KR20180081252A - Halogen-free resin composition having high flame retardancy and low emitting smoke and UTP cable comprising a sheath formed from the same - Google Patents

Abstract

The present invention relates to a nonhalogenated resin composition having high flame retardancy and low smoke emission for forming a sheath layer of a UTP cable and a UTP cable including a sheath layer formed therefrom. More specifically, the present invention relates to the nonhalogenated resin composition meeting requirements of C grade or higher standards in high flame retardancy and low smoke emission with a Construction Products Regulation (CPR) standard, wherein a CPR standard is applied in Europe in recent years.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a halogen-free resin composition and a low-smoke non-halogen resin composition and a sheath layer formed therefrom,

TECHNICAL FIELD The present invention relates to a UTIFICA cable comprising a high sheen and low-smoke non-halogen resin composition for forming a sheath layer of a UTP cable and a sheath layer formed therefrom. More specifically, the present invention relates to a non-halogen resin composition satisfying a flame retardancy and low ductility of C grade or higher according to a CPR (Construction Products Regulation) standard recently applied in Europe, and a UTS cable including a sheath layer formed therefrom will be.

A UTP cable is an abbreviation for unshielded twisted pair, also known as unshielded twisted pair cable or unshielded twisted pair. The most common form of UTP cable is a copper wire, which is used as a signal line to connect the environment of a general telephone line or LAN (Local Area Network).

The outer surface of the UTP cable is covered with a sheath material, and the sheath layer of the sheath material is exposed in direct contact with the outside. In the case of a plenum-class UTP cable, since smoke is used to install on a ceiling without a duct, smoke is excessively generated when a fire occurs in a space where the cable is installed.

Therefore, the plastic material having a low flammability and high flame retardant property should be used in that the plastic material can be used as a path of fire spreading in the case of a material having high combustibility. Specifically, a polyolefin resin is used as a sheath material of a cable which requires a flame retardant polyvinyl chloride resin as a sheath material of a cable which requires high shear resistance and a relatively low flame retardancy and a low flammability halogen.

Especially, in the case of UTP cable using polyolefin sheath, it satisfies CM and CMX flame retardancy in general, and various flame retardants based on metal hydroxide are applied to satisfy the requirement. The CM flame retardancy is evaluated by the burning length after flame is applied for 20 minutes at a heat quantity of 21 kW. However, in the case of the recent CPR (Construction Products Regulation) certification applied in Europe, the flame retardant evaluation method is similar but requires a specific level of combustion length, maximum heat release rate, total heat release rate, do.

On the other hand, in the case of the UTP cable to which the polyolefin sheath satisfying the CM flame retardancy has been applied, it is confirmed that the cable has a grade of D according to the CPR standard. In order to satisfy the higher grade C or higher, a new low- .

It is an object of the present invention to provide a non-halogen resin composition that satisfies C flame retardancy and low flame retardancy in accordance with the CPR (Construction Products Regulation) standard and a UTS cable including a sheath layer formed therefrom.

In order to solve the above problems,

A non-halogen resin composition for forming a sheath layer of a UTP cable, comprising a first ethylene vinyl acetate (EVA) resin having a vinyl acetate content of 25 to 30 wt%, a second ethylene vinyl acetate (EVA) resin having a vinyl acetate content of 40 to 50 wt% A non-halogen flame retardant, comprising: a base resin comprising an ethylene vinyl acetate (EVA) resin and a linear low density polyethylene resin grafted with a polar group; and the non-halogen flame retardant includes a first flame retardant comprising a metal hydroxide, And a fourth flame retardant including a zinc flame retardant, wherein the UTP cable including the sheath layer formed from the halogen-based resin composition is a CPR (Construction Products Regulation) certification. The present invention also provides a halogen-free resin composition.

Here, the content of the first ethylene vinyl acetate (EVA) resin is 30 to 40 parts by weight, the content of the second ethylene vinyl acetate (EVA) resin is 40 to 50 parts by weight, And the content of the linear low density polyethylene resin in which the polar group is grafted is 20 to 30 parts by weight.

The content of the first flame retardant may be in the range of 190 to 220 parts by weight, the content of the second flame retardant may be in the range of 20 to 40 parts by weight, the content of the third flame retardant may be in the range of 20 to 40 parts by weight, And the content of the fourth flame retardant is 5 to 10 parts by weight.

The present invention also provides a halogen-free resin composition, wherein the polar group is maleic anhydride.

On the other hand, the metal hydroxide includes magnesium hydroxide.

Here, the non-halogenated resin composition is characterized in that the magnesium hydroxide is not surface-treated.

Also, the melamine-based flame retardant includes melamine cyanurate, and the antimony-based flame retardant includes antimony trioxide.

The present invention also provides a halogen-free resin composition, characterized in that the zinc flame retardant contains zinc borate.

On the other hand, a UTP cable including a sheath layer formed from the non-halogen resin composition is provided.

The non-halogenated resin composition according to the present invention has the mechanical strength required in the sheath layer of the UTP cable and exhibits excellent effects such as high flame retardancy and low ductility of C grade or higher according to CPR (Construction Products Regulation) standard.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

TECHNICAL FIELD [0001] The present invention relates to a thermosetting and low-fume non-halogen resin composition for forming a sheath layer of a UTP cable.

The non-halogenated resin composition according to the present invention comprises a polyolefin base resin and a flame retardant, and may further contain other additives such as antioxidants and lubricants. Here, the polyolefin base resin may include a linear low density polyethylene resin grafted with two ethylene vinyl acetate (EVA) resins and a polar group such as maleic anhydride, glycidyl methacrylate, and the like .

The polyolefin base resin is formed by the blending of the specific resin described above, thereby realizing the mechanical properties and flame retardancy required in the sheath layer of the UTP cable and achieving sufficient filler loading for the flame retardant.

Specifically, the two types of ethylene vinyl acetate (EVA) resins include a first ethylene vinyl acetate (EVA) resin having a vinyl acetate content of 25 to 30 wt% and a second ethylene vinyl acetate (EVA) resin having a vinyl acetate content of 40 to 50 wt% Vinyl acetate (EVA) resin.

In addition, as the content of vinyl acetate increases in the first and second ethylene vinyl acetate (EVA) resins, the flame retardancy of the non-halogen resin composition improves while the mechanical strength decreases. On the contrary, as the content of vinyl acetate decreases, The mechanical strength of the non-halogenated resin composition is improved while the flame retardancy is lowered.

Therefore, the content of the first ethylene vinyl acetate (EVA) resin is 30 to 40 parts by weight and the content of the second ethylene vinyl acetate (EVA) resin is 40 to 50 parts by weight based on 100 parts by weight of the polyolefin based resin Can be.

Here, when the content of the first ethylene vinyl acetate (EVA) resin is less than 30 parts by weight or the content of the second ethylene vinyl acetate (EVA) resin is more than 50 parts by weight, the mechanical strength of the polyolefin- Whereas when the content of the first ethylene vinyl acetate (EVA) resin is more than 40 parts by weight or the content of the second ethylene vinyl acetate (EVA) resin is less than 40 parts by weight, the flame retardancy of the polyolefin base resin is greatly lowered .

On the other hand, the linear low-density polyethylene resin in which the polar group is grafted in the polyolefin-based resin improves the filler loading capacity of the flame retardant to the base resin, It is possible to improve the flame retardancy of the non-halogen resin composition and to improve the dispersibility of the flame retardant in the base resin, thereby suppressing deterioration of the mechanical properties and extrudability of the non-halogen resin composition due to agglomeration of the flame retarder can do.

Here, the content of the linear low density polyethylene resin in which the polar group is grafted may be 20 to 30 parts by weight based on 100 parts by weight of the polyolefin based resin, and the content of the linear low density polyethylene resin in which the polar group is grafted is 20 parts by weight By weight, the flame retardancy of the non-halogen resin composition may be significantly lowered, or the mechanical properties and extrudability may be insufficient. When the content of the first and second ethylene vinyl acetate (EVA) resins is more than 30 parts by weight, And the flame retardancy or mechanical properties of the above-mentioned non-halogenated resin composition can be selectively greatly lowered.

The flame retardant includes a non-halogen flame retardant, specifically, a first flame retardant containing a metal hydroxide, preferably magnesium hydroxide, a melamine flame retardant, preferably a second flame retardant including melamine cyanurate, an antimony flame retardant, Preferably a third flame retardant comprising antimony trioxide, and a fourth flame retardant comprising zinc flame retardant, preferably zinc borate.

The first flame retardant including magnesium hydroxide or the like mainly improves flame retardancy, fire resistance and abrasion resistance of the halogen-free resin composition when a fire occurs, and in particular, magnesium hydroxide decomposes to a metal oxide, that is, a ceramic and water Halogen-containing resin composition can not only lower the ambient temperature but also maintain the flame retardancy, fire resistance and abrasion resistance of the non-halogenated resin composition even under harsh conditions by the ceramic having improved strength and excellent water resistance .

Mg (OH) ₂ -> MgO + H ₂ O - 330 kJ / mol at ≥340 ° C

Here, the magnesium hydroxide and the like may not be surface-treated with other materials. Generally, in order to improve the compatibility with the base resin, the surface of the additive having a hydrophilic surface can be surface-treated with a hydrophobic property. However, when the surface of the magnesium hydroxide is treated with a hydrophobic property, the flame retardancy of the non- . On the other hand, when the surface of the magnesium hydroxide is not surface-treated with other materials, the compatibility of the magnesium hydroxide and the base resin is lowered due to the improvement of the filler loading property of the flame retardant by the linear low density polyethylene resin in which the polar group is grafted can do.

The second flame retardant including the melamine cyanurate and the like and the third flame retardant including the antimony trioxide may be vaporized when a fire occurs to lower the ambient temperature so as to maintain the fire resistance characteristics of the non- Flame retardant, refractory, and abrasive properties can be achieved.

On the other hand, the melamine cyanurate has a problem of generating a caustic combustion gas containing an acid after combustion, while the antimony trioxide has a problem of high cost, and therefore, it is necessary to appropriately control the compounding ratio thereof.

The fourth flame retardant containing zinc borate and the like forms a char in the event of a fire to maintain the structure of the sheath layer formed from the non-halogen resin composition and the structure of the UTP cable including the flame retardant, It is possible to realize the abrupt characteristic.

Wherein the content of the first flame retardant is 190 to 220 parts by weight based on 100 parts by weight of the polyolefin base resin, the content of the second flame retardant and the content of the third flame retardant is 20 to 40 parts by weight, Parts by weight.

The non-halogenated resin composition of the present invention can achieve high flame retardancy and low ductility of C grade or higher in CPR (Construction Products Regulation) certification by controlling the combination and blending ratio of the specific flame retardants described above.

[Example]

1. Manufacturing Example

The non-halogenated resin composition and the cis layer specimens and the UTP cable specimens formed therefrom were prepared with the components and contents shown in Table 1 below. The unit of the content shown in Table 1 below is parts by weight.

Example Comparative Example One 2 3 One 2 3 4 5 6 7 8 Resin 1 30 40 30 20 50 30 30 30 30 30 30 Resin 2 50 40 40 60 30 30 50 50 50 50 50 Resin 3 20 20 30 20 20 40 20 20 20 20 20 Flame Retardant 1 210 220 200 210 210 210 180 230 210 210 210 Flame Retardant 2 30 20 40 30 30 30 30 30 10 30 30 Flame Retardant 3 25 30 20 25 25 25 25 25 25 10 25 Flame Retardant 4 10 5 10 10 10 10 10 10 10 10 3 Other 10 10 10 10 10 10 10 10 10 10 10

- Resin 1: Ethylene vinyl acetate (EVA) resin (vinyl acetate content 28% by weight)

- Resin 2: Ethylene vinyl acetate (EVA) resin (vinyl acetate content 46% by weight)

- Resin 3: Linear low density polyethylene resin grafted with maleic anhydride

- Flame retardant 1: Magnesium hydroxide

Flame retardant 2: melamine cyanurate

- flame retardant 3: zinc borate

- Others: antioxidants and lubricants

2. Property evaluation

(1) Room temperature tensile strength and elongation evaluation

Tensile strength and elongation were measured for each of the cis-layer specimens of Examples and Comparative Examples in accordance with standard UL444 (evaluation speed: 200 mm / min). The tensile strength was 0.96 kgf / mm 2 or more and elongation was 100% or more.

(2) Evaluation of tensile strength and elongation after heating

EXAMPLES AND COMPARATIVE EXAMPLES Each of the cis-layer specimens was left in an oven at 100 ° C for 168 hours, and the tensile strength and elongation were measured (evaluation rate: 200 mm / min) Should be 75% or more and 50% or more, respectively.

(3) Evaluation of flame retardancy and ductility

① Measurement of combustion length

According to the standard EN 50399, for each of the UTP cable specimens, the flame was spontaneously applied for 20 minutes, and then the length of the cable propagated vertically was measured. To satisfy the CPR B rating, It must be less than 1.5 m and the burning length should be less than 2.0 m to satisfy CPR C rating.

② Peak Heat Release Rate (PHRR)

According to the standard EN 50399, the flame was applied to each of the UTP cable specimens of the Examples and Comparative Examples for 20 minutes to collect the smoke generated during the combustion, to measure the amount of oxygen consumed, the amount of released monoxide and carbon dioxide, Temperature, flow rate, pressure difference, etc. were calculated, and the heat release rate was calculated comprehensively, and the maximum value was selected. In order to satisfy the CPR B rating, the maximum heat release rate should be 30 kW or less. To satisfy the CPR C rating, the maximum heat release rate should be 60 kW or less.

③ Total Heat Release (THR)

(HRR) values expressed as a function of time, and the total heat release rate to satisfy the CPR B class is 15 MJ or less, and the total heat release rate to satisfy the CPR C class should be 30 MJ or less.

④ Fire Growth Rate (FIGRA)

The flame propagation speed was obtained by dividing the maximum heat release rate by the time for which the heat release rate was maximum after the flame was applied to the cable specimen. Flame propagation speed to satisfy CPR B class is 150W / s or less, and flame propagation speed to satisfy CPR C class should be 300W / s or less.

The results of the physical property evaluation are shown in Table 2 below.

Example Comparative Example One 2 3 One 2 3 4 5 6 7 8
Prize
On The tensile strength
(kgf / mm2) 1.023 1.002 1.248 0.957 1.011 1.439 1.184 0.987 1.034 1.104 1.111 Elongation rate
(%) 122.3 128.0 115.7 121.1 120.7 99.7 131.8 98.4 124.6 119.9 127.1
end
Ten Tensile Residue
(%) 99.8 97.8 99.6 94.7 95.7 91.3 97.4 86.0 98.9 97.8 98.9 Renal survival rate
(%) 79.7 71.2 71.6 74.7 74.6 68.1 80.3 71.8 80.3 81.6 81.4 Combustion length
(m) 0.55 0.6 0.55 0.45 1.25 2.25 2.0 0.5 1.75 1.8 1.25 Maximum heat release rate
(kW) 12.1 15.4 18.7 11.9 64.3 70.7 61.1 10.9 63.5 64.3 62.2 Thermal Emission Rate
(MJ) 13.4 14.7 17.6 13.5 21.6 24.2 20.4 13.4 25.7 24.4 22.4 Flame propagation speed
(W / s) 80.7 128.3 155.8 76.8 490.8 523.7 470.0 72.7 409.7 401.9 444.3

As shown in Table 2, the non-halogenated resin composition of Comparative Example 1 was inferior in the content of the first ethylene vinyl acetate resin and the content of the second ethylene vinyl acetate resin in the base resin and the tensile strength at room temperature was below specification, The non-halogenated resin composition of Example 2 had an excessive amount of the first ethylene vinyl acetate resin in the base resin and an insufficient amount of the second ethylene vinyl acetate resin, And the non-halogenated resin composition of Comparative Examples 4 and 6 to 8 were not satisfactory because the content of the second ethylene vinyl acetate resin was below the content of the second ethylene vinyl acetate resin and the content of the polar group-grafted linear low density polyethylene resin exceeded the room temperature elongation, The flame retardancy and flame retardancy were below specification because of the content of the first to fourth flame retardants, It was confirmed that the non-halogenated resin composition had an excessive amount of the first flame retardant and a room temperature elongation of less than the specification.

The non-halogenated resin composition of Examples 1 and 2 according to the present invention is a material for forming a sheath layer of the UTP cable, and both the high temperature flame retardancy and low ductility of the B grade according to the mechanical properties after heating and CPR certification And it was confirmed that the UTP cable to which the non-halogen resin composition of Example 3 was applied satisfies both the room temperature and the mechanical properties after heating and the C flame retardancy and the low ductility according to the CPR certification at the same time.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. . It is therefore to be understood that the modified embodiments are included in the technical scope of the present invention if they basically include elements of the claims of the present invention.

Claims (9)

A non-halogen resin composition for forming a sheath layer of a UTP cable,
A first ethylene vinyl acetate (EVA) resin having a vinyl acetate content of 25 to 30 wt%, a second ethylene vinyl acetate (EVA) resin having a vinyl acetate content of 40 to 50 wt% and a linear low density grafted polar group A base resin comprising a polyethylene resin and a non-halogen flame retardant,
The non-halogen flame retardant includes a first flame retardant including a metal hydroxide, a second flame retardant including a melamine flame retardant, a third flame retardant including an antimony flame retardant, and a fourth flame retardant including a zinc flame retardant,
Wherein the UTP cable comprising the sheath layer formed from the non-halogen resin composition satisfies the CPR (Construction Products Regulation) certification C rating or higher. The method according to claim 1,
Wherein the content of the first ethylene vinyl acetate (EVA) resin is 30 to 40 parts by weight, the content of the second ethylene vinyl acetate (EVA) resin is 40 to 50 parts by weight, the polar group is Wherein the content of the grafted linear low density polyethylene resin is 20 to 30 parts by weight. 3. The method according to claim 1 or 2,
Wherein the content of the first flame retardant is from 190 to 220 parts by weight, the content of the second flame retardant is from 20 to 40 parts by weight, the content of the third flame retardant is from 20 to 40 parts by weight, 4 flame retardant is 5 to 10 parts by weight. 3. The method according to claim 1 or 2,
Wherein the polar group is maleic anhydride. 3. The method according to claim 1 or 2,
Wherein the metal hydroxide comprises magnesium hydroxide. 6. The method of claim 5,
Wherein the magnesium hydroxide is not surface-treated. 3. The method according to claim 1 or 2,
Wherein the melamine-based flame retardant comprises melamine cyanurate, and the antimony-based flame retardant comprises antimony trioxide. 3. The method according to claim 1 or 2,
The non-halogenated resin composition according to claim 1, wherein the zinc flame retardant comprises zinc borate. A UTP cable comprising a sheath layer formed from the non-halogenated resin composition of claim 1 or claim 2.