phosphorus-based flame retardant is a powdery substance with a particle size (D50) of 0.5 to 50 μm. Therefore, if a large amount of powdery phosphorus-based flame retardant is added to the resin, much of the resin will adhere to the surface of the phosphorus-based flame retardant, significantly reducing the ability of the phosphorus-based flame retardant to bind to itself and to the fiber layer. As a result, the adhesion between the fiber layer 12 and the flame-retardant coating layer 14 will be reduced, and the flame-retardant coating layer 14 may fall off from the fiber layer 12. Here, D50 indicates particle size, and is the particle size (median size) at which the cumulative distribution value of a particle size distribution, calculated by dividing the particle size distribution into the proportions of particles of each size obtained from measurements of multiple particles, reaches 50%.

[0025] Examples of phosphorus-based flame retardants that can be used include polyphosphates, phosphate esters, melamine phosphate, metal phosphinates, phosphoric acid amide compounds, and phosphazene compounds. Phosphorus-based flame retardants generate strong acids such as polyphosphoric acid and polymetaphosphoric acid through an oxidation reaction of phosphorus during combustion. These strong acids are carbonized during combustion, forming a barrier layer (carbonized coating). Because this barrier layer blocks heat and oxygen, phosphorus-based flame retardants exhibit excellent flame retardancy. Furthermore, because the acids exhibit a radical trapping effect in the gas phase, phosphorus-based flame retardants exhibit excellent flame retardancy.

[0026] From the viewpoint of a balance between cost, flame retardancy, and moldability, it is preferable to use ammonium polyphosphate as the phosphorus-based flame retardant. Ammonium polyphosphate forms a porous, foamed carbonized layer upon combustion. This foamed carbonized layer functions as a heat insulating layer, so ammonium polyphosphate exhibits excellent flame retardancy.

[0027] (3) Metal compounds The flame-retardant coating layer 14 of the present invention contains a metal compound. F1 and the mass of the metal compound W F2 and the ratio (W F2 / W F1 ) is preferably 0.01 or more. F2 / W F1 By making the mass W of the resin 0.01 or more, it is possible to obtain the desired low smoke generation while maintaining excellent flame retardancy. R and the mass W of the phosphorus-based flame retardant F1 and the mass of the metal compound W F2 The ratio of the sum of [(W F1 +W F2 ) / W R ] is preferably 10.0 or less, more preferably 7.0 or less. The reason for this is explained below. In the present invention, the metal compound is a powder having a particle size (D50) of 0.1 to 50 μm. Therefore, if a large amount of powdery metal compound is added to the resin, much of the resin will adhere to the surface of the metal compound, significantly reducing the ability to bind the metal compounds together and the metal compound to the fiber layer. As a result, the adhesion between the fiber layer 12 and the flame-retardant coating layer 14 will decrease, and there is a risk that the flame-retardant coating layer 14 will fall off from the fiber layer 12. Here, D50 indicates particle size, and is the particle size (median size) at which the cumulative distribution value of a particle size distribution, calculated by dividing the results of multiple measurements into a particle size distribution and expressing the proportion of particles with each size, is 50%.

[0028] The metal compound is composed of one or both of a metal oxide and a metal hydroxide. The metal oxide is not particularly limited, but is preferably at least one selected from silicon oxide, magnesium oxide, aluminum oxide, zinc oxide, magnesium hydroxide, and aluminum hydroxide.

[0029] Some metal compounds have the effect of acting as acid acceptors. They are thought to be able to suppress smoke generation by accepting acidic gases such as phosphine gas that are generated during combustion.

[0030] Among metal compounds, metal oxides have a melting point of 1500 to 3000°C, which is higher than the melting points of metals and metal hydroxides. Therefore, even when the temperature rises due to combustion, the presence of metal oxides in the flame-retardant coating layer 14 provides flame retardancy. Furthermore, when the metal oxides melt to form a layer, they also provide flame retardancy by blocking oxygen, and they also suppress smoke generation. Furthermore, when metal hydroxides are burned, they produce metal oxide and water. The water molecules then dilute flammable gases. Therefore, metal hydroxides provide flame retardancy and suppress smoke generation.

[0031] (4) Other In addition to the compositions (1) to (3) above, the flame-retardant coating layer 14 of the present invention may further contain a curing agent, if necessary. The curing agent may be contained in an amount that does not impair the effects of the phosphorus-based flame retardant and the metal compound, and the mass W of the resin R The mass ratio of the curing agent to the resin is preferably 0.5 or less. For example, when the resin has a hydroxyl group, where the hydroxyl group equivalent is represented by OH and the isocyanate group equivalent is represented by NCO, the NCO / OH ratio is preferably 1 or more, and more preferably 2 or 5 or more.

[0032] The flame-retardant coating layer 14 of the present invention may further contain additives such as a flame retardant aid, a heat stabilizer, an antioxidant, a lubricant, etc. One of these may be contained alone, or two or more may be contained in combination. These additives may be contained within a range that does not impair the effects of the phosphorus-based flame retardant and the metal compound, and the amount of the additives contained in the resin mass W R The mass ratio of the additive to the total mass is preferably 0.05 or less.

[0033] In the present invention, the mass W of the resin R , mass W of phosphorus-based flame retardant F1 , and the mass of the metal compound W F2 are the mass of the resin, the mass of the phosphorus-based flame retardant, and the mass of the metal compound added to the medium when producing the sheet according to the present invention, respectively.

[0034] Resin mass W R , mass W of phosphorus-based flame retardant F1, and the mass of the metal compound W F2 The mass of the resin, W, can also be determined as follows: The flame-retardant coating layer 14 is dissolved in an appropriate solvent, and then repeatedly filtered through an appropriate type of filter membrane or filter paper. The filtrate is dried and the mass of the resulting material is measured to determine the mass of the resin, W. R The filtrate is then dried and the resulting substance is analyzed using an infrared spectrophotometer, a Raman spectrophotometer, and a pyrolysis gas chromatograph mass spectrometer. The type of resin can then be identified by comprehensively assessing the analytical results.

[0035] Meanwhile, the powder remaining on the filter membrane or filter paper is analyzed using an X-ray fluorescence analyzer to identify the elements contained therein. The type of phosphorus-based flame retardant in the powder can be identified by comprehensively analyzing the results of an infrared spectrophotometer, a Raman spectrophotometer, and a pyrolysis gas chromatograph mass spectrometer. Furthermore, the type of metal compound in the powder can be identified by analyzing the same powder using a powder X-ray diffractometer. Furthermore, the elemental ratios of the flame-retardant coating layer 14 can be examined using an electron probe microanalyzer and an electron microscope equipped with energy-dispersive X-ray fluorescence analysis or wavelength-dispersive X-ray fluorescence analysis. The masses of the phosphorus-based flame retardant and the metal compounds can be calculated from the molecular structures of the phosphorus-based flame retardant and the metal compounds identified as described above.

[0036] (Thickness of flame-retardant coating layer) The thickness of the flame-retardant coating layer 14 is preferably 20 μm or more, and more preferably 40 μm or more. By making the thickness of the flame-retardant coating layer 14 20 μm or more, the sheet 10 of the present invention can achieve the desired flame retardancy and low smoke generation. On the other hand, the thickness of the flame-retardant coating layer 14 is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 120 μm or less. If the thickness of the flame-retardant coating layer 14 is too thick, the adhesion between the fiber layer 12 and the flame-retardant coating layer 14 will decrease, and there is a risk that the flame-retardant coating layer 14 will fall off from the fiber layer 12.

[0037] The thickness of the flame-retardant coating layer 14 is measured as follows. First, the thickness of the sheet 10 is measured using a high-precision thickness gauge (minimum graduation 0.001 mm). Next, if the flame-retardant coating layer 14 and adhesive layer are provided, the adhesive layer is dissolved with a suitable solvent. If any is stuck, it is scraped off with a metal medicine spoon or spatula, and the thickness of the remaining fiber layer 12 is measured using a high-precision thickness gauge (minimum graduation 0.001 mm). The thickness of the flame-retardant coating layer 14 is then obtained by subtracting the thickness of the fiber layer 12 from the thickness of the sheet 10.

[0038] (fiber layer) The fiber layer 12 includes paper and nonwoven fabric. The type of material used for the fiber layer 12 is not particularly limited. For example, paper made of chemical fiber, glass fiber, or natural fiber can be used for the fiber layer 12. Alternatively, nonwoven fabric made of these fibers chemically or physically laminated without being woven can also be used for the fiber layer 12. It is preferable to use insulating paper for the fiber layer 12 to ensure electrical insulation from the cable of the electronic device. An example of insulating paper is paper made of Manila hemp.

[0039] In particular, it is preferable to use a cellulose nonwoven fabric for the fiber layer 12, and to employ a phosphorus-based flame retardant containing phosphorus and nitrogen as its constituent components, a so-called intumescent flame retardant. When the flame-retardant coating layer 14 is formed on the cellulose nonwoven fabric, the phosphorus-based flame retardant in the flame-retardant coating layer 14 tends to foam during combustion, forming an expanded char layer. As a result, it is easy to achieve insulation and oxygen blocking effects for flammable materials that make up the cables used in electronic devices, industrial equipment, buildings, and outdoor areas surrounding buildings.

[0040] The fiber layer may be composed of a single layer or multiple layers. The configuration of the fiber layer in the case of multiple layers will be explained using FIG. 2. FIG. 2 is a schematic cross-sectional view in the thickness direction of a sheet 10a according to the present invention. As shown in FIG. 2, the sheet 10a according to the present invention comprises a fiber layer 13 including a first layer 13a and a second layer 13b, and a flame-retardant coating layer 14 provided on one surface of the first layer 13a of the fiber layer 13. An adhesive layer may be provided on the other surface 17 of the second layer 13b of the fiber layer 13.

[0041] The same materials as above can be used for the first layer 13a of the fiber layer 13. It is preferable to use rayon paper for the second layer 13b of the fiber layer 13. By providing the second layer 13b in addition to the first layer 13a of the fiber layer 13, the voids in the rayon paper act as a heat insulating layer, further improving flame retardancy.

[0042] (Method of producing coating liquid) The coating solution for producing the sheet according to the present invention can be prepared by dispersing a resin, a phosphorus-based flame retardant, a metal compound, a curing agent, and additives (hereinafter, the solid materials dispersed in the organic solvent are collectively referred to as "filler") in a medium (liquid medium) primarily composed of a known organic solvent, according to a conventionally known method. To disperse the filler, for example, a disperser mixer, a planetary mixer, a three-roll mixer, ultrasonic dispersion, an emulsifier such as a bead mill, a ball mill, or a homomixer, or a high-pressure homogenizer can be used. Among these, a bead mill is preferred for breaking down filler agglomerates and dispersing the filler to an optimal particle size for achieving flame retardancy and low smoke generation.

[0043] Here, examples of the organic solvent that can be used include known solvents such as ester-based solvents such as ethyl acetate (EA), n-propyl acetate (NPAC), isopropyl acetate, isobutyl acetate, propylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; alcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol (IPA), n-butanol, propylene glycol monoethyl ether, and propylene glycol monomethyl ether; ketone-based solvents such as methyl ethyl ketone (MEK) and methyl isobutyl ketone; and hydrocarbon-based solvents such as methylcyclohexane (MCH), ethylcyclohexane, and toluene.

[0044] Here, the resin, phosphorus-based flame retardant, metal compound, curing agent, and additives to be dispersed in the organic solvent are preferably mixed in the proportions described above in (1) to (4).

[0045] (Sheet manufacturing method) The above-described coating solution is uniformly applied to one surface of the material to be used for the fiber layer. The material to which the coating solution has been applied is then placed in a dryer at 70 to 90°C to volatilize the organic solvent in the coating solution and dry the coating solution to form a flame-retardant coating layer 14. The fiber layer 12 on which the flame-retardant coating layer 14 has been formed is stored in a thermostatic chamber at 40°C for three days to harden the resin. A known adhesive layer may then be provided on the other surface 16 of the fiber layer 12.

[0046] When the fiber layer 13 is composed of a first layer 13a and a second layer 13b, the first layer 13a and the second layer 13b are bonded together by a known method, and then the flame-retardant coating layer 14 is provided on the first layer 13a of the fiber layer 13. Alternatively, after the flame-retardant coating layer 14 is provided on the first layer 13a of the fiber layer 13 by the above-mentioned method, the second layer 13b may be bonded to the other surface 17 of the first layer 13a of the fiber layer 13 by a known method. Then, a known adhesive layer may be provided on the other surface 17 of the fiber layer 13.

[0047] (Flame-retardant tape) The sheet 10 or sheet 10a described above may be formed into a tape shape, which makes it easier to wrap around and attach to cables of electronic devices and the like.

[0048] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples. [Example]

[0049] Using toluene as an organic solvent, slurries were prepared by stirring and dispersing the substances of the types and masses shown in Tables 1 to 3 using a propeller blade and a bead mill. The amount of each substance added in Tables 1 to 3 refers to the mass of each substance when the mass of the polyester resin or ethylene vinyl acetate copolymer is taken as 100.

[0050] In film configuration 1 in Tables 1 to 3, insulating paper (29 g / m 2 ) was coated with an adhesive solution on one side and dried in a dryer at 80°C. Then, a rayon paper (12 g / m 2 ) are pasted together and stored in a thermostatic chamber at 40°C for 3 days to harden the adhesive resin (polyester polyurethane resin). 2 The above slurry was applied to one side of the insulating paper (29 g / m), which was then dried in a dryer at 80°C and stored in a thermostatic chamber at 40°C for 3 days to harden the resin in the slurry. 2 The slurry was applied to the substrate, dried in a dryer at 80°C, and then stored in a thermostatic chamber at 40°C for 3 days to harden the resin in the slurry. Isocyanate was used as the crosslinking agent.

[0051] For film configuration 3, the above slurry was applied to polyethylene terephthalate (PET) (thickness: 25 μm), dried in a dryer at 80°C, and stored in a thermostatic chamber at 40°C for 3 days to harden the resin in the slurry. For film configuration 4, the adhesive solution was applied to one side of PET (thickness: 12 μm), dried in a dryer at 80°C, and then the adhesive solution was applied to rayon paper (12 g / m 2) and store them in a thermostatic chamber at 40°C for 3 days to harden the adhesive resin (polyester polyurethane resin). 2 The slurry was applied to one side of the sheet, dried in a dryer at 80°C, and then stored in a thermostatic chamber at 40°C for 3 days to harden the resin in the slurry. In this way, a 24 cm x 35 cm sheet was produced.

[0052] Here, in Tables 1 to 3, W F1 is the mass of ammonium polyphosphate, W R is the mass of polyester resin or ethylene vinyl acetate copolymer, W F2 is the total mass of magnesium oxide, aluminum oxide, silicon oxide, zinc oxide, magnesium hydroxide, and aluminum hydroxide, and W F1 / W R , W F2 / W F1 , and (W F1 +W F2 ) / W R The value was calculated.

[0053] The ammonium polyphosphate used was Exolit AP462 manufactured by Clariant. The polyester resin used was Aronmelt PES310S30 manufactured by Toagosei Co., Ltd. The ethylene vinyl acetate copolymer used was EVAFLEX 40X manufactured by Mitsui-DuPont Chemical Co., Ltd. The magnesium oxide used was Starmag U or Starmag L manufactured by Konoshima Chemical Co., Ltd. The aluminum oxide used was SA31 or AA101 manufactured by Nippon Light Metal Co., Ltd. The silicon oxide used was Sylysia 530 manufactured by Fuji Silysia Chemical Ltd. or Nipsil manufactured by Tosoh Corporation. The zinc oxide used was two types of zinc oxide manufactured by Hakusui Tech. The magnesium hydroxide used was Kisuma 5A or Kisuma 8SN manufactured by Kyowa Chemical Industry Co., Ltd. The aluminum hydroxide used was BF-013S manufactured by Nippon Light Metal Co., Ltd. The isocyanate used was Takenate A-65 manufactured by Mitsui Chemicals, Inc.

[0054] <Test specimen and thickness of flame-retardant coating layer> The thickness of the flame-retardant coating layer was measured as follows. First, the thickness of the test specimen was measured using a high-precision thickness gauge (minimum division 0.001 mm). Next, the flame-retardant coating layer was dissolved in toluene, and if any was remaining, it was scraped off using a metal spoon or spatula, and the thickness of the remaining fiber layer was measured using a high-precision thickness gauge (minimum division 0.001 mm). The thickness of the fiber layer was then subtracted from the thickness of the test specimen to obtain the thickness of the flame-retardant coating layer.

[0055] <Flexibility> The test specimen was cut to a width of 2 cm and a length of 10 cm. If it could be wrapped around a φ2 mm rod so that half the width of the test specimen overlapped, it was marked as ○; if it could not be wrapped, it was marked as △.

[0056] <Limiting oxygen index> The limiting oxygen index was measured using the following method. A test specimen was cut to a width of 2 cm and a length of 10 cm, wrapped around a φ2 mm rod so that half the width of the specimen overlapped, and burned in a combustion tester under each oxygen index condition to measure the limiting oxygen index (LOI). An LOI of 48 or higher was marked △, an LOI of 54 or higher was marked ○, and an LOI of 65 or higher was marked ◎. On the other hand, an LOI of less than 48 was marked ×.

[0057] In test No. 49, since it was not possible to wrap the specimen around a φ2 mm rod so that half of its width overlapped, the specimen was wrapped around a φ6 mm rod so that half of its width overlapped, and the LOI was measured.

[0058] <Smoke generation test> The smoke generation test was carried out as follows: A 76 mm square sheet sample was placed in the chamber (box) of the NBS smoke generation test device and heated with an electric wire heater (heater heat output 25 kW / m 2) was evaluated using the non-Fleming method, which does not use a pilot burner. Specifically, the amount of smoke generated was evaluated by measuring the light transmittance of the space blocked by the smoke generated after 20 minutes of heating. A light transmittance of 43.0% or higher was evaluated as △, a light transmittance of 44.0% or higher was evaluated as ○, and a light transmittance of 60.0% or higher was evaluated as ◎. On the other hand, a light transmittance of less than 43.0% was evaluated as ×.

[0059] These results are shown in Tables 1 to 3. In Tables 1 to 3, the underlined values indicate values outside the range specified in the present invention.

[0060] [Table 1]

[0061] [Table 2]

[0062] [Table 3]

[0063] As shown in Tables 1 to 3, the examples of the present invention that fulfill all the requirements of claim 1 of the present invention were given the results of ○ or ⊚ in both the limiting oxygen index and smoke generation tests. On the other hand, test specimens No. 8 and 58 did not contain any metal compounds, so they were given the results of × in low smoke generation. Test specimens Nos. 9 to 16 and 21 did not contain ammonium polyphosphate, so they were given the results of × in flame retardancy. Test specimens Nos. 22 and 23 were given the results of × in W F1 / W R Since the value was below 1.5, the flame retardancy was rated as x. [Industrial Applicability]

[0064] According to the present invention, a sheet and tape having excellent flame retardancy and low smoke generation can be obtained. [Explanation of symbols]

[0065] 10, 10a sheets 12, 13 Fiber layer 13a First layer of the fiber layer 13 13b Second layer of fiber layer 13 14 Flame-retardant coating layer 16 Other surface of fiber layer 12 17 the other surface of the second layer 13b of the fiber layer 13

Claims

1. A fiber layer; a flame-retardant coating layer provided on the surface of the fiber layer, the flame-retardant coating layer contains a resin, a phosphorus-based flame retardant, and a metal compound composed of a metal oxide and / or a metal hydroxide, The mass W of the resin Ｒ and the mass W of the phosphorus-based flame retardant Ｆ１ Ratio to (W Ｆ１ / W Ｒ ) is 1.5 or more; Sheet.

2. The mass W of the phosphorus-based flame retardant Ｆ１ and the mass W of the metal compound Ｆ２ and the ratio (W Ｆ２ / W Ｆ１ ) is 0.01 or more, The sheet according to claim 1.

3. The mass W of the resin Ｒ and the mass W of the phosphorus-based flame retardant Ｆ１ and the mass W of the metal compound Ｆ２ The ratio of the sum of [(W Ｆ１ +W Ｆ２ ) / W Ｒ ] is 10.0 or less, The sheet according to claim 2.

4. the metal compound is at least one selected from silicon oxide, magnesium oxide, aluminum oxide, zinc oxide, magnesium hydroxide, and aluminum hydroxide; The sheet according to claim 1.

5. the fiber layer is composed of a first layer and a second layer, The flame-retardant coating layer is provided on one surface of the first layer, and the second layer is provided on the other surface of the first layer. The sheet according to claim 1.

6. A sheet according to any one of claims 1 to 5, tape.

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