KR101314010B1 - Fire-retardant polyolefine composition - Google Patents

Abstract

PURPOSE: A flame retardant polyolefin composition is provided to have excellent heating modification resistance, heat resistance, and mechanical properties, thereby having excellent physical properties simultaneously satisfying flexibility, elongation, and extrusion properties in trade-off of flame retardancy. CONSTITUTION: A flame retardant polyolefin composition includes a base resin, a non-halogen flame retardant, and a crosslinking agent. The gel fraction of the polymer resin after crosslinking is 50-75 %. The oxygen index measured by ISO4589 is 30 % or more, and the viscosity is 1.0-1.6 g/cc. The base resin includes a vinylsilane-grafted low density polyolefin with a melting temperature of 90-130 °C and a vinylsilane-grafted polyolefin elastomer with a melting temperature of 50-95 °C, with a mixing ratio of 35:65-45:55. The melting temperature difference between the vinylsilane-grafted low density polyolefin and the vinylsilane-grafted polyolefin elastomer is 10 °C or greater, and the total heat absorption for melting is 30-60 J/g. [Reference numerals] (AA) Over; (BB) 13-05-29 afternoon 5:23 28

Description

Fire-retardant polyolefine composition

The present invention relates to a polyolefin composition used for insulating materials such as cables. Specifically, the present invention is environmentally friendly, not only excellent in mechanical properties, heat resistance, heat resistance deformation, etc., but also excellent physical properties that satisfy flexibility, elongation, extrudability, etc., which are in a trade-off relationship with flame retardancy. It relates to a flame retardant polyolefin composition having.

Internal wiring of electronic devices, such as wires for indoor distribution of buildings, copiers, printers, and office equipment, wire harnesses for supplying or transmitting signals between electronic components such as actuators and motors, etc. PVC wire using vinyl (PVC) is used.

PVC wire is not only excellent in flexibility, handleability, strength, etc. but also economical, but contains halogen element, so it generates hydrogen chloride-based toxic gas in case of fire or incineration for disposal. It causes environmental pollution problem.

Recently, as the demand for solving the environmental pollution problem increases, KS C 3328 HIV, which is a standard for flexible PVC cables, has been abolished, and converged to KS C 3341 HFIX, which is a standard for wires using eco-friendly insulating materials that replace them. The trend is showing.

In particular, since 2009, the Korea Land and Housing Corporation has completely ruled out the use of PVC wires, existing products, and permits the use of wires using eco-friendly insulation materials for multi-family houses built under its leadership.

To meet this trend, halogen-free wires have been developed that use insulating materials that do not contain polyvinyl chloride (PVC) resins or halogen-based flame retardants. On the other hand, wires such as insulated wires or insulated cables are generally required to have various characteristics that comply with the KS C 3341 standard, and in such standards, the flame retardancy, heat deformation characteristics, low temperature characteristics, tensile characteristics, etc., which the insulating materials must satisfy The various characteristics of the are defined in detail.

Generally, the resin composition which flame-retarded by mix | blending metal hydroxides, such as magnesium hydroxide and aluminum hydroxide, with polyolefin resins, such as polypropylene, as an insulating material of a halogen-free electric wire. However, in order to secure sufficient flame retardancy, it is necessary to mix a large amount of metal hydroxide in the polyolefin resin, and as a result, the flexibility and extensibility of the insulating material are remarkably impaired, and there is a problem that the molding processability such as extrudability also decreases remarkably. .

Therefore, there is a need for a new insulation material that is eco-friendly without using a halogen-based flame retardant and at the same time ensures the same level of flame retardancy as conventional PVC, and simultaneously secures flexibility, elongation, and moldability that are in conflict with the flame retardant. It's happening.

An object of the present invention is to provide a non-halogen-based environmentally friendly polyolefin composition that is environmentally friendly by generating no toxic gas during fire or incineration for disposal.

In addition, it is an object of the present invention to provide a flame retardant polyolefin composition that can ensure not only sufficient flame retardancy but also flexibility, elongation, moldability, etc. which are in conflict with this.

In order to solve the above problems,

A melting point of 50 to 130 ° C., a melting point of two or more polyolefin resins having a difference of 10 ° C. or more, and a base resin, a non-halogen-based flame retardant and a crosslinking agent having a total endothermic amount of 30 to 60 J / g required for melting; The gel fraction of the polymer resin after crosslinking is 50 to 75%; An oxygen index of at least 30% as measured according to ISO 4589; It provides a flame retardant polyolefin composition having a specific gravity of 1.0 to 1.6 g / cc.

Here, the two or more types of polyolefin resin having a difference in melting point of 10 ° C. or more provide a flame retardant polyolefin composition comprising a polyolefin resin having a melting point of 50 to 95 ° C. and a polyolefin resin having a melting point of 90 to 130 ° C.

In addition, the polyolefin resin having a melting point of 50 to 95 ° C is a polyolefin elastomer grafted with vinyl silane, and the polyolefin resin having a melting point of 90 to 130 ° C is a low density polyolefin grafted with vinyl silane, flame retardant polyolefin To provide a composition.

In addition, the compounding ratio of the low density polyolefin grafted with the vinylsilane and the polyolefin elastomer grafted with the vinylsilane is 35:65 to 45:55 to provide a flame retardant polyolefin composition.

On the other hand, the non-halogen-based flame retardant is magnesium hydroxide or aluminum hydroxide, the content of the non-halogen-based flame retardant provides a flame retardant polyolefin composition, characterized in that 5 to 70 parts by weight based on 100 parts by weight of the base resin.

In addition, the cross-linking agent is an organic vinyl silane, characterized in that 0.5 to less than 2 parts by weight based on 100 parts by weight of the base resin, provides a flame-retardant polyolefin composition.

Meanwhile, at least one conductor; And an insulation layer formed from the flame retardant polyolefin composition surrounding the conductor.

The flame retardant polyolefin composition according to the present invention exhibits sufficient flame retardancy by incorporating a non-halogen flame retardant into a polyolefin resin, and does not generate toxic gas in case of fire or incineration for disposal.

In addition, the flame retardant polyolefin composition according to the present invention exhibits excellent effects on physical properties such as flexibility, extensibility, moldability, etc., which are in a conflict with the flame retardant, even though the flame retardant polyolefin composition contains a sufficient amount of flame retardant through the combination of the base resin and the adjustment of physical properties. It is.

1 is a graph showing the melting point (melting point) of the base resin measured by a differential scanning calorimeter (DSC) in Example 1 according to the present invention.
2 is a schematic cross-sectional view of an electric wire comprising an insulating layer made from a flame retardant polyolefin composition according to the present invention.
3 is a schematic longitudinal sectional view of an electric wire comprising an insulating layer made from a flame retardant polyolefin composition according to the present invention.

The present invention relates to a flame retardant polyolefin composition, in which the non-halogen flame retardant is blended in the base resin.

The base resin may include two or more resins, and the two or more resins may include two resins having a melting point of 50 to 130 ° C. and a difference in melting point of 10 ° C. or more. For reference, FIG. 1 is a melting point of a base resin measured by a differential scanning calorimeter (DSC) for a flame retardant polyolefin composition according to the present invention including two resins having a melting point difference of 10 ° C. or more. A graph representing.

Among the two resins having a difference in melting point of 10 ° C. or more, a resin having a relatively low melting point may have a melting point of about 50 to 95 ° C., and a resin having a relatively high melting point may have a melting point of about 90 ° to 130 ° C. The mixing ratio of the resin having a relatively low melting point and the resin having a relatively high melting point is not particularly limited, but the total endothermic amount required for melting the two kinds of resins is 30 to 60 J / g.

Here, when the total endothermic amount required for melting of the resin is less than 30 J / g, it means that the content of the resin having a relatively low melting point is excessive, whereby the heat deformation characteristics may be poor, whereas when the total endothermic amount is more than 60 J / g, This means that the content of the resin having a relatively high melting point is excessive, which may result in poor flexibility, elongation, and the like.

When the total endothermic condition required during melting is satisfied, the mixing ratio of the resin having a relatively low melting point and the resin having a relatively high melting point may be, for example, 35:65 to 45:55, preferably 40:60. .

The resin having a relatively low melting point is not particularly limited as long as it is used as an insulating material such as a cable. For example, polyolefin elastomer (POE), styrene butadiene rubber (SBR), and ethylene vinyl acetate (EVA) have a weak vinyl acetate content. 15 to 40% by weight) and the like.

The polyolefin elastomer (POE) may be prepared using one or more metallocene catalysts. Also, the elastomeric resin may be made with more than one metallocene catalyst or may be a blend of multiple elastomeric resins made with different metallocene catalysts. The polyolefin elastomer (POE) may be, for example, a linear ethylene polymer (SLEP).

The styrene-butadiene rubber (SBR) is, for example, a styrene-ethylenebutene-styrene copolymer, a styrene-ethylenepropylene-styrene copolymer, a styrene-ethylene-ethylenepropylene-styrene copolymer, a styrene-ethylene-ethylenepropylene-styrene copolymer And styrene butylene styrene copolymer, etc., and what introduce | transduced carboxylic acid, such as maleic anhydride, can also be used by mixing suitably.

On the other hand, the resin having a relatively high melting point is an olefin homopolymer or copolymer such as polyethylene, particularly low density polyethylene (LDPE), ultra low density polyethylene (SLDPE), linear low density polyethylene (LLDPE), polypropylene, for example, ethylene vinyl. Acetate (EVA; vinylacetate content less than about 15% by weight) and the like.

The flame retardant polyolefin composition according to the present invention comprises a non-halogen flame retardant in addition to the base resin. The flame retardant may be a metal hydroxide flame retardant such as magnesium hydroxide or aluminum hydroxide, or a nitrogen-based flame retardant such as melamine resin or melamine cyanurate. The flame retardant may be surface treated with a silane or titanate coupling agent, and the surface treated flame retardant may have improved dispersibility in the base resin.

The content of the flame retardant may be sufficient to ensure sufficient flame retardancy of the composition, for example, an oxygen index measured according to ISO 4589 or more 30%, for example, about 5 based on 100 parts by weight of the base resin To 70 parts by weight, preferably 10 to 40 parts by weight, the flame retardant is less than 5 parts by weight of the flame retardancy is insufficient, while if it exceeds 70 parts by weight of molding processability such as flexibility, elongation, extrudability This can be degraded.

The flame retardant polyolefin composition according to the present invention may further comprise a crosslinking agent selected from the group consisting of organovinylsilane-based crosslinking agents such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxyethoxysilane and mixtures thereof. Can be. Here, the crosslinking agent may be included in less than 0.5 to 2 parts by weight based on 100 parts by weight of the base resin.

Each of the two resins having a difference in melting point of 10 ° C. or more may be a resin grafted with vinylsilane. The resin grafted with the vinylsilane may be crosslinked, preferably by contacting or exposing moisture in the presence of a condensation catalyst. Suitable condensation catalysts include metal carboxylates such as dibutyltin dilaurate, tin octoate, tin acetate, lead naphthenate, zinc octoate; Organometallic compounds such as titanium esters and chelates and tetrabutyl titanate; Organic bases such as ethylamine, hexylamine and piperidine; Acids, such as an inorganic acid and a fatty acid, are mentioned. Sufficient catalyst amount for curing the silane-grafted resin may generally be about 0.01 to 0.2 parts by weight based on 100 parts by weight of the resin.

In order to ensure sufficient flame retardancy of the flame retardant polyolefin composition according to the present invention and at the same time to secure physical properties such as flexibility, extensibility and extrudability, the resin grafted with the vinyl silane is used in the content of the grafted vinyl silane. By this, the degree of crosslinking of the resin must be precisely controlled. Preferably, in relation to the degree of crosslinking of the resin, the gel fraction of the resin after crosslinking in the composition may be 50 to 75%, and when the gel fraction of the resin after crosslinking is less than 50%, the crosslinking degree is insufficient, resulting in hotset, The heat deformation characteristics may be poor, and in the case of more than 70%, the degree of crosslinking may be excessive, thereby degrading the molding processability such as flexibility, extensibility, and extrudability. In addition, the flame retardant polyolefin composition according to the present invention may have a specific gravity of 1.0 to 1.6.

The flame retardant polyolefin composition according to the present invention may suitably include other additives such as antioxidants, processing stabilizers, colorants, heavy metal deactivators, foaming agents, lubricants, and multifunctional monomers. These other additives can be mixed with the base resin using known melt mixers such as single screw extruder mixers, pressure kneading machines, Banbury mixers and the like.

The flame retardant polyolefin composition according to the present invention includes two kinds of resins having a melting point difference of 10 ° C. or higher as the base resin, and the total endothermic amount required for melting the base resin, the gel fraction of the resin in the composition, the oxygen index of the composition, and the like. By satisfying the conditions as described above, it is possible to effectively suppress the deterioration of molding processability such as flexibility, elongation, and extrudability while ensuring sufficient flame retardancy of the composition.

The present invention relates to a cable having an insulating layer formed by the flame retardant polyolefin composition. 1 and 2 schematically show a cross-sectional view of a cable according to the invention. As shown in Figs. 1 and 2, the cable according to the invention comprises at least one conductor 1 of copper, aluminum or the like and an insulating layer 2 of the flame retardant polyolefin composition.

[Example]

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 introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art.

1. Manufacturing Example

Each base resin was prepared using a twin screw extruder with the composition shown in Table 1 below, where the unit of content is parts by weight.

Resin 1 Resin 2 Resin 3 Resin 4 Resin 5 Resin 6 Resin 7 LDPE 40 20 70 40 40 POE 60 80 30 70 100 60 60 r-PP 30 VTMO 1.3 1.3 1.3 1.3 1.3 0.65 2.0 Antioxidant 0.07 0.07 0.07 0.07 0.07 0.04 0.1 DCP 0.07 0.07 0.07 0.07 0.07 0.04 0.1

-LDPE: Low Density Polyethylene (LG Chem, SEETEC BC500, Melting Point: 105.33 ℃)

-POE: Polyolefin Elastomer (Mitsui Chemical, TAFMER DF840, Melting Point: 67.26 ℃)

r-PP: Random Polypropylene Copolymer (Lotte Chemical, SFC-851, Melting Point: 135.27 ℃)

-VTMO: organovinylsilane (vinyltrimethoxysilane, ebony, Dynasylan VTMO)

-Antioxidant: Phenolic antioxidant (Songwon Industry, Songnox 1010)

DCP: organic peroxide

Insulation compositions of the Examples and Comparative Examples were prepared using a twin screw extruder with the composition shown in Table 2 below, and the temperature during extrusion was maintained in the extruder while the temperature of the molten resin maintained a value between 180 and 230 ° C. The time was within 5 minutes. Here, the unit of content is parts by weight.

After preparing the insulating composition, the mixture was mixed for 10 minutes in an 8-inch two roll of 140 ℃, press-molding at a pressure of 200 bar at 170 ℃ to prepare a sample of each of Examples and Comparative Examples. In order to implement the crosslinking properties of the prepared sample, crosslinking was performed for 8 hours in a 70 ° C. water bath.

Example
One Comparative Example One 2 3 4 5 6 7 8 Resin 1 100 100 100 Resin 2 100 Resin 3 100 Resin 4 100 Resin 5 100 Resin 6 100 Resin 7 100 Flame retardant 150 150 150 150 150 50 200 150 150 Antioxidant One One One One One One One One One Lubricant 3 3 3 3 3 3 3 3 3 catalyst 6 6 6 6 6 6 6 6 6

-Resin 1: Total endothermic amount required for melting is 51.58 J / g, gel fraction is 60%

-Resin 2: Total endotherm required for melting is 25.13 J / g, gel fraction is 62%

Resin 3: 65.16 J / g of total endotherm required for melting, 61% of gel fraction

-Resin 4: Total endotherm required for melting is 57.23 J / g, gel fraction is 59%

-Resin 5: Total endotherm required for melting is 20.2 J / g, gel fraction is 61%

-Resin 6: Total endotherm required for melting is 51.58 J / g, gel fraction is 45%

-Resin 7: Total endotherm required for melting is 51.58 J / g, gel fraction is 80%

Flame Retardant: Magnesium Hydroxide (Albemar, Magnifin H5A)

-Antioxidant: Phenolic antioxidant (Songwon Industry, Songnox 1010)

-Lubricant: Polyethylene wax (Lion Chemtech, LC Wax 102N)

Catalyst: Polyolefin resin containing 1.5% by weight of dibutyltin dilaurate

2. Property evaluation

Examples and Comparative Examples Each crosslinked sample was used to evaluate the key properties, extrudability and flame retardancy required by the KS C 3341 HFIX specification, and the results are shown in Table 3 below.

Item unit standard
Example 1 Comparative Example One 2 3 4 5 6 7 8 importance g / cc ISO R 1183 1.4 1.39 1.41 1.41 1.39 1.12 1.63 1.4 1.4 The tensile strength kgf / mm2 KS C IEC 60811-1-1 1.4 1.43 1.28 1.45 1.35 1.1 1.6 1.3 1.5 Elongation rate % KS C IEC 60811-1-1 150 180 100 120 170 270 80 200 130 Oxygen index % ISO 4589 33 32 33 33 32 27 35 32 34 Melt Index g / 10 min ASTM D1238 ^{1 )} 10 8 11 4 9 20 3 15 One Heat distortion % KS C IEC 60811-3-1 20 60 15 12 55 25 8 40 8 Hotset % 50/0 45/0 50/0 60/0 55/0 50/0 65/0 225/30 15/0

¹⁾ : Measure for 10 minutes at 21.6 kgf load at 170 ℃

As shown in Table 3, Comparative Example 1 has an excessively low content of polyolefin elastomer, which is a resin having a relatively low melting point, so that the total endothermic amount required for melting the base resin is excessively low as 25.13 J / g, resulting in poor heat deformation of 60%. Was confirmed,

In Comparative Example 2, it was confirmed that the total endothermic amount required for melting the base resin was excessively high as 65.16 J / g due to the excessive content of the low density polyethylene resin, which has a relatively high melting point resin, and the elongation was poor as 100%.

In Comparative Example 3, since the base resin includes a random polypropylene copolymer having a melting point of more than 130 ° C., the melt index indicating the extrudability of the resin composition is very poor at 4 g / 10 min, which may significantly reduce productivity in manufacturing wires. Confirmed,

Comparative Example 4 was found to be poor heat deformation of 55% due to low melting temperature by using only low viscosity polyethylene, not using two kinds of resins having a melting point of more than 10 ℃,

Comparative Example 5 was confirmed that the oxygen index indicating the flame retardancy is poor at 27% due to insufficient content of the flame retardant,

In Comparative Example 6, the content of the flame retardant was excessive, the elongation was very poor at 80%, and the melt index showing the extrudability due to the increase of internal friction was also very poor at 3 g / 10 min. Became,

In Comparative Example 7, the gel fraction of the resin after crosslinking was insufficient as 45%, which means that the crosslinking degree of the resin was excessively low due to insufficient vinyl silane content. As a result, it was confirmed that the hotset and heat deformation characteristics were poor.

In Comparative Example 8, the gel fraction of the resin after crosslinking was excessively 80%, which means that the crosslinking degree of the resin was excessively high due to the excessive content of vinylsilane, and as a result, the melt index showing the extrudability was 1 g / 10 minutes. As it was very poor, the productivity during the wire manufacturing was significantly reduced.

On the other hand, Example 1 according to the present invention was confirmed that the oxygen index showing the flame retardancy and the elongation rate and the melt index showing the extrudability in conflict with the flame retardancy, all suitable, in addition to specific gravity, tensile strength, heat deformation, hotset characteristics Again all were found to be appropriate.

Although the present specification has been described with reference to preferred embodiments of the invention, those skilled in the art may variously modify and change the invention without departing from the spirit and scope of the invention as set forth in the claims set forth below. Could be done. Therefore, it should be seen that all modifications included in the technical scope of the present invention are basically included in the scope of the claims of the present invention.

1: conductor 2: insulation layer

Claims (7)

A low density polyolefin having a melting point of 90 to 130 ° C. and grafted vinyl silane and a polyolefin elastomer having a melting point of 50 to 95 ° C. and grafted vinyl silane in a compounding ratio of 35:65 to 45:55, wherein the vinylsilane is grafted. A low density polyolefin and a vinyl grafted polyolefin elastomer having a melting point of 10 ° C. or more and a base resin, a non-halogen-based flame retardant and a crosslinking agent having a total endotherm amount of 30 to 60 J / g required for melting;
The gel fraction of the polymer resin after crosslinking is 50 to 75%;
An oxygen index of at least 30% as measured according to ISO 4589;
A flame retardant polyolefin composition having a specific gravity of 1.0 to 1.6 g / cc. delete delete delete The method of claim 1,
The non-halogen-based flame retardant is magnesium hydroxide or aluminum hydroxide, the content of the non-halogen-based flame retardant is characterized in that 5 to 70 parts by weight based on 100 parts by weight of the base resin, flame retardant polyolefin composition. The method of claim 1,
The crosslinking agent is an organovinylsilane, and the content of the crosslinking agent is characterized in that 0.5 to less than 2 parts by weight based on 100 parts by weight of the base resin, flame retardant polyolefin composition. One or more conductors; And
A cable comprising an insulation layer formed from the flame retardant polyolefin composition according to claim 1 surrounding the conductor.

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