TW201938869A - Non woven fablic - Google Patents

Abstract

In order to provide a non-woven fabric that has outstanding flame retardance and flame blocking properties as well as outstanding carder-passing properties and durability, this non-woven fabric includes: non-melting fibers A with a high-temperature contraction rate of 3% or less; thermoplastic fibers B with an LOI value of at least 25 in accordance with JIS K 7201-2 (2007); and thermoplastic fibers C that have an LOI value of less than 25 in accordance with JIS K 7201-2 (2007) and have a crimp count of at least 8 (crimps/25 mm) in accordance with JIS L 1015 (2000).

Description

   Non-woven   

The present invention relates to non-woven fabrics.

Non-woven fabrics made of synthetic fibers composed of synthetic polymers such as polyamide, polyester, polyolefin, etc. have been used since the beginning. However, these synthetic polymers are generally not flame-resistant, and they are formed at the raw material stage or formed. After the fiber and non-woven fabric, most of them are treated with some kind of flame retardant.

Various proposals have been made for a method for obtaining a non-flammable non-woven fabric. For example: a method of spinning a polymer copolymerized with flame-retardant components into a non-woven fabric; a method of kneading a flame-retardant agent into a polymer at a raw silk stage and then spinning to form a non-woven fabric; A method of processing to attach a flame-resistant component to a non-woven fabric and the like. 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-based flame retardant and a polyester resin (Patent Document 1). Patent Document 2 also discloses a flame-retardant nonwoven fabric in which a flame-retardant adhesive is added to a nonwoven fabric containing polyphenylene sulfide fibers and polyester fibers.

Furthermore, the method of obtaining a non-flammable non-woven fabric is as follows: applying a specific treatment to the fiber after spinning to impart non-flammability, and then forming the non-woven fabric, or using a fiber material that is inherently non-flammable to perform spinning. Non-woven method. For example, the non-woven fabric disclosed in Patent Document 3 is composed of flame-resistant fibers with high flame retardancy obtained by processing after spinning, or flame-retardant fibers obtained by polymerizing a specific raw material; and The disclosed non-woven fabric contains flame-resistant fibers with high flame resistance obtained by spinning after treatment, and polyphenylene terephthalate fibers.

    [Prior technical literature]         [Patent Literature]    

Patent Document 1: Japanese Patent Laid-Open No. 2013-169996

Patent Document 2: Japanese Patent Laid-Open No. 2012-144818

Patent Document 3: Japanese Patent Laid-Open No. 2003-129362

Patent Document 4: International Publication No. 2017/6807

However, although the methods described in Patent Documents 1 and 2 are the easiest among the methods for imparting flame retardancy, the flame retardant attached is easy to fall off, and even if the flame retardant has an excellent flame retarding effect, it is durable. Sexual issues.

In addition, the non-woven fabric described in Patent Document 3 uses flame-resistant fibers having a high limiting oxygen index LOI value, but the fibers easily fall when passing through a card, and as a result, they remain regardless of flame resistance or processability. problem. In addition, the non-woven fabric described in Patent Document 4 contains flame resistant fibers and polyphenylene terephthalate (PPS), and therefore has high flame resistance and flame retardancy. There is still room for improvement in card passing.

The present invention has been made in view of the problems of such conventional flame-retardant non-woven fabrics, and an object thereof is to provide a non-woven fabric which is excellent in both flame-retardant properties and flame retardancy, and also has excellent card passing properties and durability.

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

(1) A non-woven fabric comprising: non-melt fiber A having a high-temperature shrinkage of 3% or less; thermoplastic fiber B having a LOI value of 25 or more according to JIS K 7201-2 (2007); and JIS K 7201 Thermoplastic fiber C having a LOI value of -2 (2007) of less than 25 and a warpage number of 8 (pieces / 25 mm) or more according to JIS L 1015 (2000).

(2) The non-woven fabric according to the above (1), wherein the thermoplastic fiber C based on 100% by mass of the non-woven fabric contains 20 to 50% by mass.

(3) The non-woven fabric according to the above (1) or (2), wherein the non-melting fiber A based on 100% by mass of the non-woven fabric contains 10% by mass or more.

(4) The non-woven fabric according to any one of the above (1) to (3), wherein the thermoplastic fiber B based on 100% by mass of the non-woven fabric contains 20% by mass or more.

(5) The non-woven fabric according to any one of (1) to (4) above, wherein the non-fused fiber A is based on ISO 22007-3 (2008) and has a thermal conductivity of 0.060 W / m · K or less.

(6) The non-woven fabric according to any one of (1) to (5), wherein the non-melting fiber A is one or more selected from flame-resistant fibers and meta-aramid fibers.

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

(8) The non-woven fabric according to any one of (1) to (7) above, wherein the thermoplastic fiber B is composed of a flame-retardant polyester fiber, a non-isotropic molten polyester, and a flame-retardant polymer. (Acrylonitrile-butadiene-styrene), flame retardant polyfluorene, poly (ether-ether-ketone), poly (ether-ketone-ketone), polyetherfluorene, polyarylate, polyarylene sulfide, Fibers of at least one resin selected from the group consisting of polyphenylenesulfonium, polyethersulfonylimine, polyfluorenthyleneimine, and mixtures thereof.

(9) The non-woven 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 the above (1) to (9), wherein the nonwoven fabric has a basis weight 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 is a non-woven fabric having excellent flame retardancy and flame retardancy, and excellent card passing properties and durability by having the above-mentioned configuration.

1‧‧‧ Mini Burner

2‧‧‧ test body

3‧‧‧ spacer

4‧‧‧burning body

L‧‧‧ Flame length

th‧‧‧ spacer thickness

FIG. 1 is an explanatory diagram of a flame retardance evaluation test method.

The present invention has been found to contain non-melt fibers A having a high-temperature shrinkage of 3% or less; thermoplastic fibers B having a LOI value of 25 or more according to JIS K 7201-2 (2007); and JIS K 7201-2 ( (2007) Thermoplastic fiber C with a LOI value of less than 25 and a warpage number of 8 (pieces / 25mm) or more according to JIS L 1015 (2000); a non-woven fabric that can solve the above problems.

In the present invention, the non-melting fiber A having a high-temperature shrinkage of 3% or less constitutes a non-woven fabric together with the thermoplastic fibers B, C, etc. However, when the non-woven fabric is heated near the flame, the thermoplastic fiber C starts to melt first, and then heat The plastic fibers B are melted, and the molten thermoplastic fibers B and C expand in a film shape along the surface of the non-melt fibers A (aggregate). If the temperature is further increased, eventually A to C fibers are carbonized, but because the non-melt fiber A has a high-temperature shrinkage of less than 3%, the non-woven fabric is not easy to shrink even at high temperatures, and it is difficult to form pinholes, so it can block the flame. In this regard, the lower the high-temperature shrinkage rate of the non-melting fiber A, the better, but even if it does not shrink, it still expands greatly due to heat and causes pinholes due to structural collapse. Therefore, the high-temperature shrinkage rate is preferably -5%. the above. Especially high temperature shrinkage is preferably 0 ~ 2%.

In addition, the so-called "high-temperature shrinkage rate" is (i) the fibers of the nonwoven fabric are left in a standard state (20 ° C, 65% relative humidity) for 12 hours, and then a tension of 0.1 cN / dtex is applied to measure the original length L0, ) In the state where no load is applied to the fiber, it is exposed to a dry heat environment at 290 ° C for 30 minutes, and then fully cooled in a standard state (20 ° C, relative humidity 65%), and then the fiber is applied with a tension of 0.1 cN / dtex and the length is measured L1, (iii) are obtained from L0 and L1 according to the following formula.

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

The non-melting fiber A is preferably one having a thermal conductivity of 0.060 W / m · K or less. When the thermal conductivity of the non-fused fiber A is within this range, the thermal insulation performance is also excellent.

In addition, the so-called "thermal conductivity [W / m‧K]" is a basic thermal constant of a material, and a coefficient of thermal movement of a single material. Expresses the easiness of heat transfer in the material, divided by the heat flux density (thermal energy per unit time per unit area) divided by the value of the temperature difference between the surface and the back of the material. Specifically, the thermal conductivity of the fiber is a test piece made of a non-woven fabric having a thickness of 0.5 mm using the measurement target fiber. The thermal diffusivity of the test piece is measured according to ISO 22007-3 (2008), and the test piece is measured according to JIS K 7123 (1987). And determine the specific gravity of the test piece in accordance with JIS K 7112 (1999), and then based on the measurement results of the thermal diffusivity, specific heat, and specific gravity, calculate from the following formula: thermal conductivity = thermal diffusivity × specific heat × specific gravity

In the present invention, the "non-melting fiber A" means a fiber that does not liquefy or the like when exposed to a flame and can maintain the fiber shape. The non-melting fiber system used in the present invention is sufficient as long as the high-temperature shrinkage rate is within the range specified in the present invention, and specific examples thereof include meta-aramid fiber and flame-resistant fiber.

In general, meta-aramid fibers are high in high temperature shrinkage and do not meet the high temperature shrinkage specified in the present invention. However, if the treatment for suppressing high temperature shrinkage is performed, the high temperature shrinkage within the range specified in the present invention will be reduced. Meta-aramid fibers are suitable for use because they have high elasticity and can improve the sewing properties of nonwoven fabrics. Flame-resistant fibers are fibers which are selected from acrylonitrile-based, pitch-based, cellulose-based, phenol-based fibers and the like and subjected to flame-resistant treatment. These systems can be used alone or in combination of two or more.

Among them, from the viewpoint of low-temperature shrinkage, flame-resistant fibers are preferred, and among various flame-resistant fibers, fibers having a small specific gravity, softness, and excellent flame resistance are preferably acrylonitrile-based flame resistant fibers. Chemical fiber. This flame-resistant fiber system can be obtained by heating and oxidizing acrylic fiber belonging to the precursor in high-temperature air.

The commercially available non-melting fiber A that can be used in the present invention includes, for example, flame-resistant fiber "PYRON" (registered trademark) manufactured by Zoltek Corporation used in the examples and comparative examples described later, and Toho Tenex silk (stock) Ferro Max (Pyromex) and others.

If the content of the non-melting fiber A in the nonwoven fabric is too low, the function as an aggregate material is likely to be insufficient. On the other hand, if it is too high, the thermoplastic fibers are not easily expanded into a sufficient film shape. Therefore, the non-melted fiber A content in the non-woven fabric is preferably 10% by mass or more, more preferably in the range of 15 to 60% by mass, and particularly preferably in the range of 30 to 50% by mass.

Next, the thermoplastic fiber B expanded into a film-like substance has a LOI value of 25 or more in accordance with JIS K 7201-2 (2007), and the LOI value of the thermoplastic fiber C is less than 25.

The LOI value is the volume percentage of the minimum amount of oxygen necessary for the substance to continue to burn in a mixed gas of nitrogen and oxygen. 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 not easy to burn. Even if it catches fire, it will immediately turn off as soon as it leaves the source of fire. Usually, a carbonized film is formed on the slightly burned and enlarged portion, and the carbonized portion prevents post-burn. On the other hand, the thermoplastic fiber C series with a LOI value of less than 25 does not extinguish and continues to burn even when it leaves the ignition source. Therefore, if heated, the thermoplastic fiber C will start to melt before the thermoplastic fiber B.

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

The thermoplastic fiber B used in the present invention is only required if the above-mentioned LOI value is within the range specified in the present invention. Specific examples include, for example, flame-retardant polyester fiber (polyethylene terephthalate fiber). , Polytrimethylene terephthalate fiber, polyalkylene terephthalate fiber, etc.), anisotropic molten polyester, flame-retardant poly (acrylonitrile-butadiene-styrene), flame-retardant Poly (fluorene), poly (ether-ether-ketone), poly (ether-ketone-ketone), poly (ether-ketone-ketone), poly (ether-ketone), polyarylate, polyarylene sulfide, polyphenylene, polyether, imine, polyamine Fibers made of a thermoplastic resin selected from the group consisting of imines and mixtures thereof. These systems can be used alone or in combination of two or more.

If the glass transition point of the thermoplastic fiber B is below 120 ° C, the bonding effect that can maintain the shape of the non-woven fabric can be obtained at a relatively low temperature, so the apparent density is increased and the strength is improved, so it is preferable. In particular, from the viewpoint of a high LOI value and ease of acquisition, the best polyphenylene sulfide fiber (hereinafter also referred to as "PPS fiber"). In addition, the "bonding effect" means that the thermoplastic fiber is melted or softened by heat, and is fused to other fibers. The thermoplastic fiber B is preferably a fiber containing sulfur atoms. In this case, it is not limited to fibers composed of a sulfur atom-containing resin, and it is also preferable to provide sulfur atoms to the fibers after processing.

The PPS fiber suitable for use in the present invention is a synthetic fiber composed of a polymer having a polymer structural unit having-(C ₆ H ₄ -S)-as a main structural unit. Representative examples of these PPS polymers include, for example, polyphenylene sulfide, polyphenylene sulfide fluorene, polyphenylene sulfide ketone, random copolymers, block copolymers, and mixtures thereof. The main structural unit of the particularly good polymer of the PPS polymerization system is a para-phenylene unit represented by-(C ₆ H ₄ -S)-, and preferably contains polyphenylene sulfide at 90 mol% or more. From a mass point of view, it is preferred that the paraphenylene unit contains 80% by mass, more preferably 90% by mass or more of polyphenylene sulfide.

Furthermore, the PPS fiber is preferably used in a case where a non-woven fabric is obtained by a papermaking method as described later. The fiber length in this case is preferably in the range of 2 to 38 mm, and more preferably in the range of 2 to 10 mm. If the fiber length is in the range of 2 to 38 mm, the stock solution for papermaking can be uniformly dispersed, and has the tensile strength required to pass the wet state (wet paper) immediately after the papermaking through the drying step. In addition, the thickness of the related PPS fibers can be uniformly dispersed in the stock solution for papermaking without agglomeration, so the single fiber fineness is preferably in the range of 0.1 to 10 dtex.

The manufacturing method of the PPS fiber is preferably a method in which the polymer having a phenylene sulfide structural unit is melted at a melting point or higher, and then discharged from a spinning nozzle to form a fiber. The discharged fibers belonged to unstretched PPS fibers when they were intact. Most of the unstretched PPS fibers have an amorphous structure, and by applying heat, they can function as a binder that adheres the fibers to each other. On the other hand, because such fibers lack dimensional stability to heat, there are commercially available drawn filaments that are aligned after being extruded and then heated to increase the strength and thermal stability of the fibers.

As described above, the content of the thermoplastic fiber B in the non-woven fabric is preferably 10% by mass or more, and more preferably 20% by mass or more in order to form a film-like substance and further improve the flame retardancy and flame retardancy. On the other hand, the upper limit is preferably 55% by mass or less. The content ratio is preferably within a range of 30 to 50% by mass.

On the other hand, the thermoplastic fiber C used in the present invention has the above-mentioned LOI value of less than 25, and the number of warps according to JIS L 1015 (2000) is 8 (pieces / 25 mm) or more. Accordingly, in the present invention, a thermoplastic fiber B having a LOI value of 25 or more and a thermoplastic fiber C having a LOI value of less than 25 are used in combination. Fibers with a LOI value of 25 or higher are not easy to be subjected to curling processing, so they are relatively straight and easily fall off during non-woven processing. However, if they are thermoplastic fibers C with a LOI value of less than 25, it is easy to perform curling processing as described above. It is difficult to fall off due to the three-dimensional spiral structure caused by curling. Therefore, by mixing thermoplastic fibers B and C, not only the thermoplastic fibers C, but also the thermoplastic fibers C are not easy to fall off due to the warpage of the thermoplastic fibers C, and the flame retardant and flame retardance caused by the film effect are both uniform. A non-woven fabric that is excellent in card passing properties, durability, and quality.

In addition, if the number of flexures of the thermoplastic fiber C is too large, the fibers are not easily dispersed uniformly, and the texture and mechanical strength may be reduced when the nonwoven fabric is made into a non-woven fabric. Moreover, from the viewpoint of further improving the curling processability and the card passability, the more preferable range is 10 to 50 (pieces / 25mm), and the particularly preferable line is 10 to 30 (pieces / 25mm).

Specific examples of the thermoplastic fiber C are, for example, thermoplastic cellulose fibers, acrylic fibers, nylon fibers, polyester fibers (polyethylene terephthalate fibers, polytrimethylene terephthalate fibers, etc.) ). These systems can be used alone or in combination of two or more. From the viewpoint of curling processability and ease of acquisition, the best polyethylene terephthalate fiber (hereinafter also referred to as "PET fiber") is used. The content of the thermoplastic fiber C in the nonwoven fabric is preferably 20 to 50% by mass, and more preferably 35 to 50% by mass.

The above-mentioned non-melting fibers A, and thermoplastic fibers B and C are used to form such hybrid fiber webs. For example, by imparting heat exceeding the melting point of the thermoplastic fibers C, the thermoplastic fibers C are temporarily melted, and then cooled and solidified. The plastic fiber C is fused to the non-melt fiber A and the thermoplastic fiber B to form a non-woven fabric integrally formed. In addition, at the time of welding, the method of applying heat exceeding the glass transition point of the thermoplastic fiber C may be applied, and the thermoplastic fiber C is softened before applying pressure to make the thermoplastic fiber C, the non-melting fiber A, and the thermoplastic fiber. Phase B crimping. Thereby, a higher bonding effect can be obtained, so it is preferable.

The method for forming the fiber web may be any method such as a dry method and a wet method, but in order to uniformly disperse various fibers, it is best to use the dry method, and it is best to combine different types of fibers in an interwoven state. Therefore, it is preferable that the non-melting fibers A and the thermoplastic fibers B and C are cut to a length of, for example, 2 to 10 mm, and are interwoven with each other. The fiber bonding method can be applied by any method such as thermal bonding method, needle-pinning method, and water flow interlacing method, but in order to increase the density of the non-woven fabric, the water line interlacing method is more preferably used. In addition, the non-melt fibers A may be subjected to fiber web formation, and then the thermoplastic fibers B and C are laminated using a spunbond method or a melt-blown method.

In order to improve the smoothness of the step and the strength of the non-woven fabric during the thermal bonding method, it is preferable to make a part of the thermoplastic fibers B and C into low-crystallinity fibers like unstretched filaments. Specifically, because the fibers of the same material have better compatibility with each other and can be firmly welded to each other, it is best to use stretched PPS fibers and unstretched PPS fibers as thermoplastic fibers B as described above. The non-woven fabric is reinforced by the enhanced welding effect. In addition, the mass ratio of the stretched PPS fibers to the unstretched PPS fibers is preferably 3 to 1 to 1 to 3, and more preferably 1 to 1.

The density of the nonwoven fabric of the present invention is preferably 50 kg / m ³ or less. The thermal conductivity becomes smaller, and excellent thermal insulation performance can be obtained. In order to exhibit light weight and excellent thermal insulation performance, the density is more preferably 50 to 30 kg / m ³ , and the more preferably 50 to 40 kg / m ³ .

In addition, in order to further improve the flame retardancy, the relevant basis weight is preferably 50 g / m ² or more, and more preferably 100 g / m ² or more.

Furthermore, in order to improve flame retardancy, the thickness of the nonwoven fabric according to the JIS L 1096-A method (2010) is preferably 0.08 mm or more.

    [Example]         "Combustion resistance test"    

The test was performed in accordance with JIS L 1091 (Flammability Test Method for Fiber Products, 1999), 8.1.1 A-1 Method (45 ° Micro Burner Method). That is, the afterflame time (less than 3 seconds), the afterburning time (less than 5 seconds), the burning area (less than 30cm ² ), and the burning length (less than 20cm) after the heating for 1 minute are measured, and then the flame after 3 seconds of ignition is measured. flame time (three seconds or less), burning time (5 seconds or less), a combustion area (30cm ² or less), and be distinguished. If the values shown in (brackets) are within these values, they are in accordance with "Division 3" of the evaluation division according to the above JIS L 1091, and are respectively rated as "combustible".

    "Evaluation of Flame Resistance"    

Ignition was performed in accordance with the method of 8.1.1 A-1 method (45 ° micro-burner method) of JIS L 1091 (Flammability Test Method for Fiber Products, 1999), and flame retardancy was evaluated as follows. That is, as shown in FIG. 1, the micro-burner 1 with a flame length L of 45 mm is standing in a vertical direction, and the test body 2 is arranged at a 45-degree angle from the horizontal plane. The test body 2 is separated by a spacer having a thickness of 2 mm. 3 The combustion body 4 is arranged, a combustion test is performed, and flame retardance is evaluated. The combustor 4 is a qualitative filter paper grade 2 (1002) sold by GE Healthcare Japan Co., Ltd. for 24 hours in a standard state in order to make the moisture content uniform, and the ignition from the micro burner 1 is measured in seconds. The time after which the combustion body 4 ignites. This measurement was performed 3 times and the average value was used.

When the flame 4 ignites within 3 minutes of contact with the flame, it is rated as "flame-free" and marked as "F". When the burner 4 does not ignite even after being exposed to the flame for more than 3 minutes, it is rated as "with flame retarding performance". The longer the flame retarding time, the better. Mark "B" for more than 3 minutes and less than 20 minutes. ", Mark" A "for more than 20 minutes.

    "base weigh"    

It was measured according to JIS L 1096 (2010 years) of 8.3 (A method), by mass per 1m ² (g / m ²⁾ FIG. The measurement was performed twice, and the average value was used.

    "Thickness"    

The measurement was performed in accordance with 6.1.3 (C method) of JIS L 1913 (2010). The measurement was performed 10 times, and the average value was used.

    "Glass Transfer Point"    

The glass transition point was measured three times in accordance with JIS K 7121 (2012), and the average value was used.

    "Song number"    

The measurement was performed in accordance with JIS L 1015 (2010) 8.12.1. The measurement was performed 20 times, and the average value was used.

    《Using Fiber》         <Non-fused fiber A-1>    

1.7dtex flame resistant fiber "PYRON" (registered trademark) made by Zoltek, 6mm in length, 1.6% shrinkage at high temperature, 0.033W / m‧K thermal conductivity

    <Non-fused fiber A-2>    

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

    <Thermoplastic fiber B-1>    

PPS fiber (100% by mass of PPS fiber, 35% by mass of PPS unstretched yarn), length 5.1mm, LOI value 34, glass transition temperature 90 ° C, warp number 6 (pieces / 25mm)

    <Thermoplastic fiber B-2>    

PPS fiber (100% by mass of PPS fiber, 40% by mass of PPS unstretched yarn), length 5.1mm, LOI value 34, glass transition temperature 90 ° C, warp number 6 (pieces / 25mm)

    <Thermoplastic fiber B-3>    

PPS fiber (33% by mass of 100% by mass of PPS fiber, PPS unstretched yarn), length 5.1mm, LOI value 34, glass transition temperature 90 ° C, and warp number 6 (pieces / 25mm).

    <Thermoplastic fiber C-1>    

PET fiber (100% by mass of PET fiber, 35% by mass of PET unstretched yarn), length 5.1mm, LOI value 20, glass transition temperature 68 ° C, warpage number 16 (pieces / 25mm)

    <Thermoplastic fiber C-2>    

PET fiber (100% by mass of PET fiber, 33% by mass of PET unstretched yarn), length 5.1mm, LOI value 20, glass transition temperature 68 ° C, warpage number 16 (pieces / 25mm)

    <Thermoplastic fiber C-3>    

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

    <Thermoplastic fiber C-4>    

PET fiber (100% by mass of PET fiber, 50% by mass of PET unstretched yarn), length 5.1mm, LOI value 20, glass transition temperature 68 ° C, and warpage number 13 (pieces / 25mm).

    <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 (100% by mass of nylon fiber, 33% by mass of nylon unstretched yarn), length 5.1mm, LOI value 21, glass transition temperature 58 ° C, warp number 15 (pieces / 25mm)

    <Other fibers D-3>    

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

    <Other fibers D-4>    

PET fiber (100% by mass of PET fiber, 35% by mass of PET unstretched yarn), length 5.1mm, LOI value 20, glass transition temperature 68 ° C, and warpage number 3 (pieces / 25mm).

    [Example 1]    

The non-melting fiber A-1, the thermoplastic fiber B-1, and the thermoplastic fiber C-1 are mixed in a manner of mass ratio of 3: 4: 3, and the fiber is opened by a carding machine to form a fiber web (basis weight: 98g / m ² ). For the above-mentioned fiber web, the needles are acted upon at a density of 40 needles / cm ² , and these fibers are interwoven to form an integrated sheet having flame-resistant fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. Next, the integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fibers, PPS fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-bonded sheet was washed with warm water at 70 ° C. for 6 seconds, and then naturally dried to obtain a non-woven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The mass of the nonwoven fabric was 98% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 100 g / m ² and a density of 50 kg / m ³ , which is dense and soft, and also has sufficient tension. As a result of the fire resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 10 cm ² or less and the combustion length was 10 cm, which had sufficient flame resistance. In addition, the non-woven fabric does not break or open holes even when bent at 90 ° or more, and has excellent bending workability. In the evaluation of flame retardancy, the combustion body did not ignite even after 21 minutes, and had sufficient flame retardancy.

    [Example 2]    

The non-melting fiber A-2, the thermoplastic fiber B-1, and the thermoplastic fiber C-1 are blended according to a mass ratio of 2: 3: 5, and are opened with a carding machine to form a fiber web (basis weight: 130g / m ² ). For the above-mentioned fiber web, the needles are acted according to a needle density of 40 per cm ² , and the fibers are woven to form an integrated sheet having meta-aramid fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. Next, the above-mentioned integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the meta-aramid fibers, PPS fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-bonded sheet was washed with warm water at 70 ° C. for 6 seconds, and then naturally dried to obtain a non-woven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The quality of the nonwoven fabric was 97% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric had a basis weight of 135 g / m ² and a density of 45 kg / m ³ , and was dense and had tension. However, compared with the non-woven fabric of Example 1, the softness was slightly lacking. As a result of the combustion resistance test, even if heated for 1 minute, the combustion body still does not ignite, and the combustion area is 10 cm ² or less and the combustion length is 12 cm, which has sufficient flame resistance. In addition, the non-woven fabric does not break or open holes even when bent at 90 ° or more, and has excellent bending workability. In the evaluation of flame retardancy, the combustion body did not ignite even after 15 minutes, and had sufficient flame retardancy.

    [Example 3]    

The non-melting fiber A-1, the thermoplastic fiber B-1, and the thermoplastic fiber C-2 are mixed in a manner of mass ratio of 3: 3: 4, and the fiber is opened by a carding machine to form a fiber web (basis weight: 115g / m ² ). For the above-mentioned fiber web, the needles are acted upon at a density of 40 needles / cm ² , and these fibers are interwoven to form an integrated sheet having flame-resistant fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. Next, the integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fibers, PPS fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-bonded sheet was washed with warm water at 70 ° C. for 6 seconds, and then naturally dried to obtain a non-woven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The quality of the nonwoven fabric was 97% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 122.5 g / m ² and a density of 35 kg / m ³ , which is dense and flexible, and has sufficient tension. As a result of the fire resistance test, even after heating for 1 minute, although the combustion body did not ignite, afterflame was found, and the afterflame time was 3 seconds. In addition, the combustion area is 29 cm ² or less and the combustion length is 11 cm, which has sufficient flame resistance. In addition, the non-woven fabric did not break or open holes even when it was bent at 90 ° or more, and was found to have excellent bending workability. In the evaluation of flame retardancy, the combustion body did not ignite even after 15 minutes, and had sufficient flame retardancy.

    [Example 4]    

The non-melting fiber A-2, the thermoplastic fiber B-3, and the thermoplastic fiber C-2 are mixed in a manner of mass ratio 4: 1: 5, and the fiber is opened with a carding machine to form a fiber web (basis weight: 38g / m ² ). For the above-mentioned fiber web, the needles are acted according to a needle density of 40 per cm ² , and the fibers are woven to form an integrated sheet having meta-aramid fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. Next, the above-mentioned integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the meta-aramid fibers, PPS fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-integrated sheet was washed with warm water at a temperature of 70 ° C. for 6 seconds, and then naturally dried to obtain a nonwoven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The quality of the nonwoven fabric was 97% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 40 g / m ² and a density of 40 kg / m ³ , which is dense and soft, and has sufficient tension. As a result of the combustion resistance test, even after heating for 1 minute, the combustion body did not ignite, but afterburning was found, and the afterburning time was 3 seconds. The combustion area is 27 cm ² and the combustion length is 18 cm, which has sufficient flame resistance. In addition, the non-woven fabric did not break or open holes even when it was bent at 90 ° or more, and was found to have excellent bending workability. In the evaluation of flame retardancy, the combustion body did not ignite even after 9 minutes, and had sufficient flame retardancy.

    [Comparative Example 1]    

The thermoplastic fiber C-3 and other fibers D-1 and D-2 are mixed according to a mass ratio of 3: 3: 4, and the fiber is opened by a carding machine to form a fiber web (basic weight: 98g / m ² ). For the above-mentioned fiber web, the needles are acted according to a needle density of 40 pieces / cm ² , and these fibers are woven to form an integrated sheet having acrylic fibers, nylon fibers, and PET fibers in the same nonwoven fabric layer. The integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the acrylic fibers, nylon fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-integrated sheet was washed with warm water at a temperature of 70 ° C. for 6 seconds, and then naturally dried to obtain a nonwoven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The quality of the nonwoven fabric was 99% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 100 g / m ² and a density of 50 kg / m ³ , which is dense and soft, and also has sufficient tension. After carrying out the fire resistance test, it was found that the burner had not covered the test body for 3 seconds, openings appeared in the part directly above the burner, and the test body itself ignited. It is difficult to say that it is flame-resistant. In addition, as described above, since the test body itself ignites and fires, the measurement cannot be performed, and it can be said that there is no flame retardance.

    [Comparative Example 2]    

The non-melting fibers A-1, thermoplastic fibers C-4, and other fibers D-3 are blended in a manner of mass ratio 3: 3: 4, and opened with a carding machine to form a fiber web (basis weight: 75g / m ² ). For the above-mentioned fiber web, the needles are acted upon at a density of 40 needles / cm ² , and these fibers are woven to form an integrated sheet having flame-resistant fibers, flame-resistant fibers, and PET fibers in the same nonwoven fabric layer. The integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fibers, flame-resistant rayon fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-integrated sheet was washed with warm water at a temperature of 70 ° C. for 6 seconds, and then naturally dried to obtain a nonwoven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The quality of the nonwoven fabric was 99% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 180 g / m ² and a density of 40 kg / m ³ , which is dense and soft, and also has sufficient tension. As a result of 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 resistance. However, in the flame retardancy evaluation, the test body itself ignited after 2 minutes of contact with the flame, so it did not have flame retardancy.

    [Comparative Example 3]    

The non-melting fiber A-1 and the thermoplastic fiber B-1 were blended in a manner with a mass ratio of 4: 6, and the fiber was opened with a carding machine to form a fiber web (basis weight: 97 g / m ² ). Aiming at the above-mentioned fiber web, the needles are activated according to a needle density of 40 pieces / cm ² , and these fibers are woven to form an integrated sheet having flame-resistant fibers and PPS fibers in the same nonwoven fabric layer. Next, 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 fused integrated sheet. The fusion-integrated sheet was washed with warm water at a temperature of 70 ° C. for 6 seconds, and then naturally dried to obtain a nonwoven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The mass of the nonwoven fabric is 50% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 100 g / m ² and a density of 50 kg / m ³ , which is dense and soft, and also has sufficient tension. As a result of the fire resistance test, the combustion body did not ignite even when heated for 1 minute, and the combustion area was 5 cm ² or less and the combustion length was 8 cm, which had sufficient flame resistance. In addition, the non-woven fabric did not break or open holes even when it was bent at 90 ° or more, and was found to have excellent bending workability. In the flame retardancy evaluation, the combustion body did not ignite even after 30 minutes, and had sufficient flame retardancy. However, since the fiber web formation rate is 50% by mass, the fibers are easily dropped from the card, and therefore it is necessary to reduce the card passing speed of the fibers.

    [Comparative Example 4]    

The non-melting fibers A-1, thermoplastic fibers B-1, and other fibers D-4 were mixed in a manner of mass ratio 3: 4: 3, and opened with a carding machine to form a fiber web (basic weight: 98g / m ² ). For the above-mentioned fiber web, the needles are acted upon at a density of 40 needles / cm ² , and these fibers are interwoven to form an integrated sheet having flame-resistant fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. Next, the integrated sheet is heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fibers, PPS fibers, and PET fibers constituting the sheet are fused to form a fused integrated sheet. The fusion-integrated sheet was washed with warm water at a temperature of 70 ° C. for 6 seconds, and then naturally dried to obtain a nonwoven fabric from which the oil agent had been removed. Each short fiber was taken out from the nonwoven fabric using tweezers, and the number of curls was measured. As a result, the number of curls of the raw materials described in "Using Fibers" was the same. The mass of the nonwoven fabric is 50% by mass (fiber web formation rate) based on the mass of the raw cotton.

The obtained non-woven fabric has a basis weight of 100 g / m ² and a density of 50 kg / m ³ , which is dense and soft, and also has sufficient tension. 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 10 cm ² or less and the combustion length was 10 cm, which had sufficient flame resistance. In addition, the non-woven fabric does not break even when it is bent at 90 ° or more, or has holes, and has excellent bending workability. In the evaluation of flame retardancy, the combustion body did not ignite even after 21 minutes, and had sufficient flame retardancy.

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

    (Industrial availability)    

The invention can effectively prevent fire from burning, and can be suitably used for wall materials, floor materials, ceiling materials, etc., which require flame resistance, and is particularly suitable for flame-resistant materials such as furniture and bedding.

Claims (10)

    A non-woven fabric comprising: non-melting fiber A having a high-temperature shrinkage of 3% or less; thermoplastic fiber B having a LOI value of 25 or more according to JIS K 7201-2 (2007); and JIS K 7201-2 (2007 ) Is a thermoplastic fiber C having a LOI value of less than 25 and having a warpage number of 8 (pieces / 25 mm) or more according to JIS L 1015 (2000).         For example, the non-woven fabric according to claim 1, wherein the thermoplastic fiber C contains 20 to 50% by mass of 100% by mass of the non-woven fabric.         The non-woven fabric according to claim 1 or 2, wherein in the 100% by mass of the non-woven fabric, the non-melted fiber A-based content contains 10% by mass or more.         The non-woven fabric according to any one of claims 1 to 3, wherein the thermoplastic fiber B system contains 20% by mass or more of 100% by mass of the non-woven fabric.         The non-woven fabric according to any one of claims 1 to 4, wherein the non-melt fiber A-based thermal conductivity is 0.060 W / m‧K or less.         The non-woven fabric according to any one of claims 1 to 5, wherein the non-melting fiber A is one or more types selected from flame-resistant fibers and meta-aramid fibers.         The nonwoven fabric according to any one of claims 1 to 6, wherein the glass transition point of the thermoplastic fiber B is 120 ° C or lower.         The non-woven fabric according to any one of claims 1 to 7, wherein the thermoplastic fibers B are selected from the group consisting of flame-retardant polyester fibers, non-isotropic molten polyester, and flame-retardant poly (acrylonitrile-butadiene- Styrene), flame retardant polyfluorene, poly (ether-ether-ketone), poly (ether-ketone-ketone), polyether fluorene, polyarylate, polyarylene sulfide, polyphenylene fluorene, polyether fluorene Fibers of at least one resin selected from the group consisting of amines, polyamides, imines and mixtures thereof.         The non-woven fabric according to any one of claims 1 to 8, wherein the thermoplastic fiber B contains a sulfur atom.     The non-woven fabric according to any one of claims 1 to 9, wherein the non-woven fabric has a basis weight of 50 g / m ² or more and a density of 50 kg / m ³ or less.