KR19990073096A - Poly olefin resin composition - Google Patents

Abstract

The present invention relates to a polyolefin-based resin composition for insulating materials excellent in flexibility and flame retardancy, and more particularly, as a basic resin, there is no fact that the resin is used at all in the manufacture of the resin composition for insulating materials together with a polyethylene resin having a specific density range. Polyolefin copolymer rubber has a specific content ratio, and the metal mixture, flame retardant, and carbon black are added to the resin mixture to greatly improve strength, tracking resistance, flame retardancy, and flexibility, which is useful as a material for manufacturing insulation cover of high voltage wire. It relates to a polyolefin resin composition.

Description

Polyolefin resin composition for insulation material excellent in flexibility and flame retardancy

The present invention relates to a polyolefin-based resin composition for insulating materials excellent in flexibility and flame retardancy, and more particularly, as a basic resin, there is no fact that the resin is used at all in the manufacture of the resin composition for insulating materials together with a polyethylene resin having a specific density range. Polyolefin copolymer rubber has a specific content ratio, and the metal mixture, flame retardant, and carbon black are added to the resin mixture to greatly improve strength, tracking resistance, flame retardancy, and flexibility, which is useful as a material for manufacturing insulation cover of high voltage wire. It relates to a polyolefin resin composition.

Polyethylene resins, which are generally classified as low density polyethylene, linear low density polyethylene, or high density polyethylene, have excellent physical and chemical properties, as well as excellent electrical insulation, so as to protect conductors and prevent leakage of electricity to the outside. It is widely used. The fields in which electrical insulation materials are mainly applied are coatings of electric power cable cables and communication cables, but are also used for various types of connection materials such as terminations, straight lines, elbows, tees (T), and the like.

When binding high voltage wires for outdoor use to the insulator in addition to the cable sheath and the connecting member, it is necessary to reinforce the insulation of the wires directly in contact with the insulator, and the parts used are called 'insulation cover'. Materials that can be used in the manufacture of the insulating insulation cover for the bind requires strength, voltage resistance, tracking resistance, cold resistance, heat resistance, weather resistance, flame retardancy, ozone resistance, and other excellent flexibility is required to facilitate installation work.

Looking at the example of the prior art to satisfy all these properties are as follows.

In Korean Patent Application No. 95-8471, a method of improving tracking resistance and flame retardancy by adding an organic flame retardant, antimony oxide and a metal hydroxide to a polyolefin resin has been proposed, but since the composition is poor in flexibility, it is not practical because of problems in installation workability. Can not do it.

As a method for solving such a problem, Korean Patent No. 86,562 and Korean Patent No. 91,777 have a density of 0.92-0.95 g / cm ³ and a relatively high density polyethylene resin and low Mooney viscosity at 100 ° C. of 20-60. A method of improving flexibility by performing dynamic vulcanization by adding different crosslinking agents to a mixture of polyolefin rubbers has been proposed. However, this method also uses a polyolefin resin having a density of 0.92 g / cm ³ or more, and also has a problem in that the flexibility of the composition is reduced by crosslinking, and there is a problem in that flame retardancy and tracking resistance are not satisfactory.

Korean Patent No. 87,005 discloses a composition for insulating materials in which a copolymer of ethylene-vinyl acetate copolymer resin, a copolymer of vinylidene fluoride, which is a fluorine-based elastomer, and hexafluoropropylene is added to polyethylene resin. This composition is not only able to achieve the desired flexibility, but also has the disadvantage of not being satisfactory in flame retardancy and tracking resistance.

In addition, Korean Patent No. 91,778 proposes a method of using a mixture of low density polyethylene and ultra low density polyethylene as a base resin and adding an ethylene-vinyl acetate copolymer to improve the flexibility of the composition. Although the composition is improved in flexibility, the use of the base resin by mixing a low density polyethylene and an ultra low density polyethylene has the drawback of lowering the tensile strength and the heat resistance, and in addition, there is a problem of poor flame retardancy and tracking resistance.

Accordingly, in the present invention, various methods have been studied in order to solve the problems of the prior art, and as a result, the basic physical properties of the polyethylene resin and the polyolefin copolymer rubber contained as the base resin are specified, and the metal hydroxide, flame retardant and By adding an additive such as carbon black, the present invention has been completed by finding out that a polyolefin resin composition excellent in strength, tracking resistance, and flame retardancy and greatly improved in flexibility can be used as an insulating material.

An object of the present invention is to provide a polyolefin-based resin composition which is excellent in strength, tracking resistance and flame retardancy, and greatly improved in flexibility, which can be used as an electrical insulation material.

The present invention provides 40 to 80% by weight of polyethylene resin having a density of 0.915 to 0.919 g / cm 3, and 20 to 90% by weight of propylene and a polyolefin copolymer rubber having a Mooney viscosity of 61 to 100 at 100 ° C. 5 to 100 parts by weight of metal hydroxide, organic flame retardant, 10 to 60 parts by weight, 5 to 30 parts by weight of antimony trioxide, and 0.1 to 5 parts by weight of carbon black, based on 100 parts by weight of the base resin mixture composed of 60% by weight. It is characterized by the polyolefin resin composition for insulating materials excellent in flexibility and flame retardance.

Referring to the present invention in more detail as follows.

The base resin contained in the resin composition according to the present invention is composed of 40 to 80% by weight of polyethylene resin and 20 to 60% by weight of polyolefin copolymer rubber. If the content of the polyolefin copolymer rubber in the base resin is less than 20% by weight, there is a problem in that the dispersibility and flexibility of the additive is worsened, and in the case of more than 60% by weight, the tensile strength and heat resistance are deteriorated.

Polyethylene resins usable in the present invention are ethylene homopolymers or copolymers of ethylene with one monomer selected from α-olefins such as 1-butene, 1-pentene, 1-hexene, 1-octene, and have a density. Preference is given to using from 0.915 to 0.919 g / cm ³ .

As the polyolefin copolymer rubber contained as another basic resin, ethylene-propylene binary copolymer rubber and ethylene-propylene-diene terpolymer rubber are preferable, and particularly preferably, the propylene content is 20 to 90% by weight and at 100 ° C. It is to use the polyolefin copolymer rubber whose Mooney viscosity is 61-100. The reason is that when the content of propylene in the polyolefin copolymer rubber is less than 20% by weight, the surface gloss of the molded product is lowered. When the content of propylene in the polyolefin copolymer rubber is more than 90% by weight, the productivity, form, etc. of the produced ethylene-propylene copolymer rubber are bad. Difficult to do and not practical. In addition, when a polyolefin copolymer rubber having a Mooney viscosity of less than 61 or more than 100 is added to the polyethylene resin, the physical properties of the obtained resin composition may be uneven because the particle size of the dispersed polyolefin copolymer rubber is too small or too large. not.

On the other hand, the present invention is to include a metal hydroxide in order to improve the tracking resistance to the base resin mixture, the metal hydroxide is used as aluminum hydroxide, magnesium hydroxide or a mixture thereof. The metal hydroxide is to be contained 5 to 100 parts by weight based on 100 parts by weight of the base resin mixture, if the content is less than 5 parts by weight it is difficult to expect the improvement of the tracking resistance of the resin composition, more than 100 parts by weight If it is contained, the dispersibility to the resin is worsened, thereby greatly reducing the tensile strength and flexibility.

In addition, in order to impart flame retardancy to the polyolefin resin composition, an organic flame retardant is contained. Examples of the organic flame retardant include decabromodiphenyl oxide, tetrabromobisphenol A, dibromocresyl ether, tribromophenol, and tribro. Bromine compounds such as mophenylaryl ether and chlorine compounds such as perchlorocyclodecane, perchlorocyclopentadecane, chlorinated paraffin and chlorinated polyethylene can be used. It is most preferable to contain decabromo diphenyl oxide among the said organic type flame retardants. The organic flame retardant preferably contains 10 to 60 parts by weight based on 100 parts by weight of the base resin mixture.

In addition, in the present invention, in order to further increase the flame retardancy of the resin composition, antimony trioxide having an excellent synergistic effect with the organic flame retardant is used in combination. Antimony trioxide contained with the organic flame retardant was found to be excellent synergistic effect when contained in the range of 5 to 30 parts by weight based on 100 parts by weight of the base resin mixture.

Moreover, in this invention, carbon black is contained in order to improve the weather resistance of a resin composition. Carbon black has a wide variety of types depending on the production method and the size of the particles thereof. In the present invention, it is more preferable to use carbon black having a particle size in the range of 30 to 60 µm. The carbon black is contained in the range of 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the base resin mixture. When the content is less than 0.1 parts by weight, it is difficult to expect improved weather resistance of the resin composition, and more than 5 parts by weight. If used, there is a problem that the tracking resistance is lowered.

Each composition as described above is mixed using a ribbon blender (Ribbon Blender), V-type blender, Henschel Mixer (Henchel Mixer), etc., then Internal Mixer, Banbury Mixer, Kneader It mixes with a kneader, a twin screw extruder, etc., and obtains the resin composition aimed at by this invention.

As described above, the polyolefin resin composition for an insulating material according to the present invention has a tensile strength of 100 kg / cm ² or more, an elongation of 600% or more, and a Shore D hardness of 30 to 55. It has optimum physical properties required as a material for producing an insulating cover of an electric wire.

Such the present invention will be described in more detail based on the following examples and comparative examples, but the present invention is not limited thereto.

Examples 1-5

Linear low density polyethylene resins with a density of 0.918 g / cm 3 and a melt index of 2.1 g / 10 min; ethylene with a propylene content of 28 wt%, a Mooney viscosity of 88 at 100 ° C. and a melt index of 0.4 g / 10 min at 230 ° C. The propylene-diene terpolymer rubber and aluminum hydroxide, decabromodiphenyloxide, antimony trioxide, and carbon black were mixed for 5 minutes at 600 rpm at room temperature using a Henschel Mixer. The polyolefin resin composition mixed with the Henschel mixer was kneaded at 250 rpm using a twin screw extruder (L / D = 13) controlled at 180 to 185 ° C, and pellets were prepared by a strand cutting method. The prepared polyolefin resin composition was prepared for various physical property measurement samples using an injection tester.

Tensile strength and elongation were measured by ASTM D638, hardness was ASTM D785 (Shore D), flame retardancy was measured by UL 94 V type, and tracking resistance was measured by KS C3004 (paragraph 15). The results are shown in Table 1 below.

Example 6

Ethylene-propylene binary having a propylene content of 27% by weight, a Mooney viscosity of 70 at 100 ° C and a melt index of 0.7 g / 10min at 230 ° C in place of the ethylene-propylene-diene terpolymer rubber used in Example 1 Except for using a copolymer rubber, a polyolefin resin was prepared under the same conditions as in Example 1, and the measurement results of the physical properties of the prepared resin are shown in Table 1 below.

Comparative Examples 1 to 4

To the polyolefin-based resin was prepared under the same conditions as in Example 1 and the composition ratio as shown in Table 2, the physical property measurement results for each resin are shown in Table 2 below.

Comparative Example 5

A polyolefin-based resin was prepared under the same conditions as in Example 1, except that linear low-density polyethylene having a density of 0.920 g / cm ³ and a melt index of 1.0 g / 10 min was used instead of the polyethylene resin used in Example 1. The physical property measurement results for each resin are shown in Table 2 below.

Comparative Example 6

Ethylene-propylene- with 28% by weight of propylene, a Mooney viscosity of 40 at 100 ° C and a melt index of 0.7 g / 10min at 230 ° C, in place of the ethylene-propylene-diene terpolymer rubber used in Example 1 above. Except for using a diene terpolymer copolymer rubber, a polyolefin-based resin was prepared under the same conditions as in Example 1, and the measurement results of the physical properties of the prepared resin are shown in Table 2 below.

As can be seen from the above results, the polyolefin resin composition prepared according to the present invention is excellent in strength, tracking resistance, and flame retardancy, and shows a result of greatly improved flexibility. Therefore, the polyolefin resin composition according to the present invention is very useful as a material for insulation.

Claims (7)

40 to 80% by weight of polyethylene resin having a density of 0.915 to 0.919 g / cm 3 and 20 to 90% by weight of polyolefin copolymer rubber having a Mooney viscosity of 61 to 100 at 100 ° C and a content of 20 to 90% by weight of propylene. 5 to 100 parts by weight of metal hydroxide, organic flame retardant, 10 to 60 parts by weight, 5 to 30 parts by weight of antimony trioxide, and 0.1 to 5 parts by weight of carbon black, based on 100 parts by weight of the base resin mixture composed of Polyolefin resin composition for insulating materials excellent in flexibility and flame retardancy. The method of claim 1, wherein the polyethylene resin is an ethylene homopolymer or a copolymer of ethylene and one monomer selected from α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene. Polyolefin resin composition for insulating materials excellent in flexibility and flame retardancy. The polyolefin resin composition for insulating materials having excellent flexibility and flame retardancy according to claim 1, wherein the polyolefin copolymer rubber is an ethylene-propylene binary copolymer rubber or an ethylene-propylene-diene terpolymer rubber. The polyolefin resin composition for insulation materials having excellent flexibility and flame retardancy according to claim 1, wherein the metal hydroxide is aluminum hydroxide, magnesium hydroxide or a mixture thereof. The bromine compound and perchlorocyclo according to claim 1, wherein the organic flame retardant is selected from decabromodiphenyl oxide, tetrabromobisphenol a, dibromocresyl ether, tribromophenol and tribromophenylaryl ether. A polyolefin resin composition for insulating materials having excellent flexibility and flame retardancy, characterized in that one or two or more selected from chlorine compounds selected from decane, perchlorocyclopentadecane, chlorinated paraffin, and chlorinated polyethylene. The polyolefin-based resin composition for insulating materials having excellent flexibility and flame retardancy according to claim 1, wherein the carbon black particles have a size in the range of 30 to 60 µm. The polyolefin-based insulating material having excellent flexibility and flame retardancy according to claim 1, wherein the resin composition has a tensile strength of 100 kg / cm ² or more, an elongation of 600% or more, and Shore D hardness of 30 to 55. Resin composition.