JPS63309645A - Interior material of airplane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aircraft interior material with excellent fire blocking properties (fire resistance).

(Prior Art) In recent years, regulations on making interior materials flame retardant have become stricter year by year, triggered by aircraft fire accidents. Therefore, various fire-retardant materials, ie, fire-blocking materials, are used for interior materials such as seats, walls, ceilings, and floors of aircraft in order to protect human lives from fires. For example, a flame-resistant fabric called a fire blocking layer is placed between the outer material of the seat and the polyurethane foam inside.

By the way, various materials have been proposed for the fire blocking layer. For example, in JP-A No. 61-55268, flame-resistant fibers (semi-carbon fibers) are made by heating and oxidizing acrylic fibers in the air.
A flame-resistant fabric is disclosed in which a fabric made of para-oriented aromatic polyamide fibers is coated with a silicone resin.

However, flame-resistant fibers produced by heating and oxidizing acrylic fibers in high-temperature air have a non-uniform oxidation structure in which the surface area of the fibers is extremely oxidized compared to the inside of the fibers. Because of this, it has low mechanical strength, especially tensile strength, and low toughness, making spinning or knitting difficult. , was not satisfactory.

Therefore, as mentioned above, large amounts of para-oriented aromatic polyamide fibers are used in combination to improve wear resistance.
There is a problem in that when a large amount of this para-oriented aromatic polyamide fiber is used, the flame retardance of the fabric decreases.

On the other hand, the walls, ceilings, and floors of aircraft are constructed by laminating FRP made of fabrics such as glass fiber, carbon fiber, or para-aramid fiber on a honeycomb of meta-aramid fibers, but each has its own merits and demerits as a fire-blocking material. However, it is not always sufficient. For example, glass fibers are heavy, carbon fibers are expensive, and para-aramid fibers lack flame retardancy.In particular, it will be difficult for para-aramid fibers to meet future strict flame retardant regulations.

(Problems to be Solved by the Invention) An object of the present invention is to use a sulfur-containing acrylic flame-resistant fiber fabric with high tensile strength, excellent toughness, and flame retardancy as a fire blocking material. The purpose of the present invention is to provide an aircraft interior material that is highly strong, has excellent wear resistance, is lightweight, and is inexpensive.

(Means for Solving the Problems) As described in the claims, the object of the present invention is to have a tensile strength of at least 3°5 g/d, a limiting oxygen index (LOI) of 40 or more, and This can be achieved by using an aircraft interior material made of a sulfur-containing acrylic flame-resistant fiber fabric having a sulfur content of 5% by weight or more as a fire blocking material.

The sulfur-containing acrylic flame-resistant fiber (hereinafter simply referred to as flame-resistant fiber) constituting the aircraft interior material of the present invention has a flame retardancy that is not due to the introduction of oxygen bonds but to the introduction of sulfur bonds. and has a sulfur content of 5% by weight or more, preferably 8 to 25% by weight, and a limiting oxygen index (LOI) representing the degree of flame retardancy of 40 or more,
45-70 and a tensile strength of at least 3.5 g/d, preferably 4-9 g/d. In order to impart superior processability and wear resistance to the sulfur-containing acrylic flame-resistant fiber, the flame-resistant fiber has a It is desirable that the displayed toughness is 10 or more, preferably 12 to 35.

If the sulfur content is less than 5% by weight, it will not be possible to provide sufficient properties such as flame retardancy, heat resistance, and chemical resistance, and if it is too large, mechanical strength will decrease. So I don't like it.

Furthermore, if the tensile strength is less than 3.5 g/d,
When the flame-resistant fibers are converted into yarns, fabrics, etc. by spinning, knitting, needle punching, etc., fluff is likely to occur, making it impossible to obtain good yarns, fabrics, and other products. Furthermore, during use as a fire blocking layer, the fibers wear out and fall off, resulting in poor durability and unsatisfactory practicality.

The tensile strength used in the present invention is at least 3.5 g/d, L
Flame-resistant fibers with an OI of 40 or more and a sulfur content of 5% by weight or more can only be obtained by using specific acrylic fibers and by adopting specific sulfiding processes and conditions as detailed below. can.

That is, first, the degree of polymerization of the acrylic fiber is at least 1.5 in terms of intrinsic viscosity, preferably 2.0 to 5.
Acrylic fibers with as high strength and high modulus as possible from such high polymerization degree polymers are used.
i.e. a tensile strength of at least 7 g/d, preferably 9
It is necessary to form acrylic fibers of y/d or more, more preferably 10 g/d or more.

Flame-resistant fibers are produced by heating and sulfurizing the acrylic fibers in a sulfur-containing atmosphere under relatively slow reaction conditions to fully introduce sulfur bonds into the fibers, resulting in flame-resistant fibers with little difference in internal and external structure. However, in order to manufacture such high-strength flame-resistant fibers with small differences in internal and external structures, acrylic fibers are required to have small differences in internal and external structures, be dense, and have high strength. be.

Here, the acrylonitrile (hereinafter abbreviated as AN)-based polymer constituting the acrylic fiber used in the present invention may be an AN sole polymer or a carboxylic acid such as acrylic acid, methacrylic acid, itaconic acid, etc. as a copolymer component. Lower alkyl esters thereof, hydroxyalkyl acrylates containing a carboxyl hydroxyl group such as hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylamide, methacrylamide, α-chloroacrylonitrile, hydroxyethyl acrylic acid,
Examples include awalsulfonic acid and methacrylsulfonic acid, but among these, acrylamides are particularly preferred because they undergo a quick sulfurization reaction and produce flame-resistant fibers with high tensile strength, and their copolymerization amount is 10 mol% or less. , preferably 1 to 7 mol%.

These AN-based polymers can be used in their solvents, such as dimethyl sulfoxide (DMSO), dimethyl acetamide (D
MAc>, dimethylformamide (DMF>, etc.), a concentrated aqueous solution of an inorganic salt such as calcium chloride, zinc chloride, Rodan soda, etc., an inorganic solvent such as nitric acid, preferably an organic solvent such as DMSO, to increase the polymer concentration. 5
~20% spinning dope.

The spinning method of the obtained spinning dope includes dry/wet spinning, dry spinning, wet spinning, That is, the distance between the spinneret surface and the coagulation bath liquid level is set within the range of 1 to 20 m, preferably 3 to 10 m, and the microscopic particles formed by the spinneret surface and the coagulation bath liquid surface are separated from the spinneret hole. After discharging the spinning stock solution into the space, a method is adopted in which it is introduced into a coagulation bath and coagulated, and then the obtained coagulated fiber thread is washed with water, desolventized, primary stretched, dried and densified, and then subjected to conventional methods.
The fibers are subjected to post-processing steps such as secondary drawing and heat treatment to form drawn fiber threads. The fiber yarn obtained by this dry/wet spinning has extremely excellent drawability, but preferably the secondary drawing method is at least 1.1 times, preferably 1. Stretched 5 times or more so that the total effective stretching ratio is at least 10 times, preferably 12 times or more, and the fineness is in the range of 0.5 to 7 denier (d), preferably 1 to 5 d. It is better.

If the fineness is smaller than 0.5d, the spinnability of the resulting flame-resistant fiber will be reduced, making it difficult to obtain textile products with good abrasion resistance.If the fineness is larger than 7d, the fiber during sulfurization will This is not preferable because sulfidation becomes uneven in the cross section.

The acrylic fiber thus obtained is exposed to a sulfur-containing atmosphere,
For example, the fibers are flame-proofed by heating in single or mixed gases such as carbon disulfide, hydrogen sulfide, sulfur dioxide, and sulfur gas, but preferably the fibers are uniformly sulfurized (not double-layered) over the entire fiber cross section. It is preferable to use sulfur dioxide as the sulfur-containing atmosphere. Further, it is preferable to heat and sulfurize the flameproofing temperature in a temperature range of 230 to 400'C.

In other words, according to the studies of the present inventors, when the acrylic fibers are heated and sulfurized in this sulfur dioxide atmosphere, the flame resistance reaction is faster than the oxidation reaction in an oxidizing atmosphere such as ordinary air. Sulfur dioxide penetrates smoothly into the fiber, and as a result, sulfur atoms are distributed evenly over the entire cross section of the fiber, making it possible to create a flame-resistant fiber with a fiber WI structure with no difference between the inner and outer structures. Therefore, it is advantageous.

Incidentally, in the present invention, the sulfur-containing atmosphere, especially the sulfur dioxide atmosphere, may be a heated atmosphere in which other gases such as nitrogen and oxygen are mixed together. In particular, the mixed gas of sulfur dioxide and nitrogen is It is effective in efficiently reacting sulfur with fibers.

The heating in this flameproofing step may be performed under constant temperature conditions,
The temperature may be elevated, and the acrylic fibers may be under tension, constant length, or relaxation.

As an example, the first stage heating is carried out in a heating furnace maintained at a temperature range of 230-280'C, and the second stage heating is carried out at a temperature range of 280-440'C.
One example is a method in which sulfurization is completed within a temperature range of 00'C in a heating furnace set to temperature increasing conditions in stages.

Next, the fabric constituting the aircraft interior material of the present invention is made into a 145-woven fabric using the above-mentioned flame-resistant fibers by a conventional method.

For example, it can be easily made into a fabric by weaving or knitting filament yarns or spun yarns made of flame-resistant fibers. Alternatively, it may be a nonwoven fabric that is formed by needle punching a staple of the flame-resistant fiber.

In order to provide higher tensile strength and abrasion resistance during knitting, weaving, and non-woven fabric production,
Aramid fibers (e.g. Kevlarpa, Technora and Nomex), polyphenylene sulfide (PPS) fibers, polyimide fibers, phenolic weave, cotton, wool, non-woven fibers, etc. are blended, spun or mixed and twisted for various purposes. can provide product performance suitable for

Furthermore, in order to impart higher fire-blocking properties, the fabric may be impregnated with or coated with a flame-retardant resin or rubber.

Next, examples of the aircraft interior material of the present invention will be specifically explained based on the drawings.

FIG. 1 is a cross-sectional view of a seat that is an embodiment of the aircraft interior material according to the present invention, in which a nonwoven fabric made of sulfur-containing acrylic flame-resistant fiber is used as a fire blocking layer between the outer material 1 and the polyurethane foam 2 of the seat. 3 is arranged.

FIG. 2 is a cross-sectional view of a wall or ceiling that is an embodiment of the aircraft interior material according to the present invention, in which a carbon fiber filament fabric 5 is placed before and after a honeycomb 4 made of meta-aramid fibers, and 7 fiber blocks are placed above the honeycomb 4. A filament fabric 6 of sulfur-containing acrylic flame-resistant fiber is arranged as a packing material, bonded with a phenol resin 7, and its surface is coated. In the present invention, the limiting oxygen index (LOI) and tensile strength are values measured by the following measuring method.

Limiting Oxygen Index (LOI): A value measured according to the measurement method specified in JIS-7201, and the specific details are as follows.

Wrap 1 g of the sample to be measured around a wire (support) with a diameter of about 1 m, form a string with a diameter of about 4#, and fix it to a frame with a length of 150 m. Next, this is set in a combustion cylinder, and after flowing a mixed gas of oxygen and nitrogen into it at a flow rate of 11.41/min for about 30 seconds, the upper end of the sample is ignited, and the sample continues to burn for more than 3 minutes. Or, after ignition, determine the minimum oxygen flow rate (A) necessary to continue burning to a combustion length of 50#I#I or more, and the nitrogen flow rate 1 (B) at that time. The ratio of the oxygen flow rate to the total flow rate of the mixed gas is LOf, which is expressed by the following equation.

LOI=(A/(A+B>)×100 Tensile strength: Measured according to the measuring method specified in J15-L-1069.

(Effects of the Invention) The aircraft interior material according to the present invention uses, as a fire blocking material, a fabric made of sulfur-containing acrylic flame-resistant fibers that are uniformly sulfurized in the cross-sectional direction of the fibers and have high strength and excellent flame retardancy. Not only does it have excellent fire blocking properties, but it also has excellent mechanical properties such as abrasion resistance, so it can fully comply with the flame retardant regulations for aircraft interior materials that are becoming stricter every year. is inexpensive and lightweight, making it extremely useful for aircraft applications.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a seat, which is an embodiment of the aircraft interior material according to the present invention, and FIG. 2 is a cross-sectional view of a wall or ceiling, which is an embodiment of the aircraft interior material according to the present invention. 1: Outer material 2: Urethane foam 3: Nonwoven fabric of sulfur-containing acrylic flame-resistant fiber 4: Honeycomb 5: Filament fabric of carbon fiber 6: Filament fabric of sulfur-containing acrylic flame-resistant fiber 7: Phenol resin 8: Paint

Claims (1)

[Claims] (1) The fire blocking material is composed of a sulfur-containing acrylic flame-resistant fiber fabric having a tensile strength of at least 3.5 g/d, a limiting oxygen index (LOI) of 40 or more, and a sulfur content of 5% by weight or more. Aircraft interior materials featuring: