JP2010006986A - Flame retardant, flame retardant composition, insulated wire and wire harness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame retardant capable of improving cold resistance and productivity of a composition, a flame retardant composition, an insulated wire and a wire harness. <P>SOLUTION: The flame retardant is produced by crushing a natural mineral composed mainly of magnesium hydroxide and surface-treating the crushed mineral with an organic polymer having a melting point of ≤100°C. The organic polymer preferably has a melt viscosity of ≤1,000 mPa s at 140°C. The flame retardant composition contains the flame retardant. The insulated wire is produced by covering the outer circumference of a conductor with the flame retardant composition, and the wire harness contains the insulated wire. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flame retardant, a flame retardant composition, an insulated wire, and a wire harness.

  Conventionally, as an insulated wire used for wiring of vehicle parts such as automobile parts and electrical / electronic equipment parts, generally, the outer periphery of a conductor is widely coated with a vinyl chloride resin composition to which a halogen-based flame retardant is added. Has been used.

  However, since this type of vinyl chloride resin composition contains a halogen element, a large amount of harmful halogen gas is released into the atmosphere during combustion such as in the event of a vehicle fire or incineration and disposal of electrical and electronic equipment. There was a concern about environmental pollution.

  Therefore, from the viewpoint of reducing the burden on the global environment, in recent years, metal hydroxides such as magnesium hydroxide have been added as non-halogen flame retardants to olefin resins that do not emit harmful halogen gases during combustion. Therefore, an alternative to the so-called non-halogen flame retardant composition is underway.

  In this type of flame retardant composition, a large amount of magnesium hydroxide is added in order to impart sufficient flame retardancy. Among magnesium hydroxides, synthetic products synthesized from seawater and the like are relatively expensive, and recently, for the purpose of reducing manufacturing costs, proposals have been made to use inexpensive natural products.

  For example, Patent Document 1 discloses a flame retardant obtained by pulverizing a natural mineral mainly composed of magnesium hydroxide and surface-treating with a fatty acid, a fatty acid metal salt, a silane coupling agent or a titanate coupling agent, and the flame retardant. A flame retardant composition using, and an insulated wire coated with the flame retardant composition are disclosed.

Japanese Patent No. 3339154

  The covering material for insulated wires is required to have various characteristics such as mechanical characteristics, flame retardancy, and cold resistance. However, in the conventional flame retardant using a pulverized natural mineral mainly composed of magnesium hydroxide, the cold resistance of a composition obtained by adding this to an olefin resin is not sufficient. Further, when preparing the composition, there is a problem that the amount of discharge from the kneader is small and the productivity of the composition is low.

  The problem to be solved by the present invention is to provide a flame retardant, a flame retardant composition, an insulated wire, and a wire harness that can improve the cold resistance and productivity of the composition.

  The flame retardant according to the present invention is obtained by subjecting a pulverized natural mineral mainly composed of magnesium hydroxide to a surface treatment with an organic polymer having a melting point of 100 degrees or less.

  In this case, it is desirable that the melt viscosity at 140 degrees of the organic polymer is 1000 mPa · s or less.

  Moreover, the flame-retardant composition which concerns on this invention makes it a summary to contain the said flame retardant.

  The gist of the insulated wire according to the present invention is that the outer periphery of the conductor is coated with the flame retardant composition.

  And the wire harness which concerns on this invention makes it a summary to contain the said insulated wire.

  According to the flame retardant according to the present invention, the cold resistance of a flame retardant composition obtained by adding it to a base resin such as an olefin resin can be enhanced. This is because the pulverized product is surface-treated with an organic polymer having a melting point of 100 ° C. or less, so that the surface irregularities of the pulverized product are smoothed. As a result, aggregation of particles is suppressed, and a flame retardant is contained in the composition. Presumably because of high dispersion.

  Moreover, the discharge amount from the kneader of the flame-retardant composition containing the said flame retardant can be increased. Thereby, productivity of the said flame-retardant composition can be improved. This is because the pulverized product is surface-treated with an organic polymer having a melting point of 100 degrees or less, so that when the flame retardant and the base resin are kneaded, the flame retardant is easily dispersed in the base resin. This is presumably because the base resin is more easily mixed. In addition, since organic polymers are difficult to be thermally decomposed compared to conventional surface treatment agents such as fatty acids, moisture and organic polymers contained in the natural minerals in the process of heat-kneading the flame retardant and the base resin. It is presumed that the generation of volatile gas from the above is suppressed and the raw material is smoothly fed into the kneader.

  In this case, when the melt viscosity at 140 degrees of the organic polymer is 1000 mPa · s or less, the above effect is further improved.

  On the other hand, since the flame retardant composition according to the present invention contains the flame retardant, it is excellent in cold resistance and productivity.

  Furthermore, according to the insulated wire and the wire harness including the insulated wire according to the present invention, since the flame retardant composition is coated on the outer periphery of the conductor, the deterioration of the insulation coating material can be suppressed, and high reliability can be obtained over a long period of time. Sex can be secured.

  Next, an embodiment of the present invention will be described in detail.

  The flame retardant according to the present invention is obtained by subjecting a pulverized natural mineral mainly composed of magnesium hydroxide to a surface treatment with a specific organic polymer. The melting point of the organic polymer that surface-treats the pulverized natural mineral is 100 degrees or less from the viewpoint of uniformly dispersing the flame retardant in the base resin. This is because when the melting point of the organic polymer exceeds 100 degrees, the dispersibility of the flame retardant deteriorates. The melting point of the organic polymer is preferably 90 degrees or less, and more preferably 80 degrees or less. On the other hand, from the viewpoint of storage stability, the lower limit of the melting point of the organic polymer is 40 degrees or more, more preferably 50 degrees or more, and further preferably 60 degrees or more. The melting point of the organic polymer can be measured by a method such as thermal analysis (DSC method).

  Moreover, the melt viscosity at 140 degrees of this organic polymer is preferably 1000 mPa · s or less. This is because when the melt viscosity at 140 degrees of the organic polymer exceeds 1000 mPa · s, the fluidity tends to be low, and the dispersibility is deteriorated. Preferably, it is 900 mPa · s or less, more preferably 800 mPa · s or less. On the other hand, from the viewpoint of storage stability, the lower limit of the melt viscosity at 140 degrees of the organic polymer is 10 mPa · s or more, more preferably 20 mPa · s or more, and further preferably 30 mPa · s or more. The melt viscosity of the organic polymer can be measured by a method such as thermal analysis (DSC method).

  Here, the surface treatment amount with the organic polymer is represented by the weight (% by weight) of the organic polymer used for the surface treatment with respect to the weight of the flame retardant, and the surface treatment amount is 0.1 to 10%. It is preferable to be in the range of% by weight. More preferably, it is in the range of 0.5 to 5% by weight, and still more preferably in the range of 1 to 2% by weight. This is because, if it is less than 0.1% by weight, for example, the effect of improving the cold resistance and the effect of improving the productivity of the flame retardant composition obtained by adding a flame retardant to the base resin is likely to decrease. On the other hand, if it exceeds 10% by weight, the cost of the flame retardant increases.

  As the organic polymer, an α-olefin such as 1-heptene, 1-octene, 1-nonene, 1-decene or the like, or a copolymer thereof, or a mixture thereof can be used.

  The organic polymer may be acid-modified. As the acid, an unsaturated carboxylic acid or a derivative thereof can be used. Specifically, examples of the unsaturated carboxylic acid include maleic acid and fumaric acid. Examples of the derivatives include maleic anhydride, maleic acid monoester, maleic acid diester and the like. Of these, maleic acid and maleic anhydride are more preferred. These may be used alone or in combination of two or more. This is because when it is acid-modified, it easily becomes compatible with the pulverized material that is an inorganic substance.

  Examples of the method for introducing an acid into the organic polymer include a graft method and a direct (copolymerization) method. The amount of acid modification is preferably 0.1 to 20% by weight based on the organic polymer. More preferably, it is 0.2-10 weight%, More preferably, it is 0.2-5 weight%. If the amount of acid modification is small, the effect of increasing the affinity with the pulverized product tends to be small, and if the amount of acid modification is large, self-polymerization may occur, and the effect of increasing the affinity for the pulverized product tends to be small. is there.

  Examples of natural minerals that are surface-treated by the organic polymer include natural brucite ore. The pulverization method may be either wet or dry. Since the flame retardant according to the present invention is produced by pulverizing natural minerals, the production cost is lower than that of a flame retardant produced by synthesizing magnesium hydroxide from seawater or the like. The initial moisture content of the pulverized product is preferably 1% by weight or less.

  The average particle size of the pulverized product is preferably in the range of 0.1 to 20 μm. If the thickness is less than 0.1 μm, secondary aggregation of the particles is likely to occur, and the mechanical properties of the composition containing the flame retardant and the organic polymer are likely to deteriorate. On the other hand, when it exceeds 20 μm, for example, when used as a flame retardant for a wire coating material, the appearance of the coating material tends to deteriorate. More preferably, it exists in the range of 0.2-10 micrometers, More preferably, it exists in the range of 0.5-5 micrometers.

  The method for surface-treating the organic polymer on the pulverized product is not particularly limited. A wet process using an organic polymer melted in a solvent may be used, or a dry process without using a solvent may be used. In the case of wet processing, suitable solvents include aliphatic solvents such as pentane, hexane, and heptane, and aromatic solvents such as benzene, toluene, and xylene. The organic polymer may be surface-treated on a pulverized product pulverized to a predetermined particle size, or may be surface-treated at the same time as pulverizing natural minerals. Furthermore, at the time of manufacturing the flame retardant composition of the present invention, the organic polymer may be kneaded simultaneously with the base resin, and the pulverized product may be surface-treated.

  The pulverized material only needs to be partially or entirely covered with an organic polymer by surface treatment. What is partially covered with the organic polymer may be covered to such an extent that, for example, the flame retardant and the base resin are mixed well and the moisture in the magnesium hydroxide is suppressed.

  Next, the flame retardant composition according to the present invention will be described.

  The flame retardant composition according to the present invention contains the flame retardant. The flame retardant is preferably contained in an amount of 30 to 250 parts by weight with respect to 100 parts by weight of the base resin. More preferably, it is 50-200 weight part, More preferably, it is 60-180 weight part. This is because if the amount is less than 30 parts by weight, the flame retardancy tends to decrease, and if it exceeds 250 parts by weight, sufficient mechanical properties are difficult to obtain.

  As the base resin, polyolefin, styrene copolymer, and the like are preferable. Specifically, polyethylene, polypropylene, ethylene-propylene rubber, styrene-ethylene-butylene-styrene block copolymer, and the like can be exemplified.

  The base resin may be acid-modified. As the acid, an unsaturated carboxylic acid or a derivative thereof can be used. Specifically, examples of the unsaturated carboxylic acid include maleic acid and fumaric acid. Examples of the derivatives include maleic anhydride, maleic acid monoester, maleic acid diester and the like. Of these, maleic acid and maleic anhydride are more preferred. These may be used alone or in combination of two or more.

  Examples of the method for introducing an acid into the base resin include a graft method and a direct (copolymerization) method. The amount of acid modification is preferably 0.1 to 20% by weight based on the organic polymer. More preferably, it is 0.2-10 weight%, More preferably, it is 0.2-5 weight%. This is because when the acid modification amount is less than 0.1% by weight, the wear resistance tends to decrease, and when it exceeds 20% by weight, the moldability tends to deteriorate.

  In the flame-retardant composition according to the present invention, if necessary, other additives may be blended within a range that does not impair the physical properties of the composition. For example, a general filler used for a wire coating material or the like, a pigment, an antioxidant, an anti-aging agent, or the like may be blended, and is not particularly limited.

  The method for producing a flame retardant composition includes a step of kneading the flame retardant and a base resin. The step of kneading the flame retardant and the base resin can be performed using a general kneader such as a Banbury mixer, a pressure kneader, a kneading extruder, a twin screw extruder, or a roll.

  In the kneading step, the base resin may be added to the kneader in advance, and the flame retardant may be added to the stirring site, or the flame retardant is added to the kneading machine in advance and the base resin added to the stirring location. You can do it. Further, before kneading, after dry blending with a tumbler or the like, it may be transferred to a kneader and kneaded.

  The temperature at the time of kneading is preferably a temperature at which the viscosity of the organic polymer is lowered to such an extent that the flame retardant is easily dispersed in the base resin. Specifically, it is preferably in the range of 100 to 300 ° C. If heat is generated by shearing the organic polymer during kneading, the temperature may be adjusted to an optimum temperature in consideration of the temperature rise due to heat generation.

  After kneading, the composition is taken out from the kneader. At that time, the composition may be formed into pellets with a pelletizer or the like.

  As described above, the flame retardant according to the present invention is made by subjecting a pulverized natural mineral containing magnesium hydroxide as a main component to a surface treatment with the organic polymer, so that mixing when kneading with a kneader is performed. The temperature rise during kneading is smooth. Further, the mesh of the kneader is not clogged and the internal pressure is hardly increased.

  Next, the insulated wire and the wire harness according to the present invention will be described.

  The insulated wire according to the present invention uses the above-mentioned flame retardant composition as a material for an insulating coating material. As a configuration of the insulated wire, the outer periphery of the conductor may be directly coated with an insulating coating material, or another intermediate member such as a shield conductor or other insulator between the conductor and the insulating coating material. Etc. may be interposed.

  The conductor is not particularly limited, such as the diameter of the conductor or the material of the conductor, and can be appropriately determined according to the application. Also, the thickness of the insulating coating material is not particularly limited and can be appropriately determined in consideration of the conductor diameter and the like.

  The insulated wire is, for example, a flame retardant composition according to the present invention kneaded using a commonly used kneader such as a Banbury mixer, a pressure kneader, or a roll. It can be produced by extrusion coating.

  On the other hand, the wire harness which concerns on this invention comprises the said insulated wire. It may be a wire bundle composed only of the above insulated wires, or an insulated wire coated with another organic polymer composition, for example, a vinyl chloride-based insulated wire or other insulated wires not containing a halogen element An electric wire bundle configured to include For example, the wire bundle may be covered with a wire harness protective material. The number of electric wires can be determined arbitrarily and is not particularly limited.

  A wire harness protective material has a role which covers the outer periphery of the electric wire bundle in which the multiple insulated electric wire was bundled, and protects an internal electric wire bundle from the external environment. Although it does not specifically limit as a base material which comprises a wire harness protective material, Polyolefin-type resin compositions, such as polyethylene and a polypropylene, are preferable. A flame retardant may be appropriately added to the resin composition.

  For wire harness protection materials, for example, those with adhesive applied to at least one surface of a tape-shaped substrate, or those having a substrate formed in a tube shape, sheet shape, etc. It can be appropriately selected and used accordingly.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

(Test material and manufacturer)
The test materials used in the present examples and comparative examples are shown together with the manufacturer, product name, and the like.

(A) Base resin / polypropylene [made by Nippon Polypro Co., Ltd., trade name “EC7”]

(B) Magnesium hydroxide made by Phimatec Co., Ltd.

(C) Organic polymer (a) Ethylene-octene copolymer [ethylene: octene = 5: 5, weight average molecular weight: 5000]
(B) Ethylene-octene copolymer [ethylene: octene = 6: 4, weight average molecular weight: 5000]
(C) Ethylene-decene copolymer [ethylene: decene = 6: 4, weight average molecular weight: 5000]
(D) Ethylene-decene copolymer [ethylene: decene = 6: 4, weight average molecular weight: 5000]
(E) Ethylene-dodecene copolymer [ethylene: dodecene = 6: 4, weight average molecular weight: 5000]
(F) Ethylene-dodecene copolymer [ethylene: dodecene = 6: 4, weight average molecular weight: 5000]
(G) Polyethylene wax [trade name “800p” manufactured by Mitsui Chemicals, Inc.]
(H) Polypropylene wax [trade name “NP805” manufactured by Mitsui Chemicals, Inc.]
(I) Stearic acid [reagent]
(J) Zinc stearate [reagent]

(D) Antioxidant / Ciba Specialty Chemicals Co., Ltd., trade name “Irganox 1010”

(Preparation of flame retardant)
While stirring magnesium hydroxide in a super mixer at a temperature of 200 ° C., the surface treatment agent shown in Table 1 was gradually added into the mixer over about 5 minutes. After adding a predetermined amount, the mixture was further stirred for about 20 minutes to prepare flame retardants according to Examples and Comparative Examples.

(Production of composition and insulated wire)
First, each component shown in Table 1 was kneaded at a mixing temperature of 200 ° C. using a twin-screw kneader, and then formed into pellets with a pelletizer, and the composition according to this example and the composition according to the comparative example. I got a thing. Then, each composition obtained by extrusion molding machine, the outer periphery to the extrusion coated with 0.2mm thickness of the conductor of the annealed copper wire seven twisted soft copper stranded wire (cross sectional area 0.5 mm ^2), this embodiment An insulated wire according to an example and an insulated wire according to a comparative example were produced.

(Test method)
The discharge amount (kg / h) of each composition produced as described above was evaluated. Moreover, the cold resistance test was done about each insulated wire.

(Cold resistance test)
This was performed according to JIS C3005. That is, the produced insulated wire was cut into a length of 38 mm to obtain a test piece. The sample was put on a testing machine, hit with a striking tool while cooling, and the temperature when all five were cracked was defined as the cold resistant temperature. Those having a cold resistant temperature of −20 ° C. or lower were regarded as acceptable.

  Table 1 shows the composition ratio (unit: parts by weight) of the composition and the evaluation results.

  It turned out that the insulated wire which concerns on a comparative example is inferior to cold resistance. This is presumably because the magnesium hydroxide particles aggregated and the dispersibility deteriorated. Moreover, the insulated wire which concerns on a comparative example has few discharge amounts of a composition, and is inferior to productivity.

  On the other hand, it was confirmed that all the insulated wires according to the examples were excellent in cold resistance. Moreover, it turned out that the insulated wire which concerns on an Example has many discharge amounts of a composition and is excellent in the productivity of a composition.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Claims (5)

  A flame retardant obtained by surface-treating a pulverized natural mineral mainly composed of magnesium hydroxide with an organic polymer having a melting point of 100 degrees or less.   The flame retardant according to claim 1, wherein the organic polymer has a melt viscosity at 140 ° C. of 1000 mPa · s or less.   A flame retardant composition comprising the flame retardant according to claim 1.   An insulated wire obtained by coating the outer periphery of a conductor with the flame retardant composition according to claim 3.   A wire harness comprising the insulated wire according to claim 4.