JP2001002850A - Thermoplastic resin composition and wire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition obtained by recycling without fractionation a polyvinyl chloride-based resin and a polyethylenic resin recovered from waste wires and to provide a wire using this resin composition as an insulator or a covering material. SOLUTION: The title thermoplastic resin composition comprises (1) 1-99 wt.% of a resin composition mainly composed of a polyvinyl chloride-based resin and a polyethylenic resin recovered from waste wires and (2) 1-99 wt.% of a multiphase type graft copolymer comprising 5-99 wt.% of a segment A composed of a polyolefinic (co)polymer and 95-1 wt.% of a segment B composed of a vinyl (co)polymer, one of the two segments forming a dispersed phase having a particle diameter of 0.001-10 μm in the other segment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition which can be reused without separating polyvinyl chloride resin and polyethylene resin recovered from waste electric wires and has excellent mechanical properties, and a thermoplastic resin composition having excellent mechanical properties. The present invention relates to an electric wire using as an insulator or coating.

[0002]

2. Description of the Related Art In general, a polyvinyl chloride resin, a polyethylene resin, or the like is used as a single layer or a composite layer in an insulator portion of an electric wire. Conventionally, in the recycling of electric wires, only copper, which is a conductor, is collected, and resin in an insulator is often buried or incinerated. However, in recent years, the shortage of landfill sites and environmental problems due to exhaust gas generated during combustion of polyvinyl chloride resin have been highlighted, and the resin used as an insulator has been reused.

There are two methods for recycling resin recovered from waste electric wires. One is a method in which all the resins are collectively collected, crushed and reused. Another method is a method of separating and collecting the resin constituting the electric wire for each type and reusing the resin. This is a method in which the covering material of the electric wire is separated in a manner of peeling the skin into portions such as a sheath material and an insulator (generally called a "peeling"), and the obtained material is crushed.

[0004]

The method of collectively collecting and pulverizing all the resin from the waste electric wire is not problematic in the case of an electric wire composed of only one kind of resin, but an electric wire covered with a plurality of resins. In case (1), the mechanical properties of the recovered resin, particularly the elongation at the time of tension, were significantly inferior to those of the virgin material, so that the recovered resin could not be reused for electric wires. On the other hand, the mechanical properties of the resin separated and recovered according to the type are not significantly reduced as compared with the virgin material, and thus the resin can be reused as an electric wire. However, since this method is very complicated and costly, it has not been practiced much. SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition which can be reused without separating polyvinyl chloride-based resin and polyethylene-based resin recovered from waste electric wires, and has excellent mechanical properties, and an insulator or coating thereof. An object of the present invention is to provide an electric wire used as an object.

[0005]

Means for Solving the Problems In order to solve the above problems, the first invention provides (1) a resin composition mainly composed of a polyvinyl chloride resin and a polyethylene resin recovered from waste electric wires. 1 to 99% by weight, (2) 5 to 99% by weight of A segment which is a polyolefin (co) polymer and 1 to 95 of B segment which is a vinyl (co) polymer
% By weight of the graft copolymer, wherein the one segment has a particle size of 0.001 to
A thermoplastic resin composition comprising 1 to 99% by weight of a multiphase structure type graft copolymer forming a 10 μm dispersed phase. A second invention is the thermoplastic resin composition according to the first invention, wherein the A segment is polyethylene or a copolymer formed from ethylene and a polar vinyl monomer.
A third invention is the thermoplastic resin composition according to the first invention or the second invention, wherein the B segment is a (co) polymer formed from a (meth) acrylate. 4th
According to the invention, there is provided an electric wire using the thermoplastic resin composition of the first to third inventions as an insulator or a covering.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A resin composition mainly composed of a polyvinyl chloride resin and a polyethylene resin recovered from waste electric wires used in the present invention (hereinafter abbreviated as "recovered resin").
The term “resin” refers to a resin recovered from a waste electric wire and containing, as a main component, a resin composed of only a polyvinyl chloride resin or a polyethylene resin, or both a polyvinyl chloride resin and a polyethylene resin. The content of the polyvinyl chloride resin in the recovered resin is usually 5 to 5.
95% by weight. The polyvinyl chloride resin may be a homopolymer of vinyl chloride, a copolymer of vinyl chloride and another monomer, or a mixture thereof. Other monomers copolymerizable with the vinyl chloride monomer include, for example, olefins such as propylene and butene, fatty acid vinyl esters such as vinyl acetate, and unsaturated acids such as acrylic acid, methacrylic acid, maleic acid, and fumaric acid. , Unsaturated acid esters such as methyl acrylate, unsaturated anhydrides such as maleic anhydride,
Examples thereof include nitrile compounds such as acrylonitrile, alkyl vinyl ethers such as methyl vinyl ether and cetyl vinyl ether, and vinylidene compounds such as vinylidene chloride.

Examples of the polyethylene resin include low-density polyethylene, ultra-low-density polyethylene, ultra-low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ultra-high-molecular-weight polyethylene, and polyethylene synthesized with a metallocene catalyst. Can be mentioned.
These polyethylenes may be used as a mixture or may be partially crosslinked.

[0008] In the recovered resin, besides vinyl chloride resin or polyethylene resin, other thermoplastic elastomers such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene rubber, etc. May be included. The content of the other resin in the recovered resin is usually 0 to 30% by weight.

The multiphase structure type graft copolymer referred to in the present invention may be a polyolefin-based (co) polymer A segment or a vinyl-based (co) polymer (where the (co) polymer is a polymer or B segment which constitutes a matrix, and one segment is a graft copolymer in which the other segment forms a dispersed phase with a specific particle diameter.

The specific particle size is 0.001 to 10 μm.
m, preferably 0.01 to 5 μm. In any case where the dispersed resin particle diameter is less than 0.001 μm or more than 10 μm, the compatibility with the polyvinyl chloride resin and the polyethylene resin is reduced, so that the mechanical properties aimed at cannot be maintained. It is in.

The polyolefin (co) polymer as the A segment includes, for example, ethylene, propylene,
It is a (co) polymer based on a non-polar α-olefin monomer such as 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, or a copolymer with a polar vinyl monomer. .

The polar vinyl monomer includes a non-polar α
A monomer having a vinyl group copolymerizable with an olefin monomer, such as acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride,
Α, β-unsaturated carboxylic acids such as bicyclo (2,2,1) -5-heptene 2,3-dicarboxylic acid and metal salts thereof,
Methyl acrylate, ethyl acrylate, acrylic acid n-
Α, β-unsaturated carboxylic esters such as butyl, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and vinyl acetate Vinyl esters such as vinyl propionate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl stearate, and vinyl trifluoroacetate; and unsaturated glycidyl groups such as glycidyl acrylate, glycidyl methacrylate, and monoglycidyl itaconate. Monomers.

Specific examples of the copolymer formed from the non-polar α-olefin monomer and the polar vinyl monomer include, for example, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene- Ethyl acrylate copolymer, ethylene-isopropyl acrylate copolymer, ethylene-n-butyl acrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-acrylic acid 2
-Ethylhexyl copolymer, ethylene-methylethyl methacrylate copolymer, ethylene-isopropyl methacrylate copolymer, ethylene-n-butyl methacrylate copolymer, ethylene-isobutyl methacrylate copolymer, ethylene-methacrylic acid 2 -Ethylhexyl copolymer, ethylene-vinyl acetate copolymer or saponified product thereof, ethylene-vinyl propionate copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer, ethylene-ethyl acrylate-glycidyl methacrylate Copolymers, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer and the like can be mentioned. These copolymers composed of a nonpolar α-olefin and a polar vinyl monomer can be used as a mixture.

Among the polyolefin-based (co) polymers as the A segment, polyethylene, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-glycidyl methacrylate copolymer are recovered from waste electric wires. And high compatibility with the polyethylene resin.

The vinyl (co) polymer which is the B segment of the present invention is obtained by (co) polymerizing at least one kind selected from vinyl monomers. Specific examples of the vinyl monomer include a vinyl aromatic monomer such as styrene; a nuclear-substituted styrene such as methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene and chlorostyrene; an α-substituted styrene such as α
-Methylstyrene, α-ethylstyrene; (meth) acrylic acid ester monomers, for example, alkyl esters of (meth) acrylic acid having 1 to 20 carbon atoms such as methyl (meth) acrylate and ethyl (meth) acrylate; (Meth) acrylonitrile; vinyl ester monomers such as vinyl acetate and vinyl propionate. Among these monomers, (meth) acrylate monomers are preferred from the viewpoint of compatibility with the polyvinyl chloride resin.

The weight average molecular weight of the vinyl (co) polymer which is the B segment in the present invention is usually from 1,000 to 1,000.
1,000,000, preferably 5,000-500,
000. More preferably, from 7,000 to 3
It is in the range of 00,000. Weight average molecular weight of 1,000
If it is less than 0, the compatibility with the polyvinyl chloride resin tends to decrease, which is not preferable. Also, when the weight average molecular weight exceeds 1,000,000, the compatibility with the polyvinyl chloride resin decreases, which is not preferable.

In the multiphase structure type graft copolymer of the present invention, the A segment is 5 to 99% by weight, preferably 20% by weight.
~ 95% by weight. Accordingly, the B segment accounts for 1 to 95% by weight, preferably 5 to 80% by weight. If the content of the A segment is less than 5% by weight, the compatibility with the polyethylene resin decreases, which is not preferable. If the content of the A segment exceeds 99% by weight, the compatibility with the polyvinyl chloride resin decreases, which is not preferable.

The grafting method for producing the multi-phase structure type graft copolymer in the present invention may be any of generally known methods such as a chain transfer method and an ionizing radiation irradiation method. , According to the following method. Because the graft efficiency is high and secondary aggregation by heat does not occur, the expression of performance is more effective,
Also, this is because the manufacturing method is simple.

Next, the method for producing the multi-phase structure type graft copolymer of the present invention will be described in detail. That is, 100 parts by weight of polyolefin (co) polymer particles are suspended in water, and at least one kind of at least one vinyl monomer 1-4 is suspended.
One part or a mixture of two or more radically polymerizable organic peroxides represented by the following general formula 1 or 2 is added in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the vinyl monomer.
20 parts by weight and a polymerization initiator having a decomposition temperature of 40 to 90 ° C. for obtaining a half-life of 10 hours in an amount of 0 to 100 parts by weight of the total of the vinyl monomer and the radical polymerizable organic peroxide. .01 to 5 parts by weight, and heated under a condition that decomposition of the polymerization initiator does not substantially occur. When the copolymer particles are impregnated, and when the impregnation rate reaches 50% by weight or more of the initial addition amount, the temperature of the aqueous suspension is increased, and the vinyl monomer and the radical polymerizable organic peroxide are increased. The above-mentioned polyolefin (co)
It is (co) polymerized in the polymer particles to obtain a grafted precursor. By melting and kneading the grafting precursor at 100 to 300 ° C., a multiphase structure type graft copolymer composed of an A segment and a B segment is obtained.

However, the grafting precursor does not necessarily have to be melt-kneaded before mixing with the recovered resin. That is, the grafting precursor may be directly melt-mixed with the recovered resin. This is because the grafting precursor becomes a graft copolymer even by melt-kneading with the recovered resin.

The grafting precursor was added to separately synthesized A
Has the same structure as segment or B segment (co)
Even if the polymers are mixed and kneaded under melting, a multi-phase structure type graft copolymer can be obtained. Further, in the above polymerization process, a grafting precursor is synthesized without using a vinyl-based monomer, and the grafting precursor and the vinyl monomer are mixed and melt-kneaded. Coalescence can be obtained. Most preferred is a multiphase structure type graft copolymer obtained by melt-kneading the grafting precursor.

The thermoplastic resin composition of the present invention can be obtained by melt-kneading the multiphase structure type graft copolymer thus obtained and the recovered resin. The radically polymerizable organic peroxide represented by the general formula 1 is the following compound.

[0023]

Embedded image

In the formula, R ¹ is a hydrogen atom or a group having 1 to 2 carbon atoms.
R ² is a hydrogen atom or a methyl group; R ³ and R ⁴ are each an alkyl group having 1 to 4 carbon atoms; R ⁵ is an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group or a carbon atom; Shows cycloalkyl groups of the numbers 3 to 12. m is 1 or 2.

The radically polymerizable organic peroxide represented by the general formula 2 is the following compound.

[0026]

Embedded image

In the formula, R ⁶ is a hydrogen atom or a group having 1 to 4 carbon atoms.
R ⁷ is a hydrogen atom or a methyl group; R ⁸ and R ⁹ are each an alkyl group having 1 to 4 carbon atoms; R ¹⁰ is an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group or a carbon atom; Shows cycloalkyl groups of the numbers 3 to 12. n is 0, 1 or 2.

Specific preferred examples of the radically polymerizable organic peroxide represented by the general formula 1 or 2 include t-butylperoxyacryloyloxyethyl carbonate; t-butylperoxymethacrylic acid. Leuroxyethyl carbonate; t-butyl peroxyallyl carbonate
Bones; t-butyl peroxymethacrylic acid-bone
It is.

The content of the multiphase structure type graft copolymer in the thermoplastic resin composition of the present invention is usually 1 to 99% by weight. From the viewpoint of recycling waste electric wires, the content is more preferably 1 to 50% by weight. When the content of the multi-phase structure type graft copolymer is less than 1% by weight, the compatibility between the polyvinyl chloride resin and the polyethylene resin becomes low, and when it exceeds 99% by weight, it tends to be economically disadvantageous. .

The thermoplastic resin composition of the present invention has a temperature of 15
It is manufactured by melting and mixing at 0 to 350 ° C. If the temperature is lower than 150 ° C., the melting is incomplete or the melt viscosity is high, the mixing becomes insufficient, and phase separation or delamination appears in the molded product, which is not preferable. On the other hand, when the temperature exceeds 350 ° C., decomposition or gelation of the mixed resin occurs, which is not preferable.

As a method of melting and mixing, for example, a commonly used kneading machine such as a Banbury mixer, a pressure kneader, a kneading extruder, a twin screw extruder or a roll can be used. In the present invention, for example, inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide, organic flame retardants such as halogen-based and phosphorus-based, metal powder, antioxidant, and ultraviolet ray inhibitor within a range not departing from the gist of the present invention. , A lubricant, a dispersing agent, a coupling agent, a foaming agent, a crosslinking agent, a coloring agent, and additives such as carbon black.
The electric wire of the present invention uses the above-mentioned thermoplastic resin composition as an insulator or a covering.

[0032]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. The abbreviations in the table represent the following substances. PE: polyethylene (trade name: Sumikasen G401, manufactured by Sumitomo Chemical Co., Ltd.) EVA: ethylene-vinyl acetate copolymer (trade name: NU
C3150, manufactured by Nippon Unicar Co., Ltd., vinyl acetate 20%
EEA: Ethylene-ethyl acrylate copolymer (trade name: DPDJ9169, manufactured by Nippon Unicar Co., Ltd., containing 20% ethyl acrylate) EGMA: Ethylene-glycidyl methacrylate copolymer (trade name: RA3150, Nippon Polyolefin) (stock)
MMA: methyl methacrylate BMA: butyl methacrylate St: styrene MAA: methacrylic acid

Reference Example 1 (Production of Graft Copolymer of Multi-Phase Structure Type) In a stainless steel autoclave having a volume of 5 liters, 2500 g of pure water was added, and 2.5 g of polyvinyl alcohol as a suspending agent was further added. Dissolved. 800 g of an ethylene-vinyl acetate copolymer (EVA) was put therein, and stirred and dispersed. Separately, 1.5 g of benzoyl peroxide as a polymerization initiator, 4 g of t-butylperoxymethacryloyloxyethyl carbonate as a radical polymerizable organic peroxide, and methyl methacrylate 20 as a vinyl monomer.
0 g, and the solution was charged and stirred into the autoclave.

Next, the autoclave was heated to 60 to 65 ° C. and stirred for 2 hours to convert the polymerization initiator, the radically polymerizable organic peroxide and the vinyl monomer into ethylene.
It was impregnated in a vinyl acetate copolymer. Next, after confirming that the total amount of the impregnated vinyl monomer, the radical polymerizable organic peroxide and the polymerization initiator is 50% by weight or more, the temperature is increased to 80 to 85 ° C, The temperature was maintained for 4 hours to complete the polymerization, followed by washing with water and drying to obtain a graft precursor. Extracting polymethyl methacrylate from the grafted precursor with tetrahydrofuran,
The weight average molecular weight measured by gel permeation chromatography (GPC) was 100,000.

Next, this grafted precursor was subjected to a Labo Plastomill single screw extruder (manufactured by Toyo Seiki Seisaku-sho, Ltd.) for 20 minutes.
It was extruded at 0 ° C. and subjected to a grafting reaction to obtain a multi-phase structure type graft copolymer.

The graft copolymer was subjected to a scanning electron microscope “JEOL JSM T300” (manufactured by JEOL Ltd.).
As a result, it was a multiphase structure type graft copolymer in which spherical resins having a particle diameter of 0.3 to 0.4 μm were uniformly dispersed. At this time, the grafting efficiency of the methyl methacrylate polymer was 75% by weight.

Reference Examples 2 to 13 By the same operation as in Reference Example 1, a polyolefin (co) polymer as the A segment and a vinyl (co) polymer as the B segment were added to the components shown in Tables 1 to 3, By changing the ratio, a multi-phase structure type graft copolymer was synthesized. Further, the weight average molecular weight, the particle diameter and the graft efficiency were measured in the same manner as in Reference Example 1 and are shown in Tables 1 to 3. The A segment used in Reference Example 10 was EVA, and the A segment used in Reference Example 11 was EVA.
The segment is PE, and Reference Examples 12 and 13 are graft copolymers outside the scope of the present invention.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3]

Example 1 (Production of Thermoplastic Resin Composition) Reference Example 1 was added to 950 g of recovered resin (a resin portion was collectively recovered from waste electric wires and contained 70% by weight of polyethylene and 30% by weight of polyvinyl chloride). After dry-blending 50 g of the multi-phase structure type graft copolymer synthesized in the above, the cylinder was set to a temperature of 210 ° C. and the screw diameter was 30 mm.
And extruded after extrusion. A test piece (size of a No. 2 type tensile test piece: 115 mm × 25 m) was obtained from the granulated resin using an injection molding machine having a cylinder temperature of 210 ° C.
mx 3 mm), and a tensile test was performed according to JIS K7113. The results are shown in Table 4.

Examples 2 to 12 The multiphase structure type graft copolymer and the recovered resin were melt-kneaded at the ratios shown in Tables 4 to 6, and test pieces were prepared in the same manner as in Example 1. Thereafter, a tensile test was performed in the same manner as in Example 1, and the results are shown in Tables 4 to 6.

[0043]

[Table 4]

[0044]

[Table 5]

[0045]

[Table 6]

Comparative Examples 1 to 3 A test piece was prepared in the same manner as in Example 1 by melt-kneading the multiphase structure type graft copolymer and the recovered resin in the proportions shown in Table 7, and the same as in Example 1. The tensile test was performed by the method described in Table 7, and the results are shown in Table 7.

[0047]

[Table 7]

Comparative Example 4 The same test as in Example 1 was conducted on a thermoplastic resin composition prepared without using the multi-phase structure type graft copolymer, and the results are shown in Table 7.

As described above, the thermoplastic resin composition of the present invention has excellent mechanical properties as compared with Comparative Examples. Therefore, it is suitable as an insulator or a covering material for electric wires.

[0050]

The thermoplastic resin composition of the present invention has excellent mechanical properties, particularly excellent elongation at a tensile breaking point, and can be reused as an electric wire without separating the recovered resin from the waste electric wire. Therefore, it is very excellent from the viewpoint of environmental problems.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 51/06 C08L 51/06 H01B 3/44 H01B 3/44 Z FM // H01B 7/02 7 / 02 Z 15/00 ZAB 15/00 ZAB F-term (Reference) 4J002 BB03X BD03W BN05Y BN07Y BN12Y GQ01 4J026 AA12 AA38 AA45 AC04 AC07 AC17 AC19 AC24 BA02 BA05 BA20 BA24 BA27 BB02 BB04 5G305 CA15 AB13 CA15 AB CA51 5G309 LA06 LA14 RA04 RA07 RA10

Claims (4)

[Claims] 1. A resin composition containing (1) a polyvinyl chloride-based resin and a polyethylene-based resin recovered from waste electric wires in a proportion of 1 to 99% by weight and (2) a polyolefin (co) polymer. A graft copolymer comprising 5 to 99% by weight of an A segment and 1 to 95% by weight of a B segment which is a vinyl (co) polymer, wherein one of the segments has a particle size of 0.001 to 0.005 in the other segment. 10
A thermoplastic resin composition comprising 1 to 99% by weight of a multiphase structure type graft copolymer forming a μm dispersed phase. 2. The thermoplastic resin composition according to claim 1, wherein the A segment is polyethylene or a copolymer formed from ethylene and a polar vinyl monomer. 3. The thermoplastic resin composition according to claim 1, wherein the B segment is a (co) polymer formed from a (meth) acrylate. 4. An electric wire using the thermoplastic resin composition according to claim 1 as an insulator or a covering.