JPS59176351A - Flame-retardant material - Google Patents

Abstract

PURPOSE:To provide a flame-retardant material which is harmless to the human body and has an excellent effect of imparting flame retardance to combustible materials such as building materials, by incorporating a highly water-absorptive high-molecular material as a water-retaining material. CONSTITUTION:A highly water-absorptive high-molecular material (e.g. a saponified ethylene/vinyl ester/acrylate ester copolymer or a crosslinked acrylic acid/ acrylate salt copolymer) alone or a mixture thereof with a rubber or a resin is used as the titled flame-retardant material. Examples of the rubbers are an ethylene/propylene rubber, chloroprene rubber, etc. Examples of the resins are polyethylene, polyvinyl chloride, etc. The flame-retardant material is wetted with water, hermetically sealed to retain-water and put to practical use. Alternatively, the material in a dry state is put to practical use and, when a fire occurs, the material is wetted with water by means of a sprinkler to make it flame-retardant.

Description

[Detailed Description of the Invention] It is well known that flame retardant materials are required in many fields such as architecture and vehicles, and that demands for flame retardancy are increasing and standards are becoming stricter. It's here. The demands are expanding from simply improving ``flammability'' to encompassing reductions in toxic scum and smoke. In particular, the construction field in which synthetic chemical products are used in many materials and flame retardancy is highly required will be described below as a representative example, but this is not intended to limit the present invention.

In the construction field, combustible wood and petrochemical products are used for many materials such as ceiling panels, wall panels, and flooring materials. These materials include a method of laminating or mixing inorganic non-combustible materials, mainly gypsum, etc., and a method of coating and mixing flame retardants and flame retardant aids containing halogens, phosphorus, etc. However, inorganic noncombustible materials have many problems in compounding, such as increasing the weight of the building material and adhesion with other materials.

Furthermore, when flame retardants and flame retardant aids are used in building materials, they degrade the physical properties of combustible materials, and sometimes even cannot be mixed.

Chemical extinguishing agents that generate incombustible scum, such as carbon dioxide and nitrogen, are available as extinguishing agents, but it goes without saying that the most common extinguishing agent is water. However, many combustible synthetic chemical building materials are hydrophobic, so the extinguishing power of water is low, and even if the fire is extinguished, it can re-ignite, which is a major practical problem.

The present inventors have diligently studied flame retardation of combustible materials,
The present invention provides flame retardancy to combustible materials by utilizing water itself. More specifically, the present invention relates to a flame retardant material characterized by using a super absorbent polymer as a water retainer.

It is of great significance that the present inventors have obtained a new flame retardant technology that is harmless to the human body and is very effective in practice through the present invention. The present invention will be described in more detail below.

In the present invention, superabsorbent polymers include ethylene-vinyl ester-acrylic acid ester keticides, acrylic acid-acrylate copolymer crosslinked products, and starch-acrylate copolymers.
Crosslinked product of alkali metal salt of acrylic acid graft polymer,
Examples include an alkali salt of a reaction product of polyvinyl alcohol and maleic anhydride. These superabsorbent polymers can be used by themselves or in combination with combs or resins. Typical rubbers include natural rubber, imprene rubber, styrene-butadiene rubber, chloroprene rubber, acrylonitrile rubber, ethylene propylene rubber, urethane rubber, polysulfide rubber, silicone rubber, chlorinated polyethylene,
Examples include chlorosulfonated polyethylene, and typical resins include polyethylene, polyvinyl chloride, polyethylene vinyl acetate, and polystyrene. In general, flame retardant materials need to have a long lifespan, and must have weather resistance, heat resistance, cold resistance, ozone resistance, etc., and are also used as the middle layer of buildings while making use of custom-made insulation materials. As water-absorbing polymers, saponified products of ethylene-vinyl ester acrylate esters and cross-linked products of acrylic acid-acrylate copolymers are most important, and as rubbers, ethylene propylene rubber, chloroprene rubber, and urethane rubber are most important. (Ethylene propylene rubber as used herein means an ethylene-α-olefin copolymer or an ethylene-α-olefin-nonconjugated diene copolymer. As the α-olefin, propylene or most (Because it is common and important, it is abbreviated as ethylene propylene rubber.) These super absorbent polymers, rubbers or resins containing super absorbent polymers are filled with fillers, softeners, pigments, and various anti-aging agents as necessary. Compounding agents such as additives and stabilizers are used in combination to serve as a flame retardant material. Vulcanized products and crosslinked products can be made using vulcanizing agents, vulcanization accelerators, cross-linking agents, cross-linking aids, etc., and they can also be used as flame-retardant materials as foams by using foaming agents, foaming aids, etc. be.

The present flame retardant material may be subjected to a hydrous treatment before being put to practical use, or it may be used in a dry state and then subjected to a hydrous treatment as necessary.

A typical example of the latter is one in which water is supplied by a sprinkler or the like in the event of a fire, and water is treated to make it flame retardant. In the latter case, it is generally necessary to carry out water treatment in a short period of time, and therefore it is often preferable to use a large amount of highly water-absorbing polymer, or to use a foam or an elastic material rather than a solid material.

In the latter case, sealing treatment for water retention is taken as necessary.

Until now, the use of superabsorbent polymers has been widely known. However, these are used as so-called water-stopping materials such as sealants and waterproof sheets, and there have been no examples of actively utilizing the "flame retardant" property newly imparted by water absorption as in the present invention.

The flame-retardant material of the present invention has excellent water-holding ability, so it has excellent flame-retardant properties. show. The flame retardant material of the present invention can also be used as an intermediate layer between the interior material of a building and the main body of the building, or as a heat insulating material. Furthermore, since the flame-retardant material of the present invention increases in volume by absorbing water, it also exhibits smoke-proof sealing performance in the case of a building fire.

Examples of the present invention will be shown below, but the present invention is not limited thereto. In addition, ethylene propylene rubber (manufactured by Sumitomo Chemical Industries, Nisprene 0) will be described as a representative example, which is a flame-retardant material that is flammable in itself, but has a long service life when used in combination with a superabsorbent polymer as mentioned above. This is because it can be created. Furthermore, a saponified product of ethylene to hinyl ester 7/L/acrylic acid ester (Sumikagel 0, manufactured by Sumitomo Chemical) was used as a super absorbent polymer, as this is also the most preferable super absorbent polymer from the viewpoint of flame retardant material. It is. The present invention is not limited to these combs or superabsorbent polymers.1.Example 1 An example in which a superabsorbent polymer is used sparingly is shown.

Sumika gel film sheet (thickness O, l = s11)
After spraying water on the surface of the surface to make it hydrated, the flame retardance of the surface was evaluated by applying a fire from a flame retardant to the back surface.

Example 2 An example of a flame retardant material using ethylene propylene rubber and a super absorbent polymer is shown.

(Mixed wire) Knead for 5 minutes using a BR type Banbury, and add additional milling below calcium oxide using a 10-inch roll (preparation of test pieces) Non-crosslinked product: Create a sheet with a thickness of 2B using a 90°C low-temperature press. Warp cross-linked-hood product: A 2-thick sheet was created using a high-temperature press at 160°C for 10 min. Cross-linked sponge product: Created by hot air vulcanization at 170°C for 3 minutes using a 211-Ill thick ribbon-like extrusion sample. A test piece with a width of 2c+++ and a length of 12σ was prepared from each sample.

(Combustion test method) The test piece was placed vertically, and a gas burner flame was applied from the bottom for 5 seconds to measure the combustion state. It shows that it can be tilted. According to the present invention, it is possible to obtain extremely excellent flame retardancy even in high-mail compositions and sponge bodies, which was impossible even with the use of conventional flame retardants and flame retardant aids. The volume increase rate due to water content corresponds to the water content. It can be seen that it has a very high water content (water retention rate) of 280 to 560%. Up to now, methods have been studied to improve flame retardancy by using substances containing water of crystallization (for example, aluminum hydroxide, etc.) as fillers.
Since the present invention contains much more water than these conventional methods, its flame retardant properties are also very good.

Moreover, it is advantageous in terms of cost.

Since the volume increases after it absorbs water, for example, when used for buildings, it can fill gaps in various places and prevent smoke and debris from leaking to other places.

The sponge body can also be used as a heat insulating material.
The sponge according to the invention is very practical and useful.

Claims (1)

[Scope of Claims] 1) A super absorbent polymer, or a hydrous flame retardant material characterized by containing a super absorbent polymer and imparted flame retardancy by containing water, or by containing water. A water absorbable flame retardant material that can be imparted with flame retardancy. 2) The flame retardant material or flame retardant material according to claim 1, which is made of rubber or resin containing a superabsorbent polymer. 3) The flame retardant material or flame retardant according to claim 1, characterized in that it is composed of an ethylene-○ olefin copolymer or an ethylene-○ olefin-nonconjugated diene copolymer containing a superabsorbent polymer. material. 4) Claim 1 characterized in that it is a foam.
Flame retardant materials or materials for flame retardancy as described in Items 2 and 3.