KR101123504B1 - Vinyl chloride based resin composition containing dioctyl terephthalate for covering of electric wire - Google Patents

Abstract

Disclosed is a vinyl chloride resin composition for an electric wire coating material to which an optimal combination of a specific plasticizer and a specific stabilizer is applied. The plasticizer used in the present invention is dioctyl terephthalate alone or a mixture of dioctyl terephthalate and phthalic ester plasticizer. In addition, a calcium-zinc (Ca-Zn) stabilizer is used as the stabilizer. The composition of the present invention may include 100 parts by weight of the vinyl chloride resin, 5 to 100 parts by weight of plasticizer, 1 to 10 parts by weight of stabilizer and 5 to 70 parts by weight of filler. The vinyl chloride-based resin composition for wire coating material according to the present invention has a small amount of volatile organic compounds released, high stability to the environment, it can implement excellent heat aging resistance, heating loss improvement characteristics.

Plasticizer, vinyl chloride-based resin composition, wire sheath coating material, volatile organic compound, environmental safety, heat resistance

Description

Vinyl chloride-based resin composition containing dioctyl terephthalate for covering of electric wire

The present invention relates to a vinyl chloride-based resin composition which is highly suitable for electric wire coating material having high environmental safety, excellent heat aging resistance and heating loss by minimizing the amount of volatile organic compounds (VOCs).

Vinyl chloride-based resins plasticized by plasticizers are used in most fields such as electric wires, hoses, or building materials because of their flexibility and excellent mechanical properties. In particular, the flexible vinyl chloride-based wire coating material is divided into general use and heat resistance according to the characteristics. In general use, it is used as a wire sheath coating material, and the plasticizer used at that time mainly uses di-2-hexyl phthalate (DEHP). However, in recent years, the use of the DEHP is particularly limited as the substance is regulated as its content is tightened, and its use is limited. On the other hand, in the case of heat resistance, it is an electric wire interior coating material, and the plasticizer used at that time uses di-isodecyl phthalate (DIDP) which is excellent in heat resistance. DIDP is excellent in durability and low volatility, but cannot be said to be poor in oil resistance and good in workability.

Therefore, there is a demand for development of a plasticizer for replacing DEHP for vinyl chloride-based resins for electric wire sheathing materials, and development of alternative plasticizers for improving the processability of DIDP plasticizers used for vinyl chloride-based resins for electric wire coverings. It is becoming. However, the development of a new plasticizer for a specific polymer suitable for a specific application should not only be excellent in the properties of the plasticizer itself, but also excellent in coherence with the target polymer resin, and also excellent in compatibility with various additives. Because of this, difficulties will follow.

On the other hand, in the vinyl chloride resin composition, it is common to use a stabilizer together in order to prevent deterioration of resin and a plasticizer by heat, light, oxygen in air, etc. in a use environment. As such stabilizers, conventionally, a metal-based stabilizer, tin compounds such as stearic acid salts such as lead tribasic lactate, cadmium and barium, dibutyl tin sulfonate, and the like are used. Such metal compounds have some degree of toxicity or contaminants to humans or the environment, and recently, calcium stearate, a complex stearic acid salt of calcium and zinc (Ca-Zn type), or a complex carbonate of aluminum and magnesium (so-called hardrotal) Many stabilizers have been proposed.

The present inventors endeavor to find a plasticizer that is excellent in heat aging resistance and heat loss characteristics and overcomes limitations in processability such as DIDP when applied to a vinyl chloride-based resin composition for wire coating, without adversely affecting the environment such as DEHP. In addition, efforts to find an additive having an optimum matching property with such a plasticizer led to the present invention.

Accordingly, it is an object of the present invention to provide heat aging resistance (extension residual after heating), which is an important property required for wire coating materials by using no diethylhexyl phthalate (DEHP) as a plasticizer or a reduced amount beyond the regulated content. Other properties such as tensile strength and elongation, while improving heating loss, are to provide a vinyl chloride-based resin composition for wire covering materials that is equivalent to or better than that of DEHP.

It is also an object of the present invention to provide a vinyl chloride-based resin composition for an electric wire coating material having the above-described physical properties and excellent processing characteristics.

It is also an object of the present invention to provide an electric wire coating material prepared from the vinyl chloride resin composition as described above.

In order to achieve the above object, the present invention provides a vinyl chloride-based resin composition for an electric wire coating material containing a vinyl chloride-based resin, a specific plasticizer and a specific stabilizer. It is preferable that the vinyl chloride resin composition which concerns on this invention contains 5-100 weight part of plasticizers and 1-10 weight part of stabilizers with respect to 100 weight part of vinyl chloride resins. In addition, the vinyl chloride-based resin composition for an electric wire coating material of the present invention may further include 5 to 70 parts by weight of a filler based on 100 parts by weight of the vinyl chloride-based resin.

The plasticizer is dioctyl terephthalate (DOTP) alone or a mixture of dioctyl terephthalate and phthalic ester plasticizer. Such phthalic acid ester compounds may be dialkylphthalates which may be prepared from phthalic acid or phthalic anhydride and C4 to C12 alcohols, in particular diethylhexylphthalate (DEHP), diisononylphthalate (DINP) and diisodecylphthalate (DIDP). It may be selected from the group consisting of), especially diisononyl phthalate is preferred. The dialkyl phthalate contained in the plasticizer used in the present invention is 0 to 50% by weight, preferably 0 to 30% by weight. When dialkyl phthalate is added to the plasticizer of the present invention, it is preferable to add 1% by weight or more.

The stabilizer is also a calcium-zinc stabilizer.

The vinyl chloride resin composition according to the present invention comprises dioctyl terephthalate (DOTP) alone or a mixture of this and a phthalic ester plasticizer as a plasticizer and also includes a Ca-Zn system as a stabilizer. Therefore, such a vinyl chloride-based resin composition of the present invention minimizes the amount of volatile organic compounds generated in the existing electric wire, and thus has high environmental stability, and provides heat aging resistance and heating loss characteristics that are very suitable for wire coating materials.

Hereinafter, the present invention will be described in detail.

The dioctyl terephthalate (DOTP) plasticizer used in the composition of the present invention can be prepared by the following method. Preparation method by esterification reaction using terephthalic acid and 2-ethyl hexanol and dimethyl terephthalate and 2-ethyl hexanol Production method by ester exchange reaction using the raw material or polyester resin such as polyethylene terephthalate or polybutylene terephthalate and 2-ethyl hexanol (2 -ethyl hexanol) as a raw material and the production method by the decomposition transesterification (degradative transesterification).

In the manufacture of dioctyl terephthalate (DOTP), catalysts can be used to accelerate the reaction, depending on the reaction temperature. In general, the reaction is carried out at 130 ℃ to 280 ℃, various catalysts are used to suit the appropriate temperature. For example, tetra-isobutyl titanate (TIBT), tetra-isopropyl titanate (TIPT), dibutyl tin oxide, para-toluenesulfonic acid (para-toulene sulfonic acid) acid, PTSA) and the like may optionally be used. Particularly preferred is paratoluenesulfonic acid or tetraisopropyl titanate, but is not limited thereto.

The post-treatment after completion of the esterification reaction is not particularly limited, but the excess raw material may be removed by a method such as vacuum distillation and neutralized with a basic solution such as NaOH, KOH, Na ₂ CO ₃ aqueous solution, or the like. . The resultant can then be washed with water, optionally dried under reduced pressure and dehydrated, and then the adsorbent is added and filtered to obtain the final plasticizer.

On the other hand, the phthalic ester plasticizer used in the composition of the present invention is prepared by the esterification reaction is carried out while removing the phthalic anhydride and excess alcohol in the presence or absence of the esterification catalyst continuously removing the water produced under normal pressure or reduced pressure out of the reaction system. Can be. The alcohol is preferably 4 to 12 carbon atoms, more preferably selected from the group consisting of diethylhexyl phthalate (DEHP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP), in particular diisononyl Phthalates are preferred.

In the present invention, a plasticizer of dioctyl terephthalate alone can be used as the plasticizer, and a mixed plasticizer obtained by mixing dioctyl terephthalate and the above-mentioned phthalic ester plasticizer can also be used.

Next, the vinyl chloride resin composition according to the present invention will be described.

The vinyl chloride resin composition according to the present invention has good processability, improves heat aging resistance and heat loss, and may deviate from the regulated content of DEHP, thereby using a plasticizer having high environmental stability and a specific stabilizer for wire coating. fit. In particular, the vinyl chloride resin composition has a low heat loss compared to diethylhexyl phthalate (DEHP) having the same molecular weight, and thus has excellent heat resistance and high environmental stability. Suitable.

According to the present invention, the vinyl chloride resin composition preferably contains 5 to 100 parts by weight of the plasticizer, more preferably 40 to 70 parts by weight, per 100 parts by weight of the vinyl chloride resin. When the plasticizer composition is contained in less than 5 parts by weight, there is a problem of insufficient flexibility of the composition, poor elongation properties as the wire coating material properties, and when contained in excess of 100 parts by weight, the bleeding effect (plasticizer) molded article Phenomena coming out of the surface of the substrate tend to occur, and sticky or dirty contaminants tend to adhere.

As the plasticizer used in the present invention, dioctyl terephthalate alone can be used, and a mixed plasticizer of dioctyl terephthalate and a phthalic ester plasticizer can also be used. When using such a mixed plasticizer, the phthalic acid ester compound contained in the plasticizer used in the present invention is 0 to 50% by weight, preferably 0 to 30% by weight. When a phthalic acid ester compound is added to the plasticizer of this invention, it is preferable to add 1 weight% or more.

As a stabilizer which is another component of the present invention, a calcium-zinc-based (Ca-Zn-based) stabilizer such as a calcium stearate complex stearic acid salt is used. The amount of the stabilizer may include 1 to 10 parts by weight, preferably 3 to 7 parts by weight, per 100 parts by weight of the vinyl chloride resin. If the stabilizer is included in less than 1 part by weight, there is a problem that the thermal stability is poor, and when included in more than 10 parts by weight, there is a problem that more than necessary heat stability is expressed. That is, these stabilizers are superior to other plasticizers because they are particularly compatible with the plasticizer and the vinyl chloride-based resins used in the present invention and have excellent synergistic effects.

In addition, by adding a filler to the vinyl chloride resin composition of the present invention, the productivity of the vinyl chloride resin composition and a dry touch feeling (dry touch feeling) can be improved. Such fillers may be calcium carbonate, clay, talc or diatomaceous earth, and the like. In the vinyl chloride resin composition according to the present invention, the filler may be included 5 to 70 parts by weight, more preferably 30 to 60 parts by weight. When the filler is included in less than 5 parts by weight, there is a problem that the dimensional stability and economics are lowered, and when included in more than 70 parts by weight, there is a problem that the workability is reduced.

The method for preparing the vinyl chloride resin composition according to the present invention is not particularly limited, and the vinyl chloride resin composition according to the present invention may be prepared by a method well known in the art by adding a plasticizer and other additives used in the present invention. Can be.

Such a vinyl chloride-based resin composition of the present invention has an excellent residual elongation and a low heating loss after heating, especially when manufactured with a wire coating material. In particular, the vinyl chloride resin composition according to the present invention is stretched after heating for the initial length calculated based on the length measured after heating at 100 ℃ for 168 hours according to ASTM D638 test method and the initial length measured at room temperature The residual rate is at least 80%, preferably at least 90%, and even in combination with diisononylphthalate (DINP), up to about 95% or more is achievable. In addition, according to the ASTM D638 test method, the ratio of heating loss measured for the initial weight measured at room temperature after heating at 100 ° C. for 168 hours is 2.1% or less, preferably 1.8% or less, and more preferably 1.5% or less. In combination with diisononylphthalate (DIDP), up to approximately 1.2% or less can be achieved.

It can be easily understood that manufacturing the wire coating material from the vinyl chloride resin composition according to the present invention can be applied to a method used for the production of a conventional electric wire.

(Preparation of Plasticizer Composition)

Manufacturing example  One

249.21 g of terephthalic acid, 781.38 g of 2-ethyl hexanol and 1.00 g of TIPT as a catalyst were added to a four-necked 2L round flask equipped with a stirrer and a condenser, and heated to 220 ° C. while stirring under a nitrogen atmosphere. The reaction proceeded for a time.

After the reaction, unreacted terephthalic acid and excess 2-ethyl hexanol were removed under reduced pressure using a vacuum pump at 150-220 ° C, and neutralized water washing process was performed using 10 wt% sodium hydroxide solution and 10 wt% forget-me-not solution. After sequentially carrying out dehydration under reduced pressure, the adsorbent was added to the reaction product from which the water was removed, filtered through a filter medium, and finally, DOTP having a purity of 99.7% was obtained.

(Production of Vinyl Chloride Resin Composition)

In the following manner, the vinyl chloride resin composition Examples 1 to 4 according to the present invention using the plasticizer of Preparation Example 1 were prepared by mixing the respective components according to the composition ratio of Table 1, while each according to the composition ratio of Table 1 The vinyl chloride resin composition Comparative Example 1 was prepared by mixing and coating the components.

Example  One

60 parts by weight of plasticizer DOTP alone, 7 parts by weight of Ca-Zn-based stabilizer, and 50 parts by weight of filler were added to 100 parts by weight of polyvinyl chloride resin, and then kneaded for 3 minutes at 165 ° C. in an 8 inch diameter test roll. Make a sheet with a thickness of 1 mm or more. Preheat this sheet to 60 kgf / cm ³ for 3 minutes in press, pressurize to 200 kgf / cm ^{3 and} press for 3 minutes. After cooling to 50 ℃ or less to obtain a final sheet, each of the physical properties are shown in Table 2.

Example  2

60 parts by weight of a plasticizer was used with respect to 100 parts by weight of polyvinyl chloride resin, and it was prepared in the same manner as in Example 1 except for using 5 to 5 mixing ratios of DOTP and DEHP (Di-ethylhexyl phthalate) as the plasticizer. Physical properties are shown in Table 2.

Example  3

It was prepared in the same manner as in Example 1 except that 60 parts by weight of a plasticizer was used with respect to 100 parts by weight of polyvinyl chloride resin, and a mixing ratio of DOTP and di-isononyl phthalate (DINP) was used 5 to 5 as a plasticizer. Sexual characteristics are listed in Table 2.

Example  4

It was prepared in the same manner as in Example 1 except that 60 parts by weight of a plasticizer was used based on 100 parts by weight of polyvinyl chloride resin, and a mixing ratio of DOTP and DIDP (Di-isodecyl phthalate) was used 5 to 5 as a plasticizer. Sexual characteristics are listed in Table 2.

Comparative example  One

A plasticizer was prepared in the same manner as in Example 1 except that 100 parts by weight of polyvinyl chloride resin was used as DEHP (Di-ethylhexyl phthalate), and the physical properties thereof are shown in Table 2.

Example
One Example
2 Example
3 Example
4 Comparative example
One Polyvinyl chloride 100 100 100 100 100 DOTP 60 30 30 30 - DEHP - 30 - - 60 DINP - - 30 - - DIDP - - - 30 - Ca-Zn system
stabilizator 7 7 7 7 7 Filler 60 60 60 60 60

Experimental Example

The specimens prepared using the vinyl chloride resin compositions obtained in Examples 1 to 5 and Comparative Example 1 were evaluated for tensile strength, elongation rate, tensile residual and elongation after heating, and heating loss in the following manner. 2 is shown. At this time, care should be taken that the thickness of the specimen at room temperature does not deviate by ± 0.2 mm, and the temperature of the oven shall not deviate by ± 1 ℃.

(Performance evaluation)

The tensile strength

Tensile strength was measured by pulling the cross head speed to 200 mm / min using a test instrument UTM (manufacturer; Instron, Model Name; 4466) by the ASTM D638 method. (kgf / mm 2) = Load value (kgf) / thickness (mm) x width (mm) was calculated.

Elongation

By the ASTM D638 method, after pulling the cross head speed (200 mm / min) using the U.T.M, and measuring the point where the specimen is cut,

Elongation (%) = calculated after elongation / initial length × 100.

After heating Tensile residual rate  And After heating  kidney Residual rate

After standing at 100 ° C. for 168hr using a gear oven, the cross head speed was pulled to 200mm / min using UTM, a test instrument, and measured at the point where the specimen was cut by the ASTM D638 method. after,

Elongation% was calculated as {extension / initial length} × 100.

Heating loss

After the composition was operated at 165 ° C. for 3 minutes using a roll mill, a 0.8 mm thick sheet was produced, and then 60 g of this composition was also taken at 185 ° C. for 10 minutes using a roll mill to produce 0.4 mm. Specimens were fabricated to thickness and weighed. Then, after 168 hours in an oven at 100 ℃, the weight of the specimen was measured,

Heating loss (% by weight) = (initial weight-weight after heating) / initial weight × 100 was calculated.

division Example
One Example
2 Example
3 Example
4 Comparative example
One Room temperature The tensile strength
(Kg / mm ² ) 1.35 1.30 1.31 1.34 1.39 Elongation (%) 261 243 256 253 250 After heating (100 ^o C, 168 hr) Tensile Residual (%) 96 96 95 88 98 Elongation (%) 93 68 95 90 55 Heating loss (%) 1.3 2.1 1.8 1.1 3.2

From Table 2, it can be seen that Examples 1 to 4 are improved compared to Comparative Example 1, the tensile residual ratio after heating and the elongation residual ratio after heating are lowered and the heating loss is also lowered.

In addition, the vinyl chloride resin composition Examples 5 to 8 according to the present invention using the plasticizer of Preparation Example 1 were prepared by mixing each component according to the composition ratio of Table 3 in the following manner.

Example  5

7 parts by weight of Ca-Zn-based stabilizer, filler 50 to a resin composition using 60 parts by weight of a plasticizer based on 100 parts by weight of polyvinyl chloride resin, and a mixture ratio of DOTP and DINP (Di-isononyl phthalate) as a plasticizer 6 to 4. After mixing the parts by weight and kneading for 3 minutes at 165 ℃ in a test roll (diameter 8 inch) roll to produce a sheet 1 mm or more in thickness. Preheat this sheet to 60 kgf / cm ³ for 3 minutes in press, pressurize to 200 kgf / cm ^{3 and} press for 3 minutes. After cooling to 50 ℃ or less to obtain a final sheet, each of the physical properties are shown in Table 4.

Example  6

60 parts by weight of a plasticizer was used with respect to 100 parts by weight of polyvinyl chloride resin, and was prepared in the same manner as in Example 5 except that DOTP and DINP (Di-isononyl phthalate) were used in a ratio of 7 to 3. Sexual characteristics are listed in Table 4.

Example  7

It was prepared in the same manner as in Example 5 except that the plasticizer was 60 parts by weight based on 100 parts by weight of the polyvinyl chloride resin, and the mixing ratio of DOTP and DIN-di-isononyl phthalate (DINP) was 8 to 2 as the plasticizer. Sexual characteristics are listed in Table 4.

Example  8

60 parts by weight of a plasticizer was used with respect to 100 parts by weight of polyvinyl chloride resin, and was prepared in the same manner as in Example 5 except that the mixing ratio of DOTP and Di-isononyl phthalate (DINP) was used 9 to 1 as a plasticizer. Sexual characteristics are listed in Table 4.

Example
3 Example
5 Example
6 Example
7 Example
8 Polyvinyl chloride 100 100 100 100 100 DOTP 30 36 42 48 54 DINP 30 24 18 12 6 Ca-Zn system
stabilizator 7 7 7 7 7 Filler 60 60 60 60 60

division Example
3 Example
5 Example
6 Example
7 Example
8 Room temperature The tensile strength
(Kg / mm ² ) 1.31 1.32 1.34 1.34 1.35 Elongation (%) 256 255 258 260 261 After heating (100 ^o C, 168 hr) Tensile Residual (%) 95 96 95 96 95 Elongation (%) 95 94 94 93 93 Heating loss (%) 1.8 1.5 1.3 1.3 1.3

From Table 4, Examples 5 to 8 it can be seen that the tensile strength and elongation is somewhat improved compared to Example 3. In addition, there is no reduction in tensile residual ratio and elongation residual ratio after heating, and the heating loss can be similar to that when using DOTP alone (Example 1). On the other hand, when the content of DINP is too high, the loss of heating increases, so that physical properties such as the plasticizer's resistance and extraction resistance tend to be lowered, so that the vinyl chloride-based resin composition according to the present invention may be used as a wire covering material. It is preferable that the ratio of DOTP is 70 weight% or more.

In addition, the vinyl chloride resin compositions of Comparative Examples 2 and 3 were prepared by mixing the components according to the composition ratios of Table 5 in the following manner, and the sheet was prepared and tested. At this time, the plasticizer of Preparation Example 1 was used, but there is a difference in using another stabilizer as described instead of using the Ca-Zn-based stabilizer which is the stabilizer according to the present invention.

Comparative example  2

With respect to 100 parts by weight of polyvinyl chloride resin, the mixing ratio of DOTP and DINP in 60 parts by weight of plasticizer was set to 7 to 3, and was prepared in the same manner as in Example 1 except that 7 parts by weight of Ba-Zn stabilizer was used. Sexual characteristics are listed in Table 6.

Comparative example  3

It was prepared in the same manner as in Example 1 except that the mixing ratio of DOTP and DINP was set to 7 to 3 in 60 parts by weight of the plasticizer and 100 parts by weight of polyvinyl chloride resin, and 7 parts by weight of Ca-stearate stabilizer was used. Physical properties are shown in Table 6.

Example
3 Comparative example
2 Comparative example
3 Polyvinyl chloride 100 100 100 DOTP 42 42 42 DINP 18 18 18 Ca-Zn Type Stabilizer 7 - - Ba-Zn-based stabilizer - 7 - Ca-Stearate Stabilizer - - 7 Filler 60 60 60

division Example
3 Comparative example
2 Comparative example
3 Room temperature The tensile strength
(Kg / mm ² ) 1.31 1.30 1.39 Elongation (%) 256 249 250 After heating (100 ^o C, 168 hr) Tensile Residual (%) 96 92 87 Elongation (%) 95 88 80 Heating loss (%) 1.8 2.0 1.9

From Table 6, the results of Comparative Examples 2 and 3 using a stabilizer other than the Ca-Zn-based stabilizer shows that the vinyl chloride-based resin composition is particularly inferior in elongation remaining after heating due to the use of other stabilizers. Also decreases. It can be seen that Ca-Zn-based stabilizers are particularly suitable as stabilizers in order to obtain excellent heat aging resistance and heat loss characteristics for the wire coating material.

Claims (15)

In a vinyl chloride resin composition comprising a vinyl chloride resin, a plasticizer and a stabilizer, The plasticizer 1 to 50 phthalic ester compound selected from the group consisting of 50 to 99% by weight of dioctyl terephthalate, diethylhexyl phthalate (DEHP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) Wt% is a mixed mixture, The stabilizer is characterized in that the Ca-Zn-based stabilizer Vinyl chloride-based resin composition for electric wire coating material. The method of claim 1, The amount of the plasticizer is 5 to 100 parts by weight based on 100 parts by weight of the vinyl chloride resin, and the content of the stabilizer is 1 to 10 parts by weight based on 100 parts by weight of the vinyl chloride resin. Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, The amount of the plasticizer is 40 to 70 parts by weight based on 100 parts by weight of the vinyl chloride resin. Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, The stabilizer content is 3 to 7 parts by weight based on 100 parts by weight of the vinyl chloride resin. Vinyl chloride-based resin composition for electric wire coating material. delete The method of claim 1, The plasticizer is characterized in that consisting of 70 to 99% by weight of dioctyl terephthalate and 1 to 30% by weight of phthalic ester compound Vinyl chloride-based resin composition for electric wire coating material. delete The method of claim 1, The phthalic acid ester compound is diisononyl phthalate (Diisononyl phthalate; DINP), characterized in that Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, To about 100 parts by weight of the vinyl chloride resin, characterized in that it further comprises 5 to 70 parts by weight of filler Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, The vinyl chloride resin composition was calculated based on the length measured after heating at 100 ° C. for 168 hours according to ASTM D638 test method and the initial length measured at room temperature, and the elongation after heating for the initial length is 80% or more. Characterized by Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, The vinyl chloride-based resin composition is calculated based on the length measured after heating at 100 ℃ for 168 hours according to the ASTM D638 test method and the initial length measured at room temperature, the elongation after heating for the initial length is more than 90% Characterized by Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, The vinyl chloride-based resin composition is characterized in that the ratio of the heating loss measured to the initial weight measured at room temperature after heating at 100 ℃ for 168 hours according to ASTM D638 test method is 2.1% or less Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, The vinyl chloride-based resin composition is characterized in that the ratio of heating loss measured to the initial weight measured at room temperature after heating at 100 ℃ for 168 hours according to ASTM D638 test method is 1.8% or less Vinyl chloride-based resin composition for electric wire coating material. The method of claim 2, According to the ASTM D638 test method, the vinyl chloride-based resin composition was heated at 100 ° C. for 168 hours, and then the ratio of heating loss measured to the initial weight measured at room temperature was 1.5% or less. Vinyl chloride-based resin composition for electric wire coating material. Claims 1 to 4, 6, 8 to 14 made from the vinyl chloride-based resin composition according to any one of claims Wire coverings.