JP6754313B2 - A vinyl chloride resin composition for coating an insulated wire and an electric wire / cable having an insulating coating containing the resin composition. - Google Patents

Description

The present invention relates to a vinyl chloride resin composition for coating an insulated wire and an electric wire / cable having an insulating coating containing the resin composition.

As environmental issues are attracting worldwide attention, miniaturization and weight reduction of automobile-related products is one of the important issues. As for wire harnesses, the number of circuits is increasing due to needs for improving vehicle safety and comfort, so there is an increasing demand for weight reduction and diameter reduction.
Currently, electric wires coated with a vinyl chloride resin composition having excellent flame retardancy and mechanical properties that satisfy automobile electric wire standards such as JASO and ISO have been used in the vehicle body, but the diameter and weight have been further reduced. For the purpose of this, the development of ultrafine electric wires having a conductor area of 0.08 sq or less is in progress.
On the other hand, vinyl chloride resin compositions as coating materials for electric wires and cables in the fields of automobiles and electric / electronic devices are being actively studied because they have excellent mechanical properties and are advantageous in terms of cost. In particular, various plasticizers have been studied, and in addition to ordinary low molecular weight plasticizers such as phthalates and trimellitic acid esters, high molecular weight plasticizers are also known.
For example, Patent Document 1 proposes an ethylene-vinyl acetate-carbon monoxide copolymer. Further, Patent Document 2 describes a vinyl chloride resin composition used for coating electric wires and cables from the viewpoint of reducing environmental load and flame retardancy. Specifically, a technique is disclosed in which a vinyl chloride resin composition containing a specific amount of a high molecular weight plasticizer, a low molecular weight plasticizer, a lead-free stabilizer and a flame retardant is used for coating electric wires and cables.

Japanese Unexamined Patent Publication No. 61-113637 Japanese Unexamined Patent Publication No. 2013-23134

Patent Document 1 describes a vinyl chloride resin composition composed of a vinyl chloride resin, an ethylene / vinyl acetate / carbon monoxide copolymer, and chlorinated polyethylene.
Chlorinated polyethylene is used to improve kneading characteristics while maintaining the desired texture of the composition, but its compatibility with vinyl chloride resins and plasticizing ability are the copolymerization of ethylene, vinyl acetate, and carbon monoxide. Inferior to coalescence. Therefore, when a composition containing chlorinated polyethylene is applied as a coating material for an automobile electric wire, there is a problem that wear resistance and trauma resistance are lowered.
On the other hand, in the technique of using a vinyl chloride resin composition containing a specific amount of a polymer plasticizer, a low molecular weight plasticizer, a lead-free stabilizer and a flame retardant of Patent Document 2 for coating electric wires and cables, abrasion resistance and abrasion resistance In order to use it as an electric wire for automobiles, which requires traumatic resistance, it was necessary to further improve the abrasion resistance.

The present invention provides a vinyl chloride resin composition for coating an insulated wire, which is excellent in durability by improving mechanical properties, has cold resistance, and is excellent in moldability, and includes the resin composition. An object of the present invention is to provide an electric wire / cable having an insulating coating.

The above object of the present invention is achieved by the following means.
<1>
(A) With respect to 100 parts by mass of a vinyl chloride resin composed of a vinyl chloride homopolymer and / or an ethylene / vinyl chloride copolymer.
(B) Ethylene, (meth) acrylic acid ester, carbon monoxide copolymer 10 or more and less than 30 parts by mass,
(C) 0 to 20 parts by mass of plasticizer, and (D) 0.5 to 5 parts by mass of acrylic processing aid,
Vinyl chloride resin composition for insulating wire coating including.
<2>
The vinyl chloride resin composition for coating an insulated wire according to <1>, wherein the plasticizer (C) is a trimellith-based, pyromerit-based, or polyester-based plasticizer.
<3>
The vinyl chloride resin composition for coating an insulated wire according to <1> or <2>, wherein the acrylic processing aid (D) has a mass average molecular weight of less than 500,000.
<4>
A coated wire / cable having an insulating coating containing the vinyl chloride resin composition for coating an insulated wire according to any one of <1> to <3>.

According to the present invention, a vinyl chloride resin composition for insulating wire coating that has both mechanical properties (tensile properties, wear resistance, hardness), wire properties such as cold resistance, and wire workability by improving moldability. Can be provided.

The vinyl chloride resin composition for coating an insulated electric wire of the present invention is a vinyl chloride resin composed of (A) a vinyl chloride homopolymer and / or an ethylene / vinyl chloride copolymer, and (B) an ethylene / (meth) acrylic acid ester. Includes carbon monoxide copolymer and (D) acrylic processing aid.

(A) Vinyl chloride resin As the vinyl chloride resin used as the base resin, ordinary vinyl chloride resin can be used. Examples of the vinyl chloride resin include vinyl chloride homopolymers and ethylene / vinyl chloride copolymers. In particular, the ethylene / vinyl chloride copolymer has excellent compatibility with the (B) ethylene / (meth) acrylic acid ester / carbon monoxide copolymer, and improves the moldability without increasing the embrittlement temperature.
The form of the ethylene / vinyl chloride copolymer is not particularly limited, and may be any of a block copolymer, a graft copolymer, and a random copolymer.

The vinyl chloride resin according to the present invention preferably contains 20 mol% or more of an ethylene / vinyl chloride copolymer, more preferably 40 mol% or more, and may be 100 mol%. Further, the vinyl chloride homopolymer is preferably contained in an amount of 80 mol% or less, more preferably 40 to 60 mol%, and the vinyl chloride homopolymer may not be contained.
In the vinyl chloride homopolymer, the average degree of polymerization of the vinyl chloride homopolymer is preferably 800 or more from the viewpoint of suppressing the decrease in the effect of improving the trauma resistance. Further, the average degree of polymerization of the vinyl chloride homopolymer is preferably 2800 or less from the viewpoint of suppressing the decrease in the mixing property with other components. More preferably, the average degree of polymerization of the vinyl chloride homopolymer is in the range of 1000 to 2500.
In the present invention, these vinyl chloride resins may be used alone or in combination of two or more.

(B) Ethylene / (meth) acrylic acid ester / carbon monoxide copolymer Ethylene / (meth) acrylic acid ester / carbon monoxide copolymer is a copolymer of ethylene, (meth) acrylic acid ester and carbon monoxide. It is a polymer. The alkyl group (alkyl group corresponding to R of −C (= O) OR) of the alcohol part in the (meth) acrylic acid ester is linear or branched, and the number of carbon atoms is preferably 1 to 18. Is. Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, isobutyl, hexyl, and octyl. Specifically, ethylene / butyl (meth) acrylate / carbon monoxide copolymer, ethylene / ethyl acrylate / carbon monoxide copolymer, ethylene / methyl (meth) acrylate / carbon monoxide copolymer Can be mentioned.

Among the constituent components of the ethylene / (meth) acrylic acid ester / carbon monoxide copolymer, the content of the ethylene component is 40 to 80% by mass, and the content of the (meth) acrylic acid ester component is 15 to 60% by mass. The content of the carbon monoxide component is preferably 5 to 30% by mass. Further, it is also possible to further copolymerize other monomers as needed.

The blending amount of ethylene / (meth) acrylic acid ester / carbon monoxide copolymer is 10 or more and less than 30 parts by mass, preferably 10 to 28 parts by mass with respect to 100 parts by mass of the vinyl chloride resin (A). Yes, more preferably 12 to 25 parts by mass.
If the blending amount of ethylene / (meth) acrylic acid ester / carbon monoxide copolymer is less than 10 parts by mass, the low temperature characteristics and flexibility of the resin composition may deteriorate. On the other hand, when the blending amount of ethylene / (meth) acrylic acid ester / carbon monoxide copolymer is 30 parts by mass or more, the mechanical properties of tensile strength are lowered, and the hardness, abrasion resistance, etc. are lowered to withstand. Traumaticity may be reduced.

Further, ethylene / (meth) butyl acrylate copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / methyl (meth) acrylate copolymer and the like can be blended, and the blending amounts thereof are as described above. (B) It is preferable that the amount of the resin is less than or equal to the blending amount.
Although the copolymer of (B) is a high molecular weight polymer, it can be uniformly dispersed with the polyvinyl chloride resin to soften the vinyl chloride resin even if it does not contain a phthalate ester plasticizer. ..

(C) Plasticizer The plasticizer preferably contains 0 to 20 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. As the plasticizer, it is preferable to use a trimellit-based, pyromerit-based, or polyester-based plasticizer, particularly from the viewpoint of heat resistance. The trimellitic plasticizer, trimellitic acid tri-2-ethylhexyl, trimellitic acid tri-n-alkyl _{(C 8,} C _10), trimellitic acid triisodecyl the like. Further, examples thereof include trimellitic acid 2-ethylhexyl ester, trimellitic acid mixed linear alkyl ester, and trimellitic acid isononyl ester. Examples of the pyromellitic plasticizer include pyromellitic acid 2-ethylhexyl ester, pyromellitic acid mixed linear alkyl ester, tetraoctyl pyromellitic acid, tetra n-decyl pyromellitic acid, and tetrabutyl pyromellitic acid. Examples of the polyester-based plasticizer include polyester adipic acid and polyester phthalate. Further, in order to improve the melt viscosity, the viscosity of the plasticizer at 25 ° C. is preferably 500 mPa · s or less, and more preferably 300 mPa · s or less.

The blending amount of the plasticizer is preferably 0 to 20 parts by mass, more preferably 1 to 15 parts by mass, and further preferably 2.5 to 10 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. .. If the amount of the plasticizer compounded is too large, the embrittlement temperature may become too high.

(D) Acrylic processing aid The composition of the present invention contains an acrylic processing aid. The acrylic processing aid is not limited to its name in function, but has a broad meaning. Therefore, it may function as a lubricant, for example. The composition of the present invention contains 0.5 to 5 parts by mass, preferably 0.5 to 3 parts by mass, and more preferably 1 to 1 parts by mass of the acrylic processing aid with respect to 100 parts by mass of the vinyl chloride resin (A). Contains 2.5 parts by mass.
If the amount of the acrylic processing aid is too small, the melt elongation may be insufficient, and if the amount of the acrylic processing aid is too large, the melt viscosity may become too high.

The acrylic processing aid is a homopolymer of (meth) acrylic acid or an ester thereof, or a copolymer of (meth) acrylic acid and an ester thereof. Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate and the like. Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate and the like.
The acrylic processing aid may be used alone or in combination of two or more. Examples of the acrylic processing aid used in the composition of the present invention include commercially available Metabrene (registered trademark: manufactured by Mitsubishi Rayon Corporation) and Kane Ace (registered trademark: manufactured by Kaneka Corporation). Examples of metabrene include Metabrene P531A, Metabren P530A, Metabren P551A, Metabren P550A, Metabren P501A, Metabren P570A, Metabren P700, Metabren P710, and Metabren L-1000 (all trade names). Examples of Kaneace include Kaneace PA-10, Kaneace PA-20, Kaneace PA-30, Kaneace PA-40, Kaneace PA-60, Kaneace PA-100, and Kaneace PA-101 (all trade names).

The mass average molecular weight of the acrylic processing aid is less than 500,000, preferably 400,000 or less, and more preferably 300,000 or less. The lower limit is not particularly limited, but is preferably 50,000 or more, and more preferably 200,000 or more. When the mass average molecular weight of the acrylic processing aid is within the above range, the composition of the present invention can have a melt viscosity (extrudability) suitable for the extrusion coating step when manufacturing an insulated wire.
In the description of the present invention, the mass average molecular weight of the compound can be measured as a polystyrene-equivalent molecular weight by gel permeation chromatography (GPC).

(E) Lead-free stabilizer The composition of the present invention may contain (E) lead-free stabilizer. The use of (E) lead-free stabilizer is preferable from the viewpoint of safety and reduction of environmental load.
The lead-free stabilizer is a lead-free stabilizer, and a normal lead-free stabilizer can be used. Such stabilizers are not particularly limited, but are calcium hydroxide-based, barium zinc-based, calcium-zinc-based, magnesium-zinc-based, organic tin-based (octyl tin-based, butyl tin-based, methyl tin-based, etc.), hydrotal. Examples include site-based, epoxy-based, and phosphite-based.

Here, the barium-zinc-based, calcium-zinc-based, and magnesium-zinc-based are preferably composed of a mixture of barium, calcium, magnesium, or a zinc salt of fatty acids having 8 or more carbon atoms. Examples of the barium salt include barium laurate, barium stearate, and barium ricinoleate. Examples of the calcium salt include calcium laurate and calcium stearate. Examples of the magnesium salt include magnesium laurate and magnesium stearate. Examples of the zinc salt include zinc octylate and zinc stearate. One example of these is the ADEKA stub series manufactured by ADEKA CORPORATION.

Typical examples of the organic tin system include monoalkyl, dialkyl type octyl tin system, butyl tin system, and methyl tin system, and each of them further has a laurate system, a malate system, and a mercapto system. These can be purchased from, for example, Tokyo Fine Chemicals and Nitto Kasei.
These lead-free stabilizers may be used alone or in combination of two or more.

The blending amount of the lead-free stabilizer is preferably 1 to 20 parts by mass, and more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the vinyl chloride resin (A).
If the amount of the lead-free stabilizer is too small, the thermal stability of the resin composition may not be obtained. On the other hand, even if the amount of the lead-free stabilizer is too large, the characteristics of the resin composition do not change, so the upper limit is set to 20 parts by mass.

In the composition of the present invention, in addition to the above components, a filler, an ultraviolet absorber, a light stabilizer, a lubricant, a colorant, a processability improver, and other modifiers may be used alone or as necessary. More than seeds can be used together.

The vinyl chloride resin composition of the present invention comprises the above-mentioned (A) vinyl chloride resin, (B) ethylene / acrylic acid ester / carbon monoxide copolymer, (C) plasticizer, (D) acrylic processing aid and necessary. (E) The desired amount of each of the lead-free stabilizers can be obtained by melt-mixing using a batch kneader such as a roll or a Banbury mixer or a continuous kneader such as a twin-screw extruder. it can.

The vinyl chloride resin composition of the present invention can be suitably used as a coating material for electric wires and cables, which are required to have mechanical properties (tensile properties, wear resistance, hardness), cold resistance, and moldability. In particular, it can be suitably used for an automobile ultra-fine ultra-thin electric wire. Further, the vinyl chloride resin composition may be directly coated around the conductor. Further, the periphery of the ordinary insulated wire may be coated as a sheath material, or may be coated as a sheath material for a non-conductive cable such as an optical fiber cable.

The present invention will be described in more detail based on the following examples.
The present invention is not limited to the examples shown below.

[material]
(A) Vinyl chloride resin (A-1) Vinyl chloride homopolymer (PVC) having an average degree of polymerization of 1300 (trade name: TH-1300, manufactured by Taiyo PVC Co., Ltd.)
(A-2) Ethylene-vinyl chloride copolymer (PVC) having an average degree of polymerization of 1300 (trade name: TE-1300, manufactured by Taiyo PVC, ethylene content 1.6% by mass)

(B) Ethylene / acrylic acid ester / carbon monoxide copolymer (EAECO) (trade name: Elvalois HP661, manufactured by Mitsui DuPont Polychemical)

(C) Trimellitic acid ester plasticizer (trade name: Trimex N-08: trinormal alkyl trimellitic acid (C ₈ , C ₁₀ ), (viscosity 115 mPa · S), manufactured by Kao Corporation)

(D) Acrylic processing aid (D-1) Acrylic processing aid (trade name: Metabrene L-1000 (mass average molecular weight 230,000), manufactured by Mitsubishi Rayon)
(D-2) Acrylic processing aid (trade name: Metabrene P-570A (mass average molecular weight 250,000), manufactured by Mitsubishi Rayon)
(D-3) Acrylic processing aid (trade name: Metabrene P-530A (mass average molecular weight 3.1 million), manufactured by Mitsubishi Rayon)

(E) Lead-free stabilizer: (Product name: ADEKA STAB RUP109, manufactured by ADEKA Corporation)

[Production method]
The mixture blended in parts by mass shown in Table 1 below was kneaded with an open roll (manufactured by Nishimura Machinery Co., Ltd.) set at 180 ° C. for 5 minutes to produce a vinyl chloride resin composition. Then, by compression molding for 5 minutes using a compression molding machine (manufactured by Kitagawa Seiki Co., Ltd.) set at 180 ° C., evaluation samples of Examples 1 to 10 and Comparative Examples 1 to 5 used for the following physical property evaluation were prepared. did.

[Evaluation method, judgment criteria]
The physical properties of each vinyl chloride resin sheet were evaluated by the following methods, and the results are shown in Table 1 below.
(1) Tensile properties Evaluation was made by a tensile test of the compression molded sheet. The test method was based on JIS K7162-2, and the tensile breaking strength (tensile strength) (MPa) and the tensile breaking elongation (%) were measured. However, the shape of the test piece was JIS K6251-5 dumbbell, sample thickness 1 mm, and test speed 200 mm / min.
<Criteria for determining tensile strength>
A: Tensile strength 25 MPa or more C: Tensile strength less than 25 MPa "A" is acceptable.
<Criteria for tensile elongation at break>
A: Tensile breaking elongation 200% or more B: Tensile breaking elongation 100% or more and less than 200% C: Tensile breaking elongation less than 100% "A" and "B" are acceptable.

(2) Cold resistance It was evaluated by a low temperature embrittlement test of a compression molded sheet. The test method was based on JIS K7216, and the minimum temperature at which all the test pieces were unbroken was determined as the embrittlement temperature.
<Criteria for embrittlement temperature>
A: Embrittlement temperature -40 ° C or less B: Embrittlement temperature higher than -40 ° C and less than -20 ° C C: Embrittlement temperature -20 ° C or more "A" and "B" are acceptable.

(3) Hardness The shore D hardness of the compression molded sheet was evaluated. The test method was based on JIS K7215, and the value after 10 seconds of indenter pushing time was determined.
<Criteria for hardness (shore D)>
A: Hardness (shore D) 60 or more C: Hardness (shore D) less than 60 "A" is acceptable.

(4) Abrasion resistance Evaluation was made using a scrape wear tester conforming to JASOD618. However, the sample is a compression molded sheet with a thickness of 0.1 mm fixed to a round bar with a diameter of 10 mm, and the wear needle until it penetrates the sample under the conditions of a test load of 7 N, a wear needle diameter of 0.45 mm, and a test speed of 60 mm / min. The number of round trips was calculated.
<Criteria for wear resistance>
A: Abrasion resistance 500 times or more B: Abrasion resistance 100 times or more and less than 500 times C: Abrasion resistance less than 100 times "A" and "B" are acceptable.

(5) Extrudability (melt elongation, melt viscosity)
The melt viscosity was measured with a capillary rheometer conforming to JIS K7199. However, the capillary die had a hole diameter of D: 1 mm, a length of L: 10 mm, a set temperature of 180 ° C., and an extrusion speed of 50 mm / min. For the melt elongation, the strand extruded from the die was picked up by a take-up machine, and the maximum take-up speed (m / min) until the strand was broken was determined as the melt elongation. <Criteria for melt elongation>
A: Melt elongation 20 m / min or more B: Melt elongation 15 m / min or more and less than 20 m / min C: Melt elongation 10 m / min or more and less than 15 m / min D: Melt elongation less than 10 m / min "A" and "B" pass is there.
<Criteria for melt elongation>
A: Melt viscosity 700 Pa ・ s or less B: Melt viscosity 700 Pa ・ s or more and less than 800 Pa ・ s C: Melt viscosity 800 Pa ・ s or more and less than 1000 Pa ・ s D: Melt viscosity 1000 Pa ・ s or more “A” and “B” pass is there.

(6) Formability As for the formability, the high-speed formability of the electric wire was evaluated. Using a wire extruder whose temperature was set to 160 ° C to 180 ° C, a copper conductor with a cross-sectional area of 0.08 sq, which was made by twisting seven copper wires with a wire diameter of 0.12 mm, was coated with a coating thickness of 0.1 mm. In this case, the maximum line speed at which the appearance of the electric wire was not poor or the wire was not broken was obtained.
<Criteria for moldability>
A: Maximum linear speed 200 m / min or more B: Maximum linear speed 100 m / min or more and less than 200 m / min C: Maximum linear speed 50 m / min or more and less than 100 m / min D: Maximum linear speed less than 50 m / min "A" and "B" Is a pass.

In Table 1, the numerical values described in the rows of each component in each Example and Comparative Example represent parts by mass, and "-" means that the substance is not included. The molecular weights in D-1 to D-1 to 3 represent the mass average molecular weight. Further, in each item of tensile strength, tensile elongation at break, embrittlement temperature, hardness, wear resistance, melt elongation and melt viscosity, the measured values are described in the upper row and the judgment results are described in the lower row.

As is clear from Table 1 above, the contents of (B) ethylene, (meth) acrylic acid ester, carbon monoxide copolymer, (C) plasticizer and (D) acrylic processing aid are defined in the present invention. All of the resin sheets prepared from the unsatisfied compositions were evaluated as having any one of tensile strength, tensile elongation at break, embrittlement temperature, hardness (shore D), abrasion resistance, melt elongation and melt viscosity. And did not meet the standard value. On the other hand, the resin sheet produced by using the vinyl chloride resin composition for covering insulated wires of the present invention has tensile strength, tensile elongation at break, embrittlement temperature, hardness (shore D), wear resistance, and moldability. In each of the evaluations, the evaluation was "A" or "B", which satisfied the standard value and passed. In addition, the plasticizer penetrates between the molecules of the vinyl chloride resin (PVC) and acts to weaken the cohesive force due to the polarity of the PVC. Therefore, the resin composition prepared in the same manner as in Examples 1 to 10 using a pyrolymerit-based plasticizer or a polyester-based plasticizer satisfying the melt viscosity, similarly to the trimellit-based plasticizer preferable as the plasticizer used in the present invention. The product also showed good results as in Examples 1 to 10.

Claims (4)

(A) With respect to 100 parts by mass of a vinyl chloride resin composed of a vinyl chloride homopolymer and / or an ethylene / vinyl chloride copolymer.
(B) Ethylene, (meth) acrylic acid ester, carbon monoxide copolymer 10 or more and less than 30 parts by mass,
(C) 0 to 20 parts by mass of plasticizer, and (D) 0.5 to 5 parts by mass of acrylic processing aid,
Vinyl chloride resin composition for insulating wire coating including. The vinyl chloride resin composition for coating an insulated wire according to claim 1, wherein the plasticizer (C) is a trimellith-based, pyromerit-based, or polyester-based plasticizer. The vinyl chloride resin composition for coating an insulated wire according to claim 1 or 2, wherein the acrylic processing aid (D) has a mass average molecular weight of less than 500,000. An electric wire / cable having an insulating coating containing the vinyl chloride resin composition for insulating the insulated wire according to any one of claims 1 to 3.