JPS6237055B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is directed to a so-called foamed fire-retardant resin composition which produces a foamed carbide having heat insulating properties when combusted. As a foamed fireproofing composition that has been proposed in the past, for example, a foamed fireproofing composition based on a blend of ethylene/vinyl acetate and vinyl chloride containing a large amount of vinyl acetate is known. However, although the above-mentioned composition has excellent oil resistance, the foamed carbonized layer is brittle, and therefore, if exposed to flame for a long time, the foamed carbonized layer will fall off, resulting in poor fire protection performance. The present invention proposes a novel foam fireproofing composition that does not have the above-mentioned problems, and according to the research of the present inventors, a graft of polyvinyl chloride and an alkyl acrylate, zinc or a zinc compound, and a specific organic A composition comprising this compound exhibits excellent oil resistance in high-temperature oil, is further flame retardant, and foams when burned. However, it was discovered that the foamed carbide that is formed during combustion has low flow deformability and is hard, strong against wind pressure, etc., and has oil resistance. The present invention proposes a new foamed fireproofing resin composition completed based on the above new knowledge, which consists of component (A), component (B), and component (C). Component (A) is 100 parts by weight of a graft copolymer of polyvinyl chloride and alkyl acrylate, and component (B) is 3 to 3 parts by weight of zinc or a zinc compound.
50 parts by weight, and 5 to 70 parts by weight of one or more selected from the group consisting of organic amines, organic amides, and sulfonyl cabazides as component (C). (A) Component A graft copolymer of a vinyl chloride resin and an alkyl acrylate to serve as the backbone polymer. It is a copolymer with other polymerizable monomers, etc.
On the other hand, the alkyl acrylates include those having 1 to 18 carbon atoms, such as methyl acrylate, ethyl acrylate, propyl acrylate, lauryl acrylate, stearyl acrylate, or their methacrylates. In addition, in the present invention, component (A) is 50% by weight.
Polyvinyl chloride, ethylene/vinyl acetate copolymer, ethylene/vinyl acetate copolymer -
It may be substituted with one or more vinyl chloride graft copolymers. As the polyvinyl chloride, ethylene, vinyl acetate copolymer, and ethylene/vinyl acetate copolymer-vinyl chloride graft copolymer, commercially available products can be used, but preferably, the average degree of polymerization is 800.
~2500 polyvinyl chloride, vinyl acetate content 20
~75% by weight especially 40~75% by weight of ethylene/vinyl acetate copolymer, 40~95% of polyvinyl chloride is graft polymerized to ethylene/vinyl acetate copolymer with vinyl acetate content of 50%. It is an ethylene/vinyl acetate copolymer-vinyl chloride graft polymer. (B) Ingredient Since the zinc element is essentially effective, various organic and inorganic compounds containing the zinc element are used as zinc compounds, but this (B) ingredient is used in powder form. For example, one that can pass through a 300-mesh sieve is preferable, and one that is finer than that is preferable. Furthermore, preferable examples of component (B) are 3ZnO・2B ₂ O ₃・3H ₂ O, 2ZnO・3B ₂ O ₃・
Boric acid/zinc compounds such as 3.5H ₂ O, ZnO/
Molybdenum zinc compounds such as ZnM ₀ O ₄ , CaO, ZnM ₀ O ₄ , ZnO, ZnCO ₃ , Zn ₃ (PO ₄ ) ₃ , 4H ₂ O, ZnO
and MgO composite calcined products. Especially preferably
These include ZnO, ZnO.ZnMO ₄ and the above-mentioned zinc borate compounds. Component (B) is converted to the amount of zinc element (A) component.
3 to 50 parts by weight are used per 100 parts by weight, but 3
If it is less than 5 parts by weight, the effect of addition will be poor, and if it is more than 50 parts by weight, the flexibility and extrusion processability of the composition will be impaired, so 5 to 30 parts by weight is preferable. Particularly preferred is 10-20
Parts by weight. Component (C) A substance with a boiling point or decomposition temperature of 150° C. or higher, especially 180° C. or higher, and which is solid at room temperature is particularly preferable, and like component (B), a fine powder that can pass through a 300-mesh sieve is more preferable. Examples of ingredients (C) include melamine,
Organic amines such as urea formaldehyde, aminoacetic acid, trimethylol melamine, hexamethylol melamine, melamine resin, N,N′ dinitrosopentamethylenetetramine, guanidine, dicyandiamide, butyl urea, polyamide resin, azodicarbonamide nitrososulfonamide, etc. These include amides and sulfonylcarbazides such as P-toluenesulfonylcarbazide. Particularly preferred among these are melamine and its derivatives as exemplified above, particularly JIS K 1531-
These are No. 1 and No. 2 melamine specified in 1971. The amount of component (C) is 5 to 70 parts by weight per 100 parts by weight of component (A), but if it is less than 5 parts by weight, the addition effect will be poor, and if it is more than 70 parts by weight, the flexible extrusion processability of the composition will be impaired. . The amount is preferably from 5 to 70 parts by weight, particularly preferably from 10 to 30 parts by weight. In the present invention, if necessary, ordinary compounding agents for rubbers and plastics such as ordinary flame retardants, anti-aging agents, plasticizers, lubricants, pigments, fillers, etc. may be added in ordinary amounts. Among these, the use of flame retardants is particularly preferred in the present invention. The flame retardant may be of any kind as long as it can make component (A) flame retardant, but preferred ones include antimony trioxide, antimony dioxide, molybdenum trioxide, aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, organic flame retardants such as tetrabromobisphenol, decabromodiphenyl oxide, perchloropentacyclodecane, trisbromochloropropyl phosphate, etc. The amount of flame retardant to be used is preferably 1 to 50 parts by weight, particularly 5 to 30 parts by weight per 100 parts by weight of component (A). The composition of the present invention can be produced by kneading rubber or plastic in a conventional manner using a commonly used kneading machine such as a two-roll mixer or a Banbury mixer. Hereinafter, the present invention will be explained in more detail with reference to examples and comparisons. Examples and comparative formulations are shown in Table 1 below (however, all parts are expressed in parts by weight) The composition of each formulation was extruded and coated on a three-core polyethylene insulated vinyl chloride sheath cable to a thickness of 2 mm. The following combustion tests and oil resistance tests were carried out. Physical properties are also listed. (1) Combustion test City gas 2 with burner temperature 1100℃ and flame length 20-25cm
The cable sample was supported directly above the main burner (angle between burners 90°), and the cable sample was directly heated with the gas burner.
The insulation resistance between cable cores was measured at 10 minutes, 10 minutes, and 30 minutes. The results of each test are shown in Table 1 below. According to the observation results through this test, the foaming expansion of the example composition used for the cable sheathing in the example was remarkable, and there was hardly any flow deformation of the carbonized layer, and the vinyl chloride sheath was not exposed. Ta. (2) Oil resistance test An oil resistance test was conducted at 100°C for 4 days in accordance with UL Standard 83. Items with an elongation rate of 60% or more after being immersed in oil passed, and items with an elongation rate of less than 60% failed. (3) Physical properties Good or bad physical properties in terms of extrusion processability and flexibility are also listed. As is clear from the comparison of the test results for each example and the sample results for Comparative Example 1, the coating layer made of the foamed fireproof resin composition of the present invention is effective for the addition of melamine or a melamine compound and a zinc compound. , can protect polyethylene insulated cables (flammable) from flames for long periods of time. On the other hand, in Comparative Example 1, the coating layer sagged due to long-term exposure to flame, resulting in a short circuit in the polyethylene insulation approximately 12 minutes after ignition, and a portion of the conductor was exposed. Furthermore, as is clear from each Example and Comparative Example 2, the flame-retardant resin according to the present invention is also excellent in extrusion processability, flexibility, and oil resistance.

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Claims (1)

[Claims] 1 (A) Per 100 parts by weight of the graft copolymer of polyvinyl chloride and alkyl acrylate (B) Zinc or a zinc compound with an amount of 3 to 50 parts by weight of zinc (C) Organic amines, organic amides, and sulfonyl A foamed fireproof resin composition comprising 5 to 70 parts by weight of one or more selected from the group consisting of carbazides.