KR20110107609A - High performance flame retardant and low smoke composition for sheath and a cable including the sheath formed therefrom - Google Patents

Abstract

The present invention relates to a cable having a high flame retardant and low smoke sheath material composition and a sheath formed therefrom. The sheath material composition is 100 parts by weight of polyvinyl chloride resin having a polymerization degree of 800 to 2000; 20 to 130 parts by weight of a plasticizer which is a mixture of 10 to 50 parts by weight of a brominated flame retardant plasticizer, 5 to 40 parts by weight of ethylene copolymer resin and 5 to 40 parts by weight of trimellitic plasticizer; 40 to 110 parts by weight of a flame retardant; And 5 to 50 parts by weight of depressant. The sheath formed from the sheath material composition according to the present invention not only has excellent tensile strength, elongation and thermal stability at room temperature, but also has properties of high flame retardancy and low smoke.

Description

High Performance Flame Retardant And Low Smoke Composition For Sheath And A Cable Including The Sheath Formed Therefrom}

The present invention relates to a cable having a high flame retardant and low smoke retardant sheath material composition and a sheath formed therefrom. Sheaths formed from the high flame retardant and low smoke sheath material compositions of the present invention can be used to make plenum grade cables that meet UL910 specifications.

When a fire occurs in an office or a building, problems such as generation of toxic gas due to cable combustion and propagation of a fire are caused, and efforts to develop cables having high flame retardancy and low smoke are continuing.

As part of this effort, conventionally, Category 5 among unshielded twisted pair (UTP) cables has a fluorine-based system that self-extinguishing the cable to satisfy the plenum level, which is the highest flame retardant grade of the cable. It consisted of a polyvinyl chloride sheath with the copper conductor insulated with resin and the addition of a flame retardant. In category 6 of the UTP cable, a cable was formed by inserting a cross-shaped cross filler made of a fluorine resin between conductors. In addition, the sheath of a cable was manufactured using resin which added phosphate type plasticizer or bromine type plasticizer independently to polyvinyl chloride, or mixed and added them. However, phosphate-based plasticizers have the disadvantage of deteriorating heat resistance although they have flame retardant properties. In addition, the bromine-based plasticizer has a high flame retardant characteristics, but also does not satisfy the low smokeability, there was a disadvantage that emits toxic gases harmful to the human body during the combustion process.

Method of adding ammonium octamolybdate (AOM) as a smoker to overcome the disadvantages of the plasticizer, aluminum hydrate (ATH, aluminum trihydrate) and magnesium hydrate (MDH) as a depressant and flame retardant , magnesium dihydrate) has been proposed. However, when the ammonium octamolybdate is added in a predetermined amount or more, the low smokeability of the cable is improved, but the thermal stability is lowered. As a result, a problem occurs that causes a decrease in the physical properties of the cable. In addition, when the aluminum hydrate (ATH) and magnesium hydrate (MDH) is added more than a predetermined content, low smokeability and flame retardancy is improved, but there is a problem of lowering the mechanical properties such as flexibility of the cable, elongation after heating.

The technical problem of the present invention is to develop a sheath material composition which can provide a high flame retardant and low smoke retardant cable at room temperature.

In order to achieve the above object, the highly flame retardant and low-flammable sheath material composition of the present invention is 100 parts by weight of polyvinyl chloride resin having a polymerization degree of 800 to 2000, 20 to 130 parts by weight of plasticizer, 40 to 110 parts by weight of flame retardant and depressant 5 to 50 parts by weight. In this case, a mixture of 10 to 50 parts by weight of a brominated flame retardant plasticizer, 5 to 40 parts by weight of ethylene copolymer resin and 5 to 40 parts by weight of trimellitic plasticizer is used.

The present invention also provides a cable having a sheath produced using the high flame retardant and low smoke retardant sheath material composition.

The cables produced using the high flame retardant and low smoke retardant sheath material compositions of the present invention are excellent in tensile strength, elongation and thermal stability as well as high flame retardancy and low smoke retardancy.

Hereinafter, the present invention will be described in detail.

The high flame retardant and low flame retardant sheath material composition of the present invention comprises 20 to 130 parts by weight of plasticizer, 40 to 110 parts by weight of flame retardant and 5 to 50 parts by weight of flame retardant based on 100 parts by weight of polyvinyl chloride resin having a polymerization degree of 800 to 2000. It is characterized by.

It is preferable that the polymerization degree of the polyvinyl chloride resin of this invention is 800-2000. When using a polyvinyl chloride resin having a polymerization degree of less than 800, there is a problem that the tensile strength at room temperature is lowered and the heat resistance of the product is inferior. When a polyvinyl chloride resin having a polymerization degree of more than 2000 is used, the extrusion load increases during processing. The problem of deterioration occurs. Therefore, in the present invention, in order to supplement the above problems, it is intended to use a polyvinyl chloride resin having a polymerization degree of 800 to 2000.

Preferably, the plasticizer is a mixture of 10 to 50 parts by weight of a brominated flame retardant plasticizer, 5 to 40 parts by weight of ethylene copolymer resin and 5 to 40 parts by weight of trimellitic plasticizer. Instead of using the spate-based plasticizer as a plasticizer in the prior art, in the present invention, the ethylene copolymer resin copolymerized with ethylene, acetate and carbon monooxide was used. By using the ethylene copolymer resin, high heat stability, plasticization characteristics, and low smoke characteristics can be imparted to the produced sheath.

The brominated flame retardant plasticizer preferably contains 10 to 50 parts by weight. If the bromine-based flame-retardant plasticizer is included less than 10 parts by weight, it is difficult to implement the flame retardancy of the plenum class, and when included in excess of 50 parts by weight causes a problem of increasing the smoke density. The brominated flame retardant plasticizer may be brominated dioctyl phthalate, brominated diisodecyl phthalate, brominated diisononyl phthalate, or the like. have.

The ethylene copolymer resin is preferably contained 5 to 40 parts by weight. If the ethylene copolymer resin is contained in less than 5 parts by weight, it is impossible to implement the desired properties, if it contains more than 40 parts by weight, the room temperature tensile strength is lowered and the stickiness of the composition increases in the extruder during processing This is because there is a problem that the heat stability is lowered to occur.

The trimellitic plasticizer preferably contains 5 to 40 parts by weight. This is because when the trimellitic plasticizer is included in less than 5 parts by weight, the flexibility of the composition may be lowered, and when it is included in excess of 40 parts by weight, the problem of flame retardancy may occur.

In the present invention, as the flame retardant, aluminum hydroxide, magnesium hydroxide, futite, magnesium hydrate are used. The flame retardant may be used alone or in combination of two or more thereof. In addition, the flame retardant is preferably used in an amount of 40 to 110 parts by weight. If the content is less than 40 parts by weight, it is difficult to obtain the effect of high flame retardancy, and if the content is more than 110 parts by weight, it is because the filling and workability are lowered and the thermal stability is lowered.

In the present invention, magnesium hydrate coated with the zinc molybdate composite is used as an inhibitor. Preferably magnesium hydrate coated with nano-sized zinc molybdate composites may be used. Instead of the ammonium octamolybdate used as a depressant in the prior art, the magnesium hydrate coated with the zinc molybdate composite was used in the present invention. Thereby, the flame retardance and the low smokeability of the sheath manufactured using the sheath material composition of this invention can be improved significantly.

Moreover, this invention provides the cable provided with the sheath manufactured using the said resin material composition. The cable has excellent tensile strength and elongation at room temperature, excellent thermal stability, and high flame retardancy and low smoke resistance.

[Example]

The present invention will be described in more detail with reference to the following Examples. The average person skilled in the art to which the present invention pertains may change the present invention in various other forms in addition to the embodiments described in the following examples, and the following examples merely illustrate the present invention, and the scope of the technical spirit of the present invention is given below. It is not to be construed as limiting the scope of the examples.

In order to examine the performance change according to the components of the highly flame retardant and low-flammable sheath material composition of the present invention, the sheath material compositions of Examples and Comparative Examples were prepared with the compositions shown in Table 1 below. All units in Table 1 are parts by weight.

ingredient
Example Comparative example One 2 3 One 2 3 4 Polyvinyl chloride resin 100 100 100 100 100 100 100 Brominated Flame Retardant Plasticizer 20 20 30 20 - - 20 Ethylene copolymer resin 15 15 10 - - - - Trimellitic plasticizer 15 15 20 - 20 50 10 Isodecyldiphenyl phosphate plasticizer - - - 30 30 - 30 Aluminum hydroxide flame retardant 50 80 50 50 50 50 - Depressant 20 30 10 - 20 20 20 Phenolic Antioxidants 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Lead-free thermal stabilizer 5 5 5 5 5 5 5

[Description of Components Used in Table]

Ethylene Copolymer Resin: Elvaloy 741 from Dupont

Trimellit-based plasticizer: trioctyl trimellit

Depressant: Magnesium hydrate coated with zinc molybdate composite (PAG Charmax FS-BZMA)

Measurement and evaluation of physical properties

A sheath was prepared using the sheath material composition according to the above Examples (1 to 3) and Comparative Examples (1 to 4), and a cable having the sheath was produced by a conventional method. The results of testing the mechanical properties, flame retardancy and thermal stability of the specimens of Examples and Comparative Examples thus obtained are summarized in Table 2 below. Brief experimental conditions are as follows.

㉠ Mechanical properties at room temperature

The cable was measured for tensile strength and elongation in accordance with ASTM D638.

㉡ flame retardant

Combustion experiments were conducted on cone calorimeters in accordance with ASTM 1356-90. Specimens of a certain size (100 mm × 100 mm × 3 mm) were placed horizontally under the cone-shaped heater, and then a constant amount of heat (70 kW / m 2) was applied to measure the amount of heat released during combustion of the material. Empirically, the flame retardancy of UL910 level should have a total heat evolved (TH) value of less than about 25 MJ / m 2 when applying a heat of 70 kW / m 2.

㉢ smoke density

Smoke density was measured in the same manner as in THE. Empirically, the low smoke characteristics of the UL910 level should have a total smoke released (TSR) value of less than about 700 when applying a heat of 70 kW / ㎡.

㉣ thermal stability

After leaving for 6 hours in an oven at 175 ℃, it shall be free from discoloration when checking for discoloration of the specimen.

Test Items
Example Comparative example One 2 3 One 2 3 4
Room temperature The tensile strength
(kgf / ㎡) 2.0 1.8 1.78 1.85 1.90 1.95 2.2 Elongation
(%) 160 145 250 220 200 220 280 Flame Retardant (MJ / ㎡) 22 18 24 22 28 35 30 Smoke density 500 350 550 1200 900 1200 1500 Thermal stability discoloration
none discoloration
none discoloration
none discoloration discoloration discoloration
none discoloration

As a result of measuring the physical properties as summarized in Table 2, the cables having the sheaths of Examples 1 to 3 all met the standard values in the mechanical properties, flame retardancy, and smoke density at room temperature, and no discoloration occurred after standing in the oven.

However, the cable comprising the sheath made using the sheath material composition of Comparative Example 1 had a high smoke density and discolored after being left in the oven. This result was not only because no depressant was used, but also bromine-based plasticizer and isodecyldiphenyl phosphate, which is a phosphorus-based plasticizer, were used as a plasticizer.

The cable including the sheath manufactured using the sheath material composition of Comparative Example 2 satisfied the criteria for room temperature properties and elongation, but had a high smoke density and was discolored after being left in an oven. These results result from the mixing of trimellitic plasticizer and isodecyldiphenyl phosphate, which is a phosphorus plasticizer, as a plasticizer.

The cable containing the sheath prepared using the sheath material composition of Comparative Example 3 did not discolor after being left in the oven, but did not meet the criterion of flame retardancy and had a high smoke density. These results are due to the use of trimellitic plasticizers only as plasticizers.

The cable comprising the sheath prepared using the sheath material composition of Comparative Example 4 did not meet the criteria for flame retardancy and had a high smoke density as well as discoloration after leaving in the oven. This result is due to not only using aluminum hydroxide which is a flame retardant, but also using the trimellitic plasticizer and the isodecyl diphenyl phosphate which is a phosphorus plasticizer, and using it as a plasticizer.

From these results, it can be seen that the cable having the high flame retardant and low smoke retardant sheath of the present invention satisfies all the standard values in the mechanical properties, flame retardancy, and smoke density at room temperature, and does not cause discoloration after standing in an oven. These results were obtained by using a sheath material composition comprising a mixture of three plasticizers, a brominated flame retardant plasticizer, an ethylene copolymer resin, and a trimellitic plasticizer, thereby producing a highly flame retardant and low flame retardant sheath. Because

As described above, optimal embodiments of the present invention have been disclosed. Although specific terms have been used in the specification including the present embodiment, it is only used for the purpose of describing the present invention to those skilled in the art in detail and used to limit the meaning or limit the scope of the present invention described in the claims. Make it clear.

Claims (4)

To 100 parts by weight of polyvinyl chloride resin having a degree of polymerization of 800 to 2000;
20 to 130 parts by weight of a plasticizer;
40 to 110 parts by weight of a flame retardant; And
Including 5 to 50 parts by weight of a depressant,
The plasticizer is a high flame retardant and low-flammable sheath material composition, characterized in that a mixture of 10 to 50 parts by weight of brominated flame retardant plasticizer, 5 to 40 parts by weight of ethylene copolymer resin and 5 to 40 parts by weight of trimellitic plasticizer. The method of claim 1,
The flame retardant is a highly flame-retardant and low-flammable sheath material composition, characterized in that any one or more selected from the group consisting of aluminum hydroxide, magnesium hydroxide, futite and magnesium hydrate. The method of claim 1,
The flame retardant is a highly flame retardant and low-flammable sheath material composition, characterized in that the zinc molybdate composite is coated magnesium hydrate. 100 parts by weight of polyvinyl chloride resin having a degree of polymerization of 800 to 2000;
20 to 130 parts by weight of a plasticizer which is a mixture of 10 to 50 parts by weight of a brominated flame retardant plasticizer, 5 to 40 parts by weight of ethylene copolymer resin and 5 to 40 parts by weight of trimellitic plasticizer;
40 to 110 parts by weight of a flame retardant; And
Cable having a highly flame-retardant and low-flammable sheath formed of a composition comprising 5 to 50 parts by weight of a depressant.