JP5564850B2 - Flame retardant, flame retardant composition and insulated wire - Google Patents

Description

  The present invention relates to a flame retardant, a flame retardant composition, and an insulated wire, and more particularly, a flame retardant suitable as a flame retardant component in a covering material for an insulated wire used for wiring such as vehicle parts and electrical / electronic equipment parts. The present invention relates to a flame retardant composition and an insulated wire using the same.

  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, there is a risk of releasing a halogen-based gas into the atmosphere during combustion such as when a vehicle fires or when incinerating and discarding electrical and electronic equipment. There was 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 release halogen-based gases during combustion. Alternatives to so-called non-halogen flame retardant compositions are underway.

  For example, Patent Document 1 discloses that a flame retardant obtained by pulverizing a natural mineral mainly composed of magnesium hydroxide is used as a coating material for electric wires and cables. Under the present circumstances, the flame retardant is surface-treated using the surface treating agent which has a fatty acid, a fatty-acid metal salt, a silane coupling agent, or a titanate coupling agent as a main component.

  In the electric wire field, magnesium hydroxide, a crystal growth product obtained by growing crystals of magnesium hydroxide obtained by aqueous solution reaction with calcium hydroxide using magnesium chloride in seawater as a raw material, is used. Proposals for use have also been made.

  On the other hand, in the steel industry, not in the electric wire field, for the purpose of flue gas desulfurization, agglomerated products obtained by aggregating magnesium hydroxide fine particles obtained from magnesium chloride in seawater using a flocculant are used. There are examples.

Japanese Patent No. 3339154

  However, conventionally, the magnesium hydroxide crystal growth product proposed in the electric wire field has a problem that it is difficult to use because of its high manufacturing cost compared to a natural product.

  On the other hand, the aggregate product of magnesium hydroxide has an advantage that the production cost is lower than that of the crystal growth product. However, there are only examples used in the steel industry, which is completely different from the electric wire field, and for the purpose of flue gas desulfurization. For this reason, in the electric wire field, it has never been unexpected to use it as a flame retardant. Therefore, until now, no attempt has been made to use an aggregate product of magnesium hydroxide as a flame retardant.

  The problem to be solved by the present invention is to propose a flame retardant having an unconventional structure, a flame retardant capable of improving cold resistance and productivity of a flame retardant composition containing the flame retardant, and It is providing the flame-retardant composition and insulated wire using this.

  Then, when the present inventors tried to mix | blend the magnesium hydroxide aggregate product with the composition for wire coating materials for the first time, the knowledge that the cold resistance of the coating material was not enough was acquired. Moreover, when preparing the composition for electric wire coating materials, the amount of discharge from the kneader which knead | mixes a composition was small, and the knowledge that productivity was not enough was acquired. Furthermore, the present inventors also tried to use the aggregated product after surface treatment with a general surface treatment agent described in Patent Document 1, but the knowledge that cold resistance and productivity were not sufficiently improved. Got. Therefore, in order to apply the aggregate product of magnesium hydroxide to the electric wire field, further ingenuity is required. The present invention has been obtained on the basis of these findings.

  That is, the flame retardant according to the present invention comprises an aggregate of particles mainly composed of magnesium hydroxide, and a surface treatment agent containing an organic polymer that covers the surface of the aggregate. The gist is that the melt viscosity at 140 ° C. is 500 mPa · s or more.

  At this time, the organic polymer is preferably a resin having a melting point of 100 ° C. or higher.

  The organic polymer is preferably an olefin resin. As the olefin-based resin, one or more selected from polyethylene, polypropylene, ethylene-ethyl acrylate copolymer, and ethylene-vinyl acetate copolymer can be suitably shown.

  Moreover, it is preferable that content of the said surface treating agent exists in the range of 0.1-10 mass parts with respect to 100 mass parts of said aggregates.

  On the other hand, the summary of the flame retardant composition according to the present invention is to contain the flame retardant and a matrix polymer. And the insulated wire which concerns on this invention makes it a summary to coat | cover the said flame-retardant composition on the outer periphery of a conductor.

  The flame retardant composition containing the flame retardant according to the present invention is excellent in cold resistance. In addition, the flame retardant composition containing the flame retardant according to the present invention is excellent in productivity because the discharge amount from the kneader is difficult to decrease.

  This is presumed as follows. That is, in the flame retardant according to the present invention, the surface treatment agent that covers the surface of the aggregate of particles mainly composed of magnesium hydroxide has a relatively high melt viscosity, and is a conventional surface treatment agent such as fatty acid. Compared to the above, it contains an organic polymer that is difficult to be thermally decomposed, so that the surface treatment agent is also applied to the surface of the aggregate by heat kneading or molding the flame retardant composition containing the flame retardant. Easy to stay. Thereby, it is guessed that aggregation of aggregates is suppressed and a flame retardant is highly dispersed in a flame retardant composition.

  In addition, since it contains an organic polymer that is difficult to be thermally decomposed as compared with fatty acids that are conventional surface treatment agents, the heat retardant composition containing the above flame retardant is heat-kneaded or depends on the heat history during molding. Generation of volatile gas is suppressed. Thereby, since the supply of the flame retardant composition containing the flame retardant into the kneader is performed smoothly, a decrease in productivity can be suppressed.

  At this time, if the organic polymer is a resin having a melting point of 100 ° C. or higher, the surface treatment agent is agglomerated by heat kneading or molding the flame retardant composition containing the flame retardant. It tends to stay on the surface of the aggregate.

  And when organic polymer is an olefin resin, it is easy to become familiar with the matrix polymer which consists of an olefin resin. Therefore, the flame retardant is more easily dispersed in the flame retardant composition.

  Moreover, when content of a surface treating agent exists in a specific range, the effect which improves the cold resistance and productivity of a flame-retardant composition is still higher.

  On the other hand, the flame retardant composition according to the present invention contains the flame retardant and a matrix polymer. Therefore, it is excellent in cold resistance and productivity. Moreover, according to the insulated wire which concerns on this invention, it is excellent in cold resistance and productivity.

It is sectional drawing which shows the flame retardant which concerns on one Embodiment of this invention.

  Next, an embodiment of the present invention will be described in detail. As shown in FIG. 1, a flame retardant 10 according to an embodiment of the present invention includes an aggregate 12 of particles 12 a mainly composed of magnesium hydroxide, and a surface treatment agent 14 containing an organic polymer. Is. The surface of the aggregate 12 is covered with a surface treatment agent 14.

  The aggregate 12 is a flame retardant component mainly composed of magnesium hydroxide. Aggregate 12 is obtained by aggregating particles containing magnesium hydroxide as a main component, which is precipitated (crystallized) by an aqueous solution reaction with calcium hydroxide, using magnesium chloride in seawater as a raw material. In the aqueous solution reaction between magnesium chloride and calcium hydroxide, particulate magnesium hydroxide with a very fine particle size (submicron order) precipitates (crystallizes), so the magnesium hydroxide does not settle and floats in water. ing. Since the obtained particulate magnesium hydroxide cannot be separated from water by filtration or the like, it can be precipitated and separated as an aggregate by aggregating with a flocculant.

  Aggregate 12 is formed by agglomerating particles 12a containing magnesium hydroxide as a main component due to the production method thereof, and thus has an almost spherical shape as a whole. Because of the adhesion, the surface is not smooth and is rough. Therefore, the aggregates 12 tend to aggregate. On the other hand, magnesium hydroxide, a crystal growth product, is composed of clean crystals, so its surface is not rough.

  The average particle diameter of the aggregate 12 is not particularly limited, but the lower limit is preferably 0.1 μm or more from the viewpoint of easy sedimentation. On the other hand, for example, when used as a flame retardant for a wire coating material, the upper limit is preferably 20 μm or less from the viewpoint of suppressing deterioration of the appearance of the coating material. 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 surface treatment agent 14 for surface-treating the surface of the aggregate 12 smoothes the surface of the aggregate 12 having a rough surface. The surface treatment agent 14 contains an organic polymer. The surface treatment agent 14 may contain additives and the like in addition to the organic polymer. Examples of the additive include an antioxidant.

  The organic polymer of the surface treatment agent 14 has a melt viscosity at 140 ° C. of 500 mPa · s or more. More preferably, it is 550 mPa * s or more, More preferably, it is 600 mPa * s or more. Since the melt viscosity is relatively high, the surface treatment agent tends to stay on the surface of the aggregate even by the heat history. Thereby, aggregation of aggregates is suppressed. The melt viscosity of the organic polymer can be measured with a Brookfield viscometer.

  On the other hand, when the melt viscosity is too high, the organic polymer tends to be a binder between the aggregates. If it does so, aggregates will aggregate and it will become easy to form particle | grains with a comparatively large particle size. In this case, since the yield of particles having a small particle size is reduced, a large production loss is likely to occur. From such a viewpoint, the melt viscosity at 140 ° C. of the organic polymer is preferably 30000 mPa · s or less, more preferably 28000 mPa · s or less, and further preferably 25000 mPa · s or less.

  In addition, the organic polymer of the surface treatment agent 14 is preferably a resin having a relatively high melting point from the viewpoint that the surface treatment agent is likely to remain on the surface of the aggregate due to thermal history. Specifically, the melting point is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, and further preferably 110 ° C. or higher.

  On the other hand, if the melting point is too high, coating may be difficult. Therefore, the melting point of the organic polymer is preferably 200 ° C. or lower, more preferably 195 ° C. or lower, and further preferably 190 ° C. or lower. The melting point of the organic polymer can be measured by a thermal analysis method (DSC method).

  Although it does not specifically limit as a kind of organic polymer of the surface treating agent 14, An olefin resin is preferable. Examples of the olefin resin include homopolymers or copolymers of olefins such as ethylene and propylene, or copolymers of olefins and other monomers such as acrylates and vinyl monomers. These can be used alone or in combination of two or more. More specifically, preferable examples include polyethylene (PE), polypropylene (PP), ethylene-ethyl acrylate copolymer (EEA), ethylene-vinyl acetate copolymer (EVA), and the like.

  Examples of the polyethylene include low density polyethylene, ultra low density polyethylene, linear low density polyethylene, high density polyethylene, and metallocene polymerized polyethylene.

  The organic polymer of the surface treatment agent 14 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. When it is acid-modified, it is easy to adapt to the aggregate which is an inorganic substance.

  Examples of the method for introducing an acid into the organic polymer of the surface treatment agent 14 include a graft method and a direct (copolymerization) method. The amount of acid modification is preferably 0.1 to 20% by mass with respect to the organic polymer. More preferably, it is 0.2-10 mass%, More preferably, it is 0.2-5 mass%. When the amount of acid modification is small, the effect of increasing the affinity with the aggregate tends to be small, and when the amount of acid modification is large, self-polymerization may occur, and the effect of increasing the affinity with the aggregate tends to be small.

  The content of the surface treatment agent 14 in the flame retardant 10 is preferably in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the aggregate 12. If the content of the surface treatment agent 14 is less than 0.1 parts by mass, the effect of smoothing the surface of the aggregate 12 tends to be reduced. On the other hand, when the content of the surface treatment agent 14 exceeds 10 parts by mass, the effect of improving the cold resistance and productivity of the flame retardant composition is small, but the cost increases. The content of the surface treatment agent 14 is more preferably in the range of 0.5 to 8 parts by mass, and still more preferably in the range of 1 to 5 parts by mass with respect to 100 parts by mass of the aggregate 12.

  In the flame retardant 10, the surface treatment agent 14 may cover the entire surface of the aggregate 12 or may cover a part thereof. Moreover, the thickness of the surface treating agent 14 which covers the aggregate 12 surface is not specifically limited. Preferably, it exists in the range of 0.001-0.01 micrometer.

  The surface treatment method of the aggregate 12 with the surface treatment agent 14 is not particularly limited. A wet method using a solvent for dissolving the organic polymer of the surface treatment agent 14 may be used, or a dry method using no solvent may be used. In the case of the wet method, examples of suitable solvents include aliphatic solvents such as pentane, hexane and heptane, and aromatic solvents such as benzene, toluene and xylene. Surface treatment can be performed by immersing the aggregate 12 in the surface treatment agent 14 in a molten state or in a dissolved state, or spraying the surface treatment agent 14 on the aggregate 12.

  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 and a matrix polymer.

  Although it does not specifically limit as a matrix polymer, Polyolefin, a styrene-type copolymer, etc. are preferable. Specifically, polyethylene, polypropylene, ethylene-propylene rubber, styrene-ethylene-butylene-styrene block copolymer, and the like can be exemplified.

  The matrix 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.

  Examples of the method for introducing an acid into the matrix polymer include a graft method and a direct (copolymerization) method. The amount of acid modification is preferably 0.1 to 20% by mass with respect to the organic polymer. More preferably, it is 0.2-10 mass%, More preferably, it is 0.2-5 mass%. When the amount of acid modification is less than 0.1% by mass, the cold resistance and the wear resistance tend to decrease. On the other hand, if it exceeds 20% by mass, the moldability tends to deteriorate.

  The flame retardant is preferably contained in an amount of 30 to 250 parts by mass with respect to 100 parts by mass of the matrix polymer. More preferably, it is 50-200 mass parts, More preferably, it is 60-180 mass parts. If it is less than 30 mass parts, a flame retardance will fall easily. On the other hand, when it exceeds 250 parts by mass, it is difficult to obtain sufficient mechanical properties.

  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 flame retardant composition can be prepared by, for example, heat-kneading a flame retardant, a matrix polymer, and an additive blended as necessary. At this time, a conventional kneader such as a Banbury mixer, a pressure kneader, a kneading extruder, a twin screw extruder, or a roll can be used. Prior to heat-kneading, dry blending can be performed in advance with a tumbler or the like. After heating and 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, when preparing the flame retardant composition, the flame retardant is heated together with the matrix polymer and the like during kneading and extrusion.

  In the flame retardant according to the present invention, the surface treatment agent that covers the surface of the aggregate of particles mainly composed of magnesium hydroxide has a relatively high melt viscosity, and is compared with a fatty acid that is a conventional surface treatment agent. And organic polymers that are difficult to be thermally decomposed. Therefore, it is presumed that the surface treatment agent tends to stay on the surface of the agglomerate also by the heat history when preparing the flame retardant composition.

  Therefore, according to the flame retardant composition containing the flame retardant, aggregation of the flame retardant aggregates is suppressed, and it is assumed that the flame retardant is highly dispersed in the flame retardant composition. As a result, the flame retardant composition is presumed to be excellent in cold resistance. Moreover, it is estimated that a flame-retardant composition is excellent in productivity, since the discharge amount from a kneader becomes difficult to fall.

  In addition, since it contains an organic polymer that is difficult to be thermally decomposed as compared with fatty acids that are conventional surface treatment agents, the flame retardant composition containing this flame retardant is heat-kneaded or depends on the heat history during molding. Generation of volatile gas is suppressed. Thereby, since the supply of the flame retardant composition into the kneader is performed smoothly, a decrease in productivity can be suppressed.

  Next, the insulated wire 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 a covering material. As for the configuration of the insulated wire, the outer periphery of the conductor may be coated directly with a covering material, and other intermediate members such as a shield conductor and other insulators are provided between the conductor and the covering material. It 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. Further, the thickness of the covering 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.

  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.

・ Matrix polymer (polypropylene) [Nippon Polypro Co., Ltd., trade name “EC7”]
Magnesium hydroxide (aggregate) [manufactured by Nippon Seawater Chemicals Co., Ltd., trade name “MS-1H”]
Surface treatment agent (a) Polypropylene (PP) (manufactured by Sun Allomer, trade name “PMA20V”)
(B) Polypropylene (PP) (manufactured by Sun Allomer, trade name “PMA20V”)
(C) Polyethylene (PE) (manufactured by Nippon Polyethylene Co., Ltd., trade name “UJ790”)
(D) Polyethylene (PE) (manufactured by Nippon Polyethylene Co., Ltd., trade name “UJ790”)
(E) Ethylene-ethyl acrylate copolymer (EEA) [Mitsui Chemicals, trade name “EV550”]
(F) Ethylene-vinyl acetate copolymer (EVA) [manufactured by Nippon Polyethylene Co., Ltd., trade name “LV371”]
(G) Metallocene polyethylene [manufactured by Nippon Polypro, trade name “RFG4VA”]
(H) PP wax [manufactured by Clariant, trade name “2602”]
(I) PE wax [manufactured by Clariant, trade name “PE190”]
(J) Polypropylene (PP) (trade name “PMA20V” manufactured by Sun Allomer)
(K) Polypropylene (PP) (trade name “PMA20V” manufactured by Sun Allomer)
(L) Polyethylene (PE) (manufactured by Nippon Polyethylene Co., Ltd., trade name “UJ790”)
(M) Polyethylene (PE) (manufactured by Nippon Polyethylene Co., Ltd., trade name “UJ790”)
(N) Stearic acid (reagent)
(O) Zinc stearate (reagent)
(P) Methacrylsilane (reagent)
Antioxidant [Ciba Specialty Chemicals Co., Ltd., trade name “Irganox 1010”]

(Preparation of flame retardant)
While stirring magnesium hydroxide (aggregate) in a super mixer at a temperature of 200 ° C., the surface treatment agent 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. Table 1 shows the type, content, melting point (° C.), and melt viscosity (mPa · s) at 140 ° C. of each surface treatment agent. The content (treatment amount) of each surface treatment agent is indicated by the ratio (parts by mass) to 100 parts by mass of magnesium hydroxide (aggregate). The viscosity shown in Table 1 is the melt viscosity (mPa · s) of each surface treatment agent at 140 ° C. The method for measuring the melt viscosity and the method for measuring the melting point are shown below.

(Production of flame retardant composition and insulated wire)
After kneading each component (parts by mass) shown in Table 1 or 2 at a mixing temperature of 200 ° C. using a biaxial kneader, the kneaded product is discharged from the biaxial kneader and formed into pellets with a pelletizer. Thus, flame retardant compositions according to Examples and Comparative Examples were obtained. Next, each flame-retardant composition obtained was extrusion-coated with a thickness of 0.2 mm on the outer periphery of an annealed copper stranded wire conductor (cross-sectional area 0.5 mm ² ) obtained by twisting seven annealed copper wires with an extruder. Insulated wires according to Examples and Comparative Examples were produced.

(Test method)
The discharge amount (kg / h) from the biaxial kneader of each flame retardant composition produced as described above was evaluated. Moreover, the cold resistance test was done about each insulated wire. The results are shown in Tables 1 and 2.

(Melt viscosity)
The melt viscosity at 140 ° C. of each surface treatment agent was measured using a Brookfield viscometer.

(Melting point)
Using a differential scanning calorimeter (DSC), the melting point of each surface treatment agent was measured at a temperature rising rate of 10 ° C./min.

(Discharge rate)
The discharge amount (kg / h) of each flame retardant composition from a biaxial kneader was measured at a barrel temperature of 230 ° C. and a resin temperature of 230 ° C.

(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.

  Comparative Examples 1-4 use the flame retardant which consists of what coat | covered resin with low melt viscosity on the surface of the aggregate of the particle | grains which have magnesium hydroxide as a main component. According to the insulated wire which concerns on Comparative Examples 1-4, it turns out that it is inferior to cold resistance. Moreover, in Comparative Examples 1-4, it turns out that the discharge amount of the kneaded material at the time of preparing a flame-retardant composition is small, and it is inferior to productivity.

  Comparative Examples 5 to 7 use a flame retardant made of a particle aggregate mainly composed of magnesium hydroxide and coated with a conventional surface treatment agent that is not an organic polymer. According to the insulated wire which concerns on Comparative Examples 1-4, it turns out that it is inferior to cold resistance. Moreover, in Comparative Examples 1-4, it turns out that the discharge amount of the kneaded material at the time of preparing a flame-retardant composition is small, and it is inferior to productivity.

  On the other hand, the Example uses the flame retardant which consists of what coat | covered resin with high melt viscosity on the surface of the aggregate of the particle | grains which have magnesium hydroxide as a main component. It was confirmed that the insulated wire according to the example was excellent in cold resistance. Moreover, it was confirmed that the amount of the kneaded material discharged in preparing the flame retardant composition was large and the productivity was excellent.

  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.

10 Flame Retardant 12 Aggregate 12a Particles Containing Magnesium Hydroxide 14 Surface Treatment Agent

Claims (7)

Aggregates obtained by aggregating particles containing magnesium hydroxide as a main component obtained using magnesium chloride as a main component using an aggregating agent ;
A surface treatment agent containing an organic polymer covering the surface of the aggregate,
The organic polymer is a resin having a melt viscosity at 140 ° C. of 500 mPa · s or more.   The flame retardant according to claim 1, wherein the organic polymer is a resin having a melting point of 100 ° C. or higher.   The flame retardant according to claim 1, wherein the organic polymer is an olefin resin.   The olefin-based resin is one or more selected from polyethylene, polypropylene, ethylene-ethyl acrylate copolymer, and ethylene-vinyl acetate copolymer. Flame retardants.   The flame retardant according to any one of claims 1 to 4, wherein the content of the surface treatment agent is in a range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the aggregate.   A flame retardant composition comprising the flame retardant according to any one of claims 1 to 5 and a matrix polymer.   An insulated wire, wherein the flame retardant composition according to claim 6 is coated on the outer periphery of a conductor.

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