JPS6140380A - Fire-proof paint and electric wire and cable coated therewith - Google Patents

Abstract

PURPOSE:A fire-proof paint, consisting of specific amounts of an aqueous emulsion resin, inorganic powder, phosphoric acid ester and inorganic fibers, capable of giving films having improved fire resistance and flexibility without emitting hydrogen halides on combustion, and suitable for protecting electric wires, etc. CONSTITUTION:A fire-proof paint, obtained by incorporating (A) 9.5-20wt%, based on solid (15-30wt% in the dried film), aqueous emulsion resin, e.g. polyvinyl acetate emulsion, with (B) 30-50wt% (45-75wt% in the dried film) inorganic powder, preferably hydrated alumina, (C) 1-10wt% (1.5-15wt% in the dried film) phosphoric acid ester, e.g. trimethyl phosphate, and (D) 0.1-3wt% (0.2-4.5wt% in the dried film) organic incombustible fibers, e.g. phenolic fibers.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a fire-retardant paint that protects combustible objects from burning in the event of a fire, and electric wires and cables coated with a coating made of this fire-retardant paint. .

[Prior art] For example, if a fire occurs in electrical equipment where a large number of wires and cables are installed, the wires and cables may be disconnected.
! There is a risk that material A may become fuel and cause the fire to spread.

In order to prevent such a situation, it is common practice to apply fireproof paint to the outer periphery of electric wires and cables.

Conventional fire protection paints include water-based emulsion resins with halogenated flame retardants, inorganic fillers, and nonflammable fibers.

Water-based emulsion resins function as binders for various compounding agents during coating film formation, and provide mechanical strength and flexibility to coating films. They are usually vinyl acetate-ethylene copolymer emulsions, acrylic ester copolymer emulsions, etc. is used.

The halogen flame retardant makes the water-based emulsion resin flame retardant, and the inorganic filler and nonflammable MS, IT improve the fire resistance of the coating film and prevent the coating film from falling off during combustion. be.

[Problems to be Solved by the Invention] The above-mentioned conventional fire prevention paint uses a halogen-based flame retardant, which causes hydrogen halide to be generated during combustion. Of course, the hydrogen halide can reduce the concentration released outside the system in correspondence with the inorganic components among the components.

For example, calcium carbonate is known as a trap for hydrogen halides. However, such a method cannot capture all the hydrogen halide, and a trace amount of hydrogen halide will be released.

The object of the present invention is to provide a fireproof coating that does not generate hydrogen halide during combustion, and electric wires and cables coated with the same.

[Means for Solving the Problems] The fireproofing paint of the present invention has a composition mainly composed of an aqueous emulsion resin solid content of 9.5 to 20% by weight and 30 to 50% by weight.
inorganic powder, 1-10% by weight phosphoric acid ester, 0.1
It is characterized by consisting of ~3% by weight of organic nonflammable fibers.

Further, the electric wire/cable of the present invention has a composition after drying in which the main parts are 15 to 30% by weight of aqueous emulsion resin solids, 715 to 75% by weight of inorganic powder, and 1.5 to 15% by weight.
The invention is characterized in that it is coated with a fireproof coating film containing 0.2 to 4.5% by weight of organic noncombustible fibers.

In the present invention, examples of the aqueous emulsion resin include polyvinyl acetate emulsion, vinyl acetate-ethylene copolymer emulsion, vinyl acetate-vinyl propionate copolymer emulsion, vinyl acetate-acrylate copolymer emulsion, acrylic ester copolymer emulsion, etc. They can be used alone or in combination of two or more.

These resins act as binders for paint films, but since they are generally flammable, it is preferable to use them in a minimum amount, and the solid content of the resins is 9.
．． 5-20% by weight (15-30% by weight in the dry coating film)
) should be within the range.

If it is less than 945% by weight, the function as a binder is reduced and flexibility becomes poor, and if it exceeds 20% by weight, M flammability is reduced.

Examples of inorganic powders include calcium carbonate, aluminum oxide, magnesium silicate, silica, hydrated alumina, boron/acid zinc, and clay. In this case, hydrated alumina is most effective in imparting flame retardancy, and it is preferable that hydrated alumina accounts for 50% or more of the inorganic powder.

Inorganic powder is the backbone of fire-retardant paint, and is 30 to 5
It should be in the range 0% by weight (45-75% by weight in the dry coating).

If the amount is less than 30% by weight, the fire resistance is insufficient, and if the amount is less than 50% by weight.
If it exceeds this, the flexibility of the coating film will decrease.

Phosphate esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, t.
Examples include lioctyl phosphate, 2-ethylhexyl-diphenyl phosphate-1-, tributoxyethyl phosphate, cresyl-diphenyl phosphate, isodecyl-diphenyl phosphate, tricresyl phosphate, tritolyl phosphate, tricylenyl phosphate, etc. Alternatively, two or more types can be used in combination.

Phosphate ester is 1 to 10% by weight (1 to 10% by weight in the dried coating film)
．． 5-15% by weight).

If it is less than 1% by weight, the coating film will have poor flexibility, and if it exceeds 15% by weight, no corresponding effect will be observed.

Organic nonflammable! Examples of miscellaneous fibers include phenolic LiI fibers and poly P-phenylene terephthalamide fibers. These I! If the rough length is less than 0.5 In#1, the reinforcing effect of the coating film will decrease, and if it exceeds 10 In#I, uniform dispersion becomes difficult, so a range of 0.5 to 8 In#I is preferable. .

The organic non-combustible fiber is concentrated in the range of 0.1 to 3% by weight (0.2 to 4.5% by weight in the dried coating film), and 0.1 to 3% by weight.
If it is less than % by weight, it will not be very effective in improving coating workability.
If it exceeds 3% by weight, dispersibility will deteriorate.

In the present invention, in addition to the above-mentioned components, various pigments, dispersants, thickeners, bactericides, etc. may be included as necessary.

Such fire-retardant paints are applied to the surface of combustible objects, but
Among these, it is suitable for application to electric wires and cables.゛Specific materials for electric wires and cables include polyethylene,
Examples include polyvinyl chloride, polychloroprene, butyl rubber, etc., but particularly remarkable effects are observed when using easily flammable materials such as polyethylene.

[Example 1] A uniform paint was prepared using a stirrer according to the mixing ratios shown in Table 1.

This paint was applied to the outer periphery of the polyethylene sheath of the cable using a brush so that the coating thickness after drying was 1.5 mm.

Table 2 shows the composition of the dried coating film and the evaluation results for various properties.

The evaluation was based on the following.

Fire resistance: A cable coated with paint was tilted at an angle of 45 degrees, and the lower part of the cable was exposed to flame for 1 minute using a gas burner, and the presence or absence of the paint film falling off and the presence or absence of damage to the cable insulation layer were observed.

Flexibility: The presence or absence of cracks in the coating film was observed when the sample cable was bent along a mandrel 8 times the diameter of the cable (bending test).

) 1 (, I generation amount: Take a 0.5 g sample from the coating film,
The combustion gas was heated to 50° C., passed through a nitric acid aqueous solution, and measured according to JISKO107 (silver nitrate method).

[Effects of the Invention] As is clear from the above explanation, the fireproof coating of the present invention does not generate hydrogen halide during combustion, and the coating film after drying has excellent fireproofing properties and flexibility. .

Spontaneous writing of procedural amendment> Showa 60. , Table of '3.08 1 incident, Showa 59 Patent Application No. 161681
No. 2 Name of the invention Fire-retardant paint and electric wires/cables coated with the same 3 Person making the amendment 5, subject of the amendment (1) Column for detailed explanation of the invention in the written lit.

6. Contents of amendment (1) Tables 1 and 2 on pages 9 to 10 of the specification
Replace the table with attached Tables 1 and 2.

7.8 List of attached documents (1) One or more copies of Replacement Tables 1 and 2

Claims (2)

[Claims] (1) The main part of the composition is 9.5-20% by weight of aqueous emulsion resin solids, 30-50% by weight of inorganic powder, 1
A fire-retardant paint characterized by comprising ~10% by weight of phosphoric acid ester and 0.1-3% by weight of organic nonflammable fibers. (2) On the outer periphery of the electric wire/cable, the main component after drying is 15-30% by weight of aqueous emulsion resin solids, 45-75% by weight of inorganic powder, and 1.5-15% by weight of phosphorus. An electric wire/cable coated with a fireproof coating containing an acid ester and 0.2 to 4.5% by weight of organic nonflammable fiber.