WO2019167750A1

WO2019167750A1 - Non-woven fabric

Info

Publication number: WO2019167750A1
Application number: PCT/JP2019/006296
Authority: WO
Inventors: 陳瑶; 原田大; 土倉弘至
Original assignee: 東レ株式会社
Priority date: 2018-03-01
Filing date: 2019-02-20
Publication date: 2019-09-06
Also published as: EP3760776A1; RU2020130606A; CA3090924A1; JPWO2019167750A1; TW201938869A; CN111819316A; US20200392657A1; KR20200126364A

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 a nonwoven fabric.

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

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

In addition, as a method of obtaining a flame-retardant nonwoven fabric, the fiber after spinning is subjected to a specific treatment to impart flame retardancy, and the nonwoven fabric is used, or the fiber raw material itself has flame retardancy There is also a method of spinning it into a non-woven fabric. For example, Patent Document 3 discloses that a non-woven fabric is composed of a flame-resistant fiber that has obtained high flame retardancy by a treatment after spinning or a fiber that has obtained flame retardancy by polymerizing a specific raw material. Patent Document 4 discloses a non-woven fabric containing flame-resistant fibers and polyphenylsulfone fibers that have obtained high flame barrier properties by the processing after spinning.

JP 2013-169996 A JP 2012-144818 A JP 2003-129362 A International Publication No. 2017/6807

However, the methods described in Patent Documents 1 and 2 are the simplest methods for imparting flame retardancy, but the attached flame retardant tends to drop off, and the flame retardant has an excellent flame retarding effect. Even if it has, the problem remains in terms of its durability.

In addition, the nonwoven fabric described in Patent Document 3 uses a flame-resistant fiber having a high critical oxygen index LOI value. However, such a fiber tends to fall when passing through a card machine, and in the end, it is also flame retardant. Problems also remain in terms of workability. Furthermore, since the nonwoven fabric described in Patent Document 4 contains flame-resistant fibers and polyphenylsulfone (PPS), it has high flame retardancy and flame barrier properties. There is room for improvement.

The present invention has been made in view of the problems of such a conventional flame retardant nonwoven fabric, and provides a nonwoven fabric excellent in card permeability and durability while being excellent in flame retardancy and flame barrier properties. It is intended to do.

In order to solve the above problems, the present invention employs any of the following means.
(1) Non-melted fiber A having a high temperature shrinkage rate 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) And a thermoplastic fiber C having a LOI value in accordance with JIS L 1015 (2000) of less than 25 and a crimp number of 8 (pieces / 25 mm) or more in accordance with JIS L 1015 (2000). Non-woven fabric.
(2) The nonwoven fabric according to (1), wherein the thermoplastic fiber C is contained in an amount of 20 to 50% by mass in 100% by mass of the nonwoven fabric.
(3) The non-woven fabric according to (1) or (2), wherein the non-melted fiber A is contained in an amount of 10% by mass or more in 100% by mass of the non-woven fabric.
(4) The nonwoven fabric according to any one of (1) to (3), wherein the thermoplastic fiber B is contained in an amount of 20% by mass or more in 100% by mass of the nonwoven fabric.
(5) Any of (1) to (4) above, wherein the non-melting fiber A has a thermal conductivity of 0.060 W / m · K or less according to ISO 22007-3 (2008). The non-woven fabric according to crab.
(6) The non-woven fabric according to any one of (1) to (5), wherein the non-melting fiber A is at least one selected from flameproof fibers and meta-aramid fibers.
(7) The nonwoven fabric according to any one of (1) to (6), wherein the thermoplastic fiber B has a glass transition point of 120 ° C. or lower.
(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 mixture of at least one resin selected from the group consisting of these The nonwoven fabric according to any one of (1) to (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), 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 retardance and flame barrier properties but also excellent card passing properties and durability by having the above-described configuration.

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

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

In the present invention, the non-molten fiber A having a high temperature shrinkage rate of 3% or less constitutes a nonwoven fabric together with the thermoplastic fibers B, C, etc., but when the flame approaches the nonwoven fabric and heat is applied, the thermoplastic fiber C is the first. It begins to melt, then the thermoplastic fiber B melts, and the melted thermoplastic fibers B and C spread in a thin film along the surface of the non-molten fiber A (aggregate). As the temperature rises, all of the fibers A to C eventually carbonize, but the non-melt fiber A has a high temperature shrinkage rate of 3% or less. Because it is difficult to open, it can block the flame. In this respect, the high-temperature shrinkage rate of the non-melt fiber A is preferably low, but the high-temperature shrinkage rate is -5% or more because the structure collapses and causes pores even if it is not shrunk and expands greatly due to heat. It is preferable. In particular, the high temperature shrinkage rate is preferably 0 to 2%.

The high-temperature shrinkage rate is as follows: (i) The fiber as a raw material of the nonwoven fabric is left in a standard state (20 ° C., relative humidity 65%) for 12 hours, and then a tension of 0.1 cN / dtex is applied to obtain the original length L0 (Ii) without applying a load to the fiber, exposed to a dry heat atmosphere at 290 ° C. for 30 minutes, sufficiently cooled in a standard state (20 ° C., relative humidity 65%), and further fiber The length L1 is measured by applying a tension of 0.1 cN / dtex to (iii), and (iii) is a numerical value obtained from L0 and L1 by the following formula.
High temperature shrinkage = [(L0−L1) / L0] × 100 (%)
Further, as the non-molten fiber A, it is preferable to use a fiber having a thermal conductivity of 0.060 W / m · K or less. When the thermal conductivity of the non-molten fiber A is within this range, the thermal insulation performance is also excellent. The thermal conductivity [W / m · K] is the basic thermal constant of the material, It is a single heat transfer coefficient. Expresses the ease of heat transfer in the material, and refers to the value obtained by dividing the heat flow density (heat energy passing through the unit area per unit time) by the temperature difference between the front and back surfaces of the material. Specifically, the thermal conductivity of the fiber is a non-woven fabric test piece having a thickness of 0.5 mm using the fiber to be measured, and the thermal diffusivity of the test piece according to ISO 22007-3 (2008), The specific heat of the test piece is measured according to JIS K 7123 (1987), and the specific gravity of the test piece is further measured according to JIS K 7112 (1999).

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

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

Of these, flame-resistant fibers are preferable because they have a low high temperature shrinkage rate. Among various flame-resistant fibers, acrylonitrile-based flame-resistant fibers are preferably used as fibers that have a small specific gravity and are flexible and excellent in flame retardancy. Such flame-resistant fibers can be obtained by heating and oxidizing acrylic fibers as precursors in high-temperature air.

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

If the content of the non-molten fiber A in the nonwoven fabric is too low, the function as an aggregate tends to be insufficient, whereas if it is too high, the thermoplastic fibers are difficult to spread into a sufficient film shape. Therefore, the content of the non-molten fiber A in the nonwoven fabric is preferably 10% by mass or more, more preferably in the range of 15 to 60% by mass, and in the range of 30 to 50% by mass. Most preferred.

Subsequently, the thermoplastic fiber B that will spread as a film-like substance has an LOI value of 25 or more according to JIS K 7201-2 (2007), while the thermoplastic fiber C has an LOI value of less than 25. .

The LOI value is the volume percentage of the minimum oxygen amount necessary for sustaining the combustion of the substance in the mixed gas of nitrogen and oxygen, and it can be said that the higher the LOI value, the more difficult it is to burn. Therefore, the thermoplastic fiber B having a LOI value of 25 or more is difficult to burn, even if it is ignited, it immediately extinguishes when the fire source is released, and a carbonized film is usually formed in the part where the fire spreads slightly. The carbonized part prevents the spread of fire. On the other hand, the thermoplastic fiber C having a LOI value of less than 25 does not extinguish even when the fire source is released, 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, more preferably in the range of 25 to 50, from the viewpoint of forming a carbonized film at a high temperature. 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 of the speed of carbonization coating.

The thermoplastic fiber B used in the present invention is not particularly limited as long as the LOI value is within the range specified in the present invention. Specific examples thereof include flame retardant polyester fiber (polyethylene terephthalate fiber, polytrimethylene). Terephthalate fiber, polyalkylene terephthalate fiber, etc.), anisotropic molten polyester, flame retardant poly (acrylonitrile butadiene styrene), flame retardant polysulfone, poly (ether-ether-ketone), poly (ether-ketone-ketone), poly Mention may be made of fibers composed of thermoplastic resins selected from the group of ether sulfones, polyarylate, polyarylene sulfides, polyphenyl sulfones, polyetherimides, polyamideimides and mixtures thereof. These may be used alone or in combination of two or more.

If the glass transition point of the thermoplastic fiber B is 120 ° C. or less, the binder effect for maintaining the form as a nonwoven fabric can be obtained at a relatively low temperature, so the apparent density increases and the strength increases. ,preferable. Among these, polyphenylene sulfide fiber (hereinafter also referred to as PPS fiber) is most preferable from the viewpoint of high LOI value and easy availability. The binder effect means that the thermoplastic fiber is melted or softened by heat and fused to another fiber. In addition, the thermoplastic fiber B preferably contains a sulfur atom as a fiber, but in that case, not only a fiber made of a resin containing a sulfur atom but also a fiber in which a sulfur atom is imparted by post-processing is preferable.

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

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

As a method for producing the PPS fiber, a method in which a polymer having the above-described phenylene sulfide structural unit is melted at a melting point or higher and spun from a spinneret to form a fiber is preferable. The spun fiber is an unstretched PPS fiber as it is. Most of the unstretched PPS fibers have an amorphous structure, and can act as a binder for bonding the fibers by applying heat. On the other hand, since such fibers have poor dimensional stability due to heat, stretched yarns are commercially available in which the fiber is stretched and oriented following spinning to improve the strength and dimensional stability of the fiber.

The content of the thermoplastic fiber B as described above in the nonwoven fabric is preferably 10% by mass or more, more preferably 20% by mass or more in order to reliably form a film-like substance and to further improve flame retardancy and flame barrier properties. It is more preferable that On the other hand, the upper limit is preferably 55% by mass or less. The content 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 a LOI value of less than 25, and at the same time, the crimp number according to JIS L 1015 (2000) is 8 (pieces / 25 mm) or more. Thus, in the present invention, the thermoplastic fiber B having a LOI value of 25 or more and the thermoplastic fiber C having a LOI value of less than 25 are mixed. Fibers with an LOI value of 25 or more are relatively straight and are easy to fall off during non-woven fabric processing because they are difficult to crimp. However, if the thermoplastic fiber C has an LOI value of less than 25, it is crimped as described above. It is easy to process and is difficult to fall off due to the three-dimensional helical structure due to crimping. Therefore, by mixing the thermoplastic fibers B and C, not only the thermoplastic fibers C but also the thermoplastic fibers B are less likely to fall off due to the crimping of the thermoplastic fibers C. It is a non-woven fabric that is excellent and has excellent card passage, durability, and quality.

If the number of crimps of the thermoplastic fiber C is too large, uniform dispersion of the fibers becomes difficult, and the formation and mechanical strength of the nonwoven fabric may be reduced. / 25 mm) or less. Furthermore, 10 to 50 (pieces / 25 mm) is more preferable, and 10 to 30 (pieces / 25 mm) is more preferable from the viewpoint of further improving crimp processability and card passing property.

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

The non-melting fiber A and the thermoplastic fibers B and C as described above are formed in a web in which they are mixed. For example, the thermoplastic fiber C is formed by applying heat exceeding the melting point of the thermoplastic fiber C. Once melted and then cooled and solidified, the thermoplastic fiber C is fused to the non-melted fiber A and the thermoplastic fiber B and integrated to form a nonwoven fabric. In fusing, the thermoplastic fiber C is softened by a method of applying heat exceeding the glass transition point of the thermoplastic fiber C, and pressure is applied to the thermoplastic fiber C, the unmelted fiber A, and the thermoplastic. The fiber B may be pressure-bonded. By carrying out like this, the higher binder effect can be acquired and it is preferable.

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

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

In the nonwoven fabric of this invention, it is also preferable that a density is 50 kg / m < ³ > or less. Thermal conductivity becomes smaller and excellent heat insulation performance can be obtained. In order to exhibit light weight and excellent heat insulation performance, the density is more preferably 50 to 30 kg / m ³ , and further preferably 50 to 40 kg / m ³ .

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

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

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

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

When the combustion body 4 ignites within 3 minutes of flame contact, it is indicated as “no flameproof” and indicated as F. If the combustor 4 does not ignite even if exposed to flame for 3 minutes or longer, “flame shielding performance is provided”, but the longer the flame shielding time, the better. Indicated as A.

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

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

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

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

<Used fiber>
<Non-melting fiber A-1>
1.7 dtex flame-resistant fiber “PYRON” (registered trademark) manufactured by Zoltek, length 6 mm, high temperature shrinkage 1.6%, thermal conductivity 0.033 W / m · K
<Non-melting fiber A-2>
1.67 dtex meta-aramid fiber, length 6 mm, high temperature shrinkage 2.8%, thermal conductivity 0.055 W / m · K.

<Thermoplastic fiber B-1>
PPS fiber (containing 35% by mass of unstretched PPS fiber in 100% by mass of PPS fiber), length 5.1 mm, LOI value 34, glass transition temperature 90 ° C., crimp number 6 (pieces / 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., crimp number 6 (pieces / 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., crimp number 6 (pieces / 25 mm).

<Thermoplastic fiber C-1>
PET fiber (containing 35% by mass of PET unstretched yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68 ° C., crimp number 16 (pieces / 25 mm)
<Thermoplastic fiber C-2>
PET fiber (containing 33% by mass of PET unstretched yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68 ° C., crimp number 16 (pieces / 25 mm)
<Thermoplastic fiber C-3>
PET fiber (containing 30% by mass of PET unstretched yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68 ° C., crimp number 16 (pieces / 25 mm)
<Thermoplastic fiber C-4>
PET fiber (containing 50% by mass of PET unstretched yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68 ° C., crimp number 13 (pieces / 25 mm).

<Other fiber D-1>
Acrylic fiber, length 5.1 mm, high temperature shrinkage 35%, thermal conductivity 1.02 W / m · K
<Other fibers D-2>
Nylon fiber (containing 33% by mass of nylon unstretched yarn in 100% by mass of nylon fiber), length 5.1 mm, LOI value 21, glass transition temperature 58 ° C., crimp number 15 (pieces / 25 mm)
<Other fiber D-3>
Flame retardant rayon fiber, length 5.1mm, LOI value 27, crimp number 5 (pieces / 25mm)
<Other fibers D-4>
PET fiber (containing 35% by mass of PET unstretched yarn in 100% by mass of PET fiber), length 5.1 mm, LOI value 20, glass transition temperature 68 ° C., crimp number 3 (pieces / 25 mm).

[Example 1]
Non-melt fiber A-1, thermoplastic fiber B-1, and thermoplastic fiber C-1 are blended so that the mass ratio is 3 to 4 to 3, and opened by a card machine to obtain a fiber web (weight: 98 g / m ² ) was formed. By causing needles to act on the fiber web at a needle density of 40 / cm ² , the fibers are intertwined to form an integrated sheet having flameproof fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. did. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fiber, PPS fiber, and PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 98% by mass with respect to the raw cotton mass (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 soft, but had sufficient elasticity. As a result of performing the flame resistance test, even when heated for 1 minute, the combustion body did not ignite, the combustion area was 10 cm ² or less, and the combustion length was 10 cm. . In addition, the nonwoven fabric did not break or perforate even when bent at 90 ° or more, and had excellent bending workability. Furthermore, in the flameproof evaluation, the combustor did not ignite for 21 minutes and had a sufficient flameproofness.

[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 opened by a card machine to obtain a fiber web (weight: 130 g / m ² ). By causing the needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were entangled to form an integrated sheet having meta-aramid fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. . Subsequently, the integrated sheet was heat treated with a hot air dryer set at a temperature of 150 ° C., and the meta-aramid fiber, the PPS fiber, and the PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 97% by mass with respect to the raw cotton mass (web formation rate).

The obtained non-woven fabric had a basis weight of 135 g / m ² and a density of 45 kg / m ³ , was dense and provided with elasticity, but was slightly softer than the non-woven fabric of Example 1. As a result of conducting the flame resistance test, even when heated for 1 minute, the combustion body did not ignite, the combustion area was 10 cm ² or less, and the combustion length was 12 cm. . Further, even when the nonwoven fabric was bent at 90 ° or more, it was not broken or perforated, and had excellent bending workability. Furthermore, in the flame barrier evaluation, the combustion body did not ignite for 15 minutes and had sufficient flame barrier properties.

[Example 3]
Non-melt fiber A-1, thermoplastic fiber B-2, and thermoplastic fiber C-2 are blended so that the mass ratio is 3 to 3 to 4, and the fiber web is opened by a card machine. (A basis weight: 115 g / m ² ) was formed. By causing needles to act on the fiber web at a needle density of 40 / cm ² , the fibers are intertwined to form an integrated sheet having flameproof fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. did. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flameproof fiber, PPS fiber, and PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 97% by mass with respect to the raw cotton mass (web formation rate).

The obtained nonwoven fabric had a basis weight of 122.5 g / m ² , a density of 35 kg / m ³ , and was dense and soft, but also provided sufficient tension. As a result of the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, but residual dust was observed, and the residual time was 3 seconds. Further, the combustion area was 29 cm ² or less, and the combustion length was 11 cm, which was sufficiently flame retardant. Further, it was found that even when the nonwoven fabric was bent at 90 ° or more, it was not broken or perforated, and had excellent bending workability. Furthermore, in the flame barrier evaluation, the combustion body did not ignite for 15 minutes and had sufficient flame barrier properties.

[Example 4]
Non-melt fiber A-2, thermoplastic fiber B-3, and thermoplastic fiber C-2 are blended so that the mass ratio is 4 to 1: 5, opened by a card machine, and a fiber web (weight: 38 g / m ² ) was formed. By causing the needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were entangled to form an integrated sheet having meta-aramid fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. . Subsequently, the integrated sheet was heat treated with a hot air dryer set at a temperature of 150 ° C., and the meta-aramid fiber, the PPS fiber, and the PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 97% by mass with respect to the raw cotton mass (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 soft, but had sufficient elasticity. As a result of the combustion resistance test, the combustion body did not ignite even when heated for 1 minute, but residual dust was observed, and the residual time was 3 seconds. Further, the combustion area was 27 cm ² , and the combustion length was 18 cm. Further, it was found that even when the nonwoven fabric was bent at 90 ° or more, it was not broken or perforated, and had excellent bending workability. Furthermore, in the flame barrier evaluation, the combustion body did not ignite for 9 minutes and had sufficient flame barrier properties.

[Comparative Example 1]
The thermoplastic fiber C-3 and the other fibers D-1 and D-2 are blended so that the mass ratio is 3 to 3 to 4, and opened by a carding machine to obtain a fiber web (weight per unit: 98 g). / M ² ). By causing needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were entangled to form an integrated sheet having acrylic fibers, nylon fibers, and PET fibers on 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 acrylic fiber, nylon fiber, and PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 99% by mass with respect to the mass of raw cotton (web formation rate).

The obtained non-woven fabric had a basis weight of 100 g / m ² and a density of 50 kg / m ³ , and was dense and soft, but had sufficient elasticity. As a result of conducting the combustion resistance test, a hole was opened in the portion directly above the burner in less than 3 seconds by holding the burner over the test piece, and the test piece itself was ignited and burned. Therefore, it cannot be said that it has a flame retardance. Further, as described above, the test specimen itself ignited and burned, and it can be said that it does not have flameproofing properties without being measured.

[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 opened by a card machine to obtain a fiber web (weight: 75 g / m ² ). An integrated sheet having flame resistance fibers, flame-retardant rayon fibers, and PET fibers in the same nonwoven fabric layer by tangling those fibers by causing needles to act on the fiber web at a needle density of 40 / cm ^2. Formed. The integrated sheet was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fire fiber, flame retardant rayon fiber, and PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 99% by mass with respect to the mass of raw cotton (web formation rate).

The obtained non-woven fabric had a basis weight of 180 g / m ² and a density of 40 kg / m ³ , and had sufficient tension while being dense and soft. 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 15 cm ² , and the combustion length was 8 cm. However, in the flameproof evaluation, the specimen itself ignited after 2 minutes from the flame contact, and therefore it did not have flameproofness.

[Comparative Example 3]
Unmelted fiber A-1 and thermoplastic fiber B-1 were blended so that the mass ratio was 4 to 6, and opened by a card machine to form a fiber web (weight per unit: 97 g / m ² ). By causing needles to act on the fiber web at a needle density of 40 / cm ² , the fibers were intertwined to form an integrated sheet having flameproof 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 flameproof fiber and the PPS fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 50% by mass based on the raw cotton mass (web formation rate).

The obtained non-woven fabric had a basis weight of 100 g / m ² and a density of 50 kg / m ³ , and had sufficient tension while being dense and soft. As a result of conducting the flame resistance test, even if heated for 1 minute, the combustion body did not ignite, and the combustion area was 5 cm ² or less and the combustion length was 8 cm, which was sufficiently flame retardant. . Further, it was found that even when the nonwoven fabric was bent at 90 ° or more, it was not broken or perforated, and had excellent bending workability. Furthermore, in the flameproof evaluation, the combustor did not ignite for 30 minutes and had sufficient flameproofness. However, as indicated by the fact that the web formation rate is 50% by mass, the fibers are likely to fall from the card machine, so it was necessary to reduce the fiber passing speed of the card machine.

[Comparative Example 4]
Non-melt fiber A-1, thermoplastic fiber B-1, and other fibers D-4 are blended so that the mass ratio is 3 to 4 to 3, and opened by a carding machine to obtain a fiber web (weight: 98 g / m ² ) was formed. By causing needles to act on the fiber web at a needle density of 40 / cm ² , the fibers are intertwined to form an integrated sheet having flameproof fibers, PPS fibers, and PET fibers in the same nonwoven fabric layer. did. Subsequently, the integrated sheet was heat-treated with a hot air dryer set at a temperature of 150 ° C., and the flame-resistant fiber, PPS fiber, and PET fiber constituting the sheet were fused to form a fused integrated sheet. The fused 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 was removed. When each short fiber was taken out from this nonwoven fabric using tweezers and the number of crimps was measured, it was equivalent to the number of crimps of the raw material described in << used fibers >>. The mass of the nonwoven fabric was 50% by mass based on the raw cotton mass (web formation rate).

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

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

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

Claims

Non-melted fiber A with a high temperature shrinkage rate of 3% or less, thermoplastic fiber B with a LOI value of 25 or more in accordance with JIS K 7201-2 (2007), and JIS K 7201-2 (2007) A non-woven fabric comprising a thermoplastic fiber C having a conforming LOI value of less than 25 and having a crimp number of 8 (pieces / 25 mm) or more conforming to JIS L 1015 (2000).
The nonwoven fabric according to claim 1, wherein 20 to 50 mass% of the thermoplastic fiber C is contained in 100 mass% of the nonwoven fabric.
The non-woven fabric according to claim 1 or 2, wherein the non-melted fiber A is contained in an amount of 10% by mass or more in 100% by mass of the non-woven fabric.
The nonwoven fabric according to any one of claims 1 to 3, wherein the thermoplastic fiber B is contained in an amount of 20 mass% or more in 100 mass% of the nonwoven fabric.
The nonwoven fabric according to any one of claims 1 to 4, wherein the non-melting fiber A has a thermal conductivity of 0.060 W / m · K or less.
The nonwoven fabric according to any one of claims 1 to 5, wherein the non-melting fiber A is at least one selected from flameproofing fibers and meta-aramid fibers.
The nonwoven fabric according to any one of claims 1 to 6, wherein the thermoplastic fiber B has a glass transition point of 120 ° C or lower.
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-). 2. A fiber of at least one resin selected from the group of ketone), polyethersulfone, polyarylate, polyarylene sulfide, polyphenylsulfone, polyetherimide, polyamideimide, and mixtures thereof. The nonwoven fabric according to any one of 7 to 7.
The nonwoven fabric according to any one of claims 1 to 8, wherein the thermoplastic fiber B contains a sulfur atom.
The nonwoven fabric according to any one of claims 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.