JP3047911B1 - Non-halogen flame-retardant resin composition and its applied products - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a non-halogen flame-retardant resin which is flexible, has high heat resistance, has excellent terminal workability, hardly causes stress whitening, and has high insulation resistance, while maintaining high flame retardancy not containing halogen. Obtaining the composition. SOLUTION: A blend of a styrenic thermoplastic elastomer and an ethylene-α olefin copolymer or a block polymer of a polypropylene phase and an olefin copolymer rubber phase is used as a base polymer, and a metal hydroxide is mixed with the blend.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-halogen flame-retardant resin composition which does not generate harmful gases such as hydrogen halide when burned, and a power cord, an insulated wire, a plug, an adapter, etc. using the composition. And electrical insulating parts.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of safety and hygiene,
Non-halogen flame-retardant resin compositions have been used as insulating coatings or sheath materials for cables and the like, which have low smoke emission in the event of fire and do not generate harmful gases such as hydrogen halide. These resin compositions mainly use polyolefin resin materials as base polymers, use metal hydroxides such as magnesium hydroxide and aluminum hydroxide as flame retardants, and use red phosphorus and phosphoric acid compounds as flame retardant aids. It is common to do. However, these resin compositions have the following problems. 1) Polyolefin polymers, especially high-pressure low-density polyethylene, copolymers of ethylene and α-olefin (linear low-density polyethylene), ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA) And the like have a crystal part in a normal temperature range, though having a degree of difference, and have relatively high rigidity. Therefore, an insulated wire or the like using a non-halogen flame-retardant resin composition containing them as a base polymer for coating gives a more rigid feel than one using vinyl chloride or the like. 2) In order to lower the rigidity, it is necessary to lower the crystallinity. However, in the case of high-pressure polyethylene, there is a limit in reducing the crystallinity due to the production method. In the case of an ethylene copolymer, it can be dealt with by increasing the content of the comonomer, which improves the flexibility, but reduces the crystal part which has contributed to maintaining the strength, thereby lowering the material strength. 3) To lower the rigidity, it is necessary to lower the crystallinity, but the lowering of the crystallinity lowers the thermal deformation resistance. For example, in the case of linear low-density polyethylene having a density of 0.920, the Vicat softening point is around 100 ° C, and at higher temperatures, the heat deformation characteristics are significantly reduced, so that it can withstand use above 100 ° C as an insulator. Absent. 4) In the case of a crystalline polymer, necking occurs and is stretched when it is deformed beyond the yield point. The material is unlikely to break due to the stretching, but since the stretching state is irreversible, it does not return to its original state once it has stretched beyond the yield point. At the time of processing the end of the wire coating, lightly insert a knife into the insulator and pull it out. At this time, if the material is based on polyethylene, EVA, EEA, etc. (especially when the crystallinity is high),
Stretching is likely to occur, and there is a case where a whisker-like residue is left on the terminal and the terminal processability is impaired. 5) A crystalline polymer such as polyethylene shows a yield point in the stress-strain behavior, but the material becomes white due to irreversible deformation beyond the yield point (stress whitening). When a material based on polyethylene, EVA, EEA, or the like is used for covering the electric wire (especially when the crystallinity is high), stress whitening occurs when the electric wire is bent, and the bent portion turns white and bends. It is difficult to return to the original state. 6) The non-halogen flame-retardant resin composition filled with a metal hydroxide tends to have lower insulation resistance than a system not filled with a metal hydroxide because the metal hydroxide easily contains moisture.

[0003]

SUMMARY OF THE INVENTION The present invention is free from the problems of the above-mentioned conventional non-halogen flame-retardant resin composition, and is flexible and has high heat resistance while maintaining a high degree of flame retardancy without halogen. It is an object of the present invention to obtain a non-halogen flame-retardant resin composition having excellent end workability, hardly causing stress whitening, and having high insulation resistance.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in consideration of the various problems described above, and as a result, have found the following solutions and completed the present invention. The first feature of the present invention is to mix the following materials at a predetermined ratio. Styrenic thermoplastic elastomer, MFI of 0.1 at 190 ° C and 2.16 kg load
~ 5.0g / 10min range and density 0.860 ~
An ethylene-α-olefin copolymer in the range of 0.935 g / cm ^{3, in} the range of
A block polymer of a polypropylene phase and an olefin copolymer rubber phase in a range of 0 to 0.890 g / cm ³ , a metal hydroxide having an average particle size (D50) in a range of 0.5 to 9.0 μm, The present invention has a very high flexibility and heat resistance, which has been difficult to realize as a halogen-free flame-retardant material, by combining the materials of the above-mentioned materials at a predetermined ratio, and has both the resistance to terminal processing and the resistance to stress whitening. Provided is a non-halogen flame-retardant resin composition for covering a power cord or an insulated wire which has been laid.
Here, the average particle diameter (D50) refers to the particle diameter when the relative particle amount is 50% using a laser diffraction particle size distribution analyzer.

[0005] Since the material exhibits rubber elasticity due to the presence of the rubber phase therein, cold stretching and whitening of stress, which cause uncut portions during terminal processing, can be suppressed. However, in the case of a styrene-based thermoplastic elastomer alone, a very high temperature and a high shearing force are required to melt and lower the viscosity. If the processing temperature is low and the viscosity at the time of melting is too high, a molten state suitable for processing cannot be obtained. Further, if the processing temperature is excessively increased in order to lower the melt viscosity, the dehydration reaction of the metal hydroxide occurs in the addition of the metal hydroxide, resulting in problems such as foaming.

In the present invention, a non-halogen flame-retardant resin having higher processability, flexibility, heat resistance, terminal processability, and stress whitening resistance is selected by selecting and blending ratio with respect to. A composition can be obtained. If the blend amount of the styrene-based thermoplastic elastomer is too large, the effect of the styrene-based thermoplastic elastomer is reduced. Therefore, a particularly preferable blend ratio for satisfying both processability, flexibility, heat resistance, terminal processability, and stress whitening resistance is ( /
), 60/40 to 80/20. (Claim 1)

Further, as the copolymer having a polar group, at least one selected from ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methyl acrylate copolymer (EMA) By substituting a part of the polymer, the flame retardancy and the like of the resin composition can be improved. (Claim 2)

Further, the present invention comprises 0.1 to 10 parts by weight of at least one kind of organosilicon compound selected from the group consisting of organopolysiloxane, organofunctional silane (silane coupling agent) and alkoxysilane. And a non-halogen flame-retardant resin composition having high abrasion resistance and flame resistance. (Claim 3) Since an appropriate sliding occurs between the conductor and the insulator due to the action of the organosilicon compound, the wires and cords coated with the non-halogen flame-retardant resin composition of the present invention are not easily deformed even when bent. . In particular, the use of an organopolysiloxane is effective for improving abrasion resistance and flame retardancy and preventing bending.

Further, the present invention provides a non-halogen flame-retardant resin composition having high insulating performance, containing 0.1 to 10 parts by weight of an organofunctional silane represented by the general formula (A). provide. (Claim 4)

Embedded image Here, R is an alkyl group having an epoxy group or an amino group, X1, X2, and X3 are selected from the group consisting of an alkoxy group and an alkyl group, and an atomic group in which at least one of X1, X2, and X3 is an alkoxy group. Represents As a result of the interaction between the organofunctional silane and the metal hydroxide, the active metal hydroxide surface is coated with the organic silicate compound, and the electron transfer path is restricted, so that the insulating property is improved. It is thought that.

Further, by using an acid-modified styrenic thermoplastic elastomer in which a part or all of the styrenic thermoplastic elastomer has a carboxylic acid or an acid anhydride group, the metal hydroxide and the styrenic thermoplastic elastomer can be combined with each other. Forms pseudo-crosslinking, and can further improve material strength, heat resistance, end workability, and stress whitening resistance.
(Claim 5) Further, by adding an organosilicon compound (organofunctional silane) represented by the general formula (A) to this system, the pseudo-crosslinking generation efficiency is further increased, so that the material strength, heat resistance and terminal Workability and stress whitening resistance can be further improved.

In the present invention, a non-halogen flame-retardant resin composition having stable processability can be obtained by using magnesium hydroxide as the metal oxide. In the case of using a styrene thermoplastic elastomer, it is necessary to set the extrusion processing temperature to a relatively high temperature (170 to 190 ° C.). The use of magnesium is very effective in stabilizing workability. When used in combination with an organopolysiloxane, an organofunctional silane, or an alkoxysilane, those using magnesium hydroxide without surface treatment are particularly effective in preventing bending whitening. (Claim 6)

According to the present invention, the non-halogen flame-retardant resin composition is applied to a covering material of a power cord and an insulated wire, whereby the composition has high flame retardancy, flexibility, heat resistance, and excellent terminal workability. Further, the present invention provides a non-halogen flame-retardant power cord and an insulated wire which are less likely to cause stress whitening and have high insulation resistance. (Claim 7)

Another feature of the present invention is that a styrene-based thermoplastic elastomer having a melt flow index (MFI) at 200 ° C. under a load of 5.0 kg in the range of 10 to 90 g / 10 min. MFI under load is 2.0
~ 20g / 10min, density 0.860 ~
Ethylene-α olefin copolymer in the range of 0.935 g / cm ³ or MFI in the range of 0.
A blend ratio of a polypropylene phase and an olefin copolymer rubber phase in the range of 880 to 0.890 g / cm ³ with a block ratio (/) of 40/60 to 60/40.
The present invention provides a non-halogen flame-retardant resin composition suitable for electric insulation parts by injection molding or the like by using a polymer blended in the range of 1) as a base resin and obtaining high flow characteristics. Examples of the electrically insulated component here include a plug connector that is integrally formed with a plug, a cord connector body, an adapter, and the like. The thus obtained electrically insulating component can achieve both high flexibility, heat resistance and stress whitening resistance, which have been difficult to achieve with conventional halogen-free flame retardant materials. Furthermore, by using an organosilicon compound, particularly an organopolysiloxane, abrasion resistance, flame resistance, bending whitening resistance, and water repellency can be improved. Since the accumulation of dirt due to dew condensation can be reduced by improving the water repellency, tracking resistance is improved.

Further, the present invention provides an insulated wire, an electrically insulated component such as a plug and an adapter, wherein the degree of crosslinking is in the range of 10 to 80% using the above-described non-halogen flame-retardant resin composition. I will provide a. (Claim 15) Crosslinking further improves heat resistance stability and stress whitening resistance. The cross-linking may be introduced using a method such as dynamic vulcanization, or may be chemical cross-linking such as organic peroxide cross-linking or silane cross-linking using equipment such as a vulcanizing kettle, and molding of electric wires and insertion devices. It may be introduced later by electron beam crosslinking or the like.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The styrene-based thermoplastic elastomer used in or for the present invention includes a terminal restricted phase of polystyrene and a polybutadiene (SB) as a rubber phase.
S) or block copolymers such as polyisoprene (SIS) and their hydrogenated products (SEBS, SEPS). These styrene-based thermoplastic elastomers may be used alone or as a blend of two or more. In terms of material cost, unhydrogenated SBS, S
Since IS is cheaper than hydrogenated polymers (SEBS, SEPS), it is preferable to use IS within a range in which deterioration due to heat aging due to unsaturated bonds in unhydrogenated polymers can be tolerated in characteristics. In some cases, a blend of an unhydrogenated polymer and a hydrogenated polymer may be used. Although the ratio between the polystyrene end-constrained phase and the rubber phase in the styrene-based thermoplastic elastomer is not particularly specified,
From the viewpoint of flexibility and heat resistance, the styrene / rubber ratio = 20 /
80 to 40/60 is preferred.

As for the ethylene-α-olefin copolymer used in the present invention, the higher the density, the lower the flexibility of the material. Therefore, the upper limit of the density of the polyolefin suitable for use is 0.935 g / cm ³ . The lower limit is 0.860 g / cm ³ from the material strength.

As the molecular weight distribution (MWD) of the polymer is closer to monodispersion (MWD = 1), the material strength tends to be higher, which is effective for increasing the filling of the filler. Extrusion torque is high and workability is poor. On the other hand, a broader molecular weight distribution results in a higher content of low molecular weight components, resulting in a higher efficiency of lowering the shear viscosity during high shear and contributing to a reduction in screw torque during high speed extrusion, thus improving extrusion processability. Strength decreases. The molecular weight distribution of the ethylene-α-olefin copolymer polymer used in or for the present invention is MWD: 3.0 to 3.0 in consideration of the balance between processability and material strength.
A range of 8.0 is preferred.

The MFI of a polymer is an index of the average molecular weight. When the MFI is small, the high molecular weight component increases,
Extrusion becomes difficult. On the other hand, when the MFI is large, the low molecular weight component becomes excessive and the material strength is reduced. The composition used for coating the power cord and the insulated wire of the present invention has an MFI of an ethylene-α-olefin copolymer which is used for blending in order to obtain the strength characteristics specified in “Technical standards and handling details of electric appliances”. , 0.1 to 5.0, more preferably 0.5 to 2.0. In addition, in the case of a composition for an electrically insulating component by injection molding, the MFI of the ethylene-α-olefin copolymer used for blending with the composition is 2.0 to 20.
Is preferably within the range.

As the ethylene α-olefin copolymer used in the present invention, a single-site catalyst represented by a metallocene catalyst, a multi-site catalyst represented by a so-called Ziegler-based catalyst (titanium-based, chromium-based, etc.) is used. Can be used. Further, as the comonomer, propylene, butene-
Copolymers using 1, hexene-1, 4-methylpentene-1 or octene-1 are preferred. Although the polymerization method is not particularly limited, a resin polymerized by a gas phase method using butene-1 or hexene-1 as a comonomer, or a resin polymerized by a solution polymerization method using 4-methylpentene-1 or octene-1 as a comonomer. Resin, butene-
1, a resin obtained by polymerizing hexene-1 as a comonomer by a high-pressure ion polymerization method or the like is suitable.

As the block polymer (olefin-based thermoplastic elastomer) of the polypropylene phase and the olefin copolymer rubber phase used in the present invention, any of a blend type and a polymerization type can be used. In terms of cost performance, the use of a polymerization type having a small number of production steps is effective. Those obtained by partially cross-linking the rubber phase or those completely cross-linked by dynamic cross-linking or the like can also be used. The use of a material subjected to a cross-linking treatment increases reliability in heat resistance, oil resistance and the like.

[0021] The copolymer having a polar group used for or has a smaller total calorific value in a filler-filled system than an ethylene homopolymer, and is suitable for use in a flame-retardant composition. If the content of the polar group is too low, the effect of reducing the calorific value decreases.
In addition, the polar group reduces the crystallinity of the polyethylene skeleton, so that the higher the content, the more the flexibility can be improved. However, if the content is too high, the heat resistance deteriorates, which is not preferable. The range of the content that can be suitably used is 5 to 30 wt.
%. This copolymer is not limited to the polymerization method, and any of an autoclave reactor and a tubular reactor can be used.

As the metal hydroxide used in the present invention, it is effective to use magnesium hydroxide, aluminum hydroxide and the like. The average particle diameter (D50) is preferably in the range of 0.5 to 9.0 μm, more preferably in the range of 1.0 to 7.0 μm. These methods may be used alone or in combination. The presence or absence of the surface treatment is not particularly specified, but the hydroxide-based filler has a hygroscopic property, and the insulation resistance of the material tends to decrease. This can prevent a decrease in insulation resistance. On the other hand, when pseudo-crosslinking is formed by an organosilicon compound, those without surface treatment have better pseudo-crosslinking formation efficiency. When an organosilicon compound is used for the purpose of forming pseudo-crosslinking, either a method of using a metal hydroxide which has been subjected to a surface treatment in advance, or a method of simultaneous addition by an integral blend method using a material which has not been subjected to a surface treatment is applied. It is possible.

As the magnesium hydroxide, both those using natural brucite ore as a raw material and those synthesized using seawater or the like as a raw material can be used in the same manner. Since synthetic products are superior in purity, high flame retardancy tends to be obtained. On the other hand, a resin composition using one manufactured from natural brucite provides extremely high cost performance. As described above, since metal hydroxides have different lengths, the type of hydroxide to be used may be determined in consideration of the characteristics of the final product to be applied in selection.

Examples of the organosilicon compound include organopolysiloxane, organofunctional silane (silane coupling agent), alkoxysilane and the like.
It is also possible to use two or more kinds in combination. Organopolysiloxanes are classified into low molecular weight oils, high molecular weight resins and gums in terms of molecular weight, but they have abrasion resistance, flame retardancy, slip between conductor and insulator, water repellency, etc. in the present invention. Regarding the improvement effect, there is no great difference due to the difference in the molecular weight of the organopolysiloxane used. However, in the case of using oil, if the molecular weight is too low, the surface state of electric wires and plugs is deteriorated by bleeding and the like.
Use those that are in the centistoke range.

The basic structure of alkoxysilane is RnSi
In the present invention, an alkoxysilane having a structure having a methyl group, an ethyl group, or the like as the R ′ group and a methyl group, a phenyl group, an octadecyl group, or the like as the R group can be used. is there. The larger the number of carbon atoms in the alkyl group of the R group, the higher the hydrophobicity and the slower the hydrolysis rate (the rate-limiting reaction of the surface treatment reaction). Therefore, use in consideration of processing conditions, effects on other compounding agents, and the like. Determine the type.

For the purpose of improving the flexibility and processability of the flame-retardant resin composition of the present invention, a softener used for a rubber material or the like, in particular, a petroleum compound oil (process oil) may be used. Any common process oil can be used,
The use of paraffinic oils is preferred in consideration of contamination and safety. The upper limit of the amount added is equal to the weight of the entire styrene-based thermoplastic elastomer. Addition of more than this is undesirable because it causes stickiness after molding.

In addition, inorganic fillers commonly used in resin blends can be used. For example, talc,
By using clay (kaolin), mica, magnesium oxide, magnesium carbonate, calcium carbonate, etc., it is possible to exhibit effects such as prevention of warpage and sink marks during injection molding, and improvement of a cooling rate by improving thermal conductivity. it can. These addition amounts are determined based on the addition amount of the metal hydroxide added earlier, within a range that does not impair properties such as material strength. If necessary, a flame-retardant auxiliary such as red phosphorus and phosphate may be used.

Regarding the cross-linking in the present invention, since the melt processing (kneading, extrusion, etc.) of the styrene-based thermoplastic elastomer requires relatively high temperature conditions of 170 ° C. or higher, molding and cross-linking are performed in separate steps. In this case, it is necessary to select an organic peroxide-based crosslinking agent having a high decomposition temperature, such as a hydroperoxide-based crosslinking agent. Organic peroxides (such as dicumyl peroxide) generally used for the crosslinking reaction of polyolefin resins have a low decomposition temperature, and gelation proceeds during melt processing, which may impair the appearance and mechanical properties. In the case of injection molding or continuous crosslinking, a dialkyl peroxide-based organic peroxide can be adequately used. In addition, a quinone dioxime-based cross-linking agent can be used as a cross-linking agent having a high decomposition temperature, but due to contamination, it is necessary to sufficiently consider the use of the product, the use environment, and the like. It goes without saying that various crosslinking assistants (accelerators, anti-scorch agents, etc.) can be used in combination during crosslinking. In addition, crosslinking can be performed by a method of irradiating ionizing radiation such as γ-rays or accelerated electron beams.

The flame-retardant resin composition of the present invention further comprises a hindered phenol-based resin as long as its properties are not impaired.
Antioxidants such as hindered amines, lactones, phosphorus, sulfur, and vitamin E, metal deactivators such as hydrazine, heat stabilizers such as hindered amine, and ultraviolet absorbers such as benzotriazole Additives generally used in resin molding materials, such as ultraviolet shielding agents such as titanium oxide, carbon, and other coloring pigments may be blended.

The compound of the resin composition of the present invention is melt-mixed in a single-screw or twin-screw kneading extruder, a kneading kneader, a Banbury, a kneading roll, etc., which are usually used for compound production, and if necessary, an appropriate shape is obtained. It can be manufactured by performing granulation or the like. Extrusion coating of insulators and sheaths for electric wires, plugs, etc.
Injection molding of an adapter or the like can be performed by a general facility according to a general method. The processing temperature at that time may be set between 160 and 210 ° C. based on the blending system.

[0031]

The present invention will be specifically described below with reference to examples and comparative examples. First, compounds having respective formulations of Examples and Comparative Examples shown in Tables 1 to 9 above were produced. Mixing is performed by a kneader type mixer. Temperature setting is 180 ~
The temperature was set to 200 ° C (160 to 180 ° C in the material system of the comparative example). After mixing, the mixture was pelletized.

The sheet used for the evaluation was prepared as a press sheet having a predetermined thickness after the compound was sufficiently melted and mixed using an open roll or the like. For the electric wires (Examples 1 to 13), a flat cord having a conductor cross-sectional area of 2 mm ² and a number of wire cores of 2 was manufactured by extrusion and used as a test sample. In Example 12, after processing the sheet and cord in the same manner as described above, the sheet and cord were processed at 220 ° C.
A cross-linking treatment for 0 minutes was performed to evaluate the characteristics. As a plug-in connector formed by integral molding, a plug was manufactured and evaluated by horizontal injection molding.

As the evaluation method, a method based on the following standards and conditions was used. Tensile properties: After using the flame-retardant resin composition compound of the present invention and sufficiently melting and mixing using an open roll or the like,
A press sheet having a thickness of 1 mm was prepared and used for the test. The test method is "Technical Standards and Detailed Regulations for Electrical Appliances", Appendix 1, Appendix 14 "Test of Tensile Strength and Elongation", or JIS
The test was carried out in accordance with K6301 (JIS K6301 uses a No. 3 dumbbell). The pulling speed is 200mm /
Went in minutes.

Heat deformation test: The test was carried out in accordance with "Appendix 18 of Appended Table 1" of "Technical Standards and Detailed Regulations for Electric Appliances". A flat cord having a conductor cross-sectional area of 2 mm ² and a number of wire cores of 2 was manufactured by extrusion and used as a test sample. Test conditions are: set temperature; 120 ± 3 ° C, load: 5N, load time: 30 minutes

Bending elastic modulus: The flame-retardant resin composition of the present invention was sufficiently melt-mixed using an open roll or the like, and then a standard test piece was prepared from a press-formed sheet having a thickness of 4 mm, according to JIS K7199. In compliance with
It was measured and evaluated at a test speed of 50 mm / min.

Specific resistance: The flame-retardant resin composition of the present invention was sufficiently melt-mixed using an open roll or the like, and then a 1-mm-thick sheet formed by press molding was used as a test sample, according to JIS K6760 “Transformer Bridge. Method.

Flame retardancy: A flat cord having a conductor cross-sectional area of 2 mm ² and a number of cores of 2 is manufactured by extrusion, used as a test sample, tested in accordance with JIS C3005.28, extinguished after keeping the fire away. Time (seconds) was measured.
Those that disappeared naturally within 60 seconds were marked with “○”, and those that did not disappear were marked with “x”.

End workability: A flat cord having a conductor cross-sectional area of 2 mm ² and a number of wire cores of 2 was manufactured by extrusion and used as a test sample. A terminal processing machine for plug processing was used to perform terminal processing with a flat blade. Ten terminals were processed, and all of them were processed without any breaks, and were marked with “○”, those with cuts were marked with “△”, and those with beard-shaped cuts were marked with “x”.

Bending whitening resistance: A flat cord having a conductor cross section of 2 mm ² and a number of wire cores of 2 was manufactured by extrusion and used as a test sample. The sample was bent 180 ° and held for 1 minute, after which the bent was released and the condition of the coating was observed. The one that almost returned to the original state was judged as “◎”, the one with some swelling remaining but not conspicuous was evaluated as “、”, the one with noticeable swelling was evaluated as “、”, and the one with swelling and whitening was evaluated as “x”. . In the case of a plug, the bellows of the plug is
(4) Bending was held for 5 minutes, and it was checked whether any troubles such as cracks occurred or no bending marks remained. "○" if no problem occurs, "X" if any trouble occurs
It was determined.

Degree of crosslinking: Based on JIS C3005.27. A flat cord having a conductor cross-sectional area of 2 mm ² and a number of wire cores of 2 is manufactured by extrusion, and a plug is injection-molded with a 15 A, 125 V plug.
5 g) was used as a cut sample. The sample was kept in xylene heated to 110 ± 2 ° C. for 24 hours, after which the dry weight of the sample was measured, and the ratio to the sample weight before immersion in xylene was defined as the degree of crosslinking.

Extrusion processability / injection moldability: The product was actually molded and evaluated. For extrudability, conductor cross-sectional area 2
mm ² , a flat cord with 2 wire cores is extruded into a 70 mm extruder (L / D
= 23), a processing linear speed of 50 m / min or more, an extrusion load of 80 A or less, and a smooth extrusion appearance of 3
It was examined whether or not all the items were satisfied. The case where all items were satisfied was evaluated as “○”, the case where the items were not satisfied was 1 or 2 as “Δ”, and the case where all items were not satisfied was evaluated as “×”. Injection moldability is "4 pieces" of 15A, 125V plug
Forming (forming 4 plugs in one shot)
The case where all four were molded was indicated by “○”, the case of two was indicated by “△”, and the case of 0 was judged by “×”.

The results of the evaluation are shown below the table, respectively, and are summarized as follows. Electric wires The electric wires manufactured in Examples 1 to 13 all had good extrudability, end workability of the electric wires, and resistance to bending whitening. Focusing on the terminal processability, those having a relatively high blending ratio of the styrene-based thermoplastic elastomer (Example 4:60)
%, Example 9: 70%), and those obtained by adding an acid-modified styrene-based thermoplastic elastomer and an organofunctional silane (Examples 10 to 14) were particularly good. Focusing on bending whitening resistance, those using magnesium hydroxide without surface treatment were particularly good. (Examples 10 and 1
1,12,14) On the other hand, Comparative Examples 1 to 4 are conventional non-halogen flame-retardant resin compositions containing no styrene-based thermoplastic elastomer. And the bending whitening resistance was poor. In addition, those containing a styrene-based thermoplastic elastomer and having a small ratio (Comparative Examples 8 to 12) have poor reversion after bending, tend to have a habit, and exhibit a defect in the item of bending whitening property. did. Conversely, those having an excessively large ratio of the styrene-based thermoplastic elastomer (Comparative Examples 5, 6, and 16) were extremely poor in extrusion processability and could not satisfactorily extrude the electric wire. In the case of a styrene-based thermoplastic elastomer, by using an acid-modified product, end processing properties and bending whitening resistance tended to be improved, but in the case of crystalline polymers,
Even when the acid-modified product was used, no tendency to improve the end workability and bending whitening property was observed. (Comparative Example 11: Acid-modified LL
DPE) In addition, MDPE (MFI) whose MFI is not in the scope of claim 1
In Comparative Example 13 using (= 0.05), a whisker-like uncut portion was generated, so that the end workability was poor, the bending habit tended to remain, and the bending whitening resistance was also poor. This is considered to be due to the remarkable stretching property and stress whitening property due to the influence of the high molecular weight component contained in MDPE. Workability was not so good either. LLDPE with high MFI (MFI =
In the system using (8.0) (Comparative Example 14), the average molecular weight is reduced, so that the workability and the end workability are good, but microcracks occur when bent, and the bending whitening resistance is poor. became. Comparative Example 15 using a polymer having a density outside the range of Claim 1 has a slightly poor processability,
End workability and bending whitening resistance were poor. In particular, regarding the bending whitening property, a remnant bending habit considered to be influenced by a crystalline portion was remarkable.

Plugs The plug examples (15 to 18) had good bending whitening resistance and injection molding properties, and all four pieces could be molded by "four-cavity" molding, and had good moldability. . On the other hand, in Comparative Examples 17 to 19 in which the ratio of the styrene-based thermoplastic elastomer was high,
No matter how much the pressure was increased during injection, all four materials did not turn, indicating poor workability. Further, even in Comparative Example 20 in which the MFI of the styrene-based thermoplastic elastomer was smaller than the range described in claim 9, the flowability was deteriorated, and the material did not reach all four. A similar tendency is observed for crystalline polymers (LLD
The MFI of PE) was also observed, and even in Comparative Example 21 using a grade of MFI = 0.5, the material did not turn in all four at the time of injection molding. On the other hand, in Comparative Example 22 in which the MFI of the EVA was larger than the range described in claim 9, the molding could be performed well, but a minute crack occurred in the bending test of the bellows portion, and the bending whitening resistance was poor. .

[0044]

As described above, the composition of the present invention solves the problems of the conventional non-halogen composition, and achieves high flexibility and high heat resistance while maintaining high flame retardancy without halogen. Thus, a non-halogen flame-retardant resin composition having excellent terminal processability, hardly causing stress whitening, and having high insulation resistance was obtained.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01B 3/44 H01B 3/44 K C08K 5/54 A 7/42 H01B 7/34 Z (56) 194795 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01B 3/00 C08K 3/22 C08K 5/541 C08L 53/00 H01B 3/28 H01B 3/44 H01B 7/42

Claims (15)

(57) [Claims] 1. A styrenic thermoplastic elastomer,
The MFI at 190 ° C. under a load of 2.16 kg is 0.
It is in the range of 1-5.0 g / 10 minutes and has a density of 0.860.
Ethylene-α olefin copolymer in the range of 0.935 g / cm ³ or polypropylene phase and olefin copolymer rubber phase in the range of the same MFI and the density in the range of 0.880 to 0.890 g / cm ³ With a block polymer of (/) 40/60 to 80/2
Halogen-free flame retardant resin composition comprising a polymer blended in the range of 0 to 50 to 250 parts by weight of a metal hydroxide having an average particle diameter (D50) in the range of 0.5 to 9.0 μm. object 2. The resin composition according to claim 1, wherein
Part of ethylene-vinyl acetate copolymer (EV
A), ethylene-ethyl acrylate copolymer (EE
A), ethylene-methyl acrylate copolymer (EM
Halogen-free flame-retardant resin composition replaced by at least one polymer selected from A) 3. The non-halogen flame-retardant resin composition according to claim 1 or 2, wherein at least one selected from the group consisting of organopolysiloxanes, organofunctional silanes (silane coupling agents), and alkoxysilanes. Non-halogen flame-retardant resin composition containing 0.1 to 10 parts by weight of various organosilicon compounds 4. An organosilicon compound to be compounded in the halogen-free flame-retardant resin composition according to claim 3, which has the general formula (A)
A halogen-free flame-retardant resin composition characterized by adding a compound represented by the formula: Embedded image Here, R is an alkyl group having an epoxy group or an amino group, X1, X2, and X3 are selected from the group consisting of an alkoxy group and an alkyl group, and an atomic group in which at least one of X1, X2, and X3 is an alkoxy group. Represents 5. The non-halogen flame retardant according to claim 1, wherein a part or all of the styrene-based thermoplastic elastomer is an acid-modified styrene-based thermoplastic elastomer having a carboxylic acid or an acid anhydride group. Resin composition. 6. The non-halogen flame-retardant resin composition according to claim 3, wherein the average particle diameter (D50) is 0.5 to 9.0 μm as a part or all of the metal hydroxide.
Non-halogen flame-retardant resin composition characterized by using magnesium hydroxide without surface treatment 7. A power cord and an insulated wire manufactured using the resin composition according to claim 1 by a molding method such as extrusion. 8. The melt flow index (MFI) at 200 ° C. under a load of 5.0 kg is 10 to 90 g / 1.
A styrene thermoplastic elastomer in the range of 0 minutes,
MFI of 2.0 to 20 at 0 ° C and 2.16 kg load
g / 10 min, with a density of 0.860-0.93
Ethylene-α-olefin copolymer in the range of 5 g / cm ³ or MFI in the range of 0.880 to
A polymer obtained by blending a block copolymer of a polypropylene phase and an olefin copolymer rubber phase in a range of 0.890 g / cm ^{3 in} a blend ratio (/) of 40/60 to 60/40 as a base resin, Non-halogen flame-retardant resin composition comprising 50 to 250 parts by weight of a metal hydroxide having an average particle diameter (D50) in the range of 0.5 to 9.0 μm. 9. The resin composition according to claim 8, wherein
MF at 190 ° C, 2.16 kg load
At least one selected from the group consisting of ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methyl acrylate copolymer (EMA) in which I is in the range of 2.0 to 20 g / 10 min. Halogen-free flame-retardant resin composition replaced by polymer 10. The non-halogen flame-retardant resin composition according to claim 8, wherein at least one selected from the group consisting of organopolysiloxane, organofunctional silane (silane coupling agent), and alkoxysilane. Non-halogen flame-retardant resin composition containing 0.1 to 10 parts by weight of various organosilicon compounds 11. An organosilicon compound to be added to the non-halogen flame-retardant resin composition according to claim 10 as a general formula
A non-halogen flame-retardant resin composition comprising the compound represented by (A). Embedded image Here, R is an alkyl group having an epoxy group or an amino group, X1, X2, and X3 are selected from the group consisting of an alkoxy group and an alkyl group, and an atomic group in which at least one of X1, X2, and X3 is an alkoxy group. Represents 12. The non-halogen flame-retardant flame retardant according to claim 8, wherein a part or all of the styrene-based thermoplastic elastomer is an acid-modified styrene-based thermoplastic elastomer having a carboxylic acid or an acid anhydride group. Resin composition. 13. The non-halogen flame-retardant resin composition according to claim 10, wherein an average particle diameter (D50) of at least 0.5 as at least a part of the metal hydroxide.
Non-halogen flame-retardant resin composition using magnesium hydroxide in the range of 9.0 μm without surface treatment 14. An electrically insulating component using the resin composition according to claim 8. Description: 15. The power cord / insulated wire and the electrical insulation component according to claim 7, wherein the degree of crosslinking of the insulating material is in the range of 10 to 80%.