JP2002356590A - Thermoplastic resin composition and molding thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having excellent moldability and capable of producing moldings excellent in the balance between tensile elongation and strength at break, and suitable for electric cable sheath or coating. SOLUTION: This thermoplastic resin composition comprises 25 to 50 wt.% of (A) random interpolymer e.g. an ethylene-styrene copolymer comprising 1 to 99 mol% of a polymer unit derived from an aromatic vinyl- or vinylidene- monomer and/or a hindered aliphatic or alicyclic vinyl- or vinylidene-monomer, and 1 to 99 mol% of a polymer unit derived from at least an α-olefin having 2-20 carbon atoms, and 50 to 75 wt.% of (B) magnesium hydroxide having 0.5 to 2 μm average particle size. The interpolymer (A) may be grafted by silane.

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 and a molded product thereof, and more particularly to a thermoplastic resin composition suitable for use as a sheath (sheath or jacket) material of a power cable and for forming an electric wire coating layer. More particularly, it relates to an α-olefin / vinyl or vinylidene compound copolymer composition and a molded article thereof.

[0002]

BACKGROUND OF THE INVENTION Conventionally, polyvinyl chloride (PVC) has been frequently used as a sheath material and a part of an insulating material of a power cable, and its flexibility, flame retardancy, and insulation have been evaluated.

However, in recent years, due to the environmental problems of polyvinyl chloride, there is a demand for the development of eco-friendly electric wires (cables) having no chlorine and plasticizer, that is, electric wires (cables) that are environmentally friendly.

Under these circumstances, an inorganic filler is compounded based on polyolefin, vinyl acetate copolymer, or the like.
The so-called eco wire material was developed, but this wire material does not always have a sufficient balance between tensile elongation and tensile strength at break, and extrudability is inferior to polyvinyl chloride. Has led to a decline.

In Japanese Patent Publication No. 3-60122,
Electrically insulated cable using a blend of styrene-ethylene random copolymer and polyethylene or a cross-linked product thereof as an insulator; Japanese Patent Publication No. 3-60123 discloses a styrene-ethylene copolymer or a cross-linked product thereof as an insulator. Although an invention relating to an electrically insulated cable is described, these electrically insulated cables are still unsatisfactory in the above points.

[0006] Accordingly, it has been desired to develop a thermoplastic resin composition having excellent balance between tensile elongation and tensile strength at break and excellent moldability, and to provide a molded article thereof.

[0007]

An object of the present invention is to solve the problems associated with the prior art as described above, and it is possible to prepare a molded article having an excellent balance between tensile elongation and tensile strength at break. It is an object of the present invention to provide a thermoplastic resin composition which is excellent in moldability and is particularly suitable for sheathing electric power cables (or electric wires) and for covering electric wires, and a molded article thereof.

[0008]

SUMMARY OF THE INVENTION The thermoplastic resin composition according to the present invention comprises:
(A) (1) (a) at least one aromatic vinyl or vinylidene monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (c) at least one aromatic From 1 to 99 mol% of polymer units derived from the combination of vinyl or vinylidene monomers and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and (2) at least one of 2 to 20 carbon atoms At least one substantially random interpolymer of from 1 to 99 mol% of polymer units derived from α-olefins of
50% by weight, and (B) 50 to 75% by weight of magnesium hydroxide having an average particle size of 0.5 to 2 μm.

Preferably, the interpolymer (A) is silane-grafted.

The interpolymer (A) comprises 5-65 mol% of polymer units derived from at least one aromatic vinyl or vinylidene monomer and at least one α-olefin having 2 to 20 carbon atoms. Substantially random interpolymers consisting of 35 to 95 mol% of polymer units derived are preferably used, especially polymer units 5 to 5 derived from styrene.
65 mol%, and at least one type having 2 to 1 carbon atoms
A polymer unit derived from an α-olefin of 0 to 35
A substantially random interpolymer of 95 mol% is preferably used.

Further, as the interpolymer (A), 5 to 50 mol% of a polymer unit derived from at least one kind of aromatic vinyl or vinylidene monomer;
Pseudorandom interpolymers composed of 50 to 95 mol% of polymer units derived from at least one α-olefin having 2 to 20 carbon atoms are also preferably used, and particularly, polymer units 5 to 5 derived from styrene.
50 mol%, and at least one type having 2 to 1 carbon atoms
A polymer unit derived from an α-olefin of 0 to 50
A pseudo-random interpolymer composed of 95 mol% is preferably used.

Here, the "pseudo" of the pseudo-random interpolymer means that there is no homopolymer segment composed of vinyl or vinylidene monomer in the interpolymer molecular structure, as disclosed in JP-A-7-070223. Means that. That is, with a pseudo-random interpolymer, insertion of the vinyl or vinylidene monomer from head to head and head to tail does not occur.

The tensile elongation (JIS K6301) of a molded article obtained from the thermoplastic resin composition is usually 300%.
It is desirable that this is the case.

The above-mentioned thermoplastic resin composition according to the present invention is preferably used for an electric wire sheath (or a power cable sheath) and an electric wire covering.

The molded article according to the present invention is characterized by comprising the above-mentioned thermoplastic resin composition according to the present invention.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the thermoplastic resin composition according to the present invention and its molded product will be described in detail.

The thermoplastic resin composition according to the present invention contains a substantially random interpolymer (A) and magnesium hydroxide (B).

Interpolymer (A) The interpolymer (A) used in the present invention comprises (A)
(1) (a) at least one kind of aromatic vinyl or vinylidene monomer, or (b) at least one selected from a hindered aliphatic vinyl monomer, a hindered cycloaliphatic vinyl monomer, a hindered aliphatic vinylidene monomer and a hindered cycloaliphatic vinylidene monomer 1
Species, or (c) at least one aromatic vinyl or vinylidene monomer, and at least one selected from hindered aliphatic vinyl monomers, hindered cycloaliphatic vinyl monomers, hindered aliphatic vinylidene monomers, and hindered cycloaliphatic vinylidene monomers; And 1 to 99 mol% of polymer units derived from the combination of
Α-olefin-derived polymer units 1 to 9
It is a substantially random interpolymer consisting of 9 mol%.

The term "interpolymer" as used herein means a copolymer obtained by polymerizing at least two kinds of monomers to form an interpolymer.

The term “copolymer” as used herein means a polymer obtained by polymerizing at least two types of monomers to form a copolymer.

As used herein, an α-olefin comprises an aromatic vinyl monomer, an aromatic vinylidene monomer, a hindered aliphatic vinyl monomer, a hindered cycloaliphatic vinyl monomer, a hindered aliphatic vinylidene monomer or a hindered cycloaliphatic vinylidene monomer. "Substantially random" in a substantially random interpolymer refers to Academic of New York.
Press 1977 "POLYMER SE
QUEEN DEDERMINATION, Carb
on-13 NMR Method, pp. 71-78. C. As described by Randall, it means that the monomer distribution of the interpolymer can be described by "Bernuri's statistical model" or by "first or second order Marcobian statistical model".

Preferably, the substantially random interpolymer of at least one α-olefin having 2 to 20 carbon atoms and an aromatic vinyl or vinylidene monomer has more than 3 units of the aromatic vinyl or vinylidene monomer. The block (for example, a styrene monomer having at least 4 repeating units derived from styrene) does not contain 15% or more of the total amount of the aromatic vinyl or vinylidene monomer. More preferably, the interpolymer is not characterized by a high degree of isotacticity or syndiotacticity. This is due to the fact that in the carbon-13 NMR spectrum of the substantially random interpolymer, the peak region corresponding to the main chain methylene and methine carbon showing either the mesodiad sequence or the racemic diad sequence is the sum of the main chain methylene and methine carbon. Meaning should not exceed 75% of the peak area.

Interpolymers suitable for preparing the thermoplastic compositions of the present invention include one or more α-olefins, one or more aromatic vinyl or vinylidene monomers and / or one or more hindered aliphatic or cyclic Includes, but is not limited to, interpolymers obtained by polymerizing with an aliphatic vinyl or vinylidene monomer.

Examples of preferred α-olefins include those having 2 to 20, preferably 2 to 12, more preferably 2 to 8 carbon atoms. Among them, ethylene, propylene, 1-butene, 4-methyl-1-pentene,
1-Hexene and 1-octene are particularly preferred. These α-olefins do not contain aromatic groups.

Examples of aromatic vinyl or vinylidene monomers suitable for use in the production of the interpolymer used in the present invention include monomers represented by the following formula:

[0026]

Embedded image

In this formula, R ¹ is an atom or group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and is preferably a hydrogen atom or a methyl group.

Each R ² is independently an atom or a group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and is preferably a hydrogen atom or a methyl group.

Ar represents a phenyl group or a halogen atom, an alkyl group having 1 to 4 carbon atoms and 1 carbon atom.
And a phenyl group substituted with 1 to 5 substituents selected from the group consisting of 1 to 4 haloalkyl groups.

N is an integer of 0 to 4, preferably 0
２2, most preferably 0.

Specific examples of the aromatic monovinyl or monovinylidene monomer include styrene, vinyltoluene, α-methylstyrene, t-butylstyrene, chlorostyrene and the like, and all isomers thereof are also included.
Particularly preferred aromatic monovinyl or monovinylidene monomers include styrene and its lower alkyl- or halogen-substituted derivatives. Preferred monomers include styrene, α-methylstyrene, lower alkyl (C 1-4 alkyl)-or phenyl-ring substituted derivatives of styrene, such as ortho-, meta-, para-
Examples include methylstyrene, ring-substituted styrene, para-vinyltoluene or mixtures thereof. A more preferred aromatic monovinyl or monovinylidene monomer is styrene.

The term "hindered aliphatic or cycloaliphatic vinyl or vinylidene compound" means an addition polymerizable vinyl or vinylidene monomer corresponding to the compound represented by the following formula.

[0033]

Embedded image

In this formula, A ¹ has 20 carbon atoms.
The following are sterically bulky aliphatic or cycloaliphatic substituents.

R ¹ is a hydrogen atom or a group having 1 to 4 carbon atoms.
Or an atom or group selected from the group consisting of the above alkyl groups, and is preferably a hydrogen atom or a methyl group.

Each R ² is independently an atom or a group selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and is preferably a hydrogen atom or a methyl group.

R ¹ and A ¹ may together form a ring system.

The term "sterically bulky" means that the monomer having the aliphatic or cycloaliphatic substituent cannot be normally subjected to addition polymerization with a standard Ziegler-Natta catalyst at a rate comparable to ethylene polymerization. I do.

Preferred hindered aliphatic or cycloaliphatic vinyl or vinylidene compounds are monomers in which one of the carbon atoms having an ethylenically unsaturated bond is tertiary or quaternary. Examples of these substituents include
There are cycloaliphatic groups such as cyclohexyl, cyclohexenyl, cyclooctenyl, or cyclic alkyl or aryl substituted derivatives thereof. The most preferred hindered aliphatic or cycloaliphatic vinyl or vinylidene compounds are cyclohexane and various isomeric vinyl-ring substituted derivatives of substituted cyclohexane, and 5-ethylidene-2.
-Norbornene. Particularly preferred are 1-, 3- and
4-vinylcyclohexene.

The interpolymer obtained by polymerizing one or more α-olefins and one or more aromatic vinyl or vinylidene monomers and / or one or more hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers used in the present invention is substantially Is a random copolymer. These interpolymers usually contain from 1 to 99 mol%, preferably at least one, of at least one aromatic vinyl or vinylidene monomer and / or a hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer.
６５65 mol%, more preferably 5-50 mol%, and 1-99 mol%, preferably 35-95 mol%, more preferably 50-95 mol% of at least one α-olefin having 2 to 20 carbon atoms. Mol%.

The number average molecular weight (Mn) of the interpolymer (A) is usually at least 10,000, preferably at least 20,
000 to 1,000,000, more preferably 50,000
00 to 500,000.

By the way, during the production of a substantially random interpolymer, some amount of atactic aromatic vinyl or vinylidene homopolymer may be formed by homopolymerization of the aromatic vinyl or vinylidene monomer under heating. The presence of an aromatic vinyl or vinylidene homopolymer is generally not preferred for the purposes of the present invention and cannot be ignored. If desired, the aromatic vinyl or vinylidene homopolymer can be separated from the interpolymer by extraction techniques such as selective precipitation from solution using a non-solvent for either the interpolymer or the aromatic vinyl or vinylidene homopolymer. . For the purpose of the present invention, it is desirable that the amount of the aromatic vinyl or vinylidene homopolymer is not more than 20% by weight, preferably not more than 15% by weight of the total amount of the interpolymer.

A substantially random interpolymer is
James C.W. Stevens et al., July 3, 1990
No. 07 / 545,403 (EP-A-)
US Patent Application Serial No. 08 / 469,828, filed and granted on June 6, 1995.
(US Pat. No. 5,703,187). All of these disclosures in these U.S. applications are incorporated herein by reference. Preferred operating conditions for these polymerization reactions are as follows:
The temperature is between -30 and 200C. If the polymerization and unreacted monomer removal are performed at temperatures higher than the automatic polymerization temperature of the respective monomers, free radical polymerization may produce some amount of homopolymer polymerization products.

An example of a preferred catalyst and method for preparing the substantially random interpolymer used in the present invention is 199 corresponding to EP-A-416,815.
US application 07 / 545,403 filed July 3, 009; E
May 20, 1991, corresponding to PA-514,828.
EP-A-5
U.S. application Ser. No. 07 / 876,268 filed on May 1, 1992 and U.S. Application No. 08 / 241,523 filed on May 12, 1994 corresponding to U.S. Pat.
0,993); U.S. Patent 5,055,438; 5,05.
7,475; 5,096,867; 5,064,80
2, 5,132,380; 5,189,192; 5,3
21,106; 5,347,024; 5,350,72
3, 5,374,696; 5,399,635 and 5,556,928. All of these disclosures are cited herein.

The substantially random α used in the present invention
-Olefin / aromatic vinyl or vinylidene interpolymers are also available from WO 95/32095 John.
C. To Bradfute et al. (WR Grace &
Co) described in WO 94/00500.
B. Pannell (Exxon Chemical P
attents, Inc. ), And "P
plastics Technology ", page 25 (1
(September 992), all of which are hereby incorporated by reference.

Further, Francis J. et al. Timer
US Application 08 / 708,809 filed Sep. 4, 1996 (US Pat. No. 5,879,149).
Also preferred are the substantially random interpolymers of at least one α-olefin / vinyl aromatic / vinyl aromatic / α-olefin tetrad disclosed in US Pat. These interpolymers have an additional signal with an intensity that is more than three times peak-to-peak noise. These signals are 43.75-44.25 ppm and 38.0-3.
Appears in the 8.5 ppm chemical shift range. In particular, peaks are observed at 44.1, 43.9 and 38.2 ppm. In the proton test NMR experiment, 43.75-4
The signal in the 4.25 ppm chemical shift region is methine carbon, and the signal in the 38.0-38.5 ppm region is methylene carbon.

The pseudo-random interpolymer comprising an aliphatic α-olefin and an aromatic monovinyl or monovinylidene compound used in the present invention is disclosed in US Pat. No. 5,545,403, filed Jul. 3, 1990 (European Patent Publication No. No. 0416815).

These interpolymers are -30 to 2
It can be produced by carrying out the polymerization at a temperature of 50 ° C. in the presence of a catalyst as represented by the following formula and, if desired, preferably a cocatalyst.

[0049]

Embedded image

Wherein each Cp is independently in each case a substituted cyclopentadienyl group π-bonded to M, E is a carbon or silicon atom, and M is A Group IV metal, preferably Zr or Hf, most preferably Zr, wherein each R is independently at each occurrence a hydrogen atom, or hydrocarbyl, silahydrocarbyl or hydrocarbylsilyl, up to 30 and preferably from 1 to 20; More preferably a group having from 1 to 10 carbon or silicon atoms, each R ′ is independently in each occurrence a hydrogen atom, a halogen atom, or hydrocarbyl, hydrocarbyloxy, silahydrocarbyl, hydrocarbylsilyl, A group having 30 or less, preferably 1 to 20, more preferably 1 to 10 carbon or silicon atoms Or two R 'groups together forms a C _1-10 hydrocarbyl substituted 1,3-butadiene, m is 1 or 2. Particularly preferred substituted cyclopentadienyl groups include groups represented by the following formula.

[0051]

Embedded image

Here, each R is independently in each case a hydrogen atom or hydrocarbyl, silahydrocarbyl or hydrocarbylsilyl, and is not more than 30, preferably 1 to 20, more preferably 1 to 10 carbon or silicon atoms. Or two R groups are taken together to form a divalent derivative of these groups. Preferably, R is independently at each occurrence (including all isomers, if any), hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenyl or silyl, or (possibly Two) these R groups are taken together to form indenyl, fluorenyl,
It forms fused ring systems such as tetrahydroindenyl, tetrahydrofluorenyl or octahydrofluorenyl.

Specific examples of particularly preferred catalysts include racemic- (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl) zirconium dichloride, racemic
(Dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl) zirconium 1,4-diphenyl-1,3-butadiene, racemic- (dimethylsilanediyl) -bis- (2-
Methyl-4-phenylindenyl) zirconium di-C
_1-4 alkyl, racemic- (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl) zirconium di-C _1-4 alkyl, racemic- (dimethylsilanediyl) -bis- (2-methyl- 4-phenylindenyl) zirconium di-C _1-4 alkoxide, or a combination thereof.

Further, the following titanium-based constrained geometric catalyst (Tita
Specifically, as [nium-based constrained geometry catalysts], [N- (1,1-dimethylethyl) -1,1-dimethyl
-1-[(1,2,3,4,5-η) -1,5,6,7-tetrahydro-s-indacen-1-yl] silane aminato (2-)-N] titanium dimethyl; Indenyl) (t-butylamido) dimethyl-
Silane titanium dimethyl; ((3-t-butyl) (1,2,3,
4,5-η) -1-indenyl) (t-butylamido) dimethylsilanetitanium dimethyl; and (3-iso-propyl) (1,2,3,4,5-η) -1-indenyl) (t- Butylamido) dimethylsilane titanium dimethyl or a combination thereof.

Another type of the interpolymer used in the present invention
Is manufactured by Longo and Grassi. (Ma
cromol. Chem. , Vol. 191, 2387
-2396 (1990)), and D'Anniel.
lo etc. (Journal of Applied Po
lymer Science, Vol. 58, 1701
-1706 (1995)).
Is methylaluminoxane (MAO) and cyclopen
Tadienyl titanium trichloride (CpTiCl _Three) Of
The catalyst is used to prepare ethylene styrene copolymer.
You. Xu and Lin (Polymer Pre
prints, Am. Chem. Soc. , Div. P
olym. Chem. ) Vol. 35, 686, 687
Page (1994))_Two/ TiCl_Four/ NdC
l_Three/ Al (iBu)_ThreeUsing a catalyst, styrene and pro
A random copolymer with pyrene is being prepared. Further
And Lu etc. (Journal of Applied
Polymer Science, Vol. 53, 14
53-1460 (1994))_Four/ Nd
Cl_Three/ MgCl_Two/ Al (Et)_ThreeEchile using catalyst
Reports the copolymerization of styrene and styrene.

Sernets and Mulhup
aupt) (Macromol. Chem. Phys., v. 197, pp. 1071-108
3, 1997) is Me ₂ Si (Me ₄ Cp) (Nt-butyl) Ti
Cl ₂ / methylaluminoxane, describes the effects of the polymerization conditions in the copolymerization of styrene and ethylene using Ziegler-Natta catalysts. For ethylene-styrene copolymers produced with bridged metallocene catalysts, Arai, Toshiaki and Suzuki (Polymer Prepr.
ints, Am. Chem. Soc., Div. Polym. Chem.) Vol. 38, p.
349, 350, 1997) and U.S. Patent 5,652,315 (Mitsui Toatsu Chemical Co., Ltd.). For a method for producing an interpolymer composed of an α-olefin / aromatic vinyl monomer (for example, propylene / styrene or butene / styrene), see US Pat. 315
(Mitsui Petrochemical Industry Co., Ltd.), German Patent Publication DE19711339A1, and US Pat.
3, 213 (Electrical Chemical Industry Co., Ltd.). The method of preparing the interpolymer component disclosed above is incorporated herein by reference. Aria,
PolymerPreprints Vol. 39, No. 1, Mar
ch / 1998 random ethylene / styrene copolymer can also be used as a component of the present invention.

An example of a suitable catalyst and method for producing the pseudorandom interpolymer suitably used in the present invention is described in US Patent Application No. 5, filed July 3, 1990.
No. 45403 (EP-A-0416815)
US Patent Application No. 5 filed July 3, 1990.
No. 47718 (European Patent Publication No. 468,651)
U.S. Patent Application No. 702475 filed May 20, 1991 (European Patent Publication 514828).
No. 876,268, filed May 1, 1992 (EP-A-520732).
No. 8003 (U.S. Pat. No. 5,374,696), filed Jan. 21, 1993.
U.S. Patent Application No. 82197 filed June 24, 3 years
No. (corresponding to WO 95/00526), and U.S. Patent Applications Nos. 5055536, 5057475, 509686.
7, 5064802, 5132380 and 51891
No. 92, each of which is incorporated herein by reference.

The interpolymer (A) used in the present invention is preferably silane-grafted.

The silane-grafted interpolymer (A) uses a silane coupling agent,
It is prepared in combination with a peroxide to promote silane grafting. In the present invention, the silane-grafted interpolymer (A) includes various conventionally known non-silane-grafted interpolymers (A), magnesium hydroxide (B), silane coupling agents and peroxides. The resulting silane-grafted interpolymer (A) is contained in the thermoplastic resin composition according to the present invention obtained by melt-mixing according to the above method.

As the silane coupling agent, specifically, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyl Examples include diethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltributoxysilane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, and methyltrimethoxysilane. Among them, vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane are preferred.

The silane coupling agent is a total of 100 of the interpolymer (A) and magnesium hydroxide (B).
It is used in a proportion of usually 0.1 to 2.5% by weight, preferably 0.2 to 2% by weight with respect to% by weight. When the silane coupling agent is used in the above ratio, the thermoplastic resin composition containing the interpolymer (A) and the magnesium hydroxide (B) can be obtained at a high silane grafting rate and an appropriate silane grafting degree. Thus, a molded article having an excellent balance between tensile elongation and tensile strength at break, for example, a wire covering layer can be formed.

In the present invention, as described above, a peroxide is used together with a silane coupling agent to promote a silane graft reaction of the interpolymer (A).

As such peroxides, organic peroxides, specifically, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t
-Butyl peroxide, 2,5-dimethyl-2,5-di (peroxidebenzoate) hexine-3, 1,4-bis (t-butylperoxyisopropyl) benzene, lauroyl peroxide, t-butylperacetate, 2,5- Dimethyl-2,5-
Di- (t-butylperoxide) hexyne-3,2,5-dimethyl-2,5-di (t-butylperoxide) hexane, t-butylperbenzoate, t-butylperphenylacetate, t-butylperisobuty Rate, t-butyl per-sec-
Octoate, t-butyl perpivalate, cumyl perpivalate, t-butyl perdiethyl acetate; azobisisobutyronitrile, dimethylazoisobutyrate, and the like.

Among these, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 2,5-dimethyl-2,5
-Dialkyl peroxides such as di (t-butylperoxy) hexane and 1,4-bis (t-butylperoxyisopropyl) benzene are preferably used.

The peroxide is used in an amount of usually 0.005 to 0.15% by weight, preferably 0.1% to 100% by weight of the total of the interpolymer (A) and the magnesium hydroxide (B).
It is used in a proportion of from 0.1 to 0.1% by weight. When the peroxide is used in the above proportion, the reaction of grafting the silane coupling agent to the interpolymer (A) can be appropriately promoted.

In the present invention, the interpolymer (A) is used in an amount of 25 to 50 with respect to 100% by weight of the total of the interpolymer (A) and the magnesium hydroxide (B).
%, Preferably 25 to 40% by weight. When the interpolymer (A) is used in the above ratio, a thermoplastic resin composition excellent in moldability, which can prepare a molded article excellent in balance between tensile elongation and tensile strength at break, is obtained.

Magnesium Hydroxide (B) The magnesium hydroxide (B) used in the present invention has an average particle size of 0.5 to 2 μm, preferably 0.5 to 2 μm.
It is desirable that the thickness be 1 μm.

In the present invention, the magnesium hydroxide (B) is used in an amount of 50 to 75 with respect to 100% by weight of the total of the interpolymer (A) and the magnesium hydroxide (B).
%, Preferably 60 to 75% by weight. When magnesium hydroxide (B) is used in the above ratio,
A thermoplastic resin composition capable of preparing a molded article having an excellent balance between tensile elongation and tensile strength at break is obtained.

Thermoplastic Resin Composition The thermoplastic resin composition according to the present invention contains the above interpolymer (A), magnesium hydroxide (B), and if necessary, a silane coupling agent and a peroxide. It is contained in a specific ratio.

The thermoplastic resin composition according to the present invention contains the above-mentioned interpolymer (A) and magnesium hydroxide (B), or the interpolymer (A), magnesium hydroxide (B), a silane coupling agent and In addition to oxides, if necessary, additives such as antioxidants, ultraviolet absorbers, weather stabilizers, heat stabilizers, antistatic agents, flame retardants, pigments, dyes, etc., do not impair the purpose of the present invention. It can be blended in the range.

The thermoplastic resin composition according to the present invention is prepared by mixing the above-mentioned interpolymer (A), magnesium hydroxide (B) and, if necessary, additives with various conventionally known methods. It is prepared by melt mixing.

That is, the thermoplastic resin composition according to the present invention is prepared by charging the above components simultaneously or sequentially, for example, into a Henschel mixer, a V-type blender, a tumbler mixer, a ribbon blender, etc., and mixing them. It is obtained by melt-kneading with a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer or the like.

Among these, a multi-screw extruder, a kneader,
When a device having excellent kneading performance such as a Banbury mixer is used, a high-quality thermoplastic resin composition in which each component is more uniformly dispersed can be obtained.

At any of these stages, the above additives, for example, antioxidants, can be added as necessary.

The melt flow rate (MFR; AS) of the thermoplastic resin composition according to the present invention obtained as described above
TM D 1238, 190 ℃, 2.16kg load) is usually 0.01 ~
It is 5 g / 10 min, preferably 0.05 to 2 g / 10 min. A thermoplastic resin composition having a melt flow rate within the above range is excellent in moldability such as extrusion moldability.

Molded article The molded article according to the present invention can be prepared by using the thermoplastic resin composition according to the present invention obtained as described above and various conventionally known melt molding methods such as extrusion molding, rotational molding, and calendering. It can be formed into various shapes by methods such as molding, injection molding, compression molding, and blow molding.

When the thermoplastic resin composition according to the present invention is used for an electric wire sheath and an electric wire covering, the molded article according to the present invention is an electric wire sheath and a coating layer. It is formed around the electric wire by a known method such as an extrusion method.

The molded article according to the present invention obtained as described above has a tensile elongation (JIS K6301) of 300%.
As described above, it is usually desirable that the content be 300 to 800%.

[0079]

The thermoplastic resin composition according to the present invention contains a specific interpolymer (A) and magnesium hydroxide (B) having a specific average particle diameter in a specific ratio, and therefore has a high moldability. And a molded article excellent in balance between tensile elongation and tensile strength at break can be prepared. In particular, when the interpolymer (A) in the thermoplastic resin composition according to the present invention is silane-grafted, a molded article excellent in balance between tensile elongation and tensile break strength can be obtained.

Since the molded article according to the present invention is composed of the thermoplastic resin composition according to the present invention as described above, it has an excellent balance between tensile elongation and tensile strength at break, and is suitable for wire sheaths and coating applications. .

[0081]

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

The melt flow rate, tensile elongation and tensile strength at break of the thermoplastic resin compositions in the examples and comparative examples of the present invention were measured according to the following test methods. (1) Melt flow rate Melt flow rate (MFR) of thermoplastic resin composition
According to ASTM D 1238, 190 ° C, 2.
It was measured under the condition of a 16 kg load. (2) Tensile elongation and tensile strength at break According to JIS K 6301, a tensile test is performed using a JIS No. 3 dumbbell at a span of 20 mm and a tensile speed of 200 mm / min to measure the tensile elongation and tensile strength at break. did.

The interpolymer (ethylene-styrene copolymer), magnesium hydroxide and aluminum hydroxide used in the examples and the like are as follows. Interpolymer Ethylene-styrene copolymer (interpolymer) (E
SI-30) Styrene content: 30% by weight (= 10.3 mol%) MI (ASTM D 1238, 190 ° C, 2.16 load): 1.0 g / 1
0 minute magnesium hydroxide (1) magnesium hydroxide (B-1) Trade name Kisuma 5B, manufactured by Kyowa Chemical Industry Co., Ltd., average particle diameter = 0.6 μm (2) Magnesium hydroxide (B-2) Trade name Site PC-500C, Kanamar Co., Ltd.
Ltd., average particle diameter = 3.2 .mu.m aluminum hydroxide tradename BF013, Nippon Light Metal Co., Ltd., average particle diameter = 1 [mu] m

[0084]

Example 1 Ethylene-styrene copolymer (ESI-3)
0) 33.3 parts by weight and magnesium hydroxide (B-1)
66.7 parts by weight and 0.67 vinyltrimethoxysilane
Parts by weight and 0.033 parts by weight of dicumyl peroxide were melt-kneaded and granulated at a resin temperature of 190 ° C. using a Banbury mixer to obtain pellets of a thermoplastic resin composition. The melt flow rate (ASTM D 1238, 190 ° C, 2.16 kg load) of the obtained thermoplastic resin composition was 0.1 g /
10 minutes.

Next, press molding was performed at 190 ° C. using the obtained pellets of the thermoplastic resin composition to obtain a press molded body. With respect to the obtained molded body, the tensile elongation and the tensile strength at break were performed according to the methods described above.

The results are shown in Table 1.

[0087]

Example 2 In Example 1, an ethylene-styrene copolymer (ESI-30) and magnesium hydroxide (B
Pellets of the thermoplastic resin composition were obtained in the same manner as in Example 1, except that the blending amount of -1) was changed to 50 parts by weight and 50 parts by weight, respectively. The melt flow rate (ASTM D 1238, 190 ° C, 2.16 kg load) of the obtained thermoplastic resin composition was 0.18 g / 10 minutes.

Hereinafter, a pressed product was obtained in the same manner as in Example 1 using the pellets of the thermoplastic resin composition.
With respect to the obtained molded body, the tensile elongation and the tensile strength at break were performed according to the methods described above.

The results are shown in Table 1.

[0090]

Comparative Example 1 In Example 1, the average particle diameter was 0.6 μm.
Of magnesium hydroxide (B-1) having an average particle size of 5 μm instead of 66.7 parts by weight of magnesium hydroxide (B-1).
2) except that 66.7 parts by weight were used and vinyltrimethoxysilane and dicumyl peroxide were not used
In the same manner as in Example 1, pellets of the thermoplastic resin composition were obtained. The melt flow rate (ASTM D 1238, 190 ° C., 2.16 kg load) of the obtained thermoplastic resin composition was 1.0 g /
10 minutes.

Hereinafter, a pressed product was obtained in the same manner as in Example 1 using the pellets of the thermoplastic resin composition.
With respect to the obtained molded body, the tensile elongation and the tensile strength at break were performed according to the methods described above.

Table 1 shows the results.

[0093]

Comparative Example 2 In Example 1, the average particle diameter was 0.6 μm.
Of magnesium hydroxide (B-1) having an average particle size of 3.2 μm instead of 66.7 parts by weight of magnesium hydroxide (B-1)
-2) Pellets of the thermoplastic resin composition were obtained in the same manner as in Example 1 except that 66.7 parts by weight was used. The melt flow rate of the resulting thermoplastic resin composition (ASTM D12
38,190 ° C, 2.16 kg load) was 0.15 g / 10 min.

Thereafter, a pressed product was obtained in the same manner as in Example 1 using the pellets of the thermoplastic resin composition.
With respect to the obtained molded body, the tensile elongation and the tensile strength at break were performed according to the methods described above.

The results are shown in Table 1.

[0096]

Comparative Example 3 In Example 1, the average particle diameter was 0.6 μm.
Instead of 66.7 parts by weight of magnesium hydroxide (B-1), aluminum hydroxide 66.7 having an average particle diameter of 1 μm.
Pellets of a thermoplastic resin composition were obtained in the same manner as in Example 1 except that parts by weight were used. The melt flow rate of the obtained thermoplastic resin composition (ASTM D 1238, 190 ° C, 2.
16 kg load) was 0.08 g / 10 minutes.

[0097] Thereafter, a pressed product was obtained in the same manner as in Example 1 using the pellets of the thermoplastic resin composition.
With respect to the obtained molded body, the tensile elongation and the tensile strength at break were performed according to the methods described above.

The results are shown in Table 1.

[0099]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 3/00 H01B 3/00 A 3/44 3/44 KL 7/17 7/18 Z F term ( 4F071 AA14 AA15 AA20 AA21 AA22 AB17 AB18 AH12 BB03 BB05 BB06 BC02 BC05 4J002 BB021 BB041 BB141 BC041 BC081 BC091 BC111 BN041 DE076 GQ00 GQ01 5G303 AA06 AB20 BA12 CA09 CB17 CA03 ACOB5A033

Claims (9)

[Claims] (A) (1) (a) at least one aromatic vinyl or vinylidene monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (c) at least one From 1 to 99 mol% of polymer units derived from a combination of one aromatic vinyl or vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer; and (2) at least one carbon atom 25 to 50% by weight of at least one kind of substantially random interpolymer composed of 1 to 99% by mole of a polymer unit derived from an α-olefin having 2 to 20 atoms, and (B) an average particle diameter of 0.1 to 0.2%.
A thermoplastic resin composition comprising 50 to 75% by weight of magnesium hydroxide of 5 to 2 μm. 2. The thermoplastic resin composition according to claim 1, wherein the interpolymer (A) is silane-grafted. 3. The interpolymer (A) comprises from 5 to 65 mol% of polymer units derived from at least one aromatic vinyl or vinylidene monomer, and at least one α-olefin having 2 to 20 carbon atoms. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is a substantially random interpolymer composed of 35 to 95 mol% of a polymer unit derived from 4. The interpolymer (A) comprises 5 to 65 mol% of polymer units derived from styrene and 35 to 95 polymer units derived from at least one α-olefin having 2 to 10 carbon atoms. Mol%,
The thermoplastic resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin composition is a substantially random interpolymer. 5. The interpolymer (A) comprises 5 to 50 mol% of polymer units derived from at least one aromatic vinyl or vinylidene monomer, and at least one α-olefin having 2 to 20 carbon atoms. 3. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is a pseudo-random interpolymer composed of 50 to 95 mol% of a polymer unit derived from 6. The interpolymer (A) comprises 5 to 50 mol% of polymer units derived from styrene and 50 to 95 polymer units derived from at least one α-olefin having 2 to 10 carbon atoms. Mol%,
6. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is a pseudo-random interpolymer. 7. The thermoplastic resin composition according to claim 1, wherein a molded product obtained from the thermoplastic resin composition has a tensile elongation (JIS K6301) of 300% or more. object. 8. The thermoplastic resin composition according to claim 1, which is used for an electric wire sheath or an electric wire coating. 9. A molded article comprising the thermoplastic resin composition according to claim 1.