JP2019173225A - Nonwoven fabric - Google Patents

Abstract

To provide a nonwoven fabric having excellent low-smoking properties in addition to excellent fire retardancy and smoke insulation.SOLUTION: A nonwoven fabric comprises a non-melting fiber A having a high-temperature shrinkage of 3% or less and a thermoplastic fiber B having an LOI value in accordance with JIS K 7201-2 (2007) of 25 or more, further comprising a smoking inhibitor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-woven fabric having flame retardancy.

  Conventionally, nonwoven fabrics using synthetic fibers made of synthetic polymers such as polyamide, polyester, polyolefin, etc. as fiber materials have been used, but these synthetic polymers usually do not have flame retardancy and are in the raw material stage. Or after making into a fiber or a nonwoven fabric, a certain flame-retardant process is performed in many cases.

  Various methods for obtaining flame retardant nonwoven fabrics have been proposed. For example, a method of spinning a polymer copolymerized with a flame retardant component into a nonwoven fabric, a method of kneading a flame retardant agent into a polymer at the raw yarn stage, spinning it into a nonwoven fabric, and post-processing into a nonwoven fabric For example, a method of attaching components. More specifically, Patent Document 1 discloses a flame retardant fiber sheet obtained by treating a fiber sheet with a binder composed of a phosphoric acid flame retardant and a polyester resin (Patent Document 1). Patent Document 2 also discloses a flame retardant nonwoven fabric obtained by adding a flame retardant binder to a nonwoven fabric including polyphenylene sulfide fibers and polyester fibers.

  In addition, as a method of obtaining a flame-retardant nonwoven fabric, the fiber after spinning is subjected to a specific treatment to impart flame retardancy, and the nonwoven fabric is used, or the fiber raw material itself has flame retardancy There is also a method of spinning it into a non-woven fabric. For example, Patent Document 3 discloses a non-woven fabric including a flameproof fiber and a polyphenylsulfone fiber that have obtained high flame barrier properties by processing after spinning.

JP 2013-169996 A JP 2012-144818 A International Publication No. 2017/6807

However, the methods described in Patent Documents 1 and 2 are the simplest methods for imparting flame retardancy, but the attached flame retardant is easy to drop off, and the flame retardant itself has an excellent flame retarding effect. However, the non-woven fabric described in Patent Document 3 specifically contains flame-resistant fibers and polyphenylsulfone (PPS), and thus has high flame retardancy. Although it has flame barrier properties, PPS has a room for improvement in that it tends to be incompletely burned during combustion and tends to decompose into smoke such as moophenol and phenylene sulfend.

  The present invention has been made in view of the problems of such a conventional flame retardant nonwoven fabric, and provides a nonwoven fabric that is excellent in flame retardancy and flame barrier properties but also in low smoke generation. It is the purpose.

In order to solve the above problems, the present invention employs any of the following means.
(1) A non-melting fiber A having a high temperature shrinkage rate of 3% or less and a thermoplastic fiber B having a LOI value of 25 or more in accordance with JIS K 72021-2 (2007), and a smoke suppression agent A non-woven fabric characterized by comprising:
(2) The smoke suppressant is a phenol compound, a molybdenum compound, a borate compound, magnesium silicate, zinc phosphate, magnesium hydroxide, a tin compound, a silicone compound, a nickel compound, a palladium compound, alumina trihydrate, The nonwoven fabric according to (1), wherein the nonwoven fabric is one or more selected from the group consisting of aluminum hydroxide, ferrocene, fumaric acid, maleic acid and reaction products thereof.
(3) The nonwoven fabric according to (1) or (2), wherein 0.1 to 50 mass% of the smoke suppressant is contained in 100 mass% of the nonwoven fabric.
(4) The nonwoven fabric according to any one of (1) to (3), wherein 10% by mass or more of the thermoplastic fiber A is contained in 100% by mass of the constituent fibers of the nonwoven fabric.
(5) The nonwoven fabric according to any one of (1) to (4), wherein 10% by mass or more of the thermoplastic fiber B is contained in 100% by mass of the constituent fibers of the nonwoven fabric.
(6) The said (1)-(5) which contains fibers C other than the said non-melting fiber A and the said thermoplastic fiber B in 70 mass% or less in 100 mass% of the constituent fibers of the said nonwoven fabric. The nonwoven fabric in any one of.
(7) The nonwoven fabric according to any one of (1) to (6), wherein the non-molten fiber A has a thermal conductivity of 0.060 W / m · K or less.
(8) The non-woven fabric according to any one of (1) to (7), wherein the non-molten fiber A is one or more selected from flameproof fibers and meta-aramid fibers.
(9) The thermoplastic fiber B is a flame retardant polyester, anisotropic molten polyester, flame retardant poly (acrylonitrile butadiene styrene), flame retardant polysulfone, poly (ether-ether-ketone), poly (ether-ketone). -Ketone), polyethersulfone, polyarylate, polyarylene sulfide, polyphenylsulfone, polyetherimide, polyamideimide, phenol, and fibers made of a resin selected from the group consisting of the above (1) to ( The nonwoven fabric according to any one of 8).
(10) The nonwoven fabric according to any one of (1) to (9), wherein the thermoplastic fiber B has a glass transition point of 120 ° C. or lower.

  By providing the above-described configuration, the nonwoven fabric of the present invention is a nonwoven fabric that is excellent in flame retardancy and flame barrier properties but also in low smoke generation.

It is a figure for demonstrating the flame-proof evaluation test method.

  The nonwoven fabric of the present invention includes non-melted fiber A having a high temperature shrinkage rate of 3% or less, and thermoplastic fiber B having a LOI value of 25 or more in accordance with JIS K 72021-2 (2007), and Has a smoke suppressant.

  In the present invention, the non-melted fiber A having a high temperature shrinkage rate of 3% or less constitutes a nonwoven fabric together with the thermoplastic fiber B and the like, but when the flame approaches the nonwoven fabric and heat is applied, the thermoplastic fiber B melts and melts. The thermoplastic fiber B spreads in a thin film along the surface of the non-molten fiber A (aggregate). As the temperature rises, both A and B fibers will eventually carbonize, but the non-melt fiber A has a high temperature shrinkage rate of 3% or less, so it is difficult to shrink even at high temperatures and it is difficult to open holes. Can block the flame. In this respect, it is preferable that the high temperature shrinkage rate is low, but even if it does not shrink, even if it expands greatly due to heat, the structure collapses and causes pores. Therefore, the high temperature shrinkage rate is preferably −5% or more. Especially, it is preferable that a high temperature shrinkage rate is 0 to 2%.

The high-temperature shrinkage rate is as follows: (i) The fiber used as the raw material for the nonwoven fabric is left in a standard state (20 ° C., relative humidity 65%) for 12 hours, and then the tension of 0.1 cN / dtex is applied to obtain the original length L0. And (ii) exposed to a dry heat atmosphere at 290 ° C. for 30 minutes without applying a load to the fiber, sufficiently cooled in a standard state (20 ° C., relative humidity 65%), and then further fiber The length L1 is measured by applying a tension of 0.1 cN / dtex to (iii), and (iii) is a numerical value obtained from the following formula from L0 and L1.
High temperature shrinkage = [(L0−L1) / L0] × 100 (%)

  In the present invention, since the non-woven fabric as described above contains a smoke suppressant, when the non-molten fiber A and the thermoplastic fiber B are carbonized, it is possible to promote complete combustion / vaporization of the non-carbonized fiber constituents, thereby generating smoke. Can be suppressed. Furthermore, when heat is applied to the nonwoven fabric, the smoke suppressant spreads in a thin film shape, so that the carbonized film can be strengthened.

  In the present invention, as the non-molten fiber A, it is preferable to use one having a thermal conductivity of 0.060 W / m · K or less. When the thermal conductivity of the non-molten fiber A is within this range, the heat insulation performance is also excellent.

The thermal conductivity [W / m · K] is a basic thermal constant of a material and is a heat transfer coefficient of the material alone. Expresses the ease of heat transfer in the material, and refers to the value obtained by dividing the heat flow density (heat energy passing through the unit area per unit time) by the temperature difference between the front and back surfaces of the material. Specifically, the thermal conductivity of the fiber is a non-woven fabric test piece having a thickness of 0.5 mm using the fiber to be measured, and the thermal diffusivity of the test piece according to ISO 22007-3 (2008), The specific heat of the test piece is measured according to JIS K 7123 (1987), and the specific gravity of the test piece is further measured according to JIS K 7112 (1999), and based on the measurement results of these thermal diffusivity, specific heat and specific gravity, the specific heat is obtained from the following formula.
Thermal conductivity = thermal diffusivity x specific heat x specific gravity

  In the present invention, the non-molten fiber A refers to a fiber that maintains its fiber shape without being liquefied when exposed to a flame. As the non-melted fiber used in the present invention, any non-melting fiber may be used as long as the high temperature shrinkage rate is within the range defined by the present invention. Specific examples include meta-aramid fiber and flame resistant fiber.

  In general, meta-aramid fibers have a high temperature shrinkage rate and do not satisfy the high temperature shrinkage rate specified in the present invention. However, the meta-aramid fiber has a high temperature shrinkage rate within the range specified by the present invention by suppressing the high temperature shrinkage rate. If it exists, since elasticity is high and the sewing property of a nonwoven fabric can be improved, it can be preferably used. The flame-resistant fiber is a fiber that has been flame-resistant using a fiber selected from acrylonitrile-based, pitch-based, cellulose-based, phenol-based fiber, and the like as a raw material. These may be used alone or in combination of two or more.

  Of these, flame-resistant fibers are preferred from the viewpoint of low high temperature shrinkage, and among various flame-resistant fibers, acrylonitrile-based flame-resistant fibers are preferably used as fibers having a small specific gravity and being flexible and excellent in flame retardancy. Such flame-resistant fibers can be obtained by heating and oxidizing acrylic fibers as precursors in high-temperature air.

  Examples of commercially available non-molten fibers A that can be used in the present invention include flame resistant fiber “PYRON” (registered trademark) manufactured by Zoltek and used in Examples and Comparative Examples described later, and Toho Tenax Co., Ltd. Pyromex. (Pyromex) and the like.

  If the content of the non-melting fiber A in the nonwoven fabric is too low, the function as an aggregate tends to be insufficient, while if too high, the thermoplastic fiber is difficult to spread into a sufficient film shape. The content of A is preferably 10% by mass or more, more preferably in the range of 15 to 60% by mass, and most preferably in the range of 30 to 50% by mass.

  Subsequently, the thermoplastic fiber B that will spread as a film-like substance has a LOI value of 25 or more in accordance with JIS K 72021-2 (2007). The LOI value is a volume percentage of the minimum oxygen amount necessary for sustaining the combustion of a substance in a mixed gas of nitrogen and oxygen, and it can be said that the higher the LOI value, the more difficult it is to burn. Therefore, the thermoplastic fiber B having a LOI value of 25 or more is difficult to burn, even if it is ignited, it immediately extinguishes when the fire source is released, and a carbonized film is usually formed in the part where the fire spreads slightly. The carbonized part prevents the spread of fire.

  The LOI value of the thermoplastic fiber B is preferably 55 or less, and more preferably in the range of 25 to 50 from the viewpoint of carbonizing at a high temperature.

  The thermoplastic fiber B used in the present invention is not particularly limited as long as the LOI value is within the range specified in the present invention. Specific examples thereof include flame retardant polyester (polyethylene terephthalate, polytrimethylene terephthalate, poly Alkylene terephthalate), anisotropic molten polyester, flame retardant poly (acrylonitrile butadiene styrene), flame retardant polysulfone, poly (ether-ether-ketone), poly (ether-ketone-ketone), polyethersulfone, polyarylate And fibers composed of a thermoplastic resin selected from the group of polyarylene sulfide, polyphenylsulfone, polyetherimide, polyamideimide, and mixtures thereof. These may be used alone or in combination of two or more.

  If the glass transition point of the thermoplastic fiber B is 120 ° C. or less, the binder effect for maintaining the form as a nonwoven fabric can be obtained at a relatively low temperature, so the apparent density increases and the strength increases. ,preferable. Among these, polyphenylene sulfide fiber (hereinafter also referred to as PPS fiber) is most preferable from the viewpoint of high LOI value and easy availability. The binder effect means that the thermoplastic fiber is melted or softened by heat and fused to another fiber.

PPS fibers preferably used in the present invention, the polymer constituent units _{- (C 6 H 4 -S)} - which is a synthetic fiber made of a polymer whose main structural unit. Typical examples of these PPS polymers include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. As a particularly preferred PPS polymer, polyphenylene sulfide containing a p-phenylene unit represented by — (C ₆ H ₄ —S) —, preferably 90 mol% or more, as the main structural unit of the polymer is desirable. From the viewpoint of mass, polyphenylene sulfide containing 80% by mass, more preferably 90% by mass or more of p-phenylene units is desirable.

  The PPS fiber is preferably used in the case of obtaining a non-woven fabric by a papermaking method as will be described later. In this case, the fiber length is preferably in the range of 2 to 38 mm, more preferably in the range of 2 to 10 mm. preferable. If the fiber length is in the range of 2 to 38 mm, it can be uniformly dispersed in the stock solution for papermaking, and has a tensile strength necessary for passing through the drying step in a wet state (wet paper) immediately after papermaking. Further, the thickness of the PPS fiber is preferably in the range of 0.1 to 10 dtex because the fiber can be uniformly dispersed without aggregating in the stock solution for papermaking.

  As a method for producing the PPS fiber, a method in which a polymer having the above-mentioned phenylene sulfide structural unit is melted at a melting point or higher and spun from a spinneret to form a fiber is preferable. The spun fiber is an unstretched PPS fiber as it is. Most of the unstretched PPS fibers have an amorphous structure and can act as a binder for bonding the fibers to each other by applying heat. On the other hand, since such fibers have poor dimensional stability due to heat, stretched yarns are commercially available in which the fiber is stretched and oriented following spinning to improve the strength and thermal dimensional stability of the fibers. Specifically, “Torcon” (registered trademark) (manufactured by Toray Industries, Inc.), “Procon” (registered trademark) (manufactured by Toyobo Co., Ltd.), etc. are in circulation. In the present invention, the unstretched PPS fiber and the stretched yarn can be used in combination as long as the object of the invention is achieved. Of course, other types of drawn yarns and undrawn yarns satisfying the scope of the present invention may be used in combination with PPS fibers.

  In addition, the thermoplastic fiber B preferably contains a sulfur atom as a fiber, but in that case, not only a fiber made of a resin containing a sulfur atom but also a fiber in which a sulfur atom is imparted by post-processing is preferable.

  The content of the thermoplastic fiber B as described above in the nonwoven fabric is preferably 10% by mass or more, more preferably 30 to 30% in order to reliably form a film-like substance and to further improve the flame retardancy and flame barrier properties. It is preferable to be within the range of 70% by mass.

  Furthermore, as the thermoplastic fiber B used in the present invention, at least the LOI value is 25 or more, and at the same time, the number of crimps in accordance with JIS L 1015 (2010) is 5 (pieces / 25 mm) or more. It is preferable to use some. The non-molten fiber A is relatively straight and is easy to fall off during processing because it is difficult to crimp. However, by using a thermoplastic fiber B having a crimp number of 5 (pieces / 25 mm) or more as at least a part of the thermoplastic fiber B, it becomes difficult for the fiber to fall off due to the three-dimensional helical structure due to the crimp. That is, by mixing the thermoplastic fibers B as described above, not only the thermoplastic fibers B but also other non-molten fibers A and the like are not easily dropped due to crimping of the thermoplastic fibers B. As a result, the non-woven fabric is excellent in flame retardancy and flame barrier properties due to the coating effect, and also can suppress fiber dropout in the non-woven fabric process, and thus has excellent durability and quality.

  If the number of crimps of the thermoplastic fiber B is too large, it will be difficult to make the fibers homogeneous in the nonwoven fabric, and the mechanical strength of the nonwoven fabric may be reduced. Therefore, the number of crimps is 50 (pieces / 25 mm). It is preferable that Furthermore, 10-40 (pieces / 25 mm) is more preferable, and 10-35 (pieces / 25 mm) is more preferable from the viewpoint of crimp processability and suppression of fiber dropout in the nonwoven fabric manufacturing process.

  Further, in the present invention, fibers C other than the non-molten fibers A and the thermoplastic fibers B may be contained. For example, it is also preferable to mix a fiber having a LOI value of less than 25 and being crimped as the fiber C without using the thermoplastic fiber B having the above-mentioned crimp number. In this case, the number of crimps of the fibers C is preferably 5 to 80 (pieces / 25 mm).

  Examples of the fiber C include phenol fiber, thermoplastic cellulose fiber, acrylic fiber, nylon fiber, and polyester fiber (polyethylene terephthalate fiber, polytrimethylene terephthalate fiber, and the like). These may be used alone or in combination of two or more. Most preferred are phenol fiber and polyethylene terephthalate fiber in terms of smoke suppression and availability.

  70 mass% or less is preferable with respect to 100 mass% of constituent fibers of the said nonwoven fabric, and, as for the preferable content rate of the fiber C in a nonwoven fabric, More preferably, it is the range of 30-60 mass%. In addition, 100 mass% of the constituent fibers of the nonwoven fabric means that the total mass of fibers used in the nonwoven fabric is 100%.

  The non-melt fiber A, the thermoplastic fiber B, and the fiber C as described above are formed in a web in which they are mixed, and, for example, the thermoplastic fiber B and the fiber C are heated to give the thermoplastic fiber. B and fiber C are fused and integrated with non-molten fiber A to form a nonwoven fabric. In fusing, the thermoplastic fiber B and fiber C are softened by a method of applying heat exceeding the glass transition point of the thermoplastic fiber B and fiber C, and pressure is applied to the non-melt fiber A and heat. The plastic fiber B and the fiber C may be pressure-bonded. By carrying out like this, the higher binder effect can be acquired and it is preferable.

  As a method for forming the web, any method such as a dry method or a wet method may be used, but a dry method is preferable for uniformly dispersing various fibers, and different types of fibers are bonded in an intertwined state. preferable. Therefore, it is preferable that the non-molten fiber A, the thermoplastic fiber B, and the fiber C are each cut to a length of, for example, 2 to 10 mm and entangled with each other. As the fiber bonding method, a thermal bond method, a needle punch method, a hydroentanglement method, and the like are all applied, but it is more preferable to apply the hydroentanglement method in order to increase the density of the nonwoven fabric. Further, the non-melt fiber A may be formed into a web and the thermoplastic fiber B or fiber C may be laminated by a spunbond method or a melt blow method.

  In order to increase the process passability by the thermal bond method and the strength of the nonwoven fabric, it is also preferable that a part of the thermoplastic fiber B or fiber C is a fiber having a low crystallinity such as an undrawn yarn. Specifically, since fibers of the same material have better compatibility and are firmly bonded to each other, for example, as described above, a PPS fiber stretched as the thermoplastic fiber B and an unstretched PPS fiber are used. It is preferable to construct the nonwoven fabric by strengthening the binder effect by fusing. The mass ratio of stretched PPS fibers to unstretched PPS fibers is preferably 3: 1 to 1: 3, more preferably 1 to 1.

  The nonwoven fabric of this invention comprised with the above fibers has a smoke suppression agent. Since the non-woven fabric as described above contains a smoke suppressant, complete combustion of the fiber constituents is promoted during combustion, smoke generation is suppressed, and the carbonized film is strengthened.

  Examples of the smoke suppressant include phenol compounds, molybdenum compounds, borate compounds, magnesium silicate, zinc phosphate, magnesium hydroxide, tin compounds, silicone compounds, nickel compounds, palladium compounds, alumina trihydrate, water Examples thereof include aluminum oxide, ferrocene, fumaric acid, maleic acid and reaction products thereof, and one or more selected from such groups can be preferably used. Examples of the molybdenum compound include ammonium dimolybdate, ammonium molybdate, molybdenum trioxide, calcium zinc molybdate compound, and zinc molybdate compound. Examples of the borate compound include zinc borate, calcium borate, and aluminum borate. Examples of the silicone compound include silicone acrylic compounds.

  Among the above smoke suppressants, phenol compounds, borate compounds, and silicone acrylic compounds are particularly preferable, but such smoke suppressants are 0.1 to 50% by mass, more preferably 0.1 to 40% in 100% by mass of the nonwoven fabric. It is preferable to contain in the range of mass%. Without affecting the formation of the carbonized film of the non-molten fiber A and the thermoplastic fiber B, it is possible to selectively promote the decomposition of the fiber constituent components that do not become the carbonized film, and as a result, it is possible to further suppress smoke generation. Furthermore, the silicone acrylic compound becomes a glass film upon combustion, and has an effect of strengthening the carbonized film. In addition, 100 mass% of nonwoven fabric means that the mass of the nonwoven fabric finally obtained including a smoke suppression agent etc. shall be 100%.

  Some smoke suppressants can take the form of fibers. Specifically, for example, the phenol compound may be a phenol fiber. In the case where the fibrous smoke suppressant can also correspond to any of the fibers A to C, the content is handled as each content. For example, when the phenol compound is a fiber having a length of 5 mm and a crimp number of 15/25 mm, it functions as a smoke suppressant and also functions as a fiber C. Therefore, fiber A 20 g, thermoplastic fiber B 20 g, phenol fiber If the composition is 10 g, the content of the fiber C is 20% by mass, and the content of the smoke suppressant is 20% by mass.

  The smoke generation inhibitor may be applied by any method, may be applied later to the web composed of the above-mentioned fibers, may be applied to the fibers before constituting the web, and further May be kneaded into the fiber itself. As a specific method to be applied after the web formation, for example, the nonwoven fabric is dipped in a desired concentration of smoke suppressant treatment solution and then squeezed with mangles, or applied to the nonwoven fabric by spraying, roll coating, knife coating, etc. An example is a method of drying after coating. In addition, when the web is formed by a wet method, a smoke suppression process including a binder in water can be added.

The nonwoven fabric of the present invention includes what is called paper, but the density is preferably 50 kg / m ³ or less. A nonwoven fabric having such a density has a lower thermal conductivity and an excellent heat insulating performance. To express the light and excellent thermal insulation performance, density is more preferably from 50~30kg / ^{m 3,} more preferably a 50~40kg / ^{m 3.}

The basis weight is preferably 50 g / m ² or more, and more preferably 100 g / m ² or more in order to further improve the flame shielding performance.

<Flame resistance test>
The test was conducted according to 8.1.1 A-1 method (45 ° micro burner method) of JIS L 1091 (flammability test method for textile products, 1999). That is, after flame time after heating for 1 minute (less than 3 seconds), afterglow time (5 seconds or less), a combustion area (30 cm ² or less), burn length of (20 cm or less) was measured, then Chakuen 3 seconds after flame time (3 seconds or less) in, afterglow time (5 seconds or less), measured combustion area (30 cm ² or less), and partitioned. If these values are in (parentheses), it corresponds to the “category 3” of the evaluation category according to JIS L 1091, and it was judged that it was combustible.

<Evaluation of flame barrier properties>
Ignition was performed by a method according to JIS L 1091 (Flameability test method for textile products, 1999) according to 8.1.1 A-1 method (45 ° micro burner method), and the flame shielding property was evaluated as follows. That is, as shown in FIG. 1, a micro burner 1 having a flame length L of 45 mm is set up in a vertical direction, and a specimen 2 is arranged at an angle of 45 degrees with respect to a horizontal plane. Flameproofness was evaluated in a test in which the combustor 4 was placed through a spacer 3 having a thickness of 2 mm and burned. For the combustible 4, qualitative filter paper grade 2 (1002) sold by GE Healthcare Japan Co., Ltd., which was left in the standard state for 24 hours in advance to make the moisture content uniform, ignites the micro burner 1. The time until the combustor 4 was ignited was measured in seconds. This measurement was performed 3 times and the average value was adopted.

  When the combustion body 4 ignited within 3 minutes of flame contact, “no flame shielding” was indicated and indicated as “x”. If the combustion body 4 does not ignite even after being exposed to flame for 3 minutes or longer, it is said that “there is flameproof performance”, but the longer the flameproof time, the better. Indicated as ◎.

《Smokeability evaluation》
Smoke particles measured according to JIS C 60695-6.1 6.1, smoke specific attenuation area σ _r (m ² / g), that is, per unit mass reduction Δm (g) of the combustion material The total area (m ² ) of the shadow projected by. The measurement was performed 3 times and the average value was adopted.

《Weight weight》
JIS L 1096 was measured in accordance with 8.3 (A method) of (2010), expressed in 1 m ² per mass (g / ^{m 2).} The measurement was performed twice and the average value was adopted.

"thickness"
It was measured according to JIS L 1913 (2010) 6.1.3 (Method C). The measurement was performed 10 times and the average value was adopted.

《Glass transition point》
The glass transition point was measured three times according to JIS K 7121 (2012), and the average value was adopted.

<< crimp number >>
Measured according to JIS L 1015 (2010) 8.12.1. The measurement was performed 20 times and the average value was adopted.

<Used fiber>
<Non-melting fiber A-1>
1.7 dtex Zoltek flameproof fiber “PYRON” (registered trademark), length 6 mm, high temperature shrinkage 1.6%, thermal conductivity 0.033 W / m · K
<Non-melting fiber A-2>
1.67 dtex meta-aramid fiber, length 6 mm, high temperature shrinkage 2.8%, thermal conductivity 0.055 W / m · K
<Thermoplastic fiber B-1>
PPS fiber (containing 35% by mass of unstretched PPS fiber in 100% by mass of PPS fiber), length 5.1 mm, LOI value 34, glass transition temperature 90 ° C., crimp number 7 (pieces / 25 mm)
<Thermoplastic fiber B-2>
PPS fiber (contains 40% by mass of PPS fiber in 100% by mass of PPS fiber), length 5.1 mm, LOI value 34, glass transition temperature 90 ° C., crimp number 7 (pieces / 25 mm)
<Other fibers B-3>
PPS fiber (containing 100% by mass of PPS fiber and 35% by mass of undrawn PPS yarn), length 5.1 mm, LOI value 34, glass transition temperature 90 ° C., crimp number 0 (pieces / 25 mm)
<Other fibers C-1>
PET fiber (containing 35% by mass of PET unstretched yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68 ° C., crimp number 15 (pieces / 25 mm)
<Other fibers C-2>
Rayon fiber, length 5.1 mm, LOI value 20, crimp number 13 (pieces / 25 mm).

[Example 1]
Non-melt fiber A-1 and thermoplastic fiber B-1 were blended so that the mass ratio was 4 to 6, and opened with a card machine to form a fiber web (weight per unit: 98 g / m ² ). By causing the needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were entangled to form a fiber web having flameproof fibers and PPS fibers in the same layer. Subsequently, the fiber web was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flameproof fiber and the PPS fiber constituting the fiber web were fused to form a fusion-integrated fiber web. The fusion-integrated fiber web was washed with warm water at a temperature of 70 ° C. for 6 seconds and then naturally dried to obtain a nonwoven fabric substrate from which the oil was removed. The mass of the nonwoven fabric substrate was 98 mass% with respect to the raw cotton mass. A mixture of a silicone acrylic compound and magnesium hydroxide was sprayed onto the nonwoven fabric substrate to obtain a nonwoven fabric.

The obtained nonwoven fabric had a weight per unit area of 100 g / m ² and a density of 50 kg / m ³ , and was dense and soft, but had sufficient elasticity. As a result of the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 6 cm ² , and the combustion length was 7 cm. In addition, the nonwoven fabric did not break or perforate even when bent at 90 ° or more, and had excellent bending workability. Furthermore, in the flame barrier evaluation, the combustion body did not ignite for 30 minutes and had sufficient flame barrier properties. Furthermore, the specific light reduction area of the smoke was 0.02 (m ² / g).

[Example 2]
Unmelted fiber A-2 and thermoplastic fiber B-2 were mixed so that the mass ratio was 4 to 6, and opened by a card machine to form a fiber web (weight per unit: 98 g / m ² ). . By causing the needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were entangled to form an integrated fiber web having metaaramid fiber and PPS fiber in the same layer. Subsequently, the integrated fiber web was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the meta-aramid fiber and the PPS fiber constituting the fiber web nonwoven fabric were fused to form a fused integral fiber web. The fusion-integrated fiber web was washed with warm water at a temperature of 70 ° C. for 6 seconds and then naturally dried to obtain a nonwoven fabric substrate from which the oil was removed. The mass of the nonwoven fabric substrate was 98 mass% with respect to the raw cotton mass. A mixture of a silicone acrylic compound and aluminum hydroxide was sprayed onto the nonwoven fabric substrate to obtain a nonwoven fabric.

The obtained nonwoven fabric had a basis weight of 101 g / m ² and a density of 49 kg / m ³ , and was dense and soft, but also provided sufficient elasticity. As a result of the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 7 cm ² , and the combustion length was 7 cm. In addition, the nonwoven fabric did not break or perforate even when bent at 90 ° or more, and had excellent bending workability. Furthermore, in the flameproof evaluation, the combustion body did not ignite for 29 minutes and had a sufficient flameproofness. Furthermore, the specific light reduction area of the smoke was 0.02 (m ² / g).

[Example 3]
The non-molten fiber A-2, the thermoplastic fiber B-1, and the fiber C-1 are sufficiently mixed and dispersed in a dispersion containing a mixture of a silicone acrylic compound and aluminum hydroxide so that the mass ratio is 4 to 2 to 4. after allowed, inclined short paper machine (inclination angle 8 °, machine speed 10 m / min) after papermaking, the heated dried Yankee dryer surface temperature 145 ° C., basis weight 20 g / ^{m 2,} a wet density of 520 kg / ^{m 3} A nonwoven substrate was obtained. Subsequently, it was pressure-bonded under the conditions of a metal roll surface temperature of 200 ° C. and a linear pressure of 200 kg / cm with a calendar processing machine composed of a metal / paper roller to obtain a wet nonwoven fabric.

The obtained nonwoven fabric had a weight per unit area of 20 g / m ² and a density of 525 kg / m ³ , and was dense and soft, but had sufficient elasticity. As a result of the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 7 cm ² , and the combustion length was 7 cm. In addition, the nonwoven fabric did not break or perforate even when bent at 90 ° or more, and had excellent bending workability. Furthermore, in the flameproof evaluation, the combustor did not ignite for 21 minutes and had a sufficient flameproofness. Furthermore, the specific light reduction area of the smoke was 0.03 (m ² / g).

[Example 4]
Non-melt fiber A-1 and thermoplastic fiber B-3 were mixed so that the mass ratio was 4 to 6, and opened by a card machine to form a fiber web (weight per unit: 100 g / m ² ). By making the needles act on the fiber web at a needle density of 40 / cm ² , the fibers are intertwined, and the flame retardant fiber, the PPS fiber drawn yarn, and the PPS fiber undrawn yarn are integrated in the same layer. A modified fiber web was formed. Subsequently, the integrated fiber web was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fiber and the PPS fiber constituting the fiber web were fused to form a fused integrated fiber web. The fusion-integrated fiber web was washed with warm water at a temperature of 70 ° C. for 6 seconds and then naturally dried to obtain a nonwoven fabric substrate from which the oil was removed. The mass of the nonwoven fabric substrate was 60% by mass with respect to the raw cotton mass. A mixture of a silicone acrylic compound and aluminum hydroxide was sprayed onto the nonwoven fabric substrate to obtain a nonwoven fabric.

The obtained nonwoven fabric had a weight per unit area of 70 g / m ² and a density of 40 kg / m ³ , and was dense and soft, but had sufficient elasticity. As a result of conducting the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 8 cm ² and the combustion length was 9 cm, which was sufficiently flame retardant. In addition, the nonwoven fabric did not break or perforate even when bent at 90 ° or more, and had excellent bending workability. Furthermore, in the flame barrier evaluation, the combustor did not ignite for 27 minutes and had sufficient flame barrier properties. Furthermore, the specific light reduction area of the smoke was 0.03 (m ² / g).

[Comparative Example 1]
Non-melted fiber A-1 and other fibers C-1 and C-2 are mixed so that the mass ratio is 4 to 1: 5, and opened by a card machine to obtain a fiber web (weight per unit: 98 g / m). ² ) was formed. By causing the needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were entangled to form an integrated fiber web having flameproof fibers, polyester fibers and rayon in the same layer. . Subsequently, the integrated fiber web is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fiber, the polyester fiber, and the rayon constituting the fiber web are fused by using the polyester fiber as a binder, A fusion-integrated fiber web was formed. The fusion-integrated fiber web was washed with warm water at a temperature of 70 ° C. for 6 seconds and then naturally dried to obtain a nonwoven fabric substrate from which the oil was removed. The mass of the nonwoven fabric substrate was 98 mass% with respect to the raw cotton mass. A mixture of a silicone acrylic compound and calcium borate was sprayed onto the nonwoven fabric substrate to obtain a nonwoven fabric.

The obtained nonwoven fabric had a weight per unit area of 103 g / m ² and a density of 50 kg / m ³ , and was dense and soft, but had sufficient elasticity. As a result of the combustion resistance test, a hole was opened in the portion directly above the burner in less than 3 seconds by holding the burner over the specimen, and the combustion body itself was ignited and burned. Therefore, it cannot be said that it has sufficient flame retardancy. Moreover, since the test body itself was burned as described above, it can be said that it does not have a flame barrier property without being measured. Furthermore, the specific light reduction area of the smoke was 0.2 (m ² / g).
[Comparative Example 2]
Non-melt fiber A-1 and thermoplastic fiber B-1 were blended so that the mass ratio was 4 to 6, and opened by a card machine to form a fiber web (weight per unit: 95 g / m ² ). By causing the needles to act on the fiber web at a needle density of 40 / cm ² , these fibers were entangled to form an integrated fiber web having flameproof fibers and PPS fibers in the same layer. Subsequently, the integrated fiber web was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fiber and the PPS fiber constituting the fiber web were fused to form a fused integrated fiber web. The fusion-integrated fiber web was washed with warm water at a temperature of 70 ° C. for 6 seconds and then naturally dried to obtain a nonwoven fabric substrate from which the oil was removed. The mass of the nonwoven fabric substrate was 98 mass% with respect to the raw cotton mass.

The obtained non-woven fabric base material had a basis weight of 98 g / m ² and a density of 53 kg / m ³ , and was dense and soft, but had sufficient elasticity. As a result of the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 7 cm ² , and the combustion length was 7 cm. Moreover, the nonwoven fabric base material did not break or perforate even when bent at 90 ° or more, and had excellent bending workability. Furthermore, in the flameproof evaluation, the combustion body did not ignite for 31 minutes and had sufficient flameproofness. However, the specific light reduction area of the smoke was 11 (m ² / g).

  Table 1 summarizes the evaluation results of Examples 1-4 and Comparative Examples 1-2.

  The present invention is effective for preventing the spread of fire and is suitable for use as a wall material, floor material, ceiling material, etc. that require flame retardancy, and is particularly used as a fire blocking material for furniture, bedding, etc. It is suitable for doing.

1 Micro burner 2 Specimen 3 Spacer 4 Combustion body L Flame length
th spacer thickness

Claims (10)

  A non-melting fiber A having a high temperature shrinkage rate of 3% or less and a thermoplastic fiber B having a LOI value of 25 or more in accordance with JIS K 72021-2 (2007), and comprising a smoke suppressant A nonwoven fabric characterized by   The smoke suppressant is a phenol compound, molybdenum compound, borate compound, magnesium silicate, zinc phosphate, magnesium hydroxide, tin compound, silicone compound, nickel compound, panadium compound, alumina trihydrate, aluminum hydroxide The nonwoven fabric of Claim 1 which is 1 or more types selected from the group of ferrocene, ferrocene, fumaric acid, maleic acid, and these reaction products.   The nonwoven fabric according to claim 1 or 2, wherein 0.1 to 50 mass% of the smoke suppressant is contained in 100 mass% of the nonwoven fabric.   The nonwoven fabric according to any one of claims 1 to 3, wherein 10% by mass or more of the thermoplastic fiber A is contained in 100% by mass of the constituent fibers of the nonwoven fabric.   The nonwoven fabric in any one of Claims 1-4 which contains the said thermoplastic fiber B 10 mass% or more in 100 mass% of constituent fibers of the said nonwoven fabric.   6. The fiber according to claim 1, wherein the non-melt fiber A and the fiber C other than the thermoplastic fiber B are contained in a range of 70% by mass or less in 100% by mass of the constituent fibers of the nonwoven fabric. Non-woven fabric.   The said non-melting fiber A is a nonwoven fabric in any one of Claims 1-6 whose heat conductivity is 0.060 W / m * K or less.   The non-woven fabric according to any one of claims 1 to 7, wherein the non-molten fiber A is one or more selected from flameproof fibers and meta-aramid fibers.   The thermoplastic fiber B is a flame retardant polyester, anisotropic molten polyester, flame retardant poly (acrylonitrile butadiene styrene), flame retardant polysulfone, poly (ether-ether-ketone), poly (ether-ketone-ketone). A fiber comprising a resin selected from the group consisting of polyethersulfone, polyarylate, polyarylene sulfide, polyphenylsulfone, polyetherimide, polyamideimide, phenol, and mixtures thereof. The nonwoven fabric described.   The nonwoven fabric in any one of Claims 1-9 whose glass transition point of the said thermoplastic fiber B is 120 degrees C or less.