KR20200126364A - Non-woven - Google Patents

Abstract

In order to provide a nonwoven fabric with excellent flame retardancy, flame retardancy, card penetration, and durability, non-melt fiber A with a high temperature shrinkage of 3% or less, and an LOI value of 25 or more in accordance with JIS K 7201-2 (2007). Non-woven fabric comprising thermoplastic fiber B and thermoplastic fiber C having an LOI value of less than 25 in accordance with JIS K 7201-2 (2007) and a number of crimpings of 8 (pieces/25 mm) or more in compliance with JIS L 1015 (2000) To

Description

Non-woven

The present invention relates to a nonwoven fabric.

Conventionally, nonwoven fabrics made of synthetic fibers made of synthetic polymers such as polyamide, polyester, and polyolefin have been used as fibrous materials, but these synthetic polymers usually do not have flame retardancy, and at the raw material stage or after making fibers or nonwovens In many cases, some kind of flame retardant treatment is performed.

Various methods have been proposed for obtaining a flame-retardant nonwoven fabric. For example, a method of spinning a polymer with a flame retardant component into a nonwoven fabric, a method of spinning a nonwoven fabric by kneading a polymer with flame retardant effect at the yarn stage, and attaching the flame retardant component to the nonwoven fabric by post-processing. Method, etc. More specifically, Patent Document 1 discloses a flame-retardant fiber sheet obtained by treating a fiber sheet with a binder comprising a phosphoric acid-based flame retardant and a polyester-based resin (Patent Document 1). Patent Document 2 also discloses a flame-retardant nonwoven fabric in which a flame-retardant binder is provided to a nonwoven fabric containing polyphenylene sulfide fibers and polyester fibers.

In addition, as a method of obtaining a flame-retardant nonwoven fabric, a specific treatment is given to the fiber after spinning to give it flame retardancy, and there is a method of using it as a nonwoven fabric, or using one having flame retardancy in the raw material of the fiber itself, and spinning it to make a nonwoven fabric. . For example, Patent Document 3 discloses that a nonwoven fabric is formed of flame-retardant fibers obtained by the treatment after spinning, or fibers obtained flame retardancy by polymerizing a specific raw material. Disclosed is a nonwoven fabric comprising a flame-resistant fiber and a polyphenylsulfone fiber obtained with a dye-resistant property.

Japanese Patent Publication No. 2013-169996 Japanese Patent Publication No. 2012-144818 Japanese Patent Publication No. 2003-129362 International Publication No. 2017/6807

However, the method described in Patent Documents 1 and 2 is the simplest method for imparting flame retardancy, but the attached flame retardant is easy to fall off, and even if the flame retardant has an excellent flame retardant action, a problem remains in terms of its durability. will be.

In addition, the nonwoven fabric described in Patent Literature 3 uses flame-resistant fibers having a high limiting oxygen index LOI value, but these fibers tend to fall off when passing through the card machine, and in the end, from the point of flame retardancy and also from the point of processability. The problem remains. In addition, since the nonwoven fabric described in Patent Document 4 contains flame-resistant fibers and polyphenylsulfone (PPS), it is highly flame-retardant and has flame-retardant properties, but this is also room for improvement in terms of card penetration properties of flame-resistant fibers and PPS fibers. There is.

The present invention has been made in view of the problems of such conventional flame-retardant nonwoven fabrics, and an object of the present invention is to provide a nonwoven fabric having excellent flame retardancy and flame retardancy, and excellent card passability and durability.

In order to solve the above problems, the present invention employs any one of the following means.

(1) Non-melt fiber A with a high-temperature shrinkage of 3% or less, thermoplastic fiber B with an LOI value of 25 or more in compliance with JIS K 7201-2 (2007), and LOI in accordance with JIS K 7201-2 (2007) A nonwoven fabric comprising thermoplastic fibers C having a value of less than 25 and having a number of crimps of 8 (pieces/25 mm) or more in conformity with JIS L 1015 (2000).

(2) The nonwoven fabric according to the above (1), wherein 20 to 50% by mass of the thermoplastic fiber C is contained in 100% by mass of the nonwoven fabric.

(3) The nonwoven fabric according to the above (1) or (2), wherein 10% by mass or more of the non-melt fiber A is contained in 100% by mass of the nonwoven fabric.

(4) The nonwoven fabric according to any one of (1) to (3), wherein 20% by mass or more of the thermoplastic fiber B is contained in 100% by mass of the nonwoven fabric.

(5) The non-woven fabric according to any one of (1) to (4) above, wherein the non-melt fiber A has a thermal conductivity of 0.060 W/m·K or less in conformity with ISO22007-3 (2008).

(6) The nonwoven fabric according to any one of (1) to (5) above, wherein the non-melt fiber A is at least one selected from flame-resistant fibers and meta-aramid fibers.

(7) The nonwoven fabric according to any one of (1) to (6) above, wherein the thermoplastic fiber B has a glass transition point of 120°C or less.

(8) The thermoplastic fiber B is a flame-retardant polyester fiber, 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, and a fiber of at least one resin selected from the group of a mixture thereof. The nonwoven fabric according to any one of-(7).

(9) The nonwoven fabric according to any one of (1) to (8), wherein the thermoplastic fiber B contains a sulfur atom.

(10) The nonwoven fabric according to any one of (1) to (9) above, wherein the nonwoven fabric has a weight per unit area of 50 g/m ² or more and a density of 50 kg/m ³ or less.

The non-woven fabric of the present invention has the above-described configuration, and thus it becomes a non-woven fabric having excellent flame retardancy and flame-retardant properties, as well as card passability and durability.

It is a figure for demonstrating the evaluation test method of a dye-resistant property.

The present invention relates to a non-melt fiber A having a high-temperature shrinkage of 3% or less, a thermoplastic fiber B having an LOI value of 25 or more in accordance with JIS K 7201-2 (2007), and an LOI in accordance with JIS K 7201-2 (2007). It has been found that the above problem can be solved by a nonwoven fabric containing thermoplastic fibers C having a value of less than 25 and having a number of crimpings of 8 (pieces/25 mm) or more conforming to JIS L 1015 (2000).

In the present invention, the non-melt fiber A having a high-temperature shrinkage of 3% or less constitutes a nonwoven fabric with thermoplastic fibers B and C, etc., but when heat is applied to the nonwoven fabric because the flame is close, the thermoplastic fiber C begins to melt first, and continues to be thermoplastic. Fiber B melts, and the melted thermoplastic fibers B and C are spread in a thin film shape along the surface of the non-melted fiber A (aggregate). In addition, when the temperature rises, immediately, all fibers of A to C are carbonized, but since the high-temperature shrinkage of non-melted fiber A is 3% or less, it is difficult to shrink even at high temperature as a non-woven fabric, and because it is difficult to create holes, it is difficult to block the flame. I can. From this point of view, it is preferable that the high-temperature shrinkage rate of the non-melt fiber A is lower, but even if it does not shrink, even if it expands significantly by heat, the structure collapses and causes pores, so the high-temperature shrinkage rate is preferably -5% or more. Among them, it is preferable that the high-temperature shrinkage is 0 to 2%.

In addition, the high-temperature shrinkage is (i) the fiber used as the raw material of the nonwoven fabric is allowed to stand for 12 hours in a standard state (20°C, relative humidity 65%), and then a tension of 0.1 cN/dtex is applied to measure the original length L0, and (ii ) The fiber is exposed to a dry heat atmosphere of 290°C for 30 minutes without applying a load, cooled sufficiently in a standard condition (20°C, 65% relative humidity), and then a tension of 0.1 cN/dtex is applied to the fiber. Then, the length L1 is measured, and (iii) it is a numerical value calculated|required by the following formula from L0 and L1.

High temperature shrinkage=[(L0-L1)/L0]×100(%)

In addition, it is preferable to use a non-melt fiber A having a thermal conductivity of 0.060 W/m·K or less. When the thermal conductivity of the non-melt fiber A is within this range, it is also excellent in thermal insulation performance.

In addition, the thermal conductivity [W/m·K] is a basic thermal number of a material, and is the thermal transfer coefficient of a single material. It indicates the ease of heat transfer within the material, and refers to the value obtained by dividing the heat flow density (heat energy passing through a unit area per unit time) by the temperature difference between the front and back surfaces of the material. Specifically, for the thermal conductivity of the fiber, a test piece of a non-woven fabric having a thickness of 0.5 mm was prepared using the fiber to be measured, and the thermal diffusivity of the test piece was determined according to ISO22007-3 (2008), according to JISK7123 (1987). The specific heat is further measured by measuring the specific gravity of the test piece according to JISK7112 (1999), and is obtained from the following equation based on the measurement results of these thermal diffusivity, specific heat and specific gravity.

Thermal conductivity = heat diffusion rate × specific heat × specific gravity

In the present invention, the non-melt fiber A refers to a fiber that is not liquefied and maintains a fibrous shape when exposed to a flame. As the non-melt fiber used in the present invention, the high-temperature shrinkage may be within the range specified in the present invention, but specific examples include meta-aramid fibers and flame-resistant fibers.

In general, meta-aramid-based fibers have high high-temperature shrinkage and do not satisfy the high-temperature shrinkage stipulated in the present invention. However, meta-aramid-based fibers having a high-temperature shrinkage within the range prescribed by the present invention by suppressing the high-temperature shrinkage rate have high elasticity. Since the sewing property of the nonwoven fabric can be improved, it can be preferably used. The flame-resistant fibers are fibers subjected to a flame-resistant treatment using fibers selected from acrylonitrile-based, pitch-based, cellulose-based, and phenolic fibers as a raw material. These may be used individually or may use two or more types simultaneously.

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

As commercially available non-melt fiber A that can be used in the present invention, the flame-resistant fiber "PYRON" (registered trademark) manufactured by Zoltek used in the examples and comparative examples described later, and Toho Tenax Co., Ltd. Pyromex and the like are listed.

When the content rate of the non-melt fiber A in the nonwoven fabric is too low, the function as an aggregate tends to be insufficient, while when it is too high, the thermoplastic fiber is difficult to spread into a sufficient film shape. Therefore, the content rate of the non-melt fiber A in the nonwoven fabric is preferably 10% by mass or more, and most 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 stretched out as a film-like substance has an LOI value of 25 or more in conformity with JIS K 7201-2 (2007), while the thermoplastic fiber C has an LOI value of less than 25.

The LOI value is a volume percentage of the minimum amount of oxygen required to sustain combustion of a substance in a mixture of nitrogen and oxygen, and it can be said that the higher the LOI value, the more difficult it is to burn. Therefore, thermoplastic fiber B with an LOI value of 25 or more is difficult to combust. For example, even if it is ignited, it is immediately extinguished if the fire source is away, and a carbonized film is formed in the area where the flame spreads a little, and this carbonized part stops combustion. Block. On the other hand, the thermoplastic fiber C having an LOI value of less than 25 is not digested even if the fire source is removed, and combustion continues. Therefore, when heat is applied, the thermoplastic fiber C starts to melt before the thermoplastic fiber B.

The LOI value of the thermoplastic fiber B is preferably 55 or less, or preferably in the range of 25 to 50 from the viewpoint of being carbonized at high temperature. On the other hand, the LOI value of the thermoplastic fiber C is preferably 15 or more, or preferably 18 or more and less than 25 from the viewpoint of the rate of carbonization.

As the thermoplastic fiber B used in the present invention, the LOI value may be within the range specified in the present invention, but as a specific example, for example, flame retardant polyester fiber (polyethylene terephthalate fiber, polytrimethylene terephthalate fiber, polyalkyl Lenterephthalate fiber, etc.), anisotropic molten polyester, flame retardant poly(acrylonitrile butadiene styrene), flame retardant polysulfone, poly(ether-ether-ketone), poly(ether-ketone-ketone), polyethersulfone, polyarylene Fibers composed of a thermoplastic resin selected from the group of polyarylene sulfide, polyphenyl sulfone, polyetherimide, polyamideimide, and mixtures thereof. These may be used alone or two or more may be used simultaneously.

When the glass transition point of the thermoplastic fiber B is 120° C. or less, the binder effect for maintaining the shape as a nonwoven fabric can be obtained at a relatively low temperature, and therefore the apparent density increases and the strength increases, so it is preferable. Among them, polyphenylene sulfide fibers (hereinafter, also referred to as PPS fibers) are most preferable from the viewpoint of the high LOI value and ease of availability. In addition, the binder effect refers to melting or softening of the thermoplastic fiber by heat and fusion to other fibers. Further, it is preferable that the thermoplastic fiber B contains a sulfur atom as the fiber, but in that case, not only the fiber formed of a resin containing a sulfur atom, but also the fiber is preferably imparted with a sulfur atom in post-processing.

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

In addition, PPS fibers are preferably used when obtaining a nonwoven fabric by a papermaking method as described later, and in that case, the fiber length is preferably in the range of 2 to 38 mm, more preferably in the range of 2 to 10 mm. Do. When the fiber length is within the range of 2 to 38 mm, it can be uniformly dispersed in the stock solution for papermaking, and has tensile strength necessary to pass the drying process in a wet state (wetland) immediately after papermaking. Further, regarding the thickness of the PPS fibers, the single fiber fineness is preferably in the range of 0.1 to 10 dtex from the point that the fibers can be uniformly dispersed without agglomeration in the stock solution for papermaking.

As a method for producing a PPS fiber, a method of melting the polymer having the above-described phenylene sulfide structural unit at a melting point or higher and releasing it from a spinneret to form a fibrous shape is preferable. The released fibers are themselves undrawn PPS fibers. Most of the unstretched PPS fibers have an amorphous structure, and can function as a binder that bonds the fibers together by applying heat. On the other hand, since such fibers lack dimensional stability due to heat, a stretched yarn is commercially available in which the strength and thermal dimensional stability of the fibers are improved by continuing to heat elongate and oriented after release.

The content of the thermoplastic fiber B in the nonwoven fabric as described above is preferably 10% by mass or more, and more preferably 20% by mass or more, in order to reliably form a film-like substance to further increase flame retardancy and flame retardancy. On the other hand, the upper limit is preferably 55% by mass or less. In addition, the content rate is most preferably in the range of 30 to 50% by mass.

On the other hand, the thermoplastic fiber C used in the present invention has an LOI value of less than 25, but at the same time, the number of crimps in accordance with JIS L 1015 (2000) is 8 (pieces/25 mm) or more. As described above, in the present invention, thermoplastic fibers B having an LOI value of 25 or more and thermoplastic fibers C having an LOI value of less than 25 are mixed. Fibers with an LOI value of 25 or more are difficult to perform crimping, so they tend to fall off when processing nonwoven fabrics in a relatively straight shape, but thermoplastic fibers C with an LOI value of less than 25 are easy to perform the crimping process as described above. It becomes difficult to drop out due to the spiral structure. Therefore, by mixing the thermoplastic fibers B and C, not only the thermoplastic fibers C but also the thermoplastic fibers B are difficult to fall off due to crimping of the thermoplastic fibers C, and the flame retardancy and flame retardancy due to the coating effect are excellent. Or, it becomes a nonwoven fabric with excellent quality.

In addition, if the number of crimpings of the thermoplastic fiber C is too large, uniform dispersion of the fibers becomes difficult, and the texture and mechanical strength of the nonwoven fabric may be reduced. Therefore, the number of crimpings is preferably 80 (pieces/25 mm) or less. In addition, from the viewpoint of further improvement in crimp workability and card passability, 10 to 50 (pieces/25 mm) are more preferable, and 10 to 30 (pieces/25 mm) are more preferable.

Specific examples of the thermoplastic fiber C include, for example, thermoplastic cellulose fibers, acrylic fibers, nylon fibers, and polyester fibers (polyethylene terephthalate fibers, polytrimethylene terephthalate fibers, etc.). These may be used individually, or two or more types may be used simultaneously. From the viewpoint of crimp processability and availability, polyethylene terephthalate fibers (hereinafter referred to as PET fibers) are most preferable. The preferable content of the thermoplastic fiber C in the nonwoven fabric is 20 to 50% by mass, more preferably 35 to 50% by mass.

The non-melting fibers A and the thermoplastic fibers B and C as described above are formed into a web so that they are mixed, and for example, the thermoplastic fiber C is once melted and then cooled and solidified by applying heat exceeding the melting point of the thermoplastic fiber C. As a result, the thermoplastic fiber C is fused to the non-melted fiber A and the thermoplastic fiber B and is integrated to form a nonwoven fabric. In addition, in the fusion bonding, the thermoplastic fiber C may be softened by a method of applying heat exceeding the glass transition point of the thermoplastic fiber C, and then pressure may be applied, and the thermoplastic fiber C, the non-melted fiber A, and the thermoplastic fiber B may be compressed. . In this way, a higher binder effect can be obtained, which is preferable.

As a method of forming the web, any method such as a dry method or a wet method may be used. However, in order to uniformly disperse various fibers, a dry method is preferable, and different types of fibers are preferably bonded together in a entangled state. Therefore, it is preferable that the non-melt fibers A and the thermoplastic fibers B and C are each cut to a length of, for example, 2 to 10 mm so that they are entangled with each other. As the fiber bonding method, a thermal bonding method, a needle punching method, a water flow entanglement method, etc. are all applied, but it is more preferable to apply a water flow entanglement method in order to increase the density of the nonwoven fabric. Further, after the non-melt fiber A is web-formed, the thermoplastic fibers B and C may be laminated by a span bond method or a melt blow method.

In order to increase the process passability and the strength of the nonwoven fabric in the thermal bonding method, it is also preferable to use some of the thermoplastic fibers B and C as fibers with low crystallinity such as undrawn yarn. Specifically, since the fibers of the same material have good compatibility and are firmly fused to each other, for example, as described above, PPS fibers drawn and undrawn PPS fibers are used as thermoplastic fibers B, and a binder by fusion bonding them It is desirable to enhance the effect to form a nonwoven fabric. Further, the mass ratio of the stretched PPS fibers to the unstretched PPS fibers is preferably 3 to 1 to 1 to 3, more preferably 1 to 1.

In the nonwoven fabric of the present invention, it is also preferable that the density is 50 kg/m ³ or less. The thermal conductivity becomes smaller, and excellent heat insulation performance is obtained. Light weight and to exhibit excellent heat insulating performance, the density is more preferably 50~30kg / m ³ is more preferable, and 50~40kg / m ³ to.

Further, in order for the weight increase per unit area than the chayeom performance, preferably at least 50g / m ^2, more preferably not less than 100g / m ^2.

In addition, in order to improve the dyeing performance, it is also preferable that the thickness of the nonwoven fabric conforming to the JIS L 1096-A method (2010) is 0.08 mm or more.

Example

《Combustion resistance test》

It was tested according to the 8.1.1 A-1 method (45° micro burner method) of JIS L 1091 (Fiber Product Flammability Test Method, 1999). That is, after 1 minute heating, the residual salt time (3 seconds or less), after glow time (5 seconds or less), combustion area (30 cm ² or less), and combustion length (20 cm or less) are measured, followed by complex salt 3 seconds. Afterwards, the residual salt time (3 seconds or less), residual time (5 seconds or less), and combustion area (30 cm ² or less) were measured and classified. If these are the values in (parentheses), they corresponded to "Category 3" of the evaluation category according to JIS L 1091, and they were taken and judged as a passable combustibility.

《Evaluation of anti-inflammatory properties》

It was ignited by the method according to the 8.1.1 A-1 method (45° micro burner method) of JIS L 1091 (Fiber Product Flammability Test Method, 1999), and the flame resistance was evaluated as follows. That is, as shown in Fig. 1, a microburner 1 having a flame length (L) of 45 mm is set in a vertical direction, and the test body 2 is disposed at an angle of 45° with respect to the horizontal plane, and the thickness (th) with respect to the test body 2 The flame-retardant property was evaluated by a test in which the combustion body 4 was disposed and burned through a spacer 3 of 2 mm in length. For the combustion body 4, a qualitative filter paper grade 2 (1002) sold by GE Health Care Japan Co., Ltd., which has been left in a standard condition for 24 hours in advance in order to make the moisture content uniform, was used, and after igniting the micro burner 1 The time until the combustion body 4 ignites was measured in seconds. This measurement was performed three times and the average value was adopted.

When ignited to the combustion body 4 within 3 minutes of contact flame, it was set as "no flame retardant", and was expressed as F. The case where the combustion body 4 does not ignite even when exposed to the flame for 3 minutes or longer is referred to as ``there is a flame-retardant performance,'' but the longer the flame-retardant time is, the better, B for 3 minutes or more and less than 20 minutes, and A for 20 minutes or more .

《Weight per unit area》

Measured according to 8.3 (A method) of JIS L 1096 (2010 years), and are shown in mass (g / m ²⁾ per 1m ^2. The measurement was performed twice, and the average value was adopted.

"thickness"

It measured according to 6.1.3 (C method) of JIS L 1913 (2010). 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.

《The number of crimsons》

It 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-melt fiber A-1>

1.7dtex's flame-resistant fiber "PYRON" (registered trademark) manufactured by Zoltek, 6mm in length, high temperature shrinkage 1.6%, thermal conductivity 0.033W/m·K

<Non-melt fiber A-2>

1.67 dtex meta-aramid fiber, length 6 mm, high temperature shrinkage 2.8%, thermal conductivity 0.055W/m·K.

<Thermoplastic Fiber B-1>

PPS fiber (containing 35% by mass of PPS undrawn yarn in 100% by mass of PPS fiber), length 5.1 mm, LOI value 34, glass transition temperature 90°C, number of crimps 6 (piece/25 mm)

<Thermoplastic fiber B-2>

PPS fiber (containing 40% by mass of PPS undrawn yarn in 100% by mass of PPS fiber), length 5.1 mm, LOI value 34, glass transition temperature 90°C, number of crimps 6 (piece/25 mm)

<Thermoplastic Fiber B-3>

PPS fiber (containing 33% by mass of PPS undrawn yarn in 100% by mass of PPS fiber), length 5.1 mm, LOI value 34, glass transition temperature 90°C, number of crimps 6 (piece/25 mm).

<Thermoplastic Fiber C-1>

PET fiber (containing 35% by mass of PET undrawn yarn in 100% by mass of PET fiber), length 5.1mm, LOI value 20, glass transition temperature 68°C, number of crimps 16 (piece/25mm)

<Thermoplastic Fiber C-2>

PET fiber (containing 33% by mass of PET undrawn yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68°C, number of crimpings 16 (piece/25 mm)

<Thermoplastic Fiber C-3>

PET fiber (containing 30% by mass of PET undrawn yarn in 100% by mass of PET fiber), length 5.1mm, LOI value 20, glass transition temperature 68°C, number of crimps 16 (pieces/25mm)

<Thermoplastic Fiber C-4>

PET fiber (containing 50% by mass of PET undrawn yarn in 100% by mass of PET fiber), a length of 5.1 mm, an LOI value of 20, a glass transition temperature of 68°C, and the number of crimpings 13 (pieces/25 mm).

<Other fibers D-1>

Acrylic fiber, length 5.1mm, high temperature shrinkage 35%, thermal conductivity 1.02W/m·K

<Other fibers D-2>

Nylon fiber (containing 33% by mass of nylon undrawn yarn in 100% by mass of nylon fiber), length 5.1 mm, LOI value 21, glass transition temperature 58°C, number of crimpings 15 (piece/25 mm)

<Other fibers D-3>

Flame-retardant rayon fiber, length 5.1mm, LOI value 27, number of crimps 5 (piece/25mm)

<Other fibers D-4>

PET fiber (containing 35% by mass of PET undrawn yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68° C., number of crimpings 3 (piece/25 mm).

[Example 1]

Non-melt fiber A-1, thermoplastic fiber B-1, and thermoplastic fiber C-1 are mixed cotton so that the mass ratio is 3 to 4 to 3, and the fiber web (weight per unit area: 98 g) is opened by a card machine. /m ² ) was formed. The fibers were entangled with each other by applying needles to the fibrous web with a needle density of 40 pieces/cm ² to form an integrated sheet having flame-resistant fibers, PPS fibers, and PET fibers in the same nonwoven layer. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the flame-resistant fibers constituting the sheet, PPS fibers, and PET fibers were fused to each other to form a fusion-integrated sheet. The fusion-integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and it was equal to the number of crimps of the raw material described in &quot;Used fiber&quot;. The mass of the nonwoven fabric was 98 mass% based on the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 100 g/m ² and a density of 50 kg/m ³ , and had sufficient elasticity while being dense and flexible. As a result of performing the combustion resistance test, even if heated for 1 minute, there was no case of ignition to the combustion body, and the combustion area was 10 cm ² or less and the combustion length was 10 cm, and it had sufficient flame retardancy. In addition, even if the present nonwoven fabric is bent by 90° or more, no fracture or perforation occurs, and has excellent bending workability. In addition, in the evaluation of flame-retardant properties, there was no case of ignition to the combustion body for 21 minutes, and thus had sufficient flame-retardant properties.

[Example 2]

Non-melt fiber A-2, thermoplastic fiber B-1, and thermoplastic fiber C-1 are blended so that the mass ratio is 2 to 3 to 5, and the fiber web is opened by a card machine (weight per unit area: 130 g/m ² ) Formed. The fibers were entangled with each other by applying needles to the fibrous web with a needle density of 40 pieces/cm ² , and an integrated sheet having meta-aramid fibers, PPS fibers and PET fibers was formed on the same nonwoven layer. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the meta-aramid fibers constituting the sheet, PPS fibers, and PET fibers were fused to form a fusion bonded integrated sheet. The fusion bonded integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and the number of crimps was equal to the number of crimps of the raw material described in "Used fiber". The mass of the nonwoven fabric was 97 mass% with respect to the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 135 g/m ² , a density of 45 kg/m ³ , and was dense and also equipped with elasticity, but was slightly lacking in softness compared to the nonwoven fabric of Example 1. As a result of conducting the combustion resistance test, even if heated for 1 minute, there was no case of ignition to the combustion body, and the combustion area was 10 cm ² or less and the combustion length was 12 cm, which had sufficient flame retardancy. In addition, even if the present nonwoven fabric was bent by 90° or more, no breakage or perforation occurred, and excellent bending workability was observed. In addition, in the evaluation of flame-retardant properties, there was no case of igniting the combustion body for 15 minutes, and thus had sufficient flame-retardant properties.

[Example 3]

Non-melt fiber A-1, thermoplastic fiber B-2, and thermoplastic fiber C-2 are blended to have a mass ratio of 3 to 3 to 4, and then open with a card machine, and a fiber web (weight per unit area: 115 g/ m ² ) was formed. By applying a needle to the fibrous web with a needle density of 40 pieces/cm ² , their fibers were entangled to form an integrated sheet having flame-resistant fibers, PPS fibers, and PET fibers in the same nonwoven layer. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the flame-resistant fibers constituting the sheet, PPS fibers, and PET fibers were fused together to form a fusion bonded integrated sheet. The fusion bonded integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimping was measured, and it was equal to the number of crimping of the raw material described in &quot;Used fiber&quot;. The mass of the nonwoven fabric was 97 mass% with respect to the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 122.5 g/m ² , a density of 35 kg/m ³ , and was dense and flexible, and had sufficient elasticity. As a result of conducting the combustion resistance test, even if heated for 1 minute, there was no case of ignition in the combustion body, but residual dust was observed and the residual residual time was 3 seconds. Further, the combustion area was 29 cm ² or less, and the combustion length was 11 cm, which had sufficient flame retardancy. Further, it was confirmed that even if the present nonwoven fabric was bent by 90° or more, no fracture or perforation occurred, and excellent bending workability was observed. In addition, in the evaluation of flame-retardant properties, there was no case of igniting the combustion body for 15 minutes, and thus had sufficient flame-retardant properties.

[Example 4]

Non-melt fiber A-2, thermoplastic fiber B-3, and thermoplastic fiber C-2 are mixed together so that the mass ratio is 4 to 1 to 5, and the fiber web is opened by a card machine (weight per unit area: 38 g/m ² ) Formed. The fibers were entangled with each other by applying needles to the fibrous web with a needle density of 40 pieces/cm ² to form an integrated sheet having meta-aramid fibers, PPS fibers and PET fibers in the same nonwoven layer. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the meta-aramid fibers constituting the sheet, PPS fibers, and PET fibers were fused to form a fusion bonded integrated sheet. The fusion bonded integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and the number of crimps was equal to the number of crimps of the raw material described in "Used fiber". The mass of the nonwoven fabric was 97 mass% with respect to the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 40 g/m ² and a density of 40 kg/m ³ , and was dense and flexible, and had sufficient elasticity. As a result of conducting the combustion resistance test, even if heated for 1 minute, there was no case of ignition in the combustion body, but residual dust was observed and the residual residual time was 3 seconds. In addition, the combustion area was 27 cm ² and the combustion length was 18 cm, which had sufficient flame retardancy. Further, it was confirmed that even when the present nonwoven fabric was bent by 90° or more, no fracture or perforation occurred, and it had excellent bending workability. In addition, in the flame-retardant evaluation, there was no flammability to the combustion body for 9 minutes, and had sufficient flame-retardant properties.

[Comparative Example 1]

Thermoplastic fibers C-3 and other fibers D-1 and D-2 are mixed with a mass ratio of 3 to 3 to 4, and then opened by a card machine to form a fiber web (weight per unit area: 98 g/m ² ). did. The fibers were entangled with each other by applying a needle to the fibrous web with a needle density of 40 pieces/cm ² to form an integrated sheet having acrylic fibers, nylon fibers and PET fibers on the same nonwoven layer. The integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and acrylic fibers, nylon fibers, and PET fibers constituting the sheet were fused together to form a fusion bonded integrated sheet. The fusion bonded integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and the number of crimps was equal to the number of crimps of the raw material described in "Used fiber". The mass of the nonwoven fabric was 99 mass% with respect to the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 100 g/m ² and a density of 50 kg/m ³ , and had sufficient elasticity while being dense and flexible. As a result of performing the combustion resistance test, a hole was formed in the part directly above the burner within 3 seconds after the burner was placed on the test body, and the test body itself was also ignited and burned. Therefore, it cannot be said that it has flame retardancy. In addition, as described above, since the test object itself was ignited and burned, it can be said that it does not have a flameproof property without even measuring it.

[Comparative Example 2]

Non-melt fiber A-1, thermoplastic fiber C-4, and other fibers D-3 are blended so that the mass ratio is 3 to 3 to 4, and the fiber web is opened by a card machine (weight per unit area: 75 g/m ² ) Formed. By applying a needle with a needle density of 40 pieces/cm ² to the fibrous web, their fibers were entangled to form an integrated sheet having flame-resistant fibers, flame-retardant rayon fibers and PET fibers in the same nonwoven layer. The integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the flame-resistant fibers constituting the sheet, flame-retardant rayon fibers, and PET fibers were fused together to form a fusion-integrated sheet. The fusion bonded integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and the number of crimps was equal to the number of crimps of the raw material described in "Used fiber". The mass of the nonwoven fabric was 99 mass% with respect to the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 180 g/m ² and a density of 40 kg/m ³ , and was dense and flexible, and had sufficient elasticity. As a result of performing the combustion resistance test, even if heated for 1 minute, the combustion body did not ignite, and the combustion area was 15 cm ² and the combustion length was 8 cm, which had sufficient flame retardancy. However, in the anti-dyeing property evaluation, since it was ignited on the test body itself after 2 minutes of contacting contact, it did not have the anti-dyeing property.

[Comparative Example 3]

The non-melt fiber A-1 and the thermoplastic fiber B-1 were blended so that the mass ratio was 4 to 6, and the fiber web (weight per unit area: 97 g/m ² ) was formed by opening with a card machine. By applying a needle with a needle density of 40 pieces/cm ² to the fiber web, the fibers were entangled with each other to form an integrated sheet having flame-resistant fibers and PPS fibers in the same nonwoven fabric layer. The integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the flame-resistant fibers and PPS fibers constituting the sheet were fused to form a fusion-integrated sheet. The fusion bonded integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then dried naturally to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and the number of crimps was equal to the number of crimps of the raw material described in "Used fiber". The mass of the nonwoven fabric was 50% by mass based on the mass of the raw surface (web formation rate).

The obtained nonwoven fabric had a weight per unit area of 100 g/m ² and a density of 50 kg/m ³ , and had sufficient elasticity while being dense and flexible. As a result of performing the combustion resistance test, even if heated for 1 minute, there was no case of ignition to the combustion body, and the combustion area was 5 cm ² or less and the combustion length was 8 cm, which had sufficient flame retardancy. Further, it was confirmed that even when the present nonwoven fabric was bent by 90° or more, no breakage or pores occurred, and excellent bending workability was observed. In addition, in the flame-retardant evaluation, there was no ignition to the combustion body for 30 minutes, and thus had sufficient flame-retardant properties. However, as also shown in the case where the web formation rate is 50% by mass, since the fibers are liable to fall out of the card machine, it was necessary to lower the speed of passing the fibers through the card machine.

[Comparative Example 4]

Non-melt fiber A-1, thermoplastic fiber B-1, and other fibers D-4 are mixed with a mass ratio of 3 to 4 to 3, and then open with a card machine to form a fiber web (weight per unit area: 98 g/m ² ). Formed. The fibers were entangled with each other by applying needles to the fibrous web with a needle density of 40 pieces/cm ² to form an integrated sheet having flame-resistant fibers, PPS fibers, and PET fibers in the same nonwoven layer. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150°C, and the flame-resistant fibers constituting the sheet, PPS fibers, and PET fibers were fused to form a fusion-integrated sheet. The fusion-integrated sheet was washed with hot water at a temperature of 70° C. for 6 seconds, and then naturally dried to obtain a nonwoven fabric from which the oil agent was removed. Each staple fiber was taken out from this nonwoven fabric using tweezers, and the number of crimps was measured, and the number of crimps was equal to the number of crimps of the raw material described in "Used fiber". The mass of the nonwoven fabric was 50% by mass based on the mass of the raw surface (web formation rate).

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 flexible, and had sufficient elasticity. As a result of conducting the combustion resistance test, even if heated for 1 minute, there was no case of ignition to the combustion body, and the combustion area was 10 cm ² or less and the combustion length was 10 cm, which had sufficient flame retardancy. Further, even when the nonwoven fabric is bent by 90° or more, no breakage or holes occur, and it has excellent bending workability. In addition, in the evaluation of flame-retardant properties, there was no case of ignition to the combustion body for 21 minutes, and thus had sufficient flame-retardant properties.

In Table 1, the evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4 are collectively shown.

(Industrial availability)

The present invention is effective in preventing the combustion of fire, and is suitable for use in wall materials, flooring materials, ceiling materials, etc., which require flame retardancy, and is particularly suitable for use as fire blocking materials such as furniture and bedding.

1 micro burner
2 test body
3 spacers
4 combustor
L flame length
th spacer thickness

Claims (10)

Non-melt fiber A with a high-temperature shrinkage of 3% or less, thermoplastic fiber B with an LOI value of 25 or more in accordance with JIS K 7201-2 (2007), and an LOI value of 25 in accordance with JIS K 7201-2 (2007). A nonwoven fabric comprising thermoplastic fibers C having a number of crimpings of 8 (pieces/25 mm) or more in accordance with JIS L 1015 (2000). The method of claim 1,
A nonwoven fabric comprising 20 to 50 mass% of the thermoplastic fiber C in 100 mass% of the nonwoven fabric. The method according to claim 1 or 2,
A nonwoven fabric comprising 10% by mass or more of the non-melt fiber A in 100% by mass of the nonwoven fabric. The method according to any one of claims 1 to 3,
A nonwoven fabric comprising 20 mass% or more of the thermoplastic fiber B in 100 mass% of the nonwoven fabric. The method according to any one of claims 1 to 4,
The non-fused fiber A is a non-woven fabric, characterized in that the thermal conductivity is 0.060 W / m · K or less. The method according to any one of claims 1 to 5,
Non-woven fabric, characterized in that the non-melt fiber A is at least one selected from flame-resistant fibers and meta-aramid fibers. The method according to any one of claims 1 to 6,
The nonwoven fabric, characterized in that the glass transition point of the thermoplastic fiber B is not more than 120 ℃. The method according to any one of claims 1 to 7,
The thermoplastic fiber B is a flame-retardant polyester fiber, anisotropic molten polyester, flame-retardant poly(acrylonitrile butadiene styrene), flame-retardant polysulfone, poly(ether-ether-ketone), poly(ether-ketone-ketone), polyether Nonwoven fabric characterized in that it is a fiber of at least one resin selected from the group of sulfone, polyarylate, polyarylene sulfide, polyphenyl sulfone, polyetherimide, polyamideimide, and mixtures thereof. The method according to any one of claims 1 to 8,
Nonwoven fabric, characterized in that the thermoplastic fiber B contains a sulfur atom. The method according to any one of claims 1 to 9,
The nonwoven fabric has a weight per unit area of 50g/m ² or more and a density of 50 kg/m ³ or less.

Images