JPS5846145B2 - Foamed fireproof resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called foamed fireproofing composition which, when burned, produces a foamed char which has heat insulating properties.

It is known that an ethylene/vinyl acetate copolymer-vinyl chloride graft polymer produces foamed char when burned.

However, the polymer is easily flammable, and during combustion, the unburned portion is free-flowing, so it has the disadvantage that it is greatly deformed by its own weight and wind pressure, and may drip in some cases.

Moreover, the foamed carbide produced by combustion is brittle and has the disadvantage of being blown away by wind pressure, etc., so the above polymer alone is not practical as a foamed fireproofing material.

By the way, according to the research of the present inventors, when zinc or a zinc compound and a specific organic compound are made to coexist in the above-mentioned graft polymer, it is possible to make the graft polymer flame retardant without hindering its foamability. Flow deformation during combustion can be largely prevented.

Furthermore, the foamed carbide produced is hard and resistant to wind pressure and the like.

The present invention proposes a novel foaming fireproofing composition based on the above-mentioned new knowledge, which contains 100 parts by weight of an ethylene/vinyl acetate copolymer-vinyl chloride graft polymer as component (a). , 3 to 50 parts by weight of zinc or a zinc compound as component (b), and organic amines, organic amides, and sulfonylcarbazides as component (e). Or it consists of 5 to 70 parts by weight of two or more types.

As component (a), a known ethylene/vinyl acetate copolymer-tetravinyl vinyl graft copolymer is used.

In particular, ethylene with a vinyl acetate bond content of 20 to 50% by weight
A vinyl acetate copolymer to which vinyl chloride is grafted and whose vinyl chloride content is 40 to 70% by weight of the total amount of both is preferably used.

In addition, in the present invention, component (a) is 50% by weight.
It may be substituted with polyvinyl chloride, ethylene/vinyl acetate copolymer, or both, as long as it is below.

As the above-mentioned polyvinyl chloride/ethylene vinyl acetate copolymer, commercially available products are used, but preferably polyvinyl chloride has an average degree of polymerization of 800 to 2,500, and a vinyl acetate content of 20 to 75% by weight, especially 40 to 75% by weight. 75% by weight
It is an ethylene/vinyl acetate copolymer.

In the present invention, the zinc element is essentially effective as the component (middle), so various organic or inorganic compounds containing the zinc element are used as the zinc compound.

Component (b) is used in powder form, but it is preferably a fine powder, for example one that can pass through a 300 mesh sieve or more.

Preferred examples of component (b) are 3 ZnO-282
03.3 Zinc borate compounds such as H2O1 2ZnO-3B2O3-3, 5H20, molybdenum/zinc compounds such as ZnO-ZnMoO4, CaO/ZnMoO4, ZnO, ZnCo3, Z
n3 (PO4)3-4H20, etc.

Particularly preferred are ZnO, ZnO-ZnMo04, and the above zinc borate compounds.

Component (b) is 100% of component (a) converted to the amount of zinc element.
It is used in an amount of 3 to 50 parts by weight, but if it is less than 3 parts by weight, the effect of addition is poor, and if it is more than 50 parts by weight, the flexibility and extrusion processability of the composition will be impaired.

Therefore, the preferred amount of component (b) is 5 to 30 parts by weight, especially 1
It is 0 to 20 parts by weight.

Preferred components as component (e) have a boiling point or decomposition temperature of 1
50°C or higher, preferably 180°C or higher, solid at room temperature, particularly preferably one that passes through a 300 mesh sieve or a finer powder, similar to component (b). is preferred.

Examples of component (e) include melamine, urea formaldehyde, aminoacetic acid, trimethylolmelamine, hexamethylolmelamine, melamine resin N-N'dinitron,
Organic amines such as pentamethylenetetramine and guanidine, organic amides such as dicyandiamide, butyl urea, boria oxide resin, azodicarbonamide, nitrososulfonamide, P-)luenesulfonyl semicarhasite, P-P'-oxybenzene These include nosulfonyl carbazides such as sulfonyl carbacites.

Among these, particularly preferred are melamine and its derivatives as exemplified above, particularly JIK1531-
It is a No. 1 or No. 2 melan as defined in 1971.

The amount of component (e) is 5 parts per 100 parts by weight of component (a).
~70 parts by weight.

If the amount is less than 5 parts by weight, the effect of addition will be poor, and if it is more than 70 parts by weight, the flexibility, extrusion processability, etc. of the composition will be impaired.

The preferred amount of component (e) used is 5 to 50 parts by weight, particularly 10 to 30 parts by weight.

In the present invention, if necessary, ordinary rubbers such as flame retardants, anti-aging agents, plasticizers, lubricants, pigments, fillers, etc.
There is no problem even if a normal amount of a compounding agent for plastics is blended.

Among these, the use of a flame retardant is particularly preferred in the present invention.

According to the research of the present inventors, the above-mentioned (b) component and (e
The component (a) not only further promotes the effect of preventing the deformation of the component (a) during combustion, but also has the remarkable effect of lengthening the mechanical strength of the foamed carbide produced by combustion, the lifespan of the carbide burned out by flames, etc.

Furthermore, it has the effect of further improving the flame retardancy of the composition of the present invention.

The flame retardant may be of any type as long as it can make component (a) flame retardant, but preferred are inorganic retardants such as antimony trioxide, antimony dioxide, molybdenum trioxide, aluminum hydroxide, and ammonium polyphosphate. These include flame retardants, organic flame retardants such as tetrabromobisphenol, decabromodiphenyl oxide, perchloropentacyclodecane, and tris-bromochloropropyl phosphate.

The preferred amount of flame retardant used is 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 prepared using a two-roll, Banbury mixer-1.
It can be manufactured by kneading rubber, plastics, etc. using a conventional kneading machine.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

The formulations of each Example and Comparative Example (all parts are parts by weight) are shown in the following table.

Each of these compositions was extruded and coated on a three-core polyethylene insulated vinyl chloride sheathed cable in two thicknesses, and each was subjected to the following combustion test.

Combustion test A cable sample was supported directly above two city gas burners with a burner temperature of 1100°C and a flame length of 20 to 25 cIrL (angle between burners 900), and this cable sample was directly heated by the gas burner, and under DC 120OV voltage application, After heating starts, 5
Measure the insulation resistance between the cable cores at minutes, 10 minutes, and 30 minutes.

The results of each test are shown in the table below.

According to the observation results through this test, in the cable material coated with the example composition, foaming expansion of the coating layer was remarkable, and hardly any flow deformation of the carbonized layer was observed, and the vinyl chloride sheath was exposed. There was no.

In addition, the table also shows whether the physical properties are good or bad in terms of extrusion processability and flexibility.

As is clear from the comparison of the test results of each Example and the test results of Comparative Example 1 to Therefore, polyethylene insulated cables (flammable materials) can be stably protected from flames for a long time.

On the other hand, in Comparative Example 1, the coating layer sagged due to long-term exposure to flame, and the polyethylene insulation ignited for about 15 minutes.
A short circuit occurred in 1 minute, exposing the 1st position groove body.

Furthermore, as is clear from the comparison between each Example and Comparative Example 2, the flame-retardant resin according to the present invention also has excellent physical properties such as extrusion processability and flexibility.

Claims (1)

[Claims] 1 (a) a graft polymer of ethylene/vinyl acetate copolymer-vinyl chloride, and per 100 parts by weight of the graft polymer; (b) from the group consisting of organic amines, organic amides, and sulfonylcarbazides; A foamed fireproof resin composition comprising 5 to 70 parts by weight of one or more selected types, and (e) zinc or a zinc compound, with an amount of 3 to 50 parts by weight of zinc.