JP2525982B2 - Thin high-strength non-halogen insulated wire and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a safety standard UL (Underwriter) in which no harmful gas is generated during ignition.
s Laboratories) with a temperature rating of 105 ° C or higher that meets the standards , initial tensile strength, heat aging resistance,
Α-olefins with ethylene and polar groups with excellent electrical properties
Provided are a thin-walled high-strength non-halogen insulated wire based on a copolymer resin with a resin and a method for producing the same. More details
The thin-walled high-strength non-halogen insulated wire of the present invention is
Physically, the initial tensile strength required by UL standard is 1.06kg /
mm ² or more, the residual tensile strength of the insulator after heat aging is 70% or less
Above, the same residual growth rate of 65% or more is satisfied, and VW-1 drops
Excellent initial tensile strength and heat resistance that pass the direct combustion test
Aging, non-halogen, and high flame resistance
It Furthermore, the thin-walled high-strength non-halogen insulated wire of the present invention
Is a halogen-free and highly flame-retardant
Since it has excellent initial tensile strength and heat aging resistance, 1.0
0.1 mm or more and 1.0 m in the outer diameter of a fine ultra-fine conductor of mm or less
It is the first time to provide an insulated wire with a thin insulation thickness of m or less.
It becomes possible and is in equipment meeting safety standards such as various UL standards
Suitable as an insulated wire for wiring, safe for fire prevention, etc.
There is an advantage that pollution-free can be achieved while securing the property .

[0002]

2. Description of the Related Art Electronic computers, OA equipment, electric wires for industrial equipment such as vehicles, audio, video, consumer electronic equipment such as personal computers, indoor wiring, etc. do not generate harmful gas during combustion and are highly difficult. It is required to have flammability. Along with this, these electric wires are also required to have high flame retardancy without generating harmful gas during combustion. As a flame-retardant method that meets such a demand, there is known a method of adding a large amount of magnesium hydroxide which is a non-halogen flame retardant to a thermoplastic resin such as polyolefin (Japanese Patent Publication No. Sho 62-181). Gazette, Japanese Patent Publication No. 57-1
0898).

However, a resin composition obtained by adding a large amount of magnesium hydroxide, which is a non-halogen flame retardant, to a thermoplastic resin such as polyolefin has a good difficulty.
Although it can give flammability, it has poor compatibility with thermoplastic resins.
When applied to an insulated wire to fried, the initial tensile strength is small and moreover there is a problem of physical properties after heat aging is significantly reduced. For example, in the case of a polyolefin-based insulated wire according to UL standards, the initial tensile strength at break is 1.06 kg / mm.
^The residual tensile strength after breaking of the sample after the heat aging test is 70% or more and the residual elongation is 65% or more.

However, when an insulated wire is prepared by using a flame-retardant resin composition obtained by adding a large amount of magnesium hydroxide to the above polyolefin resin, the initial tensile strength is 1.0.
6kg / mm ² or more is not satisfied, in addition to that, UL10
5 ° C rating (136 ° C, residual strength at break ≧ 70% after 7 days heat aging test, elongation residual rate ≧ 65%, and residual strength at break ≧ 70% after 113 ° C, 60 days thermal aging test, 70% residual elongation Rate ≧ 6
5%) or UL125 ° C rating (158 ° C, residual tensile strength after breakage ≧ 70% after 7 day heat aging test, elongation residual ratio ≧ 65%, and
Breaking tensile strength residual ratio after heat aging test at 136 ° C. for 60 days ≧ 70
%, Elongation residual ratio ≧ 65%), and those satisfying heat aging resistance are not known.

Regarding flame retardancy, it is specified that the product should pass the vertical combustion test (VW-1 test) described in Subject 758. The VW-1 test is 6 when a vertically standing electric wire is exposed to a burner flame from below.
It is a test that extinguishes within 0 seconds, the absorbent cotton laid under the electric wire should not burn due to the fall of the burning material, and the kraft paper attached to the upper part of the electric wire should not burn or burn, and the ignition by this burner is the same. Repeat 5 times for the sample.

In the vertical burning test, there is a UL44 test for examining the flammability of a resin composition sheet-like molded article. However, even if the composition complies with the vertical flammability of the UL44 test, it is treated as an insulated wire and The -1 test does not always pass. Further, as an index for investigating the flammability of the material itself, there is an OI value (limit oxygen index; the minimum oxygen concentration required to sustain combustion when the material is burned in a mixed gas of oxygen and nitrogen). , A material having a larger OI value is less likely to burn, and generally, a material having an OI value of 25 or more is a flame-retardant material.

However, an insulated wire made of a material having an OI value of 25 or more as an insulation coating does not always pass the VW-1 test. In the VW-1 test, in addition to the flame retardancy of the insulating material itself, pass / fail is often influenced by the outer diameter of the insulated wire, the balance between the thickness of the insulating coating and the outer diameter of the conductor, etc. Is larger, the outer diameter of the conductor is larger, and the insulating coating thickness is smaller, the pass rate tends to be improved.

Insulated electric wires for wiring in equipment conforming to the UL standard usually have a minimum coating thickness of 30 V rating, an insulation thickness of 0.15 mm or more, a 300 V rating of 0.4 mm or more, and a 600 V rating of 0.8 mm or more. In addition, it is preferable that the insulated wire for in-device wiring has the outer diameter of the insulated wire as thin as possible in order to facilitate the routing of the wiring. 0 mmφ
The following thin ones are used (see “Sumitomo Electric's Electronic Wire Product Manual”, page 13 issued by Sumitomo Electric Co., Ltd.).

However, the outer diameter of the conductor is 1.0 mmφ or less, and the thickness of the insulating coating is 0.1 mm or more and 1.0 mm.
A halogen-free polyolefin-insulated electric wire that has passed the VW-1 test below and has satisfactory mechanical strength such as initial breaking strength and heat aging characteristics has not been known so far. Therefore, in the field where importance is attached to safety aspects such as fire prevention, it has been unavoidable to use halogen-containing flame-retardant insulated electric wires, which has been a bottleneck for making pollution-free.

[0010]

The present invention is a thin-walled, high-strength, non-halogen material that satisfies the requirements of safety standards such as UL standards for mechanical properties such as initial tensile strength, heat aging resistance, and flame retardancy. The present invention is characterized by providing an insulated wire and a manufacturing method suitable for the insulated wire, and aims to achieve pollution-free while ensuring safety such as fire prevention. The gist of the invention is:

Copolymerization of ethylene and α-olefin having a polar group on a conductor having an outer diameter of 1.0 mm or less
With respect to 100 parts by weight of resin, 100 parts by weight or more and 250 parts by weight or less of magnesium hydroxide which is not surface-treated ,
The following general formula [I]:

Embedded image (However, R is an alkyl group containing a methacrylic group or an acrylic group, and Y ¹ , Y ² , and Y ³ represent an atomic group selected from the group consisting of an alkyl group, an alkoxy group, and a halogen group.) The resin composition obtained by mixing the organosilicon compound described above in a proportion of 1 part by weight or more and 10 parts by weight or less is coated in a thickness of 0.1 mm or more and 1.0 mm or less, and the coating layer is irradiated with ionizing radiation. The present invention relates to a thin-walled high-strength non-halogen insulated wire. further,

Alpha-olefin having ethylene and polar group
100 parts by weight of the copolymer resin with
Not over 100 parts by weight magnesium hydroxide 250
1 part by weight or more and 10 parts by weight or less of each of the organosilicon compounds represented by the above formula [I] are mixed with a resin composition obtained on a conductor having an outer diameter of 1.0 mm or less. after coated with 1.0mm or less of the coating thickness over .1Mm, in the manufacturing method of thin high-strength non-halogen insulated wire consisting of irradiation with ionizing radiation to the coating layer, the
The present invention relates to a method for producing a thin high-strength non-halogen insulated electric wire, which comprises adding an organosilicon compound represented by the above formula [I] when a copolymer resin and magnesium hydroxide that has not been surface-treated are melt-kneaded.

And in a particularly preferred embodiment, the present invention is directed to a halogen-free ethylene and polar
Copolymer resin with an α-olefin having a group (hereinafter, simply referred to as
In the insulated wire to be abbreviated as styrene copolymer resin) composition is coated, (1) insulating thickness with 0.1mm or more 1.0mm or less, (2) the initial fracture strength is 1.06 kg / mm ² or more Also, (3) vertical flame retardancy (VW-1) is passed, and (4) thin-walled, high-strength, non-halogen insulated wires having a heat aging resistance of 105 ° C grade or higher are also provided.

The present invention will be described in detail below. Examples of the ethylene copolymer resin used in the present invention include ethylene- acetic acid.
Vinyl copolymer, ethylene-ethyl acrylate copolymer
Body, ethylene-methyl methacrylate copolymer, ethylene
-Methacrylic acid copolymer, ethylene-acrylic acid methyl ester
For example, a single copolymer or a mixture can be used.

Further, in the present invention, it is difficult to achieve the intended purpose even if an organosilicon compound other than the organosilicon compound represented by the general formula [I] is used. Examples of the organosilicon compound represented by the general formula [I] include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyldimethoxymethylsilane. Can be exemplified.

Further, in the present invention, it is difficult to achieve the intended purpose even if an inorganic filler other than magnesium hydroxide, such as aluminum hydroxide, is used. The magnesium hydroxide used in the present invention is not surface-treated.
If it is not magnesium hydroxide, the intended purpose is achieved.
Not done . In addition, the surface treatment is not performed
As the sium, those having an average particle diameter in the range of about 0.1 to 3 μm can be preferably used. Where surface treatment
Unprocessed magnesium hydroxide and processed natural products
The thing or synthetic products, for example magnesium ions in sea water, etc.
It means that it was manufactured using the
Therefore, when used as a filler for resin,
Molding with increased compatibility with thermoplastic resin
In order to improve heat resistance, mechanical strength, and heat aging resistance,
Coupling agents such as silanes on magnesium hydroxide
Except those that have been surface treated with fatty acids, fatty acid salts, etc.
It is what is done .

Conventionally, no surface treatment has been applied as a flame retardant.
Flame-retardant thermoplastic resin composition containing magnesium hydroxide
The product is known, but in order to achieve sufficient flame retardancy, 7
A relatively large amount of about 0% by weight (in the present invention, 100% resin
(Extremely large amount of 100 to 250 parts by weight with respect to parts by weight)
Then, due to poor compatibility with resin, etc.
May cause problems such as deterioration of dynamic strength and heat aging resistance
Known (Japanese Patent Publication No. 63-14745, Japanese Patent Laid-Open No. Sho
50-119848, JP-A-53-12943
Bulletin etc.) . Therefore, as a flame retardant for thermoplastic resins,
With coupling agents such as orchids, fatty acids, fatty acid salts, etc.
It is common to use surface-treated magnesium hydroxide.
I am familiar with it . However, in the present invention, the one obtained by treating the surface of magnesium hydroxide with a coupling agent such as the above-mentioned silanes, fatty acids, fatty acid salts, etc. may not be suitable.
I understand .

In the present invention, the addition amount of the organosilicon compound represented by the general formula [I] is 10% by weight of the ethylene copolymer resin.
With respect to 0 parts by weight, 1 part by weight or more and 10 parts by weight or less is a preferable range for satisfying the UL standard value of initial breaking strength of 1.06 kg / mm ² or more, and less than 1 part by weight improves the initial breaking strength. It is difficult to obtain the effect, and if it is 10 parts by weight or more, the flame retardancy is adversely affected.

In the present invention, it is necessary to coat the obtained resin composition on a conductor and then irradiate it with ionizing radiation, and it is difficult to achieve the intended purpose without subsequent treatment. The irradiation dose of ionizing radiation in the present invention is, for example, 3 to 50 Mrad, preferably 5 to 2 in the case of an electron beam.
The irradiation dose may be set to 5 Mrad. If the irradiation dose is 3 Mrad or less, the effect of improving the initial breaking strength is small, and if it is 50 Mrad or more, the initial breaking strength is rather decreased.

[0020] In the present invention, in order to increase the crosslinking efficiency during the irradiation of ionizing radiation, optionally, et a crosslinking assistant
It may be added to the ethylene copolymer resin . Examples of the crosslinking assistant include trimethylolpropane trimethacrylate, pentaerythritol triacrylate, ethyne glycol dimethacrylate, triallyl cyanurate,
Examples thereof include triallyl isocyanurate.

Further, the composition used in the present invention includes various heat stabilizers, ultraviolet absorbers, lubricants, antioxidants, colorants, foaming agents, processing stabilizers, organic and inorganic materials which have been conventionally used. Additives such as various fillers can be added. In the production of the composition of the present invention, a single-screw extruder, a multi-screw extruder, a Banbury mixer, a roll, a kneader, a heatable Henschel mixer type high-speed fluid mixer, or the like can be used. It is preferable to add the organosilicon compound (1) at the time of melt-kneading the ethylene copolymer resin and magnesium hydroxide that has not been surface-treated.

The thin-walled insulated wire referred to in the present invention refers to an insulated wire having a thickness in a range generally known as a thin-walled insulated wire in an equipment-insulated insulated wire complying with the UL standard. It is usually about 1 mm or more and 1.0 mm or less. Regarding the coating of the resin composition on the conductor, a technique such as melt extrusion coating can be applied,
After extrusion coating with a thickness of 0.1 mm or more and 1.0 mm or less,
The thin high-strength non-halogen insulated wire of the present invention can be obtained by irradiating ionizing radiation such as an electron beam. When the thickness is less than 0.1 mm, the withstand voltage is not practically practical because it is too thin, and when the thickness is too thick, in the case of an electric wire for device wiring having a small conductor diameter,
It causes problems in flame retardancy.

In the coated front of the present invention, ( a ) ethylene co-weight
Compound resin, ( b ) Magnesium hydroxide without surface treatment
( C ) It does not consist of a specific organosilicon compound coupling agent.
A resin composition for coating, and ( d ) the resin coating layer
With the configuration in which the ionizing radiation is applied to the
Excellent even though it has high flame retardancy with halogen
Since it has early tensile strength and heat aging resistance, various U
As an insulated wire for wiring inside equipment that meets safety standards such as L standard
Suitable for fine ultrafine conductors with a diameter of 1.0 mm or less
Insulation voltage with a thin insulation thickness of 1.0 mm to 1.0 mm
The great technical significance that the provision of lines will be possible for the first time
Have. While ensuring safety such as fire prevention,
There is a great advantage in achieving pollution-free.

[0024]

The present invention will be described below with reference to examples, but these do not limit the scope of the present invention. Examples, Reference Examples and Comparative Examples are as developed below, but in short, Example: ( Ethylene copolymer resin + magnesium hydroxide without surface treatment + organosilicon compound of formula [I]) composition Object + ionizing radiation treatment, comparative example:
( Ethylene Copolymer Resin and / or Other Filler and / or Another Organosilicon Compound) No Composition and / or Ionizing Radiation Treatment, Reference Example: ( Ethylene Copolymer Resin + Surface Treated Magnesium Hydroxide + Formula) [I] organosilicon compound) composition + ionizing radiation treatment. The abbreviations of the ethylene copolymer resins used in Examples, Reference Examples and Comparative Examples are as follows. EVA: ethylene-vinyl acetate copolymer EEA: ethylene-ethyl acrylate copolymer

(Examples 1 to 7) Materials having the compounding ratios shown in Examples 1 to 7 of Tables 1 and 2 were mixed so that the wall thickness was 0.40 mm on the conductor (0.8φ annealed copper wire). Was extrusion-coated and irradiated with an electron beam having an acceleration voltage of 1 MeV to prepare a sample. For mixing the materials, use an 8-inch open roll mixer heated to 120 ° C and use ethylene.
Copolymer resins , fillers, organosilicon compounds, antioxidants, etc. were simultaneously added and kneaded.

Initial tensile strength at break, initial elongation at break, volume resistivity, flame resistance (vertical combustion test: VW-1)
Test: n = 5), the tensile strength residual rate and the elongation residual rate of the sample heat-aged at 158 ° C. for 7 days in a gear oven and the sample heat-aged at 136 ° C. for 60 days were measured.

[0027]

[Table 1]

[0028]

[Table 2]

In Examples 1 to 7, from the results of Tables 1 and 2,
The initial breaking tensile strength is 1.06 kg / mm ² or more,
Passed the VW-1 test, 7 days at 158 ° C and 136 ° C
It can be seen that, after the heat aging test for 60 days, the tensile strength residual ratio and the elongation residual ratio of the sample satisfy 70% or more and 65% or more, respectively.

(Example 8) Materials having the compounding ratios shown in Table 3 were mixed in the same manner as in Examples 1 to 7, and 0.1 was mixed on the conductor (0.80φ annealed copper wire).
A sample was prepared by extrusion coating with a thickness of 5 mm and irradiating with an electron beam with an accelerating voltage of 1 MeV. The initial breaking tensile strength of this sample satisfied 1.06 kg / mm ² or more, passed the VW-1 test, and the tensile strength residual rate and elongation residual rate of the sample after the heat aging test were 70% or more and 65% or more, respectively. It can be seen that

(Example 9) Materials having the compounding ratios shown in Table 3 were mixed in the same manner as in Examples 1 to 7, and 0.8 was mixed on the conductor (0.80φ annealed copper wire).
A sample was prepared by extrusion coating with a thickness of 0 mm and irradiating with an electron beam with an accelerating voltage of 1 MeV. The initial breaking tensile strength of this sample satisfied 1.06 kg / mm ² or more, passed the VW-1 test, and the tensile strength residual rate and elongation residual rate of the sample after the heat aging test were 70% or more and 65% or more, respectively. It can be seen that

(Example 10) Materials having the compounding ratios shown in Table 3 were mixed in the same manner as in Examples 1 to 7 to give 0.4 on a conductor (0.80φ annealed copper wire).
After extrusion-coating with a thickness of 0 mm, the same material was further extrusion-coated with a thickness of 0.40 mm on the outer periphery thereof, and then an electron beam with an accelerating voltage of 1 MeV was irradiated to prepare a sample. Even if this sample does not have to be coated with a predetermined thickness at a time, as a result, if it is coated with a predetermined thickness, the initial breaking tensile strength satisfies 1.06 kg / mm ² or more, and passes the VW-1 test. It can be seen that the tensile strength residual ratio and the elongation residual ratio of the sample after the heat aging test satisfy 70% or more and 65% or more, respectively. The results are shown in Table 3.

<Comparative Example> Materials were mixed at the compounding ratios shown in Comparative Examples 1 to 14 in Tables 4 to 7 in the same manner as in the Examples, and the thickness of the conductor (0.8φ annealed copper wire) was 0. A sample was prepared by extrusion coating to 40 mm and irradiating with an electron beam. Initial tensile strength of extrusion coating material,
Initial elongation, volume resistivity, flame retardancy (vertical combustion test: VW
−1 test, n = 5), a sample subjected to heat aging at 158 ° C. for 7 days in a gear oven and a sample heat-aged at 136 ° C. for 60 days were measured for tensile strength residual ratio and elongation residual ratio. The results are shown in Table 3-7.

Comparative Example 1 In Comparative Example 1, the organosilicon compound of the general formula [I] was not blended, which passed the VW-1 test, but the initial breaking tensile strength was 0.69 kg / mm ² . It is below the UL standard value, and the residual elongation after heat aging is below 65% of the UL standard value.

(Comparative Example 2) Comparative Example 2 is the same material as Comparative Example 1 but not subjected to electron beam irradiation. Although it passed the VW-1 test, the initial tensile strength at break was 0.64 kg / mm ^2, which was below the UL standard value, and the residual elongation after heat aging was 65% of the UL standard value.
Below.

Comparative Example 3 In Comparative Example 3, magnesium hydroxide not surface-treated was used, and γ-methacryloxypropyltrimethoxysilane was added at the time of mixing, and no electron beam irradiation was applied. It is a thing. Although it passed the VW-1 test, the initial tensile strength at break was 0.76 kg / mm ^2, which was below the UL standard value, and the residual elongation after heat aging was 65% of the UL standard value.
Below.

Comparative Example 4 Comparative Example 4 is a composition in which aluminum hydroxide known as a halogen-free flame retardant (without surface treatment) is added instead of magnesium hydroxide, instead of magnesium hydroxide. It was used and irradiated with an electron beam. VW
-1 test is passed, but initial breaking tensile strength is 0.53k
It is below the UL standard value of g / mm ^2, and the residual elongation after heat aging is also below the UL standard value of 65%.

Comparative Example 5 Comparative Example 9 is a composition in which aluminum hydroxide (without surface treatment) is used and γ-methacryloxypropyltrimethoxysilane is added during mixing.
Passes the VW-1 test, but has an initial tensile strength of 0.5.
The value is 8 kg / mm ² , which is below the UL standard value, and the residual elongation after heat aging is also below the UL standard value of 65%.

Comparative Example 6 In Comparative Example 6, magnesium hydroxide not surface-treated was used, and vinylethoxysilane (which does not correspond to the organosilicon compound of the general formula [I]) was added during mixing. The object is used and irradiated with an electron beam. VW-
Passes 1 test, but initial breaking strength is 0.66kg
/ Mm ² below the UL standard value, and the residual elongation after heat aging is also below the UL standard value of 65%.

Comparative Example 7 Comparative Example 7 uses magnesium hydroxide which has not been surface-treated, and is mixed with γ-aminopropyltrimethoxysilane (does not correspond to the organosilicon compound of the general formula [I]). The composition was added and the composition was irradiated with an electron beam. Although it passes the VW-1 test, the initial breaking tensile strength is 0.48 kg / mm ^2, which is below the UL standard value,
The residual elongation after heat aging is also below the UL standard value of 65%.

Comparative Example 8 In Comparative Example 8, magnesium hydroxide not surface-treated was used, and γ-glycidyltrimethoxysilane was not mixed (it does not correspond to the organosilicon compound of the general formula [I]) during mixing.
The composition was added and the composition was irradiated with an electron beam. Although it passed the VW-1 test, the initial tensile strength at break was 0.67 kg / mm ^2, which was below the UL standard value, and the residual elongation after heat aging was also below the UL standard value of 65%.

Comparative Example 9 Comparative Example 9 uses magnesium hydroxide which is not surface-treated, but does not use an organosilicon compound, and is known as an additive for increasing the efficiency of crosslinking, trimethylolpropane. The composition was used in combination with trimethacrylate and was irradiated with an electron beam. Fails the VW-1 test and has an initial breaking tensile strength of 0.73 kg / m.
m ² is below the UL standard value, and the residual elongation after heat aging is also below the UL standard value of 65%.

Comparative Example 10 In Comparative Example 10, magnesium hydroxide surface-treated with vinyl silane was used, but without using an organosilicon compound, a composition containing trimethylolpropane trimethacrylate was used. , Irradiated with an electron beam. Failed the VW-1 test as in Comparative Example 9,
Moreover, the initial tensile strength at break was 0.68 kg / mm ^2, which was below the UL standard value, and the residual elongation after heat aging was also below 65% of the UL standard value.

COMPARATIVE EXAMPLE 11 In Comparative Example 11, magnesium hydroxide whose surface was previously treated with γ-methacryloxypropyltrimethoxysilane was used, but no organosilicon compound was used and trimethylolpropane trimethacrylate was used in combination. The composition was used and irradiated with an electron beam. Although it passes the VW-1 test, the initial tensile strength at break is 0.83 kg / mm ² , which is below the UL standard value, and the residual elongation after heat aging is also UL.
It is below 65% of the standard value.

<Reference Comparative Example > (Reference Comparative Example 1) Reference Comparative Example 1 uses magnesium hydroxide whose surface is preliminarily treated with vinyl silane, and is a organosilicon compound of general formula [I] γ-methacrylate. The composition was added with roxypropyltrimethoxysilane at the time of mixing and was irradiated with an electron beam. Although it passes the VW-1 test,
The initial breaking tensile strength is 0.75 kg / mm ² , which is below the UL standard value, and the residual elongation after heat aging is also the UL standard value of 65.
It is below%.

Reference Comparative Example 2 In Reference Comparative Example 2, magnesium hydroxide whose surface was previously treated with stearic acid was used, and γ was the same as in Reference Example 1.
-A methacryloxypropyltrimethoxysilane was irradiated with an electron beam using a composition added at the time of mixing. Although it passed the VW-1 test, the initial tensile strength at break was 0.52 kg / mm ^2, which was below the UL standard value, and the residual elongation after heat aging was also below the UL standard value of 65%.

Reference Comparative Example 3 In Reference Example 3, a composition was used in which magnesium hydroxide surface-treated with vinyl silane in advance was used, and clay and γ-methacryloxypropyltrimethoxysilane were added at the time of mixing. Then, it was irradiated with an electron beam. V
Passes the W-1 test, but initial breaking strength is 0.74
It is below the UL standard value of kg / mm ^2, and the residual elongation after heat aging is also below the UL standard value of 65%.

Reference Comparative Example 4 In Reference Comparative Example 4, magnesium hydroxide whose surface was previously treated with stearic acid was used, and a composition in which clay and γ-methacryloxypropyltrimethoxysilane were added at the time of mixing was used. It was irradiated with an electron beam. VW
-1 test is passed, but initial breaking tensile strength is 0.43k
It is below the UL standard value of g / mm ^2, and the residual elongation after heat aging is also below the UL standard value of 65%. The results are shown in Tables 3 to 7 below.

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

[0053]

[Table 7]

As shown in the above comparative example, the use of a filler other than magnesium hydroxide, such as aluminum hydroxide, and / or the general formula [100 parts by weight of the ethylene copolymer resin such as EVA resin or EEA resin]. In the electric wire which is different from the organosilicon compound shown in I] and is not subjected to the post-treatment with the use of the organosilicon compound and / or the ionizing radiation, the VW-1 test is passed but the initial breaking tensile strength,
The elongation residual ratio after heat aging was far below the UL standard.

Further, as shown in the reference example which is an example of the present invention, an electric wire obtained by the same treatment as that of the example except that surface-treated magnesium hydroxide was used as a filler, Although it passed the VW-1 test, and although the initial tensile strength at break and the residual elongation after heat aging gave tentatively favorable results, they were found to be UL standard in comparison with the preferred embodiment of the present invention. That is not enough.

Therefore, the preferred embodiment of the present invention, that is, the organosilicon compound represented by the general formula [I] is heat-melted with an ethylene copolymer resin and magnesium hydroxide not surface-treated. At this time, by using a composition that is added and kneaded, and by irradiating with ionizing radiation such as an electron beam, the insulation thickness is 0.1 mm or more and 1.0 mm or less even if the conductor diameter is 1.0 mmφ or less. It is found that, in the range of 1, the initial breaking strength is 1.06 kg / mm ² or more, and the non-halogen insulated wire having the vertical flame retardance that passes the VW-1 test and the heat aging resistance of 105 ° C. grade or more can be obtained.

[0057]

According to the present invention, it is possible to obtain a non-halogen insulated wire that passes the UL standard of heat aging resistance for maintaining a temperature rating of 105 ° C., and can be used for consumer electronics such as electronic calculators, OA equipment, audios and videos. It is used for internal wiring of equipment, vehicles, ships, etc., and while ensuring safety such as fire prevention in these fields, it is also possible to eliminate the generation of harmful gas, which is useful for pollution-free.

Claims (2)

(57) [Claims] 1. A conductor having an outer diameter of 1.0 mm or less,
100 parts by weight or more and not more than 250 parts by weight of magnesium hydroxide that has not been surface-treated , based on 100 parts by weight of a copolymer resin of ethylene and an α-olefin having a polar group, the following general formula [I]: (However, R is an alkyl group containing a methacrylic group or an acrylic group, and Y ¹ , Y ² , and Y ³ represent an atomic group selected from the group consisting of an alkyl group, an alkoxy group, and a halogen group.) The resin composition obtained by mixing the organosilicon compound described above in a proportion of 1 part by weight or more and 10 parts by weight or less is coated in a thickness of 0.1 mm or more and 1.0 mm or less, and the coating layer is irradiated with ionizing radiation. Thin-walled, high-strength, non-halogen insulated wire. 2. An α-olefin having ethylene and a polar group
100 parts by weight of the copolymer resin with
Though not magnesium hydroxide 100 parts by weight or more 250 parts by weight, an organic silicon compound represented by the formula (I) 1
The resin composition obtained by mixing at a ratio of not less than 10 parts by weight and not more than 10 parts by weight on a conductor having a conductor outer diameter of 1.0 mm or less.
After coating with a coating thickness of 1 mm or more and 1.0 mm or less,
The method of manufacturing a thin high-strength non-halogen insulated wire which comprises irradiating with ionizing radiation to the coating layer, co weight
A method for producing a thin high-strength non-halogen insulated wire, which comprises adding an organosilicon compound represented by the above formula [I] when hot-melt kneading a composite resin and magnesium hydroxide which has not been surface-treated. .