JP4409700B2 - Wire covering material and electric wire using the covering material - Google Patents

Description

【００２９】
表１から、実施例１〜３は優れた耐摩耗性が得られることがわかる。
【００３０】
【発明の効果】
以上の説明により明らかなように、本発明では、特定の水酸化マグネシウムと共に、酸無水物変性ポリオレフィン系樹脂、ポリイソブチレンとを配合することにより、材料中での水酸化マグネシウムと樹脂間の接着性が向上し優れた耐摩耗性を有する電線・ケーブル用の被覆材料を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating material for electric wires used for a sheath layer, an insulating layer, and the like in an electric wire, and more particularly to an electric wire coating material having wear resistance and an electric wire using the coating material.
[0002]
[Prior art]
Conventionally, polyvinyl chloride (hereinafter referred to as PVC) has been used for a coating material used for a sheath layer, an insulating layer, or the like in an electric wire / cable when flame resistance is required. However, because PVC is suspected of causing toxic gases such as dioquine and hydrogen chloride gas during waste incineration of electric wires, the use of PVC is restricted, and flame retardants made of metal hydroxides are added to polyolefin resins with low environmental impact. Blended flame retardant polyolefin resins have come to be used.
[0003]
As the flame retardant composed of the metal hydroxide, aluminum hydroxide, magnesium hydroxide and the like are common. However, a coating material made by blending a flame retardant made of a metal hydroxide with a polyolefin resin has excellent flame retardancy, but particularly when used for a sheath layer, it is rubbed or scratched with other objects. In addition, there is a problem in that scratches are likely to occur due to rubs between wires (for example, rubs between wires due to misalignment between wires in a braided wire in which a plurality of wires are twisted together).
[0004]
[Problems to be solved by the invention]
In view of the above circumstances, an object of the present invention is to provide a coating material for electric wires excellent in damage resistance.
Another object of the present invention is to provide an electric wire having a sheath layer and / or an insulating layer made of the electric wire coating material.
[0005]
As a result of intensive studies to achieve the above object, the present inventors have surface-treated with a base resin comprising a polyolefin resin with 0.001 to 1.0 part by weight of fatty acid per 100 parts by weight of magnesium hydroxide. In addition, it was found that a wire coating material with improved wear resistance and the like can be obtained by blending an acid anhydride-modified polyolefin resin and polyisobutylene together with low surface-treated magnesium hydroxide. Was completed.
[0006]
That is, the present invention has the following features.
(1) A coating material for electric wires comprising the following components A to D.
Component A: Polyolefin-based resin Component B: Acid anhydride-modified polyolefin-based resin Component C: Low surface-treated magnesium hydroxide surface-treated with 0.001 to 1.0 parts by weight of fatty acid per 100 parts by weight of magnesium hydroxide Component D: Polyisobutylene (2) The polyolefin resin of component A is at least one selected from polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, and ethylene-ethyl acrylate copolymer The electric wire of (1) above, wherein the acid anhydride-modified polyolefin resin of component B is an ethylene-maleic anhydride binary copolymer and / or an ethylene-maleic anhydride-acrylic acid ester terpolymer Coating material.
(3) The coating material for electric wires according to (1) and (2) above, wherein the blending amount of the C component per 100 parts by weight of the total weight of the A component, the B component, and the D component is 50 to 150 parts by weight (4) ) An electric wire having a sheath layer and / or an insulating layer made of the coating material according to any one of (1) to (3) above.
The “coating material for electric wire” in the present invention means a material for covering an electric wire including a sheath material and / or an insulating material.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The coating material for electric wires of the present invention has the following components A to D as essential components.
Component A: Polyolefin-based resin Component B: Acid anhydride-modified polyolefin-based resin Component C: Low surface-treated magnesium hydroxide surface-treated with 0.001 to 1.0 parts by weight of fatty acid per 100 parts by weight of magnesium hydroxide Component D: polyisobutylene
In the present invention, the component A polyolefin-based resin mainly has basic physical properties (insulation properties, electrical properties such as dielectric constant, mechanical properties such as flexibility, extensibility, and tensile strength) required for the coating material for electric wires. Chemical properties such as chemical resistance, processability, etc.), and as the polyolefin resin, a polyethylene resin or a polypropylene resin is usually used. As the polyethylene resin, a homopolymer of ethylene, a copolymer of ethylene and another vinyl compound, or a mixture thereof is used. As a copolymer of ethylene and another vinyl compound, ethylene and Copolymers with other α-olefins, copolymers of ethylene and vinyl acetate or ethyl acrylate, etc. are preferred. Examples of α-olefins in copolymers of ethylene and other α-olefins include propylene, Examples include butene-1, pentene-1,4-methyl-1, monopentene, hexene-1, octene-1. As the polypropylene resin, a homopolymer of propylene, a copolymer of propylene and another vinyl compound, or a mixture thereof is used, and as a copolymer of propylene and another vinyl compound, propylene and other vinyl compounds are used. Of α-olefins are preferred, and examples of α-olefins tonight include butene-1, pentene-1, 4-methyl-1-pentene, hexene-1, octene-1, and the like.
Among these, particularly preferred are polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), and ethylene-ethyl in view of mechanical properties and thermal properties. An acrylate copolymer (EEA). The polyethylene is preferably low density polyethylene (LDPE) from the viewpoint of acceptability of magnesium hydroxide, and particularly preferably has a density in the range of 0.800 to 0.930 g / cm 3. The ethylene-vinyl acetate copolymer preferably has a vinyl acetate content of 5 to 45% by weight. The ethylene-vinyl acetate copolymer has an ethylene-methyl acrylate copolymer with a methyl acrylate content. It is preferably 5 to 45% by weight, and the ethylene-ethyl acrylate polymer preferably has an ethyl acrylate content of 5 to 45% by weight. In addition, the said density is based on the measuring method prescribed | regulated to JISK6922.
[0009]
The component B acid anhydride-modified polyolefin resin is a polyolefin resin containing an acid anhydride having at least one vinyl group in the molecule as a copolymerization component, and is mainly responsible for whitening of the coating material. It has the effect of preventing interface peeling between magnesium and resin. Examples of the acid anhydride-modified polyolefin resin include α-olefin-acid anhydride binary copolymer, α-olefin-acid anhydride-acrylic compound, or vinyl ester compound ternary copolymer. Any of these may be used in combination.
[0010]
As the acid anhydride, maleic anhydride, itaconic anhydride, citraconic anhydride, glutaconic anhydride and the like are preferable, and maleic anhydride is particularly preferable. The acid anhydride forms a hydrogen bond between magnesium hydroxide and a strong adhesive force is obtained between the magnesium hydroxide and the resin, preventing interfacial delamination between the magnesium hydroxide and the resin in the coating material. The
[0011]
As the α-olefin, ethylene, propylene, butene-1, and the like are preferable, and ethylene is particularly preferable. The α-olefin is a component responsible for the affinity of the B component to the A component (polyolefin resin). From this viewpoint, as the α-olefin, polyethylene exemplified as a preferred example of the A component polyolefin resin. It is particularly preferable to use ethylene so that good affinity can be obtained for the ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, and ethylene-ethyl acrylate copolymer.
[0012]
As the acrylic compound, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and the like are preferable, and ethyl acrylate is particularly preferable. The vinyl ester compound is preferably vinyl acetate.
[0013]
The content of the acid anhydride in the acid anhydride-modified polyolefin resin is, for example, 0.05 to 10% by weight in the case of an α-olefin-anhydride binary copolymer, preferably 0. In the case of α-olefin-anhydride-acrylic compound or vinyl ester compound terpolymer, it is usually 0.05 to 10% by weight, preferably 0.1 to 5.0% by weight. 5.0% by weight.
[0014]
In the present invention, α-olefin-acid anhydride-acrylic compound or vinyl ester compound terpolymer can give particularly good results in terms of wear resistance. The reason for this is that the acrylic compound or vinyl ester compound reduces the crystallinity of the copolymer, and magnesium hydroxide and resin due to residual stress generated by molding shrinkage due to the decrease in the crystallinity of the copolymer. It is considered that peeling of the adhesive portion at the interface with the resin hardly occurs, and the adhesive strength of the copolymer is improved, the adhesive strength between the magnesium hydroxide and the resin is improved, and the wear resistance is increased. In addition, content of the acryl-type compound or vinyl ester-type compound in the said ternary copolymer is 0.1 to 40 weight% normally, Preferably, it is 2 to 30 weight%.
[0015]
By blending the acid anhydride-modified polyolefin resin, the wear resistance of the material is greatly improved. This is because a strong adhesive force is obtained between the magnesium hydroxide and the resin.
[0016]
As the component C magnesium hydroxide, low surface-treated magnesium hydroxide surface-treated with 0.001 to 1.0 part by weight of fatty acid per 100 parts by weight of magnesium hydroxide is used. In order to improve compatibility with the resin, magnesium hydroxide that is usually used activates the surface of magnesium hydroxide by adding more than 1 part by weight of fatty acid per 100 parts by weight of magnesium hydroxide. For this reason, when the mechanical characteristics of the composition are required, the surface treatment is performed by adding more than 1 part by weight of fatty acid per 100 parts by weight of magnesium hydroxide. According to the results of this study, surprisingly, the surface treatment is less than the conventional treatment, the adhesion between the resin (especially acid anhydride part) and magnesium hydroxide is improved and the wear resistance is good. all right.
[0017]
In this type of coating material, when using magnesium hydroxide as a flame retardant, about 50 to 200 parts by weight of magnesium hydroxide is generally blended per 100 parts by weight of the polymer component in the material in order to obtain sufficient flame retardancy. However, in the coating material of the present invention as well, the specific magnesium hydroxide of component C is 100 parts by weight of the polymer component in the coating material (that is, the total amount of component A, component B and component D) 100 parts by weight) is usually 50 to 150 parts by weight, preferably 70 to 130 parts by weight. When the amount of the C component increases outside this range, the flexibility and extensibility of the coating material tend to decrease, and when it decreases, the flame retardancy of the coating material tends to decrease.
[0018]
Magnesium hydroxide surface-treated with a fatty acid of component C was subjected to a surface treatment with a fatty acid on magnesium hydroxide used as a flame retardant, thereby improving the dispersibility of magnesium hydroxide in the resin in the coating material. Is.
[0019]
The fatty acid used in the magnesium hydroxide surface-treated with the fatty acid of the C component is a fatty acid having about 15 to 20 carbon atoms. Specific examples of the fatty acid include palmitic acid, stearic acid, and olein. Examples include acids, linoleic acid, and linolenic acid. The average particle diameter of magnesium hydroxide is usually 0.1 to 20 μm, preferably 0.5 to 5 μm.
[0020]
The surface treatment method of the magnesium hydroxide with the fatty acid is not particularly limited, and a general method, for example, a so-called slurry method in which magnesium hydroxide is added to a fatty acid alcohol solution and then dried, or the fatty acid is converted into magnesium hydroxide. A dry method in which powder is directly sprayed is used.
[0021]
The blending ratio of the D component to the total blending amount of the A component and the B component in the coating material ((A component + B component): D component) is usually 99.5: 0.5 to 90:10 (weight ratio). , Preferably 99: 1 to 95: 5. If the blending amount of the D component increases outside this range, the mechanical strength such as the tensile strength of the coating material and the heat resistance tend to decrease.
[0022]
The coating material of the present invention may contain an appropriate amount of a known halogen-free auxiliary material used in this type of field.
Such auxiliary materials include stabilizers, antioxidants, fillers, colorants, carbon black, crosslinking agents, lubricants, processability improvers, antistatic agents, flame retardant aids, and the like.
[0023]
The coating material of the present invention may be prepared by adding the above-mentioned auxiliary components to the components A to D as desired, and kneading the mixture with a known kneading apparatus such as a Banbury mixer, a pressure kneader, or a twin screw extruder. It is manufactured by molding into a desired form by injection molding, extrusion molding, rotational molding, press molding or the like.
[0024]
The coating material for electric wires of the present invention has excellent wear resistance, can be used for both the sheath layer and the insulating layer of the electric wire, and is particularly suitable for the sheath layer.
[0025]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited by such an Example.
[0026]
Each component shown in the upper column of Table 1 is put into a Banbury mixer (manufactured by Toyo Seiki Seisakusho Co., Ltd.), kneaded for 20 minutes, molded by press molding at 160 ° C. for 10 minutes, and test sheets for each example and comparative example. And the test piece was created and the following evaluation tests were done about each.
In addition, the compounding quantity of each component is a weight part. Moreover, MFR (melt flow rate) of LDPE, EEA, and ethylene-maleic anhydride-ethyl acrylate terpolymer is a value measured according to JIS K6992. The D hardness of LDPE and EEA is a value based on the durometer method. The intrinsic viscosity of polyisobutylene is a measured value using diisobutylene as a solvent.
[0027]
〔Evaluation test〕
-Tensile property Measure tensile strength (MPa) and elongation (%) according to JISK7113 for a test sheet with a thickness of 1 mm.
・ Measures the weight loss after 1000 rotations of the wear test for a 1 mm thick test sheet according to JIS K 6902. The wear wheel used was H-18 manufactured by Taber, and the load was 4.9N.
These test results are in the lower column of Table 1.
[0028]
[Table 1]

[0029]
From Table 1, it can be seen that Examples 1 to 3 have excellent wear resistance.
[0030]
【The invention's effect】
As is apparent from the above description, in the present invention, the adhesion between magnesium hydroxide and the resin in the material is blended with a specific magnesium hydroxide together with an acid anhydride-modified polyolefin resin and polyisobutylene. Thus, a coating material for electric wires and cables having improved wear resistance can be obtained.

Claims (4)

A coating material for electric wires comprising the following components A to D.
Component A: Polyolefin-based resin Component B: Acid anhydride-modified polyolefin-based resin Component C: Low surface-treated magnesium hydroxide surface-treated with 0.001 to 1.0 parts by weight of fatty acid per 100 parts by weight of magnesium hydroxide D component: polyisobutylene The component A polyolefin-based resin is at least one selected from polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, and ethylene-ethyl acrylate copolymer, and the component B acid anhydride-modified polyolefin The wire covering material according to claim 1, wherein the resin is an ethylene-maleic anhydride binary copolymer and / or an ethylene-maleic anhydride-acrylic acid ester terpolymer. The covering material for electric wires according to claim 1 or 2, wherein the blending amount of the C component per 100 parts by weight of the total weight of the A component, the B component, and the D component is 50 to 150 parts by weight. The electric wire which has a sheath layer and / or an insulating layer which consist of a coating material in any one of Claims 1-3.