JPS6383192A - Fire-proof composition - Google Patents

Abstract

PURPOSE:To provide a fire-proof compsn. capable of forming a fire-proof layer having high flame retardancy and excellent fire proofness, which comprises polychloroprene, a polyhydric hydrocarbon alcohol, and a flame-retardant dehydrating agent. CONSTITUTION:100pts.wt. polychloroprene is blended with 80-120pts.wt. polyhydric hydrocarbon alcohol (e.g., monopentaerythritol), 80-120pts.wt. flame- retardant dehydrating agent (e.g., ammonium phosphate) and, if necessary, rubber, an antioxidant for plastics, a plasticizer, a softening agent, a colorant, a stabilizer, or the like to prepare a fire-resistant compsn. The periphery of a flammable material, such as an electric wire or a cable, is extrusion-coated with the fire-proof compsn. to form a fire-proof layer. Alternatively, the fire- proof compsn. is formed into a tape or a sheet, which is in turn wound around the periphery of a flammable material to form a fire-proof layer.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a fire-resistant composition that forms a fire-resistant layer for preventing the spread of fire to electric wires, cables, and other combustible materials, particularly a highly flame-retardant composition. The present invention relates to a fire-resistant composition capable of forming a fire-resistant layer having excellent fire-resistant performance.

[Prior Art] As a method of preventing the spread of fire to electric wires, cables, and other combustible materials in the event of a fire, methods such as applying fire-retardant paint and wrapping fire-resistant tape or sheets have traditionally been adopted. There is.

[Problems to be Solved by the Invention] In methods using fireproof paints, the coating film of many fireproof paints may crack or fall off in the event of a fire, reducing the fire spread prevention effect. In addition, it is difficult to uniformly coat electric wires and cables installed in narrow places such as tunnels, and in some cases, the coating may not dry and flow after coating.

The method of winding a fireproof tape or sheet achieves a relatively good fire spread prevention effect, but the flame retardance is insufficient and a sufficient fire spread prevention effect may not be achieved.

The present invention is based on the above, and aims to provide a fire-resistant composition that can exhibit excellent fire-resistant performance by imparting high flammability.

The fireproof composition of the present invention is characterized by containing 80 to 120 parts by weight of a hydrocarbon polyhydric alcohol and 80 to 120 parts by weight of a flame retardant dehydrating agent based on 100 parts by weight of polychloroprene.

In the present invention, as the polychloroprene, those commercially available under trade names such as Neoprene W1, Neoprene WRT, and Neoprene WB can be used, and these may be used by blending them in an appropriate ratio.

Examples of the hydrocarbon polyhydric alcohol include monopentaerythritol, dipentaerythritol, polypentaerythritol, and sorbitol.

Flame-retardant dehydrating agents are those that thermally decompose and react with the hydroxyl groups contained in hydrocarbon polyhydric alcohols to form a foamed carbonized layer, such as ammonium phosphate, ammonium polyphosphate, melamine phosphate, etc. can be given.

The amount of hydrocarbon polyhydric alcohol and flame retardant dehydrating agent is 80 to 120 parts by weight per 100 parts by weight of polychloroprene.
It is necessary to contain within a range of parts by weight, and if it is less than 80 parts by weight, flame retardancy and/or foaming carbonization properties are insufficient.
If it exceeds 120 parts by weight, kneading processability will be significantly impaired.

In the present invention, in addition to the above-mentioned components, deterioration inhibitors, plasticizers, softeners, colorants, stabilizers, etc. commonly used in rubbers and plastics may be added.

In addition, if a vulcanizing agent is added to vulcanize the fireproof layer, it will not foam at all even when exposed to flame, and the intermediate product of the foaming carbonization reaction will drip from the surface, so avoid adding a vulcanizing agent. , it is necessary to keep it in an unvulcanized state.

The fire-resistant composition of the present invention can form a fire-resistant layer by directly extruding and coating the outer periphery of combustible objects such as electric wires and cables. It is also possible to form a fireproof layer by forming the fireproof composition into a tape or sheet and winding it around a combustible material.

[Examples of the Invention] The fireproof compositions having the formulations shown on each side of Table 1 were evaluated for each item of flame retardancy, foaming carbonization property, and roll kneading property.
The results are shown in the lower column of Table 1 according to the evaluation criteria in Table 2. The evaluation was based on the following.

Oxygen index: Measured using Toyo Rika Kogyo (structural combustion tester 0N-1 type).

Foaming carbonization: As shown in the attached drawing, an insulated wire 3 is used, in which a copper wire 1 with a diameter of 2 mm is coated with a cross-linked polyethylene insulator 2 with a thickness of 1 mm, and a fire-resistant composition is coated on each side with a thickness of 5 mm. A sample was prepared by extrusion coating to form a fireproof layer 4. This sample was heated with an experimental Bunsen burner 6 and placed vertically on a cross-linked polyethylene insulator 2 with a diameter of 0.4 mm.
The electrical resistance between the copper wire 5 and the copper wire 1 was measured using an insulation resistance meter Ω, and the determination was made based on the time when the electrical resistance became 1 MΩ or less. The electrical resistance was measured using a battery-type insulation resistance meter manufactured by Yokogawa Hokushin Electric Co., Ltd. (Kiku), and the voltage was 100 OV.

Roll kneading property It was judged from the kneading workability using two 28-inch rolls.

Table 2 As is clear from Table 1, the Examples within the scope of the present invention had sufficiently satisfactory results in all evaluation items. On the other hand, in Comparative Example 1, the contents of the hydrocarbon polyhydric alcohol and the flame retardant dehydrating agent were lower than the specified values, and the flame retardance and foaming carbonization were inferior. Comparative Example 2 is a case where the content of hydrocarbon polyhydric alcohol is less than the specified value, and Comparative Example 3 is a case where the content of the flame retardant dehydrating agent is less than the specified value, and although the flame retardance is good, there is almost no foaming. However, there was a phenomenon in which intermediate products caused by heating dripped from the surface. Comparative example 4 is a case where the content of hydrocarbon polyhydric alcohol and flame retardant dehydrating agent is higher than the specified value,
Roll kneading workability is extremely poor.

[Effects of the Invention] As explained above, according to the present invention, it is possible to realize a fireproof layer having good flame retardancy and fireproof performance.

[Brief explanation of the drawing]

The attached drawing is an explanatory diagram of a method for evaluating foaming carbonization property.

Claims (1)

[Claims] (1) A non-vulcanizable fire-resistant composition containing 80 to 120 parts by weight of a hydrocarbon polyhydric alcohol and 80 to 120 parts by weight of a flame retardant dehydrating agent per 100 parts by weight of polychloroprene.